Resin bonding using an all-etch or self-etch adhesive to enamel after carbamide peroxide and/or CPP-ACP treatment.

BACKGROUND: Limited evidence exists regarding the effect of carbamide peroxide and casein phosphopeptide amorphous calcium phosphate (CPP-ACP) on composite-enamel bonding. Microshear bond strengths, using either a total-etch or self-etching adhesive, to enamel treated with carbamide peroxide and/or CPP-ACP were investigated. MATERIALS AND METHODS: Twenty-six extracted human third molars were sectioned into four parts, each being allocated into one of the four groups (n=26): bleach (Polanight, 16% carbamide peroxide), CPP-ACP (GC Tooth Mousse), bleach and then CPP-ACP, or untreated (control). The surfaces were bonded with a total-etch bonding system (Single Bond) or a self-etching primer system (Clearfil SE Bond) and tested using a microshear test. RESULTS: A significant difference in bond strength was found between bonding systems. SE Bond showed the highest bond strength to untreated enamel (p < 0.05). The microshear bond strength of SE Bond decreased when the enamel was treated with carbamide peroxide, CPP-ACP or both (p < 0.05). Only combined use of carbamide peroxide and CPP-ACP significantly affected microshear bond strength with Single Bond. CONCLUSION: These findings suggest the shear bond strength of resin to enamel using a self-etching priming adhesive may be affected if the enamel is treated with a bleaching agent or CPP-ACP.

The relationship of steroid receptor expression to nuclear DNA distribution and clinicopathological characteristics in epithelial ovarian tumors.

Tumor specimens from 92 patients with ovarian carcinoma were analyzed for estrogen receptor (ER), progesterone receptor (PR), proliferative fraction, and ploidy. Seventy-one percent of tumors were either ER+ (greater than 5 fmole/mg protein) or PR+ (greater than 10 fmole/mg protein) with 27% of tumors overall being both ER+ and PR+. There was no significant relationship between receptor expression and stage, grade, or histological subtype. Thirteen percent of diploid tumors were receptor negative in contrast to 38% of aneuploid tumors (P less than 0.01). There was no significant association between ER status and ploidy, but 60% of diploid tumors were PR+ in contrast to 33% of aneuploid tumors (P less than 0.02). Eleven percent of tumors overall were both ER rich and PR rich and comprised 23% of diploid and 5% of aneuploid tumors (P less than 0.01). Receptor-negative tumors had a median S phase of 18.8% which was significantly higher than the median S phase of 12% in receptor-positive tumors (P less than 0.02). A similar analysis was also performed on specimens from 9 patients with borderline epithelial ovarian tumors and 12 with benign epithelial ovarian tumors. Up to 50% of benign and borderline epithelial tumors had measurable receptors, but all were diploid with a relatively low S phase fraction. The functional significance of steroid receptor expression in ovarian cancer is unclear, but the association with ploidy and proliferative activity particularly in patients with malignant ovarian tumors may allow better identification of prognostic subsets and aid in selection of patients for hormonal therapy.

Progesterone and oestrogen receptors in meningiomas: biochemical and clinicopathological considerations.

Specific progesterone and oestrogen receptor proteins were evaluated by a dextran coated charcoal assay and Scatchard plot analysis in 20 intracranial meningiomas. Eleven tumours (55%) were progesterone receptor (PR) positive (mean 108 fmol/mg cytosol protein), whilst all were oestrogen receptor (ER) negative (ER less than 10 fmol/mg cytosol protein). There were no trends to suggest a relationship between epidemiological data (patient age, sex and reproductive status in females) or meningioma location and size and the receptor status of the tumour. However, of the seven meningiomas that were histologically atypical, invasive or clinically recurred within 18 months, six were PR negative (PR less than 10 fmol/mg cytosol protein). These results confirm that a large proportion of intracranial meningiomas contain significant amounts of specific PR protein and suggest that PR negative meningiomas are biologically more aggressive than PR positive meningiomas. They are also consistent with the hypotheses that PR proteins are not modulated by oestrogens acting through oestrogen receptors and that there are cytokinetic differences between sex hormone receptor proteins in meningioma and breast carcinoma. The full biochemical, cytological and clinical implication of these preliminary findings will, however, require further evaluation because of the unpredictable long-term behaviour of intracranial meningiomas.

The influence of age on the DNA ploidy levels of breast tumours.

Primary tumour DNA content and estimates of cell cycle kinetic parameters were analysed by flow cytometry in 114 cases of breast cancer. Tumours were classified as: near-diploid, single aneuploid, tetraploid and greater, and multiploid (defined as having more than one aneuploid tumour cell population). No significant correlations were found between ploidy and histologic type, tumour size, lymph node involvement or receptor (oestrogen and progesterone) status. a highly significant correlation between ploidy and proliferative activity (as assessed by the percentage of cells in S phase) was observed, with near-diploid and diploid tumours being associated with a low (less than or equal to 10%) S phase fraction (P = 0.0001). A marked relationship between ploidy and patient age was also seen, with increased DNA content being associated with older patients (P = 0.025). In contrast, no patients with multiploid tumours were over 60 yr, and their age distribution was significantly different from the population as a whole (P less than 0.05), suggesting that multiploidy might be a phenomenon associated with the menopause.

A correlation between estrogen sulfotransferase levels and estrogen receptor status in human primary breast carcinoma.

Estrogen sulfotransferase (EC 2.8.2.4) activity and estrogen receptor levels were measured in 32 human primary breast cancer cytosol preparations. Two types of tumors were identified: type 1, in which estrogen sulfotransferase levels were low (less than 40 pmol 17 beta-estradiol 3-sulfate formed per mg protein per 2 hr) and were independent of [35S]adenosine 3'-phosphate 5'-phosphosulfate production from [35S]sulfate and adenosine triphosphate, and type 2, in which estrogen sulfotransferase levels ranged from 50 to 200 pmol 17 beta-estradiol 3-sulfate per mg protein per 2 hr and were correlated with [35S]adenosine 3'-phosphate 5'-phosphosulfate formation (r = 0.70; p less than 0.005). In type 1 tumors, 11 of 16 were estrogen receptor negative; in type 2 tumors, 2 of 16 were receptor negative. Estrogen sulfotransferase levels in receptor-negative tumors were significantly lower than the levels in receptor-positive tumors (p = 0.025).

PIP: Results of a study of estrogen Rc receptors in 32 primary human breast cancer cytosol preparations are presented. Tritiated sulfate activation to tritiated adenosine 3'-phosphate 5'-phosphosulfate and subsequent formation of tritiated estrogen sulfotranferase levels was assessed in these preparations. 2 groups of tumors were identified: a low estrogen sulfurylation which was predominantly Rc negative, and a high estrogen sulfurylation with almost exclusive Rc -positivity. In the 1st type of tumor, in which estrogen sulfotranferase levels were low (40 pmol of 17beta-estradiol 3-sulfate formed/mg of protein/2 hours) and were independent of tritiated adenosine 3'-phosphate 5'-phosphosulfate production from tritiated sulfate and adenosine triphosphate, and in the 2nd type of tumor, in which estrogen sulfotransferase levels ranged from 50-200 pmol of 17 beta-estradiol 3-sulfate/mg of protein/2 hours, there was a correlation between the 2 in terms of tritiated adenosine 3'-phosphate 5'-phosphosulfate formation (P.005). 11 of 16 of the 1st type of tumor were estrogen receptor negative, whereas 2 of 16 of the 2nd tumor type were receptor negative. In receptor-negative tumors, the estrogen sulfotransferasse levels were significantly lower than those in receptor-positive tumors (rho=.025).