电子直线加速器照射对NIH 3T3细胞的细胞周期及凋亡的影响

目的 探讨电子直线加速器照射对细胞周期及细胞凋亡的影响。方法 采用直线加速器对NIH 3T3细胞进行照射，观察细胞周期及细胞凋亡的改变情况；同时测定损伤前后p53蛋白的表达情况。结果 照射后细胞凋亡数增加，p53蛋白表达量上升。结论 电子直线加速器照射损伤可诱导细胞凋亡。     

ELISA法检测可溶性人类白细胞抗原—I及广东人参考值的测定

OBJECTIVE: To explore a method for quantitative detection of soluble human leukocyte antigen class I(HLA-I) antigens, with the assistance of which we attempt to define the reference value of the antigen in the population of Guangdong Province. METHODS: Sandwich enzyme-linked immunosorbent assay (ELISA) was employed with W6/32 monoclonal antibody serving as the solid phase antibody and beta2 microglobulin antibody as the first antibody. HRP-labeled second antibody and the substrate were added for enzyme-catalyzed coloring. On the basis of the standard curve obtained by sHLA-I standard reagent in serial dilution, the concentration of sHLA-I antigens in the samples of 60 normal subjects from the population of Guangdong province was detected. RESULTS: The sensitivity of this assay was 2.84 ng/ml with variation coefficients of 5.80% within the same batch and 9.00% between batches. The recovery rate ranged from 98.57% to 100.15%. The level of sHLA-I antigens in normal individuals was 699.54+/-360.10 ng/ml. CONCLUSION: Sandwich ELISA is sensitive, specific and stable in the detection of sHLA-I.     

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.     

油茶皂甙对实验动物造血机能的影响

目的：研究油茶皂甙对豚鼠和罗非鱼造血功能的影响。方法：比较油茶皂甙（1mg/kg）处理前和处理后豚鼠红细胞和血红蛋白量计数变化。罗非鱼分对照组和油茶皂甙处理组，分别在清水和含1ppm油茶皂甙水饲养6天后，再同时置入清水中净养，观察其存活20％的最高温度。结果：豚鼠用药前后红细胞计数和血红蛋白含量改变轻微，无明显统计学差异（P＞0．05），对照组和油茶皂甙处理组罗非鱼在清水中饲养的耐受最高温度为41．5℃，但在含油茶皂甙水中能耐受的最主温度为36℃。结论：油茶皂甙可短暂，轻微地降低红细胞和血红蛋白，但并不影响造血功能。     

"立交桥"高职护理人才培养模式初探

为探讨中等卫生学校毕业就读高等护理专业学生（即“立交桥”高职）的培养模式，在坚持高等教育培养目标及职业特色的前提下，结合学生特点，进行课程设置、教学方法及临床实践等方面的改革，以发挥学生的优势，弥补学生的不足，培养适应现代护理发展需要的高质量护理人才。     

后囊连续环形撕囊在儿童人工晶体植入术的应用

后发障是儿童白内障最常见的并发症，是导致术后视力下降的主要原因，故降低后发障的发生率对提高术后视力及减少弱视的发生非常重要，以往文献报道大多是术后行ND-YAG激光后囊切开术来治疗后发障。笔者近年对儿童白内障采用白内障摘除人工晶体植入联合后囊连续环形撕囊术预防人工晶体术后后囊混浊，效果肯定，报告如下。     

大学生网络成瘾量表的初步编制

目的编制可供评估网络成瘾倾向的自评量表。方法采用自编《大学生网络成瘾量表》为研究工具对197名在校大学生为被试进行测试。结果①初步编制的《大学生网络成瘾量表》共46条目,包括2个分量表:网络成瘾倾向和网络成瘾类型分量表,其中网络成瘾倾向分量表分为成瘾症状成分(即成瘾症状、消极影响2个维度)和认知、情感体验成分(即内心体验、自我认知2个维度);网络成瘾类型分为网络关系成瘾、网络娱乐成瘾、信息搜集成瘾和网络性成瘾4个维度;②本量表具有较好的信度:成瘾倾向分量表及各维度的同质性信度为0·80~0·95,网络成瘾类型分量表为0·78,符合测量学标准;网络成瘾倾向分量表及各维度的重测信度除消极影响为0·67外,其他为0·75~0·88,网络成瘾类型分量表为0·74,也都基本达到心理测量学标准;③本量表成瘾倾向分量表的成瘾标志和消极影响维度与陈淑惠《中文网络成瘾量表》各个因子以及总分的相关(0·78~0·83)均显示有统计学意义,说明其具有良好的结构效度。结论该量表评价内容范围较宽、提供信息量较大,题目量适中,并且其信、效度较好,为后续研究打下了良好基础。     

Intracellular Ca2+ suppressed a transient potassium current in hippocampal neurons

The effects of intracellular Ca2+ (Ca2+i) on K+ currents in hippocampal cells were examined using acutely isolated cells obtained from adult guinea pigs. Whole-cell voltage-clamp recordings were carried out in a configuration that allowed a continuous perfusion of the intracellular medium. Recording media were made to block inward currents and allowed selective activation of K(+)-dependent outward currents. Voltage-dependent outward currents consisted of an initial rapidly decaying component followed by a sustained component. The time constant of decay of the transient current was about 25 msec, and previous studies (Numann et al., 1987) showed that the kinetic and pharmacological properties of this current closely resembled the A current recorded in invertebrate neurons (Connor and Stevens, 1971; Thompson, 1982). Intracellular perfusion of hippocampal cells with a solution containing elevated Ca2+ (about 4.5 x 10(-4) M) elicited outward currents at the holding potential (-45 to -55 mV) and produced changes in voltage-dependent K+ currents. The transient outward current (IA) activated by depolarization was suppressed with increases in Ca2+i. Delayed, sustained K+ currents were greatly potentiated. Data also showed that, among the 3 effects elicited by Ca2+i, suppression of IA was most sensitive to Ca2+i elevation. Previous results (Numann et al., 1987) showed that IA had a lower threshold (about -45 mV) than sustained currents (about -40 mV). By using low levels of depolarization (-40 mV), IA can be selectively activated, and the suppressive effect of Ca2+i on IA was confirmed on the kinetically isolated IA.(ABSTRACT TRUNCATED AT 250 WORDS)