高糖损伤兔主动脉内皮依赖性舒张反应(英文)

目的:研究高糖对兔胸主动脉内皮依赖性舒张反应(EDR)的影响及L-精氨酸、超氧化物歧化酶(SOD)和高糖撤除的作用。方法:以主动脉环EDR为检测指标。结果:高糖可使乙酰胆碱(ACh)诱导的EDR明显受损,高糖撤除24h后不能恢复ACh的舒血管作用,而甘露醇(19.5mmol·L~(-1))不影响血管环EDR。L-精氨酸1mmol·L~(-1)或SOD 150U·L~(-1)可取消高糖对EDR的损伤作用,高糖不影响硝普钠的舒血管作用。结论:高糖可损伤血管EDR,短时间高糖撤除不能逆转,其机制可能与自由基产生及L-精氨酸代谢改变有关。     

Renal acid-base and sodium handling in hypoxia and subsequent mild metabolic acidosis in foetal sheep

1. To measure the renal contribution to acid-base homeostasis during hypoxia (not associated with hypercapnia) and in response to the subsequent mild metabolic acidosis and to determine the effects of this hypoxia on the renal handling of sodium, studies were performed in six chronically catheterized foetal sheep (129-138 days gestation) before, during and for 1 h after a 2 h period of hypoxia. 2. Hypoxia was induced in the conscious ewe by infusing nitrogen into the trachea. Foetal arterial oxygen tension fell to 12.0 +/- 0.6 mmHg (P < 0.001). Carbon dioxide tension fell during hypoxia (P < 0.001) and was still somewhat reduced in the recovery period (P < 0.005). Arterial pH fell progressively to 7.19 +/- 0.08 in the recovery period (P < 0.05). Plasma bicarbonate concentrations fell (P < 0.001) and lactate rose (P < 0.001). 3. Urinary pH and the excretion rates of bicarbonate, titratable acid, ammonium and net acid did not change during hypoxia. Ammonium excretion and, hence, generation of new bicarbonate increased in the recovery period (P < 0.05). 4. Renal sodium excretion progressively increased and was greatest after normoxia was restored (P < 0.05). This natriuresis was due to a fall in the reabsorption of sodium by the proximal tubule (P < 0.05). Proximal reabsorption of sodium was directly related to foetal pH (P < 0.0001) and bicarbonate reabsorption (P < 0.001). 5. It was concluded that: (i) the foetal kidneys began to contribute to the maintenance of acid-base balance within the first hour of recovery from a 2 h episode of hypocapnic hypoxia, even though the acidosis was relatively mild; and (ii) a reduction in bicarbonate reabsorption was probably the most important factor that limited sodium reabsorption by the renal tubule during this experiment.     

Cystic fibrosis transmembrane conductance regulator and the outwardly rectifying chloride channel: a relationship between two chloride channels expressed in epithelial cells

1. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) result in the primary defect observed in patients with cystic fibrosis. 2. The CFTR is a member of the ATPase-binding cassette (ABC) transporter family but, unlike other members of this group, CFTR conducts a chloride current that is activated by cAMP. 3. In epithelial cells, the cAMP-stimulated chloride current is conducted by both CFTR and the outwardly rectifying chloride channel (ORCC). 4. The present review summarizes the current knowledge of the properties of the two channels, as well as their relationship. Because the gene encoding the ORCC has not been identified, a discussion as to possible candidates for this chloride channel is included.     

葡萄糖氯化钠注射液中细菌内毒素定量检测研究

①目的 探讨葡萄糖氯化钠注射液中细菌内毒素的定量检测方法。②方法 按中国(2000年版)附录中检测细菌内毒素的动态浊度法，进行葡萄糖氯化钠注射液的细菌内毒素干扰实验。③结果 葡萄糖氯化钠注射液对细菌内毒素定量检测无干扰性。④结论 应用细菌内毒素定量检测法检测葡萄糖氯化钠注射液中细菌内毒素是可行的。     

注射用泮托拉唑钠治疗非曲张静脉上消化道出血疗效观察

目的　评价泮托拉唑钠治疗非曲张静脉上消化道出血的疗效和安全性 ,并与雷尼替丁做对照。方法　选择上消化道出血患者 70例 ,随机分泮托拉唑钠组 35例 ,其中胃溃疡并出血 14例 ,十二指肠球部溃疡并出血 17例 ,急性糜烂出血性胃炎 3例 ,胃癌 1例 ;雷尼替丁组 35例 ,其中胃溃疡并出血 15例 ,十二指肠球部溃疡并出血 15例 ,急性糜烂出血性胃炎 4例 ,胃癌 1例。方法 :分别用泮托拉唑钠 80mg或雷尼替丁 15 0mg加入 5 %葡萄糖液 2 5 0ml内静脉点滴 (30～ 6 0min) 1次 /d ,共 5d ,观察生命体征和出血情况的变化。结果　两组出血情况差异无显著性 (P >0 .0 5 )。治疗后 3d内泮托拉唑钠组有 2 8例止血 ,4～ 5d内止血有 6例 ,5d以上未止血者 1例 ,止血总有效率为 94 .36 % ;3d内雷尼替丁组有 2 5例止血 ,4～ 5d内有 5例止血 ,5d以上未止血者 5例 ,止血总有效率为 :85 .71%。治疗后两组总有效率比较有显著差异 (P <0 .0 1)。泮托拉唑钠组无不良反应 ,雷尼替丁组有 1例出现恶心症状 ,不良反应发生率为 2 .85 %。结论　注射用泮托拉唑钠是治疗非曲张静脉上消化道出血安全、有效的药物。     

头孢噻肟钠治疗社区获得性肺炎的观察及体会

目的探讨头孢噻肟钠(cefotaxime sodium)治疗社区获得性肺炎(community acquired pneumonia,CAP)的临床疗效及安全性.方法90例社区获得性肺炎病人,随机分为治疗组和对照组,每组45例.治疗组:静脉注射头孢噻肟钠,每次1.0～2.0g,每8 h静注1次,疗程7～14d;对照组:静脉滴注青霉素G(benzylpenicillin),每次240～480wu,每6h静注1次,疗程7～14d.结果头孢噻肟钠和青霉素G的临床有效率分别为93.3%和66.7%,细菌清除率为95.6%和71.1%,两组差异具有统计学意义(P＜0.05),治疗期间两组均未出现明显不良反应.结论头孢噻肟钠疗效肯定,安全性好,可作为治疗社区获得性肺炎的首选药.     

Mechanisms of photosystem I activity stimulation in trypsin-treated pea chloroplast membranes

Trypsin-induced effects on the PSI-photochemical activity of pea chloroplast membranes have been measured under saturating light conditions. It was found that incubation of isolated chloroplasts with trypsin in concentration range of 20–60 μg trypsin per mg Chl leads to a linear increase of the rate of PSI-mediated electron transport, measured by O₂-uptake with methyl viologen as an electron acceptor and DCPIP·H₂ as electron donor. Low temperature (77 K) chlorophyll fluorescence measurements have indicated that a remarkable redistribution of excitation light energy in favor of PSI occurs under these conditions. The results are interpreted in terms of trypsin-induced lateral reorganization of the chlorophyll—protein complexes within the thylakoid membranes and specific alteration at the level of LHC a/b-PSII supramolecular organization.     

METHYLCELLULOSE FOR ENDOTHELIAL CELL PROTECTION

A randomised trial of three types of endothelial cell protection for patients undergoing posterior chamber intraocular lens implant is described. The results confirm the superiority of a viscoelastic fluid over air as a form of endothelial cell protection. No statistically significant difference was found between sodium hyaluronate and hydroxypropylmethykellulose (HPMC). As the cost of sodium haluronate is prohibitive, a manufacturing technique for HPMC is given.     

Spectrally weighted twisted projection imaging: Reducing T2 signal attenuation effects in fast three-dimensional sodium imaging

A scheme for the reduction of T₂ signal attenuation effects in three-dimensional twisted projection imaging is presented. By purposely reducing the sample density at the high spatial frequencies, a considerable reduction in readout time is achieved. The reduction in readout time leads to decreased T₂ signal attenuation which translates into improved signal-to-noise ratio (SNR). The SNR improvement is achieved without decreasing the image's resolution since the point spread function depends on the sample weighting as well as the T₂ attenuation. The results indicate that SNR improvements of up to 40% can be achieved using the proposed scheme.