A sampling of studies being coordinated at Georgetown's Center for Sex Differences

* John Richert, chairman of Georgetown's department of microbiology and immunology, is investigating the sex differences in multiple sclerosis by working with pairs of identical twins in which one twin has MS and one twin does not. Thus far, Richert has identified candidate genes that are defective in MS. He hopes that elucidating the role of these genes in MS will provide insight into the cause of the disease and lead to drug development for both sexes.

* Mary Ann Dutton, professor in the university's department of psychiatry, is studying sex differences in the development of depression with post-traumatic stress disorder (PTSD). Dutton is seeking a $1.18 million Department of Defense grant (to study soldiers) as well as a $1 million NIH grant. Her research involves imaging the brains of women and men with PTSD.

* Along with Menachem Miodovnik at the Washington Hospital Center and collaborators from Georgetown and George Washington University, Jason Umans, associate professor of medicine in Georgetown's division of nephrology and hypertension, has landed an NIH grant to start the Washington Obstetrical Pharmacology Unit. One of only four of its kind, the unit will focus on the effects of drugs and drug metabolism in pregnant women. The goal: to determine whether the general rules used for drug administration in people who aren't pregnant may need to be modified for those who are.

* Research in rats has shown that high blood pressure and certain types of kidney failure are much more acute with more rapid progression in males. Females, on the other hand, show no damage under similar conditions. Research at Georgetown has determined that testosterone may be the culprit, since testosterone allows growth hormone to circulate and worsen kidney damage, said Susan Mulroney, associate professor in Georgetown's department of physiology and biophysics. When testosterone is given to female rats, they show the same kidney damage as males. The work will probe one of the great issues in gender science: Is estrogen really protective in some ways -- and might it be responsible for the greater lifespan of females?

* Darren Roesch, assistant professor in Georgetown's division of endocrinology and metabolism, is studying the role of estrogen in postmenopausal weight gain. The hope is that the research will help determine the feasibility of using drugs called selective estrogen receptor modulators, or SERMs, to prevent women from gaining weight after menopause.

-- Suz Redfearn