Oxysterols and redox signaling in the pathogenesis of non-alcoholic fatty liver disease.

Oxysterols are oxidized species of cholesterol coming from exogenous (e.g. dietary) and endogenous (in vivo) sources. They play critical roles in normal physiologic functions such as regulation of cellular cholesterol homeostasis. Most of biological effects are mediated by interaction with nuclear receptor LXRα, highly expressed in the liver as well as in many other tissues. Such interaction participates in the regulation of whole-body cholesterol metabolism, by acting as "lipid sensors". Moreover, it seems that oxysterols are also suspected to play key roles in several pathologies, including cardiovascular and inflammatory disease, cancer, and neurodegeneration. Growing evidence suggests that oxysterols may contribute to liver injury in non-alcoholic fatty liver disease. The present review focuses on the current status of knowledge on oxysterols' biological role, with an emphasis on LXR signaling and oxysterols' physiopathological relevance in NAFLD, suggesting new pharmacological development that needs to be addressed in the near future.

Activated sludge diffusion for odour removal --effects of H2S on the biomass.

The removal of odours from wastewater treatment plants through diffusion of odour-containing air volumes into the aerated basins was investigated in a bench scale experimental campaign which lasted more than 200 days. Hydrogen sulphide was selected as a model odorous compound and its removal efficiencies were experimentally evaluated along with its effects on the biomass and on the main biochemical processes. Two bench scale sequencing batch reactors were fed in parallel on real primary sewage and monitored for chemical oxygen demand removal, nitrification and denitrification. The balance of H2S was also monitored after adding to one of them a Na2S liquid solution of 17 mgS l(reactor)(-1) d(-1), corresponding to a gas-phase concentration of 240 mgS (Nm3)(-1). Results showed an average sulphide removal of 94% in the reactor supplied with Na2S. Moreover, microbial composition did not show relevant variations after the addition of sulphide, and the good features of activated sludge flocs were maintained also in terms of sludge settleability. No relevant effects of sulphide were detected on carbon and nitrogen metabolism and chemical oxygen demand removal, nitrification and denitrification efficiencies were always above 75%, 95%, and 50% respectively, and comparable across the two reactors.

Alterations of erythrocyte lipid pattern and of some membrane related functions as a consequence of plasma lipid disorder in diabetes mellitus.

The influence of plasma lipid disorders on red blood cell (RBC) lipid pattern and some related erythrocyte membrane functions, such as glycerol (GLT50) permeability and erythrocyte deformability was studied in diabetes mellitus. Significantly higher red blood cell cholesterol content, GLT50 and erythrocyte filtration time values were found in diabetics. GLT50 values were found closely related to both RBC cholesterol content (r = 0.84, p less than 0.001) and filtration time (r = 0.60, p less than 0.001). Interestingly, six diabetics with retinopathy showed GLT50 values above 60 sec. The RBC Cholesterol/Phospholipids molar ratio was significantly higher in diabetics. The most notable changes of plasma lipid pattern in diabetics were a decrease of both plasma HDL cholesterol, phospholipids and Apolipoprotein A levels with an increase of HDL free cholesterol/phospholipids molar ratio. RBC cholesterol content was found to be inversely related to HDL esterified/free cholesterol molar ratio (r = -0.56, p less than 0.001), while RBC cholesterol/phospholipids molar ratio was significantly related to both HDL free cholesterol/phospholipids (r = 0.51, p. 0.001) and to LDL total cholesterol/phospholipids (r = 0.25, p less than 0.05). Lastly, HDL cholesterol levels were found to inversely relate to glycosylated haemoglobin values (r = -0.54, p less than 0.01).