Search results for "Complement System"
showing 10 items of 157 documents
Functionally active complement proteins C6 and C7 detected in C6- and C7-deficient individuals
1991
SUMMARYTwo sensitive sandwich ELISAs based on monoclonal antibodies directed to native C6 and C7 allowed the detection and quantitation of these complement proteins in 20 out of 37 serum samples from individuals who had previously been classified as deficient in these proteins as assessed by immunochemical and/or functional assays. Furthermore, serum from four C6-deficient and one combined C6-/C7-deficient individual showed an increase in the terminal complement complex (TCC) and a decrease in native C6 and C7 after complement activation as assayed by specific ELISAs. Despite their (incomplete) deficiencies, these individuals therefore possess functionally active terminal complement protein…
The Clinical Enzymology of the Complement System
1989
The complement (C) system is one of the most important humoral systems mediating many activities that contribute to inflammation and host defense, e.g. various anaphylatoxin activities, Chemotaxis and opsonization for phagocytosis. The C system is similar to other humoral systems, such as coagulation, fibrinolysis and the kinin system, a multifactoral system whose activation represents sequentially occurring multi-step activation cascades of the “classical” as well as the “alternative” pathway.
Complement Activation in Peritoneal Dialysis–Induced Arteriolopathy
2017
Cardiovascular disease (CVD) is the leading cause of increased mortality in patients with CKD and is further aggravated by peritoneal dialysis (PD). Children are devoid of preexisting CVD and provide unique insight into specific uremia- and PD-induced pathomechanisms of CVD. We obtained peritoneal specimens from children with stage 5 CKD at time of PD catheter insertion (CKD5 group), children with established PD (PD group), and age-matched nonuremic controls (n=6/group). We microdissected omental arterioles from tissue layers not directly exposed to PD fluid and used adjacent sections of four arterioles per patient for transcriptomic and proteomic analyses. Findings were validated in omenta…
The soluble terminal complement complex (SC5b-9) up-regulates osteoprotegerin expression and release by endothelial cells: Implications in rheumatoid…
2009
Objective. Complement activation products contribute to a large number of inflammatory diseases, including RA. We have investigated whether osteoprotegerin (OPG) may concur with the soluble terminal complement complex (SC5b-9) to the inflammatory cascade characterizing RA. Methods. Levels of SC5b-9 and OPG in the plasma and SF of patients with active RA were determined by ELISA. The presence of SC5b-9 and OPG in RA synovial lesions was analysed by immunohistochemistry. Cultured endothelial cells were used for in vitro leucocyte/endothelial cell adhesion assays. In addition, endothelial cells were exposed to SC5b-9 in order to evaluate the effects on the production of OPG protein, as well as…
Influence of cold ischemia time on complement activation, neopterin, and cytokine release in liver transplantation.
2004
The aim of this study was to determine whether a cold ischemia time (CIT) of12 hours influences the activation of complement as well as the plasma concentrations of neopterin, interleukin (IL)-6, or IL-8 in orthotopic liver transplantation (OLT).Eighteen consecutive patients undergoing OLT using a veno-venous bypass technique were divided into 2 groups: duration of CIT12 hours (group 1; n = 11), and CIT12 hours (group 2; n = 7). Blood samples were drawn preoperatively, 1 minute before, and 120 minutes after reperfusion.Preoperatively, complement split products, neopterin, IL-6, and IL-8 levels did not differ between the groups. At 120 minutes after reperfusion, the concentrations of C3a, SC…
2017
Better identification of severe acute graft-versus-host disease (GvHD) may improve the outcome of this life-threatening complication of allogeneic hematopoietic stem cell transplantation. GvHD induces tissue damage and the release of damage-associated molecular pattern (DAMP) molecules. Here, we analyzed GvHD patients (n = 39) to show that serum heat shock protein glycoprotein 96 (Gp96) could be such a DAMP molecule. We demonstrate that serum Gp96 increases in gastrointestinal GvHD patients and its level correlates with disease severity. An increase in Gp96 serum level was also observed in a mouse model of acute GvHD. This model was used to identify complement C3 as a main partner of Gp96 i…
Echinodermata: The complex immune system in echinoderms
2018
View references (418) The Echinodermata are an ancient phylum of benthic marine invertebrates with a dispersal-stage planktonic larva. These animals have innate immune systems characterized initially by clearance of foreign particles, including microbes, from the body cavity of both larvae and adults, and allograft tissue rejection in adults. Immune responsiveness is mediated by a variety of adult coelomocytes and larval mesenchyme cells. Echinoderm diseases from a range of pathogens can lead to mass die-offs and impact aquaculture, but some individuals can recover. Genome sequences of several echinoderms have identified genes with immune function, including expanded families of Toll-like r…
Stimulation of monokine production by lipoteichoic acids
1991
Lipoteichoic acids (LTAs) isolated from bacterial species, including Staphylococcus aureus, Streptococcus pyogenes A, Enterococcus faecalis, Streptococcus pneumoniae, and Listeria monocytogenes, were tested for their ability to stimulate the production of interleukin-1 beta (IL-1 beta), IL-6, and tumor necrosis factor alpha in cultured human monocytes. LTAs from S. aureus and S. pneumoniae failed to induce monokine production when applied in the concentration range of 0.05 to 5.0 micrograms/ml. However, LTAs from several enterococcal species (0.5 to 5 micrograms/ml) induced the release of all three monokines at levels similar to those observed after lipopolysaccharide stimulation. The kinet…
Mechanism of reperfusion damage after thrombolysis and ‘direct PTCA’
1997
Summary There is general agreement between cardiologists, that reperfusion of the infarct related coronary artery (PTCA) is the method of choice for the treatment of an acute myocardial infarction. However, the method utilized for inducing a rapid and complete reperfusion is still discussed. Even if thrombolysis will remain the method of choice for the major part of the population, part of the patient cohort with acute infarction will be treated by direct PTCA. Rapid reperfusion of ischemic myocardium reduces infarct size by limiting infarct extension into the entire area at risk, although a reperfusion damage is induced in the core ischemic area. This reperfusion damage has been convincing…
Studies on the mechanism of PMN activation. I. By dextran sulfates.
1982
Evidence is presented that enhanced reduction of the dye nitroblue-tetrazolium (NBT) by polymorphonuclear leukocytes (PMN) which are stimulated by dextran sulfates (DS) is not exclusively due to the phagocytosis of particles formed by NBT and DS. Not only the size of phagocytizable particles but the degree of substitution determines the acceleration of NBT-reduction. A likely cause of this acceleration is the triggering of the alternative pathway of the complement activation.