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91.
为探讨5 HT2受体与心肌缺血 再灌注损伤的关系,观察5 HT2受体阻断剂kentanserin对心肌缺血 再灌注大鼠室颤及左室内压+dp/dtmax及-dp/dtmax的影响。结果表明,kentanserin可拮抗缺血性心功能障碍和再灌室颤。提示5 HT2受体参与了缺血性心功能障碍和再灌室性心律失常的发生。 相似文献
92.
氟脲嘧啶(5-FU)乳剂经直肠内灌注后,可于短期内在直肠壁、肝脏及门静脉血中保持较高的浓度[1]。1992年4月~1996年7月,笔者对16例无法手术切除肿瘤的晚期直肠癌患者应用5-FU乳剂直肠内给药,现报告如下。1 临床资料1.1 一般情况 5-FU组(直肠内给予5-FU)16例,男性11例,女性5例,年龄49±4岁(38~56岁)。对照组(未给予5-FU)14例,男性9例,女性5例,年龄52±6岁(27~64岁)。全部患者均经病理证实为直肠腺癌。病理类型:5-FU组中隆起型10例,溃疡型4例,缩窄型2例;对照组中隆起型7例,溃疡型5例,缩窄型2例。两组病例术后均有直肠局部疼痛、坠胀… 相似文献
93.
重组人神经营养因子-4/5蛋白抗三氧化二砷神经毒作用 总被引:5,自引:0,他引:5
目的初步观察重组人神经营养因子-4/5(hNT-4/5)蛋白对三氧化二砷毒性的抑制作用。方法利用hNT-4/5蛋白具有抗神经毒性的特点,采用本实验室克隆表达及部分纯化的具有天然hNT-4/5蛋白生物学活性的重组hNT-4/5蛋白,以不同水平的重组hNT4/5蛋白(0-100μl)与不同浓度的As2O3(0-160μmol/L)同时加入各组鸡胚前脑神经细胞和PC12细胞培养液中共同孵育24-48小时,观察其对染毒鸡胚前脑神经细胞存活和PC12细胞突起生长的影响作用。结果在鸡胚前脑神经细胞和PC12细胞中与As2O3共同培养48小时后,对照组与实验组的细胞存活率差异有显著性,而且细胞存活率和突起数目随hNT-4/5浓度增高而提高和增加。结论初步观察到重组hNT4/5蛋白具有抑制As2O3的毒性作用,为从基因工程途径寻找抗环境毒物因子提供了依据。 相似文献
94.
多普勒超声心动图评估左心室舒张末压的研究 总被引:1,自引:0,他引:1
目的探讨多普勒超声心动图评估左室舒张末压的有效方法与指标。方法对68例病人采用左心导管测压及经胸多普勒超声心动图检测。结果对比研究显示,联合肺静脉与二尖瓣血流频谱分析优于二尖瓣血流频谱分析,肺静脉A峰和二尖瓣A峰时限差值(PAd-Ad)与左室舒张末压实测值呈最佳相关性(r=0.72,P<0.01)。结论认为应用多普勒超声心动图测定PAd与Ad,并以其差值估测左室舒张末压,是一项简便、可靠的无创性评估左室舒张末压的方法。PAd-Ad≥0可作为临床判断左室舒张末压增高[≥2.0kPa(15mmHg)]的一项半定量指标。 相似文献
95.
96.
Protein S-thiolation is a process in which under oxidative stress, vulnerable sulfhydryl groups of proteins are conjugated to non-protein thiols such as glutathione (GSH) or cysteine resulting in the formation of protein-thiol mixed disulfides, protein-S-S-glutathione (PSSG) and protein-S-S-cysteine (PSSC). This process spontaneously disrupts the redox homeostasis of the cells, which in turn leads to functional disturbances in the respective tissue. In the ocular lens, such modification of proteins may trigger a cascade of events starting with the alteration of protein conformation, protein/enzyme deactivation, protein-S-S-protein aggregation and eventually lens opacification or cataract. Generally, the first line of defense system in the cells protects the lens proteins against such damage. Recent studies in our laboratory have shown that in addition to this defense system, lens cells also possess a well developed system to repair the oxidative damage to the lens proteins. We have identified this repair system as thioltransferase (TTase) and have proved that TTase by its dethiolase activity reverses the protein S-thiolation process which returns the oxidatively damaged lens proteins/enzymes to their original reduced state and restores their physiological functions. We investigated if this repair mechanism was mediated by enzymes other than TTase. We studied glutathione S-transferase (GST) and report here for the first time the cloning, high level expression, and purification of human lens mu and pi isoforms of GST. A comparative study of recombinant human lens TTase and GST (mu and pi) on their dethiolating abilities using lens crystallin-thiol mixed disulfides showed that the lens TTase is 60-70% more efficient in the dethiolation/repair process than GST. When TTase and GST were tested in conjunction for the dethiolation of thiol mixed disulfides, there was no significant enhancement of dethiolase activity. These findings suggest that TTase by itself is an efficient enzyme in the dethiolation/repair process and hence can be considered a crucial system to counteract oxidative stress in the lens. 相似文献
97.
Calcium/calmodulin-dependent protein kinase II (CaMK II) has been shown to be involved in the regulation of opioid receptor signaling. The present study showed that acute morphine treatment significantly increased both Ca2+/calmodulin-independent and Ca2+/calmodulin-dependent activities of CaMK II in the rat hippocampus, with little alteration in the protein level of either alpha or beta isoform of CaMK II. However, chronic morphine treatment, by which rats were observed to develop apparent tolerance to morphine, significantly down-regulated both Ca2+/calmodulin-independent and Ca2+/calmodulin-dependent activities of CaMK II and differentially regulated the expression of alpha and beta isoforms of CaMK II at protein and mRNA levels. Application of naloxone or discontinuation of morphine treatment after chronic morphine administration, which induced the withdrawal syndrome of morphine, resulted in the overshoot of CaMK II (at both protein and mRNA levels) and its kinase activity. The phenomena of overshoot were mainly observed in the beta isoform of CaMK II but not in the alpha isoform. The effects of both acute and chronic morphine treatments on CaMK II could be completely abolished by the concomitant application of naloxone, indicating that the effects of morphine were achieved through activation of opioid receptors. Our data demonstrated that both acute and chronic morphine treatments could effectively modulate the activity and the expression of CaMK II in the hippocampus. 相似文献
98.
99.
Jorge E. Zamora Ola P. Rosaeg M. Patrice Lindsay Mary Lou Crossan 《Journal canadien d'anesthésie》1996,43(4):347-352
Purpose
The efficacy of infusion of 0.5 L and 1.0 L Ringer’s lactate (LR) to prevent hypotension during induction of obstetric analgesia was studied. The effect of the different fluid boluses on fetal heart rate (FHR) and frequency of uterine contractions were also determined.Methods
Ninety-two ASA 1–2 parturients were randomized to receive 0.5 L (Group 1) and 1.0 L (Group 2) LR immediately before incremental epidural injections with lidocaine to achieve T10 sensory block. Systolic blood pressure (SBP) was measured with an automated BP cuff every two minutes for 30 min after infusion of fluid bolus. Fetal heart rate monitoring and tocometry were used continuously. The number of uterine contractions were recorded 30 min before and 60 min after iv bolus.Results
The SBP decreased in both groups, but there was no difference between groups in mean SBP or maternal heart rate. The incidence of hypotension (SBP < 90 mmHg or decrease of 20%) was 4% in both groups. The FHR record of a patient in Group 1 showed a single late deceleration, and a decrease in beat-to-beat variability occured in one patient in Group 2. A decrease in the frequency of uterine contractions of two or more contractions per 30 min was noted more frequently in Group 2 (P < 0.05). The duration of iv bolus was longer in Group 2 than Group 1 (18.8 ± 4.3 min vs 12.3 ± 4.5 min, P < 0.01).Conclusion
Administration of 1.0 L LR iv does not provide added protection against maternal hypotension, and is associated with delay in providing pain relief and a risk of decreasing uterine contraction frequency. 相似文献100.
中药天花粉及其类似品的鉴别研究 总被引:1,自引:0,他引:1
本文对天花粉的使用概况作了介绍。据本草考证,自古以来中药天花粉的原植物主要来源即为栝楼Trichosanthes kirilowii Maxim.,但约自南宋之后天花粉的来源有所发展,因此天花粉商品又是多来源的。据作者在21省、区的100余市、县调查,国内约有30种植物根部曾作天花粉入药(包括地区习惯用药及混淆品)。本文对较多见的17种真伪天花粉列表简介,并对其中10种主要商品或混淆品的鲜根外形、药材或干燥品性状及显微特征(包括横切面及解离组织)进行了描述比较,同时找出各种外形及组织上的鉴别特征;列表比较其间的异同点。此外我们已经对其他6种天花粉进行了鉴别研究,待拉丁学名确定后再行报道。 相似文献