First evidence of Kunjin strain of West Nile virus associated with saltwater crocodile (Crocodylus porosus) skin lesions     

SR Isberg  JL Moran  R De Araujo  N Elliott  SS Davis  L Melville 《Australian veterinary journal》2019,97(10):390-393

Recently, the Kunjin strain of West Nile virus (WNV_KUN) has been detected using qRT‐PCR in belly skin lesions of farmed juvenile saltwater crocodiles. This follows an established association between similar lesions and West Nile virus in American alligators. The lesions present as cutaneous lymphohistiocytic aggregates in the dermal layers of both species. While these lesion do not create an obvious defect on the live crocodile, upon tanning the lesion area collapses and does not uptake the dye evenly, thus reducing its aesthetic appeal. As a result, skins are being rejected jeopardising the economic viability of the Australian crocodile industry. Over 50 skin lesions have since been confirmed as WNV_KUN‐positive and preliminary evidence of lesion restructuring is presented. Horizontal transmission of WNV_KUN by mosquitoes is well‐established but other transmission routes, such as ingestion and cloacal shedding, need further evaluation. An infection trial is currently underway to ensure WNV_KUN is the causative agent of these skin lesions.  相似文献   

Effects of supplemental β‐carotene on colostral immunoglobulin and plasma β‐carotene and immunoglobulin in Japanese Black cows          下载免费PDF全文

Shuntaro Ikeda  Kenichi Yoshitani  Atsutoshi Obata  Yuji Sugie  Yoshikazu Aoki  Taisuke Yamaji  Masahiko Fujita  Yoshinobu Nakatsuji  Shinichi Kume 《Animal Science Journal》2018,89(8):1102-1106

Data from 26 Japanese Black cows were collected to clarify the effects of supplemental β‐carotene on colostral immunoglobulin (Ig) and plasma β‐carotene and Ig in the cows. Cows were assigned to control or β‐carotene groups from 21 days before the expected calving date to 60 days after parturition. Supplemental β‐carotene was provided at 500 mg/day in the β‐carotene group. Supplemental β‐carotene drastically increased plasma β‐carotene concentrations in the cows from parturition to 60 days after parturition, and plasma β‐carotene concentrations in the control and β‐carotene groups at parturition were 202 and 452 μg/dl, respectively. Supplemental β‐carotene had no effects on plasma IgG₁, IgA or IgM concentrations at parturition. Supplemental β‐carotene increased colostral IgG₁ concentrations in the cows, but colostral β‐carotene, IgA and IgM concentrations were not affected by supplemental β‐carotene. These results indicate that supplemental β‐carotene is effective to enhance colostral IgG₁ concentrations and plasma β‐carotene concentrations in Japanese Black cows.  相似文献   

On the “Metsubure” symptoms of taro corms     

Ichiro Tanabe  Tokio Kitayama  Ken'ichiro Ikeda 《Soil Science and Plant Nutrition》2013,59(3):343-351

Abstract

A water culture experiment on taro was conducted with two cultivars and two kinds of culture solution (I and II) with gradient omission treatment of calcium using newly devised culture equipment, in order to investigate their influence on so-called “Metsubure” symptoms.

Calcium omission treatment in both culture solutions resulted in a considerable increase of “Metsubure” corms. The results confirmed Miyaji's data and conclusions in respect to the main cause of “Metsubure” symptoms.

Solution II proved more suitable for water culture of taro than solution I as regards the ratio of its calcium to potassium content, the moderate renewal intervals and the slower lowering of pH. However, fürther improvements may be necessary to maintain an adequate range of pH for at least 10 days.

The possibility that there might be factor(s) responsible for “Metsubure” corm formation other than calcium deficiency is also discussed.  相似文献   

Carbon skeletons for amide synthesis during ammonium nutrition in tomato and wheat roots     

Motoki Ikeda  Takeshi Kusano  Nobuhisa Koga 《Soil Science and Plant Nutrition》2013,59(1):141-147

Heavy application of ammonium nitrogen to plant roots results in the conversion of ammonium nitrogen to the nitrogen of amides, glutamine, and asparagine, which are stored in roots or translocated to shoot. Since the net synthesis of such amides requires the supply of corresponding carbon skeletons, the carbon metabolism in amide synthesis in response to ammonium supply was investigated in tomato and wheat roots. The content of major primary amino acids was determined in tomato and wheat roots during a 4-d period of ammonium nutrition after 1-d culture in nitrogen-free nutrient solution. Ammonium supply led to a continuous increase in the asparagine content in wheat roots, whereas in tomato roots, the glutamine content increased 1 d after ammonium supply and thereafter the glutamine content was higher than the asparagine content. The amounts of amino acids synthesized from glucose-¹⁴C increased while the amounts of organic acids decreased in tomato roots by the supply of ammonium nitrogen for 1 d, compared to the roots that did not receive nitrogen. In tomato roots, the proportion of labeled glutamine was higher than that of labeled asparagine and the C5 amino acids were more strongly labeled than the C4 amino acids. These findings were different from the previous ones in wheat roots where the proportion of asparagine was found to be extremely high (Koga and Ikeda 2000: J. Fac. Agr. Kyushu Univ45, 7–13). To examine the in vivo asparagine synthesis, aspartate-'4C was fed to the roots. The labeling of asparagine, which was the most strongly labeled amino acid among the free amino acids, was remarkably strong in wheat roots whereas the labeling of glutamine was also pronounced in tomato roots. These results indicate that the ability to replenish carbon skeletons for amide synthesis in ammonium nutrition is different between tomato and wheat roots.  相似文献   

Photosynthetic Carbon Metabolism in Corn Leaves Treated with Methionine Sulfoximine and Ammonium     

Motoki Ikeda 《Soil Science and Plant Nutrition》2013,59(3):469-474

The physiological role and significance of organic acids in the metabolic parts of plant which are involved in the respiratory or photosynthetic chain has not yet been elucidated apart from that of particular accumulation of specific organic acids in some storage tissues. Large fluctuations of the organic acid concentration in plants, often reflected by some minor changes in the growing conditions and even by the sampling time, may complicate the interpretation of the results obtained.

It has been considered that one of the most probable roles of organic acid accu-mulation in plant is to adjust the cation-anion balance in plant sap, and to take part in the transport of metallic cations in plant (1–3). It may also be suggested that the excess supply of sodium chloride affects appreciably the organic acid metabolism in plant through the compensation of the disequilibrium between the amount of inorganic cations and anions in plant saps caused by the uptake of a larger quantity of sodium ion (4).

The authors are currently carrying out a series of investigations about the physiological responses of crop plants to the excess supply of sodium chloride from the view point of species differences, and some of the results have been reported previously (5, 6). Recent development in high pressure liquid ion chromatography has enabled a more reliable and sensitive determination of small quantities of organic acids. In the present report the authors investigated th.e changes in the concentration of organic acids in bleeding and leaf saps of cucumber and tomato seedlings grown at different levels of sodium chloride, in relation to the concentration of inorganic cations and anions.  相似文献   

Responses to nitrogen sources and regulatory properties of root phosphoenolpyruvate carboxylase     

Nobuhisa Koga  Motoki Ikeda 《Soil Science and Plant Nutrition》2013,59(3):643-650

Time course of changes in extractable root phosphoenolpyruvate carboxylase (PEP C) activity was investigated in wheat, barley, and tomato plants fed with different nitrogen sources. Ammonium-fed plants exhibited a 2–2.5-fold higher PEPC activity than nitrate-fed plants at 7 d after the onset of nitrogen supply. Western blot analysis revealed that the amounts of PEPC subunit proteins increased gradually as reflected in the extractable PEPC activity. These results suggest that the increase in PEPC activity may be due to de novo protein synthesis. PEPC was SO-fold purified from tomato roots after several chromatographic steps. Metabolite effects on the partially purified enzyme were also investigated under optimal or suboptimal conditions in terms of pH and concentrations of phosphoenolpyruvate. Organic acids and acidic amino acids inhibited the enzyme activity, while hexose phosphates stimulated it. Glutamine and asparagine produced in the course of ammonium assimilation hardly affected the activity.  相似文献   

Mathematical Model of Lateral Oxygen Diffusion and Respiration of Roots for Estimating the Diffusion Coefficient and Affinity to Oxygen     

Jun-ichi Ikeda  Toshiki Nakamura 《Soil Science and Plant Nutrition》2013,59(4):691-699

We propose herein a mathematical model, for calculating the oxygen diffusion coefficient (D) and K _m value of a cell (M) based on oxygen concentration-respiration rate curve obtained under the condition that oxygen was supplied by lateral diffusion in roots. The model was deductively developed on the assumption that the roots were uniform and cylindrical and that the oxygen concentration and respiration rate were interdependent.

We estimated D and M from the oxygen concentration-respiration curves of rice (cv. Fujisaka 5) and wheat (cv. Chinese Spring) using this model. These values showed a certain range as follows. In rice, 0.003 cm² h^-1 ≤ D < 0.037 cm² h^-1, and 0.55 μmol mL^-1 ≤ M < 0.75 μmol mL^-1, in wheat, 0.016 cm² h^-1 ≤ D < 0.093 cm² h^-1, and 2.1 μmol mL^-1 ≤ M < 2.2 μmol mL^-1. By comparing the values, rice appeared to be more adapted to hypoxia than wheat, because rice had lower D and M values implying the existence of a safeguard mechanism and high affinity to oxygen. Higher oxygen uptake rate under hypoxia in rice was derived from the lower M value, which exceeded the low D.  相似文献   

Mirror image reactions in the oval squid Sepioteuthis lessoniana     

Yuzuru Ikeda  Gen Matsumoto 《Fisheries Science》2007,73(6):1401-1403

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Relationships between immunoglobulin M and immunoglobulin G or A in colostrum of Japanese black multiparous cows          下载免费PDF全文

Saya Taniguchi  Mengdong Wang  Shuntaro Ikeda  Hidetugu Yoshioka  Hiroshi Nagase  Shoko Kitamura  Erina Itoyama  Hiroaki Murakami  Miki Sugimoto  Shinichi Kume 《Animal Science Journal》2016,87(4):536-540

This study was conducted to clarify the relationships among immunoglobulin (Ig)M, IgG, IgA, β‐carotene, vitamin A and α‐tocopherol contents in colostrum of 24 Japanese Black multiparous cows in order to evaluate the role of IgM on colostral IgG and IgA production. Compared with colostral IgG, colostral IgM and IgA were very low but varied widely. There was positive correlation between colostral IgM and IgG, but colostral IgM was not related with colostral IgA. There was no relationship between colostral IgM and age of cows, although colostral IgG was increased with aging. There were positive correlations among colostral β‐carotene, vitamin A and α‐tocopherol and these vitamins were positively correlated with colostral IgM and IgG. These results indicate that fat‐soluble vitamins may affect colostral IgG and IgM in cows and colostral IgG increases with the increase of colostral IgM.  相似文献   

Tetrahydrofolate-dependent vanillate and syringateO-demethylation links tightly to one-carbon metabolic pathway associated with amino acid synthesis and DNA methylation in the lignin metabolism ofSphingomonas paucimobilis SYK-6     

Tomonori Sonoki  Yuichiro Otsuka  Seiichiro Ikeda  Eiji Masai  Shinya Kajita  Yoshihiro Katayama 《Journal of Wood Science》2002,48(5):434-439

Sphingomonas paucimobilis SYK-6 strain can degrade various lignin-related compounds. In the lignin metabolic pathway of this bacterium, vanillate and syringate are demethylated by the tetrahydrofolate (THF)-dependentO-demethylation system, which requires the enzymatic function of LigH. Upstream of theligH gene is the 5,10-methylene-THF reductase gene. Its gene product was essential for one-carbon metabolism involved in the amino acid synthesis and DNA methylation in all organisms. When themetF gene was inactivated in the genome of SYK-6, the resultant mutant, DLmetF, could not grow on vanillate and syringate as a sole carbon source. Furthermore, DLmetF showed significant accumulation of methyl-THF as a result of vanillate and syringateO-demethylation. We report here that THF-dependent vanillate and syringateO-demethylation links tightly to the one-carbon metabolic pathway that is associated with amino acid synthesis and DNA methylation, and the methyl group is the sole one-carbon source inS. paucimobilis SYK-6.  相似文献