液膜法提取发酵液中的苯丙氨酸 Ⅱ.操作工艺条件

从芫花Ｄａｐｈｎｅ ｇｅｎｋｗａ条的乙酸乙酯可溶部分分到３个结果性化合物，借助于波谱分析手段推断出Ⅱ为西瑞香素，Ⅲ为ｄａｐｈｎｏｄｏｒｉｎ Ｂ。     

Duchenne型肌营养不良症105例临床分析及其发病机制的探讨（附4例肌纤维膜冷冻断裂电镜检查）

报告１０５例Ｄｕｃｈｅｎｎｅ型肌营养不良症（ＤＭＤ），其中男１０３例，女２例。年龄４～１９岁，平均６５岁。３２例有阳性家族史。文中对ＤＭＤ的临床表现，血清酶、肌肉病理、组织化学、电镜检查等特点进行了讨论。对其中４例骨骼肌进行肌纤维膜冷冻断裂电镜检查。结果表明，本病肌膜的Ｅ面和Ｐ面的膜蛋白颗粒密度降低，与２例正常骨骼肌相比有显著性差异，支持本病发病机理中的“膜缺陷”学说。     

Na+ currents near and away from endplates on human fast and slow twitch muscle fibers

Fast and slow twitch muscle fibers have distinct contractile properties. Here we determined that membrane excitability also varies with fiber type. Na⁺ currents (I_NA) were studied with the loose-patch voltage clamp technique on 29 histochemically classified human intercostal skeletal muscle fibers at the endplate border and <200 μm from the endplate (extrajunctional). Fast and slow twitch fibers showed slow inactivation of endplate border and extrajunctional I_NA and had increased I_NA at the endplate border compared to extrajunctional membrane. The voltage dependencies of I_NA were similar on the endplate border and extrajunctional membrane, which suggests thatboth regions have physiclogically similar channels. Fast twitch fibers had larger I_NA on the endplate border and extrajunctional membrane and manifest fast and slow inactivation of I_NA at more negative potentials than slow twitch fibers. For normal muscle, the differences between I_NA on fast and slow twitch fibers might: (1) enable fast twitch fibers to operate at high firing frequencies for brief periods; and (2) enable slow twitch fibers to operate at low firing frequencies for prolonged times. Disorders of skeletal membrane excitability, such as the periodic paralyses and myotonias, may impact fast and slow twitch fibers differently due to the distinctive Na⁺ channel properties of each fiber type. © 1993 John Wiley & Sons, Inc.     

Vacuolar cytoplasmic phase separation in cultured mammalian cells involves the microfilament network and reduces motional properties of intracellular water

Hep-2, human epithelial carcinoma cells, and human foreskin fibroblasts (FF9 and FF13) were exposed to either an ultrafiltrate (< 50 kD) of human sera or the weak base, procaine hydrochloride, to induce reversible cytoplasmic vacuolization. The formation of vacuoles was shown not to be due to imbibition of medium. Ultrastructural details obtained from various stages of vacuole formation were compared. In both cases of induction vacuoles were irregular and often appeared membraneless, with little in the way of electron-dense content. They started to form in the perinuclear cytoplasm and progressed towards the periphery. Osmotic stress was not involved since mitochondria remained normal throughout a vacuolization episode.
Vacuoles were often seen in close contact with filamentous structures, and this association remained detectable at late stages of the phenomenon. Fluorescent visualization of F-actin confirmed that the vacuoles were frequently bordered by microfilaments. No major metabolic impairment was apparent in vacuolized cells as judged by protein synthesis measurements, but nuclear fluorescence (DNA content) and forward light scatter (nuclear volume) by flow cytometric analysis suggested late S phase and G2 retardation. ¹H-nmr relaxation measurements indicated intracellular water restricted in motional characteristics in vacuolized cells. The possibility of a restricted cytoplasmic phase separation as part of a transient adaptation response is raised, and a hypothesis to explain the findings is discussed.     

Rapid effect of stress concentration corticosterone on glutamate receptor and its subtype NMDA receptor activity in cultured hippocampal neurons

Objective: To study the rapid effect of glucocorticoids (GCs) on NMDA receptor activity in hippocampal neurons in stress and to elucidate its underlying probable membrane mechanisms. Methods: Whole-cell patch-clamp recording was used to assess the effect of stress concentration corticosterone (B) on the responses of cultured hippocampal neurons to glutamate and NMDA (N-methy-D-asparatic acid). To make clear the target of B, intracellular dialysis of B(10μmol/L)through patch pipette and extracellular application of bovine serum albumin-conjugated corticosterone (B-BSA, 10μmol/L)were carried out to observe their influence on peak amplitude of NMDA-evoked current. Results: B had a rapid, reversible and inhibitory effect on peak amplitude of GLU-or NMDA-evoked current in cultured hippoeampal neurons. Furthermore, B-BSA had the inhibitory effect on INMDA as that of B, but intraeeUularly dialyzed B had no significant effect on INMDA. Conclusion: These results suggest that under the condition of stress, GCs may rapidly, negatively regulate excitatory synaptic receptors-glutamate receptors (GluRs), especially NMDA receptor (NMDAR) in central nervous system, which is mediated by rapid membrane mechanisms, but not by classical, genomic mechanisms.     

溶剂在嵌段共聚高分子膜中的溶解与传递现象

利用石英弹簧称重法测定了308．15K时乙醇和苯在含端羟基聚丁二烯(HTPB)和端羟基聚丁二烯／丙烯腈共聚物(HTBN)的嵌段共聚聚氨酯膜中的吸收动力学曲线。结合吸收-络合吸附双模式传递模型，研究了聚氨酯膜的微相分离程度、软硬段的比例和组成以及软段分子量等因素对溶剂在膜中溶解和传递性质的影响。     

99Tcm标记人源化抗人血小板膜糖蛋白Ⅲ a单克隆抗体SZ21F(ab)2血栓栓塞显像

目的用动物血栓栓塞模型显像评估99^Tc^m标记人源化抗人血小板膜糖蛋白（GP）Ⅲa单克隆抗体（简称单抗）F（ab）2片段SZ21F（ab）2的应用价值。方法通过体外抑制二磷酸腺苷（ADP）诱导的犬血小板聚集实验，评估SZ21F（ab）2与血小板结合的亲和性和特异性。以2-亚氨基噻吩盐酸盐（IT）法修饰SZ21F（ab）2分子的亚氨基，以99^Tc^m-葡庚糖酸钠（GH）转换络合法进行标记。分别用快速薄层层析（ITLC）法和ELISA测定标记物的放化纯及生物活性。对3条肺动脉血栓和8条（包括上述3条）后肢深静脉血栓栓塞比格犬模型进行显像研究。结果SZ21F（ab）2抑制ADP诱导的犬富含血小板血浆（PRP）聚集实验的半数有效剂量（IC50）为（2．49±1．88）μg／ml。ITLC法测得标记物的放化纯为90％～95％，ELISA测定结果表明标记后抗体保留了免疫活性。注射显像剂后1h，肺动脉血栓部位和后肢深静脉血栓部位均出现放射性浓聚。注射后3h，在体显像肺动脉血栓和后肢深静脉血栓栓塞模型的放射性靶／本底（T／B）比值分别为3．03±1．18和3．51±0.62。肺动脉血栓部位和后肢深静脉血栓部位的每克组织百分注射剂量率（％ID／g）分别为0．083％ID／g和0．076％ID／g。体外检测结果表明：肺动脉血栓与正常肺组织的单位质量放射性比值平均为12．8，后肢深静脉血栓与血液的单位质量放射性比值平均为5．2，与肌肉的比值平均为127.0。结论99^Tc^m-SZ21F（ab）2与人血小板具有较高的亲和力，有潜在的血栓显像应用前景。     

Cell surface molecules of human teratoma cell lines

Conventional antisera, monoclonal antibodies and lectins have been used to investigate the cell surface composition of several human teratoma-derived cell lines. This review summarizes our current knowledge obtained from such investigations and uses the information available on murine teratocarcinoma systems as a framework for discussion to compare and contrast the human and murine systems. The potential application of antibodies directed against cell surface molecules in such techniques as in vivo tumour imaging and drug targeting is also discussed.     

带膜金属支架治疗食管癌术后胸内吻合口瘘的临床研究

目的探讨镍钛记忆合金带膜内支架在治疗食管癌术后胸内吻合口瘘中的应用价值。方法在X线电视透视下对22例食管癌术后胸内吻合口瘘患者进行镍钛记忆合金带膜内支架植入治疗。结果19例一次植入成功，成功率86％，恢复正常饮食；不完全封堵瘘口3例（14％）；16例术后出现轻度的胸骨后疼痛不适或胃液反流的症状；1例出现上消化道大出血。22例病人均治愈出院，治愈率100％。结论镍钛记忆合金带膜内支架植入治疗食管癌术后胸内吻合口瘘成功率高，治愈率高，操作简单，安全，见效快，并发症少，有效解除患者痛苦，宜在临床上推广使用。     

芦沙坦对轻、中度高血压病患者血小板活化和肾功能的影响

目的 :研究芦沙坦对轻、中度高血压病患者血小板活化和肾功能的影响 ,并探讨血小板活化和高血压性肾损害的关系。方法 :6 0例轻、中度高血压病患者随机分为两组 ,分别接受芦沙坦、氨氯地平治疗 3个月。治疗前后检测尿蛋白排泄率 (UAER)、血浆α颗粒膜蛋白 (GMP 14 0 )、血尿素氮 (BUN)、血肌酐 (Bcr)和肌酐清除率 (CCR)。结果 :①治疗后两组患者血压均明显下降 (P <0 .0 0 1) ,GMP 14 0和UAER均显著降低 (P <0 .0 0 1) ,BUN ,Bcr,CCR无明显变化 ;②两组患者治疗前、治疗后UAER与GMP 14 0呈显著正相关 (r分别为 0 6 9和 0 4 8) ,与血压下降无显著相关。结论 :①芦沙坦、氨氯地平能有效地控制轻、中度高血压病患者血压 ,减轻早期高血压性肾损害 ;②推测该药可能通过抑制血小板活化而对肾功能产生保护作用