Neanderthal genes 'survive in us'

Many people alive today possess some Neanderthal ancestry, according to a landmark scientific study.

The finding has surprised many experts, as previous genetic evidence suggested the Neanderthals made little or no contribution to our inheritance.

The result comes from analysis of the Neanderthal genome - the "instruction manual" describing how these ancient humans were put together.

The genomes of 1% to 4% of people in Eurasia come from Neanderthals.

But the study confirms living humans overwhelmingly trace their ancestry to a small population of Africans who later spread out across the world.

The most widely-accepted theory of modern human origins - known as Out of Africa - holds that the ancestors of living humans (Homo sapiens) originated in Africa some 200,000 years ago.

A relatively small group of people then left the continent to populate the rest of the world between 50,000 and 60,000 years ago.

While the Neanderthal genetic contribution - found in people from Europe, Asia and Oceania - appears to be small, this figure is higher than previous genetic analyses have suggested.

"They are not totally extinct. In some of us they live on, a little bit," said Professor Svante Paabo, from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

Professor Chris Stringer, research leader in human origins at London's Natural History Museum, is one of the architects of the Out of Africa theory. He told BBC News: "In some ways [the study] confirms what we already knew, in that the Neanderthals look like a separate line.

"But, of course, the really surprising thing for many of us is the implication that there has been some interbreeding between Neanderthals and modern humans in the past."

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Science Explained: What is a genome?

John Hawks, assistant professor of anthropology at the University of Wisconsin-Madison in the US, told BBC News: "They're us. We're them.

"It seemed like it was likely to be possible, but I am surprised by the amount. I really was not expecting it to be as high as 4%," he said of the genetic contribution from Neanderthals.

The sequencing of the Neanderthal genome is a landmark scientific achievement, the product of a four-year-long effort led from Germany's Max Planck Institute but involving many other universities around the world.

The project makes use of efficient "high-throughput" technology which allows many genetic sequences to be processed at the same time.

The draft Neanderthal sequence contains DNA extracted from the bones of three different Neanderthals found at Vindija Cave in Croatia.

Retrieving good quality genetic material from remains tens of thousands of years old presented many hurdles which had to be overcome.

The samples almost always contained only a small amount of Neanderthal DNA amid vast quantities of DNA from bacteria and fungi that colonised the remains after death.

Svante Paabo (pictured here with a Neanderthal skull) led the research effort

The Neanderthal DNA itself had broken down into very short segments and had changed chemically. Luckily, the chemical changes were of a regular nature, allowing the researchers to write software that corrected for them.

Writing in Science journal, the researchers describe how they compared this draft sequence with the genomes of modern people from around the globe.

"The comparison of these two genetic sequences enables us to find out where our genome differs from that of our closest relative," said Professor Paabo.

The results show that the genomes of non-Africans (from Europe, China and New Guinea) are closer to the Neanderthal sequence than are those from Africa.

The most likely explanation, say the researchers, is that there was limited mating, or "gene flow", between Neanderthals and the ancestors of present-day Eurasians.

This must have taken place just as people were leaving Africa, while they were still part of one pioneering population. This mixing could have taken place either in North Africa, the Levant or the Arabian Peninsula, say the researchers.

The Out of Africa theory contends that modern humans replaced local "archaic" populations like the Neanderthals.

But there are several variations on this idea. The most conservative model proposes that this replacement took place with no interbreeding between modern humans and Neanderthals.

Unique features

Another version allows for a degree of assimilation, or absorption, of other human types into the Homo sapiens gene pool.

The latest research strongly supports the Out of Africa theory, but it falsifies the most conservative version of events.

The team also identified more than 70 gene changes that were unique to modern humans. These genes are implicated in physiology, the development of the brain, skin and bone.

The researchers also looked for signs of "selective sweeps" - strong natural selection acting to boost traits in modern humans. They found 212 regions where positive selection may have been taking place.

The scientists are interested in discovering genes that distinguish modern humans from Neanderthals because they may have given our evolutionary line certain advantages over the course of evolution.

The most obvious differences were in physique: the muscular, stocky frames of Neanderthals contrast sharply with those of our ancestors. But it is likely there were also more subtle differences, in behaviour, for example.

Dr Hawks commented that the amount of Neanderthal DNA in our genomes seemed high: "What it means is that any traits [Neanderthals] had that might have been useful in later populations should still be here.

"So when we see that their anatomies are gone, this isn't just chance. Those things that made the Neanderthals apparent to us as a population - those things didn't work. They're gone because they didn't work in the context of our population."

Researchers had previously thought Europe was the region where Neanderthals and modern humans were most likely to have exchanged genes. The two human types overlapped here for some 10,000 years.

The authors of the paper in Science do not rule out some interbreeding in Europe, but say it was not possible to detect this with present scientific methods.

Bacteria found in recalled kids' Tylenol

Risk to consumers is ‘remote,’ FDA director says

Ingredients used by Johnson & Johnson in some of the 40 varieties of children's cold medicines recalled last week in the U.S. and 11 other countries were contaminated with bacteria, according to a report by the Food and Drug Administration.

Agency officials said Tuesday none of the company's finished products tested positive for the contaminants, though such testing is not definitive.

"We think the risk to consumers at this point is remote," said Deborah Autor, director of FDA's drug compliance office, on a call with reporters.

Last week's sweeping recall is the latest quality issue to taint J&J's over-the-counter medicine franchise. In January, the company recalled a line of adult Tylenol pain relievers due to complaints of a moldy smell associated with wooden pallets used to transport the drugs.

The FDA report, which was posted online, lists more than 20 manufacturing problems found at the McNeil Consumer Healthcare plant in Fort Washington, Pennsylvania, where the formulas were made. The recalled products include children and infant formulations of Tylenol, Motrin, Zyrtec and Benadryl.

FDA inspectors visited the plant in mid-April and wrapped up their inspection Friday. J&J issued its "voluntary" recall later that night.

Among other problems, FDA inspectors said the company did not have laboratory facilities to test drug ingredients and failed to follow up on customer complaints.

J&J did not investigate more than 46 complaints received in the last year about "black or dark specks" in Tylenol products, according to the FDA's report.

Additionally, inspectors found some pieces of equipment covered with thick layers of dust, while others were held together with duct tape.

In a statement Tuesday, J&J called the problems cited by the FDA "unacceptable to us, and not indicative of how McNeil Consumer Healthcare intends to operate." The health conglomerate, which is based in New Brunswick, New Jersey, said production at the plant won't resume until the problems have been fixed.

The FDA reiterated that serious medical problems with the products are unlikely, but advised consumers to stop using the medicine as a precaution. Parents are instructed to use generic alternatives instead.

J&J's McNeil Consumer Healthcare unit has said some of the recalled medicines may have a higher concentration of the active ingredient than listed on the bottle. Others may contain particles, while still others may contain inactive ingredients that do not meet testing requirements.

FDA leadership told reporters Tuesday that they first met with J&J in February to discuss manufacturing problems identified in a warning letter about another J&J plant. The agency decided to step up inspections of the company's facilities based on those problems.

"That warning letter brought us to the point where we thought it was necessary to sit down with management and discuss our concerns," Autor said.

 

Your old mascara may spoil your looks

Out-of-date make-up can be a magnet for germs

Women are using cosmetics well past the use-by date, unaware that some products could be magnets for germs which could damage their health and looks, said Sara Stern, Director of Cosmetics at retail chain Debenhams.

"British women are famously loyal to make-up brands and products, however, their reluctance to throw away old products is a risky business," Stern said in a statement.

"We wouldn't hesitate to chuck out moldy or bacteria-ridden food and the same standards should apply to the lotions and potions and that we put on our skin. Beauty is timeless but unfortunately, products are not."

Favorite beauty essentials such as foundation, concealer, blusher, eyeshadow, eyeliner, mascara, lipstick and perfume all include a "period after opening" indicator, denoted by an open pot with the number of months of safe use written inside.

Debenhams asked 1,000 women aged 18 to 70 about the contents of their cosmetic bags and their understanding of the health considerations.

Despite European Union guidelines meaning brands have to state product shelf lives, 89 percent of respondents said they were unaware that such information exists, did not understand what the symbol meant or were unable to read the often tiny writing.

Make up, perfume and skincare products used after the expiration date carry a risk of irritation and infection, Debenhams said. This is due to air and bacteria infiltrating the products. Multiuse products carry an even higher risk as they can spread germs from eyes to skin to lips.

To add to the shock factor, 60 percent of respondents admitted they shared make-up with friends and family, multiplying the chances of infection.

More than two thirds of women (68 percent) said they only replace make-up and skincare when they run out, however long that might take.

Nearly three-quarters of those surveyed (72 percent) never wash their make-up sponges or brushes, even though they should do so at least once a week and 81 percent of British women also regularly (at least once a week) go to sleep without removing make-up.

MRSA superbug strain 'tracked' via genome

Researchers have developed a technique for precisely tracking the spread of the super bug MRSA in hospitals.                                                           

The team from the Wellcome Trust Sanger Institute in Cambridge looked at the genomes of MRSA strains from across the globe and at one hospital in Thailand.

They were able to spot small changes that allowed them to track the strain back to an individual patient.

They say this adds to the understanding of how MRSA can spread so rapidly and should lead to better treatments.

DNA sequencing

The research, which is published in the journal Science, involved teams in the UK, in Bath, Oxford and London, and Thailand, Portugal and the United States.

Scientists used new high-throughput DNA sequencing technologies to compare MRSA samples from patients to show how they were genetically related.

They were able to spot single-letter differences in the genetic code.

They looked at two different sets of samples: one set taken from people across the globe and another from a single hospital in Thailand.

They sequenced the entire genomes of each sample.

In the hospital setting it revealed single letter genetic changes in the samples showing that no two infections were caused by entirely identical bacteria.

This allowed them to discover whether one patient had infected another or whether the infection had come in from another source.

They found that the MRSA strain studied acquired about one single-letter change in its genetic code every six weeks.

Worldwide search

They also looked at samples from hospitals in several parts of the world collected over more than 20 years.

The rate of mutation apparently supports the theory that MRSA emerged in the 1960s at the time of widespread antibiotic use.

Professor Sharon Peacock, a microbiologist at the University of Cambridge said: "The implications for public health are clear. This technology represents the potential to trace transmission pathways of MRSA more definitively so that interventions or treatments can be targeted with precision and according to need."

Researchers say it would be too expensive to use the technology widely at present but the cost should fall in the next few years.

Professor Mark Enright, an expert in molecular epidemiology at Imperial College, London, said the work gave researchers "a good idea as to how this particular type of MRSA has evolved and how it behaves in and out of hospitals".

"This work is a great demonstration of new, rapid DNA sequencing that in the near future will be how important pathogens such as MRSA will be identified," he said.

"Such unambiguous identification will form the basis for rapid diagnostics of microbial infection and will tell us how they spread in hospitals identifying each human host and surface in chains of transmission between patients."