Washington, Mar 2 : Scientists have found that Vitamin A plays a major role in the process whereby dendritic cells signal the white blood cells about any intrusion in the body.

Researchers at the Emory Vaccine Center and Yerkes National Primate Research Center have discovered that dendritic cells can respond to a compound called zymosan, a component of yeast cell walls, through two different receptors by sending out both stimulatory and calming messages at once.

The scientists say that their findings may prove useful for designing vaccines against many infectious agents, as the calming receptor is known to respond to bacteria and viruses as well as yeast.

After its review of the popular over-the-counter cough and cold medicines, the Medicines and Healthcare products Regulatory Agency (MHRA) arrived at the conclusion that there was “no robust evidence that these medicines work” in children below 12 years of age.

Washington, Mar 2 : Intrinsic sleep problem might be an underlying cause of attention-deficit hyperactivity disorder (ADHD) in children, a new study has found.

Dr. Reut Gruber, Director of the Attention, Behaviour and Sleep Lab at the Douglas Mental Health University Institute, found during a study that children with ADHD had a total sleep time that was significantly shorter than that of controls.

Wurzburg, Germany  - Gourmets consider the artichoke a tasty delicacy, but for people with digestive problems its bitterness is a helpful natural cure.

"The use of artichoke leaves is scientifically recognized in treating stomach and intestinal problems, above all when they are caused by liver or gall bladder dysfunction," said Johannes Gottfried Mayer of a medical research group at the University of Wurzburg.

The report released on Friday indicates that, even though the overall prevalence rate is small (up to 0.5%), there is rising HIV occurrence among susceptible groups at increased risk for HIV virus, comprising sex workers and their customers, and injecting drug users and their partners.

The report, titled "HIV and AIDS in South Asia: An Economic Development Risk" said that despite prevention plans, targeting susceptible groups at high infection risk, are increasing proportionally, these concentrated outbreaks can further escalate.

Melanotan I and Melanotan II popularly sold as "injectable tan" can lead to worrying changes in skin moles. Medical experts have issued warning regarding use of such tanning jab as these products are not been tested for safety, quality or effectiveness and that its side-effects were unknown. These products are advertised and sold illegally on the internet and in some tanning salons and body building gyms.

Two recent cases of women who had injected "Melanotan" shortly before noticing the problem of skin moles highlighted the risk from these tanning jab.