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Results for “quantitative complementation”

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PubMed1999

Rapid onset monoclonal gammopathy in cutaneous lupus erythematosus: interference with complement C3 and C4 measurement.

Accurate nephelometric immunoassay requires both the analyte and the calibration standard to have the same molecular mass. Alteration in the size of the analyte can affect light scatter and yield erroneous results. We report a case where an autoantibody, a monoclonal IgM with immunoconglutinin activity, interfered with the nephelometric quantitation of plasma complement components C3 and C4.

Adult↗
PubMed1993

Vaccination and the role of capsular polysaccharide antibody in prevention of recurrent meningococcal disease in late complement component-deficient individuals.

This study sought to quantitate the response of late complement component-deficient (LCCD) individuals to the meningococcal vaccine, to examine antibody persistence, and to investigate the contribution of these antibodies to meningococcal killing in complement- and phagocyte-dependent bactericidal assays. The mean concentration of antibody to group A and C capsular polysaccharide after vaccination was similar in 8 LCCD, 11 family members, and 7 unrelated normal individuals. LCCD individuals had a greater percentage decline in antibody concentration to group C polysaccharide and had lower concentrations of antibody to group Y polysaccharide 2.0-2.5 years after vaccination than did normal and heterozygous deficient persons. Antibody to subcapsular antigens was minimally effective in mediating complement-dependent killing and had no effect in the opsonophagocytic assay. In contrast, antibody to capsular polysaccharide promoted meningococcal killing in both assays. These data support vaccination as a preventive measure in LCCD individuals and lend credence to the idea that these individuals are critically dependent on capsular antibody for protection against meningococcal disease.

Adult↗
PubMed1989

[Synthetic inhibitors of serine proteinases. 35. Inhibition action of amidino- and guanidinophenyl derivatives against hemolysis initiated by complement activation].

Selected amidino- and guanidinophenyl derivatives which have already proved to be inhibitors of serine proteinases were tested on their inhibitory effect on complement activation. To quantitate the inhibitory action the decreasing rate of haemolysis of sensitized sheep erythrocytes was recorded continuously. Compounds exerting a more or less pronounced inhibitory effect on trypsin-like proteinases turned out to have a corresponding inhibitory influence on complement-mediated haemolysis. The inhibitory effect of some amidinobenzyliden derivatives on the complement activity was markedly higher than could be expected from their general antiproteolytic efficacy. Changing the basic structure into amidinophenyl amino acid amides with strong and selective antithrombin effect completely abolished the inhibitory influence on complement.

Amidines↗
PubMed2001

A monoclonal antibody cytolytic to androgen independent DU145 and PC3 human prostatic carcinoma cells.

BACKGROUND: While a range of therapeutic products is available for androgen-dependent prostatic cancer, no specific intervention modality exists for androgen-independent prostatic cancer. The objective of this research was to explore whether epitopes exist on androgen-independent prostatic DU145 cancer cells, which could be susceptible to cytotoxic action of specific antibodies. METHODS: Hybrid cell clones were developed by immunization of mice with DU145 cells and tested for immunoreactivity by solid phase EIA and cytotoxicity in vitro on DU145 in the presence of the complement, employing colorimetric quantitation by MTS (3- (4-, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-(4-sulfophenyl)-2H-tetrazolium). Binding and cytotoxicity studies were also carried out by flow-cytometry. RESULTS: Of 15 stabilized clones immunoreactive with DU145 cells, one monoclonal antibody (mAb 730) manifested cytotoxicity on DU145 cells. Approximately 80% of cells in the DU145 cell line were susceptible to lysis with this antibody at saturating levels. This figure corresponded quantitatively to the number of cells binding with this antibody as determined by Flow-cytometry. Staining with ethidium monoazide bromide (EMA) showed that the cell binding the antibody was also the one killed by the antibody in the presence of the complement. MAb 730 was also cytotoxic to PC3, another androgen-independent human prostatic cancer cell line. This antibody is devoid of classical autoantibody reactivities and does not react with normal human liver, thyroid, kidney, pancreas, and adrenal tissues, as determined by immunofluorescence. Also, it shows negative immuno-reactivity to benign glandular tissue but is observed to positively react with neoplastic prostate tissue. CONCLUSIONS: Epitopes exist on androgen-independent prostatic cancer cells that are susceptible to cytolysis by monoclonal antibodies and these could be investigated for potential immunotherapy.

Animals↗
PubMed1977

A solid phase fluorescent immunoassay for the quantitation of the C3 component of human complement.

A non-competitive method for the determination of the C3 component of human complement in serum is described. This procedure involves use of a specific antibody covalently attached to derivatized polyacrylamide beads and a fluorescently labeled specific antibody. Reproducible results were achieved for C3 in serum in the range of 20 mg/d1 to 195 mg/d1 within 2 h. C3 levels as low as 125 ng/m1 can also be measured. Fluorescent immunoassay and radial immunodiffusion were used to determine C3 levels in healthy adults. Good agreement was found between the two methods.

Animals↗
PubMed1977

A solid phase fluorescent immunossay for the quantitation of the C4 component of human complement.

A non-competitive method for the determination of the C4 component of human complement in serum is described. This procedure involves use of a specific antibody covalently attached to derivatized polyacrylamide beads and a fluorescently labeled specific antibody. Reproducible results were achieved for C4 in serum in the range of 10 mg/dl to 170 mg/dl within 2 h. C4 levels as low as 150 ng/ml can also be measured. Fluorescent immunoassay and radial immunodiffusion were used to determine C4 levels in healthy adults. Good agreement was found between the two methods.

Complement C4↗
PubMed1979

Quantitation of the membrane attack complex of complement in an air-driven ultracentrifuge.

A sensitive assay of complement (C) activation via either the classical or alternative pathway was developed by evaluating assembly of the terminal complexes (C5b-9)2 or SC5b-9. Activation of serum containing [125I]C7 resulted in the formation of a stable, radiolabeled complex which was separable from its precursors by sedimentation in an air-driven ultracentrifuge. The radioactivity in the sediment was directly proportional to the amount of complex formed and assembly of the complex could be detected after C activation by aggregated IgG in concentrations as low as 10 micrograms/ml. Mild detergents such as Triton X-100 could be included in the reaction mixture, because they affected neither the assembly nor the integrity of the complexes. The assay, which detects both assembly of the membrane attack complex (MAC or (C5b-9)2) on target membranes and formation of SC5b-9 in fluid phase, measures the potential of certain substances to trigger the cytolytic phase of C regardless of whether the classical or alternative pathway was activated. However, by using serum depleted of either factor B or C1q, activation of either pathway can be assessed individually.

Cell Membrane↗
PubMed1981

Quantitative studies of the interaction of 3H-dsDNA/anti-DNA immune complexes with complement: comparison and evaluation of the Raji cell, the solution phase C1Q, and the red blood cell linked complement fixation radioimmunoassays.

We have prepared antibody/3H-dsDNA immune complexes and have used three independent radioimmunoassays to quantitate their interaction with complement; the solution phase C1q assay, the Raji cell assay, and a complement-based red blood cell adherence assay (RBC-CF). Our results indicate that although there is reasonable qualitative agreement between the Raji cell assay and the RBC-CF assay, there are some differences in the quantitative range of sensitivities of the two assays. On the other hand, we find that most of the complement-fixing antibody/3H-dsDNA complexes are not detected in the solution phase C1q assay. The results suggest this is because the absolute concentrations of the immune complexes were too low to achieve significant precipitation under the standard conditions used in the C1q assay. The implication of these findings with respect to the potential detection and analysis of antibody/dsDNA immune complexes is discussed.

Antibodies↗
PubMed1999

Relationship between resistance to complement, virulence and outer membrane protein patterns in pathogenic Escherichia coli O2 isolates.

To establish a possible relationship between resistance to complement, virulence and outer membrane protein banding patterns, ten E. coli O2 strains isolated from chickens with colibacillosis were studied for: (1) resistance to the bactericidal effect of complement by a quantitative microtiter method, (2) virulence, as determined by chicken lethality test, and (3) outer membrane protein banding patterns yielded by SDS-polyacrylamide gel electrophoresis. The ten isolates were classified into three groups: (1) Group 1, consisting of four isolates showed: (a) high resistance to complement, (b) high virulence, and (c) different pattern between 35 and 40 kDa with a weak peptide band at 35 kDa. (2) Group 2, consisting of one isolate showed: (a) high resistance to complement, (b) low virulence, and (c) a weak peptide band at 35 kDa. (3) Group 3, consisting of five isolates showed: (a) low resistance to complement, (b) low virulence, and (c) identical OMP pattern between 35 and 40 kDa exhibiting a strong peptide band at 35 kDa. The results suggest that high resistance to complement may be necessary but no sufficient for virulence and that OMP banding patterns may be a marker for virulence.

Animals↗
PubMed1986

Temperature-sensitive mutants of frog virus 3: biochemical and genetic characterization.

Nineteen frog virus 3 temperature-sensitive mutants were isolated after mutagenesis with nitrosoguanidine and assayed for viral DNA, RNA, and protein synthesis, as well as assembly site formation at permissive (25 degrees C) and nonpermissive (30 degrees C) temperatures. In addition, mutants were characterized for complementation by both quantitative and qualitative assays. Based on the genetic and biochemical data, the 19 mutants, along with 9 mutants isolated earlier, were ordered into four phenotypic classes which define defects in virion morphogenesis (class I), late mRNA synthesis (class II), viral assembly site formation (class III), and viral DNA synthesis (class IV). In addition, we used two-factor crosses to order 11 mutants, comprising 7 complementation groups, onto a linkage map spanning 77 recombination units.

Antigens, Viral↗