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1.
BMC Infect Dis ; 17(1): 763, 2017 12 12.
Artículo en Inglés | MEDLINE | ID: mdl-29233117

RESUMEN

BACKGROUND: Elizabethkingia miricola is a rare Gram-negative bacterium found in water and clinical specimens. Typical culturing methods often misidentify Elizabethkingia spp. as Flavobacterium or Chryseobacterium. Although diagnosis is based on culturing samples taken from sterile sites, such as blood, a proper identification of this bacterium requires an expertise that goes beyond the capabilities of a typical clinical laboratory. CASE PRESENTATION: A 35-year-old woman diagnosed with common variable immunodeficiency was admitted to our center. Previous treatment with antibiotics (amoxicillin plus clavulanate, first and third generation of cephalosporins, macrolides) and systemic corticosteroids (up to 120 mg/day of prednisolone) failed to arrest the spread of inflammation. Gingival recession was observed in her oral cavity, resulting in an apparent lengthening of her teeth. In addition to typical commensal bacteria, including streptococci and neisseriae, strains of Rothia mucilaginosa and Elizabethkingia miricola were identified upon a detailed microbiological examination using a MALDI-TOF MS Biotyper system. The presence of the latter strain correlated with severe periodontitis, lack of IgA in her saliva and serum, a very low IgG concentration (< 50 mg/dl), IgM-paraproteinemia, decreases in C3a and C5a and microvascular abnormality. High-dose immunoglobulin (to maintain IgG > 500 mg/dl) and targeted levofloxacin treatment resulted in immune system reconstitution, oral healing, and eradication of the Elizabethkingia infection. CONCLUSIONS: E. miricola rarely causes disease in healthy individuals. However, the overgrowth of commensal bacteria, lack of IgG/IgA, microvasculopathy and complement cascade activation in patients with humoral immunodeficiency may facilitate Elizabethkingia invasion. Overuse of antibiotics, particularly beta-lactams, may cause mucosal colonization by E. miricola, followed by its multiplication combined with periodontitis that prompts bacterial translocation. MALDI-TOF Biotyper analysis may become a method of choice for identification of Elizabethkingia infections.


Asunto(s)
Infecciones por Bacterias Gramnegativas/diagnóstico , Periodontitis/diagnóstico , Corticoesteroides/uso terapéutico , Adulto , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Complemento C3a/análisis , Complemento C5a/análisis , Femenino , Flavobacteriaceae/efectos de los fármacos , Flavobacteriaceae/genética , Flavobacteriaceae/aislamiento & purificación , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Infecciones por Bacterias Gramnegativas/inmunología , Humanos , Inmunidad Humoral , Inmunoglobulina A/análisis , Inmunoglobulina A/sangre , Inmunoglobulinas Intravenosas/uso terapéutico , Levofloxacino/uso terapéutico , Boca/microbiología , Periodontitis/tratamiento farmacológico , Periodontitis/inmunología , ARN Ribosómico 16S/aislamiento & purificación , ARN Ribosómico 16S/metabolismo , Saliva/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
2.
J Pharm Sci ; 109(1): 429-442, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31229435

RESUMEN

Concerns regarding the impact of subvisible particulate impurities on the safety and efficacy of therapeutic protein products have led manufacturers to implement strategies to minimize protein aggregation and particle formation during manufacturing, storage, and shipping. However, once these products are released, manufacturers have limited control over product handling. In this work, we investigated the effect of di(2-ethylhexyl) phthalate (DEHP) nanodroplets generated in polyvinyl chloride (PVC) bags of intravenous (IV) saline on the stability and immunogenicity of IV immunoglobulin (IVIG) formulations. We showed that PVC IV bags containing saline can release DEHP droplets into the solution when agitated or transported using a pneumatic tube transportation system in a clinical setting. We next investigated the effects of emulsified DEHP nanodroplets on IVIG stability and immunogenicity. IVIG adsorbed strongly to DEHP nanodroplets, forming a monolayer. In addition, DEHP nanodroplets accelerated IVIG aggregation in agitated samples. The immunogenicity of DEHP nanodroplets and IVIG aggregates generated in these formulations were evaluated using an in vitro assay of complement activation in human serum. The results suggested DEHP nanodroplets shed from PVC IV bags could reduce protein stability and induce activation of the complement system, potentially contributing to adverse immune responses during the administration of therapeutic proteins.


Asunto(s)
Activación de Complemento/efectos de los fármacos , Dietilhexil Ftalato/química , Inmunoglobulinas Intravenosas/química , Factores Inmunológicos/sangre , Nanopartículas/química , Cloruro de Polivinilo/química , Agregado de Proteínas , Complemento C3a/análisis , Complemento C4a/análisis , Dietilhexil Ftalato/toxicidad , Contaminación de Medicamentos/prevención & control , Embalaje de Medicamentos , Estabilidad de Medicamentos , Cromatografía de Gases y Espectrometría de Masas , Humanos , Nanopartículas/toxicidad , Tamaño de la Partícula , Plastificantes/química , Plastificantes/toxicidad , Estabilidad Proteica , Reología , Propiedades de Superficie
3.
Vox Sang ; 95(1): 33-8, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18444947

RESUMEN

BACKGROUND AND OBJECTIVES: The aim of the present study was to investigate the quality of shed blood collected in a new intraoperative autotransfusion system (Sangvia, AstraTech, Sweden) and to study whether heparin-coated surfaces in the device reduce the production of inflammatory mediators. MATERIAL AND METHODS: The study was randomized and prospective. Twelve total hip arthroplasty patients whose blood was collected with a device having a heparin-coated surface and 12 patients whose blood was collected with a device having a non-heparin-coated surface were included. Venous blood was drawn from the patients preoperatively. Intraoperatively 200 ml salvaged blood was collected and samples were also withdrawn; samples were obtained from the blood bag. RESULTS: Compared to venous blood, elevated concentrations of interleukin 6 (IL-6), IL-8, C3a and polymorphonuclear elastase were found in collected blood. No significant differences in inflammatory mediators were found between the heparin-coated and the non-heparin-coated groups. The median haemoglobin concentration in the salvaged blood was 74 g/l in both groups. Plasma haemoglobin and potassium concentrations were also elevated. There were no significant differences between the groups. CONCLUSION: The present study indicates that the blood salvaged intraoperatively contains elevated levels of complement split product and proinflammatory cytokines and that heparin-coated surfaces of the salvage device do not significantly influence the formation of inflammatory mediators.


Asunto(s)
Artroplastia de Reemplazo de Cadera/métodos , Transfusión de Sangre Autóloga/instrumentación , Materiales Biocompatibles Revestidos/química , Heparina , Cuidados Intraoperatorios/métodos , Pérdida de Sangre Quirúrgica , Transfusión de Sangre Autóloga/normas , Complemento C3a/análisis , Citocinas/sangre , Humanos
4.
Blood Purif ; 25(3): 281-9, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17622710

RESUMEN

BACKGROUND: Asymmetric dimethylarginine (ADMA) levels are increased in hemodialysis (HD) patients. Reports on the effect of various dialysis strategies on ADMA, symmetric dimethylarginine (SDMA) and L-arginine levels are inconclusive. PATIENTS/METHODS: In this randomized crossover study, 15 patients were dialyzed for 4 weeks with 4 dialyzers, differing in biocompatibility and flux. Dimethylarginine and L-arginine levels were assessed at baseline, and after 4 weeks both before and after HD. RESULTS: During HD, ADMA and SDMA levels decreased significantly with all dialyzers. Dimethylarginine and L-arginine levels remained stable after 4 weeks of HD with each membrane. After pooling all data, values were mainly explained by variation between time points and patients, not by the type of dialyzer. CONCLUSION: Despite an intradialytic decrease in dimethylarginines, no changes occurred after 4 weeks of HD with either membrane. Furthermore, the variability of AMDA, SDMA and L-arginine levels was far more dependent on patient-related factors than on the type of dialyzer applied.


Asunto(s)
Arginina/análogos & derivados , Fallo Renal Crónico/sangre , Diálisis Renal/instrumentación , Adulto , Anciano , Anciano de 80 o más Años , Arginina/sangre , Materiales Biocompatibles , Complemento C3a/análisis , Estudios Cruzados , Diseño de Equipo , Femenino , Humanos , Fallo Renal Crónico/terapia , Masculino , Membranas Artificiales , Persona de Mediana Edad , Óxido Nítrico/metabolismo , Estudios Prospectivos , Microglobulina beta-2/análisis
5.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 29(5): 638-41, 2007 Oct.
Artículo en Zh | MEDLINE | ID: mdl-18051720

RESUMEN

OBJECTIVE: To evaluate the hemocompatibility of glutaraldehyde (GA)-tanned bovine pericardium additionally treated by sodium bisulfite (SOB) solution. METHODS: The hemocompatibility of GA-tanned bovine pericardium treated by SOB solution is evaluated by using dynamic clotting time test, blood platelet adhension test, D-dimeride determination, and complement activation test. The GA-tanned bovine pericardium was used as control. RESULTS: The curve of absorbance-clotting time of two kinds of bovine pericardium was similar in dynamic clotting time test. There was no significant difference between SOB-treated and control groups in blood platelet adhension test. The D-dimeride contents of all bioprostheses were at normal level, and the D-dimeride content of GA-tanned bovine pericardium treated by SOB solution was significantly lower than that of control group (P < 0.05). In complement activation test, the level of complement C3a in SOB-treated group was significantly lower than that in control group (P < 0.05). CONCLUSION: GA-tanned bovine pericardium treated by SOB solution meets the demands of cardiac interstitial implanted materials in hemocompatibility.


Asunto(s)
Materiales Biocompatibles , Bioprótesis , Pericardio/efectos de los fármacos , Sulfitos/farmacología , Animales , Coagulación Sanguínea , Bovinos , Complemento C3a/análisis , Productos de Degradación de Fibrina-Fibrinógeno/metabolismo , Glutaral/farmacología , Ensayo de Materiales , Pericardio/metabolismo , Adhesividad Plaquetaria
6.
Biomaterials ; 77: 111-9, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26584351

RESUMEN

BACKGROUND: Inappropriate and uncontrolled activation of the cascade systems in the blood is a driving force in adverse inflammatory and thrombotic reactions elicited by biomaterials, but limited data are available on the activation of the contact system by polymers and the present study was undertaken to investigate these mechanisms in established models. METHODS: Polymer particles were incubated in (1) EDTA-plasma (10 mM) to monitor the adsorption of 20 selected proteins; (2) lepirudin-anticoagulated plasma to evaluate contact system activation, monitored by the formation of complexes between the generated proteases factor[F]XIIa, FXIa and kallikrein and the serpins C1-inhibitor [C1INH] and antithrombin [AT]; (3) lepirudin-anticoagulated whole blood to determine cytokine release. RESULTS: Strong negative correlations were found between 10 cytokines and the ratio of deposited FXII/C1INH, generated FXIIa-C1INH complexes, and kallikrein-C1INH complexes. Formation of FXIIa-C1INH complexes correlated negatively with the amount of C3a and positively with deposited IgG. CONCLUSIONS: A reciprocal relationship was found between activation of the contact system and the complement system induced by the polymers studied here. The ratios of FXII/C1INH or C4/C4BP, adsorbed from EDTA-plasma are useful surrogate markers for cytokine release and inflammatory response to materials intended for blood contact.


Asunto(s)
Materiales Biocompatibles , Activación de Complemento , Polímeros , Adsorción , Antitrombinas/metabolismo , Coagulación Sanguínea/efectos de los fármacos , Proteínas Sanguíneas/química , Proteínas Inactivadoras del Complemento 1/metabolismo , Proteína Inhibidora del Complemento C1 , Complemento C3a/análisis , Citocinas/metabolismo , Activación Enzimática , Factor XIIa/metabolismo , Factor XIa/metabolismo , Vidrio , Hirudinas/farmacología , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Inmunoglobulina G/análisis , Calicreínas/metabolismo , Tamaño de la Partícula , Poliestirenos , Cloruro de Polivinilo , Proteínas Recombinantes/farmacología
7.
Am J Kidney Dis ; 36(2): 345-52, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10922313

RESUMEN

The clinical performance during first use of a new membrane manufactured from a blend of polyarylethersulfone and polyvinylpyrrolidone (Arylane; Hospal Renal Care, Lyon, France), in which the microstructure of the membrane has been tailored by the manufacturing process and polymer blend, has been compared with Fresenius Polysulfone (Fresenius Medical Care, Bad Homburg, Germany) in a prospective, randomized, crossover study. Small-molecular clearances were similar. A reduction in plasma beta(2)-microglobulin levels was present using both membranes, with a significantly greater removal by Arylane such that the mean postdialysis plasma level difference between the membranes at the end of dialysis was 8. 7 mg/L (95% confidence interval, 3.9 to 13.5; P = 0.004). Recovery of beta(2)-microglobulin from the dialysis fluid was similar: 170 +/- 70 mg for Arylane and 110 +/- 60 mg for Fresenius Polysulfone (P = 0.04). Both membranes were impermeable to albumin but allowed the passage of low-molecular-weight proteins, with 10,046 +/- 3,239 mg for Arylane and 7,285 +/- 2,353 mg for Fresenius Polysulfone recovered from the dialysis fluid (P = 0.07). Neutropenia and platelet adhesion to the membrane were minimal, and time-averaged complement levels during dialysis for C3a and C5b-9 were 207 +/- 92 and 62 +/- 24 ng/mL for Arylane and 223 +/- 68 and 45 +/- 24 ng/mL for Fresenius Polysulfone, respectively, and were membrane independent. This study indicates that the membrane using polyarylethersulfone in conjunction with PVP has complement-activation potential and neutropenia similar to Fresenius Polysulfone but has an enhanced capacity to remove beta(2)-microglobulin. This enhanced removal arises from transmembrane transport augmented by adsorption within the membrane matrix.


Asunto(s)
Materiales Biocompatibles , Membranas Artificiales , Povidona/análogos & derivados , Diálisis Renal/instrumentación , Activación de Complemento , Complemento C3a/análisis , Complejo de Ataque a Membrana del Sistema Complemento/análisis , Creatinina/análisis , Estudios Cruzados , Soluciones para Hemodiálisis/química , Humanos , Persona de Mediana Edad , Fosfatos/análisis , Polímeros , Estudios Prospectivos , Sulfonas , Urea/análisis , Microglobulina beta-2/análisis
8.
Biomaterials ; 12(2): 119-20, 1991 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1878445

RESUMEN

The influence on blood of polyurethaneurea hydrogels in vitro was investigated based on poly(ethylene oxide). A hydrogel was compared with the regenerated cellulose membrane Cuprophan in terms of complement activation, as determined by measurement of C3a concentration. The hydrogel induced less complement activation and the presence of poly(ethylene oxide) is likely to be beneficial to platelet reactivity. The ability to vary the polymer composition and the solubility of the polymers in organic solvents makes the polyurethaneurea hydrogels strong candidates for composite biomaterials.


Asunto(s)
Materiales Biocompatibles , Sangre , Poliuretanos , Plaquetas , Celulosa/análogos & derivados , Activación de Complemento , Complemento C3a/análisis , Humanos , Membranas Artificiales , Polietilenglicoles , Valores de Referencia , Solubilidad
9.
Ann Thorac Surg ; 67(5): 1315-9, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10355404

RESUMEN

BACKGROUND: A silicone-coated microporous hollow-fiber membrane oxygenator has been developed to prevent plasma leakage during long-term use. The objective of this study was to evaluate the biocompatibility of the oxygenator. METHODS: A silicone-coated oxygenator was compared with an uncoated oxygenator in an in vitro model of cardiopulmonary bypass. Simulated circulation was maintained for 6 h at 37 degrees C. RESULTS: Platelet counts decreased significantly (p < 0.05) and leukocyte counts tended to decline; however, the differences between groups were not significant. Concentrations of C3a increased significantly in both groups (p < 0.05), but levels were significantly less in the silicone-coated oxygenator (p = 0.008). In contrast, concentrations of C4a, beta-thromboglobulin, and granulocyte elastase increased significantly (p < 0.05), but the differences between groups were not significant. CONCLUSIONS: Silicone coating over a microporous hollow-fiber membrane may improve biocompatibility by reducing C3a activation.


Asunto(s)
Materiales Biocompatibles Revestidos , Complemento C3a/análisis , Circulación Extracorporea , Oxigenadores de Membrana , Siliconas , Estudios de Evaluación como Asunto , Humanos , Técnicas In Vitro , Recuento de Plaquetas , beta-Tromboglobulina/análisis
10.
Ann Thorac Surg ; 77(5): 1678-83, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15111165

RESUMEN

BACKGROUND: Poly-2-methoxyethylacrylate (PMEA) is a new coating material, and several studies have revealed that PMEA-coated cardiopulmonary bypass (CPB) circuits have good biocompatibility. This study sought to compare this biocompatibility with those of heparin-coated and noncoated circuits. METHODS: Forty-five patients undergoing coronary artery bypass grafting were randomly assigned to PMEA-coated (group P, n = 15), heparin-coated (group H, n = 15), or noncoated (group N, n = 15) circuit groups. Clinical data and the following markers were analyzed: (1) platelet preservation by number of platelets; (2) complement (C) activation by C3a and C4a levels; (3) inflammatory response by interleukin-6 (IL-6) and interleukin-8 (IL-8) levels. RESULTS: Platelet numbers were significantly preserved in group P compared with groups N and H. Postoperative blood loss did not differ among the groups. During CPB, C3a values were significantly lower in group H (536 +/- 145 ng/mL) than in group P (1,458 +/- 433 ng/mL, p < 0.01) and group N (1,815 +/- 845 ng/mL, p < 0.01). The C4a values did not differ 60 minutes after CPB initiation among the groups. The IL-6 and IL-8 levels were significantly lower in group P and group H than in group N. CONCLUSIONS: The PMEA coating was superior to heparin coating and noncoating in preserving platelets, and was equivalent to heparin coating in terms of the perioperative clinical course and inhibition of inflammatory cytokines, but slightly inferior in reducing complement activation.


Asunto(s)
Acrilatos , Puente Cardiopulmonar , Materiales Biocompatibles Revestidos , Inflamación/prevención & control , Recuento de Plaquetas , Polímeros , Acrilatos/farmacología , Anciano , Anticoagulantes , Complemento C3a/análisis , Complemento C4a/análisis , Femenino , Heparina , Humanos , Masculino , Polímeros/farmacología
11.
Ann Thorac Surg ; 57(4): 815-8; discussion 818-9, 1994 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8166524

RESUMEN

Durable, covalently bonded, heparin-coated cardiopulmonary bypass (CPB) circuits with oxygenators have been developed. Proposed advantages of heparin-coated CPB circuits include improved biocompatibility and thromboresistance. The purpose of this study was to evaluate our experience with heparin-coated CPB circuits in 20 patients. Heparin was given to maintain an activated clotting time equal to or greater than 200 seconds, while flow rates were kept equal to or greater than 2 L/min. Indications for use of this circuit included recent stroke, posttraumatic injuries, recent gastrointestinal bleeding, protamine allergies, combined cardiac and noncardiac procedures, and ventricular assist. Mean heparin dosage was 0.50 +/- 0.18 mg/kg and protamine dosage was 57.14 +/- 39.36 mg. Postoperative blood loss and transfusion requirements were minimal. Postoperative complement levels of C3a and C5a were normal, suggesting excellent biocompatibility. There were no deaths or perioperative complications. Heparin-coated CPB circuits using a pump oxygenator can be used safely with low-dose heparin administration in select patients requiring CPB.


Asunto(s)
Puente Cardiopulmonar/instrumentación , Heparina/uso terapéutico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Materiales Biocompatibles , Velocidad del Flujo Sanguíneo , Pérdida de Sangre Quirúrgica/estadística & datos numéricos , Transfusión Sanguínea , Complemento C3a/análisis , Complemento C5a/análisis , Monitoreo de Drogas , Equipo Médico Durable , Diseño de Equipo , Femenino , Heparina/sangre , Humanos , Masculino , Ensayo de Materiales , Persona de Mediana Edad , Protaminas/uso terapéutico , Tiempo de Coagulación de la Sangre Total
12.
Ann Thorac Surg ; 70(1): 191-6, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10921707

RESUMEN

BACKGROUND: Heparin-coated circuits reduce the inflammatory response to cardiopulmonary bypass in adult patients; however, little is known about its effects in the pediatric population. Two studies were performed to assess this technology's impact on inflammation and clinical outcomes. METHODS: In a pilot study, complement and interleukins were measured in 19 patients who had either uncoated cardiopulmonary bypass circuits or heparin-bonded circuits. Subsequently, 23 additional patients were studied in a randomized fashion. Respiratory function and blood product utilization were recorded. RESULTS: In the pilot study, heparin-bonded circuit patients had less complement 3a (p < 0.001) and interleukin-8 (p < 0.05) compared with uncoated cardiopulmonary bypass circuit patients. The randomized study revealed that the heparin-bonded circuit was associated with reduced complement 3a (p = 0.02). Multiple variable analysis revealed that the following postoperative variables were increased with bypass time (p = 0.01) and diminished with heparin-bonded circuits: interleukins (p = 0.01), peak airway pressures (p = 0.05), and prothrombin time (p = 0.03). CONCLUSIONS: Heparin-bonded circuits significantly reduce cytokines and complement during cardiopulmonary bypass and lower interleukin levels postbypass; they were also associated with improved pulmonary and coagulation function. Heparin-bonded circuits ameliorate the systemic inflammatory response in pediatric patients from cardiopulmonary bypass.


Asunto(s)
Puente Cardiopulmonar , Fibrinolíticos/administración & dosificación , Heparina/administración & dosificación , Preescolar , Materiales Biocompatibles Revestidos , Complemento C3a/análisis , Complemento C5a/análisis , Femenino , Humanos , Lactante , Interleucina-1/sangre , Interleucina-6/sangre , Interleucina-8/sangre , Masculino , Proyectos Piloto , Estudios Prospectivos , Propiedades de Superficie
13.
J Cataract Refract Surg ; 17(2): 139-42, 1991 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2040970

RESUMEN

The complement activation potential of surface modified (passivated) poly(methyl methacrylate) (PMMA) intraocular lenses (IOLs) with polypropylene loops was compared to that of standard PMMA IOLs with polypropylene loops. Both lens types were incubated in human sera for six hours and then the C3a and C5a levels were measured by radioimmunoassay. Sera incubated with either IOL type generated significantly higher levels of C3a and C5a than control sera incubated without any IOL. The amount of C3a and C5a generated by the passivated PMMA IOLs was comparable to the levels generated by the standard PMMA IOLs. The results of this study show that surface passivated PMMA IOLs with polypropylene loops activated complement to the same level as standard PMMA IOLs with polypropylene loops.


Asunto(s)
Activación de Complemento , Lentes Intraoculares , Metilmetacrilatos , Complemento C3a/análisis , Complemento C5a/análisis , Humanos , Radioinmunoensayo , Propiedades de Superficie
14.
Clin Nephrol ; 40(5): 281-5, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8281717

RESUMEN

The influence of dialyzer geometry on blood coagulation, heparin requirement and complement activation was studied in fourteen chronic hemodialysis patients. Each patient was dialyzed with two different cuprophan dialyzers, hollow fiber GF 120M and parallel plate Lundia IC5N. Both dialyzers had a wall thickness of 11 microns, surface area of 1.2 m2 and both were sterilized with ethylene oxide. Heparin doses were individually titrated. The mean heparin dose was 6089 +/- 988 U. Platelet count decreased from 218 x 10(9)/l to 193 x 10(9)/l and from 235 x 10(9)/l to 197 x 10(9)/l respectively (hollow fiber/plate dialyzer, ns). The number of leucocytes decreased at 15 min after start of dialysis by 56% and 61% (hollow fiber/plate dialyzer, ns). The heparin requirement, measured as prolongation of whole blood activated coagulation time after identical doses of heparin, were the same in hollow fiber and plate dialysis sessions. The arterial fibrinopeptide A concentrations increased during dialysis from 5.4 to 7.1 nmol/l and 8.5 to 9.6 nmol/l respectively (hollow fiber/plate dialyzer, ns). The residual blood volume in the hollow fiber dialyzers was 1.3 +/- 1.1 ml and in the plate dialyzers 1.5 +/- 0.9 ml (ns). C3a activation, indicated by a marked arterio-venous difference, was observed at 15 min after start of dialysis with hollow fiber as well as plate dialyzers. The arterio-venous difference was less pronounced at the end of dialysis. There were no differences in C3a activation between hollow fiber and plate dialyzers at any timepoint. It is concluded that dialyzer geometry does not significantly influence platelet count, blood coagulation, heparin requirement or complement activation.


Asunto(s)
Materiales Biocompatibles , Coagulación Sanguínea/fisiología , Activación de Complemento/fisiología , Heparina/uso terapéutico , Membranas Artificiales , Diálisis Renal/instrumentación , Anciano , Celulosa/análogos & derivados , Complemento C3a/análisis , Diseño de Equipo , Femenino , Fibrinopéptido A/análisis , Humanos , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Recuento de Plaquetas
15.
Clin Nephrol ; 48(4): 253-9, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9352161

RESUMEN

A prospective randomised clinical study comparing the functional performance and biocompatibility of a new cellulose diacetate variant (Dicea) in which the degree of hydroxyl group substitution differs, with cellulose diacetate and low flux polysulfone incorporated into commercially produced hollow fiber hemodialysers with a surface area 1.5-1.6 m2 has been undertaken. All dialysers studied demonstrated clinically acceptable performance in terms of their small molecular removal characteristics, with minor statistical but not clinical differences. Use of both cellulose diacetate membranes but not low flux polysulfone resulted in a reduction in plasma beta(2) microglobulin levels. The membranes were impermeable to albumin, but showed some permeability to low molecular weight proteins. The average protein recovery from the dialysis fluid was 3105 mg for Dicea, 2913 mg for cellulose diacetate and 2842 mg for low flux polysulfone. For Dicea the white cell count by 15 minutes had declined to 68% of pre treatment value, compared with 59% and 86% for cellulose diacetate and low flux polysulfone. The differences between Dicea and cellulose diacetate were not significant, but both cellulose based membranes differed from low flux polysulfone (p = 0.0015). There was a strong evidence of differences between the membranes in respect of C5a and C5b-9 generation (p = 0.0001) but not for C3a (p = 0.16) furthermore the levels of C5b-9 generated during dialysis also showed a significant positive correlation compared to C5a for all membranes. (Pearson's correlation coefficient = 0.856, p = 0.0001). It is concluded that the two cellulose diacetate membranes are not identical, with the differences observed being a consequence of the degree of acetyl substitution, resulting in alteration of membrane structure and the method of sterilization. The clinical significance of these differences are difficult to characterize but the modification of the cellulose structure appears to be a promising method to improve the biocompatibility of cellulose membranes. The improved biocompatibility offered by this method still falls short of that achieved with low flux synthetic membranes such as Fresenius Polysulfone.


Asunto(s)
Materiales Biocompatibles/uso terapéutico , Celulosa/análogos & derivados , Soluciones para Hemodiálisis/química , Membranas Artificiales , Diálisis Renal/instrumentación , Adulto , Anciano , Celulosa/uso terapéutico , Activación de Complemento , Complemento C3a/análisis , Complemento C5a/análisis , Complejo de Ataque a Membrana del Sistema Complemento/análisis , Creatinina/sangre , Humanos , Recuento de Leucocitos , Ensayo de Materiales , Persona de Mediana Edad , Fosfatos/sangre , Recuento de Plaquetas , Polímeros/uso terapéutico , Estudios Prospectivos , Proteínas/análisis , Diálisis Renal/métodos , Albúmina Sérica/análisis , Sulfonas/uso terapéutico , Urea/sangre , Microglobulina beta-2/análisis
16.
ASAIO J ; 38(1): 47-51, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1554917

RESUMEN

Quantitation of complement activation by polyacrilonitrile (PAN) dialyzer membrane is complicated by the high adsorptive capacity of the membrane for fluid phase anaphylotoxins. Assays for these anaphylotoxins, therefore, underestimate the degree of complement activation produced by this membrane. Alternative methods of measuring in vitro complement activation by the PAN and Cuprophan membranes were explored by incubating normal human erythrocytes with the membranes in the presence of serum. This led to deposition of C3d on these "innocent bystander" red cells, and provided an independent parameter for measuring complement activation. The PAN membrane caused significantly more C3d deposition on red cells, and thus more complement activation than Cuprophan. The possible significance of complement activation by PAN membrane, in consideration of its property of binding the resultant anaphylotoxins, is discussed.


Asunto(s)
Resinas Acrílicas , Activación de Complemento/inmunología , Eritrocitos/metabolismo , Riñones Artificiales , Membranas Artificiales , Celulosa/análogos & derivados , Complemento C3a/análisis , Complemento C3d/metabolismo , Complemento C5a/análisis , Humanos , Técnicas In Vitro
17.
Int J Artif Organs ; 13(10): 697-703, 1990 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2254048

RESUMEN

We studied hemocompatibility of various blood tubings with C3a anaphylatoxin measurement and comparative electron scanning microscopy. The following tubing materials were tested: polyvinylchloride (PVC) plasticised with phthalate (PVC), pvc plasticised with phthalate coextruded with polyurethane (PIV), and two phthalate-free lines: pvc plasticised with trimellitate coextruded with polyurethane (TRI) and pvc plasticised with LT 360 (LTP). Results of C3a generation rate showed a significant activation by all blood tubings, with a reduced rate with PIV when compared to all others. Electron scanning microscopy showed marked alterations of PIV surface on tubings stored for 6 months. Protein deposits on internal surfaces after dialysis were similar whatever tubing material was tested, but adhesive cell number was greater with TRI when compared to PVC and LTP. Hemocompatibility is unchanged with phthalate-free tubings when compared to phthalate plasticised ones. In contrast with phthalate plasticised PVC there is no beneficial effect of polyurethane coextrusion with trimellitate plasticised PVC in regard to C3a generation.


Asunto(s)
Materiales Biocompatibles , Plastificantes , Diálisis Renal/instrumentación , Anafilatoxinas/análisis , Complemento C3a/análisis , Femenino , Humanos , Masculino , Microscopía Electrónica de Rastreo , Persona de Mediana Edad , Ácidos Ftálicos , Poliuretanos , Cloruro de Polivinilo
18.
Int J Artif Organs ; 26(6): 467-76, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12866652

RESUMEN

Beta2-microglobulin (beta2-m) is an 11.8 kD protein that is excreted by the kidneys. In renal insufficiency, it accumulates in the body and can result in AB amyloidosis with bone and joint destruction. Four modifications of a new beta2-m adsorbent material were tested for biocompatibility with human whole blood. 500 ml of heparinized blood from healthy human donors was perfused ex vivo through minicolumns (adsorber beads: divinylbenzene with different biocompatible coatings) in the single-pass mode. Blood samples were taken from the antecubital vein before and at the column outlet during the 50 min test runs. Red and white cell counts remained virtually constant. No signs of hemolysis could be detected. Thrombogenicity of the columns was low as shown by the insignificant platelet loss, only slight platelet activation and moderate thrombin-antithrombin formation. There was no activation of leukocytes nor monocytes. Complement and bradykinin activation was minimal. Electrolyte concentrations and pH remained essentially constant. In conclusion, this new beta2-m adsorbent material exhibited favorable biocompatibility features in our ex vivo model and is thus a promising candidate for future clinical beta2-m hemoperfusion studies in patients.


Asunto(s)
Materiales Biocompatibles Revestidos/uso terapéutico , Riñones Artificiales , Poliestirenos/uso terapéutico , Microglobulina beta-2/farmacocinética , Antitrombina III , Materiales Biocompatibles Revestidos/efectos adversos , Complemento C3a/análisis , Enfermedades Hematológicas/etiología , Humanos , Péptido Hidrolasas/sangre , Poliestirenos/efectos adversos , Factor de Necrosis Tumoral alfa/análisis
19.
Int J Artif Organs ; 13(3): 176-80, 1990 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2347666

RESUMEN

We studied the adsorption of anaphylatoxins C3a and C5a on acrylonitrile (AN69) hollow-fiber (AN69HF) and plate (AN69P) dialyzers in 8 patients during 4-hour hemodialyses (HD). Blood passed first through a cuprophan dialyzer and then through AN69 dialyzers that were not in contact with dialysis fluid. Plasma C3a and C5a were measured in samples taken from the afferent and efferent blood lines of the acrylonitrile dialyzers at 15, 60 and 240 min. Plasma C3a concentrations decreased significantly in blood that had passed through AN69 dialyzers. This decrease, indicating membrane adsorption, was maximal (by 65% in AN69HF and by 59% in AN69P) at 15 min and minimal (by 53% in AN69HF and by 18% in AN69P) at 240 min. The decrease in plasma C5a concentrations was smaller and significant throughout HD only with AN69HF. The amount of C3a adsorbed was at least 45,000 micrograms in AN69HF and 18,000 micrograms in AN69P. These findings demonstrate that acrylonitrile dialyzers adsorb more C3a and C5a than they produce. This membrane adsorption may explain why the increase of plasma C3a and C5a is inhibited during HD.


Asunto(s)
Complemento C3a/análisis , Complemento C5a/análisis , Riñones Artificiales , Membranas Artificiales , Acrilonitrilo , Adsorción , Adulto , Anciano , Activación de Complemento , Femenino , Humanos , Fallo Renal Crónico/inmunología , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Diálisis Renal , Factores de Tiempo
20.
Int J Artif Organs ; 15(4): 243-8, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1587648

RESUMEN

Monitoring of cardiopulmonary bypass (CPB) in terms of alterations to the concentrations of selected blood constituents leads to contrasting patterns of response. This has been verified by determining the influence of CPB on the activation of fibrinolysis, complement, leucocytes and the contact phase of coagulation. Fibrinolytic activity was determined by fibrin degradation products (X-FDP's), complement activation by C3a and C5a, leucocyte activation by granulocyte elastase and contact activation by factor XII-like activity (FXIIA). Five patients undergoing elective coronary artery surgery using a bubble oxygenator and pulsatile perfusion were studied. X-FDP's rose gradually during CPB and remained elevated. Similar patterns were observed for elastase and FXIIA. In contrast, C3a rose sharply with peak values at 1 1/2-2h of bypass while C5a did not show significant changes during bypass. The data obtained have enabled the establishment of response patterns for parameters in CPB which will provide information relevant to the clinical application of biomaterials.


Asunto(s)
Materiales Biocompatibles , Puente Cardiopulmonar , Activación de Complemento/fisiología , Complemento C3a/análisis , Complemento C5a/análisis , Factor XIIa/análisis , Femenino , Productos de Degradación de Fibrina-Fibrinógeno/análisis , Fibrinólisis/fisiología , Humanos , Elastasa de Leucocito , Activación de Linfocitos/fisiología , Masculino , Persona de Mediana Edad , Oxigenadores , Elastasa Pancreática/sangre
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