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Mosquito ‘invisibility cloak’ discovered

A hand in a mosquito cage was not attractive when covered with the chemical

A naturally occurring substance found in human skin could yield a viable alternative to existing mosquito repellent, scientists say.

They say the chemical could help render people “invisible” to the insects.

At the American Chemical Society meeting, they revealed a group of compounds that could block mosquitoes’ ability to smell potential targets.

When a hand with these chemicals was placed in a mosquito filled enclosure, it was completely ignored.

The team says their work could help prevent the spread of deadly diseases.

Mosquitoes are among the most deadly disease-carrying creatures. They spread malaria, which in 2010 killed an estimated 660,000, according to the World Health Organization (WHO).

Ulrich Bernier of the United States Department of Agriculture (USDA) who presented the work, said his team was exploring other options to Deet – a repellent which some do not favour.

Buzzing off

In fact, earlier this year a team of scientists said that the widely used repellent was losing effectiveness.

“Repellents have been the mainstay for preventing mosquito bites… [but] we are exploring a different approach, with substances that impair the mosquito’s sense of smell. If a mosquito can’t sense that dinner is ready, there will be no buzzing, no landing and no bite,” said Dr Bernier.

It has long been known that some people are more attractive to mosquitoes than others, but now the team has pinpointed a group of chemical components secreted naturally, that can mask human smell from the blood-sucking insects.

Dr Bernier explained that hundreds of compounds on the skin makes up a person’s smell. In order to see what smells attracted mosquitoes, his team sprayed various substances onto one side of a cage.

It was the compounds that didn’t attract any mosquitoes that they looked at further and when sprayed on a human hand, the insects did not react or attempt to bite.

‘Invisible hand’

These chemical compounds, including 1-methylpiperzine, were found to completely block their sense of smell.

The compounds could be added into many cosmetics and lotions, Dr Bernier added.

“If you put your hand in a cage of mosquitoes where we have released some of these inhibitors, almost all just sit on the back wall and don’t even recognize that the hand is in there. We call that anosmia or hyposmia, the inability to sense smells or a reduced ability to sense smells.”

Commenting on the work, James Logan of the London School of Hygiene and Tropical Medicine, said it was exciting to find out exactly which chemicals repelled mosquitoes.

“Although we already have good repellents on the market, there is still room for new active ingredients. The challenge that scientists face is improving upon the protection provided by existing repellents.

“If a new repellent can be developed which is more effective, longer lasting and affordable, it would be of great benefit to travellers and people living in disease endemic countries,” Dr Logan told BBC News.

But he said that it would take many years before a new product would make it to market.

Source: BBC News/health

Lung cancer drug ‘could help treat ectopic pregnancy

A lung cancer drug could be given to women with ectopic pregnancies in a bid to help them avoid surgery.

A joint study by researchers in Edinburgh and Melbourne, Australia, found that combining a drug called gefitinib with existing treatment was more effective at curing the condition.

An ectopic pregnancy is when an embryo implants in the Fallopian tube.

It can be treated with drugs if identified early, but surgery is needed when it is more developed.

Each year, about 12,000 women in the UK have an ectopic pregnancy and the condition is responsible for up to 80% of pregnancy-related deaths.

The study, published in the journal Obstetrics and Gynaecology, involved a trial of 12 women.

Gefitinib, usually used to treat lung cancer, blocks a protein that is known to encourage cell growth, and which was found to be present in high levels at the site of ectopic pregnancies.

Scientists from the Edinburgh University’s medical research council centre for reproductive health, and the University of Melbourne, suggested that combining gefitinib with the conventional treatment – called methotrexate – could reduce the need to remove the Fallopian tube in a significant number of cases.

They said this would help a patient’s level of fertility.

The researchers also found that the drug combination was able to shorten the time it took to successfully treat ectopic pregnancies in women who did not need surgery.

Dr Andrew Horne, who led the study, said: “An ectopic pregnancy can be extremely stressful for the woman involved.

“If we can reduce the need for surgery, and thereby help fertility levels, then that would be an enormous benefit.

“Reducing the treatment time for women who do not need surgery would also have a significant impact in reducing the emotional stress of such a diagnosis.”

Researchers now plan to run a larger trial.

Source: BBC News

Magic ‘mushroom diet’? Experts scoff at weight-loss claim

A new diet fad claims that replacing one meal a day with mushrooms will help women shed fat, but only in certain parts of the body — the waist, hips and thighs — but not the bust.

The two-week diet, called the M Plan, according to the Daily Mail, has been touted by celebrities such as Kelly Osbourne and Katy Perry.

Experts say that there’s nothing magical about mushrooms — replacing one meal a day with any vegetable would help a person lose weight, said Katherine Tallmadge, a registered dietitian, and op-ed contributor to LiveScience.

And the claim about selective weight loss doesn’t hold up to science. “There’s no evidence that any diet … will help you lose weight in a particular spot,” Tallmadge said.

How people lose, and also gain, weight is determined largely by genetics, Tallmadge said, but factors such as age and smoking habits also play a role.

Studies show older women are more likely to gain weight around their belly, likely due to changing hormone levels, Tallmadge said. Smoking has also been linked to an increased risk of gaining weight in the midsection.

However, studies suggest that certain exercises may help people lose weight selectively: there’s evidence that walking is an effective exercise for helping people lose belly fat, Tallmadge said.

 

Iron supplementation does not increase susceptibility to malaria

Kids in a malaria-endemic community in Ghana, who received a micronutrient powder with iron did not have an increased incidence of malaria, a study has claimed.

Previous research has suggested that iron supplementation for children with iron deficiency in malaria-endemic areas may increase the risk of malaria.

Stanley Zlotkin, M.D., Ph.D., of the Hospital for Sick Children, Toronto, and colleagues conducted a study to determine the effect of providing micronutrient powder (MNP) with or without iron on the incidence of malaria among children living in a high malaria-burden area.

The randomized trial, which included children 6 to 35 months of age (n = 1,958 living in 1,552 clusters), was conducted over 6 months in 2010 in a rural community setting in central Ghana, West Africa.

A cluster was defined as a compound including 1 or more households. Children were excluded if iron supplement use occurred within the past 6 months; they had severe anemia, or severe wasting.

Children were randomized by cluster to receive a MNP with or without iron for 5 months followed by 1-month of further monitoring. Insecticide-treated bed nets were provided at enrollment, as well as malaria treatment when indicated.

Throughout the intervention period, adherence to the use of MNP and insecticide-treated bed nets were similar between the iron group and the no iron group.

The study has been published in JAMA.

 

Differences in lung function have major health impact

A global study has suggested that large differences in lung function between healthy people from different socioeconomic and geographical regions of the world could impact their health.

The large differences in lung function could not be accounted for by variations across regions in height, weight, age, gender, education levels and rural or urban location.

Dr. MyLinh Duong, lead author of the paper and an assistant professor of medicine of the Michael G. DeGroote School of Medicine at McMaster University, said that the findings have important public health implications, as there is a well known link between low lung function and increased mortality.

Researchers at McMaster University said that these differences may be genetically determined, but more likely most relate to the socio-economic, nutritional and environmental exposures of people in the different regions. These are all conditions that could be modified or improved.

Respirologist Dr. Paul O“Byrne, who is the co-author of the paper, said that these findings are of great importance, as we need separate standards for what is considered normal in different parts of the world and may lead us to rethink how to define those with abnormal lung function.

The study included 154,000 adult non-smokers between 35 and 70 years old from 17 countries from four continents.

Some of the factors such as nutrition and pollution levels will be explored in future analysis of the study.

The study is published in the journal, The Lancet Respiratory Medicine.

 

Fish oil could help alcohol abusers keep dementia at bay

A new research has suggested that omega-3 fish oil may help protect against alcohol-related dementia.

The study, Loyola University Chicago Stritch School of Medicine, found that in the brain cells of rats exposed to high levels of alcohol, a fish oil compound protected against inflammation and cell death.

In the study, Michael A. Collins, PhD, and colleagues exposed cultures of adult rat brain cells to amounts of alcohol equivalent to more than four times the legal limit for driving.

These cell cultures were compared with cultures of brain cells exposed to the same high levels of alcohol, plus a compound found in fish oil called omega-3 docosahexaenoic acid (DHA).

Researchers found there was about 90 percent less neuro inflammation and neuronal death in the brain cells exposed to DHA and alcohol than in the cells exposed to alcohol alone.

 

New method could help in early detection of colon cancer

Bettina Scholtka, said that tumour cells are released into stool from the surface of precancers and early-stage colon cancers

Scientists have found a new method to detect genetic variations that initiate colon cancer could be readily used for non-invasive colon cancer screening.

Bettina Scholtka, Ph.D., assistant professor in the Department of Nutritional Toxicology at the University of Potsdam in Nuthetal, Germany, said that tumour cells are released into stool from the surface of precancers and early-stage colon cancers, but detecting a cancer-initiating genetic mutation among a large quantity of normal DNA from a patient’s stool is like looking for a needle in a haystack.

Scholtka said that by combining for the first time locked nucleic acid-based, wild-type blocking polymerase chain reaction and high-resolution melting, we were able to achieve the desired sensitivity.

Scholtka and colleagues used 80 human colon tissue samples representing cancers and precancers to detect genetic variations using a combination of two techniques: The first technique — locked nucleic acid (LNA)-based, wild-type blocking (WTB) polymerase chain reaction — suppressed normal DNA present in large quantities in the sample; and the second technique — high-resolution melting (HRM) — enhanced the detection of genetic variations.

The researchers were able to detect APC variations in 41 of the 80 samples. They were also able to detect previously unknown variations in APC. In contrast, the routinely used technique called direct sequencing could detect variations only in 28 samples.

They then analyzed 22 stool samples from patients whose colon tissues had APC variations, and nine stool samples from patients whose colon tissues did not have APC variations, as controls. They were able to detect APC variations in 21 out of 22 samples.

The study has been published in Cancer Prevention Research.

15% of common strokes occur in adolescents and young adults

A team of researcher including an Indian origin has suggested that 15 percent of the most common type of strokes occur in adolescents and young adults, and more young people are showing risk factors for such strokes.

Co-author neurologist Jose Biller of Loyola University Medical Center said that the impact of strokes in this age group is devastating to the adolescent or young adult, their families and society.

About 85 percent of all strokes are ischemic, meaning they are caused by blockages that block blood flow to the brain. And more young people have risk factors for ischemic strokes.

Those risks include high blood pressure, diabetes, obesity, abnormal cholesterol levels, congenital heart disease and smoking.

Strokes in young people have a disproportionally large economic impact, because they can disable patients before their most productive years. And while coping with the shock of having a stroke, “younger survivors may be dealing with relationships, careers and raising children – issues that require additional awareness and resources,” the consensus report said.

Biller, one of the nation’s leading experts on stroke in young people, is second author of the consensus report. Biller is chair of the Department of Neurology of Loyola University Chicago Stritch School of Medicine. First author of the report is Aneesh Singhal, MD of Massachusetts General Hospital.

The study has been published in the journal Neurology.

 

Genetic cause of childhood leukemia revealed

Scientists have uncovered a genetic link specific to the risk of childhood leukaemia.

Study author Kenneth Offit, MD, MPH, Chief of the Clinical Genetics Service at Memorial Sloan-Kettering Cancer Center, said that at the very least the discovery gives us a new window into inherited causes of childhood leukemia.

Offit said that more immediately, testing for this mutation may allow affected families to prevent leukemia in future generations.

The mutation was first observed in a family treated at Memorial Sloan-Kettering of which several family members of different generations had been diagnosed with childhood acute lymphoblastic leukemia (ALL).

A second, non-related, leukemia-prone family cared for at a different hospital was later found to have the same mutation. A series of experiments were conducted confirming that the observed mutation compromised the normal function of the gene, which may increase the risk of developing ALL.

The inherited genetic mutation is located in a gene called PAX5, which is known to play a role in the development of some B cell cancers, including ALL.

The findings have been published in the journal Nature Genetics.

 

Yoga may benefit prisoners psychologically

Yoga can improve the mood and mental well being of prisoners and may also affect their impulsive behaviour, a study has revealed.

The researchers at the Oxford University have found that prisoners after a ten-week yoga course reported improved mood, reduced stress and were better at a task related to behaviour control than those who continued in their normal prison routine.
“We found that the group that did the yoga course showed an improvement in positive mood, a decrease in stress and greater accuracy in a computer test of impulsivity and attention,” Dr Amy Bilderbeck and Dr Miguel Farias, who led the study at the Departments of Experimental Psychology and Psychiatry at Oxford University, said.

“The suggestion is that yoga is helpful for these prisoners,” they further explained.

The study has been presented in the Journal of Psychiatric Research.