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OBJECTIVE: The aim was to evaluate immunoexpression of matrix metalloproteinases (MMPs) 1, 2, 7, 9, and 26 in calcifying cystic odontogenic tumor (CCOT). STUDY DESIGN: Ten cases of CCOT were assessed by immunohistochemical expression of MMPs 1, 2, 7, 9, and 26 in the parenchyma and stroma. Metalloproteinase immunoexpressions and their distribution pattern were semiquantitatively scored. RESULTS: MMPs were expressed in the parenchyma and stroma in all cases of CCOT. Regarding the percentage of immunostained parenchymal cells, MMPs 1, 7, and 9 showed score 2 in 100% of cases. For MMP-2, there was a predominance of score 0 (90%), whereas for MMP-26 immunostaining was varied. CONCLUSIONS: The staining of these metalloproteinases, with the exception of MMP-2, suggests their contribution to tumor growth and expansion. The presence of these metalloproteinases in stromal cells reveals the active participation of these cells in the degradation of the extracellular matrix, contributing to the growth of the tumor studied. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The aim was to analyze the expression of E-cadherin and beta-catenin in ameloblastomas and tooth germs to determine their roles in cell differentiation processes and invasiveness compared with odontogenesis. STUDY DESIGN: Twenty-one ameloblastoma cases (16 solid and 5 unicystic tumors) and 5 tooth germs were submitted to the immunohistochemical detection of E-cadherin and beta-catenin. Immunoreactivity was evaluated using descriptive and semiquantitative analysis, investigating the location and intensity of staining. The Fisher exact test was performed, and P values of <.05 were considered to indicate statistical significance. RESULTS: There was no statistically significant difference in the expression of E-cadherin and beta-catenin between solid and unicystic ameloblastomas (P = .59; P = .63; respectively). The same was found when comparing solid and unicystic ameloblastomas with the tooth germs for both E-cadherin (P = .53; P = .44; respectively) and beta-catenin (P = .12; P = .16; respectively). Nuclear staining of beta-catenin was observed in only 4 cases (3 solid and 1 unicystic tumor). CONCLUSION: The results showed no differences in the expression of E-cadherin or beta-catenin between tooth germs and solid and unicystic ameloblastomas. The expression of these molecules seems mainly to be related to the process of cell differentiation. [ABSTRACT FROM AUTHOR]

Background The 2NN Study was a randomised comparison of the non-nucleoside reverse-transcriptase inhibitors (NNRTI) nevirapine and efavirenz.Methods In this multicentre, open-label, randomised trial, 1216 antiretroviral-therapy-naive patients were assigned nevirapine 400 mg once daily, nevirapine 200 mg twice daily, efavirenz 600 mg once daily, or nevirapine (400 mg) and efavirenz (800 mg) once daily, plus stavudine and lamivudine, for 48 weeks. The primary endpoint was the proportion of patients with treatment failure (less than 1 log10 decline in plasma HIV-1 RNA in the first 12 weeks or two consecutive measurements of more than 50 copies per mL from week 24 onwards, disease progression [new Centers for Disease Control and Prevention grade C event or death], or change of allocated treatment). Analyses were by intention to treat.Findings Treatment failure occurred in 96 (43·6%) of 220 patients assigned nevirapine once daily, 169 (43·7%) of 387 assigned nevirapine twice daily, 151 (37·8%) of 400 assigned efavirenz, and 111 (53·1%) of 209 assigned nevirapine plus efavirenz. The difference between nevirapine twice daily and efavirenz was 5·9% (95% CI –0·9 to 12·8). There were no significant differences among the study groups in the proportions with plasma HIV-1 RNA concentrations below 50 copies per mL at week 48 (p=0·193) or the increases in CD4-positive cells (p=0·800). Nevirapine plus efavirenz was associated with the highest frequency of clinical adverse events, and nevirapine once daily with significantly more hepatobiliary laboratory toxicities than efavirenz. Of 25 observed deaths, two were attributed to nevirapine.Interpretation Antiretroviral therapy with nevirapine or efavirenz showed similar efficacy, so triple-drug regimens with either NNRTI are valid for first-line treatment. There are, however, differences in safety profiles. Combination of nevirapine and efavirenz did not improve efficacy but caused more adverse events. [Copyright &y& Elsevier]