Findings Home | In This Issue | Order Free Copies | Subscribe | Back Issues | Free Publications | NIGMS Home |
October 2004 |
||||||||
|
|
|||||||
Spice Therapy? In cystic fibrosis, thick mucus clogs the lungs and other organs. In most people with the condition, the root cause of the excess mucus is the loss of function of a protein that forms a channel to control the flow of chloride into and out of cells. In diseased cells, policing mechanisms automatically quarantine the channel protein, which hasn't folded properly, to a waste bin where it is later destroyed. With the channel confined, chloride (a component of common table salt) is trapped inside the cells, leading to a thickening of mucus that traps bacteria and causes life-threatening infections. Based on what Caplan knew about curcumin's chemical properties, he suspected that the spice might be working by interrupting the protein quarantining process. This would let the channel protein—still reasonably effective in ejecting chloride—do its job. Caplan confirmed the hunch with experiments showing that curcumin restored normal chloride flow out of cells. While the findings are encouraging, people should not self-medicate with curcumin, Caplan advises. Scientists do not yet know, for example, if the substance, sold as a dietary supplement, might interact with prescription drugs. —A.D.
Hot Flash News Flash New evidence hints that taking both drugs together may not be such a good idea. NIGMS grantee David A. Flockhart of the Indiana University School of Medicine in Indianapolis knew that the body breaks down Nolvadex and Paxil with the same enzyme. He wondered whether taking both drugs together might affect blood levels of either or both of them. To test this, Flockhart and oncologist Vered Stearns of the Johns Hopkins University School of Medicine in Baltimore, Maryland, performed a study with 12 breast cancer survivors who had been taking Nolvadex for at least 1 month and were having severe hot flashes. The researchers gave Paxil to the study volunteers for 4 weeks and then took blood samples. Women who took both drugs at the same time had substantially lower levels of a key byproduct of Nolvadex, chemical evidence that Paxil does affect how the body processes Nolvadex. But the effects differed among the women depending on their innate capacity to process drugs, which helps explain why Nolvadex's effectiveness can vary among people. Flockhart cautions that until further data become available, the results of his study should not alter treatment recommendations because the health implications are still uncertain at this point. —A.D. |
|
|||||||
From Hepatitis to Anthrax NIGMS grantee Wei-Jen Tang of the University of Chicago has studied an anthrax toxin called edema factor for several years. He previously determined its atom-by-atom structure and showed how the toxin hijacks normal cell function. In a recent stroke of luck, another researcher who was studying a hepatitis B drug called Hepsera® read about Tang's work and wondered whether the drug, which mimics a natural biological target of the anthrax toxin, might also work against edema factor. Tang confirmed the hunch, discovering that Hepsera grips tightly to edema toxin and prevents it from damaging lab-grown mouse cells. If anything, Hepsera appears more potent against the anthrax toxin than in its approved use against a hepatitis B viral protein. Since the medicine is already known to be safe in humans, researchers could potentially test its ability to treat anthrax relatively quickly. Although the drug only blocks the action of one of the three major anthrax toxins, the poisons apparently magnify the effects of each other, so blocking one of them would be of great benefit. —Karin Jegalian
Blocking Bacteria NIGMS grantee John Alverdy of the University of Chicago wondered if a peace-making approach toward the germs might work. In experiments with mice, he tested whether a waxy material called polyethylene glycol, or PEG, might protect the intestines from bacterial invasion. Alverdy suspected that PEG molecules might serve as a kind of artificial mucous barrier that the bacteria would find appealing, keeping them safely in place. He found that all of the mice that had undergone liver surgery and then received PEG could resist P. aeruginosa infection. Alverdy backed up the findings in experiments with isolated human intestinal cells, showing that PEG prevented P. aeruginosa from latching onto cells. If studies in humans have similar results, patients undergoing major surgery may someday be given PEG routinely to coat their intestines and prevent P. aeruginosa infection. This approach might also be more ecologically friendly than the prolonged use of multiple antibiotics, which encourages the growth of menacing, drug-resistant bacteria. —K.J. |
Image: Centers for Disease Control and Prevention | |||||||
Reconstructing a Deadly Flu In a team effort with scientists across the country, NIGMS grantee Ian Wilson of the Scripps Research Institute in La Jolla, California, figured out the three-dimensional molecular shape of the HA protein from the now-extinct 1918 flu virus. One of Wilson's collaborators, Jeffery Taubenberger of the Armed Forces Institute of Pathology in Washington, DC, collected genetic material from preserved tissue specimens and from the remains of people who died of the flu in Alaska and were buried in the permafrost. He then pieced together the sequence of the gene for the HA protein and made enough of it in the lab to determine its structure. Knowing the exact shape of the 1918 HA protein, the researchers were able to compare it to HA proteins from humans, birds, and pigs. They found that the 1918 variety most resembles HA from birds, which suggests that the 1918 flu pandemic possibly arose from a bird virus that was unusually good at infecting people. Viruses passed from birds and other species to humans are rare and potentially very dangerous, since human immune systems are unaccustomed to them and have a tough time fighting them off. —Audrey Huang
These stories describe NIGMS-funded medical research projects. Although only the lead researchers are named, science is a team sport and it is important to realize that many researchers work together to carry out these studies. |
| |||||||
Findings Home | In This Issue | Back Issues | Free Publications | NIGMS Home |
||||