硫代乙酰胺所致急性肝衰时内毒素血症与肝内胆汁淤积关系的研究

本实验采用硫代乙酰胺（thioacetamide，TAA）灌胃复制大鼠急性肝功能衰竭的动物模型。检测血中内毒素、转氨酶、脂蛋白-x等含量以及胆汁流量。结果表明，大鼠发生了肝内胆汁淤积与内毒素血症（ETM），并且两者呈正相关（P＜0．05）。同时肝细胞膜上Na -K -ATP酶的活力明显降低，与ETM含量呈负相关（P＜0．05）。结果提示：ETM与肝内胆汁淤积的发生有密切关系．     

Congenital cytomegalovirus infection in Korean population with very high prevalence of maternal immunity.

In order to asses congenital cytomegalovirus (CMV) infection in Korea, five hundred and seventy five pregnant women (mean age 29.5 +/- 3.8 yrs., mean gestational age at test 37.5 +/- 6.7 weeks) visiting the prenatal clinic at Severance Hospital, Seoul, Korea were studied. CMV IgG antibody was present in 96% (552/575) and IgM antibody was present in 0.7% (4/575) of the pregnant women by the third trimester. Four of 445 cord sera were positive for CMV IgM antibody (0.9%). Urine samples from 514 newborns were tested for the evaluation of congenital CMV infection. Six (1.2%) of 514 newborns excreted CMV in their urine. All the congenitally infected infants had subclinical involvement at birth and during the 12 months of the follow-up period. These results indicate that Korean pregnant women were highly immunized against CMV by the third trimester. Furthermore this study suggests that the rate of congenital CMV infection is relatively as high as rates previously reported from other countries, although there is a very high prevalence of maternal immunity. The incidence of maternal primary infection during pregnancy seems to be rare and therefore most congenital infections in Korea might be following by maternal reactivation or reinfection.     

Effect of melanin produced by a recombinant Escherichia coli on antibacterial activity of antibiotics.

A recombinant plasmid, pYL-1, containing a tyrosinase gene whose expression is under the control of a phage T5 promoter and 2 lac operators, was constructed. Escherichia coli JM109 harboring pYL-1 was used for production of bacterial melanin. A simple procedure for the isolation and purification of melanin was developed. The ultraviolet (UV)-visible light absorption spectra of melanin prepared by chemical synthesis and derived from different organisms, including bacteria, a plant and an animal source, were determined. Melanins produced by both bacteria and chemical synthesis showed a steady increase of absorption at wavelengths of UV light ranging from approximately 200-400 nm, while melanin derived either from plant or animal sources showed an additional discrete absorption peak at wavelength 280 nm upon a similar steady increase of absorption. This additional absorption peak could be due to the presence of protein-bound melanins in animal and plant sources while a free form of melanin was obtained from bacteria and chemical synthesis. Analysis of the effect of bacterial melanin on the activity of antibiotics against E. coli revealed that the activities of polymyxin B, kanamycin, tetracycline, and ampicillin were markedly reduced in the presence of melanin, whereas the activity of norfloxacin was not affected. The reduction of the antibacterial activity may result directly from the interaction of antibiotics with melanin. However, the mechanism of this interaction remains to be demonstrated.     

前列腺癌病理诊断中的若干概念性、技术性和经验性问题

近10年来随着我国前列腺癌穿刺活检和切除标本量的迅速增加,国内病理学者对前列腺癌的诊断水平快速提高.早期在穿刺活检中将误穿的精囊腺组织、尿道球腺组织和神经节细胞误诊为前列腺癌的低级错误现在已很少发生,前列腺癌的形态学诊断指标、腺癌的各种组织学变异、Gleason分级标准也已经逐渐普及.但由于我国在这一领域起步较晚,地区和医院间发展不平衡,我们在日常会诊中还是经常发现一些带有共性的问题,这些错误有的是概念性,有的是经验性,也有的是在诊断前的标本处理上就存在缺陷.我们将目前前列腺癌病理诊断中的常见误区归纳为以下几点,供大家在日常工作中参考.     

中国东北汉族一个先天性白内障家系致病基因的鉴定

目的鉴定一个先天性白内障家系的致病基因。方法根据已知与先天性白内障有关的12个致病基因的染色体上的定位,分别选取3～4个的微卫星标记位点,对该家系进行连锁分析。通过测序鉴定致病基因。结果在1q21.1GJA8位点显示最大Lod值2.44。致病基因定位于1q21.1区的GJA8基因,构成缝隙连接的缝隙连接蛋白Connexin50。DNA序列分析鉴定显示其第2外显子的第191个碱基杂合突变T>G导致其蛋白产物第64位缬氨酸转变为甘氨酸。结论Connexin50的V64G新生突变是导致该家系的致病原因。     

Apolipoprotein B-100 gene Xba I polymorphism and cholesterol gallstone disease

The apolipoprotein (apo) B gene Xba I polymorphism is associated with alterations in serum lipids. Disturbances in serum lipids may be a risk factor for cholesterol gallstone disease. However, the relation between the Xba I polymorphism and cholesterol gallstones is unknown. This study was aimed at characterizing the polymorphism of the apo B gene Xba I in patients with gallbladder stones and the association of Xba I polymorphism with serum lipids. Xba I genotypes were measured by PCR-RFLP, and serum lipids assayed in 190 patients with gallbladder stones and 441 control subjects. The frequency of the X+/- genotype (20.63 vs. 7.94%) and X+ allele (10.79 vs. 3.97%) was significantly higher in the patient group than in the control group. Patients with the X+/- genotype had a significantly higher concentration of total cholesterol, low-density lipoprotein (LDL)-cholesterol, and apo B in serum than patients with the X-/- genotype. The X+ allele of the apo B gene is characterized by a higher cholesterol concentration and a higher LDL-cholesterol concentration in serum, and it may be a marker for increased risk of cholesterol gallstone disease.     

Nanog蛋白在小鼠心肌组织发育中的表达

目的:探讨Nanog蛋白在小鼠心肌组织发育中的表达规律.方法:利用ABC免疫组织化学法观察18 d胎鼠组、6 d和12 d新生鼠组心肌组织中Nanog蛋白的表达;利用计算机图像处理系统对Nanog蛋白进行定量分析.结果:Nanog蛋白在18 d胎鼠组心肌细胞质中呈云雾样强阳性表达.在6 d新牛鼠组心肌细胞质中,Nanog蛋白较18 d胎鼠组阳性表达减弱,12 d新生鼠组的心肌细胞质呈现极弱阳性表达.3个年龄组心肌中的毛细血管内皮细胞均呈现强阳性表达.定量分析显示,胎鼠组心肌组织和6 d新生鼠组心肌组织的Nanog蛋白的含量尤显著件变化,12 d新牛鼠组心肌组织的Nanog蛋白比胎鼠心肌组织明显增加.结论:Nanog蛋白在小鼠心肌组织发育中表达规律是从胎期开始随着心发育,心肌细胞Nanog蛋白的含量逐渐减少,内皮细胞中Nanog蛋白逐渐增多.     

大鼠再生肝对二乙基亚硝胺启动作用的敏感性

目的比较再生肝和正常肝对二乙基亚硝胺（ＤＥＮ）启动作用的敏感性。方法以２／３肝叶切除后８周末的大鼠为实验组,正常大鼠为对照组,作如下比较：肝重、常规组织学检查及３Ｈ－ＴｄＲ掺入试验;用修改的Ｓｏｌｔ－Ｆａｒｂｅｒ模型,通过对ＧＧＴ阳性癌前病灶的体视学测量,观察肝脏对ＤＥＮ的启动效应;在体内和体外（无血清原代培养肝细胞）经ＤＥＮ攻击后,以核酸原位缺口标记方法观察肝细胞ＤＮＡ的损伤程度。结果２／３肝叶切除后８周末的实验组肝脏的修复过程已完成,未见肝细胞继续增生的表现;经ＤＥＮ攻击后,实验组肝癌前病灶在数密度和体积密度上都显著高于对照组;无论在体内或体外接受ＤＥＮ攻击后,实验组肝细胞ＤＮＡ的损伤程度都显著大于对照组。结论即使再生过程已经完成,再生肝仍比正常肝具有较高的致癌敏感性,这与再生肝肝细胞在ＤＥＮ攻击后其ＤＮＡ损伤较重相关。     

Disconnection of the amygdala central nucleus and substantia innominata/nucleus basalis disrupts increments in conditioned stimulus processing in rats

Rats with a neurotoxic lesion of the amygdala central nucleus (CN) in one hemisphere and a 192 immunoglobulin G (192IgG)-saporin lesion of cholinergic neurons in the contralateral substantia innominata/nucleus basalis (SI/nBM) failed to show the enhanced attentional processing of a conditioned stimulus (CS) observed in sham-operated rats when that CS's predictive value was altered. Performance of these asymmetrically lesioned rats was poorer than that of rats with a unilateral lesion of either structure or with a symmetrical lesion of both structures in the same hemisphere. These results implicate connections between the CN and SI/nBM in the incremental attentional processing of CSs, extending previous research that has shown similar effects of bilateral lesions of either the CN or the SI/nBM.