Parenchymal structures

This is a thresholding technique to display all pixels with attenuation values greater than a user-specified HU threshold. Bone, opacified vessels, and calcification will be captured with a threshold of 80-100 HU however, most parenchymal structures will be excluded [77]. SSD is not as useful in acute stroke evaluation, as only pixels on the surface are displayed. This limits evaluation for partially occlusive thrombus. It has been most successfully used for surgical planning, such as for paraclinoid aneurysms. 

Especially the occurrence of fine-linear calcifications and the in part linear distribution of the calcifications is highly suggestive of malignancy. The microcalcifications are less well seen on the MLO (b) and ML (c) views, which is predominantly caused by a slight motion blur in these images. In contrast to mass lesions and architectural distortions, visibility of microcalcifications is less affected by overlying parenchymal structures... 

Bronchiolitis may be defined as a process centered in and around membranous and/or respiratory bronchioles with sparing of a considerable portion of the other parenchymal structures in which inflammatory cells and mesenchymal tissue are both present (1,4). 

Most gene therapy applications require extravasation of the DNA carriers so that only relative small DNA complexes can pass through the blood vessels and interact directly with parenchymal cells after vascular administration [2]. Under pathophysiological conditions, the structure of the vasculature can change. This phenomenon - termed the enhanced permeation effect - has been utilized to passively target macromolecules to tumors, since blood vessels in tumors are relatively more leaky. 

Berry MN, Friend DS. High-yield preparation of isolated rat liver parenchymal cells a biochemical and fine structural study. J Cell Biol 1969 43 506-520. 

The classic studies of Bryan Toole and his laboratory separate embryology into two stages, a model that can be superimposed on the development of virtually all parenchymal organs and vertebrate structures (1) a primary HA-rich phase in which undifferentiated stem cells involved proliferation and migration, followed by (2) removal of the HA and the onset of cellular differentiation and morphogenesis 94... 

Liver. In humans, chronic Cd exposure does not typically result in hepatotoxicity. In laboratory animals, the liver accumulates the largest concentrations of Cd after acute or chronic exposures. In chronically exposed rats, liver injury occurs prior to renal dysfunction. Chronic Cd effects in the liver include increased plasma activities of alanine and aspartate aminotransferases, structural irregularities in hepatocytes, and decreased microsomal mixed function oxidase and CYP450 activities. Acute exposures in rats result in hepatic necrosis, particularly in parenchymal cells. Additionally, rough endoplasmic reticulum deteriorates, while smooth endoplasmic reticulum proliferates. Mitochondria are also degraded. As is the case with chronic exposure, microsomal mixed function oxidases and CYP450s are inhibited. 

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