[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.

[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.

[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.

[Ultrastructural changes in the mitochondria of Retzius' neuron exposed to hydrocortisone].

The ultrastructure of the Retzius cell (gigantic neurone) mitochondria of the medical leech was investigated. After seven repeated injections of hydrocortisone into the coelomic cavity, the transformation of laminar cristae of mitochondria into tubule-vesiculated structures was discovered. A question of correlation between the structure and function independently of the systematical position of the organism is discussed.

[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.

[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.

[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.

[Dynamics of the early ultrastructural changes in sensorimotor cortical neurons of the rat brain after exposure to high doses of gamma-neutron radiation].

At early times (15 min to 6 h) after whole-body gamma-neutron irradiation of mature rats with a dose of 10 Gy reactive changes occur in neurons of the sensimotor cerebral cortex which can be interpreted as a manifestation of the enhancement of functional and metabolic activity of nerve cells followed by inhibition thereof.

[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.

[Electron microscopy study of microcirculation in the rat cerebral cortex after total neutron irradiation].

It was established that the ultrastructure of blood capillaries of the brain changes during the first six hours following whole-body neutron irradiation of rats (10 Gy) which was indicative of the capillary wall swelling, the increase in the microcirculatory bed permeability, and pericapillary edema development. Those processes seemed to be reversible since during this period no severe destructive changes were detected in the microvessel wall.

[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.

[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.

[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.

[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.

[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.