Biological Response to a Novel Hybrid Polyoligomer: in vitro and in vivo Models.

The aim of the study is to evaluate biocompatibility of a novel hybrid polyoligomer in in vitro and in vivo models. MATERIALS AND METHODS: Cytotoxicity of the material was investigated using the MTT assay with human dermal fibroblasts as test cultures. To study direct interaction of the hybrid polyoligomer with cells, the fibroblasts were cultured on the polymer samples for 96 h, the cultures were assessed every 24 h using fluorescence microscopy. To study the tissue reaction in the area of contact with the donor bed and the morphological features of the implanted sample restructuring, a case-control study was performed using a rabbit model. Samples of hybrid polyoligomer were implanted into the bone defect formed in the left iliac crest in 10 rabbits. In the control group, the prepared allograft samples were transplanted into similar defects in 10 animals. The rabbits were sacrificed 4 and 8 weeks after the operation. The standard morphological methods with hematoxylin and eosin staining and immunohistochemical Ki-67 proliferation marker evaluation were used to assess the state of tissues in the defect area. RESULTS: The results demonstrate that the hybrid polyoligomer is not cytotoxic (cytotoxicity score 0-1), cells adhere well to its surface, retain their viability and typical morphology throughout the entire observation period. No negative impact of material implantation on the health state and behavior of animals was detected. Morphological examination showed the absence of inflammatory changes, formation of thin-walled capillary vessels, and considerable proliferative activity of mesenchymal cells in the defect area, even though it was more intense than in the control group. CONCLUSION: No inflammation signs were detected by 8th week of the experiment. It was defined that new bone was beginning to form. The results of analysis support the conclusion that the developed hybrid materials are prospective for further research as potential bone substitute.

[Apparent motion effect under undetermined trajectory of presentation of test dot stimuli]. / Effekt kazhushchegosia dvizheniia pri nedeterminirovannoi traektorii pred'iavleniia testovogo tochechnogo stimula.

The influence of such factor as determinacy of trajectory of stroboscopically presented test spot on apparent movement illusion appearance, was studied. Six subjects took part in psycho-physiological experiments during which a test spot was presented successively along the straight line to observer on a display, randomly deviating from this line up or down by 0.39, 0.78, 1.17 or 1.56 angular minutes. It was computed that with the test spot deviating by 0.92 angular minutes from the straight trajectory prognosticated by the observer, the probability of disappearance of apparent straight uniform motion of the spot was equal to 0.75. The findings suggest than one of the conditions under which apparent movement illusion appears involves an agreement between the shape of trajectory of test object presentation as expected by the observer, and its real shape in the experiment.

[Functional morphology of the hypophyseal-adrenal-gonad system in different variants of prostatic hyperplasia]. / Funktsional'naia morfologiia gipofizarno-nadpochechnikovo-gonadnoi sistemy pri razlichnykh variantakh giperplazii predstatel'noi zhelezy.

Two forms of prostatic hyperplasia are distinguished: fibro-glandular (FGH) and glandular-fibrous (GFH). An increase in the number of adenohypophysis cells producing gonadotrophic hormone, hyperplasia of the adrenal reticular zone, hyperplasia and hypertrophy of Leydig and Sertoli cells in the testis were observed in FGH. Signs of enhanced functional activity were observed in all cases of hyperplasia. In GFH there was an increase in the number of adenohypophyseal cells producing adrenocorticotrophic hormone, hyperplasia of the fascicular layer in the adrenals, atrophy of Leydig cells in the presence of Sertoli cell hyperplasia. The variant of prostatic hyperplasia is determined by the hormonal changes and this may help in choosing of approaches to therapeutic correction of prostatic hyperplasia and its early diagnosis.