26th Apr 2014, 11:07 AM #1041
Re: Health Bulletin
Lab-grown skin to replace animal testing
British scientists have developed the first labgrown epidermis — the outermost skin layer — which may replace animal testing. The new epidermis offers a cost-effective alternative lab model for testing drugs and cosmetics , and could also help to develop new therapies for rare and common skin disorders.
An international team led by King's College London and the San Francisco Veteran Affairs Medical Center has developed the epidermis with a functional permeability barrier similar to real skin. The new epidermis was grown from human pluripotent stem cells.
The epidermis forms a protective interface between the body and its external environment . The research used reprogrammed skin cells — which offer a way to produce an unlimited supply of the main type of skin cell found in the epidermis . They grew the skin cells in a low humidity environment, which gave them a barrier similar to that of true skin.
26th Apr 2014, 11:11 AM #1042
Re: Health Bulletin
Much-hyped new tuberculosis test gives inaccurate results
In a major setback to improving tuberculosis (TB) diagnosis and treatment in the country, researchers have found that the new gene Xpert gene test being promoted by government and top health agencies of the world does not give accurate results. In fact, one out of every three sputum sample put to test using this technology gave false sensitivity to TB drug (Rifampicin) in study carried at the All India Institute of Medical Sciences (AIIMS) when they were originally drug-resistant.
Dr Sarman Singh, professor and head of the clinical microbiology and molecular medicine division at AIIMS, said GeneXpert has been a revolutionary diagnostic method in Africa but in India it can miss as many as one-third of Rifampicin-resistance cases. "The Indian strains have a peculiar gene sequence which is not recognized by the probes GeneXpert has. Hence, if such systems are used routinely, this would give a false impression that India has very low rifampicin resistance thus making the programme mangers complacent," Dr Singh added.
There are four tests approved by WHO: LED Microscope, Liquid Culture and two molecular tests - Gene Xpert and Line Probe Assay. Gene Xpert, one of the advanced tests for TB diagnosis, is available at AIIMS for a patient suffering from drug resistant TB but it is not available in all hospitals due to its high cost. But central TB division of Ministry of Health, Government of India is installing GeneExpert in all the referral TB laboratories.
Dr Singh said the national TB control program managers must evaluate the performance of Xpert MTB/RIF test before rolling it out in the Drug resistant-TB control program in view of the findings, which has been published in latest issue of the Journal of Clinical Microbiology. The AIIMS study, researchers said, was done in a double-blinded manner. "After getting the RIF mono-resistance Line Probe Assay (LPA) results, one of us asked the persons in charge for Xpert MTB/RIF to run these samples in Xpert using the newer version of cartridges as per manufacturer instruction. Comparative analysis showed only 64.4% RIF mono-resistant TB cases were correctly diagnosed by Xpert. The remaining 35.6% were detected falsely RIF susceptible," said an AIIMS researcher.
In an earlier report published in PLOS Medicine journal, researchers pointed out that Xpert MTB/RIF has a number of limitations including limited shelf-life of the diagnostic cartridges, operating temperature and humidity restrictions, requirement for electricity supply, the need for annual servicing and calibration of each machine.
26th Apr 2014, 02:42 PM #1043
Re: Health Bulletin
Feeling sick? Sleep is your doctor
When you get sick, what is the first thing you should do? Pop a pill? No. Better hit the sack.
Sleep as much as you can as research suggests that long naps can boost immune system and help fight infection better.
Researchers from University of Pennsylvania found that in fruit flies, sleep enhances immune system response and recovery to infection.
"It is an intuitive response to want to sleep when you get sick," lead author Julie Williams from the university's Perelman School of Medicine was quoted as saying.
The results provide new evidence of the direct effects of sleep on immune response and of the underlying mechanisms at work.
In experiments on fruit flies, the researchers found the flies with more sleep showed faster and more efficient rates of clearing the bacteria from their bodies.
"Increased sleep helps facilitate the immune response by increasing resistance to infection and survival after infection," the study, appeared in the journal Sleep, said.
27th Apr 2014, 02:17 PM #1044
Re: Health Bulletin
Scientists have built an ‘off switch’ for the brain
Scientists have developed an "off-switch" for the brain to effectively shut down neural activity using light pulses.
In 2005, Stanford scientist Karl Deisseroth discovered how to switch individual brain cells on and off by using light in a technique he dubbed 'optogenetics'.
Research teams around the world have since used this technique to study brain cells, heart cells, stem cells and others regulated by electrical signals.
However, light-sensitive proteins were efficient at switching cells on but proved less effective at turning them off.
Now, after almost a decade of research, scientists have been able to shut down the neurons as well as activate them.
Deisseroth's team has now re-engineered its light-sensitive proteins to switch cells much more adequately than before. His findings are presented in the journal Science.
Thomas Insel, director of the National Institute of Mental Health, which funded the study, said this improved "off" switch will help researchers to better understand the brain circuits involved in behavior, thinking and emotion.
In the upper left opsin, the red colour shows negative charges spanning the opsin that facilitated the flow of positive (stimulatory) ions through the channel into neurons. In the newly engineered channels (lower right), those negative charges have been changed to positive (blue), allowing the negatively charged inhibitory chloride ions to flow through. "This is something we and others in the field have sought for a very long time," Deisseroth, a senior author of the paper and professor of bioengineering and of psychiatry and behavioural sciences said.
"We're excited about this increased light sensitivity of inhibition in part because we think it will greatly enhance work in large-brained organisms like rats and primates."
The new techniques rely on changing 10 of the amino acids in the optogenetic protein.
"It creates a powerful tool that allows neuroscientists to apply a brake in any specific circuit with millisecond precision, beyond the power of any existing technology," Insel explained.
This technique could help scientists develop treatments for patients with some brain diseases as it could allow problematic parts of the brain to be switched off with light and tackled with minimal intrusion.
Merab Kokaia, PhD, a professor at Lund University Hospital in Sweden who has used optogenetics to study epilepsy and other conditions praised the research.
"These features could be much more useful for behavioural studies in animals but could also become an effective treatment alternative for neurological conditions where drugs do not work, such as some cases of severe epilepsy and other hyper-excitability disorders," he said.
28th Apr 2014, 11:40 AM #1045
Re: Health Bulletin
HIV slowly adapting to humans: Scientists
Scientists studying the evolution of HIV in North America have found evidence that the virus is slowly adapting over time to its human hosts.
However, this change is so gradual that it is unlikely to have an impact on vaccine design, researchers said.
"Much research has focused on how HIV adapts to antiviral drugs — we wanted to investigate how HIV adapts to us, its human hosts, over time," said lead author Zabrina Brumme, an assistant professor in the Faculty of Health Sciences at Simon Fraser University.
"HIV adapts to the immune response in reproducible ways. In theory, this could be bad news for host immunity — and vaccines — if such mutations were to spread in the population," said Brumme.
"Just like transmitted drug resistance can compromise treatment success, transmitted immune escape mutations could erode our ability to naturally fight HIV," said Brumme.
Researchers characterised the human immunodeficiency virus (HIV) sequences from patients dating from 1979, the beginning of the North American HIV epidemic, to the modern day.
The team reconstructed the epidemic's ancestral HIV sequence and from there, assessed the spread of immune escape mutations in the population.
"Overall, our results show that the virus is adapting very slowly in North America. In parts of the world harder hit by HIV though, rates of adaptation could be higher," said Brumme.
"We already have the tools to curb HIV in the form of treatment — and we continue to advance towards a vaccine and a cure. Together, we can stop HIV/AIDS before the virus subverts host immunity through population-level adaptation," Brumme added.
The study was published in the journal PLOS Genetics.
28th Apr 2014, 06:07 PM #1046
Re: Health Bulletin
Forgot your glasses? With this trick, you can still see perfectly!
Have you ever been caught in a fix after leaving your glasses behind? Here’s a trick that helps you see without one, however blurry your vision maybe.
According to a post, the video explains the science behind the trick, for which one needs to make a tiny hole with your hand, enough for you to peer through.
Doing this, look at any object or at a distance – you will surprisingly see the blur disappear into a perfectly focused view.
28th Apr 2014, 06:29 PM #1047Newbie
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- Apr 2014
Re: Health Bulletin
A very interesting topic, i found your views great but i have found that Sleeplessness is caused due to various reasons such as stress, bad food habit, etc.,. Too much of sleep during the day time can make you go insomniac at night. Consumption of sleeping pills might put you to sleep for a while, but in the long run it will eventually spoil your health. Several studies have been conducted to find a natural remedy for insomnia, one of that is using nutmeg. Powdered nutmeg in milk or hot water can relax the nerves and induces peaceful sleep in a natural way.
Stay Healthy! Stay Happy!
29th Apr 2014, 12:17 AM #1048
Re: Health Bulletin
thank for the info - insomania. but bit perplexed.Please go through my post once again .
29th Apr 2014, 12:18 AM #1049
Re: Health Bulletin
Cloning: Scientists make insulin-producing cells
Scientists said on Monday they had used cloning technology to make embryonic stem cells that carry a diabetic woman's genes, and turned them into insulin-producing beta cells that may one day cure her disease.
The team reported clearing an important hurdle in the quest to make "personalised stem cells" for use in disease therapy, but a bioethicist said the breakthrough also highlighted the need for better regulation of lab-grown embryos.
"We are now one step closer to being able to treat diabetic patients with their own insulin-producing cells," said Dieter Egli of the New York Stem Cell Foundation (NYSCF), who led the study published in the journal Nature.
Egli and a team had transplanted the nuclei of cells taken from the woman's skin into human eggs to create stem cells, which they could then coax into becoming beta cells — a shortage of which causes insulin deficiency and high blood-sugar in diabetics.
In doing so, the team confirmed a potentially important source for future cell-replacement therapy.
It was not the first study to create stem cells in this way, but it was the first to use cells sourced from a diseased adult person with the aim of producing therapy-specific cells.
Insoo Hyun, a bioethicist from the Case Western Reserve University's school of medicine in Cleveland, Ohio, said the research, the latest to produce embryonic stem cells that carry the genomes of living people, raised red flags.
"This repeated cloning of embryos and generation of stem cells, now using cells collected from adults, increases the likelihood that human embryos will be produced to generate therapy for a specific individual," he wrote in a comment carried by Nature.
"Regulatory structures must be in place to oversee it." Embryonic stem cells — neutral, primitive cells that can develop into most of the specialised tissue cells of the body — are viewed as a potential source for rebuilding organs damaged by disease or accident.
But they are controversial, as until fairly recently stem cells could only be obtained from human embryos.
They can be grown in the lab by transferring the nucleus of a cell from tissue like the skin, which contains a person's DNA, into a human egg from which the nucleus has been removed.
The egg is then given an electrical pulse to start dividing until it forms a blastocyst, a hollow, early-stage embryo made up of about 150 cells with the DNA of the donor of the tissue cell.
Technically known as somatic-cell nuclear transfer (SCNT), the technique is used for therapeutic research but is also the first step in cloning, and was used to create Dolly the sheep.
SCNT is banned in many countries. For the new study, scientists in the United States and Israel said they made "technical improvements" — altering the chemicals used in the culture in which the cells are grown.
The stem cells could in turn be coaxed into becoming various different types of adult cells — including beta cells, the team said.
"Seeing today's results gives me hope that we will one day have a cure for this debilitating disease," said NYSCF chief executive Susan Solomon.
The same team had previously made beta cells with a similar method, but using eggs with their nuclei still intact — resulting in stem cells with three sets of chromosomes that could not be used in therapy.
But using the new, improved method, the stem cells emerged with the normal two sets of chromosomes, the team wrote.
Hyun said such research could raise fears of a future in which human babies are cloned or embryos callously created and destroyed for research, and called for the strengthening of oversight structures.
But Solomon said the research was "strictly for therapeutic purposes" and adhered to strict ethical oversight.
"Under no circumstances do we or any other responsible scientific group have any intention to use this technique for the generation of humans, nor would it be possible," she told AFP.
The beta cells produced in the study cannot yet be used in replacement therapy, the team said.
Diabetics' immune systems attack beta cells, and ways have yet to be found to shield them.
29th Apr 2014, 12:21 AM #1050
Re: Health Bulletin
Child's waist can predict metabolic diseases: Study
The waist circumference of a child can be helpful in predicting if he is suffering from metabolic diseases, according to a study.
The multi centre cross-sectional study done by the International Diabetes Federation, on 10,842 children in five cities --Delhi, Chennai, Kolkata, Pune and Raipur, suggests that cut off values of waist circumferences can be used as screening for metabolic syndrome (MS) in Indian children.
"MS in children has been defined as the presence of high triglyceride levels in blood, Low HDL cholesterol (good cholesterol), increased fasting blood glucose levels, high systolic blood pressure and waist circumference > 75th percentile," said Dr Archana Dayal Arya, Paediatric Endocrinologist of Sir Ganga Ram Hospital, New Delhi and co-author of the study.
Metabolic Syndrome results in increased risk for hypertension, type 2 diabetes mellitus, and atherosclerosis cardiovascular disease. It is shocking to see children as young as 6 yrs old with diseases like hypertension, diabetes mellitus and abnormalities in the lipid profile, she said.
The International Diabetes Federation's definition of the MS in children, includes waist circumference (WC) as a criterion for the diagnosis of MS in children.
With reference to WC percentiles, it is easy to identify the cutoff level above which the risk for MS increases.
The National Health and Nutrition Examination Survey (NHANES), USA has proposed the 90th percentile as the cutoff for central obesity in children.
The previous Indian studies have suggested an empirical cutoff of the 75th percentile to screen for MS, but so far no study has proposed a biologically rational cutoff.
"The objective of the present study was to develop WC percentiles curves and to define cutoff of WC for Indian children so that they can be identified for risks for metabolic syndrome," said Dr Archana.
The study which has been accepted for publication in the forthcoming issue of the Journal of Paediatrics found that 3.3 per cent or 358 children out of total sample size of 10,842 children were hypertensive.
The study also found that risk factor for Indian children for developing MS was at 70th WC percentile which is significantly lower than International proposed WC cutoff of 90th percentile, said Dr Anuradha Khadilkar, consultant paediatrician in Jehangir Hospital, Pune and corresponding author of the study.
"We found that primary or essential hypertension, commonly seen in adults, is becoming common in children, who are obese or overweight. Therefore it is very essential for them to change their lifestyle and lose weight," she said.
They should be encouraged to participate in outdoor sports and other physical activities. They should cut down on the intake of high calorie foods with poor nutritional value (junk food) and a high fat diet, added Khadilkar.