[Complete genomic sequence of rapidly replicating strain MB-7 of hepatitis a virus and its characterization in comparison with nucleotide sequences of other hepatitis A virus strains].

Complete nucleotide sequence of genomic RNA of hepatitis A virus (HAV) rapidly replicating strain MB-7 was determined. Comparison of nucleotide and deduced amino-acid sequences demonstrated the highest level of identity of MB-7 with strain HAS-15 (above 99%) and high homology with other HAV strains (HM 175/7, CR326, and GBM/HFS) used in production of anti-hepatitis A vaccines. MB-7 was classified as subgenotype IA. Phylogenetic analysis showed that MB-7 is most closely related to the strain HAS-15 and the HAV variants circulating in Russia. Comparative analysis of genomic differences between MB-7 and HAS-15 with other HAV strains revealed among changes characteristic of MB-7 those typical of the described earlier rapidly replicating HAV strains (nt. 149-162 in 5'-untranslated region and changes in the VP3 and 2C genes). These results suggest the functional importance of changes in above-mentioned regions of HAV genome for the increased replication level of MB-7 in vitro.

[Immunological safety and sensitizing effect of an MB-7-based vaccine against hepatitis A]. / Immunologicheskaia bezopasnost' i sensibiliziruiushchee deistvie vaktsiny protiv gepatita A na osnove shtamma MB-7.

The influence of a vaccine based on the MB-7 strain of hepatitis A virus (VP-MB-7) designed at the "Vector" Center of Virology and Biotechnology was studied. VP-MB-7 was found to provoke no allergic response and to have an activating effect on the specific and non-specific responses of cell and humoral immunity similar to those evoked by hepatitis A vaccine "Hep-A-in Vac".

[Safety research of a vaccine preparation in hepatitis A derived from the MB-7 rapidly growing strain]. / Izuchenie bezvrednosti vaktsinnogo preparata protiv gepatita A iz bystrorastushchego shtamma MB-7.

A study was undertaken to prove that a vaccine drug based on the fast-growing MB-7 (MB-7 VD) of hepatitis A virus (HAV) is safe. It was established that MB-7 VD, when once injected to white outbred mice and when 4 times injected to Hartley guineas pigs, did not cause any hematological and biochemical changes in the peripheral blood or in the condition of the central nervous system of experimental animals, which shows that MB-7 VD is free of any toxic properties.

[Characteristics of reactogenic and immunogenic properties of the children's variant of the domestic vaccine, "Gep-A-in-Vak", against hepatitis A]. / Kharakteristika reaktogennykh i immunogennykh svoistv detskogo varianta otechestvenoi vaktsiny protiv gepatita A "Gep-A-in-Vak".

Russian cultural concentrated inactivated vaccine protecting from hepatitis A--Hep-A-in-vac was used for immunization of children. The vaccine is slightly reactogenic and completely safe in children aged 3-17 years vaccinated twice in a dose of 0.25 ml. Double immunization of seronegative children with a 1-month interval led to conversion in 89.7% children. In 64.1% children titers of antibodies to hepatitis A virus reached 20 mIU/ml and higher, which indicates rather high antigenic activity of the vaccine.

[Optimization of preparation conditions of an inactivated hepatitis A vaccine and its characteristics]. / Optimizatsiia uslovii polucheniia inaktivirovannoi vaktsiny protiv gepatita A i ee kharakteristika.

Modernization of the protocol and optimization of the technology of preparation of inactivated hepatitis A vaccine helped prepare the experimental lots of inactivated vaccine meeting all the requirements to such preparations and the WHO recommendations.

[The isolation and study of the characteristics of a cytopathic strain of the hepatitis A virus]. / Vydelenie i izuchenie kharakteristik tsitopaticheskogo shtamma virusa gepatita A.

A fast-growing cytopathic isolate of human hepatitis A virus (strain MB-7) was derived from fecal samples of infected patients and adapted to growth in FRhK-4 cell culture. A positive serum standard against HAV and electron microscopy were used to demonstrate that MB-7 belonged to human hepatitis A virus. The strain MB-7 induced plaque formation in FRhK-4 under agar overlay after 10-12 days of incubation. The PCR products of gene VP1 were cloned in E. coli and its primary structure was determined. MB-7 was shown to have more homology with HAV strains isolated in the USA and China.

[A karyotype study of the cells of the African green monkey kidney cell line 4647 cultured long term in media with different sera]. / Issledovanie kariotipa kletok pochki afrikanskoi zelenoi martyshki linii 4647, dlitel'no kul'tiviruemykh v sredakh s razlichnymi syvorotkami.

The karyological analysis of the cell line 4647 used for production of a killed vaccine to Hepatitis A virus was run in the 98th, 107th, 117th and 127th passages by the routine and C, G, and Ag methods of differential chromosome staining. A considerable balancing of the chromosome composition at 107-127 passage levels is shown. The cells of line 4647 present a significant heterogeneity, as to the number of chromosomes, and do not belong to any distinct modal class. The modal number of chromosomes ranged from 61 to 66 and from 121 to 125 for hyperdiploid and polyploid cells, respectively. The stable modal class of cells was established in the tetrasomic region, when culturing in the medium containing 10% CS from the 107th passage, and in the medium containing 10% FBS from the 117th passage, which conforms to one of the WHO requirements asserted to the substrate cells.

[Identification of insect cell lines]. / Identifikatsiia linii kletok nasekomykh.

Identification of 10 cell lines of 6 insect species received by the cell culture collection of Molecular Biology Institute from different research institutions of the USSR was carried out by karyological analysis and determinations of the spectrum of isoforms of the following enzymes: glucose-6-phosphate dehydrogenase (G-6-PDH), lactate dehydrogenase (LDH), isocitrate dehydrogenase (ICDH), and superoxide dismutase (SOD). Nine out of the 10 cell lines examined were shown to be identical to those of gypsy moth. Possible ways of cell contamination with other cells in long-term cultivation and preparation of new lines were determined.