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11.
Kazuyuki D. TanakaYusuke K. Kawai Yoshinori IkenakaTsunehito Harunari Tsutomu TanikawaShima Ando Hee won MinFumie Okajima Shoichi FujitaMayumi Ishizuka 《Pesticide biochemistry and physiology》2012,103(2):144-151
Warfarin is commonly used worldwide as a rodenticide. It inhibits blood coagulation by inhibiting vitamin K 2,3-epoxide reductase (VKOR) activity leading to hemorrhage. However, it has been reported that repeated or long-term treatment with warfarin results in resistance emerging in wild rodents. Such resistance may explain why it is difficult to control rodents in many regions in Japan. In this report, we studied mutations in the VKOR gene (including the VKOR complex subunit 1 (VKORC1)), while also analyzing VKOR and clotting factor activity in black rats (Rattus rattus) in order to understand better the mechanism of warfarin resistance in this species.We sequenced the VKORC1 gene from 275 rats living in the wild in Japan. We found several types of novel base substitutions, some of which conferred warfarin resistance.There was no difference in coagulation times between warfarin-sensitive and resistant rats measured under physiological conditions. However, after warfarin administration, no effect was noted in warfarin-resistant rats, although a prolonged coagulation time was noted in warfarin-sensitive rats.We also determined the kinetic differences in hepatic microsomal VKOR-dependent activity between warfarin-resistant and sensitive rats. Warfarin-resistant rats showed 2-3-fold lower Vmax/Km values than did sensitive rats. In addition, we report that resistant rats found in the Tokyo area had a VKOR activity which was poorly inhibited by warfarin.Finally, we conclude that reduced VKOR activity and warfarin resistance in the Japanese black rat might be due to mutations in the VKORC1 gene. However, further study is needed to clarify how such rats can maintain adequate vitamin K-dependent clotting factor levels, while simultaneously exhibiting low VKOR activity and warfarin resistance. 相似文献
12.
Abe F Bennett DP Bond IA Eguchi S Furuta Y Hearnshaw JB Kamiya K Kilmartin PM Kurata Y Masuda K Matsubara Y Muraki Y Noda S Okajima K Rakich A Rattenbury NJ Sako T Sekiguchi T Sullivan DJ Sumi T Tristram PJ Yanagisawa T Yock PC Gal-Yam A Lipkin Y Maoz D Ofek EO Udalski A Szewczyk O Zebrun K Soszynski I Szymanski MK Kubiak M Pietrzynski G Wyrzykowski L 《Science (New York, N.Y.)》2004,305(5688):1264-1266
Observations of the gravitational microlensing event MOA 2003-BLG-32/OGLE 2003-BLG-219 are presented, for which the peak magnification was over 500, the highest yet reported. Continuous observations around the peak enabled a sensitive search for planets orbiting the lens star. No planets were detected. Planets 1.3 times heavier than Earth were excluded from more than 50% of the projected annular region from approximately 2.3 to 3.6 astronomical units surrounding the lens star, Uranus-mass planets were excluded from 0.9 to 8.7 astronomical units, and planets 1.3 times heavier than Saturn were excluded from 0.2 to 60 astronomical units. These are the largest regions of sensitivity yet achieved in searches for extrasolar planets orbiting any star. 相似文献
13.
Nobuyuki Okajima Isao Aoki Yoshiyuki Okada Toshio Fujita 《Pest management science》1991,32(3):265-273
Potent herbicidal ethyl 5-[N-(5,7-dimethoxy2H-1,2,4-thiadiazolo-[2,3-a] pyrimidin-2-ylidene)sulfamoyl]-1,3-dimethylpyrazole-4-carboxylate (I) was hydrolyzed under weakly basic conditions to afford a sulfonylurea (VII) , a 2-pyrimidylcyanamide (IV) and a mercaptopyrazole (VI) . The formation of these products was explained by nucleophilic attack at the 1 and 2-positions of the 1,2,4-thiadiazolo[2,3-alpyrimidine ring. This is believed to mimic the process which occurs on application to the plant. I appears to be a pro-pesticide for the sulfonylurea, VII . 相似文献
14.
Okajima M Shimada A Morita T Yoshikawa M Nishida K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(3):297-299
Metastasis of malignant carotid body tumor to multiple bones was detected in a 13-year-old female Siberian husky dog. Radiographs exhibited an abnormal mass in the retropharyngeal site and osteolytic lesions in the vertebral bodies, spinous process, tibia, and ribs. At necropsy, multiple masses were observed in the bones as well as at the dorsal area of the retropharynx. Histologically, the tumor cells, arranged in sheets and clusters, had eosinophilic finely granular cytoplasm. Immunohistochemistry showed the tumor cells were positive for neuron-specific enolase and synaptophysin. Electron microscopy demonstrated a number of dense membrane-bound granules in the cytoplasm of the tumor cells. Based on these findings, this case was diagnosed as multiple bone metastases of a malignant carotid body tumor. Spinal cord damage induced by the tumor mass was the cause of the hind limb paralysis of the present dog. 相似文献
15.
Kuwamura M Okajima R Yamate J Kotani T Kuramoto T Serikawa T 《Veterinary pathology》2008,45(4):586-591
The WTC-deafness Kyoto (dfk) rat is a new mutant characterized by deafness and abnormal, imbalanced behavior. WTC-dfk rats carry an intragenic deletion at the Kcnq1 gene; KCNQ1 plays an important role in K(+) homeostasis, and the mutation of Kcnq1 causes a cardiac long QT syndrome in humans. Here, we studied stomach lesions in these WTC-dfk rats. The most characteristic pathologic feature in the stomach was the appearance of hypertrophic gastric glands in the stomach body. The hypertrophic cells had many eosinophilic granules in their cytoplasm, and these granules were stained red with Azan stain; stained positively for trypsinogen, amylase, and chymotrypsin; and did not stain positively for pepsinogen when using immunohistochemical analysis. These staining results suggested a metaplasia toward a pancreatic acinar cells. Extensive fibrosis was found in the bottom part of the mucosa of 34-week-old WTC-dfk rats, suggesting a progression of stomach lesions with aging. Although cells that were positive for proliferating cell nuclear antigen were restricted in the area of the glandular neck in WTC control rats, positive cells in WTC-dfk rats were scattered throughout the mucosa. The parietal cells in WTC-dfk rats were negative for KCNQ1 immunohistochemical analysis. These findings indicate that a deficiency in rat Kcnq1 provokes an abnormal proliferation and differentiation of gastric glandular cells. 相似文献
16.
Shoji Nakagawa Nobuyuki Okajima Keiichiro Nishimura Toshio Fujita Minoru Nakajima 《Pesticide biochemistry and physiology》1982,17(3):259-270
The substituent effects on the symptomatic and neurophysiological activities of a number of substituted benzyl (1R)-trans-chrysanthemates against American cockroaches were quantitatively analyzed using electronic, hydrophobic, and steric parameters. The effects were shown to be highly specific to substituent positions except for those on the neuroblocking activity. Steric effect of substituents represented by van der Waals volume was found to play the most significant role in determining the variation in each activity. Peculiar substituent effects depending upon the bulkiness and position of substituents, which had been observed in the toxicity of this class of compounds, can be rationalized by the present analysis indicating that the optimum van der Waals volume of substituents is largest at the ortho and smallest at the para position. 相似文献
17.
Paddy and Water Environment - The topographical features of farmland stone walls that were damaged by two heavy rains and the 2016 Kumamoto Earthquake were studied. Topographical analyses were... 相似文献
18.
Diurnal variation in microfilaremia in a cat experimentally infected with larvae of Dirofilaria immitis 总被引：2，自引：0，他引：2
In five healthy mongrel female cats used, four cats (Cats 1-4) were experimentally inoculated with 100-123 larvae (L(3)) of Dirofilaria immitis. Cat 5 was an uninfected control. Only Cat 1 became microfilaremic on Day 201 after inoculation and the diurnal changes in the microfilaria population were monitored every 2 h for 24 h on Day 237 when a sufficient number of microfilaria were detected in the circulation. The maximum number of microfilaria in the blood (1,350/ml) occurred at 9:00 p.m. and then gradually decreased to the minimum of 300/ml at 7:00 a.m., indicating that the number of microfilaria shows a nocturnal sub-periodic pattern of diurnal rhythm even in peripheral blood of cats as an abnormal host. On postmortem examination, 10 live adult worms (three males and seven females) in Cat 1 and one live adult worm (one male) in Cat 2 were detected. 相似文献
19.
Keiichiro Nishimura Nobuyuki Okajima Toshio Fujita Minoru Nakajima 《Pesticide biochemistry and physiology》1982,18(3):341-350
A procedure to evaluate the knockdown activity of pyrethroids against house flies in which metabolic factors could be eliminated as far as possible was established. With piperonyl butoxide and NIA 16388 as the inhibitors of oxidative and hydrolytic metabolism, respectively, the “intrinsic” knockdown potencies of 22 substituted benzyl (1R)-trans-chrysanthemates and related compounds were determined 2.5–3 hr after topical application to house flies. From the intrinsic knockdown potency and the rate of progress of the knockdown symptom from the earliest stage of intoxication, a “penetration” rate constant was estimated by first-order kinetics using a two-compartment model. The rate constant was correlated quantitatively with the hydrophobic parameter of the molecule. The lower the hydrophobicity, the higher the rate constant within the range of compounds used in this study. 相似文献
20.
The farm of All India Coordinated Rice Improvement Project is located in Rajendranagar, Hyderabad, which lies in the Deccan Peninsula of India. Hyderabad is in latitude 17°N with about 500 m above sea level. The average annual rainfall of this area is about 750 mm. So it is called a semi-dry area. 相似文献