30th Dec 2013, 08:31 AM #691
Re: Health Bulletin
New device allows scientists to operate on living cells
Scientists have developed a device that can take a "biopsy" of a living cell, sampling minute volumes of its contents without killing it.
The new tool, called a nanobiopsy, uses a robotic glass nanopipette to pierce the cell membrane and extract a volume of around 50 femtolitres, around one per cent of the cell's contents.
It will allow scientists to take samples repeatedly, to study the progression of disease at a molecular level in an individual cell. It can also be used to deliver material into cells, opening up ways to reprogramme diseased cells.
"This is like doing surgery on individual cells," said Dr Paolo Actis, from the department of medicine at Imperial College, London, who developed the technology with colleagues at the University of California, Santa Cruz.
"This technology will be extremely useful for research in many areas. You could use it to dynamically study how cancer cells are different from healthy cells, or look at how brain cells are affected by Alzheimer's disease. The possibilities are immense," Actis said.
To get inside the cell, the nanopipette is plunged downwards about one micrometre to pierce the cell membrane.
Applying a voltage across the tip makes fluid flow into the pipette. When the pipette is removed from the cell, the membrane remains intact and the cell retains its shape.
The device is based on a scanning ion conductance microscope, which uses a robotic nanopipette, about 100 nanometres in diameter, to scan the surface of cells.
The nanopipette is filled with an electrolyte solution and the ion current is measured inside the tip. When the pipette gets close to a cell membrane, the ion current decreases.
This measurement is used to guide the tip across the surface of a sample at a constant distance, producing a picture of the surface.
In an initial study published in the journal ACS Nano, the researchers used the nanobiopsy technique to extract and sequence messenger RNA, molecules carrying genetic code transcribed from DNA in the cell's nucleus. This allowed them to see which genes were being expressed in the cell.
They were also able to extract whole mitochondria - the power units of the cell. Mitochondria contain their own DNA, and the researchers discovered that the genomes of different mitochondria in the same cell are different.
31st Dec 2013, 07:03 PM #692
Re: Health Bulletin
Drug raises hope for cure of alcoholism
A new drug to treat alcoholism which went for sale in Japan earlier this year can improve the chances of addicts quitting drinking, doctors say.
Regtect helps by improving the chemical balance in the brain to suppress an 'alcoholic' patient's craving, whereas conventional drugs discourage drinking by causing unpleasant symptoms, such as palpitations, nausea and headaches.
The first alcohol-dependence drug to be launched in Japan in 30 years, Regtect was sold in 24 other countries before getting a green signal in the alcohol-happy nation, 'Kyodo' news agency reported.
Alcohol dependence is a mental disease that renders sufferers unable to control their drinking. Attempts to cure alcoholism through abstinence can cause shakiness, insomnia, sweating, nausea, and auditory and visual hallucinations.
31st Dec 2013, 07:03 PM #693
Re: Health Bulletin
Most women suffer from ‘carb guilt’
Nearly half of women feel guilty about eating carbohydrates, even though carbs have an essential part in a healthy diet, a new study has found. Women are about twice as likely as men to suffer from 'carb guilt', even though they were more likely to be a healthy weight, according to a survey of 3,000 people.
One in ten women said they felt guilty all the time about the amount of carbohydrates they ate while about a quarter said they would avoid them in the week to allow themselves to indulge at the weekend. Jane Ogden, a professor in health psychology at the University of Surrey who helped design the research, said that people were irrationally demonising carbohydrates. "If they realize that carbohydrates have an essential part in their diets, not only for energy but also for building long-term sustainable healthy habits, then carbohydrates can resume their place as a central part of how they eat," she said.
2nd Jan 2014, 12:40 AM #694
Re: Health Bulletin
Vitamin E may slow Alzheimer's progression
Researchers say vitamin E might slow the progression of mild-to-moderate Alzheimer's disease the first time any treatment has been shown to alter the course of dementia at that stage.
In a study of more than 600 older veterans, high doses of the vitamin delayed the decline in daily living skills, such as making meals, getting dressed and holding a conversation, by about six months over a two-year period.
The benefit was equivalent to keeping one major skill that otherwise would have been lost, such as being able to bathe without help. For some people, that could mean living independently rather than needing a nursing home.
Vitamin E did not preserve thinking abilities, though, and it did no good for patients who took it with another Alzheimer's medication. But those taking vitamin E alone required less help from caregivers _ about two fewer hours each day than some others in the study.
"It's not a miracle or, obviously, a cure," said study leader Dr Maurice Dysken of the Minneapolis VA Health Care System. "The best we can do at this point is slow down the rate of progression."
The US Department of Veterans Affairs sponsored the study, published Tuesday by the Journal of the American Medical Association.
No one should rush out and buy vitamin E, several doctors warned. It failed to prevent healthy people from developing dementia or to help those with mild impairment ("pre-Alzheimer's") in other studies, and one suggested it might even be harmful.
Still, many experts cheered the new results after so many recent flops of once-promising drugs.
"This is truly a breakthrough paper and constitutes what we have been working toward for nearly three decades: the first truly disease-modifying intervention for Alzheimer's," said Dr Sam Gandy of Mount Sinai School of Medicine in New York. "I am very enthusiastic about the results."
About 35 million people worldwide have dementia, and Alzheimer's is the most common type. In the US, about 5 million have Alzheimer's. There is no cure and current medicines just temporarily ease symptoms.
Researchers don't know how vitamin E might help, but it is an antioxidant, like those found in red wine, grapes and some teas. Antioxidants help protect cells from damage that can contribute to other diseases, says the federal Office on Dietary Supplements. Many foods contain vitamin E, such as nuts, seeds, grains, leafy greens and vegetable oils. There are many forms, and the study tested a synthetic version of one alpha-tocopherol - at a pharmaceutical grade and strength, 2,000 international units a day.
Years ago, another study found that the same form and dose helped people with more advanced Alzheimer's, and many were prescribed it. But vitamin E fell out of favor after a 2005 analysis of many studies found that those taking more than 400 units a day were more likely to die of any cause.
The new study involved 613 veterans, nearly all male, 79 years old on average, with mild to moderate Alzheimer's, at 14 VA centers. All were already taking Aricept, Razadyne or Exelon widely used, similar dementia medicines.
Participants were placed in four groups and given either vitamin E, another dementia medicine called memantine (its brand name is Namenda), both pills or dummy pills.
After a little more than two years of follow-up, those on vitamin E alone had a 19 per cent lower annual rate of decline in daily living skills compared to the placebo group. Memantine made no difference, and vitamin E did not affect several tests of thinking skills.
"It's a subtle effect but it's probably real," Dr Ron Petersen, the Mayo Clinic's Alzheimer's research chief, said of the benefit on daily living from vitamin E. "That has to be weighed against the potential risks" seen in earlier studies, he said.
Heather Snyder, director of medical and scientific operations for the Alzheimer's Association, said the group's position is that "no one should take vitamin E for Alzheimer's disease or other memory issues except under the supervision of a physician," because it can interfere with blood thinners, cholesterol drugs and other medicines.
The new results also need to be verified in a fresh study that includes more women and minorities, she said.
2nd Jan 2014, 12:41 AM #695
Re: Health Bulletin
Studies that call vitamin pills useless flawed: Expert
A majority of clinical studies on vitamin supplements have a flawed methodology that renders them largely useless in determining the real value of the micronutrients, a new analysis has claimed. Some recent clinical trials have concluded that vitamin supplements are of no value or they may even be harmful.
Many projects have tried to study nutrients that are naturally available in the human diet the same way they would a prescription drug, researchers said.
This leads to conclusions that have little scientific meaning, even less accuracy and often defy a wealth of other evidence, said Balz Frei, director of the Linus Pauling Institute at Oregon State University. These flawed findings will persist until the approach to studying micronutrients is changed, Frei said.
New methodologies are needed that accurately measure baseline nutrient levels, provide supplements or dietary changes only to subjects who clearly are inadequate or deficient, and then study the resulting changes in their health, researchers said.
Tests must be done with blood plasma or other measurements to verify that the intervention improved the subjects' micronutrient status along with biomarkers of health, they said. Other approaches are also needed that better reflect the different ways in which nutrients behave in cell cultures, lab animals and the human body.
The analysis specifically looked at problems with the historic study of vitamin C, but scientists say many of the observations are more broadly relevant to a wide range of vitamins and micronutrients.
"One of the obvious problems is that most large, clinical studies of vitamins have been done with groups such as doctors and nurses who are educated, informed, able to afford healthy food and routinely have better dietary standards than the public as a whole," said Frei, an international expert on vitamin C and antioxidants.
2nd Jan 2014, 04:46 PM #696
Re: Health Bulletin
Airport din linked to stroke, heart disease, psychoses
People living near airports frequently complain about the sound of jet engines screaming overhead. Many of them are reduced to nervous wrecks constantly anticipating the next low-flying aircraft.
A recent UK study confirmed that people who live in neighbourhoods surrounding an airport are prone to various ailments due to the high decibel blasts. Researchers from Imperial College London and King's College London, who conducted the study, say residents of such localities are more vulnerable to heart diseases, stroke and hypertension than people in other parts of a city.
Nearly 350 flights land and take off from the airport in Chennai every day so it stands to reason that people in localities like St Thomas Mount, Adambakkam, Nanganallur, Pazhavanthangal and Tirusulam, all near the Meenambakkam airstrip, could be similarly affected.
Doctors in the city say no study on the subject has been carried out in the country but admit there is enough evidence to prove that it is a problem here too. "Madras ENT Research Foundation (MERF) will conduct a study next year to record the noise levels near the airport, railway stations and busy markets and analyse the impact they have on residents in areas nearby," MERF founder Dr Mohan Kameshwaran said.
He said the average level of noise that people can be exposed to is 80 decibels for eight hours. But noise levels in and around the airport are often between 90 and 100 decibels. Studies show that a person can put up with a sound level of 91 decibels for only two hours each day before their hearing is put at risk.
"Long-term exposure to the high frequency noise from aircraft could result in hearing loss or worse," Dr Kameshwaran said. "People living close to an airport are vulnerable to psychological disorders as well."
"It is not just the noise from the aircraft. People have to change their entire audio environment. They end up increasing the television volume and talk loudly to be heard above the noise, putting a lot of strain on the body and mind," Dr Kameshwaran said. Cardiologist Dr Sengottuvelu of Apollo Hospitals said sudden blasts of noise can increase the heart rate, leading to sleep disorders. "Constant exposure to loud noise causes a rise in blood pressure, leading to cardiovascular problems," he said.
2nd Jan 2014, 04:47 PM #697
Re: Health Bulletin
Soon, bone substitute without toxins
You read it right. A fragile 'ceramic' material can now work as a bone substitute.
A team of researchers at National Polytechnic Institute (NPI) in France, have found that Hydroxylapatite - medullar component of the bone - when obtained synthetically and 'giving' it some characteristics, could be used as a bone substitute.
"Hydroxylapatite, when obtained synthetically, conserves its properties and could work as a bone substitute because, according to our studies, it doesn't cause toxicity in the human body," said Lucia TA©llez Jurado from the laboratory of heavy materials of metallurgic engineer at Superior School of Chemical Engineering and Extractive Industries (ESIQUE).
Hydroxylapatite is a widely studied material, employed as a biomaterial and can be obtained from animal skeletons or synthetically. Another of its applications is as a filter for heavy metals.
The researchers found that Hydroxylapatite obtained synthetically is a fragile 'ceramic' so it would be necessary to add other substances giving them mechanical resistance.
They are now looking for a material with optimal properties that could be applied on a large bone like femur or fingers.
"We are interested in obtaining a material that complies with mechanical characteristics so it can be implanted or used as a substitute for a broken bone when no other option is available," said Jurado.
"We are going to test several materials, checking their mechanical compositions so it has the required characteristics and works in humans. If someone has a fracture, the technology must be applied without causing further damage," Jurado added.
2nd Jan 2014, 04:52 PM #698
Re: Health Bulletin
Our bodies let us feel the emotions
Wonder why your ears feel warm when you are tensed or why your chest aches when you are anxious?
Researchers from Aalto University say that all known human emotions have different ways of playing out in our body. The sensations arising from bodily changes are an important feature of our emotional experience.
For example, anxiety may be experienced as pain in the chest, whereas falling in love may trigger warm, pleasurable sensations all over the body. The new body map constitutes the most accurate description available to date of subjective emotion-related bodily sensations.
"Our data highlights that consistent patterns of bodily sensations are associated with six basic emotions, and that these sensations are represented in a categorical manner in the body. They are in line with evidence from brain imaging and behavioural studies. Most basic emotions were associated with sensations of elevated activity in the upper chest area, like changes in breathing pattern and heart rate."
"Sensations in the upper limbs were most prominent in approach-oriented emotions, anger and happiness, whereas sensations of decreased limb activity were a defining feature of sadness. Sensations in the digestive system and around the throat region were mainly found in disgust. In contrast with all of the other emotions, happiness was associated with enhanced sensations all over the body," researchers said.
The researchers found that the most common emotions trigger strong bodily sensations and the bodily maps of these sensations were topographically different for different emotions.
The sensation patterns were, however, consistent across different West European and East Asian cultures, highlighting that emotions and their corresponding bodily sensation patterns have a biological basis.
Professor Lauri Nummenmaa from Aalto University carried out the study online and over 700 individuals from Finland, Sweden and Taiwan took part in it.
The researchers induced different emotional states in their Finnish and Taiwanese participants. Subsequently the participants were shown pictures of human bodies on a computer and asked to colour the regions whose activity they felt increasing or decreasing.
"We often experience emotions directly in the body. When strolling through the park to meet with our sweetheart we walk lightly with our hearts pounding with excitement, whereas anxiety might tighten our muscles and make our hands sweat and tremble before an important job interview. Numerous studies have established that emotion systems prepare us to meet challenges encountered in the environment by adjusting the activation of the cardiovascular, skeletomuscular, neuroendocrine and autonomic nervous system.
This link between emotions and bodily states is also reflected in the way we speak of emotions: a young bride getting married next week may suddenly have "cold feet," severely disappointed lovers may be "heartbroken," and our favourite song may send "a shiver down our spine."
4th Jan 2014, 03:07 AM #699
Re: Health Bulletin
High BP more dangerous in women than men
Doctors may need to treat high blood pressure in women more fiercely than they do in men.
In a study, the researchers for the first time found significant differences in the mechanisms that cause high blood pressure in women as compared to men.
"The medical community thought that high blood pressure was the same for both sexes and treatment was based on that premise," said Carlos Ferrario, professor of surgery at Wake Forest Baptist Medical Centre and lead author of the study.
"This is the first study to consider sex as an element in the selection of anti-hypertensive agents or base the choice of a specific drug on the various factors accounting for the elevation in blood pressure," added Ferrario.
"In fact, heart disease has become the leading cause of death in women in the United States, accounting for approximately a third of all deaths. So why the discrepancy if men and women have been treated in the same way for the same condition?" asked scientists.
In the comparative study, 100 men and women age 53 and older with untreated high blood pressure and no other major diseases were evaluated using an array of specialised tests that indicated whether the heart or the blood vessels were primarily involved in elevating the blood pressure.
The tests measured hemodynamic- the forces involved in the circulation of blood - and hormonal characteristics of the mechanisms involved in the development of high blood pressure in men and women, said the study published in the journal Therapeutic Advances in Cardiovascular Disease.
The researchers found 30 to 40 percent more vascular disease in the women compared to the men for the same level of elevated blood pressure.
"We need to evaluate new protocols- what drugs, in what combination and in what dosage- to treat women with high blood pressure," the study concluded.
4th Jan 2014, 03:08 AM #700
Re: Health Bulletin
Special immune cells keep TB in control: Study
A special class of immune cells called 'invariant natural killer T cells' keep the deadly tuberculosis infection in check - a heartening news for India that has the most number of tuberculosis cases in the world.
"Mycobacterium tuberculosis is a major cause of death worldwide. Most healthy people can defend themselves against tuberculosis, but they need all parts of their immune system to work together. We were interested in identifying the mechanisms that different types of T cells use to control Mycobacterium tuberculosis infection," said senior author Samuel Behar of University of Massachusetts Medical School, US.
His team found that when 'invariant natural killer T cells' encounter infected macrophages - the human target cells of Mycobacterium tuberculosis (Mtb) - T cells somehow prevented Mtb from growing and multiplying inside the macrophages.
Using a number of cell culture systems and experiments in mice to dissect the interaction, they found that when T cells are confronted with Mtb-infected macrophages, they respond in two different ways.
One is that they produce and release interferon gamma, a broad-spectrum immune system activator. But when the scientists blocked interferon gamma action, they found that the T cells could still inhibit Mtb growth in the macrophages, said the study published in the journal PLOS Pathogens.
"Understanding how such T cells contribute to the control and elimination of Mtb could lead to novel therapeutic approaches that strengthen their activity and boost the overall immune response during infection," concluded the study.