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本实验研究血液与非血液灌流条件下缺血预处理(IP)对心肌的保护作用。应用离体大鼠Langendorf灌流模型,分血液灌流IP组、非血液(KrebsHenseleit液,KH液)灌流IP组及相应的对照组。测量心肌电生理特性等指标。结果与KH液灌流心脏相似,用血液灌流的大鼠心脏经IP后,在随后的停灌和复灌期间,心室颤动阈升高,心律失常发生率明显降低。实验结论为在用血液灌流离体大鼠心脏模型上,IP对心肌的保护作用与用生理溶液灌流的模型基本相同。 相似文献
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Bo-Lennart Johansson Ulla Berg Ulla Freyschuss Kerstin Hall Staffan Troell 《Pediatric nephrology (Berlin, Germany)》1990,4(6):589-592
The influence of metabolic control (HbA1c), noradrenaline (NA) and insulin-like growth factors (IGF-I and IGF-II) on renal function and size was investigated in 11 insulin-dependent diabetes mellitus patients aged 11–17 years. Renal function was evaluated in terms of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal size was determined as renal parenchymal volume (RPV) by ultrasonography. The patients' HbA1c values ranged from 8.2% to 12.9% (normal range 5.5–8.5%) and their GFR and ERPF were higher than normal. Their IGF-II values were higher, and NA and IGF-I levels were lower than those of healthy controls. Inverse correlations between NA and GFR (r=–0.66) and NA and ERPF (r=–0.63) were found. No correlation was found between serum IGF-I and renal functional parameters. The IGF-II values correlated with GFR and HbA1c (r=0.63,r=0.70 respectively). There were linear correlations between RPV and GFR, RPV and ERPF, HbA1c and GFR, and ERPF and RPV. Decreased NA concentrations and increased IGF-II values appear to be factors contributing to renal hyperfunction in these patients. 相似文献
4.
人群归因危险度百分比 (populationattributableriskproportion ,PARP)是总体人群中某种疾病归因于某种因素的暴露所引起的发病 (死亡 )占全部发病 (死亡 )的百分比 ,反映该因素所引起的发病 (死亡 )占全部发病 (死亡 )的比重。通过PARP可了解各危险因素对人群中某疾病的发病所产生的影响 ,亦即消除某危险因素后 ,所产生的对预防该疾病的效果将占有多大比重。它能够为卫生政策的制订提供依据 ,有着重要的公共卫生的实际意义。目前常用的估计PARP的方法有两种 :一种是利用全国人群抽样调查获得的人群总暴露率来估计 ;另一种是利用某地区… 相似文献
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Much attention is now being focused on foods from genetically modified plants because of the risk of allergenicity. No such risk has been reported for the first generation of GM plants made resistant to herbicides and insect larvae. Current experiments with hypoallergenic GM plants are reported and discussed in the present paper. The second generation of GM plants will improve the nutritional aspects of natural foods. Transgenic proteins could reach from 4 up to 8% of the total protein content in these foods. Any potential difference in allergenicity between second generation GM plants and the natural varieties must be examined with respect to the risk for food allergy caused by food products made from these plants and the risk for respiratory allergies in the people living near the crops caused by airborne pollen originating from the plants. WHO–FAO directives as well as the Codex Alimentarius proposals and the European Food Safety Authority (EFSA) guidelines recommend that transgenic proteins be screened for homology (by in silico study) and cross-reactivity with known allergens, as well as being examined carefully for modifications of host-plant proteomes. In vivo animal studies are also to be carried out to assess any potential immunogenicity. Lacking adequate safety data, the absence of potential allergenicity of transgenic plants cannot be ruled out. This is why data that do not meet the recommended safety criteria required for commercialization of GM plants do not allow us to rule out absolutely the risk that may be associated with products that are going to be commercialized. Therefore, it is essential that commercialized GM plants be monitored. We propose the establishment of public reference serum banks based on up-to-date WHO–FAO recommendations concerning the selection of sera according to precise criteria. We also propose establishing a system of allergovigilance linking national and European health and food safety agencies and a network of university hospital-based clinical and laboratory reference centres, together with a network of clinical allergists, responsible for the creation of the serum banks. Allergists working through these networks would be able to identify new sensitizations to transgenic foods in the population, just as they now identify new types of food allergies, which, in this case, would be GM foods. Such a project is now being established in France. 相似文献
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目的 :考察 1 %盐酸丁卡因滴眼液的稳定性 ,确定其有效贮存期。方法 :采用经典恒温法预测其有效期。结果 :经典恒温法[1 ] 预测室温贮存期约为 2 0d ,冰箱贮存期约为 1 1 0d。结论 :该制剂对热不稳定 ,应冷藏。 相似文献
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We present a theoretical model of gas transport through the dead space during high-frequency ventilation (HFV) with volumes
less than dead space volume. The analysis is based on the axial distribution of transit times of gas moving through the dead
space. The model predicts that for tidal volumes (V) much less than dead space (Vd), gas exchange will be proportional to the product of frequency (f) and V2. If gas transport is analyzed in terms of Fick's law, then the effective diffusion coefficient (Deff) can be shown to be equal to fV2 times a constant, whose value equals the square of the coefficient of dispersion of axial transit times through the dead
space
. Experimental results in straight tubes fit the predictions of this model quite well. A
through the entire dead space of about 30% is more than sufficient to account for gas exchange during HFV in physical models
or in intact animals. An axial dispersion of this magnitude can be measured directly from a typical Fowler dead space determination
in healthy subjects. 相似文献
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