Semi-Quantitative Evaluation of Asymmetricity of Dialysis Membrane Using Forward and Backward Ultrafiltration.

Performance of the dialysis membrane is strongly dependent upon the physicochemical structure of the membrane. The objective of this study is to devise a new in vitro evaluation technique to quantify the physicochemical structures of the membrane. Three commercial dialyzers with cellulose triacetate (CTA), asymmetric CTA (termed ATA), and polyether sulfone (PES) membranes (Nipro Co.

Amidolytic kinetic assay of protein C by selective spectrophotometry in a centrifugal analyzer.

This rapid, simple amidolytic assay of protein C activity in whole plasma involves activation by protein C activator from the venom of Agkistrodon contortrix contortrix (Protac) and use of a Cobas Fara spectrophotometer programmed for kinetic assay. Plasma is incubated with activator venom in the presence or absence of antibody to human protein C in the instrument, chromogenic substrate (S-2366) is added, and the absorbance is measured at 405 nm. The difference between the absorbance of the sample plasma with and without antibody to human protein C correlated well with protein C antigen as assayed by enzyme-linked immunosorbent assay (ELISA) and the Laurell rocket technique in normal subjects, patients being treated with warfarin, and patients with liver cirrhosis or disseminated intravascular coagulation.