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Epidemiological studies have shown an increased obesity-related risk of asthma. In support, obese mice develop airway hyperresponsiveness (AHR). However, it remains unclear whether the increased risk is a consequence of obesity, adipogenic diet, or the metabolic syndrome (MetS). Altered L-arginine and nitric oxide (NO) metabolism is a common feature between asthma and metabolic syndrome that appears independent of body mass. Increased asthma risk resulting from such metabolic changes would have important consequences in global health. Since high-sugar diets can induce MetS, without necessarily causing obesity, studies of their effect on arginine/NO metabolism and airway function could clarify this aspect. We investigated whether normal-weight mice with MetS, due to high-fructose diet, had dysfunctional arginine/NO metabolism and features of asthma. Mice were fed chow-diet, high-fat-diet, or high-fructose-diet for 18 weeks. Only the high-fat-diet group developed obesity or adiposity. Hyperinsulinemia, hyperglycaemia, and hyperlipidaemia were common to both high-fat-diet and high-fructose-diet groups and the high-fructose-diet group additionally developed hypertension. At 18 weeks, airway hyperresponsiveness (AHR) could be seen in obese high-fat-diet mice as well as non-obese high-fructose-diet mice, when compared to standard chow-diet mice. No inflammatory cell infiltrate or goblet cell metaplasia was seen in either high-fat-diet or high-fructose-diet mice. Exhaled NO was reduced in both these groups. This reduction in exhaled NO correlated with reduced arginine bioavailability in lungs. In summary, mice with normal weight but metabolic obesity show reduced arginine bioavailability, reduced NO production, and asthma-like features. Reduced NO related bronchodilation and increased oxo-nitrosative stress may contribute to the pathogenesis.  相似文献   
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A strain of starch-assimilating yeast,Saccharomycopsis capsularis, isolated from Indian cereal-based fermented foods, produced significant levels of extracellular α-amylase and glucoamylase. The enzymes reached their peak activities during the stationary phase at the end of the 5th and 4th day of cultivation, respectively. The amylase yields were maximized by a proper choice of carbon and nitrogen sources, starting pH of the culture medium and growth temperature. High activities of the enzymes were obtained through inexpensive agricultural commodities, such as wheat bran and corn meal as carbon sources, and defatted soybean meal and peanut meal as nitrogen sources. A temperature of 28–32°C and an initial pH of 4.5–5.0 were optimum. The crude amylase mixture could liquefy and saccharify a 1% starch solution completely in 24 h at 50°C.  相似文献   
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Control of gluconeogenic growth by pps and pck in Escherichia coli.   总被引:5,自引:1,他引:4       下载免费PDF全文
It is well-known that Escherichia coli grows more slowly on gluconeogenic carbon sources than on glucose. This phenomenon has been attributed to either energy or monomer limitation. To investigate this problem further, we varied the expression levels of pck, encoding phosphoenolpyruvate carboxykinase (Pck), and pps, encoding phosphoenolpyruvate synthase (Pps). We found that the growth rates of E. coli in minimal medium supplemented with succinate and with pyruvate are limited by the levels of Pck and Pps, respectively. Optimal overexpression of pck or pps increases the unrestricted growth rates on succinate and on pyruvate, respectively, to the same level attained by the wild-type growth rate on glycerol. Since Pps is needed to supply precursors for biosyntheses, we conclude that E. coli growing on pyruvate is limited by monomer supply. However, because pck is required both for biosyntheses and catabolism for cells growing on succinate, it is possible that growth on succinate is limited by both monomer and energy supplies. The growth yield with respect to oxygen remains approximately constant, even though the overproduction of these enzymes enhances gluconeogenic growth. It appears that the constant yield for oxygen is characteristic of efficient growth on a particular substrate and that the yield is already optimal for wild-type strains. Further increases in either Pck or Pps above the optimal levels become growth inhibitory, and the growth yield for oxygen is reduced, indicating less efficient growth.  相似文献   
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Summary Laboratory incubation experiments showed that addition of rock phosphate to P-deficient acid red and laterite soils resulted in an increase in Al–P or/and Fe–P, with a consequent decrease in Ca–P during 15 days, of moist aerobic incubation. The transformations of P from Gafsa, Jordan, North Carolina and Florida rock phosphates were more than those from Tennessee, Missouri and Udaipur. Studies with North Carolina, Gafsa, and Udaipur rock phosphates showed that application of the former two to moist aerobic P-deficient acid soils 2 weeks prior to flooding and transplanting rice gave higher content of Al–P, Fe–P and Bray-P, compared to when these were applied at flooding. The grain yields obtained with the former two treatments were also at par with that obtained with the addition of superphosphate at comparable rate (100 ppm) of P application, compared to when the, rock phosphates were applied at flooding, where the grain yields were lower than the superphosphate treatment, indicating that some of these rock phosphates could be made as efficient as superphosphate for growing rice on acid soils by their application to moist aerobic soil, 2–3 weeks prior to flooding and transplanting rice and thus conserve some amount of sulphur required for the manufacture of water soluble phosphates.  相似文献   
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Background  

Tracing the genetic origin of central European farmer N1a lineages can provide a unique opportunity to assess the patterns of the farming technology spread into central Europe in the human prehistory. Here, we have chosen twelve N1a samples from modern populations which are most similar with the farmer N1a types and performed the complete mitochondrial DNA genome sequencing analysis. To assess the genetic and phylogeographic relationship, we performed a detailed survey of modern published N1a types from Eurasian and African populations.  相似文献   
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Singh  Ashutosh  Singh  Rahul Soloman  Sarma  Phulen  Batra  Gitika  Joshi  Rupa  Kaur  Hardeep  Sharma  Amit Raj  Prakash  Ajay  Medhi  Bikash 《中国病毒学》2020,35(3):290-304
The recent outbreak of coronavirus disease(COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) has already affected a large population of the world. SARS-CoV-2 belongs to the same family of severe acute respiratory syndrome coronavirus(SARS-CoV) and Middle East respiratory syndrome coronavirus(MERSCoV). COVID-19 has a complex pathology involving severe acute respiratory infection, hyper-immune response, and coagulopathy. At present, there is no therapeutic drug or vaccine approved for the disease. There is an urgent need for an ideal animal model that can reflect clinical symptoms and underlying etiopathogenesis similar to COVID-19 patients which can be further used for evaluation of underlying mechanisms, potential vaccines, and therapeutic strategies. The current review provides a paramount insight into the available animal models of SARS-CoV-2, SARS-CoV, and MERS-CoV for the management of the diseases.  相似文献   
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