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At least 145 records · Page 8Linked to original sources
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↗
PubMed1986

Assays for complement activation.

Complement is a major biologic mediation system that functions in host defense against microorganisms and other pathogens and also aids in the elimination of damaged and abnormal cells. This is accomplished by its ability to mediate the destruction of pathogens and altered cells directly through cytolytic and cytotoxic properties, as well as indirectly by its ability to augment the actions of various effector cells, which in turn destroy or inactivate these substances. Its second major action in vivo is the production of an acute inflammatory response that, by altering blood-vessel permeability, contracting smooth muscles, and promoting an influx of leukocytes, aids in the localization of the injurious process responsible for complement activation and retards its spread and dissemination throughout the body. The actions of the activated complement system upon pathogens and altered cells, as well as its phlogistic properties, are the direct consequence of the actions of complement protein-protein complexes, enzymes, peptides, and cleavage products on the activator, on biologic membranes, and on various effector and other tissue cells. Complement activation is a frequent phenomenon in infectious diseases, autoimmune diseases, and many other conditions having an inflammatory component. Because of the importance of this system in contributing to the resolution of the disease process, monitoring of the status of the system in patients is frequently indicated. Monitoring of the complement status is also appropriate in numerous other diseases, such as those with an inflammatory component, in which complement activation occurs secondarily but in which it is frequently responsible for confining the injurious process and aiding in its resolution. A number of techniques are available to assess the status of the complement system in samples obtained from patients. Among these are a group of newer tests that specifically detect complement activation. They quantitate activation-dependent complement cleavage products, antigenic changes, or protein-protein complexes. These tests are quantitative, highly sensitive, and extremely specific; furthermore, most can be employed with samples obtained from patients. Because all of the biologic actions of the complement system require complement activation, such newer activation-specific assays permit the precise evaluation of the status of this system in human diseases. Further extension of their use to additional patients and other disease complexes will undoubtedly increase the understanding of the biologic importance of the complement system in human disease processes.

Complement Activation↗
PubMed1975

Factors affecting assay of myoglobin by complement fixation or immunodiffusion.

Quantitative micro-scale complement-fixation and semi-quantitative gel immunodiffusion assays for myoglobin have been evaluated experimentally and used to measure myoglobin in the sera of more than 1500 patients. We report certain problems, observations, and methodological improvements. Serum caused enhancement of precipitin lines in the immunodiffusion assay. In the complement-fixation assay, serum interfered both by enhancing or inhibiting complement fixation. Suggested modifications in the complement-fixation assay are: (a) routine threefold or greater dilution of serum with buffer and (b) use of serum-based rather than buffer-based calibration materials in preparing standard curves. Three cycles of freeze-thaw of serum or buffer decreased detectable myoglobin by 50-100%. We conclude that certain serum-related factors and freeze-thaw phenomena are important causes of error in immunological assays for myoglobin.

Complement Fixation Tests↗
PubMed1990

[Quantitation of intact form of complement protein B and its fragment Ba in human serum by radioimmunoassay].

A sensitive solid-phase radioimmunoassay for intact complement protein B and its smaller fragment Ba is described which quantitates human B and Ba to 30 ng/ml. The assay was proved to be useful to evaluate the activation of the alternative pathway of the complement system by measuring intact B and Ba in normal human sera activated with zymosan. In sera from patients with systemic lupus erythematosus (SLE), the level of intact B was decreased and that of Ba was increased in the active phase, and the level of Ba was increased though intact B which was within normal limits in the inactive phase. The present result suggests that the activation of the alternative pathway is occurring both in the active and inactive phase in SLE, and the measurement of intact B and Ba concentration in pathological sera would be useful to evaluate the activation of the alternative complement pathway.

Adult↗
PubMedDate not supplied

An enzyme-linked immunosorbent assay (ELISA) for detecting antimitochondrial antibody.

We have developed an enzyme linked immunosorbent assay (ELISA) for antimitochondrial antibody. Polyvinyl microtiter plate wells are coated with partially purified rat kidney mitochondria, and excess protein binding sites are blocked with bovine serum albumin. Human serum, diluted 1:1,000, is incubated for 1 hr. Then beta-galactosidase-goat-anti-human IgG (H + L) is added followed by the substrate, p-nitrophenyl-beta-D-galactopyranoside. The plates are then read at 404 nM in a microelisa autoreader. A positive result was defined as optical density greater than or equal to 0.100, more than 5 standard deviations above the mean of 36 normal individuals. With this technique, 56 of 60 patients with primary biliary cirrhosis were positive for antimitochondrial antibody (93%), mean O.D., 0.456 +/- 0.031 S.E. Seventeen of 17 patients with extrahepatic bile duct obstruction and 14 or 14 patients with alcoholic cirrhosis were negative. Only 1 of 29 patients with chronic active liver disease was positive (4%). Antinuclear antibody and antimicrosomal antibody do not bind in this assay, and activity is absorbed from sera by preincubation with suspensions of rat kidney mitochondria. The ELISA is approximately 20 times more sensitive than a quantitative microtiter complement fixation technique and more convenient than radioimmunoassay. It is rapid, quantitative and uses stable reagents. In contrast to immunofluorescence techniques, it is not affected by observer interpretation.

Animals↗
PubMed1991

Use of heteropolymeric monoclonal antibodies to attach antigens to the C3b receptor of human erythrocytes: a potential therapeutic treatment.

We have prepared bispecific, cross-linked monoclonal antibodies (heteropolymers) with specificity for both targeted antigens and the human erythrocyte (RBC) complement receptor. These heteropolymers facilitate binding of target antigens (human IgG and dinitrophenylated bovine gamma globulin) to human RBCs under conditions that either allow or preclude complement activation. Quantitative analyses of this binding agree well with the number of complement receptors per RBC. In vitro "whole-blood" model experiments indicate heteropolymer-facilitated binding of antigens to RBCs is rapid and stable at 37 degrees C. It may be possible to extend these prototype experiments to the in vivo situation and use heteropolymer-attached RBCs for the safe and rapid binding, neutralization, and removal from the circulation of pathogenic antigens associated with infectious disease.

Antibodies, Monoclonal↗
PubMed1987

Serum concentrations of immunoglobulins and complement components in patients with recurrence after resection of gastric carcinoma.

Immunoglobulins and complement components were quantitated in sera sampled at 3-6-month intervals from 20 patients with recurrence after resection of gastric carcinoma stages I-III (pTNM). Concentrations of IgA, C3, C4, and C1-INH at clinical recurrence were increased in a significant number of patients as compared to the concentrations 3-6 months prior to recurrence. The mean concentration of C3, C4, and C1-INH were higher than prior to recurrence. At the time of recurrence, the concentrations of C3, C4, and C1-INH were higher than the corresponding postoperative concentrations among 14 patients alive and disease-free for 5 years or more. Three to six months prior to recurrence, the concentrations of C4 and C1-INH were also higher than those of the 5-year survivors. The data indicate that serial quantitation of immunoglobulins and complement components may beof value in the follow-up after resection of gastric carcinoma.

Aged↗
PubMed1992

Properties of a low molecular weight complement component C6 found in human subjects with subtotal C6 deficiency.

A sensitive ELISA assay was used to quantitate serum complement component C6 concentrations. Levels in the range 0.3-3 micrograms/ml were measured in samples from eight individuals (four separate pedigrees) and two subjects with subtotal combined C6/C7 deficiency who have been reported previously. We defined C6 levels in this range as subtotal C6 deficiency (C6SD). In contrast, C6 deficiency with levels below 0.03 micrograms/ml was defined as C6Q0. C6Q0 has been found in 29 unrelated cases which have already been reported. Investigations of the properties of the C6 found in the C6SD subjects showed it to be haemolytically active and able to incorporate into the terminal complement complex. The protein had a relative molecular weight (Mr) of approximately 86% of normal C6 and this Mr was identical to that of the C6 of one combined deficient subject. The Mr of the C6 of the other combined deficient subject was previously estimated as 79% of the Mr of normal C6. Isoelectric focusing (IEF) analysis with band development by haemolytic overlay revealed that all C6SD samples produced an identical weak C6 band pattern anodal to normal C6A bands. The C7 IEF patterns of the two combined deficient subjects were identical, and the C6 IEF patterns of both were identical to those of the C6SD subjects. Thus the C6 of the combined deficient subjects is probably the same abnormal protein found in the C6SD individuals. None of the C6SD or combined deficient subjects have had meningococcal disease and it may be that low C6 levels afford some protection.

Adult↗