Yoshihiro Shigemasa

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Suspension of chitin and chitosan particles (mean size of 1 micron) were found to attract canine neutrophils chemotactically as determined by a checkerboard assay through polycarbonate filter with 5 microns pore size in Blind well chamber. Suspension of chitin induced chemokinetic migrations of the neutrophils. These evidences might reflect accumulation of(More)
Chitosan is a useful nonviral vector for gene delivery. To make a pDNA/chitosan complex specific to hepatocytes, lactose-modified chitosan (lac-chitosan) was synthesized. When the percentage of lactose residues substituted was 8%, lac-chitosan showed excellent DNA-binding ability, good protection of DNA from nuclease, and the suppression of self-aggregation(More)
Various acetylated chitosan derivatives and mixtures of chitin and chitosan, covering the range of the degree of deacetylation (DDA) from 0-100% were analyzed by 1H-NMR spectroscopy and infrared spectroscopy. The use of the 1070 cm-1 or 1030 cm-1 absorption band as an internal standard in the determination of DDA from the absorbance of the amide I bands at(More)
The sponge-, cotton-, and flake-type remedies made of chitin (chitin-sponge, chitin-cotton, and chitin-flake, respectively), and non-woven fabric of polyester (NWF) composited with chitin (chitin-NWF) were applied to various types of trauma, abscess, surgical tissue defect and herniorrhaphy in 147 clinical cases including 72 dogs, 38 cows, 33 cats, 2(More)
The level of prostaglandin E2 (PGE2) in the exudate induced by subcutaneous implantation of a complex formed from non-woven fabric of polyester (NWF) and polymeric N-acetyl-D-glucosamine (chitin) (chitin/NWF) or by implantation of NWF in dogs was measured by radioimmunoassay. The amount of PGE2 in the exudate induced by chitin/NWF was about five times as(More)
Lysozyme susceptibility of partially deacetylated chitins (DACs) was investigated by viscometric and gel permeation chromatographic procedures. The highest lysozyme susceptibility was shown by the DAC of around 70% deacetylation which have already been reported to have the highest immunoadjuvant activity through mouse peritoneal macrophage activation.
Collagen synthesis was evaluated by measuring prolyl hydroxylase (PHL) activity induced within rat granulation tissue by a polyester non-woven fabric (NWF, 1 x 1 cm, 0.6 mm in thickness) impregnated with a chitin or chitosan suspension ranging in concentration from 0.1 to 10 mg/ml. In addition, PHL activity induced in rat granulation tissue by a NWF(More)
Effects of chitin/chitosan and their oligomers/monomers on migrations of fibroblasts (3T6) and vascular endothelial cells (human umbilical vascular endothelial cell: HUVEC) were evaluated in vitro. In direct migratory assay using the blind well chamber method, migratory activity of 3T6 was seen to be reduced by chitin, chitosan and the chitosan monomer(More)