The Experts below are selected from a list of 426 Experts worldwide ranked by ideXlab platform
Jürgen Floege - One of the best experts on this subject based on the ideXlab platform.
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role of contact system activation in hemodialyzer induced thrombogenicity
Kidney International, 2001Co-Authors: Rolf Dario Frank, Heike Dresbach, Herbert Thelen, Claudia Weiss, Jürgen Weber, Jürgen FloegeAbstract:BACKGROUND: The contact system is generally believed to be the main trigger of the coagulation cascade during extracorporeal circulation. However, the extent of contact activation, its role for intradialytic thrombin generation as well as the influence of different dialyzer membranes have not been well established. METHODS: In a novel full-scale ex vivo recirculation dialysis model, we investigated the thrombogenicity of three widely used hemodialyzers (Cuprophan Renak RA15-U, Polysulfone F6HPS and AN69XT Nephral 200). The activation of the contact system was evaluated using a newly developed ELISA for factor XIIa-C1-inhibitor complexes. Additionally, we determined free FXIIa (ELISA), thrombin-antithrombin (TAT) complexes, platelet factor 4 (PF4), complement activation (C5a), granulocyte elastase and blood cell counts. The findings in blood from normal volunteers were compared with factor XII-deficient blood. RESULTS: With normal blood AN69 exhibited the highest thrombogenicity in comparison to Cuprophan and Polysulfone, as assessed by TAT generation and platelet consumption. AN69 caused a rapid increase of the FXIIa-C1-inhibitor complexes and of free FXIIa. Despite significant TAT generation with Cuprophan and Polysulfone free FXIIa remained unchanged and the FXIIa-C1-inhibitor complexes stayed below the detection limit. With factor XII-deficient blood Polysulfone exhibited the same TAT generation, whereas the thrombogenicity of AN69 was greatly reduced. CONCLUSIONS: Our data challenge the common assumption that activation of the contact system with generation of FXIIa is the main trigger for coagulation and thrombus formation in hemodialysis. Only the negatively charged AN69 membrane with enhanced thrombogenicity strongly induced contact activation.
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role of contact system activation in hemodialyzer induced thrombogenicity
Kidney International, 2001Co-Authors: Rolf Dario Frank, Heike Dresbach, Herbert Thelen, Claudia Weiss, Jürgen Weber, Jürgen FloegeAbstract:Role of contact system activation in hemodialyzer-induced thrombogenicity. Background The contact system is generally believed to be the main trigger of the coagulation cascade during extracorporeal circulation. However, the extent of contact activation, its role for intradialytic thrombin generation as well as the influence of different dialyzer membranes have not been well established. Methods In a novel full-scale ex vivo recirculation dialysis model, we investigated the thrombogenicity of three widely used hemodialyzers (Cuprophan Renak RA15-U, Polysulfone F6HPS and AN69XT Nephral 200). The activation of the contact system was evaluated using a newly developed ELISA for factor XIIa-C1-inhibitor complexes. Additionally, we determined free FXIIa (ELISA), thrombin-antithrombin (TAT) complexes, platelet factor 4 (PF4), complement activation (C5a), granulocyte elastase and blood cell counts. The findings in blood from normal volunteers were compared with factor XII-deficient blood. Results With normal blood AN69 exhibited the highest thrombogenicity in comparison to Cuprophan and Polysulfone, as assessed by TAT generation and platelet consumption. AN69 caused a rapid increase of the FXIIa-C1-inhibitor complexes and of free FXIIa. Despite significant TAT generation with Cuprophan and Polysulfone free FXIIa remained unchanged and the FXIIa-C1-inhibitor complexes stayed below the detection limit. With factor XII-deficient blood Polysulfone exhibited the same TAT generation, whereas the thrombogenicity of AN69 was greatly reduced. Conclusions Our data challenge the common assumption that activation of the contact system with generation of FXIIa is the main trigger for coagulation and thrombus formation in hemodialysis. Only the negatively charged AN69 membrane with enhanced thrombogenicity strongly induced contact activation.
Z Religa - One of the best experts on this subject based on the ideXlab platform.
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the effect of repeated use of Cuprophane and polysulfone dialyzers during hemodialysis on the count of natural killer cells in blood
Polskie Archiwum Medycyny Wewnetrznej-polish Archives of Internal Medicine, 1997Co-Authors: M Liszka, Dariusz Moczulski, Władysław Grzeszczak, E Zukowskaszczechowska, Z ReligaAbstract:UNLABELLED The aim of the study was to compare the effect of hemodialysis with the reused Cuprophane and polysulfone dialyzers and bicarbonate dialysis on the count of natural killer cells in the peripheral blood in patients with chronic renal failure during the hour of haemodialysis. The study was performed in 16 patients with chronic renal failure just before haemodialysis (0') as well as 15 and 60 minutes after the beginning of haemodialysis with the first and the fourth use of membranes. The count of natural killer cells (CD3-, CD16+) in the peripheral blood was assessed using the flow cytometry. CONCLUSIONS 1) The count of natural killer cells (CD3-, CD16+) decreased transiently in the peripheral blood in observed patients during haemodialysis. 2) The use of new Cuprophane membrane decreased the count of natural killer cells in peripheral blood during haemodialysis significantly more than the haemodialysis with the use of polysulfone membranes and reused Cuprophane membrane. 3) The count of the natural killer cells (CD3-, CD16+) in the peripheral blood in patients with chronic renal failure assessed 15 minutes after the start of haemodialysis could be a marker of dialysis membrane hemocompatibility.
Pedro Aljama - One of the best experts on this subject based on the ideXlab platform.
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effect of uremia and dialysis modality on mononuclear cell apoptosis
Journal of The American Society of Nephrology, 2000Co-Authors: Alejandro Martinmalo, Julia Carracedo, Rafael Ramirez, Alberto Rodriguezbenot, Sagrario Soriano, Mariano Rodriguez, Pedro AljamaAbstract:The aim of this study was to evaluate the effect of both uremia itself and hemodialysis (HD) membranes on the induction of apoptosis. Four groups of subjects were evaluated: 21 nondialyzed (Non-D) patients, 10 continuous ambulatory peritoneal dialysis (CAPD) patients, and 53 HD patients who were on hemophan, cuprophan, cellulose acetate, AN69, and polysulfone; control subjects were nine healthy volunteers. Circulating mononuclear cells were obtained before dialysis and cultured for 48 h. Mean percentage of apoptosis was analyzed by a FACScan flow cytometer using Annexin V-FITC. Cell apoptosis was increased in Non-D patients (11.5 +/- 5.5%) compared with control subjects (2.1 +/- 0.7%, P < 0.001) and CAPD patients (7. 0 +/- 5.8%, P < 0.05). In patients on HD with cuprophan, apoptosis was higher than in control subjects and Non-D and CAPD patients. In Non-D patients, apoptosis was inversely correlated with renal creatinine clearance (r = -0.62, P = 0.003). Cell apoptosis was higher in hemophan than the other HD membranes. In seven patients on hemophan, switching to polysulfone resulted in decreased apoptosis (P < 0.01). Mononuclear cell circulation through mini-dialyzers made of different types of membranes (cuprophan, hemophan, cellulose acetate, AN69, and polysulfone) prouced a significant increase in apoptosis. However, there was a marked difference in the percentage of apoptosis induced by these five membranes, being significantly increased in hemophan and cuprohan compared with the other three membranes. Similar results were obtained when whole blood from healthy donors was circulated through the mini-dialyzers, showing that mononuclear cell apoptosis was increased in hemophan and cuprophan compared with polysulfone. In conclusion, uremia and membrane characteristics may independently affect the mononuclear cell apoptosis.
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effect of uremia and dialysis modality on mononuclear cell apoptosis
Journal of The American Society of Nephrology, 2000Co-Authors: Alejandro Martinmalo, Julia Carracedo, Rafael Ramirez, Alberto Rodriguezbenot, Sagrario Soriano, Mariano Rodriguez, Pedro AljamaAbstract:Abstract . The aim of this study was to evaluate the effect of both uremia itself and hemodialysis (HD) membranes on the induction of apoptosis. Four groups of subjects were evaluated: 21 nondialyzed (Non-D) patients, 10 continuous ambulatory peritoneal dialysis (CAPD) patients, and 53 HD patients who were on hemophan, cuprophan, cellulose acetate, AN69, and polysulfone; control subjects were nine healthy volunteers. Circulating mononuclear cells were obtained before dialysis and cultured for 48 h. Mean percentage of apoptosis was analyzed by a FACScan flow cytometer using Annexin V-FITC. Cell apoptosis was increased in Non-D patients (11.5 ± 5.5%) compared with control subjects (2.1 ± 0.7%, P P r = -0.62, P = 0.003). Cell apoptosis was higher in hemophan than the other HD membranes. In seven patients on hemophan, switching to polysulfone resulted in decreased apoptosis ( P
Dariusz Moczulski - One of the best experts on this subject based on the ideXlab platform.
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the effect of repeated use of Cuprophane and polysulfone dialyzers during hemodialysis on the count of natural killer cells in blood
Polskie Archiwum Medycyny Wewnetrznej-polish Archives of Internal Medicine, 1997Co-Authors: M Liszka, Dariusz Moczulski, Władysław Grzeszczak, E Zukowskaszczechowska, Z ReligaAbstract:UNLABELLED The aim of the study was to compare the effect of hemodialysis with the reused Cuprophane and polysulfone dialyzers and bicarbonate dialysis on the count of natural killer cells in the peripheral blood in patients with chronic renal failure during the hour of haemodialysis. The study was performed in 16 patients with chronic renal failure just before haemodialysis (0') as well as 15 and 60 minutes after the beginning of haemodialysis with the first and the fourth use of membranes. The count of natural killer cells (CD3-, CD16+) in the peripheral blood was assessed using the flow cytometry. CONCLUSIONS 1) The count of natural killer cells (CD3-, CD16+) decreased transiently in the peripheral blood in observed patients during haemodialysis. 2) The use of new Cuprophane membrane decreased the count of natural killer cells in peripheral blood during haemodialysis significantly more than the haemodialysis with the use of polysulfone membranes and reused Cuprophane membrane. 3) The count of the natural killer cells (CD3-, CD16+) in the peripheral blood in patients with chronic renal failure assessed 15 minutes after the start of haemodialysis could be a marker of dialysis membrane hemocompatibility.
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Effect of hemodialysis with Cuprophane and polysulfone membranes on counts of leukocytes, granulocytes, monocytes, lymphocytes and lymphocyte subsets
Polskie Archiwum Medycyny Wewnetrznej-polish Archives of Internal Medicine, 1994Co-Authors: Dariusz Moczulski, Religa Z, Cichoń R, Władysław Grzeszczak, Ewa Zukowska-szczechowska, I SzydłowskaAbstract:: In patients with chronic renal failure treated with haemodialysis many disorders of specific and unspecific immunity were observed. Several different parameters such as direct interaction with dialyzer membrane, hypersensitivity to components within the membrane, complement activation, or presence of endotoxins in the dialysis fluid or water supply can activate the immune system during haemodialysis and cause immunity disorders. This study aimed to compare the biocompatibility of two different dialysis membranes on the ground of the influence on the counts of immunity cells in the first hour of haemodialysis when the interaction between blood and membrane were the greatest. In 18 patients with CRF granulocytes, monocytes, lymphocytes B and T, T4 and T8 cells were counted just before haemodialysis, 15 minutes and 60 minutes after the start of haemodialysis. In all patients the investigation was done first using the Cuprophane dialysis membrane and then using polysulfone dialysis membrane. The cell populations were differentiated by flow cytometry on Fascan using the conjugated monoclonal antibodies. During the first 15 minutes of haemodialysis with Cuprophane membrane the amount of all investigated cells populations decreased significantly. With polysulfone membrane only monocytes decreased significantly in the first 15 minutes of haemodialysis. These results indicate that the polysulfone membrane is more biocompatible than the Cuprophane one and suggest that using the biocompatible membranes some disorders of immunity system in this patients can be prevented.
Rolf Dario Frank - One of the best experts on this subject based on the ideXlab platform.
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role of contact system activation in hemodialyzer induced thrombogenicity
Kidney International, 2001Co-Authors: Rolf Dario Frank, Heike Dresbach, Herbert Thelen, Claudia Weiss, Jürgen Weber, Jürgen FloegeAbstract:BACKGROUND: The contact system is generally believed to be the main trigger of the coagulation cascade during extracorporeal circulation. However, the extent of contact activation, its role for intradialytic thrombin generation as well as the influence of different dialyzer membranes have not been well established. METHODS: In a novel full-scale ex vivo recirculation dialysis model, we investigated the thrombogenicity of three widely used hemodialyzers (Cuprophan Renak RA15-U, Polysulfone F6HPS and AN69XT Nephral 200). The activation of the contact system was evaluated using a newly developed ELISA for factor XIIa-C1-inhibitor complexes. Additionally, we determined free FXIIa (ELISA), thrombin-antithrombin (TAT) complexes, platelet factor 4 (PF4), complement activation (C5a), granulocyte elastase and blood cell counts. The findings in blood from normal volunteers were compared with factor XII-deficient blood. RESULTS: With normal blood AN69 exhibited the highest thrombogenicity in comparison to Cuprophan and Polysulfone, as assessed by TAT generation and platelet consumption. AN69 caused a rapid increase of the FXIIa-C1-inhibitor complexes and of free FXIIa. Despite significant TAT generation with Cuprophan and Polysulfone free FXIIa remained unchanged and the FXIIa-C1-inhibitor complexes stayed below the detection limit. With factor XII-deficient blood Polysulfone exhibited the same TAT generation, whereas the thrombogenicity of AN69 was greatly reduced. CONCLUSIONS: Our data challenge the common assumption that activation of the contact system with generation of FXIIa is the main trigger for coagulation and thrombus formation in hemodialysis. Only the negatively charged AN69 membrane with enhanced thrombogenicity strongly induced contact activation.
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role of contact system activation in hemodialyzer induced thrombogenicity
Kidney International, 2001Co-Authors: Rolf Dario Frank, Heike Dresbach, Herbert Thelen, Claudia Weiss, Jürgen Weber, Jürgen FloegeAbstract:Role of contact system activation in hemodialyzer-induced thrombogenicity. Background The contact system is generally believed to be the main trigger of the coagulation cascade during extracorporeal circulation. However, the extent of contact activation, its role for intradialytic thrombin generation as well as the influence of different dialyzer membranes have not been well established. Methods In a novel full-scale ex vivo recirculation dialysis model, we investigated the thrombogenicity of three widely used hemodialyzers (Cuprophan Renak RA15-U, Polysulfone F6HPS and AN69XT Nephral 200). The activation of the contact system was evaluated using a newly developed ELISA for factor XIIa-C1-inhibitor complexes. Additionally, we determined free FXIIa (ELISA), thrombin-antithrombin (TAT) complexes, platelet factor 4 (PF4), complement activation (C5a), granulocyte elastase and blood cell counts. The findings in blood from normal volunteers were compared with factor XII-deficient blood. Results With normal blood AN69 exhibited the highest thrombogenicity in comparison to Cuprophan and Polysulfone, as assessed by TAT generation and platelet consumption. AN69 caused a rapid increase of the FXIIa-C1-inhibitor complexes and of free FXIIa. Despite significant TAT generation with Cuprophan and Polysulfone free FXIIa remained unchanged and the FXIIa-C1-inhibitor complexes stayed below the detection limit. With factor XII-deficient blood Polysulfone exhibited the same TAT generation, whereas the thrombogenicity of AN69 was greatly reduced. Conclusions Our data challenge the common assumption that activation of the contact system with generation of FXIIa is the main trigger for coagulation and thrombus formation in hemodialysis. Only the negatively charged AN69 membrane with enhanced thrombogenicity strongly induced contact activation.
