Direct cores for vital teeth--materials and methods used to retain cores in vital teeth

A core, or foundation restoration, is used to restore extensively damaged teeth to a form suitable for crown preparation. This literature review considers the range of materials which can be used for cores and the evidence for their suitability. The methods for their retention in vital teeth will be presented and appraised.     

The measurement and prevention of erosion and abrasion

OBJECTIVES: To develop a reproducible method to measure tooth wear and assess the protection given by dentine bonding agents in an erosive/abrasive wear regime. METHODS: Seal and Protect (Dentsply, UK) and Optibond Solo (Kerr, UK) were each applied to 20 extracted teeth and subjected to 3000 cycles in a reciprocating erosion/abrasion wear machine. A further 20 teeth, without protection, were subjected to the same wear regime and were either brushed in water or immersed in acid. Impressions were taken by a standardised technique and were scanned with a non-contacting laser profilometer. The amount of erosion was measured at the same co-ordinates before and after erosion using 2mm diameter metal discs as reference points. RESULTS: The amount of wear on Seal and Protect had a mean 24.8 microm (SD 57.4 microm) and for Solo it was 1.4 microm (24.5 microm), and this difference was statistically significant (p=0.02). There was no statistically significant difference in the wear measured on the teeth brushed in water or immersed in acid. The wear measured on the unprotected teeth was 243 microm (SD 120 microm) and was statistically significantly different to the protected surfaces (p=0.001). CONCLUSION: Both Seal and Protect and Solo protected the teeth in this wear regime and the technique could be used clinically for patients with uncontrolled dental erosion.     

A four gene signature predicts benefit from anthracyclines: evidence from the BR9601 and MA.5 clinical trials

Chromosome instability (CIN) in solid tumours results in multiple numerical and structural chromosomal aberrations and is associated with poor prognosis in multiple tumour types. Recent evidence demonstrated CEP17 duplication, a CIN marker, is a predictive marker of anthracycline benefit. An analysis of the BR9601 and MA.5 clinical trials was performed to test the role of existing CIN gene expression signatures as predictive markers of anthracycline sensitivity in breast cancer.Univariate analysis demonstrated, high CIN25 expression score was associated with improved distant relapse free survival (DRFS) (HR: 0.74, 95% CI 0.54-0.99, p = 0.046). High tumour CIN70 and CIN25 scores were associated with aggressive clinicopathological phenotype and increased sensitivity to anthracycline therapy compared to low CIN scores. However, in a prospectively planned multivariate analysis only pathological grade, nodal status and tumour size were significant predictors of outcome for CIN25/CIN70. A limited gene signature was generated, patients with low tumour CIN4 scores benefited from anthracycline treatment significantly more than those with high CIN4 scores (HR 0.37, 95% CI 0.20-0.56, p = 0.001). In multivariate analyses the treatment by marker interaction for CIN4/anthracyclines demonstrated hazard ratio of 0.35 (95% CI 0.15-0.80, p = 0.012) for DRFS. This data shows CIN4 is independent predictor of anthracycline benefit for DRFS in breast cancer.     

Should all postmenopausal patients with hormone receptor-positive breast cancer receive initial therapy with aromatase inhibitors?

BackgroundIn the past few years aromatase inhibitors (AIs) have shown superior efficacy to the previous standard adjuvant endocrine therapy, tamoxifen, and are now recommended as part of current adjuvant endocrine therapy. A range of treatment strategies have been explored.Materials and methodsWe assess the role of initial AI therapy for postmenopausal women with hormone receptor-positive breast cancer and consider the relative value of initial therapy with an AI compared with switch or extended (>5-yr) adjuvant therapy.ResultsBoth initial AI therapy and switching/sequential tamoxifen followed by an AI are associated with longer disease- and relapse-free survival versus 5 years of tamoxifen alone. Trials comparing initial therapy with the sequence of tamoxifen followed by an AI have not demonstrated any major efficacy differences between the treatment strategies. Several analyses have been conducted to identify prognostic or predictive markers of treatment benefit to enable selection of the most appropriate adjuvant therapy.ConclusionsInitial and switching/sequential regimens are equally appropriate adjuvant treatment options for postmenopausal patients with hormone receptor-positive breast cancer. The exact tumour biology which allows for initial AI therapy has not yet been determined with certainty.     

Medulloblastoma

Medulloblastomas are primary malignant embryonal tumours of the central nervous system. They are the most common childhood central nervous system tumour, but are rare in the adult population. They arise infratentorially in the cerebellum or fourth ventricle and hence the most common presenting symptoms are those associated with raised intracranial pressure. Several histological subtypes have been described, although the classical and desmoplastic subtypes account for the majority. Recent advances in molecular biology and cytogenetics have led to an improved understanding of the genetic abnormalities and alterations in cell signalling pathways associated with medulloblastomas, including how these relate to patient outcome. The Modified Chang Staging System is still in use, but a number of other factors, including age, completeness of resection, histological subtype and genetic markers now contribute to treatment decisions and prognostication. Patients are currently classified as being either standard or high risk in order to stratify treatment. There has been an improvement in survival of all groups over the past 20 years. A multimodality approach is the cornerstone of treatment and recent trials have concentrated on ascertaining the most efficacious treatment combinations and timings for each patient group. Advances in surgical techniques have allowed a greater attainment of the two primary surgical goals: restoring normal cerebrospinal fluid (CSF) flow and maximal tumour resection. Radiotherapy to the craniospinal axis with a boost to the posterior fossa has been standard practice, but improvement in radiotherapy techniques and quality control has enabled optimisation of the trade-off between tumour control and normal tissue late toxicities. Combination chemotherapy is usually given adjuvantly, although it may be used to delay or avoid the use of radiotherapy in infants. In the future, the treatment of medulloblastoma will probably become increasingly individualised, based on patient-specific genetic features. Attention will be focussed not only on improving survival, but also on maintaining quality of life.     

辽宁省省直机关中老年人群代谢综合征的现况调查

目的调查辽宁省省直机关中老年人群代谢综合征的患病情况。方法选取2005年9-11月在我院干诊科进行健康体检的辽宁省省直机关40岁以上人群体检完整资料1506份,统计分析代谢综合征及其组分的患病情况。结果对1506份调查资料分析显示,代谢综合征、超重和（或）肥胖、糖代谢异常、高血压、高三酰甘油血症和高尿酸血症的患病率分别为26.3%、46.1%、56.4%、57.4%、39.0%和28.0%,按照2000年第五次全国人口普查沈阳地区人口构成比进行标化后,上述各组分标化患病率分别为10.8%、18.9%、23.2%、23.6%、16.0%、11.5%。除超重和（或）肥胖外,代谢综合征及各组分患病率均随年龄增加逐渐增高。代谢综合征与冠心病的联系强度比值比（OR）为1.912,可信区间为1.34～2.74,代谢综合征患者并存冠心病的可能性是无代谢综合征人群的1.92倍（P〈0.01）。结论辽宁省省直机关中老年人群代谢综合征患病率较高,代谢综合征患病率在不同的年龄段有所不同。代谢综合征是心血管病发病的重要的预测因素。