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Biomedical subjects

A V Sakharova

Publications and source records attributed to A V Sakharova.

At least 19 recordsLinked to original sources

[The ultrastructural localization of NO-synthase NADPH diaphorase in a peripheral nerve and its change in diphtheritic polyneuropathy].

Light and electron microscopy was used to study the distribution and changes of NADPH-diaphorase in the cutaneous nerve biopsy specimens in different periods of diphtheritic polyneuropathy (DP). there was a reduction in the reaction rate of the enzyme in Schwann's cells of the destructively changed nerve fibers and an increase in the remyelinated nerve fibers. The enzyme is located on the nuclear and endoplasmic reticulum membranes and ribosomes. It is suggested that there is an association of the synthesis of nitric oxide with the myelin-producing function of Schwann's cells.

Biopsy↗

[In vivo diagnosis of Creutzfeldt-Jakob disease].

The paper presents the data concerning usage of some original method of vital laboratory diagnostics of Creutzfeldt-Jacob disease that belongs to the group of prionic diseases. The method consisted in the inoculation of inoculative culture of rat Gasser ganglion's neurinoma by biologic materials investigated (serum and clot of blood) with the following passivation and investigation of the contaminated culture by means of both morphologic and electron microscopic methods. As an example of vital verificated case the wide pathomorphologic analysis of the biopsy sample of brain was presented. Besides, the efficiency of the investigation of cognitive evoked potentials (P300) together with EEG was also demonstrated as the method of objectification of the development of dementia in this disease.

Brain↗

[Inclusion body myositis: its clinico-electrophysiological and morphological diagnosis].

The paper reports three cases of myositis. The findings at detailed electroneuromyographic, morphologic and ultrastructural tests were indicative of characteristic vacuole inclusions in the muscular fibers. Two patients had associated neuritic disorders diagnosed neurophysiologically and morphohistochemically. The neuritic component proved aggravating in the course of the disease. Diagnostic myographic and morphological criteria are analyzed which can distinguish myositis with inclusions from other muscular inflammatory disease.

Action Potentials↗

[The astrocyte reaction to an experimental herpes infection].

The experimental research carried out on rabbits was aimed at determination of astrocytes reaction during brain inflammation caused by Herpes simplex virus. The study was made with the help of glia marker. Immunocytochemical findings showed that the earliest structural brain responses to the infection were changes in astrocyte glia. This was evident from the swelling and hypertrophy of vessel crus and from increased number of astrocytes around the vessels. Glia complexes (astrocyte agglomeration) were formed in the affected sites. During the exudative reaction the hyperplastic alterations of astrocytes were not observed. Later the injured spots of brain tissue were replaced by proliferating astrocytes. The conducted investigation has shown the astrocyte glia to be different during different stages of the infectious process. One may suppose that different subtypes of astrocytes response has place during each stage which should be further confirmed. One may also suppose that a similar alterations of astrocytes coincide with interferon and interleukin secretion by these cells. This is suggested to be a structural base of immune response of the brain.

Acute Disease↗

[Morphologic changes in the skin and superficial temporal arteries in Sneddon's syndrome].

Skin biopsies from livedo's areas of 25 patients and fragments of superficial temporal arteries of 10 patients with Sneddon's syndrome were examined. Pathological changes in the dermis arteries of small and medium calibers were found in the form of the intima hyperplasia, proliferation of vascular wall cell elements (80%), arterial thrombosis (with diameter of 60-200 microns). These changes were found in 68% of observations when clinical and morphological signs of vasculitis were lacking. "Arteriopathy" is the most appropriate term for such lesions. Focal and diffuse fibro-muscular elastic hyperplasia of the intima and muscular layer fibrosis in the wall of superficial temporal arteries may be considered as age-associated lesions. Ultrastructurally, a selective damage of the non-adrenergic part of the nervous apparatus of the dermal arteries and superficial temporal arteries were observed; this suggests the participation of the damaged vascular neurogenic regulation in the formation of organic vascular changes.

Adolescent↗

[Natural autoantibodies of neonatal rats detectable by a hybridoma technic].

Neonatal rat hybridomas were tested for natural autoantibodies (NAA) production, using different screening procedures. NAA were discovered in 35% of immunoglobulins producing hybridomas. Radioimmunoassay (RIA) on brain and liver homogenates and immunocytochemistry on brain sections are the procedures of choice revealing the major part of the identified NAA. On the contrary, only a small portion of NAA could be detected with indirect immunofluorescence on fixed fibroblasts and with RIA on individual autoantigens. All the NAA revealed proved to be of the IgM type and almost all of them possessed neither organ nor species-specificity. In spite of that, most of the NAA reacted with definite cell populations of nervous tissue such as glia, neurons, ependyma or brain vessel cells. The studied panel of NAA from neonatal rats has common features with similar panels from newborn and old mice, though some species-specific characteristics do exist.

Animals↗

[Virus-like inclusions in the cells of the central nervous system in amyotrophic lateral sclerosis].

Electron microscopic examination of the frontal cortex of a patient with amyotrophic lateral sclerosis (ALS) with 14-year prolongation of life by artificial ventilation of the lungs revealed heretofore undescribed cytoplasmic virus-like inclusions in neurons and glial cells as well as changes in the granular endoplasmic reticulum in astrocytes consisting of large accumulations of ribosomes in which regular arrays were frequently observed. The discovered inclusions were not similar to any identified viral inclusions but were similar to virus-like particles found in the muscle in ALS and viral inclusions in experimental poliomyelitis. The role of the observed inclusions and their etiological importance remain obscure.

Adult↗

[Expression of NADPH-diaphorase in the peripheral nerve and its changes at different stages of diphtheritic polyneuropathy].

Distribution and intensity of NADPH-d reactivity, a marker for enzyme of the nitric oxide synthesis, in nervus suralis biopsies in severe DP were studied at light and electron microscopic levels. The study of control specimens has shown that NADPH-d reactivity was permanently present in Schwann cells (SC) and was distributed in all parts of their cytoplasm. Axon and myelin were devoid of NADPH-d reactivity. A decrease of enzyme reactivity in SC cytoplasm of the damaged nerve fibers and rising enzyme reactivity in the cytoplasm of activated SC were observed in DP. High reactivity in SC of small fibers was found at earlier stages and that of thick fibers at later stages. This distinction reflected, apparently, sequence of entering at first thin, then thick fibres in the reparative process. Under the electron microscope, the reaction product was deposited on membranes of endoplasmic reticulum, nuclear membrane and Golgi complex. The enzyme was also located in nucleus of activated SC. Ultrastructural location and the fact that the highest intensity of reaction is present in SC of nervous fibres with morphological signs of remyelination suggest link of this enzyme with the reparative process. This study provides the first evidence of NADPH-d reactivity in SC and shows that NADPH-d histochemistry is a useful tool for peripheral nerve biopsies study.

Diphtheria↗