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Biomedical subjects

V V Popuchiev

Publications and source records attributed to V V Popuchiev.

17 recordsLinked to original sources

Relationship between antitumor efficiency of photodynamic therapy with photoditasine and photoenergy density.

We studied the effect of photodynamic therapy with photoditasine at different protocols of photoenergy exposure on morphofunctional parameters of M-1 sarcoma. It was found that proliferative activity of tumor cells (evaluated by immunostaining for PCNA) nonlinearly decreases after exposure to 150, 300, and 600 J/cm2. The main form of cell death during the early period after photodynamic therapy was direct photocoagulation necrosis caused by destruction of sensitized cell structures and ischemic necrosis developing as a result of alteration of vascular network in the tumors. Photoenergy density was not essential for the intensity of induced apoptosis.

Animals↗

Ultrastructure of the pineal gland after gamma-irradiation under conditions of inhibition of adrenocortical function.

Electron microscopy showed that whole-body gamma-irradiation in sublethal doses led to the appearance of injuries in pinealocytes, glial cells, and vessels of the pineal gland in rats. Limitation of the nonspecific effect of gamma-irradiation via inhibition of adrenocortical function with metopirone in physiological doses reduced the radiation-induced ultrastructural damage to the pineal gland.

Adrenal Cortex↗

Immunohistochemical and morphometric analysis of effects of vilon and epithalon on functional morphology of radiosensitive organs.

Studies of the effects of vilon and epithalon on functional morphology of the thymus, spleen, and duodenum in intact rats and rats exposed to single whole-body gamma-irradiation in a dose of 6 Gy showed that vilon stimulated proliferative activity of thymocytes and enhanced proliferative potential of stem cells in the intestine, thus stimulating the postradiation recovery of critical organs. Epithalon decelerated metabolic processes in the duodenal mucosa and suppressed hemopoiesis and lymphopoiesis in the spleen.

Animals↗

Age-specific ultrastructural postradiation changes in intestinal endocrine cells.

Age-specific ultrastructural postradiation changes in the main types of duodenal endocrine cells (apudocytes) were studied in rats 6 and 12 months after single whole-body irradiation in doses of 7 and 7.5 Gy. Ultrastructural disorganization of different severity was detected, which depended on apudocyte type and term postradiation. Degranulation was the basic mechanism of hormone secretion in delayed periods after the exposure.

Age Factors↗

Modulating effects of epithalamin and epithalon on the functional morphology of the spleen in old pinealectomized rats.

Immunohistochemical and morphometric analysis showed that epithalamin and epithalon produced similar effects on the functional morphology of the spleen in pinealectomized rats. Both peptides prevented hyperplasia of lymphoid cells in follicular germinative centers induced by pinealectomy and potentiated the decrease in extramedullary hemopoiesis. These findings confirm the data on functional relationships between the pineal gland and immune system. The effects of epithalamin and epithalon on cell and tissue homeostasis in the spleen of old pinealectomized rats can be regarded as a manifestation of the general regulatory effect of these peptides.

Animals↗

[Apudocytes and mast cells in chronic inflammation of colon: clinicomorphological correlations].

AIM: To study functional morphology of a total population of endocrine cells of colon mucosa, mast and enterochromaffine cells. MATERIALS AND METHODS: Light and electrone microscopy, immunohistochemical methods, morphometry were used to study endocrine and mast cells of the sigmoid colon in inflammation. RESULTS: Changes of functional morphology and size of endocrine and mast cell population as well as apudocytes producing serotonin, melatonin, vasointestinal peptides were stated. Apudocyte and mass cell functional morphology, clinical symptoms and mucosal structural changes correlated. Specificity of some parameters in Chron's disease is shown. CONCLUSION: The results may provide additional criteria in diagnosis of different variants of chronic colitis.

APUD Cells↗

[Melatonin and serotonin in inflammatory colon diseases and colorectal neoplasms].

Patients with inflammatory intestinal diseases and colorectal adenocarcinoma in sigmoid mucosa were examined using light and electron microscopy, immunohistochemical tests, radioimmunoassay and morphometry. Functional morphology of the general population of the endocrine cells and apudocytes producing melatonin and serotonin as well as urine excretion of 6-sulfatoxymelatonin changed in quality and quantity. The parameters showed specificity depending on clinicomorphological variant of colorectal pathology. The findings provide additional criteria in diagnosis and prediction of the course of different types of inflammatory and tumor affections of the colon.

APUD Cells↗

Regulating effect of epithalone on gastric endocrine cells in pinealectomized rats.

Endocrine cells in the stomach of pinealectomized rats after injection of epithalone (pineal gland peptide) were studied by immunohistochemical tests, morphometry, and image analysis microscopic images. A functional relationship was found between the pineal gland and stomach, which is regulated by peptides produced by the pineal gland.

Animals↗

Melatonin and colon carcinogenesis. II. Intestinal melatonin-containing cells and serum melatonin level in rats with 1,2-dimethylhydrazine-induced colon tumors.

Two-month-old outbred female LIO rats were injected weekly with a single dose of 1,2-dimethylhydrazine (DMH; 21 mg/kg of body weight) administered s.c. for 15 consecutive weeks. From the day of the 1st injection of the carcinogen the part of rats were given five days a week during the night time (from 18.00 h to 08.00 h) melatonin dissolved in tap water, 20 mg/l. The experiment was terminated in 6 months after the first injection of the carcinogen. The concentration of melatonin in the serum was estimated by radioimmunoassay in rats exposed to DMH alone or in intact control rats in the morning (between 10.00 and 11.00 hours) and night (between 24.00 and 01.00 hours) time. Number of melatonin-containing cells (M-cells) and their optical density were estimated by immunohistology in normal mucosa of glandular stomach, duodenum, ileum and descending colon of tumor-bearing animals from groups exposed to DMH or DMH+melatonin. It was shown that serum melatonin levels in rats with colon tumors was increased as compared with controls. However there was no diurnal rhythm of serum melatonin of colon tumor-bearing animals as compared to intact controls. The number of M-cells was decreased in all tissues studied in rats with DMH-induced colon tumors in comparison to corresponding controls: by 2.0 times in stomach, by 1.8 time in duodenum, by 1.3 times in ileum, and by 1.8 times in colon. In ileum and colon of rats treated with DMH+melatonin the number of M-cells was similar to control level whereas in stomach and duodenum this number was significantly higher than that in rats treated with DMH alone, but less than in corresponding controls. Relative content of melatonin in enterochromaffin cells of all parts of gastrointestinal tract evaluated as optical density of the cells and was decreased in rats exposed with DMH alone in comparison to the controls and was normalized and similar to the norm level in rats treated with DMH+melatonin. Thus, exogenous melatonin prevent a decrease in numbers of melatonin-containing cells as was observed in gastrointestinal tract (GIT) of rats exposed to DMH. This preventive action of melatonin correlated well with its anticarcinogenic effect.

1,2-Dimethylhydrazine↗

[Effect of cycloferon on dissemination of Lewis lung carcinoma in mice and rhabdomyosarcoma ra-23 in rats].

Tumor growth and proliferative activity of tumor cells were suppressed and the number of pulmonary metastases in C57B16 mice decreased 3.3-fold following seven injections of cycloferon (100 mg/kg body) to induce interferon production. Injections were carried out 1-16 days after subcutaneous transplantation of Lewis lung carcinoma. After mice were immunized with ovine red blood cells, cycloferon administration raised thymus-dependent humoral immune response. After eight injections of cycloferon (50 mg/kg body) into rats, from day of intravenous transplantation of rhabdomyosarcoma RA-23 until day 20, no significant effect on metastasizing into the lung was recorded. However, single injection of cyclophosphamide 50 mg/kg inhibited metastasis formation. The highest suppressor effect was registered with combination cycloferon-cyclophophamide treatment: mean weight of metastasis decreased by half, as compared with treatment with cyclophosphamide alone. Both drugs caused karyotypical abnormalities to occur in metastatic cells. Tumor growth and spreading suppression after cycloferon should be attributed to cytotoxic antitumor action, cell proliferation inhibition and immunomodulating effect.

Acridines↗

[Effect of pineal peptides on neuroendocrine system after pinealectomy].

Removal of the pineal gland leads to structural and functional rearrangement of gastric endocrine cells and thyroid C-cells in albino rats, as was shown by immunohistological methods and morphometry. Injection of pineal peptides epithalone and epithalamine eliminated these changes. Biological activity of epithalone is believed to be higher than that of epithalamine.

APUD Cells↗