Vol 48, No 6 (2003)

Changes of the immune status are decisive in the pathogenesis of cytomegalovirus infection, which is a cause for the intrauterine infection. Therefore, complex immunological and virological examinations are advisable to make in pregnant women with compromised obstetrics history, pathological pregnancy course and with indirect signs of intrauterine fetus infection for the sake of choosing an optimal tactics of observation and treatment.

Vaccinations and revaccinations by a new Russian live associated mumps-measles vaccine and by a live trivaccine (measles-mumps-rubella) - "Priorix - were performed. We followed up 139 infants vaccinated at an age of 12-18 months, 122 children vaccinated at an age of 6-7 years and 129 persons vaccinated at an age of 18-10 years. The combined vaccines were found to be low reactogenic and high immunogenic preparations.

The stability of human immunodeficiency virus, type 1 (HIV-1), strain 1MB, was studied in liquid preparations of homemade drugs. The "Vint" preparation (containing Methamphetamine and obtained from Ephedrine) as well as "Khanka" (a liquid surrogate opiate made from poppy straw) were analyzed within the case study. HIV-1/IIIB was shown to maintain its infectious activity in "Khanka" at room temperature for least 7 days. The HIV-1 activity in neutralized "Vint" did not essentially change after a 30-minute incubation at pH 7.0. While an incubation in the acid "Vint" solution entailed a more rapidly decreasing activity. However, the virus infection ability preserved during the entire time period, during which the drug was fit for injections, i.e. for 30 minutes at room temperature or for 20 hours at 4°C. Therefore, the infection virus could well preserve in the "Khanka" and "Vint" solutions after its entry, with infected blood, of large volumes of the discussed drugs. The mentioned big volumes of HIV-1 contaminated drugs, shared later into ready-to-use portions, could be the cause for HIV-1 dissemination among those who practice the parenteral administration of these substances. Besides, "Khanka" was shown to have little or no effect on the virus replication to cell culture MT-4. Its presence brought about an insignificant 1.5-fold increase in the viral stock (observed on days 2 and 3 after contamination) only when 2 x 10s MT-4 cells per ml and HIV-1/ IIIB TCID 50 0.005 were used.

The results of polymerase chain reaction and of DNA sequencing of the Adel2 mutant variant of adenovirus serotype 5, passaged 10 times and capable of selectively infecting and lysing the p53-deficient human tumor cells, are indicative of a high stability of its genotype and of the phenotypic properties acquired by it in successive passage on 293 cells. The absence of admixtures of wild-type adenovirus was clearly shown in the cultivation and passage processes. It was revealed in an experimental analysis of virus-productive properties of the studied continuous cell culture 293 by using the method of multilayer cultivation, that the maximal Adel2 yield is obtained at the 50% cytopathic effect. Virus doses, that are effective for cell-culture contamination, are within a range of 10010 ТСРЕЯ per cell. In order to spare the viral material, the infecting dose of 10 ТСРЕЮ per cell was chosen to infect a cell monolayer.

The blood serum of the reindeer does not virtually contain any antibodies to respiratory and intestinal viruses widely spread among the cattle. The reindeer blood serum is comparable with the bovine serum by the contents of chlorides, hemoglobin, total protein and protein fractions; however, it is different from the latter by a 2.5-fold higher content of glucose and by a higher osmotic pressure. The serum stimulates the mitotic cell activity and cell monolayer production; it also contributes to accumulating the cytopathogenic viruses in cell culture. 5- and 10%-serum, when added to a nutrient medium, ensures the reproduction of bovine leucosis virus and the accumulation of the antigen of this virus in a continuous cell culture that is chronically infected with the virus. Finally, the reindeer serum stabilizes the viability of ovocytes and stimulates the bovine embryo development at transplantation.

The use of guinea pigs as a laboratory model was proven to be appropriate in investigating the vaccines developed against Lassa fever at the preclinical study stage. An adapted variant of Lassa virus was cultivated, which caused death of guinea pigs with respect for an agent's dose. Finally, it was shown to be possible to investigate the immunogenic and protective properties of the inactivated antigen of Lassa virus in experiments with guinea pigs.