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Using a high-resolution, automated confocal high-content imaging system, we investigated the sub-cellular localization of the Serine 2481-autophosphorylated form of mTOR (PP-mTOR(Ser2481)) during mitosis and cytokinesis in human cancer cells. PP-mTOR(Ser2481) exhibited a punctate nuclear distribution in interphase cancer cells, with the number of PP-mTOR(Ser2481) nuclear speckles positively relating with the proliferative capacity of cancer cells. PP-mTOR(Ser2481) expression dynamically rearranged within the cytoplasm in a close association near and between separating chromosomes during early stages of mitosis. Towards the end of anaphase and in telophase, PP-mTOR(Ser2481) drastically focused on the midzone and ultimately in the centre of the midbody at the presumptive cleavage furrow. In cells at cytokinesis, PP-mTOR(Ser2481) appeared as a doublet facing each other at the apical ends of two daughter cells. Three-dimensional analysis confirmed that PP-mTOR(Ser2481) positioned at a ring structure wrapped round by microtubule bundles to connect daughter cells. These results reveal for the first time that PP-mTOR(Ser2481) may be unexpectedly involved in the terminal stages of cytokinesis.

We report here a case of systemic lupus erythematosus with severe, active pauci-immune necrotizing and crescentic glomerulonephritis. This patient had been diagnosed of a lupus nephritis type III previously and treated with steroids and azathioprine. After a renal symptomless period of nine years, she developed heavy proteinuria and hypertension. A second kidney biopsy was then performed. The pathological study disclosed a pauci-immune necrotizing crescentic and segmental glomerulonephritis. The absence of subendothelial and mesangial deposits was confirmed by both immunofluorescent microscopy and electron microscopy. The simultaneous immunological study showed normal ANCA levels while complement, anti-dsDNA and ANA were altered. The patient was treated with steroids and cyclophosphamide eith good response. This case points out the possibility previously recognized by others of an association between lupus and an pauci-immune necrotizing glomerulonephritis.