ARTreat Project: Three-Dimensional Numerical Simulation of Plaque Formation and Development in the Arteries

Atherosclerosis is a progressive disease characterized by the accumulation of lipids and fibrous elements in arteries. It is characterized by dysfunction of endothelium and vasculitis, and accumulation of lipid, cholesterol, and cell elements inside blood vessel wall. In this study, a continuum-based approach for plaque formation and development in 3-D is presented. The blood flow is simulated by the 3-D Navier-Stokes equations, together with the continuity equation while low-density lipoprotein (LDL) transport in lumen of the vessel is coupled with Kedem-Katchalsky equations. The inflammatory process was solved using three additional reaction-diffusion partial differential equations. Transport of labeled LDL was fitted with our experiment on the rabbit animal model. Matching with histological data for LDL localization was achieved. Also, 3-D model of the straight artery with initial mild constriction of 30% plaque for formation and development is presented

Histamine index and clinical expression of rheumatoid arthritis activity

Background/Aim. Many arguments prove the pathophysiologic role of histamine in the process of remodeling and joint destruction in rheumatoid arthritis. The aim of our study was to find out if there was a relation between histamine concentration in synovial fluid and blood with clinical expression of disease activity. Methods. Histamine concentration in synovial fluid and blood was determinated in 19 patients with rheumatoid arthritis. Histamine concentration measurement was based on the Shore's fluorometric method. Histamine index (HI) was evaluated as a ratio between histamine concentration in synovial fluid and blood. Disease activity score, DAS 28 (3), with three variables (erythrocyte sedimentation rate, the number of swelled joints and the number of tender joints) was also evaluated. Results. Our results showed that there was no significant difference in concentration of histamine in synovial fluid and blood related to disease activity. However, there was a significant difference in the histamine index which was increased proportionally with disease activity. Conclusion. Our study indicates that histamine index could be useful in estimation of rheumatoid arthritis activity