Microscopes and computers in small-group pathology learning.
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Biomedical subjects
Publications and source records attributed to Fred Bosman.
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Colorectal cancer with microsatellite instability (MSI) may occur sporadically or be inherited in cases of hereditary nonpolyposis colorectal cancer (HNPCC) syndrome. However, there is no consensus as to which patients must be tested and how to test MSI. In this study, MSI was tested by immunohistochemical analysis and by polymerase chain reaction in 148 cases of colorectal cancer, and methylation of the hMLH1 promoter was examined. MSI status was correlated with tumor phenotype. We found that localization, tumor infiltrating lymphocytes, and mucinous differentiation were predictive of high-frequency MSI (MSI-H) colorectal cancer and might be used to select cases for MSI analysis. Immunohistochemical analysis detected most MSI-H colorectal cancer and might constitute the first step in MSI detection. Absence of hMLH1 promoter methylation in MSI-H colorectal cancer could be predictive of hereditary colorectal cancer, and, hence, methylation analysis might constitute the second step in the identification of patients with HNPCC.
OBJECTIVE: This study was conducted to check the feasibility of using small intestine without mucosa as a growing vascular conduit. METHOD: Autologous proximal jejunum without mucosa after treatment with heparin bonding was used as a free inferior vena cava interpositional graft between the renal veins and bifurcation of inferior vena cava in 8 piglets. Intravenous ultrasonography was performed at 1 to 3 months after the operation and at autopsy. RESULTS: One intraoperative death was related to anesthesia. At a mean follow-up of 80 days for the 7 surviving pigs, the weight had increased by 201%, from a mean of 32 kg to a mean of 94 kg. The grafts had increased in length by 128%, from a mean of 2.3 cm at implantation to a mean of 5.1 cm (P <.018) at explantation. In 6 animals the diameter of the graft was equal to that of the adjacent inferior vena cava. At postmortem examination, 6 grafts were patent. The single blocked graft had been patent 1 month after surgery. One graft had extensive septae inside, 2 had minor septae, 2 had microscopic septae, and 2 had no septae at all. Normal appearing adventitia, fibrous tissue, and endothelium (factor VIII-related antigen positive) lined all the grafts. In all 7 grafts, scattered proliferating fibroblasts (MIB1 positive) were observed. CONCLUSIONS: Small intestine without mucosa remodels and acts like a live, growing, layered, endothelialized, nonthrombogenic (after re-endothelialization) vascular conduit in a growing pig. This graft material could have potential as a growing vascular conduit in children.