长爪沙鼠腹腔巨噬细胞对流行性出血热病毒的敏感性

本文就长爪沙鼠腹腔巨噬细胞(MΦ)对流行性出血热病毒(EHFV)的敏感性进行了试验,用3株野鼠型(A9、R3、76-118)和1株家鼠型EHFV(R22),并用对EHFV敏感的Vero-E6细胞作对照,结果沙鼠腹腔巨噬细胞感染EHFV后,第1代第8天前即可查见明显的特异性荧光,第16天左右达高峰,病毒滴度≥10~(-7.5),与Vero-E6细胞比较,培养上清液的病毒滴度,沙鼠MΦ较Vero-E6细胞高1～4个对数,当感染病毒量很低时,在Vero-E6细胞内测不出特异性抗原,而在沙鼠MΦ内病毒仍可繁殖,滴度达10~(-5.(?)),中和试验、间接免疫荧光检测和荧光阻断试验均证明,沙鼠MΦ内繁殖的病毒确实为EHFV。     

中国和日本分离的几株流行性出血热病毒的抗原性比较

采用间接免疫荧光法(IFA)和ELISA法比较了几株中国和日本流行性出血热病毒(EHFV)的抗原性,IFA法不能区分大鼠属和姬鼠属来源的病毒,ELISA竞争试验表明,大鼠型病毒(R22、SR-11和TR-352株)与姬鼠型病毒(A 9株)存在弱单向交叉反应,交叉ELISA证实,A 9株与R22株、SR-11株和TR-352株均有较显著的抗原性差异,但R22,SR-11和TR-352株彼此间抗原性相近,本文讨论了有关EHFV抗原性比较中的一些问题。     

原位杂交定位实验乳鼠各脏器中流行性出血热病毒RNA

用~8H-dTTP和生物素-11-dUTP标记流行性出血热病毒(EHFV)R22株M片段R3 cDNA制备探针,采用原位杂交法对EHFV感染的Ba1b/C乳鼠各脏器进行了病毒RNA定位。实验结果,病毒RNA主要定位于脑、肾、肾上腺、肝、心脏。在脑,病毒主要侵犯大脑皮质、海马回神经元,可见阳性颗粒或阳性     

流行性出血热病毒(EHFV)在传代人淋巴细胞上的致病变作用增殖的研究

流行性出血热病毒陈株、L_99和SR_11株按种传代淋巴细胞克隆株Ly-A_6后第5～7日观察到CPE,开始时受感染细胞浆内颗粒增多,细胞圆缩、聚积成堆,随后细胞膜模糊不清,2～3天脱落,同时制片IFA检测到胞浆内特异性荧光颗粒,以上结果能被EHF免疫血清所中和。接种病毒后的细胞单层用l％甲基纤维素加维持液覆盖,第6日吸去覆盖液,加5％甲醛-1％结晶紫固定染色可见到明显的PFU。EHFV致病变细胞株的染得将为病原学研究提供了优越的基质细胞。     

安徽省流行性出血热病毒杂交瘤单克隆抗体的研制与应用

用流行性出血热病毒(EHFV)李株和陈株血凝素(HAN)分别免疫Balb/C小鼠,取其脾细胞和骨髓瘤细胞SP2/O融合,杂交瘤生长孔率为97.5％和60％,阳性率各为2.5％和22％,克隆化培养阳性率达到100％。通过筛选得2株杂交瘤细胞、一株为2B_7、另一株为1H_8。其腹水单克隆抗体(McAb)滴度均达1∶16×10~4—32×10~4。1H_8的血凝抑制滴度达1∶5120。经染色体核型分析,杂交细胞染色体2B_7为80—97条,1H_8为85—105条,每个细胞均含一条中着丝点标记染色体。McAb的Ig类别和IgG亚类检测结果2B_7为IgM,1H_8为IgG_(2b)。两者对19株不同来源的EHFV具有不同的反应,1H_8McAb与19株都具有不同程度的免疫荧光反应,滴度都较高,且对5株不同来源的EHFV-HAN具有血凝抑制活性,滴度在1∶1280—5120,故1H_8为血凝抑制抗体;2B_7只对12株EHFV起反应,对7株不起反应,且没有血凝抑制活性。这说明1H_8与2B_7具有不同的特性。     

流行性出血热病毒感染家猪的实验

本实验证明猪为流行性出血热病毒(EHFV)的敏感实验动物。从啮齿动物中分离的动物源株(R_(22))和从EHF患者血中分离的人源株(HB_(55))都可感染猪,并可在其体内许多组织中复制增殖。家猪在接种EHFV后第6—9天有一个短暂的发烧期,表现出病毒血症。于接种后的第7—11天(R_(22))和7～20天(HB_(55))可在组织中、特别是脾和肺中,用直接免疫荧光技术(DFA)很容易地捡出EHFV抗原。亦可在感染EHFV的猪血中检出EHFV抗体。从感染后的荧光阳性猪脾、肺可分离出感染性病毒。但R_(22)病毒株在感染猪后的第15天便完全消失,而HB_(55)株在感染后的第20天仍可查见,似乎动物源株(R_(22))和人源株(HB_(55))有所差异,然而都对家猪有感染性。从而,首次证实了家猪为EHFV的敏感实验动物,可作为EHFV的分离,增殖及疫苗研制等的新动物模型。这一发现,对EHF的研究将起积极作用,也提示猪在EHF流行病学上的意义不可忽视。     

流行性出血热病毒在MA-104和Vero-E6传代细胞上繁殖动态的比较

用流行性出血热病毒(陈株)分別感染MA-104和Vero-E6传代细胞,结果受病毒感染的MA-104细胞荧光阴性细胞出现早,感染滴度高,胞浆内颗粒大,提示MA-104细胞用于该病毒的分离传代及抗原片的制作等方面优于Vero-E6细胞。流行性出血热病毒(EHFV)在某些原代及传代细胞上能适应增殖,国内外已有过报导。但用对轮状病毒十分敏感的恒河猴胚肾MA-104细胞培养和增殖EHFV并与通常使用分离该病毒的VeroE6细胞进行繁殖动态观察,尚未有过报导。本文用间接免疫荧光法(IFA)比较观察EHFV在两种细胞上的增殖动态,为MA-104细胞代替常规Vero-E6细胞用于该病毒的分离、传代等研究以及抗原片的制备提供依据。     

流行性出血热病毒对健康人外周淋巴细胞和大白鼠骨髓细胞染色体影响的研究

用流行性出血热病毒(EHFV)A9株,滴度为TCID_(50)10~(-5)/0.1ml,加入10名健康人外周血,作淋巴细胞姊妹染色单体互换(SCE)和染色体畸变的检测。每份血分对照组(不加病毒悬液)和A、B、C实验组(根据加不同病毒量而分)。其结果:一、SCE频率,实验组A(8.9±0.19)、实验组B(9.9±0.2)、实验组C(11.6±0.22)与对照组(6.57±0.15)比较,A、B、C、实验组均分别高于对照组,P<0.01,差异有高度显著性,A、B、C三个实验组比较,P<0.01,差异有高度显著性。二、染色体畸变,A、B、C三个实验组分别与对照组比较,P>0.05,差异均无显著性。用EHFV HA 108株,ID_(50)10~(-6)/0.02ml接种2—5日龄大白鼠脑内,15天后颈动脉放血处死,取骨髓细胞培养,另取幼大白鼠骨髓细胞培养作对照,检测SCE和染色体畸变。结果:一、SCE频率,实验组(9.8±0.35)高于对照组(5.4±0.19),P<0.01,差异有高度显著性。二、染色体畸变,实验组与对照组比较,P>0.05,差异无显著性。以上两个实验结果表明,EHFV作用于细胞,无论是在机体或试管内,都引起SCE频率增高,即EHFV促使DNA产生初级损伤,但不致染色体畸变。     

人轮状病毒的细胞培养分离

用CV-1细胞从急性腹泻病儿7份粪便标本中直接分离出4株人轮状病毒(HRV),并适应传代14代。感染细胞出现特征性细胞病变,经电镜、ELISA、免疫荧光染色及病毒RNA电泳等试验证实HRV毒株在CV-1细胞中的繁殖及抗原特异性。病毒滴度为10~(6.0)TCID_(60)。分离的4株HRV毒株均为RNA电泳型长型,经CV-1细胞传7～14代后,RNA图型与原粪样相比未见变异。     

斑点杂交生物素法检测流行性出血热病毒RNA

为寻找一种用于检测流行性出血热病毒的分子杂交方法,以生物素-7-dATP标记流行性出血热病毒(EHFV)R_(22)株M片段的cDNAR_3克隆作探针,与人源性的EHFVH-114、H-435株RNA基因组进行斑点杂交,得到阳性结果,可检出5pg的cDNA或RNA。此探针与疱疹病毒DNA不出现杂交信号。以上结果说明这种标记探针具有EHFV特异性,可以扩大应用范围,结果还表明动物源性和人源性EHFV均具有共同的保守核苷酸序列。     

Paclitaxel administration and its effects on clinically relevant human cancer and non cancer cell lines

Comparisons of the effects of clinically relevant concentrations of the anticancer agent paclitaxel on growth, viability, and apoptosis were determined using in vitro human cell cultures. Growth of the cervical cancer cell line, HeLa-S3, was significantly reduced, and apoptotic index was significantly increased, after 24 h in cultures treated with 12 nM paclitaxel. In contrast, hepatic carcinoma (HEpG2) cells capable of detoxifying paclitaxel were only affected at paclitaxel concentrations ge120 nM. The previously uncharacterized non-cancerous human microvessel endothelial cell line HMEC-1, was more sensitive to paclitaxel treatment than both HeLa-S3 and HEpG2 cells, demonstrating decreased growth and increased apoptosis with 1.2 nM paclitaxel. These results are significant in the design of in vitro cell culture systems to study drug metabolism and toxicity.     

检测流行性出血热病毒滴度和中和抗体效价的半微量空斑法

建立了检测流行性出血热病毒滴度和中和抗体效价的半微量空斑法。小牛血清与胎牛血清的培养效果无差异。7株不同来源的出血热病毒均能在E6细胞上形成空斑。接种的病毒浓度与形成的空斑数呈直线关系。用空斑法测得的病毒滴度稍低于荧光TCIE50滴定法。空斑减少中和试验的敏感性较荧光中和试验高30倍左右。同时还初步表明了本方法可用于流行性出血热病毒的抗原性分析。     

Reduced expression of the BRCA1 gene and increased chromosomal instability in MCF-7 cell line.

Using clonal cell cultures, a significant increase in chromosomal aberrations (aneuplolidy, dicentrics and chromatid breaks) were observed in MCF-7 cells compared with HeLa. BRCA1 expression was lower in MCF-7 cells than in HeLa cells. Since BRCA1 is known to play a role in the maintenance of chromosomal integrity, the increase in chromosomal aberrations in MCF-7 clones suggests that downregulation of BRCA1 expression could be one of the possible mechanisms for increased chromosomal instability in this cell line.     

流行性出血热病毒感染NIH裸鼠免疫组织化学研究

流行性出血热病毒（ＥｐｉｄｅｍｉｃＨｅｍｏｒｒｈａｇｉｃＦｅｖｅｒｖｉｒｕｓ,ＥＨＦＶ）感染ＮＩＨ裸鼠后,濒死状态取材,应用免疫组织化学方法（ＡＢＣ）检测各组织中的特异性病毒抗原。结果表明,ＮＩＨ裸鼠对ＥＨＦＶ感染敏感,感染后其脑、肺、肝、肾和心脏组织实质细胞浆内均可检出特异性抗原。     

Lipopolysaccharide effects on sensitive and resistant variant chinese hamster ovary cell lines

Chinese hamster ovary (CHO · K1 · PRO) cell growth was inhibited by addition of a gram-negative bacterial lipopolysaccharide (LPS) to the cell culture medium. Growth inhibition began after three or four days of incubation, was dose-dependent up to a maximum at an LPS concentration of 500 μg/ml and was accompanied by cell shape changes and enhanced cytoplasmic vacuolization. Formation of bizarre CHO · K1 · PRO cell shapes and vacuole formation were most pronounced after seven days of incubation with LPS and could be observed by light and electron microscopy. An LPS-resistant cell population was obtained by intermittent in vitro exposure to high levels of LPS; these variant cells or clones derived from them failed to display growth inhibition in the presence of LPS. A clone from the LPS-resistant variant population showed altered cell properties compared to the parental cell line which included changes in cell morphology, adhesion, and endocytosis. Parental cells were markedly density-inhibited, whereas the variant clone exhibited considerable growth after confluency. The LPS-resistant variant cells showed a more elongated morphology than the parental line. No significant differences were observed between rates of detachment of parental and variant cells when sparse cultures of either line were removed from tissue culture dishes by ethylenediaminetetracetate (EDTA). However, at confluency approximately 100% of the variant cells versus 35% of the parental cells were removed by EDTA in one hour. Measurements of ¹²⁵I-ferritin uptake by parental and variant cells showed approximately twenty-fold and twofold increases, respectively, in uptake induced by LPS when compared to untreated control cultures.     

Multilocus DNA fingerprint analysis of cellbanks: Stability studies and culture identification in human B-lymphoblastoid and mammalian cell lines

The technique of multilocus DNA fingerprinting has great potential for the authentication of animal cell cultures and in identification of cross-contamination. The Alec Jeffreys probes 33.6 and 33.15 were used as multilocus probes to demonstrate the consistent DNA fingerprint profiles in human peripheral blood and its derivative Epstein-Barr virus (EBV) transformed B-lymphoblastoid cultures maintained by repeated subculture for six months. However, fingerprint analysis of EBV transformed cultures generated from small numbers of cells showed that the majority (seven of eight cultures) had anomalous profiles. Some of these altered profiles shared common features not seen in the peripheral blood pattern. Analysis of seven murine hybridoma clones from a single fusion experiment revealed only two clones which could not be distinguished using probe 33.15. Further studies of master and distribution cell banks for eleven cell lines demonstrated consistent fingerprint profiles in all cases except one (U937). However, this cell line showed only minor differences in the master and distribution bank profiles. These data indicate that, while changes in fingerprint profile may be identified in exceptional instances, the multilocus fingerprinting method using probes 33.6 and 33.15 is a powerful and reliable tool in the quality control of animal cell cultures.     

病毒疫苗制备用不同核型VERO细胞系在裸鼠体内致癌/致瘤性的系统实验研究

生产疫苗用细胞系可能具有致瘤性,一些常用的细胞系需要检查不同代次有无致癌性。在建立传代细胞种子库与工作库基础上,对研制生产病毒活疫苗所用8株VERO细胞系在219只裸鼠进行了致癌(瘤)实验。本研究结果表明,VERO细胞染色体核型可发生变异,亚四倍体JA株与超二倍体KA株具有强的致癌性,不能用于致弱活病毒疫苗制备,但可替代HeLa细胞系用作恶性肿瘤阳性对照细胞。筛出无致瘤性的YB、dC、M和JB株亚二倍体VERO细胞系,可替代BHK-21细胞用于狂犬病减毒活疫苗制备。VERO细胞系染色体遗传相对稳定。不同代次变化不大。研究发现细胞染色体遗传特征决定致瘤性质并具有种属特异性,不同核型细胞致瘤性不同,细胞染色体数目变异大小和致癌性成正相关,通过体内外交替选育可在裸鼠体内快速选育成功高变异率肿瘤细胞系。高变异率HeLa或VERO细胞系移植于裸鼠可能产生恶性横纹肌样瘤。因此,应当强调疫苗生产用细胞系致瘤性评价的重要性。     

Isolation and characterization of a bovine trophectoderm cell line derived from a parthenogenetic blastocyst

A bovine trophectoderm cell line was established from a parthenogenetic in vitro-produced blastocyst. To initiate the cell line, 8-day parthenogenetic blastocysts were attached to a feeder layer of STO fibroblasts and primary outgrowths occurred that consisted of trophectoderm, endoderm, and very occasionally epiblast tissue. Any endoderm and epiblast outgrowths were removed from the primary cultures within the first 10 days of culture by dissection. One of the primary trophectoderm cell cultures was chosen for further propagation and was passaged by physical dissociation and replating on STO feeder cells. The cell culture, designated BPT-1, was maintained in T25 flasks and passaged at a 1:3 split ratio for the first 15 passages approximately once every 2 weeks. Thereafter, the cell culture was passaged at 1:10-1:40 split ratios. Transmission electron microscopic examination showed the cells to be a polarized epithelium with apical microvilli, a thin basal lamina, and lateral junctions consisting of tight junctions and desmosomes. Lipid vacuoles and digestive vacuoles were also prominent features of the BPT-1 cells. Metaphase spread analysis at passage 59 indicated a near diploid cell population (2n = 60) with a mode and median of 60 and a mean of 64. BPT-1 cells secreted interferon-tau into the medium as measured by anti-viral assay and Western blot analysis. The cell line provides an in vitro model of parthenogenote trophectoderm whose biological characteristics can be compared to trophectoderm cell lines derived from bovine embryos produced by normal fertilization or nuclear transfer.     

Establishment and characterization of human glioblastoma cell line (HUBT-n)

We succeeded in primary culture of 3 in 4 cases of glioblastomas. The long-term passage cultures were not done from the primary cultures of original tumor, but glioblastoma cell line (HUBT-n) was established from a xenograft of nude mouse. This line grew well without interruption for 4 years and was subcultivated over 120 times. The cells were spindle like or round in shape and neoplastic and pleomorphic features contained glial fibrillar acid protein (GFAP) and S-100 protein and grew multilayering without contact inhibition. A bough-shaped long projection was noted from a small cell. One of the characteristics of the HUBT-n cells was existence of well developed intermediate filaments in their cytoplasm. The cells proliferated rapidly, and the population doubling time was about 32 hours. The chromosome number showed a narrow distribution of diploid range. Abnormal constitution was observed in all cells by G-band karyotyping. The culture cells were easily transplanted into the subcutis of nude mouse and produced the tumor resembling the original tumor.