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Biomedical subjects

A M Chernukh

Publications and source records attributed to A M Chernukh.

At least 55 records · Page 3Linked to original sources
PubMed1978

[Routes of E. coli 055 bacterial penetration through the intestinal wall in gnotobiotic and ordinary animals].

Peculiarities of permeability of intestinal barrier in germfree animals for enteropathogenic E. coli 055 were studied. Both germfree and conventional guinea pigs and rats were used. An increase of bacteriemia was revealed in gnotobiotes during the first day of oral E. coli 055 monocontamination; bacteriemia was transient in conventional animals. Under electron microscopy alterations of intercellular contacts and formation of spaces between enterocytes containing numerous microorganisms were found in the intestinal mucous membrane in gnotobiotes. Also more pronounced changes of microvessels of the intestinal mucous membrane were discovered in gnotobiotes. The processes of ingestionan and digestion of Escherichia coli by enterocytes and leukocytes were noted in conventional animals. The revealed derangements of the intestinal barrier in gnotobiotes explain the cause of higher bacteriemia in germfree animals. An important role of the microbial factor in the formation of intestinal barrier is indicated by the data obtained.

Animals↗
PubMed1978

[Role of the pituitary-adrenal system in mechanism regulating vascular permeability during stress].

Disturbances of the microvascular permeability were studied by the "vascular labelling" technique during the immobilization stress of hypophysectomized and adrenalectomized rats. Animals with sham operations served as controls. As revealed, hypophysectomy and adrenalectomy caused disturbances of vascular permeability in the mesentery. Vascular permeability disturbances in the hypophysectomized and adrenalectomized rats under conditions of immobilization were more expressed than in the sham-operated animals. Removal of the pituitary and adrenal glands produced mast cell degranulation at the earlier immobilization period.

Adrenalectomy↗
PubMed1977

[Fluorimetric determination of the concentration of histamine and serotonin in the mast cells of ordinary and germ-free rats following administration of reserpine and cyclic adenosine-3',5'-monophosphate].

The microspectrometric method was applied to the determination of the content of histamine (a test with orthophthalic aldehyde) and serotonin (Falk's test) in the mast cells of the mesentery of common and germfree rats. Reserpine (10 mg/kg of body weight, intramuscularly) failed to alter histamine content, whereas serotonin content fell by 50%. Administration of cyclic AMP (3.5 mg/kg of body weight, intraperitoneally) led to the increase in serotonin content by 80%, and histamine--by 280--320%.

Animals↗
PubMed1977

[Relationship between the kininase- and angiotensin- converting activity under normal conditions and in experimental myocardial infarct].

In rat experiments the depressor and pressor responses to kinins and angiotensins recorded in the carotid artery were compared as to the different methods of their administration. With intravenous injection, the responses to bradykinin and kallidin were lower, and to angiotensin I--higher, than with their intra-aortic administration. The responses to angiotensin II remain identical under these conditions. The administration of all the preparations against the background of 2,3-dimercaptopropanol (unithiol) resulted in levelling of the responses irrespective of the mode of administration. In experimental myocardial infarction induced in rats by ligation of the coronary artery a reduction of the kinin-destructing and an increase of the angiotensin-converting activity was noted in the early postinfarction period. The response of the peripheral vessels to angiotensin, bradykinin and noradrenaline is decreased, while that to isoproterenol remain unchanged. The obtained results support the concept of the existence of the kininase and angiotensin-converting activity connected with a common biochemical factor of pulmonary circulation. Changes in the proportion of these functions under normal conditions and in cases of pathological states are interpreted as a particular regulation mechanism of the vascular tone and arterial pressure.

Acute Disease↗
PubMed1977

[Method of studying the microcirculation of the sciatic nerve during life].

The authors describe a mehtod of bloodless exposure of the sciatic nerve in rats, of placing it on the light conductor, and of the preparation of microscope MBI-6 for the intravital study of microhemocirculation in the epineurium of the sciatic nerve. Different types of the microvessel network of rat are demonstrated.

Animals↗
PubMed1977

[Circulatory dynamics in the conjunctival vessels in ischemic heart disease with and without hypertension].

The circulatory dynamics was studied in the conjunctival vessels of 45 patients with ischaemic heart disease without hypertension (12 patients with myocardial infarction including) and in 24 patients with ischaemic heart disease and hypertension. The method of biomicroscopy of the conjunctiva permits to examine the shape of the microvessels, the vascular background and the density of the pattern, as well as the nature of the blood flow. The patients with ischaemic heart disease without hypertension had more distinct changes, in some cases -- with irreversible discontinuity of the flow (aggregation of the erythrocytes in myocardial infarction). In ischaemic heart disease with hypertension the flow in the venules restores completely by the end of therapy. Reversible changes in the microcirculation were demonstrated in cases of a good effect of therapy, as well as the possibilities of timely diagnosis of complications in repeated examinations of the conjunctival vessels.

Adult↗
PubMed1977

[Modification of the construction and insertion of a viewing chamber for the study of microcirculation in the subcutaneous compartment of the rabbit ear].

Modification of the transparent chamber and the operation of its implantation into the tissues of the rabbit ear are described. The chamber is intended for the study of microcirculation in the subcutaneous cellular tissue of the rabbit ear. The chamber design has a number of advantages in comparison with the known models: optic characteristics are improved, assembly of the chamber is simplified, new design permits to use the regenerated tissue for further histological study. Sterilization of the chamber with gamma rays is simple and effective. The chamber is fixed in the tissues of the rabbit pinna by means of a lavsan net. An additional gluing of the latter excludes a possibility of the penetration and development of secondary infection into the operation wound and fixes the chamber in the ear tissues more firmly.

Animals↗