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VEGF Immunoreactivity (vegf + immunoreactivity)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Vascular endothelial growth factor (VEGF) expression in oral tissues: possible relevance to angiogenesis, tumour progression and field cancerisation

JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 8 2001
J. Carlile
Abstract: The aim of this study was to assess whether vascular endothelial growth factor (VEGF) expression in oral tissues is associated with angiogenesis, disease progression or field cancerisation. Vascularity and VEGF immunoreactivity were quantified in 68 archival specimens including normal oral mucosa (NOM), dysplasia (DYS) and squamous cell carcinoma (SCC). Vascularity increased significantly with disease progression; it was also higher in NOM adjacent to SCC than in NOM from healthy tissue, suggesting an association with field cancerisation. VEGF expression in epithelial cells was evaluated using two antibodies and three indices. VEGF indices and vascularity were not directly correlated. The expression of VEGF was similar in all DYS and NOM specimens, whether or not adjacent to a concurrent lesion. A comparison of SCC with NOM or DYS led to opposite results, depending on the VEGF antibody and index used. We conclude that VEGF expression in the oral mucosa may play a physiological role, but does not appear to be associated with angiogenesis, field cancerisation or transition to dysplasia. Further studies concerned with tumour development require examining specific VEGF isoforms and standardisation of the methodology. [source]

TNF-,,induced NF-,B signaling reverses age-related declines in VEGF induction and angiogenic activity in intervertebral disc tissues

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2009
Tetsuro Ohba
Abstract We previously demonstrated that VEGF and its receptors were expressed in human herniated discs (HD). TNF-, induced VEGF, resulting in neovascularization of disc tissues in a model of HD. The goal of the current research was to investigate the precise role of TNF-,,induced VEGF and the mechanism of angiogenesis in disc tissues. We performed ELISAs, Western blots, and immunohistological examinations to assess the role of TNF-,,induced VEGF using organ disc cultures with wild type, TNF receptor 1-null (TNF-RInull), or TNF receptor 2-null (TNF-RIInull) mice. VEGF induction was inhibited when we used TNF-RInull -derived disc tissues. NF-,B pathway inhibitors also strongly suppressed VEGF induction. Thus, TNF-, induced VEGF expression in disc cells primarily through the NF-,B pathway. In addition, VEGF immunoreactivity was detected predominantly in annulus fibrosus cells and increased after TNF-, stimulation. TNF-, treatment also resulted in CD31 expression on endothelial cells and formation of an anastomosing network. In contrast, angiogenic activity was strongly inhibited in the presence of NF-,B inhibitors or anti-VEGF antibody. Our data show angiogenesis activity in disc tissues is regulated by VEGF and the NF-,B pathway, both of which are induced by TNF-,. The level of angiogenic activity in disc tissues was closely related to aging. Because neovascularization of HD is indispensable for HD resorption, the prognosis of HD and the rate of the resorption process in patients may vary as a function of the patient's age. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:229,235, 2009 [source]

VEGF in 105 pheochromocytomas: enhanced expression correlates with malignant outcome

APMIS, Issue 4 2003
KAISA SALMENKIVI
Pheochromocytomas are rare sympathoadrenal tumors that are highly vascular. Their malignancy is extremely difficult to estimate on the basis of histopathological features. Vascular endothelial growth factor (VEGF) is one of the most important angiogenic factors involved in both tumor growth and metastasis. In our search for new prognostic markers, we investigated the expression of VEGF in normal adrenal gland, in 105 primary pheochromocytomas, and in 6 metastases by using immunohistochemistry and Northern blot analysis. We also calculated the microvessel density of these tumors by staining the endothelial cells with monoclonal CD34 antibody. VEGF messenger ribonucleic acid was found in all pheochromocytomas studied. Immunohistochemically, VEGF was not found in normal adrenal medullary cells. Interestingly, all malignant pheochromocytomas (n=8), regardless of their primary location, had strong or moderate VEGF immunoreactivity, while most benign adrenal pheochromocytomas (26 of 37, 70.3%) were either negative or only weakly positive. The staining was heterogenous in extraadrenal pheochromocytomas as well as in a group of tumors that had histologically suspicious features but had not metastasized, here called borderline tumors (n=29). The microvessel density varied greatly in all of the tumor groups, and no statistical difference was found between these groups. Here we report moderate to strong VEGF expression in malignant pheochromocytomas, and negative or weak expression in benign adrenal pheochromocytomas. Normal medullary cells are immunohistochemically negative. Thus, low VEGF expression in pheochromocytomas favors a benign diagnosis. [source]

Inflammation and angiogenesis in osteoarthritis

ARTHRITIS & RHEUMATISM, Issue 8 2003
L. Haywood
Objective To quantify the relationship between inflammation and angiogenesis in synovial tissue from patients with osteoarthritis (OA). Methods Hematoxylin and eosin staining and histologic grading for inflammation were performed for 104 patients who met the American College of Rheumatology criteria for OA and had undergone total joint replacement or arthroscopy. A purposive sample of synovial specimens obtained from 70 patients was used for further analysis. Vascular endothelium, endothelial cell (EC) proliferating nuclei, macrophages, and vascular endothelial growth factor (VEGF) were detected by immunohistochemical analysis. Angiogenesis (EC proliferation, EC fractional area), macrophage fractional area, and VEGF immunoreactivity were measured using computer-assisted image analysis. Double immunofluorescence histochemical analysis was used to determine the cellular localization of VEGF. Radiographic scores for joint space narrowing and osteophyte formation in the knee were also assessed. Results Synovial tissue samples from 32 (31%) of 104 patients with OA showed severe inflammation; thickened intimal lining and associated lymphoid aggregates were often observed. The EC fractional area, EC proliferation, and VEGF immunoreactivity all increased with increasing histologic inflammation grade and increasing macrophage fractional area. In the synovial intimal lining, VEGF immunoreactivity was localized to macrophages and increased with increasing EC fractional area and angiogenesis. No inflammation or angiogenic indices were significantly correlated with radiographic scores. Conclusion Inflammation and angiogenesis in the synovium are associated with OA. The angiogenic growth factor VEGF generated by the inflamed synovium may promote angiogenesis, thereby contributing to inflammation in OA. [source]