Interaction of stromal and microvascular components in keratocystic odontogenic tumors.

OBJECTIVE: Little is known about the interaction of stromal components in odontogenic tumors. Thus, the aim of this study was to investigate mast cells (MCs), myofibroblasts, macrophages, and their possible association with angiogenesis and lymphangiogenesis in keratocystic odontogenic tumors (KCOTs). MATERIAL AND METHODS: Thirty cases of KCOTs were included and analyzed by immunohistochemistry for mast cell tryptase, α-SMA, CD34, CD163, and D240. For comparative purpose, 15 radicular cysts (CRs) and 7 pericoronal follicles (PFs) were included. RESULTS: There was an increase in MCs for RCs and this difference was significant when they were compared to KCOTS and PFs. A significant increase in the density of MFs was observed for KCOTs when compared to RCs and PFs (P = 0.00). No significant difference in CD163-positive macrophages (P = 0.084) and CD34-positive vessels (P = 0.244) densities was observed between KCOTs, RCs, and PFs, although KCOTs showed a higher density of all proteins. Significant difference in lymphatic vessel density was observed for KCOTs when compared to RCs and PFs (P = 0.00). Positive correlation was observed between mast cell tryptase and CD34 in KCOTs (P = 0.025). CONCLUSIONS: A significant interaction between the MC population and CD34-positive vessels in KCOTs supported the hypothesis that MCs and blood vessels contribute to the stromal scaffold of KCOT.

Immunohistochemical expression of vascular endothelial growth factor and matrix metalloproteinase-9 in radicular and residual radicular cysts

OBJECTIVE: This study assessed and compared the immunoexpression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) in radicular cysts (RCs) and residual radicular cysts (RRCs), relating them to the angiogenic index and the intensity of the inflammatory infiltrate. MATERIAL AND METHODS: Twenty RCs and 10 RRCs were evaluated by immunohistochemistry using anti-VEGF and anti-MMP-9 antibodies. The angiogenic index was determined by microvessel count (MVC) using anti-von Willebrand factor antibody. RESULTS: The expression of both VEGF and MMP-9 was higher in RCs than in RRCs. RCs and RRCs presented strong epithelial expression of VEGF, irrespective of the intensity of the inflammatory infiltrate. Lesions with strong expression of MMP-9 showed significantly higher number of immunopositive cells for VEGF (p<0.05) and higher MVC (p<0.05). Lesions with dense inflammatory infiltrate exhibited significantly higher MVC (p<0.05) and higher number of immunopositive cells for VEGF (p<0.05). There was a positive correlation between both MVC (p<0.05) and the quantity of immunopositive cells for VEGF (p<0.05), with intensity of the inflammatory infiltrate. In addition, it was observed a positive correlation between the number of immunopositive cells for VEGF and MVC (p<0.05). CONCLUSIONS: VEGF and MMP-9 might play important roles in the angiogenesis in RCs and RRCs. In these lesions, the expression of these molecules and the MVC is closely related to the intensity of the inflammatory infiltrate. The expression of VEGF in the epithelial lining of RCs and RRCs might be important for the enlargement of these lesions.

Immunohistochemical expression of vascular endothelial growth factor and matrix metalloproteinase-9 in radicular and residual radicular cysts.

OBJECTIVE: This study assessed and compared the immunoexpression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) in radicular cysts (RCs) and residual radicular cysts (RRCs), relating them to the angiogenic index and the intensity of the inflammatory infiltrate. MATERIAL AND METHODS: Twenty RCs and 10 RRCs were evaluated by immunohistochemistry using anti-VEGF and anti-MMP-9 antibodies. The angiogenic index was determined by microvessel count (MVC) using anti-von Willebrand factor antibody. RESULTS: The expression of both VEGF and MMP-9 was higher in RCs than in RRCs. RCs and RRCs presented strong epithelial expression of VEGF, irrespective of the intensity of the inflammatory infiltrate. Lesions with strong expression of MMP-9 showed significantly higher number of immunopositive cells for VEGF (p<0.05) and higher MVC (p<0.05). Lesions with dense inflammatory infiltrate exhibited significantly higher MVC (p<0.05) and higher number of immunopositive cells for VEGF (p<0.05). There was a positive correlation between both MVC (p<0.05) and the quantity of immunopositive cells for VEGF (p<0.05), with intensity of the inflammatory infiltrate. In addition, it was observed a positive correlation between the number of immunopositive cells for VEGF and MVC (p<0.05). CONCLUSIONS: VEGF and MMP-9 might play important roles in the angiogenesis in RCs and RRCs. In these lesions, the expression of these molecules and the MVC is closely related to the intensity of the inflammatory infiltrate. The expression of VEGF in the epithelial lining of RCs and RRCs might be important for the enlargement of these lesions.

Immunoexpression of vascular endothelial growth factor in periapical granulomas, radicular cysts, and residual radicular cysts.

OBJECTIVE: Our aim was to assess and compare the immunoexpression of vascular endothelial growth factor (VEGF) in periapical granulomas (PGs), radicular cysts (RCs), and residual radicular cysts (RRCs), relating it to the angiogenic index and the intensity of the inflammatory infiltrate. STUDY DESIGN: Twenty PGs, 20 RCs, and 10 RRCs were evaluated by immunohistochemistry using anti-VEGF antibody. Angiogenic index was determined by microvessel count (MVC) using anti-von Willebrand factor antibody. RESULTS: The PGs and RCs showed higher expression of VEGF than the RRCs. Lesions presenting few inflammatory infiltrate revealed the lowest immunoexpression of VEGF (P < .05). Irrespective of the intensity of the inflammatory infiltrate, most of the RCs and RRCs showed moderate to strong epithelial expression of VEGF. Lesions showing dense inflammatory infiltrate presented higher MVC indices (P < .05). VEGF expression and MVC did not reveal a significant correlation (P > .05). CONCLUSIONS: VEGF is present in periapical inflammatory lesions but at a lower level in RRCs. The expression of this proangiogenic factor is closely related to the intensity of the inflammatory infiltrate in these lesions.

The concentration of TNF-alpha correlate with number of inflammatory cells and degree of vascularization in radicular cysts.

OBJECTIVE: To correlate values of tumor necrosis factor-alpha (TNF-alpha) depending on the count of inflammatory cells with degree of vascularization in cystic fluid of radicular cysts. MATERIAL AND METHODS: We investigated TNF-alpha concentration in 43 radicular cysts obtained from patients undergoing surgery, under local anaesthesia, and after aspiration of cystic fluid from non-ruptured cysts by enzyme-linked immunosorbent assay assay in respect of different clinical parameters as well as by histomorphometric analyses. RESULTS: Significantly higher concentration of TNF-alpha is associated with smaller radicular cysts, higher protein concentration in cystic fluid as well as with higher presence of inflammatory cells, and increased degree of vascularization in pericystic tissues and cyst wall thickness. CONCLUSIONS: We believe that determination of TNF-alpha in cystic fluid simultaneously with other parameters can be an additional parameter for clinical diagnosis of inflammed cysts.

Microvessel density and vascular endothelial growth factor (VEGF) expression in human radicular cysts.

PURPOSE: To assess vascular endothelial growth factor (VEGF) expression and microvessel density (MVD) by immunohistochemistry and to relate them to the inflammatory status in a sample of radicular cysts. METHODS: Specimens of 24 human radicular cysts were examined by immunohistochemistry using antibodies anti-VEGF and anti-CD34 and to evaluate vascular density. Integrity of the epithelium and inflammatory state of the connective tissues were evaluated and related with the immunohistochemical findings. A Spearman correlation test was utilized to compare the means of each parameter. RESULTS: VEGF immunoreactivity was detected in both epithelial and connective tissues of radicular cysts. Stromal cells showed higher levels of VEGF expression when compared to epithelial cells. MVD proved to be related to VEGF expression levels (P < or = 0.01). In addition, increased MVD was associated with high levels of inflammation (P < or = 0.01). Most of the specimens showed a massive inflammatory infiltrate in the connective tissue. The integrity of the cystic lining tend to decrease with increased inflammation.

The use of hydrogen peroxide in the experimental therapy of cysts. An in vitro analysis.

AIM: Aim of the authors is to evaluate in vitro the histological alteration caused by hydrogen peroxide on a sample of radicular cysts. METHODS: Twelve radicular cysts were divided into 2 portions. The control group was histologically evaluated whereas the other portion, test, was treated with 3% hydrogen peroxide before histological analysis. Test and control portions were compared for integrity of the epithelium, inflammatory state of the cystic walls, presence of necrosis, stromal vacuolization and microvessel density (MVD). MVD was evaluated by immunohistochemistry using anti-CD34 monoclonal antibodies. RESULTS: Significantly lower epithelium integrity has been detected in the test group (p= or <0.007), (Wilcoxon test). Moreover, the test group presented a higher number of stromal vacuolization areas (p= or <0.004). However, necrosis and inflammation reported no significative differences. No significative differences were noticed for the MVD. CONCLUSION: Hydrogen peroxide showed a cytopathic and cytolytic activity in vitro. Those effects have been shown on both cysts tissues: epithelium and connective tissue. The present study did not reveal any statistically significant difference between the number of vessels in the control and in the test group. However, further in vitro and human studies are needed to validate this substance in the treatment of cysts.