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Archive - Sep 2011

Date

September 21st

Genetic Overlap Found Between Schizophrenia and Bipolar Disorder

Knowledge about the biological origin of diseases like schizophrenia, bipolar disorder, and other psychiatric conditions is critical to improving diagnosis and treatment. In an effort to push the field forward, three UCLA researchers, along with scientists from more than 20 countries, have been taking part in one of the largest collaborative efforts in psychiatry — a genome-wide study involving more than 50,000 study participants aimed at identifying which genetic variants make people susceptible to psychiatric disease. This collaborative, the Psychiatric Genome-Wide Association Study Consortium (PGC), now reports, in two articles in the September 18, 2011 online edition of Nature Genetics, that it has discovered that common genetic variants contribute to a person's risk of schizophrenia and bipolar disorder. The PGC's studies provide new molecular evidence that 11 regions on the genome are strongly associated with these diseases, including six regions not previously observed. The researchers also found that several of these DNA variations contribute to both diseases. The findings, the researchers say, represent a significant advance in understanding the causes of these chronic, severe, and debilitating disorders. The UCLA researchers who contributed to the schizophrenia study are Dr. Roel A. Ophoff, a professor of psychiatry and human genetics and one of the founding principal investigators of the schizophrenia portion of the study; Dr. Nelson Freimer, a professor of psychiatry and director of the Center for Neurobehavioral Genetics at the Semel Institute for Neuroscience and Human Behavior at UCLA; and Dr. Rita Cantor, a professor of psychiatry and human genetics. Schizophrenia and bipolar disorder are common and often devastating brain disorders.

Identificatioon of Key Molecule That Blocks Angiogenesis in Tumors

A new and better understanding of blood vessel growth and vascular development (angiogenesis) in cancer has been made possible by research carried out by a team of scientists from the Moffitt Cancer Center, the University of Florida, Harvard University, Yale University, and the Children's Hospital of Los Angeles. The research team published the results of its investigation in the September 13, 2011 issue of the Proceedings of the National Academy of Sciences. "Vascular development is a fundamental biological process that is tightly controlled by both pro-and anti-angiogenic mechanisms," said Dr. Edward Seto, a co-author of the study and professor and chairman of the Department of Molecular Oncology at Moffitt. "Physiological angiogenesis occurs in adults only under specific settings. Excess angiogenesis contributes to a variety of diseases, including cancer. In cancer, vascular endothelial growth factor (VEGF) is commonly overproduced." The goal of the research was to determine how angiogenesis is regulated by positive and negative biological activities. "Understanding the biological principles that direct vascular growth has important clinical implications because cancers are highly vascularized," concluded Dr. Seto. This meant seeking a better understanding of the relationship between the chromatin insulator binding factor CTCF and how it regulates VEGF expression. "At the heart of vascular development is VEGF which, in precise doses, is an important stimulator of normal blood vessel growth," explained Dr. Seto. "However, VEGF - probably the most important stimulator of normal and pathological blood vessel growth - is regulated by a number of factors." According to Dr. Seto, the study suggests that CTCF can block VEGF from being activated.

September 20th

Adult Stem Cells Are Potential Source of Cancer-Fighting T-Cells

Adult stem cells from mice converted to antigen-specific T-cells -- the immune cells that fight cancer tumor cells -- show promise in cancer immunotherapy and may lead to a simpler, more efficient way to use the body's immune system to fight cancer, according to Penn State College of Medicine researchers. "Cancer immunotherapy is a promising method to treat cancer patients," said Dr. Jianxsun Song, assistant professor, microbiology and immunology. "Tumors grow because patients lack the kind of antigen-specific T-cells needed to kill the cancer. An approach called adoptive T-cell immunotherapy generates the T-cells outside the body, which are then used inside the body to target cancer cells." It is complex and expensive to expand T-cell lines in the lab, so researchers have been searching for ways to simplify the process. Dr. Song and his team found a way to use induced pluripotent stem (iPS) cells, which are adult cells that are genetically changed to be stem cells. "Any cell can become a stem cell," Dr. Song explained. "It's a very good approach to generating the antigen-specific T-cells and creates an unlimited source of cells for adoptive immunotherapy." By inserting DNA, researchers change the mouse iPS cells into immune cells and inject them into mice with tumors. After 50 days, 100 percent of the mice in the study were still alive, compared to 55 percent of control mice, which received tumor-reactive immune cells isolated from donors. The researchers reported their results in the July 15, 2011 issue of Cancer Research. The work served as the cover story of the issue. A limitation of this potential therapy is that it currently takes at least six weeks for the iPS cells to develop into T-cells in the body. In addition, potential side effects need to be considered. iPS cells may develop into other harmful cells in the body.

September 19th

Genetic Mutation Eliminates Fingerprints

Like DNA, fingerprints are unique to each person or set of identical twins. That makes them a valuable identification tool for everything from crime detection to international travel. But what happens when the tips of fingers are missing those distinctive patterns of ridges? It's not the premise for a science-fiction movie, but a real-life condition known as adermatoglyphia. It’s also known as "Immigration Delay Disease," because affected individuals experience difficulty in passing through security or checkpoints where fingerprint identification is required. Now Professor Eli Sprecher from Tel Aviv University's Sackler Faculty of Medicine and the Tel Aviv Sourasky Medical Center has identified the genetic mutation responsible for this unusual condition. The findings were published in the August 12, 2011 issue of the American Journal of Human Genetics. "Immigration Delay Disease" came to the attention of the medical community when it did just that — delay the attempts of one Swiss woman to cross the border into the United States, which requires that non-citizens be fingerprinted upon entry. Border control personnel were mystified when the woman informed them that she was unable to comply. Though an exceptionally rare condition — only four documented families are known to suffer from the disease worldwide — Professor Sprecher was inspired to delve deeper into the causes of the condition, which, in addition to causing an absence of fingerprints, also leads to a reduction in the number of sweat glands. Abnormal fingerprints can also be a warning sign of more severe disorders. Scientists know that fingerprints are fully formed 24 weeks after fertilization, and do not change throughout our lives.

Scientists Find Earliest Known Evidence of 1918 Influenza Pandemic

Examination of lung tissue and other autopsy material from 68 American soldiers who died of respiratory infections in 1918 has revealed that the influenza virus that eventually killed 50 million people worldwide was circulating in the United States at least four months before the 1918 influenza reached pandemic levels that fall. The study, using tissues preserved since 1918, was led by Dr. Jeffery K. Taubenberger of the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. The study was published online on September 19, 2011, in PNAS. The researchers found proteins and genetic material from the 1918 influenza virus in specimens from 37 of the soldiers, including four who died between May and August 1918, months before the pandemic peaked. These four cases are the earliest 1918 pandemic influenza cases they know to be documented anywhere in the world, the scientists say. The clinical disease and tissue damage seen in the pre-pandemic cases were indistinguishable from those evident in cases that occurred during the height of the pandemic. This suggests, says Dr. Taubenberger, that over the course of the pandemic, the virus did not undergo a dramatic change that could explain the unusually high mortality it ultimately caused. In the current study, the autopsy materials showed that the virus replicated not only in the upper respiratory tract but also the lower respiratory tract, in a pattern very similar to that of the 2009 pandemic influenza virus. The team also found evidence that two virus variants were circulating in 1918. In one, a key viral protein called hemagglutinin bound well to receptors on human respiratory cells, while the hemagglutinin from the other variant bound less efficiently.

September 16th

Study of Ocean Bacteria Reveals Secrets

The earth's most successful bacteria are found in the oceans and belong to the group SAR11. In a new study, researchers from Uppsala University in Sweden provide an explanation for their success and at the same time call into question generally accepted theories about these bacteria. In their analysis, they have also identified a rare and hitherto unknown relative of mitochondria, the power stations inside cells. The findings were published in two articles in the journals Molecular Biology and Evolution (September 7, 2011) and PLoS ONE (September 14, 2011). "The huge amounts of DNA information now being produced from the oceans gives us a glimpse of a world that could never be studied before. It's incredibly fascinating to look for answers to the fundamental questions of life in these data,” says Dr. Siv Andersson, professor of molecular evolution and senior author of the studies. Bacteria belonging to the group SAR11 make up 30-40 percent of all bacteria cells in the oceans and therefore play a considerable role in global carbon cycles. Nowhere else are these bacteria so common. The open seas are poor in nutrients, and SAR11 bacteria have an extremely small cell volume in order to maximize the concentration of nutrients in the cells. Their genomes are small, consisting of fewer than 1.5 million building blocks. According to previous research, they are related to an equally specialized group of bacteria that includes the typhus bacterium. These bacteria also have small genomes, but they are adapted to humans, animals, and insects. However, the advanced analyses of evolutionary relationships performed by the Uppsala researchers contradict these findings, indicating instead that SAR11 bacteria evolved from ocean- and earth-dwelling bacteria with genomes that are three to ten times as large.

September 14th

Beetle Stacks Dummy Eggs to Fool Parasitoid Wasps

They lead modest lives among the palo verde, mesquite, and acacia trees throughout the Southwestern U.S., laying their eggs on seed pods and defending the survival of their offspring against the parasitic wasp species that attacks their eggs before their young can develop. They are the seed beetles Mimosestes amicus, living all around us in the trees of Tucson, and yet remaining all but invisible to our eyes – or nearly so. Now, doctoral candidate Joseph Deas in the University of Arizona's Graduate Interdisciplinary Program in Entomology and Insect Science, along with his faculty advisor Dr. Martha Hunter in the department of entomology, is peering into their world through his microscope and has discovered something novel: The beetles, whose eggs frequently are parasitized by the wasp Uscana semifumipennis, have a strategy to protect their offspring that goes beyond a helpful habit. "They're stacking their eggs in order to protect them from these parasitic wasps," said Deas, whose research was published online in the Proceedings of the Royal Society B on September 14, 2011. The wasps, called parasitoids because they kill their host rather than just taking advantage of its resources, deposit their own eggs inside the beetles’ eggs. The wasp larva gets a head start in life and develops before the beetle larva, hijacking the beetle egg yolk for its own nourishment. "You can tell when an egg has been parasitized because the egg will start to darken and blacken," said Deas. "The beetle larva by that time will never form because all of the yolk is going inside the wasp larva. And then you can see little red eyes in there; the beetles don't have red eyes. It looks very evil." As often happens in science, Deas came upon the discovery of M. amicus' strategy through the course of a different investigation.

Yale Scientists Use Human Uterine Stem Cells to Treat Diabetes in Mice

Controlling diabetes may someday involve mining stem cells from the lining of the uterus, Yale School of Medicine researchers report in a new study published August 30, 2011, in the journal Molecular Therapy. The team treated diabetes in mice by converting cells from human uterine lining into insulin-producing cells. The endometrium or uterine lining, is a source of adult stem cells. These cells generate uterine tissue each month as part of the menstrual cycle. Like other stem cells, however, they can divide to form other kinds of cells. The Yale team's findings suggest that endometrial stem cells could be used to develop insulin-producing islet cells, which are found in the pancreas. These islet cells could then be used to advance the study of islet cell transplantation to treat people with diabetes. Led by Yale Professor Hugh S. Taylor, the researchers bathed endometrial stem cells in cultures containing special nutrients and growth factors. Responding to these substances, the endometrial stem cells adopted the characteristics of beta cells in the pancreas that produce insulin. Over the course of a three-week incubation process, the endometrial stem cells took on the shape of beta cells and began to make proteins typically made by beta cells. Some of these cells also produced insulin. After a meal, the body breaks food down into components like the sugar glucose, which then circulates in the blood. In response, beta cells release insulin, which allows the body's cells to take in the circulating glucose. In this study, Dr. Taylor and his team exposed the mature stem cells to glucose and found that, like typical beta cells, the cultured cells responded by producing insulin. The team then injected diabetic mice with the mature, insulin-making stem cells. The mice had few working beta cells and very high levels of blood glucose.

Engineers Probe Mechanics Behind Premature Aging Disease (Progeria)

Researchers at MIT and Carnegie Mellon University are using both civil engineering and bioengineering approaches to study the behavior of a protein associated with progeria, a rare disorder in children that causes extremely rapid aging and usually ends in death from cardiovascular disease before age 16. The disease is marked by the deletion of 50 amino acids near the end of the lamin A protein, which helps support a cell's nuclear membrane. At MIT, the researchers used molecular modeling — which obeys the laws of physics at the molecular scale — to simulate the behavior of the protein's tail under stress in much the same way a traditional civil engineer might test the strength of a beam: by applying pressure. In this instance, they created exact replicas of healthy and mutated lamin A protein tails, pulling on them to see how they unraveled. "The application of engineering mechanics to understand the process of rapid aging disease may seem odd, but it actually makes a lot of sense," says Dr. Markus Buehler, a professor in MIT's Department of Civil and Environmental Engineering who also studies structural proteins found in bone and collagen. In this new research, he worked with Dr. Kris Dahl, professor of biomedical engineering and chemical engineering at Carnegie Mellon, and graduate students Zhao Qin of MIT and Agnieszka Kalinowski of Carnegie Mellon. They published their findings in the September 2011 issue of the Journal of Structural Biology. In its natural state, a protein — and its tail — exist in complex folded configurations that differ for each protein type. Many misfolded proteins are associated with diseases. In molecular simulations, Qin and Dr. Buehler found that the healthy lamin A protein tail unravels sequentially along its backbone strand, one amino acid at a time.

Amateur Botanists in Brazil Discover New Species of Seed-Burying Plant

José Carlos Mendes Santos (a.k.a. Louro) is a handyman in rural northeastern Bahia, Brazil - one of the areas of the world with the highest biodiversity. Two years ago, he found a tiny, inch-high plant with white-and-pink flowers in the backyards of the off-the-grid house of amateur botanist and local plant collector Alex Popovkin. The little plant was brought home to be grown on a window sill for closer observation. In parallel, work on its identification began. Thanks to solar power and a satellite connection, Popovkin had access to the Internet, and as was his habit, he uploaded some photographs of the plant to Flickr and contacted several taxonomic experts around the globe. The family (strychnine family, or Loganiaceae) and genus (Spigelia) of the plant were soon established, with a suggestion from a Brazilian botanist that it might be a new species. A collaboration was started with Dr. Lena Struwe, a specialist of the plant's family at Rutgers University, who had previously described a species in the gentian family from the Andes named after Harry Potter (apparating moon-gentian, Macrocarpaea apparata), and another after the Inca tribe (the Inca ring-gentian, Symbolanthus incaicus). More collections were made, photographs uploaded and specimens deposited at the State University at Feira de Santana (HUEFS) in Bahia, while Dr. Mari Carmen Molina, a visiting scientist in Dr. Struwe's lab from Spain, extracted the plant's DNA. In collaboration with Dr. Katherine Mathews from Western Carolina University, it was confirmed that the genus was indeed Spigelia, to which pinkroot, an old North American herbal remedy against intestinal parasites, also belongs. Only a few miniscule plants were found in the field the first year.