Comparison of genetic alterations in neuroendocrine tumors: frequent loss of chromosome 18 in ileal carcinoid tumors.

Carcinoid tumors and pancreatic endocrine tumors are uncommon neuroendocrine neoplasms, and their genetic alterations are not well characterized. These tumors have site-specific differences in neuroendocrine characteristics, clinical course and genetic alterations. We compared clinicopathological features and loss of heterozygosity of chromosomes 11q, 16q and 18, and BRAF gene mutations in 47 patients with neuroendocrine tumors including 16 with pancreatic endocrine tumors, 15 with nonileal carcinoid tumors and 16 with ileal carcinoid tumors.

Composite tissue allotransplantation in chimeric hosts part II. A clinically relevant protocol to induce tolerance in a rat model.

Background: We and others have shown that mixed allogeneic chimerism induces donor-specific tolerance to composite tissue allografts across major histocompatibility complex barriers without the need for immunosuppression. However, a delay period between bone marrow transplantation and limb allotransplantation is required, making such protocols impractical for clinical application. This study eliminates this delay period in a rat hind limb allotransplantation model by performing mixed allogeneic chimerism induction and transplantation "simultaneously.