University of Graz

About: University of Graz is a education organization based out in Graz, Steiermark, Austria. It is known for research contribution in the topics: Population & Quantum chromodynamics. The organization has 17934 authors who have published 37489 publications receiving 1110980 citations. The organization is also known as: Carolo Franciscea Graecensis & Karl Franzens Universität.

New, long-acting, potent bradykinin antagonists

Abstract: 1. Three new bradykinin (BK) antagonists, D-Arg0-Hyp3-Thi5-D-Tic7-Oic8-BK (compound I), D-Arg0-Hyp3-D-Tic7-Oic8-BK (compound II), and Arg(Tos)1-Hyp3-Thi5-D-Tic7-Oic8-BK (compound III), were tested against the effects of BK in 9 bioassay preparations including visceral smooth muscles, vasoconstriction, plasma protein extravasation, release of prostaglandin E2, bronchoconstriction, and stimulation of afferent C-fibre nociceptors. In some of these tests the effects of the new compounds were compared with those of the antagonist D-Arg0-Hyp2-Thi5,8-D-Phe7-BK (compound IV), described by Stewart & Vavrek (1987). 2. For all bioassays the general rank order of potency of the compounds was found to be I greater than II greater than III much greater than IV. The new antagonists were long-acting; in some bioassays their effects outlasted the duration of the experiment. 3. The inhibitory effects of the new BK antagonists were specific for BK; actions of noradrenaline, angiotensin II, acetylcholine or histamine were unaffected by the antagonists. They did not stimulate the release of histamine or prostaglandins. An agonistic effect was observed only with very high concentrations of compounds I and II in the plasma protein extravasation test. 4. The long duration of action of the new BK antagonists is probably due to a high and long-lasting affinity to the BK receptors. A high resistance of the antagonists to enzymatic destruction may be another reason. 5. The new BK antagonists will be valuable tools for the investigation of the pathophysiological role of BK. In addition they may offer a potential for therapeutic applications.

Induced oscillations in the alpha band: functional meaning.

Abstract: The phenomena of event-related desynchronization (ERD) and synchronization (ERS) reflect the dynamics of neural networks and can be observed on different scalp locations at the same moment of time. Whereas on one cortical area a focal 10-Hz ERD can be found, other areas can display a 10-Hz ERS. This phenomenon is called focal ERD/surround ERS and is interpreted as a correlate of an activated cortical area (ERD) and simultaneously deactivated or inhibited other areas. The induced oscillations (ERS) are dominant in the 10- to 13-Hz band and very likely mediated by thalamic gating.

The role of vitamin E and carotenoids in preventing oxidation of low density lipoproteins.

Abstract: It is well-established that an increased plasma cholesterol content is mainly due to increased levels of the low density lipoprotein (LDL), that cholesterol deposits in fatty streaks and atherosclerotic plaques stem primarily from LDL, and that high levels of plasma LDL are closely associated with an increased risk of atherosclerosis.'4 Early atherosclerotic lesions are characterized by a massive accumulation of cells filled with lipid droplets rich in cholesterylesters and cholesterol. Such cells are called foam cells because of their foamy appearance. Most of these arterial foam cells in atherosclerotic lesions have developed from resident tissue macrophages or from blood monocytes that entered the arterial intima in response to chemotactic factors (for review see ref. 5 and 6). Recently it has been shown by several groups7-\" that oxidatively modified LDL (0-LDL) possesses a number of functional properties that could explain the formation of foam cells and several other aspects of atherogenesis.

Passive Biaxial Mechanical Response of Aged Human Iliac Arteries

Abstract: Inflation and extension tests of arteries are essential for the understanding of arterial wall mechanics. Data for such tests of human arteries are rare. At autopsy we harvested 10 non-diseased external iliac arteries of aged subjects (52-87 yrs). Structural homogeneity was ensured by means of ultrasound imaging, and anamneses of patients were recorded. We measured the axial in situ stretches, load-free geometries and opening angles. Passive biaxial mechanical responses of preconditioned cylindrical specimens were studied in 37 degrees C calcium-free Tyrode solution under quasistatic loading conditions. Specimens were subjected to pressure cycles varying from 0 to 33.3 kPa (250 mmHg) at nine fixed axial loads, varying from 0 to 9.90N. For the description of the load-deformation behavior we employed five "two-dimensional" orthotropic strain-energy functions frequently used in arterial wall mechanics. The associated constitutive models were compared in regard to their ability of representing the experimental data. Histology showed that the arteries were of the muscular type. In contrast to animal arteries they exhibited intimal layers of considerable thickness. The average ratio of wall thickness to outer diameter was 7.7, which is much less than observed for common animal arteries. We found a clear correlation between age and the axial in situ stretch lambda is (r = -0.72, P = 0.03), and between age and distensibility of specimens, i.e. aged specimens are less distensible. Axial in situ stretches were clearly smaller (1.07 +/- 0.09, mean +/- SD) than in animal arteries. For one specimen lambda is was even smaller than 1.0, i.e. the vessel elongated axially upon excision. The nonlinear and anisotropic load-deformation behavior showed small hystereses. For the majority of specimens we observed axial stretches smaller than 1.3 and circumferential stretches smaller than 1.1 for the investigated loading range. Data from in situ inflation tests showed a significant increase of the axial stretch with intraluminal pressure. Thus, for this type of artery the axial in situ stretch of a non-pressurized vessel is not representative of the axial in vivo stretch. None of the constitutive models were able to represent the deformation behavior of the entire loading range. For the physiological loading range, however, some of the models achieved good agreement with the experimental data.