Tromboembolia pulmonar e infarto pulmonar / Pulmonary thromboembolism and pulmonary infarction

As manifestações radiográficas torácicas da Embolia Pulmonar são: alargamento da artéria pulmonar hiliar, constituindo o sinal mais importante; a imagem de um vaso arterial terminando abruptamente, caracterizando o "sinal do nó"; dilatação da veia cava superior e da veia ázigo, representada pela diltação do mediastino; o "sinal de Westmark"caracterizando a presença de oligoemia do parênquima pulmonar, face a oclusão da artéria pulmonar segmentar ou lobar; imagem de consolidação na área do parênquima pulmonar comprometido, frequentemente resultado de hemorragia (hemosiderose local). A imagem de hipotransparência semelhante a um cone truncado, com base voltada para a pleura visceral e o ápice voltado para o hilo, imagem essa chamada de "Corcova de Hampton", quando existe, é sugestiva de Infarto Pulmonar. O volume do derrame pleural varia, podendo ser abundante; quando é de localização predominantemente infra-pulmonar, pode simular a elevação da hemicúpula diafragmática. Um quadro clínico-radiológico de cor Pulmonale evoluindo para a descompensação cardíaca, pode estar presente

No evidence for oncogenic mutations in guanine nucleotilde-binding proteins of endocrine tumors

In recent years, the application of DNA technology has led to significant advances in the elucidation of the somatic defects which can occur in several tumors, including oncogene expression, allelic loss and inappropriate gene transcription and translation. Normal cell growth is regulated by many proto-oncogenes encoding proteins and specific mutations can convert these genes in oncogenes, leading to abnormal protein products that are responsible for the growth of malignant cells. Mutations that inhibit GTPase activity of the a subunit of the stimulatory G protein (Gsa) have been demonstrated in approximately a thrid of GH-secreting tumors, in 10 percent of functionless pituitary tumors, and also in corticotropinomas although with far less frequency. These mutations -gsp mutations - stabilize the Gsa in the active state (GTP-bound state), resulting in the permanent activation of adenylyl cyclase, leading to tumorigenesis. In addition, mutations in the a subunit of the inhibitory GTP-binding protein gene (Gi2a), or gip mutations, have been found in a subset of adrenocortical and ovarian tumors. In the present work, using the polymerase chain reaction and denaturing gradient gel electrophoresis, we investigated the existence of gsp and gip mutations in twenty three different endocrine tumors.