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991.
992.
Salmonella typhimurium ATCC 7136 exhibited major changes in lipid composition when grown in the presence of either 0.15% sodium deoxycholate or 0.15% sodium benzoate. These lipophilic compounds had directly opposing effects on the lipid profile of the organism. The saturated/unsaturated ratio was markedly elevated in benzoate-grown cells. On the other hand, it was depressed by an even greater margin from the control after growth in the presence of deoxycholate. Adjustments in the phospholipid content of the cells were also recorded. Phosphatidylethanolamines decreased by 28 and 50% in the deoxycholate- and benzoate-grown cells, respectively. Compensatory increases in phosphatidylglycerols of 87.5 and 175% occurred, along with increases in cardiolipins of 12- and 22-fold, respectively. Deoxycholate or benzoate supplementation also altered the relative distribution of neutral lipids; again, benzoate stimulated the greater change. Compositional changes were accompanied in the organism by increased heat sensitivity, but the effect on the susceptibility of S. typhimurium to injury varied with the physical properties of the supplement used. 相似文献
993.
E Gomard Y Hénin G Sterkers M Masset R Fauchet J P Lévy 《Journal of immunology (Baltimore, Md. : 1950)》1986,136(11):3961-3967
The clone TA10 is a T3+ T4+ T8- proliferative and cytolytic human T cell clone. This clone has been shown to be specific for the hemagglutinin of influenza A Texas virus and restricted by an HLA class II molecule associated with the DRw8-Dw8.1 phenotype. Here we show that TA10 and all of its subclones can also react with eight HLA-DRw8 negative, Epstein-Barr virus (EBV)-transformed cell lines or phytohemagglutinin blasts in the absence of influenza antigens. All of these cell lines are HLA-DR2/DR4 with a classic DR2 long haplotype. The only nonreactive HLA-DR2/DR4 cell line observed bears a DR2 short haplotype. Only heterozygous HLA-DR2/DR4 but not parental DR2 or DR4 EBV-transformed cell lines can be recognized by TA10, indicating that the cross-reacting determinant is a transcomplementation product between HLA-DR2 and HLA-DR4 haplotypes. DR-specific, but not DQ- or DP-specific monoclonal antibodies, inhibit in the proliferation assay and in the chromium release test both the DRw8-Dw8.1-restricted and the anti-DR2/DR4 reactions. These results show that HLA-DR-restricted, anti-viral human T cell clone can evidence cross-reactivity for allospecific class II molecules of the major histocompatibility complex, and human CTL can recognize transcomplementation products of class II HLA genes. In addition, the results suggest that a beta-chain coded for by an HLA-DR gene and associated with an alpha-chain coded for by a still unidentified but possibly HLA-DQ gene constitute this functional transcomplementation product. 相似文献
994.
995.
Processing of 45 s nucleolar RNA 总被引:29,自引:0,他引:29
996.
997.
Ye. P. Dulepova V. A. Nadtochii L. L. Budnikova 《Russian Journal of Marine Biology》2008,34(7):472-481
The trophic structure of benthic communities in the Sea of Okhotsk and Bering Sea was analyzed based on the results of macrobenthic
survey catches conducted in the Far Eastern seas in the 2000s. The production of trophic levels and entire communities was
determined. It was shown that production of benthic communities is still at a high level and has almost not changed since
the 1980s. The arrangement of the communities of some shelf areas by productivity characteristics was made. 相似文献
998.
R Lightowlers Z Chrzanowska-Lightowlers M Marusich R A Capaldi 《The Journal of biological chemistry》1991,266(12):7688-7693
Strains of the yeast Saccharomyces cerevisiae disrupted in YCOX4, the nuclear gene encoding cytochrome c oxidase subunit IV, do not assemble a functional or spectrally visible oxidase. We report the characterization of a yeast strain, RM1, expressing a mutated YCOX4 gene which is temperature sensitive for respiration at 37 degrees C, but incorporates cytochrome aa3 over all growth temperatures. The mutant enzyme is less stable than the wild type, with subunit IV readily proteolyzed without gross denaturation of the complex but with a concomitant loss of oxidase activity. When grown fermentatively at 37 degrees C, cytochrome c oxidase from the mutant strain had a turnover number of less than 3% of the normal complex, while Km values and subunit levels were comparable to normal. Thus alterations in subunit IV can perturb the enzyme structure and alter its catalytic rate, implying a role for this subunit in cytochrome c oxidase function as distinct from assembly. 相似文献
999.
Craig B. H. Surman David W. Goodman 《Attention deficit and hyperactivity disorders》2017,9(3):161-168
ADHD is a neurodevelopmental syndrome that often persists into adulthood. It is possible that different criteria are necessary for older adults than younger adults: the manifestations of ADHD could change with age; other conditions with onset in later life share presenting symptoms with ADHD; different contextual challenges and patterns of compensatory support may exist. For these reasons, we reviewed evidence for the validity of DSM ADHD criteria in adulthood for individuals over the age of 50. Specifically, we evaluated evidence that the DSM criteria for ADHD identify a valid syndrome in older adults based on clinical presentation, laboratory or testing findings, absence of alternate diagnosis to explain symptoms, course of the syndrome, or familial presence of the condition. We found evidence that various ADHD criteria identify subjects with clinical presentations similar to that seen in younger adults, but only 92 well-described cases have been reported in the literature. ADHD traits also may be less common in the general population of older adults than in younger adults, suggesting that the threshold for an atypical burden of ADHD traits may be lower in older populations. Future research can establish a richer basis for validity of diagnostic criteria for ADHD in older adults. 相似文献
1000.
Patricio H. Manríquez María Elisa Jara Mylene E. Seguel Rodrigo Torres Emilio Alarcon Matthew R. Lee 《PloS one》2016,11(3)
The combined effect of ocean acidification and warming is expected to have significant effects on several traits of marine organisms. The gastropod Concholepas concholepas is a rocky shore keystone predator characteristic of the south-eastern Pacific coast of South America and an important natural resource exploited by small-scale artisanal fishermen along the coast of Chile and Peru. In this study, we used small juveniles of C. concholepas collected from the rocky intertidal habitats of southern Chile (39°S) to evaluate under laboratory conditions the potential consequences of projected near-future levels of ocean acidification and warming for important early ontogenetic traits. The individuals were exposed long-term (5.8 months) to contrasting pCO2 (ca. 500 and 1400 μatm) and temperature (15 and 19°C) levels. After this period we compared body growth traits, dislodgement resistance, predator-escape response, self-righting and metabolic rates. With respect to these traits there was no evidence of a synergistic interaction between pCO2 and temperature. Shell growth was negatively affected by high pCO2 levels only at 15°C. High pCO2 levels also had a negative effect on the predator-escape response. Conversely, dislodgement resistance and self-righting were positively affected by high pCO2 levels at both temperatures. High tenacity and fast self-righting would reduce predation risk in nature and might compensate for the negative effects of high pCO2 levels on other important defensive traits such as shell size and escape behaviour. We conclude that climate change might produce in C. concholepas positive and negative effects in physiology and behaviour. In fact, some of the behavioural responses might be a consequence of physiological effects, such as changes in chemosensory capacity (e.g. predator-escape response) or secretion of adhesive mucous (e.g. dislodgement resistance). Moreover, we conclude that positive behavioural responses may assist in the adaptation to negative physiological impacts, and that this may also be the case for other benthic organisms. 相似文献