Cartilage A Tissue That Resists Vascularization

Skeletal development depends on the concomitant stimulation and inhibition of in s itu angiogenesis. Thus, capillaries in the prechondrogenic areas regress to allow cartilage differentiation (10-12), whereas during endochondral bone formation, proliferative cartilage undergoes vascularization and erosion, leading to bone deposition (13,14). The avascular status of resting cartilage could be owing either to absence of proangiogenic molecules or to the overproduction of inhibitors of angiogenesis...

Flt1 and Flk1KDR Tyrosine Kinases

Two VEGF receptor tyrosine kinases (RTKs) have been identified. The Flt-1 (fms-like tyrosine kinase) (80) and kinase domain region (KDR) (81) receptors bind VEGF with high affinity. The murine homolog of KDR, Flk-1 (fetal liver kinase-1), shares 85 sequence identity with human KDR (82). Both Flt-1 and KDR Flk-1 have seven immunoglobulin (Ig)-like domains in the extracellular domain (ECD), a single transmembrane region, and a consensus tyrosine kinase sequence which is interrupted by a...

References

Brem, S., Cotran, R., and Folkman, J. (1972) Tumor angiogenesis a quantitative method for histological grading. J. Natl. Cancer Inst. 48, 347-356. 2. Mlynek, M., van Beunigen, D., Leder, L.-D., and Streffer, C. (1985) Measurement of the grade of vascularisation in histological tumour tissue sections. Br. J. Cancer 52, 945-948. 3. Svrivastava, A., Laidler, P., Davies, R., Horgan, K., and Hughes, L. (1988) Prognostic significance of tumor vascularity in intermediate-thickness (0.76-4.0mm thick)...

Role Of Lactate In Angiogenesis

Crucial evidence in support of this thesis is provided by the role of lactate in tissue repair. Wound spaces are also characterized by increased levels of lactate 5-15 mM 9 . However, hypoxia only partially accounts for this. The excess of lactate is primarily the result of the influx of fibroblasts and macrophages, both of which contain few mitochondria, rely on aerobic glycolysis as their normal source of energy, and, therefore, consume small amounts of oxygen and large amounts of glucose....

Intratumoral Microvascular Density

Intratumoral microvessel density MVD has been extensively studied in a variety of solid tumors and has been reported as a powerful independent prognostic factor in many tumor types 29 . Several clinical reports have suggested a strong correlation between intratumoral MVD and the development of metastases, primary tumor growth, and the expression of certain angiogenic peptides 30 . A variety of methods for assessing MVD have been reported 31 , but the most commonly used is that proposed by...

Disease Models Involving Neovascularization And Squalamine

To determine if squalamine, like the angiostatic steroids previously studied, was effective in disease models involving neovascularization in animals, squalamine was evaluated in two tumor models, the rat 9L glioma allograft and human lung tumor xenografts in mice, and in a neonatal mouse model for corneal neovascularization, which employs hyperoxic exposure 81 . The conditions of this model simulate the ocular condition of retinopathy of prematurity ROP . Although rare, ROP in premature human...