RESUMEN
BACKGROUND: The long-term molecular changes in the central nervous system constitute an important aspect of general anaesthesia, but little is known about to what extent these molecular changes are affected by anaesthesia duration. The aim of the present study was to evaluate the effects of short duration (20 min) general anaesthesia with isoflurane or avertin on the expression of 20 selected genes in the mouse hippocampus at 1 and 4 days after anaesthesia. METHODS: Nine to eleven-weeks-old male mice received one of the following treatments: 20 min of avertin-induced anaesthesia (n=11), 20 min of isoflurane-induced anaesthesia (n=10) and no anaesthesia (n=5). One and four days after anaesthesia, gene expression in the hippocampus was determined with reverse transcription quantitative real-time polymerase chain reaction. RESULTS: We found that anaesthesia led to the upregulation of six genes: Hspd1 (heat shock protein 1), Plat (tissue plasminogen activator) and Npr3 (natriuretic peptide receptor 3) were upregulated only 1 day after anaesthesia, whereas Thbs4 (thrombospondin 4) was upregulated only 4 days after anaesthesia. Syp (synaptophysin) and Mgst1 (microsomal glutathione S-transferase 1) were upregulated at both time points. Hspd1, Mgst1 and Syp expression was increased regardless of the anaesthetic used, Npr3 and Plat were increased only in mice exposed to avertin, and Thbs4 was upregulated only after isoflurane-induced anaesthesia. CONCLUSIONS: This study shows that some of the effects of short general anaesthesia on gene expression in the mouse hippocampus persist for at least 4 days.
Asunto(s)
Anestesia General/métodos , Etanol/análogos & derivados , Expresión Génica/efectos de los fármacos , Hipocampo/efectos de los fármacos , Isoflurano/farmacología , Anestésicos por Inhalación/farmacología , Animales , Etanol/farmacología , Masculino , Ratones , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Factores de TiempoRESUMEN
Ionizing radiation persistently reduces the pool of neural stem and progenitor cells (NSPCs) in the dentate gyrus (DG) of the hippocampus, which may explain some of the learning deficits observed in patients treated with radiotherapy, particularly pediatric patients. A single dose of 8 Gy irradiation (IR) was administered to the brains of postnatal day 14 (P14) C57BL/6 mice and 1.0 × 10(5) bromodeoxyuridine-labeled, syngeneic NSPCs were injected into the hippocampus 1 day, 1 week or 6 weeks after IR. Cell survival and phenotype were evaluated 5 weeks after grafting. When grafted 1 day post-IR, survival and neuronal differentiation of the transplanted NSPCs were lower in irradiated brains, whereas the survival and cell fate of grafted cells were not significantly different between irradiated and control brains when transplantation was performed 1 or 6 weeks after IR. A young recipient brain favored neuronal development of grafted cells, whereas the older recipient brains displayed an increasing number of cells developing into astrocytes or unidentified cells. Injection of NSPCs, but not vehicle, induced astrogliosis and reduced thickness of the dorsal blade of the GCL after 5 months. In summary, we demonstrate that age and interval between IR and grafting can affect survival and differentiation of grafted NSPCs. The observed long-term gliosis and degeneration warrant caution in the context of NSPC grafting for therapeutical purposes.
Asunto(s)
Envejecimiento , Gliosis/patología , Hipocampo/patología , Células-Madre Neurales/citología , Radiación Ionizante , Animales , Astrocitos/citología , Astrocitos/metabolismo , Encéfalo/efectos de la radiación , Diferenciación Celular/efectos de la radiación , Células Cultivadas , Hipocampo/efectos de la radiación , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Confocal , Células-Madre Neurales/trasplante , Neurogénesis , Dosis de RadiaciónRESUMEN
BACKGROUND AND PURPOSE: The aim of this study was to investigate whether genetic variation at the third complement component (C3) locus is associated with ischaemic stroke (IS). METHODS: The Sahlgrenska Academy Study on Ischaemic Stroke comprises 844 patients with IS, and 668 healthy controls. Sixteen SNPs were analyzed. RESULTS: Two SNPs, rs2277984 and rs3745565, showed a significant association with overall IS. The SNP rs2277984 also showed association with the IS subtype cryptogenic stroke. These associations were independent of hypertension, diabetes, and smoking. The independent association between rs3745565 and overall IS withstands correction for multiple testing. CONCLUSION: In this sample of patients with IS, genetic variation in C3 is associated with IS.
Asunto(s)
Isquemia Encefálica/genética , Isquemia Encefálica/inmunología , Complemento C3/genética , Predisposición Genética a la Enfermedad/genética , Accidente Cerebrovascular/genética , Accidente Cerebrovascular/inmunología , Isquemia Encefálica/complicaciones , Variación Genética/fisiología , Genotipo , Humanos , Polimorfismo de Nucleótido Simple/genética , Accidente Cerebrovascular/complicacionesRESUMEN
Atherosclerosis is associated with activation of the immune system. Intravenously applied normal polyclonal immunoglobulins (IVIg) have broad therapeutic applications in the treatment of autoimmune and systemic inflammatory diseases. Recently, IVIg have been shown to inhibit atherogenesis in experimental animal models. To investigate the role of the complement system in this process, we used third complement component-deficient (C3(-/-)) and control atherosclerosis-prone apolipoprotein E (ApoE) and low-density lipoprotein receptor (LDLR) double knock-out mice fed a normal diet. IVIg treatment reduced lesion fraction area in the aortic root of complement-sufficient mice whereas the lesion fraction area of C3(-/-) mice was not affected. Thus, complement activation plays a role in the anti-atherosclerotic effects of IVIg, possibly by C3-derived fragments generated through Fc-dependent complement activation.
Asunto(s)
Apolipoproteínas E/inmunología , Arteriosclerosis/inmunología , Complemento C3/deficiencia , Inmunoglobulinas Intravenosas/inmunología , Receptores de Lipoproteína/inmunología , Animales , Activación de Complemento/inmunología , Complemento C3/inmunología , Modelos Animales de Enfermedad , Inmunoglobulinas Intravenosas/administración & dosificación , Inmunohistoquímica/métodos , Inyecciones Intraperitoneales , Macrófagos/inmunología , Masculino , Ratones , Ratones Noqueados , Monocitos/inmunología , Receptores de IgG/inmunologíaRESUMEN
To investigate the influence of antibody structure and specificity on antibody efficacy against Streptococcus pneumoniae, human monospecific antibodies (MAbs) to serotype 3 pneumococcal capsular polysaccharide (PPS-3) were generated from transgenic mice reconstituted with human immunoglobulin loci (XenoMouse mice) vaccinated with a PPS-3-tetanus toxoid conjugate and their molecular genetic structures, epitope specificities, and protective efficacies in normal and complement-deficient mice were determined. Nucleic acid sequence analysis of three MAbs (A7, 1A2, and 7C5) revealed that they use two different V(H)3 genes (A7 and 1A2 both use V3-15) and three different V(kappa) gene segments. The MAbs were found to have similar affinities for PPS-3 but different epitope specificities and CDR3 regions. Both A7 and 7C5 had a lysine at the V(H)-D junction, whereas 1A2 had a threonine. Challenge experiments with serotype 3 S. pneumoniae in BALB/c mice revealed that both 10- and 1- micro g doses of A7 and 7C5 were protective, while only a 10- micro g dose of 1A2 was protective. Both A7 and 7C5 were also protective in mice lacking either an intact alternative (FB(-/-)) or classical (C4(-/-)) complement pathway, but 1A2 was not protective in either strain. Our data suggest that PPS-3 consists of epitopes that can elicit both highly protective and less protective antibodies and that the superior efficacies of certain antibodies may be a function of their structures and/or specificities. Further investigation of relationships between structure, specificity, and efficacy for defined MAbs to PPS may identify antibody features that might be useful surrogates for antibody (and vaccine) efficacy.
Asunto(s)
Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/inmunología , Polisacáridos Bacterianos/inmunología , Streptococcus pneumoniae/inmunología , Animales , Anticuerpos Monoclonales/genética , Especificidad de Anticuerpos , Antígenos Bacterianos/inmunología , Secuencia de Bases , Activación de Complemento , Complemento C4/deficiencia , Complemento C4/genética , Factor B del Complemento/deficiencia , Factor B del Complemento/genética , ADN Recombinante/genética , Epítopos/inmunología , Genes de Inmunoglobulinas , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Ratones Transgénicos , Estructura Molecular , Infecciones Neumocócicas/inmunología , Infecciones Neumocócicas/prevención & control , Streptococcus pneumoniae/patogenicidadRESUMEN
The importance of the intermediate filament (IF) proteins glial fibrillary acidic protein (GFAP) and vimentin for astrocyte function was studied by investigating astrocytes prepared from GFAP-/- and/or vimentin-/- mice. The rate of glucose uptake through facilitative hexose transporters was not affected by depletion of GFAP or vimentin. Similarly, the absence of these IF proteins did not affect ascorbate uptake, under control or cyclic AMP-stimulated conditions, or ascorbate efflux through volume-sensitive organic anion channels. However, compared with wild-type astrocytes, glutamine concentrations were increased up to 200% in GFAP-/- astrocytes and up to 150% in GFAP+/- astrocytes and this increase was not dependent on the presence of vimentin. GFAP-/- astrocytes in culture still contain IFs (made of vimentin and nestin), whereas GFAP-/- vim-/- cultured astrocytes lack IFs. Thus, glutamine levels appear to correlate inversely with GFAP, rather than depend on the presence of IFs per se. Furthermore, the effect of GFAP is dose-dependent since the glutamine concentration in GFAP+/- astrocytes falls between those in wild-type and GFAP-/- astrocytes.
Asunto(s)
Ácido Ascórbico/metabolismo , Astrocitos/metabolismo , Proteína Ácida Fibrilar de la Glía/deficiencia , Glucosa/metabolismo , Glutamina/metabolismo , Vimentina/deficiencia , Ácido 4,4'-Diisotiocianostilbeno-2,2'-Disulfónico/farmacología , Animales , Transporte Biológico , Bucladesina/farmacología , Células Cultivadas , AMP Cíclico/farmacología , Proteína Ácida Fibrilar de la Glía/fisiología , Canales Iónicos/fisiología , Ratones , Ratones Endogámicos C57BL , Vimentina/fisiologíaRESUMEN
Mucosal surfaces are protected specifically by secretory immunoglobulin A (SIgA) and SIgM generated through external translocation of locally produced dimeric IgA and pentameric IgM. Their active transport is mediated by the epithelial polymeric Ig receptor (pIgR), also called the transmembrane secretory component. Paracellular passive external transfer of systemic and locally produced antibodies also provides mucosal protection, making the biological importance of secretory immunity difficult to assess. Here we report complete lack of active external IgA and IgM translocation in pIgR knockout mice, indicating no redundancy in epithelial transport mechanisms. The knockout mice were of normal size and fertility but had increased serum IgG levels, including antibodies to Escherichia coli, suggesting undue triggering of systemic immunity. Deterioration of their epithelial barrier function in the absence of SIgA (and SIgM) was further attested to by elevated levels of albumin in their saliva and feces, reflecting leakage of serum proteins. Thus, SIgA did not appear to be essential for health under the antigen exposure conditions of these experimental animals. Nevertheless, our results showed that SIgA contributes to maintenance of mucosal homeostasis. Production of SIgA might therefore be a variable in the initiation of human immunopathology such as inflammatory bowel disease or gluten-sensitive enteropathy.
Asunto(s)
Inmunoglobulina A Secretora/metabolismo , Mucosa Intestinal/inmunología , Receptores de Inmunoglobulina Polimérica/genética , Receptores de Inmunoglobulina Polimérica/inmunología , Animales , Anticuerpos Antibacterianos/sangre , Transporte Biológico , Transporte Biológico Activo , Escherichia coli/inmunología , Fertilidad , Glútenes/inmunología , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/metabolismo , Intestino Delgado/inmunología , Lactobacillus/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos , Ratones Noqueados , Ratas , Receptores de Inmunoglobulina Polimérica/deficiencia , Mapeo Restrictivo , Saliva/inmunología , Albúmina Sérica/metabolismoRESUMEN
Kidney glomerulus mesangial cells fail to develop in mice carrying targeted null mutations in the platelet-derived growth factor (PDGF)-B or PDGF-Rbeta genes. We have examined the pattern of expression of these genes and smooth muscle markers during kidney development, to address the possible mechanisms underlying the mutant phenotypes. In wild-type embryos, PDGF-B was expressed in vascular endothelial cells, particularly in capillary endothelial cells in the developing glomeruli, whereas PDGF-Rbeta was found in perivascular mesenchymal cells in the developing renal cortex. In the course of glomerular development, small groups of PDGF-Rbeta and desmin-expressing cells collected in the 'S'-shaped and early cup-shaped vesicles, and at later stages such cells were found in the glomerular mesangium. In PDGF-B or -Rbeta null embryos, some PDGF-Rbeta/desmin or desmin-positive cells, respectively, were seen in early cup-shaped vesicles, but fewer than in the wild type, and further development of the mesangium failed. In mouse chimeras composed of PDGF-Rbeta +/+ and -/- cells, the Rbeta-/- cells failed to populate the glomerular mesangium. Our results show that while the mesangial cell lineage is specified independently of PDGF-B/Rbeta, these molecules provide critical permissive signals in mesangial cell development. We propose a model in which mesangial cells originate from PDGF-Rbeta-positive progenitors surrounding the developing glomerular afferent and efferent arterioles, and are co-recruited in response to PDGF-B during angiogenic formation of the glomerular capillary tuft.
Asunto(s)
Mesangio Glomerular/embriología , Mesangio Glomerular/metabolismo , Factor de Crecimiento Derivado de Plaquetas/metabolismo , Receptores del Factor de Crecimiento Derivado de Plaquetas/metabolismo , Animales , Capilares/citología , Capilares/embriología , Capilares/metabolismo , División Celular , Quimera , Desmina/genética , Desmina/metabolismo , Femenino , Regulación del Desarrollo de la Expresión Génica , Mesangio Glomerular/citología , Hibridación in Situ , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Biológicos , Neovascularización Fisiológica , Factor de Crecimiento Derivado de Plaquetas/genética , Embarazo , Receptor beta de Factor de Crecimiento Derivado de Plaquetas , Receptores del Factor de Crecimiento Derivado de Plaquetas/genética , Transducción de Señal , Células Madre/citología , Células Madre/metabolismoRESUMEN
Factor B is an essential component of the complement cascade which forms the C3 and C5 convertase of the alternative pathway. Factor B cleavage products also function as cofactors in antibody-independent monocyte-mediated cytotoxicity, macrophage spreading, plasminogen activation and proliferation of B lymphocytes. Several healthy kindreds heterozygous for the factor B null or non-functional allele have been reported but the absence of homozygous factor B deficiency in humans or in animals has been speculated to be caused by the lethality of the phenotype. Here we report the generation of factor B-deficient mice by gene targeting in vivo. These mice were born at the expected Mendelian ratio and they both develop and breed normally in a conventional animal facility. These mice represent a model of complete alternative pathway deficiency. This model enables the dissection of the complement cascade in vivo and the elucidation of the relative contribution of this complement pathway in the various physiological and pathological phenomena ascribed to the complement system.
Asunto(s)
Factor B del Complemento/deficiencia , Animales , Northern Blotting , Southern Blotting , Factor B del Complemento/genética , Modelos Animales de Enfermedad , Marcación de Gen , Hemólisis , Ratones , Sondas de OligonucleótidosRESUMEN
Complement is a system of more than 30 proteins found both in plasma and on cell membranes. The complement system has several important functions in the immune response including initiation of inflammation, neutralization and elimination of pathogens, regulation of antibody responses, clearance of immune complexes and disruption of cell membranes. Under certain conditions complement may, however, act as a mediator of deleterious inflammatory reactions and complement activation has been implicated in the pathogenesis of autoimmune disorders, atherosclerosis, neurodegenerative diseases, bioincompatibility reactions and decompression sickness. Using gene targeting, we have generated mice deficient for the third complement component (C3). These mice represent an animal model in which complement activation by any pathway is prevented at an early stage. The C3-deficient mice should be valuable for the study of the roles of the complement system in vivo in a variety of physiological and pathological situations.
Asunto(s)
Complemento C3/genética , Marcación de Gen/métodos , Animales , Western Blotting , Complemento C3/biosíntesis , Complemento C3/deficiencia , Ensayo de Inmunoadsorción Enzimática , Ratones , Ratones Endogámicos C57BL , MutaciónRESUMEN
A mouse platelet-derived growth factor A chain (PDGF-A) null allele is shown to be homozygous lethal, with two distinct restriction points, one prenatally before E10 and one postnatally. Postnatally surviving PDGF-A-deficient mice develop lung emphysema secondary to the failure of alveolar septation. This is apparently caused by the loss of alveolar myofibroblasts and associated elastin fiber deposits. PDGF alpha receptor-positive cells in the lung having the location of putative alveolar myofibroblast progenitors were specifically absent in PDGF-A null mutants. We conclude that PDGF-A is crucial for alveolar myofibroblast ontogeny. We have previously shown that PDGF-B is required in the ontogeny of kidney mesangial cells. The PDGFs therefore appear to regulate the generation of specific populations of myofibroblasts during mammalian development. The two PDGF null phenotypes also reveal analogous morphogenetic functions for myofibroblast-type cells in lung and kidney organogenesis.
Asunto(s)
Factor de Crecimiento Derivado de Plaquetas/fisiología , Alveolos Pulmonares/crecimiento & desarrollo , Enfisema Pulmonar/patología , Actinas/análisis , Animales , Cardiomegalia/patología , Quimera , Cruzamientos Genéticos , Elastina/análisis , Fibroblastos/citología , Fibroblastos/patología , Marcación de Gen , Pulmón/embriología , Pulmón/ultraestructura , Ratones , Ratones Mutantes , Músculo Liso/química , Músculo Liso/citología , Fenotipo , Factor de Crecimiento Derivado de Plaquetas/deficiencia , Factor de Crecimiento Derivado de Plaquetas/genética , Alveolos Pulmonares/química , Alveolos Pulmonares/citología , Alveolos Pulmonares/patología , ARN Mensajero/análisis , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas , Receptores del Factor de Crecimiento Derivado de Plaquetas/análisis , Transducción de Señal/fisiologíaRESUMEN
A role for the activated complement system in the pathogenesis of decompression sickness has recently been suggested. In this study we aimed at evaluating the response of the complement system to decompression in 24 human volunteers. A significant reduction was observed in the levels of iC3, which is a conformationally changed form of the third complement component (C3), and C3A after decompression (P < 0.001). The levels of total C3 did not change during the experiment. A relatively mild decompression has thus led to a distinct change in the complement activation profile in human volunteers.
Asunto(s)
Activación de Complemento/fisiología , Complemento C3/metabolismo , Descompresión , Buceo/fisiología , Adulto , Complemento C3a/metabolismo , Enfermedad de Descompresión/inmunología , Femenino , Hemólisis , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Glial fibrillary acidic protein (GFAP) is the main component of the intermediate filaments in cells of astroglial lineage, including astrocytes in the CNS, nonmyelin forming Schwann cells and enteric glia. To address the function of GFAP in vivo, we have disrupted the GFAP gene in mice via targeted mutation in embryonic stem cells. Mice lacking GFAP developed normally, reached adulthood and reproduced. We did not find any abnormalities in the histological architecture of the CNS, in their behavior, motility, memory, blood-brain barrier function, myenteric plexi histology or intestinal peristaltic movement. Comparisons between GFAP and S-100 immunohistochemical staining patterns in the hippocampus of wild-type and mutant mice suggested a normal abundance of astrocytes in GFAP-negative mice, however, in contrast to wild-types, GFAP-negative astrocytes of the hippocampus and in the white matter of the spinal cord were completely lacking intermediate filaments. This shows that the loss of GFAP intermediate filaments is not compensated for by the up-regulation of other intermediate filament proteins, such as vimentin. The GFAP-negative mice displayed post-traumatic reactive gliosis, which suggests that GFAP up-regulation, a hallmark of reactive gliosis, is not an obligatory requirement for this process.
Asunto(s)
Astrocitos/fisiología , Proteína Ácida Fibrilar de la Glía/deficiencia , Filamentos Intermedios/fisiología , Ratones Mutantes , Tejido Nervioso/fisiología , Animales , Secuencia de Bases , Barrera Hematoencefálica/fisiología , Encéfalo/ultraestructura , Química Encefálica , Femenino , Proteína Ácida Fibrilar de la Glía/genética , Gliosis , Hipocampo/química , Hipocampo/ultraestructura , Histocitoquímica , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes/embriología , Ratones Mutantes/crecimiento & desarrollo , Ratones Mutantes/psicología , Datos de Secuencia Molecular , Plexo Mientérico/química , Plexo Mientérico/ultraestructura , Tejido Nervioso/anatomía & histología , Tejido Nervioso/química , Desempeño Psicomotor , ARN Mensajero/análisis , Proteínas S100/aislamiento & purificación , Médula Espinal/química , Médula Espinal/ultraestructuraRESUMEN
Blood contact with artificial surfaces during cardiopulmonary bypass (CPB) triggers a systemic inflammatory response in which complement, granulocytes and cytokines play a major role. Heparin-coated CPB circuits were recently shown to reduce complement and granulocyte activation in such circumstances. The present study comprised 20 complex heart operations, 10 with heparin-coated circuits (group HC) and 10 controls (group C), with evaluation of changes in terminal complement complex, the granulocyte enzymes myeloperoxidase and lactoferrin, and the cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8). Standard heparin dose and uncoated cardiotomy reservoir were used in all cases. In both groups the levels of enzymes and terminal complement complex rose significantly, beginning at conclusion of CPB, above base values, without significant intergroup differences. IL-6 and IL-8 also increased significantly, but tended to be lower in the HC group, starting at CPB end and continuing until 20 hours postoperatively: for IL-6 the difference was significant at CPB end (83 +/- 18 vs 197 +/- 39 micrograms/l, p = 0.21). Significantly increased inflammatory response was thus found during complex heart operations even with use of heparin-coated CPB sets. The heparin-coating of circuits seems to diminish cytokine production.
Asunto(s)
Anticoagulantes/farmacología , Puente Cardiopulmonar/instrumentación , Granulocitos/enzimología , Heparina/farmacología , Interleucina-6/sangre , Interleucina-8/sangre , Lactoferrina/sangre , Peroxidasa/sangre , Anciano , Procedimientos Quirúrgicos Cardíacos , HumanosRESUMEN
The role of complement in biocompatibility reactions and the correlation between complement activation during cardiopulmonary bypass (CPB) and postperfusion syndrome have inspired attempts to improve the biocompatibility of extracorporeal blood oxygenation devices. Here we assessed the effect of immobilized heparin on the generation of C3a and terminal complement complexes during CPB. Thirty patients undergoing aortocoronary bypass were randomized to CPB with either heparin-coated (Duraflo II; Bentley, Irvine, CA) or noncoated control membrane oxygenators (Univox; Bentley). A standard dose of heparin (300 IU/kg) was given to the control group while the heparin dose was reduced to 30% (100 IU/kg) in the heparin-coated group. Significantly lower levels of terminal complement complexes were detected in the heparin-coated group by the end of CPB. From 28 +/- 5 AU/mL (heparin-coated group) and 26 +/- 3 AU/mL (control group, mean +/- standard error of the mean) the terminal complement complex levels increased to 391 +/- 35 AU/mL and 602 +/- 47 AU/mL, respectively (p < 0.002). This difference was still apparent 180 minutes after CPB. Although there was no difference in C3a levels between the two groups at the end of CPB, C3a levels were significantly lower in the heparin-coated group 30 minutes after CPB (194 +/- 18 ng/mL and 307 +/- 18 ng/mL in heparin-coated and control groups, respectively; p < 0.001). We conclude that the heparin-coated surface is more biocompatible with regard to complement activation than is the ordinary unmodified surface in extracorporeal circuits.
Asunto(s)
Puente Cardiopulmonar , Activación de Complemento/efectos de los fármacos , Heparina/administración & dosificación , Materiales Biocompatibles , Complemento C3a/biosíntesis , Complejo de Ataque a Membrana del Sistema Complemento/biosíntesis , Método Doble Ciego , Heparina/farmacología , Humanos , Propiedades de SuperficieRESUMEN
The combined effect of heparin coating of cardiopulmonary bypass (CPB) circuits and reduced dose of systemic heparin on activation of the complement system and blood leukocytes was investigated in 19 patients undergoing coronary bypass surgery and randomly allocated to two groups. A heparin-coated CPB circuit together with a 50% reduction of the standard heparin dose were used for ten patients (HC group), and a standard CPB circuit with a standard heparin dose (300 IU/kg) for nine (C group). Significant rise in the levels of neutrophil-derived myeloperoxidase, lactoferrin and calprotectin were observed during CPB in both groups, but the total accumulated levels were significantly lower in the HC than in the C group (p < 0.05). Complement activation, assessed from levels of C3a and terminal complement complexes was similar in both groups. The lower levels of myeloperoxidase, lactoferrin and calprotectin during CPB in the HC group indicate that surface modification with end-point attached heparin enhances the biocompatibility of CPB.
Asunto(s)
Puente Cardiopulmonar/métodos , Activación de Complemento , Heparina/uso terapéutico , Activación Neutrófila , Oxigenadores , Materiales Biocompatibles/farmacología , Enzimas Activadoras de Complemento/análisis , Activación de Complemento/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Heparina/administración & dosificación , Heparina/farmacología , Humanos , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Activación Neutrófila/efectos de los fármacos , Protaminas/administración & dosificación , Protaminas/farmacologíaRESUMEN
Earlier we have shown that iC3 is generated at the blood-gas interface in vitro and that the generation of this molecule is independent of complement activation and the composition of the gas. In order to investigate whether iC3 is also generated during cardiopulmonary bypass where blood comes into contact with oxygen bubbles, two bubble oxygenators were incubated at 37 degrees C with human heparinized blood. A continuous increase in the level of iC3 was shown in the oxygen-perfused bubble oxygenator (up to 100 nmol/l after 180 min) in contrast to the unbubbled control. Similarly, in plasma drawn from patients undergoing cardiopulmonary bypass using either bubble or membrane oxygenators, the levels of iC3 were shown to increase continuously during the operation. Furthermore, this form of C3 was found to be susceptible to cleavage by factor I. The formation of iC3 at the blood-gas interface in vivo could be a mechanism by which gas bubbles induce clinical manifestations associated with complement activation, e.g. during cardiopulmonary bypass, adult respiratory distress syndrome and decompression sickness.
Asunto(s)
Puente Cardiopulmonar , Activación de Complemento , Complemento C3/biosíntesis , Intercambio Gaseoso Pulmonar , Adulto , Anciano , Western Blotting , Electroforesis en Gel de Poliacrilamida , Oxigenación por Membrana Extracorpórea , Femenino , Humanos , Masculino , Persona de Mediana Edad , Consumo de OxígenoRESUMEN
After intraocular lens implantation, despite good clinical results, many cataract patients develop a chronic uveitis, caused by an inflammatory response to the implant. One way to improve the biocompatibility of the intraocular lens is to modify the surface by end-point heparin attachment. This study shows that complement activation caused by poly(methyl methacrylate) can be diminished by end-point heparin attachment, as demonstrated by a significant reduction in the generation of C3a and fluid phase terminal complement complexes. It suggests that assessment of complement activation is a good indicator of the biocompatibility of intraocular lenses.
Asunto(s)
Materiales Biocompatibles , Activación de Complemento , Heparina/inmunología , Metilmetacrilatos , Western Blotting , Complemento C3c/inmunología , Complejo de Ataque a Membrana del Sistema Complemento , Electroforesis en Gel de Poliacrilamida , Ensayo de Inmunoadsorción Enzimática , Humanos , Lentes IntraocularesRESUMEN
Earlier studies have shown that C3 can be denatured when blood comes in contact with a polystyrene surface. This study was undertaken to see if similar denaturation of C3 occurs at the gas-plasma interface which is found in all kinds of oxygenator used during cardio-pulmonary operations. An in vitro system consisting of gas bubbling through human blood, serum or plasma was used. The generation of C3a, as an indicator of complement activation, and iC3 and iC3 fragments were monitored. Both C3a and iC3/iC3 fragments levels were increased during bubbling. In contrast to the C3a level, no reduction in iC3/iC3 fragments formation was seen in the presence of EDTA, indicating that it was independent of complement activation. The rate of iC3/iC3 fragments generation was unaffected by the composition of the gas (pure oxygen, pure nitrogen or air), suggesting that the denaturation of C3 indeed occurred at the serum-gas interface. C3 and iC3/iC3 fragments were isolated from bubbled EDTA-chelated serum by PEG precipitation and chromatography on FPLC, using a Mono S column and detected by two ELISAs, specific for native C3 and iC3/iC3 fragments. After 240 min approximately 20% of the total amount of C3 consisted of intact iC3 and it was confirmed that this population bound to human erythrocytes.