Tag Archives: medical research

Medical Studies Showing Largest Benefits Often Prove to be False

There is another study showing the results of health studies often are proven false. Medical studies with striking results often prove false

If a medical study seems too good to be true, it probably is, according to a new analysis.

In a statistical analysis of nearly 230,000 trials compiled from a variety of disciplines, study results that claimed a “very large effect” rarely held up when other research teams tried to replicate them.
…
The report should remind patients, physicians and policymakers not to give too much credence to small, early studies that show huge treatment effects, Ioannidis said.

The Stanford professor chose to publish this paper in a closed science publication. But previously he published openly on: Why Most Published Research Findings Are False.

Nobel Prize in Physiology or Medicine 2012 for Reprogramming Cells to be Pluripotent

The Nobel Prize in Physiology or Medicine 2012 was awarded “for the discovery that mature cells can be reprogrammed to become pluripotent.” The prize goes jointly to Sir John B. Gurdon, Gurdon Institute in Cambridge, UK and Shinya Yamanaka, Kyoto University (he is also a senior investigator at the Gladstone Institutes in the USA).

The Nobel Prize recognizes two scientists who discovered that mature, specialised cells can be reprogrammed to become immature cells capable of developing into all tissues of the body. Their findings have revolutionised our understanding of how cells and organisms develop.

John B. Gurdon discovered (in 1962) that the specialisation of cells is reversible. In a classic experiment, he replaced the immature cell nucleus in an egg cell of a frog with the nucleus from a mature intestinal cell. This modified egg cell developed into a normal tadpole. The DNA of the mature cell still had all the information needed to develop all cells in the frog.

Shinya Yamanaka discovered more than 40 years later, in 2006, how intact mature cells in mice could be reprogrammed to become immature stem cells. Surprisingly, by introducing only a few genes, he could reprogram mature cells to become pluripotent stem cells, i.e. immature cells that are able to develop into all types of cells in the body.

These groundbreaking discoveries have completely changed our view of the development and cellular specialisation. We now understand that the mature cell does not have to be confined forever to its specialised state. Textbooks have been rewritten and new research fields have been established. By reprogramming human cells, scientists have created new opportunities to study diseases and develop methods for diagnosis and therapy.

All of us developed from fertilized egg cells. During the first days after conception, the embryo consists of immature cells, each of which is capable of developing into all the cell types that form the adult organism. Such cells are called pluripotent stem cells. With further development of the embryo, these cells give rise to nerve cells, muscle cells, liver cells and all other cell types – each of them specialised to carry out a specific task in the adult body. This journey from immature to specialised cell was previously considered to be unidirectional. It was thought that the cell changes in such a way during maturation that it would no longer be possible for it to return to an immature, pluripotent stage.

Continue reading →

Key Indicator for Malignant Melanoma Found

Skin cancer detection breakthrough

The researchers found that certain biochemical elements in the DNA of normal pigment-producing skin cells and benign mole cells are absent in melanoma cells. Loss of these methyl groups — known as 5-hmC — in skin cells serves as a key indicator for malignant melanoma. Loss corresponded to more-advanced stages of melanoma as well as clinical outcome.

Strikingly, researchers were able to reverse melanoma growth in preclinical studies. When the researchers introduced enzymes responsible for 5-hmC formation to melanoma cells lacking the biochemical element, they saw that the cells stopped growing.

“It is difficult to repair the mutations in the actual DNA sequence that are believed to cause cancer,” said Christine Lian, a physician-scientist in the Department of Pathology at BWH and one of the lead authors. “So having discovered that we can reverse tumor cell growth by potentially repairing a biochemical defect that exists — not within the sequence but just outside of it on the DNA structure — provides a promising new melanoma treatment approach for the medical community to explore.”

Because cancer is traditionally regarded as a genetic disease involving permanent defects that directly affect the DNA sequence, this new finding of a potentially reversible abnormality that surrounds the DNA (thus termed “epigenetic”) is a hot topic in cancer research, according to the researchers.

In the United States, melanoma is the fifth most common type of new cancer diagnosis in men and the seventh most common type in women. The National Cancer Institute estimates that in 2012 there will be 76,250 new cases and 9,180 deaths in the United States owing to melanoma.

Thankfully scientists keep making great progress in understanding and finding potential clues to treating cancer. And big gains have been made in treating some cancers over the last few decades. But the research successes remain difficult to turn into effective solutions in treating patients.

I am thankful we have so many scientists doing good work in this difficult and important area (cancer).

Man in Coma for 7 Years was Given a Sleeping Pill and Woke Up

Lazarus pill miracle for E Cape man, 9 September 2012

After reading a report in City Press last month, his wife, Nomfundo, insisted that he be given a prescription for the sleeping pill Stilnox, which has the opposite effect on those with brain injuries.

It worked – and brought him out of a seven-year coma.
…
But on August 12, family friend Nceba Mokoena came across an article in City Press about a miracle recovery made by another car crash victim, hundreds of kilometres away in Gauteng.

Louis Viljoen was given the sleeping pill by chance by his mother, Sienie.

She had noticed he wasn’t sleeping peacefully and asked her doctor if she could give him half a sleeping tablet. After she did, Louis opened his eyes and said “Hello Mamma”, his first words in five years.

Very cool anecdote and example that modern medicine has many miraculous cures but the medical system can’t always use them as well as we would hope. Even with all the knowledge we have today just getting that information into the right doctor’s minds is very hard. And the complexity of diagnoses and interactions makes medical care still an art as well as a science.

So is this just some freak accident. Partially, in the mother giving her son a sleeping pill to reduce his seeming restlessness in the coma. But the effect of Stilnox in bringing coma victims out of a coma has been documented previously.

Reborn from persistent vegetative state, 12 September 2006

Four three years, Riaan Bolton has lain motionless, his eyes open but unseeing. After a devastating car crash doctors said he would never again see or speak or hear. Now his mother, Johanna, dissolves a pill in a little water on a teaspoon and forces it gently into his mouth. Within half an hour, as if a switch has been flicked in his brain, Riaan looks around his home in the South African town of Kimberley and says, “Hello.” Shortly after his accident, Johanna had turned down the option of letting him die.

Three hundred miles away, Louis Viljoen, a young man who had once been cruelly described by a doctor as “a cabbage”, greets me with a mischievous smile and a streetwise four-move handshake. Until he took the pill, he too was supposed to be in what doctors call a persistent vegetative state.

Across the Atlantic in the United States, George Melendez, who is also brain-damaged, has lain twitching and moaning as if in agony for years, causing his parents unbearable grief. He, too, is given this little tablet and again, it’s as if a light comes on. His father asks him if he is, indeed, in pain. “No,” George smiles, and his family burst into tears.

It all sounds miraculous, you might think. And in a way, it is. But this is not a miracle medication, the result of groundbreaking neurological research. Instead, these awakenings have come as the result of an accidental discovery by a dedicated – and bewildered – GP. They have all woken up, paradoxically, after being given a commonly used sleeping pill.

Medical care is still today an extremely difficult area where highly trained and continuously learning doctors still have a great deal of trouble keeping up with the latest medical knowledge.

Antibiotics fuel obesity by creating microbe upheavals

We aren’t single individuals, but colonies of trillions. Our bodies, and our guts in particular, are home to vast swarms of bacteria and other microbes. This “microbiota” helps us to harvest energy from our food by breaking down the complex molecules that our own cells cannot cope with. They build vitamins that we cannot manufacture. They ‘talk to’ our immune system to ensure that it develops correctly, and they prevent invasions from other more harmful microbes. They’re our partners in life.

What happens when we kill them?

Farmers have been doing that experiment in animals for more than 50 years. By feeding low doses of antibiotics to healthy farm animals, they’ve found that they could fatten up their livestock by as much as 15 percent.
…
Ilseung Cho from the New York University School of Medicine has confirmed that hypothesis. By feeding antibiotics to young mice, he has shown that the drugs drastically change the microscopic communities within their guts, and increase the amount of calories they harvest from food. The result: they became fatter.

I continue to believe we are far to quick to medicate. We tremendously overuse anti-biotis and those costs are huge. They often are delays and systemic and given our current behavior we tend to ignore delayed and systemic problems.

The link between the extremely rapid rise in obesity and the overuse of anti-biotics is in need of much more study. It seems a possible contributing factor but there is much more data needed to confirm such a link. And other factors still seem dominant to me: increase in caloric intake and decrease in physical activity.

Virus Kills Breast Cancer Cells in Laboratory

Some very exciting and good news from Penn State. Researchers have found a virus that kills breast cancer cells. It is great to read about research breakthroughs like this. Of course, most of these announcements never become practical solutions, unfortunately. And if they do it is many many years later and almost always in much less exciting ways than the headlines. Still, the percentage that do make it through the process into workable solutions provide us great benefits.

Virus kills breast cancer cells in laboratory

Adeno-associated virus type 2 (AAV2) is a virus that regularly infects humans but causes no disease. Past studies by the same researchers show that it promotes tumor cell death in cervical cancer cells infected with human papillomavirus. Researchers used an unaltered, naturally occurring version of AAV2 on human breast cancer cells.

“Breast cancer is the most prevalent cancer in the world and is the leading cause of cancer-related death in women,” said Samina Alam, research associate in microbiology and immunology. “It is also complex to treat.”
…
“We can see the virus is killing the cancer cells, but how is it doing it?” Alam said. “If we can determine which viral genes are being used, we may be able to introduce those genes into a therapeutic. If we can determine which pathways the virus is triggering, we can then screen new drugs that target those pathways. Or we may simply be able to use the virus itself.”
…
AAV2 does not affect healthy cells. However, if AAV2 were used in humans, the potential exists that the body’s immune system would fight to remove it from the body. Therefore, by learning how AAV2 targets the death pathways, researchers potentially can find ways to treat the cancer without using the actual virus.

In ongoing studies, the Penn State researchers also have shown AAV2 can kill cells derived from prostate cancer, mesothelioma, squamous cell carcinoma, and melanoma. A fourth line of breast cancer cells — representing the most aggressive form of the disease — also was studied in a mouse breast tumor model, followed by treatment with AAV2. Preliminary results show the destruction of the tumors in the mice, and researchers will report the findings of those mouse studies soon.

The fight against cancer has many promising breakthroughs. We have made some great progress. Still the fight is extremely difficult and we have many more frustrations than successes.

Physical Activity for Adults: Inactivity Leads to 5.3 Million Early Deaths a Year

Obviously health care doesn’t only mean sickness treatment. Avoiding sickness is much better than treating it. Sadly we spend far too little energy on creating health and far too much on treating sickness.

Physical activity guidelines for adults (follow link for more details and guidelines for others) from the UK National Health Service

To stay healthy, adults aged 19-64 should try to be active daily and should do:

At least 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity such as cycling or fast walking every week, or
75 minutes (1 hour and 15 minutes) of vigorous-intensity aerobic activity such as running or a game of singles tennis every week
and muscle-strengthening activities on 2 or more days a week that work all major muscle groups (legs, hips, back, abdomen, chest, shoulders and arms).

Sedentary lifestyle can kill

one in three adults worldwide fails to do the recommended 150 minutes of moderate aerobic physical activity per week. In the UK two out of three adults don’t manage it.

So rather than stressing the health benefits of exercise, the Lancet researchers have opted to show the harm caused by inactivity. They estimate lack of exercise is responsible for about 5.3m deaths a year – about the same number as smoking.

This is based on estimates of the impact on inactivity on coronary heart disease, Type 2 diabetes, and two specfic cancers – breast and bowel – where lack of exercise is a major risk factor.

Effect of physical inactivity on major non-communicable diseases worldwide: an analysis of burden of disease and life expectancy

Worldwide, we estimate that physical inactivity causes 6% (ranging from 3Â·2% in southeast Asia to 7Â·8% in the eastern Mediterranean region) of the burden of disease from coronary heart disease, 7% (3Â·9—9Â·6) of type 2 diabetes, 10% (5Â·6—14Â·1) of breast cancer, and 10% (5Â·7—13Â·8) of colon cancer. Inactivity causes 9% (range 5Â·1—12Â·5) of premature mortality, or more than 5Â·3 million of the 57 million deaths that occurred worldwide in 2008. If inactivity were not eliminated, but decreased instead by 10% or 25%, more than 533 000 and more than 1Â·3 million deaths, respectively, could be averted every year. We estimated that elimination of physical inactivity would increase the life expectancy of the world’s population by 0Â·68 (range 0Â·41—0Â·95) years.

An Apple a Day is Good Advice

Apples really are healthy food. They provide fiber and nutrients without a large amount of calories. Including them in your diet can contribute to a healthy lifestyle.

How apples can make you skinnier & 4 more health benefits of apples

Packing in quite a bit of soluble fiber (4 grams per medium apple) for a modest amount of calories (95) makes apples a filling, sweet snack. Plus, a medium apple counts as 1 cup of fruit, so after eating one you’re well on your way to meeting your daily fruit quota (around 2 cups for adults on a 2,000-calorie diet). They also are a good source of immune-boosting vitamin C (providing 14% of the Daily Value).
…
a survey of eating and health habits, found that people who had eaten apples in any form over the past day were 27 percent less likely to have symptoms of metabolic syndrome than those who didn’t. The apple eaters also had lower levels of C-reactive protein, a marker of inflammation whose presence in the blood suggests an increased risk for heart disease and diabetes.

“Our study suggests that ursolic acid increases skeletal muscle and brown fat leading to increased calorie burning, which in turn protects against diet-induced obesity, pre-diabetes and fatty liver disease,” Christopher Adams, M.D., Ph.D., UI associate professor of internal medicine at the University of Iowa.

Until quite recently, researchers believed that only infants had brown fat, which then disappeared during childhood. However, improved imaging techniques have shown that adults do retain a very small amount of the substance mostly in the neck and between the shoulder blades. Some studies have linked increased levels of brown fat with lower levels of obesity and healthier levels of blood sugar and blood lipid, leading to the suggestion that brown fat may be helpful in preventing obesity and diabetes.

Modeling Weight Loss Over the Long Term

Researchers at the National Institutes of Health have created a mathematical model of what happens when people of varying weights, diets and exercise habits try to change their weight. The findings challenge the commonly held belief that eating 3,500 fewer calories, or burning them off exercising, will result in a pound of weight loss.

Instead, the researchers’ computer simulations indicate that this assumption overestimates weight loss because it fails to account for how metabolism changes. The computer simulations show how these metabolic changes can significantly differ among people.

However, the computer simulation of metabolism is meant as a research tool and not as a weight-loss guide for the public. The computer program can run simulations for changes in calories or exercise that would never be recommended for healthy weight loss. The researchers hope to use the knowledge gained from developing the model and from clinical trials in people to refine the tool for everyone.

“This research helps us understand why one person may lose weight faster or slower than another, even when they eat the same diet and do the same exercise,” said Kevin Hall, Ph.D., an obesity researcher and physicist at the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases. “Our computer simulations can then be used to help design personalized weight management programs to address individual needs and goals.”

The online simulation tool based on the model enables researchers to accurately predict how body weight will change and how long it will likely take to reach weight goals based on a starting weight and estimated physical activity. The tool simulates how factors such as diet and exercise can alter metabolism over time and thereby lead to changes of weight and body fat.

The team found that people’s bodies adapt slowly to changes in dietary intake. They also found heavier people can expect greater weight change with the same change in diet, though reaching a stable body weight will take them longer than people with less fat.

The model also points to a potential simplified method to approximate weight loss in an average overweight person. An adult who has a body mass index (a measure of a person’s weight in relation to his or her height) between 25 and 29.9 is considered overweight. One example: For every pound you want to lose, permanently cut 10 calories from your current intake per day. At that rate, it will take about one year to achieve half of the total weight loss, and almost all of the weight loss will have occurred by three years. This calculation shows how long it takes to achieve a weight-loss goal for a single permanent change of diet or exercise.

Continue reading →

Using Nanocomposites to Improve Dental Filling Performance

After a dentist drills out a decayed tooth, the cavity still contains residual bacteria. Professor Huakun (Hockin) Xu says it is not possible for a dentist to remove all the damaged tissue, so it’s important to neutralize the harmful effects of the bacteria, which is just what the new nanocomposites are able to do.

Rather than just limiting decay with conventional fillings, the new composite he has developed is a revolutionary dental weapon to control harmful bacteria, which co-exist in the natural colony of microorganisms in the mouth.

“Tooth decay means that the mineral content in the tooth has been dissolved by the organic acids secreted by bacteria residing in biofilms or plaques on the tooth surface. These organisms convert carbohydrates to acids that decrease the minerals in the tooth structure,” says Xu, director of the Division of Biomaterials and Tissue Engineering in the School’s Department of Endodontics, Prosthodontics and Operative Dentistry.

The researchers also have built antibacterial agents into primer used first by dentists to prepare a drilled-out cavity and into adhesives that dentists spread into the cavity to make a filling stick tight to the tissue of the tooth. “The reason we want to get the antibacterial agents also into primers and adhesives is that these are the first things that cover the internal surfaces of the tooth cavity and flow into tiny dental tubules inside the tooth,” says Xu.

The main reason for failures in tooth restorations, says Xu, is secondary caries or decay at the restoration margins. Applying the new primer and adhesive will kill the residual bacteria, he says.

Continue reading →