Faculty Bibliography

Despite an intensive search for an immunologic explanation, none have been found. Now, an even more baffling finding has turned up in a study of 1,900 prostitutes in Nairobi, Kenya. Four of them became infected with HIV, the virus that causes AIDS, but only after they stopped working as prostitutes or took breaks of two months or more, leaders of the study reported last week at the Seventh Conference on Retroviruses and Opportunistic Infections

Estrogen strongly protected against infection by the simian AIDS virus in experiments with female monkeys, offering hope that it might be used to protect against the human AIDS virus in women, researchers have reported here at a meeting on the disease. In the study, estrogen injected into a small group of female monkeys produced a thicker layer of cells in their vaginas. That acted as a protective barrier against infection when S.I.V., the simian AIDS virus, was squirted into the vagina to test the effectiveness of the therapy. ''The results were striking,'' said the head of the research team, Dr. Preston Marx of the Aaron Diamond AIDS Research Center in New York City. Dr. Marx and public health officials cautioned that much more research was needed to prove that a topical estrogen cream applied to the vagina could protect women against H.I.V. ''We can't assume estrogen would have the same effect in women'' or that topical application would be as effective as injected estrogen, Dr. Marx said in an interview today

An international team of surgeons performed the world's first double hand-and-forearm transplant on Thursday in Lyon, France, on a 33-year-old Frenchman who lost both his hands in a fireworks accident in 1996. The same team of surgeons performed the first successful hand-and-forearm transplant, in September 1998, also in Lyon. There, Clint Hallam, a New Zealand man living in Australia, received a new right hand and forearm. In January 1999, surgeons in Louisville, Ky., gave Matthew David Scott of Absecon, N.J., a new left hand and forearm. Dr. Nadey Hakim, a member of the transplant team from England, said in a telephone interview Friday that the double-hand transplant recipient was doing well. 'He's awake and fine,' he said. 'So far so good.'

For the first time since AIDS was discovered nearly 20 years ago, more black and Hispanic gay men were diagnosed with AIDS than white gay men over a year's period, federal health officials reported yesterday. A total of 18,153 AIDS cases were diagnosed among gay men in 1998, the most recent year available, and blacks and Hispanics represented 9,182, or 51 percent, of the cases, the Centers for Disease Control and Prevention said in its weekly report. This compares with 8,678 cases, or 48 percent, for white gay men. Black gay men made up one- third of all AIDS cases among gays, Hispanics 18 percent and Asian and Pacific Islanders 1 percent of the cases in that year, the centers said. Since the AIDS epidemic began, most AIDS cases have been among gay men, and white gay men have made up the largest subgroup. But through the years, the percentages have steadily risen for black and Hispanic gay men as those for white gay men decreased

Coagulase gene (coa) short sequence repeat region sequencing was used to measure relatedness among a collection of temporally and geographically diverse methicillin-resistant Staphylococcus aureus isolates. The results show that coa polymorphism is free of strong selective pressure and has a low index of variation that may be useful for long-term epidemiological investigations. coa typing is a useful addition to spa typing for analysis of S. aureus, including methicillin-resistant strains

Ethambutol (EMB) is a central component of drug regimens used worldwide for the treatment of tuberculosis. To gain insight into the molecular genetic basis of EMB resistance, approximately 2 Mb of five chromosomal regions with 12 genes in 75 epidemiologically unassociated EMB-resistant and 33 EMB-susceptible Mycobacterium tuberculosis strains isolated from human patients were sequenced. Seventy-six percent of EMB-resistant organisms had an amino acid replacement or other molecular change not found in EMB-susceptible strains. Thirty-eight (51%) EMB-resistant isolates had a resistance-associated mutation in only 1 of the 12 genes sequenced. Nineteen EMB-resistant isolates had resistance-associated nucleotide changes that conferred amino acid replacements or upstream potential regulatory region mutations in two or more genes. Most isolates (68%) with resistance-associated mutations in a single gene had nucleotide changes in embB, a gene encoding an arabinosyltransferase involved in cell wall biosynthesis. The majority of these mutations resulted in amino acid replacements at position 306 or 406 of EmbB. Resistance-associated mutations were also identified in several genes recently shown to be upregulated in response to exposure of M. tuberculosis to EMB in vitro, including genes in the iniA operon. Approximately one-fourth of the organisms studied lacked mutations inferred to participate in EMB resistance, a result indicating that one or more genes that mediate resistance to this drug remain to be discovered. Taken together, the results indicate that there are multiple molecular pathways to the EMB resistance phenotype