News From The American Chemical Society

Main Category: Biology / Biochemistry
Also Included In: Infectious Diseases / Bacteria / Viruses;  Nutrition / Diet;  Diabetes
Article Date: 11 Dec 2007 - 4:00 PDT

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"Golden bullet" shows promise for killing common parasite

Researchers in Australia report development of a new type of gold nanoparticle that destroys the parasite responsible for toxoplasmosis, a potentially serious disease acquired by handling the feces of infected cats or eating undercooked meat. Their so-called "golden bullet" could provide a safer, more effective alternative for treating the disease than conventional drug therapy, they say. The study is scheduled for the Dec. issue of ACS' Nano Letters, a monthly journal.

Toxoplasma gondii, the parasite that causes the disease, infects more than 60 million people in the United States alone. Although most infected people have no symptoms, it can cause serious health problems in pregnant women and individuals such as AIDS patients or organ transplant recipients who have weakened immune systems.

In the new study, Michael Cortie and colleagues attached antibodies to the parasite onto gold nanorods that are activated by laser-light. A group of Toxoplasma-infected animal cells were isolated in cell culture dishes and subsequently exposed to these "golden bullets." The cells were then exposed to laser-light, which heated up the "bullets" and destroyed the parasites. The treatment killed about 83 percent of the parasites containing the gold particles, the researchers say. They hope to develop a similar technique for killing the parasite in patients.

"A Golden Bullet" Selective Targeting of Toxoplasma gondii Tachyzoites Using Antibody-Functionalized Gold Nanorods"

CONTACT:
Michael B. Cortie, Ph.D.
University of Technology Sydney
Sydney, Australia

Toward a Rosetta Stone for Microbes' Secret Language

Scientists are on the verge of decoding the special chemical language that bacteria use to "talk" to each other, British researchers report in a commentary article that appeared in the November issue of ACS Chemical Biology, a monthly journal. That achievement could lead to new treatments for antibiotic-resistant bacteria, including so-called superbugs that infect more than 90,000 people in the United States each year, they note.

David Spring, Martin Welch, and James T. Hodgkinson explain that researchers long have known that bacteria communicate with each other. Microbes release small molecules that enable millions of individuals in a population to coordinate their behavior. Disease-causing bacteria use this language to decide when to infect a person or other host. Decoding the structure and function of compounds involved in this elaborate signaling process, known as "quorum sensing," could lead to new medicines to block the signals and prevent infections.

The report describes development of a group of powerful compounds, called N-acylated homoserine lactone (AHL) analogues that are effective against a broad-range of bacterial types, including those that cause diseases in humans. These compounds are "some of the most potent synthetic modulators of quorum sensing" identified to date, they say. In addition to showing promise for fighting antibiotic-resistant infections, the compounds may help prevent the growth of biofilms that foul medical implants and cause tooth decay and gum disease, the scientists note.

"Learning the Language of Bacteria"

CONTACT: David R. Spring, Ph.D.
Department of Chemistry
University of Cambridge
Cambridge, United Kingdom

"Science Diet": New research promises personalized dietary guidelines

Better diets for fighting diabetes, obesity and heart disease may soon be only a finger-prick away. By analyzing the unique metabolic changes in an individual's body, researchers hope to develop more personalized dietary guidelines for improving health, according to an article scheduled for the Dec. 10 issue of Chemical & Engineering News, ACS' weekly newsmagazine.

In the article, C&EN Assistant Editor Carmen Drahl explains that not all people respond to diet in the same way: What makes some people healthy may in fact make others worse. Metabolomics, an emerging field whose practitioners study how foods affect metabolism, may provide new tools and data for customizing today's one-size-fits-all dietary guidelines for an individual's own body, the article notes. For example, a routine blood test that measures hundreds of compounds or more could detect shifts in a person's metabolic balance to predict future health problems. Physicians then could develop a customized diet designed to work with that patient's metabolism, while follow-up blood tests could allow caregivers to track improvements in a person's health status, the article notes.

But the field is not quite ready for prime time. Academic and industry researchers alike are hard-at-work deciphering the complex science of how foods affect metabolism with the goal of building up a framework in which sound guidance for specifying personalized diet would become possible.

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Article adapted by Medical News Today from original press release.
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The American Chemical Society - the world's largest scientific society - is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

Source: Michael Woods
American Chemical Society