Heterologous expression of rat testis GABA_A receptor P3t variant in Chinese hamster ovary cells

Aim: To study the characteristics and possible retention function of specific sequence in the 5'-end of rat testis GABAA receptor β 3t variant. Methods: Rat testis GABAA receptor β 3t variant cDNA was cloned and inserted into two eukaryotic expression vectors of pEGFP-Nl and pEGFP-Cl respectively, which have EGFP reporter gene. The recombinant plasmids were transfected into Chinese hamster ovary (CHO) cells with the calcium phosphate co-precipitation method. Fluorescence microscope and laser confocal microscope were used to analyze the transfected cells. ConA-Texas-Red was used to label cell endoplasmic reticulum (ER) and study the located area of rat testis β 3t variant in the CHO cells. Results: When the rat testis β 3t variant express in CHO cells, there were two expression pattern, the even and the concentrated expression pattern. Although rat brain β 3 can reach cell membrane, the rat testis β 3t variant can't target to the cell membrane. It may be retained in the ER of CHO cells. Conclusion:     

运动对体内代谢产物排出量的影响

选择年龄15～18岁的体育学校学生23名(男14、女9),随机分为三个不同的运动组进行跑台训练。结果显示:运动可导致尿乳酸,尿蛋白、尿糖和尿素氮含量增加。无氧训练时尿乳酸的增加尤为明显;尿蛋白的增多与尿液乳酸含量呈正相关;尿素氮水平的升高则以有氧耐力运动时为甚。     

维甲酸改变人肝癌细胞表面N－糖链的结构及其酶学机制

用３Ｈ－甘露糖标记７７２１人肝癌细胞表面糖蛋白的Ｎ－糖链，经提取和去唾液酸后，用ＣｏｎＡ和ＤＳＡ亲和柱顺序层析将３Ｈ－标记的Ｎ－糖链分成４个类型和天线数不同的组分来研究维甲酸（ＲＡ）对细胞表面Ｎ－糖链的影响。结果：１０μｍｏｌ／ＬＲＡ处理细胞３～５ｄ后，可使Ｃ２Ｃ２二天线复杂型Ｎ－糖链增加，而高甘露糖型及三、四天线，特别是带有Ｃ２，６分支结构的复杂型Ｈ－糖链减少。用ＬＣＡ亲和柱还证明二天线糖链中的核心岩藻糖也减少。进一步发现上述改变的酶学机制是ＲＡ降低Ｎ－乙酰氨基萄葡糖转移酶Ｖ和α－１，６－核心岩藻糖转移酶的活力。结论：ＢＡ通过改变某些糖基转移酶活力而改变细胞表面糖链结构，这可能是ＲＡ使７７２１细胞诱导分化的机理之－。     

cAMP对胰岛素刺激的NIH3T3细胞丝裂原激活蛋白激酶活性的抑制作用

目的 探讨cAMP-PKA信号途径对胰岛素激活的Ras-丝裂原激活蛋白激酶(MAPK)信号途径的影响。方法 以3-异丁基-1-甲基黄嘌呤(IBMX)提高细胞内环腺苷酸(cAMP)浓度，藉四唑蓝比色法(MTT法)和蛋白免疫印迹试验分别观察cAMP对胰岛素刺激的小鼠成纤维细胞(NIH3T3细胞)的生长增殖和胞内丝裂原激活蛋白激酶(MAPK)活性的影响。结果 IBMX(0．5mmol/L)抑制静息的和胰岛素(10mU／mL)刺激的NIH3T3细胞的增殖，作用呈时间依赖性。在胰岛素(10mU／mL)刺激的NIH3T3细胞，MAPK出现酪氨酸磷酸化；而以IBMX(0．5mmol/L)预处理细胞30min后，再以胰岛素作用10min，胰岛素刺激的MAPK的酪氨酸磷酸化受抑制。结论：cAMP可通过抑制MAPK磷酸化活化对NIH3T3细胞增殖起抑制作用。     

转染反义磷脂酶A2寡核苷酸抑制LPS诱导Hela细胞分泌IL-1β和IL-6

目的：研究脑浆型磷脂酶A2(cytosolic phospholipase A2,cPLA2,85—kD PLA2)在脂多糖诱导Hela细胞释放细胞因子IL-1β、IL-6的信号机制中的作用。方法：①利用脂质体将cPLA2的反义寡核苷酸转染入Hela细胞，通过聚合酶链式反应(RT—PCR)及Western杂交印迹分析检验胞浆中cPLA2人水平的变化；②用放免方法检测不同时间培养上清中的IL-1β、IL-6浓度。结果：①转染后cPLA2的蛋白表达明显减少，但mRNA水平未见显著改变；②Hela细胞释放IL-1β、IL-6随cPLA2人反义寡核苷酸浓度的增加而减少。结论：cPLA2人LPS刺激的Hela细胞释放炎性细胞因子IL-1β、IL-6的过程中可能发挥重要的信号传递作用。     

人胃癌SGC-7901细胞胞浆胞核性激素受体测定

 作者采用葡聚糖包被活性碳饱和分析法(DCC法)分别测定了培养的人胃低分化腺癌SGC-7901细胞的胞浆及胞核KCL抽提液中的雌激素受体(ER)、孕激素受体(PR)和雄激素受体(AR)的含量。 结果证明胃癌SGC-7901细胞的胞浆及胞核抽提液中ER含量为30.2和35.7fmol/mg蛋白，而PR的含量为20.3和22.7fmol/ng蛋白, 但AR均为阴性(<10fmol/mg蛋白), 这说明SGC-7901细胞为ER及PR阳性细胞, 其ER和PR在胞浆、胞核中均有分布。 提示胃癌可能为性激素依赖性肿瘤, 有内分泌治疗的可能。     

遗传代谢病所致贫血的诊疗专家共识

遗传代谢病是一大类复杂的单基因病,由于代谢通路异常导致物质代谢紊乱,可以引起单系统或多系统损害.血液系统疾病涉及红细胞、白细胞和血小板功能和数量的异常,其中贫血最常见,新生儿到老年均可发病.现有研究发现,多种遗传代谢病可导致贫血,致病机制不同,一些疾病引起铁、维生素B12、叶酸代谢异常,另一些造成红细胞膜、代谢相关酶或血红蛋白合成异常,引起不同类型不同程度的贫血.为了提高临床医生对遗传代谢病所致贫血及血液系统疾病的认识,早期诊断、精准治疗、改善预后,国内多学科专家共同讨论,结合国内外经验及指南,以巨幼细胞性贫血、溶血性贫血、铁粒幼细胞性贫血和小细胞低色素性贫血四类贫血相关的遗传代谢病的病因、发病机制、临床表现和治疗为重点,制定了本共识,以期指导优化临床诊治实践.     

Effect of insulin in vitro on the isolated,perfused alloxan-diabetic rat liver

Summary Withdrawal of exogenous insulin and a subsequent fast (24 h) of alloxan diabetic rats stimulated rates of gluconeogenesis, ureogenesis, ketogenesis, and amino acid release by in situ perfused livers when compared to those from normal, fasted rats. The contribution of liver glycogen to the high rates of gluconeogenesis observed with the diabetic liver could be excluded. Perfusate lactate concentrations remained constant during the period when the elevated rate of gluconeogenesis was observed with diabetic liver. Addition of insulin as a bolus (750 mU) and continuous infusion (12.5 mU/min) to the perfusion medium of diabetic livers resulted in constant perfusate levels of glucose, urea and -amino nitrogen indicating a suppression of the catabolic processes present in the fasted, diabetic liver. The rate of ketogenesis was also slowed by insulin to about half the rate prior to addition of the hormone. These data indicate that insulin has an immediate anti-catabolic effect in the perfused, diabetic liver.     

正常人生长激素基因簇的结构分析及生长激素缺乏症的DNA诊断

利用DNA诊断技术,对正常人及16例侏儒症患者外周血白细胞DNA生长激素基因簇进行分析,在中国人种中首次发现2例患者(系同胞姐妹)为缺失包括hGH-N基因在内的7.1kbDNA片段的纯合子。患者的双亲、祖母及外祖母为携带缺失基因的杂合子,但表型正常;患者的祖父及外祖父为正常的纯合子,此疾病为常染色体隐性遗传病。其他14例患者均未发现hGH-N基因的缺失。对绒毛DNA分析结果表明与正常人白细胞DNA是一致的。这一方法在优生学上可作产前及婚前诊断,避免hGH-N基因缺失的纯合子出生。