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Biomedical subjects

E C Keystone

Publications and source records attributed to E C Keystone.

At least 91 records · Page 5Linked to original sources
PubMed1981

Role of viable mycoplasmas in the pathogenesis of arthritis induced by M. pulmonis.

The role of viable M. pulmonis organism in the pathogenesis of both the acute and chronic phases of M. pulmonis-induced arthritis was examined. In the acute phase of the arthritis most clinically involved joints contained organisms and the degree of clinical arthritis in a given joint correlated with the number of organisms isolated. The more severe the acute arthritis, the more frequently the M. pulmonis organism was isolated from the joints during the chronic phase. In the chronic phase, arthritis defined histologically correlated with the presence of M. pulmonis organisms within a given joint. No correlation was observed between clinical arthritis during the chronic phase and histopathology or the presence of M. pulmonis organisms within the joint. In chronically infected mice, M. pulmonis was isolated from the joints only but not from the blood, liver, spleen, lung or kidney of any mouse examined. The results support the concept that viable organisms play an essential role in the pathogenesis of the acute and chronic phases of M. pulmonis-induced arthritis in mice.

Animals↗
PubMed1981

Enhanced resistance of mice to Mycoplasma pulmonis-induced arthritis by administration of killed Corynebacterium parvum.

Inoculation of mice with Corynebacterium parvum 14 days before intraperitoneal inoculation of Mycoplasma pulmonis resulted in arthritis of significantly lesser magnitude than in control mice as measured both clinically and histologically. Mycoplasmas were isolated from the joints of mice inoculated with C. parvum less frequently than from control mice when the arthritis was maximal. Mycoplasmas were also isolated in smaller numbers from the blood and joints of mice pretreated with C. parvum within 2 hr after M. pulmonis inoculation. Complement-fixing antibody to M. pulmonis did not account for the differences observed. C. parvum given during an established mycoplasmal infection, although capable of enhancing elimination of M. pulmonis from the joints of infected mice, had no effect upon the arthritis as measured clinically or histologically. The results provide evidence that immunomodulators such as C. parvum are capable of enhancing elimination of mycoplasmas from the joints of infected mice prior to or after the induction of arthritis.

Animals↗
PubMed1980

Impaired antigen-specific suppressor cell activity in patients with rheumatoid arthritis.

Antigen-specific suppressor cell activity of peripheral blood mononuclear cells was investigated in 20 patients with rheumatoid arthritis (RA) and 16 age- and sex-matched healthy controls. Suppressor cell activity was generated by priming peripheral blood mononuclear cells with high dose antigen (ovalbumin) and adding the washed primed or control (unprimed) cells to autologous, optimally stimulated, target plaque forming cell (PFC) cultures. The ability of the primed cells to interfere with an optimal ovalbumin specific PFC response in the target culture was used as a measure of antigen-specific suppressor cell activity. The results demonstrated that the mean (+/- SE) PFC response of the rheumatoid patients (669 +/- 76 PFC/10(6) cells) was not statistically different from that of the normal controls (722 +/- 83 PFC/10(6) cells), P = 0.1. However, reduced suppressor cell activity was observed in the rheumatoid patients relative to controls (46.4 +/- 4.2% versus 64.6 +/- 2.7% suppression, respectively; P < 0.001). No correlation was demonstrated between suppressor cell activity in rheumatoid patients and disease activity or therapy.

Adult↗
PubMed1980

Effect of T-cell deficiency on the chronicity of arthritis induced in mice by Mycoplasma pulmonis.

Mycoplasma pulmonis inoculated parenterally into athymic nude mice congenitally deficient in T cells caused a chronic arthritis of significantly greater magnitude than in immunologically normal mice. During the chronic phase of arthritis, M. pulmonis organisms were isolated from the joints and spleens of athymic nude mice more frequently and in larger numbers than from immunologically normal mice. The results support the concept that impaired T-cell function predisposes the mice to a severe degree of chronic arthritis as a result of their failure to eliminate the causative organisms.

Animals↗
PubMed1980

Polyarthritis due to Mycobacterium kansasii in a patient with rheumatoid arthritis.

A case of destructive polyarthritis due to infection by Mycobacterium kansasii is described in a 68-year-old patient with long-standing rheumatoid arthritis (RA) receiving prednisone and azathioprine therapy. Superimposed infection was suggested by positive Ziehl-Neelsen stains of synovial fluid from the patient's right shoulder and wrists, with confirmation on culture. Histological examination of synovium revealed abundant noncaseating granulomata within subsynovial cellular infiltrates. Treatment with triple antituberculous chemotherapy resulted in substantial extra-articular improvement within 3 months. However, articular destruction progressed unabated. A high index of suspicion is needed to diagnose joint infections in patients with underlying polyarthritis who are receiving immunosuppressive therapy. The progressive joint damage, despite periarticular resolution, may suggest the need for a combination of surgical synovectomy and antituberculous chemotherapy.

Aged↗
PubMed1980

Enhanced delayed hypersensitivity skin test reactivity with serial testing in healthy volunteers.

Delayed hypersensitivity skin testing with multiple antigens is frequently used to evaluate immunopotentiation therapy in man. Since serial skin testing with a single antigen has been shown to augment the skin test response, the present study was undertaken to assess the effect of serial delayed hypersensitivity skin testing on skin test reactivity with multiple antigens. Each of twelve healthy volunteers received 0.1 ml of five antigens on two occassion, 6 weeks apart. The antigens used were streptokinase-streptodornase, Candida, Trichophyton, mumps and Mycobacterium tuberculosis (PPD). The results demonstrated enhancement of skin test reactivity in the majority of tests. Indeed, 38.9% of the tests which were negative with the first skin test ( less than 10 mm induration) converted to positive. Enhancement in reactivity was observed in the majority of test subjects with all antigens except PPD. Similar enhanced skin test reactivity was observed in fifteen additional subjects tested serially with Candida only. The observations in this study suggest that uncontrolled studies of immunopotentiation must be interpreted with caution since serial delayed hypersensitivity skin testing with single or multiple antigens results in enhanced skin test reactivity.

Adult↗
PubMed1979

Serologically active clinically quiescent systemic lupus erythematosus: a discordance between clinical and serologic features.

The significance of abnormal serologic tests in systemic lupus erythematosus (SLE) in the absence of active clinical disease is unclear. In this report we describe a group of 14 patients with SLE in whom a discordance between clinical and serologic features was apparent. These patients had persistently positive lupus erythematosus preparations and antinuclear antibody tests, low serum complement levels and high levels of DNA binding. Their lymphocyte response to concanavalin A (Con A) mitogen was suppressed. They have been asymptomatic and have remained untreated for a mean of four and a quarter years.

Adult↗
PubMed1979

Leucapheresis in severe rheumatoid arthritis.

Two patients with severe seropositive rheumatoid arthritis previously unresponsive to conventional therapy have been treated with leucapheresis. This technique involves continuous cell separation daily to remove primarily lymphocytes. Clinical improvement was recorded with the use of standard rheumatological measures of inflammation. It is concluded that leucapheresis may help in the management of severely active rheumatoid arthritis when conventional therapy has been unsuccessful.

Adult↗
PubMed1978

Effects of lymecycline on Mycoplasma pulmonis-induced arthritis in mice.

The effect of lymecycline treatment on arthritis in C3H mice produced 5 months previously by i.v. inoculation of Mycoplasma pulmonis was examined. Treatment had little effect on the severity of the clinical disease. However, there was a marked reduction the severity of the histopathological inflammatory reaction in joints from lymecycline-treated mice when compared with untreated controls. This reduction was associated with eradication of viable mycoplasmas from the joints. The findings suggest that persistent arthritis in C3H mice is due to the continued presence of viable M. pulmonis organisms in the joint tissues.

Animals↗
PubMed1975

Inhibition of mitogen mediated lymphocyte blastogenesis by adenosine.

The effect of adenosine on the proliferative response of human peripheral circulating lymphocytes to stimulation by concanavalin A, phytohemagglutinin and pokeweed mitogen was evaluated. Increasing concentrations of adenosine substantially inhibited mitogen mediated lymphocyte blastogenesis. Erythro-9(2-hydroxyl-3-nonyl) adenine. HCl enhanced the inhibitory effect of adenosine. Inosine, the deamination product of adenosine, had an inhibitory effect which was less than that of adenosine. Inhibition by adenosine may be relevant to the normal regulation of immune function and may account in part for the pathophysiological relationship between severe combined immunodeficiency disease and adenosine deaminase deficiency.

Adenine↗
PubMedDate not supplied

Mixed leukocyte reaction in rheumatoid arthritis.

The mixed leukocyte reaction (MLR) responses of 29 patients with classic rheumatoid arthritis (RA) were compared with those of 24 age- and sex-matched healthy controls. Pools of stimulating cells were selected to include the major cross-reacting HL-A specificities. In pooled human serum the MLR response of the RA lymphocytes was significantly enhanced relative to the response controls (P less than 0.05). In autologous serum there was suppression of the MLR response in patients with RA which correlated with disease activity. The data suggest the presence of an intrinsically enhanced cellular reactivity of RA lymphocytes suppressed by serologic factor(s). The mechanisms of this enhancement of suppression are discussed.

Adult↗
PubMedDate not supplied

Zymosan-induced arthritis: a model of chronic proliferative arthritis following activation of the alternative pathway of complement.

Zymosan particles, which are able to activate complement by the alternative pathway and to induce enzyme secretion from macrophages, were injected into knee joints of mice. After various time intervals, synovia were assessed histologically for various markers of inflammation. Within 7 days after intraarticular injection of zymosan, a chronic inflammatory arthritis with mononuclear cell infiltration, synovial hypertrophy and pannus formation was observed. Latex particles, which do not activate complement or macrophages, produced only mild, transient inflammatory reactions.

Animals↗
PubMedDate not supplied

Malignant pyoderma.

A patient with malignant pyoderma brought into complete remission with immunosuppressive cyclophosphamide treatment after the failure of multiple other therapies is reported. The entity of malignant pyoderma with its clinical characteristics, laboratory and biopsy findings, complications, and modalities of therapy is reviewed.

Adult↗
PubMedDate not supplied

Antigen-specific suppressor cell activity in patients with scleroderma.

Antigen-specific suppressor cell activity (SCA) of peripheral blood mononuclear cells was investigated in 22 patients with scleroderma (PSS) and 22 age and sex matched healthy controls. SCA was induced by priming peripheral blood mononuclear cells with high dose antigen (ovalbumin). Antigen-specific SCA was measured by determining the ability of the primed cells to suppress an optimal ovalbumin specific plaque forming cell (PFC) response in an autologous target culture. The in vitro PFC response and suppressor cell activity of the PSS patients was not different from that of the normal controls. Antigen dose-response curves of the priming phase of the assay were similar in both the patient and control groups.

Adult↗