Szaniszló Jávor

Examination of Protective Effect of Ischemic Postconditioning After Small Bowel Autotransplantation

Ischemia/reperfusion (I/R) injury is a serious condition that results from some surgical procedures, including intestinal transplantation. Ischemic postconditioning is defined as brief periods of reperfusion alternating with reocclusion applied during the early minutes after reperfusion. The objective of this study was to investigate the effect of ischemic postconditioning before small bowel autotransplantation. Total orthotopic intestinal autotransplantation was performed in 30 white domestic pigs. Grafts were stored in cold University of Wisconsin solution for 1, 3, or 6 hours. Duration of reperfusion was 3 hours in all grafts. Before reperfusion, the intestine was postconditioned via 3 cycles of ischemia for 30 seconds and reperfusion for 30 seconds (ischemic postconditioning protocol). Tissue from the small intestine was obtained after laparotomy (control group) and at the end of reperfusion periods. To monitor oxidative stress, tissue concentrations of malondialdehyde and reduced glutathione, and activity of superoxide dismutase were determined at spectrophotometry. Tissue damage on sections stained with hematoxylin- eosin was evaluated using a quantitative method (Scion Image software; Scion Corp, Frederick, Maryland). Our results demonstrated that ischemic postconditioning significantly decreased the reperfusion-ended lipid peroxidation value (mean +/- SEM, 142.0 +/- 7.1 micromol/g vs 125.0 +/- 2.1 micromol/g; P < .05). Moreover, the capacity and activity of endogenous antioxidant protective systems (glutathione 789+/-8.0 micromol/g vs 934 +/- 5.7 micromol/g, and superoxide dismutase 110 +/- 9 IU/g vs 126 +/- 4 IU/g; P < .05) remained higher in the ischemic postconditioning groups compared with tissues without ischemic postconditioning. At quantitative analysis, tissue injury was increased by the duration of cold preservation. The greatest injury was observed in the mucosal and submucosal layers and in the depth of crypts after 6 hours of preservation. Ischemic postconditioning significantly decreased intestinal wall injury in each group (P < .05). It was concluded that ischemic postconditioning before reperfusion mitigated oxidative stress and histologic damage during small bowel autotransplantation.

Efficacy of different hemostatic devices for severe liver bleeding: a randomized controlled animal study.

Background. Correct hemostasis in liver surgery is hard to achieve because of the oozing bleeding. The aim of this study was to compare the potential benefits of a new compress to the 2 commercial hemostatic compresses. Methods. Collagen- and cellulose-based hemostatics were investigated. A standardized resection was treated by applying different hemostatics in a randomized order, and bleeding times were measured. Macroscopic evaluation of the liver and tissue sampling for histological investigations were carried out after 21 days. Results . The bleeding times of bovine collagen (BoCo), protein-coated equine collagen (PECo), and oxidized cellulose (OxCe) were 140 ± 88, 243 ± 140 (P = .005 vs BoCo), and 352 ± 70 s (P < .001 vs BoCo), respectively. Microscopic evaluation of the PECo presented fibrosis and significant inflammation in the implantation zone, whereas BoCo and OxCe caused only fibrosis in the wound area. Conclusion. BoCo showed significantly better hemostatic effect than PECo and OxCe.

TIP47 confers resistance to taxol-induced cell death by preventing the nuclear translocation of AIF and Endonuclease G

Tail-interacting protein (TIP47, also named PP17) has been implicated in lipid droplet metabolism and in the development of late endosomes, to date however, no data about its possible role in regulating cell death processes has been available. Here, we provide evidence for the role of TIP47 in the regulation of mitochondrial membrane stability and cell death. Overexpression of TIP47 protected NIH3T3 cells from taxol-induced cell death, while suppression of TIP47 by siRNA facilitated cell death. TIP47, but not its truncated form, t-TIP47, decreased taxol-induced cell death as determined by propidium iodide and fluorescent Annexin V staining. Recombinant TIP47, but not t-TIP47, partially prevented taxol-induced depolarization of mitochondria in vitro. Overexpression of TIP47, but not its truncated form, prevented the taxol-induced nuclear and cytoplasmic translocation of AIF and Endonuclease G, as well as the taxol-induced depolarization of mitochondria in NIH3T3 cells. Furthermore, overexpression of TIP47 facilitated Bcl-2 expression and suppressed Bax expression in taxol-treated cells. These data show that besides its previously known functions, TIP47 is involved in the regulation of mitochondria-related cell death by directly stabilizing the mitochondrial membrane system and by favorably affecting the expression of Bcl-2 homologues. Since TIP47 is overexpressed in certain tumors, it is possible that TIP47 contributes to the development of cytostatic resistance.

Transvaginalis cholecystectomia állatmodellen – kezdeti tapasztalatainkr

INTRODUCTION The Natural Orifice Transluminal Endoscopic Surgery (NOTES) is the newest trend in minimally invasive surgery. Based on clinical experiences, transvaginal cholecystectomy causes less pain and operative stress, requires shorter hospitalization and allows patients to return quicker to normal activity. MATERIALS AND METHODS A transvaginal cholecystectomy was carried out using hybrid technique in animal model first time in Hungary. A 5 mm umbilical trocar was used for preparation of cystic artery and duct, clip application and gallbladder dissection. A transvaginally inserted 10 mm trocar was used for laparoscopic camera to follow the procedure. Gallbladder was fixed and secured with a special curved instrument inserted also transvaginally during the procedure. At the end of procedure the gallbladder was removed transvaginally. RESULTS Six transvaginal cholecystectomies was performed on pigs. The mean time of operations was 78 min (40-145 minutes). During the operations and the follow up period (3 months) no complications and mortality was detected. CONCLUSIONS According to our experiences both procedures can be safely carried out on animal model, but further refinement of devices is necessary.

A különböző szilikonbevonatú polipropilén hálók szöveti integrációja

INTRODUCTION/AIM Laparoscopic ventral hernia repair requires a surgical mesh implanted in intraperitoneal position. The combined, double layer meshes are promising in animal models as well as in human practice. The aim of this study was to compare the biological behaviour of two different textured silicone covered polypropylene mesh. MATERIALS AND METHODS 3 × 4 cm big full thickness defect of the abdominal wall was created in New Zealand White rabbits. The defect was covered in 20 animals with a polypropylene mesh with laminar silicone layer on the visceral surface (LSPP), while the remaining 20 cases the defects were covered with a macroporous textured silicone impregnated polypropylene mesh (MSPP). Intraperitoneal adhesion formation and tissue ingrowth in the meshes were investigated. Immunohistochemistry was used to detect proliferation activity (Ki-67), neovascularization (VEGF), and to visualize mesothelial layer (CK) over the mesh. Scanning electron microscopy was used to investigate the visceral surface of the meshes. RESULTS While intraperitoneal adhesion formation showed no difference after 1 week, LSPP mesh induced significantly less adhesions after 21 days. The Ki-67 positivity was significantly lower and the number of the VEGF positive cells increased with time in the MSPP group, this was missing in the LSPP group. The thin neoperitoneum layer was detected over MSPP mesh only with CK antibody. CONCLUSION The material and texture of the mesh are responsible for tissular incorporation which is in accordance with the generated foreign body reaction.

Preconditioning is a method that may reduce the negative side-effect of pneumoperitoneum

Abstract Increased intra-abdominal pressure during laparoscopy leads to hypoxia due to reduced blood flow. Aim of our study was to investigate whether preconditioning can reduce this negative effect of the pneumoperitoneum. Fifty female Wistar rats were used, divided into 5 groups. I: Sham operation (Sham), II: conventional pneumoperitoneum (PP), III: transvaginal pneumoperitoneum (TV), IV: preconditioning for 2.5 minutes in two cycles (Pre 2.5), V: preconditioning for 5 minutes (Pre 5). Malondialdehyde (MDA), reduced glutathione (GSH), sulfhydrylgroup (SH-) concentrations, superoxide-dismutase (SOD) and mieloperoxidase (MPO) activity, and anti-apoptotic pathway marker p-AKT level and inflammatory cytokine TNF-α were measured. SOD activity and GSH concentration were decreased in PP and TV groups comparing to Sham and preconditioning groups. MPO activity was decreased also in PP and TV groups comparing to the Sham group but in the preconditioning groups it has remained high. MDA concentration in plasma was...

A különböző szilikonbevonatú polipropilén hálók szöveti integrációja@@@Tissular incorporation of different silicone covered polypropylene meshes is distinct

INTRODUCTION/AIM Laparoscopic ventral hernia repair requires a surgical mesh implanted in intraperitoneal position. The combined, double layer meshes are promising in animal models as well as in human practice. The aim of this study was to compare the biological behaviour of two different textured silicone covered polypropylene mesh. MATERIALS AND METHODS 3 × 4 cm big full thickness defect of the abdominal wall was created in New Zealand White rabbits. The defect was covered in 20 animals with a polypropylene mesh with laminar silicone layer on the visceral surface (LSPP), while the remaining 20 cases the defects were covered with a macroporous textured silicone impregnated polypropylene mesh (MSPP). Intraperitoneal adhesion formation and tissue ingrowth in the meshes were investigated. Immunohistochemistry was used to detect proliferation activity (Ki-67), neovascularization (VEGF), and to visualize mesothelial layer (CK) over the mesh. Scanning electron microscopy was used to investigate the visceral surface of the meshes. RESULTS While intraperitoneal adhesion formation showed no difference after 1 week, LSPP mesh induced significantly less adhesions after 21 days. The Ki-67 positivity was significantly lower and the number of the VEGF positive cells increased with time in the MSPP group, this was missing in the LSPP group. The thin neoperitoneum layer was detected over MSPP mesh only with CK antibody. CONCLUSION The material and texture of the mesh are responsible for tissular incorporation which is in accordance with the generated foreign body reaction.

Investigation of the Oxidative Stress, the Altered Function of Platelets and Neutrophils, in thePatients with Peripheral Arterial Disease

Ischemia reperfusion injury (I/R) is a relevant problem in case of myocardial infarction (Moens AL, Claeys MJ et al. 2005.), stroke, (Kato H and Kogure K 1999), coronary bypass surgery, (Bakkaloglu C, and Soyagir B, 2006), under thrombolysis, (Krumholz HM and Goldberger 2006), revascularization surgery of lower limb (Arato et al 2006., Laird IR 2003), balloon angioplasty (Weissand A.G. and Zahger AT 1999) and in every cases, when the physiological blood flow in the occluded vessels are restored (Falkensammer J and Oldenburg WA 2006), (Ferencz A et al 2004). Vessel closure and hypoxia can be caused by embolism (thrombus, tumour, fat, foreign body) stenotic arteriopathy, arterial spasm, compression, arterial thrombus, trauma, etc. During the exclusion of a segment of the vessels from the circulation, ischemia and acidosis appeared in the surrounding tissues. In case of the heart, when oxygen supply is inadequate, the respiration shift from aerobic fatty acid consumption and metabolism to anaerobic glycolysis, resulting in a reduced ATP production. The results of hypoxia in the metabolically active tissues (cardiac, skeletal muscle and neuronal tissues) are more profound than in other cell types. The cells are exposed to hypoxia try to adapt to the absence of oxygen, by switching their metabolism from aerobic to anaerobic. Finally this strategy leads to tissue damages and loss of cells too, as it can be seen in acute or chronic occlusive diseases, as well. The measures of the tissue injuries depend on the duration of hypoxia, the mass of tissues are involved, the ATP requirement of the cell types and the blood pressure of the patients. Under hypoxic condition the generations of reactive oxygen species (ROS), such as O2.-, H2O2, are increased. During normoxyc, physiological condition mitochondria generate low level of ROS by the respiratory chain. These are managed by natural antioxidants, such as manganese superoxid dismutase (SOD) in the mitochondria, or copper-zinc SOD in the inter-membrane space in the mitochondria, and in the cytosol, making the dismutation of superoxide anion