Month: January 2014

New method makes stem cells in about 30 minutes, scientists report

In a feat that experts say is a significant advance for regenerative medicine, scientists have discovered a surprisingly simple method for creating personalized stem cells that doesn’t involve human embryos or tinkering with DNA.

Two studies published Wednesday in the journal Nature describe a novel procedure for “reprogramming” the blood cells of newborn mice by soaking the cells in a mildly acidic solution for 30 minutes. This near-fatal shock caused the cells to become pluripotent, or capable of growing into any type of cell in the body.

When the reprogrammed cells were tagged and injected into a developing mouse, they multiplied and grew into heart, bone, brain and other organs, the scientists found.
“It was really surprising to see that such a remarkable transformation could be triggered simply by stimuli from outside of the cell,” said lead study author Haruko Obokata, a biochemistry researcher at the RIKEN research institute in Japan. “Very surprising.”

The simplicity of the technique, which Obokata and her colleagues dubbed stimulus triggered acquisition of pluripotency, or STAP, caught many experts off-guard.
“So you mistreat cells under the right conditions and they assume a different state of differentiation? It’s remarkable,” said Rudolf Jaenisch, a pioneering stem cell researcher at MIT who was not involved in the study. “Let’s see whether it works in human cells, and there’s no reason why it shouldn’t.”

Obokata said that researchers had already begun experiments on human cells, but offered no details.

Due to their Zelig-like ability to form any number of specialized cells, pluripotent stem cells are considered the basic building blocks of biology. Scientists are working on ways to use them to repair severed spinal cords, replace diseased organs, and treat conditions as varied as diabetes, blindness and muscular dystrophy.

By using stem cells spawned from the patient’s own cells, replacement tissues would stand less of a chance of being attacked by the patient’s own immune system, researchers say. That would spare patients the need to undergo a lifetime regimen of dangerous, immune-suppressing drugs.

But progress toward these lofty goals has been slow, due in part to the challenges of current stem cell production methods. The practice of harvesting stem cells from human embryos makes many people uncomfortable, and some religious groups have pressed for limits or bans on their use. Even scientists who want to study them say they may not be practical for medical therapies because they could be rejected by a patient’s body.

Another approach is to rewind a patient’s own mature cells to a pluripotent state. Dr. Shinya Yamanaka, the first person to make these induced pluripotent stem cells, won a Nobel Prize for this work in 2012. However, the reprogramming process converts only about 1% of the cells into iPS cells, and questions remain about their long-term stability and safety.

The STAP method presents a simpler, cheaper and faster method of producing stem cells, said Chris Mason, a professor of regenerative medicine bioprocessing at University College London.

“How much easier can it possibly get,” Mason told the Science Media Centre, an English organization that promotes scientific understanding on controversial subjects.
“If it works in man, this could be the game changer that ultimately makes a wide range of cell therapies available using the patient’s own cells as starting material,” he said. “The age of personalized medicine would have finally arrived.”

The STAP approach was inspired by observations of plant cells that changed character when they were exposed to environmental stress, according to the research team from RIKEN and Harvard’s Brigham and Women’s Hospital in Boston.

Obokata and her colleagues set about “stressing” mouse blood cells in a variety of ways to see if they would change. They exposed them to heat, deprived them of nutrition and repeatedly poured them through narrow glass pipes.

The method they ultimately published involved placing the cells in an acid solution for 30 minutes and then spinning them in a centrifuge for five minutes. The process converted 7% to 9% of the original cells into STAP cells, Obokata said.

To see whether the cells had been reprogrammed, researchers engineered the mice with a gene that would cause their cells to glow a fluorescent green under ultraviolet light if they became pluripotent. After torturing the blood cells, they began to glow after three days and appeared to peak at seven days, suggesting that they had become pluripotent in just a week’s time. The researchers bolstered the cells’ ability to proliferate by treating them with hormones and an immune cell secretion called leukemia inhibitory factor.

To fully prove that they had become pluripotent, the STAP cells were injected into normal mouse embryos. The resulting offspring, called a chimera, were a mix of regular cells and glowing STAP cells.

Andrew McMahon, director of USC’s Eli and Edyth Broad Center for Regenerative Medicine, said the creation of a chimera was critical to proving that blood cells had changed in a fundamental way.

“That’s the most rigorous [test] you could possibly do,” said McMahon, who was not involved in the study. It shows that the STAP cells can make every type of cell in the embryo and that they “can organize in a normal-looking way, so that what comes out is a normal looking fetus.”

McMahon said the study was also surprising in that it showed that mature cells could be reprogrammed without having to divide.

“That’s why the change is so rapid, because the cells don’t have to undergo division for this to occur,” he said. “It’s a really interesting and novel finding.”

Yamanaka, who was not involved in the STAP study, said the research would undoubtedly help scientists understand the basic biology of cellular reprogramming.

“The findings are important,” said Yamanaka, who directs Kyoto University’s Center for iPS Cell Research.

The reasons why stress causes cells to drastically alter their function remains a mystery, Obokata and her colleagues said.

She declined to say whether the researchers were seeking a patent on the STAP procedure.

Source: latimes

Diabetes and Pregnancy are a Dangerous Mix

Recently, the U.S. Preventative Services Task Force published recommendations in the Annals of Internal Medicine — a widely-respected, peer-reviewed journal — that strongly advise all pregnant women be screened for gestational diabetes, a test which many physicians (including those at the North Shore-LIJ Health System) routinely perform.

Testing guidelines in the article are highly specific and stringent, and if followed, may help reduce the risks associated with undiagnosed and untreated gestational diabetes. Gestational diabetes happens during pregnancy due to the changes that are happening in a woman’s body, and it affects 10 percent to 18 percent of all pregnant women. The changes can cause the blood glucose (sugar) level to go too high. The associated risks include preeclampsia (a pregnancy-related condition associated with high blood pressure and other symptoms), macrosomia (large, for gestational age, babies) and birth-related injuries.

The ongoing obesity epidemic has led to an increased number of women having undiagnosed type 2 diabetes at the time of their child’s conception, as well as an increased number of women who are developing gestational diabetes.

Diabetes during pregnancy carries risk for both mother and baby. In order to avoid complications, screening and appropriate treatment are imperative. Women with such risk factors as being overweight, family history of diabetes, coming from a high-risk ethnic back ground (African American, Latino, Native American or Asian), physicalinactivity, delivering a baby that weighed more than 9 lbs., high blood pressure or polycystic ovarian disease should be screened at their first prenatal visit for type 2 diabetes.

In the first trimester it is recommended physicians screen mothers for diabetes using either a fasting glucose, 2 hour 75 gram glucose tolerance test (where a woman drinks 75 grams of sugar and then has her blood drawn 2 hours later), or an HbA1c test (athree-month average of blood glucose levels). If the mother screens negative, she should be screened again later in the pregnancy for gestational diabetes. Many of the complications caused by diabetes can be avoided if a woman achieves and maintains good glucose control during her pregnancy. Early identification and treatment is key to preventing these complications.

Source: escience news

Obesity Is Found to Gain Its Hold in Earliest Years

For many obese adults, the die was cast by the time they were 5 years old. A major new study of more than 7,000 children has found that a third of children who were overweight in kindergarten were obese by eighth grade. And almost every child who was very obese remained that way.

Some obese or overweight kindergartners lost their excess weight, and some children of normal weight got fat over the years. But every year, the chances that a child would slide into or out of being overweight or obese diminished. By age 11, there were few additional changes: Those who were obese or overweight stayed that way, and those whose weight was normal did not become fat.

“The main message is that obesity is established very early in life, and that it basically tracks through adolescence to adulthood,” said Ruth Loos, a professor of preventive medicine at the Icahn School of Medicine at Mount Sinai in New York, who was not involved in the study.

These results, surprising to many experts, arose from a rare study that tracked children’s body weight for years, from kindergarten through eighth grade. Experts say they may reshape approaches to combating the nation’s obesity epidemic, suggesting that efforts must start much earlier and focus more on the children at greatest risk.

The findings, to be published Thursday in The New England Journal of Medicine, do not explain why the effect occurs. Researchers say it may be a combination of genetic predispositions to being heavy and environments that encourage overeating in those prone to it. But the results do provide a possible explanation for why efforts to help children lose weight have often had disappointing results. The steps may have aimed too broadly at all schoolchildren, rather than starting before children enrolled in kindergarten and concentrating on those who were already fat at very young ages.

Previous studies established how many children were fat at each age but not whether their weight changed as they grew up. While valuable in documenting the extent of childhood obesity, they gave an incomplete picture of how the condition developed, researchers said.

“What is striking is the relative decrease in incidence after that initial blast” of obesity that occurs by age 5, said Dr. Jeffrey P. Koplan, the vice president of the Emory Global Health Institute in Atlanta. “It is almost as if, if you can make it to kindergarten without the weight, your chances are immensely better.”

Dr. Koplan, a former director of the Centers for Disease Control and Prevention, was not associated with the new study, although its lead author, Solveig A. Cunningham, is an assistant professor in the School of Public Health at Emory.

The study involved 7,738 children from a nationally representative sample. Researchers measured the children’s height and weight seven times from kindergarten to eighth grade.

When the children entered kindergarten, 12.4 percent were obese — defined as having a body mass index at or above the 95th percentile — and 14.9 percent were overweight, with a B.M.I. at or above the 85th percentile. By eighth grade, 20.8 percent were obese and 17 percent were overweight. Half of the obese kindergartners were obese when they were in eighth grade, and nearly three-quarters of the very obese kindergartners were obese in eighth grade. The risk that fat kindergartners would be obese in eighth grade was four to five times that of their thinner classmates, the study found.

Race, ethnicity and family income mattered in younger children, but by the time the overweight children were 5 years old, those factors no longer affected their risk of being fat in later years.

The study did not track the children before kindergarten, but the researchers had their birth weights. Overweight or obese children often were heavy babies, at least 8.8 pounds, something other studies have also found.

The study’s results, Dr. Koplan and others said, “help focus interventions.”

Most efforts to reduce childhood obesity concentrate on school-age children and apply the steps indiscriminately to all children, fat and thin — improving meals in schools, teaching nutrition and the importance of physical activity, getting rid of soda machines.

“This suggests that maybe one reason it didn’t work so well is that by the time kids are 5, the horse is out of the barn,” said Leann L. Birch, a professor in the department of foods and nutrition at the University of Georgia, who was not involved with the study.

The most rigorous studies of efforts for school-age children, conducted in the 1990s, randomly assigned thousands of children to either participate in intensive programs that encouraged them to exercise and improve their diets, or go on as usual.

One study involved 1,704 third graders in 41 elementary schools in the Southwest, where most of the students were Native Americans, a group that is at high risk for obesity. A second study included 5,106 children in 96 schools in California, Louisiana, Minnesota and Texas.

Neither study found any effect on children’s weights.

Some obesity researchers said the new study following kindergartners over the years also hinted at another factor: the powerful influence of genetics on obesity, something that can be a challenge to overcome.

Source: New York Times

 

Scratching Away at the Mystery of Itch

The sensation of feeling itchy is pretty universal, and yet scientists still don’t completely understand the complex processes that give us the urge to scratch.

Itching can be annoying, but like pain, a little bit can be a good thing. Itching can help people learn to avoid dangers such as mosquitoes carrying malaria, or poison ivy. But many people suffer from chronic itch, which has no direct cause and can be a debilitating condition with few options for relief.

“When people hear about itch, they think about a mosquito bite or chicken pox, which is irritating but very temporary,” said Diana Bautista, a cell and developmental biologist at the University of California, Berkeley, who wrote an article summarizing our current understanding of itch

Bautista said people often laugh when she tells them she studies itch. But “from a clinical perspective, chronic itch is a really widespread problem, and incredibly difficult to treat,” she told LiveScience.
Itch, or ouch?

Like the feelings of touch, temperature and pain, itching involves a complex system of molecules, cells and circuits reaching from the skin into the brain. Most over-the-counter treatments for itching target histamine, a compound involved in inflammation. But many kinds of itch can’t be treated with antihistamines or other available treatments.

Skin conditions such as eczema and psoriasis, systemic conditions including multiple sclerosis, and even some cancers, can all lead to chronic itch, which affects about 10 percent of the world’s population at some point during their lives, Bautista said.

Recent research on itch is revealing its mysterious relationship with pain, according to the paper. For example, scientists have found that the reason scratching an itch offers relief is because scratching causes pain, which suppresses the itch, at least temporarily. They’ve also found that the cells and circuits that transmit pain and itch overlap somewhat.

But although pain can block out itch, some painkillers – such as morphine – can cause itchiness. And some things that cause itch also cause pain, such as capsaicin, the ingredient that makes chili peppers hot.

Scientists now have several theories about this odd connection between pain and itch. One theory suggests the same set of neurons produce an itch when activated slightly, but result in pain when activated fully. Alternatively, different cells might trigger pain and itch signals, but the signals might interact in the spinal cord. There is some evidence for both ideas, Bautista said.

Itching to understand

But itch and pain don’t always go together.

For example, the antimalarial drug chloroquine is known to have a side effect of severe itch. In one recent study, scientists bred mice to have nerves that lacked a receptor that responds to chloroquine. These mice didn’t show signs of itching, but they did have normal responses to pain. The findings suggest these nerve cells are required for itch, but not necessarily for pain, the researchers said.

Many itch receptors found in mice are also found in humans. Often, researchers take molecules known to play a role in chronic itch in humans, and study the effects in mice that lack these molecules.

From this research, scientists have identified some of neurons and signals involved in chronic itch, but the search for treatments continues.

“It’s an exciting time, because there have been a lot of basic discoveries in the last five years,” Bautista said.

Some promising treatment approaches involve targeting receptors on immune cells, which may be somewhat effective against forms of itch that can’t be treated with anti-histamines.

“As we learn more about the system, and which cell types we should target,” Bautista said, “I think we’re going to be able to treat chronic itch more effectively.”

Source: huffington post

Antioxidants speed lung cancer growth: Study

Although some people spend countless dollars on antioxidant supplements to improve their health, many studies have found that these would-be panaceas could actually exacerbate the diseases they claim to prevent.

Now, a team of Swedish scientists has shown that two antioxidants—vitamin E and N-acetylcysteine (NAC)—can fuel the growth of lung cancers in mice. The team also worked out why.

Antioxidants protect cells from chemically unstable molecules called reactive oxygen species (ROS), which can easily react with DNA and cause damage that leads to cancer. But Martin Bergo’s team at the University of Gothenburg showed that antioxidants neutralize ROS in tumors as well as healthy cells. “If we give extra antioxidants in the diet, we’re helping the tumor to reduce radicals that would otherwise block its growth,” Bergo said. “Then it can speed up all it wants.”

The results, published today (January 29) in Science Translational Medicine, are particularly important for people with an increased risk of lung cancer, including smokers or people with chronic obstructive pulmonary disorder (COPD). “There’s no scientific evidence to suggest that these people should take extra antioxidants,” said Bergo. “It may even be harmful”

“They might have a small undiagnosed tumor, and no one knows the frequency of those,” he added. “There’s a possibility that antioxidants would speed up the growth of those tumors.” This word of caution is especially relevant to people with COPD, who often take large amounts of NAC to relieve the build-up of mucus in their airways.

“A warning seems appropriate for everyone who has been seduced to use antioxidants or vitamins on a regular basis, as a preventive measure,” the University of Syndey’s Nico van Zandwijk told The Scientist in an e-mail.

These results fit with those from a long line of human clinical trials, in which antioxidants failed to prevent disease or made things worse. The first of these was published in the New England Journal of Medicine in 1994, and showed that male smokers who took beta-carotene supplements were more likely to develop and die of lung cancer than those who did not. Other trials found similar results for other antioxidants and other cancers, and some of those studies were even stopped early.

In 2012, the Cochrane Collaboration analyzed the results of 78 earlier trials and, based on the most careful of them, concluded that people who took antioxidant supplements (including both healthy people and those with chronic diseases) were more likely to die prematurely than those who did not.

Few studies had looked at the reasons behind these seemingly paradoxical effects. Bergo’s team, led by graduate student Volkan Sayin, began by feeding NAC and vitamin E to mice with early lung cancers, at doses comparable to those in human multivitamin pills. The mice that ingested the antioxidants developed tumors that were three times bigger, and they died twice as fast.

Sayin then showed that tumors normally have lower levels of ROS than normal tissues. The antioxidants reduced these levels even further, protecting the tumors from DNA damage. They also dramatically reduced the activity of p53—a guardian protein that prevents cancer by detecting damaged DNA and putting the brakes on cell division.

By lifting p53’s suppression, the antioxidants allowed the cancer cells to grow and divide faster than usual. Indeed, when the team abolished p53 entirely, neither NAC nor vitamin E affected the growth of the lung tumors. “P53 is normally inactivated in late-stage lung cancer, so what we’re doing is speeding up the progression of malignancy,” said Bergo.

“This is an extremely striking observation, but not surprising given the rather disappointing outcomes of patients at risk for developing lung cancer who had been treated with various antioxidants,” David Tuveson from Cold Spring Harbor Laboratory, who was not involved in the work, said in an e-mail. “We should now consider whether people consuming high doses of antioxidants are ironically promoting cancers that they seek to prevent.”

Although Bergo’s team focused on mice in this study, the scientists found the same mechanisms at work in human cells. They also used mice with the same genetic defects as those that cause human lung cancers, and whose tumors look identical to human ones under the microscope.

They are now doing similar experiments in melanomas, leukaemias, and gastrointestinal tumors to see whether the same mechanisms hold true for other types of cancer.

Source: The Scientist

Scientists identify protein that can fight against MERS virus infection

Scientists have identified a protein within the Middle East Respiratory Syndrome (MERS) virus that blocks further infection in cells.

Shibo Jiang at Fudan University in Shanghai and his colleagues found that a type of small protein, also known as a peptide, prevents the virus from fusing with human respiratory cells.

MERS-CoV enters into host cell mainly through membrane fusion mechanism and hijack its cellular machinery in order to reproduce.

The peptide, called heptad repeat 2 (HR2P), has “good potential” for development into a future drug against MERS.

So far, HR2P’s effects have only been studied on cells in a lab dish and not yet on animals — the next step in a long process to validate any new drug for safety and effectiveness.

The first case of MERS surfaced in Saudi Arabia April 2012.

It is considered a more virulent but less transmissible cousin of SARS, a so-called coronavirus that erupted in Asia in 2003 and infected 8,273 people, nine percent of whom died.

There have been 180 laboratory-confirmed cases of MERS, including 77 deaths, according to a World Health Organisation (WHO) toll issued on Tuesday.

The study is published in the journal Nature Communications.

Source; Zee news

How often should you wash your bed sheets?

The majority of people are aware of the importance of personal hygiene, although many people may not be aware of how important it is to wash your sheets regularly.

Think of it this way, would you wear the same clothes for several weeks unwashed? We may spend more time in our sheets than we do in our clothes, yet we wouldn’t wear the same clothes everyday as that would be considered not hygienic.

Imagine what happens every night to your sheets as you rest on your most sanction of places. While you sleep your body sheds dead skin cells, you secrete oils from your skin, your body sweats and to top it off you may often leave small amounts of fluids from our groin region. On top of all of that, if you’re in a healthy relationship, it’s likely you have sex in your sheets every week which leaves behind even more stuff.

How does this affect our health?

Dust mites
These microscopic creatures thrive off of your dead skin. They live, eat, reproduce and die right in your bed and pillows; leaving behind their own rotting bodies. The average bed has anywhere from 100,000 to 10 million dust mites living there. Your health is greatly affected by these creatures if not properly kept under control. You may develop severe allergies and have a lowered immune system.

Allergies
Many people suffer from allergies and may not be aware that you can prevent them by properly cleaning your living space, especially your bedding. If you wake up with allergy symptoms this may be due to your sleeping environment.

Bacteria
Many kinds of bacteria and germs live on your dirty sheets. This can cause you numerous health problems if your sheets remain unwashed.

How often should you wash your sheets?

At least once every two weeks will keep your resting place hygienic. Every week would be ideal and any less than once a month would affect your health.

To keep your bed in the best condition you should wash your sheets every two weeks in hot soapy water and dry them completely through in the dryer. Washing your pillow every month is also important to disinfect and wash away the dust mites. You can purchase dust mite proof covers for your mattress and pillows which will help in controlling the dust mites. Wash your bedding more often if there is reason to do so

Source: love lifestyle

Breath Test May Detect Signs of Lung Cancer: Study

Examining breath samples from patients with suspicious growths might help determine who needs surgery

Researchers tested the exhaled breath of people with suspicious lung lesions that were detected on CT scans. The breath was tested for levels of four cancer-specific substances, called “carbonyls.”

The breath samples were analyzed using a special device developed at the University of Louisville.

Having elevated levels of three of the four carbonyls was predictive of lung cancer in 95 percent of patients, while having normal levels of these substances was predictive of a noncancerous growth in 80 percent of patients, the researchers found.
Elevated carbonyl levels returned to normal after lung cancer patients had surgery to remove the cancer, according to the study, which was to be presented Tuesday at the Society of Thoracic Surgeons annual meeting in Orlando, Fla.

“Instead of sending patients for invasive biopsy procedures when a suspicious lung mass is identified, our study suggests that exhaled breath could identify which patients” may be referred for immediate surgery, study author Dr. Michael Bousamra, of the University of Louisville, said in a society news release.

This approach offers something new, he said, including “the simplicity of sample collection and ease for the patient.”

The data and conclusions of research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.

Source: webmd

Woman Gets Pregnant Thanks to Yolk from a Hen’s Egg

A British couple who spent £40,000 and went through 12 IVF cycles trying to get pregnant have found success with an unusual treatment involving egg yolks.

Mark and Suzanne Harper agreed to the procedure after doctors revealed Suzanne had high levels of natural “killer cells” in her body that were attacking her embryos and preventing her from getting pregnant. The rare technique involved treatment with intralipid infusion – a special drip mixture that includes yolk from a hen’s egg and soy oil. The fatty acids of this combination were thought to control the aggressive cells – and it worked.

The Harpers were surprised by the main ingredient. Suzanne reveals:We were very surprised when we were told what the treatment consisted of. You don’t expect to be treated using yolk from a hen’s egg. But we were willing to try anything to try to have a baby.

Suzanne was one of the first women in Britain to undergo the pioneering treatment. When the couple decided to conceive again, they used the yolk combination along with IVF and had their second daughter. She said:

We are so happy to be parents at last — and it’s all thanks to egg yolk. It has given us both our daughters and we can’t be grateful enough.

Source: celeb baby

Low-sugar vs. low-fat: Twin doctors experiment to see which diet works best

In the quest to lose weight, is cutting out sugar or cutting out fat the solution?

To find the answer, 35-year-old identical twins Chris and Xand van Tulleken, who are both doctors, conducted a month-long experiment. While Chris, a physician at University College Hospital, London went on a low-fat, high-carb regime, Xand, director of the Institute of Humanitarian Affairs at Fordham University in New York, chose a high-fat, low-carb diet.

The brothers both lost weight. Xand lost the most– nine pounds in one month.

In conclusion, the brothers found that eliminating a single macro-nutrient like fat or sugar is not a solution to weight loss, nor are fad diets.

“It is about building an environment in your life where you could easily eat a cheap and healthy diet and get enough exercise. It is amazing that we are not all fat and I come away with a sense that I know enough about diet and nutrition and I should be reducing the calories and building an environment where I can do that rather than looking for one toxic ingredient,” Chris said.

After the experiment ended, the British twins also concluded that the real villains when it comes to weight gain are processed foods that contained a combination of high fat and high sugar.

Susan Jebb, professor of diet and population health at the University of Oxford, agreed with their conclusion.

“Processed foods pack calories in and are unbelievably attractive and delicious,” she told the Daily Express. “They are temptations for all of us and it is astonishing that any of us stay slim.”

The brothers’ experiment will be featured in the UK on BBC Two’s Horizon program tonight.

Source: met4love