[Isolation and study of influenza A viruses in different cell cultures]. / Vydelenie i izuchenie virusov grippa A na raznykh kletochnykh kul'turakh.

The usefulness of some cells cultures (BSC-I, VERO, MDSK) for isolation and study of reproduction of influenza A viruses was explored. Out of 50 clinical specimens examined, in 16 cases the virus was isolated both in chick embryos and in MDSK cell cultures. MDSK cultures were found to be highly sensitive to influenza A viruses, which produced cytopathic effect and hemagglutinin accumulation. The plaques formed by freshly isolated strains under an agar overlay containing trypsin were markedly polymorphous. MDSK cells may be recommended for use in virus isolation studies. Examinations of virion morphology revealed their diversity both in size and shape.

[Laboratory studies of an epidemic outbreak caused by influenza A1 viruses]. / Nekotorye laboratornye issledovaniia épidemicheskoi vspyshki, vyzvannoi virusami grippa A1.

Virological and serological studies of an epidemic influenza outbreak in December, 1977, carried out in the clinical department of D. I. Ivanovsky Institute of Virology of the USSR AMS established the disease to have been caused by influenza Al viruses. The marked incidence of the disease among younger age groups was due to a low humoral immunity level to the strains which had circulated before the young people's birth. The reduced effectiveness of protection by antibody against viruses which had caused influenza disease 20--30 years ago was conducive to the spread of influenza Al cases among middle-aged and senile population.

[Karyological study of the continuous cell lines. Comparative analysis of the Hela and Detroit-6 cell lines]. / Kariologicheskoe issledovanie perevivaemykh kletochnykh linii. I. Sravnitel'nyi analiz linii Hela i Detroit-6.

Comparison of the results of the karyologic analysis of two Hela cell sublines (HeLa1 and HeLa2), obtained from different sources, and of Detroit-6 cell line has shown that all the lines contain marker chromosomes characteristic of the HeLa cell line. Detroit-6 cell line marker chromosomes are similar to markers of the HeLa subline (HeLa1). At the same time, part of marker chromosomes in the two sublines of HeLa cell line (HeLa1 and HeLa2) are different. These data show that HeLa1 and Detroit-6 cell lines are more similar than two sublines of the same HeLa cell line.

[Study of organ cultures of human embryonic intestines infected with the human cytomegalovirus and the Japanese encephalitis virus]. / Izuchenie organnykh kul'tur kishechnika émbriona cheloveka, infitsirovannykh tsitomegalovirusom cheloveka i virusom iaponskiogo éntesfalita.

Reproduction of human cytomegalovirus (CMV) and Japanese encephalitis virus (JE) was studied in organ cultures of human embryo intestine under conditions of mono- and combined infection. The titer of JE virus in monoinfection reached its maximum level (10(7) TCD50/ml) whereas the titer of CMV did not exceed 10(2) TCD50/ml. In combined infection the titer of CMV increased to 10(5.5) TCD50/ml and the titer of JE virus remained at the same level (10(7) TCD50/ml). The results obtained in light and scanning electron microscopy studies indicate that in monoinfection CMV causes considerably earlier and more profound degenerative changes in mesanchymal elements of embryonal intestinal tissues than does JE virus. At the same time the combined infection of organ cultures with these viruses is not cytocidal.