Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lethally irradiated Lewis (LEW) rats, reconstituted with syngeneic bone marrow and next given Cyclosporin A (CyA) for several weeks, develop disease (Cyclosporin A-induced autoimmunity; CyA-AI) after withdrawal of CyA. This disease resembles in terms of dermal changes the acute dermatitis and chronic scleroderma also seen in graft-versus-host disease (GVHD). In this study we report the relative resistance of the Brown Norway (BN) rat strain to the induction of CyA-AI. In contrast to LEW rats, in which CyA-AI was originally described, BN rats showed no acute dermatitis or scleroderma-like skin pathology in spite of comparable changes in the thymus and a maturation arrest of CD4+ T cells. The difference was also demonstrated functionally for whereas in LEW rats delayed-type hypersensitivity (DTH) reactions could not be elicited during CyA-AI, these were within normal limits in BN rats subjected to the same protocol; NK activity on the other hand was unaffected in both strains. The observation that BN rats developed very mild late disease as evidenced by a slight though significant weight loss suggests that the BN strain is susceptible to the disease but that lesser effector cell generation or, alternatively, stronger suppressor cell responses may prevent dermal disease. These observations may contribute to the elucidation of the mechanisms involved in this experimental autoimmune disease.
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PMID:Susceptibility and resistance to cyclosporin A-induced autoimmunity in rats. 813 64

The recent success in controlling acute rejection in clinical small bowel transplantation has resulted in a number of patients with functioning grafts and an occasional occurrence of graft-versus-host disease (GVHD). To better understand this complication following small bowel transplantation, a model of chronic GVHD was developed, using the Brown Norway-->Lewis rat strain combination. When the Lewis recipients were immunocompromised at the time of transplantation and received a graft specifically sensitized against Lewis, fatal GVHD developed in 3 of 5 animals. Serial histologic evaluation and determination of donor major histocompatibility complex (MHC) class I antigens were used to delineate the course of GVHD. Although the histologic results were inconsistent, with the exception of the animals developing fatal GVHD, the detection of donor MHC antigens correlated well with the development of GVHD. Determination of donor MHC class I antigens may serve as useful indicators for the development of GVHD.
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PMID:Induction of chronic graft-versus-host disease in a rat model after transplantation of sensitized small bowel allografts. 820 32

The small bowel (SB), an organ replete with lymphocytes, may provoke graft-versus-host disease (GVHD) after transplantation (Tx). Since tumor necrosis factor (TNF) has been suspected of mediating the tissue lesions of GVHD, we sought to determine whether TNF could be detected in the serum of rats undergoing GVHD after SBTx or lymphocyte transfer. For this purpose, postoperative serum TNF activity was determined in Lewis x Brown Norway (LBNF1) hybrid rats suffering from GVHD after undergoing transplantation of an entire (group 1; n = 8) or a segmental (group 2; n = 4) Lew SB, or after i.p. injection with lethal doses (500 x 10(6)) of Lew lymphocytes (group 3; n = 3). Control LBNF1 received i.p. small doses (50 x 10(6)) of Lew lymphocytes (group 4; n = 4). Serum TNF activity was assessed using the WEHI bioassay. In rats with acute and lethal GVHD after entire SBTx (group 1) or injection with large doses of lymphocytes (group 3), TNF activity gradually increased and reached high levels by the time the rats were agonal. In segmental SBTx rats (group 2), GVHD was less severe than in entire SBTx rats. Similarly, the increase in TNF activity was less intense and only transient since it had returned to control levels by the time the rats had completely recovered from GVHD. In control rats primed with small doses of lymphocytes (group 4), GVHD did not occur and no increase in TNF activity was detected.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Relevance of tumor necrosis factor to graft-versus-host disease after small bowel transplantation. 821 1

In the present experiments, a multimodality regimen was developed that included an anti-T cell receptor R73 monoclonal antibody and the pharmacologic agents brequinar (BQR), cyclosporine (CsA), and sirolimus (rapamycin; RAPA) to prolong the survival of small bowel (SB) allografts. BQR was the most potent single drug: the 4.0 or 8.0 mg/kg/day BQR doses delivered every second day (q.o.d.) per gavage for 28 days prolonged the survival of Brown Norway (BN; RT1n) SB allografts in Lewis (LEW; RT1l) recipients from a mean survival time of 10.6 +/- 1.9 days in untreated controls to 29.2 +/- 5.8 days, respectively (both P < 0.001). When treatment was extended to 56 days, 8.0 mg/kg/q.o.d BQR produced a mean survival time of 83.8 +/0 33.8 days (P < 0.001), with 2/5 hosts surviving more than 100 days. In a host-versus-graft model, BQR (8.0 mg/kg/q.o.d) delivered for 28 days with CsA (2.0 mg/kg/day) and RAPA (0.04 mg/kg/day) delivered intravenously for 14 days prolonged the survival of BN SB grafts in LEW recipients to 54.4 +/- 21.0 days (P < 0.001). Extending triple-drug therapy to 42 days induced the prolongation of SB allograft survival to greater than 100 days in 5/7 recipients. Although pretransplant perfusion of the grafts with R73 mAb was ineffective alone, the combination of graft perfusion and a 28-day course of BQR (8.0 mg/kg/q.o.d) in the GVH model indefinitely prolonged LEW graft in F1 recipients. Alternatively, indefinite survival of SB allografts ( > 100 days; P < 0.001) was achieved by the combination of a 14-day course of a triple-drug regimen using each agent at subtherapeutic doses, namely BQR (2.0 mg/kg/q.o.d.), CsA (2.0 mg/kg/day), and RAPA (0.04 mg/kg/day). The state of transplantation tolerance is these hosts was documented by the acceptance of donor-type but not third-party heart allografts.
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PMID:Beneficial effect of graft perfusion with anti-T cell receptor monoclonal antibodies on survival of small bowel allografts in rat recipients treated with brequinar alone or in combination with cyclosporine and sirolimus. 861 Mar 61

Interstitial lung disease (ILD) after allogeneic bone marrow transplantation (BMTx) is an important clinical problem in terms of diagnosis, therapy, and pathogenesis. Graft-versus-host disease (GvHD) and cytomegalovirus (CMV) infection seem to be major risk factors for ILD, but their role in the pathogenesis is not well established. We previously reported CMV-induced ILD in allogeneic bone marrow recipient rats, which was prevented by antiviral drug treatment. In this paper, we describe the pathology of ILD in allogeneic bone marrow transplant recipient rats and the relation of ILD with CMV infection and GvHD. Brown Norway rats received an allogeneic (Lewis) BMTx and rat CMV infection, after an allogeneic (Lewis) lung transplantation and immunosuppression. CMV infection was recorded by the amount of infectious virus and viral antigens in the lung. ILD was monitored by the presence of diffuse histopathologic changes in the alveolar septal wall. GvHD was scored by the relative splenic weights and the presence of perivascular infiltrates in the lung. Cells expressing CMV antigens were more numerous in the alveolar septa of the allogeneic recipient lungs than in the syngeneic donor lungs (p < 0.05). The high viral load in the recipient lung of allogeneic BMTx recipient rats was accompanied by diffuse ILD, marked by extensive microvascular damage and congestion of the alveolar septa. ILD was observed neither in the syngeneic donor lung nor in both lungs of mock-infected animals. GvHD was not observed in rat-CMV-infected or in mock-infected animals. Our results indicate that CMV induces microvascular damage, resulting in ILD. This process is independent of GvHD.
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PMID:Cytomegalovirus induces interstitial lung disease in allogeneic bone marrow transplant recipient rats independent of acute graft-versus-host response. 878 Jan 54

To facilitate recognition of the oral mucosal lesion that develops in rats with graft-versus-host disease (GVHD) induced by injecting spleen cells of parental strain rats (Brown Norway) into non-irradiated (Brown Norway x Lewis) F1 hybrid rats, we followed the development of the tongue lesion histologically and immunohistochemically. This assessment revealed an increase in the number of MHC class II+ cells with dendritic shape in the lamina propria to be the earliest stage of the tongue lesions in GVHD rats. The subsequent mononuclear cell infiltration with epithelial cell destruction, characteristic of GVHD, consisted of CD8+ cells and macrophages. Our findings seem to indicate that MHC class II+ cells with dendritic shape may provide antigen presentation in the induction of local immunological responses, including tissue destruction, by CD8+ cells and macrophages in the tongue of GVHD rats.
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PMID:Oral mucosal lesions in experimental graft-versus-host disease: morphological and immunohistochemical characterization of infiltrating cells. 888 76

As a preclinical step to human studies with combined stem cell-enriched peripheral leukocytes and organ transplantation from the same donor, a series of studies in rats was undertaken. These studies indicated that Lewis rats infused intravenously with major histocompatibility complex-incompatible (from Brown-Norway rats), stem cell-enriched peripheral leukocyte preparation alone never developed graft-versus-host disease (GHVD). However, GVHD invariably manifested in all animals a few days after the kidney was transplanted in rats that had been previously primed with stem cell-enriched peripheral leukocytes from the same kidney donor strain. GVHD was prevented by substituting the crude preparation of stem cell-enriched peripheral leukocytes with a purified preparation that was almost completely free of T lymphocytes. However, in these latter experiments all rats rejected their kidney graft within 10 days from the surgery. In rats previously given the crude stem cell-enriched peripheral leukocyte preparation, perioperative administration of the fusion protein CTLA4lg also prevented GVHD and prolonged kidney graft survival up to 106 to 175 days. By contrast, animals with kidney transplants, which were given CTLA4lg without stem cells, rejected their grafts within 35 days. All together, these findings may possibly contribute to the creation of rationally designed strategies of combining organ and bone marrow from the same donor to enhance mixed chimerism and prolong survival after organ transplantation.
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PMID:The kidney triggers graft-versus-host disease in experimental combined transplantation of kidney and stem cell-enriched peripheral leukocytes. 891 87

We have prevented graft-versus-host disease (GVHD) by tolerizing graft donors to host antigens by intrathymic injection of recipient-type splenocytes into donors. A unidirectional GVHD model was used in which intravenous injection of 3-4 x 10(8) Lewis rat (donor) lymphocytes into (Lewis x Brown Norway)F1 rats (recipients) causes lethal GVHD. The donor animals were divided into five treatment groups. The group 1 donor animals received no treatment. The group 2 donors received a single intraperitoneal injection of 1 ml of antilymphocyte antiserum (ALS). The group 3 donors received an intrathymic injection of 50x10(6) host splenocytes. The group 4 donors received both ALS (intraperitoneally) and intrathymic allograft. The group 5 donors received both ALS (intraperitoneally) and intravenous allograft. Two weeks after these treatments, 3-4x10(8) lymphocytes from each of these donors were injected (intravenously) into the recipients. The clinical signs of GVHD, as measured by profound weight loss, hair loss, inflammation of foot pads and ears, and profound splenomegaly, were evident in recipients of groups 1, 2, and 3 between days 9 and 10 and in the recipients (two of four) of group 5 on day 17. No GVHD was observed by histopathology in all 14 hosts that received lymphocyte injection from the group 4 donor animals (up to 300 days). These results demonstrate that GVHD can be eliminated by tolerizing donors toward host by intrathymic injection of the recipient-type lymphocytes into the donor. A single injection of ALS is necessary to possibly eliminate antihost response from the donor for the tolerance induction. The thymic route appears to be superior to the intravenous route for tolerance induction.
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PMID:Prevention of graft-versus-host disease by intrathymic injection of recipient-type splenocytes into donor. 893 89

Previous histologic studies of tongue lesions in graft-versus-host disease (GVHD) in non-irradiated (Brown Norway x Lewis) F1 rats given parental spleen cells have demonstrated an increase in the number of MHC class II+ cells with dendritic shape in the lamina propria to be the earliest event in the development of the lesion. We studied this histologic finding by electron microscopy to increase understanding of the early cellular events occurring in the lesion. Electron microscopically, the most prominent cell type observed in the lamina propria was the cell with a dendritic shape. These dendritic cells possessed large nuclei that often showed irregular indentations and ample cytoplasm containing numerous filaments and mitochondria. A few lysosomal or phagocytic structures were also seen in the cytoplasm. No Birbeck granules were identified. These findings were very similar to those of indeterminate cells in the epidermis and dermis. Our data strongly support the hypothesis that MHC class II+ cells with dendritic shape present antigen during the induction of local immunological responses in the tongue of GVHD rats.
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PMID:Electron microscopic studies of the early cellular events occurring in oral mucosa of rats affected by graft-versus-host disease (GVHD). 904 8

Ultraviolet-B (UVB) irradiation is known to inhibit lymphocyte activity and consequently to reduce the incidence of graft-versus-host disease (GVHD) in experimental models for allogeneic bone marrow transplantation (BMT). GVHD is frequently associated with morbidity and mortality, but also with the beneficial graft-versus-leukemia (GVL) effect, demonstrated by a reduction in the incidence of leukemia relapse. In this study, we investigated whether UVB treatment of allogeneic T cells could prevent GVHD while sparing the beneficial GVL effect following allogeneic BMT in the Brown Norway myelocytic leukemia (BNML) rat model analogous to human acute myelocytic leukemia (AML). The dose of UVB required to abolish lethal GVHD in the rat allogeneic BMT model (WAG/Rij donors into BN recipients) was 4000 J/m2. However, this UVB dose simultaneously abrogated all GVL activity mediated by the T cells in the graft, while the radio-protective capacity of rat BM cells was strongly reduced. The number of allogeneic BM cells required to protect lethally irradiated BN rats was increased 50 to 100-fold. It is concluded that UVB acts as a non-selective form of T cell inactivation, and that UVB pretreatment of an allogeneic marrow graft is unlikely to be useful clinically as a preventive measure for GVHD, since other means of reduction of the number of functional T cells are less damaging to bone marrow stem cells.
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PMID:Influence of ultraviolet-B irradiation on engraftment, graft-versus-host disease and graft-versus-leukemia effect in a rat model for allogeneic bone marrow transplantation. 960 4


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