Clinical integration, round two: finding success with economic coordination.

To establish an effective, and lasting, collaboration with physicians, a hospital must: Create a positive vision of the future. Structure the collaboration to reflect market imperatives. Work only with the best partners and make it clear from the start what the expectations are for those partners. Establish accounting and governance practices that promote the venture's near-term profitability and the long-term goals.

Incentives and the management of physician behavior in health service organizations.

The performance of a health services organization is affected by the cumulative behavior of physicians out of proportion to their numbers or the economic value of their services. Managers are challenged to optimize physician behavior and to change it in concert with the evolving expectations of health service customers. Incentives are the tools available for this effort. This article discusses the interrelation of physician behavior, physician needs, and the major classes of incentives: economic, noneconomic, and rules. While most organizations recognize and use financial incentives, few utilize noneconomic incentives systematically. Given the financial restrictions of advanced markets, managers should understand the role of rules and the value of noneconomic issues to physicians when developing incentive programs.

Intestinal diffusion barrier: unstirred water layer or membrane surface mucous coat?

The dimensions of the small intestinal diffusion barrier interposed between luminal nutrients and their membrane receptors were determined from kinetic analysis of substrate hydrolysis by integral surface membrane enzymes. The calculated equivalent thickness of the unstirred water layer was too large to be compatible with the known dimensions of rat intestine. The discrepancy could be reconciled by consideration of the mucous coat overlying the intestinal surface membrane. Integral surface membrane proteins could not be labeled by an iodine-125 probe unless the surface coat was first removed. The mucoprotein surface coat appears to constitute an important diffusion barrier for nutrients seeking their digestive and transport sites on the outer intestinal membrane.

Food sensitivity in reflux esophagitis.

We examined 66 patients with pain of possible esophageal origin for sensitivity to intraesophageal infusions of coffee, orange juice, spicy tomato drink, or HCl of varying concentrations as an addendum to their acid infusion (Bernstein) tests. Compared to Berstein-negative subjects, acid-sensitive patients were sensitive to infusion of coffee (P less than 0.01), orange juice (P less than 0.001), and tomato drink (P less than 0.001). Patients were largely insensitive to HCl solutions with a titratable acidity of 1 mEq per liter or less, less than the least acidic food solution tested. However, Berstein-positive patients were still highly sensitive to infusions of coffee, orange juice, and tomato drink adjusted to pH 7 (P less than 0.001). Patients were unable to differentiate symptoms caused by acid or food infusions, and solutions did not differ in the duration of infusion needed either to cause symptoms or to relieve them by saline. We conclude that the pain of esophagitis is nonspecific and can be precipitated by variety of seemingly unrelated substances.

Intestinal assimilation of a tetrapeptide in the rat. Obligate function of brush border aminopeptidase.

The small intestine is capable of taking up peptide nutrients of two or three amino acid residues, but the mechanism of intestinal assimilation of larger oligopeptides has not been established. The amino-oligopeptidase of the intestinal brush border possesses high specificity for oligopeptides having bulky side chains and is a candidate for a crucial role in the overall assimilation of dietary protein. Rat jejunum was used for in vitro gut sac and in vivo perfusion experiments with Gly-l-Leu-Gly-Gly (2 mM) as the test substrate with analysis of parent peptide and products by automatic ion-exchange chromatography. In these experiments, the tetrapeptide disappeared rapidly from the test solution (20 mumol/s per cm(2) in vitro; 17 mumol/s per cm(2) in vivo) by sequential removal of amino acid residues from the N-terminus to yield amino acids and the C-terminal dipeptide. In gut sac experiments, 61-100% of these products of hydrolysis appeared in the incubation medium and the remainder in the tissue. In contrast, only small amounts of hydrolytic products were found within intestinal lumen in vivo.Gly-l-Pro (10 mM), a peptide known to be transported intact but not to be hydrolyzed by the brush border aminopeptidase, failed to inhibit Gly-l-Leu-Gly-Gly disappearance suggesting that the tetrapeptide does not utilize the known intact transport mechanism. Hypoxic conditions (N(2) atmosphere) in vitro markedly inhibited transport of glucose, leucine, and Gly-Gly but failed to impair Gly-l-Leu-Gly-Gly disappearance suggesting that the first step in assimilation of the tetrapeptide does not involve a transport process. Disappearance of the tetrapeptide was completely blocked by l-leucyl-beta-naphthylamide (10 mM), a specific substrate for brush border aminopeptidase and by the phthalimido derivative of l-leucine bromomethyl ketone, a potent peptidase inhibitor. Hence, the amino-oligopeptidase at the intestinal surface appears to be essential for the initial stages of assimilation of this model tetrapeptide.