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Updated 2:00 PM January 13, 2004
 

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Research notes


Scientists discover how anthrax creates its deadly spores

In the age-old battle between man and microbe, it pays to know your enemy. This is especially true for Bacillus anthracis, the bacterium that causes anthrax. Tiny spores of this highly infectious pathogen can survive drought, bitter cold and other harsh conditions for decades, yet still germinate almost instantly to infect and kill once inside an animal or human host.

In a collaboration funded by the U.S. Office of Naval Research and the National Institutes of Health, scientists from U-M, The Institute for Genomic Research and The Scripps Research Institute are working together to identify the genes and proteins involved in anthrax's deadly metamorphosis.

The first results of the collaboration's work were published as the cover story in the Jan. 1 issue of the Journal of Bacteriology. Major findings include: when compared to other bacteria, anthrax spore formation is an unusually complex and intricate process; up to one-third of all the genes in the Bacillus anthracis genome are involved in spore production; genes are expressed in five discrete phases over a five-hour time period; each mature anthrax spore contains about 750 individual proteins.

Philip Hanna, assistant professor of microbiology and immunology in the Medical School, is the paper's corresponding author. Nicholas Bergman, a research investigator in the U-M Bioinformatics Program, is a primary author. U-M research associate Joseph Crossno collaborated on the study.

To read the full story, visit http://www.med.umich.edu/opm/newspage/2003/anthraxspores.htm.

Museum collections and satellite images aid conservation efforts

As tropical forests and other ecologically sensitive areas throughout the world rapidly disappear, conservationists often find themselves scrambling to identify and protect a critical habitat before it is destroyed.

A male Parson’s chameleon (Calumma parsonii) from Madagascar. This is one of 11 chameleons for which museum specimens and satellite data were used to predict species distributions. (Photo by Christopher Raxworthy)

But knowing where to focus their efforts isn't easy, and sometimes decisions must be made before detailed surveys of an area's plants and animals can be completed. Using museum collection data and satellite images, a team has developed a way of predicting where particular species are most likely to be found—information that can help ensure that conservation efforts have the greatest payoff. The researchers describe their approach and a test of the method—involving reptile species in Madagascar—in the Dec. 18 issue of the journal Nature.

In the test, the researchers were able to predict with 75 to 85 percent success where 11 species of chameleons would be found in Madagascar. The method also pinpointed three areas where subsequent surveys uncovered at least seven previously undescribed species.

"That information is significant not just because of chameleons in Madagascar, but because the method can be used for any species, anywhere in the world—in the Amazon, for instance, where there are even fewer people doing surveys relative to the amount of forest that's there and the rate at which it's disappearing," says Ronald Nussbaum, professor of ecology and evolutionary biology and a curator at the U-M Museum of Zoology. "This is a way to get ahead of the problem of disappearing rainforests."

Nussbaum collaborated on the project with Greg Schneider, coordinator of the museum's reptile and amphibian collection; Christopher Raxworthy of the American Museum of Natural History and a research associate of the U-M Museum of Zoology; and others outside the University. The research was supported by NASA, the American Museum of Natural History, Conservation International, Earthwatch, the National Geographic Society, the National Science Foundation and the World Wide Fund for Nature.

Doctors more likely to prescribe pricey new blood pressure drugs despite standards

Even though research has shown inexpensive treatments for high blood pressure are just as effective as pricey new drugs, doctors perceive the new drugs as more effective and think they carry fewer side effects, according to a study by a U-M Health System (UMHS) physician.

Diuretics and beta-blockers are recommended by the Joint National Commission on High Blood Pressure Treatment as the first-line treatment for uncomplicated high blood pressure. But in the survey of 1,700 primary care doctors, diuretics were rated less effective at lowering blood pressure and beta-blockers were thought to have more side effects than the newer calcium channel blockers and ACE inhibitors.

Further, doctors who favored prescribing the more expensive drugs were more likely to give patients free drug samples from pharmaceutical representatives.

"These new, more expensive medications are being more heavily promoted by the drug companies, and one way or another that information influences how people perceive the drug's effectiveness," says study author Dr. Peter Ubel, associate professor of internal medicine at the Medical School and director of UMHS's Program for Improving Health Care Decisions.

The study was published in the December issue of the Journal of General Internal Medicine. Ubel is supported by a Presidential Early Career Award for Scientists and Engineers. This study also was supported by the Matthew Slap Foundation and the National Cancer Institute.

Quitting smoking reduces medical costs, but chronic conditions slow effects

Smoking costs employers billions of dollars in lost productivity and medical expenses.

But if employees quit smoking, how long do the cost savings take? Nearly twice as long for former smokers with arthritis, allergies or back pain than for those without these chronic conditions, according to the U-M Health Management Research Center (HMRC).

"It took about five years for former smokers without chronic conditions and nearly 10 years for former smokers with chronic conditions to reduce their medical charges to levels close to those of never-smokers," HMRC senior research analyst Shirley Musich reported in the November/December American Journal of Health Promotion.

The study looked at 20,332 General Motors Corp. employees and spouses who completed a Health Risk Appraisal in 1996. People who had never smoked and had no chronic conditions had the lowest medical costs—about $2,200. Smokers without chronic conditions averaged $2,600. Among those with chronic conditions, current and former smokers cost in the $4,000 range, about $1,000 higher than those with chronic conditions who never had smoked.

Musich's study is the first to address the time frame for the decrease in medical utilization or costs among those with chronic diseases, says HMRC Director Dee Edington.

Men do not cause yeast infections in women

Women may blame their husbands or boyfriends for headaches, tears and stress. But they can't be blamed for those nasty, recurrent yeast infections, contrary to popular belief.

A study by U-M Health System (UMHS) researchers finds that the presence of yeast in male sex partners does not make women more prone to recurrent yeast infections. Certain sexual activities, however, were linked to increased risk of recurrent yeast infections in women, according to the study.

"Many physicians, and many women, believe that women get recurrent yeast infections because their partner passes the yeast back to them during intercourse. This study refutes that belief," says study author Dr. Barbara Reed, professor of Family Medicine at the Medical School. "This study suggests the risk for recurrent infections is related to something else—perhaps the woman's immune response to the yeast."

Candida vulvovaginitis, or yeast infection, is one of the most common diagnoses in American women. About three-quarters of women will have at least one yeast infection in their lives, and 40 percent have recurrent infections.

The study was published in the December Journal of Women's Health. The study received funding from the National Institute of Allergy and Infectious Diseases. In addition to Reed, study authors from U-M include Dr. Philip Zazove and Daniel Gorenflo from the Department of Family Medicine and Carl Pierson from the Department of Pathology.

Exploring the origins of high velocity clouds in spiral galaxies

U-M astronomers have found evidence for clouds of high-speed gases around galaxies that may help scientists understand the mysteries of similar material in our own Milky Way galaxy.

The spiral galaxy M 83 as seen at radio wavelengths. (Image courtesy U-M and National Radio Astronomy Observatory)

Postdoctoral fellow Eric Miller and astronomy professor Joel Bregman presented their results Jan. 8 at the 203rd meeting of the American Astronomical Society in Atlanta, where they described their studies of the faint radio and optical signals from two nearby galaxies.

The Milky Way galaxy has a disk of stars and gas that rotates in an orderly fashion, but the galaxy also contains clouds of neutral gas that are not part of this motion.

"These high-velocity clouds have been a mystery for some time, mainly because we do not know their distance, which is necessary to determine their mass," Miller says. Both mass and distance provide clues to the clouds' origins. Observing clouds of this type in another galaxy solves the distance problem because the clouds are at nearly the same distance as the galaxy being observed.

The astronomers' observations of the Whirlpool galaxy in the constellation Canes Venatici (the Hunting Dogs) help explain the origin of high velocity clouds in the Milky Way. "If the Whirlpool galaxy has the same amount of high velocity gas as the Milky Way—and there is evidence that this is the case—then we can use that information to solve for the distance of the high velocity clouds in the Milky Way galaxy," Miller says. "When we do that, the distance we obtain places the clouds in the halo of the Milky Way," suggesting that the clouds formed from the galaxy, possibly when another galaxy passed nearby, pulling off outer parts from each galaxy and creating long streamers of gas.

Employers can predict workers' medical costs based on wellness scores

In the 1990s, the U-M Health Management Research Center (HMRC) developed a wellness score as a way of measuring individuals' overall health and providing them incentives to make or maintain positive lifestyle changes.

HMRC senior research analyst Louis Yen, who helped develop the system, now has confirmed a link between the wellness scores for a large employee population and medical claims costs for the employer. His findings were reported in the October issue of the Journal of Occupational and Environmental Medicine.

Wellness scores, ranging from 50 to 100, are calculated from information that individuals report on the HMRC's Health Risk Appraisal (HRA) questionnaire. The appraisal measures personal health status based on health behaviors, disease status and preventive services usage.

The study involved 19,861 active employees of General Motors Corp. who completed an HRA during 1996-97 and enrolled in indemnity or preferred provider organizations medical plans for the period of 1996-98.

Although HMRC researchers have extensively documented the validity of the HRA's wellness score in terms of future disease, this is the first study to show its direct association with medical claims costs.

No higher risk of colorectal cancer with BRCA mutations

People with mutations in BRCA genes or a family history of breast cancer now have one less thing to worry about. Although their chances of developing breast or ovarian cancer are high, new research shows their colorectal cancer risk is about the same as that of the general population.

"People carrying BRCA1 or BRCA2 mutations already have their plates full managing a high risk of breast and ovarian cancer," says Dr. Stephen Gruber, a cancer geneticist in the Comprehensive Cancer Center, assistant professor of internal medicine and human genetics in the Medical School, and assistant professor of epidemiology in the School of Public Health. "The good news in our study is that they don't have to deal with an increased risk of colorectal cancer, as well."

Results of the study were published in the Jan. 7 issue of the Journal of the National Cancer Institute. Bethany Niell, a student in the Medical School's M.D./Ph.D. program, was the paper's first author. Co-authors from the Medical School were Joseph Bonner and Lynn Tomsho. The research was funded by the National Institutes of Health.

To read the whole story, visit http://www.med.umich.edu/opm/newspage/2004/brca.htm

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