9th Dec 2014, 01:28 PM #1631
Re: Health Bulletin
New compound offers malaria cure in 48 hours
A promising new anti-malarial compound tricks the immune system to rapidly destroy red blood cells infected with the malaria parasite without damaging healthy cells, a new study has found.
Researchers determined that the compound (+)-SJ733 uses a novel mechanism to kill the parasite by recruiting the immune system to eliminate malaria-infected red blood cells. In a mouse model of malaria, a single dose of (+)-SJ733 killed 80% of malaria parasites within 24 hours. After 48 hours the parasite was undetectable. Planning has begun for safety trials of the compound in healthy adults, researchers said.
Laboratory evidence suggests that the compound's speed and mode of action work together to slow and suppress development of drug-resistant parasites. "Our goal is to develop an affordable, fast-acting combination therapy that cures malaria with a single dose," said corresponding author R Kiplin Guy, from the St Jude Children's Research Hospital in the United States.
Whole genome sequencing of the Plasmodium falciparum, the deadliest of the malaria parasites, showed that (+)-SJ733 disrupted activity of the ATP4 protein in the parasites. The protein functions as a pump that the parasites depend on to maintain the proper sodium balance by removing excess sodium.
Investigators used the laboratory technique to determine the makeup of the DNA molecule in different strains of the malaria parasite. "This rapid clearance response depends on the presence of both the parasite and the investigational drug. That is important because it leaves uninfected red blood cells unharmed," said Joseph DeRisi, a Howard Hughes Medical Institute investigator. Laboratory evidence also suggests the mechanism will suppress development of drug-resistant strains of the parasite.
9th Dec 2014, 08:15 PM #1632
Re: Health Bulletin
Why people crave for sugar-rich foods
Researchers have discovered a mechanism that prompts people to seek food rich in glucose - the body's main energy source.
An enzyme called glucokinase in the brain, involved in sensing glucose in the liver and pancreas, plays a key role in driving our desire for glucose, researchers showed in their findings.
It might be possible to reduce cravings for glucose by altering one's diet, it suggested.
"Our brains rely heavily on glucose for energy. So we have a deep-rooted preference for glucose-rich foods," said lead researcher James Gardiner from Imperial College London.
The researchers discovered that when rats go for 24 hours without eating, the activity of glucokinase in an appetite-regulating centre of the brain increases sharply.
The rats were given access to a glucose solution as well as their normal food pellets, called chow.
When the researchers increased the activity of glucokinase in the hypothalamus using a virus, rats consumed more glucose in preference to chow. When glucokinase activity was decreased, they consumed less glucose.
"This is the first time anyone has discovered a system in the brain that responds to a specific nutrient, rather than energy intake in general," Gardiner pointed out.
It suggests that when you are thinking about diet, you have to think about different nutrients not just count calories, Gardiner added.
The study appeared in the Journal of Clinical Investigation.
10th Dec 2014, 02:48 PM #1633
Re: Health Bulletin
Flu vaccines boost immunity against many strains
Researchers have found that seasonal flu vaccines protect individuals not only against the strains of flu they contain but also against many additional types.
"The finding suggests the seasonal flu vaccine boosts antibody responses and may provide some measure of protection against a new pandemic strain that could emerge from the avian population," said senior study author Paul Thomas from St. Jude Children's Research Hospital in Tennessee.
The researchers found that some participants who reported receiving flu vaccines had a strong immune response not only against the seasonal H3N2 flu strain from 2010, but also against flu subtypes never included in any vaccine formulation.
"There might be a broader extent of reactions than we expected in the normal human population to some of these rare viral variants," Thomas added.
For the study involving 95 bird scientists as participants, the researchers tested whether exposure to different types of birds can elicit immune responses to avian influenza viruses in humans.
Most individuals tested had a strong antibody response to the seasonal H3N2 human virus-derived H3 subtype, but many also had strong measurable antibody responses to avian subtypes.
The study appeared in the journal mBio.
10th Dec 2014, 02:48 PM #1634
Re: Health Bulletin
Simple potato extract can control obesity
To the delight of potato lovers, researchers have found a simple potato extract may limit weight gain from a diet which is high in fat and refined carbohydrates.
The benefits of the extract are due to its high concentration of polyphenols, a beneficial chemical component also found in fruits and vegetables, said the scientists from McGill University in Canada.
"We were astonished by the results," said Luis Agellon, one of the study's authors.
"We thought this can't be right - in fact, we ran the experiment again using a different batch of extract prepared from potatoes grown in another season, just to be certain," Agellon explained.
Popularly known for its carbohydrate content, the potato is also a source of polyphenols.
While carrying out the study, the researchers fed mice an obesity-inducing diet for 10 weeks.
As a result, the mice that started out weighing on average 25 grams put on about 16 grams. But mice that consumed the same diet but with a potato extract gained much less weight - only seven more grams.
"The daily dose of extract comes from 30 potatoes, but of course we do not advise anyone to eat 30 potatoes a day," principal author of the study Stan Kubow pointed out.
Although humans and mice metabolize foods in similar ways, clinical trials are absolutely necessary to validate beneficial effects in humans. Besides, the optimal dose for men and women also needs to be determined, since their metabolisms differ.
The study appeared in the journal Molecular Nutrition & Food Research.
11th Dec 2014, 04:51 PM #1635
Re: Health Bulletin
Lower IQ seen after exposure to plastic chemicals
Pregnant women who were exposed to high levels of common household chemicals found in plastics, cosmetics and air fresheners had children whose intelligence suffered years later, a US study said Wednesday.
Kids whose moms had elevated traces of di-n-butyl phthalate (DnBP) and di-isobutyl phthalate (DiBP) had an average IQ that was around six points below their peers whose mothers had lower levels of chemical exposure.
Based on the findings, researchers urged pregnant women to limit their exposure to scented products including air fresheners and dryer sheets, avoid microwaving food in plastics, and steer clear of recyclable plastics labeled as 3, 6, or 7 in order to reduce risks to their offspring.
"Pregnant women across the United States are exposed to phthalates almost daily, many at levels similar to those that we found were associated with substantial reductions in the IQ of children," says lead author Pam Factor-Litvak, PhD, associate professor of Epidemiology at the Mailman School of Public Health at Columbia University in New York.
"While there has been some regulation to ban phthalates from toys of young children, there is no legislation governing exposure during pregnancy, which is likely the most sensitive period for brain development."
The study in the journal PLOS ONE is the first to report a link between prenatal exposure to phthalates and IQ in school-age children.
The research is based on 328 low-income New York City women and their children.
They measured the women`s exposure to four phthalates -- DnBP, DiBP, di-2-ethylhexyl phthalate, and diethyl phthalate -- in the third trimester of pregnancy by taking urine samples.
Their children were given IQ tests when they turned seven years of age.
"Children of mothers exposed during pregnancy to the highest 25 percent of concentrations of DnBP and DiBP had IQs 6.6 and 7.6 points lower, respectively, than children of mothers exposed to the lowest 25 percent of concentrations after controlling for factors like maternal IQ, maternal education, and quality of the home environment that are known to influence child IQ scores," said the study.
The other two phthalates studied showed no link to lower IQ.
The level of exposure found in the women was well within what the US Centers for Disease Control and Prevention observed in a national sample.
"The magnitude of these IQ differences is troubling," said senior author Robin Whyatt, professor of environmental health sciences and deputy director of the Columbia Center for Children`s Environmental Health at the Mailman School.
"A six- or seven-point decline in IQ may have substantial consequences for academic achievement and occupational potential."
DnBP and DiBP are found in dryer sheets, vinyl fabrics, lipstick, hairspray, nail polish, and some soaps. Products in the United States rarely list on the label whether they contain phthalates or not.
11th Dec 2014, 04:52 PM #1636
Re: Health Bulletin
Added sugar more harmful for heart than salt
A new study has revealed that added sugars likely to have greater role than salt in high blood pressure and heart disease.
According to the researchers, dietary approaches to lower high blood pressure have historically focused on cutting salt intake. But the potential benefits of this approach "are debatable,", because the average reductions in blood pressure achieved by restricting salt intake tend to be relatively small, and there is some evidence to suggest that 3-6 g salt daily may be optimal for health, and that intake below 3 g may actually be harmful.
The study also pointed out that most salt in the diet comes from processed foods, which also happen to be a rich source of added sugars and sugar may be much more meaningfully related to blood pressure than sodium, as suggested by a greater magnitude of effect with dietary manipulation.
They point the finger in particular to high fructose corn syrup, which is the most frequently used sweetener in processed foods, particularly fruit-flavoured and fizzy drinks.
The evidence suggests that people whose dietary intake of added sugars adds up to at least a quarter of their total daily calories have almost triple the cardiovascular disease risk of those who consume less than 10 percent.
And a daily intake of more than 74 g of fructose is associated with a 30 percent greater risk of blood pressure above 140/90 mm Hg and a 77 percent increased risk of blood pressure above 160/100 mm Hg.
A high fructose diet has also been linked to an unfavourable blood fat profile, higher fasting blood insulin levels, and a doubling in the risk of metabolic syndrome.
11th Dec 2014, 04:52 PM #1637
Re: Health Bulletin
Laughing gas may help treat depression
Laughing gas or nitrous oxide could be used as a treatment for severe depression in patients whose symptoms don't respond to normal therapies.
According to a pilot study conducted at Washington University School of Medicine in St. Louis, which is believed to be the first research, patients with depression were given laughing gas and the results showed early promises of treating depression.
In 20 patients who had treatment-resistant clinical depression, the researchers found that two-thirds experienced an improvement in symptoms after receiving nitrous oxide. In comparison, one-third of the same patients reported improved symptoms after treatment with a placebo. The patients were evaluated on the day of and day after each treatment.
The researchers said that their findings need to be replicated, but think that this was a good starting point, and believe that the therapy with nitrous oxide eventually could help many people with depression.
As part of the study, patients received two treatments, but neither the subjects nor the researchers knew the order in which those treatments were given. In one session, patients were given a gas mixture that was half oxygen and half nitrous oxide - the same mixture dentists give to patients undergoing dental procedures. In a second session, the patients received a placebo mixture of oxygen and nitrogen, the two main gases in the air we breathe.
The study subjects were surveyed about the severity of their symptoms, such as sadness, feelings of guilt, suicidal thoughts, anxiety and insomnia. One day after nitrous oxide treatment, seven patients reported mild improvement in their symptoms, while another seven reported significant improvement. Three patients reported that their symptoms had disappeared almost completely. No patients said their symptoms worsened after treatment with nitrous oxide.
Meanwhile, after receiving the placebo, one patient reported worse symptoms the next day, five reported mild improvements, and two reported that they felt significantly better.
Co-investigator Charles R. Conway, MD, said that when the patients received nitrous oxide, many of them reported a rapid and significant improvement.
The researchers said more studies were needed to learn whether nitrous oxide had the same benefits in other patients with depression. They also plan to test various concentrations of laughing gas to see how each influences symptoms of depression.
The findings were published online in the journal Biological Psychiatry.
13th Dec 2014, 02:55 PM #1638
Re: Health Bulletin
Mutation of single gene making malaria parasites drug resistant
Mutation of a single gene is making malaria parasites drug resistant in Southeast Asia.
Mekong belt is the historical epicentre for the emergence of drug-resistant malaria parasites.
The world is on high alert on a strain of malaria that has become resistant to Artemisinin — the best drug available to fight the disease. This major threat emerged in the villages on the Thailand-Cambodia border in 2007.
Now, scientists and the World Health Organization (WHO) fear that it could spread across the world in no time putting millions of children's lives at risk.
Scientists have finally found that growing resistance to malaria drugs in Southeast Asia is caused by a single mutated gene inside the disease-causing Plasmodium falciparum parasite.
Scientists from Columbia University Medical Centre say that though malaria deaths have dropped 30% worldwide since the introduction of artemisinin-based combination therapies (ACTs) in the late 1990s, these gains are now threatened by the emergence of resistance to the core artemisinin component of ACTs in Southeast Asia.
No alternative therapy is currently available to replace ACTs should resistance spread to other parts of the world.
The study builds on a recent report that mutations in the gene — K13 — are frequently found in drug-resistant parasites in Southeast Asia.
The team working with scientists at the Pasteur Institutes in Paris and Cambodia, the University of Toulouse III, Sangamo Biosciences Inc and the National Institutes of Health (NIH), showed definitively that K13 mutations directly cause drug resistance.
"The bad news about our finding is that it shows that resistance can arise through single mutations in one gene and pop up anywhere, at any time. That's quite different from past instances with former first-line drugs, when complex sets of multiple mutations were required and resistance spread only as the mutated parasites spread," the scientists added.
The good news is that K13 mutations produce a relatively weak resistance. A related study found that K13 mutations enable the parasite to hide in red blood cells in a developmental state that is naturally less vulnerable to artemisinin.
"This allows them to temporarily survive treatment, but it will not be enough for ACTs to fail across Africa, particularly as the partner drugs continue to be highly effective. But it may be a foundation for parasites to evolve stronger degrees of resistance to these therapies, so we have to watch for increasing resistance very carefully," the team said.
According to WHO director general Margaret Chan "ACTs are the gold standard. They are the most effective treatment for falciparum malaria, the most deadly form of malaria. The consequences of widespread resistance to Artemisinin would be catastrophic. Resistance to previous generations of anti-malarial drugs such as chloroquine spread from the same Mekong region to India and then Africa, killing millions".
ACT kills malaria parasite in a human bloodstream within 24 to 36 hours. With the drug-resistant strain, ACT needs up to 120 hours to kill the parasite.
"Combination therapy is a deliberate strategy to delay the development of drug resistance. ACTs deliver a two-punch attack on the malaria parasite. By combining drugs with different mechanisms of action and different time spans of activity, ACTs increase the likelihood that any parasites not killed by one drug will be killed by the second one. The usefulness of these therapies is now under threat," Chan explained.
13th Dec 2014, 02:57 PM #1639
Re: Health Bulletin
Superbugs to kill 'more than cancer' by 2050
A British review commissioned by prime minister David Cameron on the impact superbugs will have on the world has concluded that drug-resistant infections will cost the world 10 million extra deaths a year and up to $ 100 trillion by 2050, if the global increase is not stopped.
Currently, 700,000 deaths each year are attributed to drug resistance.
In Nigeria, by 2050, more than one in four deaths would be attributable to drug resistant infections, while India would see an additional two million lives lost every year, the review says.
According to a major new report launched by economist Jim O'Neill, drug-resistant infections already kill hundreds of thousands of people globally every year, and the trend is growing.
The effects of anti-microbial resistance (AMR) which could cast medicine back to the dark ages by making routine medical procedures far more dangerous through the higher risk of infection, the report said.
The reduction in population and the morbidity impact would also reduce the level of world GDP by between 2% and 3.5% by 2050, creating a cumulative hit to global wealth of $60 - $100 trillion. This is approximately the equivalent of losing the UK economy from global output every year.
Jim O'Neill, chairman of the review on AMR, said "We cannot allow these projections to materialise for any of us, especially our fellow citizens in the BRIC world".
Mr O'Neill said "To put that in context, the annual GDP of the UK is about $3tn, so this would be the equivalent of around 35 years without the UK contribution to the global economy".
The analysis found that drug resistant E coli, malaria and tuberculosis (TB) would have the biggest impact. In Europe and the United States alone, antimicrobial resistance causes at least 50,000 deaths each year, they said. If left unchecked, deaths would rise more than 10-fold by 2050.
The report said "The importance of effective antimicrobial drugs cannot be overplayed. For example, E coli is a widespread bacterial infection in rich and poor countries. It is a major cause of diarrhoea in children and can be lethal: it kills up to half of patients who get it as a bloodstream infection where antibiotics are not used. Today, doctors reserve a class of antibiotics called 'carbapenems' as a drug of last resort against E coli, meaning they use it only in cases when the other antibiotics have become ineffective due to resistance. In an alarming development, doctors have had to use more and more carbapenems in the past years and now a strain of carbapenem resistant E coli has emerged and spread around the world. For patients infected with that bacteria, there are now no effective drugs available for doctors to use".
Nick Stern, President of the British Academy said "There can be no doubt now that antimicrobial resistance is one of the biggest that we, all of us, face"
Lawrence H Summers from Harvard University added "This sobering analysis from Jim O'Neill's Review demonstrates why the world needs to get serious about tackling the rise in antibiotics resistance. We play with fire if we skimp on public health. Ignoring the tide of drug resistant infections risks rolling back the hard won medical advances of the last century at precisely the first moment in history when we can actually go the other way and close the global health gap".
Cameron commissioned the review in July of this year to address the growing global problem of drug-resistant infections.
14th Dec 2014, 07:35 PM #1640
Re: Health Bulletin
Memory lapses put highly educated at greater stroke risk
People who have attained a high level of education and also complain about memory lapses face a higher risk of a stroke, says a study, adding that the results apply evenly to men and women.
Previous studies have shown how stroke results in memory lapses.
"Given the shared underlying vascular pathology, we posed the reverse question: Do memory complaints indicate an increased risk of strokes?" said Arfan Ikram, associate professor of neuroepidemiology at the Erasmus University, Rotterdam, in The Netherlands.
The study tracked about 9,000 people in Rotterdam over a period of 20 years. All the participants, aged 55 years or older, were asked in a questionnaire whether they were already experiencing memory issues.
In 2012, of the total number, 1,134 had already suffered from strokes. An analysis of the data revealed that the people who face a higher risk of suffering a stroke were those that had earlier indicated they were experiencing lapses in their memory.
Furthermore, those with memory complaints had a 39 percent higher risk of suffering a stroke if they had also attained a higher level of education.
The finding is comparable to the association between subjective memory complaints and Alzheimer's disease among highly educated people.
"We would like to assess whether people who complain about changes in their memory should be considered primary targets for further risk assessment and prevention of stroke," he added.
The research appeared in the American Heart Association journal Stroke.