Publications by authors named "Pascal Maria Dohmen"

The effect of monomeric glutaraldehyde fixation and amino acid detoxification on biocompatibility and tissue-guided regenerative potential of decellularized bovine pericardium was evaluated. The degree of cross-linking, porosity, enzymatic degradation, alpha-galactosyl content, the efficacy of detoxification, and cytotoxicity towards human epithelial cells were assessed. Tissue was subcutaneously implanted for eight weeks in male juvenile Sprague-Dawley rats, and mechanical properties, host cell infiltration, and calcification were evaluated.

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Homograft availability and durability remain big challenges. Increasing the post-mortem ischaemic harvesting time beyond 24 h increases the potential donor pool. Cryopreservation, routinely used to preserve homografts, damages the extracellular matrix (ECM), contributing to valve degeneration.

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Background: Life-threatening heparin-induced thrombocytopenia (HIT) is treated with the alternative nonheparin anticoagulants argatroban, lepirudin, or danaparoid. Frequently, the pentasaccharide fondaparinux is used off-label.

Objectives: The authors sought to investigate the safety and efficacy of the different anticoagulants for treating HIT.

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BACKGROUND The aims of this study were to compare the morphological, biochemical, and functional properties of reprogrammed bone marrow stem cell (BMSC)-derived arterial endothelial cells (AECs) and venous endothelial cells (VECs), following adenosine triphosphate (ATP)-stimulation in a mini pig animal model. MATERIAL AND METHODS Bone marrow aspiration was performed in six adult mini pigs. Harvested mononuclear cells were isolated, cultured, and treated with vascular endothelial growth factor (VEGF) (16 µg/ml).

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This study investigated cryopreserved pulmonary homograft (CPA) structural integrity after prolonged cold ischemic harvesting times in a juvenile sheep model. Three groups with different post-mortem cold ischemic harvesting times were studied, i.e.

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We wanted to elucidate whether acetylcholine as the endogenous ligand at cholinoceptors (ChRs) may have effects on angiogenesis and whether they are transduced through muscarinic or nicotinic ChRs. Human umbilical vein endothelial cells were cultured until confluence and thereafter seeded in Matrigel in vitro angiogenesis assays for 18 hours. During the entire cell culture and angiogenesis period, cells were treated with vehicle, eserine (1 μM), in the absence or presence of additional atropine (1 μM) or mecamylamine (1 μM).

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Mechanical stretch has been shown to provoke arrhythmia. We wanted to analyze ventricular arrhythmia induced by local left ventricular stretch in order to find out, where arrhythmias originate and whether they can be prevented pharmacologically. Isolated rabbit hearts (Langendorff technique) were submitted to increased left ventricular stretch at the left wall by insertion of an additional intraventricular balloon and adjusting the end-diastolic pressure (EDP) to 25 mmHg for 10 min followed by 20 min recovery at normal EDP of 5-8 mmHg.

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Background: Increased body mass index (BMI) is often found to be a risk factor for cardiac disease. However, it is unclear whether BMI also affects the gap junction remodeling process in atrial fibrillation (AF). The aim of the study was to see if BMI can influence the connexin43 (Cx43) distribution in patients with sinus rhythm (SR) and AF.

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Article Synopsis
  • The study investigates the management of suspected acute heparin-induced thrombocytopenia (HIT) using non-heparin anticoagulants, emphasizing off-label use of fondaparinux.
  • The research involved a national registry with 195 patients, focusing on their 4T's HIT-probability scores and treatment outcomes, revealing various complications during heparin therapy.
  • Findings indicate a high reliance on immunoassays for diagnosis and significant off-label fondaparinux usage, highlighting the need for further evaluation of its efficacy and safety in treating HIT.
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Background: In the past, successful use of decellularized xenogenic tissue was shown in the pulmonary circulation. This study, however, evaluates a newly developed decellularized equine pericardial patch under high pressure circumstances.

Material And Methods: Seven decellularized equine pericardial scaffolds were implanted into the descending aorta of the juvenile sheep.

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Objectives: Reduction of cognitive function is a possible side effect after the use of cardiopulmonary bypass (CPB) during cardiac surgery. Since it has been proven that piracetam is cerebroprotective in patients undergoing coronary bypass surgery, we investigated the effects of piracetam on the cognitive performance of patients undergoing open heart surgery.

Methods: Patients scheduled for elective open heart surgery were randomized to the piracetam or placebo group in a double-blind study.

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Objectives: Decellularized porcine heart valves treated with deoxycholic acid (DOA) have demonstrated complete recellularization and absence of calcification when implanted into the pulmonary position in sheep. We studied recellularization and calcification in stented DOA-treated heart valves compared with conventional stented glutaraldehyde-treated valves in the aortic position in juvenile pigs 6 months after implantation.

Methods: DOA heart valves (n=12) and glutaraldehyde-treated valves (Carpentier-Edwards) (n=15) were implanted into the aortic position in 8-month old 90 kg female pigs.

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Coronary artery aneurysms are clinically relevant, because thromboembolism, rupture, and hemodynamic problems related to compression may occur. Surgical management is not standardized, and an individual approach toward each aneurysm is prudent. Giant coronary artery aneurysms (larger than 20 mm in diameter) originate in different ways and are extremely rare, and their surgical treatment is also not well defined.

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Background: Reduction of cognitive function is a possible side effect after cardiac surgery using cardiopulmonary bypass. We investigated the cerebroprotective effect of piracetam on cognitive performance in patients undergoing coronary artery bypass surgery under cardiopulmonary bypass.

Material/methods: Patients scheduled for elective, primary and isolated coronary bypass surgery were randomised either to piracetam or placebo group.

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Background: This study was performed to evaluate the possibility of seeding No-React-treated bovine small-diameter internal mammary arteries (SIMAs) and to record any improvement in patency rate.

Material/methods: During the in vitro study, 12 seeded SIMAs were divided into two groups; group I (n=6) was endothelial cell (EC) seeded and group II (n=6) EC seeded after pre-coating with fibrin glue to evaluate the binding capacity. During the in vivo part of the study, eight juvenile sheep received either a seeded or a non-seeded SIMA.

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The surface roughness of left ventricular assist devices (LVADs) is important for the biocompatibility of blood pumps. However, little is known about the effect of surface roughness on the antithrombogenicity of the device. The present study investigated the effect of surface roughness on the activation of the coagulation system and platelet adhesion in an impeller-type blood pump.

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Objective: Compare the immunological and echocardiographic data of decellularized versus cryopreserved allografts used for RVOT reconstruction during Ross operation.

Methods: From 16/01/03 thru 07/10/03, 20 Ross operations were performed using decellularized (n=11) or cryopreserved (n=9) allografts. Echocardiography was done at discharge, 1, 3, 6 and 12 months and annually thereafter.

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This study evaluated cryopreserved homografts (Group 1) and porcine heterografts decellularized with deoxicholic acid (Group 2), implanted in the right ventricular outflow tract of juvenile sheep. Two groups with four animals in each were used and all animals survived with good outcome. Animals were sacrificed 90 or more days after surgery (90-150 days).

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