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Biomedical subjects

A L Antelava

Publications and source records attributed to A L Antelava.

7 recordsLinked to original sources
PubMed1992

Blood flow hydrodynamic resistance in patients with ischaemic stroke or vascular encephalopathy and possibilities of its correction in vitro.

In order to determine the patient blood flow hydrodynamic properties in terms of the Toms-effect, the time blood flow was measured in special apparatus twice: (1) before and (2) after addition of poly(ethylene oxide) WSR-301 (Union Carbide, USA) in concentration of 2 x 10(6) g/ml of blood sample (50 ml with 500 units of heparin) taken from 26 patients with acute ischaemic stroke, 8 patients with vascular encephalopathy after stroke, 5 patients with vascular encephalopathy following atherosclerosis with or without arterial hypertension. The blood samples taken from 8 healthy persons formed the control group. Haematocrit (HCT) and asymptotic blood viscosity were studied also. It was established that hydrodynamic blood flow resistance (HBFR) did not depend on HCT and viscosity, but was significantly higher in all patient groups than in normal persons (p less than 0.05). Addition of polymer solution decreased HBFR of patient blood more intensively that in the control group. We believe that it indicates an insufficiency of an unidentified factor in native human blood.

Adult↗
PubMed1988

[Effect on the systemic hemodynamics of polymers that decrease hydrodynamic resistance].

It has been shown that intravenous injections of drug-reducing polymers (at a dose of 2 x1 0(-6) g/ml) to rabbits produced a decrease in the total peripheral resistance with an increase in the cardiac output and simultaneous diminution of the mean blood pressure. These hemodynamic effects did not depend on vasodilatation as it had previously been shown. The alterations were retained for not less than 72 hours after one polymer injection; the effects were due to the influence of polymers on the flow structure.

Animals↗
PubMed1988

[Quantitative morphometric evaluation of the muscular coat of arteries taking into account their functional state].

The method is suggested for the quantitative characteristics of dynamic vascular tone. It allows the determination of a degree of vascular vasoconstriction as a definite value--an index. This index is determined as real area of vascular cross-sections to their maximum possible area ratio with the inner elastic membrane fully straightened. The index determined in such a way permits to assess quantitatively the degree of vascular vasoconstriction, which is independent of the vascular diameter.

Animals↗
PubMed1975

[Changes in local cerebral blood flow during increased general arterial pressure in animals].

General blood pressure was increased in normal rabbits and in the animals with experimental renal hypertension by intravenous injection of noradrenaline; local cerebral circulation was recorded in two areas of the cortex the white matter of the large hemispheres by the method of hydrogen clearance and also by EEG. A number of successive changes of the local cerebral circulation was observed; these changes could be unitypical or different by duration and character on different electrodes. The appearance of pathological forms of electrical activity was noted on the EEG.

Animals↗
PubMedDate not supplied

[Effect of stepped isovolemic hemodilution on some parameters of systemic and cerebral hemodynamics under normal conditions and in a sharp rise of arterial pressure].

It was demonstrated in rabbit experiments that in decrease of the hematocrit value by more than 10% the increase of arterial pressure induced by intravenous noradrenaline injection and its additional rise are significantly higher than in the controls. In spite of that, the breakthrough of autoregulation of local cerebral blood flow occurred much less frequently, was less pronounced, and attended by significantly less damage to the permeability of the blood-brain barrier to labelled blood albumin. This phenomenon can be explained by the fact that in reduced blood viscosity the pseudoturbulence of its flow, and the hydrodynamic resistance of blood increase due to which it reaches the microcirculatory bed at a lesser pressure than in the controls. The results of the study substantiate the expediency of blood-letting as a therapeutic measure for patients with hypertensive disease, in hypertensive crises also.

Animals↗
PubMedDate not supplied

[Method of continuous direct recording of arterial pressure from a mercury manometer].

The article describes a transducer for continuous recording of the readings of a mercury manometer in which, to simplify the construction and calibration, the transducer of pressure changes to electric current changes is made of high-resistant (nichrome) wire passed through the tube of the mercury manometer and incorporated in the circuit of the measuring bridge.

Blood Pressure Determination↗