Public HealthNews From The American Chemical Society, May 27, 2009
Bird flu virus remains infectious up to 600 days in municipal landfills
Amid concerns about a pandemic of swine flu, researchers from Nebraska report for the first time that poultry carcasses infected with another threat - the "bird flu" virus - can remain infectious in municipal landfills for almost 2 years. Their report is scheduled for the June 15 issue of ACS" semi-monthly journal Environmental Science & Technology.
Shannon L. Bartelt-Hunt and colleagues note that avian influenza, specifically the H5N1 strain, is an ongoing public health concern. Hundreds of millions of chickens and ducks infected with the virus have died or been culled from flocks worldwide in efforts to control the disease. More than 4 million poultry died or were culled in a 2002 outbreak in Virginia, and the carcasses were disposed of in municipal landfills. Until now, few studies have directly assessed the safety of landfill disposal.
"The objectives of this study were to assess the survival of avian influenza in landfill leachate and the influence of environmental factors," says the report. The data showed that the virus survived in landfill leachate - liquid that drains or "leaches" from a landfill - for at least 30 days and up to 600 days. The two factors that most reduced influenza survival times were elevated temperature and acidic or alkaline pH. "Data obtained from this study indicate that landfilling is an appropriate method for disposal of carcasses infected with avian influenza," says the study, noting that landfills are designed to hold material for much longer periods of time.
ARTICLE: "Survival of the Avian Influenza Virus (H6N2) After Land Disposal" http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/es900370x
CONTACT:
Shannon L. Bartelt-Hunt, Ph.D.
University of Nebraska-Lincoln
Omaha, Neb.
Silver nanoparticles show "immense potential" in prevention of blood clots
Scientists are reporting discovery of a potential new alternative to aspirin, ReoPro, and other anti-platelet agents used widely to prevent blood clots in coronary artery disease, heart attack and stroke. Their study, scheduled for the June 23 issue of ACS Nano, a monthly journal, involves particles of silver - 1/50,000th the diameter of a human hair - that are injected into the bloodstream.
Debabrata Dash and colleagues point out that patients urgently need new anti-thrombotic agents because traditionally prescribed medications too-often cause dangerous bleeding. At the same time, aging of the population, sedentary lifestyle and spiraling rates of certain diseases have increased the use of these drugs. Researchers are seeking treatments that more gently orchestrate activity of platelets, disk-shaped particles in the blood that form clots.
The scientists describe development and lab testing of silver nanoparticles that seem to keep platelets in an inactive state. Low levels of the nanosilver, injected into mice, reduced the ability of platelets to clump together by as much as 40 percent with no apparent harmful side effects. The nanoparticles "hold immense potential to be promoted as an antiplatelet agent," the researchers note. "Nanosilver appears to possess dual significant properties critically helpful to the health of mankind - antibacterial and antiplatelet - which together can have unique utilities, for example in coronary stents."
ARTICLE: "Characterization of Antiplatelet Properties of Silver Nanoparticles" http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/nn900277t
CONTACT:
Debabrata Dash, M.D., Ph.D., D.Sc.
Professor and Head
Department of Biochemistry
Institute of Medical Sciences
Banaras Hindu University
Varanasi, India
"Gene silencing" may improve treatment of a deadly complication of liver disease
A technique that "silences," or turns off, genes shows promise as a potential new treatment for liver fibrosis - the disease that leads to cirrhosis - scientists in Tennessee are reporting. Their study is scheduled for the June 1 issue of ACS" Molecular Pharmaceutics, a bi-monthly journal. Cirrhosis is the 12th leading cause of death in the United States.
Ram Mahato and colleagues note that fibrosis involves build-up of scar tissue in the liver from chronic liver damage caused by hepatitis, alcohol abuse, toxins, or other factors. Advanced fibrosis can lead to cirrhosis, a condition in which the liver becomes so severely damaged that patients may require a transplant. There is no effective treatment, and patients urgently need new medications. Scientists believe one may emerge from the fascinating discovery that a protein called TGF-beta 1 triggers liver inflammation and that blocking the protein may help.
The researchers designed 10 chemically synthesized substances, termed siRNAs, with the ability to block or "silence" the TGF-beta 1 gene in the liver. When put into rat liver cells, the "gene silencers" decreased levels of type 1 collagen whose excessive production leads to fibrosis, as well as two other substances known to trigger liver inflammation, by almost 50 percent. The results suggest that gene silencing may be "an efficient and more specific approach for therapy of liver fibrosis," the report states.
ARTICLE: "TGF-#1 Gene Silencing for Treating Liver Fibrosis" http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/mp9000469
CONTACT:
Ram I. Mahato, Ph.D.
University of Tennessee Health Sciences Center
Department of Pharmaceutical Sciences
Cancer Research Building
Memphis, Tenn. 38103
New "microcapsules" put more medication into the bloodstream to treat disease
Scientists are reporting a potential solution to a problem that limits the human body"s ability to absorb and use medications for heart disease, Type-2 diabetes, cancer and other conditions. It is a "nano-hybrid microcapsule" that enables the stomach to absorb more of these so-called "poorly-soluble" medicines. Their study is scheduled for the June 1 issue of ACS" Molecular Pharmaceutics, a bi-monthly journal.
Finding ways to improve the stomach"s uptake of poorly soluble medicines has been one of the major challenges facing pharmaceutical companies. Estimates suggest, for instance, that 40 percent of potential new drugs fall into this category. In the new study, Clive Prestidge and colleagues note that one solution has been to include detergent-like substances in pills and capsules. However, that approach involves safety concerns, since the detergent can irritate the stomach lining, making it unsuitable for drugs that must be taken month after month.
The scientists describe development of a first-of-its-kind microcapsule made from lipid oils and nanoparticles 1/50,000th the width of a human hair. Although acting like conventional detergents, they seem unlikely to irritate the stomach. In test tube experiments, microcapsule versions of the arthritis drug, indomethacin, dissolved up to five times faster than a regular version of the drug. Lab rats given the new microcapsule version absorbed almost twice as much of the drug.
ARTICLE: "Dry Hybrid Lipid-Silica Microcapsules Engineered from Submicron Lipid Droplets and Nanoparticles as a Novel Delivery System for Poorly Soluble Drugs" http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/mp900063t
CONTACT:
Clive Prestidge, Ph.D.
Sector Coordinator for Bio and Polymer Interfaces
Ian Wark Research Institute
University of South Australia
Mawson Lakes, South Australia
Reducing salt in food without losing that salty taste
Food manufacturers are searching for new ways to reduce the amount of salt added to products ranging from potato chips to salad dressings while preserving the salty taste that consumers crave, according to an article scheduled for the June 1 issue of Chemical & Engineering News, ACS" weekly newsmagazine.
C&EN assistant editor Carmen Drahl notes in the article that researchers have been working toward that goal for years, as consumers concerned about high blood pressure sought to limit salt intake on the advice of public health officials. But finding a replacement for salt, or sodium chloride, is no simple task. One of the problems researchers face is lack of a detailed understanding of the basic biology of salty taste. But new pieces of the puzzle are emerging, including the discovery last year of what some scientists claim is the primary receptor responsible for human salt taste perception.
Despite this challenge, companies are forging ahead with salt reduction research. One of the most widely used salt replacers, potassium chloride, resembles salt in terms of cooking performance but has a bitter taste that some consumers find unpleasant. Several companies are developing additives to mask this bitterness. Other approaches include developing smaller salt particles so that the tongue perceives their taste more quickly. Other researchers are exploring oil-based salt emulsions that provide an enhanced perception of saltiness while using less salt. No one strategy seems to work for every food and beverage, the article notes, but help is on the way.
ARTICLE: "Seeking Saltiness" http://pubs.acs.org/cen/science/87/8722sci1.html
Michael Woods
American Chemical Society