Carcinoma hepatocelular. Parte 1: considerações gerais e diagnóstico Hepatocellular carcinoma: Part 1. General considerations and diagnosis

São revistos aspectos relativos à incidência/prevalência, fatores de risco, proliferação celular (carcinogênese), anatomia patológica, progressão e evolução das hepatites virais B e C para o carcinoma hepatocelular inicial, alguns dados clínicos da doença, seu diagnóstico clínico, laboratorial e radiológico, com especial atenção à ultra-sonografia, Doppler, tomografia computadorizada e ressonância magnética.<br>Several aspects are revised on the subject hepatocellular carcinoma related to its incidence/prevalence, risk and prognostic factors, cellular proliferation, pathological aspects, progression of chronic hepatitis B and C to cirrhosis and hepatocellular carcinoma, natural course of hepatocellular carcinoma, some clinical datas, morphological diagnosis with special emphasis on radiological findings as ultrasound, dynamic computed tomography and magnetic resonance imaging, color-power Doppler, tissue and contrast harmonic

Unravelling the Plant Cell Cycle in Nematode Induced Feeding Sites

Cell cycle activation is a key component of host plant manipulation by sedentary nematodes. It is generally believed that root-knot nematodes induce giant cells by repeated cycles of acytokinetic mitosis accompanied by endocycles while cyst nematodes induce extra rounds of DNA synthesis. Microscopic expression analysis of genes that encode key regulators of the cell cycle and the use of cell cycle inhibitors demonstrate that endoreduplication cycles may play a role in both giant cell and syncytium formation, while mitosis is essential for giant cell development and syncytium expansion (via fusion of neighbouring cells). When mitosis is blocked, gall development is completely inhibited, indicating that cycles of endoreduplication or other means of DNA amplification are insufficient to drive giant cell expansion. DNA synthesis is required for both gall and syncytium development. With the current knowledge available on the plant cell cycle, and particularly the genes involved in endoreduplication, their specific role in feeding site development can be determined more precisely to provide insight on how cell cycle processes underlie development of both giant cells and syncytia. It is still unknown whether signals from the nematode directly induce the sophisticated changes in the cell cycle that occur in developing feeding sites. Increasing knowledge on nematode secreted proteins active during parasitism will facilitate the identification of possible triggers of the plant cell cycle during this complex plant-pathogen interaction