167 research outputs found

    Recombination analysis and structure prediction show correlation between breakpoint clusters and RNA hairpins in the pol gene of human immunodeficiency virus type 1 unique recombinant forms

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    Recombination is recognized as a primary force in human immunodeficiency virus type 1 (HIV-1) evolution, increasing viral diversity through reshuffling of genomic portions. The strand-switching activity of reverse transcriptase is required to complete HIV-1 replication and can occur randomly throughout the genome, leading to viral recombination. Some recombination hotspots have been identified and found to correlate with RNA structure or sequence features. The aim of this study was to evaluate the presence of recombination hotspots in the pol gene of HIV-1 and to assess their correlation with the underlying RNA structure. Analysis of the recombination pattern and breakpoint distribution in a group of unique recombinant forms (URFs) detected two recombination hotspots in the pol region. Two stable and conserved hairpins were consistently predicted corresponding to the identified hotspots using six different RNA-folding algorithms on the URF parental strains. These findings suggest that such hairpins may play a role in the higher recombination rates detected at these positions

    Bis[4-amino- N

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    Lancet commission on hypertension group position statement on the global improvement of accuracy standards for devices that measure blood pressure

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    The Lancet Commission on Hypertension identified that a key action to address the worldwide burden of high blood pressure (BP) was to improve the quality of BP measurements by using BP devices that have been validated for accuracy. Currently, there are over 3000 commercially available BP devices, but many do not have published data on accuracy testing according to established scientific standards. This problem is enabled through weak or absent regulations that allow clearance of devices for commercial use without formal validation. In addition, new BP technologies have emerged (e.g. cuffless sensors) for which there is no scientific consensus regarding BP measurement accuracy standards. Altogether, these issues contribute to the widespread availability of clinic and home BP devices with limited or uncertain accuracy, leading to inappropriate hypertension diagnosis, management and drug treatment on a global scale. The most significant problems relating to the accuracy of BP devices can be resolved by the regulatory requirement for mandatory independent validation of BP devices according to the universally-accepted International Organisation for Standardization Standard. This is a primary recommendation for which there is an urgent international need. Other key recommendations are development of validation standards specifically for new BP technologies and online lists of accurate devices that are accessible to consumers and health professionals. Recommendations are aligned with WHO policies on medical devices and universal healthcare. Adherence to recommendations would increase the global availability of accurate BP devices and result in better diagnosis and treatment of hypertension, thus decreasing the worldwide burden from high BP

    Pyrethroid application timing to control European corn borer (Lepidoptera: Crambidae) and minimize fumonisin contamination in maize kernels

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    Ostrinia nubilalis (Hübner) (European corn borer) is the main maize pest in Central and South Europe and it promotes Fusarium verticillioides infection on maize grains, which is able to produce fumonisins. The objective of this study was to determine the effect of the timing of pyrethroid treatments on European corn borer damage, fungal ear rot and fumonisin contamination. The field experiments were performed from 2005 to 2007 in NW Italy. Four application timings were compared to an untreated control. The insecticide treatments were applied at approximately 10 days intervals, starting from the end of flowering. The last treatment was performed approximately 15 days after the ECB flight peak. At harvest, the ears were rated for the incidence and severity of European corn borer damage and fungal ear rot symptoms, and the harvested kernels were analyzed for fumonisins B 1 +B 2 . In all the years, the treatments applied 7–10 days before the European corn borer adult flight peak showed the best efficacy to control insect damage on ears. Fungal ear rot and fumonisin contamination were clearly affected by European corn borer control. The occurrence of this mycotoxin in plots treated at the best pyrethroid application timing was significantly reduced, on average by 76%, compared to the untreated control. Furthermore, early insecticide applications, at the end of maize flowering, showed significantly lower fumonisin contamination than treatments applied at approximately 15 days after the adult flight peak. This research indicates that the production of maize kernels with low fumonisin content may be enhanced by a correct timing of the insecticide application against second generation European corn borer

    Metal ion binding to a zinc finger peptide containing the Cys-X2-Cys-X4-His-X4-Cys domain of a nucleic acid binding protein encoded by drosophila fw-element.

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    The metal binding properties of a 18-residue zinc finger peptide containing a CCHC box which reproduces one of the cysteine-rich domains of a putative nucleic acid binding protein encoded by the Fw transposable element from Drosophila melanogaster were investigated through electronic and H-1 NMR spectroscopy. Dissociation constants of 2(+/-1)x10(-12) M and 4(+/-1)x10(-7) M were determined for the Zn2+ and Co2+ adduct, respectively. These values are similar to those for other CCHC-peptides investigated previously, although the length of the spacer between the second cysteine and the histidine apparently exerts some influence on the spectral properties and on the stability of the Co2+-peptide adduct. The 1H NMR spectrum of the present Co2+-derivative contains a number of well resolved hyperfine-shifted resonances between 350 and -50 ppm which arise from the metal binding residues and nearby groups. These peaks can in principle be profitably exploited to monitor protein-nucleic acid interactions
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