People who have high cholesterol levels may be much more susceptible to a particular disease transmitted by the bites of ticks, a new study in mice suggests.

Scientists infected mice with Anaplasma phagocytophilum, the bacterium that causes human granulocytic anaplasmosis (HGA), a disease with flu-like symptoms. Bacteria levels were 10 times greater in mice that were genetically predisposed to high cholesterol levels and that were also fed a high-cholesterol diet.

The results confirmed what the researchers had suspected – that A. phagocytophilum depends on its host's cholesterol stores for its survival.

Scientists will only make real breakthroughs in children’s medicine if they include children in research programmes as well as adults, according to a leading paediatric expert.

Professor John Warner was speaking today at the opening of the Paediatric Research Unit, the UK’s first unit solely devoted to paediatric clinical research. The unit is run by researchers from Imperial College London and St Mary’s Hospital, and it is based next to the hospital’s paediatric wards in Paddington.

Scientists at Children’s National Medical Center have demonstrated conclusively that a specific protein is instrumental in myelination and remyelination, processes essential to the creation and repair of the brain’s white matter.

This groundbreaking discovery in mouse models points the way to developing treatments or interventions to enhance healthy brain development and/or brain disease repair in children and adults.

“By understanding the fundamental mechanisms of brain development, we get closer to finding clear instructions to repairing developmental brain disorders and injuries,” said Vittorio Gallo, PhD, Director, Center for Neuroscience Research, Children’s Research Institute at Children’s National Medical Center.

Like crowds of people, microscopic particles can act together under the right conditions. By exposing crowd behavior at the atomic scale, scientists discover new states and properties of matter. Now, ultrafast lasers have revealed a previously unseen type of collective electronic behavior in semiconductors, which may help in the design of optoelectronic devices.

Design of optoelectronic devices, like the semiconductor diode lasers used in telecommunications, currently involves a lot of trial and error. A designer trying to use basic theory to calculate the characteristics of a new diode laser will be off by a significant amount because of subtle interactions in the semiconductor that could not be detected until recently.

A role for prion proteins, the much debated agents of mad cow disease and vCJD, has been identified. It appears that the normal prions produced by the body help to prevent the plaques that build up in the brain to cause Alzheimer’s disease. The possible function for the mysterious proteins was discovered by a team of scientists led by Medical Research Council funded scientist Professor Nigel Hooper of the University of Leeds.

Alzheimer’s and diseases like variant Creutzfeldt-Jakob Disease follow similar patterns of disease progression and in some forms of prion disease share genetic features. These parallels prompted Professor Hooper’s team to look for a link between the different conditions. They found an apparent role for normal prion proteins in preventing Alzheimer’s disease.

A virus that has been specifically designed by scientists to be safe to normal tissue but deadly to cancer is showing early promise in a preliminary study, researchers said today at the ESMO Conference Lugano (ECLU), Switzerland, 5-8 July 2007.

The virus, called NV1020, is a type of herpes simplex virus modified so that it selectively replicates in virus cells, killing them in the process.