Colorectal Neoplasms/blood supply; Endothelial Growth Factors/immunology; Immunization, Passive/methods; Immunoglobulin Variable Region/immunology; Lymphokines/immunology; Neovascularization, Pathologic/therapy; Receptor Protein-Tyrosine Kinases/immunology; Receptors, Growth Factor/immunology; Animals; Colorectal Neoplasms/immunology; Colorectal Neoplasms/therapy; Endothelial Growth Factors/metabolism; Endothelium, Vascular/immunology; Endothelium, Vascular/metabolism; Immunoglobulin Fragments/genetics; Immunoglobulin Fragments/immunology; Immunoglobulin Fragments/metabolism; Immunoglobulin Variable Region/genetics; Immunoglobulin Variable Region/metabolism; Immunohistochemistry; Lymphokines/metabolism; Mice; Mice, Nude; Neovascularization, Pathologic/immunology; Neovascularization, Pathologic/metabolism; Peptide Library; Receptor Protein-Tyrosine Kinases/metabolism; Receptors, Growth Factor/metabolism; Receptors, Vascular Endothelial Growth Factor; Recombinant Proteins/genetics; Recombinant Proteins/immunology; Recombinant Proteins/metabolism; Tissue Distribution; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors; Xenograft Model Antitumor Assays