磷脂双层膜稳定性的理论分析

目的：越来越多磷脂双层膜的原子力显微镜扫描力谱显示溶液离子浓度对磷脂双层膜稳定性有很大影响，本文从理论角度研究溶液离子浓度对磷脂双层膜稳定性的影响，同时解释两个基于不同模型模拟结果差别的原因。方法：主要根据磷脂分子极性端带电特性，将极性端看作偶极子，然后基于偶极-偶极相互作用理论以及泊松-玻尔兹曼理论解决以上问题。结论：随着离子浓度的增加，磷脂双层膜趋于更加稳定；基于两个不同模型模拟结果差别的原因是高浓度溶液的强静电屏蔽作用。     

食管分层应力-应变研究

目的　探讨食管壁各层环向应力 应变分布特征。方法　将 8只Wister大鼠的食管标记、测量在体长度后剪下置于去钙离子Krebs液中。剪下标记的中段食管用做充压试验 ,将其在显微镜下分离成内层食管 (粘膜和粘膜下层 )和外层食管 (固有肌层 )。充压时全层和分层食管均被拉长至在体长度 ,以每分钟升高 2cmH2 O速度匀速充压。根据所测图像的几何数据计算全层和分层食管的Kirchhoff应力和Green应变。零应力状态作为计算应力和应变的基本参照状态。结果　 (1 )食管离体后较在体长度缩短 2 4%。 (2 )全层食管和分层食管的环向应力 应变曲线均符合指数方程τ =(τ +β)eα(ε-ε ) -β(判定系数 >0 .96) ,为非线性关系。 (3 )与全层食管相比 ,分层后内层食管应力 应变曲线较陡直 ,且移向左侧 ,差别有统计意义 (P <0 .0 5 ) ,外层食管的曲线移向右侧 ,差别无统计意义 (P >0 .0 5 ) ,内外两层食管的应力 -应变曲线亦有统计差别 (P <0 .0 5 )。结论　食管壁各层环向应力 -应变均符合非线性关系 ,食管内层不如外层易变形     

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.     

Association of genetic polymorphisms and haplotypes in hMLH1 and hMSH3 gene with the risk of papillary thyroid carcinoma

OBJECTIVE: To explore the relationship of the genetic polymorphisms and the haplotypes in hMLH1 and hMSH3 gene with the risk of papillary thyroid carcinoma (PTC) in Chinese Hans. METHODS: A hospital based 1:1 matched case-control study was carried out. The polymorphisms for 204 pairs of PTC cases and healthy controls were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele specific oligonucleotide (PCR-ASO) assays. RESULTS: (1) The PTC risk was marginally increased in the hMLH1 1151TA genotype, with odds ratio (OR) of 2.15 (95%CI: 0.99-4.85); the PTC risk was significantly increased in the mutant genotype 1151TA+AA, with OR of 2.15 (95%CI: 1.02-4.69); (2) The haplotypes of -93G, 1151A, 655A in the hMLH1 gene could increase the PTC risk, with OR of 2.67 (95%CI: 1.16-6.53, P=0.011), compared with the haplotype of -93G, 1151T, 655A; (3) Compared to 3124A, 2835G haplotype in hMSH3 gene, the 3124G, 2835A haplotype could increase the PTC risk marginally, with OR of 3.08 (95%CI: 0.92-13.25). CONCLUSION: The 1151T/A polymorphism in hMLH1 was associated with PTC; both the haplotype of -93G, 1151A, 655A in hMLH1 and the 3124G, 2835A haplotype in hMSH3 were associated with PTC.     

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.     

The nationwide epidemiological study of mental disorders in korea

The lifetime prevalences of DSM-III mental disorders using Korean version of DIS-III are presented. They were studied in 5,100 adults (aged 18 to 65) in household selected by two stage cluster sampling. Comparisons were made between regions, sex and age groups. International comparison with Epidemiologic Catchment Area program was also made.