MRL/Mp mice are known to have autoimmune disease-prone genetic background, which contributes to the development of a lethal autoimmune disease at an early age in association with the lymphoproliferative gene, lpr. In this study, we found that MRL/Mp mice, not bearing lpr (MRL/Mp-(+)/+), spontaneously developed pancreatitis at a late stage of life, which was histopathologically characterized by destruction of pancreatic acinar cells with mononuclear cell infiltration. In female 34-38-weeks-old mice the incidence of pancreatitis reached 74%, whereas the male mice developed the disease with a reduced incidence, at a later stage of life and with a reduced severity. Cell infiltrates in the affected lesions were composed predominantly of CD4+ cells and to lesser extent Mac-2+ macrophages. Adoptive transfer of the spleen cells obtained from pancreatitis-bearing female mice generated pancreatitis in female normal mice, but not in the male mice. Transfer of the serum of pancreatitis-bearing mice failed to induce any pancreatic lesions. These findings indicate that pancreatitis in MRL/Mp-(+)/+ mice may be mediated by cellular autoimmune mechanism. This may present a useful concept for analysis of the developmental mechanisms of human chronic pancreatitis in an aspect of autoimmunity.

Objective. To characterize Fas antigen expression on the cell surface, and to determine the effect of this expression in rheumatic diseases using a newly established gld-congenic MRL strain of mice (MRLlgld), which is defective in its functional Fas ligand (Fas-L).Methods. Flow cytometric analyses of lymphoid cells and macrophages were performed using anti-Fas and other cell surface markers. Histopathologic manifestations were examined using immunochemistry and light and electron microscopy. Serum levels of IgG and anti-DNA antibodies were measured by single radial immunodiffusion and enzyme-linked immunosorbent assay, respectively.Results. MRL/gld mice developed systemic lymphadenopathy with an accumulation of Thyl.2+, B220+ and CD4-, CDS-T cells, which both express the Fas antigen. Splenic B cells positive for surface IgM and/or surface IgD, and resident peritoneal macrophages exhibited up-regulated expression of the Fas antigen, at much higher levels than those observed in MRL/ MpJ-+/+ (MRL/+) mice. Forms of rheumatic disease were observed in these mice, although not in C3H/HeJgld/gld mice. These forms included diffuse glomerulonephritis, granulomatous arteritis, and arthritis, and were associated with the infiltration of mononuclear cells expressing the Fas antigen. Serum levels of IgG and

These results suggest that increased Fmax improved walking efficiency by increasing energy utilization in the anterior-posterior/mediolateral directions while decreasing energy loss in the vertical direction.

The D value of commercial biological indicator spore strips using Bacillus stearothermophilus ATCC 7953 was increased by higher calcium concentrations in assay media. The calcium concentration in assay media varied among the manufacturers. The calcium concentration in assay media is an important factor to consider to minimize the variation of D value.

MRL/MpTn-gld/gld (MRL/gld) mice, which are deficient in a functional Fas ligand (FasL), spontaneously develop autoimmune diseases involving both lethal glomerulonephritis and systemic arteritis, while MRL/Mp-+/+ (MRL/+) and C3H/HeJ-gld/gld (C3H/gld) do not. To determine the cells responsible for the development of glomerulonephritis and arteritis, we transferred bone marrow cells from MRL/gld mice to undiseased MHC-compatible gld/gld or +/+ mice. In bone marrow irradiation chimeras, MRL/gld bone marrow cells were transferred to lethally irradiated MRL/+ or C3H/HeJ-+/+ (C3H/+) mice, and both recipients developed glomerulonephritis associated with hypergammaglobulinemia without causing graft-versus-host (GVH)-like diseases. However, a striking difference between them was that MRL/+ recipients developed arteritis, but C3H/+ recipients did not. In bone marrow mixed chimeras formed by transferring MRL/gld bone marrow cells to unirradiated mice, the MRL/gld bone marrow cells induced glomerulonephritis in C3H/gld mice, but not in C3H/+ and MRL/+ mice. These results indicate that bone marrow cells from MRL/gld mice can cause glomerulonephritis in mice, even in those with a C3H background, possibly if they survive longer by escaping from Fas-mediated apoptosis, while the development of arteritis requires the MRL genetic background in the recipients. This is the first report of the transfer of arteritis in lupus mice to undiseased recipients.