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Biomedical subjects

I V Rakovskaia

Publications and source records attributed to I V Rakovskaia.

At least 19 recordsLinked to original sources
PubMed2003

[Correlation between activity of the phosphoenol-pyruvate-dependable phosphotransferase system (PTS) and synthesis of adhesion P1 protein in Mycoplasma pneumoniae].

Three isogenous strains M. pneumoniae, i.e. virulent FH, avirulent FH400 and a revertant with a restored virulence (FHR) and isolated from an avirulent strain, were studied. The mechanism of hemadsorption and the ability to cause an infection in Syrian hamsters were found to be damaged in the avirulent strain. The detection of a specific mRNA by the RT-PCR method showed, apart from the loss of the main adhesin (protein P1), a lack of general components of the phosphoenol-pyruvat-dependable phosphotranspherase system (PTS), i.e. enzyme 1 and protein HPr. The recovery of virulence by passing an attenuated strain through animals with induced immunodeficiency correlated with the recovery of the activity of a gene encoding the P1 adhesion protein and with the onset of the PTS function activity. An analysis of published data was made use of to try to detect a correlation between the functional PTS activity in cell and virulence of M. pneumoniae.

Adhesins, Bacterial↗
PubMed2003

[Role of Chlamydia, mycoplasma and cytomegalovirus infection in the development of coronary artery disease].

AIM: To assess relationship between some infection factors and presence of coronary heart disease. MATERIAL: Patients with myocardial infarction (n=56), unstable angina (n=50), stable angina (n=50) and age - matched controls (n=49). METHODS: Levels of IgG, IgM, IgA antibodies to Chlamydia pneumonia, Chlamydia trachomatis, Chlamydia psittaci, IgG, IgM antibodies to Cytomegalovirus, and also of antibodies and antigen to Mycoplasma pneumoniae were measured in blood serum. RESULTS: Compared with controls patients with coronary heart disease had higher frequency of seropositivity to Chlamydia pneumonia, Mycoplasma pneumonia and Cytomegalovirus (p< 0.05 ) and similar levels of seropositivity to Chlamydia trachomatis and Chlamydia psittaci. Infectious burden (quantity of antibodies per one patient) was significantly higher in patients with myocardial infarction, unstable and stable angina than in controls (1.58, 1.42, 1.41 and 0.95, respectively). CONCLUSION: Our results confirm presence of association between infection and coronary heart disease.

Adult↗
PubMed2001

[Role of works of S. V. Prozorovskii in solving problems of persistence of wall-free forms of microorganisms].

S. V. Prozovsky's works are of general biological significance as they show that there can be most bacteria that are two forms having various structural arrangements: one bacteria have a wall, the others have no, such as L-form ones. The paper shows the importance of persistence of bacteria as L-forms in the pathogenesis of different infectious diseases. Mechanisms that determine the long-term persistence of Mycoplasmas in the infected organisms are explored.

History, 20th Century↗
PubMed2000

[The use of polymerase chain reaction for detection of tetracycline resistance urogenital mycoplasma ].

PCR was used for detecting tetracyclin resistance genes tet-M and tet-O in Mollicutes. The tet determinants were detected in U. urealyticum and M. hominis genomes in 60 and 57.14%, respectively. PCR was used to detect urogenital mycoplasma in patients with different urogenital infections. The rate of detection of U. urealyticum was 10.71-25.1% in males and 23.08-61.91% in females, for M. hominis these values were 6.25-11.45% and 3.85-22.99%, and for M. genitalium 6.25-29.64% and 4.76-30.0%, respectively. Hence, the detection rate of tet determinants in mycoplasma by PCR was high (7-60%) in all groups of patients.

Female↗
PubMed1995

[Selective inhibition of DNA amplification in nonadhesive cultures of Mycoplasma pneumoniae].

Inhibition of amplification of various genome regions of Mycoplasma pneumoniae was observed in the polymerase chain reaction, and was dependent on cultivation conditions. A protein stably associated with DNA is responsible for the inhibitory effect. It is assumed that when the protein selectively associates with separate DNA regions, it can inhibit genes encoding pathogenicity factors, thus promoting mycoplasma transformation into persistent variants.

Bacterial Adhesion↗
PubMed1992

[Detection of Mycoplasma and its antibodies in the blood of HIV-positive patients and in healthy persons].

The comparative study of HIV-positive and clinically healthy persons has indicated that the antigens of M. pneumoniae, M. fermentans and U. urealyticum are encountered nearly twice more frequently in the blood of HIV-infected patients than in that of healthy individuals. Mycoplasma antibodies are detected in HIV-positive persons 12 times more frequently than in healthy ones. Among the HIV-infected persons there are those who have simultaneously antigens of some Mycoplasma species.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Interactions between Mycoplasma and human and animal viruses. Ultrastructural analysis].

Presented are the data on the ultrastructural analysis of interaction between mycoplasma and certain cancerogenic and infectious viruses in humans and animals. Revealed are spontaneous associations of mycoplasma with viruses of cattle leukemia, T-cell human leukemia and with a representative of Bunyaviruses. Immediate interaction of these agents is found possible. Simulated complexes of mycoplasma with infectious viruses are developed. Electron microscopy on supramolecular levels revealed immediate interaction of different agents in membranes. Some methodological procedures help to reveal that the interaction of M. pneumoniae and A. laidlawii with orthomyxo-, paramyxo and togavirus is of specific character and is realized as receptor ligand form due to the affinity in the receptor requirements of these pathogens. This property as well as a bequeath distribution and frequent association in respiratory infections enable one to suggest the possibility of their immediate interactions in a host body.

Animals↗
PubMed1991

[Mycoplasma and Ureaplasma infections in chronic genital inflammatory processes, abortion and infertility].

A total of 43 females including 13 with sterility, 23 with habitual miscarriage and 7 pregnant women with a history of chronic inflammatory diseases were examined by using various tools to detect their Mycoplasma and Ureaplasma infections. The females had been studied for bacterial and chlamydial infections. Forty of them turned out to be infected with M. hominis and U. urealyticum. In some cases, sanation led to the improvement of the patients' status, the occurrence of pregnancy, its favourable course and termination in subjects with sterility and habitual miscarriage. The value of the findings is discussed in the paper.

Abortion, Habitual↗
PubMed1991

[Contamination of fish tissue cell cultures by Mycoplasma].

The inoculated and primary cell cultures of fish (carp, salmon, and sturgeon) have been studied. Acholeplasma typed as A. laidlawii in terms of its biochemical properties shown in inhibited metabolism has been isolated from 19 samples. The authors consider the source of Acholeplasma-induced contamination of the cell cultures under study.

Acholeplasma laidlawii↗
PubMed1989

[Mycoplasma arthritis in man and mechanisms of its pathogenesis].

Possible etiologic contribution of mycoplasma to human rheumatoid arthritis (RA) is supported by their recovery from synovial fluid of RA patients, as well as Mycoplasma antigens and antibodies detection in the bloodstream. The detectability of free antigens of M. arthritidis (Ma) and M. fermentans (Mf) in the sera of patients was 22.4%, and that of antibodies against those, 52.7%. Considerable difference between the detectability of Mycoplasma antigens and antibodies can be attributed to the fact that the bulk of the antigens form part of immune complexes and cannot be detected by serologic tests. Mitogenic effect of arthritogenic Mycoplasma and their ability to produce a cytotoxic effect on various cells, including lymphocytes, appears to be a mechanism of immune process developing in association with human RA. A study of immunobiological properties of individual Ma and Mf cell components has shown that a protein factor translocated into the culture medium is responsible for mitogenic action. Ma cytotoxicity in respect of target cells is related to its cytoplasmatic membrane. Mf produces a factor, acting directly on rat lymphocytes; its synthesis is apparently taking place on the cell membrane.

Arthritis, Infectious↗
PubMed1986

[Role of the membranes in lymphocyte interaction with mycoplasmas].

The interaction of Acheleplasma laidlawii cells, derived membranes and liposomes with mouse spleen lymphocytes does not require the energy and participation of electrostatic coupling. The absence of pinocytosis of mycoplasma is demonstrated. Specific membrane receptors don't participate in mycoplasma and lymphocyte binding. The exchange by membrane lipids occurs during the interaction of mycoplasma, membranes and liposomes with lymphocytes; mycoplasma, membranes and liposomes lose saturated fat acids and enrich with cholesterol. On the contrary, lymphocytes lose cholesterol, but absorb fat acids. The intensity of lipid exchange depends on the degree of unsaturation of fat acids in mycoplasma. The carbohydrate transport into lymphocytes is stimulated considerably as a result of interaction of both cells.

Acholeplasma laidlawii↗