马氏钳蝎毒对大鼠神经和骨胳肌的作用

本工作在大鼠膈神经膈肌标本上观察马氏钳蝎(Buthus marensi Karsch)毒对神经、肌肉和神经肌肉接头传递的作用,结果如下:1.在蝎毒(3×10~(-5)g/ml)作用下,由吸附电极引导的膈神经单相动作电位的下降相逐渐延长,形成平台,3小时后电位时程可达100ms 以上。2.蝎毒(5×10~(-7)—6×10~(-5)g/ml)显著改变肌纤维动作电位的波形,降低肌细胞的静息膜电位。如用6×10~(-5)g/ml 浓度蝎毒处理膈肌,半小时内即可使肌纤维动作电位下降相大大延长,形成平台。一小时后膜电位由对照的78±4mV 降低至59±13mV,2小时后至55±8mV(平均值±S.D.)。3.河豚毒(3μM)可使被蝎毒降低了的肌细胞膜电位迅速复原,但随着时间的延续还可以再出现缓慢的轻度下降。4.在河豚毒(3μM)使肌细胞动作电位消失后,向溶液中加入蝎毒,半小时后将二者一并洗去,重新出现的动作电位亦带有明显的平台。5.在接头传递已被高 Mg~(++)或筒箭毒碱阻遏的标本上加蝎毒后,单个间接刺激可诱发出一串终板电位,甚至引起肌肉收缩。6.蝎毒(1×10~(-5)g/ml)明显增加小终板电位的发放频率,作用1小时后其频率可高达每秒100次以上。7.肌肉对间接刺激的收缩反应在加入蝎毒后首先增大,然后逐渐下降,在1×10~(-5)g/ml 浓度蝎毒作用下1.5—2小时传递阻遏,此时肌肉对直接刺激     

百令胶囊伍用维生素E治疗乙肝病毒携带者50例疗效观察

近年来 ,我们对体检中发现的 50例乙肝病毒携带者 ,采用百令胶囊为主 ,伍用维生素 E(Vit E)治疗 ,取得较好疗效 ,现报告如下。1　临床资料1 .1　一般资料　本组 50例 ,男性 38例 ,女性 1 2例 ,年龄在 2 6～ 52岁之间 ,平均年龄 (40± 2 )岁。50例中 ,乙肝表面抗原 (HBs Ag)均为阳性 ,兼有乙肝 e抗原 (HBe Ag)阳性 1 8例 ,乙型肝炎病毒前 S1抗原 (简称前 S1抗原 )阳性者 2 1例。1 .2　治疗方法　本组全部病例均服用百令胶囊 ,每粒含原粉 0 .2 g,每次 5粒 ,每天 3次 ;维生素 E,每次 0 .1 g,每天 3次 ,2个月为 1个疗程 ,共服用2个疗程。1 …     

海南尖峰岭热带山地雨林近冠层CO2及通量特征研究

采用梯度法及CI-301PS CO2系统,实现了海南尖峰岭热带山地雨林近冠层CO 2、微气象因子梯度观测研究,结果表明雨季晴、晴间少云及多云天气,900～1800CO 2浓度平均值分别在349～350ml/m3(冠上2.8m)、346～348ml/m3(冠上0.8m)、345～349ml/m3(林内16m)、352～357ml/m3(林内5m),较旱季相应天气分别小14～17.5、10.1～23.7、1 6.4～35.7和18.1～36.1ml/m3;100～800,则雨季CO2浓度大于旱季;梯度浓度廓变量和实时动力计算反映出,800～1800CO2通量由大气向林冠层,旱、雨季平均CO2通量分别为(0.61×10-6kg/(m2·s)和0.71×10-6kg/(m 2·s),1900通量甚微,2000～700CO2通量则由林冠向大气,平均CO2通量分别为0.36×10-6kg/(m2·s)和0.32×10-6kg/(m2·s);雨季昼夜大气流向冠层的净CO2通量是相应旱季的1.56倍.总辐射、冠顶净辐射通量以1300～1 500为最大时域,相对林内21m,80%的辐射热能被冠层吸收,与CO2通量正相关;晴天冠上潜热、感热最高值分别在1300～1400和900,反映热带山地雨林近冠层的汇、源即白昼光合固定CO2大于夜间呼吸排放CO2效应,且雨季高于旱季.     

用Fura-2/AM测定肺炎链球菌粘附A549细胞后胞浆游离钙离子浓度

目的 :通过体外实验 ,研究肺炎链球菌 (Streotococcus pneumoniae,S.pn)是否可触发肺 型上皮细胞 (A5 49)胞浆 [Ca2 +] i 浓度的改变。方法 :用 F ura-2 /AM荧光探针负载 A5 49细胞后测定 S.pn粘附A5 49细胞 3 0、60、90 min的胞内 [Ca2 +] i 浓度。结果 :S.pn粘附 A5 49细胞 3 0、60、90 min后的胞内 [Ca2 +] i均高于对照 [(187.4± 17.3 ) nmol/L ] ,并达到饱和 ,分别为 (4 87.5± 3 8.1)、(5 48.2± 3 5 .6)、(5 5 7.2± 47.5 )nmol/L。结论 :上述结果提示 S.pn粘附 A5 49细胞可增加胞浆内 [Ca2 +] i 浓度     

土壤中甲螨孳生与铬污染相关性研究

目的 :探讨土壤中甲螨孳生的种群数量与土壤铬污染之间的相互关系。方法 :于某大型化工厂周围土壤 10 m、1km、10 km及远郊农田土壤设立采样点 ,各采集 5 0份样本 ,每份样本采集 (10× 10× 10 )cm3的土壤 ,置 Tullgren电热分螨器中分离甲螨 ,计算甲螨在不同环境中的密度、丰度、优势属 ;同时用原子吸收光谱法分别测定化工厂周围土壤及远郊农田土壤样本中的铬含量。结果 :化工厂周围土壤总体甲螨的密度、丰度和优势度分别为 1975 7(131.71± 2 8.34)个 / m2、131.7个 /样本、嗜草甲螨、门罗点肋甲螨 ,远郊农田土壤甲螨的密度、丰度和优势度分别为 984 5 (6 5 .6 3± 18.36 )个 / m2、6 5 .6 3个 /样本、滑菌甲螨、嗜草甲螨、被盖头甲螨、棒菌甲螨、新小奥甲螨、普通尖棱甲螨 ,两者相比差异有显著性 (P<0 .0 1)。化工厂周围土壤及远郊农田土壤总体铬浓度分别为 (0 .2 5± 0 .0 7) mg/ kg、(0 .0 8± 0 .0 2 ) m g/ kg,两者相比差异有显著性 (P<0 .0 1)。化工厂周围土壤 10 m、1km、10 km、处甲螨的密度分别为 16 4 89(32 9.78± 31.2 2 )个 / m2、2 2 5 7(45 .14± 9.4 5 )个 / m2 、10 11(2 0 .0± 3.33)个 / m2 ,化工厂周围土壤样本的甲螨密度较高 ,与远效农田土壤相比 ,差异有显著性 (P<0 .0 1)。结论     

大气CO_2浓度升高对香蕉光合作用及光合碳循环过程中叶氮分配的影响

生长在高CO2 浓度 (70 0± 5 6 μl·L-1) 1周的香蕉叶片 ,其光合速率 (Pn ,μmol·m-2 ·s-1)为 5 .14± 0 .32 ,较生长在大气CO2 浓度 (35 6± 30lμl·L-1)的高 2 2 .1% ,而生长在较高CO2 浓度下 8周 ,叶片Pn较生长在大气CO2 浓度的低 18.1% ,表现香蕉叶片对较长期高CO2 浓度的驯化和光合作用抑制 .生长在高CO2 浓度的香蕉叶片有较低光下呼吸速率 (Rd) ,而不包括光下呼吸的CO2 补偿点则变幅较小 .最大羧化速率 (Vcmax)和电子传递速率 (J)分别较生长在大气CO2 浓度的低 30 .5 %和 14 .8% ,根据气体交换速率计算的表观量子产率 (α ,molCO2·mol-1光量子 ) ,生长在较高CO2 浓度下 8周的叶片为 0 .0 14± 0 .0 1,而生长在大气CO2 浓度下的为 0 .0 2 5±0 .0 0 5 .较高CO2 浓度下叶片的表观量子产率降低 44% .光能转换效率 (electrons·quanta-1)亦从 0 .2 0 3降低至0 .136 .生长在较高CO2 浓度下香蕉叶片的叶氮在Rubicos分配系数 (PR)、叶氮在生物力能学组分分配系数(PB)和叶氮在光捕组分的分配系数 (PL)均较生长在大气CO2 浓度低 ,表明在高CO2 浓度下较长期生长 (8周 )的香蕉叶片多个光合过程受抑制 ,光合活性明显降低 .     

乙型肝炎血清标志模式与病毒载量的关系及意义

为探讨乙型肝炎 (以下简称乙肝 )血清标志模式与病毒载量的关系及临床意义 ,作者选择符合 2 0 0 0年《全国病毒性肝炎诊断标准》的慢性肝炎血清 1343份 ,分别用ELISA法、PCR ELISA法检测HB血清标志、HBV -DNA和 1896位点变异株。结果显示 :HBsAg阳性血清 10 97份 (81.6 8%、)HBsAg阴性血清 2 4 6份 (81.31% )。在HBsAg阳性血清中 ,HBsAg、HBeAg、抗 HBc(1 3 5 )阳性组 4 0 4份 (30 .l% ) ,HBV -DNA阳性 347份 (85 .89% ) ,DNA阳性值呈递增趋势 (10 4～ 10 6拷贝 /ml,各占 8.6 5 %、33.71%、5 3.6 1% ) ;而HBsAg、抗 HBe阳性组血清 6 0 6份 (45 .12 % ) ,DNA阳性值 10 5拷贝 /ml,占优势 (6 4 .18% )。在HBsAg阴性血清中 ,抗 HBs、抗 HBe、抗 HBc(2 4 5 )阳性组 2 32份 (17.2 7% ) ,DNA阳性占 7.32 % ,DNA阳性值递减由 10 4～ 10 6拷贝 /ml,各占 5 2 .9%、4 1.l%、5 .9%。结论 ,各血清标志模式中的病毒载量为HBsAg阳性组 >HBsAg阴性组 ,阳性组 1 3 5 >1 4 5 >l 5 >2 4 5。但 1 3 5阳性组中 14 %在界值以下 ,1 4 5阳性组中 1896位点自然变异达 78.6 % ,2 4 5阳性组中仍存在DNA+ 血清 ,以上提示在临床判定和治疗时要慎重对待(注 :l=HBsAg,2 =抗 HBs,3=HBeAg ,4 =抗 HBe ,5 =抗 HBc)     

家兔供体卵裂球细胞周期对核移植胚胎发育的影响

通过化学药物处理使家兔桑椹胚卵裂球的细胞周期分别同期化于G1、S或G2期 ,然后分别移入去核的MⅡ期卵母细胞中 ,以研究供体核细胞周期对家兔胚胎细胞核移植效率的影响。试验结果表明供体核细胞周期对家兔核移植胚胎的发育潜力有明显影响 ,以G1期卵裂球为供体的核移植重组胚的激活率、卵裂率、桑椹胚、囊胚和孵化囊胚率及囊胚平均细胞数分别为 87 3% (32 2 / 36 9)、 84 9% (2 99/ 35 2 )、 71 5 % (193/ 2 70 )、5 8 0 % (76 / 131)、 35 1% (4 6 / 131)和 12 6± 4 8,显著高于S期 [79 6 % (10 9/ 137)、 74 4% (93/ 12 5 )、30 3% (33/ 10 9)、19 3% (17/ 88)、 6 8% (6 / 88)和 118 8± 3 5 ]、G2期 [6 3 6 % (70 / 110 )、6 0 % (6 0 / 10 0 )、16 9% (11/ 6 5 )、 16 3% (7/ 43)、 4 7% (2 / 43)和 110 6± 5 8]和未经同期化处理的卵裂球 [78 1% (185 /2 37)、 73 2 % (15 8/ 2 16 )、 49 4% (4 3/ 87)、 32 2 % (2 8/ 87)、 12 6 % (11/ 87)和 12 0 5± 4 4](P <0 0 5 )。来源于G1期卵裂球的 144枚克隆胚胎移植到 12只受体中 ,6只妊娠并产下 19只活仔 ,产仔率为 13 2 % ,显著高于来源于S期 (5 8% ,7/ 12 0 )、G2期 (0 ,0 / 12 6 )或未同期化卵裂球的克隆胚胎 (5 3% ,8/ 15 0 ) (P <0     

乙型肝炎病毒感染Babl/c乳鼠动物模型的研究

目的:目前HBV感染动物模型各有局限,无法全面研究HBV。拟建立人HBV血清感染Babl/c乳鼠的动物模型,以便于研究HBV感染与乳鼠免疫力低下的相关性。方法:将20只Babl/c乳鼠随机分为实验组、对照组、PBS组及空白组,通过高压水动力尾静脉注射法将人HBV血清、正常人血清、PBS注入各组乳鼠体内,记录接种后乳鼠体温及体质量。于接种后第7、15、30 d采集血清标本,应用ELISA检测HBs Ag、HBe Ag的表达情况,实时荧光定量PCR检测HBV DNA浓度。结果:接种后各组小鼠体温及体质量均无明显变化。实验组中共4只乳鼠可检测到HBs Ag为阳性且维持时间长达30 d,但HBe Ag均为阴性,HBV DNA浓度均未达500 IU/ml;余下各组检测HBs Ag、HBe Ag均为阴性。结论:通过高压水动力尾静脉注射法接种人HBV血清,可成功使Babl/c乳鼠感染HBV。本实验证实乳鼠免疫力低下,HBV血清进入体内未能有效清除,对HBV存在易感性,为建立HBV感染动物模型提供实验依据,可用于研究HBV对免疫状态的影响。     

非洲爪蟾卵母细胞GABA_B和GABA_C受体介导的电流反应

实验应用双电极电压箝技术 ,在具有滤泡膜的非洲爪蟾 (Xenopuslaevis)卵母细胞上记录到γ 氨基丁酸(γ aminobutyricacid ,GABA) 激活电流。此GABA 激活电流的特点及有关GABA受体类型的研究和分析如下 :( 1)在 3 5 5 % ( 5 5 / 15 5 )的受检细胞外加GABA可引起一慢的浓度依赖性的外向电流。 ( 2 )GABAA 受体的选择性拮抗剂bicuculline ( 10 -5mol/L)对GABA ( 10 -5mol/L)引起的外向电流无阻断作用 (n =6)。 ( 3 )GABAB 受体的选择性拮抗剂2 hydroxysaclofen ( 10 -4mol/L)能将GABA ( 10 -5mol/L)引起的外向电流可逆性地转变为内向电流 ,后者又可被GABAC 受体的选择性拮抗剂I4AA ( 10 -5mol/L)所消除 (n =6)。 ( 4 )GABAB 受体的特异性激动剂baclofen可引起部分 ( 2 0 % ,12 / 60 )受检细胞产生一慢的浓度依赖性的外向电流。 3× 10 -6 、3× 10 -5及 3× 10 -4mol/L 2 hydroxysaclofen分别阻断baclofen ( 10 -5mol/L) 激活电流 ( 6 3± 3 2 ) % ,( 4 4 1± 2 2 ) %及 ( 86 0± 1 6) % (n =6)。 ( 5 )baclofen激活电流的I V曲线显示逆转电位在 - 96 8± 7 2mV左右 ,此电流可分别被TEA ( 5mmol/L)和BaCl2 ( 2mmol/L)所阻断。以上结果提示 :在非洲爪蟾的卵母细胞上存在内源性GABAB 和GABAC 受体 ,GA     

Immunology of hepatitis B virus and hepatitis C virus infection

More than 500 million people worldwide are persistently infected with the hepatitis B virus (HBV) and/or hepatitis C virus (HCV) and are at risk of developing chronic liver disease, cirrhosis and hepatocellular carcinoma. Despite many common features in the pathogenesis of HBV- and HCV-related liver disease, these viruses markedly differ in their virological properties and in their immune escape and survival strategies. This review assesses recent advances in our understanding of viral hepatitis, contrasts mechanisms of virus-host interaction in acute hepatitis B and hepatitis C, and outlines areas for future studies.     

Mouse hepatitis virus

Inoculation of mice with most neurotropic strains of the coronavirus mouse hepatitis virus results in an immune response-mediated demyelinating disease that serves as an excellent animal model for the human disease multiple sclerosis. Recent work has shown that either virus-specific CD4(+) or CD8(+) T cells are able to mediate demyelination and also that the antibody response is crucial for clearing infectious virus. Another exciting advance is the development of recombinant coronaviruses, which, for the first time, will allow genetic manipulation of the entire viral genome.     

Serological relationship of woodchuck hepatitis virus to human hepatitis B virus.

Two antigenic systems of the woodchuck hepatitis virus have been identified. The relationship between viral antigens of the woodchuck hepatitis virus and the human hepatitis B virus was determined by using immunoprecipitation, hemagglutination, and immune electron microscopy techniques. Antigens found on the cores of the two viruses were cross-reactive. Lack of cross-reactivity between the surface antigens of the two viruses in immunodiffusion experiments suggested that the major antigenic determinants of the viral surfaces are different; however, results of passive hemagglutination tests indicated that there are common minor determinants. Nucleic acid homology, as measured by liquid hybridization, was found to be 3 to 5% of the viral genomes. The results of this study provide further evidence that woodchuck hepatitis virus is the second member of a new class of viruses represented by human hepatitis B virus. Since virus-infected woodchucks may acquire chronic hepatitis and hepatocellular carcinoma, these antigens and their respective antibodies will be useful markers for following the course of virus infection in investigations of the oncogenic potential of this class of viruses. The nucleocapsid antigen described may be a class-specific antigen of these viruses and, thus, may be useful in discovering new members of the group.     

Natural history and treatment of hepatitis B virus and hepatitis C virus coinfection

Hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfection is not uncommon as a result of similar routes of infection. Patients who are coinfected represent a unique group with diverse serologic profiles. Combined chronic hepatitis B and C leads to more severe liver disease and an increased risk of hepatocellular carcinoma. Furthermore, coinfected patients represent a treatment challenge. No standard recommendations exist for treatment of viral hepatitis due to dual HBV/HCV infection, and therefore treatment must be individualized based on patient variables such as serologic and virologic profiles, patient's prior exposure to antiviral treatment, and the presence of other parenterally transmitted viruses such as hepatitis D virus and human immunodeficiency virus. The natural history and treatment of patients with HBV and HCV coinfection is reviewed.     

Core particles of hepatitis B virus and ground squirrel hepatitis virus. II. Characterization of the protein kinase reaction associated with ground squirrel hepatitis virus and hepatitis B virus.

The recently described protein kinase activity in hepatitis B virus core antigen particles (Albin and Robinson, J. Virol. 34:297-302, 1980) has been demonstrated here in the liver-derived core particles of ground squirrel hepatitis virus. Both protein kinase activities were initially associated with DNA polymerase-positive heavy core particles in CsCl density equilibrium gradients and shifted to polymerase-negative cores during the course of purification. The major core-associated polypeptide of each virus was the dominant species labeled. A variable number of other polypeptide species were also labeled by this reaction. Tryptic peptide mapping of both major and minor phosphorylated polypeptides of each virus resulted in similar patterns, suggesting that many of the sites of phosphorylation were the same in the components of each core particle. Hydrolysis of these phosphorylated core particles revealed a major phosphoamino acid as serine and a minor phosphoamino acid as threonine. The products of the protein kinase reaction in both human hepatitis B and ground squirrel hepatitis virus core particles, then, share many characteristics. The possible function(s) of this protein kinase activity is discussed in the light of similarly characterized activities in other animal viruses.     

Pathogenesis of hepatitis C virus

Hepatitis C virus (HCV) infects approximately 170 million people worldwide including 2 million in Japan and induces serious chronic hepatitis that results in the development of steatosis, cirrhosis and ultimately hepatocellular carcinoma. The current combination therapy using pegylated interferon alpha and a nucleotide analogue ribavirin achieved a sustained virological response in about half population of individuals infected with HCV genotypes la and lb. More than two-thirds of the HCV-positive population has been chronically infected with genotype 1 in Western countries and Japan. Therefore, more effective therapeutics and preventative measures are needed for the treatment of hepatitis C patients who are not responsive to the current chemotherapy. HCV core protein is well known to be the viral capsid protein as well as the pathogenic factor that induces steatosis and hepatocellular carcinoma in the transgenic mice. In this review, we summarize the current status of our knowledge regarding the molecular mechanism by which HCV core protein induces liver steatosis and hepatocellular carcinoma and discuss on a future perspective for the development of novel therapeutics for chronic hepatitis C.     

Antigenic and structural relationships of the surface antigens of hepatitis B virus, ground squirrel hepatitis virus, and woodchuck hepatitis virus.

The surface antigens of human hepatitis B (HBsAg), ground squirrel hepatitis (GSHsAg), and woodchuck hepatitis (WHsAg) viruses were compared serologically, and their major polypeptides were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and tryptic peptide mapping. Results showed that both GSHsAg and WHsAg are antigenically cross-reactive, that their major pairs of polypeptides have identical mobilities on sodium dodecyl sulfate gels, and that the major polypeptides of GSHsAg and WHsAg migrate faster in sodium dodecyl sulfate-polyacrylamide gel electrophoresis than do the corresponding bands of HBsAg. The peptide maps of the major (P-22) surface antigen polypeptides of GSHsAg and WHsAg showed that they shared over half of their spots. Peptide mapping of HBsAg subtypes indicated a close relationship between the major polypeptides (P-24) of adw and adr and a more distal relationship to ayw. Only about 25% of the spots shared by the combined HBsAg subtypes were also found in the peptide maps of GSHsAg and WHsAg, indicating at least some structural homology among the major polypeptides of the human and animal virus surface antigen particles. This is also reflected in the serological cross-reactivity among HBsAg, GSHsAg, and WHsAg. Further, the detection of ground squirrel and woodchuck antigens by Ausria II radioimmunoassay, combined with peptide mapping data indicating the common origin of these viruses, suggests that the common a determinant is shared by each and is restricted to approximately 25% of the sequences in their major polypeptides.     

Replication of hepatitis C virus

Exciting progress has recently been made in understanding the replication of hepatitis C virus, a major cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma worldwide. The development of complete cell-culture systems should now enable the systematic dissection of the entire viral lifecycle, providing insights into the hitherto difficult-to-study early and late steps. These efforts have already translated into the identification of novel antiviral targets and the development of new therapeutic strategies, some of which are currently undergoing clinical evaluation.