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Experimental Small Bowel Transplantation
Kudla, Michal ; Adamec, Miloš (advisor) ; Kohout, Pavel (referee) ; Hejnal, Jiří (referee)
The small bowel transplantation (SBT) represents reasonable alternative to ultimate total parenteral nutrition of the patient suffering from terminal stage of chronic bowel failure. To date, the small bowel transplantation was not carried out in the Czech Republic. The initial experimental research and gaining experience with transplantations on animal models are inevitable before successful commencement of small bowel transplantation programme. In my dissertation thesis I am in full details describing the surgical technique of small bowel transplantation in rat. In comparison with the published data I have succeed to reach rather similar results of operating time and survival of the experimental animals. In the second part of my experiment I tried to influence the acute rejection of the small bowel graft occurrence by administration of cytostatic agent gemcitabin. The chosen dosage of the remedy did not suppress the rejection. In the third part I am describing the surgical technique of lymphatic vessels reconstruction in SBT rat model, which might lead to improvement of the SBT outcome. The last part of my dissertation thesis is preclinical. I am describing the initial experience with surgical technique of small bowel graft harvesting from cadaverous donor.
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Benefit of assesment of cytokines in inflammatory postoperative complications
Chachkhiani, Ivane ; Gürlich, Robert (advisor) ; Vokurka, Martin (referee) ; Adamec, Miloš (referee)
Infection and the resulting sepsis continue to be important causes of morbidity in surgical patients. Cytokine network causes activation of neutrophils and vascular endothelium with increased upregulation of adhesion molecules, setting at a train of pathogenic inflammatory reactions in the host. Increased concentrations of inflammatory cytokines observed in the initial phase of postoperative complications have a great significance in forecasting a potentially fatal outcome of the disease and can be used for an early diagnosis of systemic complications.Prospective, clinical trial. Levels of cytokines, procalcitonin (PCT), leptin and acute phase proteins (APP) were measured before and after the operation (planned resection of colorectal cancer) and compared with levels in sepsis. Cytokine levels were measured by ELISA method. APP were estimated by nephelometric analysis.PCT was measured by immunoluminometric analysisDuring the first 24 h after the planned resection of colorectal cancer there was a significant increase in serum concentration of interleukin (IL)-6 which declined in next 48 to 72 h. Serum concentration of tumor necrosis factor (TNF)was the highest between 18 to 24 h after the operation. IL-1 had a stable serum concentration without significant elevation. Serum concentration of IL-8 rose after 36...
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Contribution to the Hemodynamic of Vascular Anastomosis
Grus, Tomáš ; Lindner, Jaroslav (advisor) ; Adamec, Miloš (referee) ; Veverková, Lenka (referee)
The primary objective of the research project was the optimization of geometry of the infrainguinal prosthetic bypass in the site of the distal end-to-side anastomosis. Due to the negative influence of hemodynamics, it is most frequently this location, which is responsible for the longterm failure of the graft. Our prospective angiographic study in patients as well as experimental and computational simulations indicate that flow type in the anastomosis and wall shear stress (WSS) in particular are the key factors that determine the location of neointimal hyperplasia and promote its progression. Maximum of such changes was located in the toe, heel, and bottom of the anastomosis, and these clinical findings correspond with the results from the simulations. We carried out several clinical experiments that suggest the importance of the angle of the distal anastomosis of an infrainguinal prosthetic bypass as a key factor in the development (both location and quantity) of neointimal hyperplasia 6 to 24 months following the procedure. The construction of the anastomosis at a more acute angle results in WSS values that are closer to physiological flow. This reduces both mechanical impairment of the endothelial cells and stimulation of the smooth muscle cells. From the researched set of anastomotic angles (25ř, 45ř,...
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Cytokines and adipocytokines in surgically ill patients: the role of fat tissue
Teplan, Vladimír ; Gürlich, Robert (advisor) ; Adamec, Miloš (referee) ; Herget, Jan (referee)
Cytokines and adipocytokines have major effect on post-operative prognosis of patients. In obese patients, we find significantly higher expression of proinflammatory mediators. In first part of our project we focus on cytokine expresion after elective abdominal surgery. Abdominal surgery was choosen as model of stress reaction to organism. Our results show, that proinflammatory cytokine expresion was significantly higher in obese patients and especially early elevation of visfatin could be a new marker in diagnosis of postoperative inflammatory complications. Related publications describe methods, design and results of trials. Second part of our poject is focused on patients after kidney transplanation, considering obesity, type of previous dialysis, early postoperative movement a nutrition. Our results show, that there is higher proinflammatory expresion after kidney transplanation with no effect of previous type of dialysis. On the other side early exercise have positive effect on cytokine expresion and decreases ADMA. Related publicatons describe methods, details and results of trials.
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Intestinal transplantation on an experimental model.
Oliverius, Martin ; Adamec, Miloš (advisor) ; Gürlich, Robert (referee) ; Kala, Zdeněk (referee)
Intestinal transplantation represents a life-saving procedure for patients with an intestinal failure. An experiment on pigs was carried out during the preparation part of a clinical project in the Czech Republic. The main aim of the experiment was to successfully master the transplant surgery technique (i.e. small bowel harvesting, its preservation, followed by the transplantation). Another goal was to decide on the optimal immunosuppressive regime. Immunosuppression was based on tacrolimus monotherapy or its combination with sirolimus. A graft biopsy still remains the most reliable method for the diagnosis of an acute cellular rejection. In an attempt to find a suitable noninvasive humoral marker of the acute cellular rejection, we examined the correlation between plasma citrulin level and the acute rejection. The plasmatic level of proinflamatory and antiinflamatory cytokines was investigated as another potential marker of the rejection. We succeeded in standardizing the technique of intestinal transplantation. Connecting the graft to aorta and inferior vena cava is simpler and safer than connecting it to the portomesenteric vessel bed due to fewer subsequent complications. Both immunosuppressive regimes seem to be equally effective in preventing the acute cellular rejection. Histopathological...
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Current possibilities of influence long-term patency of coronary artery bypass grafts
Skalský, Ivo ; Rohn, Vilém (advisor) ; Adamec, Miloš (referee) ; Němec, Petr (referee)
The main complication of aortocoronary reconstruction with vein grafts is restenosis in the course of time. The aim was to assess the effect of a periadventitial polyester system releasing sirolimus on intimal hyperplasia of autologous grafts. The controlled-release system comprises a polyester mesh coated with a sirolimus-eluting copolymer of L lactic acid and ε-caprolactone system designed to be wrapped around an autologous venous graft during its implantation. In vitro sirolimus release and its effects on smooth muscle and endothelial cells were assessed. In vitro, the copolymer-coated polyester mesh released sirolimus over a period of 6 weeks. Mesh-eluted sirolimus inhibited the growth of smooth muscle and endothelial cells in seven-day in vitro experiments. After seven days of sirolimus release from the mesh, smooth muscle and endothelial cell counts decreased by 29% and 75%, respectively, with the cells maintaining high viability. We implanted v. jugularis ext. into a. carotis communis in rabbits. The vein graft was either intact, or was wrapped with a pure polyester mesh, or with a sirolimus-releasing mesh. Three and six weeks after surgery, the veins were subjected to standard histological staining and the thicknesses of the tunica intima, the media and the intima-media complex were...
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Cytokines and adipocytokines in surgically ill patients: the role of fat tissue
Teplan, Vladimír ; Gürlich, Robert (advisor) ; Adamec, Miloš (referee) ; Herget, Jan (referee)
Cytokines and adipocytokines have major effect on post-operative prognosis of patients. In obese patients, we find significantly higher expression of proinflammatory mediators. In first part of our project we focus on cytokine expresion after elective abdominal surgery. Abdominal surgery was choosen as model of stress reaction to organism. Our results show, that proinflammatory cytokine expresion was significantly higher in obese patients and especially early elevation of visfatin could be a new marker in diagnosis of postoperative inflammatory complications. Related publications describe methods, design and results of trials. Second part of our poject is focused on patients after kidney transplanation, considering obesity, type of previous dialysis, early postoperative movement a nutrition. Our results show, that there is higher proinflammatory expresion after kidney transplanation with no effect of previous type of dialysis. On the other side early exercise have positive effect on cytokine expresion and decreases ADMA. Related publicatons describe methods, details and results of trials.
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Current possibilities of influence long-term patency of coronary artery bypass grafts
Skalský, Ivo ; Rohn, Vilém (advisor) ; Adamec, Miloš (referee) ; Němec, Petr (referee)
The main complication of aortocoronary reconstruction with vein grafts is restenosis in the course of time. The aim was to assess the effect of a periadventitial polyester system releasing sirolimus on intimal hyperplasia of autologous grafts. The controlled-release system comprises a polyester mesh coated with a sirolimus-eluting copolymer of L lactic acid and ε-caprolactone system designed to be wrapped around an autologous venous graft during its implantation. In vitro sirolimus release and its effects on smooth muscle and endothelial cells were assessed. In vitro, the copolymer-coated polyester mesh released sirolimus over a period of 6 weeks. Mesh-eluted sirolimus inhibited the growth of smooth muscle and endothelial cells in seven-day in vitro experiments. After seven days of sirolimus release from the mesh, smooth muscle and endothelial cell counts decreased by 29% and 75%, respectively, with the cells maintaining high viability. We implanted v. jugularis ext. into a. carotis communis in rabbits. The vein graft was either intact, or was wrapped with a pure polyester mesh, or with a sirolimus-releasing mesh. Three and six weeks after surgery, the veins were subjected to standard histological staining and the thicknesses of the tunica intima, the media and the intima-media complex were...
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Posttransplant function of ischemically impaired organs (pancreas, kidney, islets) preserved by perfluorocarbon (PFC)
Marada, Tomáš ; Adamec, Miloš (advisor) ; Špatenka, Jaroslav (referee) ; Kříž, Jan (referee)
(English) Perfluorocarbons (PFC) are hydrocarbons in which some or all of the hydrogen atoms are replaced with fluorine. PFC have a very high capacity for dissolving oxygen. They are chemically and biologically inert. The most successful clinical application of PFC is the "two-layer method" for pancreas preservation before islet isolation. The two-layer organ preservation method (TLM) is based on oxygenated perfluorocarbon overlaid with University of Wisconsin (UW) solution. In experiment it has been successfully used for heart and intestine transplantation. We tested whether this technique would prevent tissue damage and improve results of kidney, pancreas and islets of Langerhans transplantation with prolonged ischemia time in an experimental model of syngenic rats. In kidney and islets of Langerhanse transplantation model we used TLM preservation method. In pancreas transplantation model we used perfluorohexyloctane (PFH) as a new generation of less lipophilic PFC. 1. Kidneys were stored for 24 hours either in UW solution (n = 16), with TLM (n = 16) or transplanted immediately (control group, n = 12). In half of the animals, survival was observed and in the other animals grafts were procured for semiquantitative histological scoring and TUNEL apoptosis assessment 24 h after transplantation....
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Intestinal transplantation on an experimental model.
Oliverius, Martin ; Adamec, Miloš (advisor) ; Gürlich, Robert (referee) ; Kala, Zdeněk (referee)
Intestinal transplantation represents a life-saving procedure for patients with an intestinal failure. An experiment on pigs was carried out during the preparation part of a clinical project in the Czech Republic. The main aim of the experiment was to successfully master the transplant surgery technique (i.e. small bowel harvesting, its preservation, followed by the transplantation). Another goal was to decide on the optimal immunosuppressive regime. Immunosuppression was based on tacrolimus monotherapy or its combination with sirolimus. A graft biopsy still remains the most reliable method for the diagnosis of an acute cellular rejection. In an attempt to find a suitable noninvasive humoral marker of the acute cellular rejection, we examined the correlation between plasma citrulin level and the acute rejection. The plasmatic level of proinflamatory and antiinflamatory cytokines was investigated as another potential marker of the rejection. We succeeded in standardizing the technique of intestinal transplantation. Connecting the graft to aorta and inferior vena cava is simpler and safer than connecting it to the portomesenteric vessel bed due to fewer subsequent complications. Both immunosuppressive regimes seem to be equally effective in preventing the acute cellular rejection. Histopathological...
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