Search results for "Complement"
showing 10 items of 2113 documents
Sensitivity and Specificity of Reiter Protein Complement-Fixation (RPCF) Test for Syphilis1
1957
D'Alessandro and his co-workers reported on the separation of four different fractions from the Reiter strain of Treponema pallidum (1, 2, 3). This report deals with the thermolabile soluble protein extract of the Reiter treponeme. The antigen employed in this study was prepared by de Bruijn (4) using the technic described by D'Alessandro. The antigen is prepared briefly as follows: The Reiter treponemes are grown in a Brewer thioglycollate medium. After harvesting the washing, the treponemes are subjected to cryolysis. The lysate is dialyzed against increasing concentrations of ammonium sulfate. The precipitate thus obtained is dissolved in a veronal-buffered saline. This solution is dialy…
Synthesis of complement by macrophages and modulation of their functions through complement activation.
1983
During the last decade considerable progress has been made to characterize intimate functional links between macrophages, a major cellular component of immunoinflammatory responses, and the complement system representing the major humoral mediator of inflammation. Macrophages of various species and tissue sites have been shown to synthesize and release most of the complement components providing these cells with their own \ldpericellular\rd complement system. Circumstantial evidence for the assembly of both classical and alternative pathway convertases has been adduced. An intricate network of feedback loops involving endogenous and extrinsic factors operates to adjust complement production…
Anaphylatoxin-like molecules generated during complement activation induce a dramatic enhancement of particle uptake in rainbow trout phagocytes.
2004
Here we have identified a serum fraction containing approximately 8-kDa molecules with an unexpected capacity to greatly enhance particle uptake in trout head kidney leukocytes (HKLs). This approximately 8-kDa particle-uptake enhancing fraction (PUEF-8) was purified from complement-activated serum by gel filtration chromatography. Mass spectrometric analysis and reactivity of anti-trout C3-1 and C4 antibodies, indicated the presence of C3a, C4a and C5a molecules in PUEF-8. Using a newly developed flow cytometric assay that measures the capacity of cells to ingest fluorescent beads, we showed that PUEF-8 induced a striking enhancement (344+/-50% higher than the PBS control value) in the numb…
Application of C1-Esterase Inhibitor During Reperfusion of Ischemic Myocardium
2001
Background—Complement activation during reperfusion of ischemic myocardium augments myocardial injury, and complement inhibition with C1-esterase inhibitor (C1-INH) at the time of reperfusion exerts marked cardioprotective effects in experimental studies. Application of C1-INH in newborns, however, was recently reported to have dangerous and even lethal side effects. This study addresses the essential role of dosage in studies using C1-INH.Methods and Results—Cardioprotection by C1-INH was examined in a pig model with 60 minutes of coronary occlusion followed by 120 minutes of reperfusion. C1-INH was administered intravenously 5 to 10 minutes before coronary reperfusion without heparin at a…
Common genetic denominators for Ca++-based skeleton in Metazoa: role of osteoclast-stimulating factor and of carbonic anhydrase in a calcareous spong…
2012
Calcium-based matrices serve predominantly as inorganic, hard skeletal systems in Metazoa from calcareous sponges [phylum Porifera; class Calcarea] to proto- and deuterostomian multicellular animals. The calcareous sponges form their skeletal elements, the spicules, from amorphous calcium carbonate (ACC). Treatment of spicules from Sycon raphanus with sodium hypochlorite (NaOCl) results in the disintegration of the ACC in those skeletal elements. Until now a distinct protein/enzyme involved in ACC metabolism could not been identified in those animals. We applied the technique of phage display combinatorial libraries to identify oligopeptides that bind to NaOCl-treated spicules: those oligop…
Adaptogens in chemobrain (Part II): Effect of plant extracts on chemotherapy-induced cytotoxicity in neuroglia cells
2019
Abstract Background Cancer chemotherapy-induced cognitive impairments are apparently associated with harmful effects on physiological functions of brain cells. Adaptogens, are known to exhibit neuroprotective effects and to increase cognitive functions in clinical studies. In our previous study (Seo et al., 2018), we demonstrated that selected adaptogenic extracts significantly attenuate cytostatic-induced regulation of more than 100 genes involved in the activation of neuronal death and inhibiting neurogenesis. Neuroprotective and cytoprotective activities of adaptogens rise the question about their possible impact on cytostatic effects of a chemotherapeutic combination of 5-fluorouracil, …
Ability of the T cell-replacing polyanion dextran sulfate to trigger the alternate pathway of complement activation.
1973
Dextran sulfate (DS) consumed C3 in C4 deficient guinea pig serum. This temperature-dependent reaction required Mg++ ions and could therefore be blocked by EDTA. Isolated C3 was not influenced by DS, but serum factors were required for C3 consumption. The C3 proactivator as well as C3 were converted to their activated state by DS in guinea pig and human serum, as revealed by immunoelectrophoretical analysis. DS generated anaphylatoxin activity in serum. It is concluded that DS activates C3 via the alternate pathway of complement activation. This potency of the polyanion might serve as a tentative explanation for its T cell-replacing effect in an antibody-forming system, which was reported b…
Activation of the alternative pathway of complement: efficient fluid-phase amplification by blockade of the regulatory complement protein β1H through…
1981
Current concepts of activation of the alternative pathway of complement (APC) focus on the central role of an amplification mechanism triggered by C3b which is covalently bound to the surfact of activating substances. Using sulfated polyanions as model substances, an efficient fluid-phase activation of complement is demonstrated in contrast to solid-phase activation. It is shown that particulate high-molecular weight sulfated polyanions are capable of reversible binding the guinea pig and human regulatory protein beta1H. This fixation leads to an extensive activation of C3 and factor B because the regulatory function of beta1H is blocked in the fluid-phase C3b-dependent amplification system…
Factors influencing the interaction of herpes simplex virus glycoprotein C with the third component of complement.
1992
The factors influencing the interaction of herpes simplex virus (HSV) glycoprotein C (gC) with the third component of complement (C3) were investigated in this study. The ability of gC of HSV type 1 (gC-1) to bind to the C3b fragment of C3 was found to be influenced by cell specific processing of gC-1 in a different manner, binding being remarkably enhanced in some cell lines following removal of sialic acid residues. Testing several intertypic recombinants of HSV we found that only strains expressing gC-1 exhibited binding to C3b, even though their genome consisted mainly of HSV-2 sequences in some recombinants. Expression of type-2 glycoproteins gB, gD, gE, gG, gH, and gI did not alter th…
The Nonvolatile and Volatile Metabolites of Prangos ferulacea and Their Biological Properties
2019
Abstract Prangos ferulacea (L.) Lindl. (Fam. Apiaceae), an orophilous species of eastern Mediterranean and western Asia, possesses a number of biological properties that are worthy of exploitation in different fields. Phytochemical investigations revealed the presence of coumarins, prenyl-coumarins, and furano-coumarins as the main constituents of this species, as well as several flavonoids. Among prenyl-coumarins, osthol is a promising apoptotic agent quite selective toward cancer cells. In addition, the essential oils have been extensively investigated, and several chemotypes have been identified. This work reviews the literature on this species published between 1965 and 2018, describes …