Quantitative in vivo measurement of central benzodiazepine receptors in the brain of cats by use of positron-emission tomography and [11C]flumazenil   总被引：1，自引：0，他引：1  

Shimada Y  Kiyosawa M  Nariai T  Oda K  Toyama H  Ono K  Senda M  Ishiwata K 《American journal of veterinary research》2003,64(8):999-1002

OBJECTIVE: To map central benzodiazepine receptors (BZRs) in the brain of cats by use of positron-emission tomography (PET) and [11C]flumazenil. ANIMALS: 6 male cats that weighed between 2.0 and 3.6 kg. PROCEDURE: Brain images obtained by PET evaluation of [11C]flumazenil were superimposed on T2-weighted magnetic-resonance imaging (MRI) scans of the same cats. Detailed anatomic regions, such as the cerebral cortex, striatum, thalamus, midbrain, and cerebellum, on the PET images were evident by PET-MRI registration. Regional binding of [11C]flumazenil to BZRs was quantitatively measured by use of a model with 2 tissue compartments and 4 variables. RESULTS: The highest value for distribution volume was observed in the cerebral cortex, and the lowest value was found in the midbrain of cats. CONCLUSIONS AND CLINICAL RELEVANCE: Binding of [11C]flumazenil to BZRs in the brain of cats can be quantitatively measured by use of PET with the aid of PET-MRI registration. It is difficult to diagnose changes in these neuroreceptors within the field of current veterinary science. In the future, PET should prove useful for investigating and diagnosing brain disorders in animals in clinical settings.  相似文献   

Lolitrem B residue in fat tissues of cattle consuming endophyte-infected perennial ryegrass straw.     

Shigeru Miyazaki  Ikumi Ishizaki  Masumi Ishizaka  Tadashi Kanbara  Yuriko Ishiguro-Takeda 《Journal of veterinary diagnostic investigation》2004,16(4):340-342

Lolitrems are neurotoxins found in endophyte-infected perennial ryegrass. Lolitrems, primarily lolitrem B, are the causative agents of ryegrass staggers in livestock. To guarantee the safety of meat produced from cattle consuming endophyte-infected perennial ryegrass, lolitrem B concentrations in tissues of Japanese Black cattle were determined using high-performance liquid chromatography. Lolitrem B was not detected in muscle, liver, kidney, or cerebrum of a Japanese Black cow with signs of ryegrass staggers. In contrast, perirenal fat contained 210 ppb lolitrem B. Three cows that received half as much perennial ryegrass straw as the cow with ryegrass staggers showed no clinical signs of ryegrass staggers. However, low concentrations of lolitrem B (less than 150 ppb) were detected in their fat tissue. These observations indicate that human exposure to the neurotoxic effect of lolitrem B through beef is unlikely. The amount of lolitrem B consumed by cattle can be estimated by the determination of lolitrem B in fat tissue.  相似文献   

Identification and characterization of ace1-type acetylcholinesterase likely associated with organophosphate resistance in Plutella xylostella     

Ji Hyung Baek  Dae-Weon Lee  Tadashi Miyata 《Pesticide biochemistry and physiology》2005,81(3):164-175

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Susceptibilities to methamidophos and enzymatic characteristics in 18 species of pest insects and their natural enemies in crucifer vegetable crops     

Gang Wu  Tadashi Miyata 《Pesticide biochemistry and physiology》2005,82(1):79-93

The susceptibilities to methamidophos as well as the kinetic and inhibitory parameter of acetylcholinesterases (AChE) and the activities of carboxyestsrases (CarE) and glutathione-S-transferases (GST) were studied in 18 species field populations of insects collected in Fuzhou, China during April and May 2000 and 2001. The insect species included five hymenopteran endoparasitoids, one hymenopteran exoparasitoid, one hymenopteran hyperparasitoid, one dipteran predator, four coleopteran predator ladybirds, six herbivorous pest insects of lepidoptera, diptera, homoptera, and coleoptera, respectively. There existed significant correlations between the susceptibility to methamidophos and the k_i values of AChE to methamidophos, dichlorvos, and carbofuran and between the k_i and V_max values of AChE among 18 species of insects. The six herbivorous pests and four ladybirds showed significantly low k_i and V_max values of AChE compared to the seven parasitoids and predator Epistrophe balteate. It was difficult to correlate the susceptibility to methamidophos or the k_i values with the K_m values of AChE, or with the activity of CarE and GST. The activities of CarE and GST varied depending on the different insect species. Significant synergisms of piperonyl butoxide (PB), triphenyl phosphate (TPP), and diethyl maleate (DEM) with methamidophos were observed in 14 pest insects and their natural enemies. Synergisms of PB were found to be the greatest. Reduced k_i values suggested that insensitive AChE might play a critical role in the tolerance to methamidophos in the 18 insect species. The detoxification enzymes, mixed-function oxidase (MFO), CarE, and GST, were believed to be involved in the tolerance to methamidophos. MFO might play the most important role, and CarE or GST might be important in the tolerance in some insect species. Different models of tolerance to methamidophos and enzymatic potential were existed in parasitoids, predators, and herbivores based on the different selection of insecticide pressure (either directly by exposing to the spray in the field, or indirectly by the insecticides penetrated into the body of host insects) as well as different ecological and biological habitats.  相似文献   

Pythium rot of Chinese cabbage (Brassica rapa L. subsp. pekinensis) caused by Pythium aphanidermatum     

Motoaki Tojo  Tatsurou Shigematsu  Hisataka Morita  Yingjie Li  Tadashi Matsumoto  Satoshi T. Ohki 《Journal of General Plant Pathology》2005,71(5):384-386

Severe rot was found at the base of leaves and stems of Chinese cabbage (Brassica rapa L. subsp. pekinensis) in Ibaraki Prefecture every year in early September from 2002 through 2004. The causal fungus was identified as Pythium aphanidermatum (Edson) Fitzpatrick. This is the first report of P. aphanidermatum on Chinese cabbage. A similar disease of Chinese cabbage caused by P. ultimum Trow var. ultimum is known as Pythium rot. We propose adding P. aphanidermatum as a new pathogen of this disease.  相似文献   

Confirmation of yessotoxin production by the dinoflagellate <Emphasis Type="Italic">Protoceratium reticulatum</Emphasis> in Mutsu Bay     

Kensuke?Eiki  Masayuki?Satake  Kazuhiko?Koike  Takehiko?Ogata  Tadashi?Mitsuya  Yasukatsu?OshimaEmail author 《Fisheries Science》2005,71(3):633-638

ABSTRACT:   Yessotoxin (YTX) is a shellfish toxin and its contamination in bivalves has seriously damaged shellfish industries. The biogenetic origin of YTX was identified as the dinoflagellate Protoceratium reticulatum (Claparède et Lachmann) Bütschli collected in New Zealand and Yamada Bay, Iwate in Japan. Scallops cultured in Mutsu Bay, Japan, were frequently contaminated with YTX, however, occurrence of P. reticulatum in this bay and YTX production by the local strains have not been investigated. Eight strains of P. reticulatum , isolated from the bay, were cultured in the laboratory, and analyzed by fluorometric high-pressure liquid chromatography and liquid chromatography/mass spectrometry methods for YTX production and composition. All strains tested were confirmed to produce YTX, and none of them produced known YTX analogs. Toxin amount and composition differed from strain to strain. This result is also confirmation of one of the biogenetic origins of YTX in Mutsu Bay.  相似文献   

Quantification of lipophilic toxins associated with diarrhetic shellfish poisoning in Japanese bivalves by liquid chromatography-mass spectrometry and comparison with mouse bioassay     

Toshiyuki?SuzukiEmail author  Taketo?Jin  Yuri?Shirota  Tadashi?Mitsuya  Yutaka?Okumura  Takashi?Kamiyama 《Fisheries Science》2005,71(6):1370-1378

ABSTRACT:   Quantification of lipophilic toxins in bivalves associated with diarrhetic shellfish poisoning was investigated by liquid chromatography–mass spectrometry (LC–MS). Using a C8-silica reversed phase column and a mobile phase of aqueous acetonitrile containing 2 mM ammonium formate and 50 mM formic acid, okadaic acid, dinophysistoxin-1, 7- O -palmitoyldinophysistoxin-1, pectenotoxin-1, pectenotoxin-2, pectenotoxin-6, pectenotoxin-2 seco-acid, yessotoxin, and 45-hydroxyyessotoxin in bivalves were quantified by LC–MS in the negative mode. When the crude 90% methanol extracts were analyzed by LC–MS, there were no significant effects from bivalve matrices on the quantification of toxins. More than 200 bivalve samples collected from various production areas in Japan were analyzed by LC–MS. Pectenotoxin-6 and dinophysistoxin-1 were the dominant toxins in scallops and mussels, respectively. Yessotoxin and 45-hydroxyyessotoxin were also detected in both species. Comparison of the quantitative results obtained for these bivalve samples between LC–MS and mouse bioassay indicates that LC–MS is suitable for routine monitoring of lipophilic toxins in Japanese bivalves.  相似文献   

Development of room-temperature curing aqueous emulsion-type acrylic adhesive I: effect of monomer composition on the initial adhesive strength     

Atsushi Mori  Kazuhisa Tashiro  Kyoko Makita  Masahiro Takatani  Tadashi Okamoto 《Journal of Wood Science》2005,51(1):33-37

For the purpose of developing a new aqueous emulsion-type adhesive for wood or paper use that does not release formaldehyde or volatile organic solvents, a honeymoon-type acrylic adhesive was examined. An adhesive system consisting of acrylic monomers copolymerized with functional monomers and a cross-linking agent was selected for the purposes of increasing initial adhesive strength and ensuring room-temperature curing. The initial adhesive strength increased by the use of cross-linkers such as dihydrazides and also polymeric methylene diphenyl diisocyanate (pMDI). Thus an adhesive with reasonable to good initial adhesive strength and room-temperature curing was obtained. The effect of pMDI on the initial adhesive strength was not significant and decreased when the amount of acrylamide in a copolymer was high.  相似文献   

Methane uptake and nitrous oxide emission in Japanese forest soils and their relationship to soil and vegetation types   总被引：1，自引：1，他引：1  

Tomoaki MORISHITA  Tadashi SAKATA  Masamichi TAKAHASHI  Shigehiro ISHIZUKA  Takeo MIZOGUCHI  Yoshiyuki INAGAKI  Kazuhiko TERAZAWA  Satoshi SAWATA  Masanori IGARASHI  Hiroshi YASUDA  Yasuhiro KOYAMA  Yoshihito SUZUKI  Nobuyuki TOYOTA  Masamichi MURO  Masaru KINJO  Hirokazu YAMAMOTO  Daitaro ASHIYA  Yoichi KANAZAWA  Tetsu HASHIMOTO  Hidetaka UMATA 《Soil Science and Plant Nutrition》2007,53(5):678-691

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低温胁迫和氮素营养对番茄畸形果发生的影响   总被引：10，自引：0，他引：10  

张光星  王靖华  杨锦忠  伊东正 《中国农业科学》1998,31(1):21-26

研究表明,番茄幼苗生长点的碳、氮水平因氮肥的多寡而异,且经低温胁迫之后变化急剧。氮素较多（4 ～8mmol/L）和低温胁迫（3～8℃）,产生畸形果30%左右。氮素较多加之较低温度胁迫（3～5℃）,会显著加重畸形程度,畸形果病情指数达17.5%以上;低氮(2mmol/L)低温胁迫时,产生椭圆果和链斑果较多,合计达到88.7% ～90.6%;中氮(4mmol/L)或高氮(8mmol/L)低温胁迫时,产生窗孔果、顶裂果的比率增大。不同类型的畸形果单果重差异明显。  相似文献