Biomedical subjects

N A Popova

Publications and source records attributed to N A Popova.

16 recordsLinked to original sources

PubMed1992

[Effectiveness of a liposomal form of rifampicin in the treatment of experimental tuberculosis in mice].

The therapeutic effectiveness of rifampicin as a free form and a component of multilamellar phosphatidylcholine cholesterol liposomes was studied on a model of generalized tuberculosis in BALB/c mice. Rifampicin as a liposomal form was found to have no advantages over its free form. Possible mechanisms of the phenomenon and prospects for using liposomes in the chemotherapy of tuberculosis are discussed.

Animals↗

PubMed1991

Genetic polymorphism of IgG in the mink. 7. Expression of the C gamma-allotypes in domestic mink infected with the Aleutian disease virus.

The Aleutian disease (AD), i.e., viral plasmocytosis in mink can be used as a model of the natural development of immune complex pathology in man. The immunogenetic aspect of AD was studied with the help of genetic markers of the constant region of the mink immunoglobulin gamma-heavy chain (the C gamma allotypes H2, H3, H4, H6, H7 and H8). The frequencies of 2 of the 6 allotypes, H3 and H4, were significantly higher in the AD-infected than in normal minks from the same population. This supports and extends the data in the literature indicating that the frequencies of certain human Gm allotypes are significantly higher among patients with multiple sclerosis, some oncological and other diseases compared with normal humans. Individual testing of 110 adult Standard minks before and after artificial inoculation with the AD virus demonstrated that change in allotype frequencies results from the activation of the expression of H3 and/or H4 in many individuals. The obtained results make it possible to consider the regulation of the expression of the two CH genes of immunoglobulins as allotype-specific.

Aleutian Mink Disease↗

PubMed1991

[Activation of expression of two immunoglobulin SN-genes in the American mink with Aleutian disease].

110 ranch-raised minks were injected with the Aleutian disease virus. Allotypes of constant regions of gamma-heavy chains of the mink immunoglobulins secreted have been analysed during 3 months. Activation of the expression of two markers (H3 and/or H4) up to minor or to nominal level (above 200 micrograms/ml) was observed. No such enhancement of expression of two other allotypes (H6 and H8) was found. The results suggest that the expression of two mink immunoglobulin CH genes induced by viral infection has allotype-specific regulation.

Aleutian Mink Disease↗

PubMed1990

[Mink IgG-allotypes and Aleutian disease].

IgG polymorphism (allotypes H3, H4, H6 and H8 of constant region of the gamma-chain) was investigated in healthy and affected with Aleutian disease (AD) minks from two Siberian and one Danish populations. In all three populations, the expression of H3 and H4 allotypes was strongly associated with AD. Among the AD minks the frequency of H6, H8 phenotype was found to be decreased, whereas the frequency of H3, H4, H6, H8 phenotype was significantly increased. At the same time, the populational distribution of the rest phenotypes was similar among healthy and AD minks. The H3, H4, H6, H8 minks showed the highest pathomorphological characteristics of AD. Based on the data concerning mink H3 and H4, and human Gm allotypes, their role as possible genetic markers for hereditary susceptibility to distinct disease is discussed.

Aleutian Mink Disease↗

PubMed1989

[Suppression of tumor growth in the liver by cis-diamminedichloroplatinum as large oligolamellar liposomes prepared by freezing and thawing].

A/HeJ mice with experimental metastases of HA-1 tumor in the liver and other organs were given therapeutic doses of cisplatin, free or encapsulated in phosphatidylcholine cholesterol freeze-thawed liposomes, intravenously. Free cisplatin treatment was found to decrease the growth rate of liver metastases by half and to extend survival by 1.5 times as compared to controls. The inhibitory effect of liposome-encapsulated cisplatin on hepatic metastases growth was more pronounced than that of the free drug although it weakly affected metastatic growth in other organs.

Animals↗

PubMed1988

[Decrease in the antimetastatic effect of vinblastine administered in liposomes].

The model of experimental metastases in the HA-1 tumour in the liver of A/He mice was used to show that the anti-tumoural effect of cis-dichlorodiamminoplatinum being used in the liposomes increases, while that of vinblastine (VB) decreases. It is suggested that the low activity of liposome-encapsulated VB as to its influence on the tumour growth in the liver is a result of preferable uptake of liposomes by Kupffer cells and hepatocytes from where VB cannot diffuse into tumour cells since it binds to intracellular tubulin.

Animals↗

PubMed1988

[Cytogenetic and virological characteristics of the initial line and clones of RH cells with various degrees of sensitivity to the tick-borne encephalitis virus].

Virological and cytogenetic characterization of line RH and its two clones (RHk-20 and RHk-13/6), having different sensitivity to the tick-borne encephalitis virus (TBE), has been made. The RHk-13/6-cells are 10,000 times more sensitive to cytopathic effect of the tick-borne encephalitis virus in comparison with the RHk-20-cells. By its sensitivity to the virus the base line is in the intermediate position. Cytogenetic analysis revealed the variability interval decrease as to the chromosome number at cloning, and showed the structural stability of the line and clone karyotypes. The line RH and its clone K-20 have modal number of chromosomes equal to 65; the cell population with the chromosome number equal to 66 dominated in RHk-13/6. The application of methods of chromosome differential (G, C) staining and these for the detection of active nucleolar organizers (NO) permitted identifying the marker chromosomes and determining the difference between the clones and the line as associated with the presence of an additional homologue of chromosome 8 in the sensitive clone.

Cell Line↗

PubMed1977

[Comparative study of the physicochemical properties of the surface of Escherichia, their sensitivity to ampicillin and tetracycline and their capacity to absorb tetracycline].

Development of resistance to ampicillin and tetracycline in Escherichia resulted in an increase in the electrokinetic potential and a decrease in the level of hydration and isoelectric values of pH. The changes in the hydration level mainly depended on the accompanying dissociation. Studies on 3H-tetracycline binding revealed a low accumulation capacity of the resistant mutants. The rate of 3H-tetracycline binding did not depend on the changes in the physico-chemical parameters of the cell surface due to resistance and dissociation.

Absorption↗

PubMed1976

[Cerebral auto-antigens in the serum of schizophrenic patients].

Brain autoantigens in the blood of 200 schizophrenic patients were investigated. It was established that the introduction of brain autoantigens caused the formation of antibrain antibodies in the animals. The brain autoantigen, limitted by the species, is also present, and there is a possibility of autoimmunization by each of them. It is shown that the autoantigen which is connected with the species of the brain, is stable to organic dissolvent activity in the paranoid form of schizophrenia (87.5%) and in the malignant and shift-like form (20%). In the other forms of schizophrenia and also in epilepsy and viluy encephalitis its inactivation is marked. The qualitative heterogeneity of brain autoantigen in different forms of schizophrenia is suggested.

Antigens↗

PubMed1976

[Physicochemical parameters of the surface of bacteria and the penicillin-binding capacity in relation to the sensitivity to penicillins and streptomycin].

Development of resistance to penicillins and streptomycin in bacteria results in an increase in the electrokinetic potential changes in the hydratation rate and isoelectric levels of pH. Changes in the physico-chemical properties of the surface of penicillin-resistant Escherichia depends mainly on the accompanying dissociation. The ability of Escherichia to bind labeled benzylpenicillin is shown. Binding of 35S-benzylpenicillin by Escherichia in S-form correlates with sensitivity of the culture to the antibiotic. The penicillin-resistant mutants in R-form bound the antibiotic to a greater extent than sensitive R-cultures. The role of penicillinase in binding 35S-benzylpenicillin by Escherichia was not shown experimentally. Only increased synthesis of the enzyme by the penicillin-resistant mutants was observed. The ability of Escherichia to bind 35S-benzylpenicillin does not depend on the physico-chemical properties of the cell surface and dissociation.

Bacterial Physiological Phenomena↗

PubMed1975