Research leading to the discovery of streptomycin - the first effective pharmaceutical treatment for tuberculosis - will
be designated a National Historic Chemical Landmark at Rutgers University in a special ceremony in New Brunswick, New Jersey,
on May 24. The American Chemical Society, the world's largest scientific society, sponsors the landmarks program.
Beginning in the 1930s, Selman Waksman, Ph.D., and his students began the search for antibiotics produced from actinomycetes,
microbes in the soil that are related to bacteria and fungi. The culmination was the isolation of streptomycin in 1943 by
Albert Schatz, a graduate student of Waksman's, using soil screening methods developed by Waksman. This deliberate search for
chemotherapeutic agents contrasts with the discovery of penicillin, which came through a chance observation by Alexander
Fleming, who noted that a mold contaminant on a Petri dish culture had inhibited the growth of bacteria.
Streptomycin was the third antimicrobial agent isolated under Waksman's direction at Martin Hall at Cook College, Rutgers
University. Streptomycin, however, was the first agent not toxic to humans, and it attacked a type of bacteria resistant to
penicillin. In addition to treating tuberculosis, streptomycin was effective against typhoid fever, cholera, bubonic plague
and other diseases. Among the other antibiotics isolated in Waksman's laboratory was neomycin, still used as a topical
antibacterial agent.
William F. Carroll, Ph.D., president of the Society, will present a commemorative bronze plaque to Tim Casey, Ph.D., Dean of
Academic and Student Programs at Cook College, Rutgers University. H. Boyd Woodruff, Ph.D., who isolated the first two
actinomycete antibiotics, will be the featured speaker. The award presentation takes place in conjunction with the ACS Middle
Atlantic Regional Meeting. The MARM meeting is being held on the nearby Busch Campus of Rutgers in Piscataway, New Jersey,
May 22-25.
Selman Waksman was born in Russia in 1888. He immigrated to the United States in 1910 and entered Rutgers University a few
years later. After completing graduate work at the University of California, Waksman joined the Rutgers faculty in 1918. Even
as an undergraduate student, Waksman studied actinomycetes in the soil, but it was not until late 1930s that he turned his
attention to the searching for microbes that attacked other microbes.
Waksman received the Nobel Prize for physiology or medicine in 1952 for "ingenious, systematic and successful studies of the
soil microbes" that led to the discovery of streptomycin. He died in 1973.
The American Chemical Society is a nonprofit organization, chartered by the U.S. Congress, with a multidisciplinary
membership of more than 158,000 chemists and chemical engineers. It publishes numerous scientific journals and databases,
convenes major research conferences and provides educational, science policy and career programs in chemistry. Its main
offices are in Washington, D.C., and Columbus, Ohio.
Contact: Judah Ginsberg
j_ginsbergacs
202-872-4400
American Chemical Society
chemistry
Michele Hujber
hujberaesop.rutgers
732-932-9559
Rutgers University
rutgers
понедельник, 13 июня 2011 г.
пятница, 10 июня 2011 г.
Method For Computing Evolutionary Trees Could Revolutionize Evolutionary Biology
Detailed, accurate evolutionary trees that reveal the relatedness of living things can now be determined much faster and for thousands of species with a computing method developed by computer scientists and a biologist at The University of Texas at Austin.
They report their new method in the journal Science.
Since Charles Darwin, biologists have constructed evolutionary trees to explain the relatedness of plants, animals and other organisms. The science of figuring out these trees, known as systematics, has progressed significantly in the last two decades largely due to advances in computation, genetics and molecular biology.
However, many of the relationships among the world's 1.5 million described species (the true number could be 10 million or more) remain to be figured out, and surprises still remain. Figuring out these relationships requires analyzing large amounts of molecular data, such as DNA and protein sequences.
Computer scientist Tandy Warnow, biologist Randy Linder and their graduate students have created an automated computing method, called SATГ©, that can analyze these molecular data from thousands of organisms, simultaneously figuring out how the sequences should be organized and computing their evolutionary relatedness in as little as 24 hours.
Previous simultaneous methods like Warnow and Linder's have been limited to analyzing 20 species or fewer and have taken months to complete.
"SATГ© could completely change the practice of making evolutionary trees and revolutionize our understanding of evolution," says Warnow, professor of computer science and lead author of the study.
In addition, SATГ© can accurately analyze DNA sequences that are rapidly evolving. These sequences have been previously avoided due to concern that the resulting trees would be poor.
Before a tree, or phylogeny, can be determined, DNA and protein sequence data must be organized. This process is called alignment. Key to Warnow and Linder's program is its ability to quickly and accurately align these data.
"Our process is novel because it rapidly and simultaneously aligns sequences and looks for the best phylogenies," says Linder, associate professor of integrative biology. "The old way of doing this for a large number of sequences was basically to align the data once, but we can look at many arrangements to find better ones."
This is important because different alignments can lead to significantly different phylogenies, and scientists must find the phylogeny that best represents the evolutionary relationships among the species in question.
For their paper, Warnow, Linder and their students tested SATГ© using computer-generated data and real biological data. The biological data had been previously aligned manually by other experts.
The new phylogenies closely match those existing, both validating the method's potential, and, in some cases, validating the evolutionary trees themselves.
"Instead of doing things by hand, evolutionary biologists can now trust our automated program," says Warnow. "It will enable the creation of much more accurate trees, especially for the Tree of Life, which deals with hundreds of thousands of gene sequences from the millions of species on Earth."
"Warnow and Linder have created a method that speeds up the process and removes any subjectivity," says Michael Braun, an evolutionary biologist at the Smithsonian Institution not associated with this project. "This is a major step forward for evolutionary biology."
Computer science graduate student Kevin Liu is first author on the paper. Students Sindhu Raghavan and Serita Nelesen also contributed to the project and co-authored the paper.
Source:
Tandy Warnow
University of Texas at Austin
They report their new method in the journal Science.
Since Charles Darwin, biologists have constructed evolutionary trees to explain the relatedness of plants, animals and other organisms. The science of figuring out these trees, known as systematics, has progressed significantly in the last two decades largely due to advances in computation, genetics and molecular biology.
However, many of the relationships among the world's 1.5 million described species (the true number could be 10 million or more) remain to be figured out, and surprises still remain. Figuring out these relationships requires analyzing large amounts of molecular data, such as DNA and protein sequences.
Computer scientist Tandy Warnow, biologist Randy Linder and their graduate students have created an automated computing method, called SATГ©, that can analyze these molecular data from thousands of organisms, simultaneously figuring out how the sequences should be organized and computing their evolutionary relatedness in as little as 24 hours.
Previous simultaneous methods like Warnow and Linder's have been limited to analyzing 20 species or fewer and have taken months to complete.
"SATГ© could completely change the practice of making evolutionary trees and revolutionize our understanding of evolution," says Warnow, professor of computer science and lead author of the study.
In addition, SATГ© can accurately analyze DNA sequences that are rapidly evolving. These sequences have been previously avoided due to concern that the resulting trees would be poor.
Before a tree, or phylogeny, can be determined, DNA and protein sequence data must be organized. This process is called alignment. Key to Warnow and Linder's program is its ability to quickly and accurately align these data.
"Our process is novel because it rapidly and simultaneously aligns sequences and looks for the best phylogenies," says Linder, associate professor of integrative biology. "The old way of doing this for a large number of sequences was basically to align the data once, but we can look at many arrangements to find better ones."
This is important because different alignments can lead to significantly different phylogenies, and scientists must find the phylogeny that best represents the evolutionary relationships among the species in question.
For their paper, Warnow, Linder and their students tested SATГ© using computer-generated data and real biological data. The biological data had been previously aligned manually by other experts.
The new phylogenies closely match those existing, both validating the method's potential, and, in some cases, validating the evolutionary trees themselves.
"Instead of doing things by hand, evolutionary biologists can now trust our automated program," says Warnow. "It will enable the creation of much more accurate trees, especially for the Tree of Life, which deals with hundreds of thousands of gene sequences from the millions of species on Earth."
"Warnow and Linder have created a method that speeds up the process and removes any subjectivity," says Michael Braun, an evolutionary biologist at the Smithsonian Institution not associated with this project. "This is a major step forward for evolutionary biology."
Computer science graduate student Kevin Liu is first author on the paper. Students Sindhu Raghavan and Serita Nelesen also contributed to the project and co-authored the paper.
Source:
Tandy Warnow
University of Texas at Austin
вторник, 7 июня 2011 г.
Distinct Mammalian Precursors Are Committed To Generate Neurons With Defined Dendritic Projection Patterns
The mammalian brain contains a large number of different classes of
neurons that are connected in a specific manner. A long-standing question
is how
such stereotyped connections emerge during the assembly of the brain. In a
new study published online this week in the open-access journal PLoS
Biology, Wolfgang Kelsch, Carlos Lois, and colleagues investigated whether
neonatal and adult brain stem cells give rise to neurons whose connections
can be influenced by the partners that they encounter while maturing, or
alternatively, whether these connections are predetermined from the moment
that a neuron is born.
They observed the existence of distinct populations
of precursor cells committed to generating neurons with a specific pattern
of connections. Furthermore, the pattern of connections formed by these
neurons was largely independent of the environment in which the neurons
matured. These results have important implications for the formation of
neuronal circuits, as they indicate that the connections of a new neuron
can
be determined in their precursors.
In particular, these observations
suggest that for neuronal replacement therapies to be successful, it will
be
necessary to understand the genetic programs that control how stem cells
are prespecified to produce neurons with a stereotypic pattern of
connections.
Citation: Kelsch W, Mosley CP, Lin CW, Lois C (2007) Distinct mammalian
precursors are committed to generate neurons with defined dendritic
projection
patterns. PLoS Biol
5(11): e300. doi:10.1371/journal.pbio.0050300
Please click here
plosbiology
About the Public Library of Science
The Public Library of Science (PLoS) is a non-profit organization of
scientists and physicians committed to making the world's scientific and
medical
literature a freely available public resource.
Public Library of Science
185 Berry Street, Suite 3100
San Francisco, CA 94107
USA
neurons that are connected in a specific manner. A long-standing question
is how
such stereotyped connections emerge during the assembly of the brain. In a
new study published online this week in the open-access journal PLoS
Biology, Wolfgang Kelsch, Carlos Lois, and colleagues investigated whether
neonatal and adult brain stem cells give rise to neurons whose connections
can be influenced by the partners that they encounter while maturing, or
alternatively, whether these connections are predetermined from the moment
that a neuron is born.
They observed the existence of distinct populations
of precursor cells committed to generating neurons with a specific pattern
of connections. Furthermore, the pattern of connections formed by these
neurons was largely independent of the environment in which the neurons
matured. These results have important implications for the formation of
neuronal circuits, as they indicate that the connections of a new neuron
can
be determined in their precursors.
In particular, these observations
suggest that for neuronal replacement therapies to be successful, it will
be
necessary to understand the genetic programs that control how stem cells
are prespecified to produce neurons with a stereotypic pattern of
connections.
Citation: Kelsch W, Mosley CP, Lin CW, Lois C (2007) Distinct mammalian
precursors are committed to generate neurons with defined dendritic
projection
patterns. PLoS Biol
5(11): e300. doi:10.1371/journal.pbio.0050300
Please click here
plosbiology
About the Public Library of Science
The Public Library of Science (PLoS) is a non-profit organization of
scientists and physicians committed to making the world's scientific and
medical
literature a freely available public resource.
Public Library of Science
185 Berry Street, Suite 3100
San Francisco, CA 94107
USA
понедельник, 6 июня 2011 г.
Latent Inhibition Of Predator Recognition By Embryonic Amphibians
It is crucial for prey to be able to learn to discriminate between predators and non-predators. While this task can be challenging and dangerous for prey animals, it appears that amphibian embryos have found a way to get a head start on their homework.
The present study indicates that woodfrogs can learn to distinguish their future predators from their future non-predators while still in the egg. Woodfrog embryos repeatedly exposed to a novel odour (salamander odour) without any reinforcement are subsequently unable to label this odour as threatening.
This mechanism, known as latent inhibition, is likely useful at limiting the number of stimuli mistakenly recognized as potentially dangerous by prey.
Royal Society Journal Biology Letters
Biology Letters publishes short, innovative and cutting-edge research articles and opinion pieces accessible to scientists from across the biological sciences. The journal is characterised by stringent peer-review, rapid publication and broad dissemination of succinct high-quality research communications.
Biology Letters
The present study indicates that woodfrogs can learn to distinguish their future predators from their future non-predators while still in the egg. Woodfrog embryos repeatedly exposed to a novel odour (salamander odour) without any reinforcement are subsequently unable to label this odour as threatening.
This mechanism, known as latent inhibition, is likely useful at limiting the number of stimuli mistakenly recognized as potentially dangerous by prey.
Royal Society Journal Biology Letters
Biology Letters publishes short, innovative and cutting-edge research articles and opinion pieces accessible to scientists from across the biological sciences. The journal is characterised by stringent peer-review, rapid publication and broad dissemination of succinct high-quality research communications.
Biology Letters
Discovery Of The Cell's Water Gate May Lead To New Cancer Drugs
The flow of water into and out from the cell may play a crucial role in several types of cancer. Scientists at the University of Gothenburg have now found the gate that regulates the flow of water into yeast cells. The discovery, which has been published in the journal PLoS Biology, raises hopes of developing a drug that inhibits the spread and growth of tumours.
All living organisms must be able to regulate the flow of water into and out from cells, in order to maintain cell form and size. This regulation is carried out by special proteins known as "aquaporins". These act as water channels and control the flow of water into and out from the cell.
Involved in cancer diseases
Aquaporins are found in most organisms, and are believed to be involved in several diseases, including cancer. Research on mice has shown that inhibiting the function of aquaporins can dramatically reduce the spread and growth of tumours.
Important for research
It is therefore extremely important for cancer research to increase our knowledge of aquaporins. Scientists at the University of Gothenburg have recently achieved a minor breakthrough in the field. Karin Lindkvist at the Department of Cell and Molecular Biology and Richard Neutze at the Department of Chemistry, University of Gothenburg have determined the three-dimensional structure of the yeast aquaporin.
Highest resolution
The structure has been determined using X-ray crystallography and is the highest resolution structure that has been determined for a membrane protein. The unique high resolution has enabled the scientists to answer one of the unsolved mysteries of biology. The aquaporins in yeast have long "tails", known as amino-terminal extensions. The function of these tails has, until now, been unknown.
"Our study shows that the amino-terminal extensions in yeast act as a gate that can be opened and closed depending on how much water the cell must release or absorb. Computer simulations and biological experiments suggest that the channel is regulated with a combination of mechanical regulation and phosphorylation", says Karin Lindkvist.
Similar to human
Yeast cells are similar to human cells in many respects, and Karin Lindkvist's research can have applications in cancer research and other fields.
"The structure of the yeast aquaporin that we have determined can be used to create inhibitors for human aquaporins, and this may in the long term lead to drugs that slow the growth of a cancer tumour", says Karin Lindkvist.
The article has been published in PloS Biology on 16 June.
Source: University of Gothenburg
All living organisms must be able to regulate the flow of water into and out from cells, in order to maintain cell form and size. This regulation is carried out by special proteins known as "aquaporins". These act as water channels and control the flow of water into and out from the cell.
Involved in cancer diseases
Aquaporins are found in most organisms, and are believed to be involved in several diseases, including cancer. Research on mice has shown that inhibiting the function of aquaporins can dramatically reduce the spread and growth of tumours.
Important for research
It is therefore extremely important for cancer research to increase our knowledge of aquaporins. Scientists at the University of Gothenburg have recently achieved a minor breakthrough in the field. Karin Lindkvist at the Department of Cell and Molecular Biology and Richard Neutze at the Department of Chemistry, University of Gothenburg have determined the three-dimensional structure of the yeast aquaporin.
Highest resolution
The structure has been determined using X-ray crystallography and is the highest resolution structure that has been determined for a membrane protein. The unique high resolution has enabled the scientists to answer one of the unsolved mysteries of biology. The aquaporins in yeast have long "tails", known as amino-terminal extensions. The function of these tails has, until now, been unknown.
"Our study shows that the amino-terminal extensions in yeast act as a gate that can be opened and closed depending on how much water the cell must release or absorb. Computer simulations and biological experiments suggest that the channel is regulated with a combination of mechanical regulation and phosphorylation", says Karin Lindkvist.
Similar to human
Yeast cells are similar to human cells in many respects, and Karin Lindkvist's research can have applications in cancer research and other fields.
"The structure of the yeast aquaporin that we have determined can be used to create inhibitors for human aquaporins, and this may in the long term lead to drugs that slow the growth of a cancer tumour", says Karin Lindkvist.
The article has been published in PloS Biology on 16 June.
Source: University of Gothenburg
Great Ape Diseases Are Threat To Humans
Humans may be more vulnerable to catching diseases from great apes chimpanzees and gorillas as these species are the closest relatives to us, says research published in Proceedings of the Royal Society B: Biological Sciences, today (Wednesday 30 April 2008).
Researchers from the Universities of California and Sheffield show that humans are almost four times more likely to share infectious diseases and viruses with chimpanzees which last shared a common ancestor with humans around 8 million years ago, than with a colobus monkey, which diverged from humans over 34 million years ago.
Emerging infectious diseases are increasingly impacting human health and species conservation. Many of the most deadly diseases known to mankind have originated among wild animals, for example AIDS and Ebola and these new findings could prove critical in predicting future trends of emerging diseases.
Dr Jonathan Davies, from the University of California and co-author of the study, said: "Infectious diseases crossing species barriers pose a huge and increasing threat to human health and the conservation of wild species. Our study helps us to understand where and how diseases jump between species, and provides a critical first step in predicting future outbreaks."
The Royal Society
Researchers from the Universities of California and Sheffield show that humans are almost four times more likely to share infectious diseases and viruses with chimpanzees which last shared a common ancestor with humans around 8 million years ago, than with a colobus monkey, which diverged from humans over 34 million years ago.
Emerging infectious diseases are increasingly impacting human health and species conservation. Many of the most deadly diseases known to mankind have originated among wild animals, for example AIDS and Ebola and these new findings could prove critical in predicting future trends of emerging diseases.
Dr Jonathan Davies, from the University of California and co-author of the study, said: "Infectious diseases crossing species barriers pose a huge and increasing threat to human health and the conservation of wild species. Our study helps us to understand where and how diseases jump between species, and provides a critical first step in predicting future outbreaks."
The Royal Society
Protein Has Pivotal Role In Obesity, Metabolic Syndrome
A protein known to play a role in development and the formation of organs is also an important factor in the control of obesity and diabetes, said researchers from Baylor College of Medicine in a report that appears in the current issue of the journal Cell Metabolism.
Drs. Ming-Jer and Sophia Tsai, professors of molecular and cellular biology at BCM, have studied COUP-TFII (Chicken Ovalbumin Upstream Promoter Transcription Factor II) for decades, but only when they bred mice that had only one gene copy for the factor did they find that the animals had smaller fat cells and increased energy metabolism as well as enhanced response to insulin.
"If a mouse loses one copy of the gene, the animal becomes lean," said Ming-Jer Tsai. "It is more sensitive to the effects of insulin and resistant to obesity from a high fat diet."
Their studies raise the likely possibility that one can use COUP-TFII as a potential drug target for diabetes and obesity treatment.
Identifying a drug that could reduce the effect of COUP-TFII activity has become a future focus for their research, said Sophia Tsai.
"We don't need to inhibit it totally," she said. "Partial inhibition will do the trick as when you lose one copy of the gene, your fat cells are already much smaller and the animal is lean."
The animals not only have less fat, they also have more muscle and burn more energy, said Ming-Jer Tsai.
Drs. Luoping Li and Xin Xie, postdoctoral associates in Dr. Tsai's laboratory were major contributors to the work. Others who took part include Jun Qin, George S. Jeha, Pradip K. Saha, Jun Yan, Claire Menoza Haueter and Lawrence Chan, all of BCM.
Funding for this research came from the National Institutes of Health and the Baylor Diabetes and Endocrinology Research Center funded by the National Institute of Diabetes and Digestive and Kidney Diseases at BCM.
This report will be available at cell/cell-metabolism/home.
For more basic science from Baylor College of Medicine, please go to bcm/fromthelab.
Source: Graciela Gutierrez
Baylor College of Medicine
Drs. Ming-Jer and Sophia Tsai, professors of molecular and cellular biology at BCM, have studied COUP-TFII (Chicken Ovalbumin Upstream Promoter Transcription Factor II) for decades, but only when they bred mice that had only one gene copy for the factor did they find that the animals had smaller fat cells and increased energy metabolism as well as enhanced response to insulin.
"If a mouse loses one copy of the gene, the animal becomes lean," said Ming-Jer Tsai. "It is more sensitive to the effects of insulin and resistant to obesity from a high fat diet."
Their studies raise the likely possibility that one can use COUP-TFII as a potential drug target for diabetes and obesity treatment.
Identifying a drug that could reduce the effect of COUP-TFII activity has become a future focus for their research, said Sophia Tsai.
"We don't need to inhibit it totally," she said. "Partial inhibition will do the trick as when you lose one copy of the gene, your fat cells are already much smaller and the animal is lean."
The animals not only have less fat, they also have more muscle and burn more energy, said Ming-Jer Tsai.
Drs. Luoping Li and Xin Xie, postdoctoral associates in Dr. Tsai's laboratory were major contributors to the work. Others who took part include Jun Qin, George S. Jeha, Pradip K. Saha, Jun Yan, Claire Menoza Haueter and Lawrence Chan, all of BCM.
Funding for this research came from the National Institutes of Health and the Baylor Diabetes and Endocrinology Research Center funded by the National Institute of Diabetes and Digestive and Kidney Diseases at BCM.
This report will be available at cell/cell-metabolism/home.
For more basic science from Baylor College of Medicine, please go to bcm/fromthelab.
Source: Graciela Gutierrez
Baylor College of Medicine
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