13th Feb 2015, 03:01 PM #1761
Re: Health Bulletin
Smoking shrinks brain’s cortex: Study
A study has found that smokers have a thinner brain cortex, the outer layer involved in critical cognitive functions such as memory and language. A thinner brain cortex is associated with adult cognitive decline, researchers said.
The study by scientists at the University of[IMG]file:///C:\Users\SVE1711G\AppData\Local\Temp\msohtmlclip1\01\clip_image002.gif[/IMG] Edinburgh and the Montreal Neurological Institute at McGill University analysed MRI scans of 244 males and 260 females with an average age of 73. Around half were former or current smokers. Those participants who had given up smoking for the longest time had a thicker cortex compared with those who had given up recently — even after accounting for the total amount smoked in their lifetime.
The group tested was part of the Lothian Birth Cohort 1936, a group of individuals who were born in 1936 and took part in the Scottish Mental Survey[IMG]file:///C:\Users\SVE1711G\AppData\Local\Temp\msohtmlclip1\01\clip_image002.gif[/IMG] of 1947. Using detailed MRI brain scans, careful image analysis and statistical models, researchers analysed how a person's smoking habit was linked with the thickness of the brain's cortex.
The study authors suggest that avoiding smoking helps to keep the brain's cortex thicker and, therefore, more normal. They also cautiously suggest that the cortex might regain some thickness once smokers quit, but that this was not seen in all regions of the brain. They said that further studies are needed to confirm these results with larger numbers of current smokers studied over long periods of time.
Ian Deary, director of the Centre for Cognitive Aging and Cognitive Epidemiology at the University of Edinburgh, who led the research project, said, "It is important to know what is associated with brain health in older age. From these data we have found a small link between smoking and having thinner brain grey matter in some regions. There are findings in our study that could suggest that stopping smoking might allow the cortex to recover some of its thickness, though we need further studies with repeat measures to test that idea."
14th Feb 2015, 02:49 PM #1762
Re: Health Bulletin
Cough and cold may also signal swine flu
Don't neglect cough and cold as they may be symptoms of swine flu. Though high fever is normally considered the first sign of H1N1 influenza, this time many patients with cough and sore throat have been testing positive for the disease, doctors and diagnostic experts said here on Friday.
Though the reason for the change in symptoms is yet to be studied, doctors say it could be because of the virus mutating.
"This time, many patients are not necessarily having fever as an early symptom. Instead, we found new symptoms such as loose motions," said Dr Suranjit Chatterjee, senior consultant (internal medicine) at Indraprastha Apollo Hospitals.
Several other doctors, pharmacists and laboratory experts TOI spoke to agreed. However, some said this could be because temperature pattern may have waned by the time such patients visited the doctor.
Typical symptoms of the disease include high fever, cough, sore throat, running nose along with body ache.
6,298 flu cases reported across India this year
Swine flu, a respiratory infection which weakens the immune system, has claimed 485 lives in the country so far this year. According to latest health ministry data, 6,298 laboratory confirmed cases of H1N1 influenza 'A' were reported from across the country between January 1 and February 12.
Medical experts say children, elderly people and those who are immune-compromised or suffering from diseases such as cancer, HIV or have undergone organ transplant are vulnerable to the disease.
Doctors, laboratory experts and pharmacists said this time many patients with common flu symptoms are getting themselves checked out of "abundant caution" as awareness has increased. Apart from government hospitals and testing centres, the test kits for swine flu are available with private laboratories such as Dr Lal Pathlabs and SRL Diagnostics, which are authorized by the government.
According to SRL CEO Sanjeev Vashishta, the laboratory is receiving close to 1000 samples every day from across the country and is looking at expanding capacity to handle more cases. The lab has also tied up with the Rajasthan government to collect and test samples from government hospitals in the state.
"We have witnessed the number of samples picking up mainly in past one week," says Vashistha.
Dr Arup Basu, chairperson (chest medicine) at Sir Ganga Ram Hospital said antiviral medicine oseltamivir should be taken at an early stage. "Once the disease develops in the body, the efficiency of the medicine starts going down," he said, adding even a vaccine, which is preventive in nature, should be taken at least 3-4 weeks in advance as it takes time to build the protection level.
16th Feb 2015, 04:03 PM #1763
Re: Health Bulletin
Seven genes tied to intellectual disability found
Scientists have identified seven new genes that can cause X-linked intellectual disability, a disorder that predominantly affects men and can have highly variable clinical manifestations.
X-linked intellectual disability is caused by defective genes on the X chromosome. As males only have one X chromosome and the disease is passed on in a recessive manner, the disorder mainly occurs in boys.
Women are affected only if both their X chromosomes carry the defective genes. Women with one healthy and one mutated X chromosome are usually healthy but have a 50 per cent chance of passing the mutated X chromosome on to their offspring.
Because of the high variability of the clinical picture, the search for the responsible genetic defect was, until a few years ago, very tedious.
An international research team headed by Vera Kalscheuer from the Max Planck Institute for Molecular Genetics in Berlin has now analysed 405 families, in which cases of X-linked intellectual disability occur.
The researchers have discovered changes in a number of genes that were already known to be related to the disorder.
In addition, they discovered that X-linked intellectual disability can also be caused by mutations in seven other genes that, until now, were not associated with the disorder.
For some years now, scientists have been aided in their research of genetic diseases by high-throughput sequencing.
This technology allows to sequence a large number of DNA segments simultaneously and to more easily identify genetic defects.
Using this method, the scientists investigated all DNA regions of the X chromosome containing protein-relevant information.
"In addition to known disease-related genes, we have discovered seven novel genes as the cause of X-linked intellectual disability and analysed what signalling pathways in the cells each protein is involved in," said Kalscheuer.
According to the researchers, the clinical presentation and severity of the disorder depend on the responsible gene and the nature of the mutation.
For example, if the mutation is located in a region that is important for brain development and protein function, the result is likely to be a more severe disease progression.
With the help of systematic re-sequencing of all X-linked genes, the responsible genetic defect can be identified in around 60 per cent of families with X-linked intellectual disability
16th Feb 2015, 04:03 PM #1764
Re: Health Bulletin
New aggressive form of HIV accelerates AIDS
A new aggressive form of HIV can progress to AIDS in just three years - so rapidly that patients may not even realize they were infected, scientists say.
Engaging in unprotected sex with multiple partners increases the risk of contracting multiple strains of HIV. Once inside a host, these strains can recombine into a new variant of the virus, researchers said.
One such recombinant variant observed in patients in Cuba appears to be much more aggressive than other known forms of HIV, researchers said. Before it can enter human cells, HIV must first anchor itself to them. The virus does this via anchor points, or co-receptors, which are proteins on the cell membrane.
In a normal infection, the virus first uses the anchor point CCR5. In many patients, after a number of healthy years, the virus then switches to the anchor point CXCR4. This co-receptor switch coincides with a faster progression to AIDS.
Researchers at KU Leuven's Laboratory for Clinical and Epidemiological Virology in Belgium have described a recombinant form of HIV observed in patients in Cuba that makes this transition much faster. The virus targets the anchor point CXCR4 early after infection, shortening drastically the healthy phase and triggering rapid progression to AIDS.
The transition from anchor point CCR5 to CXCR4 is normally very difficult. Researchers suspect that the rapid transition observed in this HIV recombinant occurs as a result of combining fragments from different HIV subtypes.
16th Feb 2015, 04:03 PM #1765
Re: Health Bulletin
Adulthood begins at 25, says new research
Kidults" could be a better term for those in their twenties, according to research which suggests that people do not become adults until about 25.
The adolescent desires of sensation-seeking and novelty in the brain increase as individuals leave home and fend for themselves, Beatriz Luna, a psychiatrist the Pittsburgh School of Medicine, believes.
Previously, such desires were thought to peak at 15, but new studies found that they extend far beyond this age. A key finding is evidence of hyper-activity in a part of the brain known as the striatum, which is stimulated by "rewards" and this continues until the mid-twenties.
It is thought that the typical "adult responsibilities" of holding down a stable job, paying a mortgage and raising a family responsibly halt the effects on the brain. Prof Luna said the age people crossed the threshold of adulthood was "probably closer to 25".
In teenagers the sensation-seeking part of the brain works together with the "planning centre", or pre-frontal cortex, in order to drive curiosity and experimentation.
"Sensation seeking, which is really information seeking, novelty seeking, is evident across species and human societies," Prof Luna said at the American Association for the Advancement of Science (AAAS) annual meeting in San Jose, California.
"I'm saying this is combining with a brand new shiny car called the pre-frontal cortex. The adolescent is, like, 'Oh, this is great, I can plan', but they're doing it in the service of this heightened sensitivity to motivation," she added.
The system allows young people to seek out novel situations and not always ask "mummy and daddy".
Prof Luna is still conducting research to discover how far into adulthood the brain changes continue, but it is possible they may extend into a person's thirties.
"There are two ways to look at it. I'm a very positive person, I'd like to think the longer you have to specialise the better," Prof Luna said.
"I guess the implication is that when the environmental demands are those that require you become a responsible adult, meaning you have a lot of responsibilities to take over, that might be signalling the brain to stop a certain type of plasticity because now you really need stability and reliability. "Having the freedom to play a bit longer in life might be a good thing," she added.
18th Feb 2015, 01:36 PM #1766
Re: Health Bulletin
Gold nanotubes can destroy cancer cells
Gold nanotubes can act as internal nanoprobes for high-resolution imaging, drug delivery vehicles and agents for destroying cancer cells, scientists say.
The study details the first successful demonstration of the biomedical use of gold nanotubes in a mouse model of human cancer.
"High recurrence rates of tumours after surgical removal remain a formidable challenge in cancer therapy. Chemo- or radiotherapy is often given following surgery to prevent this, but these treatments cause serious side effects," said study lead author Dr Sunjie Ye, from the University of Leeds.
"Gold nanotubes - that is, gold nanoparticles with tubular structures that resemble tiny drinking straws - have the potential to enhance the efficacy of these conventional treatments by integrating diagnosis and therapy in one single system," said Ye.
By controlling the length, the researchers were able to produce gold nanotubes with the right dimensions to absorb a type of light called 'near infrared'.
"When the gold nanotubes travel through the body, if light of the right frequency is shone on them they absorb the light. This light energy is converted to heat, rather like the warmth generated by the Sun on skin," said the study's corresponding author Professor Steve Evans, also from Leeds.
"Using a pulsed laser beam, we were able to rapidly raise the temperature in the vicinity of the nanotubes so that it was high enough to destroy cancer cells," said Evans.
In cell-based studies, by adjusting the brightness of the laser pulse, the researchers say they were able to control whether the gold nanotubes were in cancer-destruction mode, or ready to image tumours.
In order to see the gold nanotubes in the body, the researchers used a new type of imaging technique called multispectral optoacoustic tomography (MSOT) to detect the gold nanotubes in mice, in which gold nanotubes had been injected intravenously.
It was also shown that gold nanotubes were excreted from the body and therefore are unlikely to cause problems in terms of toxicity, an important consideration when developing nanoparticles for clinical use.
The study was published in the journal Advanced Functional Materials.
18th Feb 2015, 02:11 PM #1767
Re: Health Bulletin
Children in rural India regularly receive wrong treatment: Study
A damning study has revealed that children in rural India regularly receive wrong treatments for childhood diarrhea and pneumonia - two leading killers of children in the country.
Duke University study has revealed that very few health care providers in rural India know the correct treatments for these two killers.
But even when they do, they rarely prescribe them properly, according to researchers.
Medical practitioners typically fail to prescribe lifesaving treatments such as oral rehydration salts (ORS). Instead, they typically prescribe unnecessary antibiotics, said Manoj Mohanan, a professor in Duke's Sanford School of Public Policy, and lead author of the study.
Diarrhea and pneumonia accounted for 24% deaths among children 1 to 4 years old, totaling approximately 2 million deaths worldwide in 2011.
Bihar - where the study was conducted - has an infant mortality rate of 55 per 1000 live births, the highest in India.
For example, for diarrhea, 72% of providers reported they would prescribe oral rehydration salts - a life-saving, low-cost and readily available intervention - but only 17% actually did so. Those who did prescribe ORS also added other unnecessary or harmful drugs.
In practice, none of the providers gave the correct treatment: only ORS, with or without zinc and no other potentially harmful drugs.
Instead, almost 72% of providers gave antibiotics or potentially harmful treatments without ORS.
"We know from previous studies that providers in rural settings have little medical training and their knowledge of how to treat these two common and deadly ailments is low," Mohanan said.
He added "Around 80% in our study had no medical degree. But much of India's rural population receives care from such untrained providers, and very few studies have been able to rigorously measure the gap between what providers know and what they do in practice".
The study involved 340 health care providers. Researchers conducted interviews with providers to assess how they would diagnose and treat a hypothetical case. Later, standardized patients - individuals who portrayed patients presenting the same symptoms as in the interviews - made unannounced visits. This strategy enabled researchers to measure the gap between what providers know and what they actually do.
Providers exhibited low levels of knowledge about both diarrhea and pneumonia during the interviews and performed even worse in practice.
"Massive over-prescription of antibiotics is a major contributor to rising antibiotic resistance worldwide," Mohanan said. "Our ongoing studies aim to understand why providers who know they shouldn't be prescribing antibiotics for conditions like simple diarrhea continue to do so.
It clearly is not demand from patients alone, which is a common explanation, since none of our standardized patients asked for antibiotics but almost all of them got them," he said.
Providers with formal medical training still had large gaps between what they knew and did, but were significantly less likely to prescribe harmful medical treatments.
"Our results show that in order to reduce child mortality, we need new strategies to improve diagnosis and treatment of these key childhood illnesses," Mohanan said. "Our evidence on the gap between knowledge and practice suggests that training alone will be insufficient. We need to understand what incentives cause providers to diverge from proper diagnosis and treatment".
19th Feb 2015, 03:05 PM #1768
Re: Health Bulletin
'Bone marrow on a chip' to study impact of radiation on humans
A Harvard researcher has developed a 'bone marrow on a chip' that can help study the harmful effects of radiation on humans.
"It's unethical to expose humans to the kind of radiation that you'd see in a disaster like Fukushima, but you need to be prepared," said Donald Ingber, a bioengineer at Harvard University's Wyss Institute in Boston, Massachusetts.
With support from the US Food and Drug Administration, he is adapting his 'bone marrow on a chip' to study the effects of harmful radiation and experimental remedies.
Other researchers working along similar lines have presented their work on model organs for biodefence applications recently at a meeting of the American Society for Microbiology (ASM) in Washington DC.
The hope is that these complex three-dimensional systems will mimic human physiology better than cells grown in a dish, or even animals, 'Nature.com' reported.
A common way to form a model organ is to seed cells into channels in a small plastic chip and then feed them with nutrient-rich fluid that flows through the system to mimic blood.
The devices can be used individually or connected to other types of organs-on-chips to approximate a biological system, or perhaps an entire human body.
At the ASM meeting, microbiologist Joshua Powell of the Pacific Northwest National Laboratory in Richland, Washington, presented experiments testing the ability of anthrax spores to infect a three-dimensional 'lung' grown from rabbit lung cells.
Powell said that the US Department of Homeland Security is interested in using the system to answer questions such as how many anthrax spores are necessary to cause disease in the body.
For some viruses in particular, Ingber said, researchers have no idea about the mechanism, and they need the mechanism to get new drug targets.
Infecting model organs could allow researchers to watch how gene expression and metabolism change in real time.
This sort of information could also be used to identify an unknown agent during a chemical, biological or radiological attack, by providing baseline data on known agents for comparison.
Researchers have already developed dozens of individual model organs; the next challenge is to hook them together with the eventual goal of forming an entire human body on a chip, said Kristin Fabre, a programme manager at the National Center for Advancing Translational Sciences (NCATS) in Bethesda, Maryland.
An NCATS-funded project has 11 research teams participating to hook together at least 4 chips.
The US Department of Defense's Defense Advanced Research Projects Agency (DARPA) is supporting the development of techniques to link ten organs, and its Defense Threat Reduction Agency aims to build two four-organ systems.
19th Feb 2015, 03:08 PM #1769
Re: Health Bulletin
One in three Dutch doctors would consider assisting suicide for patients with dementia
The first of its kind study across Europe to see what doctors feel about assisted suicide has revealed that around one in three Dutch doctors would be prepared to help someone with early dementia, mental illness, or who is 'tired of living' to die.
A survey published in the Journal of Medical Ethics reveals that in the Netherlands, euthanasia or assisted suicide for those whose suffering is psychiatric/psychological in nature is legally permissible, but it represents a fraction of the numbers of patients who are helped to die in this way.
And while there is no right to euthanasia, the freedom of a doctor to refuse the request on personal grounds has been widely debated, following some well publicised cases.
In a bid to find out what Dutch doctors think of euthanasia and assisted suicide, the researchers canvassed the views of 2500 randomly targeted general practitioners (family doctors) and specialists in the fields of elderly care, cardiology, respiratory medicine, intensive care, neurology and internal medicine between October 2011 and June 2012.
The doctors were asked whether they had ever helped a patient with cancer, other physical disease, mental illness, early or advanced dementia, or someone without any severe physical ailments, but who was tired of living, to die. Those who had not done so were asked if they would even consider helping someone to die, and under what circumstances.
Among the 2269 eligible respondents, 1456 completed the survey?a response rate of 64%. Around three out of four (77%) had been asked at least once for help to die, rising to more than nine out of 10 among general practitioners.
Most (86%) respondents said they would consider helping a patient to die; just 14% said they would not. Among the 60% of respondents who had actually helped a patient to die, almost half (28%) had done so within the past 12 months.
Attitudes to euthanasia and assisted suicide varied by condition: most would consider it for a patient with cancer (85%) or other physical disease (82%). But only around a third (34%) would consider it for someone who was mentally ill.
Four out of 10 would be prepared to help someone with early stage dementia to die, but only one in three would do this for someone with late stage dementia, even if that person had written an advance directive for euthanasia.
Around one in four (27%) would be prepared to help someone tired of living to die if they had a severe medical condition. But fewer than one in five (18%) would do so in these circumstances if the person had no other medical grounds for suffering.
Only a few of the respondents (7%) had actually helped a patient who did not have cancer or another severe physical illness to die, whereas over half (56%) had helped a cancer patient to die, and around a third (31%) had assisted someone with another physical disease.
Lead author Dr Eva Bolt of the EMGO Institute for Health and Care Research, Amsterdam said "Each physician needs to form his or her own standpoint on euthanasia, based on legal boundaries and personal values. We would advise people with a future wish for euthanasia to discuss this wish with their physician in time, and we would advise physicians to be clear about their standpoint on the matter."
20th Feb 2015, 03:55 PM #1770
Re: Health Bulletin
Drug-resistant malaria parasite from Myanmar threatens India
India faces the imminent threat of malaria parasites that are resistant to the drug artemisinin, the frontline treatment against malaria, spreading from Myanmar into its territory, putting thousands of lives at risk, researchers have warned.
The research team confirmed resistant parasites in Homalin, Sagaing Region located only 25 kms from the Indian border.
If drug resistance spreads from Asia to the African sub-continent, or emerges in Africa independently, millions of lives will be at risk, the researchers added.
"We are facing the imminent threat of resistance spreading into India, with thousands of lives at risk," explained professor Mike Turner, head of infection & immunobiology at Britain-based Wellcome Trust.
The researchers examined whether parasite samples collected at 55 malaria treatment centres across Myanmar carried mutations in specific regions of the parasite's kelch gene (K13) - a known genetic marker of artemisinin drug resistance.
The team obtained the DNA sequences of 940 samples of malaria infections (known as Plasmodium falciparum malaria parasites) from across Myanmar and neighbouring border regions in Thailand and Bangladesh between 2013 and 2014. Of those 940 samples, 371 (39 percent) carried a resistance-conferring K13 mutation.
Using this information, the researchers developed maps to display the predicted extent of artemisinin resistance determined by the prevalence of K13 mutations.
The maps suggest that the overall prevalence of K13 mutations was greater than ten percent in large areas of the East and North of Myanmar, including areas close to the border with India.
The collection of samples from across Myanmar and its border regions was led by Kyaw Myo Tun of Defence Services Medical Research Centre, Napyitaw, Myanmar and coordinated by the Mahidol-Oxford Tropical Medicine Research Unit (MORU) in Bangkok, Thailand.
"Drug resistant malaria parasites in the 1960s originated in Southeast Asia and from there spread through Myanmar to India, and then to the rest of the world where it killed millions of people," Turner noted.
"The new research shows that history is repeating itself with parasites resistant to artemisinin drugs, the mainstay of modern malaria treatment, now widespread in Myanmar," Turner explained.
The study appeared online in the journal Lancet Infectious Diseases.