Crohn’s disease is a chronic relapsing inflammatory disorder of the intestinal tract that affects an estimated 0.15% of people in the developed world. Common symptoms include abdominal pain and diarrhea, but the disorder is often associated with debilitating clinical complications. Researchers from the University of Liège, Belgium, have now uncovered an important clue to the susceptibility of individuals to this disease.

Scientists have discovered one of the reasons why bladder cancer is so much more prevalent in men than women: A molecular receptor or protein that is much more active in men than women plays a role in the development of the disease. The finding could open the door to new types of treatment with the disease.

In an article in the April 4 issue of the Journal of the National Cancer Institute, Chawnshang Chang, Ph.D., of the University of Rochester Medical Center and colleagues show that the androgen receptor, which is central to the action of testosterone and other hormones that are much more plentiful in men than women, appears to play a key role in the disease.

Serotonin is a major signaling chemical in the brain, and it has long been thought to be involved in aggressive behavior in a wide variety of animals as well as in humans. Another brain chemical signal, neuropeptide Y (known as neuropeptide F in invertebrates), is also known to affect an array of behaviors in many species, including territoriality in mice. A new study by Drs. Herman Dierick and Ralph Greenspan of The Neurosciences Institute in San Diego shows that these two chemicals also regulate aggression in the fruit fly, Drosophila melanogaster.

A new study says targeting smaller (¡Ü5 mm) lesions does little to significantly reduce the incidence of colorectal cancer (CRC) and, in fact, results in extremely high financial costs and a large proportion of adverse events. Published in the June 1, 2007 issue of CANCER, a peer-reviewed journal of the American Cancer Society, a cost-benefit analysis study says the low malignancy rate among so-called diminutive polyps gives virtual colonoscopy with removal of lesions 6 mm or greater the best estimated value per life year gained and with fewer complications.

Mayo Clinic researchers, along with collaborators from the National Institutes of Health (NIH) and University of Oslo, Norway, have discovered that a miscue of the body’s genetic repair system may cause Huntington’s disease, a fatal condition that affects 30,000 Americans annually by destroying their nervous system. Until now, no one knew how Huntington’s begins, only that it is incurable. The findings appear in the online issue of the journal Nature.

The most recent census of mountain gorillas in Uganda’s Bwindi Impenetrable National Park—one of only two places in the world where the rare gorillas exist—has found that the population has increased by 6 percent since the last census in 2002, according to the Uganda Wildlife Authority, the Wildlife Conservation Society, the Max Planck Institute of Anthropology and other groups that participated in the effort.