羧乙基锗倍半氧化物对大鼠脑缺血再灌注损伤的保护作用

采用结扎双侧颈总动脉后再通的方法复制大鼠脑缺血再灌注损伤模型，通过测定再灌注后大鼠海马组织中脂质过氧化产物丙二醛（ＭＤＡ），超氧化物歧化酶（ＳＯＤ）与谷胱甘肽过氧化物酶（ＧＳＨ—Ｐｘ）及ＡＴＰａｓｅ的活性，观察了有机锗─羧乙基锗倍半氧化物（ＣＧＳ）对大鼠脑缺血再灌注后大鼠海马组织中ＭＤＡ水平，明显保护ＳＯＤ、ＧＳＨ─Ｐｘ、Ｎａ＋Ｋ＋─ＡＴＰａｓｅ及Ｃａ２＋─ＡＴ─Ｐａｓｅ活性。表明ＣＧＳ对大鼠脑缺血再灌注损伤具有保护作用。     

1-乙基-6-氟-1,4-二氢-4-氧代-7-(4-芳酰硫代氨甲酰基-1-哌嗪基)-3-喹啉羧酸的合成及抗菌作用

Thirteen new 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-aroyl-thiocarbamoyl- 1 piperazinyl)-3-quinoline carboxylic acids were prepared, Their structures were characterized by elemental analysis, IR, HNMR and MS spectra.Preliminary pharmacological tests indicated that some of compounds Ia～m possess strong inhibiting activity against Escherichia coli, Bacillus subtilis and Proteus at concentration of 100 μg/ml.     

Effect of gradual rise in plasma calcium concentration on the impairment of atrioventricular nodal conduction due to verapamil

The possible reversal by calcium of the inhibitory action of verapamil on the atrioventricular (AV) node was investigated in anesthetized, atropinized dogs, with cardiac pacing. The His bundle potentials were recorded by endocavitory electrode and the AV node effective refractory period measured by the extrastimulus method. Calcium infusion was effective against the impairment of AV nodal conduction induced by verapamil, provided it remained moderate: the gradual rise in the plasma calcium concentration counteracted the effects of an infusion of verapamil on conduction time and effective refractory period in the AV node, as long as it did not exceed 5 mmol/L. However, beyond this level, calcium appeared less and less capable of reversing the effects of verapamil. Thus, the protective action of calcium had a bell-shaped dose-response curve, with the optimum at 5 mmol/L. This biphasic influence is consistent with the opposite opinions previously given concerning the antagonism between calcium and calcium blockers, depending on whether hypercalcemia brought into play was mild or major. In any case, the prominent role played by calcium in the slow inward current in the AV node accounts for the antagonism, observed in vivo, between calcium and verapamil. The pacemaker activity of the sinoatrial (SA) node was less influenced by both calcium blocker and calcium.     

脂质体介导人β-神经生长因子基因转染培养肌母细胞的表达研究

目的　了解含 β-神经生长因子 (β- NGF)基因的表达质粒 PSVCEP NGF- CAT在培养肌母细胞中的表达及 L ipofect AMINE阳离子脂质体介导的转染效率。方法　将表达质粒 PSVCEP NGF- CAT经 L ipofectAMINE转染至培养成的肌母细胞中 ,用免疫细胞化学方法检测基因在肌母细胞内的表达。结果　培养肌母细胞在转染 6小时吞噬脂质体最显著 ,转染 48小时后约 40 %的肌母细胞胞质内有β- NGF基因表达。结论　含β- NGF基因的表达质粒 PSVCEP NGF- CAT可以在培养肌母细胞中表达 ,脂质体转染的方法简便、有效     

Functional recognition of the neuronal tyrosine hydroxylase cAMP regulatory element in different cell types.

Transient transfection of pLB2CAT constructs bearing short synthetic oligonucleotides derived either from the tyrosine hydroxylase (TH) promoter or other sources was used to examine functional cAMP regulatory element (CRE) activity in a variety of cell lines. The region containing only the putative TH CRE was found to be as or more effective in conferring cAMP responsiveness onto pLB2CAT (which employs the TK promoter) than the immediate 272 bp region of the TH promoter. Increases in CAT activity of 10- to 20-fold were observed in JEG-3 cells with a single insert of the TH CRE region (-31 to -54) in pLB2CAT, and the presence of a second insert generated only a modest further increase. This construct also responded to cAMP in 4 other cell lines tested but the degree of increase was less dramatic. Inserts containing the consensus 8 bp CRE motif embedded in other natural or artificial contexts served generally as weak functional CREs in all cell lines tested. In vitro analysis revealed that a specific protein-DNA complex apparently containing a single protein with a MW of 45-50 kDa was formed equally well with JEG-3 cell nuclear extract and CRE-bearing-TH and other fragments which produced dramatically different cAMP effects in vivo. These results suggest specificity in the effects of cAMP on different CREs which are dictated by contextual differences.     

选择性环氧化酶—2抑制剂的研究现状及应用评价

选择性环氧化酶（COX）-2抑制剂可有效地治疗炎症，同时避免或减轻由于抑制COX-1而导致的毒副作用。有乐观的临床应用前景，但其不良反应亦不容忽视，寻找临床评价好的选择性COX-2抑制剂是当前非甾体类抗类药物研究的重点。     

Calcium-activated proteolysis of intracellular domains in the cell adhesion molecules NCAM and N-cadherin.

One of the consequences of increased intracellular calcium in response to a variety of physiological stimuli is the calcium activation of cytosolic proteases. Unlike lysosomal proteases with broad specificity, these calcium-activated neutral proteases show limited proteolysis of a restricted set of substrate proteins suggesting they may play a regulatory role in cellular physiology. In this study we show that the neural cell adhesion molecules NCAM-180 and N-cadherin are substrates for such endogenous calcium-activated neutral proteases. In contrast, a third neural cell adhesion molecule G4/L1 was not susceptible to calcium-activated proteolysis. The threshold for activation of NCAM and N-cadherin proteolysis is in the micromolar range of calcium suggesting that NCAM and N-cadherin are substrates for a mu-type calpain (calpain I). The site recognized by this protease is within intracellular domains of NCAM-180 and N-cadherin which are important for their interaction with cytoskeletal components. These results suggest that calcium-activated proteolysis at these sites in vivo could disrupt the linkage between extracellular ligand binding to these adhesion molecules and the normal intracellular effectors of such extracellular binding events.     

PGA指数和透明质酸在诊断慢性乙肝肝纤维化中的价值

目的：寻找一种简便实用的诊断慢性乙型肝炎纤维化的方法。方法：以78例经肝穿刺病理证实的慢性乙型肝炎为对象，测定并比较了由PT、GGT、ApoA1组成的PGA指数和HA、LN、PⅢP、C－IV与肝内纤维化程度(S)和炎症活动度（G）的关系。结果：（1）LN、PⅢP、C－IV在轻度慢性乙肝时无明显升高，在中度慢性乙肝时明显高于正常，但与轻度慢性乙肝无差异，而PGA指数和HA不仅在轻度慢性乙肝时显著升高，而且在轻中度间差异明显.因重度慢性乙肝和活动性肝硬化时，五项指标均显著增高。（2）在G2－4期，HA、LN、PⅢP、C－IV均明显高升，但在G1期，只有PGA指数高于正常，且各期间差异显著。（3）在S1－2期，只有PGA指数、HA、C－IV明显上升，但C－IV的上升幅度远低于PGA指数和HA。（4）加以PGA＞4．5或HA＞200μg／L作为判断临界值，则两者判断肝纤维化的敏感性均＞94％，精确性＞91％，特异性＞86％，如两者结合，则分别达到98．3％、95．2％和96．4％。结论：PGA指数和HA均是反映慢性乙型肝炎患者肝内纤维化程度的良好指标，两者联合检测则可达到最大的价值效益比。