Myofibrillar proteolysis in chick muscle cell cultures during heat stress     

Kazuki NAKASHIMA  Itoko NONAKA  Shigehiko MASAKI  Makoto YAMAZAKI  Hiroyuki ABE 《Animal Science Journal》2004,75(4):353-360

The effect of heat stress on protein oxidation and myofibrillar proteolysis in chick myotubes was investigated. Myotubes were incubated at 37 or 41°C for 6 and 24 h. Protein carbonyl content, as an index of protein oxidation, increased more at 41°C than at 37°C for 6 and 24 h incubations. N^τ‐methylhistidine release as an index of myofibrillar proteolysis also increased more at 41°C than at 37°C for 6 and 24 h incubations. Proteasome activity also increased more under those same conditions. Calpain and cathepsin D but not B + L activities showed a greater increase at 41°C than at 37°C for 24 but not the 6 h incubation. These results indicate that heat stress increases protein oxidation and proteasome activity, resulting in an increase in myofibrillar proteolysis for short‐term incubation and, for long‐term incubation, it increases calpain, proteasome and cathepsin D activities, finally accelerating myofibrillar proteolysis in chick myotubes.  相似文献   

Effects of oral orbifloxacin on fecal coliforms in healthy cats: a pilot study     

Kazuki HARADA  Atsushi SASAKI  Takae SHIMIZU 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):83-89

The study objective was to determine the effect of oral orbifloxacin (ORB) on antimicrobial susceptibility and composition of fecal coliforms in cats. Nine cats were randomized to two groups administered a daily oral dose of 2.5 and 5.0 mg ORB/kg for 7 days and a control group (three cats per group). Coliforms were isolated from stool samples and were tested for susceptibilities to ORB and 5 other drugs. ORB concentration in feces was measured using high-performance liquid chromatography (HPLC). The coliforms were undetectable after 2 days of ORB administration, and their number increased in most cats after termination of the administration. Furthermore, only isolates of Escherichia coli were detected in all cats before administration, and those of Citrobacter freundii were detected after termination of the administration. E. coli isolates exhibited high ORB susceptibility [Minimum inhibitory concentration (MIC), ≤0.125 µg/ml] or relatively low susceptibility (MIC, 1−2 µg/ml) with a single gyrA mutation. C. freundii isolates largely exhibited intermediate ORB susceptibility (MIC, 4 µg/ml), in addition to resistance to ampicillin and cefazolin, and harbored qnrB, but not a gyrA mutation. HPLC revealed that the peaks of mean concentration were 61.3 and 141.0 µg/g in groups receiving 2.5 and 5.0 mg/kg, respectively. Our findings suggest that oral ORB may alter the total counts and composition of fecal coliform, but is unlikely to yield highly fluoroquinolone-resistant mutants of E. coli and C. freundii in cats, possibly because of the high drug concentration in feces.  相似文献   

Effects of Monoglycerides of Varying Fatty Acid Chain Length and Mixtures Thereof on Sponge‐and‐Dough Breadmaking Quality     

Kazuki Hattori  Brigitte Dupuis  Bin Xiao Fu  Nancy M. Edwards 《Cereal Chemistry》2015,92(5):481-486

Monoglycerides are widely used in the baking industry because of their antistaling effects, mainly suppressing crumb firming. Commercial monoglycerides are normally prepared from hydrogenated fats, with stearate being the most common fatty acid. In a previous study, monoglycerides such as monopalmitate (C16) and monostearate (C18) had positive effects on Canadian short process bread but no improvements on sponge‐and‐dough process (SDP) bread. The objective of this study was to investigate the effects of saturated monoglycerides of varying fatty acid chain length (C14–C22) on SDP breadmaking quality by using volume judgment, crumb image analysis, and texture measurements. Higher levels (1.00–1.50%) of all monoglycerides (C14, C16, and C18) significantly (P < 0.05) increased loaf volume and cell diameter. The larger cell diameter with increasing levels of these monoglycerides may have resulted from softer, more extensible dough handling properties and greater gas cell stability during baking. Addition of C16 and C18 caused the largest increase in crumb softness with increasing monoglyceride levels but showed relatively low resilience, which might be related to larger loaf volume (i.e., lower density of bread). However, addition of blended monoglycerides C14+C16 increased crumb softness and loaf volume while partially retaining resilience. Each monoglyceride had a different function in breadmaking quality and somewhat positive effects on SDP.  相似文献   

Development and promotion of laborsaving application technology for paddy herbicides in Japan     

Takafumi Takeshita  Koji Noritake 《Weed Biology and Management》2001,1(1):61-70

Total labor time on paddy rice has been decreasing year by year with the development and introduction of appropriate herbicides, especially ‘one‐shot' herbicides. However, in the case of application of granules, it is still difficult for a farmer to apply herbicides while carrying heavy power backpack sprayers. New formulation recipes and different application technology such as a throw‐in type formulation on jumbo granules or flowable has improved heavy workloads in comparison with granule application by using heavy power backpack sprayers. In addition, other advantageous points such as application volume and elimination of the drift problems of this new application technology were introduced and confirmed. As a result of this introduction, these formulations were used in 830 000 ha and reached 30% of the total treatment area in paddy rice in 2000.  相似文献   

New potyvirus isolated from <Emphasis Type="Italic">Cryptotaenia japonica</Emphasis>     

Kentaro Okuno  Tomoko Hama  Minoru Takeshita  Naruto Furuya  Yoichi Takanami 《Journal of General Plant Pathology》2003,69(2):138-142

 A potyvirus, for which the name Japanese hornwort mosaic virus (JHMV) is proposed, was isolated from Japanese hornwort plants (Cryptotaenia japonica) with mosaic disease symptoms. The virus was used to inoculate mechanically 34 plants belonging to 33 species of 10 families. Of these species seven from two families were infected. Faint chlorotic spots appeared on the inoculated leaves of Chenopodium quinoa and C. amaranticolor, but no systemic infection occurred in these plants. JHMV systemically infected only Umbelliferae plants; they did not infect 26 other species in eight families. JHMV was transmitted in a nonpersistent manner by aphids (Myzus persicae). The virus was a flexuous rod-shaped particle about 750 nm in length. Sequencing the nucleotides in the 3′ terminal region of JHMV revealed that the coat protein contains 280 amino acids with a molecular mass of 32.2 kDa. The nucleotide sequence of the coat protein of JHMV had the highest similarity with that of Zantedeschia mosaic virus (83.3%) compared to those of other potyviruses (57.0%–64.9%). An antiserum against JHMV reacted strongly with JHMV and weakly with Potato virus Y. These results indicate that JHMV is a new potyvirus. Received: September 9, 2002 / Accepted: November 7, 2002 RID="*" ID="*" The nucleotide sequence determined in this work appears in the DDBJ/EMBL/GenBank nucleotide sequence databases with the accession number AB081518  相似文献   

Interaction of dinotefuran and its analogues with nicotinic acetylcholine receptors of cockroach nerve cords     

Mori K  Okumoto T  Kawahara N  Ozoe Y 《Pest management science》2002,58(2):190-196

To investigate the action of dinotefuran (MTI-446, 1-methyl-2-nitro-3-(tetrahydro-3-furylmethyl)guanidine), a recently developed insecticide, on insect nicotinic acetylcholine receptors (nAChRs), we determined the potencies of the compound and 15 analogues in inhibiting the specific binding of [3H]epibatidine (EPI), a nAChR agonist, and [3H]alpha-bungarotoxin (alpha-BGT), a competitive nAChR antagonist, to the nerve cord membranes of American cockroaches (Periplaneta americana). Racemic dinotefuran inhibited [3H]EPI binding with an IC50 of 890 nM and [3H]alpha-BGT binding with an IC50 of 36.1 microM. Scatchard analysis indicated that the dinotefuran inhibition of [3H]EPI binding was a competitive one. Slight structural modification caused a drastic reduction in potency; only four analogues were found to be equipotent to or more potent than dinotefuran. Chloropyridinyl and chlorothiazolyl neonicotinoid insecticides displayed two or three orders of magnitude higher potency than dinotefuran. There was a good correlation between the IC50 values of tested compounds obtained with [3H]EPI and those obtained with [3H]alpha-BGT. A better correlation was observed between 3-h knockdown activities (KD50) against German cockroaches (Blattella germanica) and IC50 values obtained from [3H]EPI assays than between 24-h lethal activities (LD50) and IC50 values. While the results indicate that dinotefuran and its analogues interact with the ACh-binding site in cockroach nAChRs, it remains to be elucidated why they displayed lower potencies than those expected based on their insecticidal activities.  相似文献   

Assessing raindrop impact energy at the forest floor in a mature Japanese cypress plantation using continuous raindrop-sizing instruments     

Kazuki?NankoEmail author  Norifumi?Hotta  Masakazu?Suzuki 《Journal of Forest Research》2004,9(2):157-164

The raindrop size distribution of throughfall and open rainfall was monitored continuously during a rainfall event using laser raindrop-sizing instruments (LD gauges), in order to calculate the raindrop impact energy in a plantation of mature Japanese cypress (Chamaecyparis obtusa), where surface erosion at the forest floor had been a problem. Data from two rainfall events were analyzed. The LD gauges recorded qualitative raindrop size distribution, and the capture rate during each rainfall event was used to manipulate raindrop data quantitatively. Throughfall and open rainfall comparisons revealed several important differences. First, throughfall raindrops were fewer in number and larger in size than open rainfall drops. In one rainfall event, for example, throughfall raindrops were less than one-fifth as frequent as open rainfall raindrops; in addition, the maximum throughfall raindrop diameter was 6.35mm compared to 3.31mm for open rainfall raindrops. Second, throughfall raindrops that were larger than the largest open rainfall raindrops comprised 63.8% of the throughfall precipitation by volume. Third, total raindrop impact energy from throughfall was over twice that of open rainfall. Moreover, comparison of throughfall events implied that throughfall raindrops did not always have a uniform distribution between different events or among different periods of time in one rainfall event, in contrast to findings in previous studies which showed that throughfall raindrops had a uniform size distribution independent of rainfall intensity. It is possible that an abrupt transition of throughfall intensity from low to high changes the distribution of throughfall raindrops.  相似文献   

Antimicrobial Susceptibility of Enterococcal Species Isolated from Antibiotic-Treated Dogs and Cats     

Yasushi KATAOKA  Yurie UMINO  Hiroki OCHI  Kazuki HARADA  Takuo SAWADA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(10):1399-1402

  相似文献   

Movement of the fluvial form of masu salmon, <Emphasis Type="Italic">Oncorhynchus masou masou</Emphasis>, in a mountain stream in Kyushu,Japan     

Kazuhiro?SakataEmail author  Takuya?Kondou  Naohiko?Takeshita  Akinobu?Nakazono  Seir??Kimura 《Fisheries Science》2005,71(2):333-341

Using mark-recapture methods, the movements of the fluvial form of masu salmon (Oncorhynchus masou masou) in a mountain stream on the island of Kyushu, Japan, were studied. Most (78%) of the masu salmon were recaptured in the pool in which they had been originally caught and tagged. Of those that moved between pools, the proportion of individuals that moved during the breeding period was not significantly higher than the proportion that moved during the non-breeding period. However, during the breeding period, a higher proportion of larger salmon moved than did smaller fish. The proportion of mobile large males during breeding period was higher than that for small males. Also, it was found that a few individuals showed long-range movement in the autumn. As a long-term movement, 78 individual fish (65%) that were recaptured more than three times showed high sedentary tendencies. Sixteen individual mobile fish (13%) moved and returned to the original pool. Fluvial form of masu salmon in Kyushu show a high sedentary nature; however, large mature males seem to actively move in search of female during breeding period.  相似文献   

The presence of double-stranded RNAs in <Emphasis Type="Italic">Alternaria alternata</Emphasis> Japanese pear pathotype is associated with morphological changes     

Kuko Fuke  Kana Takeshita  Nanako Aoki  Toshiyuki Fukuhara  Mayumi Egusa  Motoichiro Kodama  Hiromitsu Moriyama 《Journal of General Plant Pathology》2011,77(4):248-252

Strains of the Japanese pear pathotype of Alternaria alternata were screened for double-stranded RNAs (dsRNAs). Four strains had several dsRNAs; strain N18 was associated with several dsRNAs and had impaired growth phenotypes such as irregular mycelium and abnormal pigmentation. We isolated dsRNA-cured isolates from strain N18 by single-conidium isolation. The dsRNA-cured isolates had recovered normal growth and pigmentation. Enlarged vesicles were observed in mycelial cells of the original dsRNA-carrying N18 strain. DAPI nuclear staining revealed regression of the nuclei in dsRNA-carrying N18 cells. These results indicate that the dsRNAs might have negative effects, such as apoptosis-like cell death, on the host fungus.  相似文献