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Apr 10
Dengue vaccine comes closer to reality
Researchers from MIT`s Koch Institute of Integrative Cancer Research including two of Indian origin have presented a novel approach to developing a dengue therapy using mutated antibodies.

According to a study by the International Research Consortium on Dengue Risk Assessment, Management and Surveillance, up to 390 million people are infected with the dengue virus each year. For most people the mosquito-borne virus causes flulike symptoms, including fever, headache and joint pain. But for some, particularly children, the virus can develop into the far more serious dengue hemorrhagic fever, causing severe blood loss and even death.

Despite the threat posed by the disease, developing a vaccine against dengue has so far proved challenging, according to Ram Sasisekharan, the Alfred H. Caspary Professor of Biological Engineering at MIT. That`s because dengue is not one virus but four different viruses, or serotypes, each of which must be neutralized by the vaccine.

Protecting people from only one or some of the four viruses could cause them to develop the more severe form of dengue if they later become infected with one of the other serotypes, in a process known as antibody-dependent enhancement, Sasisekharan explained.

"That was the motivation for carrying out our study, to generate a fully neutralizing antibody that works for all four serotypes," he stated.

This transmission electron micrograph depicts a number of round, dengue virus particles.

Efforts to develop a therapeutic antibody for dengue are focused on a part of the virus called the envelope protein.

"This is a very critical protein that allows the virus to latch on to the appropriate receptor within the host, to infect them, replicate and spread," Sasisekharan said.

The envelope protein contains two regions of interest, known as the loop and the "A" strand. Research teams have previously attempted to engineer an antibody that targets the loop region of the virus protein, as this is known to be able to attack all four serotypes if targeted in the right way.

However, the antibodies that target the loop region tend to have low potency, meaning they are unable to completely neutralize the virus. This increases the risk of more severe secondary dengue infection.

So a team led by Sasisekharan decided instead to look for antibodies that target the "A" strand region of the protein. Such antibodies tend to have much higher potency, but they are unable to neutralize all four serotypes.

The researchers chose as their model an antibody known as 4E11, which has been shown in tests to neutralize dengue 1, 2 and 3, but not dengue 4.

"We wanted to see if we could get good neutralizing activity to dengue 4, and also tweak the antibody to increase the potency associated with the other subtypes," Sasisekharan said.

The researchers mined existing antibody-antigen complexes to analyze the physical and chemical features that play an important role in their interaction, such as hydrogen bonding and ionic attraction. Taking a statistical approach, they then ranked these features in terms of their importance to each of the antibody-antigen interactions.

This significantly narrowed the number of possible changes, or mutations, the researchers needed to make antibody 4E11 in order to improve its ability to neutralize all four viruses, in particular dengue 4.

"So rather than random screening, we used a statistically driven approach so we knew the regions to focus on, and what things we had to change," Sasisekharan said.

As a result, the researchers came up with 87 possible mutations, which they were able to reduce to just 10 changes after further investigation.

When they tested their mutated antibody on samples of the four dengue serotypes in the laboratory, they found it had a 450-fold increase in binding to dengue 4, a 20-fold increase in binding for dengue 2, and lesser improvements in binding for dengue 1 and 3, Sasisekharan noted.

The researchers have developed a novel computational method for predicting protein-protein interaction that captures the essential chemical and physical features of interacting surfaces, asserted Subhash Vasudevan, an associate professor in the Emerging Infectious Diseases Program at the Duke-NUS Graduate Medical School in Singapore.

"By learning and validating data from numerous three-dimensional structures of interacting antibody and protein complexes, the researchers gained valuable insights that enabled them to redesign a dengue virus envelope antibody to improve its binding by an astounding 450-fold," Vasudevan said.

"The cross-reactive and pan-dengue neutralizing antibody was protective against all four serotypes in cell culture and in an animal model of infection," he added.

The MIT researchers are now preparing for potential preclinical trials, and hope to be ready to test the antibody on humans within the next two to three years. In the meantime, they are also investigating other targets for their immunotherapy approach, including the influenza virus.

A paper describing the study results was published in the Proceedings of the National Academy of Sciences.

Apr 10
Couch potatoes may be genetically predisposed to being lazy
Certain genetic traits may predispose people to being more or less motivated to exercise and remain active, a new research from the University of Missouri has suggested.

Frank Booth, a professor in the MU College of Veterinary Medicine, along with his post-doctoral fellow Michael Roberts, were able to selectively breed rats that exhibited traits of either extreme activity or extreme laziness. They said these rats indicate that genetics could play a role in exercise motivation, even in humans.

"We have shown that it is possible to be genetically predisposed to being lazy," Booth said.

"This could be an important step in identifying additional causes for obesity in humans, especially considering dramatic increases in childhood obesity in the United States. It would be very useful to know if a person is genetically predisposed to having a lack of motivation to exercise, because that could potentially make them more likely to grow obese," he added.

In their study, Roberts and Booth put rats in cages with running wheels and measured how much each rat willingly ran on their wheels during a six-day period. They then bred the top 26 runners with each other and bred the 26 rats that ran the least with each other. They repeated this process through 10 generations and found that the line of running rats chose to run 10 times more than the line of "lazy" rats.

Once the researchers created their "super runner" and "couch potato" rats, they studied the levels of mitochondria in muscle cells, compared body composition and conducted thorough genetic evaluations through RNA deep sequencing of each rat.

"While we found minor differences in the body composition and levels of mitochondria in muscle cells of the rats, the most important thing we identified were the genetic differences between the two lines of rats," Roberts said.

"Out of more than 17,000 different genes in one part of the brain, we identified 36 genes that may play a role in predisposition to physical activity motivation," he revealed.

Now that the researchers have identified these specific genes, they plan on continuing their research to explore the effects each gene has on motivation to exercise.

The study was recently published in the American Journal of Physiology: Regulatory, Integrative and Comparative Physiology.

Apr 09
Your skin can say a lot about health
Your skin can be a crucial early-warning system for a range of health problems, according to doctors.

They said signs of brittle bones, diabetes and vitamin deficiencies may surface on skin before other symptoms appears, the Huffington Post reported.

A study of 114 recently postmenopausal women found that deep wrinkles on the face and neck could indicate an increased risk for broken bones.

The reason is that women with such wrinkles were more likely to have lower bone density in areas like the hips, spine and heels.

Estrogen promotes the production of the protein collagen, which your skin and bones both rely on to maintain density. So as a woman`s level of estrogen declines in menopause, said Dr. Ronald Young, co-director of the Menopause Center at Texas Children`s Pavilion for Women in Houston, "collagen in the skin is depleted, which means the skin isn`t as firm and elastic, and wrinkles develop."

Deeper, worsening wrinkles are a sign that the body is producing less collagen, which often means bone density is decreasing as well.

The worse the wrinkles, the lesser the bone density, added lead researcher Lubna Pal, a Yale School of Medicine associate professor.

"This relationship was independent of age or of factors known to influence bone mass," Pal noted.

If you discover thick, dark, velvety patches on folds of skin on your neck, armpit or groin, doctors suggest a blood test to check for diabetes.

These patches, known as acanthosis nigricans, could be benign or a normal side effect of obesity, but they also could be a sign of diabetes, said dermatologist Janet Lin of Baltimore`s Mercy Medical Center.

Thyroid gland is responsible for hormones that, among other functions, regulate your body temperature, metabolism and nervous system as well as the health of skin, hair and nails.

Signs that your thyroid isn`t performing properly-it can be either overactive or underactive-tend to appear first on your skin, typically on the back of your upper arms and the back of your fingers.

At first the skin just seems rough or bumpy, like a mild rash, according to naturopath Alan Christianson of Phoenix.

But if the thyroid continues to be out of whack, other areas can be affected, he said, such as the legs, scalp and neck. An underactive gland could result in hair loss, brittle nails or dry, flaky skin.

If any such things happen, schedule a physical with your internist and ask for a thyroid function test, the doctors said.

Again dull, dry skin or complexion could indicate an omega-3 deficiency, Christianson said, because its absence can slow your natural exfoliation cycle, also potentially leading to dryness or dandruff.
Supplements are one option to restore omega-3, but the best way to correct the deficiency is through diet.

The American Heart Association recommends eating a 3- to 4-ounce serving of oily fish twice a week. Flaxseeds, walnuts and soybeans can also help maintain omega-3 levels , it said.

Apr 09
FDA approves once-banned morning sickness drug
The US Food and Drug Administration (USFDA) has approved a drug to treat morning sickness that was banned 30 years ago amid claims that the pills caused birth defects. The safety scare however proved to be a false alarm.

The drug, which was initially approved in the United States under the name Bendectin in 1956, is set to return to the pharmacies in June under a different name Diclegis.

Bendectin was withdrawn in 1983 following a slew of lawsuits from mothers claiming their children had been harmed by it. The US health agency, however, confirmed that the drug had not been withdrawn because it was ineffective or posed a danger but because the company, Merrell Dow, found the litigation cost too high.

Morning sickness, also called nausea gravidarum, affects more than half of all pregnant women. Though the symptoms usually persist in the early hours of the morning, for some it can occur at any time of the day. Nausea and vomiting due to pregnancy usually improve after the first trimester.

Apr 08
Low melatonin levels tied to diabetes risk
Low levels of melatonin, a hormone regulating the sleep-wake cycle, may increase the risk of Type 2 diabetes in women, a new study has warned.

US researchers found that women who had low levels of melatonin at night had twice the risk of developing Type 2 diabetes over a 12-year period compared with women who had high melatonin levels.
The link between low melatonin levels and Type 2 diabetes held even after the researchers took into account other factors that could increase the risk of diabetes, such as age, weight, physical activity levels and sleep duration.

However, the study only found an association, and cannot prove that low melatonin levels cause Type 2 diabetes, website MyHealthNewsDaily reported.

The findings raise the question of whether increasing people`s melatonin levels, through supplements or prolonged exposure to darkness, could decrease diabetes risk, said study researcher Dr Ciaran McMullan, of Brigham and Women`s Hospital in Boston.

The new study involved 370 women who developed Type 2 diabetes between 2000 and 2012 (but did not have the condition before the study`s start), and 370 women who didn`t develop diabetes.

Urine samples were collected in the morning as a way to measure melatonin levels produced overnight.

Factors that can lower melatonin levels include: sleep disturbances, short sleep duration, working the night shift and taking certain drugs, such as beta-blockers, said Dr John Forman, also of Brigham and Women`s Hospital.

The study included mostly white women, so it`s not clear if the results apply to men or to other ethnic groups, the researchers said.

Since more research is needed to confirm the findings, it`s too early to recommend that people start taking melatonin to reduce their diabetes risk, Forman said.

The study appears in the Journal of the American Medical Association.

Apr 08
Healthy diet key to prevention and treatment of cancer
Eating right can help you prevent cancer and even support your treatment if you`ve already been diagnosed, say experts.

Ethan Bergman, registered dietitian nutritionist and Academy of Nutrition and Dietetics President, said that whether you, a parent, friend or a child has been diagnosed, chances are, your life has been touched by cancer.
Bergman said that while cancer can leave us feeling helpless, the good news is that there are measures you can take to prevent the disease.

Your diet is one of the most important factors under your control.

According to Bergman, a healthful eating plan can lower your risk for developing cancer and if you have been diagnosed, eating well can positively support treatment and help you live well after treatment.

He said that diet could affect disease prevention for not only cancer, but also heart attacks, Type 2 diabetes and strokes and deaths from cardiovascular disease.

While more research is needed on the precise mechanisms, Bergman noted that one could help reduce cancer risk through eating right.

Maintaining a healthy weight is key to reducing your risk of cancer and other diseases, he said.

He suggests eating fewer foods that are high in calories and fat and low in nutrients.

Foods with added sugars and fats can cause weight gain and leave little room for more healthy, cancer-preventing foods, he noted.

Eat plenty of fruits and vegetables, which are linked with a lower risk of certain cancers, he said.

He advised to limit alcohol because evidence suggests all types of alcoholic drinks may increase risk of a number of cancers, including mouth, throat (pharynx), voice box (larynx), esophageal, liver, breast, colon and rectal.

It`s unclear exactly how alcohol affects cancer risk. It is considered more harmful when combined with smoking. If you drink at all, limit alcoholic drinks to no more than one drink daily for women and two for men, he added.

Apr 06
World`s population will stop growing in 2050: Study
Global population data spanning the years from 1900 to 2010 have enabled researchers to predict that the number of people on Earth will stabilise around the middle of the century, a report has said.

The results, obtained with a model used by a research team from the Autonomous University of Madrid, coincide with the UN`s downward forecasts.
According to United Nations` estimates, the world population in 2100 will be within a range between 15.8 billion people according to the highest estimates, high fertility variant- and 6.2 billion according to the lowest, low fertility variant, a figure that stands below the current 7 billion.

A mathematical model developed by a team from the Autonomous University of Madrid (UAM) and the CEU-San Pablo University, both from Spain, seems to confirm the lower estimate, in addition to a standstill and even a slight drop in the number of people on Earth by the mid-21st century.

The population prospects between 1950 and 2100 provided by the UN were used to conduct the study, published in the journal `Simulation`.

Mathematical equations that are used in scientific fields, such as condensed matter physics, were then applied to this data.

The model`s S-shaped sigmoid curve reflects this situation with an inflection point in the mid-1980s when the speed at which the population is growing starts to slow down until it stabilises around 2050.

The data also reflected the downward trend in the UN`s series of prospects.

"Overpopulation was a spectre in the 1960s and 70s but historically the UN`s low fertility variant forecasts have been fulfilled," Felix F. Munoz, UAM researcher and co-author of the project. highlighted.

Apr 06
No sign of sustained transmission of H7N9 virus in China: WHO
The World Health Organization has said that there was no sign of `sustained human-to-human transmission` of the H7N9 virus in China.

The UN health organisation, however, said that it was important to check on 400 people who had been in close contact with the 14 confirmed cases.

WHO spokesman Gregory Hartl told a news briefing in Geneva that they have 14 cases in a large geographical area, and have no sign of any epidemiological linkage between the confirmed cases, and we have no sign of sustained human-to-human transmission.

The 400 contacts are being followed up to see if any of them do have the virus, have had it from someone else, he added.

Meanwhile, Chinese authorities slaughtered over 20,000 birds on Friday at a poultry market in Shanghai, Fox News reports.

The move came as the death toll from the new strain of bird flu mounted to six, spreading concern overseas and sparking a sell-off on Hong Kong`s share market.

Apr 05
Anti-HIV vaccine hopes rise with 'training manual'
In an important step forward in the fight against HIV, scientist at Duke University have recorded the body`s own "training manual" for successfully attacking HIV, a finding that may turn out to be useful in developing vaccines.

The research team's study is based on a patient in Africa who had a rapid diagnosis, about four weeks after being infected with the virus. However, it was found that his immune system started to an antibody named CH 103 that could neutralize bout 55 percent of all known HIV strains.

As per the study, published in the journal Nature, the super antibody was not produced in one step. Rather it was the product of the war of the immune system and HIV trying to out-evolve each other.
Using cutting edge genetic analyses tools, the scientists' pieced together each of the steps that culminated in the production of CH103 it was like a training manual for the immune system.

Human body develops antibodies to fight off infections, but HIV mutates rapidly in defense against the onslaught. Only 20 Percent of HIV patients develop them naturally. This study, however, has given an insight into how broadly neutralizing antibodies progress.
"What we were able to do was map out the arms race of both virus and antibody, and in doing so we have now a map," Prof Barton Haynes, a leader of the research from Duke University, told the BBC.

"This is the first time we`ve been able to see the actual road map."

This research could help scientists make a vaccine that would mimic the antibodies` evolution and ward off HIV.

Apr 05
Male baldness indicates heart disease risk
Male pattern baldness is linked to an increased risk of coronary heart disease, but only if it`s on the top/crown of the head, a new study has revealed.

A receding hairline is not linked to an increased risk, the analysis indicates.

The researchers from University of Tokyo trawled the Medline and the Cochrane Library databases for research published on male pattern baldness and coronary heart disease, and came up with 850 possible studies, published between 1950 and 2012.

But only six satisfied all the eligibility criteria and so were included in the analysis. All had been published between 1993 and 2008, and involved just under 40,000 men.

Three of the studies were cohort studies - meaning that the health of balding men was tracked for at least 11 years.

Analysis of the findings from these showed that men who had lost most of their hair were a third more likely (32 percent) to develop coronary artery disease than their peers who retained a full head of hair.

When the analysis was confined to men under the age of 55-60, a similar pattern emerged. Bald or extensively balding men were 44 percent more likely to develop coronary artery disease.

Analysis of the other three studies, which compared the heart health of those who were bald / balding with those who were not, painted a similar picture.

It showed that balding men were 70 percent more likely to have heart disease and those in younger age groups were 84 percent more likely to do so.

Three studies assessed the degree of baldness using a validated scale (Hamilton scale). Analysis of these results indicated that the risk of coronary artery disease depended on baldness severity, but only if this was on the top/crown of the head, known as the vertex.

Extensive vertex baldness boosted the risk by 48 percent, moderate vertex baldness by 36 percent, and mild vertex baldness by 18 percent. By contrast, a receding hairline made very little difference to risk, the analysis showed.

The study is published in the online journal BMJ Open.

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