15th Jul 2014, 07:54 PM #1271
Re: Health Bulletin
People with genetic similarity become friends: Study
In a startling finding, a study from the University of California, San Diego, and Yale University has found that friends resemble each other genetically.
"Looking across the whole genome," James Fowler professor of medical genetics and political science at UC San Diego said, "we find that, on average, we are genetically similar to our friends. We have more DNA in common with the people we pick as friends than we do with strangers in the same population."
Published in the Proceedings of the National Academy of Sciences, the study is co-authored by Fowler, and Nicholas Christakis, professor of sociology, evolutionary biology, and medicine at Yale.
The study selected 1932 unique subjects from data collected in the Framingham Heart Study. Then, they studied nearly 1.5 million known markers of gene variation, comparing pairs of unrelated friends against pairs of unrelated strangers. The same people, who were neither kin nor spouses, were used in both types of samples. The only thing that differed between them was their social relationship.
How similar are friends? On average, Fowler and Christakis find, friends are as "related" as fourth cousins or people who share great-great-great grandparents. That translates to about 1 percent of our genes.
"One percent may not sound like much to the layperson," Christakis said, "but to geneticists it is a significant number. And how remarkable: Most people don't even know who their fourth cousins are! Yet we are somehow, among a myriad of possibilities, managing to select as friends the people who resemble our kin."
In the study, Fowler and Christakis also develop what they call a "friendship score," which they can use to predict who will be friends at about the same level of confidence that scientists currently have for predicting, on the basis of genes, a person's chances of obesity or schizophrenia.
Shared attributes among friends or "functional kinship" can confer a variety of evolutionary advantages. In the simplest terms: If your friend feels cold when you do and builds a fire, you both benefit.
Some types of genetic correlation were found to be very common among friends, the scientists found. One such case was for genes related to sense of smell — the sense of smell was more common among friends than strangers. Another correlation was that friends were more dissimilar in genetic protection against various diseases.
The immunity finding supports what others have recently found in regards to spouses. And there is a fairly straightforward evolutionary advantage to this, Fowler and Christakis say: Having connections to people who are able to withstand different pathogens reduces interpersonal spread. But how it is that we select people for this benefit of immunity? The mechanism still remains unclear.
Perhaps the most intriguing result in the study is that genes that were more similar between friends seem to be evolving faster than other genes. Fowler and Christakis say this may help to explain why human evolution appears to have speeded up over the last 30,000 years, and they suggest that the social environment itself is an evolutionary force.
16th Jul 2014, 10:19 AM #1272
Re: Health Bulletin
Cellphone radiation: Will it affect your brain?
Many studies have been conducted on the possible cancer risk associated with the use of cellphones, but very few have explored its impact on the activity of the human brain.
And it is this angle of scientific exploration that gives a new dimension to the researches of Dr N K Narayanan, professor at Kannur University Information Science & Technology School, which was recognized when his paper was selected for the 18th World Multi Conference on Systemics, Cybernetics and Informatics (WMSCI 2014), organized by the International Institute of Informatics and Systemics in Orlando, USA during July 15-18.
The paper, 'Brain dynamics under mobile phone radiation - A wavelet power approach' by Narayanan and his student Smitha C K analyses the effects of mobile phone radiation on brain using EEG signal.
"It is a fact that frequent exposure of human body to electromagnetic fields by mobile phone users is a growing concern in present lifestyle, but most of the researches focused around the risk of cancer associated with the radiation, while the other major aspects are still a grey area which we wanted to explore," he said.
Since the studies in physics have found that there will not be any cell mutation thus allaying the possibility of cancer, it is time to look at other health-related aspects, he said. "When we took the EEG (Electroencephalograph) of the brain activity without the presence of the cell phone and when the cell phone is on, we found a visible change in the signals, which calls for a study on the possible impact of the radiation on human intellect," he said.
The study was conducted using Wavelet Transform, which is a mathematical tool for analysing nonlinear signals like EEG.
Power of different frequency bands of the signal provides important information about the state of the signal, which leads to give a clear idea about the state of brain at that condition, said Narayanan.
Though a research was conducted in the US in 2013 by a team led by Dr Nora D Volkow, a brain imaging scientist from the National Institute on Drug Abuse, which also said that cell phone radiofrequency radiation alters brain activity, no serious clinical study has been taken up in India in this matter and hence the findings of Narayanan assumes significance.
"We are trying to get fund from the Indian Council of Medical Research (ICMR) for further research in collaboration with National Institute of Mental Health and Neuroscience (NIMHANS), Bangalore to find the health problems associated with the exposure to mobile phone radiations," he said.
16th Jul 2014, 10:51 AM #1273
Re: Health Bulletin
Psychoactive ingredient in cannabis found to reduce tumour growth in cancer patients
Cannabis has now been found to significantly reduce tumour growth in cancer patients.
Scientists at the University of East Anglia have discovered previously unknown signalling platforms in the main psychoactive ingredient in cannabis which are responsible for the drug's success in shrinking tumours.
Scientists hope the finding will lead to the development of a synthetic equivalent with anti-cancer properties. The research was co-led with the Universidad Complutense de Madridin, Spain.
The team used samples of human cancer cells to induce tumours in mice. They then targeted the tumours with doses of the cannabis compound THC (Tetrahydrocannabinol). They found that two cell receptors in particular were responsible for the drug's anti-tumour effects.
Dr Peter McCormick from UEA said "THC, the major active component of marijuana, has anti-cancer properties. This compound is known to act through a specific family of cell receptors called cannabinoid receptors. However, it was unclear which of these receptors were responsible for the anti-tumour effects of THC".
Dr McCormick added "We show that these effects are mediated via the joint interaction of CB2 and GPR55 — two members of the cannabinoid receptor family. Our findings help explain some of the well-known but still poorly understood effects of THC at low and high doses on tumour growth. There has been a great deal of interest in understanding the molecular mechanisms behind how marijuana, and specifically THC, influence cancer pathology".
"There has also been a drive in the pharmaceutical industry to create synthetic equivalents that might have anti-cancer properties. By identifying the receptors involved we have provided an important step towards the future development of therapeutics that can take advantage of the interactions we have discovered to reduce tumour growth".
Dr McCormick added that cancer sufferers should not be tempted to self-medicate.
"Our research uses an isolated chemical compound and using the correct concentration is vital. Cancer patients should not use cannabis to self-medicate, but I hope that our research will lead to a safe synthetic equivalent being available in the future".
16th Jul 2014, 06:35 PM #1274
Re: Health Bulletin
Daily fish oil boosts memory function in older adults
A new study suggests that including oily fish like salmon and trout or fish oil supplements in one’s diet can significantly improve memory in older adults.
It is believed that DHA found in fish oil supplements could be key in preventing Alzheimer’s disease, one of the most common forms of dementia.
Researchers at Rhode Island Hospital examined the relationship between fish oil supplements during the US Alzheimer's Disease Neuroimaging Initiative (ADNI) and indicators of cognitive decline.
In this retrospective study, older adults were assessed with neuropsychological tests and brain magnetic resonance imaging (MRI) every six months.
The group included 229 older adults who were cognitively normal; 397 who were diagnosed with mild cognitive impairment; and 193 with Alzheimer's disease (AD).
The study found that fish oil supplement use was associated with significantly lower rates of cognitive decline and brain atrophy in older adults.
"Participants with normal cognition who reported taking fish oil supplements demonstrated less brain shrinkage in key neurological areas, compared to those who did not use the supplements," explained principal investigator Lori Daiello from Rhode Island Hospital.
The findings were published online in the journal Alzheimer's & Dementia.
17th Jul 2014, 12:41 PM #1275
Re: Health Bulletin
Injecting gene into heart muscle may replace pacemaker
Injecting a certain gene into cardiac muscle has been shown in animal studies to help a weakened heart beat more strongly, scientists said on Wednesday.
If shown to be safe and effective in people, experts said the procedure might one day replace the need for electronic pacemakers, though that knowledge is years away.
"This development heralds a new era of gene therapy, where genes are used not only to correct a deficiency disorder, but actually to convert one type of cell into another to treat disease," said lead author Eduardo Marban, director of the Cedars-Sinai Heart Institute.
It is the first time that a heart cell has been preprogrammed in a living animal in order to cure a disease, said Marban.
Gene therapy has long been viewed as a promising but risky field, particularly after early attempts to use it in people in the 1990s showed it could be dangerous and even fatal.
Marban said the use of a mild virus as a delivery vector for the gene should reduce concerns that typically arise in gene therapy, such as the potential for a deadly immune reaction or the possibility that the process could lead to the formation of a tumor, but acknowledged that more research is needed.
The study in the journal Science Translation Medicine details a therapy in which a gene known as TBX18 is injected into an area the size of a peppercorn in the pumping chambers of the heart.
The gene converts some of the normal heart cells into another type, called sinoatrial cells, which take over the heart's pumping duties.
"In essence, we create a new sinoatrial node in the part of the heart that ordinarily spreads the impulse but does not originate it," he told reporters on a conference call to discuss the research.
"The newly created node then takes over as the functional pacemaker."
The minimally invasive approach was tried in pigs with a condition known as complete heart block, a severe condition in which the heart's electrical system is impaired and produces an irregular heartbeat.
The gene was injected with a catheter, and open heart surgery was not required.
The day after the gene was injected, pigs who received it showed significantly faster heartbeats than those who did not undergo the treatment.
It worked in the animals for the duration of the two-week study. The research team is continuing its work to see how long the effect may last.
- 'Sci-fi to reality' -
David Friedman, chief of heart failure services at North Shore-LIJ's Franklin Hospital in New York, who was not involved in the study, said future work in animals should reveal more safety and efficacy data, "such as lack of inflammation or systemic infection from the gene delivery process."
Another outside expert, Tara Narula, associate director of the cardiac care unit at Lenox Hill Hospital in New York City, described the work as taking "science fiction into the realm of reality."
"Genetically re-engineering heart tissue so it becomes capable of generating electrical cardiac impulses is truly a remarkable step in the direction of one day freeing patients from the need for pacemaker implantation," she told AFP.
Some 300,000 electronic pacemakers are implanted each year in the United States, costing the healthcare system some eight billion dollars per year, researchers said.
Those who might initially be aided by this kind of new therapy include the two percent of pacemaker patients who develop infections.
Other include fetuses with a condition called congenital heart block, which affects one in 22,000 and causes an irregular heart beat in the womb.
Since it is impossible to implant fetuses with pacemakers, there is little that can be done to treat congenital heart block and it often results in stillbirth.
The approach developed by Marban and colleagues is still at least two to three years away from human trials, he said.
"It offers the potential, at least, for a single-shot curative therapy without the need for follow up interventions, repeated procedures or dependence on artificial hardware that has been implanted in the body," said Marban.
17th Jul 2014, 12:41 PM #1276
Re: Health Bulletin
A ‘James Bond’ drug to stop you from getting drunk
A pill could soon protect you against getting drunk, irrespective of how much alcohol you gulp down.
Neuroscientists at The University of Texas at Austin have genetically tweaked a type of worm that do not get intoxicated by alcohol, a result that could lead to new drugs to treat the symptoms of people going through alcohol withdrawal.
The scientists accomplished this feat by inserting a modified human alcohol target into the mutant worms.
Researchers speculated that their research could even be used to develop a 'James Bond' drug someday, which would enable a spy to drink his opponent under the table, without getting drunk himself. Such a drug could potentially be used to treat alcoholics, since it would counteract the intoxicating and potentially addicting effects of the alcohol.
The worms used in the study, Caenorhabditis elegans, model intoxication well. Alcohol causes the worms to slow their crawling with less wriggling from side to side. The intoxicated worms also stop laying eggs, which build up in their bodies and can be easily counted.
"This is the first example of altering a human alcohol target to prevent intoxication in an animal," says Jon Pierce-Shimomura from the university's College of Natural Sciences.
An alcohol target is any neuronal molecule that binds alcohol, of which there are many.
One important aspect of this modified alcohol target, a neuronal channel called the BK channel, is that the mutation only affects its response to alcohol.
The BK channel typically regulates many important functions including activity of neurons, blood vessels, the respiratory tract and bladder. The alcohol-insensitive mutation does not disrupt these functions at all.
"We got pretty lucky and found a way to make the channel insensitive to alcohol without affecting its normal function," says Pierce-Shimomura.
The scientists believe the research has potential application for treating people addicted to alcohol.
"Our findings provide exciting evidence that future pharmaceuticals might aim at this portion of the alcohol target to prevent problems in alcohol abuse disorders," says Pierce-Shimomura. "However, it remains to be seen which aspects of these disorders would benefit".
Unlike drugs such as cocaine, which have a specific target in the nervous system, the effects of alcohol on the body are complex and have many targets across the brain. The various other aspects of alcohol addiction, such as tolerance, craving and the symptoms of withdrawal, may be influenced by different alcohol targets.
Unfortunately, C elegans are not as ideal for studying the other areas of alcohol addiction, but mice make an excellent model. The modified human BK channel used in the study, which is based on a mutation discovered by lead author and graduate student Scott Davis, could be inserted into mice. These modified mice would allow scientists to investigate whether this particular alcohol target also affects tolerance, craving and other symptoms relevant to humans.
17th Jul 2014, 12:42 PM #1277
Re: Health Bulletin
Late nights can harm fertility in women
Expectant moms or women who are trying to get pregnant should avoid light during the night, according to a new research.
Darkness is important for optimum reproductive health in women, and for protecting the developing fetus, said study researcher Russel J Reiter, a professor of cellular biology at the University of Texas Health Science Center in San Antonio.
In a review of studies published in the journal Fertility and Sterility, Reiter and his colleagues evaluated previously published research, and summarised the role of melatonin levels and circadian rhythms on successful reproduction in females.
The evidence showed that every time the light at night was turned on, it turned down the production of melatonin, 'Live Science' reported.
Melatonin, a hormone secreted by the pineal gland in the brain in response to darkness, is important when women are trying to conceive, because it protects their eggs from oxidative stress, Reiter said.
"If women are trying to get pregnant, maintain at least eight hours of a dark period at night. The light-dark cycle should be regular from one day to the next; otherwise, a woman's biological clock is confused," he said.
Eight hours of darkness every night is also optimal during pregnancy, and ideally, there should be no interruption of nighttime darkness with light, especially during the last trimester of a pregnancy, Reiter said.
Turning on the light at night suppresses melatonin production in women, and means the foetal brain may not get the proper amount of melatonin to regulate the function of its biological clock, he said.
17th Jul 2014, 12:46 PM #1278
Re: Health Bulletin
Google contact lens to detect diabetes
Beauty might lie in the eye of the beholder, but if Google has its way, so will medical diagnostics. In the first step towards designing miniature technology products that can monitor body functions Google has joined forces with pharmaceutical giant Novartis to advance the Silicon Valley giant's work on "smart" contact lenses that can measure the wearers' blood sugar levels, a basic for people with diabetes.
The move comes just a day after one of the principals behind the technology, Babak Parviz, an Iranian-American who also pioneered the Google Glass, left the company to join Amazon. But Google pressed ahead with the tie-up with Swiss multinational, which is at the center of a drug spat with India. The two companies said Novartis's Alcon eye-care division would license and commercialize ''smart lens'' technology designed by Google[x], a development team at the search engine giant.
The announcement is the latest in a trend of tech companies getting into the health and fitness domain. Google already has a platform called Google Fit to measure heath metrics such as sleep and exercise on devices running on its android platform headed by the Indian-American Sundar Pichai. Apple has a similar platform called HealthKit.
But Google Smart Lens is, literally, visionary technology to address diabetes. It is particularly relevant to India, which already has 65 million diabetics (dismissively called ''sugar disease"), a figure that is expected to top a staggering 100 million by 2030.
In a note they published earlier this year, Babak Parviz and Brian Otis, the project co-founders, explained the reasoning and technology behind the smart lens, pointing to the difficulties in measuring blood sugar through traditional methods such as wearing glucose monitors, which involves disruptive and painful process of pricking the figure and drawing blood.
Since scientists had developed ways to measure glucose through body fluids such as tears, they figured that miniature electronics -- including chips and sensors so small they look like bits of glitter, and an antenna thinner than a human hair -- might be a way to crack the mystery of tear glucose and measure it with greater accuracy. The result: ''smart lens'' that contains a miniaturized glucose sensor and a tiny wireless chip (to transmit information) that are embedded between two layers of soft contact lens material.
Early prototypes they tested could generate a reading once per second. They said they were also investigating the potential for this to serve as an early warning for the wearer, including exploring integrating tiny LED lights that could light up to indicate that glucose levels have crossed above or below certain thresholds.
Evidently, Google has made sufficient progress to draw Novartis/Alcon into a tie-up. Novartis CEO Joe Jiminez has indicated that the technology could be commercialized within five years.
18th Jul 2014, 11:51 AM #1279
Re: Health Bulletin
Proxy euthanasia common in India
Law or no law, euthanasia in a surrogate form is practised in India. Instances of doctors scaling down medical intervention where patients have no chance of recovery aren't unheard of. Such decisions are taken only after families are convinced they exhausted all options. The terminally-ill are allowed to sink till they breathe their last.
In some cases, the de-escalation is so sharp that it resembles passive euthanasia — withdrawing life support to patients in a permanently vegetative state. The two key inputs needed to sustain life in the terminally-ill are ventilator support to help respiration and medicines to maintain blood pressure. The intensity of both is either reduced or withdrawn to allow life to ebb away. Doctors say giving this practice a legal framework is important to ensure death with dignity.
"Every week, we get at least three to four requests from families for discontinuation of treatment to kin -terminally-ill or in a vegetative state. Loss of hope of recovery is the main cause. Sometimes it's because families can't afford the treatment," says Dr Sumit Ray, vice-chairperson, critical care medicine at Sir Ganga Ram Hospital. In cases where there's zero chance of recovery or improvement in quality of life the `end-of-life care' approach is adopted on the family's request.
Dr Deepak Agarwal, senior neurosurgeon at AIIMS trauma centre, says many families dump their kin in hospital and leave when they're told there's no scope of recovery. "Such people are mostly poor. I recall a poor woman whose husband had suffered a terrible spinal cord injury sending him into a vegetative state. She didn't have the money to get him treated, left him at the hospital and focused on finding a way to feed her children," he says.
Shabnam, whose father died after prolonged illness, says: "My father was declared brain dead. Doctors said even if he came off the ventilator -which was virtually impossible -his vision, respiration and limb movements were gone for good. We as a family decided to go one step further with the medication and then stop. What we decided that day was in a way euthanasia."
But, there are doctors who oppose euthanasia. "We should be thinking of ways to save more lives. Euthanasia is not an option. There can't be greater service to humanity than giving quality palliative care to the terminally-ill," said Dr Sushma Bhatnagar, head of pain and palliative care at AIIMS' Cancer Centre.
18th Jul 2014, 11:56 AM #1280
Re: Health Bulletin
Asthma inhalers make children half a centimetre shorter
Common inhalers used by millions of children have now been found to curtail their height, stunting growth by around half a centimetre.
Two new reviews focussing on the effects of inhaled corticosteroid drugs (ICS) — that are given by inhalers to children with asthma, on growth rates found children's growth slowed in the first year of treatment, although the effects were minimised by using lower doses.
Inhaled corticosteroids are prescribed as first-line treatments for adults and children with persistent asthma. They are the most effective drugs for controlling asthma and clearly reduce asthma deaths, hospital visits and the number and severity of exacerbations, and improve quality of life. Yet, their potential effect on the growth of children is a source of worry for parents and doctors.
Worldwide, seven ICS drugs are currently available.
The first systematic review focused on 25 trials involving 8,471 children up to 18 years old with mild to moderate persistent asthma. These trials tested all available inhaled corticosteroids and showed that, as a group, they suppressed growth rates when compared to placebos or non-steroidal drugs. Around 14 of the trials, involving 5,717 children, reported growth over a year. The average growth rate, which was around 6-9cm per year in control groups, was reduced by about 0.5 cm in treatment groups.
"The evidence we reviewed suggests that children treated daily with inhaled corticosteroids may grow approximately half a centimetre less during the first year of treatment," said lead author of the review Linjie Zhang who is based at the Faculty of Medicine at the Federal University of Rio Grande in Rio Grande, Brazil.
"But this effect is less pronounced in subsequent years, is not cumulative, and seems minor compared to the known benefits of the drugs for controlling asthma and ensuring full lung growth".
In the second review, authors reviewed data from 22 trials in which children were treated with low or medium doses of inhaled corticosteroids. These trials tested different doses of all drugs.
Only three trials followed 728 children for a year or more, with one of these trials testing three different dosing regimens. In the three trials, using lower doses of the inhaled corticosteroids, by about one puff per day, improved growth by a quarter of a centimetre at one year.
More long-term trials and trials comparing different doses are also needed, particularly in children with more severe asthma requiring higher doses of inhaled corticosteroids, the researchers conclude.
"Only 14% of the trials we looked at monitored growth in a systematic way for over a year. This is a matter of major concern given the importance of this topic," said Francine Ducharme, one of the authors of both reviews from the University of Montreal.
"We recommend that the minimal effective dose be used in children with asthma until further data on doses becomes available. Growth should be carefully documented in all children treated with inhaled corticosteroids, as well in all future trials testing inhaled corticosteroids in children."