No abstract

The in vitro measurement of whole-blood viscosity, plasma viscosity, and erythrocyte aggregability is easy to perform, but they only allow a partial insight into the complexity of blood flow characteristics; however, they permit definition of the rheological properties of new hemorheological therapeutic modalities such as extracorporeal plasma therapy as described in this paper. Under more theoretical aspects, it becomes obvious that such hemorheological approaches should either improve the vasomotoric properties of blood vessels, reduce the circulating red blood cell concentration, or improve the viscosity by reducing the concentration of hemorheologically relevant plasma proteins. In this review, the rheological effect of a single apheresis treatment with different devices was compared. Due to their differences in selectivity, the extracorporeal methods have different effects on the rheologically relevant plasma proteins, and, therefore, their rheological effectiveness differs remarkably. Today, the classical blood letting and plasma exchange treatment have been replaced by erythrapheresis and selective devices for extracorporeal plasma treatment, respectively. For more than 10 years, the following 5 more-or-less selective apheresis procedures are commercially available: immunoadsorption, differential filtration, polyanion adsorption by dextrane sulfate as well as by polyacrylate, and polyanion precipitation by heparin as polyanion. The last three procedures are semiselective and, therefore, relatively unspecific whereas immunoadsorption only affects the plasma lipoprotein concentration. Several studies have shown the effective use of extracorporeal hemorheotherapy for the treatment of various diseases including macro- and cryoglobulinemia, Raynaud's disease, hyperlipoproteinemia (often characterized by premature atherosclerosis and coronary heart disease and peripheral arterial occlusive disease), cerebral multi-infarct demention and acute ischemic stroke, sudden hearing loss, and acute occlusion of the central retinal artery.

We conclude that the newly developed automated assay represents a user-friendly and analytical tool to determine urinary AAP activity in a medium- to high-throughput laboratory. Potential applications include clinical diagnostic work and toxicological studies.

It has been shown that serum total homocysteine (HC) is a risk factor for vascular disease which characterizes endothelial damage. The incidence of vascular disease is increased in continuous ambulatory peritoneal dialysis (CAPD) patients. Our aim was to investigate: (1) whether concentration of HC correlates with atherosclerotic and inflammatory events, and (2) if fish oil therapy can retard the disturbance in lipid metabolism which promotes atherosclerosis. Fourteen patients with various degrees of impaired peritoneal clearance and lipid metabolism were observed. In all patients the serum HC was elevated. Seven patients were treated with fish oil for three months. The results indicate an average increase of HC (+18%), total cholesterol (+6.6%), aggregation of erythrocytes (+9%), and an average decrease of dialysate-to-plasma creatinine (DIP) ratio (-7%), deformability of erythrocytes (-8%), and normalization of elevated soluble interleukin2 receptor (sIL-2R) values. Regression analysis of all data demonstrated a significant correlation between HC and parameters of lipid metabolism and hemorheology. There were no significant correlations between HC and peritoneal function and serum cytokine levels. We conclude that the treatment in CAPD patients with fish oil did not improve the lipid metabolism disturbances in atherosclerosis and peritoneal function. Elevated HC confirms the progression of the disease.

Objective To study changes in the peritoneal micro-circulation during continuous ambulatory peritoneal dialysis (CAPD) by studying change in the microcirculation of the fingernails of CAPD patients. Setting A university department. Design A cross-sectional study of 10 nondiabetic patients on CAPD. Intervention Hemorrheological tests of fingernail microcirculation using equipment built at our university. Main Outcome Measures Microcirculation was characterized by estimation of capillary density, red blood cell (RBC) column diameter, torque index, and RBC flow velocity semiquantitatively using videocapillaroscopy at the fingernail fold and plasma viscosimetry. Findings were correlated with treatment duration, peritoneal clearance, state of capillary morphology and hemodynamics, and lipid and fibrinogen levels. Results Treatment duration was significantly correlated (p ≤ 0.05) with low-density lipoprotein (LDL) (r = 0.776) and clearances of urea (r = -0.583), uric acid (r = -0.666), and potassium (r = -0.764). Changes in capillary morphology were correlated to clearances of urea (r = 0.643) and uric acid (r = 0.701). The fibrinogen concentration increases plasma viscosity (r = 0.799) and deteriorates the capillary state (r = -0.706). In addition, plasma viscosity correlates to cholesterol (r = 0.620, NS) and LDL (r = 0.781), but not to high-density lipoprotein and triglycerides. Conclusion CAPD treatment results in lipid abnormalities and high fibrinogen levels that may cause microvascular damage and poor perfusion. These interactions may explain the deterioration of peritoneal transport in some CAPD patients.