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R Gottschalk

Publications and source records attributed to R Gottschalk.

At least 37 records · Page 2Linked to original sources
PubMed1997

Use of CTLA4-Ig in combination with conventional immunosuppressive agents to prolong allograft survival.

BACKGROUND: The objective of our study was to determine the effectiveness of CTLA4-Ig, a novel immunosuppressive agent, in augmenting allograft survival when combined with either cyclosporine, sirolimus, donor-specific bone marrow alone (BM), or bone marrow in conjunction with antilymphocyte serum (ALS). METHODS: Full-thickness skin allografts were used in C3H to B6AF1 (class I mismatch) and AKR to C57BL/6 (complete mismatch) models. Groups of mice (n=6-14) were treated with various combinations of the following treatment protocols: murine CTLA4-Ig, L-6 control Ig, sirolimus, cyclosporine, ALS, or ALS/BM. RESULTS: In the class I mismatch model, L-6 control Ig had no effect whereas use of CTLA4-Ig alone resulted in a doubling of the median graft survival compared with controls. The addition of either sirolimus or cyclosporine to CTLA4-Ig increased graft survival over that achieved with CTLA4-Ig alone. CTLA4-Ig demonstrated no efficacy when used in combination with BM, ALS, or ALS/BM. CTLA4-Ig was clearly less effective in the complete mismatch model. CONCLUSION: These data suggest that CTLA4-Ig may be effective clinically in combination with cyclosporine or sirolimus but offers no additional effectiveness in combination with antilymphocyte serum with or without donor-specific bone marrow.

Abatacept↗
PubMed1997

Superiority of sirolimus (rapamycin) over cyclosporine in augmenting allograft and xenograft survival in mice treated with antilymphocyte serum and donor-specific bone marrow.

BACKGROUND: Sirolimus is a potent immunosuppressive agent with great therapeutic potential. The objective of our study was to evaluate the efficacy of sirolimus versus cyclosporine in augmenting the unresponsiveness induced by an antilymphocyte serum (ALS)/donor-specific bone marrow (BM)-based regimen across three levels of histoincompatibility: class I and II disparate (DBA/2 to B6AF1), complete mismatch (AKR to C57BL/6), and xenograft (ACI rat to B6AF1). METHODS: Full-thickness skin grafts were taken from donors and placed on recipients in standard fashion. Seven groups of recipient mice (n=10-28) received various combinations of the following treatment protocols: sirolimus, 1.5 mg/kg (3.0 mg/kg for xenografts) every other day from day 0 to day 12; cyclosporine, 50 mg/kg every other day from day 10 through 22; ALS, 0.5 ml on days -1 and 2 for allografts and days -1, 2, and 4 for xenografts; and BM, 25 million donor-specific cells IV on day 7. RESULTS: The administration of ALS or ALS/BM resulted in modest but significant prolongation of skin graft survival in all combinations tested. Cyclosporine combined with ALS or ALS/BM significantly extended allograft survival compared with ALS or ALS/BM alone (P<0.05) but had no effect on xenograft survival. In contrast, the combination of sirolimus with ALS or ALS/BM resulted in a two- to threefold increase in allograft survival and over a fourfold increase in xenograft survival when compared with the comparable cyclosporine-based regimen. Additionally, lymphocytes isolated from class I and II incompatible mice with skin grafts surviving >100 days demonstrated markedly reduced interleukin 2 and interferon-gamma secretion in response to irradiated donor-specific lymphocytes in culture. CONCLUSIONS: In the regimens tested, sirolimus was superior to cyclosporine in augmenting donor BM-induced skin graft prolongation in ALS-treated mice across all levels of histoincompatibility.

Adjuvants, Immunologic↗
PubMed1996

PGG-glucan, a leukocyte-specific immunostimulant, does not potentiate GVHD or allograft rejection.

PGG-glucan is an immunomodulator which can enhance the host response to infection. Phase I/II clinical trials have documented the safety and potential efficacy of this compound to reduce postoperative infectious complications in high risk surgical patients. Organ transplant recipients may benefit from this drug due to their high rates of postoperative infectious complications. A rat cardiac rejection model (ACI --> Lew) and a mouse skin graft model (C3H/HeJ --> B6AF1/J) were used with four treatment arms (control, Cyclosporine A (CsA), antilymphocyte serum (ALS), and CsA + ALS with and without PGG-glucan). Small intestinal allografts (Lew --> LBNF1) were performed in rats to evaluate GVHD. In the mouse GVHD model, donor splenocytes were given to irradiated recipients (C57BL/6 --> B6AF1), with and without PGG-glucan treatment. There was no difference in survival between PGG-glucan treatment and placebo for the control, CsA, and CsA + ALS groups in rat cardiac recipients. Recipients receiving ALS and treated with PGG-glucan survived a median of 42.5 days versus 63.5 days for those ALS-treated animals not receiving PGG-glucan (P = 0.045). In the remaining groups there was no difference in survival between PGG-glucan-treated groups and the control groups. PGG-glucan did not shorten survival in three of four treatment groups in the rat cardiac rejection model. High dose ALS with PGG-glucan did result in a marginal decrease in survival in cardiac allograft recipients. If the one outlying animal with indefinite survival is excluded, the difference is not statistically significant (P = 0.098). These results show that even though PGG-glucan has immunostimulatory properties, it does not significantly potentiate rejection or GVHD in these animal models. This preliminary work may be important in determining whether PGG-glucan can be safely given to immunosuppressed organ transplant recipients to reduce postoperative infectious complications.

Adjuvants, Immunologic↗
PubMed1996

Increased pigmentation in scleroderma.

OBJECTIVE: Increased pigmentation is found in patients with scleroderma (systemic sclerosis, SSc) even in areas that have never clinically been involved with skin thickening. We wanted to determine if the pigmentation is due to subclinical sclerodermatous changes, or a systemic factor such as an increase in adrenocorticotropic hormone (ACTH). METHODS: To determine if clinically uninvolved skin that is pigmented differs from nonpigmented skin, skin biopsies were taken from patients with scleroderma from 2 different sites: (1) from pigmented but otherwise clinically normal skin, and (2) from nonpigmented clinically normal skin adjacent to the first site. Biopsies were examined by a dermatopathologist for evidence of dermal and epidermal changes. Cosyntropin stimulation tests were performed after baseline cortisol and ACTH samples were obtained. RESULTS: Six patients with diffuse SSc (dSSc) and 4 with limited SSc (ISSc) had skin biopsies. Patients with dSSc were more likely than those with ISSc to have increased pigmentation in uninvolved skin. Pigmented skin specimens had either a higher content of epidermal melanin and/or a more severe degree of pigmentary incontinence with a higher number of dermal melanophages in the superficial dermis. The cosyntropin stimulation tests were normal and there were no differences between subjects with diffuse and limited SSc or between those with and without increases in pigmentation. CONCLUSION: Clinically uninvolved skin in many of these patients with SSc was abnormal, and subtle changes of SSc were present, especially in the pigmented biopsies. There was no evidence of adrenal deficiency in these patients. It is difficult pathologically to differentiate the changes in pigmented compared to unpigmented skin in patients with SSc, except for changes of increased melanin and pigmentary incontinence.

Adrenocorticotropic Hormone↗
PubMed1995

Marked prolongation of rat skin xenografts induced by intrathymic injection of xenogeneic splenocytes and a short course of rapamycin in antilymphocyte serum-treated mice.

The effect of intrathymic (IT) injection of donor splenocytes and a short course of rapamycin (Rapa) treatment on rat to mouse skin xenograft survival was investigated. ACI rat skin xenografts were transplanted to (C57BL/6 x A)F1 mice treated with rabbit anti-mouse lymphocyte serum (ALS) on days -1, +2, and +4 relative to skin grafting on day 0. Fifty million donor-type splenocytes were injected intrathymically on day 7 after transplantation. Rapa was given intraperitoneally every other day from day 0 to day 12 at a dose of 3.0 mg/kg. Prolonged skin xenograft survival was observed in ALS- and Rapa-treated recipients (no IT injection) with a median survival time of 47 days. However, skin graft survival was markedly more prolonged in the group treated with ALS, Rapa, and IT injection of donor splenocytes did not have a beneficial effect on skin xenograft survival in ALS-treated recipients. An increased presence of donor-type cells was observed in the thymus of the ALS- and Rapa-treated recipients for 7 days after IT injection of donor splenocytes. In conclusion, a short course of Rapa markedly augments rat skin xenograft survival in ALS-treated mice injected intrathymically with donor-type splenocytes.

Animals↗
PubMed1995

Analysis of donor reactive cells in ALS-treated mice bearing skin allografts after the intrathymic injection of donor specific spleen cells.

The intrathymic injection of donor spleen cells into antilymphocyte serum (ALS)-treated mice induces significant prolongation of donor skin grafts. The intrathymic route of antigen presentation in this model is superior to the intravenous route in achieving unresponsiveness. To elucidate possible mechanisms involved in the induction of unresponsiveness in ALS-treated mice after intrathymic injection of donor spleen cells, we have analysed the reactivity of lymphoid cells from unresponsive mice in various ways. Deletion of donor reactive cells has been studied using the Mls antigen system. Functional inactivation was analysed by a sequential study of the frequency of donor reactive cells. Suppressor cell activity was studied using an adoptive transfer assay. Deletion of donor reactive cells was partial and occurred largely in the spleen in both early and late stages of unresponsiveness. The frequency of donor reactive cytotoxic cells was suppressed in both spleen and lymph nodes from day +/- 13 until grafts were rejected, with the exception of a rebound period at day +/- 22. In contrast, donor reactive cells were not deleted or inactivated in the thymus. Suppressor cell activity could only be detected in mice bearing long-term grafts. These results suggest that donor reactive cytotoxic cells are functionally inactivated in the spleen and nodes in the early and late stages of unresponsiveness after intrathymic injection of antigen. In contrast, donor reactive cells in the thymus do not appear to be affected.

Animals↗
PubMed1994

The evaluation of a cell dispersion method of sputum examination.

In recent studies, sputum smear cell counts were found to be reproducible and usefully applied to research in asthma and other airway conditions. However, cell definition on the smears is poor, and the procedure is tedious and has limited utility. The objective of this study is to improve the methods of sputum examination. The subjects used in this study were people with bronchitis or asthma from whom sputum could be obtained. By inverted microscopy, portions of fresh sputum were selected to exclude salivary contamination. These portions were exposed to different volumes of dithiothreitol for varied time intervals. We used the resulting cell suspensions to perform total cell counts and prepare cytospins for differential cell counts and immunohistochemical stains for GM-CSF, EG2, TNF alpha and IL-8. Cytospins were compared with smears for differential cell counts on the same sputum specimens. Excellent cell dispersion and definition in cytospins could be observed. The time required for differential cell counting on cytospins was reduced and cytospin counts were more reproducible than smears. Greater duration of treatment of sputum with dithiothreitol tended to increase total cell counts and significantly decreased EG2 staining but had no effect on differential cell counts or the cytokine cell components. Therefore the proposed method of sputum examination involving cell dispersion and use of cytospins overcomes a number of the disadvantages of the examination of smears.

Cell Count↗
PubMed1993

[Incidence of Lyme borreliosis in a rheumatologic patient sample. Study of 153 patients of an internal medicine-rheumatologic ambulatory clinic].

PROBLEM: Arthritis of the large joints is considered a typical manifestation of Lyme disease. With an estimated incidence in the population of about 2%, Lyme disease arthritis would be expected to be a fairly common diagnosis in a rheumatology unit. METHODS: In 153 successive patients seen in a rheumatology clinic of the University Hospital Frankfurt am Main, who had historical or clinical evidence of arthritis, the IgG antibody titers against Borrelia burgdorferi in the serum were compared with the clinical presentation. RESULTS: Twelve patients had positive or borderline positive antibodies titers. In three of the 153 patients, the diagnosis of Lyme disease-associated arthritis appears possible, although not probable. CONCLUSIONS: At least in the greater area of Frankfurt, Lyme disease as a differential diagnosis of arthritis is apparently of no great significance.

Adolescent↗
PubMed1992

The effect of injection of donor bone marrow on the frequency of donor-reactive CTL in antilymphocyte serum-treated, grafted mice.

The survival of C3H/He skin grafts can be prolonged on B6AF1 mice immunosuppressed with ALS by the injection of C3H/He marrow 1 week postgrafting. The precursor frequencies of donor-reactive CTL in the spleen and lymph nodes of ALS-treated, grafted mice given donor marrow were compared with CTL frequencies observed in ALS-treated, grafted controls. Spleens and nodes were removed from experimental and control mice on days +8, +14, +21, +58, and 1 year postgrafting, and used as effectors in the LDA. Donor-reactive CTL in the marrow-injected group remained suppressed as long as the recipients maintained their grafts. The frequency of CTL to third-party antigens was normal in mice bearing long-term C3H/He grafts. When marrow-injected mice rejected their grafts, the total donor-reactive CTL frequency returned to normal. In contrast, in ALS-treated controls that did not receive marrow, the total number of donor-reactive CTL returned to normal levels with recovery from the immunosuppressive effects of ALS. These results suggest that donor marrow suppresses the regeneration of donor-reactive CTL in the lymphoid tissues of ALS-treated mice, possibly by veto cell activity.

Animals↗
PubMed1991

[Serum level of beta-glucuronidase as potential indicator of disease activity in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE)].

The lysosomal enzyme beta-glucuronidase is involved in the degradation of glycosaminoglycans to monosaccharides. beta-glucuronidase-activity has been found to correlate well with histomorphological changes in active arthritis. By use of a new--enzyme kinetic--assay serum activity of beta-glucuronidase was measured in 32 patients with rheumatoid arthritis (RA) and 23 patients with systemic lupus erythematodes (sLE) and compared to 120 healthy volunteers. In 72% of the patients with RA and 65% of the patients with sLE increased beta-glucuronidase-activity was found (greater than 97.5. percentile of healthy volunteers). There was no correlation with an estimated score of disease activity, duration of morning stiffness, or blood sedimentation rate. The determination of beta-glucuronidase revealed increased serum levels in most of the patients with RA and sLE. The role of beta-glucuronidase as a predictor of joint destruction remains to be evaluated in a prospective study. For this evaluation the use of the enzyme-kinetic method described here is recommendable.

Adult↗
PubMed1991

Characterization of spleen cells capable of inducing unresponsiveness in ALS-treated mice.

C3H/He skin allografts are significantly prolonged in ALS-treated B6AF1 mice by the injection of 50 x 10(6) C3H/He spleen cells 1 week postgrafting. To identify and characterize the spleen cell active in promoting graft survival, C3H/He spleen cells were separated on a discontinuous Percoll gradient and the various fractions were assayed for the ability to prolong skin graft survival in ALS-treated B6AF1 mice. In addition, unfractionated spleen and spleen fractions were depleted of specific cell populations before injection to determine the effect of various cell populations on graft prolongation. The active cell was recovered primarily in the 52.5% Percoll fraction. Cells in the 60% fraction also had a graft-prolonging effect, but not as significant as that of the 52.5% fraction. Depletion of Thy 1, Ia and Ig-positive cells from unfractionated spleen or spleen fractions did not decrease the graft-prolonging effect. Both Fc gamma R-positive and Fc gamma R-negative cells prolonged graft survival, but the Fc gamma R- cells were the most effective. In contrast to the effect of spleen cells, lymph node cells and thymocytes are relatively ineffective in prolonging graft survival in ALS-treated mice. When lymph node lymphocytes and thymocytes were separated on a Percoll gradient, the cell population active in prolonging graft survival was recovered primarily in the 52.5% fraction. Treatment of the 52.5% fraction of lymph node lymphocytes or thymocytes with monoclonal antibody to Thy 1 before injection abrogated the graft-prolonging effect. These results indicate that the spleen cell(s) active in prolonging graft survival in ALS-treated mice is a non-T, non-B cell, as it lacks Thy 1, Ia, and Ig surface markers. Both Fc gamma R+ and Fc gamma R- spleen cells are effective in prolonging grafts, but Fc gamma R- cells are the most effective. In contrast, the active cell in lymph node and thymus is Thy 1-positive, indicating that it is a T lymphocyte.

Animals↗
PubMed1991

Effect of granulocyte-macrophage colony-stimulating factor on the induction of unresponsiveness by lymphoid cells.

Skin grafts can be significantly prolonged in ALS-treated mice by the injection of 25 x 10(6) donor bone marrow cells or 50 x 10(6) spleen cells. Lymph node cells and thymocytes are only minimally effective in prolonging grafts. The effect of a hematopoietic growth factor, granulocyte-macrophage colony stimulating factor (GM-CSF) was studied in this model of unresponsiveness. C3H/He lymphoid cell donors were treated with GM-CSF. Either normal or GM-CSF-treated cells were injected into ALS-treated B6AF1 mice grafted with C3H/He skin. GM-CSF treatment significantly augmented the effect of marrow in prolonging graft survival at doses of 1 to 25 x 10(6) cells. In contrast, GM-CSF had no effect on the graft-prolonging effect of spleen cells when 50 x 10(6) cells were given. When the dose of cells was reduced to 25 x 10(6), graft survival in the group given GM-CSF-treated cells was prolonged compared with survival in the group given normal cells. Grafts in the group given GM-CSF-treated lymph node cells were rejected in sensitized fashion. When marrow and spleen are separated on a Percoll gradient, the cell active in promoting graft survival is recovered primarily in the 52.5% fraction. The graft-prolonging effect of the 52.5% marrow fraction was not affected by GM-CSF treatment. In contrast, GM-CSF-treated marrow cells in the 60% fraction significantly prolonged graft survival, while normal marrow cells in this fraction had no effect on graft survival. GM-CSF-treated spleen cells in the 52.5% and 60% fractions significantly decreased graft survival compared with normal cells when given at a dose equal to the number of cells recovered from 50 x 10(6) cells. When the dose of fractionated spleen cells was reduced, GM-CSF-treated spleen cells were more effective than normal cells in prolonging graft survival. These results indicate that GM-CSF activates a cell in marrow that promotes graft survival. This cell is recovered in the 60% Percoll fraction. In contrast, GM-CSF appears to affect two cell populations in spleen, one beneficial and one detrimental to graft survival. The predominant effect depends on the dose of spleen cells that is given.

Animals↗