Nonalcoholic steatohepatitis/nonalcoholic fatty liver disease is considered to be a hepatic manifestation of various metabolic disorders.However,its precise pathogenic mechanism is obscure.Oxidative stress and consequ...Nonalcoholic steatohepatitis/nonalcoholic fatty liver disease is considered to be a hepatic manifestation of various metabolic disorders.However,its precise pathogenic mechanism is obscure.Oxidative stress and consequent lipid peroxidation seem to play a pivotal role in disease progression.In this study,we analyzed the localization of oxidized phosphatidylcholine(oxPC),a lipid peroxide that serves as a ligand for scavenger receptors,in livers of patients with this steatotic disorder.Specimens of nonalcoholic fatty liver disease(15 autopsy livers with simple steatosis and 32 biopsy livers with steatohepatitis)were examined via immunohistochemistry and immunoelectron microscopy using a specific antibody against oxPC.In addition,scavenger receptor expression,hepatocyte apoptosis,iron deposition,and inflammatory cell infiltration in the diseased livers were also assessed.Oxidized phosphatidylcholine was mainly localized to steatotic hepatocytes and some macrophages/Kupffer cells.A few degenerative or apoptotic hepatocytes were also positive for oxPC.Immunoelectron microscopy showed oxPC localized to cytoplasmic/intracytoplasmic membranes including lipid droplets.Steatotic livers showed enhanced expression of scavenger receptors.The number of oxPC cells was correlated with disease severity and the number of myeloperoxidase-positive neutrophils,but not with the degree of iron deposition.In conclusion,distinct localization of oxPC in liver tissues suggest that neutrophil myeloperoxidase-derived oxidative stress may be crucial in the formation of oxPC and the progression of steatotic liver disease.展开更多
There are two kinetic regimes in high temperature oxidation of metals and alloys.One is the parabolic kinetics in which the ionic diffusion through oxide scales is the rate-determining step.The other is the linear kin...There are two kinetic regimes in high temperature oxidation of metals and alloys.One is the parabolic kinetics in which the ionic diffusion through oxide scales is the rate-determining step.The other is the linear kinetics in which rate determining process is the supply of oxidant through the gaseous boundary layer.The oxygen chemical potential is almost the same as that in the atmosphere in the former case,but in the later case,the oxygen chemical potential is much lower than that in the atmosphere.The oxygen chemical potential at the surface of scale is a good measure of the protective character of the scale.展开更多
文摘Nonalcoholic steatohepatitis/nonalcoholic fatty liver disease is considered to be a hepatic manifestation of various metabolic disorders.However,its precise pathogenic mechanism is obscure.Oxidative stress and consequent lipid peroxidation seem to play a pivotal role in disease progression.In this study,we analyzed the localization of oxidized phosphatidylcholine(oxPC),a lipid peroxide that serves as a ligand for scavenger receptors,in livers of patients with this steatotic disorder.Specimens of nonalcoholic fatty liver disease(15 autopsy livers with simple steatosis and 32 biopsy livers with steatohepatitis)were examined via immunohistochemistry and immunoelectron microscopy using a specific antibody against oxPC.In addition,scavenger receptor expression,hepatocyte apoptosis,iron deposition,and inflammatory cell infiltration in the diseased livers were also assessed.Oxidized phosphatidylcholine was mainly localized to steatotic hepatocytes and some macrophages/Kupffer cells.A few degenerative or apoptotic hepatocytes were also positive for oxPC.Immunoelectron microscopy showed oxPC localized to cytoplasmic/intracytoplasmic membranes including lipid droplets.Steatotic livers showed enhanced expression of scavenger receptors.The number of oxPC cells was correlated with disease severity and the number of myeloperoxidase-positive neutrophils,but not with the degree of iron deposition.In conclusion,distinct localization of oxPC in liver tissues suggest that neutrophil myeloperoxidase-derived oxidative stress may be crucial in the formation of oxPC and the progression of steatotic liver disease.
文摘There are two kinetic regimes in high temperature oxidation of metals and alloys.One is the parabolic kinetics in which the ionic diffusion through oxide scales is the rate-determining step.The other is the linear kinetics in which rate determining process is the supply of oxidant through the gaseous boundary layer.The oxygen chemical potential is almost the same as that in the atmosphere in the former case,but in the later case,the oxygen chemical potential is much lower than that in the atmosphere.The oxygen chemical potential at the surface of scale is a good measure of the protective character of the scale.
