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Abstract: Vascular endothelial growth factor-C (VEGF-C) and its receptor, vascular endothelial growth factor receptor-3 (VEGFR-3), have been implicated as important factors in the formation of lymphatic vessels, but its role in osteosarcomas has not yet been fully investigated. This study aims to define the expression of VEGF-C and VEGFR-3 in primary and metastatic osteosarcomas and their relationship to various clinicopathologic parameters. Thirty-three primary osteosarcomas and two pulmonary metastatic samples were immunostained for VEGF-C and VEGFR-3. In addition, VEGF-C and vascular endothelial growth factor-D (VEGF-D) mRNA expression levels in three different human osteosarcoma cell lines and control fibroblasts were evaluated by real-time quantitative polymerase chain reaction (PCR). Both VEGF-C and VEGFR-3 were expressed mainly in the cytoplasm of the tumor cells. Of the 35 patients with osteosarcoma, 16 patients (45.7%) showed strong positive reaction with VEGF-C. Four cases (11.4%) were negative, and 15 cases (42.9%) showed weak immunoreactivity. For VEGFR-3, 12 patients (34.3%) showed strong positive reaction. Fifteen cases (42.9%) were negative, and eight cases (22.8%) showed weak immunoreactivity. A significant, positive correlation (Rs=0.42, p=0.01) was found between the expression of VEGF-C and VEGFR-3 in osteosarcomas. The expression of VEGF-C was significantly associated with the osteoblastic subtype and high histologic grade in osteosarcomas. However, the expression of VEGF-C showed no significant correlation with the presence of metastasis. Expression of VEGFR-3 was not related to any clinicopathologic features analyzed. Two of the three osteosarcoma cell lines tested showed amplification of VEGF-C mRNA compared with control cells. No amplification of VEGF-D was noted in these cell lines. Our data suggest that VEGF-C and its receptor are expressed in osteosarcomas. Although the level of VEGF-C was high, it does not seem to have a direct influence on tumor metastasis in osteosarcomas. [Copyright &y& Elsevier]

Objective: The purpose of this study was to assess the diagnostic performance of CT in the detection of intestinal ischemia associated with small-bowel obstruction using the maximal attenuation of a region of interest (ROI)., Materials and Methods: Abdominal CT scans of 60 patients with small-bowel obstruction were retrospectively reviewed. The reference standard of the clinicopathologic groups was classified into four categories: no bowel necrosis, mucosal-submucosal necrosis, superficial muscle necrosis, and transmural necrosis. The viability of the small bowel on CT was evaluated by visual assessment using five categories (i.e., definitely intestinal ischemia, probably intestinal ischemia, possibly intestinal ischemia, equivocal CT results, and no intestinal ischemia) and by measurement of the maximal attenuation of an ROI at selected obstructed small-bowel loops on contrast-enhanced and unenhanced CT scans. Diagnostic performances were evaluated by one-way analysis of variance and receiver operating characteristic (ROC) curve analysis., Results: The sensitivity, specificity, positive and negative predictive values, and accuracy of visual assessment for intestinal ischemia were 91.7% (33/36), 66.7% (16/24), 80.5% (33/41), 84.2% (16/19), and 81.7% (49/60), respectively. The maximal attenuation of the ROIs on contrast-enhanced CT and the subtraction value between the maximal attenuation on contrast-enhanced CT and that on unenhanced CT scans at selected bowel were significantly different according to clinicopathologic group (p < 0.001). The area under the ROC curve of the maximal attenuation subtraction values between contrast-enhanced and unenhanced CT scans (0.995) was higher than that of visual assessment (0.908) for the detection of intestinal ischemia., Conclusion: The quantification of bowel wall enhancement using the maximal attenuation of an ROI was a reliable and useful method for the diagnosis of intestinal ischemia and showed good correlation with pathology results.