Vitamin A, also known as retinol, is present in milk, liver, egg yolk, butter and other foodstuffs and as carotene in vegetables that have a yellow-orange colour, such as carrots and pumpkins.

This vitamin is accumulated in the liver where it is transformed into retinoid. Given that vitamin A, as such, has no effect on our organism, it is the retinoids that are responsible for the physiological activity of the vitamin.

Retinoids take part in three processes: in cell d

Scientists from Imperial College London and the University of Surrey have developed a new technique for crystallising proteins, a discovery which could help speed up the development of new medicines and treatments.

Crystallisation is the process which converts materials, such as proteins, into three dimensional crystals, thus enabling their atomic structure to be studied. The three dimensional structure of the crystals indicates the proteins function, and from this, researchers

Hydration in the presence of borane or iodine catalysts smoothes the way for the liquefaction of semianthracite coal

The tightening of worldwide oil reserves is causing the price of oil to escalate — and makes coal, which is much more abundantly available, an interesting starting material for liquid fuels and chemical raw materials. Researchers at the Max Planck Institute for Coal Research in Mülheim on the Ruhr have developed a new process that makes it possible to liquefy high-gr

A new study in Japan examining the effects of combination therapy on older patients with hepatitis C found more adverse effects necessitating discontinuation of treatment, lowering of dosages, and lower long-term benefits in this age group.

The results of this study appear in the January 2006 issue of Hepatology, the official journal of the American Association for the Study of Liver Diseases (AASLD). Published by John Wiley & Sons, Inc., Hepatology is available online via Wiley

While few Americans remain abstinent until marriage and most initiate sexual intercourse as adolescents, abstinence from sexual intercourse is an important behavioral strategy for preventing human immunodeficiency virus (HIV), other sexually transmitted infections (STIs), and unintended pregnancy among adolescents, according to the report, Abstinence and Abstinence-Only Education: A Review of U.S. Policies and Programs. The paper also notes that while there is broad support for abstinence as a n

A study examines new pathways linking liver disease to changes in the central nervous system

Liver disease is often associated with “sickness behaviors,” such as malaise, listlessness, anorexia, difficulty concentrating, and fatigue. In cholestatic liver diseases (where bile production is impaired) such as primary biliary cirrhosis, fatigue occurs in up to 86 percent of patients. Previous studies have suggested that these symptoms originate from changes to the central nervous sys

New findings that long-overlooked brain cells play an important role in regulating blood flow in the brain call into question one of the basic assumptions underlying today’s most sophisticated brain imaging techniques and could open a new frontier when it comes to understanding Alzheimer’s disease.

In a paper to appear in the February issue of Nature Neuroscience and now available on-line, scientists at the University of Rochester Medical Center demonstrate that

The Science Museum’s Dana Centre has come up with a way to beat the winter blues with the creation of the Dana Centre ‘Light Lounge’.

Many people suffer from seasonal blues, although for some, winter can be a disabling time with the onset of SAD (Seasonal Affective Disorder) – a term used to describe depression during darker months.

The Light Lounge will contain four specially designed lightboxes, which are used to treat SAD, and a circular sofa where visitors can relax

Preliminary data are encouraging, though researchers stress no helmet can prevent concussions and proper injury management is of critical importance

Newer football helmet technology and design may reduce the incidence of concussions in high school football players, according to results from the first phase of a three-year study by the University of Pittsburgh Medical Center’s (UPMC) Sports Medicine Concussion Program. The current study compared concussion rates and recovery times

Periodontitis, an infection of the gingiva and tooth-supporting tissues, may influence the effectiveness of antibiotics used for the prevention of recurrent cardiovascular events. A three-month course of treatment with antibiotics decreased recurrence of cardiovascular events in patients without periodontitis, while the medication was found to have no effect in patients with periodontitis. This is the first time dental infections have been linked to the effectiveness of long-term treatment

For the more than 18 million Americans who suffer from depressive illnesses, the best pharmacological treatments are those that increase levels of serotonin, the brain chemical that regulates mood, sleep and memory. New research by an international team of scientists, led by Rockefeller University researchers in Paul Greengard’s laboratory of Molecular and Cellular Neuroscience, shows that a gene called p11 is closely related to serotonin transmission in the brain – and may play a key role in

Scientists may have found a way to keep a protein “watchdog” on high alert to stop hereditary cancers from overrunning our bodies – if they can keep it on a leash of just the right length.

In a collaborative effort, a team of scientists including Purdue University’s Susan M. Mendrysa has found that one of the proteins found naturally in cells has the ability to halt the progression of intestinal tumors that arise from genetic predisposition. When the activity of this prote

In the January issue of the journal Genome Research, two teams of scientists describe a widespread phenomenon in the human genome called transcription-induced chimerism (TIC), where two adjacent genes produce a single, fused RNA transcript. The work has implications for drug development, as well as for understanding mechanisms underlying gene evolution, transcription regulation, and genomic organization.

Dr. Roderic Guigó’s group from the Centre de Regulació Genòmica (Barcel

Researchers identify large tracks of DNA refractory to mobile element insertion

Scientists from the University of Queensland report in the journal Genome Research that large segments of the human genome are conspicuously devoid of ubiquitous mobile DNA elements called transposons. The locations of these regions are highly conserved among mammalian species and are enriched in genes crucial for the regulation of developmental processes.

Transposons, often called “jumping

Unlike their cousins, rods and cones, newly discovered retinal cells don’t aid sight in a traditional sense. Instead, they constrict the eye’s pupil and set the body’s circadian clock. But new research from Brown University – where the photoreceptors were discovered by David Berson and colleagues – shows that these cells are sensitive to lighting conditions in a manner similar to rods and cones. Results appear in Neuron.

A new retinal photoreceptor adjusts its sensitivity in differe

The diversity of marine life in the Gulf of Maine region is much greater than previously thought

The Gulf of Maine Program of the Census of Marine Life, with the Huntsman Marine Science Center of St. Andrews, New Brunswick, announced today the first count of known marine species in the Gulf of Maine region — more than 50% larger than previous estimates. The count is 3,317 species and includes both year-round species and those that migrate to the region seasonally. The Canadian-US p