口服脊髓灰质炎活疫苗糖丸的病毒滴度及其分析

对１９９４～１９９８年共５年间生长的口服脊髓灰质炎活疫苗糖丸的病毒滴度的检定结果进行质量分析。结果显示：近５年生产的口服脊髓同炎活疫苗糖丸中,其病毒滴度稳中有升,平均工由６．１３ｌｏｔＴＣＩＤ５０／人份上升到６．２５ｌｏｇＴＣＩＤ５０／人份;同时疫苗的热稳定性试验结果也在逐步提高,其病毒滴度的平均基础滴度与３７℃４８ｈ平均滴度差值的平均值由０。８７ｌｏｇ／ＴＣＩＤ５０／人份下降到０．６３ｌｏｇ／Ｔ     

国内外几家脊髓灰质炎疫苗的质量比较

目的比较国产脊灰疫苗与进口疫苗的各项指标。方法依据《中国生物制品规程》和《WHO生物制品规程》,对17批进口脊髓灰质炎液体疫苗和抽检国产脊灰糖丸疫苗进行质量检产。该研究还分析了国产疫苗半成品的质量和43名1岁龄儿童服用糖丸疫苗的免疫效果。结果进口疫苗的基础滴度和热稳定性试验的合格率均为82．4％（14／17）。国产疫苗与进口疫苗在基础滴度上无显著性差异,但其热稳定性略低于进口液体疫苗。国产脊灰糖丸疫苗经全程免疫后Ⅰ型抗体阳转率为97．6％（42／43）,Ⅱ型和Ⅲ型均为100％（43／43）。结论进一步提高国产脊灰疫苗的热稳定性是必要的。     

RT—PCR法检测甲肝疫苗滴度

建立快速灵敏特异的甲肝减毒活疫苗滴度的ＲＴ－ＰＣＲ检测法。方法：以编码甲肝病毒（ＨＡＶ）ＶＰ３羧基端的基因区为目标区，运用ＲＴ－ＰＣＲ法对甲肝疫苗病毒进行检测，并与ＴＣＩＤ５０检测法进行比较。结果：ＲＴ－ＰＣＲ法灵敏度和特异性均与ＴＣＩＤ５０法相似，...     

L20B细胞在脊髓灰质炎病毒分离中的应用

由于Ｈｅｐ－２细胞、ＲＤ细胞不仅对脊灰病毒敏感,而且对其他非脊灰肠道病毒（ＮＰＥＶ）也敏感,所以在使用Ｈｅｐ－２细胞、ＲＤ细胞对脊灰病毒分离鉴定的过程中,浪费了大量的人力物力在非目标病毒上。为此ＷＨＯ下发一种新细胞株Ｌ２０Ｂ细胞,取代Ｈｅｐ－２细胞在脊灰病毒分离鉴定中的作用。我们用Ｌ２０Ｂ细胞对１９９８年上半年Ｈｅｐ－２、ＲＤ细胞分离阳性的４６份ＡＦＰ病例粪便标本进行复检,并与Ｈｅｐ－２和ＲＤ细胞的结果进行比较,现将结果报告如下：１　材料与方法１－１　标本来源广东省１９９８年ＡＦＰ病例中Ｈｅｐ－…     

两种剂型的脊髓灰质炎疫苗基础免疫的血清学效果观察

比较了脊髓灰质炎（脊灰）糖丸疫苗和液体疫苗基础免疫的血清学效果。观察对象为近５年无脊灰流行的农村．共１０２名２～６月龄未服过脊灰疫苗的婴儿，按月龄和性别均衡地分为糖丸疫苗组和液体疫苗组。两组都有部份婴儿有母传抗体，服苗前各型脊灰中和抗体的阳性率为１１．７６％～１９．１５％。几何平均滴度（ＧＭＴ）１：１．１８～１：２．４５。全程３次服苗后，抗体阳转率和４倍增长率均达到１００％，两组之间差异无显著的统计学意义；ＧＭＴ亦达到１：７８．７６～１：１１５．３６，两组之间也无显著性差异。这表明两种剂型的脊灰疫苗均有良好的免疫效果。液体疫苗因服用方便，更适合于０～８月龄婴儿。     

L20B RD与Hep-2三种细胞用于脊髓灰质炎病毒分离鉴定的比较

采用世界卫生组织（ＷＨＯ） 推荐使用的方法,用Ｌ２０Ｂ、ＲＤ和Ｈｅｐ２ 三种细胞进行脊髓灰质炎（脊灰）病毒的分离鉴定。结果表明,Ｌ２０Ｂ细胞具有良好的特异性,对非脊灰肠道病毒均不敏感。在脊灰分离株和粪便悬液标本中脊灰病毒的检出率分别为１００％ 和９３－３ ％ ,优于ＲＤ和Ｈｅｐ２ 细胞,特别是在病毒分布不均及混有非脊灰肠道病毒的情况下,能更好地、准确地捕捉到脊灰病毒。采用Ｌ２０Ｂ加ＲＤ细胞分离脊灰病毒优于ＲＤ加Ｈｅｐ２,但对非脊灰肠道病毒分离率有影响。     

脊髓灰质炎三价糖丸疫苗与液体疫苗的免疫效果观察

１９９４年５－７月在广州市荔湾区和越秀区的２－６月龄的健康婴幼儿分别使用脊髓灰炎三价糖丸疫苗和液体疫苗进行基础免疫。结果表明，两种剂型疫苗免疫后的脊灰Ⅰ，Ⅱ，Ⅲ型中抗体阳性率均为９７－１００％，ＧＭＴ在５６－１０５之间。在免疫效果方面，两者间无显著性差异。     

国产脊髓质炎糖丸与进口液体疫苗免疫后的血清学效果观察

为比较脊髓灰质炎国产糖丸疫苗与进口液体疫苗基础免疫血甭学效果，对１０２名２－１２月龄婴儿，随机分为两组分别全组接种两种疫苗后，检测血清和抗体的阳性率和几何平均滴度（ＧＭＲＴ）。结果显示两种疫苗和各型别中和抗体性率达８０％以上，且两苗型间无显著差别，但免疫后Ⅱ型抗体ＧＭＲＴ水平，糖丸疫苗组显著高于液体疫苗组，说明现任上疫苗虽均能获得良好的免疫效果，但国产糖丸疫苗更优于进口液体疫苗。     

无血清培养基用于Vero细胞培养的效果

应用美国Ｈｙｃｌｏｎｅ生产的无血清培养基（Ｂ３）用于Ｖｅｒｏ细胞的培养。结果Ｖｅｒｏ细胞用１０％小牛血清加入基础培养基使细胞贴壁后换以无血清培养基后，Ｖｅｒｏ细胞用１０％小牛血清加入基础培养基使细胞贴壁后换以无血清培养基后，Ｖｅｒｏ细胞可以生长繁殖，其繁殖数量在培养９６ｈ可达１５万／ｍｌ，但少于对照１９９加１０％小牛血清组（３０万／ｍｌ），细胞长成单层后接种狂犬病固定毒ＣＴＮＣＰ３０，病毒生长繁殖，第７天达到高峰，毒力为６．０ｌｏｇＬＤ５０／ｍｌ，低于对照组（毒力７．５ｌｏｇＬＤ５０／ｍｌ），表明无血清培养基（Ｂ３）虽可促进Ｖｅｒｏ细胞生长并对感染病毒敏感，但其细胞生长数量和促进病毒繁殖较加入小牛血清差。     

两种剂型脊髓灰质炎疫苗的免疫效果观察

为了解国产糖丸剂型和法国产液体剂型３价脊髓灰质炎减毒活疫苗的免疫效果，在本市农村进行了观察。对１２６名≥２月龄婴儿分２组，分别以一种剂型疫苗免疫，免疫前和每次免疫后１个月采血，用ＥＬＩＳＡ法检测脊灰ＩｇＧ抗体。结果表明，两种剂型疫苗免疫后，３个型ＩｇＧ抗体阳性率均在９６％以上；几何平均滴度（ＧＭＴ）糖丸疫苗Ⅰ、Ⅱ、Ⅲ型分别为１：３８２５．１、１：２９５４．４和１：２７６３．３，液体疫苗则为１：４４６７．６、１：３１４１．４和１：２７５３．３。两种剂型疫苗免疫后的抗体阳性率和ＧＭＴ的差异均无显著的统计学意义     

HIV-1VN Jurkat细胞株HIV-1病毒分泌动力学及培养优化的研究

目的：研究HIV-1VN Jurkat细胞株HIV-1病毒分泌动力学及新生小牛血清对细胞生长及病毒产量质量的影响。方法：通过对HIV-1VN Jurkat细胞分泌病毒的滴度、细胞活力指数、活细胞密度、病毒比分泌速率和细胞比生长速率进行观察来评价其动力学；通过对抗原纯度的变化来说明不同浓度的新生小牛血清对分泌的病毒质量的影响。结果：HIV-1VN Jurkat细胞分泌病毒的滴度与细胞活力指数、活细胞密度呈现正相关性；病毒滴度、病毒比分泌速率与细胞比生长速率不相关，随着小牛血清浓度的增加，抗原纯度有下降趋势。结论：细胞生长对数期几乎同步出现病毒分泌对数期，小牛血清浓度为9％～12％的培养基是最佳的培养条件。     

牛源乳铁蛋白体外抗HBsAg分泌的研究

目的探讨牛源乳铁蛋白(BLF)体外抑制HbsAg分泌作用。方法以天然HBV感染HepG2细胞为模型,应用ELISA法测定细胞上清中的HBsAg水平,并用MTT法对BLF对HepG2细胞的毒性进行研究。结果BLF对细胞的最大无毒剂量(TD0)为3.0g/L,半数中毒剂量(TD50)为11.08g/L;先用HBV对HepG2细胞进行感染,再加入BLF,各浓度组BLF均对HBsAg分泌有一定抑制作用,BLF浓度3.0g/L时对HBsAg的抑制率达58.34%;将BLF与HBV阳性血清作用后再接种于细胞,各实验组均不能抑制HBsAg分泌,将BLF先与细胞作用后洗去BLF,在接种病毒后,BLF浓度0.5g/L以上各组均能显著抑制HBsAg分泌,但BLF0.1g/L组不能抑制HBsAg分泌。乳铁蛋白水解物不能抑制HBsAg分泌。结论牛源乳铁蛋白不能通过与HBV结合来阻断对HepG2细胞的感染,但可以通过对HepG2细胞的保护来阻断感染;当HepG2细胞感染HBV后,牛源乳铁蛋白仍可抑制HBsAg分泌,将乳铁蛋白水解后无抑制作用,说明是乳铁蛋特有结构起作用。     

Stability of oral polio vaccine at different temperatures

The stability of five batches of oral polio vaccine stored at -20, 4-8, 22 and 36 degrees C for 7, 14 and 21 days was studied. The virus titrations were performed by the standard macro-method. There was little loss in virus titre when samples were kept at -20 and 4-8 degrees C for 21 days, whereas the samples exposed to 36 degrees C for 21 days showed almost complete loss in virus titre. The average loss in virus titre in a year (log TCID50) was 0.47 at -20 degrees C and 0.65 at 4-8 degrees C when various samples were stored at these temperatures. At 22 degrees C the average loss in virus titre after 21 days was about 1.50. The samples subjected to ten cycles of freezing and thawing did not show any loss in virus titre. Likewise there was not much loss in virus titre in three samples stored at 4-8 degrees C for a year. Oral polio vaccine stabilized with magnesium chloride is quite a stable vaccine and maintenance of a proper cold chain is recommended for the delivery of a potent vaccine in countries with high ambient temperature.     

Serum-free influenza virus production avoiding washing steps and medium exchange in large-scale microcarrier culture

A complete serum-free process without washing steps and medium exchange before infection for influenza A virus vaccine production (equine and human) is described for cultivation in roller bottles and in a 5-L stirred tank microcarrier system. Adherent Madin-Darby canine kidney cells (MDCK) were adapted from growth in serum containing GMEM medium to growth in serum-free Ex-Cell MDCK medium. Roller bottle experiments showed that the medium exchange step, typically required for serum containing vaccine production processes, could be omitted without losses in virus titre and without limitations in glucose or glutamine supply in the cultivation medium. The serum-free medium could even be used glutamine-free as it contained pyruvate, resulting in very low levels of ammonia. Cell attachment onto microcarriers was critical. Therefore, microcarriers had to be preconditioned in medium. Also, trypsin concentration used for inoculum preparation had to be reduced. After these modifications 1.3 x 10(6)cells/mL were obtained after 97 h (2g/L Cytodex 1) of cell growth. Maximum virus titres of 2.3-2.9 log HA units/100 microL were obtained from infections with a multiplicity of infection (moi) of 0.05-0.10 for human and equine influenza A virus. Metabolite and amino acid profiles as well as on-line data for the serum-free process are compared with the serum containing process. Omission of the medium exchange before infection clearly simplified the process and reduced sterility risks due to washing steps.     

Oral polio vaccination of children in the tropics. III. Intercurrent enterovirus infections, vaccine virus take and antibody response.

The effect of intercurrent enterovirus infections on host responses to oral polio vaccine (OPV) was studied in groups of infants and children who were without antibodies to one, two or three serotypes of poliovirus. The prevalence of enterovirus infections as detected in fecal specimens collected at weekly intervals and inoculated in primary monkey kidney cell culture, HEp 2 cells and newborn mice ranged between 60 and 70 per cent. The presence of such infections at the time of, 1 week prior to, or during the 3 weeks prior to the administration of OPV did not appear to inhibit either vaccine virus take or antibody response. However, in both the infected and uninfected children the rates of vaccine virus take and seroconversion were found to be considerably lower than those reported from several temperate climate countries.     

大鼠海马神经细胞在含硒介质中的生长及存活研究

目的 研究硒对大鼠海马神经细胞生长、存活及突起发育的影响。方法 利用新生大鼠海马神经细胞原代培养技术,培养液内加入不同浓度的硒（62．5、125．0、187．5μg／L）和碘加硒,观察有血清和无血清条件培养下海马神经细胞的生长、存活数;同时还测量了接种后4个不同观测点的平均最长突起长度。结果 硒不仅对海马神经细胞早期突起生长有显著的促进作用,在接种16、24、36、48h后有明显突起伸长趋势,咯硒组与对照组相比平均增加15－20μm,而且无论有无血清,硒均能延长神经细胞存活时间,提高存活率。结论 硒对海马神经细胞的早期突起生长、存活有重要作用。     

Survival of a hepatitis C virus surrogate in anaesthetic and analgesic drugs

The re-use of solutions used in surgical procedures provides an opportunity for transmission of infectious agents should a breakdown in good work practices occur. Agents that are blood-borne are particularly important in this respect. We examined whether a hepatitis C virus surrogate (bovine viral diarrhoeal virus) could survive exposure to Propafol and Fentanyl, drugs commonly used for induction of anaesthesia and analgesia, respectively. Testing involved the spiking of ampoules of these solutions with a high-titred preparation of virus. Following incubation of this mixture at ambient temperature for various periods of time, attempts were made to isolate the virus in cell cultures. Our results showed that the surrogate virus survived for up to 2 hours without loss of titre in these solutions, suggesting that the hepatitis C virus would also survive and could also be transmitted in a surgical setting under some circumstances.     

Growth characteristics of canine pathogenic viruses in MDCK cells cultured in RPMI 1640 medium without animal protein

Madin Darby canine kidney (MDCK) cells were adapted to serum-free RPMI 1640 medium and used for cultivation of canine viruses. RPMI 1640 medium was supplemented with a soybean peptone, L-glutamine and antibiotics, so that the protein concentration was less than 5 microg/ml (RPMI/SP medium). The resulting adapted MDCK-SP cells showed steady growth after the twenty-eighth passage in RPMI/SP medium (MDCK-SP cell culture). Canine distemper virus, canine parvovirus, canine adenoviruses and canine parainfluenza virus, which are the principal components of canine combined virus vaccines, grew in the MDCK-SP cell culture as efficiently as the parental MDCK cells cultured in the conventional Eagle's MEM containing fetal bovine serum. Consequently, the use of MDCK-SP cell culture can make current canine vaccine products much safer, of higher quality and at lower cost.     

Studies on serum requirements for the cultivation of Plasmodium falciparum. 1. Animal sera

Pooling a number of freshly collected lots of human serum eliminated the variability observed between individual serum samples, and reduced the amount of human serum required for optimum parasite growth in continuous culture. In the present experiments the addition of 50 ml of pooled human serum per litre of RPMI (5% serum) resulted in optimum growth. Batches of RPMI 1640 supplemented with freshly collected and pooled lots of bovine, porcine, goat, equine, or ovine sera, as well as commercially available fetal-and young-calf sera, were tested and compared with 5% pooled human serum. Various combinations of animal sera with and without Neopeptone were also examined as supplements to the basic culture medium. As an alternative to human serum, only bovine serum supplemented with Neopeptone could support continuous parasite growth, but at significantly reduced levels. Continuous parasite growth was obtained by transferring parasites directly from 5% human serum into medium plus freshly collected, Neopeptone-supplemented, pooled bovine serum, without any need for an adaptation period.     

A modification of Diamond's medium for the axenic culture of Entamoeba histolytica.

The use of casein hydrolysate in Diamond's axenic culture medium TPS-1 in replacement of trypticase allowed good growth of the trophozoites of Entamoeba histolytica. This modified medium also supported growth of trophozoites preserved for 16 months in liquid nitrogen. Considerable labour and cost of serum can be saved by using 5% instead of 10% bovine serum in combination with this modified medium.