Biomedical subjects

R Brauer

Publications and source records attributed to R Brauer.

At least 19 recordsLinked to original sources

PubMed1996

Immunomodulation of rat antigen-induced arthritis by leflunomide alone and in combination with cyclosporin A.

The effects of the new immunomodulating isoxazol derivative leflunomide, in comparison with cyclosporin A, on established antigen-induced arthritis in rats as well as serum antibody levels were determined. When treatment with leflunomide, at concentrations from 2.5 to 10 mg/kg/d, was started on day 3 of arthritis, the acute and chronic phases of arthritis were effectively inhibited. This was demonstrated by decreased joint swelling and reduced histopathological arthritis score at the end of experiment (day 26). Furthermore, the treatment resulted in a significantly reduced level of serum antibodies to the matrix components collagen type I, type II and proteoglycans. Neither leflunomide nor cyclosporin A, at doses of 1 mg/kg/d, had an effect on the severity of arthritis and antibody levels. However, when both drugs were used together, at these non-effective doses, the histopathological score of chronic arthritis was significantly reduced. The results of our experiments demonstrate that leflunomide has a strong suppressive effect on both acute and chronic phases of antigen-induced arthritis and formation of autoantibodies in rats. Furthermore, orally administered doses of leflunomide were as effective as doses of cyclosporin A given intraperitoneally. The combination of sub-effective doses of leflunomide and cyclosporin A resulted in significant inhibition of chronic arthritis.

Animals↗

PubMed1991

On the inheritance of primary spontaneous pneumothorax.

We report on 15 families with familial primary spontaneous pneumothorax detected through a retrospective study of a large group of male patients. Genetic analysis of these families together with 14 families from the literature in which enough details were available suggested 2 possible models of inheritance. First, the familial cases are due to an autosomal dominant gene with incomplete penetrance, the penetrance being lower in females (21%) than in males (50%). Second, the familial cases represent a heterogeneous group of patients: some of the familial cases are due to an X-linked recessive gene and others to an autosomal dominant gene with the incomplete penetrance (35% in females and 50% in males). The second model may explain the excess of female carriers found in the families of the patients and is supported by the existence of clinical differences between the patients in each of the sub-groups. In particular the number of episodes of pneumothorax per patient was significantly higher in the sub-group with the autosomal dominant form than in the sub-group with the X-linked recessive form of the disease.

Female↗

PubMed1990

Direct evidence of a functional separation of alloreactive T lymphocytes from bystander cells infiltrating rat allografts. Interleukin 2 receptor-positive cells reacting with the monoclonal antibody ART 18 mediating second-set rejection.

In this study we examined the functional capacity of unseparated, IL-2R positive and IL-2R negative leukocytes infiltrating BN rat hearts or kidneys grafted into allogeneic LEW rats. Upon adoptive transfer into syngeneic LEW recipients, splenocytes or day-3 graft infiltrate cells of either cardiac or renal transplants were ineffective to alter BN cardiac test graft survival (controls 7.8 +/- 0.8 day). However, adoptive transfer of day-5 heart infiltrate cells resulted in a delay of test graft rejection (9.4 +/- 0.7 day, P less than 0.001), while day-5 kidney-graft-infiltrating cells produced second set rejection (6.2 +/- 0.5, P less than 0.001). Specificity controls of day-5 cells infiltrating DA heart or kidney grafts rejected at 7.8 +/- 0.8 or 7.7 +/- 0.5 days. Following separation into IL-2R positive and negative subpopulations by use of the mAB ART 18, IL-2R positive but not IL-2R negative cells caused second set rejection in both the renal and the cardiac model (6.2 +/- 0.4, respectively, 6.3 +/- 0.5 days, P less than 0.001 or P less than 0.005). Furthermore, in the kidney model IL-2R positive nylon-wool nonadherent cells also caused second set rejection (6.2 +/- 0.4, P less than 0.005) suggesting that IL-2R positive T cells present in the graft at maximal infiltration are the mediators of rejection. Thus, it appears that these cells can be phenotypically and functionally separated from bystander cells.

Animals↗

PubMed1989