Tag Archives: medical research

The US is debating the use of chimps in medical research

The United States and Gabon are the only countries left in the world that are still using chimps for medical research. While research made on our closest relatives is considered invaluable by scientists studying deadly diseases such as HIV, animal rights activists are pressuring the authorities to ban the use of chimps in research labs, considered cruel by all means. This was the subject of debate opened at a Institute of Medicine (IOM) conference this weekend.

It’s well known that once chimps reach the confinements of a lab cell, they become socially withdrawn, agitated – most became traumatized. In the U.S. there are currently 1.000 medical research chimps. The European Union banned lab chimps last year, and pharmaceutical companies nowadays have almost exclusively turned to cheaper alternatives (chimps are the hardest lab animals to care for, and thus deemed expensive).

“If you’re a scientist, a chimp is really a sort of last resort,” said Harold Watson, who directs the chimpanzee research program at the National Institutes of Health, which manages 734 of the nearly 1,000 medical research chimps in the United States.

Now, the IOM debated the fate of nearly all the medical research chimps left in the world.

Through the constant experimentation on chimps along the years, significant progress has been made in the medical field, like vaccines against hepatitis A and B, in which chimp research was considered crucial. Scientists studying hepatitis C say that chimps are vital to their work as the only lab animal susceptible to the virus.

Just because chimpanzees have the closest matching DNA to humans, it doesn’t mean that they’re susceptible to the same diseases as humans, though. Although extensive HIV studies were made on chimps in the 1980s and 1990s, scientists have found that rhesus monkeys are more likely to mimic human-like HIV infections, for example. So, having a similar DNA, doesn’t necessarily mean that two species will be affected similarly by a disease.

Biomedical research chimp numbers have dramatically declined in recent years, as scientists turn to other alternatives like mice or other means that new technology has been able to offer. Actually, scientists have now been able to engineer mice with more human-like immunity for hepatitis studies, which might release chimps of their principal cause of use.

“We are more than halfway” to mice that could replace chimps in hepatitis studies, Alexander Ploss of Rockefeller University said. “Whether we have that mouse in two years, five years, 10 years . . . who knows?”

Ethics and medical science, acting in the most honest good interest of humankind, have clashed for a long time whenever chimp reserach was concerned. Both sides have a solid say, and the matter is far from an easy solving in the near future.

“We wouldn’t be having this meeting if ethics wasn’t an issue,” Frans de Waal told the IOM committee. The Emory University researcher, whose pioneering studies with captive chimpanzees have revealed their human-like empathy, continued, “We don’t have this kind of meeting about rats.”

Over half of Alzheimer’s cases could be avoided

According to a study conducted by Deborah Barnes, PhD, a mental health researcher at the San Francisco VA Medical Center, more than half of all Alzheimer’s cases could be prevented through lifestyle changes or light treatment.

Analyzing thousands of cases worldwide, she concluded that the biggest impacting factors on Alzheimer that can be modified are, in descending order, low education, smoking, physical inactivity, depression, mid-life hypertension, diabetes and mid-life obesity. In the United States for example the biggest modifiable factors are physical inactivity, depression, smoking, mid-life hypertension, mid-life obesity, low education and diabetes. Together, these factors are associated with 51 percent of Alzheimer’s cases worldwide (17.2 million cases) and up to 54 percent of Alzheimer’s cases in the United States (2.9 million cases), according to Barnes.

“What’s exciting is that this suggests that some very simple lifestyle changes, such as increasing physical activity and quitting smoking, could have a tremendous impact on preventing Alzheimer’s and other dementias in the United States and worldwide,” said Barnes, who is also an associate professor of psychiatry at the University of California, San Francisco.

However, it has to be said that the conclusions are drawn based on the idea that there is a causal association between each risk factor and Alzheimer’s disease.

“We are assuming that when you change the risk factor, then you change the risk,” Barnes said. “What we need to do now is figure out whether that assumption is correct.”

New imaging method reveals stunning methods of brain connections

The typical healthy human brain contains about 200 billion nerve cells, called neurons, all of which are connected through hundreds of trillions of small connections called synapses. One single neuron can lead to up to 10.000 synapses with other neurons, according to Stephen Smith, PhD, professor of molecular and cellular physiology.

Along with a team of researchers from the Stanford School of Medicine, he was able to quickly and accurately locate and count these synapses in unprecedented detail, using a new state of the art imaging system on a brain tissue sample. Because the synapses are so small and close to each other, it’s really hard to achieve a thorough understanding on the complex neuronal circuits that make our brain work. However, this new method could shed some new light on the problem; it works by combining high-resolution photography with specialized fluorescent molecules that bind to different proteins and glow in different colors. The computer power required to achieve the imagery was massive.

A synapse is less than a thousandth of a millimeter in diameter, and the spaces between them are not much bigger either. This method, array tomography, is at its starting years, but as time passes, it will probably become more and more reliable, and more and more efficient.

“I anticipate that within a few years, array tomography will have become an important mainline clinical pathology technique, and a drug-research tool,” Smith said. He and Micheva are founding a company that is now gathering investor funding for further work along these lines. Stanford’s Office of Technology Licensing has obtained one U.S. patent on array tomography and filed for a second.

Full study here.

Function found for Alzheimer protein

Recently, numerous developments in Alzheimer research have been made, including a ‘brain pacemaker‘ and the discovery of an extremely promising chemical, p7c3, that might help treat patients. This time, researchers went for a different approach; what happens in Alzheimer is that the brain basically grows some lumps of protein, developing formations known as amyloid plaques that prevent it from working properly. This study, revealed in the September 17th print issue of Cell seems to have found a way to make something useful with the amyloid precursor protein (APP for short), the main ingredient in these plaques.

At its very core, APP is a iron oxidase whose job is to transform iron into a safer form and ready it for transport throughout the body. If it doesn’t work right, like in Alzheimer’s disease, iron levels get really high and they become toxic.

“This opens a big window on Alzheimer’s disease and iron metabolism,” said Ashley Bush of The Mental Health Research Institute, University of Melbourne.

“Although people have attributed several important physiological roles to APP,” added Jack Rogers of Harvard Medical School, “this now gives us an idea of what this critical protein does to underpin its role in iron metabolism.”

However, this amyloid alone can not explain what happens in the brain during Alzheimer. In order to do that, you have to look deeper and analyze the different metal concentrations in the brain.

“There has been a lot of attention on amyloid, but it seems it is not a simple matter of amyloid as the sole culprit,” Bush said. For one thing, trials of drugs designed to target and clear amyloid plaques haven’t worked as intended.

The findings suggest that zinc may be the ideal target in the war on Alzheimer.

“Our findings authenticate zinc as a target,” Bush said. “It really makes it look like an attractive place to hit.”

Although researchers don’t want to raise hopes too much, an Alzheimer cure, or at least a way to significantly slow down the progression of the disease seems more and more close.