PubMed Health⌕ Search

Biomedical subjects

V S Siniakov

Publications and source records attributed to V S Siniakov.

11 recordsLinked to original sources
PubMed1988

[Effect of helium-neon laser on the microcirculation in blood vessels of the rat pia mater].

The sensitivity of rat's microvessels of microcirculatory bed of brain's pia matter was studied by helium-neon laser radiation. Changes in the reactivity by the microscopy findings were studied on the 7, 30, 45, 60, 90th days of animals postnatal development. Laser radiation was used during 30 min. Local changes in all components of the microcirculatory bed were fixed. It is mentioned that in adult rat the expressiveness of arteriole's local widening reaction in the radiated place reduces, but the degree of the reduction is below or over the radiated place, on the contrary, increases. The arteriole diameter in 30-day old rats increases to 59% in comparison to the initial level, and 90th day old animals--to 16%. The degree of reaction's expressiveness depends upon the microvessel diameter and the animal's age.

Aging↗
PubMed1986

[Holographic recording of the interference waves in muscle tissues].

The method of interference holography is suggested for the investigation of biomechanical properties of human skeletal muscles. The method permitted the registration of a profile of deforming waves induced on the muscle surface by a special striking mechanism. Analytically and in model experiments it was demonstrated that deforming waves penetrated much deeper than skin and subcutaneous tissue layer. The experiments have confirmed that the skin has but little effect on interference pattern. The interferogram of deforming waves in the biceps muscle reflect distinctions in the muscle tissue elasticity along and transverse muscle fibers.

Biomechanical Phenomena↗
PubMed1983

[Method of measuring the modulus of elasticity of human muscle tissue].

An experimental method is described for estimating the mechanical properties of human soft tissues by calculating Young's modulus which was defined according to the slope of the hysteresis curve of the test subject, reflecting the dependence of its deformation on the force applied. The main causes of numerous difficulties in obtaining such data and the ways for their overcoming are considered. Experiments were made on the biceps in the isometric mode under different degrees of internal tension. It has been shown that the higher the physical development of the test subject the less the magnitude of Young's modulus. The dependence of its magnitude on the degree of muscular tension is sublinear in character in the group with good physical development and superlinear in that with poor physical development.

Adult↗
PubMed1982

[Differential evaluation of excitatory conduction rats along different segments of motor nerves and functional tests in the diagnosis of diseases of the human peripheral neuromotor apparatus].

In 61 patients with neurono- and neuropathies and affections of the synaptic apparatus and the muscular matter of various etiology, the state of the peripheral nerves was examined. It was found that various forms of the pathology are characterized by specific changes in the speed of the stimulus transmission along various parts of motor nerves. The changes of the functional state can be seen especially clearly on comparing the speed of the stimulus transmission along the proximal and the distal parts of a peripheral nerve (the difference being named "transmission speed gradient"). In neuronopathies the transmission speed changes are prevailing in the proximal, in neuropathies in the distal, and in synaptic structure abnormalities in the extreme distal parts of the nerve. A 15-minute artificial ischemia of the nerve (a functional test) led to characteristic changes of the transmission speed, these changes correlating with the process stage. In cases of mild changes of the transmission speed the nerve was more sensitive, while in cases of pronounced changes more resistant to the ischemia. It was shown that the transmission speed changes in ischemia manifested themselves along the whole nerve, but not only in the site of its affection. In cases of the carpal canal syndrome the ischemia-induced lowering of the transmission speed in the nerve distal part was extremely sharp.

Diagnosis, Differential↗
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↗
PubMedDate not supplied

[Some problems in the use of holography in medical-biological studies].

Various fields of the holographic methods application in medico-biological investigations are discussed. Special consideration is given to the methods of holographic interferometry, holographic microscopy, ultrasonic holography and to the technique of optic filtration of images. The paper sets forth brief characteristics of diverse holographic methods, technical possibilities of each one of them and a review of some practical work done in this field.

Holography↗
PubMedDate not supplied

[Interhemispheric asymmetry in unilateral brain damage].

Hemispheric functional changes and interhemispheric interactions were studied by the bioelectrical parameters of asymmetry in the unilateral brain damage. The magnitude of interhemispheric asymmetry was found to depend upon the site of injury, achieving its maximum at the right-sided localization of a pathological process and slightly changing at the left hemispheric tumor site. The application of functional tests was accompanied by profound increases in asymmetry as compared with the baseline. The findings may be an informative predictive tests for the course of an inflammatory process.

Adult↗