Effects of hepatitis C and B viruses infection on the development of hepatocellular carcinoma

A case control study consisting of 102 patients with HCC, 102 sex-matched and age-matched patients with nonhepatic disease, and 204 matched healthy controls was carried out to investigate the effect of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection on the development of hepatocellular carcinoma (HCC). The prevalence of antibody to HCV (anti-HCV) in HCC (34.3%) was higher than in nonhepatic disease (10.7%, P< 0.001) or in healthy controls (2.4%, P< 0.001). The prevalence of hepatitis B surface antigen (HBsAg) in HCC (77.4%) was higher than in nonhepatic disease (16.6%, P< 0.001) or in healthy controls (19.6%, P< 0.001). Anti-HCV positivity in nonhepatic disease was higher than in healthy controls (P<0.01). Using patients with nonhepatic disease as controls, stepwise logistic regression analysis indicated that both anti-HCV (odds ratio, 3.4; 95% confidence interval, 2.1-5.6) and HBsAg (odds ratio, 5.6; 95% confidence interval, 3.6–8.5) are independent risk factors for HCC. Using healthy controls, the development of HCC was also strongly associated with anti-HCV (odds ratio, 8.0; 95% confidence interval, 4.3–14.6) and HBsAg (odds ratio, 5.5; 95% confidence interval, 3.7–8.2). Calculation of incremental odds ratio indicated that there is no interaction between HBV and HCV. In conclusion, HBV and HCV are risk factors of HCC. They act independently and without interaction. © 1994 Wiley-Liss, Inc.     

Mechanism of action and inhibition of dehydrosqualene synthase

"Head-to-head" terpene synthases catalyze the first committed steps in sterol and carotenoid biosynthesis: the condensation of two isoprenoid diphosphates to form cyclopropylcarbinyl diphosphates, followed by ring opening. Here, we report the structures of Staphylococcus aureus dehydrosqualene synthase (CrtM) complexed with its reaction intermediate, presqualene diphosphate (PSPP), the dehydrosqualene (DHS) product, as well as a series of inhibitors. The results indicate that, on initial diphosphate loss, the primary carbocation so formed bends down into the interior of the protein to react with C2,3 double bond in the prenyl acceptor to form PSPP, with the lower two-thirds of both PSPP chains occupying essentially the same positions as found in the two farnesyl chains in the substrates. The second-half reaction is then initiated by the PSPP diphosphate returning back to the Mg(2+) cluster for ionization, with the resultant DHS so formed being trapped in a surface pocket. This mechanism is supported by the observation that cationic inhibitors (of interest as antiinfectives) bind with their positive charge located in the same region as the cyclopropyl carbinyl group; that S-thiolo-diphosphates only inhibit when in the allylic site; activity results on 11 mutants show that both DXXXD conserved domains are essential for PSPP ionization; and the observation that head-to-tail isoprenoid synthases as well as terpene cyclases have ionization and alkene-donor sites which spatially overlap those found in CrtM.     

转化生长因子β1在大鼠纤维化腹膜组织中的表达及作用

目的:检测转化生长因子β1在腹膜透析大鼠腹膜内表达,并探讨其在腹膜纤维化中的意义。方法:实验于2005-06/2006-03在中南大学湘雅二医院肾内科实验室完成。①实验材料:雄性SD大鼠,体质量180～240g,由中南大学湘雅二医院动物实验中心提供。②实验方法:将28只大鼠按随机数字表随机分为4组,每组7只。正常对照组不予任何干预;生理盐水组腹腔注射20mL生理盐水;低糖透析液组腹腔注射20mL1.5%葡萄糖透析液;高糖透析液组腹腔注射20mL4.25%葡萄糖透析液,均为1次/d。4周后,向大鼠腹腔注射4.25%葡萄糖腹膜透析液20mL,4h后于大鼠右下腹缓慢插入带有多个侧孔的10号静脉留置针,缓慢低位引流腹透液,量取引流液。③实验评估:取大鼠壁层腹膜组织,以苏木素-伊红染色,镜下测量腹膜厚度,采用免疫组织化学方法检测大鼠腹膜中转化生长因子β1及纤连蛋白。结果:28只大鼠均进入结果分析。①高糖透析液组、低糖透析液组超滤量均明显低于正常对照组与生理盐水组,并且高糖透析液组超滤量明显少于低糖透析液组(P均<0.05)。②高糖透析液组腹膜明显增厚,表面粗糙,间皮细胞肿胀,脱落,间皮下有大量血管生成以及胶原纤维沉积,还可见单核细胞等炎症细胞浸润,与其他组比较,腹膜厚度明显增加(P<0.05)。③高糖透析液组转化生长因子β1、纤连蛋白表达量均明显高于其他组;低糖透析液组转化生长因子β1、纤连蛋白表达量均明显高于正常对照组与生理盐水组(P<0.05)。④大鼠腹膜组织转化生长因子β1蛋白与纤连蛋白表达量、腹膜厚度之间呈明显的正相关(r=0.86,0.83,P<0.05)。结论:葡萄糖透析液可诱导腹膜组织转化生长因子β1明显上调,腹膜转化生长因子β1高表达与腹膜透析腹膜纤维化密切相关。     

汉语阅读障碍儿童在本顿视觉保持测验中的反应特征

目的:比较阅读障碍儿童与正常儿童在本顿视觉保持测验中的反应特征,探索阅读障碍儿童视觉空间记忆能力的特点。方法:①2005-07/2006-05在儿童发育行为门诊遴选阅读障碍儿童20名(平均年龄10.2岁),按1∶1配对原则,选择年龄、性别、年级和家庭状况等条件与阅读障碍组相似的20名正常阅读能力儿童为对照组(平均年龄10.1岁)。②应用国内修订版本顿视觉保持测验C式B法,D式C法和E式D法对两组儿童进行个别测试。C式图卡呈现5s后让被试默画(视觉记忆能力),D式图卡让被试临摹(视觉结构能力),E式图卡呈现10s后间隔15s再让被试默画(视觉延迟记忆能力)。③对两组儿童的视觉记忆保持能力、视觉结构能力和延迟记忆能力进行测试,分别记录两组儿童测验的正确分(每一图卡根据全或无的原则记1或0分,总分0～10)及错误次数(错误类型分为遗漏或增加、变形、持续、旋转、位置错误和大小错误6个范畴),进行配对t检验。结果:40名受试者均进入结果分析。①正确得分:在视觉记忆和视觉结构能力测验中阅读障碍组低于对照组(5.00±2.45,6.60±1.82,P=0.019;7.50±2.44,8.95±1.32,P=0.015),在视觉延迟记忆测试中,两组得分比较差异不显著(P=0.077)。②总错误分:在视觉记忆和视觉结构能力测验中阅读障碍组高于对照组(7.65±4.20,4.90±3.24,P=0.016;3.20±3.93,1.15±1.46,P=0.035),在视觉延迟记忆测试中,两组得分比较差异不显著(P=0.389)。③错误类型:阅读障碍组儿童在视觉记忆能力测试中变形和持续性错误次数均显著多于对照组(3.95±2.40,1.75±1.52;0.35±0.67,0;P均<0.05),在视觉结构能力测试中变形错误次数显著多于对照组(1.35±1.69,0.35±0.75,P<0.05)。结论:阅读障碍儿童的视觉空间短时记忆能力、视觉结构和视觉运动整合能力存在缺陷。     

痰、瘀、虚为慢性阻塞性肺疾病发病的关键环节

目的:近年来,应用中医药治疗慢性阻塞性肺疾病研究已经深入到细胞分子生物学及病理形态学水平。本文对慢性阻塞性肺疾病从痰、瘀、虚三个关键环节进行辨证论治。方法:应用计算机检索万方数据库1994-01/2005-12期间的相关文章,检索词为“痰,瘀,虚,慢性阻塞性肺疾病”,并限定文章语言种类为中文。对资料进行初审,并查看每篇文献后的引文。纳入标准:文章所述内容应与慢性阻塞性肺疾病或痰、瘀、虚三个关键环节相关。排除标准:重复研究或Meta分析类文章。结果:共收集到176篇相关文献,20篇文献符合纳入标准,排除的156篇文献为内容陈旧或重复。符合纳入标准的20篇文献中,6篇从痰论治,4篇从瘀论治,5篇从虚论治,5篇以痰、瘀、虚综合论治慢性阻塞性肺疾病。结论:痰、瘀、虚三者互相影响,共同导致慢性阻塞性肺疾病的发生。今后应立足中医揭示中药治疗的作用靶点和起效途径,从而展示中医药在防治慢性阻塞性肺疾病领域的优势。     

Comparative cytotoxicity of five current dentin bonding agents: Role of cell cycle deregulation

To compare the cytotoxicity of three nano-dentin bonding agents (nano-DBAs) and two non-nano-DBAs using Chinese hamster ovary (CHO-K1) cells. We found that nano fillers were not the major contributing factor in DBA cytotoxicity, as analyzed by colony forming assay and 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Exposure of CHO-K1 cells to all three tested total-etching DBAs led to G₀/G₁ cell cycle arrest, whereas exposure to higher concentrations of two tested nano-DBAs induced G₂/M arrest. All five DBAs further induced apoptosis at the highest concentration, as analyzed by propidium iodide staining flow cytometry. The toxicity of all DBAs (1:4000 v/v or higher) is related to increased reactive oxygen species (ROS) production, as analyzed by single cell DCF fluorescence flow cytometry. These results indicate that clinical application of DBAs may be potentially toxic to dental pulp tissues. Cytotoxicity of DBAs is associated with ROS production, cell cycle deregulation and apoptosis. Presence of methacrylate monomers such as PENTA and UDMA is possibly the major cytotoxic factor for DBAs. Further studies on other toxicological endpoints of nano-DBAs are necessary to highlight their safe use.     

Alterations in vitamin D status and anti-microbial peptide levels in patients in the intensive care unit with sepsis

Background  

Vitamin D insufficiency is common in hospitalized patients. Recent evidence suggests that vitamin D may enhance the innate immune response by induction of cathelicidin (LL-37), an endogenous antimicrobial peptide produced by macrophages and neutrophils. Thus, the relationship between vitamin D status and LL-37 production may be of importance for host immunity, but little data is available on this subject, especially in the setting of human sepsis syndrome and other critical illness.     

Areca nut‐induced micronuclei and cytokinesis failure in Chinese hamster ovary cells is related to reactive oxygen species production and actin filament deregulation

Epidemiological studies have shown a strong association between environmental exposure to betel quid (BQ) and oral cancer. Areca nut (AN), an ingredient of BQ, contains genotoxic and mutagenic compounds. In this study, we found that AN extract (ANE) inhibited the growth of Chinese hamster ovary cells (CHO‐K1) in a dose‐ and time‐dependent manner. Intracellular reactive oxygen species (ROS) levels and micronuclei (MN) frequency were significantly increased following ANE treatment in CHO‐K1 cells. Addition of catalase markedly inhibited ANE‐induced MN formation, indicating that ANE‐induced genotoxicity was correlated with intracellular H₂O₂. Incubation of CHO‐K1 cells with ANE (400–800 μg/ml) for 24 hr caused G2/M arrest, and prolonged exposure to ANE (800 μg/ml) significantly induced cell death. Surprisingly, ANE itself caused cytokinesis failure and subsequent increase in binucleated cell formation. Coexposure to catalase (2,000 U/ml) and ANE (800 μg/ml) reduced the generation of binucleated cells, indicating that ANE‐induced cytokinesis failure was associated with oxidative stress. Following prolonged exposure to ANE, an accumulation of hyperploid/aneuploid cells concomitant with bi‐, micro‐ or multinucleated cells was found. In summary, our results demonstrate that ANE exposure to CHO‐K1 cells caused increased MN frequency, G2/M arrest, cytokinesis failure, and an accumulation of hyperploid/aneuploid cells. These events are associated with an increase in intracellular H₂O₂ level and actin filament disorganization. Environ. Mol. Mutagen., 2009. © 2009 Wiley‐Liss, Inc.     

L‐type Ca2+ channel opener BayK 8644‐induced Ca2+ influx and Ca2+ release in human oral cancer cells (OC2)

The effect of BayK 8644, a chemical widely used to activate L‐type Ca²⁺ channels, on cytosolic free Ca²⁺ concentrations ([Ca²⁺]_i) in human oral cancer cells (OC2) has not been explored to date. The present study examined whether BayK 8644 altered basal [Ca²⁺]_i levels in suspended OC2 cells by using fura‐2. BayK 8644 (10 pM–10 µM) increased [Ca²⁺]_i in a concentration‐dependent manner. The Ca²⁺ signal was reduced partly by removing extracellular Ca²⁺. BayK 8644‐induced Ca²⁺ influx was blocked by nifedipine, but was not altered by the store‐operated Ca²⁺ entry inhibitors, econazole and SKF96365; protein kinase C modulators phorbol 12‐myristate 13‐acetate (PMA) and GF109203X; the protein kinase A inhibitor H89; and the phospholipase A₂ inhibitor, aristolochic acid. In Ca²⁺‐free medium, after pretreatment with 1 µM BayK 8644, 1 µM thapsigargin (an endoplasmic reticulum Ca²⁺ pump inhibitor)‐induced [Ca²⁺]_i rises were abolished; and conversely, thapsigargin pretreatment abolished BayK 8644‐induced [Ca²⁺]_i rises. Inhibition of phospholipase C with U73122 did not change BayK 8644‐induced [Ca²⁺]_i rises. Collectively, in OC2 cells, BayK 8644 induced [Ca²⁺]_i rises by causing phospholipase C‐independent Ca²⁺ release from the endoplasmic reticulum; and Ca²⁺ influx via L‐type Ca²⁺ channels. Drug Dev Res 69: 2008. © 2008 Wiley‐Liss, Inc.     

Additive effect modification of hepatitis B surface antigen and e antigen on the development of hepatocellular carcinoma.

To assess the role of hepatitis B e antigen (HBeAg) and its interaction with hepatitis B surface antigen (HBsAg) on the development of hepatocellular carcinoma (HCC), this case-control study included 361 age- and sex-matched pairs of patients with histologically proven HCC and healthy control subjects. HBsAg, HBeAg and antibody to HBeAg (anti-HBe) were detected by radioimmunoassay. Antibodies to hepatitis C virus (anti-HCV) were detected by second-generation enzyme immunoassay. The prevalences of HBeAg (20.2%), HBsAg (80.3%) and anti-HCV (29.5%) in cases were higher than in controls (1.9%, 20.7%, and 2.7% respectively; each P < 0.0001). Using patients negative for HBsAg, HBeAg and anti-HBe as a referent group, univariate analysis indicated that HBsAg alone or HBsAg and HBeAg were risk factors for HCC (P for trend < 0.0001). Calculation of incremental odds ratio indicated that there was additive interaction between HBsAg and HBeAg. Multivariate analysis indicated that HCC development was strongly associated with the presence of HBeAg (odds ratio, 8.1; 95% confidence interval, 2.4-27.1), HBsAg (odds ratio, 68.4; 95% confidence interval, 20.5-227.8) and anti-HCV (odds ratio, 59.3; 95% confidence interval, 13.6-258.4). In conclusion, HBsAg, HBeAg and anti-HCV are independent risk factors for HCC. There is additive and independent effect modification between HBsAg and HBeAg on the development of HCC.