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A B S T R A C T Prior studies of the effect of hemodialysis on left ventricular function have not distinguished between the removal of uremic toxins and the change in cardiac filling volume. To separate these effects, left ventricular function was examined by serial echocardiography in five stable hemodialysis patients before and after three different dialysis procedures: (a) hemodialysis with volume loss, (b) ultrafiltration (volume loss only), and (c) hemodialysis without volume loss. The patients were similarly studied under control conditions and after increased (50 of headdown tilt for 90 min) and decreased (lower body negative pressure) cardiac filling volume.After hemodialysis with volume loss, end-diastolic volume (EDV) decreased from 167 to 128 ml (P < 0.001) and end-systolic volume (ESV) decreased from 97 to 51 ml (P < 0.001) without a change in stroke volume (SV). Ejection fraction increased from 42 to 52% (P < 0.001) and mean velocity of circumferential fiber shortening (VCF) increased from 0.61 to 1.04 circumferences (circ)/s (P < 0.001). After ultrafiltration, EDV decreased from 167 ml to 124 ml (P < 0.001) and SV from 73 ml to 39 ml (P < 0.001), without significant changes in ESV or VCF. In contrast to the maneuvers in which volume loss occurred, after hemodialysis without volume loss ESV decreased from 95 to 66 ml (P < 0.001) and SV increased from 74 ml to 97 ml (P < 0.001) without changes in EDV. EF increased from 44 to 59% (P < 0.001) and VCF increased from 0.64 to 1.26 circ/s (P < 0.001). Ventricular function curves plotted from data obtained under conditions of altered cardiac filling volume before and after the three dialysis maneuvers demonstrate that ultrafiltration produced a pure Frank-Starling effect, while Received for publication 9 March 1982 and in revised form 23 August 1982. hemodialysis with or without volume loss produced a shift in the ventricular function curves, which demonstrated an increase in the contractile state of the left ventricle. The changes in left ventricular function produced by regular hemodialysis are the combined effects of a decrease in EDV and an increase in the contractile state of the left ventricle.

A B S T R A C T Eluates from glomerulonephritic kidneys of nine patients with anti-glomerular basement membrane (anti-GBM)-mediated nephritis were studied to define their antigenic specificity and content of kidney-fixing antibodies. Five of these patients had Goodpasture's syndrome with pulmonary and renal involvement clinically; four patients did not. All had in vivo fixation of JgG in the characteristic linear pattern by direct immunofluorescence, and eluted JgG fixed to normal human kidney sections. Eluates from kidneys of patients with Goodpasture's syndrome fixed more frequently to homologous nonglomerular renal and extrarenal antigenic sites and to heterologous GBM than did non-Goodpasture eluates over a hundredfold range of antibody concentrations; both could be blocked by prior absorption with soluble GBM antigens. By radial immunodiffusion and precipitation tests the content of JgG in the eluates was measured to range from 2 to 20% of the total protein eluted. By paired label isotopic fixation studies with some of the eluates the per cent of IgG that was kidney fixing ranged from 0.6 to 23.4%. Although the in vivo fixation studies with radiolabeled eluates failed to indicate significant fixation to monkey lung, the observations define quantitative as well as qualitative differences between anti-GBM antibody populations mediating the Goodpasture syndrome compared to those causing glomerulonephritis without lung involvement. This is publication No. 355 from the

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