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To estimate the number of full-time-equivalent (FTE) physicians and geriatricians needed to provide medical care in the years 2000 to 2030, we developed utilization-based models of need for non-surgical physicians and need for geriatricians. Based on projected utilization, the number of FTE physicians required to care for the elderly will increase two- or threefold over the next 40 years. Alternate economic scenarios have very little effect on estimates of FTE physicians needed but exert large effects on the projected number of FTE geriatricians needed. We conclude that during the years 2000 to 2030, population growth will be the major factor determining the number of physicians needed to provide medicare care; economic forces will have a greater influence on the number of geriatricians needed.

To estimate the adequacy of current and future supply of geriatrics faculty, we conducted a national survey to determine the current supply of geriatrics faculty in five specialties and compared these estimates to standards for optimal faculty supply in geriatrics. Finally, we generated a model to project future faculty supply based on both current training capacity and differing assumptions regarding future training capacity. Our findings indicate that the current supply of geriatrics physician faculty is less than half the number needed in each specialty. (Existing numbers range from a high of 909 faculty in internal medicine to a low of 86 in physical medicine.) Moreover, given the current capacity for training, there will be a net loss of such faculty each year in each specialty. We conclude that the number of geriatrics faculty currently available is insufficient to provide an appropriate "core" level of geriatrics training for all undergraduate medical students and residents in relevant residency programs. In addition, the current training capacity for geriatrics faculty cannot even sustain the current level of faculty over the next 10 years. To correct the current and future deficit, substantial increases in both geriatrics fellowship positions and mid-career training positions will be necessary.

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A new approach to the prevention of sickling in vitro by use of the bifunctional crosslinking reagent, dimethyl adipimidate, is described. Prior treatment of sickle erythrocytes with dimethyl adipimidate will inhibit sickling in completely deoxygenated erythrocytes. Treated erythrocytes do not demonstrate the potassium loss and viscosity increase that usually accompany sickling. The oxygen affinity of hemoglobin in these cells is increased independently from changes in the concentration of 2,3-diphosplioglycerate. The (v/v) formaldehyde in saline for fixation. Five hundred cells were counted by described criteria (6). The viscosity of dimethyl adipimidate-treated and control cells was measured in a Wells Brookfield cone plate microviscomneter model LVT, adapted to maintain controlled atmospheric gas tension (7). After adjustment of the hematocrit to 40 i 1%, the blood was equilibrated for 1 hr with humidified 95% N2 and 5% CO2 in an IL tonometer model no. 237, then transferred in a closed system to the viscometer. The viscosity was measured at shear rates ranging from 4.5 to 90 sec' during continued exposure to nitrogen.Studies in vitro of erythrocyte metabolism and of net K + loss were conducted by incubation at 370 of thrice-washed erythrocytes in Krebs Henseleit buffer with added glucose (10 mM) in the presence of 0.1 mM ouabain. The samples were continuously equilibrated with moistened gas mixtures consisting of nitrogen plus 20%, 3.3%, or 0% oxygen, and pH was maintained at 7.45 4i 0.05 by varying the CO2 concentration with a gasometric pH stat (8). Supernatant K+ concentration was determined by flame photometry. 2,3-Diphosphoglycerate (9) concentrations in erythrocytes were determined in perchloric acid extracts.The oxygen affinity of whole blood, expressed as p50 (that oxygen tension at which hemoglobin is half-saturated), was determined by measurement of hemoglobin oxygen saturation and P02 after equilibration of the samples with gas mixtures containing 2.2%, 2.8%, 3.2%, and 3.9% oxygen plus 5% CO2 and the remainder nitrogen. The p50 was calculated by a best fit analysis of these data and corrected to a pH of 7.4 (10).Hemolysates and globin were prepared by standard methods. Gel filtration in Sephadex G-100 was performed by the method of Andrews (11). The column was calibrated with aldolase (molecular weight 158,000), ovalbumin (molecular weight 45,000), and chymotrypsinogen A (molecular weight 25,000). Hemoglobin electrophoresis was performed on cellulose acetate strips at pH 8.65 in a Beckman microphor system. Barbital buffer, 25 mMI, pH 8.0, was used for electrophoretic separation of globin chains and the cellulose acetate strips were soaked in the same buffer with 8 M urea and 5 mM 2-mercaptoethanol. Spectra were recorded with a Cary 14 recording spectrophotometer.

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Hemoglobin Gun Hill, a new variant of adult hemoglobin, was found in a Caucasian and one of his three daughters. The abnormal hemoglobin had only half of the expected number of heme groups. Five amino acid residues appeared to be missing from the beta-globin chains. These residues occur in linear sequence in normal beta-chains in a region involved in heme-globin binding. A deletion of five amino acids in the beta-chains of hemoglobin Gun Hill is postulated. The most likely mechanism for the origin of such a hemoglobin variant would appear to be unequal crossing-over during meiosis.