Yoshitaka Horiuchi

Tokushima Bunri University, Tokusima, Tokushima, Japan

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Publications (6)12.28 Total impact

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    ABSTRACT: A bactericidal mechanism mediated by human serum was investigated by a field emission scanning electron microscope and a strain of drug-resistant Pseudomonas aeruginosa. When the bacteria were treated with meropenem, a carbapenem antibiotic, spheroplasts and bulges (spheroidization) appeared after 1-3 h. When 40% serum was added to the bacteria, the bacteria agglutinated within 2 min and then lysed after 5-30 min. Immunoelectron micrographic analyses showed dispositions of complement component C9 molecules on the cell surface of lysed bacteria by the serum treatment that might suggest formation of a membrane attack complex. Immunoglobulin G (IgG) depletion from the serum diminished the lytic activity and adding human intravenous immunoglobulin (IVIG) restored it, suggesting that lysis was induced by specific IgG binding to the bacteria. IVIG may help patients with less IgG against bacteria to overcome severe infection.
    Journal of Infection and Chemotherapy 12/2010; 16(6):383-7. · 1.55 Impact Factor
  • Masae Takahashi, Yoshitaka Horiuchi, Tadashi Tezuka
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    ABSTRACT: Hematoxylin-stainability of keratohyalin granules (KHG) using biochemical and immunohistochemical techniques is due to the presence of a fibrinogen γ-chain protein. A protein with a molecular weight of 100 kDa was stained with anti-Ted-H-1 monoclonal antibody and hematoxylin solution (hematoxylin-stainable protein). Since the amino acid sequence of the hematoxylin-stainable protein was to that of fibrinogen γ-chain protein, a peptide was synthesized and an antibody against the peptide was produced. This antibody reacted with the hematoxylin-stainable protein and fibrinogen γ-chain protein on immunoblot analysis and with KHG on immunohistochemical examination. Furthermore, a commercial anti-fibrinogen γ-chain protein antibody (Ab) also reacted with the hematoxylin-stainable protein as well as fibrinogen. In contrast, anti-fibrinogen β-chain protein Ab did not react with the hematoxylin-stainable protein. The fibrinogen γ-chain protein also stained with hematoxylin. These findings suggested that fibrinogen γ-chain protein may be a novel component protein of KHG and may induce the hematoxylin-stainability of KHG.
    Archives for Dermatological Research 11/2010; 302(9):679-84. · 2.71 Impact Factor
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    ABSTRACT: Erythropoietin supports the survival of erythroblasts. We previously demonstrated that 24 malignant human cell lines expressed erythropoietin and its receptor and that erythropoietin secretion was enhanced under anoxia. In this study, we examined the viability of 22 of these cell lines excluding two leukemia cell lines under anoxia. Twenty-two cancer cell lines of various origins were cultured under anoxia or normoxia for 4 days, and their viability was examined at 1-day intervals. The levels of lactate and ATP were measured. The expressions of hypoxia-inducible transcription factor 1alpha (HIF-1alpha) and Bcl-2 family proteins were examined by western blotting analysis. The cellular and mitochondrial features were examined by microscopy. Eleven of the 22 cancer cell lines examined showed 80% to 100% cell viability after 4 days under anoxia; 2 cell lines showed similar viability for 3 days, 3 cell lines showed similar viability for 2 days, and 6 cell lines showed similar viability for 1 day or less. These 11 death-resistant cell lines, which secrete various amounts of erythropoietin under anoxia, produced significantly more lactate during 2 days under anoxia than under normoxia, with ATP levels about 60% of those before anoxia. ATP returned to the normal level when normoxia was restored after 4 days of anoxia. However, the nonresistant cell lines responded to anoxia by yielding significantly more lactate without a reduction of the ATP level. The expression patterns of Bcl-2 family proteins revealed that apoptosis-inhibiting signals predominated over proapoptotic signals in the death-resistant cells under anoxia. The majority of the cancer cell lines examined survived under anoxia in vitro, through the Pasteur effect, in a dormant state without direct support of erythropoietin.
    International Journal of Clinical Oncology 01/2008; 12(6):455-62. · 1.73 Impact Factor
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    ABSTRACT: We obtained an antibody, anti-inner root sheath cells antibody (anti-IRSC Ab), that reacted with the inner root sheath (IRS) cells especially trichohyalin granules (THG). In order to compare the properties of anti-IRSC Ab and AE15, which is a specific monoclonal antibody against THG, histochemical and biochemical examinations were performed. In vivo localization with anti-IRSC Ab and AE15 indicated that both antibodies reacted with THG, but anti-IRSC Ab reacted with THG in the suprabulbar region of the Huxley layer, whereas AE15 reacted with THG in the suprabulbar region and upper bulbar portion of the Huxley layer, as shown by immunohistochemical and immunoelectron microscopic analyses. The results of immunoblot analysis showed that anti-IRSC Ab reacted with a protein spot at 45 kDa, pI 6.5, but AE15 reacted with high molecular weight proteins at pI 5.5. Furthermore, anti-IRSC Ab reacted with specimens of squamous cell carcinoma (SCC) but did not react with those of basal cell carcinoma (BCC). In contrast, AE15 reacted with neither SCC nor BCC. These findings suggest that anti-IRSC Ab and AE 15 recognized different component proteins in THG, and therefore indicated that THG, like as keratohyalin granules, might consist of several proteins. It is the novel finding that the anti-IRSC Ab positive substance in THG in the normal hair and SCC cells.
    Archives for Dermatological Research 05/2007; 299(1):33-9. · 2.71 Impact Factor
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    ABSTRACT: Heretofore, epithelial cells have been considered to be the only source of keratin (K) polypeptides that assemble into 10-nm filaments to form an extensive cytoplasmic network in conjunction with nuclear and cytoplasmic membranes. However, K was recently found to be expressed also in cultured non-epithelial normal and tumor cells: melanocyte, fibroblast, endothelial cell, malignant melanoma, fibrosarcoma, and angiosarcoma. Nevertheless, electron microscopy was incapable of detecting the K filaments (Katagata et al., J Dermatol Sci, 30, 1-9, 2002, see ref. 11). That is, K may present as subunits in each of the cultured cells named above, not as a filament formation. We used squamous cell carcinoma observed with immunoelectron microscopy, a more precise and conclusive technique, to further confirm whether or not K filament is formed in those cultured cells. HaCaT, an immortalizd keratinocyte cell line used as a positive control, yielded elegant immunoelectron microscopic images. Considerable K filament formations existed in malignant melanoma using anti-K or anti-vimentin antibodies, as revealed by the presence of linear immune gold particles on high electron density substances. In the case of squamous cell carcinoma, the gold particles were fewer than those of malignant melanoma. By contrast, no K filaments were detected in the other non-epithelial normal and tumor cell lines: fibroblast, endothelial cell, fibrosarcoma and angiosarcoma. These results suggest that the formation of K filaments in malignant melanoma (and slight presence in squamous cell carcinoma) is a particular and cell-dependent characterization. Key words: tumor cells, keratins, filament formation, immunoelectron microscopy
  • Masae Takahashi, Yoshitaka Horiuchi, Tadashi Tezuka
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    ABSTRACT: To examine the presence of bactericidal/permeability-increasing protein (BPI) in skin, which is an antibacterial protein, has cytotoxicity toward Gram-negative bacteria, and may have an important role against bacterial infection in the skin, immunohistochemical and biochemical analyses were performed. Anti-BPI/KLH Ab reacted with the cytoplasm of the inner root sheath cells of both human and rat hair follicles by immunohistochemical examination. A protein band in 10-M alkaline urea extracts of human scalp skin or 7-day-old rat skin reacted with an antibody against BPI conjugated with KLH (anti-BPI/KLH Ab). Purified skin BPI (sBPI) from rat was a single protein spot and reacted with both anti-BPI/KLH Ab and a commercially available monoclonal antibody against BPI (anti-BPI MoAb). Moreover, sBPI possessed inhibitory activity against LPS. Bactericidal/permeability-increasing protein mRNA was expressed not only in leukocytes but also in human scalp skin and cultured keratinocytes. These findings suggest that sBPI could exist in the inner root sheath cells of human and rat hair follicles, and might play a role as a barrier against anaerobic bacteria in the isthmus of hair follicles.
    Experimental Dermatology 02/2004; 13(1):55-60. · 3.58 Impact Factor

Publication Stats

14 Citations
12.28 Total Impact Points


  • 2007–2010
    • Tokushima Bunri University
      • Institute for Health Sciences
      Tokusima, Tokushima, Japan
    • Kinki University
      • Life Science Research Institute
      Ōsaka, Ōsaka, Japan