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51.
Chronic alcoholics may present with hyperglycemia or hypoglycemia. Because alcohol induces glycogenolysis, chronic alcoholics usually have higher blood glucose values than do nonalcoholic subjects. In a prospective study of blood glucose concentration in 201 chronic alcoholics, blood alcohol concentration, sex, weight, type of beverage consumed and time since last eating were not generally associated with lower blood glucose values. The infrequency of hypoglycemia in ambulatory chronic alcoholics may reflect the relatively ready availability of hostels, detoxification centres and hospitals in large cities. It is, however, important to be aware of the possible occurrence of hypoglycemia in chronic alcoholics, particularly when community facilities for the chronic alcoholic are not available. 相似文献
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Immobilization and orientation‐dependent activity of a naturally occurring antimicrobial peptide
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Jason W. Soares Romy Kirby Laurel A. Doherty Alexa Meehan Steven Arcidiacono 《Journal of peptide science》2015,21(8):669-679
A naturally occurring antimicrobial peptide, SMAP‐29, was synthesized with an n‐terminal or c‐terminal cysteine, termed c_SMAP and SMAP_c, respectively, for site‐directed immobilization to superparamagnetic beads. Immobilized SMAP orientation‐dependent activity was probed against multiple bacteria of clinical interest including Acinetobacter baumannii, Pseudomonas aeruginosa, Bacillus anthracis sterne and Staphylococcus aureus. A kinetic microplate assay was employed to reveal both concentration and time‐dependent activity for elucidation of minimum bactericidal concentration (MBC) and sub‐lethal effects. Immobilized SMAP activity was equivalent or reduced compared with soluble SMAP_c and c_SMAP regardless of immobilization orientation, with only one exception. A comparison of immobilized SMAP_c and c_SMAP activity revealed a bacteria‐specific potency dependent on immobilization orientation, which was contrary to that seen in solution, wherein SMAP_c was more potent against all bacteria than c_SMAP. Sub‐MBC kinetic studies displayed the influence of peptide exposure to the cells with multiple bacteria exhibiting increased susceptibility and efficacy at lower concentrations upon extended exposure (i.e. MBC enhancement). For instances in which complete killing was not achieved, two predominant effects were evident: retardation of growth rate and an increased lag phase. Both effects, seen independently and concomitantly, indicate some degree of induced cellular damage that can serve as a predictor toward eventual cell death. SMAP_c immobilized on glass through standard silanization chemistry was also investigated to ascertain the influence of substrate on activity against select bacteria. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. 相似文献
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Sallaud C Giacalone C Töpfer R Goepfert S Bakaher N Rösti S Tissier A 《The Plant journal : for cell and molecular biology》2012,72(1):1-17
Leaves of tobacco (Nicotiana tabacum) are covered with glandular trichomes that produce sucrose esters and diterpenoids in varying quantities, depending on cultivar type. The bicyclic diterpene Z‐abienol is the major labdanoid present in some oriental tobacco cultivars, where it constitutes a precursor of important flavours and aromas. We describe here the identification and characterization of two genes governing the biosynthesis of Z‐abienol in N. tabacum. As for other angiosperm labdanoid diterpenes, the biosynthesis of Z‐abienol proceeds in two steps. NtCPS2 encodes a class‐II terpene synthase that synthesizes 8‐hydroxy‐copalyl diphosphate, and NtABS encodes a kaurene synthase‐like (KSL) protein that uses 8‐hydroxy‐copalyl diphosphate to produce Z‐abienol. Phylogenetic analysis indicates that NtABS belongs to a distinct clade of KSL proteins that comprises the recently identified tomato (Solanum habrochaites) santalene and bergamotene synthase. RT‐PCR results show that both genes are preferentially expressed in trichomes. Moreover, microscopy of NtCPS2 promoter‐GUS fusion transgenics demonstrated a high specificity of expression to trichome glandular cells. Ectopic expression of both genes, but not of either one alone, driven by a trichome‐specific promoter in transgenic Nicotiana sylvestris conferred Z‐abienol formation to this species, which does not normally produce it. Furthermore, sequence analysis of over 100 tobacco cultivars revealed polymorphisms in NtCPS2 that lead to a prematurely truncated protein in cultivars lacking Z‐abienol, thus establishing NtCPS2 as a major gene controlling Z‐abienol biosynthesis in tobacco. These results offer new perspectives for tobacco breeding and the metabolic engineering of labdanoid diterpenes, as well as for structure–function relationship studies of terpene synthases. 相似文献
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Ekkehart Lausch Romy Keppler Valerie Cormier-Daire Gen Nishimura Jürgen Spranger Bernhard Zabel 《American journal of human genetics》2009,85(2):168-535
The matrix metalloproteinases MMP9 and MMP13 catalyze the degradation of extracellular matrix (ECM) components in the growth plate and at the same time cleave and release biologically active molecules stored in the ECM, such as VEGFA. In mice, ablation of Mmp9, Mmp13, or both Mmp9 and Mmp13 causes severe distortion of the metaphyseal growth plate. We report that mutations in either MMP9 or MMP13 are responsible for the human disease metaphyseal anadysplasia (MAD), a heterogeneous group of disorders for which a milder recessive variant and a more severe dominant variant are known. We found that recessive MAD is caused by homozygous loss of function of either MMP9 or MMP13, whereas dominant MAD is associated with missense mutations in the prodomain of MMP13 that determine autoactivation of MMP13 and intracellular degradation of both MMP13 and MMP9, resulting in a double enzymatic deficiency. 相似文献
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More than anticipated - production of antibiotics and other secondary metabolites by Bacillus amyloliquefaciens FZB42 总被引:1,自引:0,他引:1
Chen XH Koumoutsi A Scholz R Borriss R 《Journal of molecular microbiology and biotechnology》2009,16(1-2):14-24
The genome of environmental Bacillus amyloliquefaciens FZB42 harbors numerous gene clusters involved in synthesis of antifungal and antibacterial acting secondary metabolites. Five gene clusters, srf, bmy, fen, nrs, dhb, covering altogether 137 kb, direct non-ribosomal synthesis of the cyclic lipopeptides surfactin, bacillomycin, fengycin, an unknown peptide, and the iron siderophore bacillibactin. Bacillomycin and fengycin were shown to act against phytopathogenic fungi in a synergistic manner. Three gene clusters, mln, bae, and dif, with a total length of 199 kb were shown to direct synthesis of the antibacterial acting polyketides macrolactin, bacillaene, and difficidin. Both, non-ribosomal synthesis of cyclic lipopeptides and synthesis of polyketides are dependent on the presence of a functional sfp gene product, 4'-phosphopantetheinyl transferase, as evidenced by knockout mutation of the sfp gene resulting in complete absence of all those eight compounds. In addition, here we present evidence that a gene cluster encoding enzymes involved in synthesis and export of the antibacterial acting dipeptide bacilysin is also functional in FZB42. In summary, environmental FZB42 devoted about 340 kb, corresponding to 8.5% of its total genetic capacity, to synthesis of secondary metabolites useful to cope with other competing microorganisms present in the plant rhizosphere. 相似文献
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Joëlle Magné François Mariotti Romy Fischer Véronique Mathé Daniel Tomé Jean François Huneau 《The Journal of nutritional biochemistry》2010,21(6):550-555
In the postprandial period, low-grade inflammation may contribute to vascular endothelial dysfunction, a hallmark of atherogenesis. Little is known about the involvement of the adipose tissue in the initiation of the postprandial inflammatory response such as obtained after a high-saturated fat meal (HFM). In the present study, we first studied the time course of appearance of systemic inflammation after a HFM in healthy rats, and then we investigated whether a HFM activates the inflammatory signaling in the visceral adipose tissue, with a focus on the key component, nuclear factor-κB (NF-κB).Two hours after the HFM, plasma IL-6 and PAI-1, but not plasma C-reactive protein and soluble intracellular adhesion molecule-1, showed a marked, transient increase. These changes were specific to the postprandial state as not observed after a control water load. Neutrophils count and activation markers CD11B and CD62L, assessed by flow cytometry, also rose significantly 2 h after the HFM, while remaining steady after the control. At the same time, the HFM decreased significantly B-cell count and expression of the activation marker CD62L. Interestingly, at the same early time after the HFM, in the visceral adipose tissue, there was a 2.2-fold increase in the activation of NF-κB (p65) in nuclear extract and an increase in IL-6 mRNA.As far as we know, this is the first study evidencing an acute, postprandial activation of inflammation in visceral adipose tissue. This early activation of NF-κB pathway after a HFM may play a triggering role in the initiation of the complex postprandial proatherogenic phenotype. 相似文献
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Benjamin N. Bimber Dawn M. Dudley Michael Lauck Ericka A. Becker Emily N. Chin Simon M. Lank Haiying L. Grunenwald Nicholas C. Caruccio Mark Maffitt Nancy A. Wilson Jason S. Reed James M. Sosman Leandro F. Tarosso Sabri Sanabani Esper G. Kallas Austin L. Hughes David H. O'Connor 《Journal of virology》2010,84(22):12087-12092
Rapid evolution and high intrahost sequence diversity are hallmarks of human and simian immunodeficiency virus (HIV/SIV) infection. Minor viral variants have important implications for drug resistance, receptor tropism, and immune evasion. Here, we used ultradeep pyrosequencing to sequence complete HIV/SIV genomes, detecting variants present at a frequency as low as 1%. This approach provides a more complete characterization of the viral population than is possible with conventional methods, revealing low-level drug resistance and detecting previously hidden changes in the viral population. While this work applies pyrosequencing to immunodeficiency viruses, this approach could be applied to virtually any viral pathogen.The viral population within each human immunodeficiency virus (HIV)-infected individual is highly diverse and constantly evolving (2, 3). However, our understanding of the viral population is based largely on the consensus sequence of the dominant circulating virus because the full diversity of the viral population is extremely difficult to characterize. One recent study showed that despite viral fitness recovery in vitro, recovery was not correlated with changes observed in the consensus sequence of HIV. Instead, increased fitness correlated with general viral heterogeneity (5). This finding suggests that by limiting our studies to consensus sequences, we are missing many aspects of viral evolution that influence fitness, drug resistance, and immune evasion, among other characteristics. Studies that examined minor viral variants have provided new insights into HIV transmission and pathogenesis, with direct implications for HIV treatment (7, 13). Unfortunately, traditional techniques to identify rare variants, such as molecular cloning, single-genome amplification, or quantitative real-time (qRT)-PCR, are either labor intensive or restricted to the detection of single variants, limiting their widespread use (8, 11, 12, 14).New second-generation technologies have radically altered DNA sequencing. Recent work by our group and others has employed pyrosequencing for targeted ultradeep sequencing of short regions of the viral genome, including CD8+ T-lymphocyte epitopes and regions of known drug resistance mutations, demonstrating a practical method to identify extremely low-frequency viral variants (4, 15). While sequencing short regions is appropriate in certain circumstances, the region of interest must be identified in advance, and the effect of mutations in that region on the remaining genome is ignored. Studying the heterogeneity of HIV across the entire genome may provide insights into interactions between minor variants, improve our understanding of HIV evolution, and ultimately provide insights into disease pathogenesis.In this study, we combined pyrosequencing with a transposon-based fragmentation method to allow powerful ultradeep sequencing of the full-length HIV and simian immunodeficiency virus (SIV) genomes, demonstrating a new and highly practical approach to study the complexity of the viral population within a host and identify minor variants on a genome-wide scale. While this study applied pyrosequencing to immunodeficiency viruses, this approach could be applied to any viral pathogen. 相似文献