[Primitive myxoid melanoma: An unusual histological aspect]. / Mélanome myxoïde primitif : une forme histologique inhabituelle.

BACKGROUND: Myxoid melanoma is a rare variant of melanoma that must be recognised. Herein we describe a new metastatic case. PATIENTS AND METHODS: A 78-year-old woman consulted for a firm, pinkish nodule measuring 25mm and present for six months on her left leg. Analysis of the biopsy revealed achromic fusiform tumour cells separated by large myxoid plaques. Labeling of SOX10, HMB45 and PS100 was diffuse and of moderate to strong intensity. A diagnosis of myxoid melanoma was considered, with Breslow thickness of 9mm. Surgery was carried out with a 2-cm margin and confirmed the diagnosis. Dermatological follow-up at one year revealed metastatic spread to the ganglia, pleura, liver and bone. DISCUSSION: Few cases of primary myxoid melanoma have been described, and the condition is probably underdiagnosed. The classic clinical presentation of this condition consists of a solitary achromic nodule found chiefly on the limbs. The microscopic appearance is relatively non-specific. Immunohistochemical analysis may indicate melanocytic involvement: cells exhibit expression of SOX10, diffuse expression of protein S100, and less consistent and more variable expression of HMB45. The increasingly common use of anti-SOX10 is of value since it is expressed in the nucleus of melanocytes. Mastocytes and TGF-ß secretion appear to be involved in myxoid stroma production. In the absence of specific codification, management of myxoid melanoma is comparable to that of other types of melanoma. There is uncertainty about the prognosis, with the involvement of TGF-ß possibly indicating the aggressive potential of this type of tumour.

Diagnostic performance of dobutamine stress echocardiography: A South African experience.

BACKGROUND: Dobutamine stress echocardiography (DSE) is a well-established modality for the diagnosis of coronary artery disease, but there are no reported diagnostic data in southern Africa. Objectives. To compare the safety, sensitivity and specificity of a South African (SA) DSE programme with larger, international series. Methods. All patients undergoing DSE from 2019 to 2021 at a single SA centre were included. A new wall motion abnormality (≥2 segments) signified inducible ischaemia. Results. A total of 106 patients (mean (standard deviation) age 61 (11) years, 68% male) were analysed. Six patients (6%) experienced chest pain during DSE and 4 (4%) developed an atrial arrhythmia. The sensitivity and specificity for epicardial coronary stenosis were 77% and 74%, respectively, changing to 82% and 72% when excluding those who had previous coronary artery bypass surgery. Conclusion. The sensitivity, specificity and safety of an SA DSE programme were comparable to international series. A DSE programme is feasible in a resource-constrained environment.

[Focus on the smear layer in 1990]. / Le point sur la "smear layer" en 1990.

The smear layer is a debris-ladden layer, adhering firmly to the hard tissues of the tooth. It plays a major role in the different adhesive systems. An update of the recent knowledge on smear layer will be done in this article. When the carious lesion is removed, a microscopic debris-ladden layer forms at the level on the enamel and the dentine. This layer of materials is extremely adherent to the dental structure, and will come in between the hard dental tissues and the filling materials. In this article different studies were reviewed on the formation, structure and physiology of the smear layer. Consequences of this smear layer's removal on the pulp are discussed. A small study of different adhesive systems is conducted.

[Adaptation of composites to enamel: relation to the appearance of marginal staining]. / Contribution à l'étude de l'adaptation des composites à l'émail: relation avec l'apparition des colorations marginales.

Marginal staining is the major cause of failure of composite resin restorations. The following reasons were incriminated: The nonrespect of the integrity of the cavity limits during cavity obturation, as for instance, when a simple bevel is made. The appearance of fractures or composite bond strength failures during polishing procedures. This phenomenon can be enhanced by the use of composite finishing knives (KOMET) and by overfilling the cavity.

[Comparative study of the seal and porosity of provisional coronal filling materials in endodontics]. / Etude comparative de l'étanchéité et de la porosité des matériaux d'obturation provisoire coronaire en endodontie.

The porosity and the leakage properties of 13 temporary fillings used between each appointment during endodontic treatment were investigated by means of thermocycling and dye staining of the interface between the teeth and the filling material. A scanning electron microscope was also used for these observations. The 8 commercially produced temporary fillings seal adequately the cavity whereas the 5 materials prepared and mixed by the practitioner allowed wide staining diffusion and therefore were leaky.

[Use of the CO2 laser in enamel-dentin bonding procedures: experimental findings]. / Utilisation du laser CO2 lors des procédures de collage amélo-dentinaire: arguments expérimentaux.

The objective of this study is to verify if laser (CO2) preparation of dental tissues has an effect on the quality of the seal of composite fillings. Forty-eight cavities were filled with the Scotchprep/Scotchbond 2 system, using P 50 (3M) as filling material, following the clinical protocol of the system; 40 cavities had previously been treated with a CO2 laser Sharplan 1020 (SBM). The teeth were thermocycled (240 cycles 4 degrees C/55 degrees C), then placed in a 0.5% basic fuschine solution for 48 hours after isolation of the root dentin. After inclusion and section, the penetration of the coloring agent was examined at the interface tooth-filling. This was followed by examination of the interface composite-tooth with the Scan Electronic Microscope. In order to visualize a possible alteration of the dentinal seal, 4 cavities treated with laser were placed in a 0.5% basic fuschine solution for 48 hours after isolation of the root dentin. Four reference cavities were cut with a diamond bur on a high speed handpiece. The following results were obtained: 1) the dentinal permeability of the laser-treated samples increases markedly in comparison with the reference group. 2) the filling-tooth junction of the laser-treated samples were never dye-tight (contrary to the reference samples). 3) fissures were created in the enamel and the dentin. The Scan Electron Microscopy confirms these results.