Norbert Zimmermann

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BACKGROUND Aspirin inhibits platelet activation and reduces atherothrombotic complications in patients at risk of myocardial infarction and stroke. However, a sufficient inhibition of platelet function by aspirin is not always achieved. The causes of this aspirin resistance are unknown. METHODS AND RESULTS Patients undergoing coronary artery bypass(More)
Type 1 phosphatase activity was increased in membrane vesicles from failing human ventricles compared with non-failing controls. Likewise, expression of the mRNA encoding for type 1 phosphatase was enhanced by 37%. The present study provides evidence that alterations of phosphatase activity coincide with end-stage heart failure. Thus, enhanced activity of(More)
In spontaneously beating guinea pig right atria, levosimendan (LS, or R-[[-(1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyridazinyl)- phenyl]-hydrazono]propanedinitrile) exerted a positive chronotropic effect starting at 0.1 microM. In electrically driven guinea pig left atria, LS (0.1-10 microM) increased force of contraction without changing time parameters of(More)
OBJECTIVE C-Reactive protein (CRP) is known to be a sensitive indicator of infection. Since it is also involved in the acute phase reaction, it is of great interest, whether an isolated preoperative increase of CRP without further signs of infection is of any prognostic value for postoperative outcome after cardiac surgery with cardiopulmonary bypass (CPB),(More)
Diadenosine tetraphosphate (AP4A) is an endogenous compound and exerts diverse physiological effects in animal systems. However, the effects of AP4A on inotropy in ventricular cardiac preparations have not yet been studied. The effects of AP4A on force of contraction (FOC) were studied in isolated electrically driven guinea pig and human cardiac(More)
There are conflicting reports about the expression of cyclooxygenase (COX)-2 in human platelets. The present study describes a flow cytometric method for the measurement of platelet COX. Both COX-1 and COX-2 were shown to be expressed in platelets from patients undergoing a coronary artery bypass graft. There was a significant increase in COX-2 expression(More)
Cantharidin concentration dependently increased the force of contraction in isolated guinea pig papillary muscles (1-100 microM). The positive inotropic effect is accompanied by a reduction in time to peak tension and relaxation time. Cantharidin did not exert a positive chronotropic effect in spontaneously beating right atria. L-type calcium channel(More)
beta-Adrenoceptor stimulation acts in the heart in part by increasing the phosphorylation state of phospholamban and phospholemman. There is evidence that the beta-adrenoceptor-mediated increase in phospholamban phosphorylation is in part due to inhibition of type 1 phosphatases. The aim of the present study was to elucidate which phosphatases(More)
The success of coronary artery bypass graft surgery (CABG) depends mainly on the patency of the graft vessels. Aortocoronary vein graft disease is comprised of three distinct but interrelated pathological processes: thrombosis, intimal hyperplasia and atherosclerosis. Early thrombosis is a major cause of vein graft attrition during the first month after(More)