Objective To compare the pathological and serological difference of rheumatoid arthritis (RA) models in severe combined immunodeficiency (SCID) mice transplanted with synovial tissues from patients with rheumatoid arthritis (SCID-HuRAg mice) established either by renal capsule or subcutaneous back heterotopic transplantation. Methods RA synovium and normal human cartilage were co-implanted subcutaneously into the backs or under the renal capsule of 15 SCID mice. Engrafted tissues and serum were taken at the 4th and 8th week after transplantation. Histopathology and ELISA were performed to compare their histological and serological differences with RA. Results The morbidity and taken rate were significantly increased in the subcutaneous back of the mice group than the renal capsule group. The degree of cartilage erosion as well as the titers of serum IgM type rheumatoid factor suggested no significant difference between the two groups of SCID-HuRAg model devel oped by different engraft methods. Conclusion Back subcutaneous transplantation SCID-HuRAg model can be an ideal and stable animal model for studies on the pathogenesis and biotherapy of RA.

Objective To investigate the incidence rate, pathologic changes, mechanisms and diagnostic methods in renal bone disease.Methods The blood levels of carboxyterminal parpthyriod hormone (C-PTH), 1,25(OH)2D3, calcium and phosphate, aluminum in serum and bone tissue were measured. The bone biopsy and bone scan with 99m technetium methylene diphosphonate (99m TC-MDP) were performed in 51 uremic patients.Results One hundred per cent of the patients had varying degree of pathologic changes in bone, in which 50.9% of the patients presented high-turnover bone disease, 7.8% of the patients presented lowe-turnover bone disease and 41.8% of the patients had mixed-type bone disease. The levels of serum C-PTH were predominently high in high-turnover bone disease while the levels of serum 1,25(OH)2D3 were significantly decreased in low-turnover bone disease. There was a high positive rate for the diagnosis of renal bone disease by bone scan with 99m TC-MDP.Conclusions The examination of bone pathology is the most valuable method for the diagnosis of renal bone disease. Bone scan with 99m TC-MDP has reference value when clinical conditions do not allow to make bone biopsy.