A cottonseed oil extract developed in China and touted for more than a decade as a possible male birth control drug is being prepared for human testing, in conjunction with condoms, as a method of preventing transmission of the AIDS virus.
The possible anti-AIDS application is just the latest development in the circuitous and controversial development of gossypol, which has shown sometimes significant promise as a male equivalent of the Pill. The drug is in limited use in China but its approval in the United States is generally viewed as being at least several years away.
Though gossypol's ability to inhibit sperm production has been clear since early in its development, attempts to introduce it more broadly have been constrained by questions about its possible side effects.
Researchers have identified gossypol as an apparently promising anti-viral agent in addition to a birth control drug. The drug perviously has been identified as useful against herpes, which is also spread by a virus.
The new development into the fight against AIDS was described by Katherine Ch'iu Lyle, a Rockefeller Foundation researcher involved in gossypol studies in collaboration with experts in Bejing. The joint Chinese-American team published two new studies of gossypol's birth control effectiveness in the latest issue of the journal Fertility and Sterility.
In the studies, gossypol pills or placebos were given to 152 male volunteers. The drug requires 2 1/2 months to become effective as a birth control pill. Gossypol was effective in producing marked reductions in sperm counts with few side effects. One complication was a significant inhibition of the body's potassium production, but Lyle said the problem appeared to be doserelated.
Lyle also said Rockefeller researchers are preparing to evaluate, as a possible means of impeding the spread of the AIDS virus, an ointment form of gossypol used to coat the surfaces of condoms. Condoms coated with the vaginal spermicide nonoxynol-9--already widely available--have been identified as an effective way to prevent the passage of AIDS, as long as the condoms do not break or tear.
Lyle said gossypol as a topical spermicide and AIDS preventive may have greater promise than nonoxynol-9. Some problems remain with it, including difficulties in controling gossypol's tendency to stain everything with which it comes in contact. But just as many birth control researchers believe gossypol will eventually become the male Pill, Lyle says the chemical's role in the AIDS epidemic could eventually prove to be just as significant.
Parking Gate Dangers
Motorized security gates used at apartment and office buildings may present a danger to children who could be severely injured or even killed by the devices, warns a UC Irvine medical team.
The Irvine team's warning, in a letter to the editor of the New England Journal of Medicine, was prompted by an incident in which a 5-year-old boy died after he was wedged against a wall by an apartment house parking lot gate. The youngsters were playing a game in which they dared one another to run in front of the closing gate.
The fatality followed another incident in which a boy caught his leg in a gate while playing a similar game. He was not seriously hurt.
The Irvine team urged consideration of requirements for safety devices like those already used on elevator doors. Safety switches would turn off the closing mechanism before a child could be harmed.
"Safety devices . . . could prevent such tragedies," wrote the three Irvine physicians. "Spirited children will find new ways to get into trouble with modern technology."
Doubts on Lasers
The apparently bright future of lasers as high-tech alternatives to the scalpel has encountered a minor snag.
In a study of the comparative effectiveness of laser beams and scalpels in surgery to remove tissue affected by malignant melanoma--the worst form of skin cancer--Israeli researchers have found the laser causes significantly more problems than it solves, making it more difficult to apply skin grafts than surgery with a conventional scalpel.
A report of the research was published this month in the journal Surgery, Gynecology and Obstetrics. The study involved melanoma surgeries on 219 patients, about evenly divided between laser operations and procedures in which a scalpel was used. Recurrence rates in the laser group were significantly higher than in the scalpel group and unexpectedly severe tissue damage caused by the heat of the laser beam interfered with attempts to cover areas operated on with new skin.
The thermal damage to surrounding tissue may be the cause of higher recurrence rates, the researchers speculated.