[Root canals dentinal wall structure after photodynamic exposure]. / Izuchenie struktury stenki kornevykh kanalov zubov posle fotodinamicheskogo vozdeistviia.

The aim of the study was to assess root canal dentinal walls structure after photodynamic exposure with the use of 0.5% photoditazine. A root canal dentin of 46 single root intact teeth removed for orthodontic indications was examined by scanning electron microscope JEOL JSM-6510 (Japan). Microphotographs of the root canal wall were obtained in the orifice, central and apical parts under×2000 magnification. It was found that photoactivation of 0.5% gel photoditazine by a light source, laser or diode, with a wavelength of 635-660 nm and a power of 150-200 mW is an effective technique for removing the smear layer of the root canal wall, which facilitates the maximum opening of the dentinal tubules to a depth of 2-3 µm. The best result (the maximum number of open dentinal tubules, the absence of a smear layer) is observed with 3 min photoditazine exposure and 2 min of laser exposure. The method can be proposed as an alternative supplement to the conventional root canals irrigation.

[Formation of S-100 containing cells of the hypothalamus and adenohypophysis in normal ontogenesis and in protein deficiency]. / Formirovanie S-100-soderzhashchikh kletok gipotalamusa i adenogipofiza v usloviiakh normal'nogo ontogeneza i pri belkovoi nedostatochnosti.

By means of the indirect immunohistochemical method distribution of S-100 containing cells has been studied in sections of the mediobasal hypothalamus (astrocytes) and adenohypophysis (follicular-stellate cells) in newborn, 10- and 21-day-old rats under normal development and under protein insufficiency. For this the animals are given the diet containing 6% of protein (control--25% of protein). S-100 containing cells are revealed in the hypothalamus and adenohypophysis in 10- and 21-day-old animals. In the brain of the newborn rats S-100 immunoreactive cells are not revealed. At the ultrastructural level the diaminobenzidine (DAB) reaction products in the immunoreactive cells are revealed diffusely along the whole cytoplasm of the cells, in nuclei the DAB reaction products are absent. Part of S-100 containing cells is essentially lowered, comparing with the control. In the rat adenohypophysis part of S-100 containing cells from the 10th up to the 21st day also decreases. Unlike the hypothalamus, however, content of cells, immunopositive to S-100 exceeds the analogous index in the control rats of the corresponding age groups.

[Development of ACTH-containing cells in the hypothalamus and hypophysis in their normal state and in protein deficiency]. / Formirovanie AKTG-soderzhashchikh kletok gipotalamusa i gipofiza v norme i pri belkovoi nedostatochnosti.

In cryostate sections of the brain and hypophysis of newborn, 10- and 21-day-old rats, by means of the indirect method immunohistochemical reaction has been performed. As a primary serum rabbit antiserum against ACTH has been used. The ventromedial hypothalamus and adenohypophysis have been studied by means of light and electron microscopy. Relationship of ACTH-containing cells in the adenohypophysis in the process of the postnatal ontogenesis and protein insufficiency remains constant. Unlike the adenohypophysis, in the hypothalamus part of the ACTH-containing cells decreases with age. When the animals develop under conditions of protein insufficiency, changes in the part of the ACTH-positive cells, that are age-dependent, do not coincide with corresponding parameters in the control. In the adenohypophyseal cells the products of diaminobensidine reaction are distributed in cytoplasm of granules with a dense center 100-200 nm in the diameter. The ACTH-containing cells in the hypothalamus are presented as small neurons with an even distribution of the immunohistochemical reaction products in cytoplasm and in large granules 200-280 nm in the diameter. Since in the adenohypophysis and in the hypothalamus various dynamics on contents of ACTH-reactive cells in the postnatal ontogenesis and at protein insufficiency has been revealed, and various localization of the diaminobenzidine reaction products has been demonstrated, a conclusion is made on heterogenous nature of antigenic determinants against ACTH, situating in these structures.