Do-it-yourself dentistry.
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Denture Design↗
Biomedical subjects
O Paes de Almeida
Publications and source records attributed to O Paes de Almeida.
Do-it-yourself dentistry.
Explore the source record for details and available documents.
Denture Design↗
Central mucoepidermoid carcinoma of the mandible: report of four cases with long-term follow-up.
Central mucoepidermoid carcinomas are uncommon tumours, representing about 2 to 4% of all mucoepidermoid carcinomas. They are histologically low-grade cancers, usually affecting the mandible as uni- or multilocular radiographic lesions. The authors report four cases of central mucoepidermoid carcinomas affecting the mandible and discuss their clinical, radiographic and histological findings. Four females were affected, with a mean age of 42 years and all cases involved the posterior mandible. Treatment included surgery in three cases and surgery associated to neck dissection and radiotherapy in one case. Two patients showed no recurrence and were alive without signs of the disease after a mean follow-up of 78 months. The other two patients showed local recurrence and one was alive with disease after a follow-up of 384 months, and the other was followed-up for 324 months dying by other causes without signs of the tumour. Central mucoepidermoid carcinomas of the mandible are low-grade tumours, and effective surgical treatment involving wide local excision or en bloc resection allows patients to have a favourable prognosis after long-term follow-up.
Adult↗
A clinicopathologic study of 196 intraoral minor salivary gland tumours.
We present a retrospective study of 196 patients with intraoral minor salivary gland tumours, 128 malignant and 68 benign, diagnosed from 1954 to 1993 in the A. C. Camargo Hospital, São Paulo, Brazil. Sixty-five percent of the cases occurred in the palate, followed by tongue (9.7%) and retromolar area (6.1%). Pleomorphic adenoma was the most common benign tumour, and mucoepidermoid carcinoma was predominant among the malignant tumours. Surgery was the main treatment method and postoperative radiotherapy and radiotherapy alone were used in 40 and 15 patients, respectively. Local recurrence was observed in two patients with pleomorphic adenoma and in eight patients with malignant tumours. Regional lymph node metastases occurred in four cases and distant metastases in five. Forty-six of 47 patients with benign tumours who were followed up from 1 to 7 years were alive without disease. Twenty-four of 79 patients with malignant tumours who were followed up for at least 5 years died due the tumour and 47 were alive without disease.
Adenoma, Pleomorphic↗
Oral focal acantholytic dyskeratosis induced in sialoadenectomized rats painted orally with the carcinogen 4-nitroquinoline N-oxide.
This study examines the effects of xerostomia on the development of mucosal changes proceeding carcinoma in rats painted orally with 4-nitroquinoline N-oxide (4NQO). Sialoadenectomy enhanced the incidence of focal acantholytic dyskeratosis (FAD) on the palate and tongue of rats painted on the palate with 0.5% 4NQO three times weekly. At one month, no changes were observed. After two months of painting with 4NQO, sialoadenectomized rats, but not controls, had FAD. After three months, FAD was seen in both test and control groups, but the incidence of FAD was higher in the test group and seen more on the palate than on the tongue of xerostomic animals. Neither test nor control animals developed carcinoma within this study period.
4-Nitroquinoline-1-oxide↗
The cardiac muscle in the pulmonary vein of the rat: a morphological and electrophysiological study.
The pulmonary veins of albino Wistar rats were studied by means of light and electron microscopy. The media of larger veins consists of cardiac muscle fibers which extend until the vessels attain about 100 mu in diameter. This coat consists of external longitudinal fibers and internal circular fibers. The vasa vasorum are well developed and the capillaries show pseudofenestrations. The numerous adrenergic and cholinergic nerve endings do not form typical motor end-plates as seen in skeletal muscles. The ultrastructure of these media muscle fibers is similar to that of the rat hearts. The smooth muscle layer of larger pulmonary veins is not continuous as it is in smaller veins where it forms cushions. Comparison of albino rats and other rodents reveal striking differences. Action potential shape and propagation velocity (0.5-1.2 m/s) along the myocardial coat of the pulmonary vein were similar to those observed in the left atrium and so was their sensitivity to locally applied acetylcholine. The physiological direction of propagation in rat pulmonary veins is toward the lung. This fingind lends support to the hypothesis of a rhythmic, valve-like action of the striated musculature of the pulmonary venous wall during the systole and a possible role in the capacitance of the pulmonary circulation.
Acetylcholine↗