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Biomedical subjects

S V Logvinov

Publications and source records attributed to S V Logvinov.

At least 19 recordsLinked to original sources
PubMed2006

Plasticity of secretory neurons in the supraoptic and paraventricular nuclei of the hypothalamus on exposure to light.

Light and electron microscopic methods were used to analyze changes in secretory neurons in the supraoptic (SON) and paraventricular (PVN) nuclei in the hypothalamus in 100 adult male rats at time points from the first minutes to 180 days after 48 hours of full-time exposure to bright light. At the early time points after exposure, the cellular formulae of the SON and PVN shifted towards functionally active neurons with minimal quantities of secretory granules, large nuclei and nucleoli, low RNA contents, small numbers of rough endoplasmic reticulum cisterns, vacuoles, and lysosomes in the perikarya. The number of cells depositing secretion was greater than in controls at 24 h in the SON and PVN and at 10 days in the SON. Normalization of the cellular formula and the structural organization of the protein-synthesizing apparatus of PVN neurons occurred at 10-30 days, with normalization in the SON at 30-180 days. These data provide evidence that the range of plasticity of neurons in the PVN on exposure to full-time bright light was more significant than that in the SON.

Adaptation, Physiological↗
PubMed2005

Effect of ascovertin on morphological changes in rat retina exposed to high-intensity light.

Experiments on rats showed that high-intensity light exposure (6000 lux, 6 h) caused focal injuries in the retina. The most sensitive structures were neurosensory cells, pigmented epithelium, radial gliocytes, and choroid capillaries. Injection of ascovertin led to disappearance of foci of injuries, limited blood supply disorders in the retina, and destruction of neurosensory and glial cells.

Animals↗
PubMed2005

[Plastisity of secreteory neurons of hypothalamic supraoptic and paraventricular nuclei during light exposure].

Changes of secreteory neurons of hypothalamic supraoptic (SON) and paraventricular nuclei (PVN) were analyzed using light and electron microscopy in 100 adult male rats from the first minutes up to 180 days after their round-the-clock 48 hours-long exposure to bright light. At the early stages after the exposure, SON and PVN cellular formula was changed in favor of functionally active neurons containing few secretory granules, large nucleus and nucleoli, low RNA content, sparse complexes of rough endoplasmic reticulum, vacuoles and lysosomes in their perikarya. After 24 hours in both SON and PVN and after 10 days in SON the number of cells accumulating secretion was greater than that in control group. Normalization of the cellular formula and of the structural organization of protein-synthesis apparatus in PVN secretory neurons took place at days 10-30, while those ones in SON--at days 30-180. The results obtained suggest that the range of plasticity in PVN neurons in animals exposed to continuous bright light is larger than that in SON neurons.

Animals↗
PubMed2005

[Structural changes of the retina and corpus vitreum in the model of proliferative vitreoretinopathy in alloxan diabetes].

The present study was conducted to determine the role of blood mononuclear cells in a morphogenesis of proliferative vitreoretinopathy (PVR) and to detect the peculiarities of PVR development in hyperglycemia. Experiments were performed in 75 mature male Wistar rats. In animals of group 1, the model of PVR was reproduced by injection of mononuclear cells into the corpus vitreum. In animals of group 2, alloxan diabetes was induced 6.5 weeks prior to intravitreal injection of mononuclear cells. The material obtained was studied using the methods of light and electron microscopy. Development of PVR by intravitreal injection of mononuclear cells in diabetic rats was found to be associated with more severe destructive and proliferative changes. Considering the integrative role of blood mononuclear cells in the intercellular networks, it is suggested that these cells are involved in the pathogenesis of PVR.

Animals↗
PubMed2005

[Morphological changes of rat ovaries after their monopolar coagulation and ascovertin correction].

Using the methods of light and electron microscopy, morpho-functional changes of the ovaries of albino rats after their monopolar coagulation were studied. Electrocoagulation was shown to cause hemodynamic changes in a perifocal area and short-term stimulation of follicular growth, but starting already at postoperational day 3, their atresia was increased, while by day 30 a significant reduction in number of both primordial and growing follicles, as well as of corpora lutea, was found. Ultrastructural changes of oocytes in primary and secondary follicles outside the coagulation zone were demonstrated at early stages and included the reduction of porous plate, cortical and yolk granule numbers, and the increase in numbers of lysosomes and multivesicular bodies. Ascovertin, due to its antioxidant properties and by improving hemorheological parameters, exerts a protective action on ovarian generative apparatus and the state of microcirculation in the organ.

Animals↗
PubMed2004

[Ultrastructure of the pinealocytes in rats exposed to light and radiation].

Changes in pinealocytes (PC) were analysed using quantitative electron microscopy in 240 adult male rats from first minutes up to 180 days after their continuous exposure to bright light (CLE) for 48 hours, X-ray irradiation (XRI) or their combination (CE). After CLE early changes of PC included the reduction of rough endoplasmic reticulum (RER), Golgi complex and synaptic ribbons. At 24 hours and 10 days PC secretory activity was increased, while their ultrastructural organization was normalized by 30-180 days. 10 days after XRI degenerative changes were detected in PC that included dilation, fragmentation and vacuolization of RER cisterns, mitochondrial swelling, appearance of large vacuoles and osmiophilic inclusions, increase in lysosome content. Volume density of mitochondria and RER was lower, while that of Golgi complex was higher than in control. PC ultrastructure was restored 30-180 days after XRI. Following CE, the changes in PC ultrastructural organization were more significant at all time interval studied than after the action of single factors. The results obtained indicate that CLE increased the extent of postradiation changes in PC ultrastructural organization during the early time intervals after XRI and at the peak of radiation sickness development.

Adaptation, Physiological↗
PubMed2003

Effect of ascovertin on morphofunctional changes in the ovaries in monopolar coagulation.

A course of ascovertin therapy reduced manifestations of perifocal inflammation and atresia of growing follicles, corrected vascular disorders and changes in the tissue volume ratios outside the necrotic zone after monopolar coagulation of the ovaries in rats. The drug prevented the increase in blood viscosity, erythrocyte aggregation, and LPO activation in the early postoperation period.

Animals↗
PubMed2003

Dynamics of structural changes in the retina during long-term exposure to bright light.

Exposure to high-intensity light led to pronounced destructive changes in the retina and focal loss of layers formed by neurosensory cells in rats. Photoinjury led to progressive decrease in the numerical density of nuclei in the outer nuclear layer (by 30% after 2 days, by 75% after 1 week, and more than by 90% after 2 weeks of exposure). After 30 days the photosensory layer completely disappeared, while the outer nuclear layer was presented by solitary nuclei of neurosensory cells.

Animals↗
PubMed2003

[Structural changes in the granular duct epitheliocytes and terminal areas of the submandibular glands induced by exposure to light and radiation in rats].

This investigation was aimed at the evaluation of radiomodifying effect of round-the-clock light exposure on the salivary glands. The changes of morphometric parameters of granular duct epitheliocytes and acinar cells in rat submandibular glands were analyzed by means of light and electron microscopy after 48 h of light exposure by 3500-lux cool white fluorescent lamps, single 5 Gy whole-body X-irradiation and their combination. Early changes of granular duct epitheliocytes after light and combined exposure were more significant in comparison with those on acinar cells. On the 10-th day after combined irradiation reduction of nucleoli and endoplasmatic reticulum in the duct cells was more pronounced as compared with similar period following light and X-ray irradiation. Long-term morphological changes in the glands after X-ray and combined irradiation were similar. It is concluded that radiation and round-the-clock light exposure act synergistically.

Animals↗
PubMed2001

Ischemia-induced changes in synaptoarchitectonics of brain cortex and their correction with ascovertin and Leuzea extract.

Peroral administration of 70 mg/kg ascovertin and 150 mg/kg Leuzea extract to rats with cerebral ischemia for 5 days prevented destructive changes and decrease in the density of synapses in the cerebral cortex. These preparations activated compensatory and reparative mechanisms underlying plasticity of the synaptic pool, which was realized through hypertrophy and destruction of synaptic contacts. Ascovertin possessed more pronounced cerebroprotective activity than Leuzea extract.

Animals↗
PubMed2000

Photo-induced damage to neurosensory retinal cells after preliminary X-ray irradiation.

Preliminary X-ray irradiation (5 Gr) enhances damages to neurosensory retinal cells by visible light (3500 lx, 48 h) in rats. This combined treatment caused early destruction of the external and preterminal processes, karyopyknosis and karyolysis of about 30% neurosensory cells followed by focal destruction of the corresponding retinal layers.

Animals↗
PubMed2000

[The ultrastructural changes to the ovaries and oviducts in experimental inflammation under the influence of eplir phonophoresis].

Ultrastructural changes of blood vessels of ovaries and oviducts, destruction of the part of follicular epitheliocytes and disruption of other structures of blood-follicular barrier occur at the early period of experimental inflammations of appendage uterus on the background of traditional antibiotic therapy. All changes lead to atresia of growing follicules. Fibrotic-sclerotic changes develop on the 30th day and during later period. Course of eplir phonophoresis decreases ultrastructural disruptions of vessels, follicular apparatus of ovaries and oviducts epithelium. Effect of physiotherapy is manifested though activity of fibroclasts and macrophages, that regulate collagen production/resorption ratio thus preventing the development of fibrotic changes of ovary stroma and oviduct wall.

Acute Disease↗
PubMed2000

[Structural changes to the retina in combined exposure to light and x-rays].

Preceding total X-ray irradiation of rats 5 gy in dose amplifies the impairing action of high-level light (3500, 48 Hrs) on retina at early short terms (1-10 d). The changes occurring at late (1 month) and distant (6 months) terms of the irradiation are similar. Neurosensory cells and pigmentocytes were most damaged by light and combine effect of all cellular elements of retina. Disturbance of blood-retina barrier, vasculogenesis are one of the basic links of tissue mechanisms of retina dosder impairment by light and combined effect.

Animals↗
PubMed2000

Cerebroprotective effects of diquertin and ascorbic acid.

Electron microscopy and electrophysiological studies revealed pronounced structural and functional changes in the brain cortex in rats with experimental cerebral ischemia. Repeated administration of diquertin and ascorbic acid significantly attenuates ischemic damage induced by circulatory disturbances.

Alpha Rhythm↗