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Results for “quantitative complementation”

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PubMed1985

Deleterious effects of cardiopulmonary bypass. A prospective study of bubble versus membrane oxygenation.

A number of hematologic and immunologic parameters that reflect erythrocyte and platelet damage and host defense mechanisms against infection were studied in 20 patients undergoing cardiopulmonary bypass during coronary operations. The patients were randomly assigned to a group in which a bubble oxygenator or a hollow-fiber membrane oxygenator was used. Hemolysis, thrombocytopenia, and significant release of beta thromboglobulin occurred in patients from the bubble oxygenator group and, to much lesser extent, in patients from the membrane oxygenator group. Polymorphonuclear leukocytes and monocytes from bubble oxygenator patients demonstrated increased generation of reactive oxygen species in the resting state and in the presence of the stimulating agents N-formyl-methionyl-leucyl-phenylalanine, concanavalin A, and opsonized zymosan, as compared with cells from membrane oxygenator patients. No difference was found between bubble and membrane oxygenator patients in the time of occurrence or intensity of leukopenia during bypass, of leukocytosis at the end of bypass, nor in the rate of complement activation, as assessed by quantitation of plasma C3a antigen. Complement activation was dependent on the alternative pathway. Immunoglobulin M concentration significantly decreased during bypass in both groups of patients. The serum opsonizing capacity for endotoxin and serum bactericidal activity for Serratia marcescens were decreased in both groups, mainly because of hemodilution, although they were additionally affected by bubble oxygenation. Several deleterious hematologic consequences of cardiopulmonary bypass can be minimized by the use of a membrane oxygenator. However, complement activation remains a potential risk factor even in membrane oxygenator patients and requires further investigation to obtain better hemocompatible materials for cardiopulmonary bypass circuits.

Blood Bactericidal Activity↗

PubMed1986

Dirofilaria immitis: diethylcarbamazine-induced anaphylactoid reactions in infected dogs.

The immunopathogenesis of the anaphylactoid Mazzotti reactions has been studied by comparing physiologic and immunologic aspects of diethylcarbamazine-induced shock in Dirofilaria immitis infected dogs with antigen induced anaphylaxis in infected and uninfected controls. Filarial antigen, specific host IgG antibody, and C1 and C3 complement levels were quantitatively measured over time in relation to the levels of histamine and prostaglandin D2 in the blood and changes in mean blood pressure. D. immitis antigen injected into uninfected dogs having no detectable IgG antibody to D. immitis or Toxocara canis produced a rapid drop in blood pressure that paralleled a drop in C1 and C3 levels and an increase in prostaglandin D2. Antigen injected into infected dogs with IgG antibody produced a similar drop in blood pressure and complement and increase in prostaglandin D2 which differed from the uninfected group only in the slower clearance of antigen from the blood. Diethylcarbamazine alone produced no measurable changes in blood pressure or complement in uninfected hosts. Diethylcarbamazine, however, administered into skin test positive infected dogs, produced a temporally slower but quantitatively similar loss in blood pressure, drop in complement, and increase in prostaglandin D2 and histamine to that induced by antigen injection. Complement activation and immune complex formation are initiated by antigen release, and subsequent vasoactive mediator release leads to shock with prostaglandin D2 being quantitatively higher in blood than is histamine.

Airway Resistance↗

PubMed1977

Quantitative estimation of serum Ss level: changes upon the development of autoantibodies, environment and acute inflammation in inbred mice.

The level of the fourth complement component was quantitated in sera from several inbred strains of mice of various ages. In NZB and NC mice, which are known to produce autoantibodies spontaneously, the level of C4 increased from one month to six months of age, maintained high C4 levels until 10 months but showed a gradual decrease in serum C4 beginning at one year of age. Direct and indirect Coombs' antibodies were detected after 6 months of age in both strain. C4 level in BALB/c and C57BL/6J mice were relatively constant throughout their life span. In order to determine whether or not antigen-antibody complexes induce the elevation of serum C4 level, either rabbit anti-mouse IgG serum or normal rabbit serum was injected intravenously into BALB/c mice. Sera obtained at various times were tested for C3 and C4 by single radial immunodiffusion. The results indicate that the C4 level elevated after the injection of rabbit anti-mouse IgG, but C3 levels did not change after the same treatment. Normal rabbit serum did not induce a detectable change in C3 and C4 level under the conditions used.

Age Factors↗

PubMed1979

Quantitation of the third component of human complement attached to the surface of opsonized bacteria: opsonin-deficient sera and phagocytosis-resistant strains.

The role of the third component of human complement (C3) in the opsonization of bacteria in nonimmune human sera was evaluated. The amount of C3 that becomes attached to the surface of bacteria upon incubation in serum was measured in a quantitative fluorescent immunoassay using fluorescein-conjugated monospecific antiserum to human C3. The intensity of the fluorescence from opsonized bacteria was found to be directly proportional to the absolute amount of C3 fixed, and this enabled the detection of as few as 300 molecules of bound C3 per bacterium. In normal serum the rate of C3 fixation was closely correlated with an increase in opsonization of the bacteria for human PMNs. Both C3 fixation and opsonization were maximal after 15 min of incubation. C3 fixation was also observed, albeit at a significantly slower rate, in human serum with a nonfunctional classical pathway but an intact alternative complement pathway and in serum deficient in immunoglobulins. Again, the kinetics of C3 fixation correlated with bacterial opsonization. Using a total of 21 strains of several bacterial species, including Staphylococcus aureus and Escherichia coli, encapsulation of bacteria was found to interfere with the process of C3 fixation in normal human serum, rendering these organisms resistant to subsequent phagocytosis by human polymorphonuclear leukocytes.

Bacteria↗

PubMed1977

Immune lysis of spin label loaded liposomes incorporating cardiolipin; a new sensitive method for detecting anticardiolipin antibodies in syphilis serology.

Liposomes prepared from a mixture of the pure lipids cholesterol, lecithin and cardiolipin (molar ratio 50/45/5), are able to bind antibodies directed against Treponema pallidum. When the liposomes are loaded with the water soluble spin label tempocholine chloride, the release of spin label from the liposomes can be monitored directly by observing changes in the paramagnetic resonance (ESR) spectrum from the spin label. The method offers a convenient technique for monitoring the complement-mediated lysis of liposomes, and may be applied in the serological diagnosis of syphilis, and a method for quantitative measurement of complement.

Animals↗

PubMed1987

Quantitative analyses of the binding of soluble complement-fixing antibody/dsDNA immune complexes to CR1 on human red blood cells.

We have used direct binding isotherm analyses to measure the association constant (Ka) and number of binding sites for the binding of prepared complement-fixing antibody (Ab)/dsDNA immune complexes (IC) to human red blood cells (RBC). In order to generalize this study we have examined the binding reaction for a number of different anti-dsDNA Ab (from systemic lupus erythematosus plasmas), complement sources, RBC donors, and dsDNA sizes. The affinity of the IC for the RBC is quite high, and the Ka values fall within a narrow range (5 to 14 X 10(10) liter/mol). Similarly, the limiting stoichiometries for the number of IC bound per RBC were between 40 and 91. The very high affinity and limiting stoichiometries both suggest that the IC bind to the RBC via multiple contacts with clusters of complement receptor type 1 (CR1). Furthermore, we have used three specific monoclonal AB (mAb) to quantitate CR1 on human RBC in the presence and absence of bound IC. One of these Ab, mAb 1B4, is blocked from binding to the RBC if IC are previously bound, and we have used this observation to verify the multivalent nature of the interaction of complement-fixing IC with CR1 on human RBC.

Antibodies, Antinuclear↗

PubMed1990

Quantitation of components of the alternative pathway of complement (APC) by enzyme-linked immunosorbent assays.

Sensitive enzyme-linked immunosorbent assays (ELISA) using monoclonal antibodies have been developed to specifically detect components of the alternative pathway of complement in human blood plasma. Normal values of the factor B split products Ba (1.01 +/- 0.30 micrograms/ml, mean +/- SD), Bb (0.65 +/- 0.23 micrograms/ml), of the C3-fragments C3b/iC3b/C3dg (17.9 +/- 5.7 micrograms/ml), native factor B (238 +/- 48 micrograms/ml), factor D (1.05 +/- 0.27 micrograms/ml), and factor H (702 +/- 292 micrograms/ml) were determined in the EDTA-plasma of healthy probands (n = 55). The simultaneous quantitation of the main cleavage products and of control proteins in the plasma samples permits precise analysis of the activation of the alternative pathway of complement in various disease states. In addition, we describe a method for the specific depletion of factor B prior to fragment-specific assays utilizing monoclonal antibodies conjugated to paramagnetic beads. The latter should permit the quantitation of other complement split products.

Animals↗

PubMed1976

[Quantitative structure comparison of protein surfaces by micro-complement fixation].

Microcomplement fication (MCF) is a rapid and most sensitive method for the quantitation of slight modifications on protein surfaces not accessible by other immunologic means. Single amino acid substitutions (0.7 percent sequence differences) are readily detected. A firm relationship between sequence information and immunologic distance as measured by MCF could be established. The rate of molecular evolution of homology proteins can be derived from MCF measurements without prior knowledge of primary structures.

Amino Acids↗

PubMed1984

Rapid, homogeneous phase, liposome-based assays for total complement activity.

A simple, rapid assay for determining total complement activity has been developed. Complement activity is quantitated spectrophotometrically by measuring the amount of liposome-encapsulated enzyme unmasked by the action of anti-Dnp antibody and complement on Dnp-tagged liposomes. The assay is homogeneous in nature and is nonisotopic. The activity of complement in guinea pig serum has been measured and shown to be proportional to complement concentration. The assay was modified to measure the complement-fixing titer of anti-Dnp antibody preparations. We have compared two monoclonal anti-Dnp antibodies (IgG1 and IgM) for their ability to fix complement. The IgM antibody preparation was 450-fold more effective than the IgG1 preparation in mediating complement-dependent damage to Dnp liposomes. In addition, the test was modified to measure complement fixation by soluble antigen-antibody complexes. This complement fixation format is capable of detecting 2 pmol Dnp antigen.

2,4-Dinitrophenol↗

PubMed1991

Functionally active complement proteins C6 and C7 detected in C6- and C7-deficient individuals.

Two 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 proteins with respect to their ability to generate the TCC. As these individuals have no history of a susceptibility to neisserial infections, even low concentrations of functionally active C6 and C7 may provide sufficient protection against those micro-organisms whose destruction requires TCC formation.

Antibodies, Monoclonal↗

PubMed1996

Phospholipids in meibomian gland secretion.

The bulk of the lipid layer overlying the aqueous portion of the precorneal tear film is composed of polar and nonpolar components. The nonpolar lipids have been the subject of numerous studies; however, the polar lipids have remained relatively uncharacterized. The polar lipids are thought to contain surfactant phospholipids that are critical to the spreading of a lipid film over the aqueous layer, by providing an interface between this layer and the nonpolar lipids. The purpose of the present study is to identify and quantitate the phospholipid complement of meibomian gland secretion which provides the tear film with phospholipids. Meibomian gland secretion was collected from rabbits and phospholipids identified and quantitated by 31P nuclear magnetic resonance spectroscopy. Ten phospholipids were detected from meibomian gland secretion: diphosphatidylglycerol, dihydrosphingomyelin, ethanolamine plasmalogen, phosphatidylethanolamine (PE), phosphatidylserine, sphingomyelin, lysophosphatidylcholine, phosphatidylinositol, alkylacylphosphatidylcholine, and phosphatidylcholine (PC). The two major phospholipids were PC and PE, together comprising nearly 60% of the total phospholipid profile. The nature and relative concentrations of the meibomian gland secretion phospholipids are congruous with a surfactant role at the aqueous-lipid interface and, considering the physical chemistry of the tear film, suggest that the phospholipids should be organized in a very flat or planar configuration.

Animals↗

PubMed1977

Complement fixing site of human IgG1.

A number of chemical modifications were made to purified human IgG1. The effects of these modifications on the complement activity of the immunoglobulin were studied using aggregation on latex and measuring the consumption of the complement by CH50-quantitation. Tryptophan and tyrosine are implicated in the complement fixing site of this human immunoglobulin, and an arginine moiety probably provides a binding site for the complement.

Adsorption↗

PubMed1984

Protein loss induced by complement activation during peritoneal dialysis.

A variable loss of macromolecules during peritoneal dialysis has been noted in both humans and experimental animals. We investigated the potential role of the complement system for inducing protein loss during peritoneal dialysis, both to shed light on clinical variability of protein loss and to develop a model for quantitatively studying complement-induced microvascular protein leakage. Rats received intra-arterial injections of a fluorescent dye conjugated to rat serum albumin and underwent a 3.5-hr series of 15-min peritoneal dialysis exchanges. After the control exchanges, rats received either intra-arterial zymosan-activated rat serum, saline, unactivated rat serum, or endotoxin; other rats received an intraperitoneal injection of endotoxin, histamine, phenylephrine, or nitroprusside. The drainage volume from each exchange was measured, and the concentrations of labeled albumin, total protein, and urea were determined by spectroscopy. Zymosan-activated rat serum and endotoxin injections (both intraperitoneal and intra-arterial), each of which may activate the alternative pathway of complement, produced a dramatic increase in dialysate protein concentrations. In addition, histamine, which is a vasodilator but which may also be involved as a mediator of the activated complement system and/or endotoxemia, also produced an increase in dialysate protein concentrations. On the other hand, drugs which may alter peritoneal blood flow such as the vasodilator nitroprusside or the vasoconstrictor phenylephrine, did not affect dialysate protein concentrations. These data suggest that activation of the alternative pathway of complement may cause variation in protein loss during peritoneal dialysis and that in some situations, pharmacological control of this system could be an important therapeutic consideration.

Animals↗

PubMed1981

Rocket immunoelectrophoresis of C4 and C4d. A simple sensitive method for detecting complement activation in plasma.

Activation of complement component C4 has recently been measured by the quantitation of C4 and C4d (a cleavage fragment of C4) by electroimmunodiffusion in gels containing specific precipitating antibodies for C4 and C4d (Rocket immunoelectrophoresis, RIE). Quantitative measurements of the complement component C4 and its fragment C4d were determined in rocket immunoelectrophoresis (RIE) and compared with measurements of total hemolytic complement activity (CH50) or concentrations of C4 as determined by single radial immunodiffusion (RID). This newly developed RIE assay shows activation of the classical complement pathway and involves electroimmunodiffusion in gels containing specific precipitating antibodies for C4 and its cleavage fragment, C4d. In 37 plasma samples, excellent correlation was demonstrated between the C4 in RIE and CH50 (r = .70) and C4 by RID (r = .87). In vivo activation of C4 was determined by measuring the ratio of C4d to C4; 21 of the plasma samples assayed had ratios greater than 1.1 indicating activation of C4. In 13 of the plasma samples there were correspondingly low CH50 values, whereas 8 had normal CH50 levels. Therefore, activation can be detected in those instances when other measurements (CH50 and C4 quantitation) are normal. Thus the RIE assay for plasma C4 activation appears to be the most sensitive method available for assessing in vivo activation of the classical pathway of complement.

Animals↗

PubMed1980

Hemolytic complement in nonhuman primates.

Hemolytic serum complement activity was quantitatively compared in baboons, squirrel monkeys, cebus monkeys, and cotton-top marmosets. Squirrel monkeys showed the highest activity, and marmosets had the lowest activity. The complement level in squirrel monkeys and tenfold greater than marmosets and almost four times higher than that of man. Cebus monkeys had levels most similar to that of man while the baboon exhibited activity almost as low as that of the marmoset.

Animals↗

PubMed1983

A quantitative microassay for leukocyte chemotaxis, using a microscopic slide system with complement-activating yeast particles as gradient source.

A simple quantitative microassay was developed for studying polymorphonuclear leukocyte (PMNL) chemotaxis under conditions where the number of available cells is a limiting factor, e.g., pustules, neutropenia, small children and cerebrospinal fluid. PMNL suspensions are placed on glass slides to which fluorescein-labeled yeast particles have been fixed. After adherence, normal human serum is added to the slides. Owing to complement activation, a chemotactic gradient which attracts the adherent PMNL is formed around the yeast particles. The number of PMNL-associated yeast particles in the presence of normal serum is scored, and compared with cells migrating in the presence of inactivated serum or in the absence of serum. A locomotory index is calculated as the number of yeast particles associated with PMNL divided by the total number of yeast particles.

Blood Physiological Phenomena↗

PubMed1994

Autogenic training: a narrative and quantitative review of clinical outcome.

This review of controlled outcome research on Autogenic Training complements the literature by pooling narrative and quantitative approaches, by including only studies with experimental controls, by integrating the English and German literature, and by adding research findings published since the last review. Whereas previous reviews have already reported positive effects of Autogenic Training for migraine, insomnia, and test anxiety, additional supportive findings for angina pectoris, asthma, childbirth, eczema, hypertension, infertility, Raynaud's disease, and recovery from myocardial infarction are discussed here. The impact of protocol variations on outcome is described, and the specificity of Autogenic Training relative to other stress management techniques is highlighted. Quantitative findings suggested that Autogenic Training was associated with medium-sized pre- to posttreatment effects ranging from d = .43 for biological indices of change to d = .58 for psychological and behavioral indices thus matching effect sizes for other biobehavioral treatment techniques like biofeedback and muscular relaxation. Length of treatment did not affect clinical outcome. The discussion emphasizes how narrative and quantitative strategies complement one another.

Autogenic Training↗

PubMed1983

Humoral defence factors in the breast milk of Ethiopian women with leprosy and healthy controls.

Secretory IgA, lactoferrin, albumin, and total protein were quantitated in colostrum and milk samples obtained from 215 Ethiopian nursing mothers over a period ranging from 1 day to 2 yr postparturition. IgG, IgM, C3, and C4 complement components were quantitated in 11 day 1 samples. The subjects were classified into three groups: lepromatous leprosy, borderline lepromatous leprosy, and a nonlepromatous group consisting of women with tuberculoid leprosy and healthy controls. Results obtained from the above groups were also compared with a group from Edinburgh. No major variation in levels of secretory IgA, lactoferrin, albumin, and total protein was found between the three groups of Ethiopian women. Results from the Edinburgh group were significantly higher, mainly in the level of total protein. When the individual proteins were expressed as a percentage of the total protein, there was no difference between the milk samples from the Ethiopian and Edinburgh mothers.

Albumins↗