PCR-based detection of betanodaviruses from cultured and wild marine fish with no clinical signs   总被引：8，自引：0，他引：8  

Gomez DK  Sato J  Mushiake K  Isshiki T  Okinaka Y  Nakai T 《Journal of fish diseases》2004,27(10):603-608

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Novel antioxidative metabolites in rat liver with ingested sesamin   总被引：10，自引：0，他引：10  

Nakai M  Harada M  Nakahara K  Akimoto K  Shibata H  Miki W  Kiso Y 《Journal of agricultural and food chemistry》2003,51(6):1666-1670

Sesamin, a major lignan in sesame oil, is known to have many biological activities, especially protective effects against oxidative damage in the liver. As sesamin itself has no antioxidative properties in vitro, to elucidate the mechanism of its antioxidative effects, the reaction products of sesamin in rat liver homogenate were analyzed. The methylenedioxyphenyl moiety in the structure of sesamin was shown to be changed into a dihydrophenyl (catechol) moiety. The enzymatic reaction products in vitro were identified as (1R,2S,5R,6S)-6-(3,4-dihydroxyphenyl)-2-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3,3,0]octane and (1R,2S,5R,6S)-2,6-bis(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3,3,0]octane, which showed strong radical scavenging activities; the latter was a novel compound. The same metabolites were found as glucuronic acid and/or sulfic acid conjugates in substantial amounts in rat bile after oral administration of sesamin. It is suggested that sesamin is a prodrug and the metabolites containing the catechol moieties in their structures are responsible for the protective effects of sesamin against oxidative damage in the liver.  相似文献   

Gas chromatography/principal component similarity system for detection of E. coli and S. aureus contaminating salmon and hamburger     

Nakai S  Wang ZH  Dou J  Nakamura S  Ogawa M  Nakai E  Vanderstoep J 《Journal of agricultural and food chemistry》1999,47(2):576-583

Coho, Atlantic, Spring, and Sockeye salmon and five commercial samples of hamburger patties were analyzed by processing gas chromatography (GC) data of volatile compounds using the principal component similarity (PCS) technique. PCS scattergrams of the samples inoculated with Escherichia coli and Staphylococcus aureus followed by incubation showed the pattern-shift lines moving away from the data point for uninoculated, unincubated reference samples in different directions with increasing incubation time. When the PCS scattergrams were drawn for samples incubated overnight, the samples inoculated with the two bacterial species and the uninoculated samples appeared as three separated groups. This GC/PCS approach has the potential to ensure quality of samples by discriminating good samples from potentially spoiled samples. The latter may require further microbial assays to identify the bacteria species potentially contaminating foods.  相似文献   

Molecular mapping of quantitative trait loci for domestication traits and β-glucan content in a wheat recombinant inbred line population     

Alagu?Manickavelu  Kanako?Kawaura  Hisako?Imamura  Michiko?Mori  Yasunari?OgiharaEmail author 《Euphytica》2011,177(2):179-190

Genetic maps are useful for analysis of quantitative trait loci (QTLs) and for marker-assisted selection (MAS) in breeding. A simple sequence repeat (SSR) marker linkage map of common wheat was constructed based on recombination inbred lines (RILs) derived from a cross between Chinese Spring and spelt wheat. The map included 264 loci on all wheat chromosomes covering 2,345.2 cM with 962, 794.6, and 588.6 cM for the A, B, and D genomes, respectively. Using the RILs and the map, we detected 42 putative QTLs on 15 chromosomes for ear length, spikelet number, spike compactness, kernel length, kernel width, kernel height and β-glucan content. Each QTL explained 4–45% of the phenotypic variation. Five QTL cluster regions were detected on chromosomes 1A, 5AL, 2B, 2D, and 4D. The first QTLs for β-glucan content in wheat were identified on chromosomes 3A, 1B, 5B, and 6D.  相似文献   

Amino acid sequence of rabbit muscle aldolase and the structure of the active center   总被引：11，自引：0，他引：11  

C Y Lai  N Nakai  D Chang 《Science (New York, N.Y.)》1974,183(130):1204-1206

Elucidation of the amino acid sequence of fructose-1,6-bis-phosphate aldolase from rabbit muscle has made it possible to assign the positions of the functional groups known to play specific roles in the catalytic activity, and also to locate the buried, exposed, and active site cysteine residues. The results indicate that the middle portion of the polypeptide chain, including Cys-134, Cys-149, Cys-177, and Cys-l99, is buried in the native structure, with regions containing Cys-72, Lys-107, Lys-227, Cys-336, His-359, and the COOH-terminal residue (Tyr-361) folded into the active center of the enzyme, at or near the surface of the enzyme molecule.  相似文献   

Biochemical and genomic analysis of neoculin compared to monocot mannose-binding lectins     

Shimizu-Ibuka A  Nakai Y  Nakamori K  Morita Y  Nakajima K  Kadota K  Watanabe H  Okubo S  Terada T  Asakura T  Misaka T  Abe K 《Journal of agricultural and food chemistry》2008,56(13):5338-5344

Neoculin occurring in an edible tropical fruit is a heterodimeric protein which has both sweetness and a taste-modifying activity that converts sourness to sweetness. Both the primary and the overall tertiary structures of neoculin resemble those of monocot mannose-binding lectins. This study investigated differences in biochemical properties between neoculin and the lectins. Structural comparison between the mannose-binding sites of lectins and the corresponding regions of neoculin showed that there is at least one amino acid substitution at each site in neoculin, suggesting a reason for the lack of its mannose-binding ability. This was consistent with hemagglutination assay data demonstrating that neoculin had no detectable agglutinin activity. DNA microarray analysis indicated that neoculin had no significant influence on gene expression in Caco-2 cell, whereas kidney bean lectin (Phaseolus vulgaris agglutinin) greatly influenced various gene expressions. These data strongly suggest that neoculin has no lectin-like properties, encouraging its practical use in the food industry.  相似文献   

Structural requirements of Angiotensin I-converting enzyme inhibitory peptides: quantitative structure-activity relationship study of di- and tripeptides     

Wu J  Aluko RE  Nakai S 《Journal of agricultural and food chemistry》2006,54(3):732-738

A database consisting of 168 dipeptides and 140 tripeptides was constructed from published literature to study the quantitative structure--activity relationships of angiotensin I-converting enzyme (ACE) inhibitory peptides. Two models were computed using partial least squares regression based on the three z-scores of 20 coded amino acids and further validated by cross-validation and permutation tests. The two-component model could explain 73.2% of the Y-variance (inhibitor concentration that reduced enzyme activity by 50%, IC50) with the predictive ability of 71.1% for dipeptides, while the single-component model could explain 47.1% of the Y-variance with the predictive ability of 43.3% for tripeptides. Amino acid residues with bulky side chains as well as hydrophobic side chains were preferred for dipeptides. For tripeptides, the most favorable residues for the carboxyl terminus were aromatic amino acids, while positively charged amino acids were preferred for the middle position, and hydrophobic amino acids were preferred for the amino terminus. According to the models, the IC50 values of seven new peptides with matchable primary sequences within pea protein, bovine milk protein, and soybean were predicted. The predicted peptides were synthesized, and their IC50 values were validated through laboratory determination of inhibition of ACE activity.  相似文献   

Distribution patterns of settlement-stage juveniles of <Emphasis Type="Italic">Girella punctata</Emphasis> and <Emphasis Type="Italic">Girella leonina</Emphasis> on the rocky coast of the Kanto–Izu region,Japan     

Takeshi Ito  Yudai Iino  Shizuko Nakai  Shiro Itoi  Haruo Sugita  Noriyuki Takai 《Fisheries Science》2018,84(4):627-640

The early life history of girellid fishes in Japanese waters is unclear, and little is known about their species-specific reproductive strategies. We examined seasonal changes of distribution patterns for settlement-stage juveniles of Girella punctata and Girella leonina on the rocky shore in the regions of Kanto and Izu, Japan, to infer the influence of the Kuroshio Current on their reproduction. We collected 813 settlement-stage juveniles mainly in Sagami Bay and genetically identified the species. The juveniles of G. punctata were collected on the rocky shore in Sagami Bay during April to August, with the abundant catch in May and June. Thus, we infer that juvenile G. punctata ubiquitously inhabit the rocky shore in the area in spring and summer. By contrast, juveniles of G. leonina were rarely collected in Sagami Bay, with a total catch of only 66. Notably, no juveniles were collected during the wintertime in Sagami Bay, although an abundant catch of G. leonina had been previously reported for Sagami Nada off Sagami Bay during January to March. This clear-cut difference between the areas likely reflects the difference in proximity to the path of the Kuroshio Current. We expect that the Kuroshio Current strongly influences the reproductive success of G. leonina.  相似文献   

人工林杉木和杨树木材物理力学性质的株内变异研究   总被引：4，自引：0，他引：4  

任海青  中井孝 《林业科学》2006,42(3):13-20

按照中国国家标准研究杉木和I-214杨树木材的抗弯弹性模量、抗弯强度、顺纹抗压强度和密度,同时按照日本国家标准研究2个树种的顺纹抗剪强度.结果表明:杉木的抗弯强度、顺纹抗压强度和密度由胸高直径处向上呈波浪形增加,抗弯弹性模量则稳定降低,但不同高度间杉木的物理力学性质没有显著差异;近树皮处木材的物理力学性质高于近髓心处木材,并有极显著差异.对于I-214杨树,只有抗弯弹性模量从髓心到树皮逐渐增加,其他的物理力学性质,最小值在从髓心到树皮的过渡区,最大值在近树皮处,从髓心到树皮,杨树的物理力学性质有极显著的差异.杉木和杨树的径面顺纹抗剪强度从髓心到树皮有极显著差异,并且近树皮的高于近髓心的木材,而弦面顺纹抗剪强度从髓心到树皮没有显著差异.木材密度与力学性质有很好的线性相关关系,木材密度是一个很好的力学强度的预测手段.  相似文献   

Nodavirus associated with pathological changes in adult spotted coralgroupers (Plectropomus maculatus) in Thailand with viral nervous necrosis     

Pirarat Nopadon  Ponpornpisit Aranya  Nakai Toshihiro  Maita Masashi 《Research in veterinary science》2009,87(1):97-95

The present study characterized viral nervous necrosis in sea cage-reared adult spotted coralgroupers (Plectropomus maculatus). Histopathological study showed extensive vacuolation and neuronal necrosis of the olfactory bulb and the optic lobe of the forebrain and the inner and outer nuclear layer of retina. Mild necrosis was observed in the spinal cord. Homogeneous intranuclear inclusion bodies were noted in the hyperplastic and hypertrophic glandular epithelial cells of the swim bladder suggesting viral etiology. Etiological diagnosis of VNN was confirmed by RT-PCR, immunohistochemistry and in situ hybridization. The immunohistochemistry and in situ hybridization gave strongly positive staining in the same area of the infected cells of the brain, spinal cord and retina correlating with histopathological changes. No positive reaction was detectable in the affected gas glandular epithelium and other organs, confirming the consistent neurotropism of this nodavirus. Nodavirus was mainly detected in the olfactory bulb of the brain. The result suggests nasal transmission was the major route of infection.  相似文献