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Biomedical subjects

A V Potapov

Publications and source records attributed to A V Potapov.

At least 19 recordsLinked to original sources
PubMed2006

Circular dichroism of crude oil and its derivatives. Role of permolecular structures.

Petrols with different octane numbers, diesel fuel and solutions of crude oil in toluene have been studied by the methods of absorption spectroscopy, circular dichroism spectroscopy and correlation spectroscopy of scattered light. Circular dichroism signal was registered for crude oil solutions in the spectral ranges corresponding to the measured earlier resonance absorption of asphaltene solutions in toluene. We show that the optical activity of crude oil solutions is due to the aggregation of asphaltene molecules in one spectral range and is intensified with the aggregation of asphaltene molecules in another spectral range. Petrols have no optical activity. The optical activity registered for diesel fuel is possibly due to the aggregation of asphaltene molecules.

Journal Article↗
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

[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↗
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↗
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

[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↗
PubMed1996

[The possibility of the occurrence of hyperventilation apnea and loss of consciousness].

In work influence of various temporary modes of free hyperventilation of the lungs was investigated, usually used by the sportsmen before diving on reduction of the contents of CO2 in exhaling air of healthy men-divers. Attention was paid to the opportunity of occurrence of posthyperventilation apnea and loss of consciousness. It is shown, that washing away CO2 from organism at hyperventilation is limited. Hyperventilation (their depth and frequency was chosen arbitrary), spent during 60, 120, 180, 360 seconds causes in healthy trained men apnea and loss of consciousness.

Adult↗
PubMed1993

[Typical pathology during the free immersion of a man under water].

The free immersion of a man under the water is accompanied by the threat of specific disorders which could cause the drowning. The article examines the causes, conditions and mechanisms of two most frequent pathological states, i.e. the compression of thorax and loss consciousness caused by CO2 action and hypoxia. The symptoms of these states, as well as prophylactic measures and first aid recommendations are enclosed.

Consciousness Disorders↗
PubMed1992

[Arrhythmia in athletes during length diving].

On diving at a distance of 50 m by arresting their breathing, some male athletes were shown to develop cardiac arrhythmias which occurred at min 2 of a restorative period and entirely disappeared at the end of the second-fifth min. It is essential to make further studies of the impact of diving on the cardiac rhythm in athletes in order to elucidate how these disturbances should be regarded: abnormal or physiological.

Adolescent↗