Inner ear of chicken yields clues to human deafness and balance disorders

Scientists at Washington University School of Medicine in St. Louis have gained new insights into the causes of human deafness and balance disorders by studying the inner ear of chickens. The research provides new clues as to why birds can replace critical cells in the inner ear and humans cannot. Loss of these so-called sensory hair cells in humans is a leading cause of deafness and impaired balance due to aging, infectious disease and exposure to loud noise. The study will be published in the June 1 issue of the journal Human Molecular Genetics and appears online today.

Rapid increase of opioids benefits some dying pediatric cancer patients

Researchers at Washington University School of Medicine in St. Louis have found that terminally ill children with cancer who have neuropathic pain require more opioids during the final days of life than those without neuropathic pain. In addition, the team found preliminary evidence that a “cocktail” of several narcotics was significantly more effective at treating these patients than dramatically increasing the dosage of two commonly used opioids — morphine and benzodiazepine.

Genome of a major member of gut bacteria sequenced

Researchers have completed sequencing the genome of Bacteroides thetaiotaomicron, one of the most prevalent bacteria that live in the human intestine. “Now that the draft sequence of the human genome is complete, it’s critical that we study the environmental forces that regulate our gene expression,” says principal investigator Jeffrey I. Gordon. “Humans enjoy mutually beneficial relationships with billions of bacteria that live in our gut. Discovering how these microbes manipulate our biology to benefit themselves and us should provide new insights about the foundations of our health and new therapeutic strategies for preventing or treating various diseases.”

Researchers discover gene that contributes to sense of balance

Researchers have discovered a gene that appears to be critical for maintaining a healthy sense of balance in mice. The study, led by a team at Washington University School of Medicine in St. Louis, appears in the April 1 issue of the journal Human Molecular Genetics and online March 24. “Loss of balance is a significant problem in the elderly because it can lead to dangerous falls and injuries,” says one of the study’s principal investigators, David M. Ornitz, M.D., Ph.D., professor of molecular biology and pharmacology at the School of Medicine. “Loss of balance also is a problem for astronauts following exposure to zero gravity. Now that we’ve discovered this new gene, we can begin to understand the mechanisms that allow the body to sense gravity and maintain balance.”

Novel molecule may contribute to intestinal health

New data suggests that a novel molecule appears to be involved in the intestine’s response to infection. The study was a collaboration between researchers at Washington University School of Medicine in St. Louis and the Institut Curie in Paris. “This is the first identified function for this molecule,” says co-senior author Susan Gilfillan, Ph.D., research instructor in pathology and immunology at the School of Medicine. “Our findings suggest that this molecule may play a fundamental role in gut immunology.”

New mouse virus may help scientists better understand cruise ship epidemics

A close relative of a common little-understood human virus that causes an estimated 23 million episodes of intestinal illness, 50,000 hospitalizations and 300 deaths each year has been discovered in mice. The finding by scientists at Washington University School of Medicine in St. Louis is reported in the March 7 issue of the journal Science. Discovery of the new virus, known as murine norovirus 1 (MNV-1), may lead to a better understanding of its disease-causing cousins known as Norwalk viruses, or human noroviruses (HNVs). HNVs cause 90 percent of epidemic viral gastroenteritis worldwide, including those that sweep through cruise ships, nursing homes and military encampments causing debilitating diarrhea and vomiting.

Researchers Discover Possible New Mechanism for High Blood Pressure

Genetic differences that prevent tiny blood vessels from relaxing may be one reason why some people have high blood pressure, or hypertension, according to research led by scientists at Washington University School of Medicine in St. Louis. The findings are published in the February issue of the Journal of Clinical Investigation. “These findings provide new insights into the cause of hypertension and how normal blood pressure is regulated,” says lead investigator Kendall J. Blumer, Ph.D., professor of cell biology and physiology. “This may lead to a way of determining the underlying cause of a person’s hypertension and the most effective treatment for that individual.”

Pediatric Anesthesia Causes Brain Damage in Infant Rats

A team of researchers has found that drugs commonly used to anesthetize children can cause brain damage and long-term learning and memory disturbances in infant rats. The researchers report their findings in the Feb. 1 issue of the Journal of Neuroscience. “We frequently perform surgical procedures on children, including premature infants, and those procedures have become increasingly more complex and take longer to perform,” says the study’s lead author Vesna Jevtovic-Todorovic, M.D., associate professor of anesthesiology at the University of Virginia Health System. “That means many pediatric patients are being exposed to anesthetic drugs more frequently and for longer periods of time. Our results would suggest that might be problematic.”

Search and Destroy: Newly Identified Gut Protein Kills Bacteria

Researchers have discovered a new antibiotic protein that appears to kill certain types of bacteria in the intestine. Their results are published Jan. 27 in the online version of the journal Nature Immunology and are slated for print publication in March. “These findings were completely unexpected,” said the study’s lead scientist. “We initially thought that this protein might be involved in blood vessel formation. What we discovered, though, is that it’s a potent killer of bacteria.”

Scientists Discover How to Grow Cells That Suppress Immune Responses

Researchers have discovered how to grow a little-understood type of human immune cell. The cells, known as T-regulatory cells type 1 (Tr1), are thought to turn off unnecessary immune reactions and to block the action of immune cells that otherwise would attack the body and cause dangerous inflammation. The findings are reported in the Jan. 23 issue of the journal Nature.