SOTM: February 2011

Justin Guldager – General Biology

Once again a high performing freshman in a sophomore class. Justin has provided great effort and the work is paying off. His work ethic and easy going attitude are the reason that he was selected for this recognition. He has improved from last semester and never been shy about asking a question when he needs help. He is both accepting of help when classmates offer and willing to return the favor and help his classmates. Justin is a good teammate and individual performer.

Surgery for Traumatic Brain Injury May Cause Harm Later

Rachael Rettner
MyHealthNewsDaily Staff Writer
Date: 25 March 2011 Time: 06:39 PM ET

Surgery to remove part of the skull after a traumatic brain injury allows the brain to swell and relieves pressure in the head. But the procedure might cause problems over the long term for some patients, a new study suggests.

Patients in the study who had this procedure, known as decompressive craniectomy, spent fewer days in the intensive care unit, but were at greater risk for disability six months later compared with those who did not have the procedure.

Decompressive craniectomy has been increasingly performed at major trauma centers over the last decade, especially in the United States, the researchers say. However, until now, a rigorously designed study to see whether the operation is beneficial to patients’ health over the long term has never been conducted.

The findings suggest that some treatments performed today to help traumatic brain injury patients might, in the long run, cause more harm than good for some, the researchers say.

Only about 10 percent of patients with severe traumatic brain injury would be candidates for this operation, said study researcher Dr. D. Jamie Cooper, of Alfred Hospital in Melbourne, Australia. But “these patients are by far the most expensive in terms of lifetime costs in all of trauma care,” Cooper told MyHealthNewsDaily. If clinicians used standard medical treatments, such as drugs, to lower pressure inside the skull of these patients, instead of decompressive craniectomy, the U.S. health care system might save more than $1 billion to $2 billion per year, Cooper said. The cost savings would arise because “the cost of care of the severe disability survivors is so enormous,” he said.

However, the findings apply only to patients who are similar to those included in the study. Patients did not have a penetrating injury, as would be caused by a knife or a gun. And they were only included in the study if the pressure in their skull could not be controlled by medication or other nonsurgical therapies.

The results are published online today (March 25) in the New England Journal of Medicine.

Brain surgery for brain injury

Between December 2002 and April 2010, close to 3,500 severe traumatic brain injury patients from 15 hospitals in Australia, New Zealand and Saudi Arabia were screened for eligibility in the study. Of these, 155 were chosen, most of whom were treated at the New Zealand and Australian centers.

Patients were randomly assigned to receive either standard care or decompressive craniectomy. Those who received decompressive craniectomy had a large piece of the front of their skull removed, stored in a freezer for two months, and then replaced with a second surgery.

Patients who received the operation had lower pressure inside their skull than those who did not have the procedure. Both groups of patients spent about the same amount of time in the hospital, but those in the decompressive craniectomy group spent less time in the ICU.

Six months after the injury, patients in the decompressive craniectomy group had lower scores on a scale used to measure patients’ physical function. Those who had the operation were at greater risk for unfavorable outcomes, such as requiring assistance to complete everyday activities.

One explanation for these findings is that, when the brain is allowed to expand outside the skull, axons in the brain become stretched and damaged. Axons, which are the appendages of brain cells, “are brain fibers which are not designed to stretch,” Cooper said.

Should doctors still perform the surgery?

Continuing to perform decompressive craniectomy in this specific patient population would be “very unwise,” Cooper said. The results emphasize the need for so-called randomized controlled clinical trials (studies in which patients are randomly assigned to receive an intervention or a placebo)”to find out what really works,” Coopersaid.

Experts caution against generalizing the study results to all patients with severe traumatic brain injury.

“There is absolutely still a role for decompressive craniectomy,” said Dr. Deborah Stein, chief of critical care at the University of Maryland School of Medicine’s Shock Trauma Center, who was not involved in the current study. The results highlight the need for selection the right patients for the procedure, Stein added.

The study “certainly highlights that there are risks to everything we do and that not everything that seems to intuitively seem beneficial, is in fact good for our patients,” Stein said.

Stein notes that patients in the study underwent decompressive craniectomy after they experienced a pressure in their skull of 20 millimeters of mercury(20 mm Hg) or more for a period of 15 minutes. Performing this procedure after such a short time “is much more aggressive than is generally used in most clinical practice,” she said.

Researchers are awaiting the results of another, larger controlled clinical trial in which patients underwent decompressive craniectomy after enduring pressures of 25 mm Hg for more than 1 to 12 hours, Dr. Franco Servadei, of the University Hospital of Parma in Italy, wrote in an editorial accompanying the study.

Acute myeloid leukaemia genes’ role discovered

By James Gallagher
Health reporter, BBC News

Three groups of mutations which cause acute myeloid leukaemia, a cancer of the white blood cells, have been identified by scientists.

The researchers suggest their work on mice, published in Nature Genetics, could lead to new treatments.

Two thousand people in the UK are diagnosed with acute myeloid leukaemia each year.

The charity Leukaemia and Lymphoma Research said the study offered invaluable insight.

Immature
During the illness, the bone marrow, which produces blood cells, starts to churn out immature white blood cells.

This changes the balance of the blood.

The white blood cells are not properly developed so they cannot fight infection and there are too few red blood cells to carry oxygen around the body.

The disease can be fatal within weeks if left untreated.

The research group at the Wellcome Trust Sanger Institute investigated how this form of leukaemia arises because they say there had been little progress in developing new drugs.

Three groups
The most common mutation implicated in the cancer is to the Npm1 gene.

By switching this gene on in blood cells in mice, the researchers were able to show that it boosted the ability of cells to renew themselves, which is a sign of cancer. Yet only a third of mice went on to develop leukaemia.

The researchers concluded other mutations must also play a part.

They randomly mutated genes in mice, with a technique known as insertional mutagenesis. By looking at mice which developed cancer, they could then trace which mutations were involved.

They found two additional types of mutation. One affects cell division and growth, while the other modifies the cell’s environment.

Dr George Vassiliou, consultant haematologist from the Wellcome Trust Sanger Institute, said they had “found critical steps that take place when the cancer develops. Identifying the biological steps in turn means we can look for new drugs to reverse the process.”

He told the BBC: “Getting new drugs to patients could take decades, but what can happen sooner is using drugs which are already on the shelf, but in a more targeted way.”

Dr David Grant, scientific director at Leukaemia & Lymphoma Research, said: “New designer drugs which target specific genetic mutations are proving increasingly effective in the treatment of blood cancers.

“This is a very important study as it offers an invaluable insight into the role of the most common form of mutation found in acute myeloid leukaemia. It explains how it develops and the other genetic factors that drive the leukaemia’s growth.

“It offers a potential model for the development of new drugs for this terrible disease in the future.”

Kudzu Vines Spreading North from US Southeast With Warming Climate

Kudzu, the plant scourge of the U.S. Southeast. The long tendrils of this woody vine, or liana, are on the move north with a warming climate.

But kudzu may be no match for the lianas of the tropics, scientists have found. Data from sites in eight studies show that lianas are overgrowing trees in every instance.

If the trend continues, these “stranglers-of-the-tropics” may suffocate equatorial forest ecosystems.

Tropical forests contain more than half of Earth’s terrestrial species, and contribute more than a third of global terrestrial carbon and a third of terrestrial net primary productivity, says ecologist Stefan Schnitzer of the University of Wisconsin-Milwaukee.

Schnitzer is co-author with Frans Bongers of Wageningen University in the Netherlands of a paper on lianas in the current issue of the journal Ecology Letters.

“Any alteration of tropical forests has important ramifications for species diversity, productivity–and ultimately the global carbon cycle,” says Schnitzer.

Tropical forests are indeed experiencing large-scale structural changes, the most obvious of which may be the increase in lianas, according to Robert Sanford, program director in the National Science Foundation’s (NSF) Division of Environmental Biology, which funded the research.

Lianas are found in most tropical lowland forests. The woody vines are “non-self-supporting structural parasites that use the architecture of trees to ascend to the forest canopy,” says Schnitzer.

In tropical forests, lianas can make up some 40 percent of the woody stems and more than 25 percent of the overall woody species.

Lianas usually have a high canopy-to-stem ratio, says Schnitzer, “which allows them to deploy a large canopy of leaves above those of the host tree, competing aggressively with their hosts for sunlight, water and nutrients.”

Intense competition from lianas for above- and below-ground resources limits tropical tree growth and survival.

Increasing liana abundance and biomass may have far-reaching consequences for tropical forest community composition, says Sanford.

For example, in a tropical moist forest on Barro Colorado Island, Panama, researchers found that the proportion of liana infestation in the crowns of trees changed from 32 percent in 1967-68 to 47 percent in 1979, to nearly 75 percent in 2007.

The number of trees with severe liana infestation (more than 75 percent of a tree’s canopy covered by lianas) increased by 65 percent between 1996 and 2007.

In this forest, liana leaf litter and flower production, compared with that of host trees, increased substantially from 1986 to 2002, says Schnitzer.

Lianas have also overgrown other tropical forests.

In an old-growth forest surrounding the Nouragues Biological Research Station in French Guiana, scientists found that over the decade from 1992 to 2002, the number of lianas shot up while that of trees fell.

In a forest in the central Amazon, biologists discovered that over the six-year-period from 1993 to 1999, new liana seedlings were 500 percent higher than estimates from previous periods whereas tree seedling recruitment decreased.

But a tree need not live in the tropics to fall victim to lianas.

More than 80 non-native liana species have invaded North America.

Kudzu is joined by English ivy, Japanese honeysuckle and oriental bittersweet, to name a few. Oriental bittersweet is expanding in North American forests, where it has reduced native tree survival.

After hurricane damage in a Florida forest, invasive lianas rapidly colonized the damaged trees and persisted for many years afterward, reducing numbers of native trees, shrubs and herbs.

In 50-year-old forests in the Piedmont region of New Jersey, lianas are now abundant.

“A major factor limiting liana abundance in temperate forests is freezing temperatures,” says Schnitzer. “Both native and invasive lianas are likely to increase most rapidly in forests that don’t have long, cold winters.”

For snow-birds–both avian and human–who escape to tropical climes each winter, a strangler-free paradise may be in the woods they left behind.

The Discovery of Insulin – April 14 (Cozmic Pizza)

The Discovery of Insulin: Lifting the Death Sentence of Diabetes
Thursday, April 14, 2011 – 7:00pm
Eugene – Cozmic Pizza
On October 31, 1920, Frederick Banting was an orthopedic surgeon looking for work when, half-asleep in the midst of a restless night, he scrawled 25 words that would lead to the life-saving solution to a problem that had confounded scientists for centuries. Less than two years later, the fourteen-year-old diabetic daughter of the U.S. Secretary of State, Elizabeth Hughes, became one of the first recipients of an experimental drug called insulin. This improbable meeting would change both of their lives—and millions of others. But for nearly 60 years, Elizabeth’s story was virtually lost to history. More than 23 million people in the United States, or about 8% of the population, have diabetes, and 5 to 10% of these have Type 1 diabetes. Yet many do not know the amazing story that led to the medical breakthrough on which they depend.