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Results for “quantitative complementation”

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PubMed1978

Direct demonstration and quantitation of the first complement component in human serum.

The first component of complement, C1, can be demonstrated and quantitated in normal and pathological human serums by simple immunochemical techniques. All of the C1q, C1r, and C1s detected in normal serum was found to be in the C1 complex. A simple modification of these methods permitted the quantitation of free C1s in the presence of macromolecular C1, a technique which may prove useful in screening pathological serums.

Calcium↗
PubMed1988

Complement activation in patients with renal failure as detected through the quantitation of fragments of the complement proteins C3, C5, and factor B.

Using sensitive and highly specific enzyme-linked immunosorbent assays fragments of the complement proteins C3, C5, and factor B were quantitated in patients with renal failure. During hemodialysis on new cuprophan membranes raised levels not only of C3a, but in addition of activated C3, C5a, and Ba were demonstrated. In patients with chronic renal failure and end-stage renal disease plasma concentrations of Ba and activated C3 were markedly elevated independent of hemodialysis. This finding is taken as an indication of a continuous recruitment of the alternative pathway of complement in these patients. As the detected complement protein fragments are known to exert immune regulatory functions these findings may imply that these peptides are involved in the maintenance of the immune suppressed state in renal failure.

Acute Kidney Injury↗
PubMed1976

A complement fixation method for quantitative differentiation of reactions to 45/20 vaccine and Brucella infection.

Brucella complement fixing antibodies may be titrated independently in adult vaccinated (strain 45/20) and in naturally infected cattle by serological tests utilizing a specially prepared antigen. Serum samples are subjected to the standard complement fixation test for the diagnosis of brucellosis (MacKinnon 1963) and subsequently retested by the same method but with a saline extract antigen prepared from strain 45/20 Brucella abortus. The results obtained in the two tests are compared in five specific categories of brucella reactors. An evaluation and discussion of the test method, on the basis of the results obtained, indicates that informed diagnoses can be made in parallel with a continuous adult vaccination programme.

Animals↗
PubMed1992

Sublytic complement attack protects tumor cells from lytic doses of antibody and complement.

Sublytic doses of the membrane attack complex (MAC) of complement are known to exert multiple stimulatory effects on metabolically active cells. Results presented herewith demonstrate that pretreatment of the human leukemic cells K562 and HL-60 with sublytic doses of antibody and normal human serum protects them from lytic complement concentrations, a phenomenon proposed to be called "complement-induced protection". C7- and C8-deficient human sera are ineffective in inducing resistance unless they are reconstituted with purified human C7 and C8, respectively. The complement-induced protection is inhibitable by actinomycin D and cycloheximide indicating that the increased complement resistance depends on RNA and protein synthesis triggered by the sublytic complement doses. Free extracellular Ca2+ is also required to achieve maximal protection, indicating a role for Ca2+ ions in the cell stimulatory events which culminate in increased complement resistance. Quantitative analysis of bound complement components indicated that similar amounts of C3 and C9 molecules are deposited on "protected" and control cells during complement activation. The "protected" K562 and HL-60 cells regain sensitivity to lytic MAC doses after about 8 or 3 h, respectively, of culture in growth medium, in the absence or presence of actinomycin D and cycloheximide. The "induced protection" is not species restricted and protection from human complement can be induced in K562 cells by treatment with sublytic doses of antibody and rabbit or guinea pig sera.

Animals↗
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↗