Posts Tagged ‘ Biology ’

Medicinal tree used in chemotherapy drug faces extinction

November 11, 2011

Peeling Pacific Yew (Taxus brevifolin) Bark for Taxol

The forests and jungles are being harvested faster than it can be replaced. Trees are an important resource that needs to be protected from extinction. I am surprise that we are still talking about saving trees…its time to shut up and take action…save our trees before its too late…where is my medicinal tree?

http://www.yepod.com/?p=18558

Pass it on,

Dr Anthony


Powered by Guardian.co.ukThis article titled “Medicinal tree used in chemotherapy drug faces extinction” was written by Hanna Gersmann and Jessica Aldred, for The Guardian on Thursday 10th November 2011 07.30 UTC

A species of Himalayan yew tree that is used to produce Taxol, a chemotherapy drug to treat cancer, is being pushed to the brink of extinction by over-harvesting for medicinal use and collection for fuel, scientists warned on Thursday.

The medicinal tree, Taxus contorta, found in Afghanistan, India and Nepal, has seen its conservation status change from “vulnerable” to “endangered” on the IUCN’s annual “red list” of threatened species.

Taxol was discovered by a US National Cancer Institute programme in the late 1960s, isolated in the bark of the Pacific yew tree, Taxus brevifolia. All 11 species of yew have since been found to contain Taxol. “The harvesting of the bark kills the trees, but it is possible to extract Taxol from clippings, so harvesting, if properly controlled, can be less detrimental to the plants,” said Craig Hilton-Taylor, IUCN red list unit manager.

“Harvest and trade should be carefully controlled to ensure it is sustainable, but plants should also be grown in cultivation to reduce the impact of harvesting on wild populations,” he added.

The red list is currently the most detailed and authoritative survey of the planet’s species, drawn from the work of thousands of scientists around the globe. For the first time, more than 61,900 species have been reviewed. The latest list categorises 801 species as extinct, 64 as extinct in the wild, and 9,568 as critically endangered or endangered. A further 10,002 species are vulnerable, with the main threats being overuse, pollution, habitat loss and degradation.

Tim Entwisle from the Royal Botanic Gardens, Kew, said: “There are 380,000 species of plants named and described, with about 2,000 being added to the list every year. At Kew we estimate one in five of these are likely to be under threat of extinction right now, before we even factor in the impacts of climate change.”

The Chinese water fir, for example, which was formerly widespread throughout China and Vietnam, is critically endangered. The main cause of decline is the loss of habitat to expanding intensive agriculture. The largest of the recently discovered stands in Laos was killed through flooding for a newly constructed hydropower scheme.

In the granitic Seychelles Islands, 77% of the assessed endemic flowering plants are at risk of extinction, including the Coco de Mer, which is illegally harvested for its supposed aphrodisiac properties.

Some 25% of all mammals were deemed to be at serious risk, according to the list. The black rhino in western Africa has officially been declared extinct. The white rhino in central Africa is on the brink of extinction and has been listed as possibly extinct in the wild. In Vietnam, poaching has driven the Javan rhinoceros to extinction, leaving the critically endangered species’ only remaining population numbering less than 50 on the Indonesian island that gave it its name.

But it is not all bad news for conservationists. Przewalski’s horse, also known as the Mongolian wild horse, was listed as extinct in the wild in 1996. Thanks to captive breeding and a successful reintroduction programme, the population in central Asia is now estimated at more than 300 and the wild horse has improved its status from critically endangered to endangered.

“This update offers both good and bad news on the status of many species around the world,” said Jane Smart, director of the IUCN Global Species Programme. “We have the knowledge that conservation works if executed in a timely manner, yet, without strong political will in combination with targeted efforts and resources, the wonders of nature and the services it provides can be lost forever.”

The overall message is that biodiversity continues to decline and governments need to take action to achieve the goal of a 10-year plan that was agreed on the international biodiversity summit in Japan last year. It reads: “By 2020 the extinction of known threatened species has been prevented and their conservation status, particularly of those most in decline, has been improved and sustained.”

 

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Resveratrol pills may mimic effects of exercise and low-calorie diet

November 4, 2011

grapes

Resveratol has been known for some time to be of benefits to a healthy life-style. Recent studies have uncovered additional qualities that may encourage more persons to add resveratrol to their diets. Reducing blood sugar is a wonderful metabolic side effect that can benefit the millions of people diagnosed with diabetes. So perhaps resveratrol deserves a closer look at…..

http://www.yepod.com/?p=17431

Pass it on,

Dr Anthony


Powered by Guardian.co.ukThis article titled “Resveratrol pills may mimic effects of exercise and low-calorie diet” was written by Nic Fleming, for The Guardian on Tuesday 1st November 2011 16.08 UTC

Taking supplements of a substance found in grape skin can lower sugar and fat levels in the blood and reduce blood pressure, according to a small study.

Scientists who gave tablets containing purified resveratrol to obese men found it had some metabolic effects similar to those from exercise and calorie restriction, including lowering blood pressure and blood sugar levels.

Research in animals over the past decade has suggested the compound can slow the development of age-related diseases and increase lifespan. However, these studies have attracted growing criticism and have yet to be replicated in humans.

“The effects of resveratrol were modest but they consistently point towards beneficial metabolic adaptions,” said Prof Patrick Schrauwen of Maastricht University in the Netherlands, who led the new study. Although the chemical is found naturally in grape skin and red wine, there is no suggestion that it would be possible to ingest enough of it from these sources to gain the beneficial effect.

Prof Schrauwen and colleagues gave 11 obese men either a daily 150mg resveratrol supplement or a placebo for 30 days. Four weeks later, the two groups swapped over so that those who took the supplements first time around were given placebos and vice versa.

Regular measurements showed resveratrol lowered blood sugar levels and improved insulin sensitivity, as well as cutting triglycerides – fats found in the blood that can increase heart disease risk. Resveratrol also reduced both sleeping and resting metabolic rate and cut blood pressure.

Previous research has shown that calorie restriction can extend lifespan in laboratory animals. Some studies suggest it also offers protection from diseases such as cardiovascular disease and type 2 diabetes, though this remains controversial.

Calorie restriction works in a similar way to resveratrol, by triggering the production of a protein called SIRT1 which improves metabolic function and keeps cells healthy in the face of stress.

Muscle biopsies carried out by Prof Schrauwen’s team confirmed that participants taking resveratrol saw increased SIRT1 levels. They also strongly suggested the beneficial effects on metabolism were associated with improved functioning of mitochondria, the energy factories within cells.

“Healthy people are good at switching efficiently from using fat as an energy source to glucose in the blood when it becomes available,” said Prof Schrauwen. “The results of our pilot study tended to suggest that might be part of the link to the beneficial health effects of resveratrol, but that needs further study.”

The results are published in the journal Cell Metabolism.

Prof Schrauwen, acknowledging that his sample size was small, said he was seeking funding for a larger and longer trial. “This is small, proof of principle study, but the results are so promising that I think it is important that we conduct a bigger study,” he said.

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Can a blood test really tell you when you’ll die?

October 12, 2011

a telomere

Telomere Science still has a lot of work ahead of itself…there are many factors that contribute to the aging process…so if a test can predict when I will die…perhaps in the future we can manipulate the strands of our DNA to extend our lives to 120 years of age. It sounds like science fiction ….but remember many ideas have started out as an impossibility…only to develop into a feasible application to enhance the quality of life.

http://www.yepod.com/?p=14786

Pass it on,

Dr Anthony  


Powered by Guardian.co.ukThis article titled “Can a blood test really tell you when you’ll die?” was written by Giles Tremlett, for The Guardian on Tuesday 11th October 2011 19.00 UTC

As a taxi takes me across Madrid to the laboratories of Spain’s National Cancer Research Centre, I am fretting about the future. I am one of the first people in the world to provide a blood sample for a new test, which has been variously described as a predictor of how long I will live, a waste of time or a handy indicator of how well (or badly) my body is ageing. Today I get the results.

Some newspapers, to the dismay of the scientists involved, have gleefully announced that the test – which measures the telomeres (the protective caps) on the ends of my chromosomes – can predict when I will die. Am I about to find out that, at least statistically, my days are numbered? And, if so, might new telomere research suggesting we can turn back the hands of the body’s clock and make ourselves “biologically younger” come to my rescue?

The test is based on the idea that biological ageing grinds at your telomeres. And, although time ticks by uniformly, our bodies age at different rates. Genes, environment and our own personal habits all play a part in that process. A peek at your telomeres is an indicator of how you are doing. Essentially, they tell you whether you have become biologically younger or older than other people born at around the same time.

The key measure, explains María Blasco, a 45-year-old molecular biologist, head of Spain’s cancer research centre and one of the world’s leading telomere researchers, is the number of short telomeres. Blasco, who is also one of the co-founders of the Life Length company which is offering the tests, says that short telomeres do not just provide evidence of ageing. They also cause it. Often compared to the plastic caps on a shoelace, there is a critical level at which the fraying becomes irreversible and triggers cell death. “Short telomeres are causal of disease because when they are below a [certain] length they are damaging for the cells. The stem cells of our tissues do not regenerate and then we have ageing of the tissues,” she explains. That, in a cellular nutshell, is how ageing works. Eventually, so many of our telomeres are short that some key part of our body may stop working.

The research is still in its early days but extreme stress, for example, has been linked to telomere shortening. I think back to a recent working day that took in three countries, three news stories, two international flights, a public lecture and very little sleep. Reasonable behaviour, perhaps, for someone in their 30s – but I am closer to my 50s. Do days like that shorten my expected, or real, life-span?

People with similar worries – or, perhaps, just Woody Allen-style neuroses about their health – have begun to contact the company set up by Blasco. Requests have poured in from around the world since a headline writer at the Independent, perhaps misled by Life Length‘s ambiguous name, invited readers to find out about “The £400 test that tells you how long you’ll live.” The internet did the rest.

Originally set up to help researchers and the pharmaceutical, health food and cosmetics industries test the impact of their products on telomeres, the flood of individual requests has caught Blasco’s still tiny company by surprise. But the test is available, as of this month, via doctors in Spain and Portugal and there are plans to make it easier to carry out in the UK and the US as soon as possible. It sees a potential gold-mine in testing of what it calls people’s “biological age” – though it is by no means alone in the field. So what can Blasco tell me about my test?

“You actually have very good news,” she says, pointing at a chart that looks as if it has been blasted by shotgun pellets. My telomeres – especially the more dangerous, shortest ones – are in better shape than would be normal for my age. The pellet points are individual results from those people who have been tested and introduced into this database so far, and the red dot representing my blood sample is on the better side of the two graphs Blasco shows me. One graph shows median telomere length, while the other shows how many crucially short telomere endings I have. In each case, a line on the graph shows the average result against age. The test on some 100,000 of my telomeres, compared with the other results on the admittedly small database being used by Life Length when this test was done in the summer, give me a “biological age” six years below my real age. With only 90 other men on the chart so far, all with different lifestyles and genetic backgrounds to mine, I should avoid feeling smug. Eventually, when there are thousands or more on the database, I might get a better idea of what results people more like me should expect. I have a reasonably healthy lifestyle, after all, and previous generations on both sides of my family have been long-lived.

However, according to a New York Times interview with 2009 Nobel prize-winner Carol Greider – who Blasco trained under – individual telomere tests are not much use. “The science really isn’t there to tell us what the consequences are of your telomere length,” she said.

Blasco, obviously, disagrees. So does Elizabeth Blackburn, who shared the Nobel prize for telomere research with Greider and Jack Szostak, and has set up her own Telome Health company to start offering tests later this year.

Blasco compares the current state of telomere testing to the early days of cholesterol tests – and believes it should become common once the price drops and research is done to beef up databases, improve interpretation and create telomere-restoring treatments. “This is a different kind of marker. It is a new, molecular marker. Even though we measure telomere length in blood cells, it has been shown to be an indicator of the degree of telomere shortening in the whole organism,” she says. “And we think it is very powerful, based on what we know from hard science.” Even so, she is insistent that the test is not a magic measure of individual life length. “We don’t tell anyone how long they will live.

“It is the doctor – and we want to do this with doctors – who will tell you what is known about the meaning of this measurement and what you can do and what you cannot do,” says Blasco. In fact, the benefits of telomere science still lie mostly in the future. As with early cholesterol tests, a doctor is currently unable to tell you much about what those results mean – or what you can do about a bad result, beyond fairly obvious advice about looking after your health.

I notice that a few of the 90 men on my chart have apparently alarming results. Their telomeres indicate a “biological age” 20 years or more higher than their real age. This means that, at least statistically, they may be much closer to death than most people their age. One of these men comes from a family with a long history of early cancers, according to Life Length’s CEO Stephen Matlin. He has offered those with worryingly high results a free second test after three months, to see whether anything has changed. My report also warns, however, that results may reflect temporary illness or ongoing medical treatments – effectively skewing them. And some results on the chart look plain bizarre. One tester, for example, appears to have – at least statistically – a biological age of around 120. Two people aged above 60, together with a clutch of 30-year-olds, have an estimated biological age below zero – presumably because their telomeres are in better shape than might be expected of the average baby. Life Length said this reflected the fact that little research had been done on the telomeres of the very young.

Individual testing, then, is still in nappies. Far more exciting are the possible future advances to come from telomere research, says Blasco. “One is telomerase activation, because of its potential to reverse ageing. And proving which diseases can benefit from telomerase activation, in order for this to be something druggable.”

“Some of the new [research] papers appearing in top journals are to do with telomorase activation,” she says. “That is one aspect. The other is that we are seeing a lot of epidemiological studies showing correlations between telomere length and certain diseases, and which habits are good or bad for telomere length.”

She says the idea that telomeres can be “re-elongated” and, hence, that biological age can be reversed does not open the door to immortality – even if scientists have been able to extend a mouse’s age by up to 40%. “That’s a lot, but nobody has been able to make a mouse that is immortal,” she says.

It does, however, throw up philosophical and ethical dilemmas. The US Food and Drug Administration (FDA), for example, refuses to approve drugs that are simply designed to prevent ageing. “Although I – and many more scientists – believe ageing is the cause of diseases, this is not perceived like that yet by the FDA,” says Blasco. “But what is clear is that there are a number of diseases associated with ageing which are caused because our cells age.”

Activating telomerase to counter that, she says, might help prevent major illnesses and allow drugs to be approved by the FDA. If drugs are found to activate telomerase and prevent, say, Parkinson’s disease, Alzheimer’s disease or some cardiovascular problems then the inevitable result will be not just a healthier life, but also a longer one.

Blackburn agrees that the idea that the new tests can tell you your life length is silly, but she insists that the evidence connecting telomere length and disease risk is becoming clearer.

“We and other groups are seeing clear statistical links between telomere shortness and risk for a variety of diseases that are becoming very common, such as cardiovascular disease, diabetes and certain cancers,” she told the nature.com website in August. “We have also looked at chronic psychological stress, including depression and post-traumatic stress disorder, and more and more we see associations with telomere shortness. There are even links with education — in one study telomere shortness was related to not finishing school. We’re seeing the data unfolding in front of us. A lot of them are not published yet.”

So what has telomere testing done for me? Not a lot, frankly, though I might have reacted differently had I been dangerously off the chart. Nor am I a woman in her 30s, who might like to know how fast the biological clock that may eventually limit fertility is ticking.

I am tempted to repeat the test again, mainly out of a competitive desire to get better, but only if (as on this occasion, when Life Length waived the $500 fee) I can get it for free. Far more interesting, however, has been the glimpse of the future – when telomere testing, and popping pills to repair the tips of our chromosomes, may allow us to live both longer and healthier. I am persuaded, too, that the aim should be to make sure we live our years out in good health. So why all the rushing about? Time, perhaps, to take things more calmly.

 

guardian.co.uk © Guardian News & Media Limited 2010

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Mapping the body: gastric pits

September 22, 2011

A close-up of a gastric pit

The human stomach is a facinating organ responsible for the breakdown of food that will be absorbed into the body. Problems with the stomach is a source of hugh profits for the pharmaceutical companies. Individuals sometimes become dependent on laxatives,acid,or stomachache medications to relieve symptoms. If stomach symptoms do not subside within a week from onset, seek medical attention and allow a doctor to do a complete workup to determine the cause of your problems in your gastic pits .

Pass it on,

Dr Anthony   


Powered by Guardian.co.ukThis article titled “Mapping the body: gastric pits” was written by Gabriel Weston, for The Guardian on Monday 19th September 2011 20.30 UTC

There’s a funny kind of hierarchy that exists among the organs. You simply don’t hear bladder surgeons boasting about their art in quite the same way that heart and brain surgeons do. And yet, even the most humble body part has its own complex and fascinating physiology.

I realised this when learning about the structure and function of the stomach. Previously, I had thought of the tummy as a lowly place, a mere dumping ground for anything we might choose to stuff in our mouths. I couldn’t have been more mistaken, and my new-found respect for the stomach gained focus when I read about the gastric pit.

If you look inside a stomach when dissecting a cadaver, or during an operation, it appears like a bag whose surface is thrown into a series of visible folds. These are called rugae, and enable the stomach to increase dramatically in size when it fills with food. What you can’t see with the naked eye is that the lining of the stomach (the mucosa) is interrupted by multiple tiny openings, each of which leads to a tiny hormone-producing tunnel. These are the gastric pits and each one is lined with a number of different types of cell, producing a separate, important gastric secretion.

The cells at the top of the pits produce mucus, which protects the stomach lining against gastric acid. Deeper down are two other cell types. Parietal cells generate stomach acid as well as a substance called intrinsic factor, which enables a vitamin called B12 to be absorbed further along in the gut. The impressively named chief cells secrete pepsinogen which, when it mixes with stomach acid, becomes an enzyme called pepsin. This helps to break down the protein we eat into smaller units that can be absorbed.

The heart may be in charge of pumping blood around the whole body. The brain may be master of all we do. But, at the tissue level, wonders are also to be found in those organs that we may think of as being more ordinary.

Gabriel Weston is a surgeon and author of Direct Red: A Surgeon’s Story

 

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Antibiotic resistance: Bacteria are winning the war

April 7, 2011

Antibiotic pills

Superbugs will inherit the Earth…thats exactly where we are headed. Doctors have been over prescripting  antibiotics for years…and the bacteria are now becoming resistant to the medication that used to so effective in eliminating them. Health professionals are concern that we may be on borrowed time before a serious pandemic holds this world hostage. We need to investigate new options in controling the continued proliferation of superbugs…science needs to find an answer.

Pass it on,

Dr Anthony

www.Yepod.com 

Powered by Guardian.co.ukThis article titled “Antibiotic resistance: Bacteria are winning the war” was written by Frank Swain, for guardian.co.uk on Thursday 7th April 2011 12.45 UTC

In what has surely become the most ritualised medical practice since the Hippocratic Oath, the World Health Organization took to the stage again today to warn that the misuse of antibiotics was threatening to render one of our most potent medicines useless. This comes a decade after an identical appeal from the organisation warned of a global crisis in the making.

Health experts have been ringing the alarm over antimicrobial resistance for so long that it seems to have become part of our collective background noise, like the endless rasp of waves on the shore. And like stupid tourists, we sleep in the sun while the tide comes in.

It might surprise you to learn that resistance to antibiotics was identified even before Fleming’s wonder drug hit the shelves. The first clinical application of penicillin came in the early 1940s, but the discovery of beta-lactamase – a bacterial enzyme capable of destroying penicillin – preceded that revolution by a few years. The microbes were always one step ahead. As early as 1960, it was clear that overuse of antibiotics was driving the emergence of resistant species.

We also knew how to combat the problem: restricting the use of antimicrobials, ensuring patients completed their courses, containing outbreaks of resistant species. But despite repeated appeals at every level, we couldn’t match the tenacity of microbes. Last year, resistant bacterial infections killed around 25,000 people in Europe alone.

In 2008 the rising waters were finally lapping at our feet. An unusually hardy strain of Klebsiella pneumoniae was isolated from a 59-year-old Swedish patient who had been treated in a New Delhi hospital. The bacterium was found to be indifferent to even our most powerful antibiotics. To make matters worse, the genes that gave it this superpower were found on a small ring of DNA that is easily traded between different species of bacteria.

New Delhi metallo-beta-lactamase (NDM-1) has since turned up in more than 16 countries across the world, including Britain. A study published in Lancet Infectious Diseases today shows the resistance factor has spread to 14 different species of bacteria, including pathogenic varieties responsible for dysentery and cholera. Most bacteria holding the NDM-1 plasmid are resistant to all but a couple of our most clumsy, brutal antibiotics. One strain is immune to all of them.

In a report published last year, the US Institute of Medicine described antimicrobial resistance as “a global public health and environmental catastrophe”, while the WHO called the rise of NDM-1 a “doomsday scenario of a world without antibiotics”.

These are not hollow words. Beyond antibiotics, we have few options left on the table. New antibiotics take around 10-20 years to develop, and there are few in the pipeline. Vaccines are the most obvious alternative, but vaccination programmes are challenging to run even in the most industrialised societies.

Scientists have been training viruses to chase down bacterial cells like packs of hunting dogs for the better part of a century, but Georgia is the only country in the world where such phage therapy is licensed. More exotically, an experimental procedure using a jet of ionised argon gas shows promise, although it can only treat external infections.

After a torrent of dramatic headlines, interest in NDM-1 fell away. After all, in a world well-stocked with superbugs – MRSA, MDRTB, C diff – what was another acronym? The media tend to train their spotlight on highly pathogenic diseases – those that kill in no time flat – at the expense of untreatable diseases, which are far less dramatic. The trouble with superbugs like NDM-1 is that once they gain a foothold in hospitals, even minor surgerical procedures are burdened with a much higher risk of serious postoperative complications.

Last year, the chairman of the Board for the Canadian Committee on Antibiotic Resistance, Professor John Conly, spoke out on the issue. I asked him why NDM-1 had elicited such little concern. “None of us have the answers as to why the issue of antimicrobial resistance does not capture more meaningful attention by governments and governmental agencies,” he wrote. “The problem is that it is somewhat akin to climate change and so slow and insidious that people, and notably our politicians, are lulled asleep.”

Although previous campaigns in France and the USA have achieved substantial reductions in the prescription of antibiotics, their uncontrolled use in other countries has undermined those successes – microbes do not respect national borders. As such, the failure of governments to control drug resistance has often been labelled a “tragedy of the commons”.

But there’s a crucial difference. Left to their own devices, forests and fisheries restock themselves. Medicine cabinets don’t. Even if we rein in our appetite for antibiotics, NDM-1 is here to stay. Perhaps that will be enough to prompt the action called for by health practitioners 50 years ago, but it’s hard to shake the feeling that the microbes have us in checkmate.

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