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Biomedical subjects

L Lange

Publications and source records attributed to L Lange.

At least 55 records · Page 3Linked to original sources
PubMed1979

Noninvasive assessment of surgical systemic to pulmonary artery shunts by range-gated pulsed Doppler echocardiography.

Suprasternal range-gated pulsed Doppler echocardiography was used to evaluate surgical shunt patency in children with cyanotic congenital heart disease and right ventricular outflow obstruction following systemic artery to pulmonary artery anastomoses. Normal patients had laminar Doppler auditory signals and time interval histogram flow patterns because right pulmonary artery turbulence was not present during systole or diastole. Patients with pulmonary valvar stenosis had turbulence during systole only. In all nine postoperative patients with surgical shunts, turbulent systolic and diastolic time interval histograms and abnormal auditory signals were present. A typical shunt murmur was not audible to auscultation in six of the postsurgical patients at the time of the study. Suprasternal range-gated pulsed Doppler echocardiography affords an accurate, safe and simple noninvasive bedside means for confirming shunt patency in patients who have undergone surgical systemic artery to pulmonary artery anastomoses.

Adolescent↗
PubMed1979

[Recommendations regarding the standardization in m-mode- and two-dimensional echocargiography in the U.S.A. (author's transl)].

After a long discussion a standardization of quantitative measurements is m-mode echocardiography as well as standardization for displays of two-dimensional echocardiograms in the long and short axis views of the left ventricle was agreed upon in the U.S.A. in 1978. It seems to be reasonable to follow the recommendations in Germany also in order to have more uniformity in echocardiographic diagnosis. Standardization would help for the overall understanding of data between laboratories.

Adult↗
PubMed1979

[The usefulness of range-gated pulsed Doppler echocardiography. A review (author's transl)].

Single-crystal RGPD Echocardiography has clearly become a useful noninvasive ultrasonic method which enlarges the capabilities of investigating the heart. Recording of flow direction and showing disturbed flow allows additional clarification and confirmation of various diagnoses. This single-crystal technique does not allow flow quantification at the present time. The TIH and auditory signal displays of Doppler shift as presently utilized in commercial devices allow qualitative observation but require much experience in test performance and evaluation. The future here is probably in the area of spectral analysis. Present instrumentation employs M-mode echo for Doppler sample localization. Drawbacks include inprecise sample beam localization and non-variable sample volume size. Further, standardization of the Doppler signal is necessary. Combination with 2-D echo in the future will allow more precise sample beam localization and accuracy in flow quantification. The latter area has particular promise and is under investigation but is not yet commercially available.

Aortic Coarctation↗
PubMed1978

Enzymatic attack on immobilized substrates. 2. Diffusional limitations in the alpha-chymotrypsin-catalyzed hydrolysis of polyacrylamide-bound l-phenylalanine 4-nitroanilide.

1. The chymotrypsin-catalyzed hydrolysis of polyacrylamide-bound L-phenylalanine 4-nitroanilide was studied. As a spacer, one or two 6-aminohexanoyl residues were inserted between the matrix and ligand. 2. In the course of the enzymatic hydrolysis of polyacrylamide-bound substrates, enzyme adsorption by the gel substrates was observed. A quasi equilibrium of enzyme partitioning was reached after approximately 20-min incubation time. The enzyme adsorption could be described by the Langmuir adsorption isotherm. 3. The substrates attached via spacers to the matrix were completely hydrolyzed. 4. The initial course of the product vs time curves, as well as the dependence of the initial hydrolysis rates on enzyme concentration or substrate concentration, have been interpreted by the Nernst reaction theory. From the results obtained it has been concluded that the inital rate of the hydrolysis of polyacrylamide-bound L-phenylalanine 4-nitroanilide depends on the velocity of enzyme diffusion into the matrix.

Acrylamides↗
PubMed1978

[Echocardiographic normal data for premature and normal newborn infants (author's transl)].

Sufficient echocardiographic analysis of premature infants has not yet been presented. Therefore echocardiograms of 105 babies without cardiovascular disease weighing 0.6--4.0 kg were analyzed. Normal data for right ventricular dimension, diastolic left ventricular inner dimension, left atrium, aorta, septums left ventricular posterior wall, cardiac depth, amplitude and closing velocity of the anterior mitral leaflet have been established. All measurements are a linear function of bodyweight with a very good correlation.

Aorta, Thoracic↗