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Archive - May 1, 2013

Traditional Dispensing Processes Are Important Source of Error in High-Throughput Screening; Acoustic Approach More Predictive of Biological Activity

In experiments involving the generation of computational pharmacophores based on data derived either by acoustic transfer using direct dilution or by traditional tip-based transfer using serial dilutions, scientists have shown that the acoustic approach generates a pharmacophore that is predictive for biological activity in new compounds. It is also consistent with pharmacophores generated from X-ray crystallographic data. The tip-based approach, on the other hand, generates a pharmacophore that is both non-predictive of biological activity and inconsistent with the X-ray crystallographic data. The authors conclude that traditional tip-based dispensing processes are an important source of error in high-throughput screening that can impact computational and statistical analyses. They suggest that these findings have far-reaching applications in biological research. This study was published online in an open-access article in PLOS ONE on May 1, 2013. The authors were Sean Elkins Ph.D., VP of Science at Collaborative Drug Discovery, Inc., and Adjunct Professor in the Division of Chemical Biology and Medicinal Chemistry at the Eshelman School of Pharmacy, University of North Carolina at Chapel Hill; Joe Olechno, Ph.D., Senior Research Fellow, Labcyte Inc.; and Antony Williams, Ph.D., VP of Strategic Development at the Royal Society of Chemistry. The image is courtesy of Labcyte Inc. [PLOS ONE article]

Evidence That Fluoride Reduces Bacterial Adhesion to Teeth

In an advance toward solving a 50-year-old mystery, scientists are reporting new evidence on how the fluoride in drinking water, toothpastes, mouth rinses, and other oral-care products prevents tooth decay. Their report was published online on April 4, 2013 in the American Chemical Society journal Langumir. Dr. Karin Jacobs and colleagues at Saarland University in Germany explain that despite a half-century of scientific research, controversy still exists over exactly how fluoride compounds reduce the risk of tooth decay. Research established long ago that fluoride helps to harden the enamel coating that protects teeth from the acid produced by decay-causing bacteria. More recent studies have shown that fluoride penetrates into and hardens a much thinner layer of enamel than previously believed, lending credence to other theories about how fluoride works. The current report describes new evidence that fluoride also works by impacting the adhesive force of bacteria that stick to the teeth and produce the acid that causes cavities. The experiments — performed on artificial teeth (hydroxyapatite pellets) to enable high-precision analysis techniques — revealed that fluoride reduces the ability of decay-causing bacteria to stick, suggesting that, on teeth, it would be easier to wash away the bacteria by saliva, brushing, and other activity. [Press release] [Langmuir abstract]