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Biomedical subjects

A F Bykovskiĭ

Publications and source records attributed to A F Bykovskiĭ.

At least 37 records · Page 2Linked to original sources
PubMedDate not supplied

[Comparative study of antigens specific for hepatitis B in transfected cell cultures].

A comparative study of antigens detected in the livers of patients with hepatitis B. in the mesonephros of the human tissue--chick embryo system infected with the agents isolated from the blood of hepatitis patients, as well as antigens detectable in cell cultures transfected by the DNA isolated from these tissues was carried out. The results are in favour of the hypothesis on the integrational nature of serum hepatitis.

Animals↗
PubMedDate not supplied

[Properties of influenza virus strains causing the influenza epidemic in Moscow in 1972-3].

The antigenic and some biological properties of influenza virus strains isolated during 1972-1973 epidemic were studied. Altogether 114 strains were isolated from sick infants of the first months of life beginning from neonatality. The strains under study were found to have high adaptation and elution activity, to be highly sensitive to inhibitors and to produce polymorphous allantoic population in the adaptation period. The hemagglutinating and neuraminidase components were shown to be fairly closely related to those of the membrane of the reference A2/Hong Kong/1/68 strain (H3N2). At the same time, a low neutralizing activity of the antisera for this strain against Moscow strains of 1972-1973 in biological neutralization tests in chick embryos was observed, explaining very high susceptibility of the population to influenza type A infection in the winter of 1972-1973. The strains under study were antigenically homogenous and most closely related to the reference A2/England/42/72 (H3N2) strain.

Antigens, Viral↗
PubMedDate not supplied

[Unfragmented nucleocapsid of influenza virus in infected cells].

In the cytoplasms of chick embryo fibroblast and Ehrlich ascitic carcinoma cells infected with influenza virus (fowl plague virus), in addition to fragmented virus nucleocapsid larger nucleocapsid structures were found which sedimented in the region of 90 -120S. The structures were detected upon short 3H-uridine label of the cells. Their buoyant density in cesium chloride was higher than that of the fragmented nucleocapsid (1.34 -1.39 g/cm3). In electron microscope, the structures were visualized as thin nonhelical filaments 3.5 nm in diameter, their morphology being no different from that of a similar rapidly sedimenting structure isolated from the nucleoplasms of the same cells. To determine the possibility of transfer of the rapidly sedimenting structure from the nucleus into the cytoplasm, a cell-free system was used containing nuclei from influenza virus-infected cells labeled with 3H-uridine for 5 min, as well as the cytoplasm from uninfected and unlabeled cells. The presence of a labeled rapidly sedimenting structure in the cytoplasm of the cell-free system suggests that the structure is synthesized in the nucleus and then transported into the cytoplasm. The relation of this structure to the fragmented nucleocapsid is unknown. It may be assumed to be its intracellular precursor.

Capsid↗
PubMedDate not supplied

[Isolation and study of biophysical properties of oncornaviruses type A and C minimal forms].

The method of differential centrifugation was used for concentration and purification of the minimal form of oncornaviruses type A and C. The structures showed heterogeneous distribution in sucrose density gradient and formed a peak in the zone of 1.135 g/ml. Electron microscope examinations of negatively stained preparations showed that the size of the minimal forms of oncornaviruses type A and C was 25-60 nm, the diameter of nucleoids 10-30 nm.

Cell Line↗
PubMedDate not supplied

[Use of immune electron microscopy for detecting the hepatitis A virus].

Attempts were made to isolate and identify hepatitis A virus by the method of immune electron microscopy using also biophysical methods and the transfection procedure of cell cultures by nucleic acid preparations. In fecal specimens from patients with infectious hepatitis A, virus-like particles 25-30 nm in diameter were found which reacted with convalescent antisera and could be detected by the immune electron microscopy method. By the same method virus-like particles 22-25 nm in diameter were detected in the blood serum of the patients collected early in the disease. A method for their purification and concentration in cesium chloride density gradients has been developed. Attempts at transfection of the cell cultures with preparations of nucleic acids failed. In the course of the study, however, data were obtained which would subsequently facilitate isolation of the causative agent of hepatitis A.

Biophysical Phenomena↗
PubMedDate not supplied

[Detection of an agent similar to rotavirus in infantile gastroenteritis].

The etiology of nonbacterial enterovirus infections in children was studied in autumn and winter under conditions of focal outbreaks in Moscow hospitals. Electron microscopy revealed a reovirus-like agent in concentrated suspensions of feces collected in the acute period of the disease from children suffering from diarrhea. Examinations of paired sera from the patients by the CF test with the antigen of Nebraska calf disease virus established significant rises in antibody titers in 68.3% of cases. The results permit a conclusion that in this country a virus of acute gastroenteritis of children (viral gastroenteritis A) is circulating, causing outbreaks of the disease. The virus belongs to the genus Rotavirus of the Reoviridae family.

Antibodies, Viral↗
PubMedDate not supplied

[Influence of mycoplasma on the production of the oncogenic leukemia virus HTLV by HUT-102 T-lymphoblastoid cells].

A suspension culture of human T-lymphoblasts HUT-102 producing type C oncovirus (HTLV) was examined electron microscopically. Control decontaminated HUT-102 cells spontaneously contaminated with M. orale and exogenously infected with M. pneumoniae were examined in ultrathin sections. The variation statistics method demonstrated that in the mycoplasma-infected cells the number of HTLV virions was significantly higher than in control cultures. It is assumed that the increased production of HTLV is due to mycoplasma-induced changes of physico-chemical properties of the cell membrane which facilitate virion budding.

Cell Line↗