乙型肝炎病毒Ⅹ基因对肝细胞凋亡的影响及其作用机制

乙型肝炎病毒X基因(HBx)在HBV慢性感染导致肝硬化,原发性肝癌(HCC)的发生过程中,起着重要的作用[1].X连锁凋亡抑制因子(XIAP)为凋亡抑制蛋白(IAPs)家族成员,是一种强效的凋亡抑制蛋白,可以抑制半胱氨酸蛋白酶活性,阻断细胞凋亡过程[2].我们观察了肝癌细胞株以及正常肝细胞株在转染HBx前后凋亡抑制蛋白XIAP表达的差异,了解和分析HBx对不同肝细胞系细胞凋亡的作用及其是否与凋亡抑制蛋白XIAP基因相关.     

HBx致原发性肝癌机制研究进展

作为乙型肝炎病毒（HBV）致肝癌的主要物质，X蛋白（HBx）己成为近年研究的热点之一。已知HBx对肝细胞内许多基因的表达均有直接或间接的影响，在肝癌形成中起重要作用。近年来对HBx致原发性肝癌（HCC）机制的研究显示，HBx可影响肝细胞的生存和前凋亡信号通路、抑制细胞DNA的修复、促进细胞的侵袭和转移以及干扰细胞有丝分裂和细胞周期进程等。     

乙型肝炎病毒X蛋白在原发性肝癌中的作用

乙型肝炎病毒X蛋白(HBx)是一种由HBV X基因编码的多功能蛋白,参与调节基因转录、细胞信号转导、细胞增殖转化、细胞周期和细胞凋亡。目前HBx蛋白被认为在HBV诱发原发性肝癌的过程中发挥重要作用。介绍了HBx蛋白与癌基因、抑癌基因、细胞增殖、细胞凋亡、肝癌侵袭转移和肝癌干细胞的关系,探讨了HBx蛋白在肝癌发生发展中的作用。     

HBx致原发性肝癌机制研究进展

作为乙型肝炎病毒(HBV)致肝癌的主要物质,X蛋白(HBx)己成为近年研究的热点之一。已知HBx对肝细胞内许多基因的表达均有直接或间接的影响,在肝癌形成中起重要作用。近年来对HBx致原发性肝癌(HCC)机制的研究显示,HBx可影响肝细胞的生存和前凋亡信号通路、抑制细胞DNA的修复、促进细胞的侵袭和转移以及干扰细胞有丝分裂和细胞周期进程等。     

小干扰RNA沉默人胰腺癌细胞内连锁凋亡抑制因子基因表达的研究

X连锁凋亡抑制因子（X-linked inhibitor of apoptosis protein，XIAP）是凋亡抑制蛋白（IAP）家族中最有效的caspases抑制剂，它可直接抑制caspases并可多途径调节细胞凋亡，因而在肿瘤的发生和发展中发挥着重要作用。研究表明，多种肿瘤细胞中XIAP呈高表达，抑制XIAP基因表达可诱导肿瘤细胞凋亡，进而抑制肿瘤生长。本研究应用近年来开展的RNA干扰技术（RNA interference，RNAi），设计并合成针对XIAP编码基因的小干扰RNA（siRNA），于胰腺癌细胞BxPC-3中，观察siRNA能否产生肿瘤细胞内源性XIAP表达的转录后沉默，为胰腺癌基因沉寂疗法提供实验依据。     

乙型肝炎病毒X蛋白在肝细胞癌发生中的作用机制

HBx蛋白（HBxAg）被认为是乙型肝炎病毒（HBV）致肝细胞癌（HCC）的病毒蛋白,能影响肝细胞的生长、转化、迁移和凋亡以及DNA的修复等过程,己成为近年来研究的热点之一。HBx是一种多功能的病毒蛋白,有转录调控作用,对肝细胞内许多癌基因和／或抑癌基因的表达有直接或间接的影响,在肝癌形成中起重要作用。通过对HBx在肝癌发生、发展中机制的深入研究,有望在HCC防治方面开辟新途径。     

肝癌组织中HBx基因的多态性及其突变体对QSG7701细胞生物学行为的影响

目的研究中国南部部分地区肝细胞癌患者中是否存在特征性HBx基因突变，以及基因变异在肝癌发病中的作用。方法采用巢式PCR，单链构象多态分析（SSCP）、异源性双链分析（HA）和DNA测序等方法对51份肝细胞癌组织石蜡包埋切片标本和25份HBV携带者血清HBx基因多态性进行分析，对有明显缺失变异的HBx基因进行克隆，转染肝细胞，通过体外和体内实验比较变异和野生型HBx基因转染对肝细胞QSG7701生物学行为的影响。结果肝癌组织中HBx基因存在点突变和缺失型突变，B和C基因型之间突变类型和数量有一定差异，C基因型点突变频率更高（t=-2．522，P〈0．05），而B基因型存在缺失变异（HBx—d382和HBx—d431）。获得了含HBx缺失变异的基因的稳定转染细胞株。该细胞株细胞大小形态不一、体积增大、核浆比例增大，生长速度更快，克隆形成率高（P〈0．05），在裸鼠体内成瘤机会和速度更快。结论HBx基因在肝细胞癌组织中频繁地发生突变，nt382～400位置上的缺失型突变体转染QSG7701后能促进肝细胞的生长速度，细胞凋亡减少，使之获得肿瘤性细胞特性，因此HBx—d382缺失型突变体可能在中国南部部分地区肝癌发生发展中发挥重要作用。     

Omi／HtrA2对人肝癌细胞系凋亡的调控作用研究

目的探讨丝氨酸蛋白激酶Omi／HtrA2在肝癌细胞中在促凋亡基因p53与抑凋亡基因XIAP之间调控机制的研究,并探讨其今后用于靶向治疗的可能性。方法用Western blotting的方法半定量测定4种不同的肝细胞株（L02、HepG2、Hep3B、Huh7）中p53、XIAP、Omi／HtrA2蛋白的表达量,以及使用Omi／HtrA2特异性抑制剂ucf-101后各自的表达量。结果在p53表达不同的细胞株中XIAP蛋白和Omi／HtrA2蛋白的表达也是不同的,p53可上调Omi／HtrA2蛋白表达,下调XIAP蛋白表达。使用ucf-101后,肝癌细胞中XIAP蛋白表达明显上调。结论Omi／HtrA2是p53与XIAP之间凋亡调控作用的信号因子之一,参与细胞凋亡的调控,有可能作为肿瘤细胞凋亡的治疗靶点。     

HBV X基因与肝细胞恶性转化相关性的初步研究

目的研究HBVX基因对L02肝细胞生物学特性的影响，初步探讨HBVX基因在肝细胞恶性转化中的作用，为进一步研究HBx致原发性肝细胞癌（HCC）的机制及HCC新的防治策略奠定基础。方法．构建稳定表达HBx的转基因细胞株L02／HBx，运用倒置相差显微镜、四唑盐（MTT）比色试验、流式细胞仪观察和检测L02／HBx在形态学、增殖、凋亡和细胞周期等方面的变化。结果成功构建L02／HBx，观察发现细胞形态发生明显改变，MTT检测结果表明L02／HBx生长速度加快但经阿霉素（ADM）处理后凋亡速度加快。流式细胞仪（FCM）检测结果显示，与对照组细胞相比，L02／HBx凋亡率及G1期细胞比例降低，S期细胞所占比例增高，二倍体细胞比例降低，非整倍体细胞比例增高。经阿霉素处理后，L02／HBx细胞的凋亡率大大增加，G1期细胞的比例仍比对照组低，S期细胞的比例亦比对照组高，二倍体细胞的比例显著降低，非整倍体细胞的比例明显增加。结论HBx能引起细胞增殖失控而导致恶性转化，在凋亡因子的作用下，HBx抑制损伤DNA的修复而促进细胞凋亡，并可能引起细胞的变异而导致恶变。     

XAF1基因在肝癌细胞凋亡中的诱导作用

背景：X连锁凋亡抑制蛋白（XIAP）与凋亡抑制和肿瘤细胞耐药现象密切相关。目的：研究XIAP相关因子1（XAF1）基因抑制人肝癌细胞株Bel-7404和HepG2增殖和诱导凋亡的作用。方法：以腺病毒Ad5／F35为载体,构建重组腺病毒Ad5／F35-XAF1、对照空病毒Ad5／F35-Null和报告病毒Ad5／F35-增强型绿色荧光蛋白（EGFP）,分别以相同感染复数（MOI）感染人肝癌细胞株Bel-7404和HepG2,并设立空白组作为对照。作用48h后,以荧光显微镜检测Ad5／F35-EGFP的感染效率;分别以逆转录聚合酶链反应（RT—PCR）和蛋白质印迹法检测XAF1 mRNA和蛋白表达;以MTT法检测细胞活力;以Annexin V—FITC／PI双染法和原位末端标记（TUNEL）法检测细胞凋亡率。结果：Ad5／F35-EGFP感染48h后,几乎所有Bel-7404和HepG2细胞均表达EGFP。Ad5／F35-XAF1感染48h后,两种肝癌细胞中XAF1 mRNA和蛋白表达均明显增高．细胞活力呈剂量依赖性地降低,细胞凋亡率显著增加。结论：重组腺病毒Ad5／F35-XAF1在人肝癌细胞株Bel-7404和HepG2中的感染效率高,XAF1在不同的肝癌细胞株中恢复表达后,能显著抑制肝癌细胞增殖并促进其凋亡,有可能成为肝癌基因治疗的新靶点。     

Control of intraabdominal hemorrhage and shock: a comparison of fluid resuscitation, MAST, and balloon occlusion

Our study examined the efficacy of four treatment modalities in controlling hemorrhage and achieving hemodynamic stabilization in hemorrhagic shock: intravenous fluid replacement (IV); military antishock trousers used concomitantly with fluids (MAST); balloon occlusion at the level of the diaphragm with concomitant fluid replacement (balloon); and a combination of MAST inflation, balloon occlusion, and fluid resuscitation (MAST and balloon). Twenty-eight mongrel dogs were anesthetized, and the spleen was exposed and completely crushed. The abdomen was closed, and treatment was initiated and continued for four hours or until the dog died. For all conditions the hematocrit dropped during the course of the experiment; balloon occlusion was effective at slowing this drop (P less than .0001), but MAST had no statistically significant effect. Animals with balloons bled more slowly into the abdominal cavity than did animals in the other two groups (P less than .0001). MAST also were effective at slowing the bleeding (P less than .05). Of the balloon and the MAST and balloon dogs, all except one survived the entire four hours; this difference between balloon and nonballoon dogs is significant (P = .002). MAST did not have a statistically significant effect on survival. Perfusion pressure (PP) declined during the course of the experiment, and the balloon was effective at slowing this decline (P less than .0001); none of the other comparisons was statistically significant.     

Use of fab fragments of digoxin-specific antibodies in the therapy of massive digoxin poisoning

A case of massive digoxin ingestion with multiple arrhythmias, consisting of high grade A-V block and ventricular ectopy not responsive to lidocaine, is described. The arrhythmias ceased following administration of digoxin-specific Fab fragments. The patient improved and was transferred to the psychiatric unit.     

Comparison of intravenous and oral routes of theophylline loading in acute asthma

In a prospective, randomized clinical trial, 19 patients with an acute exacerbation of asthma were given a loading dose of aminophylline by the IV (n = 10) or oral route (n = 9) of administration following treatment with epinephrine. Plasma concentrations of theophylline were measured prior to giving the loading dose, and one, two, three, and 24 to 48 hours later. Therapeutic effectiveness was evaluated by analyzing spirometric measurements prior to giving the loading dose, and one, three, and 24 to 48 hours later. Side effects also were recorded. In the IV group, the mean peak plasma theophylline concentration was 15.1 micrograms/mL one hour after loading, and in the oral group the mean peak serum theophylline concentration was 14.2 micrograms/mL three hours after loading. There was no correlation between theophylline concentrations and normalized change in spirometric values. There was no significant difference in spirometric values between the IV and oral groups. Nausea was slightly more common in the IV group. We conclude that there is no therapeutic advantage to giving a loading dose of aminophylline by the IV route rather than orally in patients with mild-to-moderate exacerbation of asthma initially treated with epinephrine.     

Application of Granular Biocomposites Based on Homogenised Peat for Absorption of Oil Products

Among the various methods for collecting oil spills and oil products, including from the water surface, one of the most effective is the use of sorbents. In this work, three-component bio-based composite granular adsorbents were produced and studied for oil products’ pollution collection. A bio-based binder made of peat, devulcanised crumb rubber from used tyres, and part fly ash as cenospheres were used for absorbent production. The structure, surface morphology, porosity, mechanical properties, and sorption kinetics of the obtained samples were studied. Composite hydrophobicity and sorption capacity to oil products, such as diesel fuel (DF) and motor oil (MO), were determined. The obtained pellets are characterised by a sufficiently pronounced ability to absorb oil products such as DF. As the amount of CR in the granules increases, the diesel absorption capacity increases significantly. The case of 30-70-0 is almost three times higher than the granules from homogenised peat. The increase in q is due to two factors: the pronounced surface hydrophobicity of the samples (Θ = 152°) and a heterogeneous porous granule structure. The presence of the cenosphere in the biocomposite reduces its surface hydrophobicity while increasing the diesel absorption capacity. Relatively rapid realisation of the maximum saturation by the MO was noted. In common, the designed absorbent shows up to 0.7 g·g⁻¹ sorption capacity for MO and up to 1.55 g·g⁻¹ sorption capacity for diesel. A possible mechanism of DF absorption and the limiting stages of the process approximated for different kinetic models are discussed. The Weber–Morris diffusion model is used to primarily distinguish the limiting effect of the external and internal diffusion of the adsorbate on the absorption process.     

Role of microRNA in regulation of myeloma-related angiogenesis and survival

Multiple myeloma (MM) is a malignant disease caused by clonal proliferation of plasma cells that result in monoclonal gammopathy and severe end organ damage. Despite the uniform clinical signs, the disease is very diverse in terms of the nature and sequence of the underlying molecular events. Multiple cellular processes are involved in helping the malignant cells to remain viable and maintain proliferative properties in the hypoxic microenvironment of the bone marrow. Specifically, the process of angiogenesis, triggered by the interactions between the malignant MM cells and the stroma cells around them, was found to be critical for MM progression. In this review we highlight the current understanding about the epigenetic regulation of the proliferation and apoptosis of MM cells and its dependency on angiogenesis in the bone marrow that is carried out by different microRNAs.     

RNA-Seq在老年神经退行性疾病研究中的应用

阿尔茨海默病及帕金森病是老年人最常见的两种神经退行性疾病,但其发病机制及治疗是研究的热点。随着高通量测序技术的进步及成本的下降,RNA-Seq也成为神经退行性疾病机制研究及生物标志物发现的有力手段。RNA-Seq相对于microarray具有高灵敏度、高准确性、高重复性以及噪声低等优势,在阿尔茨海默病及帕金森病研究中有较为广泛的应用,包括检测差异表达基因,可变剪接、新长链非编码RNA预测分析和miRNAs调控等,但是容易受病理复杂性及样本等因素影响。目前阿尔茨海默病及帕金森病转录组研究相比于癌症等还不够深入,在临床诊断及治疗应用还面临较大挑战。但是随着新技术及新方法的发展,RNA-Seq将进一步推动神经退行性相关疾病的研究和临床转化。     

安徽巢湖市丝虫病控制、消除历程和监测报告

【摘要】 目的  回顾并总结巢湖市丝虫病的流行、控制,以及消除丝虫病的历程。 方法  统计分析1970~1989年在该市采取以消灭传染源、切断传播途径为主的防治策略,以及展开大规模防治的各个阶段。 结果  1989年,采用分层整群抽样调查方法调查,微丝蚴率下降至0.032%,以行政村为单位,微丝蚴率已控制在1.0%以下,达到卫生部规定的基本消灭丝虫病标准;1991年,经省级调查考核,认定全市已达到卫生部规定的基本消灭丝虫病标准。1996年,省级审评确认已达到卫生部颁布的消灭丝虫病标准。经过10年的监测和跟踪治疗,到2005年,全市丝虫病病原学监测未查见微丝蚴阳性者,解剖镜检人房内淡色库蚊1 348只,蚊体内均未查见人体幼丝虫。 结论  巢湖市达到了消除丝虫病的标准。     

A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation

The role of the external and internal anal sphincters in the mechanism of anal continence is presented. The external sphincter induces continence by 1) preventing internal sphincter relaxation, what I have called the “voluntary inhibition action,” and 2) mechanical compression of the rectal neck and anal canal proper. The mechanism of both actions is described. The internal sphincter plays a significant role not only in involuntary, but also in voluntary, continence. The importance of this role in the correction of anal incontinence is clarified. “Stress defecation,” a condition which follows internal sphincter damage, is discussed. A “single loop continence” theory is presented, based on the fact that each of the three loops of the external sphincter has its own innervation, attachment, and direction of muscle bundles; each loop thus acts as a separate sphincter. The clinical application of this theory is presented.