Science: Theoretically...

A protein abnormality which affects yeast has parallels with the prion disease CJD and could point the way to a cure, US scientists believe.

The yeast "disease" can be reversed by tampering with the production of a second protein, raising hopes that similar strategies might work for the human disease.

Researchers at the University of Chicago observed that a yeast protein called Sup35 could flip into a different shape and subsequently convert normal protein to its own shape in the same way that the abnormally folded protein PrP in human CJD converts normal PrP to its own distorted form.

At the annual meeting of the American Society for Microbiology in Miami, reported in New Scientist, the researchers revealed that the yeast aggregations of abnormal protein look almost identical to the PrP plaques found in the brains of mammals with prion diseases.

The first X-ray laser with a wavelength of less than 10 nanometers has been developed by British and American researchers. It produces a saturated laser beam generated from X-rays of seven nanometers in length.

Such lasers are used by biologists and physicists in everything from microscopy to the radiography of dense plasmas. The new laser, reported in Science, has a short wavelength, short pulse duration, high efficiency and high brightness - factors which make it ideal for many X-ray laser applications, the authors say.

The 24-hour clock that governs the sleep cycle in mammals is controlled by a gene which its US discoverers have named Clock.

Clock stands for circadian locomotor output cycles kaput. A mutant form of the gene destroys the 24-hour rhythm that governs the body when there are no cycles of light and dark to tell an animal when it is time to sleep.

The research, reported in Cell, may help investigators understand jet lag and other disturbances of normal sleep rhythm. The team, from Evanston University, Illinois, identified the mouse version of the gene, cloned it, and confirmed its function by using the snippet of genetic material to restore the daily rhythm in a group of mutant mice that had lost it. They also discovered that an extra copy of the gene causes the internal clock to run a bit faster.

A new front in the battle against malaria has been opened up by scientists who have identified the transport network that allows nutrients to reach the parasite.The finding may be used to starve or poison the organism directly.

During one part of its life cycle, the malaria parasite invades the host's red blood cells and survives there by exporting waste and importing nutrients. The red blood cells do not provide enough food for the parasite so it must get food through a network of tubes that it constructs within the cell.

Researchers from Stanford University, California, report in Science that they have found a way of breaking the pathway. They say it could also be used to channel poison into the parasite.

The strategy is being tried in rats but it will a couple of years before scientists know whether it can be safely tried in humans.