蛋黄磷脂中磷脂酰乙醇胺的薄层扫描测定

将超临界ＣＯ２萃取法得到的蛋黄粉中的磷脂经薄层色谱分离，采用双波长薄层扫描仪对其磷脂酰乙醇胺进行测定。平均回收率为９７．６７％，ＲＳＤ为２．３１％。     

Activity-dependent Decay of Early LTP Revealed by Dual EPSP Recording in Hippocampal Slices from Young Rats

The early maintenance of long-term potentiation (LTP) was studied in the CA1 region of hippocampal slices from 12- to 18-day-old rats in a low-magnesium solution (0.1 mM). The α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptor-mediated components of the field excitatory postsynaptic potential were estimated in parallel using early and late measurements of the composite potential. At the normal test stimulus frequency of 0.1 Hz, LTP was seen initially as a predominant increase in the AMPA component, but converted, via a substantial decay of this component and a gradual growth of the NMDA component, into nearly equal changes of the two components. Interrupting the test stimulation for 10 min, changing the test stimulus frequency to 1/60 Hz after LTP induction, or using a test stimulus frequency of 1/60 Hz during the entire experiment significantly reduced the decay of the potentiation of the AMPA component while enhancing the potentiation of the NMDA one. The ratio between the magnitudes of the two excitatory postsynaptic potential (EPSP) components showed a decaying time course that was independent of the manipulations used. Application of the NMDA antagonist D(-)-2-amino-5-phosphonopentanoic acid (50μM) after LTP induction stabilized the LTP of the AMPA component until washout was started. On the other hand, the phosphatase inhibitor okadaic acid (1 μM) resulted in decay of the potentiation of both EPSP components back to around baseline and altered the time course of the ratio between the components. Our results show that the early maintenance of LTP is controlled in an activity-dependent and NMDA-dependent manner. This process accelerates the decay of LTP of both AMPA and NMDA components in parallel, suggesting that it is similar to homosynaptic long-term depression, although it operates at the normal test stimulus frequency. The data support a scenario in which LTP ensues as a selective AMPA receptor modification and subsequently converts to another modification, possibly a presynaptic one.     

钙拮抗剂TMB-8抑制BHQ,NE和KCl引起的培养乳牛基底动脉单个平滑肌细胞内游离钙的升高

用AR CM MIC阳离子测定系统,测量单个细胞内游离钙浓度([Ca²⁺]i),研究8-(N,N-二乙胺)-n-辛基 3,4,5-三甲氧基苯甲酸酯(TMB-8)对培养乳牛基底动脉平滑肌[Ca²⁺]i的作用。在细胞外钙浓度为1.3mmol·L^-1时,TMB-8(30μmol·L^-1)可明显抑制BHQ,NE及KCl引起[Ca²⁺]i的升高。在细胞外钙为零+EGTA 0.1mmol·L^-1时,TMB-8(10,30及100μmol·L^-1)可浓度依赖性地降低静息[Ca²⁺]i,TMB-8(30μmol·L^-1)可几乎完全阻断BHQ及NE引起[Ca²⁺]i的增加。研究表明TMB-8降低培养乳牛基底动脉平滑肌[Ca²⁺]i的机制,主要是抑制肌浆网Ca²⁺的释放,或增加肌浆网对Ca²⁺的摄入,并由此间接地抑制细胞外钙的内流。     

铜绿假单胞菌全细胞脂肪酸气相色谱分析及应用

本研究用计算机控制，可程序升温的毛细管柱气相色谱（ＧＣ）仪分析４８株铜绿假单胞菌标准株和临床株、部分常见假单胞菌、肠杆菌的细胞脂肪酸。结果表明：月桂烯酸（Ｃ１２：１），月桂酸（Ｃ１２：０）、十三碳烯酸（Ｃ１３：１）、十三碳酸（Ｃ１３：０）、肉豆劳动脑酸（Ｃ１４：１）、十七碳稀酸（Ｃ１７：１）、十七碳酸（Ｃ１７：０）、硬脂酸（Ｃ１８：０）和花生四烯酸（Ｃ２０：４）是铜绿包菌有鉴别意义的脂肪酸，组成与     

脉络膜挫伤

回顾６４例外伤性脉络膜挫伤。多发于２０－３０岁的青年男性；最常见有拳击伤；临床主要表现为视力下降，眼底可见脉络膜出血灶及裂伤口，荧光眼底血和造影可帮助诊断。脉络膜挫伤多发生于黄斑部，其次为视乳头周围，多为单个，１－ＰＤ大小，脉络膜破裂的形态多为长弧形，脉络膜出血多为圆形；脉络膜破裂与出血常同时出现。     

丝裂霉素C化学稳定性的研究

在广泛ＰＨ范围内对丝裂霉素Ｃ的化学稳定性进行了研究，测定不同温度下不同ｐＨ时的速率常数，得到不同ｐＨ时的分解活化能及不同温度下的稳定ｐＨ值。活化能数据在ｐＨ５．５及７．８时出现极大值，而不同温度下的两上最稳定（ｐＨ）ｍ恰恰位于两个ｐＨ范围内。     

胸部高分辨率CT检查技术的临床应用

笔者对５０例肺部疾病胸部常规ＣＴ和高分辨率ＣＴ（ＨＲＣＴ）图像进行了对照分析。其中特发性肺间质纤维化（ＩＦＰ）８例，肺转移癌５例，支气管扩张１５例，慢性阻塞性肺气肿１５例，周围型肺癌７例，结果表明：ＨＲＣＴ在ＩＦＰ、支气管扩张和肺气肿的显示明显优于常规ＣＴ（Ｐ＜０．００１），在对肺部原发或转移性肿瘤的显示能提供更多的诊断信息。笔者还讨论了ＨＲＣＴ的检查技术和图像后处理，分析了影响ＨＲＣＴ的若干因素，指出通过缩小视野（ＦＯＶ），减少象素做图像的重建放大显示肺部局部结构更为清楚方便，应灵活运用。     

胃癌D17S261和D17S799位点二核苷酸重复序列不稳定性的意义

目的研究二核苷酸重复序列不稳定性〔ＤＲＳＩ〕在胃癌发生中的作用及其临床意义．方法采用ＰＣＲ方法检测了Ｄ１７Ｓ２６１和Ｄ１７Ｓ７９９位点二核苷酸重复序列不稳定性．结果胃癌总ＤＲＳＩ发生率为３４％（１７／５０），其中高中分化腺癌ＤＲＳＩ阳性率（６６７％，１０／１５）显著高于低分化癌（１９４％，６／３１，Ｐ＜００１）；肠型胃癌ＤＲＳＩ阳性率（５５６％，１０／１８）显著高于胃型胃癌（２０％，６／３０，Ｐ＜００５），ＤＲＳＩ与胃癌部位、大小、浸润、分期、淋巴结转移无显著相关．结论ＤＲＳＩ在胃癌的发生中可能起重要作用．     

松龄血脉康抑制肺动脉高压的实验研究

为观察松龄血脉康胶囊对肺动脉高压大鼠肺动脉压的影响，取１００只健康Ｗｉｓｔａｒ大鼠，其中６０只背部注射野百合碱ｍｏｎｏｃｒｏｔａｌｉｎｅ，ＭＣＴ８０ｍｇ／ｋｇ复制出肺动脉高压模型。再将其分为两组，各３０只，其中一组以标准饲料喂养，另一组加用松龄血脉康胶囊１．５ｇ·ｋｇ－１·ｄ－１。其余４０只健康大鼠做为正常对照组，在实验当天、７天、１４天、２１天、２８天、３５天从各组中随机抽取５只行右心导管测肺动脉压。结果：注射ＭＣＴ后肺高压组２８天时达高峰，但加用松龄血脉康组上升幅度明显小于未用药组。结论：松龄血脉康有显著抑制大鼠肺动脉高压发展的作用     

HCV的检测方法

从发现丙型肝炎病毒以来 ,丙肝的检测技术发展迅速 ,灵敏度和特异性都有明显的提高 ,方法学在不断改进完善。笔者就近年来丙型肝炎的实验室检测方法作简要的综述