Jörg Wiemer - Academia.edu (original) (raw)
Papers by Jörg Wiemer
Clinical Kidney Journal, 2012
The association of membranoproliferative glomerulonephritis (MPGN) with Lyme borreliosis has only... more The association of membranoproliferative glomerulonephritis (MPGN) with Lyme borreliosis has only been reported for the C1q-negative subtype. A 64-year-old male presenting with rising creatinine, nephrotic syndrome and monoarthritis few months after a tick bite was noted to have mixed cryoglobulinaemia, a positive borrelia western blot and 'full-house' pattern MPGN with interstitial granuloma. Findings resolved with prednisolone and doxycyclin therapy. The histology is consistent with MPGN secondary to cryoglobulinaemia, which has most likely been caused by borrelia infection. 'Full-house' pattern MPGN may result from Lyme borreliosis through cryoglobulinaemia and may be treated successfully with the appropriate antibiotic therapy.
MMW Fortschritte der Medizin, Jan 28, 1999
Dyslipoproteinemia in patients on hemodialysis is characterized by a decrease in high density lip... more Dyslipoproteinemia in patients on hemodialysis is characterized by a decrease in high density lipoprotein (HDL), cholesterol, hypertriglyceridemia, increased triglyceride-rich lipoproteins, such as very low density lipoprotein (VLDL) and intermediate density lipoprotein (IDL), a higher proportion of the small dense low density lipoprotein (small dense LDL) subfraction, and higher lipoprotein(a) concentration. The reason for the changes in triglyceride metabolism is an increase in the production of apolipoprotein B, and a decrease in the metabolism of VLDL as a consequence of decreased endothelial cell delipidation. The endothelial lipoprotein lipase, which plays a major role in this process, is released by heparin, which is essential for the function of the enzyme. Repeated administration of heparin for anticoagulation during hemodialysis apparently leads to an LPL depletion in the endothelium. This results in further exhaustion of lipolysis. Clinical studies in hemodialysis patient...
European journal of clinical chemistry and clinical biochemistry : journal of the Forum of European Clinical Chemistry Societies, 1992
Dipeptidyl peptidase IV (EC 3.4.14.5) and angiotensinase A (EC 4.4.11.7) were purified to homogen... more Dipeptidyl peptidase IV (EC 3.4.14.5) and angiotensinase A (EC 4.4.11.7) were purified to homogeneity from pooled urine concentrate of patients with renal damage, using ultrafiltration, ammonium sulphate precipitation, lectin affinity chromatography, FPLC-ion-exchange(Mono-Q-)chromatography, and FPLC-gel filtration (Superdex). Based on the specific enzyme activity of the starting material, dipeptidyl peptidase IV was enriched 1629 fold, angiotensinase A 1183 fold. The relative molecular masses, Michaelis constants and isoelectric points were determined. Negative staining of the purified enzymes revealed globular proteins (5-7 nm). Antisera raised against dipeptidyl peptidase IV and angiotensinase A reacted specifically with tubular and, in the case of anti-angiotensinase A sera, with tubular and glomerular structures. In addition, urinary membrane vesicles of proximal tubule origin were eluted with the void volume (Superdex-gel filtration), indicating heavy epithelial cell disintegr...
International Journal of Cardiology, 1999
Following heart transplantation remodeling of the donor heart causes changes in the extracellular... more Following heart transplantation remodeling of the donor heart causes changes in the extracellular myocardial matrix. We investigated 20 right ventricular endomyocardial biopsies taken 17+/-4 days (group I, n=9) and 63+/-13 days (group II, n=11) after heart transplantation from 16 patients transplanted for end-stage cardiomyopathy (15 dilated/1 ischemic). Immunohistochemical staining for collagen I, collagen III, collagen IV, and fibronectin was used. Evaluation was performed at a magnification of 400x using a computer-assisted image analyzing system measuring the relative area stained by the immunoperoxidase method, the number of cells in the given area, and the total area. Collagen I per cell was 13.9+/-5.9 microm2 in group I and increased significantly 66+/-13 days after heart transplantation in the perimysium around the myocardial cells as well as in the endocardium to 49.9+/-15.1 microm2 (P<0.05). No quantitative change in collagen III was noted (75.7+/-12.4 versus 75.5+/-16.0 microm2 n.s.). Collagen IV was found in the perimysial, in the capillary bed and in the vascular network. Significant quantitative change in the amount of collagen IV was not found (64.1+/-12.6 versus 61.0+/-8.9 microm2). Fibronectin was found in the entire perimysial extracellular matrix and in the endocardium in relationship with collagen I and III. An increased amount of fibronectin from 87.09+/-9.9 microm2 (group I) to 140.8+/-17.9 microm2 (group II, P<0.05) was found. The cell area and cell diameters were not significantly different (group I; cell area 772+/-227 microm2, diameter 31.3 microm; group II; cell area 776+/-224 microm2, diameter 31.4 microm). It is concluded that remodeling of the donor heart after transplantation is characterized by a specific increase in collagen I and fibronectin, whereas a change in other collagen subtypes was not observed.
Clinical and Experimental Immunology, 2001
SUMMARYIn peripheral blood the majority of circulating monocytes present a CD14highCD16− (CD14++)... more SUMMARYIn peripheral blood the majority of circulating monocytes present a CD14highCD16− (CD14++) phenotype, while a subpopulation shows a CD14lowCD16+ (CD14+CD16+) surface expression. During haemodialysis (HD) using cellulosic membranes transient leukopenia occurs. In contrast, synthetic biocompatible membranes do not induce this effect. We compared the sequestration kinetics for the CD14+CD16+ and CD14++ monocyte subsets during haemodialysis using biocompatible dialysers. Significant monocytopenia, as measured by the leucocyte count, occurred only during the first 30 min. However, remarkable differences were observed between the different monocyte subsets. CD14++ monocyte numbers dropped to 77 ± 13% of the predialysis level after 15 min, increasing to ≥ 93% after 60 min. In contrast, the CD14+CD16+ subset decreased to 33 ± 15% at 30 min and remained suppressed for the course of dialysis (67 ± 11% at 240 min). Approximately 6 h after the end of HD the CD14+CD16+ cells returned to b...
American Heart Journal, 1997
Endothelial dysfunction is a common phenomenon after cardiac transplantation. However, qualitativ... more Endothelial dysfunction is a common phenomenon after cardiac transplantation. However, qualitative differences in endothelial vasoregulation at different coronary segments and at different postoperative times have rarely been explored. To uncover the functional variations of endothelium responses we infused the endothelium-dependent vasodilator acetylcholine (50 t.tg)followed by the endothelium-independent vasodilator 3-morpholinosydnonimine (SIN-1)(1 mg; 16 patients) or nitroglycerin (0.3 mg; 14 patients) sequentially into the left coronary artery. We investigated the responses of 120 nonstenotic coronary segments (proximal and distal lefl anterior descending and right circumflex coronary arteries) in 30 patients with quantitative angiography (group 1:13 patients, 12 + 1 months after cardiac transplantation; group 2:17 patients, 55 + 3 months after cardiac transplantation). Continuous-flow measurement was performed to exclude significant reduction of microvascular response influencing epicardial dilation. Five responses to acetylcholine administration followed by nitrates were observed. On the one end of the spectrum, segments dilate to acetylcholine administration with no further dilation to exogenous nitric oxide, indicating completely preserved endothelial function. On the other end, segments constrict to acetylcholine with no change after endogenous nitric oxide, reflecting a defective endothelial and defective smooth muscle function. The different patterns of coronary vasomotor tone responses to endogenous nitric oxide followed by exogenous nitric oxide represent different degrees of endothelial [unction after cardiac transplantation. In addition, the functional assessment of endothelial integrity shows qualitative time-dependent differences between proximal and distal coronary parts. The existence of coronary segments with functioning endothelium indicates that the latter is not diffusely disturbed in all cardiac transplant recipients and that the endothelial damage is perhaps not irreversibly lost. (Am HeartJ 1997;134:306-15.) Although the introduction of cyclosporine A has greatly improved the prognosis of patients after cardiac transplantation, cardiac allograft vasculopathy is still a major complication of long-term follow up3 Transplant vasculopathy develops in 10% to 20% of patients per year. 2 It is a diffuse, occlusive form of accelerated corona W artery disease that affects the corona W circulation and results in ischemic myocardial injury.
Nephrology Dialysis Transplantation, 2002
Background. In haemodialysis (HD) patients, low density lipoprotein (LDL) particle distribution i... more Background. In haemodialysis (HD) patients, low density lipoprotein (LDL) particle distribution is characterized by a higher proportion of more atherogenic dense LDL. Though clinical studies showed favourable effects of low molecular weight (LMW) heparin compared to standard heparin on triglycerides (TG) and cholesterol (CH) in HD patients with hypertriglyceridaemia, it is not known if LMW heparin influences LDL subfraction pattern. Thus, the aim of this pilot study was to investigate if a switch to LMW heparin influences LDL subfractions and apolipoproteins. Methods. Ten outpatients with fasting TG)230 mgudl in the chronic HD programme on heparin for anticoagulation (AC) were switched to dalteparin (80 IUukg body weight as a bolus). Blood samples were drawn for CH, TG, LDL-CH, HDL-CH, apolipoproteins (apo), very low density lipoproteins (VLDL), intermediate density lipoproteins (IDL), and LDL subclasses at the beginning and after 12 months of therapy. Lipoproteins were isolated by preparative ultracentrifugation. Total LDL were fractionated into six density classes by equilibrium density gradient ultracentrifugation [(density in kgul
Clinical Kidney Journal, 2012
The association of membranoproliferative glomerulonephritis (MPGN) with Lyme borreliosis has only... more The association of membranoproliferative glomerulonephritis (MPGN) with Lyme borreliosis has only been reported for the C1q-negative subtype. A 64-year-old male presenting with rising creatinine, nephrotic syndrome and monoarthritis few months after a tick bite was noted to have mixed cryoglobulinaemia, a positive borrelia western blot and 'full-house' pattern MPGN with interstitial granuloma. Findings resolved with prednisolone and doxycyclin therapy. The histology is consistent with MPGN secondary to cryoglobulinaemia, which has most likely been caused by borrelia infection. 'Full-house' pattern MPGN may result from Lyme borreliosis through cryoglobulinaemia and may be treated successfully with the appropriate antibiotic therapy.
MMW Fortschritte der Medizin, Jan 28, 1999
Dyslipoproteinemia in patients on hemodialysis is characterized by a decrease in high density lip... more Dyslipoproteinemia in patients on hemodialysis is characterized by a decrease in high density lipoprotein (HDL), cholesterol, hypertriglyceridemia, increased triglyceride-rich lipoproteins, such as very low density lipoprotein (VLDL) and intermediate density lipoprotein (IDL), a higher proportion of the small dense low density lipoprotein (small dense LDL) subfraction, and higher lipoprotein(a) concentration. The reason for the changes in triglyceride metabolism is an increase in the production of apolipoprotein B, and a decrease in the metabolism of VLDL as a consequence of decreased endothelial cell delipidation. The endothelial lipoprotein lipase, which plays a major role in this process, is released by heparin, which is essential for the function of the enzyme. Repeated administration of heparin for anticoagulation during hemodialysis apparently leads to an LPL depletion in the endothelium. This results in further exhaustion of lipolysis. Clinical studies in hemodialysis patient...
European journal of clinical chemistry and clinical biochemistry : journal of the Forum of European Clinical Chemistry Societies, 1992
Dipeptidyl peptidase IV (EC 3.4.14.5) and angiotensinase A (EC 4.4.11.7) were purified to homogen... more Dipeptidyl peptidase IV (EC 3.4.14.5) and angiotensinase A (EC 4.4.11.7) were purified to homogeneity from pooled urine concentrate of patients with renal damage, using ultrafiltration, ammonium sulphate precipitation, lectin affinity chromatography, FPLC-ion-exchange(Mono-Q-)chromatography, and FPLC-gel filtration (Superdex). Based on the specific enzyme activity of the starting material, dipeptidyl peptidase IV was enriched 1629 fold, angiotensinase A 1183 fold. The relative molecular masses, Michaelis constants and isoelectric points were determined. Negative staining of the purified enzymes revealed globular proteins (5-7 nm). Antisera raised against dipeptidyl peptidase IV and angiotensinase A reacted specifically with tubular and, in the case of anti-angiotensinase A sera, with tubular and glomerular structures. In addition, urinary membrane vesicles of proximal tubule origin were eluted with the void volume (Superdex-gel filtration), indicating heavy epithelial cell disintegr...
International Journal of Cardiology, 1999
Following heart transplantation remodeling of the donor heart causes changes in the extracellular... more Following heart transplantation remodeling of the donor heart causes changes in the extracellular myocardial matrix. We investigated 20 right ventricular endomyocardial biopsies taken 17+/-4 days (group I, n=9) and 63+/-13 days (group II, n=11) after heart transplantation from 16 patients transplanted for end-stage cardiomyopathy (15 dilated/1 ischemic). Immunohistochemical staining for collagen I, collagen III, collagen IV, and fibronectin was used. Evaluation was performed at a magnification of 400x using a computer-assisted image analyzing system measuring the relative area stained by the immunoperoxidase method, the number of cells in the given area, and the total area. Collagen I per cell was 13.9+/-5.9 microm2 in group I and increased significantly 66+/-13 days after heart transplantation in the perimysium around the myocardial cells as well as in the endocardium to 49.9+/-15.1 microm2 (P<0.05). No quantitative change in collagen III was noted (75.7+/-12.4 versus 75.5+/-16.0 microm2 n.s.). Collagen IV was found in the perimysial, in the capillary bed and in the vascular network. Significant quantitative change in the amount of collagen IV was not found (64.1+/-12.6 versus 61.0+/-8.9 microm2). Fibronectin was found in the entire perimysial extracellular matrix and in the endocardium in relationship with collagen I and III. An increased amount of fibronectin from 87.09+/-9.9 microm2 (group I) to 140.8+/-17.9 microm2 (group II, P<0.05) was found. The cell area and cell diameters were not significantly different (group I; cell area 772+/-227 microm2, diameter 31.3 microm; group II; cell area 776+/-224 microm2, diameter 31.4 microm). It is concluded that remodeling of the donor heart after transplantation is characterized by a specific increase in collagen I and fibronectin, whereas a change in other collagen subtypes was not observed.
Clinical and Experimental Immunology, 2001
SUMMARYIn peripheral blood the majority of circulating monocytes present a CD14highCD16− (CD14++)... more SUMMARYIn peripheral blood the majority of circulating monocytes present a CD14highCD16− (CD14++) phenotype, while a subpopulation shows a CD14lowCD16+ (CD14+CD16+) surface expression. During haemodialysis (HD) using cellulosic membranes transient leukopenia occurs. In contrast, synthetic biocompatible membranes do not induce this effect. We compared the sequestration kinetics for the CD14+CD16+ and CD14++ monocyte subsets during haemodialysis using biocompatible dialysers. Significant monocytopenia, as measured by the leucocyte count, occurred only during the first 30 min. However, remarkable differences were observed between the different monocyte subsets. CD14++ monocyte numbers dropped to 77 ± 13% of the predialysis level after 15 min, increasing to ≥ 93% after 60 min. In contrast, the CD14+CD16+ subset decreased to 33 ± 15% at 30 min and remained suppressed for the course of dialysis (67 ± 11% at 240 min). Approximately 6 h after the end of HD the CD14+CD16+ cells returned to b...
American Heart Journal, 1997
Endothelial dysfunction is a common phenomenon after cardiac transplantation. However, qualitativ... more Endothelial dysfunction is a common phenomenon after cardiac transplantation. However, qualitative differences in endothelial vasoregulation at different coronary segments and at different postoperative times have rarely been explored. To uncover the functional variations of endothelium responses we infused the endothelium-dependent vasodilator acetylcholine (50 t.tg)followed by the endothelium-independent vasodilator 3-morpholinosydnonimine (SIN-1)(1 mg; 16 patients) or nitroglycerin (0.3 mg; 14 patients) sequentially into the left coronary artery. We investigated the responses of 120 nonstenotic coronary segments (proximal and distal lefl anterior descending and right circumflex coronary arteries) in 30 patients with quantitative angiography (group 1:13 patients, 12 + 1 months after cardiac transplantation; group 2:17 patients, 55 + 3 months after cardiac transplantation). Continuous-flow measurement was performed to exclude significant reduction of microvascular response influencing epicardial dilation. Five responses to acetylcholine administration followed by nitrates were observed. On the one end of the spectrum, segments dilate to acetylcholine administration with no further dilation to exogenous nitric oxide, indicating completely preserved endothelial function. On the other end, segments constrict to acetylcholine with no change after endogenous nitric oxide, reflecting a defective endothelial and defective smooth muscle function. The different patterns of coronary vasomotor tone responses to endogenous nitric oxide followed by exogenous nitric oxide represent different degrees of endothelial [unction after cardiac transplantation. In addition, the functional assessment of endothelial integrity shows qualitative time-dependent differences between proximal and distal coronary parts. The existence of coronary segments with functioning endothelium indicates that the latter is not diffusely disturbed in all cardiac transplant recipients and that the endothelial damage is perhaps not irreversibly lost. (Am HeartJ 1997;134:306-15.) Although the introduction of cyclosporine A has greatly improved the prognosis of patients after cardiac transplantation, cardiac allograft vasculopathy is still a major complication of long-term follow up3 Transplant vasculopathy develops in 10% to 20% of patients per year. 2 It is a diffuse, occlusive form of accelerated corona W artery disease that affects the corona W circulation and results in ischemic myocardial injury.
Nephrology Dialysis Transplantation, 2002
Background. In haemodialysis (HD) patients, low density lipoprotein (LDL) particle distribution i... more Background. In haemodialysis (HD) patients, low density lipoprotein (LDL) particle distribution is characterized by a higher proportion of more atherogenic dense LDL. Though clinical studies showed favourable effects of low molecular weight (LMW) heparin compared to standard heparin on triglycerides (TG) and cholesterol (CH) in HD patients with hypertriglyceridaemia, it is not known if LMW heparin influences LDL subfraction pattern. Thus, the aim of this pilot study was to investigate if a switch to LMW heparin influences LDL subfractions and apolipoproteins. Methods. Ten outpatients with fasting TG)230 mgudl in the chronic HD programme on heparin for anticoagulation (AC) were switched to dalteparin (80 IUukg body weight as a bolus). Blood samples were drawn for CH, TG, LDL-CH, HDL-CH, apolipoproteins (apo), very low density lipoproteins (VLDL), intermediate density lipoproteins (IDL), and LDL subclasses at the beginning and after 12 months of therapy. Lipoproteins were isolated by preparative ultracentrifugation. Total LDL were fractionated into six density classes by equilibrium density gradient ultracentrifugation [(density in kgul