Scientists said Wednesday they had found evidence that SARS-like coronaviruses can jump straight from a type of Chinese bat to humans without the need for an intermediary animal "host".

The find has "enormous implications" for public health control, with potentially pandemic viruses present, right now, in bats in China that could cause another outbreak, said the authors of the study published in the journal Nature.

"Even worse, we don`t know how lethal these viruses would be if such an outbreak erupted," co-author Peter Daszak of the EcoHealth Alliance, a New York-based research group, said in a statement.

Bats have long been thought to be the origin of the Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) outbreak that killed hundreds of people in Asia 10 years ago, but other SARS-like viruses found in bats lacked the genetic ability to "bind" to human cells for infection.

SARS had also been found in civet cats in wildlife markets in China, and many scientists believed they were a necessary intermediary host for the bat virus to mutate into a form able to target humans.

"Our current paper shows that this isn`t necessary -- we have found SARS-like coronaviruses in Chinese horseshoe bats that are much more closely related to human SARS and that can use the human cell receptor," Daszak told AFP by email.

"That means they could emerge directly from bats to people anywhere there is contact with this species of Chinese bat, not just in the wildlife markets where civets are also found."

A receptor is a molecule on the surface of a human cell that receives chemical signals via a spike protein on the surface of a virus -- a kind of lock and key mechanism. But not all viruses have the key to unlock just any cell.

The study authors said their findings constituted the strongest evidence yet that SARS itself may have originated in bats.

"I think it`s the most likely hypothesis for how SARS emerged -- that bats carrying viruses similar to our new CoVs were in the market, and infected both civets and people at the same time," said Daszak.

The results underlined the importance of continued surveillance of viruses in bats to preemptively identify ones that could cross species, said the research team from China, Australia, Singapore and the United States.

"It is not uncommon for bats to be a food source for many people in China and other parts of Asia, so the risk is substantial," said an EcoHealth Alliance statement.

Horseshoe bats are also used in Chinese medicine.

The Middle East Respiratory Syndrome Coronavirus (MERS-CoV) which first appeared in September 2012 and has claimed 62 lives worldwide, is also believed to originate in bats -- in Saudi Arabia.

"Our work shows that bats are important reservoirs of a number of viruses including MERS and we should be more careful about how we interact with bats -- let`s give them the natural space for their habitat, conserve them, and avoid hunting and trading in bats -- this is good for conservation and good for our health," said Daszak.

The results published in Nature were based on a genetic analysis of virus samples taken over the course of a year from members of a horseshoe bat colony in the southwestern Chinese city of Kunming.

Coronaviruses are a large family of viruses that cause an array of human illnesses -- everything from the common cold to SARS. They also cause a number of animal diseases.

Daszak said the team had managed to isolate and cultivate one of the viruses live in the laboratory, which will be used to work on a possible vaccine.

"The biggest threat for a pandemic now is not SARS itself because that outbreak happened and ended. The biggest threat is for something similar to SARS to emerge from wildlife and start off a new SARS-like pandemic," he said.

Commenting on the study, Sanjaya Senanayake, associate professor of medicine at the Australian National University, said the chances of direct disease transmission from animals to humans increased as we encroach further into their natural habitats.

"Of the 40 or so new infections in humans discovered in the last 40 years, most have come from animals," Senanayake said.

"This increasingly intricate cohabitation becomes a long-term issue for pandemic planners."

A novel autism intervention program is using theatre to teach reciprocal communication skills to improve social deficits in adolescents with the disorder, a new study has revealed.

The newly released study assessed the effectiveness of a two-week theatre camp on children with autism spectrum disorder and found significant improvements were made in social perception, social cognition and home living skills by the end of the camp.

Called SENSE Theatre, the Social Emotional Neuroscience and Endocrinology (SENSE) program evaluates the social functioning of children with autism and related neurodevelopmental disorders.

Camp participants ages 8 to 17 years join with typically developing peers who are specially trained to serve as models for social interaction and communication, skills that are difficult for children with autism.

The camp uses techniques such as role-play and improvisation and culminates in public performances of a play.

Lead author Blythe Corbett, Ph.D., associate professor of Psychiatry and Vanderbilt Kennedy Center investigator, said that the findings show that treatment can be delivered in an unconventional setting, and children with autism can learn from unconventional 'interventionists' - their typically developing peer.

Corbett said that their findings show that the SENSE Theatre program contributes to improvement in core social deficits when engaging with peers both on and off the stage.

The study has been published in the journal Autism Research.

The Food and Drug Administration is recommending new restrictions on prescription medicines containing hydrocodone, the highly addictive painkiller that has grown into the most widely prescribed drug in the U.S.

In a major policy shift, the agency said in an online notice Thursday that hydrocodone-containing drugs should be subject to the same restrictions as other narcotic drugs like oxycodone and morphine.

The move comes more than a decade after the Drug Enforcement Administration first asked the FDA to reclassify hydrocodone so that it would be subject to the same restrictions as other addictive painkilling drugs. The FDA did not issue a formal announcement about its decision, which has long been sought by many patient advocates, doctors and state and federal lawmakers.

For decades, hydrocodone has been easier to prescribe, in part because it is only sold in combination pills and formulas with other non-addictive ingredients like aspirin and acetaminophen.

That ease of access has made it many health care professionals' top choice for treating chronic pain, everything from back pain to arthritis to toothaches.

In 2011, U.S. doctors wrote more than 131 million prescriptions for hydrocodone, making it the most prescribed drug in the country, according to government figures. The ingredient is found in blockbusters drugs like Vicodin as well as dozens of other generic formulations.

It also consistently ranks as the first or second most-abused medicine in the U.S. each year, according to the DEA, alongside oxycodone. Both belong to a family of drugs known as opioids, which also includes heroin, codeine and methadone.

Earlier this year the Centers for Disease Control and Prevention reported that prescription painkiller overdose deaths among women increased about fivefold between 1999 and 2010. Among men, such deaths rose about 3.5-fold. The rise in both death rates is closely tied to a boom in the overall use of prescribed painkillers.

The FDA has long supported the more lax prescribing classification for hydrocodone, which is also backed by professional societies like the American Medical Association.

But the agency's top drug regulator, Dr. Janet Woodcock, said in a statement Thursday: "The FDA has become increasingly concerned about the abuse and misuse of opioid products, which have sadly reached epidemic proportions in certain parts of the United States."

The FDA says it will formally request in early December that hydrocodone be rescheduled as a Schedule II drug, limiting which kinds of medical professionals can write a prescription and how many times it can be refilled.

The Controlled Substances Act, passed in 1970, put hydrocodone drugs in the Schedule III class, which is subject to fewer controls. Under that classification, a prescription for Vicodin can be refilled five times before the patient has to see a physician again. If the drug is reclassified to Schedule II, patients will only be able to receive one 90-day prescription, similar to drugs like OxyContin. The drug could also not be prescribed by nurses and physician assistants.

The FDA's request for reclassification must be approved by officials in other agencies within the Department of Health and Human Services.

News of the FDA decision was applauded by lawmakers from states that have been plagued by prescription drug abuse, many who have been prodding the agency to take action for months.

"Today was a tremendous step forward in fighting the prescription drug abuse epidemic that has ravaged West Virginia and our country," said Democratic Sen. Joe Manchin, in a statement. "Rescheduling hydrocodone from a Schedule III to a Schedule II drug will help prevent these highly addictive drugs from getting into the wrong hands and devastating families and communities

Sen. Charles Schumer of New York noted that the FDA's own expert panel recommended the reclassification more than nine months ago.

"Each day that passes means rising abuse, and even death, at the hands of hydrocodone-based drugs," Schumer said in a statement.

Still, Thursday's action immediately sparked criticism from some professional groups that said that the tighter restrictions could have unintended consequences, such as burdening health care workers and patients.

"The FDA's reported decision will likely pose significant hardships for many patients and delay relief for vulnerable patients with legitimate chronic pain, especially those in nursing home and long-term care," said Kevin Schweers, a spokesman for the National Community Pharmacists Association.

Scientists have taken a step closer to prevent cataract from striking by finding out the activation mechanism of the protective protein that saves human eyes from falling prey to disease.

The lens of the human eye is made up of a highly concentrated protein solution that imparts the eye its high refractive power. Yet, despite this high protein content the ocular lens must remain clear and transparent.

To this end ocular lens cells have developed a remarkable strategy: They have thrown overboard the complex machinery present in all other cells of the human body for building up and breaking down proteins. Instead, lens proteins are created only once in a lifetime - during embryonic development.

In 2009, Johannes Buchner, professor for biotechnology at the Technische Universitaet Muenchen collaborated with Sevil Weinkauf, professor for electron microscopy at the Technische Universitaet Muenchen, and helped the first part of the aB-crystallin puzzle fall into place.

The team successfully deciphered the molecular structure of the most important form of this versatile protein - a molecule comprising 24 subunits. Under normal conditions, i.e. when the cell is not exposed to stress, this complex is the most common variant.

However, it is merely an idle form that contributes little to the prevention of clumping in other proteins. It was clear that there must be another molecular switch that triggers the protective protein.

It is this trigger mechanism that the team headed by Buchner and Weinkauf uncovered now. When a cell is exposed to stress, for instance when subjected to heat, phosphate groups are attached to a specific region of the protein.

The negative charges of these phosphates break the links between the subunits and the large complexes consequently disintegrate into numerous smaller ones of only six or twelve subunits each.

As a result of this breakup, the regions at the ends of the complexes become more flexible allowing the molecules to dock up with different partners, thereby preventing them from clumping - the protective protein is now active.

The study has been published in Proceedings of the National Academy of Sciences.

A new study has suggested that testosterone treatment in hypogonadal (testosterone deficient) men restores normal lipid profiles and may reduce the risk of cardiovascular disease.

In this observational study, researchers from Boston University School of Medicine (BUSM), investigated the effects of testosterone treatment in 255 hypogonadal men between the ages of 33-69 and followed them for a period of five years.

They found that men treated with testosterone therapy experienced a gradual reduction of their total cholesterol, low density lipoprotein cholesterol, triglycerides and increased high density lipoprotein.

"In addition to improving their cholesterol levels, we found that the testosterone treatment resulted in marked reductions in systolic and diastolic blood pressure as well, suggesting amelioration of hypertension," lead author Abdulmaged M. Traish, MBA, PhD, professor of biochemistry and urology as well as Research Director of the Institute of Sexual Medicine at BUSM explained.

Traish found this treatment also reduced fasting blood glucose and hemoglobin A1c, a surrogate marker of hyperglycemia, suggesting that testosterone treatment may improve insulin sensitivity and hyperglycemic control.

It also reduced the levels of inflammatory biomarkers such as C-reactive protein (CRP) and markers of liver dysfunction such as alanine aminotransferase and aspartate aminotransferase, suggesting reduction in the inflammation responses.

The study is published in the International Journal of Clinical Practice.