Search PubMed⌕ Search

Biomedical subjects

I V Viktorov

Publications and source records attributed to I V Viktorov.

At least 19 recordsLinked to original sources
PubMed2005

Organotypic cultures of free-floating slices of human embryo medulla oblongata.

The aim of the present work was to produce organotypic cultures of human embryo brain tissues, as needed for investigation of the effects of serum factors on mental diseases and their pharmacological treatment. Cultures were made using slices of medulla oblongata from human embryos aged 9-10 weeks, obtained from medical abortions. Free-floating slices were cultured using a modified roller method for four weeks. Light and electron microscopy, along with immunocytochemistry, demonstrated that cultured slices showed differentiation and growth of neurons, astro- and microgliocytes, with formation of the synaptic contacts and glioneuronal interactions typical of organotypic cultures. However, along with differentiated neurons and glial cells, there was some persistence of undifferentiated cellular elements with signs of stem cells and neuron and gliocyte precursor cells. These experiments showed that organotypic roller cultivation of free-floating slices of human embryo brain tissue can be used to study the processes of neuron and gliocyte development, the mechanisms of neurotoxicity and neuroprotection using a variety of morphological (including stereological) and biochemical study methods.

Adult↗
PubMed2005

Characteristics of the development of the sensorimotor cortex in rats aged 7-8 days in roller cultures of free-floating brain slices.

The development and formation of the neuronal architectonics of organotypic structures of the sensorimotor cortex in rats aged 7-8 days were studied in roller cultures. Free-floating slices were cultured for 2-3 weeks. Serial paraffin sections of cultured tissue were stained with fast cresyl violet as described by Nissl. Initially planar sections of the cortex were found to change their configuration during the process of cultivation and were transformed into spherical structures, retaining the major histotypic features of cortical formations. Radially orientated pyramidal cells and fusiform neurons formed a cortical rudiment, not discriminated into layers, over the whole surface of the spherical tissue structures. In free-floating slices of the sensorimotor cortex of rats aged 7-8 days in roller cultivation, histogenetic processes continued, leading to the formation of histotypic cortical structures similar to the phylogenetically more ancient allocortical formations of the forebrain.

Animals↗
PubMed2004

Roller organotypic cultures of postnatal rat retina.

Floating retinal sections from 7-12-day-old rats form ball-shaped retinal bodies during roller culturing. Histological studies of serial sections of retinal bodies showed that their outer surface is formed by the retina completely retaining organotypic cytoarchitectonics. Some retinal bodies have laminar structure consisting of several layers of the retina. At the initial stages of culturing some retinal bodies contain a cavity, which later is completely obliterated due to the growth of axons of ganglion cells and migration of glial cells and fibroblasts. This study demonstrated the possibility of long-term survival, differentiation, and in vitro axonal regeneration of ganglion cells, the main retinal efferent neurons, which can provide the basis for investigation of pathology and drug correction of injuries and stimulation of regeneration of these cells in experimental glaucoma models.

Animals↗
PubMed2004

[Developmental characteristics of the sensorimotor cortex of 7-8 days old rats in the roller cultures of free-floating brain slices].

Development and formation of neuronal architectonic of organotypic structures of sensomotor cortex of 7-8-day-old rats was studied in roller cultures. Free-floating cortical slices were cultured for 2-3 weeks. Serial paraffin sections of cultured tissue were stained with cresyl violet fast using Nissl's method. It was shown that during cultivation cortical slices changed their initial flat configuration and transformed into spherical bodies that retained main histiotypic features of cortical formations. Radially oriented pyramidal and fusiform neurons formed cortical structure that was not subdivided into individual layers and covered the whole surface of spherical tissue bodies. It is concluded that histogenetical processes were continuing in free-floating slices of sensomotor cortex of 7-8-day-old rats during roller cultivation. They result in formation of histiotypic cortical structure similar to phylogenetically more ancient allocortical formations of the forebrain.

Animals↗
PubMed2003

Use of isopropyl alcohol in histological assays: dehydration of tissue, enbessing into paraffin, and processing of paraffin sections.

Isopropyl alcohol (isopropanol) can be used as a substitute for ethyl alcohol in tissue dehydration during embedding into paraffin and dehydration of stained sections. The use of isopropyl alcohol during paraffinization allows us to exclude treatment with intermediate solvents of paraffin (chloroform, xylene, and benzene), which reduces the degree of tissue compaction and simplifies and accelerates histological assay.

2-Propanol↗
PubMed2003

[Organotypic cultures of free-floating sections of human embryonic medulla oblongata].

The aim of the present study was the development of organotypic culture of embryonic nerve tissue of human brain, which is necessary for the study of the effect of blood serum factors in mental diseases and their medicinal treatment. For the cultivation the sections of medulla oblongata were taken from human 9-10 week embryos obtained at legal medical abortion. Free-floating sections were cultured using a modified roller method for 4 weeks. By using the methods of light and electron microscopy, as well as of immunocytochemistry, it was demonstrated that within the cultured sections the differentiation and growth of neurons, astrocytes and microgliocytes took place accompanied by the formation of synaptic contacts and the establishment of glial-neuronal relationships, characteristic to the organotypical cultures. However, along with the differentiated neurons and glial cells, undifferentiated cellular elements were partially retained, that had the signs of neuronal and glial stem cells and progenitor cells. The studies performed have demonstrated that the method of organotypic roller culture of free-floating sections of human embryonic brain tissue could be applied for the study of the processes of neuronal and gliocyte development, mechanisms of neurotoxicity and neuroprotection using various morphological (including stereological) and biochemical research methods.

Astrocytes↗
PubMed2002

[Ischemic injury of the ultrastructure of neurons in organotypic hippocampal tissue culture].

An ultrastructural study of organotypic hippocampal explants subjected to the effect of ischemia for 30 min followed by a period of reoxygenation lasting for 20-24 hours, was performed. The data obtained indicate that ischemic injury of area CA1 neurons develops mainly as a necrosis. In addition, some neurons along with necrotic changes, demonstrate some signs of apoptosis, suggesting that the execution of its program may accompany these changes, thus leading the cells to the state of so-called apoptotic-necrotic continuum. On the other hand, the observed ultrastructural changes directed to metabolic activation and energy deficit compensation, may indicate the ability of neurons for realization of reparative processes following ischemic injury.

Animals↗
PubMed2001

Structure of cell clusters formed in cultures of dissociated human embryonic brain.

Cell clusters in a culture of dissociated brain from human fetuses at 8-12 weeks gestation in a serum-free growth medium were studied by immunohistochemical methods and electron microscopy. Heterogeneity of cell population in culture was demonstrated. Despite the influence of proliferation-stimulating factors, cell clusters contained not only nestin-immunopositive stem cells, but also beta-tubulin-, vimentin-, and GFAP-positive cells differentiating by the neural pathway. Stem cells were localized on the surface of clusters. The percentage of stem cells in large clusters was lower than in small clusters.

Brain↗
PubMed2001

Histogenesis of hippocampus and neocortex isolated from postnatal rats in organotypic roller tube cultures of floating brain sections.

Floating sections of the hippocampus and neocortex isolated from 6-10-day-old rats retained their spatial cell organization after 2-week roller-tube culturing. Cell structure in CA1, Ca2, and CA3 fields, polymorphic layer of the fascia dentata and its medial and lateral limbs were revealed in sections of the dorsal hippocampus. In neocortical sections, cortical neurons and subcortical structure were preserved, however, some cortical fragments changed their configuration and formed spherical structures, where cortical neurons were located in the external layer without forming typical of neocortex 6-layer structure.

Animals↗
PubMed2001

[Ultrastructural plasticity in the hippocampus organotypic tissue culture].

Hippocampal cross sections of 7-9 day old rats were explanted onto semipermeable microporous membranes for 14-16 days followed by electron microscopic investigation. Besides the structures typical for adult hippocampus in vivo, substantial ultrastructural signs of metabolism and synaptic connections in explants were revealed: redistribution of polysomes and cisterns of granular endoplasmic reticulum, numerous pinocytotic invaginations, growth cones, somatic filopods, dotted (perforated) contacts, new formation of synapses and vacant postsynaptic sites. The data obtained indicate the active compensatory processes of plasticity, which ensure the maintenance of structure and function of hippocampal tissue in vitro.

Animals↗
PubMed2000

[The role of nitric oxide and other free radicals in ischemic brain pathology].

Nitric oxide (NO), an intercellular messenger and a normal metabolic product, takes an active part in the regulation of physiologically significant functions of the cardiovascular, immune, and nervous systems. At the same time when produced in excess amounts, NO as a free radical and an agent that gives rise to highly toxic oxidants (peroxynitrile, nitric dioxide, nitron ion), becomes a cause of neuronal damage and death in some brain lesions (parkinsonism, Alzheimer's disease, Huntington's chorea). Numerous experimental data show the ambiguous effects of NO on the development of cerebral infarct. NO as an active vasodilatory and antithrombogenic agent may reduce cerebral damage in early ischemia. There is evidence for the involvement of NO in the body's adaptation to oxygen starvation and ischemic tolerance formation. In the postischemic period, NO is a major factor of neuronal necrosis and apoptosis. The currently established ideas on the processes of cerebral NO production and on the pathogenetic mechanisms of this agent's cytotoxicity open up new vistas for selective blockers of various NO synthesis enzymes (neuronal, endothelial, glial cellular, and macrophagal and neutrophilic NO synthases) used in the treatment of acute vascular abnormalities of the central nervous system.

Animals↗
PubMed2000

[Effect of gangliosides on intensity of the lipid peroxidation process and structural changes in neuronal membranes, caused by toxic doses of glutamate].

We studied effects of gangliosides on the level of lipid peroxides and microviscosity of membrane lipid bilayer in primary dissociated cultures of cerebellar granule cells prepared from 8 day-old rats under conditions of neurotoxic effect of glutamate. It was found that glutamate (100 mkM) treatment of primary cultures activated the processes of lipid peroxidation and decreased microviscosity of neuronal membranes determined as a degree of pyrene excimerization. It was also shown that preincubation of granule cells with gangliosides did not prevent the accumulation of TBA-reactive products induced by glutamate. At the same time gangliosides significantly decreased the membrane-fluidizing effect caused by glutamate.

Animals↗