Postprandial hemodynamic changes evaluated by a Doppler echocardiographic method.

To evaluate postprandial hemodynamic changes, Doppler measurements of stroke volume before and after lunch were carried out in 10 healthy volunteers (all men) with a mean age of 28 years. The stroke volume was calculated as the product of echocardiographically determined aortic valve area and the ejection flow velocity integral obtained by continuous wave Doppler. The stroke volume before lunch was 61 +/- 7 ml, which was increased to 72 +/- 8 ml 1 hour after lunch and remained constant for the next 4 hours. Five hours later the stroke volume was then decreased to the baseline. M-mode echocardiography revealed an increase in left ventricular end-diastolic dimension and ejection fraction after lunch. Another 9 healthy subjects (6 women and 3 men) with a mean age of 52 years received a 75 g oral glucose tolerance test (OGTT) instead of a common lunch; stroke volumes were not altered in association with the elevation of plasma glucose level. In conclusion, ingestion of food had a positive inotropic effect and caused circulating blood volume expansion with an increment of heart rate. Therefore, Doppler studies that are not standardized for patients' mealtimes may affect the validity of data in serial studies of left ventricular function.

Reliability of Doppler echocardiographic stroke volume measurement.

To evaluate the accuracy and utility of the echocardiographic Doppler method of determining the stroke volume, the stroke volume was measured in 64 instances in 15 patients and compared to the simultaneous thermodilution stroke volume determinations. Stroke volume, varied by atrial pacing at various heart rates, was calculated noninvasively by the product of the cross-sectional area of the aortic orifice determined by echocardiography and the flow velocity integral measured by continuous wave Doppler. While the cardiac output was increased moderately by atrial pacing, the stroke volume was decreased in relation to the increase in the heart rate. The stroke volume calculated by the echo-Doppler method exhibited a significant linear relationship to the stroke volume determined by thermodilution (r = 0.84) and to the cardiac output (r = 0.75, p less than 0.01). Inter-observer and intra-observer variability was 7 +/- 4% and 5 +/- 4%, respectively. The noninvasive echo-Doppler method of estimating the stroke volume is concluded to be accurate, specifically, to be comparable to the values obtained by thermodilution and with a low inter- and intra-observer variability.

The physiochemical and immunological characteristics of rat lymph binding protein for 25-hydroxyvitamin D3.

The binding proteins for 25-hydroxyvitamin D3(25-OH-D3) in rat lymph and plasma were purified to apparent homogeneity as determined by sodium dodecyl sulfate disc gel electrophoresis. The purification procedures included the following techniques: gel filtration on Sephadex G-100 and G-200; affinity chromatography on Blue Sepharose CL-6B; ion-exchange chromatography on DEAE-Sepharose CL-6B; chromatofocussing on a Mono P column. Both proteins from lymph and plasma were eluted with the same retention time from an isoelectric column at a pH of approximately 4.53 and showed nearly identical data on the analysis of amino acid composition. When specific anti-lymph 25-OH-D3-binding protein antiserum was prepared in a rabbit, and Ouchterlony immunodiffusion was performed, the same precipitate line was observed on both lymph and plasma binding proteins. These results strongly suggest that a common transport protein exists in both rat lymph and plasma and circulates in the blood-lymph system.