Twelve things one should avoid doing when it comes to sex

Washington: While much has been written about how to boost action in the bedroom, there are things one should never do when it comes to sex.

In her new book, titled 'Sex with Your Ex & 69 Other Things You Should Never Do Again... Plus a Few That You Should', author Dr. Yvonne K. Fulbright has mentioned things that one should strictly refrain to keep a healthy sex life, reports Fox News. And, according to her, the don'ts of sex are:

1. Never have a 'type' of orgasm - have your orgasm

Instead of trying to have a breast, clitoral, G-spot or blended orgasm, forget the labels and have yours. Don't worry about having a specific type, but focus on pampering your whole body, attending to any of its hot spots. This beckons your orgasm by not being so goal-oriented.

2. Never talk about past sexual relationships

Don't invite distress into your current romance by reminiscing about the good times or bad times you've had with other jerks, hotties, players or loves. Focus on the present and making it the most memorable.

3. Never let sex get routine

While it's wise to get in a routine to make sure sex happens, don't let the sex itself get routine. This only invites monotony and the mundane. To keep things hot, be sure to keep things new and fresh.

4. Never just lie there

A big complaint you'll hear from men and women alike is that their lover didn't do much of anything during sex. Men have grumbled that she doesn't move during lovemaking. Most people like an active lover - one responsive to the action, which shows that they're into the moment.

5. Never move in together (or get married) a second time

Things didn't work out the first time for good reason. Maybe you love each other, but if you're incompatible or fight too much, it's better to cut your losses and move on to a situation that does work.

6. Never drink cheap beer and stay overnight

Don't set yourself up to be someone's gassy guest. Get the walk of shame over with sooner rather than later, lest you stink up someone's bedroom and bathroom. This is not the kind of lasting impression most seducers are after.

7. Never drink more than 1-2 glasses of alcohol

While spirits can do a lot for one's spirits, sexual self-confidence, and libido, keep your booze to a minimum. More than a couple of glasses can cause erectile difficulties in men and vaginal dryness in women. Being buzzed or drunk can also lead to high-risk sexual behaviours.

8. Never compare yourself to Victoria's Secret or Abercrombie models.

It's no good to think that these real-life moving mannequins are the standard by which you should judge your face or form. You've got your own unique look and that can be super sexy, depending on how you wear it. That starts with a smile and indicating to others that you feel quite good about yourself.

9. Never totally trust magazine sex tips

Don't mindlessly copy magazine sex tips. Think about the suggestion first. Is it hot or completely ridiculous? Will it work for your sexual relationship? Or does it have the potential to sabotage your sex life?

10. Never douche before sex

Despite popular belief, douching is not a safe or healthy way to clean the vagina. Doing so upsets the vagina's delicate chemical balance, increasing your chance of developing pelvic inflammatory disease or other health problems. Let the vagina naturally cleanse itself and worry about other much sexier activities pre-sex.

11. Never attempt tricky Kama Sutra positions if you are not flexible.

Stick with pursuing sexual positions that are comfortable for you.

12. Never listen to somebody slamming your sexy self.

Is a guy suggesting that you get breast implants? Is some gal making fun of your penis size? In either case, ignore the criticism, or in the very least, fire back.

Testosterone replacement improves men's liver function

Washington: A new study suggests that testosterone replacement for men with low levels of the hormone greatly improves their fatty liver disease as well as their risk factors for cardiovascular disease and diabetes.
"Physicians often are reluctant to prescribe testosterone for conditions not related to sexual function. However, our study shows that testosterone has a much wider therapeutic role than just for improving sexual desire and erectile function," said the study's co-author, Dr. Farid Saad, of Berlin-headquartered Bayer Schering Pharma.
During a presentation at The Endocrine Society's 91st Annual Meeting in Washington, D.C., it was revealed that the study included 122 testosterone-deficient men, aged 36 to 69 years.
The researchers found that restoring testosterone to normal levels led to major and progressive improvements in many features of the metabolic syndrome over the 2 years of treatment.
They said that, particularly, the men's weight, waist line and body mass index continued to decline over the full study period.
According to them, the other metabolic risk factors also significantly improved during the first year of testosterone treatment.
Of the 47 men who met the criteria for a diagnosis of the metabolic syndrome at the beginning of the study, 36 no longer had the diagnosis after 2 years of treatment, the authors reported.
Furthermore, liver function significantly improved during the first 12 to 18 months of therapy and stabilized for the remainder of the study period.
The researchers said that the treatment also greatly decreased blood levels of C-reactive protein, a measure of inflammation that is linked to increased risk of cardiovascular disease.
"We conclude that testosterone therapy in men with testosterone deficiency can largely improve or even remedy the metabolic syndrome, which will most likely decrease their risk of diabetes and cardiovascular disease," Saad said. [From Internet]

'Pullout method' nearly as effective as using condoms: Study

Washington: A new study has indicated that the old 'pullout method', pulling out just before ejaculation, works nearly as well as condoms in preventing pregnancies.
The study, titled "Better than nothing or savvy risk reduction practice? The importance of withdrawal," appears in the June edition of the journal Contraception, reports CBS News.
The authors find:
"If the male partner withdraws before ejaculation every time a couple has vaginal intercourse, about 4 percent of couples will become pregnant over the course of a year.
"However, more realistic estimates of typical use indicate that about 18 percent of couples will become pregnant in a year using withdrawal.
"These rates are only slightly less effective than male condoms, which have perfect- and typical-use failure rates of 2 percent and 17 percent, respectively."

Binge drinking harms teens' brains

Washington: In a study on adolescent binge drinkers, scientists have found that even rare consumption of large doses of alcohol during youth may compromise the coherence of the brain's white matter fibre.
Such incoherence has been known in adult alcoholics, but researchers were unaware as to when during the course of drinking white matter abnormalities become apparent.
"Because the brain is still developing during adolescence, there has been concern that it may be more vulnerable to the effects of neurotoxins, such as high doses of alcohol," said Susan F. Tapert, associate professor of psychiatry at the University of California, San Diego.
The study's corresponding author has claimed that animal studies have suggested this to be true.
Duncan Clark, associate professor of psychiatry at the University of Pittsburgh Medical Center, said that "'white matter'" refers to brain areas that appear light in colour due to being primarily lipids."
He added: "White matter is composed of bundles of myelinated axons connecting grey matter areas of the brain, and has been shown to continue to develop throughout adolescence. These systematic changes in white matter organization reflect not only maturation of interconnections but continued maturation of the brain as a whole."
"White matter, and its integrity, are essential to the efficient relay of information within the brain. Indicators of white matter integrity are linked to performance on a range of cognitive tests, including measures of reading, copying complex figures, and speeded coding of information. Abnormalities in white matter health could relate to compromised ability to consider multiple sources of information when making decisions, and to emotional functioning," said Tapert.
For the study, the researchers enrolled 28 teens and used diffusion tensor imaging - an MRI technique sensitive to the random movement of water in cells of a target tissue - to examine fractional anisotropy, a measure of directional coherence of white matter tracts, in them.
It was found that out of the 28 adoloscents, 14 (12 males, 2 females) had and 14 (12 males, 2 females) did not have histories of binge drinking.
No participants had a history of an alcohol use disorder-drinkers were matched to non-drinkers on age, gender and education.
"This study showed that adolescents with histories of binge drinking episodes have lower coherence of white matter fibers, suggesting poorer white matter health, in a variety of brain regions. Frankly, I was surprised we found this, because the drinkers did not meet criteria for alcohol abuse or dependence," said Tapert.
Clark said: "These findings add to a growing literature indicating that adolescent alcohol involvement is associated with specific brain characteristics. One of the advantages of this study was that the adolescents with binge drinking did not have major mental disorders. Adolescents with alcohol-use disorders often have other problems. This suggests that the observed brain characteristics may be associated with alcohol involvement specifically rather than other complications."
"These findings indicate that adolescents who engage in binge drinking show low levels of brain organization," he said. "This characteristic could be a risk factor for accelerated alcohol use or an effect of alcohol. We need to know more about how alcohol influences adolescent brain development, [given] that alcohol may disrupt brain development."
The results of the study will be published in the July issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View

Diet high in fruits, veggies may protect against cancer

London: A diet rich in fruit and vegetables may protect against cancer and heart disease, claim researchers.
Fruit and vegetables contain high levels of salicylates, which are also the active anti-inflammatory ingredient of aspirin.
According to a review of the possible association of cancer prevention with this substance found in aspirin, published in the medical journal The Lancet, many herbs and spices are also especially rich in salicylates, reports The Independent.
Professor Peter Elwood, of the University of Cardiff's school of medicine, who led the review, said: "I think this is a very exciting area that should be researched in considerable depth.
"Most medical authorities have said for 20 years that it is the antioxidants in fruit and vegetables that account for their protective effects. It leads us to wonder if the beneficial effects of fruit and vegetables are because of the salicylates they contain," he said.
Salicylates were first identified in strawberries at the beginning of the 20th century, and they have been found to occur naturally in a wide range of plants.

Daily Drinking Poses Biggest Threat to Liver

London: Daily drinking, rather than binge drinking, poses the biggest threat to the liver, according to a new study.
University of Southampton researchers attributed increases in liver-related deaths to daily or near daily heavy drinking, not episodic or binge drinking, a pattern discernable at an early age.
In the study of alcohol dependency of 234 people with liver disease - 106 had alcohol-related liver disease (ALD) and 80 of them had evidence of cirrhosis or progressive fibrosis - the team found that 71 percent of ALD patients drank on a daily basis.
Conversely, patients with other forms of liver disease tended to drink sparingly with only 10 people (eight percent) drinking moderately on four or more days each week.
The study also explored lifetime drinking histories of 105 people and found that ALD patients started drinking at a significantly younger age (15 years) than other subjects and had significantly more drinking days and units than non-ALD patients from the age of 20 onwards, said a Southampton release.
Senior lecturer and consultant hepatologist Nick Sheron at Southamption, who led the study, said, "If we are to turn the tide of liver deaths. . . which means tackling cheap booze and unregulated marketing - we need to find a way to identify those people who are most likely to develop alcohol-related illnesses at a much earlier stage."
These findings were published in Addiction.

Surgeons announce world's first successful transvaginal nephrectomy using intra-umbilical Tri-port

Washington: Doctors at Instituto Medico La Floresta in Caracas, Venezuela, have successfully performed the world's first live human transvaginal nephrectomy using the Tri-port multi-channel port supplied by Advanced Surgical Concepts Ltd.
Dr. Rene Sotelo, the leader of the team of surgeons who carried out the operation, has revealed that the majority of the intra-operative endoscopic visualization and tissue mobilization for the natural orifice transluminal endoscopic surgery (NOTES) nephrectomy was performed transvaginally, with observation and occasional assistance from an intra-umbilical Tri-port.
According to him, no extra-umbilical incisions were needed.
The patient on whom the operation was performed was a 65 year-old woman with a 6 cm left kidney tumour, and a prior history of hysterectomy.
Sotelo revealed that it took 220 minutes for the surgery to complete, and that patient thereafter had to stay in the hospital for two days.
He said that the patient did not experience any complications, and was discharged with no visible abdominal scar.
Sotelo says: "The procedure went well and has great potential for the future."

Sleeping during the day ups mortality risk in older women

Washington: A new study has found that older women who take daily naps are at a greater risk of dying.
Researchers have found that women who reported napping daily were 44 percent more likely to die from any cause while 58 percent more likely to die from cardiovascular causes
Also 59 percent were more likely to die from non-cardiovascular, non-cancer causes.
The study involving 8,101 Caucasian women aged 69 and older that showed that those who reported sleeping between 9-10 hours per 24-hour period also had a greater risk of mortality compared to those who slept between 8-9 hours.
The association was strongest for cardiovascular-related mortality.
However, researchers urge that the results should not be interpreted to mean that napping causes poor health outcomes, and it is not recommended that older adults avoid napping.
Napping and long sleep duration may be caused by sleepiness due to underlying sleep disorders or other medical conditions.
"Since excessive sleep suggests that night time sleep is disrupted, interventions to treat sleep disorders and improve sleep quality in older women may reduce mortality risk," said Katie L. Stone, co-author of the study.
However, further studies are required to explain why napping is linked with increased risk of death.
This study is published in Journal of the American Geriatrics Society.

HIV beats our immune system by 'innovative mutations'

Washington : The human immunodeficiency virus or HIV adapts so well to the body's immune system that any successful AIDS vaccine must keep pace with its ever mutating profile, researchers say.
A new study, based on a survey of 2,800 HIV patients on five continents, better describes HIV's ability to adapt by spelling out at least 14 different "escape mutations" that keeps the virus alive after it interacts genetically with immunity molecules that attack HIV.
"Key genetic regions of HIV introduced into individuals of different ancestry in different places have been evolving to a greater or lesser degree according to inherited factors controlling immune response," said Richard Kaslow.
Kaslow is a professor at the University Kasof Alabama-Birmingham (UAB) School of Public Health and study co-author. "If HIV adapts differently in genetically distinct hosts, the challenge ahead in vaccine design is formidable," he said.
Researchers looked at different DNA variations of HIV in conjunction with different forms of human leukocyte antigen (HLA), a group of molecules that orchestrate immune response.
Normally HLA molecules present fragments of HIV proteins on the surface of infected cells to the immune system, acting as a signal for HIV destruction.
The Nature study shows just how efficiently the virus evolves escape mutations that help infected cells avoid destruction, Kaslow said, according to an UAB release.
The future of vaccine exploration will need to address the escape mutation capacity and identify new drug targets that work against an ever-changing HIV immunology landscape, said Philip Goulder, professor of immunology at the University of Oxford and the study's senior author.
These findings were published online in Nature......

Violent video games, movies make people insensitive towards other's sufferings

Washington: People who play violent video games become insensitive towards the pain and suffering of others, according to new research.
Detailing the findings of two studies conducted by University of Michigan professor Brad Bushman, and Iowa State University professor Craig Anderson, the research fill an important gap in the literature on the impact of violent media.
Past studies demonstrated that exposure to violent media produces physiological desensitisation-lowering heart rate and skin conductance-when viewing scenes of actual violence a short time later.
However, the current research has shown that violent media also affects a person's willingness to offer help to an injured person, both in a field study as well as in a laboratory experiment.
"These studies clearly show that violent media exposure can reduce helping behavior," said Bushman, professor of psychology and communications and a research professor at the U-M Institute for Social Research.
He added: "People exposed to media violence are less helpful to others in need because they are 'comfortably numb' to the pain and suffering of others, to borrow the title of a Pink Floyd song."
In a study of 320 college students, the participants played either a violent or a non-violent video game for approximately 20 minutes, and then after a few minutes overheard a staged fight that ended with the "victim" sustaining a sprained ankle and groaning in pain.
It was found that those who had played a violent game took significantly longer to help the victim than those who played a non-violent game-73 seconds compared to 16 seconds.
Also, people who had played a violent game were less likely to notice and report the fight. And in case they did report it, they judged it to be less serious than did those who had played a non-violent game.
In the second study, the participants were 162 adult moviegoers. The researchers staged a minor emergency outside the theatre in which a young woman with a bandaged ankle and crutches "accidentally" dropped her crutches and struggled to retrieve them.
Participants who had just watched a violent movie took over 26 percent longer to help than either people going into the theatre or people who had just watched a non-violent movie.
The findings of the study have been published in the journal Psychological Science.

Mending broken hearts with skin stem cells possible

Washington: After turning skin cells back into stem cells successfully, scientists now have proof that they can indeed form specialised cells making up heart muscle.
University of Wisconsin-Madison (UW-M) School of Medicine and Public Health professor Tim Kamp and his research team showed that they were able to grow working heart-muscle cells (cardiomyocytes) from induced pluripotent stem cells, known as iPS cells.
The heart cells were originally reprogrammed from human skin cells by James Thomson and Junying Yu, two of Kamp's co-authors on the study.
"It's an encouraging result because it shows that those cells will be useful for research and may someday be useful in therapy," said Kamp, who is also a cardiologist with UW Health.
"If you have a heart failure patient who is in dire straits - and there are never enough donor hearts for transplantation, we may be able to make heart cells from the patient's skin cells, and use them to repair heart muscle. That's pretty exciting."
It's also a few more discoveries away. The researchers used a virus to insert four transcription factors into the genes of the skin cell, reprogramming it back to an embryo-like state.
Because the virus is taken up by the new cell, there is a possibility it eventually could cause cancer, so therapies from reprogrammed skin cells will likely have to wait until new methods are perfected.
Still, the iPS cardiomyocytes should prove immediately useful for research. And Kamp said the speed at which knowledge is progressing is very encouraging.
Jianhua Zhang, study co-author noted that it took 17 years, from when a mouse embryonic stem cells were first created in 1981, to 1998, when Thomson created the first human embryonic stem cells, said a UW-M release.
In contrast, the first mouse iPS stem cells were created in 2006, and Thomson and Yu published their paper in November 2007, announcing the creation of human iPS stem cells that began as a skin cells.
The study was published online Thursday in Circulation Research, a journal of the American Heart Association.

Potential new treatment for prostate cancer developed

Washington: Scientists at Melbourne's Burnet Institute claim to have developed a potential new treatment for prostate cancer patients.
The team led by Associate Professor Pei Xiang Xing, head of the Burnet Institute's Cancer Immunotherapy, has produced a monoclonal antibody to a unique tumour marker for the treatment of prostate cancer.
The monoclonal antibody is directed at cancer-producing cells carrying the specific molecule known as PIM-1, which is responsible for cell survival, proliferation and differentiation.
Over-expression of PIM-1 plays a critical role in the development, progression and metastasis of prostate cancer and other cancers such as leukaemia.
The researchers found that the monoclonal antibody significantly inhibited cancer cell growth when used in laboratory models of prostate cancer.
During the study, the team demonstrated that the monoclonal antibody binds to PIM-1 present in cancer cells and creates a chain of events leading to the death of the cells.
Moreover, the therapeutic effect was improved by combination of the antibody with other drugs currently used to treat prostate cancer.
"This is an exciting step in the development of new treatments for patients with prostate cancer with very promising laboratory-test results," said Professor Crabb.

Three simple steps to treat erectile dysfunction

Washington: Is erectile dysfunction taking the joy out of your sex life? Take heart, for Temple urologist Jack Mydlo has offered three simple steps to get back the pleasure - cut back on fat, control cholesterol, and kick the butt.
Men often rely on the "little blue pill" to score in the bedroom but following these three simple steps can improve their performance without a visit to the doctor or a drugstore.
After diabetes and high blood pressure the next culprit in the line for erectile dysfunction (ED) is cigarette.
"The number one thing we can do to stop erectile dysfunction is to stop smoking. It's the number one environmental cause of ED in our society," said Mydlo.
It restricts the blood flow to the penis. He said it takes 12 to 24 months for better function once you quit the habit.
Men with high cholesterol are at two fold risk of developing ED.
"Men with a cholesterol level of 240 or higher have almost a twofold increase of ED compared to a man who has lower cholesterol numbers," said Mydlo.
High levels of cholesterol lead to plaque buildup in tubes (in the penis and arteries, which can greatly reduce blood flow.
Obesity is to blame not only for men with self-esteem issues involving their appearance, but also their performance.
"Adipose tissue in body fat converts testosterone to estrogen, and lower levels of testosterone can make it difficult for a man to achieve an erection, no matter how many pills they take," said Mydlo.
Losing weight will improve the testosterone to estrogen ratio, which may improve sex drive, or libido, as well as erections. It also decreases cholesterol, which will help improve blood flow.

A cold as dangerous as a drink when it comes to driving

London : Having a bad cold or the flu can be as bad for driving as a couple of whiskies, a new reports has revealed.
According to the study, symptoms such as a stuffed-up head, grogginess and sneezing have the same impact on people's abilities as a level of alcohol close to or at the drink-drive limit.
In the research, for Lloyds TSB Insurance, one hundred drivers with a range of conditions including colds, stress and headaches and 50 who were healthy were put through a hazard simulator test, reports the BBC.
From the analysis, the study revealed that drivers with colds scored, on average, 11 percent worse - equivalent to the effect of a double whisky.
The study, carried out by PCP research agency, looked at 60 people with colds and flu as well as 40 with other conditions including premenstrual syndrome.
They said that applying the 11percent effect to reaction times would add 1m (3.3ft) to stopping distance if travelling at 30mph (48km/h) - on top of a normal distance of 12m (40ft).
It would add 2.3m (7.5ft) onto the normal stopping distance of 96m (315ft) if travelling at 70mph (113km/h).

Watching TV every day can damage health

London: Regular television watching could harm your health, a British report has suggested.
According to the British Social Attitudes report, only 43 per cent of those who said they were regular viewers claimed their health was excellent or very good.
In stark contrast, 59 per cent of 4,000 respondents who said they rarely watched TV rated themselves as healthy.
Also, only 54 per cent of daily TV viewers said they had joined a social or cultural group in the past year, compared with 66 per cent of those who watch less frequently.
In total, 91 per cent of the total adults questioned for comprehensive study admitted to switching their TV set on several times a week, with 74 per cent watching it every day, reports the Telegraph.
Alison Park, co-author of the study, said: "These findings don't prove that a particular leisure activity causes ill-health or promotes civic engagement. But it is clear that our leisure choices are linked to our physical and mental wellbeing, as well as to the extent to which we are connected to others through things like voluntary groups.
"And it is notable that one leisure activity - watching TV - is negatively linked to many of these things. Efforts to promote different ways of spending our free time could well be beneficial."

Alcohol gives men's sexual performance a boost

Melbourne: Australian scientists have given men the perfect reason to drink: alcohol improves performance in the bedroom.
According to News.com.au, the boffins believe that the latest finding will reassure blokes who worry about the affects of drinking on their sex lives.
Until now, it has been widely believed that boozing could cause erectile dysfunction, commonly called "brewer's droop''.
However, the latest study of 1580 Australian men has shown the reverse may be true - since drinkers reporting as many as 30 per cent fewer problems than teetotalers.
Infact, binge drinkers had lower rates of erectile dysfunction than those who never drank, although this type of drinking can cause other health problems.
According to lead researcher Dr Kew-Kim Chew, of Western Australia's Keogh Institute for Medical Research, who told The Sunday Telegraph, men who drank within safe guidelines appeared to have the best erectile function.
"We found that, compared to those who have never touched alcohol, many people do benefit from some alcohol, including some people who drink outside the guidelines,'' Dr Chew said.

Coming soon, a Contraceptive Pill to "Ease Women's Pain"

Melbourne: A new contraceptive pill is on its way, which will bring relief to women who suffer from a loss of libido and other symptoms when taking the Pill.
The Royal Hospital for Women in Randwick will trial the oral contraceptive, which uses a natural form of the female hormone oestrogen, called estradil, reports News.com.au
It comes with international research finding that hormones used in traditional contraceptives have a wide range of side-effects on women, including the loss of libido, aches and pains and mood swings, The Daily Telegraph reports.
"There is no reason why women have to have a seven-day pill-free interval," sexual health physician Terri Foran said.
"A lot of women suffer these symptoms and believe they are normal or its PMT, but they don't have to (suffer).
"We believe it will work but before we put our hand on our heart and declare that, we have to test its effectiveness," the expert added.
The pill shortens the hormone-free interval from seven to two days and aims to end the withdrawals.
Dr Foran said that by reducing the pill-free interval to two days, the body would not have enough time to experience the "withdrawals".
"The difference with this pill to others on the market is that it alters the amount of hormone given and alters when it is given in the cycle," she said.
"There is a suggestion that if you can manipulate that pill-free week, you might be able to lessen the symptoms. The shortened break might well mean they don't get the symptoms," she added.

Drinking Three Cups of Tea a day can cut Breast Cancer Risk by a Third

London: Consuming three cups of tea a day can reduce the risk of breast cancer by more than a third, a new research led by an Indian-origin scientist has revealed.
To reach the conclusion, a team of US researchers led by Dr Nagi Kumar at the Moffitt Cancer Centre in Tampa, Florida, studied 5,000 women aged between 20 and 74 who had been treated for breast cancer.
The boffins compared medical histories and lifestyles with a similar group of women free of breast cancer, reports the Telegraph.
From the analysis, they also found even greater benefits when it came to "lobular" breast cancer, with tea reducing the risk by 66 per cent.
Lobular cancer, where cancer affects the lobes deep inside breast tissue, accounts for one in ten cases of the disease.
The researchers said: "Regular tea consumption, particularly at moderately high levels, might reduce breast cancer risk in younger women.
"Given that tea is the most common beverage consumed in the world, it makes an attractive candidate for breast cancer prevention."

Smoking Linked to Most Male Cancer Deaths

Washington: Smoking led to 70 per cent of the cancer deaths among Massachusetts men in 2003, much higher than the previous estimate of 34 per cent in 2001, according to a recent study.
Bruce Leistikow, a UC Davis associate adjunct professor of public health sciences, says that this finding strengthens the association between tobacco smoke and cancer deaths.
In a report on his epidemiological analysis, published online in BMC Cancer, the researcher writes that the study's findings suggest that increased tobacco control efforts could save more lives than previously estimated.
"This study provides support for the growing understanding among researchers that smoking is a cause of many more cancer deaths besides lung cancer. The full impacts of tobacco smoke, including second-hand smoke, have been overlooked in the rush to examine such potential cancer factors as diet and environmental contaminants. As it turns out, much of the answer was probably smoking all along," said Leistikow.
Leistikow used National Center for Health Statistics data to compare death rates from lung cancer to death rates from all other cancers among Massachusetts males.
The assessment revealed that the two rates changed in tandem year-by-year from 1979 to 2003, with the strongest association among males aged 30-to-74 years.
Smoking is known to be behind most of the lung cancer cases, and the study authors concluded that the very close relationship over 25 years between lung and other cancer death rates suggested a single cause for both: tobacco smoke.
Leistikow, whose research is dedicated to uncovering the causes of premature mortality, said: "The fact that lung and non-lung cancer death rates are almost perfectly associated means that smokers and nonsmokers alike should do what they can to avoid tobacco smoke. It also suggests that increased attention should be paid to smoking prevention in health care reforms and health promotion campaigns."

Tiny 'robotic submarine' in blood to help operate on stroke victims

Washington: Researchers from Monash University have developed micro-motors that can drive around the body and even into the delicate structures of the brains of stroke victims to carry out potentially life-saving operations.
Lead researcher James Friend explained, motors provide the key to making robots small enough for injection into the bloodstream.
With the right sensor equipment attached to the microbot motor, the surgeon's view of, for example, a patient's troubled artery can be enhanced and the ability to work remotely also increases the surgeon's dexterity.
"If you pick up an electronics catalogue, you'll find all sorts of sensors, LEDs, memory chips, etc that represent the latest in technology and miniaturisation," said Friend.
"Take a look however at the motors and there are few changes from the motors available in the 1950s," he added.
Methods of minimally invasive surgery, such as keyhole surgery and a range of operations that utilise catheters, tubes inserted into body cavities to allow surgical manoeuvrability, are preferred by surgeons and patients because of the damage avoided when contrasted against cut and sew operations.
Serious damage during minimally invasive surgery is however not always avoidable and surgeons are often limited by, for example, the width of a catheter tube which, in serious cases, can fatally puncture narrow arteries.
The microbot motors just 250 micrometres, a quarter of a millimetre wide have so far succeeded in swimming through human blood in the laboratory, but scientists hope it could also power its way up the narrow arteries of the brain.
"Opportunities for micro-motors abound in fields as diverse as biomedicine, electronics, aeronautics and the automotive industry," said Friend.
"Responses to this need have been just as diverse, with designs developed using electromagnetic, electrostatic, thermal and osmotic driving forces," he added.
The study is published in Journal of Micromechanics and Microengineering

Brain stimulation via mild electrical current may enhance motor skill learning

Washington: A new study conducted by researchers at the National Institutes of Health (NIH) suggests that mild electrical current may prove very helpful in rehabilitating people with traumatic brain injury, stroke, and other conditions.
Revealing the observations made during the study in the Proceedings of the National Academy of Sciences, the researchers said that people who had received a mild electrical current to a motor control area of the brain were significantly better able to learn and perform a complex motor task than those in control groups.
Motor skills, which are used for activities from typing and driving, to sports, require practice and learning over a prolonged period of time.
During practice, the brain encodes information about how to perform the task, but even during periods of rest, the brain is still at work strengthening the memory of doing the task. This process is known as consolidation.
Working in collaboration with scientists from Columbia University in New York City and Johns Hopkins University in Baltimore, the research team from NIH's National Institute of Neurological Disorders and Stroke (NINDS) presented the study subjects with a novel and challenging motor task, which involved squeezing a "joy stick" to play a targeting game on a computer monitor, which they practiced over five consecutive days.
One group received 20 minutes of transcranial direct current stimulation (tDCS) while practising, but the other group received only a 30 second "sham" stimulation.
The stimulation process involved mild electrical stimulation applied through surface electrodes on the head, and worked by modulating the activity of cells in the brain's outermost layers.
Dr. Leonardo Cohen, of NINDS Human Cortical Physiology and Stroke Neurorehabilitation Section, revealed that his team directedt DCS to the primary motor cortex, the part of the brain that controls movement.
He and his colleagues observed that over the five-day training period, the skill of the tDCS group improved significantly more than those of the control group, apparently through an effect on consolidation.
During the three-month follow-up period, the two groups forgot the skill at about the same rate, but the tDCS group continued to perform better because they had learnt the skill better by the end of training.

Hope for Women who Suffer Infertility, Pelvic Pain during Sex

Washington: There is some hope for women who suffer from endometriosis, infertility and pelvic pain during sex, a chronic disease that affects five to 10 million women in the US.
Serdar Bulun, professor of gynaecology at Northwestern University's Feinberg School of Medicine and colleagues have discovered key epigenetic abnormalities in endometriosis and identified existing chemicals that now help treat it.
Epigenetics is the study of the processes involved in the genetic development of an organism, especially the activation and deactivation of genes.
One of the abnormalities is the presence of enzyme aromatase - which produces oestrogen - in endometriosis, the diseased tissue that exists on pelvic organs and mimics the uterine lining. Normal endometrium, located in the uterine cavity, does not contain aromatase.
Consequently, women with endometriosis have excessive oestrogen in this abnormal tissue found on surfaces of pelvic organs such as the ovaries.
Bulun found the protein SF1 that produces aromatase, which is supposed to be shut down, is active in endometriosis.
"Oestrogen is like fuel for fire in endometriosis," Bulun said. "It triggers the endometriosis and makes it grow fast."
As a result of the aromatase finding, Bulun launched clinical trials in 2004 and 2005 testing aromatase inhibitors - currently used in breast cancer treatment - for women with endometriosis.
The drug blocks oestrogen formation and secondarily improves progesterone responsiveness. "We came up with a new treatment of choice for post-menopausal women with endometriosis," Bulun said.
Moreover, treatment with an aromatase inhibitor is a very good option for premenopausal women with endometriosis not responding to existing treatments, he noted.
Bulun believes that these abnormalities result from epigenetic defects that occur very early on during embryonic development and may be the result of early exposure to environmental toxins, said a Northwestern release.
These findings were published in the January issue of the New England Journal of Medicine.

Why some drinkers, smokers die young and others don't

London: Two newly identified genes hold the key to why some people who indulge in smoking and boozing die young, while others continue into old age.
While smoking and drinking have been linked to many types of cancer, still some people appear to be more prone to their effects than others, and scientists have attributed this tendency to genetics.
Scientists found that the genes if present in a human being, put their carriers at an increased risk of developing five different types of cancer- skin, lung, bladder, prostate and cervical cancer.
The researchers can use the findings to identify people who are at highest risk of suffering from the potentially deadly conditions because of a combination of genetics and their unhealthy lifestyle.
According to researchers almost 25 percent around of the population have the highest risk that their unhealthy lifestyle would give them cancer.
The researchers also estimated that another quarter of the population have the lowest risk, because they do not carry these genes, reports The Telegraph.
And these people could be the ones who remain hale and hearty into old age despite smoking, drinking, using sunbeds of having a poor diet.
But, till date scientists did not know by how much these two genes could increase the overall lifetime chance of developing a form of the disease.
Tim Bishop, professor of genetic epidemiology at the University of Leeds, and one of the co-authors of the paper, said that cancer was often caused by a "complex" interplay between genetic and environmental factors.
He also said that the newly identified genes might explain their relationship.
In the study, the researchers managed to isolate the genes by looking at the genetic make up of more than 33,000 cancer survivors and another 45,000 people who had never suffered from the disease.
Later, they compared the genes against their carrier's lifestyle and history of the disease.
While the genes were found to increase the chance of suffering from five types of cancer, they were not linked to an increased risk of another nine cancers for which the researchers could test, including breast cancer.
The study was published in the journal Nature Genetics.

Six most Common Sex myths Busted

Washington: Despite creating a lot of awareness people are still sexually misinformed, and now a sex educator and relationship expert has debunked some of the myths surrounding the clandestine aspect of an individual's life.
Dr. Yvonne K. Fulbright, the founder of Sexuality Source Inc, has shed light on six common sex myths, reports Fox News
First on his list was the myth that Viagra is 100 percent effective, regarding which Fulbright wrote that men bearing this notion needed to think again because a desire component is needed for males to become sexually aroused and attain erection.
The second myth debunked in the report was that the presence of a hymen is an indicator that a female is a virgin, and it is broken she has intercourse.
The expert said that this might not happen with every girl, and since girls are born with hymens of various sizes and openings, some might appear to have no hymen at all.
Fulbright also said that some girls might have their hymen stretched from activities like bicycling or horseback riding.
The next myth to have been debunked was the notion that withdrawal is the best method of birth control, regarding which Fulbright said that pregnancy could occur any time unprotected sex was had, whether or not a male had climaxed.
Thus, according to the expert, withdrawal is not recommended as a form of birth control, especially for males who are sexually inexperienced.
Another misconception on the list was that oral sex does not put people at risk for sexually transmitted diseases.
As regards thoughts that women can't get pregnant if you aren't ovulating, the expert said that it was not true.
Lastly, Fulbright debunked the myth that contraceptive pills protects against STDs. The expert said that such pills provide protection only from pregnancy, adding that it's the condom that can protect against STDs when sexually active.
Six common sex myths are:
1. Myth: Viagra is 100 Percent Effective2. Myth: A Virgin's Hymen Always Breaks3. Myth: Withdrawal = Good Birth Control4. Myth: Oral Sex is Safe Sex5. Myth: You Can't Get Pregnant if You Aren't Ovulating6. Myth: The Pill Protects Against STDs

Healthy Vaginal Tract Lining no Barrier against HIV

Washington: The human immunodeficiency virus (HIV) can penetrate healthy vaginal tract lining during sexual intercourse. This lining had earlier been thought to be an effective barrier against the deadly virus.
"This is an unexpected and important result," said Thomas Hope, principal investigator and professor of cell and molecular biology at the Northwestern University Feinberg School of Medicine. "We have a new understanding of how HIV can invade the female vaginal tract."
"Until now, science has really had no idea about the details of how sexual transmission of HIV actually works," Hope added. "The mechanism was all very murky."
Hope, his Northwestern colleagues, and collaborators at Tulane University discovered that interior vaginal skin is vulnerable to HIV invasion at the level where it naturally sheds and replaces skin cells, a point where the cells are not as tightly bound together.
Women and female adolescents now account for 26 percent of all new HIV cases in the US, according to the Centres for Disease Control (CDC).
Based on its most recent analysis of 2005 data, the CDC estimated that there were 56,300 new HIV infections that year and traced 31 percent of the total to high-risk heterosexual contact. More than half of the new cases of HIV infection worldwide are in women.
Hope expects his findings, if confirmed by future studies, will provide information to help develop microbicides and vaccines to protect against HIV.
"We urgently need new prevention strategies or therapeutics to block the entry of HIV through a woman's genital skin," Hope said. While condoms are 100 percent effective in blocking the virus, "people don't always use them for cultural and other reasons", he noted.
By labelling the HIV viruses with photo-activated fluorescent tags, Northwestern researchers were able to view the virus as it penetrated the outermost lining of the female genital tract, called the squamous epithelium, in female human tissue obtained from a hysterectomy and in animal models.
Researchers found that HIV penetrated the genital skin barrier primarily by moving quickly - in just four hours - between skin cells to reach 50 microns beneath the skin, a depth similar to the width of a human hair.
This is the depth at which some of the immune cells targeted by HIV are located. HIV penetration was more common in the outermost superficial layers of skin and likely occurred during the normal turnover and shedding of skin cells. In the shedding process, the skin cells are no longer as tightly bound together so water - and HIV - can easily enter.
"As pieces of the skin flake off, that's the loose point in the system where the virus can get in," Hope said, according to a Northwestern release.
Previously, scientists thought that the HIV invaded a woman's immune system through the single layer of skin cells that line her cervical canal. "That was always thought to be the weak point in the system," Hope said.
However, a previous trial in Africa in which women used a diaphragm to block the cervix did not reduce transmission. Nor are women who have had hysterectomies less vulnerable to contracting HIV through sex.
Hope presented his findings at the American Society for Cell Biology's 48th annual meeting in San Francisco Friday.

Study Debunks Herbal Menopause Remedy Myth

Washington: Scientists have found no strong evidence proving the efficacy of commonly taken herbal remedies in relieving troublesome menopausal symptoms.
In fact, for some of these medicines there is hardly any evidence at all, according to the researchers.
A large number of women experience vasomotor symptoms around the menopause, such as hot flushes and night sweats, prompted by the sharp fall in oestrogen levels.
Commonly used herbal remedies to relieve menopausal symptoms include black cohosh, red clover, Dong quai, evening primrose oil, and ginseng. Others include wild yam extract, chaste tree, hops, sage leaf, and kava kava.
However, according to the study, only a little good quality evidence on the effectiveness of herbal medicines, or how they might react with prescription medicines is available.
Generally speaking, safety has been under researched, which is a major concern given that herbal remedies are often assumed to be "safe" just on the grounds that they are "natural," said the authors.
Usually published studies are poorly designed, include too few participants, or don't last long enough to be of real value.
Also, the chemical make-up of various preparations of the same herb may differ, which can make it difficult to compare trial results.
The drugs regulator, the Medicines and Healthcare products Regulatory Agency (MHRA), has given a Traditional Herbal Registration to Menoherb, which contains black cohosh, under a scheme designed to boost the safety of herbal products on sale.
However, the authors said that clinical trial data on black cohosh are "equivocal," with some studies suggesting that the remedy works well, while others suggest that it does not relieve symptoms effectively.
One of the potential side effect of black cohosh is liver toxicity.
The authors said that there is "no convincing evidence" that red clover extract is effective.
Also little evidence is there one way or another for dong quai, evening primrose oil, wild yam, chaste tree, hops, or sage.
The study, titled 'Herbal medicines for menopausal symptoms' is published in the latest issue of the Drug and Therapeutics Bulletin (DTB).

How our brains work as GPS devices to bring things back in perspective

Washington: Very often people forget where they are, but luckily enough, the feeling of being disoriented doesn't last for more than a few seconds-all thanks to the mind. Now, scientists have described how our brain works as a GPS device and tells us the right direction.
The researchers have indicated that animals and young children mainly rely on geometric cues (e.g. lengths, distances, angles) to help them get reoriented.
On the other hand, human adults can also make use of feature cues (e.g. color, texture, landmarks) in their surrounding area.
However, to know which method do we use more often, scientists conducted a set of experiments investigating if human adults have a preference for using geometric or feature cues to become reoriented.
The first experiment, conducted by psychologists Kristin R. Ratliff from the University of Chicago and Nora S. Newcombe from Temple University, was set in either a large or small white, rectangular room with a landmark (a big piece of colourful fabric) hanging on one wall.
Volunteers in the study saw the researcher place a set of keys in a box in one of the corners. All of them were blindfolded and spun around, and were made disoriented. After removing the blindfold, they had to point to the corner where the keys were.
After a break, the volunteers were told the experiment would be repeated, although they wouldn't watch the researcher hide the keys. Without telling the volunteers, the researchers moved the landmark to an adjacent wall during the break.
The change forced the volunteers to use either geometric cues or feature cues, but not both, to reorient themselves and locate the keys.
In the second experiment, the researchers used a similar method, except they switched room sizes (the volunteers moved from a larger room to a smaller room and vice versa) during the break.
According to the results, the brain does not have a distinct preference for certain cues during reorientation.
In the first experiment, volunteers reoriented themselves by using geometric cues in the smaller room but used feature cues in the larger room.
However, the volunteers who went from the larger room to the smaller room in the second experiment also relied on feature cues, searching for the landmark to become reoriented.
During the second experiment, the researchers concluded that the volunteers had a positive experience using feature cues in the large room, so they kept on relying on the landmark in the smaller room to become reoriented.
The results suggested that the brain takes into account a number of factors, including the environment and our past experiences, while determining the best way to reorient us to our surroundings.
The findings were reported in Psychological Science, a journal of the Association for Psychological Science.

Ugg-style boots could cripple women

London: Chic Ugg-style boots, which cost from 50 pounds to 100 pounds, increase the risk of ankle sprains and bad posture, experts have warned.
The soft structure and heel-less sole create a breeding ground for fungi that cause foot infections, according to health researchers.
The boots are often spotted on the sexy legs of Katie Price and Coleen Rooney who like their soft sheepskin interior.
And the cherry on the icing is that, their woollen or sheepskin exteriors go with anything from skinny jeans to dresses, reports The Sun.
However, podiatrist Linda Hawkins, of Lee, South London, said: "Sheepskin boots, like other footwear without heel and sole support, are only suitable for short-term wear.
"Use all day leads to the boot structure breaking down, increasing the risk of a twisted ankle."
Pharmacist Hasan Ukra, who works in the flagship Boots store in London's Oxford Street, said: "Wearing these kind of boots could increase the risk of fungal infections due to the moist environment created.
"And I've seen a marked rise in ankle sprains due to the soft and comfortable nature of the boots."

Laughing gas' pain-relieving effect can be enhanced via hypnosis

Washington: Scientists from University College London have revealed that pain relieving effect of nitrous oxide, popularly known as laughing gas, can be enhanced by suggestions or hypnosis in dental patients.
The study showed that people are more suggestible under the influence of gas. This suggests that dental patients may benefit from being coached to relax while undergoing sedation.
A number of dentists have been trained in hypnosis and find that their patients respond well to being spoken to in a quiet, hypnotic manner.
For the study, the researchers recruited thirty participants, who took part in two sessions. They were given a mask from which they breathed in air or 25 per cent nitrous oxide. The mask was scented to disguise the sweet smell of the laughing gas.
During each session, participants were given a series of mental imagery tests and were asked to rate their response according to a scale of 1-7, where 1 was 'as clear and vivid as the real thing' and 7 was 'no image present at all'.
The participants were asked to close their eyes and imagine tasting oranges or smelling roast beef, feeling linen or hearing the honk of a car horn.
The volunteers were also put through a series of 'imaginative suggestibility' tests based on suggestions given to them while under the gas.
The participants were asked to experience hallucinated sensations.
For instance, they were told to imagine a sour taste in their mouth, and were told that after a while they would actually begin to experience a sour taste in their mouth, and that this would become stronger and stronger.
If the participant responded well to the suggestion, he/she would answer some of the questions that the hallucinated voice had asked.
The researchers found that the nitrous oxide boosted imaginative suggestibility by approximately 10 per cent.
"Many dentists use laughing gas to relieve discomfort in their patients, but our study suggests that combining the gas with instructions and suggestions to help them to relax and become absorbed in imagery, for example, might enhance the pain-relieving effect," said Dr Matthew Whalley, Honorary Research Fellow at UCL.
"Our findings are preliminary, however, so it would be helpful to do a larger scale study to confirm our results and explore the best ways in which to use and combine nitrous oxide and suggestion," he added.

C-sections best for baby when close to due date

Babies do better after a scheduled Caesarean section if they’re born no sooner than seven days before their due date, a new large study of U.S. births shows.
Those delivered earlier had more complications, including breathing problems, even though they were full term, the researchers reported in Thursday’s New England Journal of Medicine. Even just a few days made a difference, they said.
The findings offer important guidance to the growing number of women who face planned C-sections. And the study supports recommendations that elective C-sections be scheduled after 39 weeks unless tests show the infant’s lungs are fully mature. Due dates are set at 40 weeks gestation and infants are full term at 37 weeks.
"Take your due date and subtract seven and any one of those seven days is fine," said one of the researchers, Dr. John Thorp, of the University of North Carolina at Chapel Hill School of Medicine.
He delivered a healthy baby girl on Tuesday after persuading her mother to wait a few more days for a C-section, even though last week would have been more convenient for both mother and doctor.
"We bit the bullet and did it at the right time," said Thorp.
The rate of Caesarean sections in the United States is at an all-time high, accounting for about 31 percent of births. There are lots of reasons: older moms, multiple births, the threat of malpractice lawsuits, the preference of mothers and doctors and the risks of having a vaginal birth after a previous Caesarean. In 2006, a government panel urged women not to seek a C-section without a medical reason; surgery brings risks and babies born by Caesarean have a greater chance for respiratory problems.
In the new study, the researchers, led by Dr. Alan Tita of the University of Alabama at Birmingham, examined a C-section registry from 19 academic medical centers to see how many of the surgeries were being done before the recommended 39 weeks and if the timing made a difference in the risk of complications.
They focused on 13,258 women who had a single child at a planned Caesarean and who had previously given birth the same way. Excluded were cases where medical issues warranted an early or immediate delivery. The infants were followed until they left the hospital or for four months.
More than a third of the C-sections were performed before 39 weeks, the researchers found. Those delivered at 37 weeks were twice as likely to have health problems, including breathing troubles, infections, low blood sugar or the need for intensive care. Fifteen percent of those born at 37 weeks and 11 percent born at 38 weeks had complications, compared to 8 percent of the babies delivered at 39 weeks. The only death was an infant born at 39 weeks.
The biggest difference was in breathing problems, with a fourfold increase for those born at 37 weeks compared to 39 weeks. Babies born by C-section already have a higher risk of breathing trouble than those born vaginally; labor helps clear the lungs of fluid.
The risk of complications also increased for births after 41 weeks, but there were few births in that category, the researchers said.
Tita said the researchers didn’t know the reasons behind the chosen delivery dates. They speculated that some mothers might want to deliver as soon as the fetus reaches full term, or an earlier time may have been more convenient for the mother or doctor.
Dr. Michael Greene, of Massachusetts General Hospital in Boston, noted the research showed that there’s even an increased risk of complications in the last few days before the 39th week. That’s something most doctors wouldn’t suspect, he said.
"I generally try to wait to 39 weeks, although I confess that I’m as guilty as anybody else with a busy practice and scheduling being what it is," said Greene, who wrote an accompanying editorial in the journal. "I really hadn’t thought much about it until now."
The study only looked at live births, and didn’t account for the small risk of the fetus dying while waiting to reach 39 weeks, Greene said. That risk has been estimated up to 1 in 1,000, he said.Thorp’s patient in Chapel Hill, Shannon Eubanks, said she was glad that she held off a few days to reach the 39-week threshold before having her daughter, Kathleen Conley Eubanks. Her first child, 2-year-old Charlie, was born by C-section.
"It was hard to wait," said Eubanks, business manager of the political science department at the university. "I was very over being pregnant and ready to get the show on the road."
And she had another reason for wanting to deliver last week.
As an accountant, "It just killed me not to have this kid in 2008" to get the tax deduction, Eubanks said hours after delivering.

Obesity linked to ovarian cancer: Study

London: A new study by researchers in the US has confirmed that obesity is linked to ovarian cancer.
In a study of almost 95,000 women, researchers found that among women aged 50 to 71, being obese increased the risk of the disease by almost 80 per cent.
A link between obesity and ovarian cancer was already known, but the new study provides confirmation of the association.
The study also highlights the way hormones play a role in the way body fat influences cancer risk.
The link was only seen in women who had never used hormone replacement therapy (HRT) after the menopause.
No link between body weight and ovarian cancer was evident among women who had been on HRT.
The new study supports the hypothesis that obesity may up ovarian cancer risk through hormonal effects.
"The observed relations between obesity and ovarian cancer risk have relevance for public health programmes aimed at reducing obesity in the population," the Independent quoted Dr Michael Leitzmann, from the US National Cancer Institute, as saying.
Researchers found that a total of 303 women in the study group developed ovarian cancer over a period of seven years. Among women who had never taken hormones after the menopause, obesity increased the risk of the disease by almost 80 per cent.
The study appears in the journal Cancer.

Scientists develop new technique to fuse cells for stem cell research

London: Researchers at Massachusetts Institute of Technology (MIT) have created a new, highly efficient way to pair up cells so that they can be fused together into a hybrid cell.
The technique, which resulted from collaboration between Joel Voldman, associate professor of electrical engineering and computer science, and Rudolf Jaenisch, professor of biology and a member of the Whitehead Institute, might make it a lot easier for scientists to study what happens when two cells are combined.
For instance, fusing an adult cell and an embryonic stem cell may help researchers study the genetic reprogramming that occurs in such hybrids.
The scientists have developed a simple but ingenious sorting method, which can boost the rate of successful cell fusion from around 10 percent to about 50 percent.
The technique also facilitates thousands of cell pairings at once.
Voldman said that despite the presence of cell fusion techniques in research, there were many technical limitations involved in the process.
And one of the biggest hindrances was how to get the right cells to pair up before fusing them, the researcher added.
If scientists are working with a mixture of two cell types, for example A and B, they end up with many AA and BB pairings, as well as the desired AB match. Earlier, the scientists could successfully trap cells in tiny cups as they flowed across a chip. Each cup could hold only two cells, but there was no way to control whether the cups capture an A and a B, two As or two Bs.
On the other hand, the cell-trapping cups on the new sorting device are arranged strategically to capture and pair up cells of different types.
First, type A cells are flowed across the chip in one direction and caught in traps that are large enough to hold only one cell.
After the cells are trapped, liquid is flowed across the chip in the opposite direction, pushing the cells out of the small cups and into larger cups across from the small ones. Once one A cell is in each large cup, type B cells are flowed into the large cups. As each cup can only hold two cells, thus each ends up with one A and one B.
After the cells are paired in the traps, they can be joined together by an electric pulse that fuses the cell membranes.
Besides helping with studies of stem cell reprogramming, the new method could help to study interactions between any types of cells.
"It's a very general type of device," Nature magazine quoted Voldman as saying.
The study has been published in the online edition of the journal Nature Methods.