Life Sciences and Chemistry

To test whether chemicals are toxic to humans, researchers need to use liver cells that have been freshly harvested from mice or other mammals. A new collection of stable cell lines, described in BMC Biotechnology this week, could reduce the numbers of animals needed in such experiments.

The MMH-GH cell lines are derived from the liver cells of transgenic mice. These cells have been engineered to secrete human growth hormone when they are exposed to toxic compounds. The cells also continuou

Five years ago, University of North Carolina at Chapel Hill researchers first reported finding that the nutrient choline played a critical role in memory and brain function by positively affecting the brain’s physical development.

Differences in development influenced action, the scientists and their colleagues found. In animal experiments conducted at Duke University, both young and old rats performed significantly better on memory tasks if they received enough choline before birth compared

Two independent research groups have established conclusively that prions are proteins, and that they do not depend on genes or other factors for transmission of their traits. According to the scientists, the studies answer a nagging question that had raised doubts among some researchers about the validity of the so-called “protein-only” hypothesis of prion infectivity.

Scientists have grappled for years with one of the central tenets of the protein-only hypothesis, namely, that a single pri

UCSF scientists have demonstrated for the first time that a change in the folded shape of a prion protein changes its infectious properties — including the prion’s ability to jump “species barriers.”

The research, based on studies of prion infectivity in yeast, solves one of the great puzzles about prions: If they are infectious proteins with no genetic material of their own and no ability to mutate genetically, how can a single prion exist in different strains that can cause differen

The mechanism used by the bacteria that cause anthrax, bubonic plague and typhoid fever to avoid detection and destruction by the body’s normal immune response – leading to life-threatening bacterial infections – has been identified by researchers at the University of California, San Diego (UCSD) School of Medicine.

Published in the March 18, 2004 issue of the journal Nature, the lab-culture research with mouse cells identifies a protein kinase called PKR that causes the death of macrophage

British ecologists have gathered compelling new experimental evidence on how tropical rain forest food webs are constructed, findings that may have important implications for their environmental management.

The research reported in Nature today (18 March) demonstrates how species that never meet may nevertheless influence each other’s ecology through shared parasites, and confirms the action of an important ecological theory in the highly biodiverse rain forest environment.

Eco