转醛醇酶在不同发育阶段小鼠睾丸中的表达及其亚型的分离和鉴定

目的：研究转醛醇酶在不同发育阶段小鼠睾丸中的表达并分离鉴定其亚型，方法：应用SDS－聚丙烯酰胺胶电泳（SDS－PAGE）、蛋白免疫印迹（Western bloting)对转醛醇酶在不同发育阶段小鼠睾丸中的表达进行半定量分析，同时利用双向电泳免疫印变技术分离，鉴定转醛醇酶的亚型。结果：（1）转醛醇酶在生后1周小鼠睾丸中表达量平均比成年高47．8％（P＜0．005）。（2）双向电泳Wester blotting示小鼠睾丸转醛醇酶共有10余个亚型，生后1周小鼠睾丸中a8亚型表达量极低，而在成年小鼠睾丸中a8亚型高表达。结论：（1）生后1周小鼠生长发育快，合成代谢旺盛，转醛醇酶基因绝对表达量高。（2）a8亚型可能与生殖功能（精子发生、睾酮生成）密切相关。     

藏药三果汤散抗氧化有效成分的薄层色谱-生物自显影及HPLC指纹图谱

目的:初步建立藏药三果汤教的HPLC指纹图谱,研究藏药三果汤散的抗氧化活性,初步筛选出三果汤散中抗氧化有效成分.方法:采用薄层色谱-生物自显影技术和1,1-二苯基-2-三硝基苯肼(DPPH)分光光度法对不同来源的三果汤散、单味药对照药材及其中单体成分没食子酸、没食子酸乙酯、鞣花酸、柯里拉京进行抗氧化作用初步测定,并采用高效液相色谱法初步建立了三果汤散的指纹图谱.结果:不同来源的三果汤散的抗氧化作用差异不大,所含化学成分以没食子酸抗氧化作用最强,揭示没食子酸可能是三果汤散抗氧化的主要有效成分之一.结论:该方法准确、简便可行,为进一步探索三果汤散抗氧化有效成分提供了科学依据.     

Acute influence of cigarette smoke in platelets, catecholamines and neurophysins in the normal conditions of daily life

Cigarette smoking is firmly linked to the occurrence of acutecoronary events. In twenty-two healthy volunteers in normalconditions of daily life we studied the acute influence of smokingon the following parameters: beta-thromboglobulin, thromboxaneB₂, epinephrine, norepinephrine, estrogen-stimulated neurophysin,and nicotine-stimulated-neurophysin. Our results show that inour population and following our protocol, smoking did not induceplatelet activation, thromboxane formation, catecholamine releaseor estrogen-stimulated-neurophysin secretion. However, smokingdid provoke a significant increase of nicotine-stimulated-neurophysin(p<0.05) which reflects vasopressin increase and which mightexplain the high incidence of ischaemic accidents in cigarettesmoking via the vasoactive properties of vasopressin.     

Low-dose aspirin in patients recovering from myocardial infarction. Evidence for a selective inhibition of thromboxane-related platelet function

The adequacy, selectivity and long-term persistence of inhibitionin cyclooxygenase-dependent platelet function by a daily low-dose(0.45 mg kg^–1 day^–1) aspirin treatment have beenevaluated in 15 patients after a recent (less than 17 days)acute myocardial infarction. Serum thromboxane (TX) B₂, an indexof platelet TXA₂ production, was decreased by 94–98% (P<0.001)by aspirin, while urinary excretion of 6-keto-prostaglandinF^la, as an index of extraplatelet cyclooxygenase activity, remainedunchanged. Compared to placebo, aspirin induced a persistentincrease in bleeding time (% difference 45.6±21.4, mean± SD) and a decrease in platelet aggregation by ADP,epinephrine, collagen and arachidonic acid. No tendency towardsan attenuation of the effects was apparent for the period ofaspirin administration (4 weeks). Aspirin 0.45 mg kg^–1 day^–1 is adequate and selectivein the long-term inhibition of TX-related platelet functionin patients after acute myocardial infarction. The clinicaleffectiveness of such a regimen remains to be proven in clinicaltrials.