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941.
Stephanie J. Salyer Esther M. Ellis Corvil Salomon Christophe Bron Stanley Juin Ryan R. Hemme Elizabeth Hunsperger Emily S. Jentes Roc Magloire Kay M. Tomashek Anne Marie Desormeaux Jorge L. Mu?oz-Jordán Lesly Etienne Manuela Beltran Tyler M. Sharp Daphne Moffett Jordan Tappero Harold S. Margolis Mark A. Katz 《PLoS neglected tropical diseases》2014,8(10)
In October 2012, the Haitian Ministry of Health and the US CDC were notified of 25 recent dengue cases, confirmed by rapid diagnostic tests (RDTs), among non-governmental organization (NGO) workers. We conducted a serosurvey among NGO workers in Léogane and Port-au-Prince to determine the extent of and risk factors for dengue virus infection. Of the total 776 staff from targeted NGOs in Léogane and Port-au-Prince, 173 (22%; 52 expatriates and 121 Haitians) participated. Anti-dengue virus (DENV) IgM antibody was detected in 8 (15%) expatriates and 9 (7%) Haitians, and DENV non-structural protein 1 in one expatriate. Anti-DENV IgG antibody was detected in 162 (94%) participants (79% of expatriates; 100% of Haitians), and confirmed by microneutralization testing as DENV-specific in 17/34 (50%) expatriates and 42/42 (100%) Haitians. Of 254 pupae collected from 68 containers, 65% were Aedes aegypti; 27% were Ae. albopictus. Few NGO workers reported undertaking mosquito-avoidance action. Our findings underscore the risk of dengue in expatriate workers in Haiti and Haitians themselves. 相似文献
942.
Brigitte Tréton Marie -Thérèse Le Dall H. Heslot 《Applied microbiology and biotechnology》1978,6(1):67-77
Summary We investigated the excretion of citric and isocitric acids in a strain of Saccharomycopsis lipolytica grown on either n-paraffins, glucose, or glycerol. These acids were excreted in the ratio of 67:33 on n-paraffins and roughly 92:8 on either glucose or glycerol. However, with all the carbon sources used, the relative amount of isocitric acid in the intracellular pool remained below 10%. The assimilation of citric and isocitric acids was prevented when glucose or glycerol were the carbon sources, but not when n-paraffins were used. Citric acid stopped isocitric acid assimilation. These phenomena of selective assimilation and/or uptake might explain the variations observed in the ratio of citric to isocitric acids excreted on different carbon sources. 相似文献
943.
Involvement of IS1 in the dissociation of the r-determinant and RTF components of the plasmid R100.1
Summary Detailed mapping localized the PHO 1 mutation between the OLI 2 and OLI 4 loci on mitochondrial DNA of Saccharomyces cerevisiae.In its mitochondrially integrated form, the PHO 1-ATPase3 was difficult to identify either immunologically or by specific inhibitors like oligomycin and DCCD. Solubilization by Triton X-100 allowed unambiguuous identification of this enzyme as an authentic mitochondrial ATPase. However, Triton extraction produced a 2 to 3 fold enhancement of the PHO 1-ATPase activity which also became drastically cold-sensitive. The wild type ATPase was neither activated nor made cold-labile by solubilization, and retained full sensitivity to oligomycin and DCCD.Sucrose gradient analysis of the Triton-extracted ATPase from wild type, PHO 1 mutant and rho
-
strains showed a density difference between the solubilized PHO 1-and wild type ATPase, and similarity between solubilized PHO 1-and rho
- ATPase (F1).Whole cells of the PHO 1 mutant present considerably increased respiration rates.Comparison of oligomycin-sensitivity in whole cells, coupled isolated mitochondria and membrane-bound ATPase indicates a contrast between oligomycin-resistance of the ATPase and oligomycin-sensitivity of in vivo or in vitro coupling systems, which might characterize the products of this region of mitochondrial DNA. 相似文献
944.
Background
The maturation of hydrogenases into active enzymes is a complex process and e.g. a correctly assembled active site requires the involvement of at least seven proteins, encoded by hypABCDEF and a hydrogenase specific protease, encoded either by hupW or hoxW. The N2-fixing cyanobacterium Nostoc sp. strain PCC 7120 may contain both an uptake and a bidirectional hydrogenase. The present study addresses the presence and expression of hyp-genes in Nostoc sp. strain PCC 7120. 相似文献945.
Guylène Page Sylvie Chalon Patrick Emond Jean Marie Maloteaux Emmanuel Hermans 《Neurochemistry international》2002,40(2):105-113
The interaction of (E)-N-(3-iodoprop-2-enyl)-2beta-Carbomethoxy-3beta-(4'-methylphenyl) nortropane (PE2I) with the rat neuronal dopamine transporter (DAT) was studied in transfected COS cells by measuring its ability to inhibit DA uptake and by measuring its affinity in radioligand binding experiments. Saturable [3H]DA uptake was measured in COS cells transiently transfected with the cDNA sequence encoding the rat DAT. Pharmacological characterisation of this uptake revealed functional properties with a V(max) value of 45.05+/-2.62 pmol/mg protein per min and a K(m) value of 2.86+/-0.28 microM. The specific [3H]DA uptake was fully inhibited by 1 microM PE2I. Concentration response curves revealed the high potency of PE2I in inhibiting DA uptake (pEC(50) value of 8.70+/-0.33), 25 times higher than that observed for the reference DAT inhibitor, GBR 12935. On crude homogenates from transfected COS cells, PE2I displaced the specific binding of [3H]GBR 12935 with a pK(i) value of 7.73+/-0.13. Accordingly, [125I]PE2I was found to specifically recognise a single binding site population which is almost completely displaced by GBR 12935 and nomifensine. Saturation experiments revealed the high affinity of [125I]PE2I (K(D) value of 3.8+/-0.63 nM) that correlates with the high potency of PE2I in inhibiting the [3H]DA uptake. This contrasts with the results obtained with GBR 12935 for which a discrepancy was found between its high affinity in binding assays (K(D) value of 0.43+/-0.04 nM) and its rather low potency in functional assays (pEC(50) value of 7.30+/-0.05). A relatively high level of [3H]GBR 12935 binding was detected in non transfected COS cells. Such nomifensine resistant binding is attributed to the interaction of GBR 12935 with cytochrome P-450 as it was displaced by cis-(Z)-flupentixol (an inhibitor of cytochrome P-450). Such interaction was not observed using PE2I. Taken together, these data demonstrate that PE2I was a highly potent inhibitor of cloned DAT compared with GBR 12935 and provided a useful tool for further investigations in cells transfected with cDNA encoding the DAT. 相似文献
946.
Christopher E. Ramsden Marie Hennebelle Susanne Schuster Gregory S. Keyes Casey D. Johnson Irina A. Kirpich Jeff E. Dahlen Mark S. Horowitz Daisy Zamora Ariel E. Feldstein Craig J. McClain Beverly S. Muhlhausler Maria Makrides Robert A. Gibson Ameer Y. Taha 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2018,1863(10):1206-1213
Background
Linoleic acid (LA) is abundant in modern industrialized diets. Oxidized LA metabolites (OXLAMs) and reactive aldehydes, such as 4-hydroxy-2-nonenal (4-HNE), are present in heated vegetable oils and can be endogenously synthesized following consumption of dietary LA. OXLAMs have been implicated in cerebellar degeneration in chicks; 4-HNE is linked to neurodegenerative conditions in mammals. It unknown whether increasing dietary LA or OXLAMs alters the levels of oxidized fatty acids (oxylipins), precursor fatty acids, or 4-HNE in mammalian brain.Objectives
To determine the effects of increases in dietary OXLAMs and dietary LA, on levels of fatty acids, oxylipins, and 4-HNE in mouse brain tissues.Methods
Mice (n?=?8 per group) were fed one of three controlled diets for 8?weeks: (1) a low LA diet, (2) a high LA diet, or (3) the low LA diet with added OXLAMs. Brain fatty acids, oxylipins, and 4-HNE were quantified in mouse cerebellum and cerebral cortex by gas chromatography-flame ionization detection, liquid chromatography-tandem mass spectrometry, and immunoblot, respectively.Results
Increasing dietary LA significantly increased omega-6 fatty acids, decreased omega-3 fatty acids, and increased OXLAMs in brain. Dietary OXLAMs had minimal effect on oxidized lipids but did decrease both omega-6 and omega-3 fatty acids. Neither dietary LA nor OXLAMs altered 4-HNE levels.Conclusion
Brain fatty acids are modulated by both dietary LA and OXLAMs, while brain OXLAMs are regulated by endogenous synthesis from LA, rather than incorporation of preformed OXLAMs. 相似文献947.
948.
949.
Capacity for NADPH regeneration in the leaves of two poplar genotypes differing in ozone sensitivity
Ata Allah Dghim Jennifer Dumont Marie‐Paule Hasenfratz‐Sauder Pierre Dizengremel Didier Le Thiec Yves Jolivet 《Physiologia plantarum》2013,148(1):36-50
Cell capacity for cytosolic NADPH regeneration by NADP‐dehydrogenases was investigated in the leaves of two hybrid poplar (Populus deltoides × Populus nigra) genotypes in response to ozone (O3) treatment (120 ppb for 17 days). Two genotypes with differential O3 sensitivity were selected, based on visual symptoms and fallen leaves: Robusta (sensitive) and Carpaccio (tolerant). The estimated O3 flux (POD0), that entered the leaves, was similar for the two genotypes throughout the treatment. In response to that foliar O3 flux, CO2 assimilation was inhibited to the same extent for the two genotypes, which could be explained by a decrease in Rubisco (EC 4.1.1.39) activity. Conversely, an increase in PEPC (EC 4.1.1.31) activity was observed, together with the activation of certain cytosolic NADP‐dehydrogenases above their constitutive level, i.e. NADP‐G6PDH (EC 1.1.1.49), NADP‐ME (malic enzyme) (EC 1.1.1.40) and NADP‐ICDH (NADP‐isocitrate dehydrogenase) (EC1.1.1.42). However, the activity of non‐phosphorylating NADP‐GAPDH (EC 1.2.1.9) remained unchanged. From the 11th fumigation day, NADP‐G6PDH and NADP‐ME profiles made it possible to differentiate between the two genotypes, with a higher activity in Carpaccio than in Robusta. At the same time, Carpaccio was able to maintain high levels of NADPH in the cells, while NADPH levels decreased in Robusta O3‐treated leaves. All these results support the hypothesis that the capacity for cells to regenerate the reducing power, especially the cytosolic NADPH pool, contributes to improve tolerance to high ozone exposure. 相似文献
950.
Marie Deghorain Laetitia Fontaine Blandine David Jean-Luc Mainardi Pascal Courtin Richard Daniel Jeff Errington Alexei Sorokin Alexander Bolotin Marie-Pierre Chapot-Chartier Bernard Hallet Pascal Hols 《The Journal of biological chemistry》2010,285(31):24003-24013
Cell wall peptidoglycan assembly is a tightly regulated process requiring the combined action of multienzyme complexes. In this study we provide direct evidence showing that substrate transformations occurring at the different stages of this process play a crucial role in the spatial and temporal coordination of the cell wall synthesis machinery. Peptidoglycan substrate alteration was investigated in the Gram-positive bacterium Lactococcus lactis by substituting the peptidoglycan precursor biosynthesis genes of this bacterium for those of the vancomycin-resistant bacterium Lactobacillus plantarum. A set of L. lactis mutant strains in which the normal d-Ala-ended precursors were partially or totally replaced by d-Lac-ended precursors was generated. Incorporation of the altered precursor into the cell wall induced morphological changes arising from a defect in cell elongation and cell separation. Structural analysis of the muropeptides confirmed that the activity of multiple enzymes involved in peptidoglycan synthesis was altered. Optimization of this altered pathway was necessary to increase the level of vancomycin resistance conferred by the utilization of d-Lac-ended peptidoglycan precursors in the mutant strains. The implications of these findings on the control of bacterial cell morphogenesis and the mechanisms of vancomycin resistance are discussed. 相似文献