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PubMedDate not supplied

[The activation of the complement system in various connective tissue diseases].

A knowledge of the complement system in patients with collagen diseases is of interest as it may serve to indicate the existence of activity or non-activity in these diseases. We have studied the existence or non-existence of the activity of the complement system through evaluation of the levels of C3, as well as the implicated mechanism of the classical or alternate pathways through the measure of C'4 and C'3 proactivator components. Quantitation of complement components was obtained by electroimmunodiffusion, employing specific antiserum. From the results obtained, we observed that the complement activity in patients with SLE, the classic pathway was affected more (7 patients of the 24 studied), than the alternate pathway (3 patients). However, in those patients affected by sclerodermia, there seems to be an equal incidence of the activation of complement through both pathways (2 patients with activation through each way). Also of interest is the existence of a patient with SLE and another affected by sclerodermia in which a selective reduction of C'3 was observed. This observation suggests the possible existence of a selective destruction, perhaps mediated through a factor type such as the nephritic factor. However, there may exist other patients of whom we have already commented on, with a parallel reduction in the three components which suggests a change in the synthesis or in the simultaneous activation in both of the pathways. When realizing the comparative studies of the state in which the immunoglobulins (IgG, IgA and IgM) and complement components are to be found, the conclusion is that there is no significative correlation between the two. This is particularly interesting as it assumes the necessity of knowing the state of the complement and not only of the immunoglobulin, in order to know the state of activity in which the process is.

Complement C3↗
PubMed1979

Fluctuation of serum complement levels in children with neuroblastoma.

Serum samples from eleven children with neuroblastoma were drawn at diagnosis and again every 15 days or a month after the beginning of treatment over the course of 17 months observation. Twenty healthy children of the same age with no appreciable clinical manifestation were also studied as controls. Investigations included quantitative serum complement levels (total complement hemolytic activity, C3 and C4), anticomplementary serum activity and urine catecholamine levels (VMA and HVA). Complement levels of tumor patients were significantly higher than those of healthy subjects, but fluctuations were seen at different stages of the disease; patients at admission with active tumors or tumor recurrence had higher complement levels than those of patients in remission. Temporary recurrences of the disease were usually accompanied by fluctuations of urinary catecholamines, serum complement levels (mainly C3) and anticomplementary serum activity. At the terminal phase of the disease a drop in complement levels was usually seen, while urinary catecholamines were progressively increasing.

Bacterial Infections↗
PubMed1992

Time for new concepts about measurement of complement activation by cardiopulmonary bypass?

Fifty-one patients admitted for routine coronary bypass operations were randomized to cardiopulmonary bypass with a membrane oxygenator (Capiox) or a bubbler (Polystan or William Harvey). Complement activation was measured using enzyme immunoassays for concentrations of C3 activation products and the terminal complement complex. From 5.8 to 8.1 arbitrary units (AU)/mL (medians), the plasma concentrations of C3 activation products increased by 119.9 AU/mL (Capiox), 124.6 AU/mL (Polystan), and 79.5 AU/mL (William Harvey) to a peak at closure of the sternum (not significant when related to baseline concentrations). The increase in C3 activation products and baseline C3 activation were linearly correlated (R2 = 0.30; p less than 0.0001). From 5.5 to 6.1 AU/mL, the plasma terminal complement complex concentrations increased by 45.2 AU/mL (Capiox), 15.4 AU/mL (Polystan), and 17.4 AU/mL (William Harvey) to a peak before termination of cardiopulmonary bypass. Maximal terminal (C5-C9) activation was significantly higher in the membrane oxygenator group (p less than 0.0001) and showed no relationship to C3 activation. Measurement of C3 activation only gives no information about C5-C9 activation. At present, terminal complement complex quantitation is probably the best index of C5-C9 activation during cardiopulmonary bypass.

Cardiopulmonary Bypass↗
PubMed1991

Quantitative and antigenic differences in complement component C4 between American blacks and whites.

A population of 98 healthy Black Americans was studied in order to determine normal ranges for total C4, C4A and C4B. Mean total C4 in Blacks measured by an enzymelinked immunoassay (EIA) was 44 +/- 12.8 mg/dl which was significantly different (p less than 0.001) from Caucasian levels of 31.7 +/- 11.5 mg/dl. The difference in total C4 was due to increased levels of C4B in Blacks (means = 24.4 mg/dl) as compared to Whites (means = 15.7 mg/dl; p less than 0.001). These results remained significantly different even when 8 samples having the C4A 91 phenotype were excluded. Since EIAs using monoclonal antibodies with Ch 1 specificity may yield false results, C4 allotyping is recommended when quantitating C4A and C4B levels in Blacks.

Alleles↗
PubMed1978

Eosinophilic gastroenteritis with obstruction. Immunological studies of seven patients.

We studied 7 patients with eosinophilic gastroenteritis presenting with obstruction of the gastrointestinal tract. Five had required surgical treatment for relief of obstructive symptoms or because of diagnostic uncertainty. Immunological studies, including serum immunoglobulins, serum complement, lymphocyte quantitation, and lymphocyte response to nonspecific mitogens revealed no striking abnormalities. None was clinically allergic or food sensitive, and serum IgE was normal in all. A review of the literature since 1970 suggests that the obstructive form of eosinophilic gastroenteritis accounts for about half of the reported cases. Allergy, especially hypersensitivity to food, is not required for the diagnosis.

Adolescent↗
PubMed1975

Immunofluorescence and anti-complement immunofluorescence absorption tests for quantitation of Epstein-Barr virus-associated antigens.

Immunofluorescence absorption methods are described which permit quantitative estimation and differentiation of Epstein-Barr virus (EBV)-associated antigens (virus capsid antigen, VCA, early antigen, EA and EBV-determined nuclear antigen, EBNA) in cell extracts. EBNA was present in all cell lines (producer and non-producer) which carried the EBV-genome, while VCA and EA were present in producer lines only. All the antigens were absent from a lymphoid cell line (MOLT-4) which lacked the EBV-genome, as well as from leukemia cells from peripheral blood. The techniques demonstrated antigenic identity of the various antigens when prepared from different cell lines.

Absorption↗
PubMed1979

Complement proteins and macrophages. 1. Quantitative estimation of factor B produced by mouse peritoneal macrophages.

Cobra venom factor was used for the detection of factor B synthesized by mouse peritoneal macrophages. This method was shown to be specific for factor B assay by neutralization by antimouse factor B antibody. The amount of factor B in the culture supernatant, assessed by this method, was found to be dependent on the medium used for cultivation of macrophages. The addition of 25% L cell-conditioned medium to minimal essential medium (LCM-MEM) enhanced the production of factor B and also of lysozyme. Kinetic analysis in LCM-MEM showed that factor B produced by 6 x 10(4) cells/cm2 increased up to 72 hr and reached a plateau at 96 hr. The amounts of factor B and lysozyme produced in LCM-MEM depended upon the number of macrophages. Production of factor B was completely inhibited by 1 microgram of cycloheximide per ml and was restored by its removal.

Animals↗
PubMed2026

Development and Validation of a Predictive Model for Identification of Cognitive Impairment Risk in Older Adults with Subjective Cognitive Decline：A Longitudinal Study.

BACKGROUND: Subjective cognitive decline (SCD) is a transitional state between objective cognitive impairment and cognitively intact mental status, providing a critical window for implementing preventive interventions to delay objective cognitive decline. AIMS: We aimed to develop a predictive model for SCD progression in older adults with mild cognitive impairment (MCI). This model will facilitate the identification of risk factors and establishment of targeted interventions for community-based SCD management. METHODS: Data from the China Health and Retirement Longitudinal Study (CHARLS) was utilized in this study, extracting 18 indicators. Potential predictors selected through univariate Cox regression and LASSO regression analyses were sequentially incorporated into a multivariable Cox regression model. A nomogram was constructed to establish a predictive model. Model validation encompassed Area Under Curve (AUC) metrics for discriminative capacity, complemented by quantitative assessments using calibration curve analysis for precision verification and decision curve analysis (DCA) for clinical utility evaluation. RESULTS: A total of 1099 older adults with SCD were included in the final analysis, of whom 114 (10.3%) developed MCI. Multivariable Cox regression identified residence, marital status, educational level, social participation, gait speed, and baseline cognitive function. The model demonstrated time-dependent AUC values of 0.885, 0.830, 0.839, and 0.836 in the training set when evaluating discriminative capacity at 2-, 4-, 7-, and 9-year, respectively. The predictive model showed excellent predictive ability according to AUC, calibration curve, and DCA. CONCLUSIONS: A predictive model was created to estimate the risk of developing MCI in older individuals with SCD, offering clinician-actionable intervention benchmarks for preventive care.

Humans↗
PubMed1978

Comparison of an enzyme-linked immunosorbent assay for quantitation of rotavirus antibodies with complement fixation in an epidemiological survey.

The development of a micro-scale enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase as the marker enzyme for the detection and measurement of human rotavirus antibodies is described. A semipurified preparation of the serologically related simian agent, SA-11 virus, was used as the antigen. Test sera were reacted with antigen-sensitized wells in disposable poly-vinyl microplates. Any attached antibody was detected by the addition of peroxidase-labeled anti-species immunoglobulin (conjugate) followed by assay of the enzyme reaction with its substrate, hydrogen peroxide plus 5-aminosalicylic acid. This micro-ELISA was compared with complement fixation in a seroepidemiological study of the age prevalence of rotavirus antibody in Aboriginal and European populations living in the same outback area in Australia. The ELISA (results read with the naked eye) proved to be approximately 16 times more sensitive than complement fixation. Of Aborigines, 71% had rotavirus complement-fixing antibody, as compared to 45% of Europeans. By ELISA 100% of both populations had rotavirus antibodies. Mean antibody titers in the different age groups were higher in Aborigines than in Europeans. Antibody levels rose steeply throughout the first 20 years of life, remained high during the next 20 years, then increased again at least up to the age of 60 years. The micro-ELISA was practical, simple to perform, and more suitable than complement fixation for large seroepidemiological rotavirus studies. It also has potential for serodiagnosis of the disease, both in the laboratory and in the field.

Adolescent↗
PubMed1978

Quantitative influence of antibody and complement coating of red cells on monocyte-mediated cell lysis.

Monocyte-mediated lysis in vitro of human red cells coated with measured amounts of immunoglobulin G (IgG) or complement were studied. 1,000-1,500 molecules of IgG anti-D are necessary to effect measurable lysis, and lysis increases linearly with increasing levels of antibody sensitization. 100 microgram/ml of IgG1 abolished lysis even at maximal levels of anti-D sensitization (15,000 molecules/cell). Two isoimmune IgG anti-A or anti-B antisera were 5 to 10-fold less efficient in promoting phagocytosis or lysis per molecule of IgG bound; however, because of the greater antigen density of A or B, more than 100,000 molecules IgG/cell could be bound, producing equivalent lysis to anti-D-coated cells. Although inhibition by IgG1 was similar at equivalent levels of sensitization with anti-A, anti-B, or anti-D at high levels of coating with anti-A or anti-B (not attainable with anti-D), lysis was not inhibited by IgG1. Cells coated with human complement components alone were not lysed by monocytes; however, complement coating augmented IgG-mediated lysis and reduced the quantity of anti-D necessary to produce lysis to less than 1,000 molecules/cell. After thorough degradation of C3b by serum to C3d, complement augmentation persisted.

ABO Blood-Group System↗
PubMedDate not supplied

Failure of the Congo red dye uptake test to discriminate between virulent and avirulent avian Escherichia coli.

Twenty avian Escherichia coli isolates from normal and diseased chickens were compared by use of three virulence tests. These tests included the uptake of Congo red dye, an embryo lethality test, and a quantitative microtiter complement resistance test. A direct correlation was seen between the results of the complement resistance test and the embryo lethality test. The results of the Congo red test did not correlate with the two other tests.

Animals↗
PubMedDate not supplied

Preliminary note on the antipsychotic efficacy of bromperidol.

Bromperidol was administered to 20 acute and chronic psychotic inpatients during six to eight weeks at a mean daily dose of 18 to 10 mg. The neuroleptic was given orally or intramuscularly once a day (in the morning in order to evaluate its therapeutic and side effects). In 13 patients, bromperidol was substituted for haloperidol; in 7 cases, it was given immediately after the washout period. Descriptive psychopathology was complemented with quantitative psychopathology (ad hoc 29-item scale, AMDP Psychopathology Scale, Bf/Bf' Mood Scales). According to a preliminary analysis of data, both descriptive and psychometric, bromperidol seems to be a potent antipsychotic drug without disturbing adrenolytic side-effects or sedation, with classical extrapyramidal effects of the hypertonia type.

Adult↗
PubMed1977

Quantitative relationships of the fourth complement component in human cerebrospinal fluid.

A technique for the measurement of cerebrospinal fluid C4 concentration in unconcentrated specimens has been developed with the methods of electroimmunodiffusion and immunofixation. The method has proved to be reproducible and requires only microliter volumes of undiluted cerebrospinal fluid (CSF). The mean value for CSF C4 concentrations in 16 neurologically normal individuals was 325 +/- 32 mug/100 ml. A positive correlation between CSF C4 concentration and the concentration of CSF albumin and total protein was observed. The positive correlation between the concentrations of CSF C4 and albumin was, however, more clearly defined than the relationship of CSF C4 to total CSF protein.

Albumins↗
PubMed1976

Serum immunoglobulin and complement levels in patients with psoriasis vulgaris.

In 102 patients with psoriasis vulgaris, divided into group with slight psoriatic form and the group with severe psoriatic form, the serum immunoglobulin and complement levels were determined. The quantitation of immunglobulin and complement was carried out by single radial immundiffusion. It was found that the IgM levels were significantly decreased in both investigated groups. The IgA and IgG levels were significantly increased only in patients with severe psoriatic form. While the beta1A (C'3) levels were significantly increased in both investigated groups the beta1E (C') levels were not significantly changed compared to control group. It is concluded that the immunoglobulin imbalance in patients with psoriasis, opposite to complement, is depended on the severity of clinical form.

Adolescent↗
PubMed1976

Critical role of the conversion of the third complement component C3 (beta 1C/beta 1A) for its immunochemical quantitation.

For the immunochemical quantitation of the third component of complement C3 the state of conversion of this protein in the sample and the reference serum has to be guarded. Antisera raised against C3 may show different antibody specificity for the antigenic pattern of the C3 proteins which change during proteolysis by activation and also by ageing. It is shown that anti-C3-sera gave differences from -17% to + 91% comparing fresh and aged aliquots of the same sera directly on the same immunodiffusion plate corresponding to a particular anti-C3-serum. The use of three different monospecific antisera directed against the A determinant of C3 seemed to give results with good correlation in respect to C3 conversion. Glass and polystyrene plastic tubes did not have a significantly different effect on the C3 values in respect to C3 conversion. The in vitro acceleration of C3 conversion by thrombin or an inulin-like polysaccharide did not give consistent results in this context.

Complement C3↗
PubMed1979

Analysis of genetic complementation by whole-cell microtechniques in fibroblast heterokaryons.

A whole-cell microtechnique for the determination of complementation of human metabolic disorders is presented. This procedure permits the isolation of individual multinucleate cells produced by cell fusion for the quantitative evaluation of complementation. Mutant fibroblasts with a deficiency of propionyl-CoA carboxylase activity (EC 6.4.1.3) that had been mapped to complementation groups pcc and bio were used to evaluate the microtechnique. Complementation was monitored by the determination of [14C]propionate incorporation into cellular macromolecules. Single cells or a small number of cells were isolated from plastic film dishes after radioactive incubation by cutting out the portion of the plastic film holding the desired cells. Isotope incorporation was linear in 10-50 unfused cells and in 10-50 fused normal cells containing five or more nuclei. There was also a direct correlation between the nuclear content of cells and the amount of isotope incorporated. Three pcc and two bio mutants were fused in pairwise combinations by means of polyethylene glycol and complementation was determined by isotope incorporation in sets of 50 multinucleate cells, each cell isolated individually. The results agreed with autoradiographic data for both complementing and noncomplementing strains. The method is quantitative and gives severalfold higher sensitivity than current procedures. The method can be applied to the complementation analysis of a wide variety of inherited disorders of intermediary metabolism.

Acyl Coenzyme A↗