[Participation of pharmacists in the medical team at home]

This report reviews drug consultations at patients' home and collaboration of pharmacists with medical teams over 4 years. The participation of pharmacists is necessary for home care service, because of their pharmaceutical expertise and the demands from the medical team and patients at home.

Forced expression of terminal deoxynucleotidyl transferase in fetal thymus resulted in a decrease in gammadelta T cells and random dissemination of Vgamma3Vdelta1 T cells in skin of newborn but not adult mice

The repertoire of lymphocyte receptor genes encoded in a germline is further diversified by a number of processes, including the template-independent addition of nucleotides (N regions) by means of terminal deoxynucleotidyl transferase (TdT). Normally, mouse gammadelta T cells in the early fetal thymus, whose T-cell receptor (TCR) genes lack N regions and are encoded by Vgamma3-Jgamma1 and Vdelta1-Ddelta2-Jdelta2 with canonical junctions (invariant Vgamma3Vdelta1), are thought to be the precursors of dendritic epidermal T cells (DETC). We generated mutant mice whose endogenous TdT promoter was replaced with the lck promoter through homologous recombination. These mutant mice expressed TdT in fetal thymus, had abundant N regions and infrequent canonical junctions in gamma and delta rearrangements, and showed a decreased number of gammadelta T cells. Various Vgamma3Vdelta1 T cells, most of which had N regions in their TCR genes, were found to disseminate in the skin of newborn mutant mice, whereas normal numbers of DETCs with the invariant Vgamma3Vdelta1 rearrangement were observed in adult mutants. These data demonstrate that the regulation of TdT expression during fetal development is important for the generation of gammadelta T cells, and that Vgamma3Vdelta1 T cells, which have various junctional sequences in their TCR genes, randomly disseminate in skin, but invariant Vgamma3Vdelta1 T cells have a great advantage for proliferation in skin.

Growth disturbance in fetal liver hematopoiesis of Mll-mutant mice

The MLL (ALL-1, HRX) gene is frequently involved in chromosomal translocations in acute leukemia and has homology with Drosophila trithorax, which controls homeobox gene expression and embryogenesis. To elucidate the function of Mll, we generated mice with a mutated Mll locus. Mice with a homozygous mutation were embryonic lethal and died at embryonic day 11.5 to 14.5, showing edematous bodies and petechiae. Histological examination revealed that hematopoietic cells were decreased in the liver of homozygous embryos, although they were composed of erythroid, myeloid, monocytic, and megakaryocytic cells with normal differentiation. Colony-forming assays using cells from fetal livers and yolk sacs showed that the number of colonies was markedly reduced and many of the colonies delayed to be recognized in Mllmu/mu embryos, although some of the colonies from Mllmu/mu embryos developed similarly with that from Mll+/+ and Mll+/mu embryos, suggesting the delayed onset of the proliferation of hematopoitic precursors. These data show that the hematopoietic precursors were greatly reduced in mutant mice, and suggest that Mll functions as a regulator of the growth of hematopoietic precursors.

Structure and function of a new STAT-induced STAT inhibitor

The signalling pathway that comprises JAK kinases and STAT proteins (for signal transducer and activator of transcription) is important for relaying signals from various cytokines outside the cell to the inside. The feedback mechanism responsible for switching off the cytokine signal has not been elucidated. We now report the cloning and characterization of an inhibitor of STAT activation which we name SSI-1 (for STAT-induced STAT inhibitor-1). We found that SSI-1 messenger RNA was induced by the cytokines interleukins 4 and 6 (IL-4, IL-6), leukaemia-inhibitory factor (LIF), and granulocyte colony-stimulating factor (G-CSF). Stimulation by IL-6 or LIF of murine myeloid leukaemia cells (M1 cells) induced SSI-1 mRNA expression which was blocked by transfection of a dominant-negative mutant of Stat3, indicating that the SSI-1 gene is a target of Stat3. Forced overexpression of SSI-1 complementary DNA interfered with IL-6- and LIF-mediated apoptosis and macrophage differentiation of M1 cells, as well as IL-6 induced tyrosine-phosphorylation of a receptor glycoprotein component, gp130, and of Stat3. When SSI-1 is overexpressed in COS7 cells, it can associate with the kinases Jak2 and Tyk2. These findings indicate that SSI-1 is responsible for negative-feedback regulation of the JAK-STAT pathway induced by cytokine stimulation.

Potent ectopic bone-inducing activity of bone morphogenetic protein-4/7 heterodimer

We have purified and characterized recombinant Xenopus bone morphogenetic proteins (xBMPs): homodimers of xBMP-4, 7 and heterodimers (xBMP-4/7) produced by a baculovirus expression system. Highly purified xBMPs had homogeneous NH2-termini predicted from a consensus motif, Arg-X-X-Arg, while they possessed diverse sugar chains. Implantation of xBMPs together with pure collagen carrier in rats induced new bone formation in a dose-dependent manner. The xBMP-4/7 heterodimer showed the strongest activity, with an effective dose of 1-30 micrograms, while more than 10 micrograms of xBMP-4 or 7 homodimer was required for a significant effect. Histological examination revealed that xBMP-4/7 implants showed intramembranous ossification without chondrogenesis. In primary cultures of rat bone marrow stromal cells, xBMP-4/7 induced alkaline phosphatase 3-fold more strongly than xBMP-7 and 20-fold more than xBMP-4. These results suggest that the heterodimeric form of BMP would generate the strongest signal triggering osteogenic differentiation of osteoprogenitor cells in adult tissues.

Efficient expression of a heterodimer of bone morphogenetic protein subunits using a baculovirus expression system

Recombinant baculoviruses as expression vectors for Xenopus bone morphogenetic protein (xBMP)-2, 4 and 7 were generated. The conditioned medium of insect cells infected with the virus for xBMP-2 or 4 showed strong alkaline phosphatase-inducing activity in a mouse osteoblastic cell line, MC3T3-E1, although a large portion of the activity remained in the infected cells. In contrast, xBMP-7 was preferentially secreted into the medium, but had only weak activity. Conditioned media following simultaneous inoculation with the viruses for xBMP-7 and for xBMP-2 or 4 showed a remarkably increased level of activity. The increased activity was clearly separated from other peaks derived from single infection on a cation-exchange column and was found to arise from the disulfide-linked heterodimer consisting of xBMP-4 and 7 subunits by immunoblot analysis. The heterodimer also augmented osteocalcin production and parathyroid hormone-sensitivity more strongly than the homodimers. These results suggest that our expression system provides a convenient source of heterodimeric BMP with high osteogenic differentiation-inducing activity.