PubMed Health⌕ Search

Biomedical subjects

S B Stefanov

Publications and source records attributed to S B Stefanov.

At least 19 recordsLinked to original sources
PubMed1990

[Index of microcirculatory changes in experimental dehydration in animals].

On the basis of morphokinetic synthesis principles the method of determination of summarizing criterion of microcirculatory system changes was developed. It consists of marked characteristics of changes of a number of the most important morphofunctional phenomena of each of this system compartments -- interstitial, lymphatic, blood and cellular -- with their successive summation to obtain the systemic microcirculation index. The experimental dehydration in rats being a model has shown that systemic microcirculatory index was 2 times as large in 3 days of dehydration, more than 3 times -- in 6 days, and 4, 5 times -- in 12 days. In the initial stage of the experiments maximal changes were found in interstitial compartment of the microcirculatory system. The intermediate period of dehydration differed by predominant changes of vascular compartment when the lymphatic phenomena were more evident than the hemomicrocirculatory ones. In the later stage of dehydration the cellular component changes of tissues and organs were predominant.

Animals↗
PubMed1988

[Reaction of lymphocytes of the endometrium to the intrauterine administration of antigens].

In the mucosal membrane of the uterine horns in Wistar white rats mainly small and middle lymphocytes (predominantly T-cells) and rather small amount of plasmocytes and macrophages are presented. After intrauterine administration of bacteria and viruses (BCG vaccine, influenza inactivated liquid vaccine of A type) the local immune reaction develops according to the cellular type with maximum at the first week, before the total immune response, with its peak occurring on the 14th day of the experiment.

Animals↗
PubMed1984

[Effect of noise-induced stress on the quantitative characteristics of rat brain synapses].

Rats were exposed to white noise for 1, 2 and 3 weeks. Electron microscopy was used to examine brain sections. The number of synaptic junctions was calculated in the auditory and motor areas of the brain cortex. It has been shown that there was a significantly incremental increase in the number of synaptic junctions in all the layers of the auditory and motor areas of the brain cortex 1, 2 and 3 weeks after exposure to noise.

Animals↗
PubMed1983

[Method of visually classifying synapses from a multiplicity of attributes].

Seven electron microscopic signs of synapses were recognized and classified visually. Altogether 2250 synapses of the stratum radiatum of the hippocamp of 15 white rats were examined on a statistical basis. Five rats (750 synapses) showed a significant decrease in the magnitudes of two signs of the synapses (the active zone length and the mean sectional area of the terminal) after the elaboration of the conditioned reflex. The concentration of synaptic vesicles adjucent to the active zone rose as compared to that seen in a passive control group (5 rats, 750 synapses). An active control group (5 rats) demonstrated a significant increase in the postsynaptic membrane thickness and sectional area of the terminal occupied by synaptic vesicles. The concentration of vesicles neighboring the active zone was noticeably lowered.

Animals↗
PubMed1981

[Quantitative histochemical determination of acetylcholinesterase activity in layers of the rat hippocampus].

A technique has been suggested for quantitative determination of the activity of acetylcholinesterase (AChE) in each layer of rat hippocamp histochemical preparations. The data obtained have been used for making up the maps of layer distribution of AChE activity. The maps have been prepared of AChe activity distribution for the field CA1, CA2 and CA3 of the hippocamp of rats decapitated in summer and autumn. The map for the field CA1 was compared with those made up with the aid of other quantitative histochemistry techniques. The maps for the field CA2 have been compared in rats decapitated in spring, summer and autumn. AChE activity has been found to be greater in spring than in summer or in autumn, with the relations between the layers being unchanged throughout all the seasons.

Acetylcholinesterase↗
PubMed1980

[Quantitative comparison of the ultrastructures of the blood capillaries and muscle fibers in all stages of obliterating endarteritis].

The time course of quantitative changes in the ultrastructure of capillaries and muscle fibrers was studied by the totality of morphological signs in 33 patients with obliterating endarteritis of the lower extremities. As the disease develops, the area of luminal surface and the volume of basal membrane of the capillaries and mitochondria of muscle fibers increase progressively; the volume and number of micropinocytotic vesicles, the volume of myofibrills and the ratio of myofibrill to the mitochondria volume decrease. In early stages of the disease the size of capillary lumen decreases and subsequently increases along with a decrease in the volume of endothelial cells. An increase in the number of mitochondria in a unit of area of muscle fiber at early stages with subsequent decrease was noted. All the values of observed changes are statistically significant. None of the examined features of the structure can be considered pathognomonic separately, but the totality of the quantitative alterations gives a whole picture of the progressive disease.

Adult↗
PubMed1980

[Specificity of the chromatin changes in viral infections].

Nine microdensitometric signs (MDMS) of chromatin in cell cultures have been investigated after injecting with 11 viruses of three taxonomic groups. The technics of numeric comparison of systems demonstrated a high specificity of chromatin alterations in relation to the taxonomic position of viruses. The cultures of different groups differ in their MDMS. The group-to-group relations in respect to MDMS are expressed by even more numerous differencies. A test value is suggested to appreciate the specificity in groups of alterations measured upon the great number of signs.

Cell Transformation, Viral↗
PubMed1979

Morphometric method for evaluating the neurovirulence of live poliomyelitis vaccine.

A method for measuring morphological changes caused by residual neurovirulence in live poliomyelitis vaccine is described. The entire area of 16 standard parts of the central nervous system is measured directly under the microscope using a morphometric eyepiece grid. The method can be used to supplement the conventional system of scoring morphological lesions.

Animals↗