Researchers catch stem cells in the act of morphing

Researchers at Stanford University have tracked the path of bone marrow stem cells as they transform into an adult tissue. This work, published in the Nov. 15 issue of the journal Cell, marks the first time scientists have seen the individual steps of the progress. In previous work, researchers have seen injected bone marrow cells integrate into the muscles, livers and brains of mice. But until now, they have not witnessed the sequence of events that leads to this transformation. In their Cell paper, the researchers describe how they saw transplanted bone marrow cells first locate to the muscle as a muscle-specific stem cell called a satellite cell. These former bone marrow cells lurked in the muscle until exercise-induced muscle damage signaled them to help repair the injury by fusing with existing muscle cells.

Defeating ‘clingy’ bacteria could help treat urinary tract infections

Clingy bacteria often spell trouble. Scientists have discovered how bacteria manufacture hair-like fibers used to cling to the lining of the kidney and bladder where they cause urinary tract infections (UTIs). The results are published in the Nov. 15 issue of the journal Cell. “Our findings should lead to new drugs to treat UTIs by blocking the formation of these protein fibers,” says study leader Scott J. Hultgren, Ph.D., the Helen Lehbrink Stoever Professor of Molecular Microbiology. “They also should improve our general understanding of how disease-causing bacteria build, fold and secrete proteins that enable them to cause disease.”

Heads to roll as gov’t fights fire ants with decapitating flies

Heads will roll as a U.S. Department of Agriculture plan to control imported fire ants is put into practice this month in Florida. The plan introduces tiny South American phorid flies to the United States to control the pesky ants, whose spread has been unaffected by poisons and other measures. Phorid flies use the decapitated heads of imported fire ants to reproduce. “This is the only way we’re ever going to see a reduction in the number of fire ants in North America,” said one official associated with the plan.

Scientists show how Kaposi’s sarcoma virus causes cancer cells to grow

Scientists have shown for the first time how the virus that causes Kaposi’s sarcoma inhibits the body’s immune response and causes cancer cells to grow through a technique called immune evasion. Kaposi’s sarcoma-associated herpesvirus, or KSHV,causes Kaposi’s sarcoma, a cancer of the blood vessel cells that often occurs in tissues under the skin or mucous membranes, and is the most common malignancy occurring among AIDS patients. KSHV belongs to the family of herpesviruses that includes the causes of genital herpes, cold sores and chickenpox. The same researchers who previously discovered KSHV examined the expression of a virus-derived cytokine (a hormone-like substance that regulates cells during an immune response) in KSHV and found it not only inhibits immune function, but also causes cancerous cells to grow

Infant stroke severely under-recognized, researcher says

A neurologist at the University of California at San Francisco says stroke in neonates and children is severely under-recognized, with about 1 case per 4,000 live births. About 6 percent of those children will die, 20 to 35 percent will go on to have another stroke, and more than two-thirds of survivors will have neurological deficits or seizures.

Climate Change Linked to Population Shifts Among Mammals

Scientists have shown, for the first time, that changes in a large-scale climate system can synchronize population fluctuations in multiple mammal species across a continent-scale region. The study, to be published in the 14 November 2002 issue of the journal Nature, compares long-term data on the climate system known as the North Atlantic Oscillation with long-term data from Greenland on the population dynamics of caribou and muskoxen, which are large mammals adapted to breeding in the Arctic.

Causes of Life-Expectancy Gap Between Races, Education Levels ID’d

Researchers for the first time have identified and ranked which diseases contribute most to the life-expectancy gap between races and between education levels. The top four contributors to the life-expectancy disparity between blacks and whites are hypertension, HIV, homicide and diabetes. The top six contributors of mortality differences between education levels are all smoking-related diseases.

Dietary vitamin E associated with sharply lower risk of Parkinson’s

Previous research has implicated oxidative damage (cell degradation) in the development of Parkinson’s disease. Because vitamins E, C and carotenoids are antioxidants, researchers recently studied the associations between their intake and risk of Parkinson’s disease. Their conclusions point not to supplements, but to dietary intake of vitamin E (from the foods we eat) as having a protective factor in the risk of developing Parkinson’s disease. The study is reported in the October 22 issue of Neurology, the scientific journal of the American Academy of Neurology.

One in Three Children Regularly Exposed to Tobacco Smoke at Home

Second-hand tobacco smoke threatens the health of 21 million American children ? 35 percent of everyone age 17 and younger ? who live in homes where residents or visitors smoke once a week or more, according to a study published Nov. 13 by researchers from RAND and UCLA. The study is the most thorough ever conducted of youths’ exposure to environmental second-hand tobacco smoke at home. It found that 19 million American children ? 28 percent of everyone in the United States 17 and younger ? are exposed to tobacco smoke at home on a daily basis.

Scientists Eavesdrop on Cellular Conversations by Making Mice ‘Glow’

Scientists have coupled the protein that makes fireflies glow with a device similar to a home video camera to eavesdrop on cellular conversations in living mice. The team’s research will allow scientists to study how cellular proteins talk to one another. These communications trigger changes that regulate a healthy body and cause disease when the signals go awry. The findings may speed development of new drugs for cancer, cardiovascular diseases and neurological diseases.

Exceptionally Bright Eruption on Io Rivals Largest in Solar System

Routine monitoring of volcanic activity on Jupiter’s moon Io has turned up the largest eruption to date on Io’s surface or in the solar system. The eruption took place in February 2001, though image analysis was only recently completed by a team of University of California, Berkeley, astronomers. Their results are published in the November issue of the planetary sciences journal Icarus. “The Surt eruption appears to cover an area of 1,900 square kilometers, which is larger than the city of Los Angeles and even larger than the entire city of London,” said the lead researcher. “The total amount of energy being released by the eruption is amazingly high, with the thermal output from this one eruption almost matching the total amount of energy emitted by all of the rest of Io, other volcanoes included.”

New HIV Vaccine Aims for Global Effectiveness

Clinical tests began today of a novel vaccine directed at the three most globally important HIV subtypes, or clades. Developed by scientists at the Dale and Betty Bumpers Vaccine Research Center, part of the National Institute of Allergy and Infectious Diseases, the vaccine incorporates HIV genetic material from clades A, B and C, which cause about 90 percent of all HIV infections around the world. “This is the first multigene, multiclade HIV vaccine to enter human trials,” said NIAID Director Anthony S. Fauci, M.D. “It marks an important milestone in our search for a single vaccine that targets U.S. subtypes of HIV as well as clades causing the global epidemic.”