Protective effects of postconditioning in transvaginally created pneumoperitoneum.

There are reports of ischemic complications in clinical practice after laparoscopy using pneumoperitoneum. Conditioning has a beneficial effect for various ischemic diseases. This experimental study was designed to evaluate the effects of postconditioning in transvaginally created pneumoperitoneum. Sixty adult female rats, weighing 300±50 g were divided into four equal groups. Pneumoperitoneum was created by CO2 insufflation under a pressure of 10 mmHg. Rats in the first group (sham) were subjected to only sham-operation or gas insufflation. The second group (TV/PP) was subjected to pneumoperitoneum for 60 min followed by 30 min of desufflation. The third group (post-5) was subjected to pneumoperitoneum for 60 min followed by 5 min of desufflation, 5 min of insufflation and again followed by 30 min of desufflation. The fourth group (post-2.5) was subjected to pneumoperitoneum for 60 min followed by 2.5 min of desufflation and 2.5 min of insufflation-repeated in two cycles- and then followed by 30 min of desufflation. The rats were sacrificed, and blood was collected after 30 min, 2 and 6 h from the last desufflation. Levels of oxidative stress markers, malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione (GSH), sulfhydryl groups (SH) and inflammatory cytokine TNF-α, were analyzed. Levels of MDA in the post-5 group were significantly reduced compared to the TV/PP and post-2.5 groups. The level of GSH in TV/PP animals was markedly reduced compared to the Sham, Post-5 and Post-2.5 groups. In addition, levels of SH were increased in the Post-5 group in comparison to the Sham, TV/PP and Post-2.5 groups. No difference in the activity of SOD between the groups was found, and the concentration of TNF-α in TV/PP animals was significantly higher than that in the Sham and postconditioning groups. Overall, the results of the present study indicate that postconditioning can reduce pneumoperitoneum-induced oxidative injury.

Histological and Mechanical Assessment of Decellularized Porcine Biografts, and Its Biological Evaluation following Aortic Implantation during Mid-Term Follow-Up.

AIMS: Prosthetic graft infection frequently requires graft replacement. Among other options, a biological graft could serve as an alternative choice. Decellularization reduces tissue immunogenicity. Our aim was to determine an efficient decellularization method and to evaluate the decellularized porcine biografts' adaptability. METHODS: Four different protocols were implemented to decellularize porcine aortic segments (n = 4). Cell removal effectiveness and matrix structure preservation were histologically examined. Mechanical tests were performed. Decellularized porcine grafts were interpositioned in a porcine aorta. After a 6-month period, implanted samples were removed and evaluated using light and electron microscopy. RESULTS: Histological results showed complete removal of cells and preserved connective tissue fiber structure following decellularization, using sodium dodecyl sulfate and sodium azide. Pressure tests demonstrated similar compliance to fresh vessels. In 9 out of 10 cases, pigs survived the follow-up period. Graft rejection, intimal hyperplasia, reocclusion and/or aneurysm formation were not observed. Presence of host cells and neoendothelialization were microscopically confirmed. CONCLUSIONS: This decellularization protocol enables a cost-effective preparation of biological grafts featuring reduced immunogenicity. The implanted grafts did not degenerate during the 6-month follow-up period, the lack of graft rejection suggests acceptable immunological tolerance, while recipient cells migrate into, proliferate and differentiate, thus creating the possibility for further use as an optional vascular graft.

Comparative immunohistochemical study of tissue integration of macroporous and laminar surgical meshes.

Intraperitoneal surgical mesh implantation is required for laparoscopic ventral hernia repair. Composite meshes are well known in animal models and human practice. The aim of our study is to compare the biological behaviour of two different textured silicone-covered polypropylene meshes. Transmural abdominal wall defect was created in 40 rabbits and treated as follows: In 20 animals a polypropylene mesh with a laminar silicone covering (LSPP) and in the rest a macroporous textured mesh knitted of silicone-impregnated polypropylene filaments (MSPP) was applied. One and three weeks after implantation we evaluated the intraperitoneal adhesion formation of the mesh macroscopically, histologically and immunohistochemically to detect the reactive cells, especially inflammatory, endothelial and mesothelial cells, as well as their proliferative activity, and with Scanning Electron microscopy to visualize the surface of the meshes. The adhesion formation caused by the composites showed no statistical difference after one week although in the three weeks old samples the LSPP adhesion was significantly weaker than that of MSPP. As complications, serome formation in both groups, fistulas, abscesses, and sc. haematoma in the LSPP group were found. Only in MSPP containing tissues was the decrease of Ki-67 positive proliferating cells significant. A significant increase in VEGF expressing cells was observed only in MSPP containing three week old samples, suggesting better regulation of vascular growth in tissues surrounding the implants. In one week old specimens we observed an irregular proliferation of cytokeratin containing mesothelial cells in both group. The intraperitoneal surface of MSPP mesh was covered with neoperitoneum, while it was not regularly seen on LSPP mesh after three week.

[Tissue integration of various silicone-coated polypropylene surgical mesh]. / A különbözo 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.

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.

[A new method for prosthetisation of vascular patients with lower limb amputation: initial experiences with osseointegration technique]. / Alsóvégtag-amputált érbetegek új protetizációs lehetôsége: kezdeti tapasztalataink az osseointegrációs technikával.

INTRODUCTION/AIMS: Prostheses use for lower limb amputees is difficult, while the socket is hard, the prosthesis is heavy. Drawbacks of conventional prosthesis are mainly associated with the socket, therefore osseointegration technique is a promising solution, since it doesn't require a socket. Our aim was to introduce this technique in Hungary and extend indication for vascular patients. METHODS: The method includes two operative and one rehabilitation phases: during first operation a titanium screw is fixed into the femoral bone marrow cavity, this connects to an abutment, which also penetrates the skin, making a direct connection between the femur and the prosthesis during the second intervention. During rehabilitation the patient makes loading exercises and learns to walk with new prosthesis. RESULTS: This method was launched in Hungary in 2005. Two female amputees were operated on initially, their second surgery was performed in 2006 (when titanium screw was applied in the male patients, as well). Incorporation of titanium screw was exquisite, and rehabilitation was successful. One of our male patients died eight months after his first operation due to myocardial infarction. CONCLUSION: Based on our experiences, the osseointegration technique facilitates rehabilitation of vascular patients for prostheses use. Adequate follow-up and stable vascular diseases are not contraindications, although further clinical trials are needed to determine its indication.

[Transvaginal cholecystectomy in animal model: first series in Hungary]. / Transvaginalis cholecystectomia állatmodellen--kezdeti tapasztalataink.

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.