7th Apr 2014, 02:51 PM #971
Re: Health Bulletin
3D structure of malaria parasite genome generated
For the first time, scientists have generated a 3D model of the human malaria parasite genome at three different stages in the parasite's life cycle, an advance that could help identify new anti-malaria drugs.
A research team led by University of California, Riverside has generated the first such 3D architecture during the progression of the life cycle of a parasite.
According to the World Health Organisation, an estimated 207 million people were infected with malaria in 2012, leading to 627,000 deaths, researchers said.
"Understanding the spatial organisation of chromosomes is essential to comprehend the regulation of gene expression in any eukaryotic cell," said Karine Le Roch, an associate professor of cell biology and neuroscience, who led the study.
Her research team also found that those genes that need to be highly expressed in the malaria parasite — for example, genes involved in translation — tend to cluster in the same area of the cell nucleus.
On the other hand genes that need to be tightly repressed — for example, those involved in virulence — are found elsewhere in the 3D structure in a "repression center."
Virulence genes in the malaria parasite are a large family of genes that are responsible for the parasite's survival inside humans, researchers said.
Le Roch's team found that these genes, all organized into one repression centre in a distinct area in the nucleus, seem to drive the full genome organization of the parasite.
"We successfully mapped all physical interactions between genetic elements in the parasite nucleus," Le Roch said.
Scientists used a 'chromosome conformation capture method,' followed by high throughput sequencing technology — a recently developed methodology to analyze the organisation of chromosomes in the natural state of the cell.
They then used the maps of all physical interactions to generate a 3D model of the genome for each stage of the parasite life cycle analyzed.
To understand the biology of an organizm or any cell type, scientists need to understand not only the information encoded in the genome sequence but also how the sequence is compacted and physically organised in each cell/tissue, and how changes in the 3D genome architecture can play a critical role in regulating gene expression, chromosome morphogenesis and genome stability.
"If we understand how the malaria parasite genome is organized in the nucleus and which components control this organization, we may be able to disrupt this architecture and disrupt, too, the parasite development," Le Roch said.
"We know that the genome architecture is critical in regulating gene expression and, more important, in regulating genes that are critical for parasite virulence. Now we can more carefully search for components or drugs that can disrupt this organisation, helping in the identification of new anti-malaria strategies," said Le Roch.
The study appears in the journal Genome Research.
7th Apr 2014, 02:51 PM #972
Re: Health Bulletin
Junk food may make you lazy
Gorging on junk food may not only make you overweight, but also turn you sluggish, a study suggests. The study by University of California, Los Angeles, suggests that being overweight makes people tired and sedentary - not the other way around.
The researchers Scientists led by UCLA's Aaron Blaisdell put 32 rats on one of two diets for six months. The first, a standard rat's diet, consisted of relatively unprocessed food like ground corn and fish meal. The ingredients in the second were highly processed, of lower quality and included substantially more sugar - a proxy for a junk food diet.
After three months, it was seen significant difference in the amount of weight the rats had gained, with the the 16 rats on the junk food diet had become fatter. "One diet led to obesity, the other didn't," said Blaisdell. The experiments the researchers performed suggest fatigue may result from a junk food diet, Blaisdell said. The rats were given a task in which they were needed to press a lever to receive food or water. The rats on the junk food diet demonstrated impaired performance, taking took longer breaks than the lean rats.
8th Apr 2014, 02:16 PM #973
Re: Health Bulletin
Social stress takes a toll on chromosomes, affects aging
Humans experiencing high levels of social stress and deprivation have shorter telomeres.
Telomeres are the protective caps at the end of chromosomes which are the best indicators of biological age (cell age) as against chronological age.
Scientists say the length of telomeres is crucial in deciding biological age - long ones indicate healthy ageing, short ones indicate some form of irreparable damage.
Several studies suggest that telomere shortening is accelerated by stress but until now no studies examined the effects of social isolation on telomere shortening.
To test whether social isolation accelerates telomere shortening, Denise Aydinonat, a doctorate student at the Vetmeduni Vienna conducted a study using DNA samples that she collected from African grey parrots during routine check-ups.
African greys are highly social birds, but they are often reared and kept in isolation from other parrots. She and her collaborators compared the telomere lengths of single birds versus pair-housed individuals with a broad range of ages (from 1 to 45 years).
The telomere lengths of older birds were shorter compared to younger birds, regardless of their housing.
But the important finding of the study was that single-housed birds had shorter telomeres than pair-housed individuals of the same age group.
Dustin Penn from the Konrad Lorenz Institute of Ethology at the Vetmeduni Vienna said, "This study is the first to examine the effects of social isolation on telomere length in any species."
Penn and his team previously conducted experiments on mice which were the first to show that exposure to crowding stress causes telomere shortening. He points out that this new finding suggests that both extremes of social conditions affect telomere attrition.
There is extensive scientific evidence showing the strong correlation between the percentage of short telomeres and the risk of developing diseases associated with ageing, such as cancer, cardiovascular diseases and Alzheimer's.
In turn, lifestyle habits (nutrition, obesity and exercise) are increasingly being shown to impact telomere length.
Telomeres shorten with each cell division, and once a critical length is reached, cells are unable to divide further. Although cellular senescence is a useful mechanism to eliminate worn-out cells, it appears to contribute to aging and mortality.
8th Apr 2014, 02:20 PM #974
Re: Health Bulletin
Paralyzed patients regain movement after spinal implant: Study
Four men who had each been paralyzed from the chest down for more than two years and been told their situation was hopeless regained the ability to voluntarily move their legs and feet, though not to walk, after an electrical device was implanted in their spines, researchers reported on Tuesday.
The success, albeit in a small number of patients, offers hope that a fundamentally new treatment can help many of the 6 million paralyzed Americans, including the 1.3 million with spinal cord injuries. Even those whose cases are deemed so hopeless they are not offered further rehabilitation might benefit, scientists say.
The results also cast doubt on a key assumption about spinal cord injury: that treatment requires damaged neurons to regrow or be replaced with, for instance, stem cells. Both approaches have proved fiendishly difficult and, in the case of stem cells, controversial.
"The big message here is that people with spinal cord injury of the type these men had no longer need to think they have a lifelong sentence of paralysis," Dr Roderic Pettigrew, director of the National Institute of Biomedical Imaging and Bioengineering, part of the National Institutes of Health, said in an interview. "They can achieve some level of voluntary function," which he called "a milestone" in spinal cord injury research. His institute partly funded the study, which was published in the journal Brain.
The partial recovery achieved by "hopeless" patients suggests that physicians and rehabilitation therapists may be giving up on millions of paralyzed people. That's because physical therapy can mimic some aspects of the electrical stimulation that the device provided, said Susan Harkema, a specialist in neurological rehab at the University of Louisville's Kentucky Spinal Cord Injury Research Center (KSCIRC), who led the new study.
"One of the things this research shows is that there is more potential for spinal cord injury patients to recover even without this electrical stimulation," she said in an interview. "Today, patients are not given rehab because they are not considered 'good investments.' We should rethink what they're offered, because rehabilitation can drive recovery for many more than are receiving it."
The research built on the case of a single paralyzed patient that Harkema's team reported in 2011. College baseball star Rob Summers had been injured in a hit-and-run accident in 2006, paralyzing him below the neck.
In late 2009, Summers received the epidural implant just below the damaged area. The 2.5-ounce (72-gram) device began emitting electrical current at varying frequencies and intensities, stimulating dense bundles of neurons in the spinal cord. Three days later he stood on his own. In 2010 he took his first tentative steps.
His partial recovery became a media sensation, but even the Louisville team thought that epidural stimulation could benefit only spinal cord patients who had some sensation in their paralyzed limbs, as Summers did. "We assumed that the surviving sensory pathways were crucial for this recovery," Harkema said.
She and her team had little hope for two of their next patients. Neither had sensation in their paralyzed legs.
One was Kent Stephenson, who had been paralyzed in a 2009 motocross crash when he was 21. After months of rehab in Colorado, "they said I would never move my legs again, and there was no hope," he said.
Eleven days after he began receiving the deck-of-cards-size RestoreAdvanced stimulator, which is made by Medtronic and used for pain control, Stephenson moved his "paralyzed" left leg while lying on his back.
"My mom, who was in the room when they turned the stimulator on and told me, 'Pull your left leg up,' cried when I did it," Stephenson said. "I got a little watery-eyed, too. I'd been told I'd never move voluntarily again."
The researchers didn't expect him to, either, said Claudia Angeli of the Frazier Rehab Institute and KSCIRC, who co-led the study: "So when Kent moved, we thought, huh, this might actually be working."
Andrew Meas, whose head-on collision with a car while he was riding home on his motorcycle in 2006 left him paralyzed from the chest down, made even more progress. He can move even when the stimulator is not emitting electrical signals.
The first time he was able to move his legs "it made me feel like a normal person again," he said. After months of rehab post-implant, "I can pick up both my legs without the stimulator on, and can also stand without it. My record is 27 minutes, and I'm still progressing."
At first, Meas could move his legs only when the implant's 16 electrodes were zapping their spinal neurons at full power. Over 28 weeks of daily physical therapy, he gradually became able to move his toes, feet, ankles, knees, legs and hips with less electrical stimulation.
Meas's experience offers clues to how epidural stimulation works in patients with spinal cord injury. Just as continuous exposure to an allergen can eventually make people so sensitized that they sneeze and wheeze at a single grain of pollen, so the electrical barrage "resets the level of excitability of spinal cord neurons," said NIH's Pettigrew. As a result, "even input from exercise could be enough to trigger a motor response."
In addition to regaining voluntary movement, the patients put on muscle mass and felt less tired and generally happier. Summers is coaching baseball. Stephenson goes whitewater rafting and motocrossing in a sidecar.
Even researchers who have pioneered competing approaches, using cells, praised the new work. "It's not a cure," said Dr Barth Green, a neurosurgeon at the University of Miami, whose Miami Project to Cure Paralysis is trying to treat spinal cord patients with cell transplants. "But it could be part of a combined biological and bioengineering strategy to help patients not just walk again but also gain control of their bowel and bladder," which many paralyzed patients identify as even more important to their quality of life.
The Louisville researchers suspect that with better stimulator technology, spinal cord patients will be able to "work toward stepping," as they carefully phrase it to avoid the hype associated with "walking again." The electrodes in the current device must either be all on or all off, for instance; alternately stimulating the left and right sides might be more effective.
The bioengineering institute at NIH is funding research to develop noninvasive stimulators. That way, the electrical pulses can be delivered through the skin rather than requiring surgery to implant a device, Pettigrew said.
Even in patients with severe spinal cord injuries, and even after experts have pronounced them incapable of recovery, "we believe there is still a capacity for recovery," Harkema said. "It's not necessarily the case that you will never move again."
8th Apr 2014, 06:08 PM #975
Re: Health Bulletin
Couch potatoes date back 7,000 years
Thought couch potatoes are the product of a modern lifestyle? They may have evolved 7,000 years ago!
A new Cambridge study has shown that couch potatoes have a history that stretches back 7,000 years when humans first picked up the plough.
Research into lower limb bones shows that our early farming ancestors in Central Europe became less active as their tasks diversified and technology improved.
Cambridge University anthropologist Alison Macintosh found that this drop in mobility was particularly marked in men.
Macintosh shows that after the emergence of agriculture in Central Europe from around 5300 BC, the bones of those living in the fertile soils of the Danube river valley became progressively less strong, pointing to a decline in mobility and loading.
Macintosh suggests that male mobility among earliest farmers (around 7,300 years ago) was, on average, at a level near that of today's student cross-country runners.
Within just over 3,000 years, average mobility had dropped to the level of those students rated as sedentary, after which the decline slowed.
Macintosh laser-scanned skeletons found in cemeteries across Central Europe.
The earliest skeletons she examined date from around 5300 BC and the most recent from around 850 AD - a time span of 6,150 years.
Using a portable desktop 3D laser surface scanner to scan femora and tibiae, she found that male tibiae became less rigid and that bones in both males and females became less strengthened to loads in one direction more than another, such as front-to-back in walking.
These findings all indicate a drop in mobility. In other words, it is likely that the people to whom the skeletons belonged became, over generations, less intensely active and probably covered less distance, or carried out less physically demanding tasks, than those who had lived before them.
"My results suggest that, following the transition to agriculture in Central Europe, males were more affected than females by cultural and technological changes that reduced the need for long-distance travel or heavy physical work," said Macintosh.
"This also means that, as people began to specialize in tasks other than just farming and food production, such as metalworking, fewer people were regularly doing tasks that were very strenuous on their legs," Macintosh said.
9th Apr 2014, 11:10 AM #976
Re: Health Bulletin
A serving of lentils could keep bad cholesterol at bad: study
A new Canadian study has said that eating lentils - such as the ones used to cook the Indian dal - is an easy way to keep the dreaded LDL or bad cholesterol in check. The study conducted in St Michael's Hospital in Toronto established this after observing 1,000 people who took a daily serving of legumes and reported a 5% reduction in LDL levels.
A press release sent by the Canadian Medical Association Journal quoted the study's lead author Dr John Sievenpiper as saying that a 5 % reduction in LDL cholesterol is actually a ``potential 5 % lower risk of heart disease''. Some of the study participants reported stomach problems such as bloating, flatulence, constipation or diarrhea as a result of eating legumes, but the gains were unmistakable, said the authors.
The study does lend credence to the fact that a healthy diet keeps the heart healthy. But one wonders where this leaves Indians. Indians consume legumes with every meal - dal is an integral part of the Indian thali - yet they have worrisome levels of cholesterol. Indian genetic makeup has been blamed for many of the cholesterol-related heart problems, but a closer look at the Indian thali would no doubt help control the epidemic of heart diseases. It would be worthwhile to know whether we should take an extra helping of dal or add another serving of fruit.
9th Apr 2014, 03:23 PM #977
Re: Health Bulletin
Kids to get lessons in handling emotions
A few likes on their Facebook profile pictures or a scolding from a parent is enough to get kids depressed today. This has left child psychologists surprised at the low emotional quotient among children. To help children deal better with situations, Bangalore University professors and a private organization have come together to prepare a curriculum for emotional literacy among primary schoolchildren.
Meant for children below 11 years of age, the curriculum consists of self-awareness , recognition and labelling of emotions and selfmanagement . Kids will attend classes on controlling anger, overcoming fear, facing failure, handling relationships as well as on decision--making and problem-solving . Lessons will be imparted through mediums like storytelling, music, role plays and theatre. The curriculum is being introduced in two schools from the next academic year.
The initiative is part of Kid and Parent Foundation, a private organization that works for child development , and VHD Central Institute of Home Science.
"A major problem we find among children today is the fear of failure. They are under constant pressure to perform. They need to know how to handle failure and accept rejection. Their attention span is so less that they are unable to sit through a storytelling session. They need to be taught how to live one moment after another," said Aparna Athreya, founder, Kid and Parent Foundation. "Another complaint we regularly get from teachers and parents is children becoming aggressive. This can have a lot do with their exposure to television . They get irritated at small things and can even start beating up others. When they get into higher classes, things like Facebook and the identity crisis it brings with it come into play," added Athreya.
Subject experts from Bangalore University are in charge of framing and reviewing the curriculum. They will develop the module and run it on the field. There will be specific periods allotted for the subject handled by facilitators who are trained in child development. Children will be evaluated through conversations and activities.
"Earlier, it was the joint family that took care of the socio-emotional development of children. With nuclear families and working parents , the task is mostly left to schools and daycare centres. Unfortunately, not many of them are doing a good job. Our curriculum is focused only on academics," said Rajalakshmi MS, associate professor, early childhood education and administration programme, department of human development, VHD Central Institute of Home Science.
There have been changes of late in the way children are academically assessed, as CBSE's Continuous Comprehensive Evaluation (CCE) or the Open Book System show. Now techniques in pedagogy are also leaning towards gauging and honing the emotional quotient or EQ and not just the intelligence quotient of a child. With newer pressures and influences mounting on children, schools and parents find themselves a little ill-equipped to assess their impact. The emotional literacy curricula designed by Bangalore University experts and the feedback it gets needs serious review.
11th Apr 2014, 02:26 AM #978
Re: Health Bulletin
Now, 'Viagra' pills for women
Lady Prelox, a new herbal pill, claims to boost women’s sex lives.
Scientists say the pill, sold by Holland & Barrett, contains extracts from French pine bark called pycnogenol. It goes on sale this month.
However, looks like pleasure doesn't come cheap. The pack contains 60 little pink tablets and will be sold at a whopping price of £37.95.
Nord Pharma, who manufactured the breakthrough innovation, told The Telegraph that Lady Prelox "boosts libido and increases arousal in women", because it "encourages blood flow to the reproductive organs as well as the brain".
Lady Prelox is the female version of Prelox for men.
11th Apr 2014, 02:29 AM #979
Re: Health Bulletin
Healthy diet can help ease asthma symptoms: study
A healthy diet could help ease asthma symptoms, according to a new Australian study. According to a report of Australia's public broadcaster ABC, two studies, explaining that people on high saturated fats food diet were likely than others to have Asthama attacks, will be presented to a Thoracic Society conference in Adelaide today.
In the study, the scientists found saturated fats reduce the effectiveness of the medicines used to treat Asthma. Nutritional biochemist at the University of Newcastle, Lisa Wood, said 'the researching team wanted to highlight the benefits of eating healthy foods to people with Asthma.
"The team had developed a scorecard of good and bad foods, which she hoped asthmatics would use to guide their eating," she said. "It's never going to replace Asthma medications but nonetheless, because of the beneficial health effects that we've seen, we really do promote this as a healthy way to change your lifestyle which will improve asthma but also which will improve your overall health status," she said.
"We've seen that fruit and vegetables can be very helpful, so if you have a diet that's high in fruit and vegetables compared with a diet that's low in fruit and vegetables that reduces your risk of having an Asthma attack.
"However, more research was required to examine if poor diet could be a risk factor for developing asthma," she said. "Some big population studies have suggested that dietary factors can lead to the development of Asthma but there isn't really a lot of strong interventional data to support that at the moment, that's another area that needs further research," she said.
11th Apr 2014, 03:07 AM #980
Re: Health Bulletin
Optimism tied to lower risk of heart failure
Want to reduce your risk of heart failure? Think positive.
Optimism — an expectation that good things will happen — can significantly lower the risk of developing heart failure in older adults, a new study has found.
Researchers from the University of Michigan and Harvard University found that compared to the least optimistic people in the study, the most optimistic people had a 73 per cent reduced risk of heart failure over the follow-up period.
Eric Kim, a doctoral student in the U-M Department of Psychology and the study's lead author, and colleagues analysed data on 6,808 older adults from the Health and Retirement Study, a nationally representative panel study of people over age 50 in the US.
The participants, who were followed for four years, provided background information about themselves, health history and psychological data.
In order to help rule out the possibility that other factors could better explain the link between optimism and heart failure, the researchers adjusted for factors that might impact heart failure risk, including demographic factors, health behaviours, chronic illnesses and biological factors.
Higher optimism was associated with a lower risk of heart failure during the study's follow-up period - a finding that could eventually contribute to creating new strategies in the health care industry to prevent or delay the onset of this epidemic, Kim said.
The researchers said that the protective effect of optimism might be explained by previous research, which has shown that optimism is associated with important health behaviours (eating healthier diets, exercising more, managing stress), enhanced physiological functioning and other positive health outcomes that are strongly linked with a decreased risk of heart failure.
The findings appear in the journal Circulation: Heart Failure.