ABSTRACT
We describe a mathematical model for a single-tube enzyme immunoassay for free thyroxin (FT4), involving use of a thyroxin/horseradish peroxidase (EC 1.11.1.7) conjugate that does not interact with thyroxin-binding globulin. In the presence of serum two populations of unassociated, or free, immunologically active constituents are present: FT4 and the conjugate. The concentrations of the former are determined by the serum constituents and of the latter by the albumin concentration. When a small quantity of antibody is added, it reacts with the variable amount of FT4 and with the constant amount of the conjugate, thus giving a measure of the FT4. We constructed a mathematical model based on thermodynamic binding constants and adsorption data. The model gives satisfactory agreement with the experimental data under a variety of experimental conditions. Results for 19 patients' serum samples demonstrate the validity of the concept.
Subject(s)
Thyroxine/blood , Horseradish Peroxidase , Humans , Immunoenzyme Techniques , Kinetics , Models, Biological , Protein Binding , Radioimmunoassay , Reference Values , Serum Albumin , Thyroxine-Binding ProteinsSubject(s)
Immunoglobulin G/analysis , Luminol , Pyridazines , Animals , Binding, Competitive , Dose-Response Relationship, Drug , Humans , Immune Sera/analysis , Immunoassay , Precipitin Tests , RabbitsABSTRACT
An extracorporeal reactor containing a packed bed of Dacron fibers has been developed. Escherichia coli II L-asparaginase was coupled to the Dacron using gamma-aminopropyltriethoxysilane and glutaraldehyde. The preparation had an activity of 37 IU per gram of Dacron (37 degrees C). The apparent Km was studied as a function of the flow rate. The data indicated that the apparent Km approached the Km of the native enzyme at flow rates of about 300 mg/min. In vivo use of L-asparaginase immobilized on the Dacron indicated effective lowering of plasmatic L-asparagine levels.
Subject(s)
Asparaginase/metabolism , Heart-Lung Machine/instrumentation , Polyethylene Terephthalates , Wool , Animals , Dogs , Escherichia coli/enzymology , Hydrogen-Ion Concentration , Temperature , TextilesSubject(s)
Digoxin/immunology , Radioimmunoassay/methods , Digoxin/analysis , Humans , Magnetics , Protein Binding , SolubilitySubject(s)
Asparaginase/administration & dosage , Chemotherapy, Cancer, Regional Perfusion/methods , Immunosuppression Therapy , Neoplasms, Experimental/drug therapy , Animals , Asparaginase/pharmacology , Asparaginase/therapeutic use , Asparagine/blood , Asparagine/metabolism , Dogs , Haplorhini , Lymphocytes/drug effects , Methylmethacrylates , Mitogens/pharmacology , Papio , Thymidine , TritiumSubject(s)
Blood Vessel Prosthesis , Heparin , Polymers , Animals , Biocompatible Materials , Biodegradation, Environmental , Dogs , Hot Temperature , Ions , Kinetics , Sterilization , Temperature , Thrombosis/prevention & controlSubject(s)
Blood Vessel Prosthesis , Heparin/administration & dosage , Polymers , Thrombosis/prevention & control , Animals , Asparaginase/administration & dosage , Dogs , Enzymes/administration & dosage , Heparin/blood , Histocompatibility , Hot Temperature , Ions , Leukemia/drug therapy , Metabolism, Inborn Errors/drug therapy , Methods , Rabbits , Radioisotope Dilution TechniqueSubject(s)
Blood Vessel Prosthesis , Heparin , Polymers , Animals , Biodegradation, Environmental , Dogs , Hot Temperature , Textiles , Vena Cava, InferiorSubject(s)
Glucose Oxidase , Nickel , Oxides , Drug Stability , Hydrogen-Ion Concentration , Kinetics , Oxidation-Reduction , Silicon , Solubility , Temperature , Time FactorsSubject(s)
Glass , Heparin , Humans , In Vitro Techniques , Propylamines , Rheology , Thrombosis/prevention & control , UltrasonicsABSTRACT
The adsorption of dodecyl, tetradecyl, hexadecyl, and octadecyl trimethylammonium chlorides at an interface between porous glass and potassium chloride solution has been characterized by measurements of membrane potentials. The specific potential Phi is 0.97 kT per methylene group (where k is the Boltzmann constant and T is the absolute temperature) or 580 calories per mole at 23 degrees C.
