Newsbriefs Medical News -------------------------- Mutation linked to non- inherited colon cancer -------------------------- Building on research conducted by scientists in the United States and Italy, investigators at the Howard Hughes Medical Institute at the Johns Hopkins Oncology Center have linked a new genetic mutation to non-inherited colon cancer. In findings reported in the June 30 issue of Science, scientists from the Istituto di Ricerche di Biologia Molecolare in Rome and the Howard Hughes Medical Institute at Duke University independently identified a mismatch repair gene known as GTBP. The GTBP gene is the fifth human mismatch repair gene identified by scientists including Bert Vogelstein, Clayton Professor of Oncology at Hopkins. While mutations of the previously identified genes were linked to an inherited form of colon cancer known as hereditary non-polyposis colon cancer, Vogelstein's team found that alterations of the GTBP gene were involved only in non-inherited, or sporadic, colon cancers, which account for the majority of colon cancers worldwide. Mismatch repair genes like GTBP act as proofreaders, looking for mistakes in the DNA copying process and correcting them. DNA is assembled like a ladder, with chemical compounds called nucleic acid bases pairing to form rungs on the ladder. The four bases that are the molecular building blocks of DNA are symbolized by the letters A, T, C, and G. A always pairs with T, and C always pairs with G. Sometimes, however, mistakes in the copying process occur, and the bases become mismatched. It is the job of proteins produced by the mismatch repair genes to correct the mistakes before the error is passed on to the next generation of cells. Mutations in mismatch repair genes allow errors to go unchecked, resulting in the inability to copy DNA correctly and causing an accumulation of cellular errors that ultimately lead to cancer. Over 500,000 individuals are diagnosed worldwide with colon cancer each year. When diagnosed early, cure rates are high, but when the disease spreads outside the colon, survival rates decrease dramatically. The researchers believe this newly identified mutation also may have future implications as a diagnostic marker for the early detection and treatment of colon cancers and potentially other cancers. ----------------------------- Forgoing care for AIDS-related disease costly ----------------------------- The failure of many people infected with HIV-1 to get preventive treatment for an AIDS-related pneumonia is needlessly costing lives and increasing medical costs, according to a study at The Johns Hopkins Medical Institutions. These individuals get a disease called Pneumocystis carinii pneumonia because they either never get treatment for it or fail to take medicine prescribed by their doctors, said the study's authors in a report published in the April issue of Chest. The authors said that if their findings apply to other hospitals in Maryland, the failure of HIV-infected individuals to get preventive treatment for PCP may have cost the state almost $5 million in 1992. News from Homewood ------------------- Getting ice cream for donating blood ------------------- Employees who register to donate blood in the university's summer blood drive--scheduled from 9 a.m. to 3 p.m. on Wednesday, July 12, in the Glass Pavilion--will receive a coupon for one free frozen yogurt cone at the Levering Market. In addition, the name of each participant will be included in a drawing for five gallons of Ben and Jerry's ice cream_with toppings--to be delivered to their academic or administrative department. To register, call Peggy Jones at 516-8039. ------------------------- Computer software helps escort vans "drive right" ------------------------- In an effort to reduce the number of escort and security van accidents and complaints of reckless driving, the Homewood security office has installed a new computer program to keep track of violations and violators. The "Drive Right" program both sets off an alarm in the van if the driver exceeds the speed limit and downloads the information into each shift's log. A driver with three violations will lose his or her job, said Patrick Bearry, a sergeant with Homewood security for the past three years and supervisor of the 30-van security escort service. The Homewood escort and security vans--not the intercampus shuttle buses--carry approximately 67,000 passengers yearly on and around the Homewood campus, said Bearry, a National Safety Council defensive driving instructor. He bought the computer program, he said, because of many reports of excessive speed and reckless driving within the past year, which have resulted in near misses as well as accidents. In a case last year, a van carrying students along winding San Martin Drive was totaled after the driver lost control traveling 55 mph over the speed limit. No one was injured. Bearry trains about 500 students each year to drive the escort vans, and he believes the "Drive Right" program will be good motivation for them to drive much more safely.