Academic survival through mission-based management.

This article summarizes the DeLisa lecture and 3-day course of the same name offered at the 2001 Annual Association of Academic Physiatrists Educational Conference, in Hilton Head, South Carolina. The authors briefly discuss the historical school of medicine management approach and the rationale behind mission-based management. The three components of mission-based management are then reviewed along with issues pertaining to their development, implementation, and utilization. Finally, potential operational and political obstacles related to mission-based management are discussed, and recommendations for avoiding political difficulties are presented.

Fluorescence localization of early colonic cancer in the rat by hematoporphyrin derivative.

Laser excitation of hematoporphyrin derivatives (HPD) localizing in tumors of the tracheobronchial tree and bladder is useful in the identification and treatment of those tumors. A comparable utility for HPD in the endoscopic localization of colonic tumors may be possible. In this study the ability of HPD to identify 1,2 dimethylhydrazine (DMH) induced colon cancer in rats is evaluated. A total of 111 rats were studied with HPD. Sixty-nine rats received weekly injections of DMH (20 mg/kg) and 42 received injections of the vehicle alone. Twenty-four hours after the intravenous injection of 5 mg/kg of HPD, 18 DMH-induced tumors were identified by visual fluorescence using excitation by either a blue light (390-436 nm) or an argon laser (488 and 514 nm). This represented 100% of the visually or microscopically detected tumors. Seventy-five fluorescent areas were noted that did not contain evidence of cancer. The majority (63) of false positive areas contained lymphoid follicles. All but 2 false positive areas (73/75, 97%, p less than .001) were seen in DMH-treated animals, suggesting that they were an artifact of DMH treatment. HPD fluorescence did not identify microscopic dysplasia. We conclude that HPD fluorescence is an effective method of identifying early colonic cancer and may have a potential clinical role in patients at high risk for colorectal cancer.

Differences in composition and fluidity of intestinal microvillus membrane vesicles prepared by different methods.

Multiple methods have been developed to isolate the intestinal microvillus membrane and facilitate the study of its composition and function. Variations in membrane composition and fluidity may result from different preparative techniques. This study shows that the use of MgCl2 and/or KSCN in vesicle preparation alters phospholipid and protein composition of the membrane compared to CaCl2 precipitation. The use of MgCl2 in membrane preparation increased phosphatidylethanolamine and decreased phosphatidylinositol content. The use of KSCN in membrane preparation decreased the protein content. The structural changes seen with the use MgCl2 alone are accompanied by an increase in both static and dynamic membrane fluidity. These results suggest that different methods of membrane vesicle preparation affect membrane phospholipid and protein content as well as membrane fluidity.

Photofrin II localization in rat cecum.

Laser excitation of photodynamic agents localizing in colonic tumors may allow the early diagnosis and treatment of colon cancer. The efficacy of these agents requires a high ratio of tumor to background photosensitizer accumulation and fluorescence. To assess normal colonic background fluorescence and hematoporphyrin accumulation 31 rats were studied after an intravenous injection of Photofrin II (PF-II) at a dose of 5 mg/kg. An increase in mucosal fluorescence and porphyrin content was noted in the cecum 24 hours after injection. Cecal accumulation of PF-II may affect its efficacy in the localization and treatment of cecal tumors. Further investigation into the mechanism and clinical significance of this finding is needed.