Publications by authors named "Gerd Hafner"

Purpose: This study analyzed the concentrations of platelets and growth factors in platelet-rich plasma (PRP), which are likely to depend on the method used for its production.

Materials And Methods: The cellular composition and growth factor content of platelet concentrates (platelet-rich plasma) produced by six different procedures were quantitatively analyzed and compared. Platelet and leukocyte counts were determined on an automatic cell counter, and analysis of growth factors was performed using enzyme-linked immunosorbent assay.

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Background: In the second generation of the point-of-care (POC) assay Roche CARDIAC proBNP, the upper limit of the measuring range was extended from 3000 to 9000 ng/L.

Methods: A thirteen-site multicentre evaluation was carried out to assess the analytical performance of the POC NT-proBNP assay and to compare it with a laboratory N-terminal pro-brain natriuretic peptide (NT-proBNP) assay.

Results: In method comparisons of six lots of POC NT-proBNP with the lab reference method (Elecsys proBNP) mean bias ranged from -10 to +17%.

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Background: Lipoproteins and their subfractions are associated with the incidence of atherosclerotic diseases. In patients with coronary artery disease (CAD), low serum concentrations of high density lipoprotein (HDL) and high low-density lipoproteins (LDL) are correlated to myocardial infarction and cardiovascular death. There is growing evidence indicating that those lipoprotein factors are related to the inflammatory process in atherogenesis.

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Purpose: The aim of this study was to compare a new method for the production of platelet-rich plasma (PRP), the plasma-rich-in-growth-factors kit (PRGF kit; G.A.C.

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Background: Low-molecular-weight heparin (LMWH) is supposed to be advantageous compared to unfractionated heparin for chronic hemodialysis (HD) with respect to lipid and bone metabolism, polymorphonuclear cell stimulation, induction of antibody-mediated thrombocytopenia, and aldosterone suppression. Due to longer biological half-life, LMWH offers the possibility of single bolus administration.

Methods: To assess safety and efficacy of single bolus anticoagulation with enoxaparin for chronic HD, 781 stable HD patients from 79 German dialysis centers (mean age 62 years; 31% ESRD due to diabetes mellitus) were monitored by clinical and laboratory parameters for 32 weeks.

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The determination of heritability is a key issue to assess the predictive power of polymorphisms for disease in clinical studies. The aim of this study was to determine the heritability of proteins and activation markers of the fibrinolytic system in a large cohort of healthy twins. Heritability was calculated as 0.

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The release of choline as a water-soluble product of phospholipid hydrolysis was measured in the perfusate of rat hearts to monitor ischemic membrane degradation and its protection by ischemic preconditioning (IPC). Hearts were subjected to global ischemia (GI; 30 min of no-flow) followed by 60 min of reperfusion. To induce IPC, GI was preceded by four no-flow episodes of 5 min each.

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Background: Treatment modalities of renal replacement therapy differ in their diffusive and convective mass transfer characteristics. It was the goal of this study to clarify whether an increase in convective mass transfer as performed with haemofiltration (HF) and haemodiafiltration (HDF) in comparison with high-flux haemodialysis (HD) is associated with an alteration in procoagulatory activity or with complement activation.

Methods: Ten stable chronic HD patients were monitored during 120 treatments in a randomized cross over design.

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Background: Cellular antioxidant enzymes such as glutathione peroxidase 1 and superoxide dismutase have a central role in the control of reactive oxygen species. In vitro data and studies in animal models suggest that these enzymes may protect against atherosclerosis, but little is known about their relevance to human disease.

Methods: We conducted a prospective study among 636 patients with suspected coronary artery disease, with a median follow-up period of 4.

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The number of infectious pathogens to which an individual has been exposed (pathogen burden) has been linked to the development and the prognosis of coronary artery disease (CAD). The interaction among infection, genetic host susceptibility, and CAD remains unclear. This study was aimed at evaluating the modulation of the association between CAD and pathogen burden, by serum levels of inflammatory markers and polymorphisms of the interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha genes.

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The potential use of autologous thrombocytic growth factors to accelerate bone regeneration requires improved methods of isolating platelet-rich plasma (PRP). In addition to discontinuous cell separation, a second method by which PRP is produced at the point-of-care has now become available. In this study, growth factor levels in PRP from these two sources were compared.

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Background: In patients with chronic renal failure undergoing long-term hemodialysis, ischemic heart disease accounts for up to 50% of mortality. Cardiac troponins T (TnT) and I (TnI) are frequently elevated in this patient group, but data on the prognostic relevance of these markers, especially TnI, are controversial. The aim of this study was to investigate the prognostic power of a new, sensitive TnI assay in comparison with TnT and other cardiac markers.

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Background: Transcatheter closure of atrial septal defects is a new and less traumatic technique than open heart surgery. In recent years, patients with a patent foramen ovale sustaining potential paradoxical embolism have also become candidates for interventional closure devices. One of the more popular occluding devices is the Amplatzer septal occluder, which, like many other occluders, is made of nitinol.

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Background: Matrix metalloproteinase (MMP)-9 secretion by macrophages and other inflammatory cells accelerates atherosclerotic progression and destabilizes vulnerable plaque in animal models. However, epidemiological data evaluating the prognostic impact of circulating concentrations and functional genetic variations of MMP-9 are lacking.

Methods And Results: In a prospective study of 1127 patients with documented coronary artery disease, we measured baseline plasma MMP-9 levels and determined the MMP-9/C-1562T and MMP-9/R279Q genotypes.

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An important reason to improve methods for isolating platelet-rich plasma (PRP) is the potential use of autogenous platelet growth factors. In addition to the Curasan PRP kit (Curasan, Kleinostheim, Germany) and the platelet concentrated collection system (PCCSTM) system, two new methods for the preparation of PRP by the surgeon are now available. This study compared the suitability of these new methods for the preparation of PRP.

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Direct thrombin inhibitors are available for prophylactic as well as therapeutic purposes. Application of hirudin in therapeutic doses has been shown to require drug monitoring. Currently, most experience is available for recombinant hirudin, but the principle aspects of drug monitoring are the same for all direct thrombin inhibitors.

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Background And Purpose: Recent findings suggest a causative role of infections in the pathogenesis of atherosclerosis. The extent of atherosclerosis and the prognosis of patients with atherosclerosis seem to be increased by the number of infections to which an individual has been exposed. In a prospective study, we evaluated the effect of 8 pathogens and the aggregate pathogen burden on the progression of carotid atherosclerosis.

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Annexin V is a calcium binding protein, which is widely present in various cells and tissues. Due to an early release reaction after myocardial injury the determination of annexin V might be useful for the rapid diagnosis of acute myocardial infarction. An enzyme-linked immunosorbent assay was used to measure annexin V in comparison to myoglobin in samples from healthy individuals, patients suffering from acute or chronic liver, renal, and pulmonary diseases as well as acute coronary syndromes and aortocoronary bypass surgery.

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Platelet concentrates (PC) are increasingly used to increase bone regeneration in pre-prosthetic surgery. Although it is generally appreciated that certain growth factors (PDGF, TGF, EGF, and ECGF) are present in thrombocyte preparations, relatively little is known about these components in quantitative terms. The study reported here analysed the amounts of growth factors in PC produced under standard conditions from healthy volunteers.

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C-reactive protein as the most important acute phase reactant in clinical use provides information about acute as well as chronic inflammatory processes. This application requires an improvement of traditional assays that have been available to the clinical laboratory regarding lipemic interference, precision especially at the lower end, assay and calibration stability as well. In the present study the improved Olympus turbidimetric assay for the determination of C-reactive protein (CRP) was evaluated on the Olympus AU640 analytical system.

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Soluble transferrin receptor (sTfR) is reported to be a reliable marker for the diagnosis of iron deficiency, especially when iron metabolism is influenced by inflammatory disorders such as infection, chronic inflammation and cancer-related anemia. In the present multicenter study the analytical performance of a recently introduced, latex-enhanced immunoturbidimetric assay for the determination of soluble transferrin receptor (Tina quant [a] sTfR, Roche Diagnostics) on different fully mechanized analyzers such as Hitachi 917 and 911, and Cobas Integra 400 and 700 was evaluated. Within-run and between-run imprecision showed good results (CV<5% and <7%, respectively).

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Introduction: Platelet-rich plasma contains autologous thrombocyte growth factors and might be promising for acceleration of dentoalveolar bone regeneration. In this study, it was analysed for platelet counts and growth factor concentrations.

Material And Method: Platelet-rich plasma was isolated by discontinuous cell separation from 158 healthy men and 55 women aged 17-62 years.

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Pathologic studies have demonstrated that atherosclerosis involves the whole arterial vessel tree. In the Framingham study, cardiovascular risk factors could be defined with different prognostic value for the development of atherosclerosis in various vascular regions. The prognosis of patients with atherosclerosis in coronary, carotid or leg arteries is worse compared to a normal population.

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Purpose: Potential treatments using autologous thrombocyte growth factors are an important reason to improve methods for isolating platelet-rich plasma (PRP). Two methods for extracting PRP directly by the surgeon are currently available; this study was conducted to compare the growth factor levels in the resulting PRP.

Materials And Methods: Whole blood was drawn from 46 healthy donors (17 men, 29 women) aged 20 to 59 years (29.

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