Search PubMed⌕ Search

Biomedical subjects

K Schick

Publications and source records attributed to K Schick.

14 recordsLinked to original sources
PubMed1999

Characterisation of the rat lung lavage model as biological assay for testing the activity of surfactant preparations.

The present report describes how pharmacological assays may be validated and sets a basis for a discussion on the validation of biological test systems. The note for guidance on the validation of analytical procedures published by the European agency for the evaluation of medicinal products was adapted to the validation of a pharmacological test system. The presently described rat lung lavage test (RLL-test) is an animal model that has great similarities to the pathophysiology of the acute respiratory distress syndrome of humans. In this RLL-test, the activity of surfactants can be tested in a standardised fashion. The usefulness of the point estimator and the corresponding confidence intervals (CI) as a statistical test procedure for equivalence was demonstrated. A validation can be based on the above mentioned guidance but should be adjusted to pharmacological needs. Based on the presented experiences, it can be concluded that a specific guideline for validation of pharmacological or biological tests is desirable.

Anesthesia↗
PubMed1998

EMG study of hand muscle recruitment during hard hammer percussion manufacture of Oldowan tools.

The activity of 17 hand muscles was monitored by electromyography (EMG) in three subjects during hard hammer percussion manufacture of Oldowan tools. Two of the subjects were archaeologists experienced in the replication of prehistoric stone tools. Simultaneous videotapes recorded grips associated with the muscle activities. The purpose of the study was to identify the muscles most likely to have been strongly and repeatedly recruited by early hominids during stone tool-making. This information is fundamental to the identification of skeletal features that may reliably predict tool-making capabilities in early hominids. The muscles most frequently recruited at high force levels for strong precision pinch grips required to control the hammerstone and core are the intrinsic muscles of the fifth finger and the thumb/index finger regions. A productive search for skeletal evidence of habitual Oldowan tool-making behavior will therefore be in the regions of the hand stressed by these intrinsic muscles and in the joint configurations affecting the relative lengths of their moment arms.

Animals↗
PubMed1996

Ouabain is a potent inhibitor of aldosterone secretion and angiotensin action in the human adrenal.

Digitalis glycosides and a putative ouabain-like substance act by inhibiting Na,K-adenosine triphosphatases and could regulate aldosterone secretion. We studied the effects of ouabain on basal and angiotensin II (AII)-induced aldosterone in rat and human adrenal glomerulosa cells. In the rat, ouabain at doses as high as 10(-4) mol/L had no effect on basal aldosterone secretion, but caused a dose-related inhibition of AII and ACTH secretion. In human glomerulosa cells, ouabain was 1000 times more potent on both basal and AII stimulation, with action at 10(-8) mol/L. The effect of ACTH was also blunted by 10(-8)-10(-7) mol/L ouabain. However, the effect of potassium (8.7 mmol/L) on aldosterone was not altered by these doses of ouabain. These results suggest that nanomolar levels of ouabain can reduce aldosterone secretion from human zona glomerulosa cells.

Adrenal Glands↗
PubMed1986

[Bicoronary-pulmonary fistula with aneurysms of the left coronary artery].

Bicoronary-pulmonary fistulae are extremely rare cardiac malformations with only ten cases reported. We describe the case of a 46-year-old woman who was referred to our hospital because of a continuum of subfebrile temperature between 37 and 39 degrees C. On chest X-ray there were no signs of right ventricular volume overload or pulmonary congestion, the electrocardiogram showed no abnormalities. Auscultation revealed a 3/6 systolic-diastolic murmur with maximal intensity in the second and third intercostal space at the left parasternal border. At catheterization a coronary-pulmonary fistula of the left coronary artery at the end of the proximal third of the anterior descending branch with an aneurysm of the left main coronary artery and the proximal part of the anterior descending artery was found. Additionally an abnormal conal branch of the right coronary artery was found draining into a venous convolute around the pulmonary artery stem. A left-to-right shunt of 15 percent was calculated. To our knowledge this is the first case report of such a combination of a bicoronary-pulmonary fistula.

Aneurysm↗
PubMed1984

[Doppler sonography of extracranial cerebrovascular and peripheral arteries in arteriosclerosis risk factors and in coronary heart disease].

Doppler examination of the neck and limbs of 160 patients with a predisposition to arterial vascular disease in the presence of hypertension, hyperlipoproteinaemia, cigarette smoking and diabetes mellitus, 66% of whom had a combination of two or more of these risk factors, showed in 48 cases single or combined lesions in the arteries of the neck. One patient had unilateral stenosis of the common carotid artery; 20 patients showed unilateral and seven bilateral stenosis of the internal carotid artery; nine patients had unilateral and two patients bilateral stenosis of the external carotid artery; 28 patients showed unilateral flow reduction in the vertebral artery. There was a combined lesion of two or three vessels of the neck in 12 patients. Stenotic peripheral arteries at different levels of the leg with ankle pressure index decrease of up to 22.5% were detected in 54 patients.These peripheral arterial diseases were associated with stenotic carotid arteries in 28%. Peripheral vascular lesions were present in 40% of patients stenotic carotid arteries. Of the 160 patients studied 67 had proven coronary heart disease; 22% of these showed stenotic carotid arteries and 29% showed stenotic peripheral arteries. Combined lesions of the coronary, carotid and peripheral arteries were found in 13%.

Adult↗
PubMed1977

[Hemodynamic changes after angiotensin II blockade by saralasin (author's transl)].

Saralasin, an angiotensin II inhibitor was infused in 10 hypertensive patients. A blood pressure reduction was achieved after stimulation of the renin-angiotensin-system by salt depletion. Heart rate and cardiac output failed to compensate for reduction of blood pressure. Thus circulatory reflex-mechanisms are inhibited by saralasin. A direct influence on baroreceptor mechanism and/or catecholamines is probable. Failure of the hypotensive effect of saralasin in salt-depleted patients after administration of beta-blockers supports this hypothesis.

Adrenergic beta-Antagonists↗
PubMed1976

[The echocardiographic diagnosis of mitral-valve prolapse (syndrome of late systolic murmur with click) (author's transl)].

The clinical diagnosis of mitral-valve prolapse was made in ten patients on the basis of a late systolic murmur with or without a click. In each case the echocardiogram confirmed the diagnosis. In five it was further confirmed by angiocardiography. The late systolic murmur, with or without click, accentuated after nitroglycerin, is characteristic for mitral-valve prolapse.

Adolescent↗
PubMed1971

Operants.

The definition of an operant as a response class each of whose members possesses the property upon which reinforcement is contingent is not broad enough to cover the units that are supposed in Skinner's accounts of extinction, superstition, and transfer of learning. A broader definition is suggested. Finally, properties defining operants are discussed.

Journal Article↗
PubMedDate not supplied

ESR dating tooth enamel from the Paleolithic site at Longola, Zambia.

A single radiation-sensitive ESR signal at g = 2.0018 occurs in fossil tooth enamel, but not in modern teeth. In dating fossil teeth, the equivalent radiation dose (AD) needed to produce the observed ESR signal is the integral with respect to time of the natural, environmental dose rate (ED) experienced by the tooth during burial. Since the age depends on the U uptake history assumed, three dates are normally calculated assuming early U uptake (EU), continuous (linear) U uptake (LU), or recent U uptake (RU). Generally the LU ages agree best with known ages determined by other methods, but the EU and RU ages are respectively the minimum and maximum ages. Longola Spring Mound, in Central Zambia, contains a Late Stone Age collection occurs on the mound surface. Embedded in layer near the base is a much older layer containing Middle Stone Age artifacts and bone material. Four ungulate teeth collected from the lower layer were ESR dated. EU, LU, and RU ages for each tooth agree very closely, but ages range from 14 to 96 ka. Although the layer may be a two component deposit with teeth averaging 18 +/- 2 ka and 91 +/- 3 ka, high sedimentary Th concentrations and ESR isochrons suggest that gamma ext dose estimates are in error. LU dates estimated from isochron plots average 204 +/- 86 ka, while LU ages calculated with the average isochron-derived gamma ext = 10.79 +/- 1.89 mrad/a average 220 +/- 62 ka. More excavation and dating are necessary to determine if the isochron data is reasonable.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗