我国分离的XJ-90260病毒鉴定为西方马脑炎病毒

XJ－90260病毒是从新疆乌苏县境内采集的赫坎按蚊中分离到的一株病毒,病毒的鉴定结果显示：XJ－90260病毒可引起BHK－21细胞病变,表现为圆缩,脱落;可引起Vero细胞病变,表现为圆缩,破碎,脱落;可以在C6／36细胞中增殖,但不引起细胞病变。对3日龄小白鼠2－3天致死,对3周龄小白鼠3－4天致死。该病毒株对酸、乙醚敏感,抵抗5－氟脱氧尿苷。病毒与甲病毒组特异性免疫腹水起反应,与乙型脑炎病毒及布尼亚病毒组特异性免疫腹水不反应。进一步的分子生物学鉴定表明,该毒株基因组3′非编码区（ntranslated region,UTR）核苷酸序列具有典型的西方马脑炎病毒特征,与标准西方马脑炎病毒的首次报导,有重要的流行病学意义。我国9省区,886份血清的流行病学调查显示,该病毒抗体阳性血清24份,阳性率为2.71%。其中新疆（8／157）,河南（6／76）、甘肃（5／94）三省区抗体阳性数较多,占总阳性数的79.2%(19/24)。     

从背点伊蚊体内检出Colti病毒

Colti病毒为呼肠孤病毒科病毒,临床上引起发热、脑炎等症状。为了解东北地区感染情况,于1996年8～9月间采集了东北三省五地蚊虫2327只,计3属5种。对其中620只蚊虫进行了病毒分离,结果从背点伊蚊（Aedesdorsalis）分离出了两株病毒。该病毒能通过0．22μm孔径滤膜,在C6／36细胞上产生病变,对5－Idu和乙醚抵抗,对酸、热敏感。病毒RNA聚丙烯酰胺电泳呈现特有的12个条带。血清学试验阳性,鉴定为Colti病毒。据病毒在传代细胞上的病变表现和对动物的致病性,以及RNA带形分析,认为该病毒可能与北京株差异较大,与云南株区别较小。     

肿瘤坏死因子－α（TNF－α）对常见呼吸道病毒的抑制作用

用人重组肿瘤坏死因子－α（Ｔｕｍｏｒｎｅｃｒｏｓｉｓｆａｃｔｏｒ－α,ＴＮＦ－α）和人天然α干扰素（Ｉｎｔｅｒｆｅｒｏｎ－α－,ＩＦＮ－α）在人胚胎肺纤维母细胞（ＨＥＦ）和Ｈｅｐ－２细胞系上对常见呼吸道病毒所致细胞病变抑制进行比较观察。病毒包括不同型别的腺病毒５株,单疱病毒Ⅰ型（ＨＳＶ－Ｉ）１株,鼻病毒１株,仙台病毒１株,ＶＳＶ１株。结果提示ＴＮＦ－α和ＩＦＮ－α均具有广谱抗病毒活性。ＴＮＦ－α的抑毒作用能被ＴＮＦ－α申抗和ＩＦＮ－β单抗完全去除,被ＩＦＮ－α单抗部分去除ＴＮＦ－α的抗病毒效应。ＴＮＦ－－α中和试验的结果提示：ＴＮＦ抗病毒活性仍为ＩＦＮ－β诱生所介导。     

从云南省蝙蝠脑组织中分离出乙型脑炎病毒

为进一步阐明蝙蝠在保存乙脑病毒中的作用,于1997年7月,在云南省耿马县捕捉蝙蝠64只,取脑组织作病毒分离,从一只金管鼻蝠脑组织中分离出1株病毒,该毒株能引起BHK21细胞病变和乳鼠发病死亡,在pH5.75-7.4时能凝集鸽红血球,经用单克隆抗体血凝抑制和免疫荧光试验鉴定,证明为乙型脑炎病毒。进一步证明蝙蝠在乙型脑炎病毒保存和扩散中具有重要作用。从金管鼻蝠体内分离出乙型脑炎病毒属国内外首次报道。     

虹鳟传染性胰脏坏死病病毒（IPNV）的初步研究

山西省虹鳟试验场用从日本引进的鱼卵孵化的虹鳟稚鱼暴发流行病,死亡率高达90％以上,经组织培养分离到病毒,能在鲑鳟细胞系中产生细胞病变,形成直径0．5－1mm的空斑。感染健康虹鳟稚鱼能复制出与天然发病相同的症状和死亡率,病毒对氯仿不敏感,耐酸,耐热,病毒负染后电镜观察为直径55－65mm的二十面体颗粒,无囊膜,具单层衣壳,经血清学鉴定为传染性胰脏坏死病病毒（Infectious pancreatic necrosis virus简称IPNV）在血清学交叉中和反应中与抗IPN－SP株的抗血清有强烈的交叉反应,提示可能为IPN－SP株。     

从云南省蝙蝠脑组织中分离出乙型脑炎病毒

为进一步阐明蝙蝠在保存乙脑病毒中的作用,于1997年7月,在云南省耿马县捕捉蝙蝠64只,取脑组织作病毒分离,从一只金管鼻蝠脑组织中分离出1株病毒。该毒株能引起BHK21细胞病变和乳鼠发病死亡,在pH5.75～7.4时能凝集鸽红血球,经用单克隆抗体血凝抑制和免疫荧光试验鉴定,证实为乙型脑炎病毒。进一步证明蝙蝠在乙型脑炎病毒保存和扩散中具有重要作用。从金管鼻蝠体内分离出乙型脑炎病毒属国内外首次报道。     

中国流行性乙型脑炎病毒分子生物学特性研究

为了从分子水平了解中国流行性乙型脑炎(乙脑)病毒与国外分离株的差异,对1949年以来在中国乙脑主要流行地区分离的19株乙脑病毒的PrM-C区及E蛋白基因区的核苷酸序列进行了对比研究,以期了解不同时间不同地区在中国流行的乙脑病毒的分子差异.结果显示:病毒生物学初步鉴定显示,病毒感染BHK细胞后56h所有细胞均发生病变,约50%以上细胞脱落(CPE( ));3日龄乳鼠接种病毒72h之内死亡;所有病毒均与乙脑病毒(A2株)抗血清发生阳性反应,但反应强度不同,提示所有病毒均为乙脑病毒.病毒PrM-C(456～695)区核苷酸序列与各个国家及地区、各个基因型以及各个年代的73株乙脑病毒相应序列,用Woan-Ru Chen建立的方法进行基因分型分析,结果显示,所有19株中国分离的病毒均属于基因型Ⅲ型,与国外相关文献所报道的乙型脑炎病毒中国分离株的基因型相符.以乙型脑炎病毒疫苗株P3株为标准,对各病毒E蛋白500个氨基酸序列进行分析.各毒株核苷酸差异在0和4.2%之间,氨基酸差异在0和4.0%之间.所有核苷酸差异均为碱基的替换,无论核苷酸或氨基酸均无插入或丢失.大多数核苷酸变异在氨基酸编码的第三位,属于沉默突变,不引起氨基酸变化.18株病毒E蛋白活性结构域与疫苗株P3株相比共有247个氨基酸的差异,平均每株病毒有12.35个氨基酸的差异,有11株病毒(SA14、TLA、CZX、CBH、G35、GSS、LYZ、SH-3、YLG、YN、ZMT)在该区的差异数低于这个平均值.而在超过这一平均数的7个病毒株(A2、HA-3、47、CH-13、CTS、LFM、ZSZ)中,LFM、ZSZ、47与疫苗株相比较分别有16～20个氨基酸的差异,相对其它17株病毒而言,差异较为明显.以上线索提示,现有的乙型脑炎灭活疫苗在理论上可以覆盖包括现存病毒在内的毒株.     

树Ju对森林脑炎病毒的敏感性及发病机理的研究

从云南新分离森林脑炎病毒（YH和T570及东北株经脑内、皮下及腹腔感染成年中国云南树Ju,均发生病毒血症,持续时间为7－9天。抗体应答反应和病理改变程度成反比,病变轻的能产生较好的免疫应答。血凝抑制抗体、中和抗体和补体结合抗体分别于感染后的第5、7、13天出现,且血凝抑制抗体和中和抗体的升高呈正相关。经抗原定位研究发现,腹腔注射后48小时,各组织器官均能查到抗原,除中枢神经系统外,其它组织内病毒抗原消失都很快,随病毒血症的消失而转阴,中枢神经系统携带抗原可持续27天,且病变随病程的延长而加重,表面为充血、血管周围淋巴细胞呈套状浸润,局灶性出血,神经元变性,胶质细胞增生,轴索断裂等,说明靶器官是中枢神经系统。试验表明,成年中国云南树Ju对森林脑炎病毒比较敏感,是森林脑炎病毒动物模型研究首选动物。     

流行性乙型脑炎减毒株的研究进展

本文介绍了流行性乙型脑炎病毒株的研究简史,并着重阐述了现用减毒活疫苗株ＳＡ_（１４）－１４－２的生物学特点、分子生物学、免疫效果及其机理。     

发热伴血小板减少综合征布尼亚病毒规模化生产培养工艺的建立

目的通过对发热伴血小板减少综合征布尼亚病毒（简称“新布尼亚病毒”）进行规模化生产培养工艺研究,为新布尼亚病毒规模化生产提供有力支持。方法采用细胞工厂培养Vero细胞,待其长成致密单层后,取工作种子批新布尼亚病毒毒种接种细胞,采用连续收获或细胞病变充分时收获培养液上清的方法收获病毒,并以病毒滴度、抗原含量作为评价指标选择基础培养基、培养基pH、人血白蛋白添加浓度、接种细胞日龄、接种病毒MOI以及病毒培养温度。结果按0．01-0．001MOI接种3-4日龄Vero细胞,病毒培养液选择含0．3％人血白蛋白pH7．6-7．8的DMEM溶液,35℃培养7d收获,病毒收获液病毒滴度7．87LgCCID50／mL、抗原含量170．1μ/mL。结论初步建立了新布尼亚病毒规模化生产培养工艺,为后续工业化生产提供了数据支持。     

海南岛两个虫媒病毒分离物的初步鉴定

本文报告,1985年夏从海南岛采集的6种蚊子中,分离到4株乙型脑炎病毒和38株非乙脑病毒,其中两株(HN8和HN99)为甲组虫媒病毒。二者抗原性非常相近,对乳小白鼠脑内、腹腔和皮下接种部有较强的致病力,能在多种组织培养细胞上增殖并产生病变,能在鸡胚纤维母细胞上形成空斑,能凝集多种动物红细胞,血凝pH范围为5.75～6.4,最适pH为5.75或6.0,血凝素在4～37℃均较稳定,血凝素对福尔马林敏感。病毒呈球形,有包膜,直径60～65nm,属RNA病毒,对热、酸、乙醚和紫外线均敏感。血清学鉴定表明这两株病毒只与甲组虫媒病毒抗体有反应,尤其与MAY病毒抗原性关系较密切。同年从当地人、畜血清中检查了HN99病毒抗体,其阳性率为:健康人14％,猪23％,山羊35％。另外还与北京的M4株病毒作了初步比较,并对新毒株及我国其它有关毒株的分类学地位提出了初步看法。     

云南辛德毕斯病毒的生物学性状研究

本文对云南首次分离到的Sindbis病毒进行了滤过试验,耐酸耐醚试验、致细胞病变、动物敏感性试验、血压 凝特性、空斑和毒力等试验研究,结果符合披膜病毒科的病毒特性。交 因抑试验和免疫荧光试验,以及空斑减小中和试验进一步证实为甲病毒属的Sindbis病毒,其空斑纯化株的生物学特性也与原株相符,纯化株的制备为该株病毒分子生物学研究的准确性和一致性提供了条件。云南Sindbis病毒的首次分离具有重要的流行病学意义,其生物学特性研究结果对我省该病的诊断和防治具有重要的指导意义。     

Bovine Diarrhea Virus

Virus strain No. 12, one of the new isolates from Japanese cattle described previously, was studied for its physicochemical properties. The new isolate was shown to be very small in size by centrifugation and filtration, being filtrable through Millipore filters of 50 mμ pore size. It appears to be an RNA virus as its replication was not inhibited by 5-iodo-2′-deoxyuridine. The virus was readily inactivated by ether and deoxycholate, and partially by trypsin; was labile at pH 3, not stabilized by 1 m MgCl₂ at 50 C, was inactivated by ultraviolet, and withstood repeated freeze-thawing. Further it was readily inactivated at 56 C but more slowly at 37 C, and was stable at lower temperatures. These findings support the identification of the isolated virus as the bovine diarrhea (BD) virus. The properties of BD virus, i.e. size, type of nucleic acid, ether, chloroform and deoxycholate sensitivities, and acid lability, appear to be similar to those of arboviruses. The trypsin sensitivity of BD virus is similar to the B group of arboviruses, which, unlike the A group, sensitive to trypsin. For the classification of BD virus as well as hog cholera virus, which is closely related, further elucidation of properties, fine structure of the virion, etc., is needed.     

Giardiavirus-resistant Giardia lamblia lacks a virus receptor on the cell membrane surface.

Giardia lamblia virus (GLV) is a small nonenveloped double-stranded RNA virus that infects specifically the parasitic protozoan G. lamblia. Among the many collected strains of G. lamblia, a few turn out to be highly resistant to the virus infection. Two of these strains, Ac and JH, were subjected to electroporation with the RNA from GLV-infected G. lamblia WB strain. Subsequent studies indicated the presence of GLV double-stranded RNA and GLV protein in the electroporated and propagated cells. Virus particles, released by the transfected cells into the culture medium, were capable of infecting the virus-sensitive G. lamblia WB strain. When the WB cells were incubated with GLV at 4 degrees C and treated with the bifunctional cross-linking reagent disuccinimidyl suberate, little GLV protein was detectable inside the cells by immunofluorescent staining. However, patches of fluorescent granules were found on the membrane surface of the cells, suggesting cross-linking of the viruses with a certain membrane component(s). Similar treatment of the resistant strains Ac and JH showed no fluorescence either inside or outside of the cells. Two other closely related parasitic protozoa, Tritrichomonas foetus and Trichomonas vaginalis, cannot be infected by GLV via either viral infection or RNA transfection. The [35S]cysteine-labeled protein profiles in Triton X-114 extracts of G. lamblia WB, Ac, and JH were compared. The profile of the WB strain differs clearly from that of Ac and JH. It remains to be seen, however, whether this difference is related at all to the different susceptibilities to GLV infection.     

Differences among human immunodeficiency virus strains in their capacities to induce cytolysis or persistent infection of a lymphoblastoid cell line immortalized by Epstein-Barr virus.

Four strains of human immunodeficiency virus (HIV) manifest consistent differences in biologic behavior after infection of the X50-7 line of human umbilical cord lymphocytes immortalized by Epstein-Barr virus (EBV). Some dilutions of the first strain examined, human T-cell lymphotropic virus type III B, which is derived from a pool of patient isolates propagated in H9 cells, caused transient cytopathic effects (CPE) followed by recovery of a subpopulation of X50-7 cells which became virus carrier cultures. Other dilutions of the same virus stock completely lysed X50-7 cells. Two other strains, RF2 and YW, both from individual patients with acquired immune deficiency syndrome, always induced complete cytolysis of X50-7 cells at all dilutions which infected the cells. However, RF2 did establish persistent infection of H9 cells. A fourth strain, PH1-MN, from a child with acquired immune deficiency syndrome-related complex, induced only transient CPE in X50-7 and H9 cells, which thereafter always recovered to form carrier cultures. For all four strains, the dilutions of HIV stocks which caused CPE corresponded to dilutions which resulted in the detection of HIV polypeptides by immunoblot. Cytolysis in HIV-infected X50-7 cells was accompanied by a decrease in the amount of EBV nuclear antigen; however, HIV infection did not induce EBV replication. Thus CPE in X50-7 cells is due to replication of HIV per se and not to activation of EBV. The observations indicate that there are differences in the cytolytic properties of HIVs and that these differences are influenced by the target cell.     

Tissue Culture of Isolated Human Pancreatic Islets Infected With Different Strains of Coxsackievirus B4: Assessment of Virus Replication and Effects on Islet Morphology and Insulin Release

The aim was to study whether different strains of Coxsackievirus B4 (CBV-4) are able to infect human pancreatic islet cells in vitro and cause morphological and functional damages. Isolated islets maintained in tissue culture were infected with five well- characterised strains of CBV-4. Aliquots of the culture medium were analysed with regard to virus replication and insulin content. Infected and uninfected islets were examined by light microscopy to determine the degree of virus-induced cytopathic effect (CPE). The results showed that the islet cells were susceptible to infection by all the strains of CBV-4 although the outcome of the infection differed. The virus titres obtained at 48 and 72 hours post infection differed significantly between all the CBV-4 strains (p < 0.001), indicating different ability to replicate in islet cells. Pronounced to weak CPE, which was partly due to the origin (donor) of the islets, was induced by four of the five CBV-4 strains. One strain (VD2921) replicated without causing CPE despite high virus titres. One (V89-4557) of the CBV-4 strains always revealed pronounced CPE. Infection by this strain also caused functional impairment that significantly affected insulin response to high glucose at 48 hours post infection (p < 0.001). Replication of another CBV-4 strain (JVB) in the islet cells significantly increased the release of insulin compared to non-infected control cells (p < 0.001) indicating damage of the β-cells leading to leakage of insulin.     

Photochromogenic and scotochromogenic mycobacteria: their clinical significance

In the period 1973--1977, Mycobacterium tuberculosis was isolated by cultivation in 4408 cases from the clinical specimens of patients with positive X-ray findings. On the basis of atypical colony morphology or pigment formation, 263 other mycobacterial strains were identified: of these 23 were photochromogenic and belonged to Mycobacterium kansasii. The strains were cultured on several occasions from the specimens of 4 patients with broncho-pulmonary mycobacteriosis. The strains were resistant to isoniazid and streptomycin, sensitive to ethambutol and rifampicin. A total of 18 scotochromogenic isolates cultured from 14 patients with positive X-ray findings were identified as Mycobacterium aquae (M. gordonae) and its variants: strains showing slow Tween hydrolysis and 1 strain of rapid growth. In 5 cases M. tuberculosis was also obtained, indicating the presence of a mixed mycobacterial population. All scotochromogens were resistant to isoniazid and sensitive to ethambutol, with the exception of two strains sensitive to rifampicin.     

Effect of various adamantane compounds on the reproduction of Sindbis virus. Isolation and properties of a resistant strain]

Rimantadine and its structural analogs, i. e. amide of 1-adamantane carboxylic acid (AACA) and 1-adamantane acetic acid amide, were shown to be able to inhibit reproduction of Sindbis virus in culture Vero cells. AACA had the maximum antiviral activity. Subcultures of the initial sensitive population of Sindbis virus in the presence of AACA led to formation of mutants resistant to AACA as well as to rimantadine, adamantane acetic acid amide and ammonium chloride. The Sindbis virus population was heterogenous in sensitivity to AACA, which was evident from isolation of separate clones with various levels of sensitivity to the above mentioned compounds from the population. It was found that reproduction of the AACA sensitive and resistant strains of Sindbis virus differed: the latent period of the resistant strain was 2 hours longer than that of the sensitive strain. The same effect was observed in the comparative study on synthesis of the virus-specific RNA.     

Virus entry is a major determinant of cell tropism of Edmonston and wild-type strains of measles virus as revealed by vesicular stomatitis virus pseudotypes bearing their envelope proteins

The Edmonston strain of measles virus (MV) that utilizes the human CD46 as the cellular receptor produced cytopathic effects (CPE) in all of the primate cell lines examined. In contrast, the wild-type MV strains isolated in a marmoset B-cell line B95a (the KA and Ichinose strains) replicated and produced CPE in some but not all of the primate lymphoid cell lines. To determine the mechanism underlying this difference in cell tropism, we used a recently developed recombinant vesicular stomatitis virus (VSV) containing as a reporter the green fluorescent protein gene in lieu of the VSV G protein gene (VSVDeltaG*). MV glycoproteins were efficiently incorporated into VSVDeltaG*, producing the VSV pseudotypes. VSVDeltaG* complemented with VSV G protein efficiently infected all of the cell lines tested. The VSV pseudotype bearing the Edmonston hemagglutinin (H) and fusion (F) protein (VSVDeltaG*-EdHF) infected all cell lines in which the Edmonston strain caused CPE, including the rodent cell lines to which the human CD46 gene was stably transfected. The pseudotype bearing the wild-type KA H protein and Edmonston F protein (VSVDeltaG*-KAHF) infected all lymphoid cell lines in which the wild-type MV strains caused CPE as efficiently as VSVDeltaG*-EdHF, but it did not infect any of the cell lines resistant to infection with the KA strain. The results indicate that the difference in cell tropism between these MV strains was largely determined by virus entry, in which the H proteins of respective MV strains play a decisive role.