News From The American Chemical Society, July 2, 2008

Main Category: Diabetes
Also Included In: Genetics;  Alzheimer's / Dementia;  Biology / Biochemistry
Article Date: 08 Jul 2008 - 2:00 PDT

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Boosting survival of insulin-cell transplants for Type 1 Diabetes

Researchers in Japan are reporting a discovery that could improve the effectiveness and expand the use of transplants of insulin-producing cells to treat diabetes. Their study is scheduled for the July 16 issue of ACS' Bioconjugate Chemistry, a monthly journal. Insulin-dependent, or Type 1, diabetes affects about 800,000 people in the United States.

In the new study, Yuji Teramura and Hiroo Iwata point out that transplantation of the pancreas's insulin producing cells, so-called islets of Langerhans, is a promising experimental technique for treating patients with insulin-dependent diabetes. However, the procedure is not sufficiently effective for many people. This is because the body destroys many of the islet cells right after transplantation in an inflammatory reaction triggered by blood clotting on the surface of the cells, the researchers say.

To address this problem, the scientists coated islet cells with a special polymer film containing heparin, an anticoagulant, or urokinase, a medication that dissolves blood clots. In laboratory studies, the researchers showed that the coatings delayed the clotting long enough to prevent the destruction that otherwise would occur immediately after transplantation. The coatings did not affect the ability of the cells to produce insulin, the researchers add. - MTS

ARTICLE: "Islets Surface Modification Prevents Blood-Mediated Inflammatory Responses" http://dx.doi.org/10.1021/bc800064t

CONTACT:
Hiroo Iwata, Ph.D.
Kyoto University
Kyoto, Japan

First DNA molecule made almost entirely of artificial parts

Chemists in Japan report development of the world's first DNA molecule made almost entirely of artificial parts. The finding could lead to improvements in gene therapy, futuristic nano-sized computers, and other high-tech advances, they say. Their study is scheduled for the July 23 issue of the Journal of the American Chemical Society, a weekly publication.

In the new study, Masahiko Inouye and colleagues point out that scientists have tried for years to develop artificial versions of DNA in order to extend its amazing information storage capabilities. As the genetic blueprint of all life forms, DNA uses the same set of four basic building blocks, known as bases, to code for a variety of proteins used in cell functioning and development. Until now, scientists have only been able to craft DNA molecules with one or a few artificial parts, including certain bases.

The researchers used high-tech DNA synthesis equipment to stitch together four entirely new, artificial bases inside the sugar-based framework of a DNA molecule. This resulted in unusually stable, double-stranded structures resembling natural DNA. Like natural DNA, the new structures were right-handed and some easily formed triple-stranded structures. The unique chemistry of these structures and their high stability offer unprecedented possibilities for developing new biotech materials and applications, the researchers say. - MTS

ARTICLE: "Artificial DNA Made Exclusively of Nonnatural C-Nucleosides with Four Types of Nonnatural Bases" http://dx.doi.org/10.1021/ja801058h

CONTACT:
Masahiko Inouye, Ph.D.
University of Toyama
Toyama, Japan

Uncertainties prevail over human health benefits of polyphenols

Despite scores of studies documenting the effects of healthful plant nutrients called polyphenols in protecting nerves from damage, it would be "unwise" to assume that the same protective effects occur for Alzheimer's disease (AD) and other human disorders, a new report concludes. It is scheduled for the July 9 issue of ACS' bi-weekly Journal of Agricultural and Food Chemistry.

In the report, Charles Ramassamy and colleagues in Canada analyzed the results of more than 200 laboratory and animal studies on these materials, found in fruits, vegetables, wine, chocolate, coffee, tea, and other foods. They found abundant evidence that polyphenols do, indeed, protect nerves from the kind of damage that occurs in AD and other chronic brain disorders.

The researchers concluded, however, that "it is not at all clear whether these compounds reach the brain in sufficient concentrations and in a biologically active form to exert beneficial effects." Resolving those uncertainties will take years of additional research, they say in the report, which includes a list of the 50 foods containing the highest amounts of polyphenols. - AD

ARTICLE:"Challenges for Research on Polyphenols from Foods in Alzheimer's Disease: Bioavailability, Metabolism and Cellular and Molecular Mechanisms" http://dx.doi.org/10.1021/jf0735073

CONTACT:
Charles Ramassamy, Ph.D.
Laval University
Quebec, Canada

Super strong antimicrobial coatings for medicine, defense

One of the world' strongest materials meets one of Nature's most powerful germ killers in a new research project that produced incredibly tough anti-bacterial surfaces with multiple applications in home appliances, medicine, aerospace, and national defense. A report on this long-awaited genre of stronger disinfectant surfaces is scheduled for the July 9 issue of ACS' Nano Letters, a monthly journal.

In the study, Virginia A. Davis and Aleksandr Simonian and colleagues point out that concern over the role of contaminated surfaces in the spread of infections has sparked a search for better antimicrobial coatings. Scientists want to harness a powerful natural enzyme called lysozyme in that quest. However, they have not found a material strong enough to hold the enzyme in the desired fashion for long periods.

Their solution involved the first successful merging of lysozyme with single-walled carbon nanotubes (SWNTs). Only 1/50th the width of a human hair, SWNTs have exceptional strength and hold lysozyme in place, while other coatings lose their antimicrobial activity over time. "The results of this research demonstrate the significant possibilities for the molecular design of hybrid structural materials from SWNTs and natural biopolymers," the report states. "Such robust, antimicrobial materials have significant promise in applications including medicine, aerospace engineering, public transportation, home appliances and sporting goods." - AD

ARTICLE: "Strong Antimicrobial Coatings: Single-Walled Carbon Nanotubes Armored with Biopolymers" http://dx.doi.org/10.1021/nl080522t

CONTACT:
Virginia A. Davis, Ph.D.
Auburn University
Auburn, Alabama 36849

Consumers call for more government oversight of commercial genetic tests

With its promises of improved diagnostic and treatment outcomes for arthritis, breast cancer, and other conditions, genetic testing is on a trajectory to becoming a mainstay of the healthcare system. But the field is poorly regulated, prompting calls for more government oversight to help ensure patient privacy and testing accuracy, according to an article scheduled for the July 7 issue of Chemical & Engineering News.

In the article, C&EN Associate Editor Britt E. Erickson points out that genetic tests are now available for some 1,200 different clinical conditions and more tests are in the development pipeline. With more and more genetic information published on the Internet and the growth of direct-to-consumer genetic testing, there's an urgent need for more government action to help maintain patient privacy while ensuring that test claims are accurate and clinically useful, the article notes.

Changes are already in the works. The Food and Drug Administration (FDA) indicates that it plans to expand oversight of genetic testing in the future. "As the FDA moves to regulate some aspects of this testing area, congressional action will likely be needed to help manage the growth of this emerging health care issue," the article states. At least two states, New York and California, already require genetic-testing companies to prove the validity of their tests.

ARTICLE: "Barriers to Genetic-Based Medicine" http://pubs.acs.org/cen/government/86/8627gov1.html

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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