[The comparative pattern of neuromidin and magnetic stimulation influence on neuroplasticity in experimental traumatic neuropathy].

OBJECTIVE: Traumatic neuropathies are among the most actual problems in neurology due to the severe neurological deficit in most cases and poor prognosis of recovery. We evaluated the effect of ipidacrin (cholinesterase inhibitor) and magnetic stimulation on neuroplastic axonal changes after experimental neurotmesis of rat's sciatic nerve. MATERIAL AND METHODS: Animals (20 rats) were stratified into 3 groups. There was no treatment in the control group; in the second -group experimental animals underwent 3-5 min daily rhythmic magnetic stimulation (0,8-1T, 3 Hz) The third group of animals received intramuscular 0,035 mg of ipidacrin daily within 1 month. RESULTS AND CONCLUSIONS: Based on the received data on the restoration of myelin, axons, myelin nodes structure and lemmocyte ultrastructure), we have concluded that both magnetic stimulation and ipidacrin can trigger restorative and compensative processes in traumatic neuropathies.

[Structural changes in the sensory ganglia of the spinal nerves after repeated magnetic stimulation on the model of ischemic myelopathy].

The aim of this study was to examine the association of morphological changes in the-sensory ganglia of the spinal nerves (SGSN) with the cilinical symptomatology in rats with the experimentally induced ischemic myelopathy (IM), untreated or treated with repeated magnetic stimulation (RMS). The efficacy and mechanisms of RMS action on SGSN were studied by electron microscopy in 16 rats with IM. According to the results of treatment, in SGSN both at a distance from the damaged area (lumbar SGSN) and close to it (cervical SGSN) the morphological signs of regenerative-reparative processes were found in the cells and nerve fibers (restoration of the organelle structure in the cytoplasm o0f neurons and neurolemmocytes, the increase in the number of he latter and fiber remyelination). The expression of the structural changes correlated with the degree of functional recovery.

Changes at the focus of experimental ischemic stroke treated with neuroprotective agents.

The aim of the present work was to compare the morphological changes occurring at the focus of experimental ischemic stroke treated with agents of the neurotrophic group (alpha-GPC, cerebrolysin), an agent with nootropic properties (piracetam), and a mixed-action agent (vinpocetine). Experiments were performed on 18 rats. Transient cerebral circulatory lesions (acute ischemia) were produced in the right hemisphere by clipping the stem of the innominate artery for 40 min. Light microscopic and electron microscopic studies were performed on fragments of cerebral cortex, brainstem, and cerebellum. Use of alpha-GPC and cerebrolysin increased the tolerance of neurons to ischemic damage and slowed the execution of the cell death program. Intracellular changes were seen and were interpreted as adaptive and reparative: these included folding of the nuclear membrane, abundance of polyribosomes, and endoplasmic reticulum and Golgi complex hypertrophy. These agents preserved the structures of the nuclear membranes and major cellular organelles. When piracetam and vinpocetine were used, all morphological measures indicated inadequate energy provision for repair processes in the acute stage of ischemic stroke. Morphological signs of functional tension of cerebral cortex neurons were seen, with gliocytes in different stages of apoptosis, along with the phenomenon of incomplete separation of gliocytes during proliferation, pathological changes to myelin and non-myelinated fibers, and abnormalities in synapse structure.

[New morphological data on multiple sclerosis].

The brain from 6 patients who died of multiple sclerosis was studied with MR tomography (MRT), macroscopy, light (CD 3, CD 20, LCA antigens) and electron microscopy (EM). Typical foci of demyelinization (plaques) were found in all cases. Alterations of brain arteries were found particularly in arteries of narrow lumen--with disturbance or even absence of elastin and muscle layer. Up to 30% of the vessels were surrounded by microcavities. Perivascular infiltrates consisting primarily of T lymphocytes were observed around the vessels (up to 70% of all vessels). This indicates the importance of vascular changes in the disease pathogenesis. Four variants of demyelinization (plaques) are distinguished depending on the degree of destruction of myelin, axons and glia. Two types of cells were found in the plaques with most pronounced changes: astrocytes and newly formed oligodendrocytes. Classification of plaques is suggested.

[Changes in the focus of experimental ischemic stroke under the influence of neuroprotective drugs].

The purpose of this study was to compare the morphological changes in the focus of ischemic stroke under the influence of the drugs of neurotrophic group (alpha-GPC, cerebrolysin), drugs possessing the nootropic properties (piracetam) and those with combined effect (vinpocetin). The experiments were performed in 18 rats. Temporary disturbance of cerebral circulation (acute ischemia) in right cerebral hemisphere was induced by clipping the trunk of innominate artery for 40 minutes. Areas of cerebral cortex, brainstem and cerebellar cortex were studied using light and electron microscopy. Treatment with alpha-GPC or cerebrolysin resulted in an increased tolerance of neurons to ischemic damage and in delayed realization of the program of cell death. Some intracellular changes were detected that could be regarded as the signs of adaptation and repair (indentation of nuclear envelope, increased number of ribosomes, hypertrophy of endoplasmic reticulum and Golgi complex). These drugs preserved the structure of the membranes in the nucleus and major organelles. In animals treated with piracetam and vinpocetin, all morphological signs were indicative of insufficient supply of energy-consuming processes of repair in the acute phase of ischemic stroke. This was accompanied by morphological features of functional stress of the neurons of the cerebral cortex, different stages of gliocyte apoptosis, phenomenon of incomplete separation of gliocytes during their proliferation, myelin and unmyelinated nerve fiber pathology, as well as by changes in synapse structure.

[Comparative analysis of the effect of magnetic fields of varying intensity under experimental conditions]. / Sravnitel'nyi analiz vliianiia magnitnykh polei razlichnykh intensivnostei v ékspermente.

Three series of experiments on mature male and female non-inbred rats weighing 160-200 g with chronic vertebrobasilar circulation disorders (CVCD) and chronic myeloischemia (CMI) of the lumbosacral segments have been performed to assess efficiency of treatment with various physical methods. It was found that measurement of ribosomal cystrone activity by bone marrow preparations staining with silver salts is a simple and fast method of estimation of cell proliferation in the cystrones in exposure to different therapeutic factors, and of prediction of the disease outcome. Combined magnetic and electric therapy is more effective than monotherapy with sinusoidal modulated currents or modulated currents. This is explained by synergism of the therapeutic factors.

Morphological changes in the skin during experimental allergic encephalomyelitis and multiple sclerosis: bases for new diagnostic test.

Skin specimen from the medial malleolar area of patients with multiple sclerosis and guinea pigs with experimental allergic encephalomyelitis were examined by light and electron microscopy. Demyelination, inflammation, and dystrophic changes in peripheral nerves and skin correlating with clinical manifestations were revealed in both sclerosis and encephalomyelitis. Maximum changes were revealed in nerve-associated cells (Merkel cells), Langerhans cells reflecting inflammation intensity, and fibroblasts responsible for nerve integrity and resistance against external stimuli.

[Mitochondrial megaconia and pleioconia in the rat brain as possible and adaptive reactions in lethal radiation and radio-modified injuries]. / Mitokhondrial'nye megakoniia i pleiokoniia v golovnom mozge krys kak vozmozhnye adaptatsionnye reaktsii pri letal'nykh radiatsionnykh i radiomodifitsirovannykh povrezhdeniiakh.

Electron microscopic study of sensomotor area of brain and cerebellar cortex was conducted in 38 outbred albino rats, following 200 Gy irradiation including that combined with preceding effect of hypoxia or 48 hrs long active vigilance. Mitochondrial megaconia and pleioconia were found 4 hrs after the irradiation in neuronal cytoplasm and axoplasm of neuropil unmyelinated and myelinated fibres. These processes were more significant after radio-modified injuries. It may be suggested that mitochondrial megaconia and pleioconia are adaptive reactions to de-energization following the action of superpowerful extreme factors.

[A morphofunctional analysis of the nuclear apparatus of the nonapeptidergic neurosecretory cells in the vertebrate hypothalamus]. / Morfofunktsional'nyi analiz iadernogo apparata nonapeptidergicheskikh neirosekretornykh kletok gipotalamusa pozvonochnykh.

A vast comparative material obtained on fishes, amphibians and mammals has been analysed using ecological and experimental histophysiological approaches. The structural organization of the nuclear apparatus of nonapeptidergic neurosecretory cells, especially in the lower vertebrates has been clearly shown to differ from that of the classic neurones. Morphometrical characteristics of nonapeptidergic neurosecretory cells of hypothalamic centers can be used for a reliable evaluation of their functional conditions. A high intensity of protein metabolism in nonapeptidergic cells of magnocellular hypothalamic centers leads to a bigger nucleolus/nucleus relation for these cells in parvocellular centers. All this proves the necessity of the morpho-functional analysis of nuclear apparatus of neurosecretory cells.

[A method for preparing a monolayer of frog brain cells for the cytophotometric determination of their DNA content]. / Metod prigotovleniia monosloia kletok golovnogo mozga liagushki dlia tsitofotometricheskogo opredeleniia v nikh soderzhaniia DNK.

An improved method for the squashing of the brain cells permitting a good preservation of cell nuclei and their subsequent quantitative cytophotometric evaluation is presented. By this method a monolayer of the brain cells can be easily obtained. The method was tested in cytophotometric study of the DNA content in the Feulgen stained cells of the frog hypothalamic preoptic area. The proposed method can be used for the quantitative evaluation of different histochemical reactions in the brain cells.

[Cytophotometric study of the DNA content in the cells of the preoptic area of the hypothalamus in hibernating common frogs]. / Tsitofotometricheskoe issledovanie soderzhaniia DNK v kletkakh preopticheskoi oblasti gipotalamusa u zimuiushchikh travianykh liagushek.

The DNA content in the squashed Feulgen stained cells of the hypothalamic preoptic region in wintering adult and juvenile frogs was measured cytophotometrically. The vast majority of hypothalamic cells studied showed diploid DNA contents. Only 0.9% of tetraploid cells (4c and 2c X 2 cells) was found in this region, both in adult and juvenile frogs. The incidence of tetraploid hypothalamic cells varied among the individuals studied. In some adult frogs as well as in some juveniles no tetraploid cells were detected. The data obtained do not confirm the age related increase in the mean DNA content in frog's hypothalamic cells population.

[Autoradiographic study of the proliferative activity of the preoptic recess ependyma in yearling and juvenile common frogs]. / Avtoradiograficheskoe issledovanie proliferativnoi aktivnosti épendimy preopticheskoi bukhty u odnoletnikh i dvukhletnikh osobei travianoi liagushki.

Proliferative activity of the ependyma, lining the recessus praeopticus in juvenile frogs was studied with 3H-thymidine radioautography. Usually much more pronounced proliferation of ependymal cells occurred in the preoptic region in one year old frogs as compared with two year old ones. It can be concluded that in the former animals the migration of postmitotic labeled cells into the subependymal zone of the recessus preoptic area is significantly more intense. By the 30th day after multiple isotope injections some newly formed neurosecretory cells with labeled nuclei were found in the 1-5 cellular position of the recessus praeopticus subependymal zone. It is postulated that in juvenile frogs the ependyma of lateral wall of recessus praeopticus is probably a source ("cambium"), from which some young neurosecretory cells may originate.