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Biomedical subjects

A Cats

Publications and source records attributed to A Cats.

At least 163 records · Page 9Linked to original sources
PubMed1983

The significance of immunofluorescent immunoglobulin inclusions in polymorphonuclear leucocytes for the detection of circulating immune complexes.

Cytoplasmic inclusions of immunoglobulins and complement, detected by fluorescent antibodies in polymorphonuclear leucocytes (PMNs) that have been incubated with sera of certain patients, are considered to represent immune complexes (IC). The usefulness of this test--the indirect PMN phagocytosis test (IPPT)--for the detection of circulating IC was investigated using preparations of free and heat-aggregated immunoglobulins. Free IgG and IgM were phagocytozed by PMNs at high concentrations only, while free IgA was not phagocytozed at all. Normal human serum slightly enhanced the uptake of free IgG and IgM, but not of free IgA. Aggregates of IgG and IgA underwent phagocytosis at low concentrations, but IgM aggregates were not taken up more readily than free IgM. The uptake of IgG aggregates decreased in the presence of serum, while there was no influence upon the phagocytosis of IgA aggregates. Phagocytosis of C3 occurred only with IgG aggregates. In the presence of aggregates of IgG or IgA the phagocytosis of free immunoglobulins of other classes, in particular IgM, increased. The results of the IPPT for patients' sera showed that inclusions of C3 were found more frequently in combination with IgA or IgM than with IgG. Comparison with the 125I-Clq binding assay and the anti-IgA inhibition binding assay disclosed significant correlation between the phagocytosis of IgG and the precipitation of 125I-Clq and between the phagocytosis of IgA and the results of the anti-IgA inhibition binding assay. The PMN phagocytosis test may be useful for the detection of IgG and IgA containing IC but inclusion of IgM and C3 should be interpreted with some reserve.

Antigen-Antibody Complex↗
PubMed1983

The use of a peroxidase-anti-peroxidase complex for the visualization of monoclonal antibodies on the ultrastructural level.

Human peripheral blood mononuclear cell (PBMC) were treated with a panel of monoclonal antibodies (MoAbs) for the demonstration of membrane antigens at the ultrastructural level. The bound MoAbs were linked by rabbit anti-mouse IgG to a peroxidase-anti-peroxidase (PAP) complex composed of monoclonal mouse anti-peroxidase antibodies and horse radish peroxidase. This labelling method with a three step incubation procedure resulted in clear demonstration of the membrane antigens. Moreover, the use of the PAP complex as marker permitted the recognition of monocytes not only by morphology but also by their endogenous peroxidase pattern. In addition, it was observed that the MoAbs used, supposedly specific for T lymphocytes, reacted to a certain degree with monocytes.

Antibodies, Monoclonal↗
PubMed1983

Relative importance of C4 binding protein in the modulation of the classical pathway C3 convertase in patients with systemic lupus erythematosus.

Serum concentrations of C1q, C4, C4 binding protein (C4bp), C3 and C2 haemolytic activity have been measured in 110 samples from 20 patients with systemic lupus erythematosus (SLE). Significant reductions in comparison to normal levels were found in the mean serum concentrations of C4, C3 and C4bp as well as C2 haemolytic activities. For patients serum concentrations of C4 correlated with C2 haemolytic activities (r = 0.91) and C4bp (r = 0.79); the C2 haemolytic levels correlated with the concentration of C4b (r = 0.72). It is concluded that serum concentrations of the complement components C4 and C2, which are the constituents of the classical pathway C3 convertase, are regulated by C4bp in vivo. Further metabolic studies are required to determine the causes of decreased serum concentrations of C4bp in patients with SLE.

Carrier Proteins↗
PubMed1983

Morphometric analysis of peripheral blood and synovial fluid lymphocytes of patients with rheumatic disease.

A morphometric analysis of lymphocytes from the peripheral blood and the synovial fluid (SF) of patients with rheumatoid arthritis (RA) was based on a determination of the nuclear contour index (NCI = perimeter divided by the square root of the area of the nucleus). Use of this method showed that a particular type of lymphocyte, the cerebriform mononuclear cell (CMC), occurred in higher percentages in the SF than in the peripheral blood of patients with RA. The mean NCI of the lymphocytes (non-CMC) was also higher in the SF. These findings indicate that lymphocytes in the inflammatory compartment are morphologically altered, compared to the corresponding cells in the peripheral blood of the same patients, the change probably expressing an alteration in functional status.

Adult↗
PubMed1982

Oral contraceptives and rheumatoid arthritis: further evidence for a preventive effect.

To investigate a reported negative association between the use of oral contraceptives (OC) and the development of rheumatoid arthritis, a case-control study was undertaken to compare the histories of OC use between 228 women with a diagnosis of probable or definite rheumatoid arthritis and 302 women with the diagnosis of soft-tissue rheumatism and/or osteoarthritis. The use of OCs before the onset of joint complaints was acknowledged by 31.1% of the rheumatoid arthritis patients and by 55.6% of the controls. After adjustment for possible confounding variables, the rate ratio for ever use became 0.42 (95% confidence interval 0.27--0.65), while it was 0.40 (0.22-0.72) for ex-users and 0.45 (0.28-0.75) for current users. These findings confirm the finding from the Royal College of General Practitioners Oral Contraceptive Study that the incidence rate of rheumatoid arthritis among OC users was halved.

Adult↗
PubMed1982

In vitro effect of (3-amino-1-hydroxypropylidene)-1,1-bisphosphonic acid (APD) on the function of mononuclear phagocytes in lymphocyte proliferation.

The effect of (3-amino-1-hydroxypropylidene)-1,1-bisphosphonic acid (APD) on pokeweed mitogen-stimulated and non-stimulated cultures of peripheral blood mononuclear cells was studied in vitro. It is shown that APD can inhibit partially lymphocyte proliferation when added to a suspension of mononuclear cells before stimulation, but that lymphocyte proliferation can continue when the drug is withdrawn. In contrast; when APD is added to the cell suspension together with the mitogen, lymphocyte proliferation remains low even when the drug is withdrawn. Addition of different concentration of mononuclear phagocytes (MNP) to non-adherent cells, followed by stimulation in the presence of APD, indicates that APD acts on MNP function preferentially and does not affect lymphocyte proliferation.

Cell Division↗
PubMed1982

Autoantibodies against Tmu and B lymphocytes in patients with rheumatoid arthritis.

Patients with rheumatoid arthritis have decreased numbers of T mu lymphocytes in their peripheral blood. To find out whether these low number of T mu lymphocytes were associated with the presence of anti-lymphocyte antibodies, the sera of 27 patients with definite or classical rheumatoid arthritis (RA) were investigated for the presence of autoantibodies against subsets of lymphocytes. In addition the numbers of T, T mu, T gamma and B lymphocytes in the peripheral blood of these patients were investigated. Patients with active RA showed lower numbers of T mu lymphocytes in their peripheral blood than patients with inactive RA. However, both groups of RA patients had significantly decreased numbers of T mu lymphocytes in their peripheral blood as compared with 22 age matched healthy donors. Moreover, mainly in patients with active RA cold reactive antibodies were found directed against T mu and B lymphocytes, but never against T gamma lymphocytes of healthy donors. Similar results were found in the indirect immunofluorescence procedure when tested for reactivity against T-cell subsets. This serum reactivity was not caused by rheumatoid factors or antinuclear antibodies. Since RA sera after precipitation with 2.5% polyethyleneglycol, still showed cytotoxicity against T and B lymphocytes, it is suggested that this serum reactivity is not caused by immune complexes but by antibodies.

Adult↗
PubMed1982

In vitro monocyte-lymphocyte interaction influenced by d-penicillamine.

The in vitro effect of d-penicillamine (Pen) on human peripheral blood mononuclear cells (PBMC) was studied in relation to pokeweed mitogen (PWM) stimulation. Incubation of PBMC with Pen during or after PWM stimulation resulted in only a slight decrease in blast-cell formation. This effect was dependent on the concentration of Pen. Preincubation of PBMC with 100 micrograms Pen/ml medium for 10 days led to a toxic effect on lymphoid cells and selective survival of mononuclear phagocytes (MNP). Preincubation with 10 and 50 micrograms Pen/ml medium resulted in limited spontaneous blast-cell formation, which did not occur after preincubation with 100 micrograms Pen/ml and 5 micrograms Pen/ml. Despite the decrease in the total number of lymphocytes after 10 days of Pen preincubation, blast-cell formation on subsequent PWM stimulation in the absence of Pen was considerably enhanced compared to controls. The blast-cell formation was suppressed when PWM stimulation of Pen-preincubated PBMC was performed in the presence of Pen. This suppression of blast-cell formation under stimulation in the presence of Pen might explain the therapeutic effect of Pen.

Cell Survival↗
PubMed1981

Presence of immune complex-like material in sera of patients with paraproteinaemia.

Immunoglobulins of all classes as well as C3 are phagocytosed by normal human granulocytes from sera containing paraproteins. The material that was phagocytosed had the sedimentation properties of immune complexes. Cytostatic treatment did not seem to have a clearcut influence on the presence or absence of these complexes. There was little correlation with two other immune complex detecting tests. The Clq binding test was frequently found positive in paraproteinaemic sera but without apparent correlation to IgG phagocytosis. On the other hand the conglutinin binding test was rarely positive, although C3 was frequently phagocytosed.

Antigen-Antibody Complex↗
PubMed1980

A teflon culture and embedding device for the study of cells by light and electron microscopy.

A method is described which permits continuous light microscopic observation of cell cultures under sterile conditions. Moreover, cells or groups of cells selected in such cultures may be processed for electron microscopy, without disturbance of possible cellular interactions, in such a way that these selected cells may be observed in the electron microscope. The method is based on the use of a transparent Teflon film in culture chambers.

Cells, Cultured↗
PubMed1980

Gastrointestinal telangietasia as a cause of severe blood loss in systemic sclerosis.

Two patients with progressive scleroderma had severe gastrointestinal blood loss. Endoscopical examination revealed multiple telangiectase in the upper gastrointestinal tract, especially in the stomach. The telangiectases in the skin and the mucosa in systemic sclerosis are indistinguishable endoscopically and histologically from those seen in hereditary hemaorrhagic telangiectasia. Recurrent and severe gastrointestinal hemorrhage originating from telangiectases is an unusual complication of systemic sclerosis.

Female↗
PubMed1980

Membrane and transformation characteristics of lymphocytes isolated from the synovial membrane and paired peripheral blood of patients with rheumatoid arthritis.

Membrane and transformation characteristics of lymphocytes isolated from the synovial membrane and from paired peripheral blood samples, obtained from patients with classical rheumatoid arthritis, were studied. Synovial tissue lymphocytes were isolated by a new technique. Two suspensions of peripheral blood lymphocytes were studied: one isolated by Ficoll-Isopaque density gradient centrifugation, the other enriched in T cells by an additional step of 1 hour nylon wool column filtration. All suspensions were characterised by the percentages of mononuclear phagocytic cells, and T and B lymphocytes. The spontaneous (3)H-thymidine uptake of synovial tissue lymphocyte suspensions always exceeded that of the peripheral blood lymphocyte suspensions. The in-vitro responsiveness of synovial tissue lymphocytes to PHA, Con-A, and PWM, as measured by (3)H-thymidine uptake, was always consistently lower than that of paired peripheral blood lymphocytes whether or not enriched in T cells. The responsiveness to antigens, including PPD, varidase, and an antigen cocktail consisting of varidase, trychophyton, and Staphylococcus aureus antigen, showed the same effect. No dissociation was found between the response to PPD and the other antigens studied. These results suggest that the relative unresponsiveness to mitogens and antigens of synovial tissue lymphocytes in comparison with blood lymphocytes is not caused by mononuclear phagocyte contamination, but either by different subsets of T lymphocytes or by different functional states of T lymphocytes present in the synovial membrane and peripheral blood of patients with rheumatoid arthritis.

Antigens↗
PubMed1980

Stabilization of the classical pathway C3 convertase C42, by a factor F-42, isolated from serum of patients with systemic lupus erythematosus.

Sera from sixteen patients with SLE were investigated for the presence of a factor which would conserve convertase activity on preformed EAClgp 4hu2hu for 30 min at 30 degrees in EDTA. Although such a factor could not be detected readily in the sera, chromatography on DE-52 cellulose yielded fractions appearing as three peaks in one patient and as two peaks in a second patient. These peaks were capable of conserving C42 activity and were designated as F-42. Purification of F-42 from the second peak eluting between 4 and 7 mS on DE-52 was obtained by SP-C50, S-300 and QAE-A50 chromatography. F-42 exhibited charge heterogeneity upon SP-C50 chromatography. On polyacrylamide gel electrophoresis the final material migrated as one band, which coincided with the position of F-42 activity upon eluation from a parallel gel. F-42 had an apparent molecular weight of 150,000 and reacted with anti-IgG in Ouchterlony analysis. Sepharose-bound anti-IgG was capable of neutralizing F-42 activity. The purified material was shown to prolong the half-life (T 1/2) of performed cell-bound C42 in GVB-EDTA at 30 degrees from 5 to 80 min.

Antibodies↗
PubMed1980

Pokeweed-mitogen induced lymphocyte proliferation: the effect of stimulation on mononuclear phagocytic cells.

Human peripheral blood mononuclear cells were stimulated with pokeweed mitogen (PWM) to study the role of mononuclear phagocytic cells (MNP) in lymphocyte proliferation. MNP were identified by cytoplasmic alpha-naphthyl acetate esterase, by the capacity of phagocytosis and by lysozyme synthesis. It appeared that after 3 days of stimulation with PWM all MNP disappeared from the cultures and remained absent during prolonged culture in mitogen-free medium. In non-stimulated cultures MNP remained. The disappearance of MNP from cell cultures was caused by a lymphocyte-derived factor, which was transferable by cell-free supernatants of stimulated mononuclear cells. From experiments in which cultures were treated with different concentations of PWM and from pre-culture experiments, it could be shown that in vitro lymphocyte proliferation required both non-stimulated lymphocytes and freshly prepared MNP. In addition, the decreasing concentration of PWM as stimulating agent, resulted in a decreasing proliferation of lymphocytes, which was inversely proportional to the presence of MNP.

Cell Division↗
PubMed1979

The efficacy of intra-articularly administered MYC 2095, triamcinolone hexacetonide and placebo in gonarthritis. A combined double-blind clinical trial.

We report the results of a double-blind three-centre study, employing a cross-over design, set up to compare the efficacy of intra-articular injections of Myc 2095 (20 mg), triamcinolone hexacetonide (Lederspan) (20 mg) and placebo in 40 patients with synovitis of the knee joint. Each patient included in the study contributed data on 2 of the 3 treatment variables being compared. Seven clinical parameters were assessed every 6 weeks, while the doctor's and the patient's assessments were scored. Intra articular treatment both with Myc 2095 and triamcinolone hexacetonide proved to be effective. Placebo response was also very high. After the first Myc 2095 injection, improvement in "tenderness", "pain under load" and "swelling and hydrops" was significantly superior to that following placebo treatment. The evaluation of the second injections indicated a marked carry-over effect from the first course. This was also evident from the doctor's and patient's assessments. The importance of including a placebo in the evaluation of anti-phlogistic drugs in clinical trials, emerged from this study.

Adult↗