Month: March 2013 (page 6 of 8)

breath test for stomach cancer

Cancer breathalyzer

A breath test for cancer.

Researchers are reporting a new test for gastric cancer in the British Journal of Cancer (Abstract is free, subscription required for full article). In the study the researchers looked at 130 patients with different gastric conditions. Of the patients 37 had gastric cancer, 32 had ulcers and 61 had less serious complaints. As it turns out, the cancer causes an identify chemical identifier.  Patients diagnosed with cancer produced elevated levels of the following volatile organic compounds: 2-propenenitrile, 2-butoxy-ethanol, furfural, 6-methyl-5-hepten-2-one and isoprene. These levels can be detected by gas chromatography, but the researchers developed a special nanoparticle sensor that could detect these compounds at the parts per billion level. This study seems to bolster previous research where dogs were able to identify cancer patients with ~71% accuracy based on breath samples. It is also supported by a study where lung cancer was detected using a breathalyzer type test. But, since this was a small study these results will have to be confirmed using a larger sample.

mice are not good models for human inflammation

lab mouse

Lab mice might not be good models for humans in pharmacological studies

Mice are often used in biology to study pharmacological phenomena before studying a drug’s effects in humans. A paper recently published in PNAS suggests that mice might not be good models for human systems – at least when it comes to inflammation pathways.

In the paper, The Inflammation and Host Response to Injury, Large Scale Collaborative Research Program analyzed data sets from several studies. In these studies, researchers looked at gene expression after events that lead to inflammation like blunt trauma or burns. They compared the genes expressed in humans after such events to the gene expression of their analogues in mice. They found that there was very little correlation in the genes that a mouse expressed during inflammation and when compared to a human.

Also, when they compared the expression rates, they saw that both mice and humans saw the change in expression responded within the first 6 hours. But the time it took for expression to returned to normal lasted up to a year in humans, but only up to a week in mice.

The authors point out that many of the clinical trials based on mice studies fail. And none of the 150 treatments in clinical trials for inflammatory ailments has been successful.

For more information check out the original research by Junhee Seok et al. at PNAS.

does thinking wear you out?

The Thinker

Maybe. Maybe not.

From Popular Science:

That said, studies show that people do slow down after performing taxing mental tasks. One experiment, conducted by Samuele Marcora of the University of Kent, split subjects into two groups. Members of the first played a mentally challenging computer game. Those in the second group watched a documentary about trains or sports cars. Then everyone took an endurance test on an exercise bike. Marcora found that people who were “mentally exhausted” gave up pedaling more quickly than the documentary-watching controls. It was as if the heavy thinking had worn them out.

At the same time, Marcora found no correlation between the mental task and measures of their cardiovascular response, such as blood pressure, oxygen consumption, or cardiac output. In other words, the mental workout didn’t seem to slow their bodies so much as it appeared to skew their perception of how hard a given physical task might be.

//aucheech.net/4/4535925