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Hokkaido University Collection of Scholarly and Academic Papers (135.711 recursos)

HUSCAP (Hokkaido University Collection of Scholarly and Academic Papers) contains peer-reviewed journal articles, proceedings, educational resources and any kind of scholarly works of Hokkaido University.

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Mostrando recursos 1 - 20 de 93

  1. Population dynamics of Bifidobacterium species in human feces during raffinose administration monitored by fluorescence in situ hybridization-flow cytometry

    Dinoto, Achmad; Marques, Tatiana M.; Sakamoto, Kanta; Fukiya, Satoru; Watanabe, Jun; Ito, Susumu; Yokota, Atsushi
    The population dynamics of bifidobacteria in human feces during raffinose administration were investigated at the species level by using fluorescence in situ hybridization (FISH) coupled with flow cytometry (FCM) analysis. Although double-staining FISH-FCM using both fluorescein isothiocyanate (FITC) and indodicarbocyanine (Cy5) as labeling dyes for fecal samples has been reported, the analysis was interfered with by strong autofluorescence at the FITC fluorescence region because of the presence of autofluorescence particles/debris in the fecal samples. We circumvented this problem by using only Cy5 fluorescent dye in the FISH-FCM analysis. Thirteen subjects received 2 g of raffinose twice a day for 4...

  2. Inhibitory Effects of 5,6,7-Trihydroxyflavones on Tyrosinase

    Gao, Hong; Nishida, Jun; Saito, Shizuka; Kawabata, Jun
    Baicalein (1), 6-hydroxyapigenin (6), 6-hydroxygalangin (13) and 6-hydroxykaempferol (14), which are naturally occurring flavonoids from a set of 14 hydroxyflavones tested, exhibited high inhibitory effects on tyrosinase with respect to L-DOPA, while each of the 5,6,7-trihydroxyflavones 1, 6, 13 or 14 acted as a cofactor to monophenolase. Moreover, 6-hydroxykaempferol (14) showed the highest activity and was a competitive inhibitor of tyrosinase compared to L-DOPA. 5,6,7- Trihydroxyflavones 1, 6, 13 or 14 showed also high antioxidant activities. Hence, we conclude that the 5,6,7-trihydroxy-flavones are useful as good depigmentation agents with inhibitory effects in addition to their antioxidant properties.

  3. Development of Cucumber mosaic virus as a vector modifiable for different host species to produce therapeutic proteins.

    Matsuo, Kouki; Hong, Jin- Sung; Tabayashi, Noriko; Ito, Akira; Masuta, Chikara; Matsumura, Takeshi
    We have developed Cucumber mosaic virus (CMV) as a plant virus vector especially for production of pharmaceutical proteins. The CMV vector is a vector modifiable for different host plants and does not require further engineering steps. CMV contains three genomic RNA molecules (RNAs 1–3) necessary for infectivity. With this system, instead of creating different vector constructs for each plant we use, we take advantage of the formation of pseudrecombinants between two CMV isolates by simply reassembling a vector construct (RNA 2 base) and an RNA molecule containing the host determinant (mostly RNA 3). In this study, the gene for acidic...

  4. Expression of Bovine Lactoferrin C-lobe in Rhodococcus erythropolis and Its Purification and Characterization

    Kim, Woan-Sub; Shimazaki, Kei-ichi; Tamura, Tomohiro
    A Rhodococcus erythropolis expression system for the bovine lactoferrin C-lobe was constructed. The DNA fragments encoding the BLF C-lobe were amplified and cloned into vector pTip LCH1.2. R. erythropolis carrying the pTip-C-lobe was cultured at 30 °C with shaking, and expression of the rBLF C-lobe was induced by adding 1 μg/ml (final concentration) thiostrepton. The rBLF C-lobe was isolated in native and denatured (8 M urea) form by Ni-NTA affinity chromatography. To obtain a bioactive rBLF C-lobe, the protein isolated in the denatured form was refolded by stepwise dialysis against refolding buffers. The antibacterial activity of the rBLF C-lobe was...

  5. Alterations of cellular physiology in Escherichia coli in response to oxidative phosphorylation impaired by defective F1-ATPase

    Noda, Sakiko; Takezawa, Yuji; Mizutani, Tomohiko; Asakura, Tomoaki; Nishiumi, Eiichiro; Onoe, Kazunori; Wada, Masaru; Tomita, Fusao; Matsushita, Kazunobu; Yokota, Atsushi
    The physiological changes in an F1-ATPase-defective mutant of Escherichia coli W1485 growing in a glucose-limited chemostat included a decreased growth yield (60%) and increased specific rates of both glucose consumption (168%) and respiration (171%). Flux analysis revealed that the mutant showed approximately twice as much flow in glycolysis but only an 18% increase in the tricarboxylic acid (TCA) cycle, owing to the excretion of acetate, where most of the increased glycolytic flux was directed. Genetic and biochemical analyses of the mutant revealed the downregulation of many TCA cycle enzymes, including citrate synthase, and the upregulation of the pyruvate dehydrogenase complex...

  6. Apyrene sperm from the triploid donors restore fecundity of cryopreserved semen in Bombyx mori

    Takemura, Yoko; Sahara, Ken; Mochida, Yuji; Ohnuma, Akio
    Female moths of Bombyx mori were artificially inseminated with cryopreserved semen. The fertility of inseminated females varied from 0% to 76.9% depending on the strain. Addition of fresh semen from triploid males, which are infertile but whose semen includes intact apyrene sperm, greatly improved fecundity of cryopreserved semen from normal males. Frozen apyrene sperm from the triploid donors also improved the fecundity of females, inseminated with cryopreserved normal semen, but less than fresh semen from triploid males. Fertilization success in B. mori requires the presence of both, intact eupyrene and apyrene sperm. Our results show that eupyrene sperm tolerate the...

  7. High frequency Agrobacterium-mediated transformation and plant regeneration via direct shoot formation from leaf explants in Beta vulgaris and Beta maritima

    Hisano, H.; Kimoto, Y.; Hayakawa, H.; Takeichi, J.; Domae, T.; Hashimoto, R.; Abe, J.; Asano, S.; Kanazawa, A.; Shimamoto, Y.
    Communicated by H. Uchimiya Abstract We have developed a new procedure for Agrobacterium-mediated transformation of plants in the genus Beta using shoot-base as the material for Agrobacterium infection. The frequency of regeneration from shoot bases was analyzed in seven accessions of sugarbeet (Beta vulgaris) and two accessions of B. maritima to select materials suitable for obtaining transformed plants. The frequency of transformation of the chosen accessions using Agrobacterium strain LBA4404 and selection on 150-mg/l kanamycin was found to be higher than that in previously published methods. Genomic DNA analysis and -glucuronidase reporter assays showed that the transgene was inherited and...

  8. The star-type color pattern in Petunia hybrida 'red Star' flowers is induced by sequence-specific degradation of chalcone synthase RNA

    Koseki, Maiko; Goto, Kazunori; Masuta, Chikara; Kanazawa, Akira
    Petunia hybrida ‘Red Star’ is a variety whose flowers exhibit a star-type red and white bicolor pattern. We analyzed the mRNA levels of six genes involved in anthocyanin biosynthesis. Only the level of chalcone synthase (CHS) mRNA was depressed in the unpigmented flower sectors. Both transcriptional activity and the accumulation of short interfering RNA of CHS in the unpigmented sectors were detected. Viral infection blocked the generation of CHS-silenced sectors. These results indicate that sequence-specific degradation of CHS RNA is the primary cause of the formation of white sectors in ‘Red Star’ flowers.

  9. Phenolic constituents of Celosia cristata L. susceptible to spinach root rot pathogen Aphanomyces cochlioides.

    Wen, Yaolin; Islam, Md. Tofazzal; Tahara, Satoshi
    Cochliophilin A (5-hydroxy-6,7-methylenedioxyflavone, 1), known as a host-specific attractant towards the zoospores of Aphanomyces cochlioides, a cause of root rot and damping-off diseases of Chenopodiaceae, was found in the Amaranthaceae plant, Celosia cristata, that is susceptible to the pathogen. The content of 1 in Celosia seedlings was quantified as 1.4 μg/g fresh weight. A new isoflavone, cristatein (5-hydroxy-6-hydroxymethyl-7,2′-dimethoxyisoflavone, 2), and five known flavonoids were also identified.

  10. The molecular phylogeny of the genus Rhizopus based on rDNA sequences

    Abe, Ayumi; Oda, Yuji; Asano, Kozo; Sone, Teruo
    In order to establish the molecular phylogeny of the genus Rhizopus, three molecules of the ribosomal RNA-encoding DNA (rDNA), complete 18S, internal transcribed spacer (ITS)1-5.8S-ITS2, and 28S D1/D2 regions of all the species of the genus were sequenced. Phylogenetic trees showed three major clusters corresponding to the three groups in the current morphological taxonomy, microsporus-group, stolonifer-group, and R. oryzae. R. stolonifer var. lyococcos was clustered independently from the major clusters. R. schipperae clustered differently in all trees. Strains of R. sexualis had multiple ITS sequences. A. rouxii clustered with R. oryzae. These results indicate the possibility of molecular identification of...

  11. Synthesis of Some Phenylpropanoid Monoglycerides via the Mitsunobu Protocol

    Batovska, Daniela I.; Kishimoto, Takao; Bankova, Vassya S.; Kamenarska, Zornitsa G.; Ubukata, Makoto
    Natural monoglycerides of cinnamic, ferulic and p-coumaric acids were synthesized in good to high overall yields from isopropylidene glycerol via the Mitsunobu reaction and further deprotection of the corresponding acetonides with Amberlyst 15. The method avoids the need of protection of the phenolic hydroxyls. During the Mitsunobu esterifications a strong influence of the acid strength on the efficacy and outcome of the reaction was observed.

  12. Intestinal absorption of zinc is promoted by low-level intake but inhibited by high-level intake of corn husk fiber in rats

    Hara, Hiroshi; Hayashi, Kumiko; Aoyama, Yoritaka
    We examined the effects of feeding several types of insoluble dietary fiber (100 g/kg diet), including cellulose (control), wheat bran (demineralized), sugar-beet fiber and corn husk fiber, on zinc absorption in rats. Zinc absorption was higher after intake of a zinc-deficient diet (0.229 mmol/kg diet) containing corn husk fiber than that after intake of a cellulose-containing diet for 3 wk. Ingestion of wheat bran or sugar-beet fiber did not influence zinc absorption. We compared the effects of cellulose and demineralized- and washed-corn husk fiber at graded levels in the diets (1, 2 and 3 parts to 10 basal diet). Zinc...

  13. Non-essential amino acids play an important role in adaptation of the rat exocrine pancreas to high nitrogen feeding.

    Hara, Hiroshi; Akatsuka, Naoki; Aoyama, Yoritaka
    We have previously demonstrated that feeding a diet with a high amino acid (60% AA diet) content, as a mixture simulating casein, induced pancreatic growth and pancreatic protease production in rats. In the present study, we examined the effects of an increasing dietary content of essential amino acids (EAA, x1 - x3 in exp. 1 and x1 - x3.3 in exp. 2) and non-essential amino acids (NEAA, x1 - x3 in exp. 1 and x1 - x5.2 in exp. 2) on pancreatic growth, amylase and protease adaptation using casein-type amino acid mixtures (exp. 1, basal diet; 20% AA diet) and...

  14. L-homoarginine suppresses exocrine pancreas in rats.

    Hira, Tohru; Ohyama, Sumika; Hara, Hiroshi
    Previously, we found that guanidinated casein, a l-homoarginine-containing protein, was a more potent stimulator of pancreatic enzyme secretion than intact casein in rats. In this study, we examined secretory response and adaptation of the exocrine pancreas to the administration of free l-homoarginine in normal and bile-pancreatic juice (BPJ)-diverted rats. An intraperitoneal injection of l-homoarginine (10mg/rats) produced immediate and transient reduction in pancreatic secretion in BPJ-diverted rats, but not in normal rats. The BPJ-diverted rats were fed with either a 25% casein, 45% casein, or 45% casein diet supplemented with l-homoarginine (19g/kg diet) for 4 days. Feeding of a diet containing...

  15. Intestinal absorption and metabolism of a soluble flavonoid, alphaG-rutin, in portal cannulated rats.

    Matsumoto, Megumi; Chiji, Hideyuki; Hara, Hiroshi
    A highly soluble quercetin glycoside, αG-rutin, is a glucose adduct of insoluble rutin, and intestinal absorption and metabolism of αG-rutin has not been known. We investigated the intestinal absorption and metabolism of αG-rutin by using portal and duodenal cannulated rats and the isolated rat intestinal mucosa. After a duodenal instillation of αG-rutin (150 μmol), intact αG-rutin, rutin and quercetin were appeared in the portal blood and these concentrations were similarly increased at 15 min. Portal quercetin reached a peak value at 60 min, and the value was higher than those of αG-rutin and rutin at that time. Quercetin-conjugates were also...

  16. Promotive effects of non-digestible disaccharides on rat mineral absorption depend on the type of saccharide.

    Asvarujanon, Patchana; Ishizuka, Satoshi; Hara, Hiroshi
    Objective: We examined the effects of feeding non-digestible disaccharides, difructose anhydride III (DFAIII), maltitol, melibiose and, cellobiose, on calcium, magnesium, and iron absorption in comparison with fructo-oligosaccharide (FOS) in normal and ovariectomized rats. Methods: In experiment 1, six groups of male Sprague-Dawley rats were fed a control diet (100 g of cellulose/kg of diet), test diets containing 30 g of FOS, or the four non-digestible disaccharides in place of the cellulose in the control diet for 4 wk. In experiment 2, two groups of female Sprague-Dawley rats (sham or ovariectomized) were assigned to one of four subgroups and fed the...

  17. Characterization of Binding Between the Rat Small Intestinal Brush-border Membrane and Dietary Proteins in the Sensory Mechanism of Luminal Dietary Proteins.

    Hira, Tohru; Hara, Hiroshi; Tomita, Fusao
    Dietary proteins are recognized by the gastrointestinal tract to display physiological functions, however, the sensory mechanism of the intestinal mucosa is not known. We examined binding properties between the rat small intestinal brush-border membrane (BBM) and proteins by using a surface plasmon resonance biosensor. BBM and solubilized BBM prepared from the rat jejunum bound to casein immobilized on the sensor surface, but not to bovine serum albumin. The ileal BBM showed less binding to casein than the jejunal BBM. Solubilized BBM binding to immobilized α-casein was slightly inhibited by aminopeptidase inhibitors, but still more inhibited by addition of casein with...

  18. Absorptive activity of calcium in the isolated cecal epithelium adaptively increased by 2 week's feeding of difructose anhydride III in rats.

    Mineo, Hitoshi; Amano, Midori; Chiji, Hideyuki; Shigematsu, Norihiro; Tomita, Fusao; Hara, Hiroshi
    We compared net Ca absorption and Lucifer Yellow (LY), a paracellular passage dye, permeability in the epithelium isolated from the rat small intestine, cecum, and colon after feeding with control and difructose anhydride (DFA) III diets for 14 days using the Ussing chamber system. Feeding of DFA III increased net Ca transport and LY passage in the cecal but not in small intestinal or colonic epithelium. Ability of paracellular Ca passage via Tight-junction (TJ) in the cecum was changed adaptively by feeding of DFA III. Changes in microbial fermentation may affect the functional changes of Ca transport in cecal epithelium...

  19. Ingestion of raffinose promotes calcium absorption in the large intestine of rats.

    Mitamura, Rieko; Hara, Hiroshi; Aoyama, Yoritaka
    We examined the effects of feeding raffinose on intestinal calcium absorption in ovariectomized rats by two separate experiments. In experiment 1, female Sprague-Dawley rats (6 wk old) were divided into two groups: sham operation and ovariectomy, and fed diets with or without raffinose (30 g/kg diet) for 4 wk. In experiment 2, ovariectomized rats with cecocolonectomy or transsection and reanastomosis (sham) were divided into two groups as in experiment 1 and fed the same diets for 3 wk. In experiment 1, calcium absorption was lower in the ovariectomized rats than in the sham rats but calcium absorption in rats fed...

  20. Reducing effect of ingesting tannic acid on the absorption of iron, but not of zinc, copper and manganese by rats.

    Afsana, Kaosar; Shiga, Kazuki; Ishizuka, Satoshi; Hara, Hiroshi
    Interest in the beneficial effects of polyphenols, including tannic acid (TA), is increasing, although, these compounds also have adverse effects; for example, on the absorption of iron (Fe), and possibly other trace minerals. We examined the effect of a graded dose of TA on the absorption of Fe and compared with that of zinc (Zn), copper (Cu) and manganese (Mn) in rats. We also investigated the effect of TA on cecal fermentation which plays a role in absorption. In Experiment 1, to set the optimum dose of Fe, male Sprague-Dawley rats (weighing 70–90 g) after acclimatization were fed with different...

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