异戊塞平和克塞平对大鼠脑内各受体亲和力的比较及慢性给药后的受体下调作用

用放射配体受体结合法测定表明:克塞平对多巴胺D_1受体的亲和力较异戊塞平高近20倍。两药对其它各受体的亲和力差別不大。慢性给药后,异戊塞平和克塞平均能使大鼠脑皮层5-HT_2受体的密度显著下降,而亲和力变化不明显。这种下调5-HT_2受体的作用发生在给异戊塞平后1～2周之间,给克塞平后的2～3周之间。慢性给药3周,异戊塞平和克塞平均未使大鼠脑皮层的β受体密度及亲和力产生显著变化。     

Modified polyalkenoate (glass-ionomer) cement – a study

summary Conventional glass-ionomer cements with varying amounts (5–15%) of borax (Na₂B₄O₇.10H₂O) as modifier were prepared. These mixtures were spatulated with an aqueous solution of polyacrylic acid with a powder to liquid (P/L) ratio of 1.5:1. Properties such as working time, setting time, compressive strength, diametral tensile stength, solubility and fluoride release of these cements were determined. It was observed that the working time and setting time of the resultant cements shortened with the addition of borax. Certain physical properties such as compressive and diametral tensile strength, solubility and disintegration of these glass-ionomer cements deteriorated with borax addition but fluoride release from them was unaffected.     

Interrelationship between TP53 gene deletion, protein expression and chromosome 17 aneusomy in gastric adenocarcinoma

Background  

This study evaluates the existence of numerical alterations of chromosome 17 and TP53 gene deletion in gastric adenocarcinoma. The p53 protein expression was also evaluated, as well as, possible associations with clinicopathological characteristics.     

诊断性ERCP研究进展

内镜下逆行胰胆管造影术(ERCP)仍是目前诊断胰胆疾病的金标准.但ERCP术后胰腺炎不可避免.自从出现磁共振胰胆管造影(MRCP)以来,MRCP已被广泛应用于临床,具有代替诊断性ERCP的潜在可能性.但目前MRCP设备尚不普及.和ERCP相比,MRCP图象不十分理想.随着技术进步,诊断性ERCP应用有可能逐渐减少,成为取得组织学、细胞学标本和功能研究的方法.     

心房颤动的电生理重构

心房颤动 (atrial fibrillation,AF)是临床上最常见的一种持续性心律失常 ,其发病率随年龄而增加 ,40岁以下人群发病率约为 0 .2 %～ 0 .3% ,6 0～ 90岁年龄组发病率增至5 %～ 9% [1 ] 。新近 Framingham的研究表明 AF可以成为一种独立的因素使患者病死率增加 [2 ] 。 AF的发病机制尚未完全清楚 ,可能为非单一机制 ,普遍认为持续性 AF是由于心房内的多子波折返 ,每 1个折返环本身都在不停地改变其大小及传导方向。近年来 ,在 AF的基础及临床研究中 ,两个方面的进展具有十分重要的意义 :一是发现部分 AF起源于心房内某些部位如肺静脉口…