Hiromi Fukamachi

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The vacuolating cytotoxin VacA produced by Helicobacter pylori causes massive cellular vacuolation in vitro and gastric tissue damage in vivo, leading to gastric ulcers, when administered intragastrically. Here we report that mice deficient in protein tyrosine phosphatase receptor type Z (Ptprz, also called PTP-ζ or RPTP-β, encoded by Ptprz) do not show(More)
Adenosine is a potent bronchoconstricting agent that is released by activated mast cells and hypoxic lung tissue. However, both inhibition and stimulation of mediator release from human lung mast cells by adenosine have been described, and this discrepancy seems to be due to contaminating cells or the effects of enzymatic treatment. We, therefore,(More)
Tryptase is a protease released from mast cells and is believed to contribute to the inflammatory process in allergic diseases including asthma. In the course of screening to find tryptase inhibitors, we isolated two new tryptase inhibitors, cyclotheonamide E4 (3) and E5 (4), from a marine sponge of the genus Ircinia. The structures of these molecules were(More)
Human recombinant granulocyte-colony stimulating factor (rhG-CSF) has one free cysteine at position 17 and has two disulfide bridges (Cys36-Cys42 and Cys64-Cys74). The Cys17 of rhG-CSF was substituted with Gly, Ala, Ser, Ile, Tyr, Arg, and Pro, or deleted using site-directed mutagenesis in order to improve its thermostability. With the exception of(More)
We examined the effects of interferon-gamma (IFN-gamma) on 100% pure human mast cells generated in suspension cultures of umbilical cord blood mononuclear cells in the presence of stem cell factor (SCF) and interleukin-6 (IL-6). When mast cells were suspended in serum-free medium without any cytokine after the withdrawal of SCF and IL-6, they died over a(More)
Specific binding sites for erythropoietin (Epo) were shown in normal and anemic rat bone marrow cells using [125I]labeled human recombinant Epo. When rats were treated once or several times with phenylhydrazine or malotilate, or by phlebotomy, the serum Epo level determined by RIA began to increase rapidly. Thereafter, both the number of erythroid(More)
Erythropoietin (Epo) titers in various hematological states were determined by a radioimmunoassay. Epo titers in patients with uremic anemia and iron deficiency anemia were inversely correlated with their respective hemoglobin concentrations. Epo titers in patients with uremic anemia were significantly lower than those in patients with iron deficiency(More)
Pleckstrin homology (PH) domains comprised of loosely conserved sequences of approximately 100 amino acid residues are a functional protein motif found in many signal-transducing and cytoskeletal proteins. We recently demonstrated that the PH domains of Tec family protein-tyrosine kinases Btk and Emt (equal to Itk and Tsk) interact with protein kinase C(More)
BACKGROUND In Japan, squid is an important seafood, and some patients with food allergies are sensitive to squid. There has been no report, however, describing the major allergens of squid. OBJECTIVE To characterize squid allergens, we isolated a major allergen from the Pacific flying squid (Todarodes pacificus) and compared it with a major allergen from(More)