title: A new method of urea removal using urease and expanded polytetrafluoroethylene membrane.
abstract: A new method for urea removal using a gas membrane is introduced along with some preliminary results. The membrane used was expanded polytetrafluoroethylene (E-PTFE) which is highly permeable to gaseous substances, while at the same time it is highly resistant to water permeation. In in vitro experiments using 10 mmol/L ammonia solution it was revealed that the single-pass reduction rate was approximately 95% at 30 degrees C at a flow rate of 200 ml/min. In animal experiments using four dogs, the extraction rate of urea was 40.4 +/- 4.4% after four hours of dialysis using 5 L dialysate. However, elevation of blood ammonia was observed in all dogs tested. Removal of ammonia by means of a gas membrane is considered to be feasible and has the possibility of being used for maintenance hemodialysis in combination with urease and charcoal.
mesh_terms: D000641:Ammonia; D000818:Animals; D004285:Dogs; D004800:Enzymes, Immobilized; D006851:Hydrochloric Acid; D066298:In Vitro Techniques; D008567:Membranes, Artificial; D011138:Polytetrafluoroethylene; D006435:Renal Dialysis; D012996:Solutions; D014508:Urea / Q000097:blood*; D014510:Urease
chemical_list: D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D012996:Solutions; D000641:Ammonia; D014508:Urea; D011138:Polytetrafluoroethylene; D014510:Urease; D006851:Hydrochloric Acid