Light, Photosynthesis Harmful to Fresh Produce

TEL-AVIV –  A study conducted by Israeli researchers suggests that exposure to light, and possibly photosynthesis, may help disease-causing bacteria to invade fresh produce, making them impervious to washing.

According to background information in a report published in journal Applied and Environmental Microbiology, past studies have already shown that salmonella enterica attaches to the surface of fresh produce, and finds its way below the surface of the skin through pores called stomata, where it can hide from and resist washing and food sanitizers.

In the new study, researchers from the Agricultural Research Organization at the Volcani Center in Israel and Tel-Aviv University examined the role that light and photosynthesis might play on the ability of salmonella bacteria to infiltrate lettuce leaves via stomata.

They exposed sterile iceberg lettuce leaves to bacteria either in the light, in the dark, or in the dark after 30 minutes of exposure to light.

Incubation in the light or pre-exposure to light resulted in aggregation of bacteria around open stomata and invasion into the inner leaf tissue.

Incubation in the dark, on the other hand, resulted in a scattered attachment pattern and very little internalization.

According to the researchers, the increased propensity for internalization in the light may be due to several factors.

First, they say, in the absence of light plants enter a period of dormancy, where stomata are closed and no photosynthesis takes place. In the light, the stomata are open.

Additional findings also suggest that the bacteria are attracted to the open stomata by the nutrients produced during photosynthesis, which are not present in the dark.

“The elucidation of the mechanism by which Salmonella invades intact leaves has important implications for both pre- and postharvest handling of lettuce and probably other leafy vegetables. The capacity to inhibit internalization should limit bacterial colonization to the phylloplane and consequently might enhance the effectiveness of surface sanitizers,” say the researchers.

Facebook May Boost your Brain’s Working Memory

LONDON – Some social networking sites, like Facebook, could help improve a person’s working memory, according to an expert.

Dr. Tracy Alloway, a psychologist at Stirling University, says that working memory – the ability to recall things over a short period of time – could be the key to success.

She believes that it may be possible to train the brain’s working memory just like an athlete trains muscles, reports the Independent.

Alloway said that some technological inventions, such as Facebook, might actually improve working memory because they require people to hold a lot of information in their heads.

However, other such websites, like spell-checks and Twitter, which requires only small bite-sized phrases, may work against improving working memory.

Instead, these websites could be contributing to some people’s lack of success, she suggested.

Alloway said that she had devised an on-line game that can improve working memory, which may help the young develop working memory skills as well helping to combat memory loss in the elderly.

Animals Using One Side of their Brains are More Successful

SYDNEY – A new study has determined animals that process information using a preferred hemisphere of the brain fare better those who use both sides of their brain simultaneously.

According to a report by ABC News, the study suggests the brain operates like a dual processor in a computer, with each of the brain’s two sides kicking into action depending on the content or context of the information.

Dr Culum Brown of the Department of Biological Sciences at Macquarie University in Sydney, and colleague Maria Magat, focused their research on several different types of Australian birds, such as gang-gangs, sulfur-crested cockatoos and Australian king parrots.

All of the birds participated in two tests designed to test their cerebral lateralisation, meaning how strongly each bird preferentially processes information using either hemisphere of the brain.

The first task was a simple pebble-seed discrimination test, where the birds had to pick seeds out of a background of similar sized pebbles.

The second task was more demanding.

The researchers attached food to the end of a suspended string that the birds had to manipulate with their beaks and feet in order to get the tasty reward.

Birds with a preference for using either of their eyes or either of their legs did better than birds that used both eyes and both legs equally.

This means that the most successful birds have a very strong cerebral lateralisation, which “is influenced by both genes and experience,” according to Brown.

He and Magat found that the pattern of lateralisation, left or right bias, did not predict success as much as the strength of the particular bias did.

Carrying the findings over to humans, this suggests, in part, that a right-handed person isn’t more successful than a left-handed one, and vice-versa.

But people who always favour a certain hand, foot or eye for certain tasks will likely perform better than those who don’t exhibit obvious preferences.

Brown said that there are several reasons why such specialized division of the brain confers benefits to the individual.

“Firstly, it means that a given hemisphere can become increasingly specialized at processing certain types of information,” he said.

According to Brown, assigning particular tasks to each side of the brain avoids conflict between the two hemispheres, and allows “multiple sources of information to be processed simultaneously, that is to say, animals can multitask like a dual processor in a computer.”

Frequent Nasal Irrigation May Increase Infections

NEW YORK – New evidence suggests that daily nasal irrigation may increase the risk of sinus infections.

Nasal irrigation with warm saline has been promoted as way to cleanse the sinuses and help prevent infections. However, using this therapy too often may not be beneficial.

The latest study, presented at the American College of Allergy, Asthma, & Immunology (ACAAI) annual meeting, included 68 adults who used nasal irrigation frequently for one year and then stopped therapy for one year. The patients were compared to 24 control patients who did not discontinue nasal irrigation.

The researchers found that number of sinus infections decreased by 62.5 percent after the participants stopped using nasal irrigation. Additionally, after stopping nasal irrigation, they were 50 percent less likely to develop sinus infections than those who continued with daily therapy.

Mucus in the nose contains important immune system molecules that help the body fight against infections. Because nasal irrigation eliminates this mucus, the authors suspect that it may lead to an increased risk of infection.

Egyptian Mummies Had Clogged Arteries

CAIRO – Rich Egyptians living 3,500 years ago may have been walking around with the same clogged arteries that modern Americans now battle, according to a presentation Monday at the American Heart Association’s annual meeting.

A group of scientists said that, on a whim, they performed a computerized tomography (CT) scan on a collection of 22 mummies housed at the Egyptian National Museum of Antiquities in Cairo to see if they too suffered from the plaque build-up in arteries that lead to coronary artery disease.

“We didn’t believe it was going to be so intense,” said Adel H. Allam, the lead author of a letter to the editor published Tuesday in the Journal of the American Medical Association. “We thought that we would find it, but maybe very rarely, and we thought that if we did find it, it wouldn’t be so severe.”

The plaque was, of course, long gone. The mummies lived between 1981 B.C. and 364 A.D., and only 16 of the mummies had heart tissue left. However, doctors could see evidence of advanced atherosclerosis (plaque build-up that causes hardening of the arteries) by looking for calcium deposits in a CT scan used to diagnose people today.

Gene Therapy Raises Hope for the Color Blind

SEATTLE – Researchers in the US have made a breakthrough discovery which could bring a cure for colour blindness and other diseases that can lead to a total loss of sight.

Using gene therapy, the boffins successfully treated a pair of squirrel monkeys that could not differentiate between red and green.

The development could bring new treatments for a variety of different diseases that are triggered by faulty cone cells at the back of the eye. The problem can lead to diseases such as macular degeneration, which often causes complete blindness.

The research, which was led by Jay Neitz, professor of ophthalmology at the University of Washington, has been published in the scientific journal Nature, reports The Daily Express.

Professor Neitz said: “People who are colour blind often feel that they are missing out. If we could find a way to do this with complete safety in human eyes, as we did with monkeys, I think there would be a lot of people who would want it.

“Beyond that, we hope this technology will be useful in correcting lots of different vision disorders.”

Trouble Thinking? Better See the Dentist

NEW YORK – A new study hints that good oral care – regular brushing and flossing and trips to the dentist — may help aging adults keep their thinking skills intact.

In a study, researchers found that adults aged 60 and older with the highest versus the lowest levels of the gum disease-causing pathogen Porphyromonas gingivalis were three times more likely to have trouble recalling a three-word sequence after a period of time.

Dr. James M. Noble of Columbia College of Physicians and Surgeons in New York City and colleagues also found that adults with the highest levels of this pathogen were two times more likely to fail three-digit reverse subtraction tests.

The findings, reported in the Journal of Neurology, Neurosurgery, and Psychiatry this month, are based on more than 2300 men and women who were tested for periodontitis and completed numerous thinking skills tests as part of the National Health and Nutrition Examination Survey III conducted between 1991 and 1994.

Overall 5.7 percent of the adults had trouble completing certain memory tasks and 6.5 percent failed reverse subtraction tests. Participants with the highest (greater than 119 units) versus the lowest (57 units or lower) pathogen levels were most likely to do poorly in these tests.

Research has already established a strong association between poor oral health and heart disease, stroke and diabetes, as well as Alzheimer’s disease. Gum disease could influence brain function through several mechanisms, the researchers note; for example, gum disease can cause inflammation throughout the body, a risk factor for loss of mental function.

In a related commentary, Dr. Robert Stewart, of King’s College in London, United Kingdom, says this study adds to a “quietly accumulating” body of evidence tying oral and dental health with brain function.

SOURCE: Journal of Neurology, Neurosurgery, and Psychiatry, November 2009

Male and Female Chromosomes do Communicate with Each Other

LONDON – Scientists in the University of Leicester’s Department of Genetics have for the first time revealed that the male and female do truly communicate -at least at the fundamental genetic level.

The research counters scientific theory that the X and Y chromosomes – that define the sexes – do not communicate at all.

In the study, Dr. Zoe Rosser and colleagues have shown that exchange of DNA does actually occur between the X and Y in the regions previously thought to be completely isolated.

“Recently it was shown that the Y chromosome can talk to itself – swapping bits of DNA from one region to another, and potentially giving it a way to fix mutations that might affect male fertility. In this new research we’ve now shown that it actually maintains a genetic conversation with the X chromosome, potentially giving it a way to fix other kinds of mutations, too. So, maybe it’s not quite the dysfunctional loner we have always imagined it to be,” said Professor Mark Jobling, who led the study.

It is the Y chromosome in men that determines maleness by triggering development of testes rather than ovaries in the early embryo.

“These days the X and Y are a very odd couple, but long ago, before mammals evolved, they were an ordinary pair of identical chromosomes, exchanging DNA in a companionable way through the process of genetic recombination. However, once the Y chromosome took on the job of determining maleness, they stopped talking to each other. The X remained much the same, but the Y set out on a path of degeneration that saw it lose many of its genes and shrink to about one third the size of the X. Some scientists have predicted that it will eventually vanish altogether,” said Jobling.

“These new findings from the Department of Genetics of the University of Leicester now challenge this interpretation of the Y chromosome’s fate,” he added.

The researchers discovered that the conversation between the X and Y chromosome goes both ways, and it is also clear that mutations arising on a decaying Y chromosome can perhaps be passed to the X – the Y chromosome’s revenge.

In future, the researchers will assess how widespread X-Y exchanges have been during evolution, and what the likely functional effects might be.

 

The study has been published in the American Journal of Human Genetics.

War Talks Can Boost Older Adults’ Mental Health

EXETER, UK – Encouraging elderly to talk about old times can actually improve their memory and limit effects of dementia, finds a new study.

The research team led by Professor Catherine Haslam, at the University of Exeter, showed that ‘reminiscence therapy’ can significantly increase cognitive recall and agility of the mind by up to 12 per cent within six weeks.

During the study, the researchers recruited 73 people – aged between 70 and 90 and some with dementia – and split them into three groups.

The first group was made to sit around once a week in sets of five and reminisce about the old days such as childhood, weddings and family holidays, as well objects that could spark memories such as old-fashioned ink pots and hats.

After six weeks, the standard cognitive tests showed that the memory had improved by 12 per cent. Those suffering dementia saw an improvement of about eight per cent.

In contrast, the two other groups – one that was encouraged to play skittles – and another that was encouraged to have one on one chats showed very little improvement in their brain power.

“The people we were talking to were more than happy to bring up the war. It emerged as a very important part of their lives. As well as it improving their memory some people found it incredibly enjoyable,” the Telegraph quoted Prof Haslam, a neuropsychologist as saying.

“It doesn’t actually reverse dementia but it seems to make the most of their residual abilities,” she added.

Professor Alex Haslam, her husband, who was also carrying out research into social groups at the university, said the result were very significant.

“If you had a drug that could do that you would that you would make a lot of money. The drug in this case is the social group,” he said.

Measles Vaccine Inhaler Shows Promise

DENVER – Scientists from University of Colorado have revealed that inhaling measles vaccine can be more effective in combating the disease that causes 197,000 deaths each year globally.

While a liquid vaccine using a hypodermic needle is presently the only way to prevent the disease, they are often difficult to store, costly to transport and may be prone to contamination when shipped to developing countries.

The study led by Dr Robert Sievers shows promise for a new method that allows the patient to inhale a finely-powdered medicine.

In order to produce the inhalant, the weakened measles virus must be mixed with high-pressure carbon dioxide to produce microscopic bubbles and droplets, which are then gently dried to produce an inhalable powder.

The powder is then puffed into a small inhaler-like device and administered.

The aerosol vaccine was shown effective in test animals, and human trials are expected to begin next year in India, where more than half of the world’s measles cases occur.

Aridis Pharmaceuticals have been working to develop a room temperature stable measles formulation that can be easily inhaled using cost-effective dry-powder inhalers in collaboration with the non-profit foundation PATH.

“There is a need for technologies that could stabilize the measles vaccine, as this would facilitate mass vaccination in developing world countries where transport, storage, administration costs and other complexities have limited vaccine coverage by 70 percent,” said Dr Satoshi Ohtake, from Aridis and the study’s principal investigator.

Ohtake’s study used a combination of mild spray drying process conditions and unique stabilizers to produce stable dry powders with excellent preservation of vaccine activity.

The potency of the dried vaccine was then tested while being stored at different Temperatures over several week-long periods.

The results found that the dry-powdered aerosol was stable for at least eight weeks at 37 degrees Celsius.

“This new method could potentially offer safer, more affordable and effective treatments to patients that need them the most,” Ohtake added.

Pituitary Tumor Caused World’s Tallest Man’s Gigantism

ISTANBUL – The Turkish man crowned as the world’s tallest man suffers from a pituitary tumor which has resulted in his gigantic height.

Sultan Kosen stands eight-foot-one-inch tall and was unveiled as the tallest man in the world by the Guinness World Records. Kosen’s height is a result of a tumor in his pituitary gland, which has led to an over production of growth hormones, reports the National Geographic News.

The condition called pituitary gigantism has also led his feet to grow to almost 15 inches, while his hands are larger than 10 inches. It was only after the tumor was removed last year, that Kosen stopped growing.

The 27-year old is forced to use crutches as his height has weakened his knee joints.

The now-famous Kosen wants to travel around the world and meet a woman who would like to marry him.

Health Canada Warns of Health Risks Posed by Rating Raw Bean Sprouts

OTTAWA – Cook those bean sprouts well, advises Health Canada, if you want to reduce the risk of exposure to food borne illness.

“Children, the elderly, pregnant women and those with weakened immune systems are particularly vulnerable to these bacteria and should not eat any raw sprouts at all,” Health Canada and the Canadian Food Inspection Agency said Wednesday.

“They should also avoid eating cooked sprouts unless they can be sure the sprouts have been thoroughly cooked.”

The agencies note that sprouts from alfalfa and mung beans are a popular choice for Canadians as a low-calorie, healthy ingredient for many meals. Onion, radish, mustard and broccoli sprouts, not to be confused with the actual plant or vegetable, are also options.

But they may carry harmful bacteria such as salmonella and E. coli, which can lead to serious illness.

The largest recent outbreak in Canada linked to sprouts was in the fall of 2005, when more than 648 cases of salmonella were reported in Ontario.

Healthy adults who choose to eat sprouts are urged to ensure they buy crisp ones that have been refrigerated and avoid those that appear dark or smell musty. They should also use tongs or a glove to place the sprouts in a plastic bag.

Symptoms from salmonella usually occur 12 to 36 hours after eating contaminated food, while symptoms from E. coli can occur within two to 10 days.

Symptoms can include nausea, diarrhea, vomiting, fever and stomach cramps. People who experience these symptoms should contact a doctor immediately. In extreme cases, E. coli can lead to acute kidney failure or even death.

Memory Test Spots Pre-Dementia

LONDON – Memory and language tests can reliably reveal “hidden” early dementia, say UK experts.

Most dementias are missed for years as the symptoms can be elusive until considerable brain tissue is lost.

But doctors from Oxford found they were able to spot very early warning signs when they looked closely enough.

The findings in Neurology could help doctors diagnose dementia sooner, which is crucial since treatment is most effective when given early.

Over a span of 20 years, the researchers studied a group of 241 healthy elderly volunteers, giving them regular tests designed to measure their thinking or cognitive powers.

Being able to spot and measure the initial stages of dementia is a crucial challenge if we are to improve drug testing and lay the groundwork for prevention trials

When they scrutinized the test results, the doctors found subtle clues that, in retrospect, hinted at ensuing impairment.

Specifically, the patients who went on to develop mild cognitive impairment or pre-dementia stumbled on tasks involving language expression, learning and recall.

For example, they had greater difficulty remembering the name for common objects or animals and explaining the meaning of a given word.

And those who were older and who scored lower on the language or memory tests tended to deteriorate more quickly.

Professor David Smith and his team say their findings fit with what we already know about dementia.

Experts have noted that the early stages of dementia are associated with linguistic problems, such as word-finding difficulties.

Early literary works by authors who have later been diagnosed with Alzheimer’s show similar changes in language use – simpler narratives and a smaller vocabulary.

 

Rebecca Wood of the Alzheimer’s Research Trust said: “This significant long-term study shows how subtle, but measurable, problems with language or memory can predict when a healthy elderly person is likely to develop mild cognitive impairment, which frequently develops into dementia.

“Early intervention will be crucial for future dementia treatments. Being able to spot and measure the initial stages of dementia is a crucial challenge if we are to improve drug testing and lay the groundwork for prevention trials.”

Latest work in Archives of General Psychiatry adds weight to the evidence that Alzheimer’s dementia is at least partly inherited, and that being healthy in mid-life could help lower your risk of the disease.

Dutch researchers found that people with a parental history of Alzheimer’s had higher blood pressure and indicators of arterial disease as well as different amounts of inflammatory proteins in their blood compared with those without a parental history of Alzheimer’s.

What Does Anti-Aging Mean?

Like it or not, “anti-aging” now has a number of quite different common meanings and connotations. Each is championed by a particular group or loose coalition of interests, but advocates for these groups have a way of diving into the fray without defining their terms. This makes reading about anti-aging techniques, technologies, medicine, products, and debates very confusing for the newcomer.

For the scientific community, anti-aging research refers exclusively to slowing, preventing, or reversing the aging process. There is no medical technology that allows this to be done – although the jury is still out on calorie restriction in humans. Nor is there any currently available method (short of waiting for people to die) to accurately measure the effects of an alleged anti-aging therapy.

In the medical and more reputable business community, anti-aging medicine means early detection, prevention, and reversal of age-related diseases. This is quite different from tackling the aging process itself, and a wide array of strategies and therapies are currently available. Calorie restriction, for example, is a demonstrated way to lower risk for a wide range of age-related degenerative conditions.

The wider business community – including a great many fraudulent and frivolous ventures – views “anti-aging” as a valuable brand and a demonstrated way to increase sales. At the worse end of the scale, this leads to snake oil salesmen, “anti-aging” cremes that may or may not make your skin look younger, and infomercials that tout the “anti-aging” benefits of exercise machines. Broadly, and very charitably, we can look at these varied definitions of anti-aging as meaning “to look and feel younger in some way” – which has no bearing on how long you live or how healthy you actually are.

The confusion of most interest is between the first two definitions. Many interventions lengthen life span for individuals by preventing or curing specific age-related diseases that would otherwise prove fatal. For example, ask yourself whether preventing heart disease or diabetes is anti-aging medicine. This would have no effect on the aging process, but it would help many people to live longer, healthier lives. Is this anti-aging research? Scientists say no, some medical and business groups say yes.

Hippocampus Governs How We Devise Concepts in the Brain

LONDON – Scientists at the University College London have found that the hippocampus in the brain is responsible for our ability to organise the world into separate concepts.

Forming a concept involves selecting the important characteristics of our experiences and categorising them.

The degree to do this effectively is a defining characteristic of human intelligence.

However, not much is known about how conceptual knowledge is created and used in the brain.

Thus, to identify the brain regions responsible, Dharshan Kumaran and colleagues at the Wellcome Trust Centre for Neuroimaging, UCL, showed 25 volunteers, pairs of fractal patterns that represented the night sky and asked them to forecast the weather – either rain or sun – based on the patterns.

Conceptual rules based on the positions and combinations of the patterns governed whether the resulting outcome would be rain or sun, but the volunteers were not told this.

Instead, they rewarded correct predictions with cash prizes, encouraging the volunteers to deduce these conceptual rules.

In an initial learning phase, the different possible combinations were repeatedly shown to the participants, so that they could make their predictions by simply memorising previous outcomes and could also begin to realise that rules based on the positions and combinations of the patterns governed whether the result would be rain or sun.

In a second phase, the volunteers were provided with less information to encourage them to apply the rules they had identified, which made the researchers to separate those volunteers who had formed the concept in the learning phase from those who hadn’t.

During both experiments fMRI scanning was used to identify areas of brain activity.

It was found that in the first phase, they could tell if a volunteer would go on to apply concepts in the second phase by the degree of activity in their hippocampus, which is known to be responsible for learning and memory.

In the second phase, activity centred on the ventromedial prefrontal cortex (vMPFC), important in decision-making, was active.

The team concluded that the hippocampus creates and stores concepts, and passes this information onto the vMPFC where it is put to use during the making of decisions.

People with amnesia are also known to have problems forming concepts, so Kumaran is expecting his findings to lead to the development of improved teaching methods and other tools for the treatment of amnesiacs.

The study has been published in the journal Neuron.