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Biomedical subjects

A Falus

Publications and source records attributed to A Falus.

At least 181 records · Page 10Linked to original sources
PubMed1986

Action of histamine on PHA chemiluminescence response of blood mononuclear cells in autoimmune patients.

Peripheral blood mononuclear cells (PBMs) of patients suffering from autoimmune diseases showed significantly lower chemiluminescence response to PHA than the controls. High doses of histamine (10(-5) M) inhibited the chemiluminescence while low doses caused a mild enhancement in all groups of patients. The preformed histamine content of the PBMs was not significantly higher in the patients than in the controls. Individually, a reverse correlation was found between the activity of the disease and the sensitivity of the cells to histamine. In very active cases, virtually no inhibition by histamine was found.

Arthritis, Rheumatoid↗
PubMed1986

Serum beta 2-microglobulin (beta 2m) and anti-beta 2m antibody in chronic hepatitis.

Serum beta 2-microglobulin (beta 2m) concentration is increased in pathological processes associated with lymphocyte activation. beta 2m and anti-beta 2m autoantibody (anti-beta 2m) determinations were made in the sera of 41 patients with chronic hepatitis and cirrhosis, respectively, in 19 with systemic lupus erythematosus (SLE) as well as in 27 healthy controls. A pathologically high beta 2m value was found in one-third of inactive persistent hepatitis, and in more than two-thirds of active hepatitis and postnecrotic cirrhosis cases. In SLE it occurred in 16 out of 19 cases. The beta 2m level was elevated mainly in HBV-negative and circulating immune complex-positive hepatic patients. Anti-beta 2m antibody occurred in one-third of chronic hepatitis, but only in one out of 13 cases in cirrhosis and in 12 out of nineteen patients with SLE. The results suggest that beta 2m and anti-beta 2m as in SLE may be further laboratory indicators of immunological activity in inflammatory hepatic disease.

Antibodies, Antinuclear↗
PubMed1985

Effect of H1 and H2 agonists on the chemiluminescence of human blood mononuclear cells induced by phytohaemagglutinin.

Previous results have shown a dose-dependent inhibition of the phytohaemagglutinin-elicited chemiluminescent response by histamine on human peripheral blood mononuclear cells (PBMs). The aim of the present experiments was to investigate the receptor specificity of this histamine action. The order of effectiveness of different histaminergic agonists was 4-methylhistamine greater than histamine = impromidine greater than dimaprit much greater than 2-methylhistamine greater than 2-pyridylethylamine. Cimetidine inhibited and mepyramine enhanced this effect of histaminergic agonists. The results are consistent with the view that histamine inhibits the chemiluminescent reaction of PBMs via H2 receptors. Histamine in low doses (10(-8) to 10(-10) M) stimulated the chemiluminescent reaction. Cimetidine enhanced the chemiluminescence-facilitatory action of histamine and unmasked that of 2-pyridylethylamine. It is concluded that histamine is a possible humoral modulator of PBM activity: it is inhibitory via H2 receptors.

Cimetidine↗
PubMed1985

Autoimmunity and normal immune functions in aged humans.

The high frequency of ANA, A-LDL and RF in advanced age suggests that AABs are present in the majority of aged subjects. CIC incidence determined by three methods is far below AAB incidence; only the Clq solubility test suggests an increased CIC incidence in aged as compared to young subjects. Simultaneous occurrence of AABs of different specificities or CIC determined by two or three methods is rare and both AAB and CIC levels are usually low. AAB prevalence in CIC-positive individuals seems to depend on the specificity of the AAB. CIC positivity is associated with relatively low Clq concentrations; however, usually not with Clq concentrations below the normal range. Neither ANA nor CIC positivity seems to correlate with DNA synthetic response to PHA, but ANA positivity may be associated with low responses to allogeneic cells. ANA positivity and, to a lesser extent, CIC positivity seems to be connected with enhanced killer cell activity. The concept of some AABs and CIC as autoregulatory factors of the humoral immune system compensating for the thymus-dependent regulation in old age is stressed.

Aged↗
PubMed1985

Induction of human rheumatoid factor and other autoantibodies by bacterial lipopolysaccharide.

In vitro autoantibody production induced by lipopolysaccharide (LPS) was studied using peripheral blood mononuclear (PBM) cell suspensions from patients with rheumatoid arthritis (RA) and healthy subjects. PBMs from both groups could be induced by LPS to secrete IgM and IgA rheumatoid factors (RF), antinuclear and anti-beta-2-microglobulin autoantibodies. Spontaneous production of IgM-RF was considerably higher in RA than in controls. The rate of IgM-RF and IgA-RF secretion detected by ELISA increased with the dose of LPS in cultures of both groups. In RA, differences were found between the kinetics of IgM- and IgA-RFs secretion. LPS augmented the relative avidity of IgM-RF produced by PBMs from RA patients and this value was significantly higher than that of healthy persons. In some cases RFs cross-reacting with nuclear antigens and beta-2-microglobulin were detected.

Antibodies, Antinuclear↗
PubMed1984

Appearance of covalently bound antigen in immune complexes formed during the activation of complement.

The effects of complement activation on the antigenic component of immune complexes have been studied, using 125I-BSA-rabbit anti-BSA-IgG complexes as models. Polyethylene glycol precipitates of 4 types of IC (those formed in native normal human serum, or NHS-containing EDTA, NHS-EDTA, and preformed soluble IC incubated in NHS or NHS-EDTA immediately after preparation) were analysed by sodium dodecyl sulphate-polyacrylamide slab gel electrophoresis. A characteristic difference in the distribution of 125I-BSA in the gel was observed between the NHS- and NHS-EDTA-treated samples. With the former type of IC, a significant part (16-23%) of the label was found in gel fractions of mol. wt. exceeding that of the antigen (80-300 kDa vs. 69 kDa), whereas with NHS-EDTA-treated IC only a minimal amount (4-5%) of the radioactivity was detected in these fractions. These findings indicate that complement activation results in the covalent binding of complement to the antigenic component of IC. The practical importance of these observations is discussed. In addition, a marked difference in precipitability was observed between IC formed in NHS and preformed IC incubated in NHS.

Antigen-Antibody Complex↗
PubMed1984

Antibodies to primate retrovirus antigens in circulating immune complexes of patients with acute myeloid leukemia.

Circulating immune complexes were isolated from sera of 8 patients with acute myeloid leukemia (AML) in relapse, and 20 healthy blood donors. F(ab')2 fragments were prepared from the isolated complexes. Using a radioimmunoassay (RIA), these F(ab')2 fragments, the undigested complexes and the original sera were examined for the presence of antibodies against a panel of primate retrovirus antigens: gp70, p15 and p30 of gibbon ape leukemia virus (GaLV) and baboon endogenous virus (BaEV). F(ab')2 fragments derived from the immune complexes of all patients reacted with one or more of the antigens tested, whereas no antibody activity was found in the sera or undigested immune complexes of the same patients. By a competitive RIA, antigens related to GaLV and/or BaEV were found in the serum of 7 out of 8 patients. No markers of these retroviruses were detected in the F(ab')2 preparations, in immune complexes or in sera of any of the 20 control subjects. Our results indicate that a part of the circulating immune complexes in AML contain antigens related to primate retroviruses and specific antibodies to these antigens.

Adult↗
PubMed1984

IgE class immune complexes in Felty's syndrome: characterisation of antibody activities in isolated complexes.

By means of a double polyethylene glycol (PEG) precipitation and PRIST technique IgE was detected in 3% PEG precipitates and in the immune complex enriched fractions purified by solid-phase Clq adsorption from sera of 11 of 20 patients with Felty's syndrome. No correlation was found between the occurrence of complexed IgE and total protein content of the immune complex enriched material. IgE rheumatoid factor and anti-IgE antibody activity were detected in some of the immune complex fractions. Serum levels of complement C3, C4, and factor B were low in IgE immune complex positive cases. Only 4 of 20 patients with articular rheumatoid arthritis had IgE-containing immune complexes.

Aged↗
PubMed1983

Precipitability and composition of HBsAg-anti-HBs immune complexes formed in the presence of complement. A model of circulating immune complex analysis.

Immune complexes (IC) of partially purified HBsAg and human anti-HBs were prepared at different antigen/antibody ratios in the presence of complement in normal human serum (NHS), and under conditions not allowing complement activation in buffers or in NHS containing 10 mM EDTA (NHS-EDTA). Commercial preparations of the radiolabelled antigen and antibody were used. IC formed in NHS were not significantly precipitated even after incubation for 24 h at 4 degrees C, whereas a typical precipitation curve was observed with complexes formed in the absence of complement. Thus, complement activation was found to markedly and permanently inhibit precipitability of HBsAg-anti-HBs immune complexes (HBsAg-IC). HBsAg-IC were precipitated from sera with 3.5% polyethylene glycol (PEG), boiled in sodium dodecyl sulphate (SDS)-urea buffer, and analysed by SDS-polyacrylamide slab gel electrophoresis (SDS-PAGE). With complexes formed in the presence of complement, about one-sixth of the antibody activity was found in high molecular weight fractions corresponding in size to IgG oligomers. By contrast, with complexes formed without complement, no significant amount of antibody was found in these fractions. With blotting technique and radiolabelled anti-human-C3 antibody, it was demonstrated that anti-HBs was covalently bound to C3b fragments in IC formed in the presence of complement and was in the high molecular weight fractions.

Animals↗
PubMed1983

High serum beta-2-microglobulin levels and circulating immune complexes containing beta 2m and anti-beta 2m antibodies in Felty's syndrome.

Serum beta-2-microglobulin (beta 2m) levels, incidence and levels of anti-beta 2m autoantibodies, and quantity of circulating macromolecular complexes containing beta 2m were studied in patients with Felty's syndrome (FS), joint-restricted rheumatoid arthritis (RA), and healthy controls. The serum beta 2m concentrations detected in the FS group (6.95 +/- 2.9 mg/liter) greatly exceeded those of the RA group (3.4 +/- 1.2 mg/liter) and the control group (1.42 +/- 0.69 mg/liter). Autoantibodies to beta 2m were frequent in the FS group. Circulating complexes containing beta 2m, prepared by precipitation in 3% polyethylene glycol, were detected in 65% of FS and 35% of RA patients. In the majority of these cases the solid-phase C1q purified immune complexes also contained beta 2m. Detection of anti-beta 2m antibodies in a significant part of complexes containing beta 2m suggests the presence of specific immune complexes in this fraction of FS and RA patients.

Antibodies↗
PubMed1983

Chemiluminescence response of human blood mononuclear cells to PHA and histamine.

Phytohaemagglutinin (PHA) elicited a short early chemiluminescence (CL) response of human blood mononuclear cells with a maximum at 2.5 min. The magnitude of the CL production was a function of the PHA concentration used. The CL response could be dose-dependently inhibited by histamine. In the presence of mepyramine the action of histamine was more pronounced while a dose-dependent reversal of the inhibition was found by cimetidine.

Cimetidine↗
PubMed1983

Partial characterization of circulating macromolecular beta 2-microglobulin complexes by density gradient ultracentrifugation and page-blotting.

beta 2-microglobulin (beta 2m)-containing, rapidly sedimenting peaks were seen when sera of patients with 3% polyethylene glycol (PEG)-insoluble beta 2m were fractionated by sucrose density gradient ultracentrifugation. No such material was found in serum of a healthy volunteer without 3% PEG-insoluble beta 2m. MW of beta 2m-containing high molecular weight fractions ranged from 1.6 X 10(5) to 2.1 X 10(6). When some fractions were recentrifuged a majority of beta 2m was recovered at the original sedimentation position. Analysis of high molecular weight beta 2m-containing peaks by SDS-PAGE followed by electroblotting revealed only monomeric beta 2m indicating that beta 2m was not covalently bound in the high molecular weight material.

Antigen-Antibody Complex↗
PubMed1983

Clinical correlates of circulating immune complex levels in advanced lung cancer. A discrimination analysis.

Sera from 53 patients with unresectable lung cancer were tested for the presence of immune complexes by 12 assays. 5 assays (EA rosette inhibition, ADCC inhibition, platelet aggregation, IgG and C3 concentrations in PEG precipitates) could discriminate cancer patients from healthy subjects with over 80% reliability. On the basis of 3 assays (EA-I, ADCC-I and PEG-C3) a function allowing a 100% correct classification could be formulated:--(EA-I)--0.5 (ADCC-I) + 2.4 (PEG-C3) greater than 69.3, i.e., results higher than 69.3 are characteristic for cancer patients and lower than 69.3 for normal subjects. The relationship between the immune complex levels and the average survival time was not altered by sex, age, histology and treatment. None of the immune complex assays or their combination were useful for the estimation of individual life expectation.

Adult↗
PubMed1983

High incidence of beta-2-microglobulin containing macromolecular complexes in sarcoidosis sera.

In thirteen out of fourteen sarcoidosis patients with elevated serum levels of immune complexes beta-2-microglobulin (beta 2m) was detected in immune complex-enriched fractions prepared by precipitation with 3% polyethylene glycol. Beta-2-microglobulin was also contained in complexes isolated by means of solid-phase Clq. The levels of free beta 2m in sarcoidosis sera did not differ from the concentrations in sera from healthy donors.

Adult↗