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Nucleotides and Nucleotide Sugars in Developing Maize Endosperms (Synthesis of ADP-Glucose in brittle-1) 总被引:4,自引:0,他引:4 下载免费PDF全文
As part of an in vivo study of carbohydrate metabolism during development of Zea mays L. kernels, quantities of nucleotides and nucleotide sugars were measured in endosperm extracts from normal, the single-mutant genotypes shrunken-1 (sh1), shrunken-2 (sh2), and brittle-1 (btl}, and the multiple-mutant genotypes sh1bt1, sh2bt1, and sh1sh2bt1. Results showed that bt1 kernels accumulated more than 13 times as much adenosine 5[prime] diphospho-glucose (ADP-Glc) as normal kernels. Activity of starch synthase in bt1 endosperm was equal to that in endosperm extracts from normal kernels. Thus the ADP-Glc accumulation in bt1 endosperm cells was not due to a deficiency in starch synthase. ADP-Glc content in extracts of sh1bt1 endosperms was similar to that in bt1, but in extracts of the sh2bt1 mutant kernels ADP-Glc content was much reduced compared to bt1 (about 3 times higher than that in normal). Endosperm extracts from sh1sh2bt1, kernels that are deficient in both ADP-Glc pyrophosphorylase (AGPase) and sucrose synthase, had quantities of ADP-Glc much lower than in normal kernels. These results clearly indicate that AGPase is the predominant enzyme responsible for the in vivo synthesis of ADP-Glc in bt1 mutant kernels, but Suc synthase may also contribute to the synthesis of ADP-Glc in kernels deficient in AGPase. 相似文献
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GC Wood 《New Zealand journal of zoology.》2013,40(3):186-195
Abstract The Westland petrel (Procellaria westlandica) is an endemic New Zealand species and one of the very few burrowing seabird species still breeding on mainland New Zealand. It nests only on a series of coastal ridgelines near to Punakaiki on the West Coast of the South Island. Between 2002 and 2005, surveys were undertaken at 28 of the 29 known colonies. The area occupied by the colonies was 73 ha; most colonies had fewer than 50 burrows, but six colonies had 201–500 burrows and four colonies had more than 1000 burrows. We find that the current breeding range of Westland petrel and the location of individual colonies are similar to those reported in both the 1950s and 1970s. Based on total burrow counts at 28 colonies and burrow occupancy rates determined by annual monitoring, the annual breeding population is estimated to be between 2954 and 5137 breeding pairs. 相似文献
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Background
Patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) commonly require hospitalization and admission to intensive care unit (ICU). It is useful to identify patients at the time of admission who are likely to have poor outcome. This study was carried out to define the predictors of mortality in patients with acute exacerbation of COPD and to device a scoring system using the baseline physiological variables for prognosticating these patients.Methods
Eighty-two patients with acute respiratory failure secondary to COPD admitted to medical ICU over a one-year period were included. Clinical and demographic profile at the time of admission to ICU including APACHE II score and Glasgow coma scale were recorded at the time of admission to ICU. In addition, acid base disorders, renal functions, liver functions and serum albumin, were recorded at the time of presentation. Primary outcome measure was hospital mortality.Results
Invasive ventilation was required in 69 patients (84.1%). Fifty-two patients survived to hospital discharge (63.4%). APACHE II score at the time of admission to ICU {odds ratio (95 % CI): 1.32 (1.138–1.532); p < 0.001} and serum albumin (done within 24 hours of admission) {odds ratio (95 % CI): 0.114 (0.03-0.432); p = 0.001}. An equation, constructed using the adjusted odds ratio for the two parameters, had an area under the ROC curve of 91.3%. For the choice of cut-off, sensitivity, specificity, positive and negative predictive value for predicting outcome was 90%, 86.5%, 79.4% and 93.7%.Conclusion
APACHE II score at admission and SA levels with in 24 hrs after admission are independent predictors of mortality for patients with COPD admitted to ICU. The equation derived from these two parameters is useful for predicting outcome of these patients. 相似文献5.
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Cutting edge: selective IL-18 requirements for induction of compartmental IFN-gamma responses during viral infection 总被引:8,自引:0,他引:8
Pien GC Satoskar AR Takeda K Akira S Biron CA 《Journal of immunology (Baltimore, Md. : 1950)》2000,165(9):4787-4791
Optimal protective effects for defense against infection require orchestration of immune responses spanning multiple host compartments and divergent local regulation at particular sites. During murine cytomegalovirus infections known to target spleen and liver, IL-12-induced IFN-gamma from NK cells is crucial for resistance. However, the roles for IL-18 and/or IL-12 in regulating hepatic IFN-gamma responses, as compared with systemic or splenic responses, have not been defined. In this report, mice genetically deficient in either IL-18 or IL-12p35 exhibited up to 95% reductions in systemic and splenic IFN-gamma responses. Surprisingly, IFN-gamma responses were preserved in the livers of IL-18-deficient, but not IL-12p35-deficient, mice. Cytokine requirements for host survival also differed. Under conditions where mice lacking IL-12p35 exhibited 100% mortality, those lacking IL-18 survived. Taken together, our results delineate contrasting compartmental requirements for IL-18 and suggest that preservation of local, hepatic IFN-gamma production is critical for host defense during murine cytomegalovirus challenge. 相似文献
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Lisa C Willcocks Paul A Lyons Andrew J Rees Kenneth GC Smith 《Arthritis research & therapy》2010,12(1):202
The aetiology of anti-neutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis has not been well defined. Here
we review two factors which may play a role in the pathogenesis of the disease: genetics and infection. In particular, we
discuss the role of autoantibodies to LAMP-2, which may arise following infection with Gram-negative bacteria, and may contribute
to the development of ANCA-associated systemic vasculitis in genetically susceptible individuals. 相似文献
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