Isolation and pathogenic characterization of an OB1 variant of Babesia rodhaini which has a glycophorin A-independent pathway to murine red blood cells     

Noriyuki Takabatake  Hiroshi Iseki  Yuzuru Ikehara  Hirotaka Kanuka  Naoaki Yokoyama  Kazuhisa Sekimizu  Ikuo Igarashi 《Veterinary parasitology》2009

Recent studies using several Babesia spp. have demonstrated that these species commonly recognize host sialic acids of red blood cells (RBCs) for their invasion. Glycophorin A (GPA), which is a major carrier of the sialic acids on RBCs, is a possible invasive receptor for Babesia parasites. In the present study, a variant of Babesia rodhaini was successfully isolated from a GPA homozygous knockout (GPA^−/−) mouse infected with an Australian strain of B. rodhaini which had originally been unable to replicate in GPA^−/− mice. The isolated parasite (designated as an OB1 variant) caused lethal infection to wild-type mice, as in the case of the parent Australian strain. However, although the growth of the OB1 variant in GPA^−/− mice was comparable with that in wild-type mice at 1–4 days after infection, the growth was significantly inhibited from day 5 onward, leading to the eventual survival of the GPA^−/− mice. Resistance of GPA^−/− mice against OB1 infection was lost by splenectomy, although the cytokine responses to the infection in the sera of GPA^−/− mice were similar to those of wild-type mice. The autoantibody levels to GPA-defective RBCs in the sera of GPA^−/− mice were depressed at a lower level at 0–2 days after infection than those of wild-type mice, while the levels of GPA^−/− mice progressively increased and reached comparable levels to those of wild-type mice at day 3 or later. These results indicate that the isolated OB1 variant has a GPA-independent invasion pathway into murine RBCs and suggest that the resistance of GPA^−/− mice against infection with the OB1 variant may be attributed to the effective clearance of the parasitized RBCs lacking GPA in the spleen, possibly mediated by preferential autoantibody binding to the RBC membrane.  相似文献   

The relationship between migration speed and release date for chum salmon Oncorhynchus keta fry exiting a 110-km northern Japanese river     

Kiyoshi Kasugai  Mitsuru Torao  Mitsuhiro Nagata  James R. Irvine 《Fisheries Science》2013,79(4):569-577

The relationship between release date and migration speed was examined for hatchery chum salmon Oncorhynchus keta fry exiting the Nishibetsu River in eastern Hokkaido, northern Japan so that future releases might be scheduled so that fry arrive at the ocean during periods favoring high survival. Separate marked groups of chum salmon released in early April, mid-April, and early May in 2008, late March and mid-April in 2009, and mid-April in 2010 were recaptured with a rotary screw trap 12 km above the river mouth. Chum salmon in later release groups tended to migrate downstream faster than fish in earlier release groups. Those released after mid-April arrived in the lower river on average 9 days after release, while those released before mid-April arrived on average 26–28 days after release. Most marked fish arrived in the lower river during late April to mid-May. These results suggest that chum salmon are adapted to adjust their migratory speed so as to arrive at the ocean during a relatively discrete period, presumably during a time of high productivity favoring good survival.  相似文献   

Involvement of NbNOA1 in NO production and defense responses in INF1-treated Nicotiana benthamiana     

Hiroaki Kato  Shuta Asai  Ayako Yamamoto-Katou  Hirofumi Yoshioka  Noriyuki Doke  Kazuhito Kawakita 《Journal of General Plant Pathology》2008,74(1):15-23

During defense responses, plant cells produce nitric oxide (NO), which may control many physiological processes. In a previous study, we reported that nitrate reductase (NR) is responsible in part for INF1 elicitor-induced NO production in Nicotiana benthamiana, but the possibility remains that other NO-generating system(s) contribute to NO production. In mammalian cells, NO production is catalyzed by NO synthase (NOS). However, NOS-like enzyme(s) have never been identified in plants, and only the gene for Arabidopsis thaliana nitric oxide-associated 1 (AtNOA1) has been identified as a putative regulator of NOS activity in plants. In this study, we cloned NbNOA1, a homolog of AtNOA1, from N. benthamiana and investigated its involvement in NO production induced by INF1. The NbNOA1 gene was silenced by a virus-induced gene-silencing (VIGS) technique. NbNOA1-silenced plants had yellowish leaves. Silencing NbNOA1 partially decreased INF1-induced NO production, while overexpressing NbNOA1 did not affect NO production. Silencing NbNOA1 suppressed INF1-induced PR1a gene expression and increased susceptibility to Colletotrichum lagenarium. These results suggest that NbNOA1 is involved in INF1-mediated NO production and is required for defense responses. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession number AB303300.  相似文献   

Detection of Pythium aphanidermatum in tomato using loop-mediated isothermal amplification (LAMP) with species-specific primers     

Shiro Fukuta  Reiko Takahashi  Satoru Kuroyanagi  Noriyuki Miyake  Hirofumi Nagai  Hirofumi Suzuki  Fujio Hashizume  Tomoko Tsuji  Hiromi Taguchi  Hideki Watanabe  Koji Kageyama 《European journal of plant pathology / European Foundation for Plant Pathology》2013,136(4):689-701

A loop-mediated isothermal amplification (LAMP) reaction with a primer set designed from the rDNA ITS sequence of P. aphanidermatum was developed. Results of a specificity test using 57 strains of Pythium spp. indicated that the LAMP assay gave no cross reactions in other 39 Pythium species, 11 strains of Phytophthora spp. and eight other soil borne pathogens. The detection limit was 10 fg of genomic DNA, which was ten times the sensitivity of the polymerase chain reaction. The LAMP assay was applied to hydroponic solution samples from tomato fields, and the results were compared to those of the conventional plating method. LAMP was observed to be effective for the specific detection of P. aphanidermatum. Furthermore, P. aphanidermatum was detected directly in tomato roots infected with P. aphanidermatum without DNA extraction. The LAMP method established in this study is a simple, sensitive and rapid tool for the detection of P. aphanidermatum.  相似文献   

合成气合成低碳醇热力学及试验研究     

袁浩然  陈新德  陈勇  马隆龙  小林敬幸  黄宏宇 《农业工程学报》2011,27(12):297-301

为了解决液体燃料缺乏以及农业废弃物处置的问题,该文分析了合成低碳醇的重要性,提供了一条解决农业废弃物的方法,并通过热力学分析指导低碳醇的合成.文中使用平衡常数法对合成气合成低碳醇进行热力学分析计算,并验证了计算结果符合理论分析的趋势,得到降低温度、提高压力有利于CO的转化和醇类的生成,以及不同H2/CO摩尔比的情况下C...  相似文献   

Effects of Cd on the fluxes of K+ and H+ in excised roots     

Hitoshi Obata  Noriyuki Inoue  Motoaki Matsuoka  Masanao Umebayashi 《Soil Science and Plant Nutrition》2013,59(2):439-442

As a result of Cd treatment, K concentrations decreased in Cd sensItive maize and kidney bean calli (Obata et al. 1994) and in intact roots of kidney bean plants (Obata et al. unpublished). Potassium may be extruded from the roots or the absorption of K may be depressed by the Cd treatment in these Cd sensitive plants. Obata et al. (1996) observed that Cd inhibited both the efflux of H⁺ and influx of K⁺ following K⁺ addition in intact roots of bean. Thus Cd may affect the activity of proteins essential to ion movement., i.e. ioncarriers, channels and ATPase embedded in the membranes and/or may affect the permeability of the lipids of the membrane.  相似文献   

Genomic organization of the porcine dopachrome tautomerase (DCT) gene     

Naohiko OKUMURA  Noriyuki HAMASIMA  Kohei SUZUKI  Takashi AWATA 《Animal Science Journal》2008,79(2):182-186

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Pharmacokinetics of procaterol in thoroughbred horses          下载免费PDF全文

K. Kusano  M. Nomura  K. Toju  Y. Ishikawa  Y. Minamijima  S. Yamashita  S. Nagata 《Journal of veterinary pharmacology and therapeutics》2016,39(3):264-270

Procaterol (PCR) is a beta‐2‐adrenergic bronchodilator widely used in Japanese racehorses for treating lower respiratory disease. The pharmacokinetics of PCR following single intravenous (0.5 μg/kg) and oral (2.0 μg/kg) administrations were investigated in six thoroughbred horses. Plasma and urine concentrations of PCR were measured using liquid chromatography–mass spectrometry. Plasma PCR concentration following intravenous administration showed a biphasic elimination pattern. The systemic clearance was 0.47 ± 0.16 L/h/kg, the steady‐state volume of the distribution was 1.21 ± 0.23 L/kg, and the elimination half‐life was 2.85 ± 1.35 h. Heart rate rapidly increased after intravenous administration and gradually decreased thereafter. A strong correlation between heart rate and plasma concentration of PCR was observed. Plasma concentrations of PCR after oral administration were not quantifiable in all horses. Urine concentrations of PCR following intravenous and oral administrations were quantified in all horses until 32 h after administration. Urine PCR concentrations were not significantly different on and after 24 h between intravenous and oral administrations. These results suggest that the bioavailability of orally administrated PCR in horses is very poor, and the drug was eliminated from the body slowly based on urinary concentrations. This report is the first study to demonstrate the pharmacokinetic character of PCR in thoroughbred horses.  相似文献   

Evaluation of duodenal perfusion by contrast‐enhanced ultrasonography in dogs with chronic inflammatory enteropathy and intestinal lymphoma     

Khoirun Nisa  Sue Yee Lim  Masayoshi Shinohara  Tatsuyuki Osuga  Nozomu Yokoyama  Masahiro Tamura  Noriyuki Nagata  Kazuyoshi Sasaoka  Angkhana Dermlim  Rommaneeya Leela‐Arporn  Tomoya Morita  Noboru Sasaki  Keitaro Morishita  Kensuke Nakamura  Hiroshi Ohta  Mitsuyoshi Takiguchi 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2019,33(2):559-568

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Manipulation of tannins in oaks by galling cynipids     

Noriyuki Ikai  Naoki Hijii 《Journal of Forest Research》2007,12(4):316-319

We measured the protein precipitation capacity of tannins in the tissues of Quercus crispula and Quercus serrata galls induced by a cynipid (Trigonaspis sp.) to examine the nutrition hypothesis on gall induction. The protein precipitation capacity was significantly lower in the nutritive tissues of galls, on which the cynipids feed, than in ungalled sound leaves and in the outer gall tissues. In addition, the protein precipitation capacities in the leaves and in the outer gall tissues were significantly larger in Q. crispula than in Q. serrata samples, whereas that of the nutritive tissues did not differ between these oak species. These results suggest that gall induction is one of the adaptations of galling cynipids to host–plant defensive compounds, and support the nutrition hypothesis.  相似文献