Can earnings decline cause a retirement flight of physicians? Financial compensation and the decision to stay in practice.

The authors analyze the historical correlation between annual change in the population of inactive physicians and annual change in the real net income earned by the average physician per hour of patient care. For a sample of nine census divisions across 8 years (1986-1989 and 1994-1997), two regression models conclude with 99% confidence that a fall in net income increases the outflow of physicians from active practice. Regression coefficients estimate that a $1.00 fall in hourly net income increases the population of inactive physicians by 1.46 percent after a 2-year period. Based on 1999 population data, the authors project that an earnings decline of $10.00 per patient care hour motivates 11,000 physicians to retire early. With projections of between 50,000 and 150,000 excess practitioners in the U.S. health care system, the analysis suggests that deterioration in financial compensation can erase part but not all of a physician surplus through early retirement.

Characterization and Solubilization of Kaurenoic Acid Hydroxylase from Gibberella fujikuroi.

A key step in gibberellin biosynthesis is the conversion of ent-kaurenoic acid to ent-7[alpha]-hydroxykaurenoic acid, mediated by the enzyme kaurenoic acid hydroxylase. A cell-free system obtained from Gibberella fujikuroi (Saw.) Wr. was used to characterize kaurenoic acid hydroxylase activity. Microsomal preparations from disrupted fungal cells, in the presence of O2 and NADPH, converted [17-14C]ent-kaurenoic acid to oxidation products that were separated by high-performance liquid chromatography and identified as ent-7[alpha]-hydroxykaurenoic acid and gibberellin A14 by combined gas chromatography-mass spectrometry. Flavin adenine dinucleotide and the chloride salts of several monovalent cations stimulated the conversion of ent-kaurenoic acid to these products, whereas CO and a number of known inhibitors of cytochrome P-450-dependent reactions, including paclobutrazol, tetcyclacis, BAS 111.W, flurprimidol, triarimol, metyrapone, and 1-phenylimida-zole, significantly reduced kaurenoic acid hydroxylase activity. Kaurenoic acid hydroxylase was solubilized from fungal microsomes by treatment with 1 M KCl. The properties of the enzyme noted above suggest that kaurenoic acid hydroxylase from G. fujikuroi is a cytochrome P-450-dependent monooxygenase.