acetylcellulose and Renal-Insufficiency

Haemodialysis membranes with a wide range of solute and hydraulic permeabilities are used clinically. Such membranes are manufactured from either cellulose or synthetic co-polymers and their biocompatibility is commonly characterized by the complement activation and white cell changes observed during their use. The cellobiosic unit may be modified by the partial or total replacement of the hydroxyl groups by diethylaminoethyl (Hemophan), acetate (cellulose acetate), triacetate (cellulose triacetate) or 2,5-acetate (Diaphan). We have undertaken a prospective study in which such renal membranes have been studied in terms of the complement activation and neutropenia produced with the aim of investigating the relationship between modification of the cellobiosic unit and the magnitude of neutropenia and complement activation, and the extent to which membrane base material influences these parameters, by comparing the changes observed in modified cellulose membranes with that for a synthetic membrane (polysulphone). Our findings show that, while the degree of substitution varies between < 1% and total substitution, there is no correlation between the numbers of hydroxyl groups replaced and alteration of complement activation and neutropenia. However, by modification of the cellobiosic unit it is possible to produce a membrane whose biocompatibility is similar to that of a membrane manufactured from a synthetic co-polymer such as polysulphone.

Topics: Biocompatible Materials; Blood Platelets; Cellulose; Complement Activation; Cross-Over Studies; Humans; Leukocyte Count; Leukocytes; Membranes, Artificial; Neutropenia; Platelet Count; Polymers; Prospective Studies; Renal Dialysis; Renal Insufficiency; Sulfones

Point-of-care testing is currently one of the subjects of growing interest in analytical chemistry. Elevated levels of urinary protein imply renal failure, which is one of the world's biggest public health problems. In spite of the urgent necessity for a screening test of protein in urine, there are no reports of a simple yet sensitive method for its detection. In this study, we developed a new visual method, using Erythrosin B and a cellulose acetate membrane film as the substrate for a new spot test of urinary protein in the presence of poly(ethylene glycol) (PEG). The noteworthy point of our work is that when a drop of dye-protein solution containing PEG is set on a membrane film, a red ring-shaped stain of the dye-bound protein is formed on the film surface. PEG plays a significant role in eliminating the reagent blank, thus providing a clear contrast. Measurements taken using a dynamic light scattering particle size analyzer indicated that the underlying mechanism of this contrast is brought about by the different sizes of the excess dye and dye-protein particles. The visual detection limit is 0.5 mg dm(-3) for human serum albumin (HSA), the main protein in urine. Our visual method is sufficiently sensitive to detect urinary protein even for healthy subjects, providing a higher sensitivity than test strips by a factor of 60-200. When 0.15 cm(3) of urine is used to prepare 10 cm(3) of sample solution, the practical detection threshold is 30 mg dm(-3) in urine using a 67x dilution factor. The proposed method will be useful as a simple, rapid, and cost-effective screening test for the diagnosis of renal failure at an early stage.

Topics: Albuminuria; Cellulose; Coloring Agents; Erythrosine; Humans; Point-of-Care Systems; Polyethylene Glycols; Proteinuria; Renal Insufficiency; Spectrophotometry