Breast cancer 1 (BRCA1) protein expression as a prognostic marker in sporadic epithelial ovarian carcinoma: an NCIC CTG OV.16 correlative study.

BACKGROUND: Breast cancer 1 (BRCA1) protein inactivation in sporadic ovarian carcinoma (OC) is common and low BRCA1 expression is linked with platinum sensitivity. The clinical validation of BRCA1 as a prognostic marker in OC remains unresolved. PATIENTS AND METHODS: In 251 patient samples from the NCIC CTG clinical trial, OV.16, BRCA1 protein expression was determined by immunohistochemistry. RESULTS: For all patients, when BRCA1 score was analyzed as a continuous variable, there was no significant correlation between BRCA1 protein expression and progression-free survival (PFS) [adjusted hazard ratio (HR) = 1.15 (0.96-1.37), P = 0.12] or response rate [HR = 0.89 (0.70-1.12), P = 0.32]. In the 116 patients with minimal residual disease (RD), higher BRCA1 expression correlated significantly with worse PFS [HR = 1.40 (1.04-1.89), P = 0.03]. Subgroup analysis divided patients with minimal RD into low (BRCA1 ≤2.5) and high (BRCA1 >2.5) expression groups. Patients with low BRCA1 expression had a more favorable outcome [median PFS was 24.7 and 16.6 months in patients with low and high BRCA1, respectively; HR = 0.56 (0.35-0.89), P = 0.01]. CONCLUSIONS: This study suggests that BRCA1 protein is a prognostic marker in sporadic OC patients with minimal RD. Further research is needed to evaluate BRCA1 as a predictive biomarker and to target BRCA1 expression to enhance chemotherapeutic sensitivity.

Occlusal philosophies and gnathologic instrumentation.

The field of occlusion continues to be prolific in publications. While no major advancement in the field was noted in the 1-year period of review, existing concepts and instrumentation continued to be refined. Topics covered in this review include occlusal tooth contacts, choice of alternate occlusal schemes, evaluation of gnathologic instruments and techniques, vertical dimension of occlusion, and mandibular flexure eliminate occurring on opening.

Evaluation of the relationship between anterior and posterior functionally disclusive angles. Part I: Literature review, instrumentation, and reproducibility.

Authors are not in agreement concerning the existence of an anatomofunctional interrelationship between condylar and anterior guidances of the mandible in humans. Current literature consists either of speculative statements or studies omitting the role of the meniscus. This article (part I) describes a unique method to correlate the condylar functional anatomy to the lingual inclines of the maxillary anterior teeth (anterior guidance) and acknowledges all components of the temporomandibular joint. The measurements obtained by means of this method were reproduced five different times on five different subjects, making possible a valid statistical analysis of the correlation between condylar and anterior guidances of the mandible (part II).

Thermal cycling distortion of metal ceramics: Part II--Etiology.

The three-dimensional geometry of conventional fixed prostheses complicates the study of the thermal cycling distortion in metal ceramic alloys. Any explanation of the etiology of thermal cycling distortion in metal ceramic restorations must account for the observed magnitude, timing, and direction of the deformation. The simplified experimental geometry developed in Part I was applied to elucidate the etiologic factors involved in metal ceramic deformation. Techniques to minimize the thermal cycling distortion were also studied. It was found that all of the significant distortion occurred during the first thermal cycling of the alloy (oxidation) and that no distortion resulted from the application of body porcelain. The specimens that were cold worked and then oxidized had significantly more distortion than any other group. A significant reduction in distortion was observed when the initial thermal cycling was completed before the specimens were cold worked. It was determined that the release of casting- and cold working-induced stresses had a synergistic effect.

Thermal cycling distortion of metal ceramics: Part I--Metal collar width.

The complex three-dimensional geometry of conventional full crown restorations severely complicates the study of thermal cycling distortion in metal ceramic castings. A simplified experimental geometry was developed to (1) maximize the measuring sensitivity, (2) eliminate the casting variables, (3) allow the direct measurement of casting distortion, and (4) evaluate the thermal cycling distortion of a wide range of metal collar widths. It was found that all of the one-walled castings distorted during the initial thermal cycling (oxidation) of the alloy. There was no significant distortion associated with porcelain application or glazing. The castings with an 0.8 mm metal collar had significantly less distortion than those with 0.1 and 0.4 mm collars at 2 of the 10 sites measured (inferior or facial margins).

Evaluation of the relationship between anterior and posterior functionally disclusive angles. Part II: Study of a population.

The lateral and protrusive anterior and posterior disclusive angles were recorded and measured by using a newly developed method (part I) on a population of 50 subjects (mean age 27.2 years). All of the subjects had natural anterior teeth, 45 had a clinically acceptable anterior guidance, and the remaining five had a partial (unilateral) or total lack of anterior guidance. A statistically significant correlation between the anterior and posterior disclusive angles was not found either in the entire population (n = 50) or in the stratum of the population that consisted of subjects with a clinically acceptable anterior guidance (n = 45). The Angle class of occlusion or anterior deep bite malocclusion were not identified as possible confounders or effect modifiers. This study suggested that the intra-articular tissues of the temporomandibular joint played a significant role in the relationship of their osseous components. Practical guidelines to determine anterior guidance could be established by using population means.

Comparison of condylar control settings using three methods: a bench study.

Articulators that program eccentric condylar pathways minimize occlusal adjustments of dental prostheses. This bench study compared three groups of methods for recording the immediate Bennett shift and the protrusive condylar path of the mandible. The experimental design restricted the variable associated with these methods. The various methods for recording protrusive excursions from best to worst were: (1) electronic pantography (Denar); (2) mechanical pantography (Denar); and (3) simplified mandibular motion analyzers (Whip-Mix and Denar). The methods of recording immediate side shift from best to worst were: (1) electronic pantograph; (2) polyether interocclusal records; (3) mechanical pantography (Denar) and simplified mandibular motion analyzer (Panadent); (4) simplified mandibular motion analyzer (Whip-Mix and Denar); and (5) zinc oxide interocclusal records.

Dimensional and formation analysis of a restorative ceramic and how it works.

In-Ceram ceramic appears to use conventional powder/liquid processing techniques to form the coping substructure; however, the process results in a near net-shape restoration with minimal sintering shrinkage. Scanning electron microscopy, Brunauer-Emmett-Teller analysis, particle size classification, and linear dimensional changes during sintering were used to analyze In-Ceram ceramic. In-Ceram ceramic had a minimal linear shrinkage of 0.21% after the sintering of the alumina powder. This shrinkage can be readily compensated for by the expansion of conventional gypsum products and should result in acceptable clinical fits for In-Ceram ceramic restorations. Theories and explanations were described to account for the near net-shape and high strength of In-Ceram. Continuous interpenetrating phase composite technologies were used to create a substantial increase in strength. Future applications of this technology are encouraging.

Effects of firing cycle and surface finishing on distortion of metal ceramic castings.

The "as-cast" fit of metal ceramic restorations has been reported to deteriorate during the high-temperature firing cycles used for application of porcelain veneer. In this study, thermocycling and surface finishing or cold working were examined for their effects on marginal adaptation of metal ceramic castings. Methods for minimizing the loss of marginal adaptation were evaluated, and casting variables were eliminated by construction of acrylic resin measuring dies directly in the restorations. Thermocycling of metal ceramic restorations resulted in increased marginal openings, and all of the loss of marginal fit occurred during the first thermocycling of the alloy. The restorations that were cold worked and then oxidized by conventional manipulation had substantially more marginal opening than any other group. A fourfold, statistically significant improvement (p < 0.001) in the marginal adaptation of a metal ceramic restoration was observed when the initial thermal cycle was completed before the specimens were finished.