Impact of hepatic rearterialization on reperfusion injury and outcome after mouse liver transplantation.

BACKGROUND: Nonarterialized mouse liver transplantation is a well-established model for immunologic studies on rejection and tolerance mechanisms. However, the importance of graft arterialization has-in contrast to rat liver transplantation-not been thoroughly examined in the mouse model. The aim of the current study was to investigate the impact of arterial reconstruction on long-term graft survival, histologic alterations, ischemic liver damage, and early immunologic activation pathways. METHODS AND RESULTS: All recipients of arterialized (n=6) and nonarterialized (n=8) syngeneic liver grafts survived indefinitely. There were no differences in their histologic architecture, including no evidence of bile duct proliferation, periductal fibrosis, or alterations in serum transaminases, in long-term survivors from either group. Twenty-four hours after syngeneic liver transplantation, aspartate aminotransferase and alanine aminotransferase levels were increased to an equivalent extent in both groups, in agreement with early reperfusion injury and solitary traumatic injuries as assessed histologically (n=3 per group). Visualized by immunohistochemistry, intercellular adhesion molecule-1 expression was increased on sinusoidal and hepatic vein endothelium at both 1 and 100 days after transplantation, in both arterialized and nonarterialized grafts. Messenger RNA for interleukin-1, interferon-gamma, and tumor necrosis factor-alpha were measured by real-time polymerase chain reaction 24 hr after transplantation. No significant changes in the expression of cytokine mRNA levels were observed. CONCLUSIONS: Arterialization of mouse liver grafts does not appear to have a major impact on survival rate or the degree of immunologic activation. Therefore, the value of arterial reconstruction in mouse liver transplantation for experimental investigations is negligible.

Intraoperative management of cystic meningiomas.

Cystic meningiomas are uncommon tumors that are easily confused with metastatic or glial tumors with cystic components. We report on our experience of intraoperative findings and management of peritumoral cyst wall and cyst fluid in cystic meningiomas. We reviewed all the meningiomas operated on at our department in a 3 1/2-year period (January 1998 to June 2001). Pathological and intraoperative findings of cystic meningiomas compared to noncystic meningiomas are examined. There were 111 cases of intracranial meningiomas operated on, including seven cystic meningiomas (6.3%). In six cases, we found peritumoral cyst configurations. The tumor locations of cystic meningiomas were the cerebral convexity and sphenoid ridge. One peritumoral cyst formation had meningioma cells in the cyst wall. Cytologic examination of the cystic fluid displayed the presence of meningiothelial cells in one case. In one case, intraoperative findings and pathological examination provided the diagnosis of two differently located meningiomas in one cyst configuration, its walls lined by clear arachnoid. Four of the seven cases had peritumoral cystic meningiomas of the atypical type according to the WHO classification. One case with intratumoral cyst configuration was associated with the anaplastic type (WHO degrees 3). Intraoperative biopsies and histopathological studies of the cyst wall are recommended in peritumoral cystic meningiomas. Our observations suggest that cystic meningiomas have the potential to spread through cystic fluid to the cystic wall in peritumoral cyst configuration. The follow-up intervals should be short in cystic meningiomas.