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Biomedical subjects

G Leopold

Publications and source records attributed to G Leopold.

At least 37 records · Page 2Linked to original sources
PubMed1978

Human-pharmacological investigations on the platelet adhesiveness- and aggregation-inhibiting effect of EMD 26 644, an oxazolyl-thio-propionic acid derivate.

EMD 26 644, a compound of novel chemical structure and with platelet aggregation-inhibiting properties, was investigated in 2 controlled clinical pharmacological studies involving 42 normal volunteers. In the first study with 22 subjects exhibiting normal or spontaneously increased platelet aggregation the influence of 1 X 250 mg EMD 26 644 p.o. on the platelet aggregation and adhesiveness was examined ex vivo. In the second study 20 subjects with and without a premedication of 1 X 250 mg EMD 26 644 were exposed an artificial climate with special platelet-irritating properties. A single oral dose of 250 mg EMD 26 644 markedly and significantly inhibited the platelet aggregation and adhesiveness over a period of several days.

Adult↗
PubMed1977

[First-past Effect (author's transl)].

Metabolism or decay of a drug prior to, during or shortly after its enteral absorption necessarily reduces the amount of unchanged drug reaching the systemic circulation. This influences the pharmacokinetic properties of a drug and is called first-pass effect. Every drug metabolized in the liver theoretically undergoes a first-pass metabolism after enteral application. Whether it results in a pharmacokinetically obvious first-pass effect depends on extent and rate of this metabolic step. The pharmacokinetic relevance of a first-pass effect does not automatically mean also its therapeutic relevance. For the assessment of the therapeutic relevance of a first-pass effect, extent and slope of its dose-effect curve in man and the therapeutic index of a drug must be taken into accounts.

Administration, Oral↗
PubMed1976

Noninvasive evaluation of ventricular hypertrophy in professional athletes.

Athletes often exhibit ECG findings which are considered to be abnormal. Therefore, we used noninvasive graphic methods to study 42 active professional male basketball players, ranging in age from 21 to 31 years, without clinically evident heart disease. Of the 42, 11 (25%) met the Romhilt-Estes ECG voltage criteria for left ventricular hypertrophy, and 12 (29%) satisfied VCG criteria for left ventricular enlargement; nine (21%) had left ventricular hypertrophy by both methods. In 33 subjects (79%) the 0.04 sec vector in the horizontal plane was anterior, and 29 of these exhibited one or more standard criteria for right ventricular enlargement; the ECG and VCG were concordant for right ventricular hypertrophy in 16 subjects (38%). Submaximal treadmill exercise tests (Bruce protocol) were normal in eight athletes, while in one subject ventricular premature beats occurred during the test. In 24 of 25 athletes (96%) from whom phonocardiograms were obtained a third heart sound was recorded, while in 14 (56%), a fourth heart sound was present. Of the 14 athletes who had a fourth heart sound, 12 (86%) had either ECG or VCG evidence of ventricular hypertrophy. Only four of 23 athletes had an increased cardiothoracic ratio (greater than .50) on routine chest X-ray. Ten athletes and ten control subjects matched for height, weight and body surface area had echocardiograms satisfactory for analysis. The left ventricular end-diastolic dimension in the athletes averaged 53.7 +/- 1.3 (SE) mm compared with a value of 49.9 +/- 0.7 mm in the control subjects (P less than 0.02), and was increased (greater than or equal to 56 mm) in four. Left ventricular posterior wall thickness averaged 11.1 +/- 0.6 mm, compared with a value of 9.8 +/- 0.5 mm in the control subjects (P less than 0.05), and was increased (greater than or equal to 11 mm) in six athletes. The right ventricular end-diastolic dimension averaged 20.8 +/- 1.1 mm compared with a value of 12.9 +/- 2.2 mm in the controls (P less than 0.004), and was increased (greater than or equal to 23 mm) in four athletes. No athlete or control subject exhibited paradoxical septal motion. In the athletes, ejection fraction (cube method) averaged 79 +/- 2.0% and mean Vcf averaged 1.13 +/- 0.04 circ/sec; these values did not differ from those of the control subjects. Thus, both right and left ventricular enlargement ("physiological hypertrophy") are often present in the well-trained athlete, but left ventricular performance remains normal in the basal state in such individuals. We condlude that these individuals represent a selected subgroup of subjects who are variants of normal.

Adult↗
PubMed1975

Nuclear medicine and ultrasound; correlation in diagnosis of disease of liver and biliary tract.

Even though the radiocolloid scan is nonspecific it will be approximately 70%-80% accurate in predicting the presence or absence of liver disease and somewhat less accurate than that in making statements as to the specific type of disease. This compares well with other modalities. The ability of nuclear medicine techniques to provide a correct diagnosis is improved when additional isotopic techniques such as hepatic blood flow studies and 131I-rose bengal and 67Ga scanning are performed. Ultrasound scanning is also non specific. To date, the major application of ultrasound in the study of the liver has been in deciphering puzzling contour abnormalities seen on nuclear medicine scans and in demonstrating fluid-filled abnormalities. Its usefulness in diffuse and solid focal lesions has been less dramatic. More recently, however, the development of gray scale has necessitated a reevaluation of the technique. Gray scale demonstrates a large number of intrahepatic interfaces that were previously invisible, and it has already been shown to demonstrate focal disorders such as metastasis more easily than the nongray-scale method. It can also demonstrate dilated biliary radicals, the gallbladder, and gallstones. In addition, while routinely studying the liver one can evaluate diaphragmatic motion and various retroperitoneal structures such as the pancreas, lymph nodes, and abdominal vascular structures.

Adult↗