810 research outputs found
Automatic configuration of the reference point method for fully automated multi-objective treatment planning applied to oropharyngeal cancer
Purpose: In automated treatment planning, configuration of the underlying algorithm to generate high-quality plans for all patients of a particular tumor type can be a major challenge. Often, a time-consuming trial-and-error tuning procedure is required. The purpose of this paper is to automatically configure an automated treatment planning algorithm for oropharyngeal cancer patients. Methods: Recently, we proposed a new procedure to automatically configure the reference point method (RPM), a fast automatic multi-objective treatment planning algorithm. With a well-tuned configuration, the RPM generates a single Pareto optimal treatment plan with clinically favorable trade-offs for each patient. The automatic configuration of the RPM requires a set of computed tomography (CT) scans with corresponding dose distributions for training. Previously, we demonstrated for prostate cancer planning with 12 objectives th
Hepatic lipase is localized at the parenchymal cell microvilli in rat liver
Hepatic lipase (HL) is thought to be located at the vascular endothelium
in the liver. However, it has also been implicated in the binding and
internalization of chylomicron remnants in the parenchymal cells. In view
of this apparent discrepancy between localization and function, we
re-investigated the localization of HL in rat liver using biochemical and
immunohistochemical techniques. The binding of HL to endothelial cells was
studied in primary cultures of rat liver endothelial cells. Endothelial
cells bound HL in a saturable manner with high affinity. However, the
binding capacity accounted for at most 1% of the total HL activity present
in the whole liver. These results contrasted with earlier studies, in
which non-parenchymal cell (NPC) preparations had been found to bind HL
with a high capacity. To study HL binding to the different components of
the NPC preparations, we separated endothelial cells, Kupffer cells and
blebs by counterflow elutriation. Kupffer cells and endothelial cells
showed a relatively low HL-binding capacity. In contrast, the blebs,
representing parenchymal-cell-derived material, had a high HL-binding
capacity (33 m-units/mg of protein) and accounted for more than 80% of the
total HL binding in the NPC preparation. In contrast with endothelial and
Kupffer cells, the HL-binding capacity of parenchymal cells could account
for almost all the HL activity found in the whole liver. These data
strongly suggest that HL binding occurs at parenchymal liver cells. To
confirm this conclusion in situ, we studied HL localization by
immunocytochemical techniques. Using immunofluorescence, we confirmed the
sinusoidal localization of HL. Immunoelectron microscopy demonstrated that
virtually all HL was located at the microvilli of parenchymal liver cells,
with a minor amount at the endothelium. We conclude that, in rat liver, HL
is localized at the microvilli of parenchymal cells
Automated Radiotherapy Planning for Patient-Specific Exploration of the Trade-Off Between Tumor Dose Coverage and Predicted Radiation-Induced Toxicity-A Proof of Principle Study for Prostate Cancer
Background: Currently, radiation-oncologists generally evaluate a single treatment plan
for each patient that is possibly adapted by the planner prior to final app
Effect of monomeric immunoglobulin G (IgG) on the clearance of soluble aggregates of IgG in man
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