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Biomedical subjects

A Cats

Publications and source records attributed to A Cats.

At least 109 records · Page 6Linked to original sources
PubMed1987

Elastase and collagenase activities in synovial fluid of patients with arthritis.

The activity of elastase and collagenase was measured in the synovial fluid (SF) of 24 patients with inflammatory and 6 patients with traumatic joint effusions. The enzyme activity was compared with local and systemic variables of the disease. Elastase and collagenase activity could be detected in 79 and 83%, respectively, of the arthritic SF, whereas no enzyme activity was found in the traumatic joint effusions. The SF enzyme activity showed no correlation with clinical, laboratory or radiographic variables of arthritis in the joint from which the fluid was obtained. Our results show that proteolytic enzyme activity in SF may help to distinguish inflammatory from noninflammatory joint effusions but does not reflect the severity of the arthritic process.

Arthritis↗
PubMed1987

Factors influencing the incidence of infections in Felty's syndrome.

To identify clinical and laboratory risk factors for the susceptibility to infections in Felty's syndrome, 46 patients were studied prospectively during a total number of 431 periods of three months ("patient-quarters"). The incidence of infections increased significantly with polymorphonuclear leukocyte (PMN) counts below 0.1 X 10(3)/mm3 (less than 0.1 X 10(9)/L). At PMN levels over 0.1 X 10(3)/mm3 (greater than 0.1 X 10(9)/L), no association was found between PMN counts and the incidence of infections. Other factors found to be associated with an increased incidence of infections were severe disability, skin ulcers, glucocorticosteroid dose, monocyte counts, hypocomplementemia, and high levels of circulating immune complexes. The activity of the rheumatoid arthritis, erythrocyte sedimentation rate, hemoglobin concentrations, and lymphocyte counts were not associated with increased incidence of infections.

Arthritis, Rheumatoid↗
PubMed1987

Changing pattern of drug use in relation to disease duration of rheumatoid arthritis.

The prevalent use of antirheumatic drugs in a cohort of 311 middle aged female patients with seropositive and seronegative rheumatoid arthritis (RA) was investigated. Seropositive patients used a greater amount and more aggressive drugs during each decade of disease duration. The overall use of drugs decreased with disease duration, except for a subgroup of seropositive patients with RA who, with increased disease duration, used more aggressive drugs.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1987

Diminished uptake and degradation of soluble aggregates of IgG by monocytes of patients with rheumatoid arthritis and vasculitis.

We investigated the capacity of monocytes to degrade soluble aggregates of IgG in vitro in the absence (Fc receptor [FcR] mediated) and presence of complement (FcR and C3 receptor mediated). Adherent monocytes from 33 patients with active rheumatoid arthritis (RA) and rheumatoid vasculitis, 32 patients with inactive RA alone, and 20 healthy controls were incubated with 125I-aggregated IgG (125I-AIgG) of restricted size with or without fresh serum. Normal monocytes degraded 9.8% of 125I-AIgG via FcR alone and the presence of complement enhanced degradation to 2.7%. Degradation of 125I-AIgG via FcR from patients without active RA suggested a depressed function of FcR. The maximal amount of 125I-AIgG which was bound by monocytes from patients with inactive and active RA, however, was increased compared to normals, suggesting a defect in intracellular processing in patients with RA. The degradation of 125I-AIgG in the presence of complement was also significantly depressed for both groups of patients. The monocytes from the patients also had decreased numbers of C3b receptors (CR1). Since CR1 are involved in the enhanced uptake of immune complexes bearing complement, the depressed capacity of monocytes from patients with RA to degrade 125I-AIgG in vitro may be caused both by a diminished uptake as well as a diminished capacity to degrade soluble AIgG.

Adult↗
PubMed1986

Noncontraceptive hormones and rheumatoid arthritis in perimenopausal and postmenopausal women.

The use of noncontraceptive hormones before onset of joint disease was compared between 490 perimenopausal and postmenopausal women with rheumatoid arthritis and a control group of 659 women with soft-tissue rheumatologic disorders and/or osteoarthritis. Both groups were sampled randomly from the attendees of five rheumatologic clinics. A negative association was found between the onset of rheumatoid arthritis and the previous use of noncontraceptive hormones (odds ratio, 0.32; 95% confidence interval, 0.16 to 0.64). This association persisted on univariate and multivariate control of potentially confounding variables and on subgroup analysis. The protective effect of oral contraceptives on the development of rheumatoid arthritis was confirmed.

Arthritis, Rheumatoid↗
PubMed1986

Electronmicroscopical observations on monocyte-lymphocyte interactions upon stimulation with pokeweed mitogen latex conjugate.

In this study we report on the preparation and application of pokeweed mitogen (PWM) conjugated to latex particles. This conjugate (PWM-latex) was prepared by incubation of PWM with latex particles in the presence of glutaraldehyde. The effect of the addition of PWM-latex to human peripheral blood mononuclear cells (PBMC) was fully comparable to the addition of PWM alone i.e. differentiation of lymphocytes into blast cells followed by proliferation of these blast cells as measured by DNA synthesis and total cell number. Electronmicroscopically PWM-latex was found to be taken up by monocytes within the first 24 h after addition. Although no direct interaction could be observed between PWM-latex and lymphocytes, the latter were found to differentiate into blast cells. Due to interactions of these blast cells with latex-containing monocytes, latex particles were obviously released from the phagocytes and close contacts between latex particles and blast cells were regularly seen. In addition, it was found that blast cells of T cell origin, as judged by their positive reaction with anti-T cell monoclonal antibodies, had taken up latex particles. Based on enzyme-cytochemical, functional and light microscopical studies, monocytes could not be detected in the PWM-latex-driven PBMC stimulation after 6 days. At the electronmicroscopical level evidence was found that the inability to demonstrate macrophages could be due to the release of the lysosomal enzyme content and of parts of the cytoplasm.

Cell Communication↗
PubMed1986

Isolated lesions of the manubriosternal joint in patients with inflammatory back pain and negative sacroiliac and spinal radiographs.

The prevalence of radiological lesions of the manubriosternal joint was assessed in 151 patients with chronic inflammatory back pain and in 31 controls with non-inflammatory back pain. Nineteen out of these 151 patients and none of the controls showed unequivocal lesions of the manubriosternal joint without accompanying radiological lesions of the sacroiliac joints or the lumbar spine. Thoracic pain and stiffness were present in 7 out of the 19 patients and in 3 out of the 31 controls (P less than 0.05); peripheral enthesopathy was present in 10 out of the 19 patients and in 4 out of the 31 controls (P less than 0.01); none of the patients or controls had rheumatoid factor, subcutaneous nodules, or peripheral arthritis. The suggestion of a "manubriosternal joint syndrome" is warranted by these findings.

Adult↗
PubMed1986

Spontaneous immunoglobulin synthesis by peripheral mononuclear cells in active rheumatoid arthritis.

Spontaneous production of immunoglobulins (Igs) by peripheral blood mononuclear cells (PBMC) in vitro was investigated to assess B cell activity in a group of 24 patients with rheumatoid arthritis (RA) with or without active joint disease and with or without rheumatoid vasculitis (RV) at the time of study. PBMC of patients with active arthritis (Ritchie index above 16) produced significantly more IgG and IgA than those of patients with inactive joint disease or those of 12 healthy controls. Enhanced production of IgG was found mainly among RA patients with concomitant RV, whereas markedly enhanced IgA production could also be found in patients without symptoms of RV. IgM production was only enhanced in two patients who had both active arthritis and RV. High production of IgG and IgA was probably due to increased numbers of Ig-secreting cells among freshly isolated PBMC, since the concentrations of Ig produced in vitro rose steadily, starting on day 0 and persisting throughout the entire culture period. Moreover, IgG and IgA concentrations measured after 7 days of culture showed significant correlations with the numbers of IgG- and IgA-containing plasma cells in PBMC on day 0. Comparison of the spontaneous production of Igs by PBMC with the levels of circulating immune complexes (CIC), showed that CIC levels were also significantly higher in active arthritis and in RV, but that there was no correlation between the CIC levels in individual patients and Ig production by their PBMC in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigen-Antibody Complex↗
PubMed1986

A double-blind study on the effect of discontinuation of gold therapy in patients with rheumatoid arthritis.

To assess the benefit of further gold treatment of rheumatoid arthritis (RA) patients who had already received more than 6 g of this metal, 24 such patients were included in a double-blind trial. Besides this "gold group" comprising 11 patients who received gold (Auromyose) in the same dosage schedule as before the study, the trial included a "placebo group" comprising 13 patients who received gold in a suspension diluted 1/100. In either group clinical, laboratory, and radiological data did not differ after 6 and 24 months in relation to the results at entry except for the serum gold concentrations, which were lower in the placebo group. We conclude that discontinuation of the treatment in RA patients who have received more than 6 g gold is not harmful to the patients for at least two years after withdrawal.

Aged↗
PubMed1986

Blind confirmation in Leiden of Geczy factor on the cells of Dutch patients with ankylosing spondylitis.

A follow-up blind study, of the ability of "cross-reactive" antisera to distinguish between the cells of Dutch patients with ankylosing spondylitis (AS) and normal controls, was performed in Leiden. Of the 45 cell samples tested, 29 were fresh peripheral blood mononuclear (PBM) cells while 15 were cryopreserved PBM. No false positives but one false negative was identified among the 45 samples, and the "negative" was confirmed after the recoded cryopreserved cells from this patient were retested. It is concluded that the "cross-reactive" antisera raised in Sydney give good discrimination between patients and normals. Factors affecting the success of the 51Cr-release cytotoxicity assay, and possible reasons for the failure of others to confirm these observations, are briefly discussed.

Antigens, Surface↗
PubMed1986

Serum immune complexes containing IgA appear to predict erosive arthritis in a longitudinal study in rheumatoid arthritis.

Fifty seven patients with rheumatoid arthritis (RA) were studied longitudinally, and the presence of rheumatoid factor (RF) and various types of immune complexes (IC) was correlated with joint activity and the presence of extra-articular features (EAF). In a cross sectional study it was found that the levels of circulating IC and RF correlated significantly with joint disease activity and the presence of EAF. Longitudinally, levels of IC measured by the C1q binding activity and IC containing IgG and IgM correlated significantly with fluctuations in joint disease activity, whereas IC containing IgG and IgA correlated with the occurrence of EAF. RF and IC levels, however, did not predict the clinical course of the disease. IC containing C3 and C4 were found infrequently and were only present in patients with active rheumatoid vasculitis (RV). The continuous presence of these IC appeared to be linked to the recurrence of vasculitis, irrespective of treatment. Significantly more erosions of hands and feet were found after one year follow up in those RA patients who presented early (disease duration less than one year) who initially had a raised serum IgA IC level (r = 0.72; p less than 0.005).

Antigen-Antibody Complex↗
PubMed1986

Immunogenetic heterogeneity of rheumatoid arthritis.

Association of HLA-DR4/Dw4 with rheumatoid arthritis (RA) is well established, but conflicting data exist on a possible association with the severity of the disease, including its extra-articular manifestations. In order to investigate whether a subgroup of RA is preferentially associated with DR4, HLA typing was performed in two groups of patients with severe extra-articular manifestations (Felty's syndrome and histologically proved leucocytoclastic vasculitis), patients with severe joint destruction (seropositive and seronegative), a group with only mild joint destruction, and in healthy controls. The frequency of HLA-DR4 was significantly raised in all patient groups compared with that in healthy controls. The two groups with severe extra-articular manifestations, however, both had a DR4 frequency of 92%, which was significantly (p = 0.002) higher than the 62.7% found in the remaining patients. No significant differences were observed between severe or mild joint destruction and seropositivity or seronegativity in the groups without the above-mentioned extra-articular manifestations. From these data we concluded that DR4 is preferentially associated with severe extra-articular disease manifestations of RA. This observation provides an immunogenetic basis for the disease heterogeneity and for the immunological analogy between RA and leprosy.

Adult↗
PubMed1986

Immune complexes and the pathogenesis of neutropenia in Felty's syndrome.

The effect of the injection of serum from patients with rheumatoid arthritis (RA) and Felty's syndrome (FS) into mice on the number of circulating polymorphonuclear cells (PMN) was studied. The number of circulating PMN dropped to 61% (range 34-98%) of the initial counts after the injection of FS serum. This phenomenon was observed less frequently after injection of RA serum. In contrast, injection of serum from healthy controls always resulted in an immediate increase in the number of circulating PMN. No decrease in PMN counts was found after injection of FS sera pretreated with polyethylene glycol to precipitate immune complexes (IC). Gel filtration of FS sera on Sepharose 4B showed that the effect on the PMN counts in mice did not coincide with the 7S peak but occurred only in fractions containing larger material. Serum fractions from FS patients that contained IC were more active in producing neutropenia than the corresponding fractions from patients with RA. Microscopic and immunohistochemical examination of the organs from mice injected with FS serum showed sequestration of PMN and deposition of human IgG, IgA, and IgM in the vascular bed of the lungs. These results indicate that the interaction between PMN and IC of patients with FS leads to sequestration of PMN in mice and suggests that this interaction in humans may have a role in the pathogenesis of FS.

Aged↗
PubMed1986

Cyclosporin treatment for rheumatoid arthritis: a placebo controlled, double blind, multicentre study.

The efficacy and safety of cyclosporin for patients with rheumatoid arthritis (RA) were assessed in a six month double blind, placebo controlled, multicentre study. The initial dosage of the drug was 10 mg/kg daily for two months. There were many discontinuations in both the cyclosporin group (eight out of 17) and the placebo group (six out of 19). Of the patients who completed the six months of therapy, those who had received cyclosporin showed a significant improvement in the number of swollen joints, the Ritchie articular index, and pain at active movement and at rest, compared not only with their condition at the start of the study, but also with the end results of the placebo group. Major adverse reactions to the drug were gastrointestinal disturbances and nephrotoxicity, which were probably due to the relatively high dosages of cyclosporin given in combination with non-steroidal anti-inflammatory drugs.

Adult↗
PubMed1986

Genetic heterogeneity of rheumatoid arthritis.

In a population survey in The Netherlands we investigated 6584 individuals for the presence of rheumatoid diseases and their determinants. We observed no overall association of rheumatoid arthritis (RA) with HLA-DR4 or GM. This result is in contrast to the marked association of HLA-DR4 with RA found in studies based mainly on hospital rheumatology clinics. The findings thus suggest a genetic basis for the disease heterogeneity. A study of 16 multicase RA families showed a co-segregation of RA with the DR4 carrying haplotype from the unaffected parent, whereas the non-DR4 haplotype was preferentially segregating to the healthy siblings (p = 0.001). These data suggest that HLA-DR4 is associated with disease susceptibility rather than with a disease modifying factor. In a further attempt to define a genetic basis for disease heterogeneity we compared five well-defined clinical groups of patients with RA. Although the frequency of HLA-DR4 was significantly elevated in all patient groups as compared to healthy controls, we observed a preferential association of HLA-DR4 with severe extra-articular manifestations as compared to patients without extra-articular manifestations (p = 0.002). These results provide an immunogenetical basis for the disease heterogeneity observed in RA and further extend the immunological analogy between RA and leprosy.

Arthritis, Rheumatoid↗