Anaplastic T-cell lymphoma presenting as fatal acute liver failure

Acute liver failure (ALF) is an uncommon manifestation of liver disease and constitutes a medical emergency for which early identification is necessary. Hepatic involvement by hematologic malignancies although frequent, rarely causes severe hepatic dysfunction. Even more, acute hepatic failure as the first manifestation of a hematologic malignancy is extremely uncommon, although some cases have been reported in the literature. We describe the case of a 61 y/o puertorrican veteran who developed acute hepatic failure secondary to massive infiltration of the liver by a recurrent non-Hodgkin's lymphoma.

Trabecular, nasal, branchial, and pericardial cartilages in the sea lamprey, Petromyzon marinus: fine structure and immunohistochemical detection of elastin.

Immunohistochemical and ultrastructural methods were used to examine the distribution of elastin and the fine structure of the trabecular, nasal, branchial, and pericardial cartilages in the sea lamprey, Petromyzon marinus. The cells and matrix, as well as the overall organization of these components, in larval and adult trabecular cartilage resemble those of adult annular and piston cartilages (Wright and Youson: Am. J. Anat., 167:59-70, 1983) Chondrocytes are similar to those in hyaline cartilage. Lamprin fibrils and matrix granules, but no collagen fibrils, are found in a matrix arranged into pericellular, territorial, and interterritorial zones. Branchial, pericardial, and nasal cartilages differ from trabecular, annular, and piston cartilages in the organization of their matrix and in the structural components of their matrix and perichondria. Furthermore, immunoreactive elastin-like material is present within the perichondria and peripheral matrices of nasal, branchial, and pericardial cartilages in both larval and adult lampreys. Oxytalan, elaunin, and elastic-like fibers are dispersed between collagen fibers in the perichondrium. The matrix contains lamprin fibrils, matrix granules, and a band of amorphous material, which is reminiscent of elastin, in the periphery bordering the perichondrium. The presence of elastic-like fibers and elastin-like material within some lamprey cartilages implies that this protein may have evolved earlier in vertebrate history than has been previously suggested.

Transformation of mucocartilage to a definitive cartilage during metamorphosis in the sea lamprey, Petromyzon marinus.

An ultrastructural analysis of the development of adult piston (tongue) cartilage in the ventromedial longitudinal bar (VMLB), an area of larval mucocartilage, was undertaken in the lamprey, Petromyzon marinus, in order to clarify the relationship between these two unique larval and adult connective tissues. At the onset of metamorphosis, the mucocartilage fibroblasts dedifferentiate into a "mesenchymal" cell type. Migration of unspecialized cells from surrounding tissues plays an important role in the development of a cellular "embryonic" tissue in the VMLB. Degradation of the mucocartilage extracellular matrix (ECM) by the unspecialized cells seems to occur prior to cartilage differentiation. This event is followed by the appearance of a blastema of undifferentiated cells, which expands by proliferation of cells in the core of the VMLB. The cells of the blastema subsequently differentiate into chondroblasts, which secrete adult ECM components consisting of 20-nm nonbanded fibrils, electron-dense branched lamprin fibrils, and proteoglycan. The present study suggests that mucocartilage, as a primitive or embryonic connective tissue, temporarily specializes to act as a skeletal support during larval life. Once metamorphosis is initiated, this tissue resumes an embryonic character (mesenchymal) and cartilage histogenesis takes place. The mechanism of cartilage development within the lamprey VMLB is similar to that observed in the chondrogenic system of higher vertebrates.