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Biomedical subjects

T V Stepanova

Publications and source records attributed to T V Stepanova.

At least 19 recordsLinked to original sources
PubMed2003

[Clinical strains of Burkholderia cepacia: characteristic and detection of the components in the quorum sensing regulatory system].

Described in the paper are characteristics of B. cepacia clinical strains isolated from patients at Moscow hospitals. The strains were investigated for the presence of proteolytic, chitinolytic, hemolytic and lipase activities as well as for presence of components of the "Quorum sensing" gene activity regulatory system by using biological test-systems and in the polymerase chain reaction with primers to genes cepI and cepR.

Anti-Bacterial Agents↗
PubMed2002

Changes in lymph microcirculation during pathological stress.

Stress caused by immobilization and acoustic stimulation produces considerable changes in lymph microcirculation. These changes manifested in dilation of microvessels, enhanced phasic contractile activity and its abnormal pattern, accelerated lymph flow, and recruitment of new lymphangions in drainage functions.

Animals↗
PubMed2002

[Nitric oxide in the lymphatic microvessel regulation].

Topical application of sodium nitroprusside on rat mesentery has a marked influence on lymph microvessels function. The drug causes a dilation of majority of lymphangions and decrease of the pacemaker activity of the vessel wall structures and valves. These changes do not lead to lymph stasis, and lymph flow velocity does not reduce. The non-selective inhibitor of NO synthase (N-nitro-L-arginine) intensifies vasomotions of lymph microvessels, modulates phasic contractile activity and increases lymph flow velocity. There is a time dependent dynamic of changes in action of N-nitro-L-arginine. During inhibition of endogenous NO synthesis the responses of lymph microvessels on sodium nitroprusside application are modified: the constriction of majority lymphangions and activation of valve work are observed.

Animals↗
PubMed2001

[Functional organization of lymphatic microvessels of the rat mesentery].

Lymph flow as measured with biomicroscopic and speckle-interferometrical techniques was very unstable and its rate did not depend on lymphangion diameter in the rat mesentery. A correlation was found between amount of cells in the lymph flow and other indices of lymphangion functions. All microvessels with phasic contractions and/or working valve were revealed as having a lymph flow. The phasic activity and the valve work correlated with each other. The higher the amplitude and frequency of the phasic activity and the longer the contraction cycle, the higher was the rate of the valve work.

Animals↗
PubMed2001

[Genital tuberculosis and surgical treatment of it].

The paper presents the specific features of diagnosis and clinical course of genital tuberculosis under the present conditions. It shows it expedient to make a differential diagnosis of genital tuberculosis in 2 steps: 1) the use of the routine examination and 2) the study of specific antituberculous immunity. Genital tuberculosis risk groups to be obligatorily examined at a specialized tuberculosis control facility are identified. The specific features of the clinical course of genital tuberculosis, such as aptness to exudative processes, a combination with extragenital tuberculosis and hormonally depended gynecological diseases are noted. Indications for and efficiency of endosurgical interventions in genital tuberculosis are shown.

Female↗
PubMed1990

[The baroreflex component in the mechanism of the hypotensive action of atrial peptides].

Changes in the arterial pressure (AP), heart rate (HR) and sensitivity of chronotropic baroreceptor reflex (SBR) evoked by i. v. infusion of alpha-ANP, AP-III, AP-II, and AP-I (1 mg/kg/min) were studied in alert Wistar rats. The SBR was tested by infusion of phenylephrine or sodium nitroprusside. All the ANP analogues, except AP-1, were shown to decrease the AP and evoke differential changes in the SBR. The SBR evoked by phenylephrine was increased by 60-80%, whereas SBR evoked by sodium nitroprusside was decreased by 30-60%. The specific changes in tachycardic and bradycardic components of the baroreceptor reflex after ANP analogues infusions seem to reflect participation of the baroreceptor reflex in the mechanism of ANP-induced hypotension.

Animals↗
PubMed1987

[The role of plasmids in the regulation of delta-endotoxin synthesis in Bacillus thuringiensis H14].

The role of plasmids in regulation of delta-endotoxin synthesis by Bacillus thuringiensis H14 was studied. The derivatives of strain Is-1 H14 containing a 4Md plasmid integrated into the chromosome synthesize small crystals and are not toxic for the gnat larvae. The transceptional transfer into this strain of a plasmid coding for crystal synthesis from the strain 69-6 serotype H5 results in restoration of insecticidal activity to the level of the parental strain Is-1. Transcipients activity is increased 10-15 fold in case of 4Md plasmid excision from the chromosome and autonomous functioning. Evidently, 4Md plasmid from the strain Is-1 as well as a plasmid coding for crystal synthesis from the strain 69-6 contains the regulatory elements participating in the expression of crystalline protein genes localized on other plasmids. The existence of two cellular regulatory groups is supposed to result in the significant increase in crystalline protein synthesis.

Bacillus thuringiensis↗
PubMed1983

[Interspecific recombinants of Bacillus thuringiensis x Bacillus cereus].

The possibility of interspecies recombination was shown by using protoplast fusion method. The Bacillus thuringiensis var. galleriae strain 48S Thi Nic Gua Rifr Strr and 56R Gua Rifr, and also Bac. cereus carrying the plasmid pBC16 responsible for resistance to tetracycline (150 mcg/ml) were used. Recombinants were selected on the medium containing rifampicin and tetracycline. They were shown to combine the properties of both parents. The majority of recombinants were resistant to phages Tg4 and Td15 and represented the mean level of sensitivity to phages Tg12, Tg13 and Td14. Examination of the plasmid profiles of recombinants revealed that their resistance to tetracycline was due to the plasmid with mobility analogous to pBC16. It was concluded that the protoplast fusion method can be used to obtain recombinants between relatively remote species of microorganisms.

Bacillus cereus↗