453 research outputs found

    Grifonin-1: A Small HIV-1 Entry Inhibitor Derived from the Algal Lectin, Griffithsin

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    Background: Griffithsin, a 121-residue protein isolated from a red algal Griffithsia sp., binds high mannose N-linked glycans of virus surface glycoproteins with extremely high affinity, a property that allows it to prevent the entry of primary isolates and laboratory strains of T- and M-tropic HIV-1. We used the sequence of a portion of griffithsin's sequence as a design template to create smaller peptides with antiviral and carbohydrate-binding properties. Methodology/Results: The new peptides derived from a trio of homologous β-sheet repeats that comprise the motifs responsible for its biological activity. Our most active antiviral peptide, grifonin-1 (GRFN-1), had an EC50 of 190.8±11.0 nM in in vitro TZM-bl assays and an EC50 of 546.6±66.1 nM in p24gag antigen release assays. GRFN-1 showed considerable structural plasticity, assuming different conformations in solvents that differed in polarity and hydrophobicity. Higher concentrations of GRFN-1 formed oligomers, based on intermolecular β-sheet interactions. Like its parent protein, GRFN-1 bound viral glycoproteins gp41 and gp120 via the N-linked glycans on their surface. Conclusion: Its substantial antiviral activity and low toxicity in vitro suggest that GRFN-1 and/or its derivatives may have therapeutic potential as topical and/or systemic agents directed against HIV-1

    Molecular identification of adenoviruses associated with respiratory infection in Egypt from 2003 to 2010.

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    BACKGROUND: Human adenoviruses of species B, C, and E (HAdV-B, -C, -E) are frequent causative agents of acute respiratory infections worldwide. As part of a surveillance program aimed at identifying the etiology of influenza-like illness (ILI) in Egypt, we characterized 105 adenovirus isolates from clinical samples collected between 2003 and 2010. METHODS: Identification of the isolates as HAdV was accomplished by an immunofluorescence assay (IFA) and confirmed by a set of species and type specific polymerase chain reactions (PCR). RESULTS: Of the 105 isolates, 42% were identified as belonging to HAdV-B, 60% as HAdV-C, and 1% as HAdV-E. We identified a total of six co-infections by PCR, of which five were HAdV-B/HAdV-C co-infections, and one was a co-infection of two HAdV-C types: HAdV-5/HAdV-6. Molecular typing by PCR enabled the identification of eight genotypes of human adenoviruses; HAdV-3 (n = 22), HAdV-7 (n = 14), HAdV-11 (n = 8), HAdV-1 (n = 22), HAdV-2 (20), HAdV-5 (n = 15), HAdV-6 (n = 3) and HAdV-4 (n = 1). The most abundant species in the characterized collection of isolates was HAdV-C, which is concordant with existing data for worldwide epidemiology of HAdV respiratory infections. CONCLUSIONS: We identified three species, HAdV-B, -C and -E, among patients with ILI over the course of 7 years in Egypt, with at least eight diverse types circulating

    Germline polymorphisms in SIPA1 are associated with metastasis and other indicators of poor prognosis in breast cancer

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    INTRODUCTION: There is growing evidence that heritable genetic variation modulates metastatic efficiency. Our previous work using a mouse mammary tumor model has shown that metastatic efficiency is modulated by the GTPase-activating protein encoded by Sipa1 ('signal-induced proliferation-associated gene 1'). The aim of this study was to determine whether single nucleotide polymorphisms (SNPs) within the human SIPA1 gene are associated with metastasis and other disease characteristics in breast cancer. METHOD: The study population (n = 300) consisted of randomly selected non-Hispanic Caucasian breast cancer patients identified from a larger population-based series. Genomic DNA was extracted from peripheral leukocytes. Three previously described SNPs within SIPA1 (one within the promoter [-313G>A] and two exonic [545C>T and 2760G>A]) were characterized using SNP-specific PCR. RESULTS: The variant 2760G>A and the -313G>A allele were associated with lymph node involvement (P = 0.0062 and P = 0.0083, respectively), and the variant 545C>T was associated with estrogen receptor negative tumors (P = 0.0012) and with progesterone negative tumors (P = 0.0339). Associations were identified between haplotypes defined by the three SNPs and disease progression. Haplotype 3 defined by variants -313G>A and 2760G>A was associated with positive lymph node involvement (P = 0.0051), and haplotype 4 defined by variant 545C>T was associated with estrogen receptor and progesterone receptor negative status (P = 0.0053 and P = 0.0199, respectively). CONCLUSION: Our findings imply that SIPA1 germline polymorphisms are associated with aggressive disease behavior in the cohort examined. If these results hold true in other populations, then knowledge of SIPA1 SNP genotypes could potentially enhance current staging protocols

    SDS-PAGE-Based Quantitative Assay for Screening of Kidney Stone Disease

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    Kidney stone disease is a common health problem in industrialised nations. We developed a SDS-PAGE-based method to quantify Tamm Horsfall glycoprotein (THP) for screening of kidney stone disease. Urinary proteins were extracted by using ammonium sulphate precipitation at 0.27 g salt/mL urine. The resulted pellet was dissolved in TSE buffer. Ten microliters of the urinary proteins extract was loaded and separated on 10% SDS-PAGE under reducing condition. THP migrated as single band in SDS-PAGE. The assay reproducibility and repeatability were 4.8% CV and 2.6% CV, respectively. A total of 117 healthy subjects and 58 stone patients were tested using this assay, and a distinct cut-off (P < 0.05) at 5.6 μg/mL THP concentration was used to distinguish stone patients from healthy subjects. The sensitivity and specificity of the method were 92.3% and 83.3%, respectively

    Automatic colorimetric calibration of human wounds

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    Contains fulltext : 88431.pdf (publisher's version ) (Open Access)BACKGROUND: Recently, digital photography in medicine is considered an acceptable tool in many clinical domains, e.g. wound care. Although ever higher resolutions are available, reproducibility is still poor and visual comparison of images remains difficult. This is even more the case for measurements performed on such images (colour, area, etc.). This problem is often neglected and images are freely compared and exchanged without further thought. METHODS: The first experiment checked whether camera settings or lighting conditions could negatively affect the quality of colorimetric calibration. Digital images plus a calibration chart were exposed to a variety of conditions. Precision and accuracy of colours after calibration were quantitatively assessed with a probability distribution for perceptual colour differences (dE_ab). The second experiment was designed to assess the impact of the automatic calibration procedure (i.e. chart detection) on real-world measurements. 40 Different images of real wounds were acquired and a region of interest was selected in each image. 3 Rotated versions of each image were automatically calibrated and colour differences were calculated. RESULTS: 1st Experiment: Colour differences between the measurements and real spectrophotometric measurements reveal median dE_ab values respectively 6.40 for the proper patches of calibrated normal images and 17.75 for uncalibrated images demonstrating an important improvement in accuracy after calibration. The reproducibility, visualized by the probability distribution of the dE_ab errors between 2 measurements of the patches of the images has a median of 3.43 dE* for all calibrated images, 23.26 dE_ab for all uncalibrated images. If we restrict ourselves to the proper patches of normal calibrated images the median is only 2.58 dE_ab! Wilcoxon sum-rank testing (p < 0.05) between uncalibrated normal images and calibrated normal images with proper squares were equal to 0 demonstrating a highly significant improvement of reproducibility. In the second experiment, the reproducibility of the chart detection during automatic calibration is presented using a probability distribution of dE_ab errors between 2 measurements of the same ROI. CONCLUSION: The investigators proposed an automatic colour calibration algorithm that ensures reproducible colour content of digital images. Evidence was provided that images taken with commercially available digital cameras can be calibrated independently of any camera settings and illumination features

    Streptococcus pneumoniae induced c-Jun-N-terminal kinase- and AP-1 -dependent IL-8 release by lung epithelial BEAS-2B cells

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    BACKGROUND: Although pneumococcal pneumonia is one of the most common causes of death due to infectious diseases, little is known about pneumococci-lung cell interaction. Herein we tested the hypothesis that pneumococci activated pulmonary epithelial cell cytokine release by c-Jun-NH(2)-terminal kinase (JNK) METHODS: Human bronchial epithelial cells (BEAS-2B) or epithelial HEK293 cells were infected with S. pneumoniae R6x and cytokine induction was measured by RT-PCR, ELISA and Bioplex assay. JNK-phosphorylation was detected by Western blot and nuclear signaling was assessed by electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP). JNK was modulated by the small molecule inhibitor SP600125 and AP1 by transfection of a dominant negative mutant. RESULTS: S. pneumoniae induced the release of distinct CC and CXC, as well as Th1 and Th2 cytokines and growth factors by human lung epithelial cell line BEAS-2B. Furthermore, pneumococci infection resulted in JNK phosphorylation in BEAS-2B cells. Inhibition of JNK by small molecule inhibitor SP600125 reduced pneumococci-induced IL-8 mRNA expression and release of IL-8 and IL-6. One regulator of the il8 promoter is JNK-phosphorylated activator protein 1 (AP-1). We showed that S. pneumoniae time-dependently induced DNA binding of AP-1 and its phosphorylated subunit c-Jun with a maximum at 3 to 5 h after infection. Recruitment of Ser(63/73)-phosphorylated c-Jun and RNA polymerase II to the endogenous il8 promoter was found 2 h after S. pneumoniae infection by chromatin immunoprecipitation. AP-1 repressor A-Fos reduced IL-8 release by TLR2-overexpressing HEK293 cells induced by pneumococci but not by TNFα. Antisense-constructs targeting the AP-1 subunits Fra1 and Fra2 had no inhibitory effect on pneumococci-induced IL-8 release. CONCLUSION: S. pneumoniae-induced IL-8 expression by human epithelial BEAS-2B cells depended on activation of JNK and recruitment of phosphorylated c-Jun to the il8 promoter

    Structural basis of outer membrane protein insertion by the BAM complex

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    All Gram-negative bacteria, mitochondria and chloroplasts have outer membrane proteins (OMPs) that perform many fundamental biological processes. The OMPs in Gram-negative bacteria are inserted and folded into the outer membrane by the β-barrel assembly machinery (BAM). The mechanism involved is poorly understood, owing to the absence of a structure of the entire BAM complex. Here we report two crystal structures of the Escherichia coli BAM complex in two distinct states: an inward-open state and a lateral-open state. Our structures reveal that the five polypeptide transport-associated domains of BamA form a ring architecture with four associated lipoproteins, BamB–BamE, in the periplasm. Our structural, functional studies and molecular dynamics simulations indicate that these subunits rotate with respect to the integral membrane β-barrel of BamA to induce movement of the β-strands of the barrel and promote insertion of the nascent OMP

    Methodology of calculation of construction and hydrodynamic parameters of a foam layer apparatus for mass-transfer processes

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    Промислова реалізація методу стабілізації газорідинного шару дозволяє значно розширити галузь застосування пінних апаратів і відкриває нові можливості інтенсифікації технологічних процесів з одночасним створенням маловідходних технологій. У статті встановлені основні параметри, що впливають на гідродинаміку пінних апаратів, розглянуті основні конструкції та режими роботи пінних апаратів. Виявлено зв'язок гідродинамічних параметрів. Розглянуто гідродинамічні закономірності пінного шару. Вказані фактори, що впливають на процес масообміну, як в газовій, так і в рідкій фазах. Проведений аналіз ряду досліджень показав, що перспективним напрямком інтенсифікації процесу масообміну є розробка апаратів з трифазним псевдозрідженим шаром зрошуваної насадки складних форм із сітчастих матеріалів. Отже, необхідне проведення спеціальних досліджень гідродинамічних режимів роботи апарату з сітчастою насадкою і визначенням параметрів, що впливають на швидкість переходу насадки з одного режиму в інший.Industrial implementation of the stabilization method of the gas-liquid layer can significantly expand the field of use of foaming apparatus and opens up new opportunities for intensifying technological processes with the simultaneous creation of low-waste technologies. The article establishes the basic parameters influencing the hydrodynamics of foam apparatus, considers the basic constructions and operating modes of foam apparatus. The connection of hydrodynamic parameters is revealed. The hydrodynamic laws of the foam layer are considered. The indicated factors affecting the process of mass transfer, both in the gas and in the liquid phases. The conducted analysis of a number of studies showed that the perspective direction of intensification of the mass transfer process is the development of apparatuses with a three-phase fluidized bed of an irrigated nozzle of complex forms with mesh materials

    Guidelines for delineation of lymphatic clinical target volumes for high conformal radiotherapy: head and neck region

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    The success of radiotherapy depends on the accurate delineation of the clinical target volume. The delineation of the lymph node regions has most impact, especially for tumors in the head and neck region. The purpose of this article was the development an atlas for the delineation of the clinical target volume for patients, who should receive radiotherapy for a tumor of the head and neck region. Literature was reviewed for localisations of the adjacent lymph node regions and their lymph drain in dependence of the tumor entity. On this basis the lymph node regions were contoured on transversal CT slices. The probability for involvement was reviewed and a recommendation for the delineation of the CTV was generated
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