Physiology: Why cold is such a pain
Katharina Zimmermann and colleagues show that a protein called Nav1.8 allows information to be transmitted along sensory nerve fibres in cold conditions. The molecule is a voltage-gated sodium channel, an integral membrane protein that allows sodium ions to pass through a neuron's outer membrane.
There are other voltage-gated sodium channels in sensory neurons, but this one keeps working when the temperature drops — in fact, its currents are actually larger in colder conditions. This may help explain why, although sensory acuity deteriorates at cold temperatures, pain perception persists and cold stimuli themselves can be painful.
CONTACTKatharina Zimmermann (University Erlangen-Nuremberg, Erlangen, Germany)
Tel: +49 91 31 85 22 228; E-mail: zimmermann@physiologie1.uni-erlangen.de
Thursday, June 14, 2007
Transients in the sky: Stellar puzzle
In 2004, astronomers observed an incredibly bright stellar flare. Then two years later, they spotted a type 1b supernova in the same vicinity. Researchers now confirm that the two events occurred in the same place, making it an unlikely coincidence and something of a puzzle.
Andrea Pastorello and colleagues offer a few explanations. The initial flare could have come from a Wolf–Rayet star — a very hot, massive, dying star that throws out a lot of gas. Or it could have come from a binary system, containing the supernova and a luminous blue variable — a bright, hypergiant, variable star that flares periodically. The authors’ conclusions support another publication by an independent group in the journal Astrophysics (R. J. Foley et al. Astrophys. J. 657, L105–L108; 2007).
CONTACT
Andrea Pastorello (Queen's University Belfast, UK)
Tel: +44 28 9097 3509; E-mail: a.pastorello@qub.ac.uk
In 2004, astronomers observed an incredibly bright stellar flare. Then two years later, they spotted a type 1b supernova in the same vicinity. Researchers now confirm that the two events occurred in the same place, making it an unlikely coincidence and something of a puzzle.
Andrea Pastorello and colleagues offer a few explanations. The initial flare could have come from a Wolf–Rayet star — a very hot, massive, dying star that throws out a lot of gas. Or it could have come from a binary system, containing the supernova and a luminous blue variable — a bright, hypergiant, variable star that flares periodically. The authors’ conclusions support another publication by an independent group in the journal Astrophysics (R. J. Foley et al. Astrophys. J. 657, L105–L108; 2007).
CONTACT
Andrea Pastorello (Queen's University Belfast, UK)
Tel: +44 28 9097 3509; E-mail: a.pastorello@qub.ac.uk
Planetary science: Saturn’s magnetosphere gets the Cassini treatment
Saturn’s magnetosphere overturns in a way similar to that of Jupiter.
It’s known that cold, dense plasma from Jupiter’s inner magnetosphere is flung outward and replaced by hotter plasma from the outer magnetosphere — a little like convection in a pot of liquid. But whether the same is true for Saturn’s magnetosphere has been a matter of debate, given that Saturn’s magnetosphere shares other features with that of Earth. William Lewis and colleagues now study the cold plasma next to hot, inward-moving plasma in its magnetosphere to show that this cold plasma is outward bound, so Saturn’s magnetosphere does indeed have similar overturning to Jupiter’s — a discovery made possible by Cassini’s plasma spectrometer.
CONTACTWilliam Lewis (Southwest Research Institute, San Antonio, TX, USA)
Tel: +1 210 522 5651; E-mail: wlewis@swri.edu
Saturn’s magnetosphere overturns in a way similar to that of Jupiter.
It’s known that cold, dense plasma from Jupiter’s inner magnetosphere is flung outward and replaced by hotter plasma from the outer magnetosphere — a little like convection in a pot of liquid. But whether the same is true for Saturn’s magnetosphere has been a matter of debate, given that Saturn’s magnetosphere shares other features with that of Earth. William Lewis and colleagues now study the cold plasma next to hot, inward-moving plasma in its magnetosphere to show that this cold plasma is outward bound, so Saturn’s magnetosphere does indeed have similar overturning to Jupiter’s — a discovery made possible by Cassini’s plasma spectrometer.
CONTACTWilliam Lewis (Southwest Research Institute, San Antonio, TX, USA)
Tel: +1 210 522 5651; E-mail: wlewis@swri.edu
Genetics: DNA ‘instruction manual’ deciphered
After sequencing the human genome, the next logical step is to figure out how cells make use of this instruction manual. With the results of a huge project that identifies and analyses functional elements taken from part of the human genome.
Thirty-five groups provided over 200 data sets, comprising around 1% of the human genome, for the pilot of the Encyclopedia of DNA Elements (ENCODE) Project. Ewan Birney and an international consortium then described which parts of the selected DNA are transcribed into RNA, where specific proteins are bound to the DNA, how the sequence compares to that of other organisms, and what form the structure of chromatin (the complex of DNA and proteins that make up chromosomes) takes in the selected regions.
From this, the consortium derived a number of exciting new insights into both the nature and evolution of DNA sequences important for biological function. For example, most of the DNA studied appears to be transcribed into RNA, and these DNA transcripts overlap extensively. This is at odds with the view that the human genome contains a relatively small set of discrete genes alongside a mass of biologically inactive 'junk DNA'.
The team also found that around one-half of the genome's functional elements appears to be able to change sequence more freely than expected across mammalian evolution. This suggests the existence of a large pool of neutral elements that are biochemically active but provide no specific benefit to the organism, which may serve as a 'warehouse' for natural selection.
CONTACT
Ewan Birney (EMBL-European Bioinformatics Institute, Cambridge, UK)
Tel: +44 1223 494 420; E-mail: birney@ebi.ac.uk
Anna-Lynn Wegener (EMBL Press Officer, Heidelberg, Germany)
Tel: +49 6221 387 452; E-mail: wegener@embl.de
Zhiping Wang (Boston University, MA, USA) Co-author
Tel: +1 617 353 3509; E-mail: zhiping@bu.edu
John M. Greally (Albert Einstein College of Medicine, Bronx, NY, USA) N&V author
Tel: +1 718 430 2875; E-mail: jgreally@aecom.yu.edu
After sequencing the human genome, the next logical step is to figure out how cells make use of this instruction manual. With the results of a huge project that identifies and analyses functional elements taken from part of the human genome.
Thirty-five groups provided over 200 data sets, comprising around 1% of the human genome, for the pilot of the Encyclopedia of DNA Elements (ENCODE) Project. Ewan Birney and an international consortium then described which parts of the selected DNA are transcribed into RNA, where specific proteins are bound to the DNA, how the sequence compares to that of other organisms, and what form the structure of chromatin (the complex of DNA and proteins that make up chromosomes) takes in the selected regions.
From this, the consortium derived a number of exciting new insights into both the nature and evolution of DNA sequences important for biological function. For example, most of the DNA studied appears to be transcribed into RNA, and these DNA transcripts overlap extensively. This is at odds with the view that the human genome contains a relatively small set of discrete genes alongside a mass of biologically inactive 'junk DNA'.
The team also found that around one-half of the genome's functional elements appears to be able to change sequence more freely than expected across mammalian evolution. This suggests the existence of a large pool of neutral elements that are biochemically active but provide no specific benefit to the organism, which may serve as a 'warehouse' for natural selection.
CONTACT
Ewan Birney (EMBL-European Bioinformatics Institute, Cambridge, UK)
Tel: +44 1223 494 420; E-mail: birney@ebi.ac.uk
Anna-Lynn Wegener (EMBL Press Officer, Heidelberg, Germany)
Tel: +49 6221 387 452; E-mail: wegener@embl.de
Zhiping Wang (Boston University, MA, USA) Co-author
Tel: +1 617 353 3509; E-mail: zhiping@bu.edu
John M. Greally (Albert Einstein College of Medicine, Bronx, NY, USA) N&V author
Tel: +1 718 430 2875; E-mail: jgreally@aecom.yu.edu
Evolution: A gigantic bird-like dinosaur
The remains of a gigantic, surprisingly bird-like dinosaur have been uncovered in Inner Mongolia, China. The animal — which lived in the Late Cretaceous (about 70 million years ago) — is thought to have had a body mass of about 1,400 kilograms, which is surprising as most theories suggest that carnivorous dinosaurs got smaller as they got more bird-like. The dinosaur has been classed as a new species and genus.
Xing Xu and colleagues carried out a phylogenetic analysis of the skeleton and have grouped the fossil with a family that included the beaked, bird-like Oviraptor because of its similarly avian features. What is most striking, however, is that at 1,400 kilograms the fossil is about 35-times heavier than other similar feathered dinosaurs, which rarely exceeded a body mass of 40 kilograms.
The authors estimate that the new dinosaur would have been about eight metres long and would have stood, at the shoulder, twice the height of a man. They suggest that a growth rate considerably faster than large North American tyrannosaurs contributed to this. The team also noticed lines of arrested growth on the fossil, indicating that it was still a young adult when it died, so the full-sized dinosaur may have been even larger than this. But, despite its great size, many features of its anatomy were more bird-like, rather than less, as would have been expected.
CONTACT
Xing Xu (Chinese Academy of Sciences, Beijing, China)
Tel: +86 10 8836 9196; E-mail: xu.xing@ivpp.ac.cn or xingxu@vip.sina.com
The remains of a gigantic, surprisingly bird-like dinosaur have been uncovered in Inner Mongolia, China. The animal — which lived in the Late Cretaceous (about 70 million years ago) — is thought to have had a body mass of about 1,400 kilograms, which is surprising as most theories suggest that carnivorous dinosaurs got smaller as they got more bird-like. The dinosaur has been classed as a new species and genus.
Xing Xu and colleagues carried out a phylogenetic analysis of the skeleton and have grouped the fossil with a family that included the beaked, bird-like Oviraptor because of its similarly avian features. What is most striking, however, is that at 1,400 kilograms the fossil is about 35-times heavier than other similar feathered dinosaurs, which rarely exceeded a body mass of 40 kilograms.
The authors estimate that the new dinosaur would have been about eight metres long and would have stood, at the shoulder, twice the height of a man. They suggest that a growth rate considerably faster than large North American tyrannosaurs contributed to this. The team also noticed lines of arrested growth on the fossil, indicating that it was still a young adult when it died, so the full-sized dinosaur may have been even larger than this. But, despite its great size, many features of its anatomy were more bird-like, rather than less, as would have been expected.
CONTACT
Xing Xu (Chinese Academy of Sciences, Beijing, China)
Tel: +86 10 8836 9196; E-mail: xu.xing@ivpp.ac.cn or xingxu@vip.sina.com
Tuesday, June 05, 2007
Physical Activity May Reduce Risk of Gestational Diabetes Mellitus
SEATTLE - Gestational diabetes mellitus (GDM) complicates 4 percent to 7 percent of all pregnancies in the United States and poses a risk to both infant and mother. However, results of a new study conducted by researchers from Swedish Medical Center's Perinatal Studies program suggests physical activity may reduce risk of GDM.
Babies born to mothers with GDM may be large at birth and suffer complications such as jaundice. These children are more likely to become obese and develop diabetes in early adulthood. Women with GDM are at increased risk of developing other complications during pregnancy, such as preeclampsia, and they are more likely to develop type 2 diabetes after pregnancy.
The results of this new study suggest that women who are physically active during the year before and/or during early pregnancy may be less likely to develop GDM.
The study, which was funded by The National Institute of Child Health and Human Development at National Institutes of Health, suggests that current efforts to encourage Americans to engage in more frequent physical activity may also benefit pregnant women and result in substantial reductions in the incidence of GDM.
Lead author Jennifer Dempsey and colleagues report that women who participated in recreational physical activity during the year before pregnancy reduced their risk of GDM by 56 percent. During this time period, women who exercised for about four hours per week were 76 percent less likely to develop GDM when compared with women who did not exercise. In addition, women who participated in recreational physical activity both before and during early pregnancy enjoyed a 69 percent reduction in risk.
The study, which is ongoing at Swedish Medical Center in Seattle and led by Drs. Michelle Williams, Tanya Sorensen and David Luthy, was presented at the 24th annual meeting of the Society for Maternal-Fetal Medicine in New Orleans.
The investigators are currently conducting additional analyses to determine which metabolic or physiological changes associated with exercise may contribute to this reduced risk of GDM. They are also conducting studies to help identify which specific types, intensities and duration of exercise are associated with optimal pregnancy outcomes.
SEATTLE - Gestational diabetes mellitus (GDM) complicates 4 percent to 7 percent of all pregnancies in the United States and poses a risk to both infant and mother. However, results of a new study conducted by researchers from Swedish Medical Center's Perinatal Studies program suggests physical activity may reduce risk of GDM.
Babies born to mothers with GDM may be large at birth and suffer complications such as jaundice. These children are more likely to become obese and develop diabetes in early adulthood. Women with GDM are at increased risk of developing other complications during pregnancy, such as preeclampsia, and they are more likely to develop type 2 diabetes after pregnancy.
The results of this new study suggest that women who are physically active during the year before and/or during early pregnancy may be less likely to develop GDM.
The study, which was funded by The National Institute of Child Health and Human Development at National Institutes of Health, suggests that current efforts to encourage Americans to engage in more frequent physical activity may also benefit pregnant women and result in substantial reductions in the incidence of GDM.
Lead author Jennifer Dempsey and colleagues report that women who participated in recreational physical activity during the year before pregnancy reduced their risk of GDM by 56 percent. During this time period, women who exercised for about four hours per week were 76 percent less likely to develop GDM when compared with women who did not exercise. In addition, women who participated in recreational physical activity both before and during early pregnancy enjoyed a 69 percent reduction in risk.
The study, which is ongoing at Swedish Medical Center in Seattle and led by Drs. Michelle Williams, Tanya Sorensen and David Luthy, was presented at the 24th annual meeting of the Society for Maternal-Fetal Medicine in New Orleans.
The investigators are currently conducting additional analyses to determine which metabolic or physiological changes associated with exercise may contribute to this reduced risk of GDM. They are also conducting studies to help identify which specific types, intensities and duration of exercise are associated with optimal pregnancy outcomes.
Sunday, May 27, 2007
Biology : Skin barrier formation and caspase-14
A protein known as caspase-14 has been identified as the enzyme involved in the protection of the skin against UVB damage and water loss, according to a study.
The involvement of caspase-family members in programmed cell death and inflammation is well understood but, a function for caspase-14 had previously not been identified. Using caspase-14 knockout mice, Wim Declercq and colleagues show that caspase-14 is responsible for the initial processing of profillagrin to fillagrin. Fillagrin is responsible for aggregating keratin and other proteins in the upper layers of the epidermis to form the stratum corneum – a layer of flattened dead-cell remnants that creates a protective barrier for the skin. The controlled processing of profillagrin to produce fillagrin ultimately maintains the integrity of the epidermis. In mice lacking caspase-14, their skin exhibits a defective stratum corneum and is more sensitive to water loss and UVB photodamage.
The identification of caspase-14 and its role in skin-barrier formation opens avenues for the pharmaceutical manipulation of this process to prevent the damage induced by UVB, the primary agent responsible for sunburn and skin ageing.
Author contact:
Wim Declercq (Ghent University, Belgium)
Tel: +32 9 33 13 660; E-mail: wim.declercq@dmbr.ugent.be
...And Control of all fates
Cell Biology investigates how pluripotency, the ability of a stem cell to differentiate into every cell type of the adult organism, is regulated.
Understanding how stem cells maintain their pluripotent state has involved the characterisation of a multitude of transcription factors – the proteins that determine whether a specific gene is expressed or not. Pluripotency in embryonic stem cells was thought to be controlled primarily by the transcription factors Oct3/4 and Sox2, as these proteins were believed to activate Oct-Sox enhancers – regulatory regions that determine the expression of pluripotent stem cell-specific genes. Shinji Masui and colleagues used mutant mice lacking the Sox2 gene to show that although Sox2 is needed for stem cell pluripotency, it is not required for the enhancers to function and in fact governs the expression of Oct3/4. The authors went on to show that this regulation is indirect, as Sox2 controls the expression of a number of transcription factors that in turn regulate Oct3/4 expression.
This study illustrates the precise regulation of pluripotency by key proteins, and reorders the hierarchy of these factors with Sox2 as the master regulator — another small step towards a complete understanding of stem cell biology.
Author contact:
Shinji Masui (International Medical Centre of Japan, Tokyo, Japan)
Tel: +81 3 3202 7181; E-mail: masui@ri.imcj.go.jp
The dual role of BRCA2 in DNA repair
The dual role of the gene BRCA2 in DNA repair is described in two independent studies. The studies from Stephen West’s and Luca Pellegrini’s groups shed light on the role of the gene, mutations of which result in predisposition to breast cancer and other malignancies.
The protein encoded by BRCA2 is involved in homologous recombination, a process whereby damaged DNA is repaired using an intact copy of DNA as a template. This process also includes the protein RAD51, which interacts directly with two different regions of BRCA2, called BRC and TR2. The BRC region had been previously suggested to be involved in terminating homologous recombination. Data from the two present studies indicate that the TR2 region can oppose the activity of BRC, suggesting that BRCA2 contains regions that both favor and disrupt homologous recombination. These activities might operate at different stages of DNA repair.
Both reports also provide insight into how the opposing activities of BRCA2 can be regulated – a phosphorylation event at TR2 results in the loss of its interaction with RAD51, acting as a turn-off switch. These findings advance our knowledge of BRCA2’s role in genetic stability, and contribute to our understanding of why mutations in BRCA2 increase the likelihood of cancer.
Author contacts:
Stephen West (Cancer Research UK, London, UK) Author paper [16]
Tel: +44 1707 625 868; E-mail: stephen.west@cancer.org.uk
Luca Pellegrini (University of Cambridge, UK) Author paper [17]
Tel: +44 1223 333 662; E-mail: luca@cryst.bioc.cam.ac.uk
Deciphering the histone code
A method to identify all modifications on histones, the proteins around which DNA is packed, is presented online. This study should allow researchers a better understanding of how genes are regulated by alterations to these proteins.
DNA holds all the information for the building blocks of life, but how a cell reads this genetic information depends on histones, and in particular on modifications to these histones. For example, the attachment of methyl groups to histones usually signals that a gene is silent, whereas the attachment of acetyl groups corresponds to gene activation. Scientists have dubbed the combinatorial use of histone modifications the ‘histone code’, but the extent to which different modifications are combined in the histone code is still unknown.
To help crack the code, Neil Kelleher and colleagues devised a method to identify all the possible modifications that occur on histones in a cell. First they separated different histone variants, depending on their degree of acetylation and methylation, by hydrophilic interaction chromatography, then they applied high-resolution tandem mass spectroscopy to identify all modifications on each variant and the exact residues carrying them. By using a mass spectrometry technique known as ‘top down,’ in which intact proteins are fragmented inside the mass spectrometer, they observed better preservation of modifications than traditional mass spectrometry methods looking at pre-digested proteins. For one particular histone alone, they found over 150 different patterns of modification.
This method helps to decipher the elements that make up the histone code and will allow researchers to relate the pattern of these modifications to the regulation of gene activity.
Author contact:
Neil Kelleher (University of Illinois at Urbana-Champaign, IL, USA)
Tel: +1 217 333 5071; E-mail: kelleher@scs.uiuc.edu
A protein known as caspase-14 has been identified as the enzyme involved in the protection of the skin against UVB damage and water loss, according to a study.
The involvement of caspase-family members in programmed cell death and inflammation is well understood but, a function for caspase-14 had previously not been identified. Using caspase-14 knockout mice, Wim Declercq and colleagues show that caspase-14 is responsible for the initial processing of profillagrin to fillagrin. Fillagrin is responsible for aggregating keratin and other proteins in the upper layers of the epidermis to form the stratum corneum – a layer of flattened dead-cell remnants that creates a protective barrier for the skin. The controlled processing of profillagrin to produce fillagrin ultimately maintains the integrity of the epidermis. In mice lacking caspase-14, their skin exhibits a defective stratum corneum and is more sensitive to water loss and UVB photodamage.
The identification of caspase-14 and its role in skin-barrier formation opens avenues for the pharmaceutical manipulation of this process to prevent the damage induced by UVB, the primary agent responsible for sunburn and skin ageing.
Author contact:
Wim Declercq (Ghent University, Belgium)
Tel: +32 9 33 13 660; E-mail: wim.declercq@dmbr.ugent.be
...And Control of all fates
Cell Biology investigates how pluripotency, the ability of a stem cell to differentiate into every cell type of the adult organism, is regulated.
Understanding how stem cells maintain their pluripotent state has involved the characterisation of a multitude of transcription factors – the proteins that determine whether a specific gene is expressed or not. Pluripotency in embryonic stem cells was thought to be controlled primarily by the transcription factors Oct3/4 and Sox2, as these proteins were believed to activate Oct-Sox enhancers – regulatory regions that determine the expression of pluripotent stem cell-specific genes. Shinji Masui and colleagues used mutant mice lacking the Sox2 gene to show that although Sox2 is needed for stem cell pluripotency, it is not required for the enhancers to function and in fact governs the expression of Oct3/4. The authors went on to show that this regulation is indirect, as Sox2 controls the expression of a number of transcription factors that in turn regulate Oct3/4 expression.
This study illustrates the precise regulation of pluripotency by key proteins, and reorders the hierarchy of these factors with Sox2 as the master regulator — another small step towards a complete understanding of stem cell biology.
Author contact:
Shinji Masui (International Medical Centre of Japan, Tokyo, Japan)
Tel: +81 3 3202 7181; E-mail: masui@ri.imcj.go.jp
The dual role of BRCA2 in DNA repair
The dual role of the gene BRCA2 in DNA repair is described in two independent studies. The studies from Stephen West’s and Luca Pellegrini’s groups shed light on the role of the gene, mutations of which result in predisposition to breast cancer and other malignancies.
The protein encoded by BRCA2 is involved in homologous recombination, a process whereby damaged DNA is repaired using an intact copy of DNA as a template. This process also includes the protein RAD51, which interacts directly with two different regions of BRCA2, called BRC and TR2. The BRC region had been previously suggested to be involved in terminating homologous recombination. Data from the two present studies indicate that the TR2 region can oppose the activity of BRC, suggesting that BRCA2 contains regions that both favor and disrupt homologous recombination. These activities might operate at different stages of DNA repair.
Both reports also provide insight into how the opposing activities of BRCA2 can be regulated – a phosphorylation event at TR2 results in the loss of its interaction with RAD51, acting as a turn-off switch. These findings advance our knowledge of BRCA2’s role in genetic stability, and contribute to our understanding of why mutations in BRCA2 increase the likelihood of cancer.
Author contacts:
Stephen West (Cancer Research UK, London, UK) Author paper [16]
Tel: +44 1707 625 868; E-mail: stephen.west@cancer.org.uk
Luca Pellegrini (University of Cambridge, UK) Author paper [17]
Tel: +44 1223 333 662; E-mail: luca@cryst.bioc.cam.ac.uk
Deciphering the histone code
A method to identify all modifications on histones, the proteins around which DNA is packed, is presented online. This study should allow researchers a better understanding of how genes are regulated by alterations to these proteins.
DNA holds all the information for the building blocks of life, but how a cell reads this genetic information depends on histones, and in particular on modifications to these histones. For example, the attachment of methyl groups to histones usually signals that a gene is silent, whereas the attachment of acetyl groups corresponds to gene activation. Scientists have dubbed the combinatorial use of histone modifications the ‘histone code’, but the extent to which different modifications are combined in the histone code is still unknown.
To help crack the code, Neil Kelleher and colleagues devised a method to identify all the possible modifications that occur on histones in a cell. First they separated different histone variants, depending on their degree of acetylation and methylation, by hydrophilic interaction chromatography, then they applied high-resolution tandem mass spectroscopy to identify all modifications on each variant and the exact residues carrying them. By using a mass spectrometry technique known as ‘top down,’ in which intact proteins are fragmented inside the mass spectrometer, they observed better preservation of modifications than traditional mass spectrometry methods looking at pre-digested proteins. For one particular histone alone, they found over 150 different patterns of modification.
This method helps to decipher the elements that make up the histone code and will allow researchers to relate the pattern of these modifications to the regulation of gene activity.
Author contact:
Neil Kelleher (University of Illinois at Urbana-Champaign, IL, USA)
Tel: +1 217 333 5071; E-mail: kelleher@scs.uiuc.edu
A red-letter day for brain connectivity
Insights into grapheme-colour synesthesia are presented in a paper of Neuroscience. People with this condition – who see a cascade of colours associated with individual letters when looking at a page of text – appear to have more neural connections in areas of the brain involved in word processing and binding perceptions together.
Romke Rouw and Steven Scholte used a technique called diffusion tensor imaging (DTI) to look at brain differences between grapheme-colour synesthetes and healthy controls without this condition. DTI allows non-invasive visualisation of the white matter tracts, or axons, connecting neural cell bodies. The researchers found that synesthetes had more axons connecting three brain areas: the right fusiform gyrus, near regions involved in word and colour processing, and the left intraparietal sulcus and frontal cortex, both part of a network of regions involved in binding and consciousness.
The study also found differences among the synesthetes, according to how they perceived the association between words and colours. Some synesthetes, known as projectors, report stronger experiences that are projected into the external world, while others, known as associators, report weaker experiences that appear in their ‘mind’s eye’. The degree of structural connectivity in a region known as the right temporal cortex was correlated with the strength of the synesthetic experience. These results suggest a two-stage model of synesthesia, with increased connectivity in some areas being important for generating perceptual binding, and connectivity in other areas determining the intensity of the resultant perceptions.
Author contact:
Romke Rouw (University of Amsterdam, The Netherlands)
Tel: +31 20 525 6742; E-mail: R.Rouw@uva.nl
Insights into grapheme-colour synesthesia are presented in a paper of Neuroscience. People with this condition – who see a cascade of colours associated with individual letters when looking at a page of text – appear to have more neural connections in areas of the brain involved in word processing and binding perceptions together.
Romke Rouw and Steven Scholte used a technique called diffusion tensor imaging (DTI) to look at brain differences between grapheme-colour synesthetes and healthy controls without this condition. DTI allows non-invasive visualisation of the white matter tracts, or axons, connecting neural cell bodies. The researchers found that synesthetes had more axons connecting three brain areas: the right fusiform gyrus, near regions involved in word and colour processing, and the left intraparietal sulcus and frontal cortex, both part of a network of regions involved in binding and consciousness.
The study also found differences among the synesthetes, according to how they perceived the association between words and colours. Some synesthetes, known as projectors, report stronger experiences that are projected into the external world, while others, known as associators, report weaker experiences that appear in their ‘mind’s eye’. The degree of structural connectivity in a region known as the right temporal cortex was correlated with the strength of the synesthetic experience. These results suggest a two-stage model of synesthesia, with increased connectivity in some areas being important for generating perceptual binding, and connectivity in other areas determining the intensity of the resultant perceptions.
Author contact:
Romke Rouw (University of Amsterdam, The Netherlands)
Tel: +31 20 525 6742; E-mail: R.Rouw@uva.nl
Gene copy number and risk of autoimmunity
Individuals with fewer than two copies of the gene FCGR3B are more susceptible to a variety of autoimmune disorders, including lupus, according to a study.
Evidence is accumulating that, in addition to gene mutations, variation in the actual number of copies of individual genes can influence susceptibility to common diseases. It was previously shown that variation in the copy number of FCGR3B, a cell-surface receptor that contributes to the protective functions of the immune system, is associated with susceptibility to a kidney disease called glomerulonephritis. Timothy Aitman and colleagues now report that FCGR3B copy number variation is associated more broadly with autoimmune disorders, including lupus, microscopic polyangiitis, and Wegener’s granulomatosis. The small group of individuals who have no copies of FCGR3B have a dramatically elevated risk of autoimmune disease. This is among the first demonstrations that common naturally occurring variation in gene copy number can influence human susceptibility to disease.
Author contact:
Timothy Aitman (Imperial College, London, UK)
Tel: +44 208 383 4253; E-mail: t.aitman@csc.mrc.ac.uk
Individuals with fewer than two copies of the gene FCGR3B are more susceptible to a variety of autoimmune disorders, including lupus, according to a study.
Evidence is accumulating that, in addition to gene mutations, variation in the actual number of copies of individual genes can influence susceptibility to common diseases. It was previously shown that variation in the copy number of FCGR3B, a cell-surface receptor that contributes to the protective functions of the immune system, is associated with susceptibility to a kidney disease called glomerulonephritis. Timothy Aitman and colleagues now report that FCGR3B copy number variation is associated more broadly with autoimmune disorders, including lupus, microscopic polyangiitis, and Wegener’s granulomatosis. The small group of individuals who have no copies of FCGR3B have a dramatically elevated risk of autoimmune disease. This is among the first demonstrations that common naturally occurring variation in gene copy number can influence human susceptibility to disease.
Author contact:
Timothy Aitman (Imperial College, London, UK)
Tel: +44 208 383 4253; E-mail: t.aitman@csc.mrc.ac.uk
Glitter of gold traps microparticles
A simple technique for trapping suspended microparticles with a laser-illuminated array of gold microdots is demonstrated by Romain Quidant and colleagues online. The technique could prove useful for manipulating living cells in ‘lab-on-a-chip’ microfluidic systems.
Until now, the most promising approach to controlling cells and other micrometre-sized particles suspended in a liquid has been with so-called optical tweezers. These devices exploit the fact that such particles are attracted to and can be trapped by a focused light field. But one of their drawbacks is that they are bulky and complex devices to set up.
The technique demonstrated by Quidant and colleagues is much simpler. It relies on the fact that when a gold microdot or other metallic microstructure is illuminated with light, it will concentrate the optical field in its vicinity, similar in effect to the focusing power of a lens. By setting out an array of gold microdots on a glass slide and illuminating it with a laser, the authors effectively create an array of optical tweezers, which they use to trap microparticles suspended in a fluid droplet placed on the slide. Moreover, they show that they can use the array to selectively trap particles of a specific size from a collection of two different sizes, by controlling the size of the gold dots.
Author contact:
Romain Quidant (Institut de Ciencies Fotoniques, Barcelona, Spain)
Tel: +34 93 55 34 076; E-mail: romain.quidant@icfo.es
A simple technique for trapping suspended microparticles with a laser-illuminated array of gold microdots is demonstrated by Romain Quidant and colleagues online. The technique could prove useful for manipulating living cells in ‘lab-on-a-chip’ microfluidic systems.
Until now, the most promising approach to controlling cells and other micrometre-sized particles suspended in a liquid has been with so-called optical tweezers. These devices exploit the fact that such particles are attracted to and can be trapped by a focused light field. But one of their drawbacks is that they are bulky and complex devices to set up.
The technique demonstrated by Quidant and colleagues is much simpler. It relies on the fact that when a gold microdot or other metallic microstructure is illuminated with light, it will concentrate the optical field in its vicinity, similar in effect to the focusing power of a lens. By setting out an array of gold microdots on a glass slide and illuminating it with a laser, the authors effectively create an array of optical tweezers, which they use to trap microparticles suspended in a fluid droplet placed on the slide. Moreover, they show that they can use the array to selectively trap particles of a specific size from a collection of two different sizes, by controlling the size of the gold dots.
Author contact:
Romain Quidant (Institut de Ciencies Fotoniques, Barcelona, Spain)
Tel: +34 93 55 34 076; E-mail: romain.quidant@icfo.es
Cancer genomics: Modelling instability
A mouse model that for the first time mimics the levels of genomic instability in human cancers is presented online. The authors show that mouse and human tumours show similar genetic alterations, and suggest that future research should use this mouse model to understand the genetics of human cancer better.
Ronald DePinho and colleagues engineered lymphoma-prone mice with chromosomal instability to assess the usefulness of mouse models in cancer gene discovery. Using a comparative genomics approach they identified mutated genes in the model that are also altered in human T-cell acute lymphoblastic lymphomas and/or in a diverse range of other tumours. The researchers demonstrate a complexity and comparability in the human and mouse oncogenes that they believe means mouse models of tumours with a high degree of genomic instability will be a valuable resource for investigating complex human cancer genomes.
Author contact:
Ronald A DePinho (Dana Farber Cancer Institute, Boston, MA, USA)
Tel: +1 617 632 6085; E-mail: ron_depinho@dfci.harvard.edu
A mouse model that for the first time mimics the levels of genomic instability in human cancers is presented online. The authors show that mouse and human tumours show similar genetic alterations, and suggest that future research should use this mouse model to understand the genetics of human cancer better.
Ronald DePinho and colleagues engineered lymphoma-prone mice with chromosomal instability to assess the usefulness of mouse models in cancer gene discovery. Using a comparative genomics approach they identified mutated genes in the model that are also altered in human T-cell acute lymphoblastic lymphomas and/or in a diverse range of other tumours. The researchers demonstrate a complexity and comparability in the human and mouse oncogenes that they believe means mouse models of tumours with a high degree of genomic instability will be a valuable resource for investigating complex human cancer genomes.
Author contact:
Ronald A DePinho (Dana Farber Cancer Institute, Boston, MA, USA)
Tel: +1 617 632 6085; E-mail: ron_depinho@dfci.harvard.edu
Evolution: Paddlefish clues to limb development
The limbs of tetrapods — land-living vertebrates — are usually thought to have been evolutionary innovations unique to that group. However, traces of limbs can be found in the development of primitive ray-finned fishes, according to a report.
The perceived uniqueness of the tetrapod limb may be a reflection of comparisons with fishes, notably the zebrafish (Danio rerio), which is often used as a model organism in embryological studies. However, the zebrafish is rather highly evolved, meaning that rather than lacking vestiges of limbs to begin with, it could have lost them during its ancestry. This latter possibility seems most likely following Neil Shubin and colleagues' study of Hox-gene expression in the development of the fins of a 'living fossil', the paddlefish Polyodon spathula.
Polyodon is one of the few relics of a type of bony fish common in the seas in the Palaeozoic era, more than 250 million years ago. Hox-gene expression in the developing fins of Polyodon shows patterns long considered to be tetrapod hallmarks. This finding demonstrates that some aspects of limb development are primitive and held in common by all bony fish — but have been lost in highly evolved fishes such as the zebrafish.
CONTACT
Neil Shubin (University of Chicago, IL, USA)
Tel: +1 773 834 7472; E-mail: nshubin@uchicago.edu
The limbs of tetrapods — land-living vertebrates — are usually thought to have been evolutionary innovations unique to that group. However, traces of limbs can be found in the development of primitive ray-finned fishes, according to a report.
The perceived uniqueness of the tetrapod limb may be a reflection of comparisons with fishes, notably the zebrafish (Danio rerio), which is often used as a model organism in embryological studies. However, the zebrafish is rather highly evolved, meaning that rather than lacking vestiges of limbs to begin with, it could have lost them during its ancestry. This latter possibility seems most likely following Neil Shubin and colleagues' study of Hox-gene expression in the development of the fins of a 'living fossil', the paddlefish Polyodon spathula.
Polyodon is one of the few relics of a type of bony fish common in the seas in the Palaeozoic era, more than 250 million years ago. Hox-gene expression in the developing fins of Polyodon shows patterns long considered to be tetrapod hallmarks. This finding demonstrates that some aspects of limb development are primitive and held in common by all bony fish — but have been lost in highly evolved fishes such as the zebrafish.
CONTACT
Neil Shubin (University of Chicago, IL, USA)
Tel: +1 773 834 7472; E-mail: nshubin@uchicago.edu
Optical materials: Semiconducting nanocrystals light up the way
A new type of nanocrystal that can be used as a laser material is reported in Nature magazine. 'Soft' optical materials like this can easily be processed in solution, offering flexibility for laser design, and the devices may find use in applications including lab-on-a-chip technologies and quantum information processing devices.
Semiconductor nanocrystals have excellent light-emitting properties, making them good candidates for use in laser applications. But achieving the crucial condition for lasing — optical amplification — has proved problematic: normally the nanocrystals need to contain at least two excitons (electron–hole pairs, which are the precursors for light emission in semiconductors), but owing to the nanocrystal’s tiny size, the excitons annihilate each other before optical amplification can occur.
Victor I. Klimov and colleagues circumvent this problem by designing nanocrystals with cores and shells made from different semiconductor materials, in such a way that electrons and holes are physically isolated from each other. In such engineered nanocrystals, only one exciton per nanocrystal is required for optical amplification, as has here been experimentally demonstrated by Klimov and colleagues. This opens the door to practical use in laser applications.
CONTACT
Victor I. Klimov (Los Alamos National Laboratory, NM, USA)
Tel: +1 505 665 8284; E-mail: klimov@lanl.gov
Todd D. Krauss (University of Rochester, NY, USA) N&V author
Tel: +1 585 275 5093; E-mail: krauss@chem.rochester.edu
A new type of nanocrystal that can be used as a laser material is reported in Nature magazine. 'Soft' optical materials like this can easily be processed in solution, offering flexibility for laser design, and the devices may find use in applications including lab-on-a-chip technologies and quantum information processing devices.
Semiconductor nanocrystals have excellent light-emitting properties, making them good candidates for use in laser applications. But achieving the crucial condition for lasing — optical amplification — has proved problematic: normally the nanocrystals need to contain at least two excitons (electron–hole pairs, which are the precursors for light emission in semiconductors), but owing to the nanocrystal’s tiny size, the excitons annihilate each other before optical amplification can occur.
Victor I. Klimov and colleagues circumvent this problem by designing nanocrystals with cores and shells made from different semiconductor materials, in such a way that electrons and holes are physically isolated from each other. In such engineered nanocrystals, only one exciton per nanocrystal is required for optical amplification, as has here been experimentally demonstrated by Klimov and colleagues. This opens the door to practical use in laser applications.
CONTACT
Victor I. Klimov (Los Alamos National Laboratory, NM, USA)
Tel: +1 505 665 8284; E-mail: klimov@lanl.gov
Todd D. Krauss (University of Rochester, NY, USA) N&V author
Tel: +1 585 275 5093; E-mail: krauss@chem.rochester.edu
Biophysics: Clustering key to membrane remodelling
A sophisticated simulation study reveals a trick that many membrane-bound proteins could use to vastly amplify their own effect on the shape of the membranes they are interacting with.
Biological membranes are much more than passive physical barriers: changes in their shape are linked to important cellular tasks such as endocytosis and protein sorting. It’s known that specialized proteins can sense and create membrane curvature, but the energy needed to accomplish complex membrane remodelling — large changes in membrane shape or topology — is only available when several proteins act together. But how do they coordinate their action?
Kurt Kremer and colleagues now show that a single protein interacting with a membrane causes local changes in membrane shape. Importantly, this attracts other proteins in the vicinity, which then cluster together yielding enough energy for the membrane to be remodelled, allowing, for example, vesicles to be formed.
CONTACT
Kurt Kremer (Max-Planck-Institut fur Polymerforschung, Mainz, Germany)
Tel: +49 6131 379 140; E-mail: kremer@mpip-mainz.mpg.de
Michael M. Kozlov (Tel Aviv University, Israel) N&V author
Tel: +972 3 640 7863; E-mail: michk@post.tau.ac.il
A sophisticated simulation study reveals a trick that many membrane-bound proteins could use to vastly amplify their own effect on the shape of the membranes they are interacting with.
Biological membranes are much more than passive physical barriers: changes in their shape are linked to important cellular tasks such as endocytosis and protein sorting. It’s known that specialized proteins can sense and create membrane curvature, but the energy needed to accomplish complex membrane remodelling — large changes in membrane shape or topology — is only available when several proteins act together. But how do they coordinate their action?
Kurt Kremer and colleagues now show that a single protein interacting with a membrane causes local changes in membrane shape. Importantly, this attracts other proteins in the vicinity, which then cluster together yielding enough energy for the membrane to be remodelled, allowing, for example, vesicles to be formed.
CONTACT
Kurt Kremer (Max-Planck-Institut fur Polymerforschung, Mainz, Germany)
Tel: +49 6131 379 140; E-mail: kremer@mpip-mainz.mpg.de
Michael M. Kozlov (Tel Aviv University, Israel) N&V author
Tel: +972 3 640 7863; E-mail: michk@post.tau.ac.il
Extreme weather: A look from the lagoon
Changes in the El Niño/Southern Oscillation and the strength of the West African monsoon have played an important part in controlling the frequency of intense hurricanes in the tropical North Atlantic over the past 5,000 years, a study suggests.
Jeffrey P. Donnelly and Jonathan D. Woodruff constructed a long-term record of intense hurricane activity in the western tropical North Atlantic Ocean. Storms associated with intense hurricanes that strike the island of Vieques in Puerto Rico deposit layers of coarse, sandy material in a lagoon, so the authors used sediment cores from the lagoon to reconstruct the frequency of intense hurricanes in this area over the last 5,000 years.
Their record shows striking similarities to records of El Niño events and rainfall in tropical Africa, suggesting that changes in the El Niño/Southern Oscillation and the strength of the West African monsoon had an important role in controlling the frequency of intense hurricanes in the tropical North Atlantic over this interval.
The lengthy time-interval studied helps to clarify the factors that control hurricane activity, because instrumental records only cover the past few decades. Furthermore, the results suggest that it is important to understand how the El Niño/Southern Oscillation and the West African monsoon will respond to future climate change to accurately predict changes in intense hurricane activity.
CONTACT
Jeffrey P. Donnelly (Woods Hole Oceanographic Institution, MA, USA)
Tel: +1 508 294 2994; E-mail: jdonnelly@whoi.edu
Changes in the El Niño/Southern Oscillation and the strength of the West African monsoon have played an important part in controlling the frequency of intense hurricanes in the tropical North Atlantic over the past 5,000 years, a study suggests.
Jeffrey P. Donnelly and Jonathan D. Woodruff constructed a long-term record of intense hurricane activity in the western tropical North Atlantic Ocean. Storms associated with intense hurricanes that strike the island of Vieques in Puerto Rico deposit layers of coarse, sandy material in a lagoon, so the authors used sediment cores from the lagoon to reconstruct the frequency of intense hurricanes in this area over the last 5,000 years.
Their record shows striking similarities to records of El Niño events and rainfall in tropical Africa, suggesting that changes in the El Niño/Southern Oscillation and the strength of the West African monsoon had an important role in controlling the frequency of intense hurricanes in the tropical North Atlantic over this interval.
The lengthy time-interval studied helps to clarify the factors that control hurricane activity, because instrumental records only cover the past few decades. Furthermore, the results suggest that it is important to understand how the El Niño/Southern Oscillation and the West African monsoon will respond to future climate change to accurately predict changes in intense hurricane activity.
CONTACT
Jeffrey P. Donnelly (Woods Hole Oceanographic Institution, MA, USA)
Tel: +1 508 294 2994; E-mail: jdonnelly@whoi.edu
Crows are smart! Research group at Keio University succeeds in drawing up the world’s first stereotaxic atlas of a crow
Prof. Shigeru Watanabe and Associate Prof. Eiichi Izawa of Keio University and his group became the first in the world to succeed in drawing up a stereotaxic atlas of a crow. Crows are known to be smart, and the findings proved that the pallium of the crow brain, which is related to intellectual activities, is well developed.
It has been known that the brain of a crow weighs 10-13g, very large compared to its total body weight. However, the details, such as which part of the brain is largely developed, were not clear. Prof. Shigeru Watanabe and Associate Prof. Eiichi Izawa of the Faculty of Letters and their group became the first in the world to succeed in drawing up a stereotaxic atlas of a crow. Recent observations had shown that crows have intelligence comparable to primates and have skills of tool-making and deceiving others. Prof. Watanabe and Associate Prof. Izawa clarified the total picture of the crow brain in detail to prove these observations, and the research can be applied in neuroscientific experiments in the future. These findings can be a breakthrough to finding out the brain evolution of animals including human beings.
1. About the stereotaxic atlas
The stereotaxic atlas is indispensable for studies of the brain. This is similar to a 3-dimensional map of a cross-section of the brain of fixed coordinates. By using this method, it is possible to identify the exact placements inside the brain. This stereotaxic atlas of the jungle crow was released on 14 May at http://www.cirm.keio.ac.jp/db/bird_brain, and will appear in “Integration of comparative neuroanatomy and comparative cognition” (Keio Univ. Press) to be published in the near future.
2. Characteristics of the crow brain
The crow is known to have a large brain compared to its body weight, and to have outstanding cognitive abilities. The stereotaxic atlas of the crow shows that brain areas called ‘pallium’ corresponding to the mammalian cortex, which controls thinking, learning and feeling, makes up a large portion of the brain, and within the ‘pallium’, the dorsal part which is related to intellectual activities, is large and well developed. This area is thought to be relevant to the association area (where multiple information such as visual or auditory signals are integrated) of the cerebral cortex in mammal brains including humans, and enables the crow to process complicated information. Crows are known to be smart, and the new completion of the stereotaxic atlas of the crow proved this.
3. Methods for drawing up the stereotaxic atlas
The research started with developing a stereotaxic holder to keep the crow brain in a fixed position. Stereotaxic holders for mice/rats and pigeons are commercially available, but for crows, it had to be custom-made. The brain was frozen under -20℃ and sliced into thin plates. The plates were then stained with cresyl violet for Nissle substance and luxol fast blue for myelinated fibers. The plates were examined under a microscope to separate the nerve cells according to density. At the same time, imaging of the plates were done to create an atlas and to name each group of nerve cells. The same process was repeated for all the plates of the crow brain from the front to the back, sliced in the thickness of 1mm. The atlas was completed by combining these data.
This research is part of the 21st Century COE Program Keio University Graduate School Toward an Integrated Methodology for the Study of the Mind. The Center of Excellence was selected by the 21st Century COE (Center of Excellence) Program of the Ministry of Education, Culture, Sports, Science and Technology toward an integrated methodology for the study of the mind. The newest findings in neuroscience, behavioral genetics are combined with philosophy, linguistics, information science and representational theories.
Inquiries: Mr. Ogawa or Ms. Kawagoe, Office of Communications and Public Relations, Keio University
TEL: ＋81-3-5427-1541 FAX: ＋81-3-5441-7640
E-mail: m-koho@adst.keio.ac.jp http://www.keio.ac.jp/
Prof. Shigeru Watanabe and Associate Prof. Eiichi Izawa of Keio University and his group became the first in the world to succeed in drawing up a stereotaxic atlas of a crow. Crows are known to be smart, and the findings proved that the pallium of the crow brain, which is related to intellectual activities, is well developed.
It has been known that the brain of a crow weighs 10-13g, very large compared to its total body weight. However, the details, such as which part of the brain is largely developed, were not clear. Prof. Shigeru Watanabe and Associate Prof. Eiichi Izawa of the Faculty of Letters and their group became the first in the world to succeed in drawing up a stereotaxic atlas of a crow. Recent observations had shown that crows have intelligence comparable to primates and have skills of tool-making and deceiving others. Prof. Watanabe and Associate Prof. Izawa clarified the total picture of the crow brain in detail to prove these observations, and the research can be applied in neuroscientific experiments in the future. These findings can be a breakthrough to finding out the brain evolution of animals including human beings.
1. About the stereotaxic atlas
The stereotaxic atlas is indispensable for studies of the brain. This is similar to a 3-dimensional map of a cross-section of the brain of fixed coordinates. By using this method, it is possible to identify the exact placements inside the brain. This stereotaxic atlas of the jungle crow was released on 14 May at http://www.cirm.keio.ac.jp/db/bird_brain, and will appear in “Integration of comparative neuroanatomy and comparative cognition” (Keio Univ. Press) to be published in the near future.
2. Characteristics of the crow brain
The crow is known to have a large brain compared to its body weight, and to have outstanding cognitive abilities. The stereotaxic atlas of the crow shows that brain areas called ‘pallium’ corresponding to the mammalian cortex, which controls thinking, learning and feeling, makes up a large portion of the brain, and within the ‘pallium’, the dorsal part which is related to intellectual activities, is large and well developed. This area is thought to be relevant to the association area (where multiple information such as visual or auditory signals are integrated) of the cerebral cortex in mammal brains including humans, and enables the crow to process complicated information. Crows are known to be smart, and the new completion of the stereotaxic atlas of the crow proved this.
3. Methods for drawing up the stereotaxic atlas
The research started with developing a stereotaxic holder to keep the crow brain in a fixed position. Stereotaxic holders for mice/rats and pigeons are commercially available, but for crows, it had to be custom-made. The brain was frozen under -20℃ and sliced into thin plates. The plates were then stained with cresyl violet for Nissle substance and luxol fast blue for myelinated fibers. The plates were examined under a microscope to separate the nerve cells according to density. At the same time, imaging of the plates were done to create an atlas and to name each group of nerve cells. The same process was repeated for all the plates of the crow brain from the front to the back, sliced in the thickness of 1mm. The atlas was completed by combining these data.
This research is part of the 21st Century COE Program Keio University Graduate School Toward an Integrated Methodology for the Study of the Mind. The Center of Excellence was selected by the 21st Century COE (Center of Excellence) Program of the Ministry of Education, Culture, Sports, Science and Technology toward an integrated methodology for the study of the mind. The newest findings in neuroscience, behavioral genetics are combined with philosophy, linguistics, information science and representational theories.
Inquiries: Mr. Ogawa or Ms. Kawagoe, Office of Communications and Public Relations, Keio University
TEL: ＋81-3-5427-1541 FAX: ＋81-3-5441-7640
E-mail: m-koho@adst.keio.ac.jp http://www.keio.ac.jp/
Saturday, May 19, 2007
IMMUNOLOGY : Another immune evasion strategy by HIV
Interaction of the human immunodeficiency virus (HIV) with dendritic cells—a specialized type of immune cell—circumvents immune activation and greatly enhances infection of T lymphocytes, reports a study to be published in the June issue of Nature Immunology.
Dendritic cells are required to initiate immune responses, and as targets of HIV infection, these cells are important contributors to HIV pathogenesis. Alison Simmons and colleagues evaluated the effect of HIV interaction with DC-SIGN, a protein receptor found largely on the surface of dendritic cells. HIV binding to DC-SIGN elicited a signalling pathway that prevented dendritic cells from actively stimulating subsequent immune responses. In addition, the authors show that HIV–DC-SIGN interaction can lead to transfer of virus to nearby T lymphocytes that then become infected leading to a burst of HIV production.
These results reveal how HIV can both evade dendritic cell immune activity and amplify its own replication. With nearly 40 million people world-wide currently living with HIV-AIDS, understanding the myriad ways that HIV can modulate immune responses is of paramount importance.
Author contact:
Alison Simmons (Weatherall Institute of Molecular Medicine, Oxford, UK)
Tel: +44 1865 222 616; E-mail: asimmons@hammer.imm.ox.ac.uk
Additional contact for comment:
Anthony Cunningham (Westmead Millennium Institute, Australia)
Tel: +61 2 9845 9005; E-mail: tony_cunningham@wmi.usyd.edu.au
Interaction of the human immunodeficiency virus (HIV) with dendritic cells—a specialized type of immune cell—circumvents immune activation and greatly enhances infection of T lymphocytes, reports a study to be published in the June issue of Nature Immunology.
Dendritic cells are required to initiate immune responses, and as targets of HIV infection, these cells are important contributors to HIV pathogenesis. Alison Simmons and colleagues evaluated the effect of HIV interaction with DC-SIGN, a protein receptor found largely on the surface of dendritic cells. HIV binding to DC-SIGN elicited a signalling pathway that prevented dendritic cells from actively stimulating subsequent immune responses. In addition, the authors show that HIV–DC-SIGN interaction can lead to transfer of virus to nearby T lymphocytes that then become infected leading to a burst of HIV production.
These results reveal how HIV can both evade dendritic cell immune activity and amplify its own replication. With nearly 40 million people world-wide currently living with HIV-AIDS, understanding the myriad ways that HIV can modulate immune responses is of paramount importance.
Author contact:
Alison Simmons (Weatherall Institute of Molecular Medicine, Oxford, UK)
Tel: +44 1865 222 616; E-mail: asimmons@hammer.imm.ox.ac.uk
Additional contact for comment:
Anthony Cunningham (Westmead Millennium Institute, Australia)
Tel: +61 2 9845 9005; E-mail: tony_cunningham@wmi.usyd.edu.au
Gene combinations influence AIDS progression
Different combinations of genetic variants of two modulators of the innate human immune system strongly influence AIDS progression in HIV-positive individuals, according to a study.
Natural killer cells are part of the antiviral immune response, and their activity is controlled by receptors called KIRs that are present on the cell surface. The KIR receptors that inhibit natural killer cell activity (KIR3DL1) are triggered by HLA-B molecules, which are presented by other cells of the immune system. Mary Carrington and colleagues examined variation in the genes encoding KIR3DL1 and HLA-B in more than 1,500 HIV-positive individuals, and found that particular combinations of variants conferred protection against AIDS progression.
These results may explain at least part of the variability in progression of the disease in infected individuals. The authors also note that the observed rapid evolution of these genes may be driven by pathogens such as HIV.
Author contact:
Mary Carrington (National Cancer Institute, Frederick, MD, USA)
Tel: +1 301 846 1390; E-mail: carringt@ncifcrf.gov
Different combinations of genetic variants of two modulators of the innate human immune system strongly influence AIDS progression in HIV-positive individuals, according to a study.
Natural killer cells are part of the antiviral immune response, and their activity is controlled by receptors called KIRs that are present on the cell surface. The KIR receptors that inhibit natural killer cell activity (KIR3DL1) are triggered by HLA-B molecules, which are presented by other cells of the immune system. Mary Carrington and colleagues examined variation in the genes encoding KIR3DL1 and HLA-B in more than 1,500 HIV-positive individuals, and found that particular combinations of variants conferred protection against AIDS progression.
These results may explain at least part of the variability in progression of the disease in infected individuals. The authors also note that the observed rapid evolution of these genes may be driven by pathogens such as HIV.
Author contact:
Mary Carrington (National Cancer Institute, Frederick, MD, USA)
Tel: +1 301 846 1390; E-mail: carringt@ncifcrf.gov
Nanotubes sort out their left and right
Left- and right-handed carbon nanotubes can be separated from one another, according to a paper. Although nanotubes have previously been sorted on the basis of their diameter or length, this method is the first to discriminate between those with opposite helical twists.
Some molecules, which are known as ‘chiral’, can exist as mirror-image forms that cannot be superimposed on each other. Louis Pasteur was, in 1849, the first to separate such molecules, by meticulously sorting asymmetric crystals of tartaric acid by hand, using tweezers and a microscope. Following in his footsteps, Naoki Komatsu and co-workers designed pairs of chemical ‘nano-tweezers’ that can selectively pluck either left- or right-handed nanotubes from a mixture.
The ability to separate carbon nanotubes — one of nanotechnology’s most promising building blocks — in this way will lead to a better understanding of their optical properties, and may offer unique opportunities for photonics and quantum optics.
Author contact:
Naoki Komatsu (Shiga University of Medical Science, Otsu, Japan)
Tel: +81 77 548 2102; E-mail: nkomatsu@belle.shiga-med.ac.jp
Left- and right-handed carbon nanotubes can be separated from one another, according to a paper. Although nanotubes have previously been sorted on the basis of their diameter or length, this method is the first to discriminate between those with opposite helical twists.
Some molecules, which are known as ‘chiral’, can exist as mirror-image forms that cannot be superimposed on each other. Louis Pasteur was, in 1849, the first to separate such molecules, by meticulously sorting asymmetric crystals of tartaric acid by hand, using tweezers and a microscope. Following in his footsteps, Naoki Komatsu and co-workers designed pairs of chemical ‘nano-tweezers’ that can selectively pluck either left- or right-handed nanotubes from a mixture.
The ability to separate carbon nanotubes — one of nanotechnology’s most promising building blocks — in this way will lead to a better understanding of their optical properties, and may offer unique opportunities for photonics and quantum optics.
Author contact:
Naoki Komatsu (Shiga University of Medical Science, Otsu, Japan)
Tel: +81 77 548 2102; E-mail: nkomatsu@belle.shiga-med.ac.jp
CHEMICAL BIOLOGY : A little sugar for the brain
The amount of sugar on proteins inside neural cells changes in response to brain stimulation, which implicates sugar modification as a new player in brain signalling, according to a paper to be published in the June issue of Nature Chemical Biology. Changes in the levels of phosphorylation of serine and threonine residues have a well-known role in cell signalling. Although most glycosylation, or modification of proteins by the attachment of sugars, occurs on proteins outside the cell, one sugar modification, called O-GlcNAc, can be attached to serine or threonine residues of proteins inside cells. Because phosphorylation and O-GlcNAc modifications occur on exactly the same amino acid side chains, O-GlcNAc could be critical in cellular signalling. However, a lack of tools to identify the precise positions of O-GlcNAc modifications in vivo has made it difficult to investigate this hypothesis.
Linda Hsieh-Wilson and colleagues have now developed a proteomic method that uses mass spectrometry to determine in vivo O-GlcNAc levels. When rats were injected with an excitatory stimulus, the authors identified changes in the sugar levels at specific sites of proteins found in the brain. With this information, it will now be possible to investigate the exact role O-GlcNAc plays in brain function.
Author contact:
Linda Hsieh-Wilson (California Institute of Technology, Pasadena, CA, USA)
Tel: +1 626 395 6101; E-mail: lhw@caltech.edu
The amount of sugar on proteins inside neural cells changes in response to brain stimulation, which implicates sugar modification as a new player in brain signalling, according to a paper to be published in the June issue of Nature Chemical Biology. Changes in the levels of phosphorylation of serine and threonine residues have a well-known role in cell signalling. Although most glycosylation, or modification of proteins by the attachment of sugars, occurs on proteins outside the cell, one sugar modification, called O-GlcNAc, can be attached to serine or threonine residues of proteins inside cells. Because phosphorylation and O-GlcNAc modifications occur on exactly the same amino acid side chains, O-GlcNAc could be critical in cellular signalling. However, a lack of tools to identify the precise positions of O-GlcNAc modifications in vivo has made it difficult to investigate this hypothesis.
Linda Hsieh-Wilson and colleagues have now developed a proteomic method that uses mass spectrometry to determine in vivo O-GlcNAc levels. When rats were injected with an excitatory stimulus, the authors identified changes in the sugar levels at specific sites of proteins found in the brain. With this information, it will now be possible to investigate the exact role O-GlcNAc plays in brain function.
Author contact:
Linda Hsieh-Wilson (California Institute of Technology, Pasadena, CA, USA)
Tel: +1 626 395 6101; E-mail: lhw@caltech.edu
Unexpected biodiversity springs from the depths
Five-hundred and eighty-five new species of crustacean have been found in the depths of the Southern Ocean, thanks to three sampling expeditions set up as part of the ANDEEP (Antarctic benthic deep-sea biodiversity) project. Unexpected levels of biodiversity were found in this dark and largely unstudied place, challenging assumptions that deep sea diversity is depressed in this area.
On their expeditions, Angelika Brandt and colleagues collected biological specimens and environmental data from different regions 774 to 6,348 metres under the surface of the Weddell Sea and adjacent areas. The Weddell Sea is an important source of deep water for the rest of the ocean and provides a possible route for species to enter the deep water. In line with this, the team found deep-sea faunas that were also found in adjacent shelf communities and in other oceans.
They spotted 674 species of isopod — a diverse order of crustaceans — of which over 80% were new to science. In some regions, groups of slope-dwelling isopods and marine worms included species that had invaded from the Southern Ocean’s deep continental shelf. Species living in the deepest parts of the Weddell Sea tended to have strong links to other oceans, particularly if they were good dispersers, like certain amoeboids. But poor dispersers, such as isopods, nematode worms and seed shrimps, were Southern Ocean-specific species.
CONTACT
Angelika Brandt (University of Hamburg, Germany)
Tel: +49 40 42838 2278; E-mail: abrandt@zoologie.uni-hamburg.de
Five-hundred and eighty-five new species of crustacean have been found in the depths of the Southern Ocean, thanks to three sampling expeditions set up as part of the ANDEEP (Antarctic benthic deep-sea biodiversity) project. Unexpected levels of biodiversity were found in this dark and largely unstudied place, challenging assumptions that deep sea diversity is depressed in this area.
On their expeditions, Angelika Brandt and colleagues collected biological specimens and environmental data from different regions 774 to 6,348 metres under the surface of the Weddell Sea and adjacent areas. The Weddell Sea is an important source of deep water for the rest of the ocean and provides a possible route for species to enter the deep water. In line with this, the team found deep-sea faunas that were also found in adjacent shelf communities and in other oceans.
They spotted 674 species of isopod — a diverse order of crustaceans — of which over 80% were new to science. In some regions, groups of slope-dwelling isopods and marine worms included species that had invaded from the Southern Ocean’s deep continental shelf. Species living in the deepest parts of the Weddell Sea tended to have strong links to other oceans, particularly if they were good dispersers, like certain amoeboids. But poor dispersers, such as isopods, nematode worms and seed shrimps, were Southern Ocean-specific species.
CONTACT
Angelika Brandt (University of Hamburg, Germany)
Tel: +49 40 42838 2278; E-mail: abrandt@zoologie.uni-hamburg.de
Materials: Silicon in a spin
The first silicon-based spintronics device reported. Spintronics, an emerging technology that uses the quantum spin states as well as (or instead of) the charge states of electrons, offers another level of control over electronic devices. So with silicon already at the forefront of conventional electronics, devices like this could find themselves integrated with standard silicon technology.
Researchers have been trying to make devices that can transport electronic signals with all of the electrons spun in one direction only. But finding the right combinations of materials to do this efficiently has proved tricky. Ian Appelbaum and colleagues have achieved this by sandwiching an extra layer inside their device. The extra layer, made from aluminium and iron cobalt sits between an insulating barrier and the silicon, where it filters out electrons of a particular spin.
CONTACT
Ian Appelbaum (University of Delaware, Newark, DE, USA)
Tel: +1 302 831 3295; E-mail: appelbaum@ee.udel.edu
Igor Zutic (State University of New York at Buffalo, NY, USA) N&V author
Tel: +1 716 645 2017 x183; E-mail: zigor@buffalo.edu
The first silicon-based spintronics device reported. Spintronics, an emerging technology that uses the quantum spin states as well as (or instead of) the charge states of electrons, offers another level of control over electronic devices. So with silicon already at the forefront of conventional electronics, devices like this could find themselves integrated with standard silicon technology.
Researchers have been trying to make devices that can transport electronic signals with all of the electrons spun in one direction only. But finding the right combinations of materials to do this efficiently has proved tricky. Ian Appelbaum and colleagues have achieved this by sandwiching an extra layer inside their device. The extra layer, made from aluminium and iron cobalt sits between an insulating barrier and the silicon, where it filters out electrons of a particular spin.
CONTACT
Ian Appelbaum (University of Delaware, Newark, DE, USA)
Tel: +1 302 831 3295; E-mail: appelbaum@ee.udel.edu
Igor Zutic (State University of New York at Buffalo, NY, USA) N&V author
Tel: +1 716 645 2017 x183; E-mail: zigor@buffalo.edu
Infectious diseases: Global early-warning system needed
Researchers are calling for a global early-warning system to identify the sources of future human infectious disease. analysis compares the origins of temperate and tropical infectious diseases, and highlights how little we know about their evolution.
Most major human infectious diseases have animal origins, yet we continue to be bombarded by new animal pathogens, jumping across species barriers. So Jared Diamond and colleagues want to see a systematic ongoing global effort monitoring for emergent animal pathogens that could infect humans. People with high levels of exposure to wild animals, such as hunters, zoo workers and wildlife veterinarians, should be regularly screened, they say.
The team made their request after comparing the characteristics and origins of 15 temperate (such as whooping cough) and 10 tropical diseases (such as cholera). Most of the diseases studied arose in Africa, Asia and Europe, but the reasons for their emergence differed between regions — infections from animal and insect vectors, for example, were more common in the tropics.
The review reveals “big gaps in our understanding” of the origins of even established major infectious diseases, such as AIDS, cholera and tuberculosis. So alongside a global early-warning system for new human infectious diseases, the authors would also like to see more research to clarify the origins of existing infectious diseases. Such work could boost understanding of how diseases emerge and suggest new laboratory models for studying public health threats.
CONTACT
Jared Diamond (University of California, Los Angeles, CA, USA)
Tel: +1 310 825 6177; E-mail: jdiamond@geog.ucla.edu
Nathan Wolfe (University of California, Los Angeles, CA, USA) Co-author
Tel: +1 310 794 7538; E-mail: nwolfe@ucla.edu
Researchers are calling for a global early-warning system to identify the sources of future human infectious disease. analysis compares the origins of temperate and tropical infectious diseases, and highlights how little we know about their evolution.
Most major human infectious diseases have animal origins, yet we continue to be bombarded by new animal pathogens, jumping across species barriers. So Jared Diamond and colleagues want to see a systematic ongoing global effort monitoring for emergent animal pathogens that could infect humans. People with high levels of exposure to wild animals, such as hunters, zoo workers and wildlife veterinarians, should be regularly screened, they say.
The team made their request after comparing the characteristics and origins of 15 temperate (such as whooping cough) and 10 tropical diseases (such as cholera). Most of the diseases studied arose in Africa, Asia and Europe, but the reasons for their emergence differed between regions — infections from animal and insect vectors, for example, were more common in the tropics.
The review reveals “big gaps in our understanding” of the origins of even established major infectious diseases, such as AIDS, cholera and tuberculosis. So alongside a global early-warning system for new human infectious diseases, the authors would also like to see more research to clarify the origins of existing infectious diseases. Such work could boost understanding of how diseases emerge and suggest new laboratory models for studying public health threats.
CONTACT
Jared Diamond (University of California, Los Angeles, CA, USA)
Tel: +1 310 825 6177; E-mail: jdiamond@geog.ucla.edu
Nathan Wolfe (University of California, Los Angeles, CA, USA) Co-author
Tel: +1 310 794 7538; E-mail: nwolfe@ucla.edu
Planetary science: Enceladus' daily grind
Scientists may have worked out what powers the plumes of gas seen escaping from the surface of one of Saturn's moons. The energy may be generated by massive ice sheets grinding together, with the vapour produced being released through rifts that open and close periodically, papers suggest.
When Cassini flew by Enceladus, a small icy satellite of Saturn, a couple of years ago, cameras snapped active vapour plumes thought to emanate from rifts in the crust dubbed 'tiger stripes.' Francis Nimmo and colleagues now suggest that these 'tiger stripes' are like strike-slip fault zones, with sheets of ice grinding back and forth against one another. This, they say, could generate enough energy to power the gas plumes.
Terry A. Hurford and colleagues show that as Enceladus orbits Saturn, the parent planet's tides make the satellite's ice flex. This, they believe, causes the 'tiger stripes' to open and close periodically, exposing volatiles and allowing them to be released.
Tidal heating was previously proposed as a potential mechanism to explain Enceladus' vapour plumes, but scientists debate whether the energy generated from tidal heating is sufficient. The two new papers offer a plausible alternative.
CONTACT
Francis Nimmo (University of California, Santa Cruz, CA, USA) Author paper [2]
Tel: +1 831 459 1783; E-mail: fnimmo@es.ucsc.edu
Terry A. Hurford (NASA Goddard Space Flight Center, Greenbelt, MD, USA) Author paper [3]
Tel: +1 301 614 6455; E-mail: hurfordt@core2.gsfc.nasa.gov
Andrew J. Dombard (Johns Hopkins University, Laurel, MD, USA) N&V author
Tel: +1 240 228 1651; E-mail: andrew.dombard@jhuapl.edu
Scientists may have worked out what powers the plumes of gas seen escaping from the surface of one of Saturn's moons. The energy may be generated by massive ice sheets grinding together, with the vapour produced being released through rifts that open and close periodically, papers suggest.
When Cassini flew by Enceladus, a small icy satellite of Saturn, a couple of years ago, cameras snapped active vapour plumes thought to emanate from rifts in the crust dubbed 'tiger stripes.' Francis Nimmo and colleagues now suggest that these 'tiger stripes' are like strike-slip fault zones, with sheets of ice grinding back and forth against one another. This, they say, could generate enough energy to power the gas plumes.
Terry A. Hurford and colleagues show that as Enceladus orbits Saturn, the parent planet's tides make the satellite's ice flex. This, they believe, causes the 'tiger stripes' to open and close periodically, exposing volatiles and allowing them to be released.
Tidal heating was previously proposed as a potential mechanism to explain Enceladus' vapour plumes, but scientists debate whether the energy generated from tidal heating is sufficient. The two new papers offer a plausible alternative.
CONTACT
Francis Nimmo (University of California, Santa Cruz, CA, USA) Author paper [2]
Tel: +1 831 459 1783; E-mail: fnimmo@es.ucsc.edu
Terry A. Hurford (NASA Goddard Space Flight Center, Greenbelt, MD, USA) Author paper [3]
Tel: +1 301 614 6455; E-mail: hurfordt@core2.gsfc.nasa.gov
Andrew J. Dombard (Johns Hopkins University, Laurel, MD, USA) N&V author
Tel: +1 240 228 1651; E-mail: andrew.dombard@jhuapl.edu
Regeneration: Hope for new hair
Adult mice can regenerate hair follicles and hair. The results help resolve a 50-year-long debate and may aid in the design of new treatments for wounds, hair loss and other degenerative skin disorders.
For half a century, most people believed that mammalian hair follicles form only during development, and that loss of adult follicles is permanent. George Cotsarelis and colleagues now show this is not the case, at least for adult mice with skin wounds. Wounding, they report, triggers new hair-producing follicles to form. Exposure to Wnt signalling — a genetic pathway involved in normal hair follicle development and cycling — following wounding increases the number of regenerated hair follicles. And Wnt signalling inhibition after regrowth of the epithelium prevents new follicles from forming.
The results suggest that mammalian skin can respond to wounding with plasticity and a much greater regenerative capacity than was previously believed. It's thought that wounding triggers an embryonic-like state in the skin which provides a window for hair follicle regeneration via the Wnt signalling pathway.
CONTACT
George Cotsarelis (University of Pennsylvania School of Medicine, Philadelphia, PA, USA)
Tel: +1 215 898 9967; E-mail: cotsarel@mail.med.upenn.edu
Cheng-Ming Chuong (University of Southern California, Los Angeles, CA, USA) N&V author
Tel: +1 323 442 1296; E-mail: chuong@pathfinder.usc.edu
Adult mice can regenerate hair follicles and hair. The results help resolve a 50-year-long debate and may aid in the design of new treatments for wounds, hair loss and other degenerative skin disorders.
For half a century, most people believed that mammalian hair follicles form only during development, and that loss of adult follicles is permanent. George Cotsarelis and colleagues now show this is not the case, at least for adult mice with skin wounds. Wounding, they report, triggers new hair-producing follicles to form. Exposure to Wnt signalling — a genetic pathway involved in normal hair follicle development and cycling — following wounding increases the number of regenerated hair follicles. And Wnt signalling inhibition after regrowth of the epithelium prevents new follicles from forming.
The results suggest that mammalian skin can respond to wounding with plasticity and a much greater regenerative capacity than was previously believed. It's thought that wounding triggers an embryonic-like state in the skin which provides a window for hair follicle regeneration via the Wnt signalling pathway.
CONTACT
George Cotsarelis (University of Pennsylvania School of Medicine, Philadelphia, PA, USA)
Tel: +1 215 898 9967; E-mail: cotsarel@mail.med.upenn.edu
Cheng-Ming Chuong (University of Southern California, Los Angeles, CA, USA) N&V author
Tel: +1 323 442 1296; E-mail: chuong@pathfinder.usc.edu
Saturday, May 12, 2007
Bagoong: Good for the Brain
A study shows that the traditional fish/shrimp paste condiment, or bagoong, of the Philippines contains the beneficial omega-3 fatty acids. In its analysis, it was found that among the samples of bagoong, shrimp paste has the highest omega-3 content.
The famous Bagoong, also referred to as fish or shrimp paste, is one of the traditional flavor extenders used in the Philippines. It has several variations according to the type of fish used, color, and taste. Bagoong is prepared by fermenting the fish or shrimp in high concentrations of salt for several months. Consumed either as a complement of green mangoes or as a seasoning to some Filipino delicacies such as pinakbet, little is known about the nutritional content of these condiments since they are usually sold without labels in local markets.
Fish and other marine food resources are known to be good sources of long-chain ω-3 (omega-3) polyunsaturated fatty acids. One in particular is the all-cis-4,7,10,13,16,19-docosahexaenoic acid (DHA), a variant of the long-chain ω-3 fatty acid, which is essential to the neural development of growing infants especially in brain and retina development. Sufficient amount of DHA is required for an active brain function throughout a human’s lifespan. DHA has also been found to lower blood pressure and chances of occurrence of heart disease and mental illness. Though high levels of DHA are produced during pregnancy and during the first two months of infancy, the normal human body condition can only manufacture these fatty acids metabolically in small amounts. DHA must then be acquired from the diet or produced through the consumption of ω-3 precursors such as α-linolenic acid found in seeds and nuts.
The composition of bagoong suggests the possibility that the said condiment may be a dietary resource of long-chain ω-3 polyunsaturated fatty acids. In the study “Polyunsaturated fatty acid contents of some traditional fish and shrimp paste condiments of the Philippines,” scientists Nemesio Montaño, Grace Gavino and Victor C. Gavino assess the fatty acid composition of various types of fish and shrimp paste in reaction to the brine solution used for fermentation.
Montaño’s team gathered samples of six types of fish and shrimp paste condiments from a public market in Bolinao, Pangasinan located at Western Luzon of the Philippines. The vendors of these products were interviewed regarding their preparation process of bagoong. The general preparation of bagoong according to them is that fish or shrimp fry are deposited alternately in layers with salt in ratios of three to four parts of salt to one part of fish or shrimp fry. The mixture is then incubated at ambient temperature in a specific period of time depending on the fish type used. The fish types used in the collected samples were verified through visual investigation. The samples were found to be made from Dalagang bukid (Fusiliers, Caesio spp.), Dilis (Silver sprat, Spratelloides gracillis), Padas-1 (Fuscescens rabbitfish, Siganus fuscescens), Padas-2 (Forktail rabbitfish, Siganus argenteus), Terong (Fusiliers, Pterocaesio spp.) and Alamang (Shrimp fry, Acetes spp.). Samples were analyzed fresh or freeze-dried. The composition of fresh untreated alamang was also compared with the composition of salt-treated alamang.
Fatty acid composition, salt content, moisture and water activity of the fish/shrimp paste samples were measured to examine if the salinity of the paste condiments and the oxidation process significantly affect the fatty acid content of the fish and shrimp fry. Ash and fat content were also studied to look further into the composition of bagoong. The salt content of the samples was determined using the Mohr Method [1] while moisture was calculated from the sample’s weight loss when dried. Water activity was determined by equilibration with the salt solution. The dried samples were then reduced to ashes to measure the ash content. Fat content was measured by Soxhlet extraction [2] of the freeze-dried samples and the fatty acid composition was determined using an adaptation of a direct methylation procedure on the sample followed by gas chromatography.
Findings show that the salt content of the bagoong samples does not tally with the ratio of salt to fish/shrimp fry given by the vendors. Salinity was found to range from 19 to 24%, which greatly differs from the 60 to 80% accounted from the vendors’ statement. The alamang condiment was also found to contain the highest level of DHA ω-3 polyunsaturated fatty acids among the samples followed by Padas-1. The Dalagang bukid paste condiment, on the other hand, has the lowest. According to Dr. Montaño, this may be explained by the phytoplanktons and bacteria the shrimp fry consume which could have produced the high levels of long-chain polyunsaturated fatty acids.
References:
1. Thomson Healthcare, PDRhealth. “Docahexaenoic Acid (DHA).”
2. DHA/EPA Omega-3 Institute. “DHA for Optimal Brain and Visual Functioning.“
3. The Kushi Institute of Europe, Encyclopedia. “Fats.”
4. University of Canterbury, Christchurch New Zealand. “Determination of Chloride Ion Concentration by Titration (Mohr’s Method).”
By MMRParreño
___________________________________________________________________
[1] Mohr Method is the process of determining chlorides in bagoong sample using titration with silver nitrate and indicator potassium chromate. The pH level of the sample to be tested should be between 6.5 to 10 for more accurate readings.
[2] Soxhlet Extraction is the process of extracting fat from the freeze-dried bagoong sample using low-boiling petroleum ether as solvent.
A study shows that the traditional fish/shrimp paste condiment, or bagoong, of the Philippines contains the beneficial omega-3 fatty acids. In its analysis, it was found that among the samples of bagoong, shrimp paste has the highest omega-3 content.
The famous Bagoong, also referred to as fish or shrimp paste, is one of the traditional flavor extenders used in the Philippines. It has several variations according to the type of fish used, color, and taste. Bagoong is prepared by fermenting the fish or shrimp in high concentrations of salt for several months. Consumed either as a complement of green mangoes or as a seasoning to some Filipino delicacies such as pinakbet, little is known about the nutritional content of these condiments since they are usually sold without labels in local markets.
Fish and other marine food resources are known to be good sources of long-chain ω-3 (omega-3) polyunsaturated fatty acids. One in particular is the all-cis-4,7,10,13,16,19-docosahexaenoic acid (DHA), a variant of the long-chain ω-3 fatty acid, which is essential to the neural development of growing infants especially in brain and retina development. Sufficient amount of DHA is required for an active brain function throughout a human’s lifespan. DHA has also been found to lower blood pressure and chances of occurrence of heart disease and mental illness. Though high levels of DHA are produced during pregnancy and during the first two months of infancy, the normal human body condition can only manufacture these fatty acids metabolically in small amounts. DHA must then be acquired from the diet or produced through the consumption of ω-3 precursors such as α-linolenic acid found in seeds and nuts.
The composition of bagoong suggests the possibility that the said condiment may be a dietary resource of long-chain ω-3 polyunsaturated fatty acids. In the study “Polyunsaturated fatty acid contents of some traditional fish and shrimp paste condiments of the Philippines,” scientists Nemesio Montaño, Grace Gavino and Victor C. Gavino assess the fatty acid composition of various types of fish and shrimp paste in reaction to the brine solution used for fermentation.
Montaño’s team gathered samples of six types of fish and shrimp paste condiments from a public market in Bolinao, Pangasinan located at Western Luzon of the Philippines. The vendors of these products were interviewed regarding their preparation process of bagoong. The general preparation of bagoong according to them is that fish or shrimp fry are deposited alternately in layers with salt in ratios of three to four parts of salt to one part of fish or shrimp fry. The mixture is then incubated at ambient temperature in a specific period of time depending on the fish type used. The fish types used in the collected samples were verified through visual investigation. The samples were found to be made from Dalagang bukid (Fusiliers, Caesio spp.), Dilis (Silver sprat, Spratelloides gracillis), Padas-1 (Fuscescens rabbitfish, Siganus fuscescens), Padas-2 (Forktail rabbitfish, Siganus argenteus), Terong (Fusiliers, Pterocaesio spp.) and Alamang (Shrimp fry, Acetes spp.). Samples were analyzed fresh or freeze-dried. The composition of fresh untreated alamang was also compared with the composition of salt-treated alamang.
Fatty acid composition, salt content, moisture and water activity of the fish/shrimp paste samples were measured to examine if the salinity of the paste condiments and the oxidation process significantly affect the fatty acid content of the fish and shrimp fry. Ash and fat content were also studied to look further into the composition of bagoong. The salt content of the samples was determined using the Mohr Method [1] while moisture was calculated from the sample’s weight loss when dried. Water activity was determined by equilibration with the salt solution. The dried samples were then reduced to ashes to measure the ash content. Fat content was measured by Soxhlet extraction [2] of the freeze-dried samples and the fatty acid composition was determined using an adaptation of a direct methylation procedure on the sample followed by gas chromatography.
Findings show that the salt content of the bagoong samples does not tally with the ratio of salt to fish/shrimp fry given by the vendors. Salinity was found to range from 19 to 24%, which greatly differs from the 60 to 80% accounted from the vendors’ statement. The alamang condiment was also found to contain the highest level of DHA ω-3 polyunsaturated fatty acids among the samples followed by Padas-1. The Dalagang bukid paste condiment, on the other hand, has the lowest. According to Dr. Montaño, this may be explained by the phytoplanktons and bacteria the shrimp fry consume which could have produced the high levels of long-chain polyunsaturated fatty acids.
References:
1. Thomson Healthcare, PDRhealth. “Docahexaenoic Acid (DHA).”
2. DHA/EPA Omega-3 Institute. “DHA for Optimal Brain and Visual Functioning.“
3. The Kushi Institute of Europe, Encyclopedia. “Fats.”
4. University of Canterbury, Christchurch New Zealand. “Determination of Chloride Ion Concentration by Titration (Mohr’s Method).”
By MMRParreño
___________________________________________________________________
[1] Mohr Method is the process of determining chlorides in bagoong sample using titration with silver nitrate and indicator potassium chromate. The pH level of the sample to be tested should be between 6.5 to 10 for more accurate readings.
[2] Soxhlet Extraction is the process of extracting fat from the freeze-dried bagoong sample using low-boiling petroleum ether as solvent.
Friday, May 11, 2007
Gender-specific differences fuel biodiversity
Many factors, such as habitat, behaviour and diet, contribute to biological diversity. But researchers now have an unexpected addition to this list — sexual differences. A study of the Anolis lizards of the Greater Antilles suggests that morphological differences between males and females are linked to increased biodiversity.
The Anolis lizards of Puerto Rico, Jamaica, Cuba and Hispaniola evolved independently on their respective islands into species that occupy particular niches, such as the short-legged twig dwellers and the long-legged open space dwellers. But males and females of the same species can be very different — in some species the sexes are the same size, but in others adult males can be three times bigger than females.
Marguerite A. Butler and colleagues studied five sexually dimorphic characteristics from male and female adults of different niche specialists living on two of the islands. They find that sexual dimorphism contributes substantially to biodiversity, helping to fuel the bursts of ‘adaptive radiation’ that produced the different niche-adapted species.
Most studies of adaptive radiation ignore sexually dimorphic traits, the authors say. But its place in evolutionary ecology should not be underestimated.
CONTACT
Marguerite A. Butler (University of Hawaii at Manoa, Honolulu, HI, USA)
Tel: +1 808 956 4713; E-mail: mbutler@hawaii.edu
Many factors, such as habitat, behaviour and diet, contribute to biological diversity. But researchers now have an unexpected addition to this list — sexual differences. A study of the Anolis lizards of the Greater Antilles suggests that morphological differences between males and females are linked to increased biodiversity.
The Anolis lizards of Puerto Rico, Jamaica, Cuba and Hispaniola evolved independently on their respective islands into species that occupy particular niches, such as the short-legged twig dwellers and the long-legged open space dwellers. But males and females of the same species can be very different — in some species the sexes are the same size, but in others adult males can be three times bigger than females.
Marguerite A. Butler and colleagues studied five sexually dimorphic characteristics from male and female adults of different niche specialists living on two of the islands. They find that sexual dimorphism contributes substantially to biodiversity, helping to fuel the bursts of ‘adaptive radiation’ that produced the different niche-adapted species.
Most studies of adaptive radiation ignore sexually dimorphic traits, the authors say. But its place in evolutionary ecology should not be underestimated.
CONTACT
Marguerite A. Butler (University of Hawaii at Manoa, Honolulu, HI, USA)
Tel: +1 808 956 4713; E-mail: mbutler@hawaii.edu
Oceanography: Oceanic short circuit
Researchers have discovered a 'short circuit' in the circulation of the world's oceans that allows cold waters that sink to the abyss to return to the surface more rapidly than previously thought. Understanding oceanic circulation is important because it transports heat, carbon and nutrients around the globe and therefore plays a central role in Earth's climate.
Ocean mixing in the current that flows around Antarctica has a key role in global ocean circulation as it influences the rate at which water sinking to the deep ocean at high latitudes returns to the surface in the Southern Ocean. But the rates of mixing processes that occur in the current and the induced upwelling are not well known. Alberto C. Naveira Garabato and colleagues studied the spread of helium released from submarine volcanoes to measure the rates of mixing and upwelling in the southwest Atlantic sector of the current.
Their results indicate that the rough topography of the ocean floor in this region leads to both rapid mixing across density surfaces and rapid upwelling along density surfaces, which together create a 'short circuit' in the global oceanic overturning circulation.
CONTACT
Alberto C. Naveira Garabato (University of Southampton, UK)
Tel: +44 23 8059 2680; E-mail: acng@noc.soton.ac.uk
Researchers have discovered a 'short circuit' in the circulation of the world's oceans that allows cold waters that sink to the abyss to return to the surface more rapidly than previously thought. Understanding oceanic circulation is important because it transports heat, carbon and nutrients around the globe and therefore plays a central role in Earth's climate.
Ocean mixing in the current that flows around Antarctica has a key role in global ocean circulation as it influences the rate at which water sinking to the deep ocean at high latitudes returns to the surface in the Southern Ocean. But the rates of mixing processes that occur in the current and the induced upwelling are not well known. Alberto C. Naveira Garabato and colleagues studied the spread of helium released from submarine volcanoes to measure the rates of mixing and upwelling in the southwest Atlantic sector of the current.
Their results indicate that the rough topography of the ocean floor in this region leads to both rapid mixing across density surfaces and rapid upwelling along density surfaces, which together create a 'short circuit' in the global oceanic overturning circulation.
CONTACT
Alberto C. Naveira Garabato (University of Southampton, UK)
Tel: +44 23 8059 2680; E-mail: acng@noc.soton.ac.uk
Planetary science: Extrasolar planet mirror ball
An extrasolar 'hot Jupiter' planet may act like a giant mirror ball, re-radiating almost all of its incident energy back out to space, suggests a paper. But a second paper, tells a very different story, making 'hot Jupiters' seem all the more intriguing and complex.
'Hot Jupiters' are extrasolar planets whose mass is similar to that of Jupiter, but which orbit much closer to their parent star. Joseph Harrington and colleagues studied one such planet and found that it acts almost as a mirror, a bizarre observation as one would expect the planet to absorb at least some heat.
But Heather A. Knutson and co-workers found that a different 'hot Jupiter' can redistribute heat around its surface. The team effectively crudely 'mapped' the temperature distribution across the planet. Their data suggest that energy absorbed by the dayside of the planet can be fairly efficiently redistributed throughout the planet's atmosphere.
CONTACT
Joseph Harrington (University of Central Florida, Orlando, FL, USA) Author paper [2]
Tel: +1 407 823 3416; E-mail: jharring@phsyics.ucf.edu
Heather A. Knutson (Harvard University, Cambridge, MA, USA) Author paper [3]
Tel: +1 617 223 1723; E-mail: hknutson@cfa.harvard.edu
Adam Burrows (University of Arizona, Tucson, AZ, USA) N&V author
Tel: +1 520 621 1795; E-mail: aburrows@as.arizona.edu
An extrasolar 'hot Jupiter' planet may act like a giant mirror ball, re-radiating almost all of its incident energy back out to space, suggests a paper. But a second paper, tells a very different story, making 'hot Jupiters' seem all the more intriguing and complex.
'Hot Jupiters' are extrasolar planets whose mass is similar to that of Jupiter, but which orbit much closer to their parent star. Joseph Harrington and colleagues studied one such planet and found that it acts almost as a mirror, a bizarre observation as one would expect the planet to absorb at least some heat.
But Heather A. Knutson and co-workers found that a different 'hot Jupiter' can redistribute heat around its surface. The team effectively crudely 'mapped' the temperature distribution across the planet. Their data suggest that energy absorbed by the dayside of the planet can be fairly efficiently redistributed throughout the planet's atmosphere.
CONTACT
Joseph Harrington (University of Central Florida, Orlando, FL, USA) Author paper [2]
Tel: +1 407 823 3416; E-mail: jharring@phsyics.ucf.edu
Heather A. Knutson (Harvard University, Cambridge, MA, USA) Author paper [3]
Tel: +1 617 223 1723; E-mail: hknutson@cfa.harvard.edu
Adam Burrows (University of Arizona, Tucson, AZ, USA) N&V author
Tel: +1 520 621 1795; E-mail: aburrows@as.arizona.edu
Genetics: Marsupial genome sequenced
The first high-quality draft of a marsupial genome sequence is revealed.The genome of the grey, short-tailed opossum (Monodelphis domestica) offers interesting insights into the genetics of the immune system and the X chromosome.
Kerstin Lindblad-Toh and colleagues identified a wide range of immune genes. Some seem to be marsupial-specific, whereas others are shared with placental mammals. This, alongside the discovery of a novel type of T-cell receptor, indicates that marsupials had already evolved a complex immune system when they diverged from the placental mammal lineage some 180 million years ago — a suggestion that is at odds with previous claims of a primitive immune system.
The results also suggest that random inactivation of the X chromosome — a phenomenon seen in placental mammals whereby one random copy of the X chromosome is switched off to avoid a double dose of 'X genes' — appeared alongside the evolution of a complex genetic locus called the X inactivation centre (XIC). The XIC is lacking in the opossum genome, a finding that may help to explain why, in the opossum, it's always the paternally derived X chromosome that is silenced.
The newly sequenced genome seems to contain 18,000–20,000 protein-coding genes, most of which have counterparts in placental mammals. Opossum-specific genes mostly originate from the expansion and rapid turnover of gene families involved in immunity, sensory perception and detoxification.
The sequencing of the opossum genome marks an important point in genetics research and not just because of the special place occupied by the marsupial in the evolutionary tree. The animals provide a good model of malignant melanoma, and are useful in studies of regeneration because newborns can heal complete transections of spinal cord.
CONTACT
Kerstin Lindblad-Toh (Broad Institute of MIT and Harvard, Cambridge, MA, USA)
Nicole Davis (Scientific Communications Specialist, Broad Institute of MIT and Harvard, Cambridge, MA, USA)
Tel: +1 617 258 0952; E-mail: ndavis@broad.mit.edu
Geoff Spencer (Public Affairs Specialist, National Human Genome Research Institute, NIH, Bethesda, MD, USA)
Tel: +1 301 451 8325; E-mail: spencerg@mail.nih.gov
Leo Goodstadt (MRC Functional Genetics Unit, University of Oxford, UK) Co-author
This author can be contacted through the MRC press office:
Tel: +44 20 7637 6011; E-mail: press.office@headoffice.mrc.ac.uk
The first high-quality draft of a marsupial genome sequence is revealed.The genome of the grey, short-tailed opossum (Monodelphis domestica) offers interesting insights into the genetics of the immune system and the X chromosome.
Kerstin Lindblad-Toh and colleagues identified a wide range of immune genes. Some seem to be marsupial-specific, whereas others are shared with placental mammals. This, alongside the discovery of a novel type of T-cell receptor, indicates that marsupials had already evolved a complex immune system when they diverged from the placental mammal lineage some 180 million years ago — a suggestion that is at odds with previous claims of a primitive immune system.
The results also suggest that random inactivation of the X chromosome — a phenomenon seen in placental mammals whereby one random copy of the X chromosome is switched off to avoid a double dose of 'X genes' — appeared alongside the evolution of a complex genetic locus called the X inactivation centre (XIC). The XIC is lacking in the opossum genome, a finding that may help to explain why, in the opossum, it's always the paternally derived X chromosome that is silenced.
The newly sequenced genome seems to contain 18,000–20,000 protein-coding genes, most of which have counterparts in placental mammals. Opossum-specific genes mostly originate from the expansion and rapid turnover of gene families involved in immunity, sensory perception and detoxification.
The sequencing of the opossum genome marks an important point in genetics research and not just because of the special place occupied by the marsupial in the evolutionary tree. The animals provide a good model of malignant melanoma, and are useful in studies of regeneration because newborns can heal complete transections of spinal cord.
CONTACT
Kerstin Lindblad-Toh (Broad Institute of MIT and Harvard, Cambridge, MA, USA)
Nicole Davis (Scientific Communications Specialist, Broad Institute of MIT and Harvard, Cambridge, MA, USA)
Tel: +1 617 258 0952; E-mail: ndavis@broad.mit.edu
Geoff Spencer (Public Affairs Specialist, National Human Genome Research Institute, NIH, Bethesda, MD, USA)
Tel: +1 301 451 8325; E-mail: spencerg@mail.nih.gov
Leo Goodstadt (MRC Functional Genetics Unit, University of Oxford, UK) Co-author
This author can be contacted through the MRC press office:
Tel: +44 20 7637 6011; E-mail: press.office@headoffice.mrc.ac.uk
Sunday, April 29, 2007
New genetic risk factor for type 2 diabetes
Variation in the gene called CDKAL1 is associated with risk of developing type 2 diabetes.
Valgerdur Steinthorsdottir and colleagues discovered this new risk variant through a large-scale survey in Iceland in which they compared the frequencies of several hundred thousand common genetic variants in healthy individuals with those who have the disease. They subsequently replicated the association between type 2 diabetes and a variant in CDKAL1 in samples from several independent populations of European or Han Chinese ancestry. Individuals with two copies of the risk variant were found to be at increased risk for developing disease compared to individuals with only a single copy of the risk variant. Such individuals also had approximately 20% less insulin response than individuals with only one copy or non-carriers, suggesting that the variant may confer risk of type 2 diabetes through reduced insulin secretion.
Author contacts:
Edward Farmer (Director of Corporate Communication, deCODE genetics Inc)
Tel: +1 646 417 4555; E-mail: edward.farmer@decode.is
Valgerdur Steinthorsdottir (deCODE Genetics, Reykjavik, Iceland)
E-mail: vstein@decode.is
Kari Stefansson (deCODE Genetics, Reykjavik, Iceland)
E-mail: kstefans@decode.is
Variation in the gene called CDKAL1 is associated with risk of developing type 2 diabetes.
Valgerdur Steinthorsdottir and colleagues discovered this new risk variant through a large-scale survey in Iceland in which they compared the frequencies of several hundred thousand common genetic variants in healthy individuals with those who have the disease. They subsequently replicated the association between type 2 diabetes and a variant in CDKAL1 in samples from several independent populations of European or Han Chinese ancestry. Individuals with two copies of the risk variant were found to be at increased risk for developing disease compared to individuals with only a single copy of the risk variant. Such individuals also had approximately 20% less insulin response than individuals with only one copy or non-carriers, suggesting that the variant may confer risk of type 2 diabetes through reduced insulin secretion.
Author contacts:
Edward Farmer (Director of Corporate Communication, deCODE genetics Inc)
Tel: +1 646 417 4555; E-mail: edward.farmer@decode.is
Valgerdur Steinthorsdottir (deCODE Genetics, Reykjavik, Iceland)
E-mail: vstein@decode.is
Kari Stefansson (deCODE Genetics, Reykjavik, Iceland)
E-mail: kstefans@decode.is
Sunday, April 22, 2007
Increasing bad cholesterol levels
A study of Nature Structural & Molecular Biology suggests how the gene PCSK9 maintains cholesterol balance in the body.
Low-density lipoproteins (LDLs, also known as ‘bad cholesterol’) are removed from the bloodstream by binding to LDL receptors (LDLRs) present on the surface of cells. After binding, cells internalize both the receptor and cholesterol, the cholesterol is processed by the cell and LDLR is recycled back to the surface, where it can bind new cholesterol molecules. The amount of surface LDLR is decreased by the PCSK9 protein, resulting in high blood cholesterol, but how PCSK9 does this was not known.
Xiayang Qiu and colleagues have now found that PCSK9 binds very tightly to LDLR. This tight binding may lower LDLR levels on the cell surface by sequestering LDLRs inside cells, preventing their recycling back to the cell surface. A mutation in PCSK9 associated with high cholesterol shows even tighter binding to LDLR, supporting this model. These findings should improve our understanding of cholesterol regulation, and may help in the development of drugs to treat cardiovascular disease.
Author contact:
Xiayang Qiu (Pfizer, Groton, CT, USA)
Tel: +1 860 715 6718; E-mail: xiayang.qiu@pfizer.com
A study of Nature Structural & Molecular Biology suggests how the gene PCSK9 maintains cholesterol balance in the body.
Low-density lipoproteins (LDLs, also known as ‘bad cholesterol’) are removed from the bloodstream by binding to LDL receptors (LDLRs) present on the surface of cells. After binding, cells internalize both the receptor and cholesterol, the cholesterol is processed by the cell and LDLR is recycled back to the surface, where it can bind new cholesterol molecules. The amount of surface LDLR is decreased by the PCSK9 protein, resulting in high blood cholesterol, but how PCSK9 does this was not known.
Xiayang Qiu and colleagues have now found that PCSK9 binds very tightly to LDLR. This tight binding may lower LDLR levels on the cell surface by sequestering LDLRs inside cells, preventing their recycling back to the cell surface. A mutation in PCSK9 associated with high cholesterol shows even tighter binding to LDLR, supporting this model. These findings should improve our understanding of cholesterol regulation, and may help in the development of drugs to treat cardiovascular disease.
Author contact:
Xiayang Qiu (Pfizer, Groton, CT, USA)
Tel: +1 860 715 6718; E-mail: xiayang.qiu@pfizer.com
Astrocytes kill neurons in ALS
Astrocytes carrying a mutated version of a protein that causes amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig’s disease) are responsible for the death of motor neurons, report two papers in the May issue of Nature Neuroscience. These findings suggest that stem cell therapy focused on replacing damaged neurons may not be feasible in ALS, because diseased astrocytes would be expected to damage the replacement neurons.
Mutations in the gene for superoxide dismutase (SOD1) cause some cases of ALS, in which progressive degeneration of motor neurons leads to paralysis and eventually death. In both studies, the authors expressed this mutant protein in single cell types in culture. Motor neurons degenerated and died when cocultured with astrocytes expressing mutant SOD1, while mutant SOD1 in neurons, fibroblasts or microglia did not cause neuronal death.
Przedborski and colleagues additionally report that the astrocytes expressing mutant SOD1 killed only the neurons that degenerate in ALS, not other types of neurons, and that this was due to a soluble toxic factor released by the astrocytes. If this toxic factor can be identified in future studies, this finding may offer novel strategies for therapy.
Author contacts:
Serge Przedborski (Columbia University, New York, NY, USA) Paper [7]
Tel: +1 212 305 1540; E-mail: sp30@columbia.edu
Kevin Eggan (Harvard University, Cambridge, MA, USA) Paper [8]
Tel: +1 617 496 5611; E-mail: eggan@mcb.harvard.edu
Additional contact for comment on papers:
Jean-Pierre Julien (Laval University, Québec, Canada)
Tel: +1 418 654 2296; E-mail: jean-pierre.julien@crchul.ulaval.ca
Astrocytes carrying a mutated version of a protein that causes amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig’s disease) are responsible for the death of motor neurons, report two papers in the May issue of Nature Neuroscience. These findings suggest that stem cell therapy focused on replacing damaged neurons may not be feasible in ALS, because diseased astrocytes would be expected to damage the replacement neurons.
Mutations in the gene for superoxide dismutase (SOD1) cause some cases of ALS, in which progressive degeneration of motor neurons leads to paralysis and eventually death. In both studies, the authors expressed this mutant protein in single cell types in culture. Motor neurons degenerated and died when cocultured with astrocytes expressing mutant SOD1, while mutant SOD1 in neurons, fibroblasts or microglia did not cause neuronal death.
Przedborski and colleagues additionally report that the astrocytes expressing mutant SOD1 killed only the neurons that degenerate in ALS, not other types of neurons, and that this was due to a soluble toxic factor released by the astrocytes. If this toxic factor can be identified in future studies, this finding may offer novel strategies for therapy.
Author contacts:
Serge Przedborski (Columbia University, New York, NY, USA) Paper [7]
Tel: +1 212 305 1540; E-mail: sp30@columbia.edu
Kevin Eggan (Harvard University, Cambridge, MA, USA) Paper [8]
Tel: +1 617 496 5611; E-mail: eggan@mcb.harvard.edu
Additional contact for comment on papers:
Jean-Pierre Julien (Laval University, Québec, Canada)
Tel: +1 418 654 2296; E-mail: jean-pierre.julien@crchul.ulaval.ca
Mutation leads to male infertility
A mutation in a gene called AURKC (Aurora Kinase C) has been identified in 14 infertile men of North African descent. While deletions of some portion of the Y chromosome have been found in infertile men, this is a rare example in which a mutation in a single gene causes male infertility.
Estimates suggest that at least 80 million individuals worldwide are infertile. Pierre Ray and colleagues studied 14 men whose infertility seemed to have a similar origin. Their sperm were characterized by large heads, increased DNA content, and a variable number of flagella—the whip-like tails that propel the sperm. A genome-wide scan identified a mutation in AURKC that severely truncates the protein. AURKC encodes an enzyme that phosphorylates other proteins, and the authors show that the mutation abolishes this activity. An analysis of the genomic region around AURKC shows that these individuals have other markers in common, suggesting that this mutation appeared in a North African common ancestor approximately 1,500 years ago. The authors note that a larger study of the prevalence of this mutation in North Africans is now warranted.
Author contact:
Pierre Ray (University Hospital of Grenoble, France)
Tel: +33 476 76 55 73; E-mail: pray@chu-grenoble.fr
A mutation in a gene called AURKC (Aurora Kinase C) has been identified in 14 infertile men of North African descent. While deletions of some portion of the Y chromosome have been found in infertile men, this is a rare example in which a mutation in a single gene causes male infertility.
Estimates suggest that at least 80 million individuals worldwide are infertile. Pierre Ray and colleagues studied 14 men whose infertility seemed to have a similar origin. Their sperm were characterized by large heads, increased DNA content, and a variable number of flagella—the whip-like tails that propel the sperm. A genome-wide scan identified a mutation in AURKC that severely truncates the protein. AURKC encodes an enzyme that phosphorylates other proteins, and the authors show that the mutation abolishes this activity. An analysis of the genomic region around AURKC shows that these individuals have other markers in common, suggesting that this mutation appeared in a North African common ancestor approximately 1,500 years ago. The authors note that a larger study of the prevalence of this mutation in North Africans is now warranted.
Author contact:
Pierre Ray (University Hospital of Grenoble, France)
Tel: +33 476 76 55 73; E-mail: pray@chu-grenoble.fr
Genetic susceptibility to Crohn disease
A genome-wide assessment of genetic variation in individuals with Crohn disease has identified seven genes or regions that are associated with elevated risk of the disease, according to a study.Three of the genes were previously known, but four are newly associated with the disease.
Crohn disease is one of the most common forms of inflammatory bowel disease, affecting 100–150 per 100,000 individuals of European ancestry. John Rioux and colleagues assessed more than 300,000 genetic variants in individuals with Crohn disease, as well as controls, and identified three previously reported risk factors (CARD15, IL23R, and ATG16L1), and four new ones (PHOX2B, NCF4, FAM92B, and a region on chromosome 10).
In combination with other studies, these ‘genome-wide association studies’ promise to flesh out the entire catalogue of genetic variants that predispose to Crohn disease, as well as provide new insight into the causes of the disease. In this case, the authors show that ATG16L1 might have a role in the degradation and processing of bacteria by the body’s inflammatory response—a process known as autophagy. This is consistent with other evidence that an inappropriate response to bacteria in the gut is important in the initiation of Crohn disease.
Author contact:
John Rioux (University of Montreal, Québec, Canada)
Tel: +1 514 376 3330; E-mail: rioux@broad.mit.edu
A genome-wide assessment of genetic variation in individuals with Crohn disease has identified seven genes or regions that are associated with elevated risk of the disease, according to a study.Three of the genes were previously known, but four are newly associated with the disease.
Crohn disease is one of the most common forms of inflammatory bowel disease, affecting 100–150 per 100,000 individuals of European ancestry. John Rioux and colleagues assessed more than 300,000 genetic variants in individuals with Crohn disease, as well as controls, and identified three previously reported risk factors (CARD15, IL23R, and ATG16L1), and four new ones (PHOX2B, NCF4, FAM92B, and a region on chromosome 10).
In combination with other studies, these ‘genome-wide association studies’ promise to flesh out the entire catalogue of genetic variants that predispose to Crohn disease, as well as provide new insight into the causes of the disease. In this case, the authors show that ATG16L1 might have a role in the degradation and processing of bacteria by the body’s inflammatory response—a process known as autophagy. This is consistent with other evidence that an inappropriate response to bacteria in the gut is important in the initiation of Crohn disease.
Author contact:
John Rioux (University of Montreal, Québec, Canada)
Tel: +1 514 376 3330; E-mail: rioux@broad.mit.edu
Friday, April 20, 2007
IMPORTANT ANNOUNCEMENT AND INFORMATIONS
EAGLES Health Lecturer Tour Grants
The European Action on Global Life Sciences (EAGLES) Health Programme is offering grants of up to €5,000 to leading biomedical scientists and other health specialists, including commentators and journalists, from developing countries to undertake lecture tours around Europe to communicate the needs of developing countries to the European public and European institutions. Applications should be submitted before 11 June 2007. Further details can be found on the EAGLES website: www.efb-central.org/eagles/site.
International Workshop on Cities, Science and Sustainability
An international workshop examining successful approaches to 'cities, science and sustainability' will be held at TWAS's headquarters in Trieste, Italy, from 20 to 22 September 2007. Institutions in developing countries are invited to respond by 1 July 2007 indicating their interest in participating in the workshop and presenting a report highlighting successful initiatives in using science and technology in solving problems of sustainability associated with large urban areas, including (but not limited to) access to safe drinking water, sanitation, air pollution, housing and construction, land use planning, transport, traffic congestion and waste disposal in a city in the developing world. The project 'Cities, Science and Sustainability' is a collaborative effort between TWAS, the Consortium for Science, Technology and Innovation for the South (COSTIS) and the United Nations Development Programme's Special Unit for South-South Cooperation (UNDP-SSC).
African Materials Research Conference in December
The 4th International Conference of the African Materials Research Society will be held in Dar-es-Salaam, Tanzania, from 10 to 14 December 2007. Main topic of the conference: "Cementing Collaborations in Materials Research in Africa." Deadline for pre-registration and abstracts: 30 June 2007
Award in Medical Sciences in the UAE
The 'Sheikh Hamdan Bin Rashid Al Maktoum Awards for Medical Sciences' (SHAMS) are accepting nominations in three categories: international, Arab world, and UAE. The awards honour "medical researchers worldwide who enrich scientific research and enhance the nature of scientific exchanges among medical doctors in UAE and medical centers abroad." Deadline for nominations is November. For more information on the Awards, please visit: www.hmaward.org.ae
EAGLES Health Lecturer Tour Grants
The European Action on Global Life Sciences (EAGLES) Health Programme is offering grants of up to €5,000 to leading biomedical scientists and other health specialists, including commentators and journalists, from developing countries to undertake lecture tours around Europe to communicate the needs of developing countries to the European public and European institutions. Applications should be submitted before 11 June 2007. Further details can be found on the EAGLES website: www.efb-central.org/eagles/site.
International Workshop on Cities, Science and Sustainability
An international workshop examining successful approaches to 'cities, science and sustainability' will be held at TWAS's headquarters in Trieste, Italy, from 20 to 22 September 2007. Institutions in developing countries are invited to respond by 1 July 2007 indicating their interest in participating in the workshop and presenting a report highlighting successful initiatives in using science and technology in solving problems of sustainability associated with large urban areas, including (but not limited to) access to safe drinking water, sanitation, air pollution, housing and construction, land use planning, transport, traffic congestion and waste disposal in a city in the developing world. The project 'Cities, Science and Sustainability' is a collaborative effort between TWAS, the Consortium for Science, Technology and Innovation for the South (COSTIS) and the United Nations Development Programme's Special Unit for South-South Cooperation (UNDP-SSC).
African Materials Research Conference in December
The 4th International Conference of the African Materials Research Society will be held in Dar-es-Salaam, Tanzania, from 10 to 14 December 2007. Main topic of the conference: "Cementing Collaborations in Materials Research in Africa." Deadline for pre-registration and abstracts: 30 June 2007
Award in Medical Sciences in the UAE
The 'Sheikh Hamdan Bin Rashid Al Maktoum Awards for Medical Sciences' (SHAMS) are accepting nominations in three categories: international, Arab world, and UAE. The awards honour "medical researchers worldwide who enrich scientific research and enhance the nature of scientific exchanges among medical doctors in UAE and medical centers abroad." Deadline for nominations is November. For more information on the Awards, please visit: www.hmaward.org.ae
Fossils: Tell it to the trees
A spectacular fossilized tree gives an unprecedented insight into the appearance of the world’s earliest forests.
William E. Stein and colleagues found their fossil tree in Schoharie County, New York. It stood at least eight metres high with fern-like branches, a long trunk and small anchoring roots. Its crown belongs to a previously known plant taxon, the cladoxylopsid Wattieza. But its trunk and base match a different group, named Eospermatopteris.
The evolution of trees was fundamental to the Earth’s terrestrial ecosystem. And until now, the earliest-known evidence of forests came from fossil tree stumps found in Gilboa, New York, that are about 385 million years old. The trees were designated Eospermatopteris but their aerial portions were missing. The new find sheds light on their possible full appearance.
CONTACT
William E. Stein (State University of New York, Binghamton, NY, USA)
Tel: +1 607 777 4391; E-mail: stein@binghamton.edu
Albert Gnidica (Media Relations, New York State Museum, NY, USA)
Tel: +1 518 474 0068 or +1 518 474 8730; E-mail: Agnidica@mail.nysed.gov
Brigitte Meyer-Berthaud (CIRAD-CNRS, Montpellier, France) N&V author
Tel: +33 4 67 61 75 22; E-mail: meyerberthaud@cirad.fr
A spectacular fossilized tree gives an unprecedented insight into the appearance of the world’s earliest forests.
William E. Stein and colleagues found their fossil tree in Schoharie County, New York. It stood at least eight metres high with fern-like branches, a long trunk and small anchoring roots. Its crown belongs to a previously known plant taxon, the cladoxylopsid Wattieza. But its trunk and base match a different group, named Eospermatopteris.
The evolution of trees was fundamental to the Earth’s terrestrial ecosystem. And until now, the earliest-known evidence of forests came from fossil tree stumps found in Gilboa, New York, that are about 385 million years old. The trees were designated Eospermatopteris but their aerial portions were missing. The new find sheds light on their possible full appearance.
CONTACT
William E. Stein (State University of New York, Binghamton, NY, USA)
Tel: +1 607 777 4391; E-mail: stein@binghamton.edu
Albert Gnidica (Media Relations, New York State Museum, NY, USA)
Tel: +1 518 474 0068 or +1 518 474 8730; E-mail: Agnidica@mail.nysed.gov
Brigitte Meyer-Berthaud (CIRAD-CNRS, Montpellier, France) N&V author
Tel: +33 4 67 61 75 22; E-mail: meyerberthaud@cirad.fr
Geology: The big melts
The Earth’s continental crust was not formed gradually but in stages, punctuated by large, potentially global, melting events. A report analyses the helium isotopic ratios from ocean island basalts, which reveal several distinct episodes of crustal growth.
Most Earth scientists agree that the continental crust formed by a process of partial melting from the mantle, although the timing and details of this process has remained controversial. Stephen Parman studied the chemical fingerprint of continental crust formation in the isotopic composition of helium isotopes recorded in ocean island basalts. The volatility of helium isotopes means that they are not reintroduced into the mantle during subduction and the record of mantle depletion is thus preserved for helium, whereas most other isotopes are continually recycled by mantle convection, largely obscuring such a record.
Parman found that peaks in the occurrence of helium isotope ratios are globally consistent and correspond with the ages of what have been proposed to be continental growth pulses. He concludes that the ultimate cause of these large melting events is still unclear, but could be related to large releases of heat from the mantle.
CONTACT
Stephen Parman (University of Durham, UK)
E-mail: stephen.parman@durham.ac.uk
Please note that the author is travelling in the US but should be contactable by email and mobile: Tel: +1 302 588 7369
Don Porcelli (University of Oxford, UK) N&V author
Tel: +44 1865 282 121; E-mail: don.porcelli@earth.ox.ac.uk
The Earth’s continental crust was not formed gradually but in stages, punctuated by large, potentially global, melting events. A report analyses the helium isotopic ratios from ocean island basalts, which reveal several distinct episodes of crustal growth.
Most Earth scientists agree that the continental crust formed by a process of partial melting from the mantle, although the timing and details of this process has remained controversial. Stephen Parman studied the chemical fingerprint of continental crust formation in the isotopic composition of helium isotopes recorded in ocean island basalts. The volatility of helium isotopes means that they are not reintroduced into the mantle during subduction and the record of mantle depletion is thus preserved for helium, whereas most other isotopes are continually recycled by mantle convection, largely obscuring such a record.
Parman found that peaks in the occurrence of helium isotope ratios are globally consistent and correspond with the ages of what have been proposed to be continental growth pulses. He concludes that the ultimate cause of these large melting events is still unclear, but could be related to large releases of heat from the mantle.
CONTACT
Stephen Parman (University of Durham, UK)
E-mail: stephen.parman@durham.ac.uk
Please note that the author is travelling in the US but should be contactable by email and mobile: Tel: +1 302 588 7369
Don Porcelli (University of Oxford, UK) N&V author
Tel: +44 1865 282 121; E-mail: don.porcelli@earth.ox.ac.uk
Quantum physics: Losing a grip on realit
It seems common sense that an object will retain its fundamental properties regardless of whether or not we are looking at it. But in the microscopic quantum world, everyday rules do not apply. Even our concept of reality may be challenged.
Classical physics clings tightly to the notions of realism (where external reality exists independent of observation) and locality (where sufficiently distant objects cannot influence each other). Quantum experiments in which the properties of distant but entangled particles are linked seem hard to reconcile with such notions, making local realistic theories untenable.
Markus Aspelmeyer, Anton Zeilinger and colleagues developed an inequality that relaxes the assumption of locality, allowing a test of non-local realism. They studied correlations between pairs of entangled photons, and found that the correlations violate non-local realistic theories. The result suggests that giving up the concept of locality is not sufficient to be consistent with quantum experiments, unless certain intuitive features of realism are abandoned.
CONTACT
Markus Aspelmeyer (University of Vienna, Austria)
Please contact the author through:
Ursula Gerber (University of Vienna, Austria)
Tel: +43 1 4277 51205; E-mail: ursula.gerber@univie.ac.at
Alain Aspect (Institut d'Optique, Palaiseau, France) N&V author
Tel: +33 1 64 53 31 03; E-mail: alain.aspect@institutoptique.fr
It seems common sense that an object will retain its fundamental properties regardless of whether or not we are looking at it. But in the microscopic quantum world, everyday rules do not apply. Even our concept of reality may be challenged.
Classical physics clings tightly to the notions of realism (where external reality exists independent of observation) and locality (where sufficiently distant objects cannot influence each other). Quantum experiments in which the properties of distant but entangled particles are linked seem hard to reconcile with such notions, making local realistic theories untenable.
Markus Aspelmeyer, Anton Zeilinger and colleagues developed an inequality that relaxes the assumption of locality, allowing a test of non-local realism. They studied correlations between pairs of entangled photons, and found that the correlations violate non-local realistic theories. The result suggests that giving up the concept of locality is not sufficient to be consistent with quantum experiments, unless certain intuitive features of realism are abandoned.
CONTACT
Markus Aspelmeyer (University of Vienna, Austria)
Please contact the author through:
Ursula Gerber (University of Vienna, Austria)
Tel: +43 1 4277 51205; E-mail: ursula.gerber@univie.ac.at
Alain Aspect (Institut d'Optique, Palaiseau, France) N&V author
Tel: +33 1 64 53 31 03; E-mail: alain.aspect@institutoptique.fr
Announcement-Four leading researchers from Japan and the UK meet in London to present:
“Frontiers of Neuroscience” Major advancements in medical research and their applications
Keio University, University College London (UCL), and Japan Society for the Promotion of Science (JSPS), London Office will host the Keio University 150th Anniversary International Symposium, “Frontiers of Neuroscience”. Four leading scholars specialising in neuroscience will present their cutting-edge research and discuss its potential for curing today’s most devastating injuries and diseases of the brain. The event, which is free and open to the public, will take place on April 27 from 3 p.m. to 6 p.m. at UCL’s Cruciform Lecture Theatre 2, Gower Street, London, UK.
Two island countries, two universities, four scientists and an office
Two universities, on two island countries at either end of the Eurasian continent, have played a leading role in the liberalisation of science and education from their respective beginnings, in 1826 (UCL) and 1858 (Keio), that continues today. Four pioneering scientists, two from each university, will gather on the UCL campus for an international symposium exploring issues surrounding ground-breaking advancements in neuroscience and related topics relevant to our current, fast-changing society. In addition to promoting collaboration between the three participating organizations and celebrating the 150th anniversary of Keio University, the event will commemorate the launch of the Keio University London Office, established in alliance with JSPS.
Frontiers of Neuroscience – Opportunities for better understanding ourselves –
Keio University’s Prof Hideyuki Okano is a specialist in damaged Central Nervous System (CNS) regeneration. His current research is breaking new ground in adult neurogenesis (birth of new neuronal cells) and brain damage repair, and may open up a number of possibilities including therapeutic intervention for spinal cord injuries and treatments for neurodegenerative disorders including Alzheimer's disease. He will discuss both the principles of regeneration and his research group’s latest findings. Prof Masato Yasui, also from Keio University, specialises in a class of integral membrane proteins known as aquaporin, which functions as a channel for transporting water through biological cell membranes. Aquaporin is a recent discovery, and has led to a series of studies into its relation to a wide range of human diseases. Prof Yasui’s interest is in aquaporin-4 (AQP4), a particular type of aquaporin that is predominantly expressed in mammalian brains. On the basis of precedent findings, including its involvement in brain edema formation, he will discuss potential connections between AQP4 and mental disorders such as bipolar diseases.
Participating scientists from UCL are prominent authorities on the fundamentals of brain function. Prof Richard Frackowiak, a specialist in brain plasticity and recovery from injury, is conducting pioneering research that is serving to clarify the relationship between the brain’s functions and its physical structure. His lecture will focus on brain organisation as observed using advanced imaging technologies and methods. Prof Semir Zeki’s research focuses on the relationship between vision, art and the brain. He has lectured on the subject worldwide and is the founder of the Institute of Neuroesthetics. His insightful and careful analyses suggest that visual consciousness is distributed in both time and space. Prof Zeki will discuss the nature of visual consciousnesses in his lecture.
The symposium will begin with a welcome from Prof Yuichiro Anzai, president of Keio University and an eminent cognitive scientist, followed by the four lectures and a panel discussion. It will conclude with a reception at 6 p.m.
Members of the press are invited to attend the symposium, which is free and open to the public. Interview requests can be forwarded to press contact Juli Morizawa (Ms) or Akiko Kurata (Ms).
For more information and to register, visit http://keio150.jp/english/events/2007/20070427e.html or email sympo-rsvp@adst.keio.ac.jp.
General Inquiries: Yuko Sakuma (Ms)
International Programme Coordinator, Keio University London Office, UK
Email: sympo-rsvp@adst.keio.ac.jp Tel: (020) 7629 3577 Fax: (020) 7629 3588
Media Inquiries: Juli Morizawa (Ms), Akiko Kurata (Ms)
Office of Communications and Public Relations, Keio University, Japan
Email: m-koho@adst.keio.ac.jp Tel: +81-3-5427-1541 Fax: +81-3-5441-7640
Meeting information
“Frontiers of Neuroscience” April 27 (3 p.m. to 6 p.m.) at UCL’s Cruciform Lecture Theatre 2, Gower Street, London, UK.
“Frontiers of Neuroscience” Major advancements in medical research and their applications
Keio University, University College London (UCL), and Japan Society for the Promotion of Science (JSPS), London Office will host the Keio University 150th Anniversary International Symposium, “Frontiers of Neuroscience”. Four leading scholars specialising in neuroscience will present their cutting-edge research and discuss its potential for curing today’s most devastating injuries and diseases of the brain. The event, which is free and open to the public, will take place on April 27 from 3 p.m. to 6 p.m. at UCL’s Cruciform Lecture Theatre 2, Gower Street, London, UK.
Two island countries, two universities, four scientists and an office
Two universities, on two island countries at either end of the Eurasian continent, have played a leading role in the liberalisation of science and education from their respective beginnings, in 1826 (UCL) and 1858 (Keio), that continues today. Four pioneering scientists, two from each university, will gather on the UCL campus for an international symposium exploring issues surrounding ground-breaking advancements in neuroscience and related topics relevant to our current, fast-changing society. In addition to promoting collaboration between the three participating organizations and celebrating the 150th anniversary of Keio University, the event will commemorate the launch of the Keio University London Office, established in alliance with JSPS.
Frontiers of Neuroscience – Opportunities for better understanding ourselves –
Keio University’s Prof Hideyuki Okano is a specialist in damaged Central Nervous System (CNS) regeneration. His current research is breaking new ground in adult neurogenesis (birth of new neuronal cells) and brain damage repair, and may open up a number of possibilities including therapeutic intervention for spinal cord injuries and treatments for neurodegenerative disorders including Alzheimer's disease. He will discuss both the principles of regeneration and his research group’s latest findings. Prof Masato Yasui, also from Keio University, specialises in a class of integral membrane proteins known as aquaporin, which functions as a channel for transporting water through biological cell membranes. Aquaporin is a recent discovery, and has led to a series of studies into its relation to a wide range of human diseases. Prof Yasui’s interest is in aquaporin-4 (AQP4), a particular type of aquaporin that is predominantly expressed in mammalian brains. On the basis of precedent findings, including its involvement in brain edema formation, he will discuss potential connections between AQP4 and mental disorders such as bipolar diseases.
Participating scientists from UCL are prominent authorities on the fundamentals of brain function. Prof Richard Frackowiak, a specialist in brain plasticity and recovery from injury, is conducting pioneering research that is serving to clarify the relationship between the brain’s functions and its physical structure. His lecture will focus on brain organisation as observed using advanced imaging technologies and methods. Prof Semir Zeki’s research focuses on the relationship between vision, art and the brain. He has lectured on the subject worldwide and is the founder of the Institute of Neuroesthetics. His insightful and careful analyses suggest that visual consciousness is distributed in both time and space. Prof Zeki will discuss the nature of visual consciousnesses in his lecture.
The symposium will begin with a welcome from Prof Yuichiro Anzai, president of Keio University and an eminent cognitive scientist, followed by the four lectures and a panel discussion. It will conclude with a reception at 6 p.m.
Members of the press are invited to attend the symposium, which is free and open to the public. Interview requests can be forwarded to press contact Juli Morizawa (Ms) or Akiko Kurata (Ms).
For more information and to register, visit http://keio150.jp/english/events/2007/20070427e.html or email sympo-rsvp@adst.keio.ac.jp.
General Inquiries: Yuko Sakuma (Ms)
International Programme Coordinator, Keio University London Office, UK
Email: sympo-rsvp@adst.keio.ac.jp Tel: (020) 7629 3577 Fax: (020) 7629 3588
Media Inquiries: Juli Morizawa (Ms), Akiko Kurata (Ms)
Office of Communications and Public Relations, Keio University, Japan
Email: m-koho@adst.keio.ac.jp Tel: +81-3-5427-1541 Fax: +81-3-5441-7640
Meeting information
“Frontiers of Neuroscience” April 27 (3 p.m. to 6 p.m.) at UCL’s Cruciform Lecture Theatre 2, Gower Street, London, UK.
Friday, April 13, 2007
Frontiers of Neuroscience - Major advancements in medical research and their applications
hosted by
Keio University, Japan
University College London, UK and Japan Society for the Promotion of Science
Friday April 27, 2007
3:00-6:00pm Entry Free Cruciform Lecture Theatre 2, UCL
Gower Street, London WC1
It is with great pleasure that Keio University, University College London, and Japan Society for the Promotion of Science (JSPS) invite you to the first Keio University 150th Anniversary International Symposium on “Frontiers of Neuroscience”.
Keio University is the oldest modern comprehensive university in Japan and will celebrate its 150th anniversary in 2008. It takes pride in having led Japanese society through innovations in both research and education from its earliest years when founder Yukichi Fukuzawa, who travelled to Europe as early as 1862, became convinced that Japan should transform itself through the introduction of western learning. In reaching this important milestone in its history, Keio is redoubling its commitment to strengthening its international profile and enhancing its global activities. To advance this endeavor, Keio has organized this symposium to highlight the university’s School of Medicine, renowned in Japan for its world-class and cutting-edge research and education, and has invited two of its distinguished academic members to participate.
Today, both the UK and Japan face the daunting reality of having become rapidly aging societies, largely as a result of major advancements in medical research and their applications. It is therefore timely and relevant for leading researchers in both countries to cooperate and share the results of their respective cutting-edge research activities in this field. It is a great pleasure for Keio University to co-host this event with University College London, the institution that introduced systematic medical education to England, and to welcome two of its leading professors as participants. The symposium will provide an opportunity to exchange current knowledge and research outcomes between UK and Japan at the highest level, which will be of interest both to academic experts and the general public.
This symposium will also commemorate the launch of the Keio University London Office, established in alliance with the JSPS London Office, a Japanese non-governmental organization committed to promoting bottom-up UK-Japan research collaboration. It is anticipated that this event will be the first of many joint activities advancing UK-Japan relations stimulated by the new partnership.
Speakers (In alphabetical order)
Professor Richard SJ Frackowiak
Vice-Provost (Special Projects)
Wellcome Department of Imaging Neuroscience, Institute of Neurology
University College London
Professor Hideyuki Okano
Department of Physiology
Keio University School of Medicine
Professor Masato Yasui
Professor and Chair, Department of Pharmacology
Keio University School of Medicine, Tokyo Japan
Professor Semir Zeki
Wellcome Department of Imaging Neuroscience
University College London
Programme
15:00-15:10 Opening address - Keio President Yuichiro Anzai
15:10-15:15 Introduction to the symposium - Professor Hideyuki Okano
15:15-15:40 "Modern Human Brain Imaging: structure-function correlations" Professor Richard Frackowiak
15:40-16:05 "Water Neurobiology: potential roles of water channel, aquaporin" Professor Masato Yasui
16:05-16:30 "Challenges toward Regeneration of the Damaged Central Nervous System" Professor Hideyuki Okano
16:30-16:55 " The Many Consciousnesses of the Brain " Professor Semir Zeki
16:55-17:15 Break
17:15-17:45 Panel discussion and Q& A
Chair: Professor Hideyuki Okano
Panelists:
President Yuichiro Anzai
Professor Richard SJ Frackowiak
Dr. Yukio Nishizawa, Research Director, Eisai London Research Laboratories
Professor Masato Yasui
Professor Semir Zeki
17:45-17:50 Closing address Ms. Yuko Furukawa, Director, JSPS London Office
-----------------------------------------------------------
18:00-19:30 Reception at the South Cloisters
While serving as a forum for advanced academic exchange, the program is designed to be accessible to all audiences. Admission is free of charge and open to the public.
Advance registration is required: sympo-rsvp@adst.keio.ac.jp (English and Japanese)
Event details: http://keio150.jp/english/events/2007/20070427e.html
For more articles and topics visit- www.medianowonline.com
hosted by
Keio University, Japan
University College London, UK and Japan Society for the Promotion of Science
Friday April 27, 2007
3:00-6:00pm Entry Free Cruciform Lecture Theatre 2, UCL
Gower Street, London WC1
It is with great pleasure that Keio University, University College London, and Japan Society for the Promotion of Science (JSPS) invite you to the first Keio University 150th Anniversary International Symposium on “Frontiers of Neuroscience”.
Keio University is the oldest modern comprehensive university in Japan and will celebrate its 150th anniversary in 2008. It takes pride in having led Japanese society through innovations in both research and education from its earliest years when founder Yukichi Fukuzawa, who travelled to Europe as early as 1862, became convinced that Japan should transform itself through the introduction of western learning. In reaching this important milestone in its history, Keio is redoubling its commitment to strengthening its international profile and enhancing its global activities. To advance this endeavor, Keio has organized this symposium to highlight the university’s School of Medicine, renowned in Japan for its world-class and cutting-edge research and education, and has invited two of its distinguished academic members to participate.
Today, both the UK and Japan face the daunting reality of having become rapidly aging societies, largely as a result of major advancements in medical research and their applications. It is therefore timely and relevant for leading researchers in both countries to cooperate and share the results of their respective cutting-edge research activities in this field. It is a great pleasure for Keio University to co-host this event with University College London, the institution that introduced systematic medical education to England, and to welcome two of its leading professors as participants. The symposium will provide an opportunity to exchange current knowledge and research outcomes between UK and Japan at the highest level, which will be of interest both to academic experts and the general public.
This symposium will also commemorate the launch of the Keio University London Office, established in alliance with the JSPS London Office, a Japanese non-governmental organization committed to promoting bottom-up UK-Japan research collaboration. It is anticipated that this event will be the first of many joint activities advancing UK-Japan relations stimulated by the new partnership.
Speakers (In alphabetical order)
Professor Richard SJ Frackowiak
Vice-Provost (Special Projects)
Wellcome Department of Imaging Neuroscience, Institute of Neurology
University College London
Professor Hideyuki Okano
Department of Physiology
Keio University School of Medicine
Professor Masato Yasui
Professor and Chair, Department of Pharmacology
Keio University School of Medicine, Tokyo Japan
Professor Semir Zeki
Wellcome Department of Imaging Neuroscience
University College London
Programme
15:00-15:10 Opening address - Keio President Yuichiro Anzai
15:10-15:15 Introduction to the symposium - Professor Hideyuki Okano
15:15-15:40 "Modern Human Brain Imaging: structure-function correlations" Professor Richard Frackowiak
15:40-16:05 "Water Neurobiology: potential roles of water channel, aquaporin" Professor Masato Yasui
16:05-16:30 "Challenges toward Regeneration of the Damaged Central Nervous System" Professor Hideyuki Okano
16:30-16:55 " The Many Consciousnesses of the Brain " Professor Semir Zeki
16:55-17:15 Break
17:15-17:45 Panel discussion and Q& A
Chair: Professor Hideyuki Okano
Panelists:
President Yuichiro Anzai
Professor Richard SJ Frackowiak
Dr. Yukio Nishizawa, Research Director, Eisai London Research Laboratories
Professor Masato Yasui
Professor Semir Zeki
17:45-17:50 Closing address Ms. Yuko Furukawa, Director, JSPS London Office
-----------------------------------------------------------
18:00-19:30 Reception at the South Cloisters
While serving as a forum for advanced academic exchange, the program is designed to be accessible to all audiences. Admission is free of charge and open to the public.
Advance registration is required: sympo-rsvp@adst.keio.ac.jp (English and Japanese)
Event details: http://keio150.jp/english/events/2007/20070427e.html
For more articles and topics visit- www.medianowonline.com
Thursday, April 12, 2007
Punish the rich- games of experimental economics We’re more likely to punish the rich than the poor, at least in games of experimental economics. The strategy is emotionally driven and the results suggest that human social behaviour is influenced by egalitarian motives.
James H. Fowler and colleagues set up a game where players were randomly allocated different sums of money, and were then able to ‘reward’ or ‘punish’ others by giving or taking money away. The richest players were penalized the hardest, whereas the poorest players were penalized the least.
The results show that people will reduce and increase others’ incomes at a personal cost, even when there is no cooperative behaviour to be reinforced. Their decisions are emotionally led, and the size and frequency of income alternations are strongly influenced by inequality — the pattern of punishments is designed to minimize inequality between the richest and poorest. The study suggests that egalitarian motives affect whether or not we donate cash to others, and this may be an important factor underlying the evolution of cooperation in humans.
CONTACT
James H. Fowler (University of California San Diego, La Jolla, CA, USA)
Tel: +1 858 534 6807; E-mail: jhfowler@ucsd.edu
For more articles and topics go to www.medianowonline.com
James H. Fowler and colleagues set up a game where players were randomly allocated different sums of money, and were then able to ‘reward’ or ‘punish’ others by giving or taking money away. The richest players were penalized the hardest, whereas the poorest players were penalized the least.
The results show that people will reduce and increase others’ incomes at a personal cost, even when there is no cooperative behaviour to be reinforced. Their decisions are emotionally led, and the size and frequency of income alternations are strongly influenced by inequality — the pattern of punishments is designed to minimize inequality between the richest and poorest. The study suggests that egalitarian motives affect whether or not we donate cash to others, and this may be an important factor underlying the evolution of cooperation in humans.
CONTACT
James H. Fowler (University of California San Diego, La Jolla, CA, USA)
Tel: +1 858 534 6807; E-mail: jhfowler@ucsd.edu
For more articles and topics go to www.medianowonline.com
Photochemistry: Quantum tricks in photosynthesis
The weird world of quantum physics meets biology with the discovery that quantum mechanical effects appear to play a role in photosynthesis.
Graham R. Fleming and colleagues used spectroscopy to study what happens inside a bacteriochlorophyll complex, and detected a ‘quantum beating’. The effect occurs when light-induced excitations in the complex meet and interfere constructively — much like the interactions that occur between the ripples formed by throwing stones into a pond.
Photosynthesis is the all-important process that transforms light, carbon dioxide and water into chemical energy in plants and some bacteria. This wavelike characteristic of this energy transfer process can explain its extreme efficiency, in that vast areas of phase space can be sampled effectively to find the most efficient path for energy transfer.
CONTACT
Graham R. Fleming (Lawrence Berkeley National Laboratory & University of California, Berkeley, CA, USA)
Tel: +1 510 643 2735; E-mail: fleming@cchem.berkeley.edu or grfleming@lbl.gov
Roseanne J. Sension (University of Michigan, Ann Arbor, MI, USA) N&V author
Tel: +1 734 763 6074; E-mail: rsension@umich.edu
For more topics and articles go to www.medianowonline.com
The weird world of quantum physics meets biology with the discovery that quantum mechanical effects appear to play a role in photosynthesis.
Graham R. Fleming and colleagues used spectroscopy to study what happens inside a bacteriochlorophyll complex, and detected a ‘quantum beating’. The effect occurs when light-induced excitations in the complex meet and interfere constructively — much like the interactions that occur between the ripples formed by throwing stones into a pond.
Photosynthesis is the all-important process that transforms light, carbon dioxide and water into chemical energy in plants and some bacteria. This wavelike characteristic of this energy transfer process can explain its extreme efficiency, in that vast areas of phase space can be sampled effectively to find the most efficient path for energy transfer.
CONTACT
Graham R. Fleming (Lawrence Berkeley National Laboratory & University of California, Berkeley, CA, USA)
Tel: +1 510 643 2735; E-mail: fleming@cchem.berkeley.edu or grfleming@lbl.gov
Roseanne J. Sension (University of Michigan, Ann Arbor, MI, USA) N&V author
Tel: +1 734 763 6074; E-mail: rsension@umich.edu
For more topics and articles go to www.medianowonline.com
Smart materials: A light touch (pp 778-781; N&V)
Researchers have developed crystals that will change their shape repeatedly when exposed to different types of light. The discovery may aid the development of light-driven actuators — mechanical devices that move or control things.
The molecular crystals, developed by Masahiro Irie and colleagues, are based on a particular type of light-absorbing molecule and range from 10 to 100 micrometres in size. When ultraviolet light is shone on one type of crystal, it changes shape from a square to a lozenge. But when the same crystal is exposed to visible light, it undergoes another mechanical deformation to change back to its original form. When put in the spotlight, a rod-shaped crystal of the material attached to a surface will even oblige and use this effect to 'bat' away a micrometre-sized gold particle.
The system is stable and responds quickly, within microseconds. Previous light-responsive systems, made from liquid crystals or polymer gels, can change shape but the effect takes seconds or longer and the deformed states are unstable. And the beauty of using light as a stimulus is that it offers the intriguing prospect of actuators that can be operated remotely.
CONTACT
Masahiro Irie (Rikkyo University, Tokyo, Japan)
Tel: +81 3 3985 2397; E-mail: irie@cstf.kyushu-u.ac.jp
J. Michael McBride (Yale University, New Haven, CT, USA) N&V author
Tel: +1 203 432 3926; E-mail: j.mcbride@yale.edu
For more articles and topics go to www.medianowonline.com
Researchers have developed crystals that will change their shape repeatedly when exposed to different types of light. The discovery may aid the development of light-driven actuators — mechanical devices that move or control things.
The molecular crystals, developed by Masahiro Irie and colleagues, are based on a particular type of light-absorbing molecule and range from 10 to 100 micrometres in size. When ultraviolet light is shone on one type of crystal, it changes shape from a square to a lozenge. But when the same crystal is exposed to visible light, it undergoes another mechanical deformation to change back to its original form. When put in the spotlight, a rod-shaped crystal of the material attached to a surface will even oblige and use this effect to 'bat' away a micrometre-sized gold particle.
The system is stable and responds quickly, within microseconds. Previous light-responsive systems, made from liquid crystals or polymer gels, can change shape but the effect takes seconds or longer and the deformed states are unstable. And the beauty of using light as a stimulus is that it offers the intriguing prospect of actuators that can be operated remotely.
CONTACT
Masahiro Irie (Rikkyo University, Tokyo, Japan)
Tel: +81 3 3985 2397; E-mail: irie@cstf.kyushu-u.ac.jp
J. Michael McBride (Yale University, New Haven, CT, USA) N&V author
Tel: +1 203 432 3926; E-mail: j.mcbride@yale.edu
For more articles and topics go to www.medianowonline.com
Cancer: Genes set scene for metastasis
Biologists have identified a set of genes expressed in human breast cancer cells that work together to remodel the vasculature at the site of the primary tumour and that also promote the spread of cancer to the lungs. The finding helps to explain how cancer metastasis can occur and highlights targets for therapeutic treatment.
Metastasis is the leading cause of mortality in cancer patients. A number of genes are already known to contribute to the spread of breast cancer cells to the lungs. But Joan Massagué and colleagues now show how four genes cooperate to promote the formation of new tumour blood vessels, the release of cancer cells into the bloodstream, and the penetration of tumour cells from the bloodstream into the lung.
The gene set comprises EREG, MMP1, MMP2 and COX2; drug combinations that target more than one of these components may prove useful for treating metastatic breast cancer.
CONTACT
Joan M Massague (Memorial Sloan-Kettering Cancer Center, Howard Hughes Medical Institute, New York, NY, USA)
Please contact:
Esther Napolitano (Public Affairs, Memorial Sloan-Kettering Cancer Center, New York, NY, USA)
Tel: +1 646 227 3139; E-mail: napolite@mskcc.org
Gerhard Christofori (University of Basel, Switzerland) N&V author
Tel: +41 61 267 3562 E-mail: gerhard.christofori@unibas.ch
Cancer: Genes linked to chemotherapy response
Scientists have identified a number of genes in lung cancer cells which, when downregulated, make the cancer cells especially vulnerable to a type of chemotherapy. The study highlights a new way to screen for alterations in cancer cells that make them specifically sensitive to therapeutics, so that treatment may leave normal tissue relatively unharmed.
Michael A. White and colleagues used a genome-wide RNA interference screen to identify 87 genes that are involved in the response of cancer cells to paclitaxel. Reducing the expression of a number of these genes sensitizes lung cancer cells to paclitaxel at concentrations 1,000-fold lower than otherwise needed for a significant response. Some of the identified genes are already targets of currently available compounds and could be tested for responses to combinations of drugs, whereas others could be new therapeutic targets.
CONTACT
Michael A. White (University of Texas Southwestern Medical Center, Dallas, TX, USA)
Tel: +1 214 648 2861; E-mail: michael.white@utsouthwestern.edu
For more articles and topics go to www.medianowonline.com
Biologists have identified a set of genes expressed in human breast cancer cells that work together to remodel the vasculature at the site of the primary tumour and that also promote the spread of cancer to the lungs. The finding helps to explain how cancer metastasis can occur and highlights targets for therapeutic treatment.
Metastasis is the leading cause of mortality in cancer patients. A number of genes are already known to contribute to the spread of breast cancer cells to the lungs. But Joan Massagué and colleagues now show how four genes cooperate to promote the formation of new tumour blood vessels, the release of cancer cells into the bloodstream, and the penetration of tumour cells from the bloodstream into the lung.
The gene set comprises EREG, MMP1, MMP2 and COX2; drug combinations that target more than one of these components may prove useful for treating metastatic breast cancer.
CONTACT
Joan M Massague (Memorial Sloan-Kettering Cancer Center, Howard Hughes Medical Institute, New York, NY, USA)
Please contact:
Esther Napolitano (Public Affairs, Memorial Sloan-Kettering Cancer Center, New York, NY, USA)
Tel: +1 646 227 3139; E-mail: napolite@mskcc.org
Gerhard Christofori (University of Basel, Switzerland) N&V author
Tel: +41 61 267 3562 E-mail: gerhard.christofori@unibas.ch
Cancer: Genes linked to chemotherapy response
Scientists have identified a number of genes in lung cancer cells which, when downregulated, make the cancer cells especially vulnerable to a type of chemotherapy. The study highlights a new way to screen for alterations in cancer cells that make them specifically sensitive to therapeutics, so that treatment may leave normal tissue relatively unharmed.
Michael A. White and colleagues used a genome-wide RNA interference screen to identify 87 genes that are involved in the response of cancer cells to paclitaxel. Reducing the expression of a number of these genes sensitizes lung cancer cells to paclitaxel at concentrations 1,000-fold lower than otherwise needed for a significant response. Some of the identified genes are already targets of currently available compounds and could be tested for responses to combinations of drugs, whereas others could be new therapeutic targets.
CONTACT
Michael A. White (University of Texas Southwestern Medical Center, Dallas, TX, USA)
Tel: +1 214 648 2861; E-mail: michael.white@utsouthwestern.edu
For more articles and topics go to www.medianowonline.com
Monday, April 09, 2007
Herbal supplement may help treat recurrent bladder infections
Washington, Apr 9 -An herbal extract that is sold in
health food stores and promoted as an allergy and fat loss aid
may improve treatment of bladder infections when it is taken
with antibiotics, research suggests.
Some 90 per cent of bladder infections are caused by E.
coli bacteria. They affect women four times more often than
men, sometimes recurring over and over.
The bladder is lined with small pouches that allow it to
stretch as it fills. Researchers at Duke University reported
in yesterday's online edition of Nature Medicine that some
bacteria were able to hide in those pouches, escaping the
antibiotics used to treat the infection.
In tests in mice, the extract forskolin can cause the
pouches to kick out the bacteria, allowing antibiotics to
kill them, said the lead researcher, microbiologist Soman N.
Abraham. Forskolin is derived from the Indian coleus plant.
"If we combine this with antibiotics we would be in a
very good position to eradicate urinary tract infection," he
said in a telephone interview.
In the experiments, forskolin was injected into some
mice and placed directly into the bladders in others, Abraham
said.
The extract is available in health food stores and some
people take it by mouth as a supplement, he said. It is
promoted as a treatment for allergies, breathing problems and
even fat loss.
That availability does "absolutely not" mean people
should attempt to treat themselves for bladder infections,
Abraham said.
Washington, Apr 9 -An herbal extract that is sold in
health food stores and promoted as an allergy and fat loss aid
may improve treatment of bladder infections when it is taken
with antibiotics, research suggests.
Some 90 per cent of bladder infections are caused by E.
coli bacteria. They affect women four times more often than
men, sometimes recurring over and over.
The bladder is lined with small pouches that allow it to
stretch as it fills. Researchers at Duke University reported
in yesterday's online edition of Nature Medicine that some
bacteria were able to hide in those pouches, escaping the
antibiotics used to treat the infection.
In tests in mice, the extract forskolin can cause the
pouches to kick out the bacteria, allowing antibiotics to
kill them, said the lead researcher, microbiologist Soman N.
Abraham. Forskolin is derived from the Indian coleus plant.
"If we combine this with antibiotics we would be in a
very good position to eradicate urinary tract infection," he
said in a telephone interview.
In the experiments, forskolin was injected into some
mice and placed directly into the bladders in others, Abraham
said.
The extract is available in health food stores and some
people take it by mouth as a supplement, he said. It is
promoted as a treatment for allergies, breathing problems and
even fat loss.
That availability does "absolutely not" mean people
should attempt to treat themselves for bladder infections,
Abraham said.
IT IS A DOG STORY
Scientists First to Isolate a Single Gene Common to All Small Dogs
From the smallest Chihuahua to the largest Great Dane, dogs dramatically vary in size, much more than most other animals. Now scientists have discovered a genetic basis for this diversity.
A new study published in research journal Science reveals a genetic marker that may determine whether dogs are big or small, and helps answer a burning question in genetics -- how could dogs as a species have such a tremendous variation in size?
"This study is a major milestone in canine genetics, made possible by the help of thousands of dog owners around the world. Together with a team of leading international researchers, we have precisely located the major gene that produces our miniature breeds," said co-author Paul G. Jones, PhD, a genetics researcher at Mars -- a world leader in pet care that has been researching canine genetic science for the last seven years.
Dogs were one of the earliest animals to be domesticated more than 15,000 years ago, although people and wolves have coexisted for some 400,000 years. While all dogs originated from wolves, which are of a fairly standard size and appearance, modern dog breeds display a wide diversity of traits, including size. The genetic origin of this diversity has baffled scientists, who have been trying to explain how and why size difference occurred so rapidly in dogs. It is now thought that a change in the gene detailed in the published paper resulted in the appearance of small dogs in the population many thousands of years ago. It is likely that people soon saw the benefits of smaller dogs, for example for protecting food stores from vermin or catching small game. This further strengthened the bond between people and dogs and led to increasing popularity of smaller dogs as companions.
The international team of researchers -- ranging from scientists at the National Human Genome Research Institute, Cornell and other leading universities in the U.S. to Mars scientists in the United Kingdom -- used 3,200 dog DNA samples provided by Mars Incorporated, which holds the most comprehensive canine genetic database in the world. This has been built up with the help of pet owners who consent to their pets providing saliva and blood samples for the database. Mars' genetic data allowed the study to fill the gap between giant and miniature breeds ensuring coverage across the entire range of sizes of breeds we have today.
"These findings are just the tip of the iceberg in canine genetics," Jones said. "We are well on our way to identifying additional genes that can provide valuable insights into our pets."
With the dog genome now fully mapped, scientists are discovering a range of potential benefits of DNA-based information on man's best friend.
"The ability to isolate a specific genetic marker in such a quick and effective manner has tremendous implications for the future," Jones said. "Applications of this cutting-edge science could be used to develop products that will benefit the health of pets -- for example, developing individualized preventative care plans for dogs that are susceptible to certain diseases will help pet owners and veterinarians. In addition, genetic information about size and behavioral traits, such as trainability and temperament could also help veterinarians identify the most lifestyle-appropriate pet for an owner. "
Dog Facts
Dogs have one of the widest variations in size of any species. The adult bodyweights of the largest breeds are up to 70 times more than those of the smallest breeds. According to the American Kennel Club, in 2006 the most popular large-breed dogs in the USA were the Labrador Retriever, the German Shepherd Dog and Golden Retrievers; the most popular small-breed dogs were Yorkshire Terriers, Dachshunds and Shih Tzus.
FOR OTHER TOPICS PLEASE VISIT OUR PORTAL www.medianowonline.com
METHODS : Enrichment of metabolites with chemical probes
A general strategy for enriching various classes of metabolites directly from biological samples is described.The method allows researchers to profile small molecule metabolites that are difficult to detect with more conventional discovery-based methods.
The proteomics community has greatly benefited from chemical enrichment methods allowing the targeted isolation of proteins with similar functional or structural properties. The ‘metabolome,’ or entire spectrum of small molecules found in an organism, is even greater than the proteome in terms of numbers and chemical complexity. Benjamin Cravatt and colleagues reasoned that metabolomics researchers would therefore also benefit from targeted chemical enrichment strategies.
The authors synthesized chemical probes to target specific functional groups on small molecules. The probes were attached to a solid bead for easy isolation of the captured small molecules. The captured metabolites were then released from the probe and analyzed by liquid chromatography-mass spectrometry. They demonstrated that the method was able to isolate and profile low mass and polar small molecules, which are usually missed with conventional analysis without enrichment.
Author contact:
Benjamin Cravatt (The Scripps Research Institute, La Jolla, CA, USA)
Tel: +1 858 784 8633; E-mail: cravatt@scripps.edu
for other topics please visit our portal www.medianowonline.com
A general strategy for enriching various classes of metabolites directly from biological samples is described.The method allows researchers to profile small molecule metabolites that are difficult to detect with more conventional discovery-based methods.
The proteomics community has greatly benefited from chemical enrichment methods allowing the targeted isolation of proteins with similar functional or structural properties. The ‘metabolome,’ or entire spectrum of small molecules found in an organism, is even greater than the proteome in terms of numbers and chemical complexity. Benjamin Cravatt and colleagues reasoned that metabolomics researchers would therefore also benefit from targeted chemical enrichment strategies.
The authors synthesized chemical probes to target specific functional groups on small molecules. The probes were attached to a solid bead for easy isolation of the captured small molecules. The captured metabolites were then released from the probe and analyzed by liquid chromatography-mass spectrometry. They demonstrated that the method was able to isolate and profile low mass and polar small molecules, which are usually missed with conventional analysis without enrichment.
Author contact:
Benjamin Cravatt (The Scripps Research Institute, La Jolla, CA, USA)
Tel: +1 858 784 8633; E-mail: cravatt@scripps.edu
for other topics please visit our portal www.medianowonline.com
IMMUNOLOGY : How one’s own DNA can cause autoimmunity
A study may shed light on the cause of immune activation associated with systemic lupus erythematosus (SLE) – the second most common autoimmune disease in humans.
Found more often in women than in men, SLE is associated with the abnormal production of antibodies that ‘attack’ normal molecules in the body, including a person’s own DNA. As a result, debilitating inflammation, including skin rashes, hypertension, arthritis, and kidney and nervous system problems, ensues. Anthony Coyle and colleagues studied a protein called HMGB1 that normally binds to DNA in the cell nucleus. HMGB1 is also found in blood plasma, where it can bind to DNA released from dying cells. In many SLE patients, such DNA is also often the target of ‘abnormal’ lupus antibodies. As a result, antibody–HMGB1–DNA protein complexes form. The new study by Coyle and colleagues finds that antibody–HMGB1–DNA complexes in blood plasma from SLE patients can stimulate immune cells to produce potent inflammatory proteins associated with autoimmunity.
By demonstrating a role for HMGB1 in SLE inflammation, Coyle and colleagues provide unique insight into the pathogenesis associated with increasingly prevalent autoimmune diseases such as SLE. However, whether blocking the inflammatory function of HMGB1 will help SLE patients remains a question for future investigation.
Author contact:
Anthony Coyle (MedImmune Inc, Gaithersberg, MD, USA)
Tel: +1 301 398 4520; E-mail: coylea@medimmune.com
for other topics please visit our portal www.medianowonline.com
A study may shed light on the cause of immune activation associated with systemic lupus erythematosus (SLE) – the second most common autoimmune disease in humans.
Found more often in women than in men, SLE is associated with the abnormal production of antibodies that ‘attack’ normal molecules in the body, including a person’s own DNA. As a result, debilitating inflammation, including skin rashes, hypertension, arthritis, and kidney and nervous system problems, ensues. Anthony Coyle and colleagues studied a protein called HMGB1 that normally binds to DNA in the cell nucleus. HMGB1 is also found in blood plasma, where it can bind to DNA released from dying cells. In many SLE patients, such DNA is also often the target of ‘abnormal’ lupus antibodies. As a result, antibody–HMGB1–DNA protein complexes form. The new study by Coyle and colleagues finds that antibody–HMGB1–DNA complexes in blood plasma from SLE patients can stimulate immune cells to produce potent inflammatory proteins associated with autoimmunity.
By demonstrating a role for HMGB1 in SLE inflammation, Coyle and colleagues provide unique insight into the pathogenesis associated with increasingly prevalent autoimmune diseases such as SLE. However, whether blocking the inflammatory function of HMGB1 will help SLE patients remains a question for future investigation.
Author contact:
Anthony Coyle (MedImmune Inc, Gaithersberg, MD, USA)
Tel: +1 301 398 4520; E-mail: coylea@medimmune.com
for other topics please visit our portal www.medianowonline.com
NEUROSCIENCE : Stabilization contra retardation
A paper published online in Nature Neuroscience this week explores the mechanisms underlying fragile X syndrome – the most common inherited form of mental retardation. This disorder is caused by loss of a protein, dubbed FMRP, which interacts with messenger RNAs. (mRNAs are the templates that a cell ‘reads’ to correctly build specific proteins.) The details of how FMRP affects mRNAs and protein synthesis, and how subtle misregulation in absence of FMRP causes mental retardation, are still unclear.
Claudia Bagni and Kirsten S. Dickson and colleagues now report that FMRP stabilizes the mRNA that encodes the protein PSD-95. PSD-95 is crucial for the structure and function of neural synapses. In the brains of mice lacking FMRP, the authors found that the PSD-95 mRNA was rapidly degraded. The level of PSD-95 protein was reduced especially in the hippocampus, a structure crucial for learning, memory and certain kinds of reasoning.
This work suggests an important role for mRNA stabilization in the circuit wiring and communication of nerve cell networks. Though it is unlikely that all fragile X mental retardation symptoms can be explained by instability of PSD-95 mRNA, it may well represent an important part of the disease mechanism.
Author contacts:
Claudia Bagni (Universita di Roma, Italy)
Tel: +39 06 501 703 213; E-mail: claudia.bagni@uniroma2.it
Kirsten S. Dickson (University of Edinburgh, UK)
E-mail: dickson.kris@gmail.com
for other topics visit our portal www.medianowonline.com
A paper published online in Nature Neuroscience this week explores the mechanisms underlying fragile X syndrome – the most common inherited form of mental retardation. This disorder is caused by loss of a protein, dubbed FMRP, which interacts with messenger RNAs. (mRNAs are the templates that a cell ‘reads’ to correctly build specific proteins.) The details of how FMRP affects mRNAs and protein synthesis, and how subtle misregulation in absence of FMRP causes mental retardation, are still unclear.
Claudia Bagni and Kirsten S. Dickson and colleagues now report that FMRP stabilizes the mRNA that encodes the protein PSD-95. PSD-95 is crucial for the structure and function of neural synapses. In the brains of mice lacking FMRP, the authors found that the PSD-95 mRNA was rapidly degraded. The level of PSD-95 protein was reduced especially in the hippocampus, a structure crucial for learning, memory and certain kinds of reasoning.
This work suggests an important role for mRNA stabilization in the circuit wiring and communication of nerve cell networks. Though it is unlikely that all fragile X mental retardation symptoms can be explained by instability of PSD-95 mRNA, it may well represent an important part of the disease mechanism.
Author contacts:
Claudia Bagni (Universita di Roma, Italy)
Tel: +39 06 501 703 213; E-mail: claudia.bagni@uniroma2.it
Kirsten S. Dickson (University of Edinburgh, UK)
E-mail: dickson.kris@gmail.com
for other topics visit our portal www.medianowonline.com
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