Sonographic appearance of gestational trophoblastic disease evolving into epithelioid trophoblastic tumor

Epithelioid trophoblastic tumor is a distinctive but rare trophoblastic tumor. It derives from intermediate trophoblastic cells of the chorion laeve and is usually associated with a previous gestational event. We report the case of a patient who had undergone dilatation and curettage for a missed miscarriage. Three months later gestational trophoblastic disease was suspected because of persistent vaginal bleeding and high levels of beta-human chorionic gonadotropin (beta-hCG). Transvaginal ultrasound revealed irregular echolucent lacunae within the myometrium, some of them filled with low-resistance, turbulent blood flow on Doppler examination, emphasizing the diagnosis of gestational trophoblastic disease. The patient was treated with 12 courses of multiagent chemotherapy. After a 2-year remission, a low rise in serum beta-hCG was observed. Transvaginal ultrasound revealed a well-circumscribed echogenic lesion with a diameter of 1.8 cm in the uterine fundus, with no detectable blood flow on Doppler imaging. A diagnosis of tumor of intermediate trophoblastic cells was suspected and total hysterectomy was performed. On pathological examination, the histological and immunohistochemical features were characteristic of epithelioid trophoblastic tumor. Most reported cases of epithelioid trophoblastic tumor have solitary nodules with sharp margins, which is consistent with our ultrasound findings. Ultrasound may be helpful in differentiating epithelioid trophoblastic tumor from placental-site trophoblastic tumor, another tumor of intermediate trophoblastic cells, which shows infiltrative growth insinuating between muscle fibers. Copyright (C) 2010 ISUOG. Published by John Wiley & Sons, Ltd.

The Object Management Group Ontology Definition Metamodel

Report of a submission being made to a major international software engineering standards group, the Object Management Group which ties together OMG standards with World-Wide Web Consortium and International Standards Organization standards. Major industry bodies including IBM are collaborating, and the submission has the support of 24 companies. OMG, W3C and ISO standards strongly influence the industry, especially in combination. Colomb was a major contributor, responsible for 30% of the submission, and the primary author of the paper.

MDA-based re-engineering with Object-Z

This paper describes a practical application of MDA and reverse engineering based on a domain-specific modelling language. A well defined metamodel of a domain-specific language is useful for verification and validation of associated tools. We apply this approach to SIFA, a security analysis tool. SIFA has evolved as requirements have changed, and it has no metamodel. Hence, testing SIFA’s correctness is difficult. We introduce a formal metamodelling approach to develop a well-defined metamodel of the domain. Initially, we develop a domain model in EMF by reverse engineering the SIFA implementation. Then we transform EMF to Object-Z using model transformation. Finally, we complete the Object-Z model by specifying system behavior. The outcome is a well-defined metamodel that precisely describes the domain and the security properties that it analyses. It also provides a reliable basis for testing the current SIFA implementation and forward engineering its successor.

Influence of differently oriented dentin surfaces and the regional variation of specimens on adhesive layer thickness and bond strength

Statement of the Problem: Adhesive systems can spread differently onto a substrate and, consequently, influence bonding. Purpose: The purpose of this study was to evaluate the effect of differently oriented dentin surfaces and the regional variation of specimens on adhesive layer thickness and microtensile bond strength (MTBS). Materials and Methods: Twenty-four molars were sectioned mesiodistally to expose flat buccal and lingual halves. Standardized drop volumes of adhesive systems (Single Bond [SB] and Prime & Bond 2.1 [PB2.1]) were applied to dentin according to the manufacturer`s instructions. Teeth halves were randomly divided into groups: 1A-SB/parallel to gravity; 1B-SB/perpendicular to gravity; 2A-PB2.1/parallel to gravity; and 2B-PB2.1/perpendicular to gravity. The bonded assemblies were stored in 37 degrees C distilled water for 24 hours and then sectioned to obtain dentin sticks (0.8 mm(2)). The adhesive layer thickness was determined in a light microscope (x200), and after 48 hours the specimens were subjected to MTBS test. Data were analyzed by one-way and two-way analysis of variance and Student-Newman-Keuls tests. Results: Mean values (MPa +/- SD) of MTBS were: 39.1 +/- 12.9 (1A); 32.9 +/- 12.4 (1B); 52.9 +/- 15.2 (2A); and 52.3 +/- 16.5 (2B). The adhesive systems` thicknesses (mu m +/- SD) were: 11.2 +/- 2.9 (1A); 18.1 +/- 7.3 (1B); 4.2 +/- 1.8 (2A); and 3.9 +/- 1.3 (2B). No correlation between bond strength and adhesive layer thickness for both SB and PB2.1 (r = -0.224, p = 0.112 and r = 0.099, p = 0.491, respectively) was observed. Conclusions: The differently oriented dentin surfaces and the regional variation of specimens on the adhesive layer thickness are material-dependent. These variables do not influence the adhesive systems` bond strength to dentin. CLINICAL SIGNIFICANCE Adhesive systems have different viscosities and spread differently onto a substrate, influencing the bond strength and also the adhesive layer thickness. Adhesive thickness does not influence dentin bond strength, but it may impair adequate solvent evaporation, polymer conversion, and may also determine water sorption and adhesive degradation over time. In the literature, many studies have shown that the adhesive layer is a permeable membrane and can fail over timebecause ofits continuous plasticizing and degradation when in contact with water. Therefore, avoiding thick adhesive layers may minimize these problems and provide long-term success for adhesive restorations.