Endodontic re-instrumentation enhances hydroxyl ion diffusion through radicular dentine.

AIM: To evaluate the diffusion of hydroxyl ions from calcium hydroxide paste (CH) before root canal filling and after retreatment. METHODOLOGY: After preparation of 60 root canals, the cementum layer was removed, and the canals and root surfaces were treated for smear layer removal. The apical third of roots was covered with adhesive. The canals were filled with CH, and the teeth were placed in individual vials containing 10 mL of distilled water, which had its pH measured after 7, 14, 21 and 28 days (pH1). The root canals were then divided into five groups and filled with Resilon/Real Seal (G1) or gutta-percha and Endofill (G2), Sealapex (G3), AH Plus (G4) or MTA Fillapex (G5) sealers. After storage for 7 days, the root canals were retreated. The CH was again inserted into the canals, and the teeth were placed in new vials containing 10 mL of distilled water. The pH was again measured at 7, 14, 21 and 28 days (pH2). The initial and final pH readings (pH1 and pH2) were compared by anova, anova2 and Tukey's tests (P < 0.05). RESULTS: The pH1 and pH2 measurements increased with time. The measurements obtained after retreatment were significantly higher than those obtained before root canal filling. CONCLUSIONS: Hydroxyl ions are able to diffuse through dentinal tubules. Regardless of the filling material, it was possible to re-establish the permeability of dentine to ionic diffusion after retreatment. Time had a positive influence on ionic diffusion.

Evaluation of Ki-67 and Bcl-2 antigen expression in breast carcinomas of women treated with raloxifene.

OBJECTIVES: To evaluate the effect of raloxifene on Ki-67 and Bcl-2 antigen expression in operable, stage II, oestrogen-receptor-positive invasive ductal breast carcinomas. MATERIALS AND METHODS: Twenty post-menopausal women who had taken 60 mg of raloxifene daily for 28 days prior to definitive surgery were enrolled in the investigation. Two tumour samples were obtained by incisional biopsy during the study, one at the time of confirmation of diagnosis of invasive ductal carcinoma and evaluation of oestrogen receptor status, and the other 29 days later, at the time of definitive surgery. Immunohistochemistry was performed on tumour samples, prior to and after raloxifene treatment, to evaluate Ki-67 and Bcl-2 expression. Friedman and McNemar tests were used for statistical analysis of the data, significance being established at 5%. RESULTS: Mean percentage of Ki-67-stained nuclei was 24.86 +/- 2.95 prior to raloxifene treatment and 13.33 +/- 1.52 after treatment (P < 0.001). Prior to raloxifene treatment, only 9/20 cases (45%) were classified as Bcl-2-positive, whereas after treatment, 17/20 (85%) were classified as Bcl-2-positive (P < 0.013). CONCLUSIONS: Raloxifene treatment significantly reduced Ki-67 antigen expression and increased Bcl-2 expression in breast carcinomas of post-menopausal women.

E-cadherin expression in estrogen receptor-positive and negative breast carcinomas of postmenopausal women.

BACKGROUND: Preservation of E-cadherin expression is usually related to non-invasive and well differentiated breast carcinomas. PURPOSE: The aim of this study was to evaluate E-cadherin immunohistochemical expression in estrogen receptor (ER) positive and negative infiltrating ductal breast carcinomas. METHODS: Twenty-three postmenopausal patients with Stage II, operable, infiltrating ductal breast carcinomas were divided into groups A (ER+; n = 13) and B (ER-; n = 10). E-cadherin immunohistochemical expression was assessed semiquantitatively according to membrane staining intensity and classified as negative (< 10% of cells with stained membranes), positive + (10-50% of cells stained) or positive ++ (> 50% of cells stained). Fisher's exact test was used to compare the distribution of staining intensity in the two groups (p < 0.05). RESULTS: In group A (ER+), E-cadherin staining was positive in all cases: + (n = 3; 23%) and ++ (n = 10; 77%) compared to three cases (30%) in group B (ER-), + (n = 2; 20%) and ++ (n = 1; 10%). This difference was statistically significant (p < 0.0005). CONCLUSIONS: The present results indicate that E-cadherin expression loss is significantly associated with ER-negative tumors and therefore with a more aggressive phenotype of invasive ductal breast carcinoma.

Bcl-2 oncogene expression in estrogen receptor-positive and negative breast carcinoma.

PURPOSE: The aim of this study was to evaluate Bcl-2 oncogene expression in estrogen receptor (ER)-positive and negative breast carcinomas. METHODS: A study involving 72 cases of infiltrating ductal carcinoma of the breast in postmenopausal women divided into two groups: Group A (ER positive, n=37) and Group B (ER negative, n=35). Immunohistochemical analysis of bcl-2 expression was carried out semiquantitatively based on the percentage of stained tumoral cells and the intensity of staining. The chi-square test was used in the statistical analysis of the data and significance was established at p < 0.05. RESULTS: Bcl-2 oncogene expression was statistically greater in tumors of Group A (59.5%) compared to those of Group B (8.6%), (p < 0.001). CONCLUSION: Bcl-2 had a significantly greater expression in the ER-positive breast tumors compared to ER-negative tumors.

Ectopic breast cancer in the anterior chest wall: a case report and literature review.

Ectopic breast cancer is rare and when situated in the chest wall, it is even rarer. This report describes the case of an 86-year old Brazilian woman with a palpable carcinoma, located in the right inframammary fold, and right axillary adenopathy. The patient was submitted to excision of the accessory breast and to right axillary lymphadenectomy. All 28 resected lymph nodes contained metastatic cells. Diagnosis and treatment of ectopic breast cancer should be carried out early in view of its aggressivity.

[Screening of Chagas disease using ELISA. Comparison of 2 antigens]. / Dépistage de la maladie de Chagas par ELISA. Comparaison de deux antigènes.

After proving, in a previous study, the efficiency of immunoenzymology (ELISA) and a primary antigen of Trypanosoma cruzi in the screening of blood donors suffering from Chagas' disease, here the authors show the benefit of the microsomial fraction of this parasite as an antigen. For comparison, it was studied with another primary antigen, Trypanosa, used initially in the adjuvant treatment of cancers, and applied here to the screening of this disease.

[ELISA methods for the detection of Trypanosoma cruzi carriers. Comparative study]. / Les méthodes ELISA pour le dépistage des sujets porteurs de Trypanosoma cruzi. Etude comparative.

Each of the serological methods used for the screening of T. cruzi carriers has its advantage and disadvantage. Owing to the detection, particularly concerning blood transfusion, a selection of techniques, as wide as possible, and which don't aim the same antibodies is now carried out. Therefore, we have tried to perfect an ELISA-like reaction. This kind of analysis appeared very sensitive, faithful and reproducible in other parasitology fields. It became evident for us to try to apply this method to the diagnosis of Chagas disease. In order to test this method , we compared the results obtained with the one given by other usual reactions: immunofluorescence and passive hemagglutination test. In an other hand, we have, for the whole three methods, estimated the possible crossed reactions, particularly with leishmaniasis, african trypanosomiasis and myeloma. From these results, it can be deduced that: --the ELISA reaction used with a total homologous antigen is sensitive and discriminant towards the other trypanosoma. The ratio of the crossed reactions with visceral leishmaniasis is the same compared to immunofluorescence. It allows the exploration of recent infestations; --the ELISA reaction done with a dislipided antigen is very sensitive. In the meantime, crossed reactions are possible with other trypanosomiasis.