| Abstract: | The angiogenic activity of various neoplastic and control tissues, cells and extracts has been tested on the chorioallantoic membrane of the chick (CAM). The vascular response was assessed macroscopically and also by histological examination. Angiogenesis was induced by a number of neoplastic implants the most potent being derived from Hodgkin's disease, histiocytic lymphoma or glioma tissue. Boiled tumour tissue was ineffective. Lymphocytes extracted from human lymphomas, activated normal peripheral blood lymphocytes and established lymphoid cell lines of neoplastic origin were generally effective in inducing neovascularisation through millipore membranes as were 90,000-100,000 MW fractions of human tumour tissue. In all cases examined histologically a mononuclear cell infiltrate in the CAM mesoderm accompanied a positive vascular response. These results implicate host monocytes in the generation of neovascularisation by neoplastic tissue. |
