Biomedical subjects

D E Chenoweth

Publications and source records attributed to D E Chenoweth.

At least 37 records · Page 2Linked to original sources

PubMed1987

Co-expression of chemotactic ligand receptors on human peripheral blood monocytes.

Directed migration of monocytes is dependent upon interaction of cell surface receptors and specific chemotactic ligands. To determine whether circulating human monocytes express multiple chemotactic ligand receptors or whether subpopulations of monocytes exist with a single receptor specificity, nonoverlapping fluorescent probes for two chemotactic ligands, N-formyl methionyl leucyl phenylalanine (FMLP) and C5a, were developed to simultaneously evaluate the expression of receptors for these ligands on individual monocytes. The subsequent incubation with different fluorochrome labeled C5a and FMLP probes and monoclonal antibodies specific for antigenic determinants on distinct subsets of mononuclear cells followed by analysis with dual parameter flow microfluorometry indicated that cells that express C5a and FMLP receptors are the OKM1, Mac-1, and Fc gamma receptor positive population. Furthermore, it was demonstrated that approximately 90% of peripheral blood monocytes expressed FMLP receptors, and the majority of FMLP+ cells were also C5a receptor positive. In addition, a parallel spectrum of chemotactic ligand receptor density from low to high levels was demonstrated for both C5a and FMLP. Additional analysis revealed that the density of chemotactic ligand receptors on resting peripheral blood monocytes did not correlate with monocyte maturation levels measured by HLA-DR expression. Elucidation of the monocyte chemotactic receptor-ligand interactions that lead to migration and/or activation may provide insight into the regulation of monocyte function in inflammation.

Antibodies, Monoclonal↗

PubMed1987

Leukocyte C5a receptor modulation during hemodialysis.

Exposure of blood to hemodialysis (HD) membranes results in the activation of the complement system. In this study, flow cytometry was used to analyze the binding of fluoresceinated chemotactic factors (C5a, f-Met-Leu-Phe-Lys [fMLPL], and casein) and aggregated IgG to PMN and monocytes isolated from normal whole blood following passage through a hemodialyzer. Analysis of ligand binding by these PMN and monocytes showed no difference in the binding of casein, fMLPL, or aggregated IgG throughout the 45 minute procedure. In contrast, a progressive decrease in the binding of C5a by PMN and monocytes occurred. By 45 minutes, the average percentage of PMN binding C5a had dropped from 95 to 61% and monocytes from 73 to 40%. In additional studies, blood samples were obtained from chronic renal failure patients undergoing hemodialysis at four different time intervals during dialysis. Total white blood cell (WBC) counts showed that the mean WBC count at 30 minutes dropped to 60.9% of the predialysis WBC count, and rebounded to 133.8% by two hours and 128.2% by four hours. Analysis of the binding of C5a, casein, fMLPL, or aggregated IgG by PMN or monocytes from HD patients indicated there were no significant differences at the four time intervals studied. When blood samples from normal subjects or chronic hemodialysis patients were incubated in vitro with dialysis membrane fibers, a loss of identifiable C5a receptors was observed on PMN from normal blood, while PMN from HD patients showed no significant change in the percentage of C5a-receptor-positive cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Complement C5↗

PubMed1987

C5a and thromboxane generation associated with pulmonary vaso- and broncho-constriction during protamine reversal of heparin.

The authors conducted a study in humans to determine the mediators associated with acute pulmonary vaso- and broncho-constriction occurring episodically with protamine reversal of heparin anticoagulation. Of 48 adult patients investigated prospectively after termination of cardiopulmonary bypass, two presented a sudden increase of airway pressure, acute pulmonary hypertension, and systemic hypotension 1-3 min after right atrial protamine injection. In these two subjects, plasma levels of C5a increased from 0.7 and 2.2 to 9.8 and 9.9 ng/ml, respectively, and thromboxane B2 increased from 0.26 and 0.34 to 7.5 and 16.2 ng/ml 1 minute after drug injection. A third subject not identified prospectively had an identical reaction and mediator profile (C5a, 10.2 ng/ml; TxB2, 18.6 ng/ml at 1 min). The plasma levels of these mediators were unchanged in the remaining patients (C5a, 0.7 +/- 1.1 [x +/- S.D.] to 0.6 +/- 0.9 ng/ml; TxB2, 0.16 +/- 0.12 to 0.15 +/- 0.07 ng/ml). Plasma histamine was not involved in this type of reaction, but increased from 0.7-10.4 ng/ml in a fourth patient who became hypotensive without acute pulmonary hypertension, bronchoconstriction, or elevation of C5a or TxB2. The authors' data indicate that the generation of high plasma levels of C5a anaphylatoxins and thromboxane is associated with pulmonary vaso- and broncho-constriction induced by protamine reversal of heparin in humans.

Adult↗

PubMed1987

Complement activation during hemodialysis: laboratory evaluation of hemodialyzers.

A laboratory method that facilitates delineation of the complement-activating characteristics of various dialyzers under defined conditions has been developed. Results obtained by circulating reconstituted human serum through these devices and measuring time-dependent production of both C3a and C5a antigens are entirely consistent with previous clinical observations. For example, the complement-activating potential of dialyzer membranes could be described as high (cuprammonium cellulose), moderate (cellulose acetate), or low (polycarbonate or polyacrylonitrile). Furthermore, these techniques provided the opportunity to identify membrane characteristics that are not readily defined by clinical studies alone. Specifically, membranes that transported and absorbed C5a antigen were readily identified by these methods. Additionally, laboratory evaluation provided the unique ability to define the efficiency of complement activation taking place on the membrane surface. Results of these investigations are compatible with a hypothetical model that not only describes the properties of a typical dialyzer membrane but may be generally applicable to other biomaterials as well.

Acrylic Resins↗

PubMed1987

Complement activation in extracorporeal circuits.

Clinical studies performed with various types of hemodialyzers provide a data base and conceptual framework for understanding blood-material interactions that result in complement activation. Current findings suggest that the complement-activating potential of biomaterials may be defined by quantitating either fluid-phase C3a antigen or measurement of surface-bound C3 fragments. Furthermore, systematic studies can reveal material properties that regulate both the production and distribution of the human anaphylatoxins. Assessing the fate of the C5a anaphylatoxin is particularly important because it is likely that generation of this bioactive molecule in extracorporeal circuits initially triggers granulocyte responses and may produce cardiopulmonary manifestations if the C5a is formed in sufficient quantities. It seems likely that detailed knowledge of these varied phenomena will permit rational design of newer "biocompatible" materials and membranes.

Biocompatible Materials↗

PubMed1987

Characterization of murine monoclonal antibodies that recognize neutralizing epitopes on human C5a.

We generated a panel of 10 murine monoclonal antibodies (MAbs) that recognize human complement fragment C5a. These MAbs were characterized for their ability to immunoprecipitate 125I-labeled C5a, bind C5a in solid-phase enzyme immunoassay, and block 125I-labeled C5a binding to polymorphonuclear leukocytes. Four of these MAbs had affinity constants for C5a in the 1 X 10(9) to 3 X 10(9) M-1 range. These MAbs blocked C5a-induced neutrophil polarization and chemiluminescence. They blocked the ability of passively administered C5a to cause neutropenia in rabbits. These anti-C5a neutralizing MAbs may have potential therapeutic use in states of complement activation.

Antibodies, Monoclonal↗

PubMed1987

Analysis of density changes and chemotactic receptors of leukocytes from chronic hemodialysis and peritoneal dialysis patients.

Analysis of standard Ficoll-Hypaque (density = 1.077 g/ml) separation profiles of peripheral white blood cells (WBC) from patients undergoing hemodialysis (HD) demonstrated that dialysis caused a marked decrease in the density of polymorphonuclear leukocytes (PMN) resulting in about 50% of these cells separating with the mononuclear cells. In vitro exposure of normal control peripheral blood to HD membranes as well as to the purified chemotactic factors C5a, C5ades-Arg, and formyl-Met-Leu-Phe (fMLP) also resulted in PMN density changes which altered the Ficoll-Hypaque separation profiles of WBC. Therefore, these results imply that C5a generation, resulting from complement activation by the HD membrane, induced the density changes in the PMN from HD patients. Further studies using flow cytometry and fluorescein-labeled chemotactic factors (C5a, formyl-Met-Leu-Phe-Lys [fMLPL] and casein) indicated that HD patients had a significant reduction in the ability of their PMN and monocytes to bind C5a. This contrasted with the findings of no significant difference in the percentage or fluorescence intensity of HD patients' PMN or monocytes binding casein or fMLPL. Functional studies to analyze chemotactic-factor-mediated responses indicated that there was a decreased ability of HD patients' PMN and monocytes to generate superoxide anion, produce H2O2 and release myeloperoxidase in response to both C5a and fMLP. Additional studies evaluated the binding of chemotactic factors to PMN and monocytes from normal blood following passage through a hemodialyzer and from patients undergoing HD. Analysis of receptor binding by control cells passed through the dialyzer showed that there was a progressive decrease in the percentage of C5a-receptor-positive PMN and monocytes but no change with casein or fMLPL. In contrast, peripheral PMN and monocytes from chronic renal failure patients on HD showed no difference in C5a, casein or fMLPL receptors during the course of HD as compared to the predialysis period. This appears to be attributable to a difference in the regulation of the C5a that is generated as a result of the dialysis-membrane-induced activation of the complement system. Although C5a has been shown to be continuously generated during the course of HD, these patients show no modulation of their C5a receptors during the course of HD or when their whole blood is exposed to dialysis membrane fibers. These findings suggest that there are mechanisms functioning in chronically dialyzed patients to protect them from the effects of excessive C5a generation during HD.(ABSTRACT TRUNCATED AT 400 WORDS)

Cell Separation↗

PubMed1987

The properties of human C5a anaphylatoxin. The significance of C5a formation during hemodialysis.

Human C5a anaphylatoxin is a potent bioactive molecule that possesses both spasmogenic and leukocyte-related properties. As such, it normally serves as a local mediator of the acute inflammatory response. Additionally, C5a, through its actions of mononuclear phagocytes, may act to bridge the gap in the acute-chronic inflammatory continuum. While these properties are critical to normal host defense mechanisms, it is now apparent that this anaphylatoxin and/or its des-Arg74 derivative, may exert significant systemic effects that are manifest as cardiopulmonary abnormalities and intravascular activation of granulocytes. Knowledge of these properties is critically important for understanding the clinical sequelae exhibited by patients undergoing extracorporeal circulation since we now know that both hemodialysis and cardiopulmonary bypass [28-30] procedures promote intravascular complement activation and C5a formation. Viewed in this context, it seems reasonable to postulate that many of the immediate and delayed responses to extracorporeal circulation might be mediated by C5a formed in the extracorporeal circuit (table IV). For example, it is now recognized that a few particularly susceptible patients display adverse reactions during the initial phases of hemodialysis. The symptoms of this so-called 'first-use syndrome' may range from severe urticaria and angioedema to life-threatening bronchospasm, hypotension, and cardiopulmonary collapse. Some investigators have presented data which suggest that complement-derived products may be causative of these symptoms in some patients [31]. While this hypothesis remains to be confirmed, present evidence clearly demonstrates that C5a alone may produce many of the observed phenomena. In addition to the acute effects produced by C5a, both our own basic studies and the clinical investigations presented by others at this conference suggest that the long-term effects of repeated C5a exposure in the dialyzed patient may be considerable. Thus, there has been a great deal of interest in the role of complement-derived mediators as initiators of leukocyte degranulation and toxic oxygen radical production and an exploration of the significance of these events in the eventual development of chronic pulmonary fibrosis in the dialyzed patient. Similarly, the effects of repeated exposure to IL-1 that has been postulated to occur as a result of C5a triggering of monocytes during dialysis is currently an active area of investigation.(ABSTRACT TRUNCATED AT 400 WORDS)

Anaphylatoxins↗

PubMed1987

Identification and characterization of a unique subpopulation (CALLA/CD10/negative) of human neutrophils manifesting a heightened chemotactic response to activated complement.

We have previously demonstrated that human neutrophils synthesize the common acute lymphoblastic leukemia antigen (CALLA/CD10). To determine whether CALLA/CD10-positive and -negative neutrophils have similar or distinct functional attributes, we sorted normal peripheral blood neutrophils for CALLA/CD10 expression and compared their chemotactic ability. Surprisingly, the low-frequency (approximately 5%), CALLA/CD10-negative neutrophils displayed a dramatically heightened chemotactic response to activated complement (C') that was (a) specific for C', (b) not observed with other minor subpopulations of neutrophils, (c) not due to previous activation in vivo or in vitro, and (d) apparently not due to an increase in C5a receptors. These results underscore the concept of neutrophil heterogeneity and prompt the hypothesis that CALLA/CD10-negative neutrophils may participate in an inflammatory response to trauma involving complement activation.

Antibodies, Monoclonal↗

PubMed1986

Lipopolysaccharide modulates receptors for leukotriene B4, C5a, and formyl-methionyl-leucyl-phenylalanine on rabbit polymorphonuclear leukocytes.

Peripheral blood polymorphonuclear leukocytes (PMNL) isolated from rabbits after an i.v. injection of endotoxin exhibited decreased chemotactic migration in response to leukotriene B4 (LTB4) and C5a, but not N-formyl-methionyl-leucyl-phenylalanine (fMLP), after endotoxin treatment. The binding of radiolabeled LTB4, fMLP, and C5a to isolated PMNL was assessed in order to determine whether altered receptor expression could account for the observed functional changes. Control PMNL expressed binding sites for fMLP, LTB4, and C5a similar to those previously characterized from human PMNL. Control PMNL expressed a single class of 14,600 +/- 2700 receptors for fMLP with a mean dissociation constant (Kd) of 2.0 +/- 0.6 nM at 0 degrees C, whereas two subclasses of binding sites were expressed for LTB4: 10,300 +/- 6800 high-affinity and 85,600 +/- 53,000 low-affinity binding sites per PMNL with mean Kd for LTB4 of 0.75 +/- 0.43 nM and 70 +/- 58 nM (mean +/- SD, n = 5), respectively. Control PMNL bound [125I]-C5a in a dose-dependent and saturable manner at 24 degrees C. At saturating concentrations of C5a, PMNL obtained from control rabbits bound 270,000 +/- 50,000 molecules of [125I]-C5a with half-maximal binding occurring at [125I]-C5a concentrations of 5.5 +/- 1.9 nM. The binding of LTB4 and C5a to PMNL obtained 24 hr after an i.v. injection of endotoxin was markedly decreased compared with control PMNL. PMNL from endotoxin-treated rabbits exhibited 68% fewer high-affinity binding sites per PMNL for LTB4 and a 51% decrease in the amount of [125I]-C5a bound at saturating concentrations compared with control PMNL. There was no significant change in the Kd of the high-affinity binding sites for LTB4, no change in the Kd and number of the low-affinity binding sites for LTB4, and a small decrease in the apparent Kd for C5a to 3.3 +/- 1.1 nM. Even though the pretreatment with i.v. endotoxin did not alter chemotactic or degranulation responses elicited by fMLP, the endotoxin pretreatment induced an eightfold increase in the receptor density without altering the Kd for fMLP. Decreased receptor expression could account in large part for the decreased chemotactic responsiveness towards C5a and LTB4 induced by LPS. The finding that a substantial increase in receptors for fMLP need not be accompanied by a comparable functional change suggests that decreased efficiency in receptor coupling to intracellular biochemical events may also result from i.v. endotoxin.

Animals↗

PubMed1986

Effects of protamine administration after cardiopulmonary bypass on complement, blood elements, and the hemodynamic state.

Nineteen patients were prospectively selected and studied before and after the administration of protamine sulfate following cardiopulmonary bypass (CPB). After protamine administration, C3a, C4a, and C4d were elevated; the peak levels of C3a and C4a were in samples taken 10 minutes after protamine administration while those of C4d were in those obtained at 5 hours. Only C3a was elevated after CPB and before protamine administration. In vitro, only the combination of protamine sulfate and heparin, and neither alone, resulted in increased C3a and C4a. Administration of protamine was associated with small and transient decreases in total white blood cells, granulocytes, and platelets, and with small and transient reductions in systemic and pulmonary arterial and left and right atrial pressures. Systemic vascular resistance fell (p = 0.07), and pulmonary vascular resistance rose but the change could be due to chance (p = 0.29). These data and those reported by others support the inference that complement activation occurs during CPB by the alternative pathway and again during protamine administration by the classic pathway; and that this accompanies a whole-body inflammatory reaction with blood cell and hemodynamic changes which, when extreme, could result in a severe hemodynamic derangement.

Blood Cell Count↗

PubMed1986

Effects of the anaphylatoxin, C5a, on renal and glomerular hemodynamics in the rat.

The effects of intrarenal infusion of the complement-derived anaphylatoxin, C5a, upon glomerular hemodynamics were examined in the Munich-Wistar rat, a strain with glomeruli on the kidney surface. Human C5a (1.5 micrograms/min) or vehicle was infused into the left renal artery for 12 min, and glomerular capillary (PG) and Bowman's space pressures, nephron plasma flow (SNPF) afferent and efferent arteriolar protein concentrations, nephron filtration rate (SNGFR) and the glomerular ultrafiltration coefficient (LpA) determined. Human C5a infusion resulted in a reduction in SNPF due to increased efferent arteriolar resistance, and PG increased which maintained SNGFR constant. LpA was numerically lower but not significantly decreased. Infusion of porcine C5ades Arg decreased glomerular filtration rate and renal blood flow. No polymorphonuclear leukocytes were observed within glomerular capillaries of C5a infused rats, and rat leukocytes did not exhibit receptors for human C5a infused. Renal artery infusion of either human C5a or porcine C5a resulted in renal hemodynamic alterations and, as documented for human C5a, effects of C5a upon renal vascular resistance can be added to the known effect of C5a on the polymorphonuclear leukocyte.

Animals↗

PubMed1986

Compartmental distribution of complement activation products in artificial kidneys.

The compartmental distribution of the human anaphylatoxins C3a and C5a has been defined during simulated hemodialysis performed with various types of hemodialyzers. New cuprophan hollow fiber dialyzers were found to activate human complement very readily in vitro, while re-used cuprophan dialyzers displayed only modest complement activating potential. The C3a and C5a antigens, formed as a result of complement activation in these dialyzers, accumulated predominantly in the blood path and were not adsorbed extensively on the membrane surface or transported into the dialysate compartment. Cellulose acetate membranes also produced complement activation in vitro, but to a lesser degree than new cuprophan hollow fibers. However, these membranes exhibited a significant capacity to bind the anaphylatoxins to their surface. Polyacrylonitrile membranes appeared to be unique in that they not only failed to activate complement significantly, but they rapidly adsorbed large quantities of C3a and C5a. These findings demonstrate that hemodialysis membranes may differ with regard to their complement activating potential as well as their ability to remove circulating anaphylatoxins from the blood path. Clinical measurements of anaphylatoxin production during hemodialysis reflect these dynamic events.

Complement Activation↗

PubMed1986

Cardiopulmonary effects of cuprophane-activated plasma in the swine.

Hemodialysis with cuprophane membrane is associated with complement activation and the formation of anaphylatoxins. Frequently, it is also complicated by various adverse reactions which include hypoxemia and hemodynamic changes. This study examined the cardiopulmonary effects of cuprophane membrane on experimental animals. To support the hypothesis that these effects were mediated by complement activation products, the effects of zymosan-activated plasma and C5adesArg challenge on the same variables were compared. We showed that intravenous infusion of autologous cuprophane-activated plasma into swine produced severe pulmonary hypertension, hypoxemia and leukopenia. In addition, mean systemic arterial pressure fluctuated and cardiac output fell. Infusion of zymosan-activated plasma produced similar results, suggesting that complement activation products are responsible for these alterations. Similar responses to porcine C5adesArg infusion suggested further that this polypeptide was the mediator. When swine were subjected to extracorporeal circulation using cuprophane membrane but without dialysis, acute pulmonary hypertension was seen preceding the onset of significant leukopenia. These data suggest that blood contact with cuprophane membrane produces both pulmonary and systemic hemodynamic changes, which are mediated by complement activation products. Furthermore, these products and/or other humoral factors, but not leukoagglutination, cause the pulmonary hypertension.

Animals↗

PubMed1986

Density changes in leukocytes following hemodialysis or exposure to chemotactic factors.

Analysis of standard Ficoll-Hypaque separation profiles of peripheral WBC from patients undergoing hemodialysis (HD) demonstrated that dialysis caused a marked alteration in the number of cells found at both the interface between the Ficoll-Hypaque and plasma which normally contains mononuclear cells and the cell pellet which normally contains granulocytes. By 30 min into dialysis, there was a 175% increase in white blood cells in the mononuclear band with a corresponding decrease in the number of cells obtained from the cell pellet. When peripheral blood samples from normal donors were pumped through various types of hemodialyzers, a shift in the cell separation profiles similar to that of patients undergoing HD was observed. Differential analysis of the cells obtained from both the interface between the Ficoll-Hypaque and plasma and the cell pellet showed that by 30 min into dialysis, the 'mononuclear' band contained 40-50% polymorphonuclear neutrophils (PMN). To ascertain whether the cell separation changes were possibly due to C5a generation resulting from complement activation by the HD membrane, whole blood was incubated with the purified chemotactic factors C5a, C5ades arg, and formyl-methionyl-leucyl-phenylalanine. This resulted in similar alterations in PMN densities. This study demonstrates that both in vivo and in vitro exposure of human peripheral blood to HD membranes as well as the chemotactic factors C5a, C5ades arg, and formyl-methionyl-leucyl-phenylalanine results in density changes in PMN.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1986

Preliminary report on complement activating potential of polycarbonate membrane.

Clinical as well as laboratory studies have been employed to assess the complement activating potential of polycarbonate membrane hemodialyzers. Blood samples from a group of patients undergoing sequential maintenance hemodialysis with cuprophane, polyacrylonitrile and polycarbonate devices were evaluated to define plasma levels of C3a antigen and leukocyte counts during the initial phases of hemodialysis. While polyacrylonitrile dialyzers did not activate complement to a significant extent, we did observe transient elevations in the plasma concentration of C3a and corresponding diminutions in the granulocyte counts of patients dialyzed with both cuprophane and polycarbonate dialyzers. However, polycarbonate devices appeared to activate complement to a lesser degree than cellulosic dialyzers. Laboratory evaluation of these three different types of dialyzers also provided evidence that polycarbonate membranes did not appear to activate human complement as readily as cuprophane. These observations suggest that polycarbonate membranes display complement-related biocompatibility properties that are intermediate between those of cuprophane and polyacrylonitrile.

Cellulose↗

PubMed1986

Anaphylatoxin formation in extracorporeal circuits.

Anaphylatoxin radioimmunoassay techniques have been employed to define both the temporal profile and the amount of complement activation taking place in two different types of extracorporeal circuits. Prospective studies of patients undergoing both maintenance hemodialysis and cardiopulmonary bypass provided essentially similar findings. In both cases, plasma C3a antigen levels proved to be the most accurate and sensitive indicator of intravascular complement activation. By contrast, plasma C5a levels varied little during the period of extracorporeal circulation. Instead, this anaphylatoxin retained considerable biologic activity in vivo as evidenced by its ability to promote granulocyte activation and transient granulocytopenia which was displayed by patients in both groups. Plasma levels of C4a antigen were not elevated during the period of extracorporeal circulation, suggesting that alternative pathway mechanisms were predominantly responsible for the complement activation taking place in both hemodialyzers and bypass oxygenators. However, classical pathway activation events could be documented when protamine sulfate was administered to heparinized patients after cardiopulmonary bypass. In this instance, elevated plasma levels of both C4a and C3a antigens were observed. Prospective studies also suggested that complement activation could be associated with the development of both acute and delayed clinical sequelae. Available data support the hypothesis that C5a anaphylatoxin might be the primary mediator of these undesirable effects of extracorporeal circulation. These types of investigations have contributed significantly to our understanding of the role of the anaphylatoxins in human disease and may be directly applied to facilitate design of more biocompatible medical devices.

Anaphylatoxins↗

PubMed1986

Attachment of human C5a des Arg to its cochemotaxin is required for maximum expression of chemotactic activity.

The chemotactic activity of human C5a des Arg is enhanced significantly by an anionic polypeptide (cochemotaxin) in normal human serum and plasma. We have found that the cochemotaxin attaches to the oligosaccharide chain of native C5a des Arg to form a complex with potent chemotactic activity for human polymorphonuclear leukocytes. Although capable of enhancing the chemotactic activity of native C5a des Arg, the cochemotaxin had no effect on the chemotactic activity of either deglycosylated C5a des Arg, native C5a, or N-formyl-methionyl-leucyl-phenylalanine. Of the known components of the oligosaccharide chain, only sialic acid prevented enhancement by the cochemotaxin of the chemotactic activity exhibited by native C5a des Arg. Sialic acid also prevented the formation of C5a des Arg-cochemotaxin complexes, detected by acid polyacrylamide gel electrophoresis, molecular sieve chromatography on polyacrylamide gels, and sucrose density gradient ultracentrifugation.

Anaphylatoxins↗