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Results for “quantitative complementation”

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PubMed1975

Ultrastructural lesions induced in vitro in guinea-pig spermatozoa by a specific autoantibody (anti-T) and complement.

A quantitative ultrastructural study has been carried out on the lesions that are induced in vitro in guinea-pig spermatozoa by the action of auto-antispermatozoa antibodies and complement. The responsibility of three-independent autoantigen-autoantibody systems (S, P and T) has been explored. The only anti-T antibody known to fix complement and to be spermotoxic (T is a membrane-linked autoantigen), caused significant and important lesions, the immunologically specific origin of which was demonstrated. These lesions began a few seconds after complement had been added. The cytoplasmic membrane is first involved, then the acrosomal membranes, and then the acrosomal contents are lysed. The remarkable rapidity of action of complement on the antibody-sensitized target is emphasized. A typical dose-effect curve is obtained with dilutions of anti-T immune sera. Non-C1-fixing anti-S as well as C1-fixing anti-P antibodies (P has been shown to be intra-acrosomal) do not provoke any significant lesions, even in the presence fo complement, as compared to normal and various controls. However, anti-P serum, when added to non-damaging dilutions of anti-T in the presence of complement, was able to provoke significant lesions in the acrosomes. The bearing of these findings on the mechanisms of in vivo lesions is discussed.

Animals↗
PubMedDate not supplied

In vitro activation of human complement by polyacrilonitrile dialyzer membrane assayed by complement binding to bystander red cells.

Quantitation of complement activation by polyacrilonitrile (PAN) dialyzer membrane is complicated by the high adsorptive capacity of the membrane for fluid phase anaphylotoxins. Assays for these anaphylotoxins, therefore, underestimate the degree of complement activation produced by this membrane. Alternative methods of measuring in vitro complement activation by the PAN and Cuprophan membranes were explored by incubating normal human erythrocytes with the membranes in the presence of serum. This led to deposition of C3d on these "innocent bystander" red cells, and provided an independent parameter for measuring complement activation. The PAN membrane caused significantly more C3d deposition on red cells, and thus more complement activation than Cuprophan. The possible significance of complement activation by PAN membrane, in consideration of its property of binding the resultant anaphylotoxins, is discussed.

Acrylic Resins↗
PubMedDate not supplied

Comparison of a quantitative microtiter method, a quantitative automated method, and the plate-count method for determining microbial complement resistance.

A quantitative microtiter method for determining the degree of complement resistance or sensitivity of microorganisms is described. The microtiter method is compared with a quantitative automated system and the standard plate-count technique. Data were accumulated from 30 avian Escherichia coli isolates incubated at 35 C with either chicken plasma or heat-inactivated chicken plasma. Analysis of data generated by the automated system and plate-count techniques resulted in a classification of the microorganisms into three groups: those sensitive to the action of complement; those of intermediate sensitivity to the action of complement; and those resistant to the action of complement. Although the three methods studied did not agree absolutely, there were statistically significant correlations among them.

Animals↗
PubMed1988

New complement fixation test with peroxidase-labeled complement Clq for direct and quantitative determination of antibodies to herpes simplex virus.

An enzyme-labeled complement fixation (ELISA-CF) test for the direct and quantitative determination of complement fixing (CF) antibodies has been developed. This paper described the introduction of the ELISA-CF test that used peroxidase-labeled Clq component of complement to detect CF antibodies which had reacted with herpes simplex virus (HSV), as a virus model. Equal volumes of heat-inactivated serum and the peroxidase-labeled Clq (P*-Clq) were simultaneously added to wells of microplates which had been coated with HSV CF antigen or with cell control antigen. The enzymatic activities of P*-Clq bound to the immune complex were determined photometrically. The ELISA-CF test allows processing of serum specimens in a 3-hr operation, with procedural simplicity and increased specificity and sensitivity compared with the conventional CF test.

Antibodies, Viral↗
PubMed1975

Complement components in normal serum and plasma quantitated by electroimmunoassay.

Sjöholm, A. G. Complement Components in Normal Serum and Plasma Quantitated by Electroimmunoassay. Scand. J. Immunol. 4, 25-30, 1975. The concentrations of C1q, C1s, C3, C4, C5, C3 proactivator, and C1 inactivator in serum and EDTA plasma from 100 normal adults were determined by electroimmunoassay. The normal range of each of the proteins is given. The C1q values varied more closely with the C1s values than with the levels of the other complement components. C3, C5, and C3 proactivator seemed to form a fairly interdependent group. The reproducibility of double determinations (interplate variation) was 4.9% to 7.9%. The variation of the complement component levels on repeated sampling from normal individuals was investigated. Also, repeated freezeing and thawing and storage at room temperature of serum and plasma were studied for their effect on the quantitation of the complement components. C3 and C4 values obtained by electroimmunoassay were in agreement with the values obtained by single radial immunodiffusion.

Adult↗
PubMed1967

Antibodies in histoplasmosis.

Production of precipitating and complement-fixing antibody in rabbits and other animals was induced by immunization with live yeast-phase cells of Histoplasma capsulatum. Results of studies of polysaccharide antigens from three strains of H. capsulatum, by quantitative complement-fixation with human and rabbit antisera, strongly suggest the presence of type specificity. The variations of titer during 11 weeks in one patient with histoplasmosis and the variations of titer among a group of patients with histoplasmosis were studied by use of quantitative complement-fixation tests.

Animals↗
PubMed1986

An enzyme-linked immunoabsorbent assay for the quantitation of the terminal complement complex from cell membranes or in activated human sera.

A sensitive and simple enzyme-linked immunoabsorbent assay (ELISA) has been developed to measure the terminal complement complex (TCC) in solution. Commercially available antibodies to the native complement (C) components C5 and C9 were used in a double antibody sandwich technique sensitive enough to detect 0.3 microgram/ml of purified TCC. The TCC was not detected in normal human serum (NHS) nor was it generated when sera from patients with a genetic deficiency of functional C5, C7, C8 beta or C9 were activated with cobra venom factor (CVF). If the C8 beta deficient serum was reconstituted with the C8 beta chain and incubated with CVF, TCC were formed and detected by the assay. In in vitro experiments, the TCC was detected in NHS activated by either the classical or alternative pathway even when there was no measurable consumption of C5, C8 or C9. In addition, adaptation of a detergent extraction procedure permitted the quantitation by the assay, of TCC which were generated on sensitized sheep erythrocyte membranes. Experiments to test sample handling conditions showed no generation of TCC in NHS after four freeze/thaw cycles and spontaneous formation only if NHS had been incubated at 37 degrees C for 48 h. The TCC in zymosan-activated NHS were stable at 37 degrees C for 1 week. Patients with C activation associated diseases such as SLE and rheumatoid arthritis had increased levels of TCC that correlated with positive clinical tests for inflammation, even though C levels were normal when measured by routine techniques. These results suggest that this ELISA will provide a valuable tool for studying the role of C in the pathogenesis of C-mediated diseases and in examining the mechanism of tissue injury in in vitro experimental systems.

Animals↗
PubMed1992

Distribution and quantitative expression of the complement receptor type 1 (CR1) on human peripheral blood T lymphocytes.

The complement receptor, type 1 (CR1) is expressed on a variety of cell types including primate erythrocytes, phagocytic cells, and B lymphocytes. On these cells, CR1 plays a role in a diverse spectrum of biological activities including the clearance of immune complexes from the circulation, down-regulation of the complement system, recognition of complement-coated microorganisms, and cellular activation. CR1 is also expressed by some, but not all, T lymphocytes. The present study was undertaken in order to examine the distribution of CR1 on normal human T cell subsets by flow cytometry and to quantify the expression of T cell CR1 by radioimmunoassay. Data presented here indicate that, in a panel of 19 normal individuals, a mean of 9.7% of the overall peripheral blood lymphocyte population expressed CR1 and that, as assessed by two-color flow cytometry, 12.0% of CD3+, 13.0% of CD4+, and 20.0% of CD8+ cells expressed CR1. While single peaks of CR1 staining were observed within the CD3 and CD4 subsets, a biphasic pattern of staining was evident within the CD8 subset in which relatively high-intensity CR1 staining was detected within the subpopulation of "dull" CD8+ cells, whereas a lower intensity of CR1 staining was observed within the subpopulation of "bright" CD8+ cells. Duplicate analyses performed over a relatively short time frame suggested that, while the overall percentage of cells that expressed CR1 varied considerably among normal individuals, in at least some individuals the percentage of cells expressing CR1 was relatively stable, especially within the CD4 subset. In cell suspensions enriched for T lymphocytes by rosetting with sheep erythrocytes, 10.0% of the cells were CR1+ and a mean of approximately 3700 CR1 were expressed per CR1+ cell. There was no apparent correlation between the number of CR1 per T cell and the number of CR1 expressed per erythrocyte in the same blood sample. The expression of CR1 on subpopulations within the CD3+, CD4+, and CD8+ lymphocyte subsets may play a role in both normal cell function and in the pathophysiology of disease states including the acquired immune deficiency syndrome (AIDS).

Adult↗
PubMed1979

The quantitation of alternative pathway complement function by timed lysis assay.

A simple timed lysis assay is described for quantifying haemolytic complement activity in human serum. Classical pathway complement function was determined by measuring the time taken to lyse 50% of a standard suspension of antibody-coated sheep erythrocytes; the time required for 50% lysis of a standard rabbit erythrocyte suspension was similarly used to evaluate alternative pathway function. Because target erythrocytes prepared on different days gave slightly different 50% lysis times, it was necessary first to construct a series of calibration curves for converting 50% lysis times into CH50 U/ml. For this purpose, a range of dilutions of the standard human serum, of known haemolytic activity, was tested against erythrocytes prepared on 10 separate occasions. The standard serum was subsequently included with each batch of unknown sera and used to select the appropriate calibration curve for direct conversion of the 50% lysis time into CH50 U/ml. Eleven samples of normal human serum were tested by both the timed lysis assay and by the dilution methods of Mayer (1971) (classical) and Platts-Mills and Ishizaka (1974) (alternative pathway). Comparable results were obtained in all cases.

Animals↗
PubMed1977

Gingival fluid and serum in periodontal diseases. I. Quantitative study of immunoglobulins, complement components, and other plasma proteins.

1. Gingival fluid from severely inflamed periodontal tissue represents a 15 to 30% dilution of serum with respect to the proteins studied, with the exception of C3 and in some subjects, C4. 2. A marked decrease in C3 levels is found in most, if not all, gingival fluids, and a marked decrease of C4 levels is found in some gingival fluids. This suggests that complement might be activated during periodontal inflammation. 3. The concentrations of proteins in the gingival fluid are not related to their molecular weight.

Blood Proteins↗