Publications by authors named "P Nusser"

A pulsatility-based control algorithm with a self-adapting pulsatility reference value is proposed for an implantable rotary blood pump and is to be tested in computer simulations. The only input signal is the pressure difference across the pump, which is deduced from measurements of the pump's magnetic bearing. A pulsatility index (PI) is calculated as the mean absolute deviation from the mean pressure difference.

View Article and Find Full Text PDF

A control strategy for rotary blood pumps meeting different user-selectable control objectives is proposed: maximum support with the highest feasible flow rate versus medium support with maximum ventricular washout and controlled opening of the aortic valve (AoV). A pulsatility index (PI) is calculated from the pressure difference, which is deduced from the axial thrust measured by the magnetic bearing of the pump. The gradient of PI with respect to pump speed (GPI) is estimated via online system identification.

View Article and Find Full Text PDF

During regular health status monitoring of the colony of amphibian, Mycobacterium (M.) gordonae were isolated from granulomatous lesions of the tiptoes from the South African clawed frog (Xenopus laevis) maintained at the Tierforschungszentrum of the University of Ulm. During a period of three years a total of 21 animals of the colony, consisting of 350-400 frogs, showed granuloma of the tip of the toes and a loss of the claws.

View Article and Find Full Text PDF

Chronic heart failure is associated with an activation of the immune system characterized among other factors by the cardiac synthesis and serum expression of proinflammatory cytokines. There is unequivocal clinical and experimental evidence that the cytokine tumor necrosis factor-alpha is involved in the development of chronic heart failure, but a putative cardiotoxic potential of the proinflammatory cytokine interferon (IFN)-gamma remains primarily unknown. To investigate this issue we analyzed the cardiac phenotype of SAP-IFN-gamma transgenic mice, which constitutively express IFN-gamma in their livers and hence exhibit high circulating serum levels of this cytokine.

View Article and Find Full Text PDF

Background/aims: Interferon gamma (IFNgamma) controls hepatitis B virus replication. As systemic application may cause severe adverse effects, approaches of liver-directed IFNgamma gene therapy may represent an attractive alternative for treatment of chronic viral hepatitis B and thus needs testing in vivo in suitable animal models.

Methods: We therefore crossbred Alb-1HBV transgenic mice overexpressing the large HBV surface protein (LHBs) in their livers and developing LHBs storage disease and ground glass hepatocyte appearance with SAP-IFNgamma transgenic animals previously shown to exhibit constitutive hepatic IFNgamma expression, and analyzed the resulting double-transgenic offspring.

View Article and Find Full Text PDF