The oxidative effect of prolonged CO2 pneumoperitoneum on renal tissue of rats.

BACKGROUND: Despite its advantages, laparoscopic donor nephrectomy is associated with prolonged operation time, which could potentially increase oxidative stress in the graft. We performed the first experimental, randomized, controlled study with blind assessment of outcome to address this possibility. METHODS: Wistar-Albino rats were randomized into three groups. The animals in the control group were subjected to a sham operation under anesthesia; the animals in the other two groups were subjected to CO(2) pneumoperitoneum (Pp) for 120 and 240 min, respectively. The kidneys were removed at the end of each experiment. The concentrations of protein carbonyl and sulfhydryl (SH) groups and the activities of superoxide dismutase (SOD) were measured in renal tissue samples as markers of oxidative stress. Renal tissue samples were also evaluated histopathologically using light microscopy. RESULTS: Exposure to 120 min of Pp significantly increased the finding of oxidative stress in renal tissue samples, with an increase in protein carbonyl content and a decrease in protein sulfhydryls and tissue (SOD) activities. When exposure to Pp was prolonged from 120 min to 240 min, Pp associated oxidative stress was found to be increased. These changes occurred in the absence of light microscopical evidence of overt tissue damage. CONCLUSIONS: In an experimental model resembling laparoscopic donor nephrectomy, we found that exposure of pneumoperitoneum prolonged from 120 min to 240 min acts as an additive factor with respect to causing increased oxidative stress in renal tissue. Because these effects imply subtle tissue injury that may contribute to the chronic demise of renal grafts obtained laparoscopically, avoiding the use of Pp if possible and keeping operation time less than 120 min during laparoscopic donor nephrectomy appear to be advisable.

Giant intraosseous lipoma of the rib.

Lipoma is defined as a benign tumor consisting of a circumscribed mass of adipose tissue. Intraosseous lipomas represent fewer than 0.08% of all primary bone tumors. We present an unusual case of intraosseous lipoma arising from the left 10th and 11th ribs and extending to the subdiaphragmatic area and abdomen. Lipoma of the rib is an extremely rare disorder presenting diagnostic challenges.

The effect of NG-nitro L-arginine methyl ester on colonic anastomosis after increased intra-abdominal pressure.

BACKGROUND: Intestinal ischemia-reperfusion (I/R) is associated with augmented nitric oxide (NO) production. Increased intra-abdominal pressure (IAP) during surgical pneumoperitoneum (P) facilitates I/R injury. We previously demonstrated decreased strength and healing of colocolic anastomoses after high IAPs. The effect of an NO synthase inhibitor, N (G)-nitro-arginine methyl ester (L: -NAME), on anastomoses realized in colonic tissue exposed to high IAPs was investigated in this study, a randomized, controlled, and experimental study with blind outcome assessment. METHOD: Fifty Wistar-albino rats were randomized to five groups; all underwent colocolic anastomosis. P was maintained for 60 min at IAPs of 14, 20, 25, and 30 mmHg in study groups 1, 2, 3, and 4, respectively; P was preceded by intraperitoneal L: -NAME (2.5 mg/kg) and followed by anastomosis. The control group was not subjected to IAP or L: -NAME. RESULTS: Anastomosis bursting pressure (ABP) values and histopathological findings were determined on the 7th-14th postoperative days. The ABPs of groups 3-4 were significantly lower than the others. Groups 1-2 had results similar to controls. Histopathological findings of the groups were consistent with their ABPs. CONCLUSION: Administration of a 2.5-mg/kg intraperitoneal L: -NAME dose was found to provide a beneficial role, implying a role in impaired anastomotic healing after IAPs of 14 and 20 mmHg.

The effects of chemotherapy on breast cancer tissue in locally advanced breast cancer.

It is well known that chemotherapy induces cytomorphological changes in neoplastic and non-neoplastic tissue. Thirty-one stage III breast-carcinoma patients, treated with both pre-operative chemotherapy and mastectomy, were evaluated to define the effects of systemic chemotherapeutic agents in tumours, non-neoplastic breast tissue, and lymph nodes. Histological changes were compared with those observed in patients who had been treated by surgery alone. Cytoplasmic vacuolization was the most striking change in the tumour cells (59%). Chemotherapy was especially effective in the terminal duct lobular unit in non-neoplastic breast tissue. Lobular atrophy was observed in 20 (65%) cases, and lobular cellular atypia was seen in 16 (52%). The rate of ductal cellular atypia (42%) was not different from the control group. The most important changes seen in the non-neoplastic stromal component were fibrosis and hyalinization. These were found in 31 out of 727 evaluated lymph nodes. In serial sections, metastatic deposits were seen in or around these fibrotic or hyalinized areas. Chemotherapy is widely used in the treatment of early and locally advanced breast carcinomas. Familiarity with chemotherapy induced changes in breast tissue and lymph nodes have considerable importance in the accurate interpretation of these specimens.

Early tissue reactions in the rat bladder wall after contact with three different synthetic mesh materials.

OBJECTIVES: To investigate bladder tissue reactions to three types of implanted mesh material, i.e. polypropylene, polyglactin and polypropylene-polyglactin combined. MATERIALS AND METHODS: Forty-eight adult female Wistar albino rats were randomized to four equal groups, i.e. group 1 (sham-operated controls), group 2 (polypropylene mesh), group 3 (polyglactin mesh) and group 4 (polypropylene-polyglactin mesh). A laparotomy incision was made to access the bladder and fix a 0.5 x 1 cm piece of mesh directly on the bladder wall. Each group was randomly divided into two subgroups of six animals, killed at 7 and 14 days after mesh implantation, respectively, to study mesh and tissue features with time. Bladders were harvested for histological and immunohistochemical investigation. Microvessels that developed around the mesh were detected with the avidin-biotin peroxidase system, using antibody to Factor VIII-related antigen as an endothelial marker. Vessels were counted in the most intensely stained area of one section from each animal's bladder. RESULTS: Compared with the other groups, group 4 had more inflammatory reaction at 7 days but the tissue reactions to all mesh materials were similar at 14 days; the mesh penetrated the bladder muscularis propria at 14 days in all six rats in group 2, in one in group 3, and two in group 4. Group 4 tended to have a greater microvessel density at 14 than at 7 days. In contrast, groups 2 and 3 had lower microvessel densities at 14 than at 7 days. CONCLUSION: The rat bladder wall had a similar early response to all three types of mesh materials. Penetration was more marked with polypropylene mesh than with the other materials. This nonabsorbable material persists in tissue and is currently widely used for clinical applications. These results for penetration suggest that the use of polypropylene mesh risks serious postoperative complications, e.g. urethral tissue erosion.