Pregnant Polar Bears Hold The Key To Preventing Osteoporosis

Three months before giving birth, the pregnant polar bear retreats to a maternity den dug deep in a snow drift.

There she hibernates, conserving her energy before she has her cubs - and while she suckles them.

During her six-month confinement, the bear does not eat or drink and barely moves. But despite this, her bones remain strong - while large amounts of new bone are made.

This remarkable ability to stop her bones from wasting away could help tackle osteoporosis, scientists believe.

The condition, in which old bone is broken down faster than new bone is made, is most common in old age but can also hit those bed-ridden by ill-health.

If experts can work out how polar bears keep their bones strong during hibernation, they may be able to develop better treatments for osteoporosis, or even drugs to prevent it.

Experts from the Royal Veterinary College, in Hertfordshire, and University College London, have been monitoring 21 pregnant bears in Hudson Bay, Canada.

Only the pregnant animal hibernates. Blood samples showed that they ratchet up bone production before going into hibernation.

Renewal of bone remains high during hibernation - despite the drain on the body of pregnancy, labour and suckling.

As a result, the mother emerges from the den with bones as strong as when she went in, the BBC natural history website LoveEarth.com reports.

Usually, physical activity boosts bone production and bones tend to weaken when animals are immobile for long periods.

Bedridden humans can wait years for their bones to recover.

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Regularly Eat Fish To Cut Sudden Coronary Death

Eating fish rich in omega-3 fatty acids may help prevent sudden coronary death, Dutch researchers report.

But the occasional slab of salmon or other fatty fish may not do the trick; following a fishy diet for the long run may be more effective, according to the researchers, who included Martinette Streppel, MSc, of the Netherlands' National Institute for Public Health and the Environment.

Streppel's team studied 40 years of data on 1,373 Dutch men age 40 and older.

Men who reported eating an average of 6 grams of fatty fish daily -- that's two servings, according to the U.S. Department of Agriculture's serving-size guidelines -- were 55% less likely than men who ate no fatty fish to die of sudden coronary death.

Those benefits were strongest before age 50 and with long-term consumption of fatty fish.

The researchers chalk up the results to the omega-3 fatty acids EPA and DHA, found in fish including salmon and mackerel.

The Dutch study doesn't show exactly how much EPA and DHA it takes to prevent sudden coronary death, or what fish the men ate. But the findings show that eating lots of fatty fish may not be better than eating a moderate amount; the big gap was between fish eaters and those who don't eat fish at all.

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Broccoli May Help Boost The Aging Immune System

Eat your broccoli! That's the advice from UCLA researchers who have found that a chemical in broccoli and other cruciferous vegetables may hold a key to restoring the body's immunity, which declines as we age.

Published in this week's online edition of the Journal of Allergy and Clinical Immunology, the study findings show that sulforaphane, a chemical in broccoli, switches on a set of antioxidant genes and enzymes in specific immune cells, which then combat the injurious effects of molecules known as free radicals that can damage cells and lead to disease.

Free radicals are byproducts of normal processes, such as the metabolic conversion of food into energy, and can also enter the body through small particles present in polluted air. A supercharged form of oxygen, these molecules can cause oxidative tissue damage, leading to disease — for example, triggering the inflammation process that causes clogged arteries. Oxidative damage to body tissues and organs is thought to be one of the major causes of aging.

A dynamic equilibrium exists in the body between the mechanisms that lead to increased free radical production and those antioxidant pathways that help combat free radicals.

"Our study contributes to the growing understanding of the importance of these antioxidant defense pathways that the body uses to fight free radicals," said Nel, a practicing clinical allergist and immunologist at the Geffen School. "Insight into these processes points to ways in which we may be able to alleviate the effects of aging."

The delicate balance between pro-oxidant and antioxidant forces in the body could determine the outcome of many disease processes that are associated with aging, including cardiovascular disease, degenerative joint diseases and diabetes, as well as the decline in efficiency of the immune system's ability to protect against infectious agents.

"As we age, the ability of the immune system to fight disease and infections and protect against cancer wears down as a result of the impact of oxygen radicals on the immune system," Nel said.

According to the UCLA study, the ability of aged tissues to reinvigorate their antioxidant defense can play an important role in reversing much of the negative impact of free radicals on the immune system. However, until this current study, the extent to which antioxidant defense can impact the aging process in the immune system was not properly understood.

"Our defense against oxidative stress damage may determine at what rate we age, how it will manifest and how to interfere in those processes," Nel said. "In particular, our study shows that a chemical present in broccoli is capable of stimulating a wide range of antioxidant defense pathways and may be able to interfere with the age-related decline in immune function."

The UCLA team not only found that the direct administration of sulforaphane in broccoli reversed the decline in cellular immune function in old mice, but they witnessed similar results when they took individual immune cells from old mice, treated those cells with the chemical outside the body and then placed the treated cells back into a recipient animal.

In particular, the scientists discovered that dendritic cells, which introduce infectious agents and foreign substances to the immune system, were particularly effective in restoring immune function in aged animals when treated with sulforaphane.

"We found that treating older mice with sulforaphane increased the immune response to the level of younger mice," said Hyon-Jeen Kim, first author and research scientist at the Geffen School.

To investigate how the chemical in broccoli increased the immune system's response, the UCLA group confirmed that sulforaphane interacts with a protein called Nrf2, which serves as a master regulator of the body's overall antioxidant response and is capable of switching on hundreds of antioxidant and rejuvenating genes and enzymes.

Nel said that the chemistry leading to activation of this gene-regulation pathway could be a platform for drug discovery and vaccine development to boost the decline of immune function in elderly people.

"This is a radical new way of thinking in how to increase the immune function of elderly people to possibly protect against viral infections and cancer," Nel said. "We may have uncovered a new mechanism by which to boost vaccine responses by using a nutrient chemical to impact oxidant stress pathways in the immune system."

Kim said that although there is a decline in Nrf2 activity with aging, this pathway remains accessible to chemicals like sulforaphane that are capable of restoring some of the ravages of aging by boosting antioxidant pathways.

The next step is further study to see how these findings would translate to humans.

"Dietary antioxidants have been shown to have important effects on immune function, and with further study, we may be adding broccoli and other cruciferous vegetables to that list," Nel said.

For now, Nel suggests including these vegetables as part of a healthy diet.

Nel said that these findings offer a window into how the immune system ages.

"We may find that combating free radicals is only part of the answer. It may prove to be a more multifaceted process and interplay between pro- and antioxidant forces," he said.

The study was funded by the National Institute on Aging, the UCLA Claude D. Pepper Older Adults Independence Center, and the National Institute of Allergy and Infectious Diseases.

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World's First Monkey Embryonic Stem Cells!

Researchers have cloned monkeys and used the resulting embryos to get embryonic stem cells, an important step towards being able to do the same thing in humans, they report.

These could provide a ready source of human embryonic stem cells, which can be turned into any cell in the body and offer the hope of developing treatments for a range of diseases including Alzheimer's, Parkinson's and diabetes.

In addition to basic research to understand disease, human stem cells could be used to replace damaged tissue. The resulting tissue would be genetically identical to a patient's own tissue, so there would be little chance of rejection.

To make such stem cells scientists must first create a cloned human embryo, something that has proved difficult. Several animal species have been cloned, but until now the technique has not been very successful in primates - and creating usable stem cells from cloned embryos has so far only been possible in mice.

In their research, published today in the journal Nature, Shoukhrat Mitalipov's team at the Oregon Health and Science University made 35 cloned embryos and successfully extracted stem cells from two of them, eventually growing them into heart and nerve cells.

Mitalipov's team overcame two barriers - first cloning a primate, the group of mammals that includes monkeys, apes and humans, and then getting embryonic stem cells from the clone.

Mitalipov says the dyes used in cloning some animals are apparently toxic to primate cells.

The researchers used somatic cell nuclear transfer to generate cloned embryos, the same method that famously led to Dolly the sheep.

The technique involves taking the nucleus from an adult cell, in this case fibroblasts, a type of skin cell, taken from nine adult males.

Then an egg cell is hollowed out and the nucleus from the adult cell inserted.

A monkey egg before its nucleus is removed and replace with the nucleus from a skin cell, as part of the somatic cell nuclear transfer process (Image: Shoukhrat M Mitalipov)

This programs the egg into behaving as if it had been fertilised and it can grow into an embryo.

It was not easy. The researchers used 304 eggs from 14 rhesus macaque monkeys and ended up with just two stem cell lines.

This means a lot more work before this would be useful for humans, they say, especially given how hard human eggs are to come by.

Tests show the embryonic stem cells are truly pluripotent, Mitalipov says, meaning they can develop into any kind of cell found in the body.

"We have been able to develop them into heart cells," he says. They also grew nerve cells.

It was important to confirm the work. The rival journal Science was forced to withdraw papers published by South Korean scientist Professor Hwang Woo-suk in 2004 and 2005 after his claims to have cloned a human embryo proved false.

Mitalipov says the team has tried, and failed, to produce cloned monkeys that could grow into live baby monkeys.

"We have a goal also of producing live monkeys using the somatic cell nuclear transfer technique," he says.

"One reason is to generate genetically modified macaques that, for example, carry a specific disease that is a model of human disease."

His team will not try to clone humans, he says.

"However we hope the techniques we develop will be useful for other labs which are working ... with human eggs," he says.

Inherited disease

Embryonic stem cells are the source of every cell, tissue and organ in the body.

Scientists hope to take a small piece of skin from a person to generate embryonic stem cells. These can then be programmed to grow tissue or even organ transplants perfectly matched to that person.

By making patient-specific cells, doctors could obtain cells whose genome would provide telltale clues of a disease.

These cells could be compared with healthy counterparts to see what is wrong, and a library of drugs could then be screened to see if a treatment is available.

All About Angina Pectoris

Millions of people around the world suffer from Angina pectoris, but only a few are aware of this condition and seek medical attention at the right time, before it worsens in to a severe heart attack. Angina pectoris or angina (a more commonly used term) is chest pain, which occurs when blood supply to the heart is restricted (because of conditions like arteriosclerosis), depriving it of oxygen and it is usually felt as a chest discomfort or heaviness / squeezing of chest.

Angina pectoris is a predecessor of myocardial infarction (heart attack) and should be treated immediately to reduce risks like heart attack or death.

In this video, Dr. Michael Farkouh, explains in detail about Angina pectoris, types and diagnosis of angina and the treatment options available to angina patients.

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