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Biomedical subjects

E I Chumasov

Publications and source records attributed to E I Chumasov.

At least 19 recordsLinked to original sources
PubMed2006

Sensory innervation of the brain - myth or reality?

This article provides a critical analysis of the concepts of the sensory innervation of the brain and spinal cord presented in Sotnikov's articles in issues 2 and 3 of this volume. Criteria for the identification of intracerebral primary sensory neurons and the possible roles of neuronal cilia are discussed. The significance of asynaptic dendrites and bipolar cells is considered. The importance of the correct use of a variety of terms is emphasized, and the need for using combined morphological and electrophysiological analysis in investigating sensory intracerebral exteroceptors is noted.

Animals↗
PubMed2006

[The histogenesis of interrenal primordium of the adrenal gland in pig (Sus domestica)].

Using light, electron microscopy and cytochemistry, the early (embryonic week 4-8) stages of adrenal gland (AG) development were studied in domestic pig. The interrelations between the cells of the fetal cortex (FC) and chromaffin cells (CC) were traced. At week 5, AG primordium is represented by FC, which consists of the epithelioid cells, with the ingrowing neural cords containing CC islets. Starting at the early embryonic period and up to fetal period, CC and interrenal cells of FC are closely interrelated with each other and sinusoidal capillaries. Both cellular types are at different stages of differentiation, including the functionally active elements. At weeks 7-8, FC cells undergo involution, while those ones, left at periphery, form definitive cortex. CC are located in the central part of the organ and form suprarenal tissue. Authors hypothesize, that CC, migrating into AG primordium, initially induce the development of interrenal primordium, and later cause the involution of FC. This, possibly, may be explained by the fact that further antenatal and postnatal development of the organism requires more corticosteroids than the amount produced by FC.

Adrenal Cortex↗
PubMed2005

[Sensory innervation of the brain--myth or reality?].

This paper contains a critical analysis of conceptions of the sensory innervation of the spinal cord and the brain, presented in the articles by O.S. Sotnikov (issues 2 and 3 of this journal). The criteria for identification of intracerebral primary sensory neurons are examined, as well as the possible role of neuronal cilia. The significance of asynaptic dendrites and bipolar cells is discussed. The importance of an adequate usage of some terms and the advisability of a combined morphological and physiological analysis for the study of sensory intracerebral exteroceptors is emphasized.

Animals↗
PubMed2003

[Development of adrenal chromaffin tissue].

The purpose of the present investigation was to study the morphological peculiarities of chromaffinoblasts and to determine their interrelations with the surrounding cellular elements of the fetal cortex at the early stages (embryonic weeks 4-7) of their migration into the developing adrenal gland of a pig. At week 5 neuro-cellular cords, consisting of so-called "naked" axons, neuroblasts, lemmoblasts, undifferentiated cells, chromaffinoblast clusters and chromaffinocytes, grow into the fetal cortex from side of abdominal aorta. In fetal cortex parenchyma chromaffin elements form cords, lobes, "medullary globes", which are enveloped by a basal membrane, which is a derivative of satellitocytes. Chromaffinocytes are stained with Wood's stain, potassium bichromate and, judging by the presence of secretory granules in their cytoplasm, are capable to synthesize summary catecholamines and to release them into the blood at the early stages of development. "Medullary globes" are the centers of proliferation and differentiation of the chromaffin cells in the adrenal medulla. The problem of chromaffin tissue stem cells is discussed.

Adrenal Glands↗
PubMed1997

[The developmental characteristics of the embryonic anlagen of rat neocortex and spinal cord when transplanted into the distal end of the dissected sciatic nerve of adult animals].

The spinal cord and cerebral cortex of 14 day old embryos of Wistar rats were transplanted into the distal stump of the adult rat cut sciatic nerve in order to study dynamics of the development of the transplanted cell elements, and to elucidate relations of neuronal elements in the central and peripheral nervous systems. By means of light and electron microscopy it has been stated that the transplanted nerve cells of the cortex and spinal cord could survive for 60 days and differentiate from neuroepithelial cells and neuroblasts up to young and mature neurons. In the transplants a neuropil is seen to form with both unmyelinated and myelinated axons and synaptic contacts. In the cortex transplants cavities appear paved with ependyma-like cells having cilia and microvilli. It has been found that axons of the transplanted spinal cord neurons may leave transplants to be myelinated by the recipient's Schwann cells of the peripheral nerve.

Animals↗
PubMed1993

[The cytodifferentiation of the rat spinal cord and neocortical neural elements when implanted into a peripheral nerve].

Using electron microscopy, a study was made of the dynamics of development of the cerebral cortex and spinal cord in 14-day-old rat embryos implanted into the sciatic nerve of mature rats. It is shown that the implanted neural elements of the cortex and spinal cord survive for 8 months and differentiate from neuroepithelial cells and neuroblasts into young and mature neurons. In addition, the synaptogenesis and myelination were studied. Mature synapses in implants of the spinal cord were detected in 14 days, and in implants of the cortex in 21 days. The spinal cord and cortex implants displayed the first myelinated axons in 21 and 30 days, resp. Implants of the fetal spinal cord became mature earlier than the cortex implants. It has been stated that the processes of synaptogenesis and myelination in implants continue longer than in situ.

Animals↗
PubMed1992

[Changes in the skin and sciatic nerve after soft-tissue damage to the extremity by a high-speed small-caliber bullet].

The character of contusive changes has been determined in the skin and sciatic nerve after lesion of soft tissues of the extremity with a high-speed small-bore bullet. A high-speed filming, tensiometry have been used. They allow to observe and measure processes of formation of the temporal pulsating cavity appearing at the moment of injury in the block of 20% gelatin and its influence on the imitator of the vascular-neural bundle. In the investigation performed on test-animals by means of neuromorphological, histological and histochemical techniques certain contusive changes are stated in the skin and sciatic nerve at various distances from the edge of the entrance and axis of the wound canal. The investigation of the material in 1, 3, 5 days after the lesion makes it possible to differentiate initial changes connected mainly with the effect of contusion from the secondary ones.

Animals↗
PubMed1991

[Structural-functional changes in the peripheral nerves after administration of several drugs].

Structural and functional changes in the sciatic nerve induced by some drugs were studied using morphological and electrophysiological methods. It was stated that the application of this drug on the nerve causes different degenerating changes. Electrophysiological data, using the regeneration of action potential, proved the presence of structural changes in the nerve after application of mentioned drugs and showed partly preserved conduction of the nerve trunks.

Action Potentials↗
PubMed1991

[The structure and nature of the macrophages participating in Wallerian degeneration of nerve fibers].

The nervus ischiadicus in white noninbred rats has been damaged by various means and then light- and electron-microscopically the sources of origin of macrophages, participating in removal of decay products in the distal part of the nerve have been studied. There is a close correlation between the process of Wallerian degeneration and aseptic inflammation. In the area of decay of the myelinated nervous fibers 4 types of cells have been identified and characterized. Three of them are precursors of macrophages, participating in removal of the myelin decay products: mononuclear cells of hematogenic origin, perineural cells, endoneural fibroblasts. The dynamics of these cells transformation into macrophages and into "foam cells" has been followed. The fourth type--Schwann cells; they do not directly participate in removal of the myelin decay products. They do not die, but, separating from the segments of the disintegrated myelin, dedifferentiate, proliferate and form cords, into which regenerating axons then grow in. To understand the role of various macrophages in the destructive and reparative processes, which develop in the nerves, is very important not only for searching definitive approaches in treatment of posttraumatic demyelinated processes, but for comprehending the mechanisms of certain autoimmune demyelinating diseases.

Animals↗
PubMed1990

[Development of the fragments of embryonal spinal cord in a damaged peripheral nerve of a mature animal].

By means of morphological methods dynamics of the spinal cord development in 14-day-old rat embryos implanted into the sciatic nerve of mature rats have been studied. The implants preserve their viability during 5 months after the operation and their cells continue to differentiate beginning from neuroepithelial cells and neuroblasts up to young and mature neurons with histotypical signs of motoneurons. In 6 h and 1 day after transplantation the neuroepithelial cells continue their mitotic division. In 3 days, however, their mitotic activity decreases essentially and differentiation of neuroblasts begins. In 7 days the implants consist mainly of differentiated neuroblasts and glial cells. As demonstrates electron microscopy, in 30 days after the operation in the implants there is a well developed neuropil, where mature neurons, myelinated axons are situated and synaptic contacts are present.

Age Factors↗
PubMed1990

[Changes in the intramural neural apparatus of the stomach and gallbladder in the late periods after vagotomy].

By means of morphological methods changes in the wall of the stomach central part and in that of the bile bladder have been studied in 15 patients after a remote vagotomy (in 7-17 years). Material of biopsies and resections has been investigated. In the wall of the organs in question focal and diffuse mono- and plasmocytic infiltrates, leucocytic invasion of the mucous membrane epithelium, microerosions, microfocal hemorrhages in the external layers of the muscular sheath have been revealed. Inflammatory-degenerative and dystrophic changes are observed in the intramural ganglia, in large and small fasciculi of the muscular-intestinal nervous plexuses. In the tissues of the organs studied there are no myelin fibers, that are ++pre-ganglial and receptor conductors. The degeneration of these fibers after vagotomy and loss of connections in the organs investigated with the CNS are supposed to result in essential changes not only of the nervous trophic of tissues in all membranes and sheaths, but bring about changes in the intramural nervous apparatus itself. These changes, in their turn, cause imbalance + in the neurogumoral regulation and can be considered as the base of a number of postvagotomic structural-functional disturbances.

Atrophy↗
PubMed1990

[Implantation of embryonic neocortex and spinal cord into injured peripheral nerve of adult rats].

Spinal cord and cerebral cortex of 14-day-old embryos of Wistar rats were implanted into the sciatic nerve of mature rats in order to study dynamics of the development of neuronal and neuroglial elements in ectopic sites. By means of light and electron microscopy it has been stated that the implanted nerve cells of the cortex and spinal cord survive during 5 month and differentiate from neuroepithelial cells and neuroblasts up to young and mature neurons. It was found that thirty days after operation the spinal cord implants contained myelinated nerve fibers and numerous synapses. The data obtained suggest that the implants of fetal spinal cord are more favorable for regeneration of the injured nervous stems than the cerebral cortex.

Animals↗
PubMed1990

[Changes in neural conductors and their end organs in the muscles and skin after major procedures of one-stage lengthening of the extremity by the G.A. Ilizarov method].

The state of the tibial nerve, intramuscular nervous fasciculi and terminals in muscles and skin has been studied in the canine extremities at large one-stage elongations after G. A. Ilizarov. By means of neuromorphological methods it has been proved that during the distraction in the tibial nerve microscopical areas of overstrain of the nervous fibers are formed. This results in appearance of degenerative alterations both in the nerve itself and in the tissues, which it innervates. Together with the destructive processes, during all stages of distraction in the extremity, regeneration of nervous apparatuses took place. However, reparative processes were poorly manifested during those stages. Only after distraction is stopped (in 6 months--period of the extremity fixation) the regenerative processes predominate. It is possible to suppose that the manifestation degree of degenerative and reparative changes depends immediately on duration of distraction.

Animals↗
PubMed1989

[An electron microscopic study of neuronal development in organotypic cultures of the anlage of the cerebral cortex from a human embryo].

Data are provided on cytodifferentiation of the cerebral cortex cultured cells taken from 10-12 week old embryos of man. It is shown that low differentiated neuroblasts well survive in culture for 21 days. Mature granular cells and middle pyramidal neurons are revealed in cultures. The number of morphological criteria may testify to the maturity of neurons: the presence of the Nissl substance, differentiation of dendrites and axons; the presence of various types of synapses. The absence of myelinized fibres testifies to the insufficient maturity of the cultures, that is probably associated with employing the low differentiated nervous tissue for cultivation and with insufficient cultivation period.

Cell Differentiation↗
PubMed1989

[Effect of neurite-stimulating protein on the growth and proliferation of peripheral glia cells].

Proliferative activity of peripheral glia was investigated in the organotypic culture of peripheral nerves of 9-10-day old chick embryos. The neurite-stimulating protein, a stimulator of the neurite growth in the organotypic culture of spinal ganglia, being added to the culture media sharply increased the mitotic activity of glia: on the 3d day its level was 3.5 times higher as compared with the control one.

Animals↗
PubMed1989

[Features of glia growth in tissue cultures of the rat cerebrum].

In the tissue culture of the newborn rat cerebrum structural peculiarities of the glial growth have been investigated, using scanning and transmissive microscopy. Glioblasts are the first to migrate into the growth zone from the explant. Formation of the glial network is accompanied with formation of multilayered structures. In the cerebral tissue culture 3 zones are distinguished differing from each other by their morphofunctional peculiarities and behavior of the glial cells: growth zone, intermediate and central ones. The growth zone is characterized with permanent moving and modification of glial cells, participating in formation of cellular cords, networks and layers. Glioblasts are predominate cells in this zone. The intermediate zone consists of multilayered glial elements, possessing a high proliferative activity. The central zone, where neuropil and neurons consisting of numerous processes are situated, is characterized with a high degree of differentiation of glial elements. The central part of the explants is covered with epitheliomorphic layer of glial cells, predominantly consisting of cytoplasmic and fibrous astrocytes. The data presented demonstrate that differentiation of glial elements into various types occurs in the cerebral cultures exclusively in the area of the neural cells localization and, possibly, under their immediate influence.

Animals↗