More Study Urged on Resistance

To Human Variant of Mad Cow

Some people have a genetic variation that may help them resist the human form of mad cow disease, a study in mice suggests. But if infection does occur, the disease takes a different form, researchers say.

This novel form of the brain-wasting disease has been observed in laboratory mice but not in humans, leading the scientists to urge a study of autopsies to see whether people also are affected.

"It's always difficult to extrapolate from laboratory animals to humans, but I think it's very likely that there's going to be more than one form of the disease" that affects people, said Jonathan D. F. Wadsworth of University College London in a telephone interview.

Known as bovine spongiform encephalopathy (BSE) in cattle, the disease raised concern when a form of it passed to humans and killed more than 140 people in Britain and at least 10 others elsewhere.

When BSE is passed to humans, it is known as variant Creutzfeldt-Jakob disease, or vCJD. Sporadic Creutzfeldt-Jakob disease occurs in humans but is not caused by BSE.

Wadsworth's team, working with lab mice, uncovered a third, novel form of the disease, which also damages the brain but produces deposits that differ in extent and location.

Monkey Trials Show Promise

For Men's Contraceptive

A shot that prompts an immune reaction to a protein produced in the male reproductive system shows promise in monkeys as a possible male contraceptive, researchers report in yesterday's issue of the journal Science.

But translating the findings into human use could take a decade, said lead researcher Michael O'Rand of the University of North Carolina at Chapel Hill.

In recent years, researchers have developed male contraceptives, based on hormones, that suppress sperm production. These are in trials.

In O'Rand's experiments, monkeys were immunized using a form of eppin, a protein produced in the tightly coiled ducts that carry sperm. Male monkeys that developed a strong immune response to the eppin were still able to copulate but could not impregnate female monkeys, the researchers said.

In the experiments, carried out in India, seven of nine male monkeys tested developed high antibody levels. Five of the seven recovered fertility once the immunization stopped.

Benefits of Arctic Thaw

Weighed Against Drawbacks

An accelerating thaw of the Arctic may open vast regions for oil and gas exploration, but that brings worries of spills in the fragile environment, experts said.

Scientists behind an eight-nation report saying the Arctic sea ice could almost vanish in summer by 2100 because of global warming said offshore oil and gas operations would be easier, but melting permafrost could destabilize installations on land.

Oil companies are unconvinced.

"We can't say for sure whether Arctic operations will become easier or more difficult," said Mark Akhurst, climate change manager for BP PLC, an observer at a scientists' conference in Reykjavik, Iceland.

Oil and gas are already produced around the Arctic from Alaska to Norway, and many environmentalists are opposed to new exploration for fossil fuels in the Arctic -- saying the burning of oil, gas and coal is already responsible for heat-trapping gases such as carbon dioxide that are warming the planet.

-- From News Services