Features of Ductular Reaction in Rats with Extrahepatic Cholestasis.

Ductular reaction develops during liver regeneration, fibrosis, and carcinogenesis. However, the types, stages of formation, and topography of ductular profiles in various pathologies remain insufficiently studied. Using the model of common bile duct occlusion, we showed that the number and topography of ductular profiles are closely related to the duration of biliary obstruction. The ductular profiles can be located inside the portal tract, along the existing bile ducts, and/or intramurally, around the portal vein, periportally, inside the lobules, in the portocaval fibrous connections, in the adventitia of the hepatic veins, in the septs connecting the portal tracts, and also in the "portal plate" of the liver. The ductular profiles can be formed as a result of expansion of existing bile ducts, cholangiocyte proliferation, as well as transdifferentiation of hepatocytes and activation of mesenchymal stem cells.

RELATIONSHIP BETWEEN ORAL SQUAMOUS CELL CARCINOMA AND IMPLANTS (REVIEW).

In this review, we have discussed the relationships between oral squamous cell carcinoma (OSCC) and dental implants. In the last decade, dental implants have been widely used for the treatment of complete or partial edentulism. Despite the fact that they have seen incredible success and the use of dental implants increases, concerns over safety and efficiency is rising as well. The literature analysis has shown that the number of reported cases when the OSCC development is associated with peri implantitis is gradually increasing. The possibility of squamous cell carcinoma development must be considered when evaluating the peri-implantitis. We highly recommend periodic oral and radiographic examination after the implant placement. The patients with peri-implantitis that do not respond to conventional treatment methods, and the patients who have a severe or rapid progression of peri-implantitis require biopsy. The histopathological examination will aid with the differential diagnosis between peri-implantitis and OSCC, and hence, provide the correct diagnosis.

INFLUENCE OF TESTOSTERONE ON MORPHOLOGICAL CHANGES IN PANCREATIC ISLETS AND LIVER TISSUE OF RATS WITH ALLOXAN-INDUCED DIABETES.

The role of exogenous testosterone (methyltrienolone) in the repair of damaged pancreatic islet and liver cells during alloxan diabetes was studied. Modeling of diabetes was performed through single intraperitoneal injection of Alloxan, with the dose 2 mg per 10 g of body weight. Pancreatic and liver tissues were investigated microscopically using 3-4 µm slices embedded in paraffin and stained with hematoxylin and eosin. Software Adobe Photoshop was used to measure the areas of pancreatic islets as well as areas of necrotic foci in these islets of animals with Alloxan-induced experimental diabetes. The degree of liver damage was assessed by a 5-score "visual scale". The animals with diabetes revealed degenerative changes of pancreatic islets and liver tissue, the intensity of which correlates with the time-period passed since diabetic modeling. These changes correspond to the metabolic abnormalities described for various experimental models or clinical cases of diabetes. The study revealed that treatment of Alloxan-induced diabetes with testosterone (methyltrienolone) restores not only the biochemical disorders (as previously described) but also supports to reverse the pathological changes in pancreatic and liver tissues.

BILIARY ATRESIA: CURRENT CONCEPTS AND FUTURE PROSPECTS (REVIEW).

Treatment of biliary atresia is a major challenge in pediatric surgery. Early diagnosis and availability of Kasai procedure with its modern modifications improve outcome of biliary atresia treatment. But Kasai procedure does not fully restore anatomical integrity of biliary tract, because Oddi sphincter is not included in reconstructed system. Constant reflux of intestinal content into the biliary tree is a cause of recurrent cholangitis and change in biliary epithelium that, which is a predisposing factor for cholangiocarcinoma. Various methods have been developed to improve Kasai procedure and prevent the reflux (anti-reflux valve, different enteric conduits, etc.). Many authors used biological grafts made from artery, vein, appendix, urether as well as synthetic materials to restore hepaticocholedochus. Although, neither of these methods were implemented in clinical practice. Nowadays, huge attention is paid to organ and tissue bioengineering. Present advances of tissue bioengineering may assist to create bile duct equivalent, which can be used to restore biliary tract in patients with biliary atresia.

Correction of Hormonal and Metabolic Disorders in Male Rats with Developing Experimental Diabetes.

Synthetic radioinert androgen methyltrienolone administered daily for 2 weeks to male rats with severe diabetes led to a sharp increase in blood testosterone and was accompanied by reduction in glucose level due to an increase in tissue sensitivity to insulin. Normalization of plasma testosterone concentration contributed to saturation of active androgen receptors in the myocardium with testosterone; the number of free receptors decreased by 1.8 times. Testosterone that diminishes the catabolic effects of glucocorticoids improved the state of the myocardium, which was confirmed by activation of DNA and RNA synthesis.

Correction of diabetes mellitus by transplanting minimal mass of syngeneic islets into vascularized small intestinal segment.

Transplantation of mature islets into portal vein has been most effective thus far, although attrition of transplanted islets constitutes a major limitation, and alternative approaches are required. We analyzed the mechanisms by which islets engrafted, vascularized and functioned over the long term in the small intestinal submucosa. To determine engraftment, survival and function, 350 syngenic islets were transplanted into either intestinal segments or portal vein of diabetic rats. Islet reorganization, vascularization and function were analyzed by histological analysis, RT-PCR analysis as well as glycemic control over up to 1 year. Transplantation of syngeneic islets in marginal numbers successfully restored normoglycemia in diabetic rats. Transplantation of semi-pure islet preparation did not impair their engraftment, vascularization and function. Islets were morphologically intact and expressed insulin as well as glucagon over the year. Expression of angiogenic genes permitted revascularization of transplanted islets. We identified the expression of transcription factors required for maintenance of beta cells. These studies demonstrated that marginal mass of transplanted islets was sufficient to restore euglycemia in streptozotocin-treated rats. These superior results were obtained despite use of an impure preparation of islets in animals with small intestinal segment. Our findings will help advance new horizons for cell therapy in patients with diabetes.

[Modulating effects of androgens on development adaptive-compensatory processes in organism of experimental animals-males].

The purpose of research is the definition of androgens role and myocardial androgen receptors and sex steroids in males under metabolic and hormonal "stress" induced by the experimental diabetes. Research was carried out on 60 rats-males, mass 180,0-200,0 g. The diabetes reproduced by single injection of alloxan (200mg/kg). Androgen receptors were revealed by the radiometric and radioautography methods. The content of glucose, immunoreactive insulin, testosteron, estradiol, corticosteron and somatotropin were defined in animals blood plasma. On the early terms of alloxan diabetes estradiol concentration increase against a background of testosteron decrease which causes the "feminization" of the sexual hormonal balance. On the other side the increase of androgen receptors expression by cardiomyocytes causes the intensification of myocardium tissue physiologic ability to androgens perception positively influencing on the metabolism. Consequently, androgens provoke stimulating effect on the myocard metabolism in males at early stages of the experimental diabetes.

[Difference between frequency of estrogen receptors distribution in the male and female rats myocardium].

The large number of reference data is proving the positive influence of exogenous hormones on the management of climacteric and dishormonal cardiomyopathies. However, the literary data concerning the influence of estrogens on the cardio-vascular system are quite controversial. For instance there is no certain opinion in the literature concerning influence of estrogens on the cardiovascular system of males, undergoing estrogen therapy due to prostate cancer. There has to be a correlation between functional condition of the heart and estrogens, that is why we do consider actual to study the distribution of estrogen receptors into the myocardium and their role in the rats heart defense in case of pituitrine and adrenaline influence. The experiments were carried out on the 40 white laboratory rats, both sexes, weighting 180-200 g. The radioactive moxestrol (spec. activity 87 c/mmol) has been administered intraperitoneally at 0, 25 mg/100g body weight to the experimental animals. The tissue pieces have been taken from the different areas of the heart (auricles and ventricles). The autoradiography both of normal and preconditioned by pituitrine and adrenaline tissue semi thin specimens has been performed. The tissue analysis has shown that total number of estrogen sensitive cells into myocardium in all areas of heart of the rats is persistently increasing in case of preconditioning by pituitrine and adrenaline comparing with intact animals. Analyzing increased number of estrogen sensitive cells in male and female rats, we suppose that during the critical condition of heart significant quantity of endogenous estrogen cells in females are used in heart auricles, and in contrary less - in ventricles. As to male rats the more quantity of endogenous estrogen is used in ventricles and less in auricles. Taking in account all of above mentioned we can conclude that estrogens certainly play a protective role in the heart of females.

[Surgical treatment of gunshot wounds to the colon]. / Khirurgicheskoe lechenie ognestrel'nykh ranenii obodochnoi kishki.

An analysis of treatment of 76 patients with gunshot wounds of the colon was made as well as of the causes of the development of pyo-inflammatory complications. The morphological alterations of the intestine wall were studied in 22 patients at different distance from the wound at the light optical and electron microscopic levels. A conclusion is made that resection of the intestine with colostomy is necessary with regard to the zone of contusion. The formation of the colostomy should be performed by the proposed method which makes the restorative operation easier. Using these methods allowed the number of intraabdominal inflammatory operations to be reduced from 46.7% to 6.5% and lethality from 17.7% to 6.5%.