PubMed Health⌕ Search

Biomedical subjects

V F Mashanskiĭ

Publications and source records attributed to V F Mashanskiĭ.

At least 19 recordsLinked to original sources
PubMed1990

[Ultrastructure of neuromuscular synapses of 3 types of muscle fibers of the rat diaphragm in acute chlorophos poisoning].

A comparative analysis of changes in ultrastructure of neuro-muscular synapses of three types has been studied in the rat diaphragmal muscle at an acute poisoning with chlorophos. A high stability to the damaging action of chlorophos in white muscle fibers has been revealed in comparison with other types. The most essential changes of the ultrastructure have taken place in slow intermediate fibers. These differences are evidently connected with certain peculiarities in morphofunctional organization of calcium-sequestring ++ components of three types of muscle fibers (sarcotubular system, mitochondria) and presence of parvalbulin.

Acute Disease↗
PubMed1989

[Structure of the surface of erythrocytes in a clot in hemolytic disease of the newborn].

Scanning electron microscopy of blood clots of 6 patients with hemolytic disease of newborn has shown specific large ball-shaped red cells with small round excrescences on their surface. After hemosorption the number of such excrescences reduces but a great number of deformed cells appears. In experimental hemolysis of healthy newborns' blood no such excrescences have been detectable on the red cell surface.

Erythroblastosis, Fetal↗
PubMed1989

[An analysis of the ultrastructure of epithelial cells of the rat proximal tubule at early stages of penicillin elimination].

A study was made of the ultrastructure of epithelial cells of the rat proximal tubules nephrons 25-30 seconds, and 15 and 30 minutes following penicillin injection. The morphological changes in the transporting cells that were observed involved the dilation of the inner cavities of canals and cisterns of the endoplasmic reticulum. The number of elements of the smooth endoplasmic reticulum concentrated on the periphery of the cell, near the basolateral border, was seen to increase. Microbodies appeared enlarged with the appearance of the nucleolus; the electron density of the cytoplasmic ground substance fell down. The space between cells augmented, and the interstitial space between infoldings of the basal plasmalemma was much broadened. Similar morphological changes but different in the intensity were found at either stage examined. The maximum changes were established 25-30 seconds following penicillin injection.

Animals↗
PubMed1986

[Protective action of serotonin on changes in the ultrastructure of the Retzius neuron induced by acetylcholine].

A combined action of acetylcholine and serotonin is demonstrated to produce, in ultrastructure of the Retzius neuron of the leech, changes similar to those resulted from synaptic activation. Nevertheless, acetylcholine alone produces much deeper morphological shifts. A conclusion is made that serotonin not only retards impulse activity of the neuron, but it "slows down" development of rather great changes in its ultrastructure.

Acetylcholine↗
PubMed1986

[Dynamics of changes in the ultrastructure of the rat cerebral cortex in the early period of acute radiation sickness caused by neutron irradiation].

A 24-hour electron microscopic examination of neuronal and capillary ultrastructure in sensorimotor complex was performed after whole-body neutron irradiation of mature rats in the dose of 10 Gy. The results suggest that postradiation neuronal changes, observed for 6 hours after irradiation, are mainly caused by direct effect of ionizing radiation. At later terms this process is influenced by blood capillary lesions. The effect of neutron irradiation at the ultrastructural level is similar to that of rarely ionizing radiation.

Acute Disease↗
PubMed1985

[Initial ultrastructural changes in the muscle fibers of the diaphragm in rats exposed to chlorophos].

Ultrastructural changes of rat diaphragm muscle fibers were studied after administration of chlorophos, i. e. organophosphorus inhibitor. Observations were made 10-180 seconds after treatment (concentrations--18 and 24 mM). The swelling of mitochondria and the increase in the length of sarcomeres were observed simultaneously. These changes were phasic. The swelling of mitochondria is probably due to the increase in energetical activity of muscle fibres.

Animals↗
PubMed1985

[Ultrastructural changes in the muscle fibers of the rat diaphragm and the dynamics of intracellular calcium redistribution as affected by an anticholinesterase substance--chlorophos].

Ultrastructural changes of the rat diaphragm muscle fibers and electron histochemical distribution of calcium ions were studied following chlorophos administration in 5, 15 and 45 minutes (dose - 300 mg/kg, intraperitoneally). The local swelling of mitochondrial matrix and the appearance of contractures were found first in postsynaptical region. Then the postsynaptical alterations increased; the swelling and fragmentation of sarcoplasmic reticulum were observed in addition to desorganization of mitochondrial ultrastructure. Granules of the histochemical product were revealed in mitochondria, in the sarcoplasmic reticulum and in filaments. Changes in distribution of calcium ions in the rat diaphragm muscle fibres after chlorophos administration and the role of Ca++ the in the mechanism of muscle alteration discussed.

Acetylcholinesterase↗
PubMed1983

[Chronic isolated brain lesions caused by respiratory viruses in children].

Combined study of 48 postmortem observations of cerebral lesions caused mainly by meningococcal infection in children was carried out. In 15 cases, isolated subclinical involvement of the brain (more frequently, of the vascular plexus and meninges) caused by influenza A viruses (8 cases), B (2 cases), adenoviruses (6), parainfluenza and respiratory syncytial virus (1 each), and chlamydia (2) was found. This was proved by the presence of the appropriate antigens in the brain revealed by immunofluorescence which were absent in respiratory organs, high titres of antibody to the same agents in the cerebrospinal fluid which were lacking in 13 cases or had significantly low titres in 2 cases in the blood, virus isolation from the brain (2 cases) and detection of virus particles in 1 out of 2 cases from which the vascular plexus was examined by electron microscopy. Histological examination of the affected areas revealed structural changes of ependymocytes which were principally similar to those described in respiratory organs as well as in other organs in cases of generalization of respiratory infections. Different degrees of sclerosis of vascular plexus (2 cases) or meninges (2 cases) were also observed.

Adolescent↗
PubMed1983

[Topography of the gap junctions in human skin and their possible role in the nonneural transmission of information].

Localization and distribution of the gap junctions in the human epidermis have been studied. They are mainly concentrated in the area of biologically active (acupunctive) points and in so called meridians connecting these points. A supposition is made that the gap junction system performs certain integration of the information from the skin surface and its aneural transmission to remote areas. Discovery of a regulated gap junction system in relatively low organized animals (previously described by the authors), as well as revealing of such a system in mammals, makes it possible to suppose that the system is phylogenetically the most ancient one performing a directed transmission of an information simultaneously with and besides the neural system.

Cell Communication↗
PubMed1983

[Distribution of calcium ions in the muscle fibers of the rat diaphragm depending upon their state and the method of histochemical treatment].

Distribution of calcium ions in the rat diaphragm muscle fibers has been studied electron histochemically using various fixation techniques and chemical treatment of the tissue. When potassium pyroantimonate in water solution is used after a short perfusate fixation with aldehydes, the reaction product granules are revealed in mitochondria, in the disk I, in the center of the disk A, more seldom the precipitate is found in the sarcoplasmic reticulum (SR) and in the T-system. The presence of calcium ions in the precipitate is proved by means of treatment the preparations with ethylenglycol- and ethylen-diamine-tetra-acetic acids. When contracture is resulted from potassium rhodanide administration, in mitochondria the reaction product granules decrease in their number, the precipitate disappears from the central part of the disk A, while the number of the granules increases in the SR terminal cisterns. The data obtained are compared with calcium ions distribution observed at the freezing-substitution method without an additional chemical fixation, as well as the histochemical fixations after Oschman method and at a usual fixation with OsO4. Certain similarity is revealed in distribution of the calcium pyroantimonate granules at aldehyde fixation and when the freezing-substitution method is used.

Animals↗
PubMed1982

[Functional restructuring of the ultrastructure of the giant neuron (Retzius') in the medicinal leech and the possible role of Ca++ ions in these processes].

As it has been demonstrated in the giant (Retzius') neuron of the leech (Hirudo medicinalis), at the synaptic activation for 5 sec. and 10 min., ultrastructural changes in the neuron are accompanied with an increasing number of Ca++ ions in hyaloplasm, mitochondria and cytosomes. After activation, the ultrastructural changes increase, and the number of Ca++ ions returns to the initial level. A suggestion is made on a trigger function of Ca++ ions when the neuronal ultrastructure changes under conditions of the synaptic activation.

Animals↗
PubMed1979

[Bioelectrical activity and ultrastructure of medicinal leech Retzius neurons during chronic direct and synaptic activation].

The threshold direct or synaptic 1/sec stimulation of the Retzius cells increases the firing rate of the neuron in the leach. The firing rate becomes synchronized with the stimulation applied. The membrane potential does not change. After 10 min of such stimulation changes occurring in the ultrastructure of neuron are similar to those in a neuron with no stimulation: these changes reveal a decrease in the synthetic processes whereas the bioelectrical activity remains the same which suggests a certain independence of the neuron electrophysiological parameters of its ultrastructure.

Animals↗
PubMed1978

[Characteristics of synaptic and intracellular neuron activation].

Stimulation of the leech abdominal neural chain with electric pulses of 1 imp/sec frequency results in alterations in the activity of the Retzius cells in addition to an increased protein metabolism in the postactivation period. The direct stimulation produces a decrease in the cellular protein metabolism.

Abdomen↗