49 research outputs found

    A new electrophoresis technique to separate microsatellite alleles*

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    Analysis of large numbers of SSR (simple sequence repeats: microsatellites) reactions can be tedious, time-consuming and expensive. The objective of this study was to report a new electrophoresis method to analyze and visualize SSR data quickly and accurately and compare it to the ability of four other electrophoresis methods. Individual PCR reactions consisting of DNA from several Cornus florida L. (flowering dogwood) cultivars and two SSR primer pairs were assembled for analysis using the following three methods: agarose gel, polyacrylamide gel and QIAxcel System. Two separate PCRreactions consisting of the same components plus a fluorescent-labeled primer were set up for analyses using the CEQTM 8000 Genetic Analysis System and ABI 3130xl DNA Sequencer. These fiveelectrophoretic methods were assessed for advantages and disadvantages. Polyacrylamide gels had highest resolution of alleles, whereas agarose gels had the lowest. However, with both separationmedia, it was difficult to score the size of alleles. Capillary electrophoresis with the CEQTM 8000 Genetic Analysis System and ABI 3130xl DNA Sequencer easily separated products and determined allelic size, but was more expensive than electrophoresis using either agarose or polyacrlamide gels. The QIAxcel System had lower  esolution than CEQTM 8000 Genetic Analysis System and ABI 3130xl DNA Sequencer. However, QIAxcel System was rapid and cost effective compared to the two widely used capillary sequencers, and also provided a computer generated gel image. For researchers in small to intermediate-sized laboratories, the QIAxcel System using a twelve channel, sieving-gel cartridge is an affordable device for SSR assays used for mapping and population diversity analysis

    Analysis of vaginal microbicide film hydration kinetics by quantitative imaging refractometry

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    We have developed a quantitative imaging refractometry technique, based on holographic phase microscopy, as a tool for investigating microscopic structural changes in water-soluble polymeric materials. Here we apply the approach to analyze the structural degradation of vaginal topical microbicide films due to water uptake. We implemented transmission imaging of 1-mm diameter film samples loaded into a flow chamber with a 1.5×2 mm field of view. After water was flooded into the chamber, interference images were captured and analyzed to obtain high resolution maps of the local refractive index and subsequently the volume fraction and mass density of film material at each spatial location. Here, we compare the hydration dynamics of a panel of films with varying thicknesses and polymer compositions, demonstrating that quantitative imaging refractometry can be an effective tool for evaluating and characterizing the performance of candidate microbicide film designs for anti-HIV drug delivery. © 2014 Rinehart et al

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

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    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
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