proceedings of the national academy of sciences

Gut Bacteria Interact with Intestine to Regulate Blood Supply

Bacteria aren’t always bad. In fact, they can be extremely helpful partners. According to research at Washington University School of Medicine in St. Louis, microbes found naturally in the mouse and human gut interact with intestinal cells, called Paneth cells, to promote the development of blood vessels in the intestinal lining. “This study provides insights into the mutually beneficial partnerships forged between mammals and their native microbes,” says the principal investigator. “These symbiotic relationships probably are most important in the gut, which contains the largest and most complex collection of bacteria.”

Bacterial protein kills tumors

The use of live bacteria to treat cancer goes back a hundred years. But while the therapy can sometimes shrink tumors, the treatment usually leads to toxicity, limiting its value in medicine. Now, researchers at the University of Illinois at Chicago have isolated a protein secreted by bacteria that kills cancer cells but appears to have no harmful side effects. Tested in mice injected with human melanomas, the protein shrank the malignancies, but, in contrast with other studies using whole bacteria, caused no deaths or adverse reactions in the laboratory animals.

Scientists decipher tooth decay bug’s genome

Researchers in Oklahoma have deciphered the complete genome sequence of Streptococcus mutans, the main organism implicated in causing tooth decay. The work, supported by the National Institute of Dental and Craniofacial Research, has been made freely available online. Said one of the team members involved in the four-year effort: “Building on this basic research may one day lead us to new approaches for preventing and treating tooth decay.” Added another: “By targeting the adherence genes, for example, we might be able to develop a way of preventing S. mutans from sticking to teeth.”

Cutting calories slows aging of the heart

Keep eating like that and I'll outlive you for sure.To remain young at heart, eat less. That’s the message drawn from new research out of the University of Wisconsin-Madison, where a team of scientists studied middle-aged mice that were put on a calorie-restricted diet. What they found were signs of a remarkable uptick in heart health in old age. “It looks like caloric restriction just retarded the whole aging process in the heart,” said one of the researchers. The new study provides evidence that — even starting in middle age — cutting calories can confer significant health benefits for the heart and extend its working life. It does so, according to the team’s results, by exerting influence on the genetic program that governs heart cells.

Screening technique may speed hunt for genes

The hunt to find a gene that causes a disease typically costs hundreds of thousands of dollars and requires years of research – and it still may fail to turn up the sought-after culprit, driving the research back to square one. The result is that while the genes involved in a few inherited diseases such as cystic fibrosis have been identified, many have not. Now, two scientists say they may have found a way to make the search more economical and speed it up. In an article to appear online in the Proceedings of the National Academy of Sciences next week, scientists from the University of Florida and Purdue University report merging two established genetic-screening techniques to create one that’s better. The new technique narrows the pool of “candidate” genes in a study from thousands of possibilities to fewer than 100 – perhaps as few as 20.

Time to adjust the compass?

Working high in the Canadian Arctic, researchers from the University of Rochester say they’ve found that several aspects of the powerhouse that drives the Earth’s magnetic field may be related. That’s new in itself. But the team also thinks it may indicate our planet’s about ready for a pole reversal, in which all compasses will begin pointing south.

Bioengineers Develop Method To Grow 3-D Bone Matrix

FROM THE TRENCHES: A new study by Rice University suggests bioengineers may be able to create the mechanical stimulation needed to grow bone outside the body. The trick appears to be stressing the sample out — literally. In the absence of mechanical stress, lab grown bone is brittle and thin. But when created under proper conditions, it emerges thick and well-developed.

Deer Before Dying

According to a study published in The Proceedings of the National Academy of Sciences, venison was the last supper for Iceman, the not-so-cleverly-named Neolithic hunter who was discovered frozen and remarkably well-preserved last decade in the Italian Alps. Researchers from the University of Camerino (Italy) analyzed DNA culled from the contents of Iceman?s 5,300-year-old intestines ? yum, anybody else hungry? ? and determined that the gourmand consumed red deer meat and possibly grains prior to succumbing to an arrow wound. Iceman?s penultimate meal, researchers speculate, was an ibex plus sides of grains and greens.