Masakatsu Usui

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Analytical methods were investigated for the discrimination of ‘nori’, the dried laver Porphyra spp. sheet products, which were organoleptically judged as excellent-grade for commercial distribution. Volatile compounds of nori were analyzed with an electronic nose and a gas chromatography-mass spectrometer (GC/MS) with headspace solid-phase(More)
As an acquired immunodeficiency, human immunodeficiency virus (HIV) infection is primarily responsible for opportunistic infections in infected patients. However, opportunistic infections also occur in individuals with human T cell lymphotrophic virus type 1 (HTLV-1) infection. Here, we report opportunistic infections in two Japanese HTLV-1-seropositive(More)
Because there is a great difference between the toxicity of inorganic arsenic (As) and organic As in food, the JECFA has set a PTWI value for inorganic As (iAs) rather than for total As. The difference in As toxicity makes it necessary to extract iAs completely from food samples for toxicological analysis, but complete extraction of As from most foods(More)
Various mutant lysozymes having the N-glycosylation signal sequence, R21T (Asn(19)-Tyr(20)-Thr(21)), G49N (Asn(49)- Ser(50)-Thr(51)), R21T/G49N (Asn(19)-Tyr(20)-Thr(21)/Asn(49)-Ser(50)-Thr(51)), were secreted in the Pichia pastoris expression system. The secreted amounts of these mutant glycosylated lysozymes were almost the same as those of wild-type(More)
An attempt was made to mask the allergenic structure of a major allergen protein, Cry j I (CJI), in Japanese cedar pollen using the Maillard-type polysaccharide conjugation. The SDS-PAGE pattern of the CJI-galactomannan conjugate prepared by the Maillard reaction showed broad bands widely distributed from 50 kDa to more than 100 kDa, suggesting the(More)
Eikenella corrodens (Ec) is one of a group of periodontopathogenic bacteria. A plasmid DNA (8.7 kb) isolated from Ec 1073 was designated pMU1. Agarose gel electrophoresis and Southern analysis suggested that pMU1-like plasmids were carried in 2 Ec strains, including 1073, with higher hemagglutination (HA) activity than other strains. We determined the(More)
The soluble aggregates of Cry j 1, a major allergen of Japanese cedar pollen, were formed without any coagulates during heat treatment at acidic pH 5, as shown in HPLC and SDS-PAGE patterns. A remarkable change in the CD spectrum was observed between native and heat-denatured Cry j 1 at a linear rate of 1 degrees C/min from 40 to 90 degrees C. The negative(More)
This study investigated the anti-allergic effect of a diethyl ether fraction from dried Sargassum fusiforme. In vivo experiments showed that percutaneous administration of this fraction suppressed mouse ear swelling induced by three types of sensitizers (arachidonic acid, 12-O-tetradecanoylphorbol-13-acetate and oxazolone). At a dose of 0.1 mg/mouse, the(More)
The soy protein-chitosan conjugate was formed by the Maillard reaction in dry state (relative humidity 65%) at 60 degrees C for 2 weeks to improve the functional properties. The antimicrobial activity of the Maillard-type soy protein-chitosan conjugates enhanced 2-3 times that of soy protein-chitosan mixture. The soy protein-chitosan conjugate showed(More)
Tropomyosins are defined as risk factors for shrimp allergy. However, their concentration in different preparations has not been clarified. We quantified the tropomyosin concentration in shrimp meat, which was cooked using several methods or was stored under various conditions. The results demonstrated that shrimp meat from various preparations and storage(More)