Postprostatectomy incontinence. Pathophysiology, evaluation, and management

Given the prevalence of bladder dysfunction (i.e., poor compliance or detrusor instability) as a cause of postprostatectomy incontinence, urodynamic studies are essential in the evaluation of such patients. Appropriate management strategies based on the findings of a pertinent history and physical examination, appropriate radiologic studies, and urodynamics optimize the opportunity for successful treatment. Because bladder dysfunction frequently accompanies sphincter insufficiency, bladder dysfunction must be diagnosed and treated effectively before implantation of an artificial urinary sphincter.

Human erythrocyte 5'-AMP aminohydrolase. Purification and characterization

Human erythrocyte 5'-AMP aminohydrolase has been obtained using phosphocellulose chromatography and affinity chromatography on a GTP-agarose column to yield a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme has a molecular weight of 285,000, and is comprised of four subunits. Since limited quantities of the homogeneous enzyme were available, the kinetic properties of a nonhomogeneous preparation purified about 20,000-fold over the red blood cell lysate by phosphocellulose chromatography were examined. Like the muscle enzyme, it exhibits a sigmoid AMP saturation curve in the absence of activating monovalent cations; a hyperbolic saturation curve is observed in the presence of 0.15 M KCl. Activation by monovalent cations and ATP, and inhibition by Pi, PPi, GDP, GTP, and 2,3-diphosphoglyceric acid were studied in more detail.

The cardiac injury panel as an experimental model for a test evaluation program

The authors devised a system of identification of specially designated laboratory tests to allow physicians and laboratory personnel to evaluate the clinical usefulness of lab procedures. They named this system Test Evaluation Program. Although most of the data are available from the literature, it is the cooperative effort between clinicians and laboratory staff at the individual hospital level which will allow rational utilization of lab procedures and which will, in future, eliminate unnecessary costly overutilization.