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Biomedical subjects

A M Chernukh

Publications and source records attributed to A M Chernukh.

At least 73 records · Page 4Linked to original sources
PubMed1976

[Modeling microcirculatory disorders using an ultraviolet laser].

Reactions of microvessels and mast cells to laser irradiation were studied in rat mesentery by applying the method of intravital microscopy. An ultra-violet laser (gamma=337 nm) was used. The diameter of the laser beam was changed from 2 to 100 mum. Different irradiation doses provoked either an increase of vascular permeability or thrombus formation or hemorrhage. Apart from the vascular wall injury, factors accompanying the damage of red blood cells and other cells of the blood may play a role in the process of thrombus formation. Changes of the vascular diameter and permeability after laser irradiation of mast cells are probably connected with the release of histamine and serotonin contained in them.

Animals↗
PubMed1976

[Effect of microvessel injury on the frequency of tumor cells' lodging in them].

The action of local laser-induced microvascular injury on the frequency of tumour-cell lodgement and on the ability of these cells to migrate out of the microvessel lumen was studied. Intravital TV-microscope with a videotape recorder and an ultra-voilet laser was used. Ascites Saidel hepatoma cells were injected into the blood stream of rats. Lodgement of tumour cells in the mesenteric vessels was observed but rarely (11%). The lodged cells adhered to the microvascular wall and gradually migrated from the lumen. The injury of the wall with laser beam results in the formation of microthrombi and in increase in the frequency of lodgement of the tumour cells in these vessels: 82% against 11%, but migration of these cells decreased. The data obtained supported the significance of the microthrombus formation in the metastatic process. However, this role is not one-sided since on the background of increased frequency of adhesion of the tumour cells there was noted a decrease in their motility in the course of several hours after the lodgement in the microvessels.

Animals↗
PubMed1976

[Effect of bradykinin on the microcirculatory bed of the rat small intestine mesentery].

The effect of application and of intravenous injection of bradykinin on the rat mesenteric microcirculation was studied by direct microscopy methods in vivo. Electrophysiological experiments failed to reveal the reaction of the vascular smooth muscle cells to bradykinin. Under the same conditions the dynamics of vasomotions was studied by the image-splitter method. It appeared that the microvascular response to bradykinin application varied and primarily depended on whether the application was primary or repeated. It is suggested that the action of bradykinin on the mesenteric vessels was mediated through the other vasoactive agents.

Animals↗
PubMed1976

[Microcirculatory and vascular permeability disorders during short-term immobilization stress].

Immobilization of rats for 1 or 3 hours increased the vascular permeability for colloid carbon particles and led to disturbances of the microcirculation in microvessels (formation of aggregates, appearance of "plasmatic vessels", opening of arteriolo-venular shunts). A prominent role of histamine, released from mast cells without any degranulation of the cells, in the pathogenesis of these disturbances was shown. It is supposed that the histamine release served as the trigger mechanism in the development of vascular permeability disturbances in the course of prolonged immobilization stress.

Animals↗
PubMed1975

[Responses of the mesenteric microcirculatory bed of rats with experimental renal hypertension to histamine and adrenaline].

Reactions of the blood flow and of the diameter of mesentery arterioles were studied in vivo after the application of histamine (100--500 gamma) and adrenaline (1--10 gamma) in normal rats and in the animals with renal hypertension. A decrease of sensitivity of the microvessels, 10--30 mu in diameter, to the action of these substances was shown in the animals with hypertension.

Animals↗
PubMed1975

[The role of mast cells in vascular permeability disorders in rats subjected to immobilization stress].

Disturbances of vascular permeability were studied by the "vascular labeling" technique in the mesentry during the 24-hour immobilization of rats. Administration of dimebolin (an antihistaminic preparation) decreased the number of labeled vessels and labeling intensity. This effect was expressed in the presence of mast cells only and was accompanied by the mast cell degranulation. The authors suppose that the mast cells contain a substance preventing the disturbance of vascular permeability and released during degranulation. Such substance might be heparin. Experiments showed that small doses of heparin failed to produce such effect. These results allowed one to conclude that mast cells played a double role in the mechanisms of disturbance of vascular permeability during immobilization--the damaging (by the action of histamine and serotonine) and the protective (by the released heparin) action.

Animals↗
PubMed1975

[Detection of neoplastic cells in the bloodstream].

A study was made of the efficacy of trypan blue, acridine orange, tetracycline and oxytetracycline for detection of tumour cells injected into the blood stream of rats. The cells were identified in the mesenteric microvessels by intravital microscopy. Fluorescence of fluorochromized cells was observed in the blue-violet (lambda max = 400 nm) and ultra-violet (lambda max = 365 nm) irradiation of the fluorescent lamp and in the laser irradiation (lambda = 337 nm). The cells stained with acridine orange had a higher fluorescence intensity and a more distinct structure than those labelled with tetracyclines. Identification of cells with trypan blue was more difficult. The fluorescent method of determination is rather simple and permits to indentify tumour cells directly in the blood stream.

Acridines↗