关键词： Infectious Disease   Protein Synthesis   Interferon   Host Cell   Normal Cell  

摘要： GMK-monolayers infected with rubella virus developed a strong inhibiting effect on the multiplication of poliovirus but did not yield interferon in detectable amounts. The adsorption and the eclipse of the superinfecting poliovirus was not altered, but an extensive poliovirus RNA-synthesis was prevented. A well known early event of poliovirus infection, the inhibition of host cell protein synthesis, however, occurred in rubella virus infected cells as well as in normal cells.

摘要： The cytoplasm from rapidly labeled normal, poliovirus-infected HeLa cells and mouse A9 cells prepared by four different extraction procedures was analyzed by isopycnic gradient centrifugation. In all cases the rapidly labeled RNA present in the polysomes (“heavy” particles with densities ranging from 1.51 to 1.54 g/cc) was quantitatively released as “light” ribonucleoprotein complexes (ϱ = 1.40, 1.45, and 1.38 g/cc for each cell type, respectively) undistinguishable from free light particles. The latter (which in HeLa cells sediment heterogeneously from 40S to 400S) contained rapidly labeled RNA together with proteins that were barely labeled after prolonged incubation with mixed amino acids of high specific activity. In addition A9 cells contained also 1.34 and 1.45 g/cc complexes while 1.35 g/cc mature poliovirus particles were detected in the cytoplasm of polio-infected HeLa cells. Good concordance with published data was found for the density values of particles present as major components in the cytoplasm but not for the density of rapidly labeled particles.

摘要： Poliovirus, dissociated by exposure to 9 M urea and 0.09 M mercaptoethanol into RNA and protein, can be reconstituted to infectious viral particles by stepwise dilution with cold isotonic phosphate buffered saline at pH 7.2.

摘要： Exposure of Escherichia coli at 6 × 1010 to poly-l -ornithine or DEAE-dextran (100 μg/ml, 20 min, at room temperature) does not alter the viability of E. coli as determined by colony formation. Poliovirus-induced double-stranded RNA (RF-RNA) does not adsorb to E. coli in the absence of polycations but is quantitatively and instantaneously bound to E. coli cells in the presence of 20–40 μg/ml of either DEAE-dextran or poly-l -ornithine. Variation in pH, Mg2+ or EDTA concentration has little effect on the polycation-stimulated interaction between RF-RNA and E. coli . However, an increase in NaCl concentration during interaction of RNA and E. coli results in a reduction of the amount of RF-RNA adsorbed. Thirty to forty per cent of the adsorbed RNA can be removed from the cells by washing with hypertonic saline (0.5 m NaCl), when the adsorption takes place in the presence of DEAE-dextran, whereas RF-RNA bound by E. coli in the presence of poly-l -ornithine is not removed by hypertonic saline. The recovery of the bound RF-RNA by phenol extraction after interaction with E. coli is low and part of the reisolated RNA is present in a partially single-stranded form.

摘要： HeLa cells adsorb 30% of poliovirus induced double-stranded RNA (RF-RNA). In the presence of 10 μg/ml of the polycation DEAE-dextran 90–95% of RF-RNA is bound by the cells. However, an optimal infectivity with RF-RNA is obtained only by exposure of the cells to 100–200 μg DEAE-dextran/ml. In contrast to single-stranded viral RNA, RF-RNA does not form sodiumdodecylsulfate (SDS) stable or salt stable complexes with DEAE-dextran. Reversible binding of the polycation to RF-RNA can be detected by an increase in the sedimentation rate in sucrose gradients.

关键词： 脊髓灰质炎   减毒活疫苗   肠道病毒感染   疫苗效价   疫苗株   小儿麻痹  

摘要： 我市“脊髓灰质炎”在未开展疫苗服用前,每年小儿麻痹病的发病都比较高,1957—1961年间,年发病率最低为8.44/十万,最高达34.94/十万,病死率在2.3～9.2％之间(仅以市郊区计)。全年病例呈散发性分布,一般从5月份开始上升,6～7月份达最高峰,9

关键词： Infectious Disease   Antibody Titre   Complement Fixation   Antibody Activity   Virus Preparation  

摘要： The relationship between antigens of polioviruses 1–3 and echovirus 6 was studied by immunization of guinea pigs. Antibody activity against virion (N) and empty capsid (H) antigens of these viruses was assayed by immunodiffusion and complement fixation. Intergroup activity was not encountered but intragroup activity within the poliovirus group was demonstrable after immunization using adjuvant. Heterologous anti N activity was encountered within the poliovirus group at a low magnitude and frequency after immunization with native poliovirus preparations; low heterologous anti H activity was more frequently demonstrable after immunization with native as well as heated virus preparations. Heterologous antibody titres were lower than the homologous ones. Activity common to all poliovirus H antigens was demonstrable. Formation of antibodies active to N antigens of two poliovirus types were provoked in at least one animal immunized with one type and booster injected with a second *** fixing activity (homologous and heterologous) was found in the 7 S fractions of sera, homologous precipitating activity in the 19 S and 7 S fractions, heterologous in 7 S only.

摘要： Poliovirus RNA directs the synthesis of virus-specific RNA in E. coli as reported previously for poliovirus-induced double-stranded RNA. Synthesis of viral RNA can be followed by conversion of viral RNA into a double-stranded RNase-resistant state, by increase in infectivity and by hybridization of newly synthesized RNA to viral RNA. Virus-specific RNA synthesis occurs also in the presence of inhibitors of protein synthesis indicating that an enzyme is present in E. coli which can use RNA as a template.

关键词： Cell Culture   Untreated Control   Maximal Yield   Early Experiment   Kidney Cell  

摘要： In earlier experiments it was shown that the replication of polio-virus in cell cultures is stimulated by polymyxin B. Data were presented indicating that this effect was due to a hastened release of the virus from the cell rather than to enhanced intracellular *** reported here further substantiate this conclusion. Primary monkey kidney cells were infected with poliovirus, type 3, at multiplicities of infection one, and cell-associated and released viruses were assayed at intervals. In drug-treated cultures release of virus was enhanced as compared with untreated controls. The maximal yields, however, were not affected.

关键词： Animals   Blood   Carbon Isotopes   Cattle   Cell Survival/drug effects   Chymotrypsin   Culture Media   Depression, Chemical   Dialysis   DNA   DNA, Neoplasm/biosynthesis   Guanine Nucleotides   Hela Cells/analysis   Hela Cells/drug effects   Hela Cells/metabolism   Hot Temperature   Humans   Lipids/biosynthesis   Lipids/isolation & purification   Lipids/pharmacology   Metabolism/drug effects   Neoplasm Proteins/biosynthesis   Phenylalanine/metabolism   Phospholipases   Poliovirus   Ribonucleases   RNA Nucleotidyltransferases   RNA, Neoplasm/biosynthesis   Solubility   Thymidine/metabolism   Time Factors   Tritium   Uridine/metabolism   Virus Replication/drug effects  

摘要： An inhibitor of RNA synthesis in HeLa cells was isolated from poliovirus-infected cells. The inhibitor appeared shortly after virus adsorption. The synthesis of DNA and protein was not affected by this inhibitor, although viability of cells declined rapidly after an initial lag period of 5 hr. Properties of this inhibitor are described. It was insensitive to ribo-nuclease or proteolytic enzymes, but the inhibitory activity was destroyed by phospholipases and heating. The active component can be extracted into an organic solvent and has been characterized as a lipid component. These results suggest that virus infection may induce the release or synthesis of lipid components which operate to shut off cellular RNA synthesis. The inhibitor shortens the latent phase of virus multiplication in treated cells, but has no effect on DNA-dependent RNA polymerases. © 1971, American Chemical Society. All rights reserved.