Efforts to quell the epidemic took three steps forward and one step back this year. The first human trials of a vaccine against African strains of HIV began in Kenya and England. The FDA approved a new anti-HIV drug. And leaders of developing nations, in which 95% of aids cases occur, pledged more funding to fight the economic and social devastation caused by the disease. But South African President Thabo Mbeki sounded a sour note when he openly questioned whether HIV causes aids. That prompted more than 5,000 scientists to sign a declaration decrying the waste of valuable time and resources arguing over a well-established scientific fact. Mbeki reportedly remains unconvinced but has stopped talking about it publicly.
Scientists began safety testing the first drug designed to tackle the root cause rather than the symptoms of this brain-addling disease. Patients in the early stages of Alzheimer's were given a gamma secretase inhibitor, a compound that blocks the formation of the sticky plaques that gum up the brain's neural connections. So far, the drug seems to have been well tolerated.
Back in 1992, NIH scientists were asked by Congress to study the safety of silicone breast implants. The first part of their investigation, completed in November, studied breast-cancer rates in 13,500 women who had breast implants (most of them silicone) and 4,000 who did not. Results: the implant patients showed no added risk for breast cancer when compared with the controls. Researchers warn, however, that further studies are needed to determine whether the implants are linked to other cancers or connective-tissue disorders.
Do they or don't they cause brain cancer? After a handful of studies yo-yoed back and forth on the answer, the Cellular Telephone Industry Association tried to seize control of the uncertainty this summer and, they hoped, pre-empt any future lawsuits. (Noted class-action attorneys have already joined an $800 million suit against Motorola.) The association suggested that cell-phone manufacturers voluntarily disclose radiation levels emitted by each unit's antenna. Meanwhile, those who walk and talk at the same time can take solace; the latest studies find no increased risk of brain tumors. But please note: the studies followed users for only two to three years and were partly funded by an organization of cell-phone manufacturers.
The human genome may have dominated the news last year, but mouse geneticists were busy too. They created an artificial mouse chromosome and, for the first time, showed that it could be passed from parent to offspring. If the same holds true in people, inherited genetic diseases may someday be corrected by injecting parents with man-made chromosomes.
Colorectal cancer is the third deadliest cancer in the U.S., and last April the FDA gave the 130,000 people in whom it is diagnosed each year some much needed help. It ruled that Camptosar, in use since 1999 as a second-line treatment, was potent enough in combination with other chemotherapy agents to now be used as a first-line therapy, even in advanced cases.
There aren't many treatments for a scarred cornea, the opaque outer layer of the eye, since corneal tissue can't be easily replaced. But it may be possible to grow a new one. Doctors have successfully transplanted tissue from other parts of the eye to reconstruct the cornea and restore sharper sight to a handful of patients.
In case of a heart attack, standard cardiopulmonary resuscitation (CPR) procedure calls for alternating mouth-to-mouth resuscitation with carefully counted chest compressions. A study of emergency medical technicians demonstrated, however, that chest compressions alone may be enough. Survival rates of heart-attack victims were the same whether they were given CPR or chest compressions alone.