Double immunolocalization of major nucleolar proteins, fibrillarin and B23, in dividing mammalian cultured cells.

Using specific autoimmune sera to the nucleolar protein fibrillarin and monoclonal antibodies to B23/nucleophosmin, we localized early and late nucleolar rRNA-processing factors in cycling human HeLa and pig PK cells. It was shown that, at the electron microscopic level, fibrillarin was located over the nucleolar fibrillar compartment, but was absent in the fibrillar centres. During mitosis, fibrillarin was located within the same domains as B23, namely, the cytoplasm, the perichromosomal layer, prenucleolar bodies, and the nucleolar cytoplasmic derivatives, but the kinetics of the two proteins during mitosis was essentially different. Thus, fibrillarin dissociated from the nucleolar remnant at prophase of mitosis or following actinomycin D treatments after B23, but was found to be more prominent within the perichromosomal layer at metaphase, and earlier migrated to the reassembled nucleoli at telophase. In contrast to B23, fibrillarin was found to be resistant to the treatment with 2 M NaCl.

Repetitive use of pulse therapy with methylprednisolone and cyclophosphamide in addition to oral methotrexate in children with systemic juvenile rheumatoid arthritis--preliminary results of a longterm study.

Patients with systemic juvenile rheumatoid arthritis (JRA) are often poorly responsive to existing therapeutic modalities. We evaluated the effectiveness of pulse therapy consisting of methylprednisolone 30 mg/kg/day for 3 consecutive days combined with cyclophosphamide 0.4 g/m2 body surface area on the 3rd day, for 18 patients with definite systemic JRA, who were enrolled in an open trial of 12 months' duration. The children received pulse therapy every 3 months; oral methotrexate 10 mg/m2 was started after the first pulse. A rapid and clinically significant suppression of systemic and articular manifestations was seen in all patients. Significant decreases in laboratory indices of disease activity were also observed. Side effects were minor and reversible. The results of our preliminary trial support the development of a controlled study to evaluate the efficacy of pulse therapy in systemic JRA.