Exclusion of known gene for enamel development in two Brazilian families with amelogenesis imperfecta

Background

Functional rehabilitation of patients afflicted with severe mandibular and maxillary alveolar atrophy might be challenging especially in malformed patients.

Methods

Treatment planning using sinus lifting and implant placement before Le Fort I maxillary osteotomy in a patient with severe mandibular and posterior maxillary alveolar atrophy and skelettal class-III conditions due to cleft palate are described.

Results

A full functional and esthetic rehabilitation of the patient was achieved by a stepwise surgical approach performed through sinus lifting as the primary approach followed by implant placement and subsequent Le Fort I maxillary osteotomy to correct the maxillo-mandibular relation.

Conclusion

Stabilisation of the maxillary complex by a sinus lifting procedure in combination with computer aided implant placement as preorthodontic planning procedure before Le Fort I maxillary osteotomy seems to be suitable in order to allow ideal oral rehabilitation especially in malformed patients.     

Prognostic value of Ki67 expression after short-term presurgical endocrine therapy for primary breast cancer

Tumor expression of the proliferation antigen Ki67 is widely used to assess the prognosis of cancer patients. A change in the expression of Ki67 after short-term exposure of patients to therapeutic agents is frequently used as a pharmacodynamic marker of efficacy, particularly among breast cancer patients before undergoing surgery. To determine the clinical significance of the level of tumor cell proliferation during endocrine therapy for breast cancer, we measured the expression of Ki67 in tumor biopsy samples taken before and after 2 weeks of presurgical treatment with anastrozole or tamoxifen or the combination of anastrozole plus tamoxifen in 158 patients with hormone receptor-positive primary disease. In a multivariable analysis, we found that higher Ki67 expression after 2 weeks of endocrine therapy was statistically significantly associated with lower recurrence-free survival (P = .004) whereas higher Ki67 expression at baseline was not. Larger baseline tumor size and lower estrogen receptor level after 2 weeks of treatment were also statistically significantly associated with poorer recurrence-free survival (P < .001 and P = .04, respectively). Our data indicate that measurements of tumor Ki67 level after short-term endocrine treatment may improve the prediction of recurrence-free survival by integrating the prognostic value of Ki67 level at baseline with changes in Ki67 level that are associated with treatment benefit.     

Topoisomerase II alpha amplification may predict benefit from adjuvant anthracyclines in HER2 positive early breast cancer

The purpose of the study was to evaluate the use of metabolic phenotype, described by high-resolution magic angle spinning magnetic resonance spectroscopy (HR MAS MRS), as a tool for prediction of histological grade, hormone status, and axillary lymphatic spread in breast cancer patients. Biopsies from breast cancer (n = 91) and adjacent non-involved tissue (n = 48) were excised from patients (n = 77) during surgery. HR MAS MR spectra of intact samples were acquired. Multivariate models relating spectral data to histological grade, lymphatic spread, and hormone status were designed. The multivariate methods applied were variable reduction by principal component analysis (PCA) or partial least-squares regression-uninformative variable elimination (PLS-UVE), and modelling by PLS, probabilistic neural network (PNN), or cascade correlation neural network. In the end, model verification by prediction of blind samples (n = 12) was performed. Validation of PNN training resulted in sensitivity and specificity ranging from 83 to 100% for all predictions. Verification of models by blind sample testing showed that hormone status was well predicted by both PNN and PLS (11 of 12 correct), lymphatic spread was best predicted by PLS (8 of 12), whereas PLS-UVE PNN was the best approach for predicting grade (9 of 12 correct). MR-determined metabolic phenotype may have a future role as a supplement for clinical decision-making-concerning adjuvant treatment and the adaptation to more individualised treatment protocols.     

Influence of neoadjuvant anastrozole (Arimidex) on intratumoral estrogen levels and proliferation markers in patients with locally advanced breast cancer.

Anastrozole (Arimidex) is a novel, selective, and potent aromatase inhibitor used for the treatment of postmenopausal breast cancer. The drug has been shown to inhibit in vivo aromatization by 96--97% and to suppress plasma estrogen levels by 84--94%. However, the effects of anastrozole on intratumoral estrogen levels have not been studied. Here we report the effects of neoadjuvant treatment with anastrozole on intratumoral levels of estrone (E(1)), estradiol (E(2)), and estrone sulfate (E(1)S), measured by a highly sensitive RIA following a multistep purification procedure involving high-pressure liquid chromatography. Tumor tissue was obtained prior to treatment and after 15 weeks on therapy with anastrozole (1 mg once daily) from 12 postmenopausal women with locally advanced breast cancer (T(3)--T(4) and/or N(2)). Pretreatment tissue levels of E(2), E(1), and E(1)S were 217.9 (69.8--679.9), 173.6 (83.9--358.9), and 80.7 (31.4--207.3) fmol/g tissue (geometric mean values with 95% confidence interval, respectively). Treatment with anastrozole suppressed tissue E(2), E(1), and E(1)S levels by 89.0% (73.2--95.5%), 83.4% (63.2--92.5%), and 72.9% (47.3--86.1%), respectively, compared with baseline levels, with no significant difference between responders and nonresponders. Plasma levels of E(2), E(1), and E(1)S were suppressed by 86.1, 83.9, and 94.2%, respectively. Anastrozole caused a decrease in the immunoexpression of the proliferation markers Ki67 and pS2 in all of the patients, with a trend for a more profound suppression in those achieving an objective response. The mean percentage of apoptotic cells was found to be decreased in responders and increased in nonresponders after 15 weeks of anastrozole therapy. Our results reveal anastrozole to cause a significant suppression of tissue estrogen levels and to influence the biology of primary estrogen receptor-positive breast cancers in postmenopausal women.     

A dose-comparative endocrine-clinical study of leuprorelin in premenopausal breast cancer patients

Twelve premenopausal patients with advanced breast cancer were randomised to receive 3.75 or 7.5 mg of a slow release formulation of the luteinising hormone releasing hormone agonist leuprorelin once every 4 weeks. All patients were oestrogen receptor positive or unknown. Serum levels of gonadotrophins and oestrogens were suppressed markedly by both doses. All oestrogen values during treatment were within the postmenopausal range except for a single oestradiol level (274 pmol l-1) in one patient on the lower dose. There was no other indication that this lower dose was less effective as an oestrogen suppressant. There were two objective responders to the 3.75 mg dose and three to the 7.5 mg dose. Toxicity was confined almost entirely to hot flushes which occurred in 11/12 patients. We conclude that the slow release formulation of leuprorelin is effective in breast cancer treatment and that there is no major detriment to the use of the 3.75 rather than 7.5 mg dose.     

Steroid and growth factor modulation of aromatase activity in MCF7 and T47D breast carcinoma cell lines.

The effect of a number of steroids, growth factors, and peptides on aromatase activity in two estrogen receptor positive breast cancer cell lines (MCF7 and T47D) was investigated. The cells were incubated in Dulbecco's minimum essential medium containing phenol red and 10% fetal calf serum. Pronounced differences in basal aromatase activity and different responses to the addition of experimental agents were found in the two cell lines. Aromatase activity in MCF7 cells was significantly stimulated by phorbol 12,13-diacetate [PDA], dibutyryl cyclic AMP [(Bu)2cAMP], transforming growth factor alpha, and epidermal growth factor individually and PDA and (Bu)2cAMP in combination, while it was inhibited by dexamethasone and unaffected by transforming growth factor beta, fibroblast growth factor, platelet-derived growth factor, prolactin, and tamoxifen. Addition of cortisol to MCF7 cells had no effect on aromatase activity at 1 nM, caused suppression of activity at 10 nM and stimulated activity at 100 nM. Aromatase activity in T47D cells was stimulated by transforming growth factor alpha, epidermal growth factor, platelet-derived growth factor, prolactin, dexamethasone, and cortisol individually and PDA and (Bu)2cAMP in combination. It was unaffected by transforming growth factor beta, PDA, (Bu)2cAMP, and fibroblast growth factor. These findings suggest that aromatase activity is induced by agents which stimulate cyclic AMP-dependent protein kinases [e.g., (Bu)2cAMP] and that this effect is potentiated by factors which stimulate protein kinase C [e.g., PDA]. The effect on aromatase activity of growth factors, the actions of which are believed to be mediated by receptors linked to tyrosine kinase activity, is not as clearly defined, with a factor causing stimulation, inhibition, and no change in activity depending on the tissue concerned. Further insight into these differences will require resolution of the molecular mechanisms that mediate the actions of stimulatory and repressive growth factors on aromatase activity of oestrogen-producing cells.