A new study is unraveling the earliest events associated with neurodegenerative diseases characterized by abnormal accumulation of tau protein. The research, published by Cell Press in the December 22 issue of the journal Neuron, reveals how tau disrupts neuronal communication at synapses and may help to guide development of therapeutic strategies that precede irreversible neuronal degeneration. Tau normally contributes to the supportive framework of proteins in the cell. It is well established that abnormal tau sometimes clumps into neuron-damaging filamentous deposits ...

Washington, DC – Researchers at the Georgetown Lombardi Comprehensive Cancer Center, a part of Georgetown University Medical Center, have found that an arsenic-based agent already FDA-approved for a type of leukemia may be helpful in another hard-to-treat cancer, Ewing's Sarcoma (ES). The research, based on animal studies, also suggests the drug might be beneficial in treating medulloblastoma, a highly malignant pediatric brain cancer. In the December 22 issue of the Journal of Clinical Investigation, the investigators describe how years of research has uncovered a common ...

STANFORD, Calif. — Researchers at the Stanford University School of Medicine have discovered that many cancer cells carry the seeds of their own destruction — a protein on the cell surface that signals circulating immune cells to engulf and digest them. On cancer cells, this "eat me" signal is counteracted by a separate "don't eat me" signal that was described in an earlier study. The two discoveries may lead to better cancer therapies, and also solve a mystery about why a previously reported cancer therapy is not more toxic. In the study to be published Dec. 22 in Science ...

Sex in mammals is genetically determined. In humans, females have two X chromosomes, while males have one X and one Y chromosome. However, some individuals are born with male genitalia despite having two X chromosomes, a condition known as XX male sex reversal. A team of researchers, led by Paul Thomas, University of Adelaide, Australia, has now determined that overexpression of the Sox3 gene in mice causes frequent XX male sex reversal. The clinical relevance of this was highlighted by the discovery of genomic rearrangements in the regulatory region of the human SOX3 gene ...

The timing of the onset of puberty is linked to levels of nutrition: later onset is associated with malnutrition, while earlier onset is linked to childhood obesity. A team of researchers, led by Carol Elias, at the University of Texas Southwestern Medical Center, Dallas, has now generated data in mice that run counter to current thinking about the molecular pathway by which nutrition status affects the onset of puberty. Further, the team defines a new regulatory pathway for the process, which, if confirmed in humans, could potentially lead to new approaches to treating ...

Arsenic is usually thought of as a poison. Despite this, it has been used in medicine for over 2000 years, and the arsenic compound arsenic trioxide (ATO) is FDA approved for the treatment of acute promyelocytic leukemia. Now, a team of researchers, led by Aykut Üren, at Georgetown University Medical Center, Washington, has generated data using human cancer cell lines that suggest that ATO might also be of benefit to individuals with certain brain tumors or connective tissue tumors. Certain cancers, in particular brain tumors known as medulloblastomas and connective tissue ...

A multinational research team led by scientists at the National Institutes of Health has found that a genetic variant of a brain receptor molecule may contribute to violently impulsive behavior when people who carry it are under the influence of alcohol. A report of the findings, which include human genetic analyses and gene knockout studies in animals, appears in the Dec. 23 issue of Nature. "Impulsivity, or action without foresight, is a factor in many pathological behaviors including suicide, aggression, and addiction," explains senior author David Goldman, M.D., ...

CAMBRIDGE, Mass.—Researchers at MIT's Picower Institute for Learning and Memory report for the first time how animals' knowledge obtained through past experiences can subconsciously influence their behavior in new situations. The work, which sheds light on how our past experiences inform our future choices, will be reported on Dec. 22 in an advance online publication of Nature. Previous work has shown that when a mouse explores a new space, neurons in its hippocampus, the center of learning and memory, fire sequentially like gunpowder igniting a makeshift fuse. Individual ...

CAMBRIDGE, Mass. (December 22, 2010) – Whitehead Institute researchers have linked hyperactivity in the mechanistic target of rapamycin complex 1 (mTORC1) cellular pathway, to reduced ketone production, which is a well-defined physiological trait of aging in mice. Their results are reported in the December 23 edition of the journal Nature. "This is the first paper that genetically shows that the mTORC1 pathway in mammals affects an aging phenotype," says Whitehead Institute Member David Sabatini. "It provides us with a molecular framework to study an aging-related process ...

SANTA CRUZ, CA--A 30,000-year-old finger bone found in a cave in southern Siberia came from a young girl who was neither an early modern human nor a Neanderthal, but belonged to a previously unknown group of human relatives who may have lived throughout much of Asia during the late Pleistocene epoch. Although the fossil evidence consists of just a bone fragment and one tooth, DNA extracted from the bone has yielded a draft genome sequence, enabling scientists to reach some startling conclusions about this extinct branch of the human family tree, called "Denisovans" after ...

EDITOR'S PICK: What sex are you? Sex in mammals is genetically determined. In humans, females have two X chromosomes, while males have one X and one Y chromosome. However, some individuals are born with male genitalia despite having two X chromosomes, a condition known as XX male sex reversal. A team of researchers, led by Paul Thomas, University of Adelaide, Australia, has now determined that overexpression of the Sox3 gene in mice causes frequent XX male sex reversal. The clinical relevance of this was highlighted by the discovery of genomic rearrangements in the regulatory ...

BOSTON (December 22, 2010) -- Is quality in the eye of the beholder? Researchers at Harvard Medical School and Massachusetts General Hospital have found wide disparities among four common measures of hospital-wide mortality rates, with competing methods yielding both higher- and lower-than-expected rates for the same Massachusetts hospitals during the same year. The findings, published Dec. 23 in a special article in the New England Journal of Medicine, stoke a simmering debate over the value of hospital-wide mortality rates as a yardstick for health care quality. ...

BOSTON, Mass. (December 22, 2010) — The sequencing of the nuclear genome from an ancient finger bone found in a Siberian cave shows that the cave dwellers were neither Neandertals nor modern humans. An international team of researchers led by Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig (Germany) has sequenced the nuclear genome from a finger bone of an extinct hominin that is at least 30,000 years old and was excavated by archaeologists from the Russian Academy of Sciences in Denisova Cave in southern Siberia, Russia, in 2008. A ...

For most of us, the "placebo effect" is synonymous with the power of positive thinking; it works because you believe you're taking a real drug. But a new study rattles this assumption. Researchers at Harvard Medical School's Osher Research Center and Beth Israel Deaconess Medical Center (BIDMC) have found that placebos work even when administered without the seemingly requisite deception. The study published on December 22 in PLoS ONE. Placebos—or dummy pills—are typically used in clinical trials as controls for potential new medications. Even though they contain ...

Specially designed probiotics can modulate the physiology of host fat cells say scientists writing in Microbiology. The findings could lead to specialised probiotics that have a role in the prevention or treatment of conditions such as obesity. Scientists from the Alimentary Pharmabiotic Centre (APC), Cork, University College Cork and Teagasc, in Ireland engineered a strain of Lactobacillus to produce a version of a molecule called conjugated linoleic acid (CLA). When this engineered bacterial strain was fed to mice, the researchers found that the composition of the mice's ...

Scientists today published catalogs of the fruit fly and roundworm's functional genomic elements: DNA sequences in the genome that carry the instructions and determine which genes are turned on and off at various times in different cells. Initially sequenced as part of the Human Genome Project, the genomes of the fruit fly, Drosophila melanogaster, and the roundworm, Caenorhabditis elegans, are powerful models for understanding human biology and disease, as many functional genomic elements have been conserved across the vast evolutionary distances separating each organism. ...

Penn State researchers have found that native pollinators, like wild bees and wasps, are infected by the same viral diseases as honey bees and that these viruses are transmitted via pollen. Their research published on December 22nd in PLoS ONE, an online open-access journal for the communication of all peer-reviewed scientific and medical research. This multi-institutional study provides new insights into viral infections in native pollinators, suggesting that viral diseases may be key factors impacting pollinator populations. According to Diana Cox-Foster, co-author ...

In the past decade researchers have made astonishing progress in the rapid and accurate sequencing of genomes from all realms of life. Yet the listing of chemical base pairs has gotten far ahead of understanding how the information they contain becomes functional. Even the best-understood genomes conceal mysteries. Genetic information carried by DNA and RNA operates together with the patterns and physical organization of chromosomes to produce a working organism. Major advances in understanding these complex relationships are published this week by the "model organism ...

DALLAS – Dec. 22, 2010 – UT Southwestern Medical Center researchers have pinpointed a tiny site in the brain where the hormone leptin may help trigger the onset of puberty. The findings in mice indicate that a site within the hypothalamus called the ventral premammillary nucleus, or PMV, is the target where the hormone leptin effectively kick starts puberty in females. Researchers have known that puberty starts when individuals have enough energy stores or fat to meet the demands of reproduction, and that leptin – a hormone produced by fat cells – acts in the brain ...

Australian scientists have discovered that changes to a gene involved in brain development can lead to testis formation and male genitalia in an otherwise female embryo. Lead Melbourne researcher Professor Andrew Sinclair, of the Murdoch Childrens Research Institute and the University of Melbourne, said the breakthrough would improve diagnosis and clinical management of patients with disorders of sex development (DSD). These conditions occur when the testes or ovaries do not develop properly in the embryo, causing genital abnormalities in one in 4500 babies. The gene, ...

University of Adelaide researchers are a step closer to unraveling the mysteries of human sexual development, following genetic studies that show male mice can be created without a Y chromosome – through the activation of an ancient brain gene. Males usually have one Y chromosome and one X chromosome, while females have two X chromosomes. A single gene on the Y, called SRY, triggers testes development in the early embryo, and once these begin to form, the rest of the embryo also becomes male. However, Adelaide researchers have discovered a way of creating a male mouse ...

Shouldering family demands and worries seems to increase the risk of angina, the precursor to coronary artery disease, reveals research published online in the Journal of Epidemiology and Community Health. Previous research has indicated that rewarding personal relationships are a boost for heart health, so the authors wanted to know if the reverse might also be true. They tracked the heart health of more than 4,500 randomly selected men and women in their 40s and 50s for six years. None had any heart problems at the start of the study in 1999. In 2006 all participants ...

Complementary medicines (CAM) can be dangerous for children and can even prove fatal, if substituted for conventional medicine, indicates an audit of kids' CAM treatment published online in the Archives of Disease in Childhood. But parents often misguidedly think CAM treatments are better for their children because they are "natural" and therefore less likely to have harmful side effects, say the authors. They base their findings on monthly reporting of adverse events associated with CAM to the Australian Paediatric Surveillance Unit between 2001 and 2003. During ...

Teen girls living in the most deprived areas are five times as likely to be assaulted as their affluent male and female peers, reveals research published online in Emergency Medicine Journal. Young men are twice as likely to be a victim of assault as young women, but the link between deprivation and assault is far stronger for their female peers, the study shows. Violence is the third leading cause of death among 15 to 19 year olds and the 14th leading cause of death among 10 to 14 year olds worldwide. In 2007, around 66,000 children and teens in England and Wales were ...

Running and swimming records are broken again and again at almost every international athletics event. But, can human performance continue to improve indefinitely? Will runners continue to accelerate off the starting blocks and reach the finish line in faster and faster times? Will swimmers always be able to dive into the record books with a quicker kick? Writing in the International Journal of Applied Management Science, researchers from South Korea have analyzed data from sports events over the last one hundred years and have calculated that we could reach the upper ...