ABSTRACT
This overview examines some selected genetic mechanisms of cancer development. Strong evidence has been accumulated suggesting that alteration in either the struture or activity of proto-oncogene contributes to the development and for the maintenance of the malignant phenotype. Many factors are known to interfere with both normal and pathological controls of growth and differentiation of thyroid cells. Among them, some are oncogenes, like those encoding g-proteins (ras, gsp, TSH-R), encoding thyrosino kinases receptors (RET, trk, c-met, c-erb, BRAF) and encoding nuclear proteins (c-myc, e-fós). Others are anti-oncogenes (p53, p15, RB), by loss of the growth suppression ativity of the suppressive gene. Cancer cell invasion and metastasis are the major causes of morbidity and mortality in cancer patients. Many genes are involved in the mechanism of invasion and metastasis of thyroid tumors, like Nis, b-catenina, E-caderina, galectina-3, GLUT, telomerase, VEGT, nm-23. All these oncogenes, antioncogenes and tumor invasion and metastasis-related genes are analysed. Several clinical and prognostic factors have been proposed to identify patients at risk for the development of metastasis and death. The role of molecular genetics in this issue is discussed. However, other studies are needed to validate molecular alterations as an independent prognostic factor in thyroid cancer.
ABSTRACT
Hyperparathyroidism is a desease caused by increase of parathormone secretion, leading to a misfunction of calcium metabolism. Although not very common among population in general, it is frequently observed in patients with cronic renal disease. It can involve a slight syntomatic form, but as a whole, its main repercurssions occur in skeletic muscles, urinary and intestinal systems. The authors conduct a broad revision of the literature, focusing on the methods of diagnosis and spot checking before and during the operations of parathyroid glands. Surgical recommendations, tatic aspects and types of surgery to be implemented are discussed. A systematization for adequate surgical technics performed at the General Surgery Service of Clementino Fraga Filho Hospital of Federal University of Rio de Janeiro is fully discribed and recommended.
ABSTRACT
Os autores realizaram um estudo comparativo entre os dados da literatura e os obtidos em 59 pacientes portadores de carcinomas dos ductos biliares extra-hepáticos. A grande maioria dos doentes evolui com icterícia, emagrecimento e dor. Há elevação de bilirrubinas totais, fosfatase alcalina e gama glutamil-transferase, em um número relevante de casos. Os exames complementares pré-operatórios fornecem subsídios importantes para a elaboração tática cirúrgica. Atuam também de forma profilática e terapêutica, através da descompressão da via biliar. O tratamento cirúrgico objetiva inicialmente a drenagem do sistema biliar. No entanto, a ressecção tumoral representa a conduta mais eficaz. As soluções paliativas compreendem, em especial, as anastomoses biliodigestivas e as drenagens através da inserção de próteses ou drenos. O óbito, por via de regra, é conseqüente a sepsis e insuficiência hepátivca, que contribuem para falência orgânica múltipla