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11.
M. Shamim Hasan ZAHID Sharda Prasad AWASTHI Atsushi HINENOYA Shinji YAMASAKI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(5):535-540
To search natural compounds having inhibitory effect on bacterial growth is important,
particularly in view of growing multidrug resistant (MDR) strains of bacterial pathogens.
Like other bacterial pathogens, MDR Vibrio cholerae, the causative agent
of diarrheal disease cholera, is becoming a great concern. As an approach of searching new
antimicrobial agents, here, we show that anethole, a well-studied natural component of
sweet fennel and star anise seeds, could potentially inhibit the growth of MDR O1 El Tor
biotype, the ongoing 7th cholera pandemic variant strains of toxigenic V.
cholerae. The minimum inhibitory concentration (MIC) of anethole against
diverse O1 El Tor biotype strains is evaluated as 200
µg/ml. Moreover, the effect of anethole is
bactericidal and exerts rapid-killing action on V.
cholerae cells. This study is the first report which demonstrates
that anethole, purified from natural compound, is a potent inhibitor of growth of
toxigenic V. cholerae. Our data suggest that anethole could be a
potential antimicrobial drug candidate, particularly against MDR V.
cholerae mediated infections. 相似文献
12.
Reduction of transport stress of ayu by obligated schooling 总被引:3,自引:0,他引:3
KEI'ICHIRO IGUCHI FUMINARI ITO KOGI OGAWA NAOTO MATSUBARA TAIGA YODO TSUGIKO YAMASAKI 《Fisheries Science》2002,68(4):849-853
We investigated stress responses of ayu Plecoglossus altivelis under the hypothesis that overcrowding during transport can be a stressor and the stress predisposes fish to disease by decline in immunocompetence. The extent of stress response was determined under different fish densities. As inferred from the serum concentration of cortisol 1 day after the treatment, the density at more than 23 kg/m3 , which was within the range of normal transporting procedures, acutely evoked intense stress responses. To examine a possible way to reduce the stress response of fish under crowding conditions, we compared two fish groups established in water tanks with circulating (whirling) and turbulent currents at the same density. The cortisol levels 1 day after the treatment were 2.5-fold higher in turbulent current than in whirling current. Fish in whirling current formed a school, while those in turbulent current aggregated with each other. Schooling of fish induced by water flow may reduce their stress responses during transport. A transport system with a directional water flow should keep fish in good condition without reducing the number of fish contained. 相似文献
13.
14.
Yuichi Ozaki Hideki Tanaka Hirohiko Kagawa Hiromi Ohta Shinji Adachi Kohei Yamauchi 《Fisheries Science》2006,72(1):13-19
ABSTRACT: The fine structure of the alimentary canal in preleptocephali produced by artificially matured Japanese eel was examined. At 1 day posthatch (dph), the alimentary canal was found only above the dorsal side of the yolk mass, and the epithelium was composed of a single layer of epithelial cells. By 5 dph, the alimentary canal was divided into three segments based on the structure of the epithelial cells: foregut, midgut and hindgut, corresponding to the future esophagus, intestine and rectum, respectively. After 7 dph, the epithelium in the foregut was surrounded by a circular muscle layer, suggesting a role in the transportation of food materials. The epithelial cells of the midgut exhibited well-developed membranous structures, which are deduced to be invaginations of the cytoplasmic membrane. Pinocytotic invaginations and vacuoles were observed in the epithelial cells of the hindgut; this observation suggests that this region is involved in the uptake of food. Significant changes in morphological features of the epithelial cells in each segment were observed until 7 dph; however, these were not evident between 7 dph and 13 dph. Consequently, the differentiation of the alimentary canal was completed by 7 dph, and preleptocephalus had developed the ability to absorb food by 7 dph. 相似文献
15.
16.
Mariko Mochizuki Masahiro Osada Katsumi Ishioka Takako Matsubara Yutaka Momota Norio Yumoto Toshinori Sako Shinji Kamiya Itaru Yoshimura 《Animal Science Journal》2014,85(3):323-329
The understanding of animal products and dairy farming is important for the promotion of dairy farming. Thus, to examine the effects of farm experience on the understanding of animal products and the management of dairy farming, the interaction between students and dairy cows was investigated in groups of first‐year veterinary nursing students in 2011 and 2012 (n = 201). These students included 181 women and 20 men. Nine items about dairy cows were presented in a questionnaire. The survey was performed before and after praxis on the educational farm attached to the authors' university. After praxis on the farm, increases occurred in the number of positive responses to the items involving the price of milk, dairy farming and the taste of milk. For these items, a significant difference (P < 0.05) was found between the scores obtained before and after training. The results of the study suggested that farm experience is useful for improving the understanding of animal products and dairy farming. 相似文献
17.
Accumulation of organotin compounds and marine birnavirus detection in Korean ascidians 总被引:1,自引:0,他引:1
Kaoru Azumi Shinji Nakamura Shin-Ichi Kitamura Sung-Ju Jung Keisuke Kanehira Hisato Iwata Shinsuke Tanabe Satoru Suzuki 《Fisheries Science》2007,73(2):263-269
ABSTRACT: Recently, a serious disease spread extensively in aquaculture sites of the ascidian Halocynthia roretzi in Korea. To understand circumstances of ascidians in Korean aquaculture sites, residue levels of organotin compounds were analyzed, and detection of a marine birnavirus (MABV) in tissues of H. roretzi was attempted. Korean H. roretzi showed high concentrations of butyltins (mono, di, and tributyltins), especially in the gill, hepatopancreas, and digestive tract. However, there was no significant difference in the residues of butyltins in the hepatopancreas between diseased and non-diseased ascidians. The positive rate of MABV detection was high in the hepatopancreas, but also no significant difference was observed between diseased and non-diseased individuals. These observations suggest that an accumulation of tributyltin and a latency of MABV in H. roretzi tissues does not directly relate to the occurrence of the disease. 相似文献
18.
Manabu OZAWA Yukiko YAMASAKI Miho HIRABAYASHI Yukio KANAI 《Animal Science Journal》2003,74(3):181-185
Mammalian preimplantation embryos are susceptible to heat stress. This present study examined how maternal heat stress affects the development of mouse zygotes in vivo and in vitro. In Experiment 1, zygotes collected from female mice that were heat‐stressed for 12 h on day 1 of pregnancy were cultured in vitro. Maternally heat‐stressed zygotes developed normally to the two‐cell stage, but the majority of embryos failed to develop into morulae or blastocysts. In Experiment 2, pregnant mice were heat‐stressed on day 1 or from day 1 to day 3 of pregnancy. The number of living fetuses on day 14 of pregnancy was lower in heat‐stressed mice than in non‐stressed mice, but the difference was significant only in successively heat‐stressed mice. These results demonstrate that maternally heat‐stressed zygotes have reduced in vitro viability, but this phenomenon does not necessarily lead to embryo loss in the maternal environment. 相似文献
19.
Kassai Y Munne P Hotta Y Penttilä E Kavanagh K Ohbayashi N Takada S Thesleff I Jernvall J Itoh N 《Science (New York, N.Y.)》2005,309(5743):2067-2070
Mammalian tooth crowns have precise functional requirements but cannot be substantially remodeled after eruption. In developing teeth, epithelial signaling centers, the enamel knots, form at future cusp positions and are the first signs of cusp patterns that distinguish species. We report that ectodin, a secreted bone morphogenetic protein (BMP) inhibitor, is expressed as a "negative" image of mouse enamel knots. Furthermore, we show that ectodin-deficient mice have enlarged enamel knots, highly altered cusp patterns, and extra teeth. Unlike in normal teeth, excess BMP accelerates patterning in ectodin-deficient teeth. We propose that ectodin is critical for robust spatial delineation of enamel knots and cusps. 相似文献
20.