The Specifics of Neovascularization of Wound Defects in the Oral Mucosa during Its Regeneration under a Piezoelectric Polymer Membrane.

We studied restoration of microvessels in the oral mucosa wound defects under a polymer piezoelectric membrane (group 2) and without it (group 1). The control group included animals with intact mucosa. On day 3, the expression of the vascular endothelial growth factor (VEGF) increased in all experimental groups, while the expression of CD34 increased only in group 2, which attested to intensive neoangiogenesis. On day 7, we observed a decrease in VEGF expression and an increase in CD34 expression that was more pronounced in group 2, which reflected the beginning of blood vessels maturation. More rapid formation and maturation of blood vessels in group 2 was confirmed by electron microscopy: on day 7, endothelial cells with mature organelles and signs of active transcapillary exchange were seen. On day 12, the immature blood vessels still predominated in group 1, while in group 2, the expression of angiogenesis markers decreased though remained above the control, which created prerequisites for the complete restoration of wound area vascularization in group 2. In group 1, the expression of VEGF and CD34 was significantly below the control, which attested to the development of poorly vascularized scar tissue.

Infradian Rhythm of the Content of Secretory Granules in Pinealocyte Cytoplasm in Mice and Rats.

The numerical density of secretory granules dense-core vesicles (DCV) in the cytoplasm of pinealocytes of the pineal gland was estimated by transmission electron microscopy in male white mice and Wistar rats. The 3-day biorhythm and lunaphase changes in the DCV content in the perikaryon and the processes of pinealocytes, which are manifested significantly in different seasons of the year, are established. The three-day biorhythm in adult male mice in comparison with younger male rats is not expressed uniformly in different phases of the moon. The in-phase manifestation of infradian biorhythms in different species of animals during the year with an unchanged daily photophase indicates the existence of common external synchronizers for mammals of these biorhythms that are not associated with the light/dark cycle.

Morphological changes in retinal neurons in streptozotocin-induced diabetes mellitus and their correction with an isobornylphenol derivative.

Along with microangiopathy, one of the main causes of blindness in diabetic retinopathy consists of degeneration of retinal neurons. Electron microscopy and morphometric analysis were used to study structural changes in neurosensory cells, associative, and ganglion neurons in the retina in 30 while mongrel male rats with streptozotocin diabetes for two months and the effects of a new semisynthetic antioxidant 4-methyl-2,6-diisobornylphenol, a screened phenol, were evaluated. Destructive changes were found to affect the outer segments of neurosensory cells and ganglion neurons. The number density of neurosensory and ganglion cells decreased, and the proportion of these cells with pyknotic nuclei increased. 4-Methyl-2,6-diisobornylphenol had neuroprotective actions, preventing destructive changes to neurosensory cells and ganglion neurons.

Changes in the synaptoarchitectonics of the retina after light-induced damage and their correction with antioxidants of plant origin.

Changes in contacts between neurons in the internal reticular layer of the retina were studied in white rats 7 and 30 days after exposure to high-intensity light. Osmium preparations on day 7 demonstrated synapse destruction, predominantly of the "light" type of. Contrasting with phosphotungstic acid was used to study juxtamembrane formations of the system of subsynaptic units, i.e., dense projections and postsynaptic thickenings of synapses. The action of light was found to induce destructive changes in synapses, with decreases in the number density of synapses due to functionally active asymmetric contacts. On day 30 after light-induced damage, there was a significant increase in the number density of symmetrical contacts and a decrease in the content of asymmetric mature synapses. Courses of ascovertin and carovertin before and after exposure to light produced different degrees of restriction of synapse destruction and activated repair mechanisms mediated by hypertrophy and neosynaptogenesis. Carovertene had the greater effect.

Effects of carovertin on the reaction of retinal pigmented epithelium and radial glia to bright light.

Light exposure (6000 lux, 6 h) caused reactive changes in rat retinal pigmented epithelium and radial glia on day 1. Foci of lesions with virtually complete absence of the layers formed by neurosensory cells appeared on day 7. The number of destructively changed radial gliocytes in these foci was by one order of magnitude higher than in the control. Carovertin reduced destruction of pigmented epithelium and radial glia and reduced the area of lesion foci.

Structural changes in components of the blood-retina barrier in rat retina during photodamage in alloxan diabetes and their correction with ascovertin.

The outer part of the blood-retina barrier was most sensitive to light exposure (6000 lx, 6 h) during photodamage. It was manifested in hemodynamic disturbances, endothelial dysfunction, and focal death of the pigment epithelium. The photo effects increased during alloxan diabetes. The specific area of open vessels decreased, while the number of thrombotic vessels in the choroid increased. Administration of ascovertin improved hemodynamic parameters of the eye and decreased the specific area of focal damage.

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.

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.