Comparison of Polypropylene Mesh and Expanded Polytetrafluoroethylene Patch for Repair of Abdominal Wall Defects in Rat

BACKGROUND: Large abdominal wall defect resulting from trauma, invasive infection, tumor resection, or other causes continue to be major problems for patients and surgeons. The lack of sufficient tissue may require the insertion of prosthetic materials. This study compares the results of PPM mesh and e-PTFE patch for repairs of abdominal wall defects. METHODS: The anterior abdominal walls of Sprague-Dawley rats, including fascia, muscle, and peritoneum were removed. The defects were repaired with a PPM mesh or an e-PTFE patch. Animals were killed at 1, 2, 6, and 12 weeks after the operation, and the implant were excised along their margins and evaluated for gross and microscopic differences. RESULTS: Histological examination showed that PPM was progressively infiltrated by whorled disorganized collagen fiber, which became densely adherent to the mesh. In contrast, the e-PTFE was infiltrated by fine fibrils of collagen, which progressively penetrated the interstices of the material, binding it firmly to the tissue. One of the most serious complications associated with fascial closure with PPM was the development of visceral adhesions. CONCLUSIONS: e-PTFE patch material has a lower foreign body reaction, a lower infectability, and a lower rate of adhesion formation than PPM mesh.

Differences in Serum CEA Level between Colon and Rectal Cancer

We investigated whether there is differences in serum level of carcinoembryonic antigen (CEA) between patients with colon and rectal cancer. Preoperative serum levels of CEA was determined in 65 patients with colon cancer and in 88 patients with rectal cancer. Cut-off value recommended by manufacturers is 5 ng/ml for CEA. At the recommended cut-off levels for CEA, overall sensitivity of CEA was 43.1 percent for colon and 42.0 percent for rectal cancer. In colon cancer CEA was elevated in 38.4, 46.2, 60 percent of patients with Dukes Stages B, C, and D, respectively. In rectal cancer CEA was elevated in 12.5, 31.6, 44.8, 84.6 percent of patients with Dukes Stages A, B, C, and D, respectively. In Stages B, and C, sensitivity of CEA was higher in colon than in rectal cancer, but the difference was not significant. In Stages D, sensitivity of CEA was higher in rectal cancer than in colon cancer, but the difference was not significant. In overall stages sensitivity of CEA was higher in colon than in rectal cancer, but the difference was not significant. The difference was not significant either in overall or in different stages of colon and rectal cancer.

Expression of p53, bcl-2 Protein in Colorectal Cancer and Its Relationship to Pathologic Factor

PURPOSE: This study was undertaken to evaluate the correlation between p53, bcl-2 expression and pathologic factors stage, anatomic location, histologic grade, gross pattern, lymph node metastasis of the colorectal cancer. METHODS: Analysis were made on archival pathology tissue of 56 patients with colorectal cancer. The oncoproteins were localized using commerically available monoclonal antibodies : DO-7 for, p53 and clone 124 for bcl-2. RESULTS: P53 protein was detected in 53 out of 56(94.6%) adenocarcinomas of the colorectal cancer and the most frequently expressed patterns of immunoreactivity of p53 were strong in intensity in 40 cases(71.4%) and were diffuse in pattern in 39 cases(69.6%). Bcl-2 protein was detected in 34 out of 56(60.7%) adenocarcinomas of the colorectal cancer and the most frequently expressed patterns of immunoreactivity of bcl-2 were weak in intensity in 17 cases(30.3%) and were diffuse in pattern in 16 cases(28.6%). There was no correlation between p53, bcl-2 expression and Dukes' stage, anatomic location ,histologic grade, gross pattern of tumor, lymph node metastasis of the colorectal cancer. CONCLUSION: 53 mutation and bcl-2 expression are frequent event in human colorectal carcinoma as shown in this study, but p53 and bcl-2 protein expression is not significant independent predicator of aggressiveness and progression of colorectal cancers.