Morphological changes of the red blood cells treated with metal oxide nanoparticles.

The toxic effect of Al2O3, SiО2 and ZrО2 nanoparticles on red blood cells of Wistar rats was studied in vitro using the atomic force microscopy and the fluorescence analysis. Transformation of discocytes into echinocytes and spherocytes caused by the metal oxide nanoparticles was revealed. It was shown that only extremely high concentration of the nanoparticles (2mg/ml) allows correct estimating of their effect on the cell morphology. Besides, it was found out that the microviscosity changes of red blood cell membranes treated with nanoparticles began long before morphological modifications of the cells. On the contrary, the negatively charged ZrO2 and SiO2 nanoparticles did not affect ghost microviscosity up to concentrations of 1µg/ml and 0.1mg/ml, correspondingly. In its turn, the positively charged Al2O3 nanoparticles induced structural changes in the lipid bilayer of the red blood cells already at a concentration of 0.05µg/ml. A decrease in microviscosity of the erythrocyte ghosts treated with Al2O3 and SiO2 nanoparticles was shown. It was detected that the interaction of ZrO2 nanoparticles with the cells led to an increase in the membrane microviscosity and cracking of swollen erythrocytes.

[The interaction of nanocrystals of corundum and quartz with erythrocyte membranes].

Mechanisms of nanocrystals of quartz and corundum interaction with erythrocyte membranes were studied by means of atomic force microscopy and fluorescence analysis. It was shown that the hydrophobic, chemically inert nanocrystals with the size larger than the critical value (20-25 nm) can bind to erythrocyte membranes, while not causing her harm. If the size of the nanocrystals is less than 15 nm, they can penetrate into the lipid bilayer membranes. This decreases their microviscosity, the pores appear, which leads to cell lysis. A thermodynamic explication of the critical size of the nanocrystals is given.

[The results of using therapeutic periorbital electrostimulations in neurology patients with partial atrophy of the optic nerves]. / Rezul'taty primeneniia lechebnykh periorbital'nykh élektrostimuliatsii u nevrologicheskikh bol'nykh s chastichnoi atrofiei zritel'nykh nervov.

Results of clinical application of method of non-contact periorbital electrostimulation in 6 groups of neurologic patients (total number-246) with optic nerve pathology of different origin (post-traumatic, hypertensive, inflammatory) are summarized. Analysis of interdependence between positive results and severity of visual disorders, type of the disease, responsible for partial atrophy of optic nerve, was performed. This method of restoration of vision in investigated patients proved to be effective both in hospitals and outpatient departments.

Clinical and physiological basis for a new method underlying rehabilitation of the damaged visual nerve function by direct electric stimulation.

A new method of rehabilitation of damaged visual nerves has been tested during clinical physiological investigations in 45 patients with pathological opticochiasmal brain tumor, inflammation and trauma. The essence of the new method was in implanting the electrode into the nerve when the patient was operated on for the pathological formation and in directly stimulating the nerves for 2 or 3 postoperational weeks. Effectiveness of electrical stimulation was increased by direct recording of the electroneurogram as well as by the results of ophthalmological observations. Considerable improvement of vision was observed in 75%, and in 25% of these cases the vision was found to actually normalize. Even in cases of total blindness, vision was partially rehabilitated in 8 of 10 cases. Direct electrophysiological investigation of the visual nerve potentials enabled us to objectively estimate their functional state, predict the probability of visual rehabilitation as well as increase the efficiency of therapy. Neurophysiological mechanisms of visual rehabilitation under the influence of electrical stimulation of the visual nerves are discussed.