Researchers have developed a new gene therapy approach that prevents the AIDS virus from entering human cells. The technique offers a potential way to treat HIV patients and could apply to any disease caused by a gene malfunction, including cancer. The research team created a new application for a genetic technology called small interfering RNA (siRNA). The synthetically designed siRNAs act as a catalyst to reduce the expression of specific genes and slow the progression of disease.
The process that makes fireflies glow bright in the summer night can also shed light on how well new medicines work, showing immediately whether the drugs are effective at killing cells or causing other effects. That’s the conclusion of a team of scientists who report that they have inserted the gene for a firefly’s glow-producing molecule into mice with cancer, and kept it from producing its telltale beacon of light until the cells started to die in response to cancer treatment.
Researchers drilling into Lake Vida, an Antarctic “ice-block” lake, have found the lake isn’t really an ice block at all. In the December 16 issue of the Proceedings of the National Academy of Sciences, the team reveals that Antarctic Lake Vida may represent a previously unknown ecosystem, a frigid, “ice-sealed,” lake that contains the thickest non-glacial lake ice cover on Earth and water seven times saltier than seawater. Because of the arid, chilled environment in which it resides, scientists believe the lake may be an important template for the search for evidence of ancient microbial life on Mars and other icy worlds.
Researchers report that satellite imagery could be used to determine areas at high-risk for exposure to Sin Nombre virus (SNV), a rodent-born disease that causes the often fatal hantaviral pulmonary syndrome (HPS) in humans. According to the researchers, satellite imaging detects the distinct environmental conditions that may serve as a refuge for the disease-carrying deer mice. Higher populations of infected deer mice increase the risk of HPS to humans.
A Canadian researcher has found new evidence that — contrary to previous belief — the past 6,000 years have been marked by large-scale climate changes occurring naturally, on a regular basis. He and his research team have documented four abrupt climate shifts over the past 5,500 years in western Canada, occurring on average every 1,220 years. Until now the last 6,000 years has been considered climatically stable, with the main evidence of large-scale shifts being found in the Greenland ice cores and sediments from the Atlantic Ocean. The team’s findings are reported in the current issue of the Proceedings of the National Academy of Sciences.
Bilirubin has been a mystery of a molecule, associated with better health if there’s just a little more than normal, but best known for being at the root of the yellow color in jaundice and, at high levels, for causing brain damage in newborns. In the current online edition of the Proceedings of the National Academy of Sciences, a research team from Johns Hopkins reports that bilirubin and the enzyme that makes it appear to be the body’s most potent protection against oxidative damage.
A baby’s first look at the world is likely a dizzying array of shapes and motion that are meaningless to a newborn, but researchers at the University of Rochester say they have now shown that babies use relationships between objects to build an understanding of the world. By noting how often objects appear together, infants can efficiently take in more knowledge than if they were to simply see the same shapes individually, says the paper published in the current issue of Proceedings of the National Academy of Sciences.
Entomologists have discovered that as adult gall wasps feed in warm weather, they change the ratio of plant chemicals so that males emerging after the winter season can recognize when they are on the right stems at the right time. The finding is the first to suggest that insects can alter the chemical composition of plants for the purpose of mate location.
Scientists have coupled the protein that makes fireflies glow with a device similar to a home video camera to eavesdrop on cellular conversations in living mice. The team’s research will allow scientists to study how cellular proteins talk to one another. These communications trigger changes that regulate a healthy body and cause disease when the signals go awry. The findings may speed development of new drugs for cancer, cardiovascular diseases and neurological diseases.
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.”
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.