Induced Resistance to Rice Blast by Antagonistic Bacterium, <Emphasis Type="Italic">Serratia marcescens </Emphasis>Strain B2     

Nobutaka SOMEYA  Masami NAKAJIMA  Tadaaki HIBI  Isamu YAMAGUCHI  Katsumi AKUTSU 《Journal of General Plant Pathology》2002,68(2):177-182

An antagonistic bacterium, Serratia marcescens strain B2, controlled rice blast after being sprayed onto rice phylloplane, as did the bacterial suspension when poured into rhizosphere soil of rice plants. Three days after root treatment, rice blast conidia were sprayed onto rice foliage. A week after pathogen inoculation, rice blast was suppressed and lesions caused by the pathogen decreased in size. Brown deposits were observed around sites of pathogen infection after root treatment. Induced resistance was not associated with an increase in the activitiy of peroxidase, phenylalanine ammonia lyase, tyrosine ammonia lyase, β-1,3-glucanase, β-1,4-glycosidase, N-acetylhexosaminidase or chitinase. However, lipoxygenase levels were elevated after the root treatment with strain B2 following inoculation with the pathogen. Strain B2 was not detected in rice foliage after root treatment. These data suggest that strain B2 induced resistance against rice blast caused by Pyricularia oryzae. Received 1 November 2001/ Accepted in revised form 25 January 2002  相似文献   

Insecticidal activity of new fluorinated pyrethroids and their stability toward chemical oxidation and photoreaction     

Tetsu Ando  Nozomu Koseki  Isamu Yasuhara  Kie Kasuga  Noritada Matsuo  Takao Ishiwatari 《Pest management science》1994,40(4):307-312

The insecticidal activity of several new fluorinated pyrethroids was measured using houseflies untreated and treated with piperonyl butoxide (PB). 10, 10-Difluorophenothrin and 10, 10-difluoroallethrin, which include fluorine atoms at a position most easily attacked by mixed function oxidases (mfo) in the acid moiety, showed smaller topical LD₅₀ values on the PB-untreated flies than the parent insecticides but rather large values on the PB-treated flies, suggesting that the introduction of fluorine prevents metabolic oxidation, although it has a negative effect on the interaction with a target site. Monofluorinated analogues of phenothrin, in which the structure of chrysanthemic acid was rearranged, still had moderate insecticidal activity, but flies were scarcely killed by 7 fluoroallethrin into which fluorine was introduced at a position most easily oxidized by mfo in the alcohol moiety. Competitive oxidation of the fluorinated derivatives and the parent compounds showed that fluorine at both the 10- and 7′-positions stabilizes the alkenyl side-chains of the pyrethroids against selenium dioxide and m-chloroperoxybenzoic acid. Photochemical studies with 10, 10-difluorophenothrin indicated that the photo-instability of the cyclopropanecarboxylic part could not be improved by this modification.  相似文献   

A case of long-term sildenafil therapy in a young dog with pulmonary hypertension   总被引：1，自引：0，他引：1  

Toyoshima Y  Kanemoto I  Arai S  Toyoshima H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(10):1073-1075

A 7-month-old male Papillon was presented to us with mild dyspnea, cyanosis and a diastolic murmur detected by cardiac auscultation. Echocardiography revealed severe pulmonary arterial hypertension (PH), and administration of 1 mg/kg of oral sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor, twice daily was initiated. Exercise capacity, cyanosis, dyspnea and cardiac murmur were improved after therapy for 4 weeks. PCV was remarkably high (74%) after therapy for 3 years, however, increasing the dose of sildenafil decreased this value (60%). Follow-up after therapy for 4 years revealed that treatment with oral sildenafil only continued to provide the dog with an excellent quality of life, without any side effects.  相似文献   

Characteristics of structures and lesions of the eye in laboratory animals used in toxicity studies     

Kazumoto Shibuya  Masayuki Tomohiro  Shoji Sasaki  Seiji Otake 《Journal of toxicologic pathology》2015,28(4):181-188

Histopathology of the eye is an essential part of ocular toxicity evaluation. There are structural variations of the eye among several laboratory animals commonly used in toxicity studies, and many cases of ocular lesions in these animals are related to anatomical and physiological characteristics of the eye. Since albino rats have no melanin in the eye, findings of the fundus can be observed clearly by ophthalmoscopy. Retinal atrophy is observed as a hyper-reflective lesion in the fundus and is usually observed as degeneration of the retina in histopathology. Albino rats are sensitive to light, and light-induced retinal degeneration is commonly observed because there is no melanin in the eye. Therefore, it is important to differentiate the causes of retinal degeneration because the lesion occurs spontaneously and is induced by several drugs or by lighting. In dogs, the tapetum lucidum, a multilayered reflective tissue of the choroid, is one of unique structures of the eye. Since tapetal cells contain reflecting crystals in which a high level of zinc has been demonstrated chemically, drug-induced tapetum degeneration is possibly related to zinc chelation. The eye of the monkey has a macula similar to that of humans. The macula consists only of cones with a high density, and light falls directly on the macula that plays an important role in visual acuity. Macular degeneration occurring in monkeys resembles histopathologically that of humans. Hence, the eye of the monkey is a suitable model to investigate macular degeneration and to assess drug-induced macular lesions.  相似文献   

Assessing the usefulness of otolith elemental compositions for evaluating the population structure of the Pacific herring <Emphasis Type="Italic">Clupea pallasii</Emphasis> in northern Japan     

Kodai Yamane  Kotaro Shirai  Yoshitomo Nagakura  Tsuguo Otake 《Fisheries Science》2012,78(2):295-307

The present study examined whether the elemental compositions of whole otoliths and chronological transect profiles of otoliths covering the complete life history are useful for evaluating the population structure of Pacific herring. Eight elemental ratios, Li:Ca, Na:Ca, Mg:Ca, K:Ca, Mn:Ca, Cu:Ca, Sr:Ca, and Ba:Ca, were measured in whole otoliths and in a series of ablations across the life-history transects by laser ablation inductively coupled plasma mass spectrometry. We studied fish from three sample groups collected from Lake Obuchinuma, Miyako Bay, and Akkeshi Bay of northern Japan from March to May 2008. Significant differences were found in the Na:Ca, Mg:Ca, P:Ca, K:Ca, Mn:Ca, and Ba:Ca ratios of the whole otoliths and in the Li:Ca, Na:Ca, K:Ca, Mn:Ca, Sr:Ca, and Ba:Ca ratios of the otolith core among the three sample groups. Therefore, the present study showed clear differences in elemental composition among the three sample groups from different locations, suggesting that otolith elemental compositions reflect the habitats experienced by individual fish.  相似文献   

A new strain of Melon necrotic spot virus that is unable to systemically infect Cucumis melo     

Ohki T  Sako I  Kanda A  Mochizuki T  Honda Y  Tsuda S 《Phytopathology》2008,98(11):1165-1170

We report a new strain of Melon necrotic spot virus (MNSV) that is unable to systemically infect Cucumis melo. A spherical virus (W-isolate), about 30 nm in diameter like a carmovirus, was isolated from watermelons with necrotic symptoms. The W-isolate had little serological similarity to MNSV, and it did not cause any symptoms in six melon cultivars susceptible to MNSV; however, the host range of the W-isolate was limited exclusively to cucurbitaceous plants, and transmission by O. bornovanus was confirmed. Its genomic structure was identical to that of MNSV, and its p89 protein and coat protein (CP) showed 81.6 to 83.2% and 74.1 to 75.1% identity to those of MNSV, respectively. Analysis of protoplast showed that the W-isolate replicated in melons at the single-cell level. Furthermore, chimeric clones carrying the CP of MNSV induced necrotic spots in melons. These results suggested that the absence of symptoms in melons was due to a lack of ability of the W-isolate to move from cell to cell. In view of these findings, we propose that the new isolate should be classified as a novel MNSV watermelon strain.  相似文献   

Spontaneous Renal Tumors Suspected of Being Familial in Sprague-Dawley Rats     

Kayoko Kudo  Toru Hoshiya  Tomomi Nakazawa  Tsubasa Saito  Natsumi Shimoyama  Isamu Suzuki  Kazutoshi Tamura  John Curtis Seely 《Journal of toxicologic pathology》2012,25(4):277-280

Spontaneous renal tubule tumors (RTTs), with a distinctive morphological phenotype, were present in three Sprague-Dawley rats, 1 male and 2 females, out a total of 120 animals of each sex from untreated and placebo control groups in a 2-year carcinogenicity study. One female had one carcinoma, adenoma and hyperplasia, and the other female had five adenomas and many hyperplastic lesions; the male case had one carcinoma. From these cases, a biological continuum of hyperplasia, adenoma and carcinoma could be recognized. The tumors were present in the renal cortex and appeared as solid lobulated growths with occasional central necrosis. The lobules were divided by a small amount of fibrovascular tissue. Occasionally the larger tumors contained a cystic area. Tumor cells appeared distinctive and exhibited variable amounts of eosinophilic/amphophilic and vacuolated cytoplasm. Nuclei were round to oval with a prominent nucleolus. Mitotic figures were uncommon, and no distant metastasis was noted. The tumors were seen as multiple and bilateral lesions in two animals and had no apparent relationship to chronic progressive nephropathy (CPN). Foci of tubule hyperplasia were also noted to contain the same type of cellular morphology. The morphological and biological features of these 3 cases resembled the amphophilic-vacuolar (AV) variant of RTT that has been posited to be of familial origin. This is a report of spontaneous familial renal tumors in Sprague-Dawley rats from Japan.  相似文献   

An evaluation of interventions for reducing the risk of PRRSV introduction to filtered farms via retrograde air movement through idle fans   总被引：1，自引：0，他引：1  

Alonso C  Otake S  Davies P  Dee S 《Veterinary microbiology》2012,157(3-4):304-310

Porcine reproductive and respiratory syndrome virus (PRRSV) is an economically significant pathogen of pigs that can be transported via the airborne route out to 9.1 km. To reduce this risk, large swine facilities have started to implement systems to filter contaminated incoming air. A proposed means of air filtration failure is the retrograde movement of air (back-drafting) from the external environment into the animal air space through non-filtered points such as idle wall fans; however, this risk has not been validated. Therefore, the purpose of this study was threefold: (1) to prove that PRRSV introduction via retrograde air movement through idle fans is a true risk; (2) to determine the minimum retrograde air velocity necessary to introduce PRRSV to an animal airspace from an external source; and (3) to evaluate the efficacy of different interventions designed to reduce this risk. A retrograde air movement model was used to test a range of velocities and interventions, including a standard plastic shutter, a plastic shutter plus a canvas cover, a nylon air chute, an aluminum shutter plus an air chute and a double shutter system. Results indicated that retrograde air movement is a real risk for PRRSV introduction to a filtered air space; however, it required a velocity of 0.76 m/s. In addition, while all the interventions designed to reduce this risk were superior when compared to a standard plastic shutter, significant differences were detected between treatments.  相似文献   

Collembolan community dynamics during deciduous forests regeneration in Japan     

Motohiro Hasegawa  Kenji Fukuyama  Shun&#x;ichi Makino  Isamu Okochi  Hideaki Goto  Takeo Mizoguchi  Tadashi Sakata  Hiroshi Tanaka 《Pedobiologia》2006,50(2):117-126

The structure and feeding group composition of collembolan communities were studied in secondary deciduous forests of different ages to investigate the collembolan community response to environmental changes associated with forest cycles. The study was carried out at eight sites forming a chronosequence (1, 4, 12, 24, 51, 54, 71 and 128 years after clear cutting) of deciduous forest stands in northern Ibaraki (Japan). Total collembolan density and species richness was low at the 1-year-old site, and there was little difference in density among sites over 4 years of age. The density of sucking feeders was especially low at the 1-year-old site. Species richness of trees of a diameter at breast height (DBH)<5 cm positively correlated with the density of fungal feeders. Species richness of total Collembolans and of sucking feeders correlated positively with the water content of the organic layer. Ordination of the collembolan community with Canonical Correspondence Analysis suggested that species richness of larger trees (DBH 5 cm) contributed to the differences in species composition of fungal feeders and sucking feeders. We conclude that total abundance and species richness of collembolans recovered within 4 years after clear-cutting, but species composition of fungal feeders and sucking feeders took longer to recover.  相似文献   

Development of green onion and cabbage certified reference materials for quantification of organophosphorus and pyrethroid pesticides     

Otake T  Yarita T  Aoyagi Y  Kuroda Y  Numata M  Iwata H  Mizukoshi K  Nakamura M  Watai M  Mitsuda H  Fujikawa T  Ota H 《Journal of agricultural and food chemistry》2011,59(16):8568-8574

Green onion and cabbage certified reference materials for the analysis of pesticide residues were issued by the National Metrology Institute of Japan, part of the National Institute of Advanced Industrial Science and Technology. Green onion and cabbage samples were grown so as to contain several kinds of organophosphorus and pyrethroid pesticides, and those were collected from a field in the Kochi Prefecture in Japan. The certification was carried out by using multiple analytical methods to ensure the reliability of analytical results; the values of target pesticides (diazinon, fenitrothion, cypermethrin, etofenprox, and permethrin for green onion and chlorpyrifos, fenitrothion, and permethrin for cabbage) were obtained by isotope dilution mass spectrometry. Certified values of target pesticides were 0.96-13.9 and 2.41-6.9 mg/kg for green onion and cabbage, respectively. These are the first green onion and cabbage powder certified reference materials in which organophosphorus and pyrethroid pesticides are determined.  相似文献