Improved porcine model for Shiga toxin‐producing Escherichia coli infection by deprivation of colostrum feeding in newborn piglets          下载免费PDF全文

Toshio Sato  Takashi Hamabata  Eiji Takita  Takeshi Matsui  Kazutoshi Sawada  Taishi Imaoka  Nobuo Nakanishi  Keizo Nakayama  Takamitsu Tsukahara 《Animal Science Journal》2017,88(5):826-831

Porcine edema disease (ED) is a toxemia caused by enteric infection with Shiga toxin 2e (Stx2e)‐producing Escherichia coli (STEC). ED occurs most frequently during the weaning period and is manifested as emaciation associated with high mortality. In our experimental infection with a specific STEC strain, we failed to cause the suppression of weight gain in piglets, which is a typical symptom of ED, in two consecutive experiments. Therefore, we examined the effects of deprivation of colostrum on the sensitivity of newborn piglets to STEC infection. Neonatal pigs were categorized into two groups: one fed artificial milk instead of colostrum in the first 24 h after birth and then returned to the care of their mother, the other breastfed by a surrogate mother until weaning. The oral challenge with 10¹¹ colony‐forming units of virulent STEC strain on days 25, 26 and 27 caused suppression of weight gain and other ED symptoms in both groups, suggesting that colostrum deprivation from piglets was effective in enhancing susceptibility to STEC. Two successive STEC infection experiments using colostrum‐deprived piglets reproduced this result, leading us to conclude that this improved ED piglet model is more sensitive to STEC infection than the previously established models.  相似文献   

Canopy temperature on clear and cloudy days can be used to estimate varietal differences in stomatal conductance in rice   总被引：1，自引：0，他引：1  

Toshiyuki Takai  Masahiro Yano  Toshio Yamamoto 《Field Crops Research》2010

Leaf photosynthetic potential, a major determinant of yield potential in rice, is mostly explained by stomatal conductance (g_s) as well as leaf N content (Rubisco protein content). Therefore, the rapid and precise evaluation of g_s as well as leaf N content would be a valuable addition to rice breeding programs aimed at improved yield potential. We established a simple method based on infrared thermography to estimate varietal differences in g_s. Seven rice varieties were cultivated in two-row plots in 2007, and canopy temperatures in three varieties, including a control variety, Koshihikari, were simultaneously measured to determine canopy temperature difference (CTd) between Koshihikari and the other varieties on clear days. The varieties Takanari, Habataki, and TUAT1-5-6a displayed significantly (P < 0.05) lower leaf temperature and higher g_s and leaf photosynthetic rate (P_n) than Koshihikari. CTd was closely correlated with g_s and P_n. These results indicate that CTd may be useful as a relative index to estimate varietal differences in g_s. A significant CTd was still observed even under cloudy conditions in 2008. Takanari and TUAT1-5-6a had lower leaf temperature than Koshihikari on cloudy days as well as on clear days. Subsequent investigation of photosynthetic light response curves revealed that Takanari and TUAT1-5-6a had higher g_s and P_n than Koshihikari under lower irradiance. These results suggest that infrared thermography may be a simple method of evaluating varietal differences in g_s through CTd, and that it may be practicable even under cloudy conditions.  相似文献   

Molecular typing and antimicrobial resistance of Salmonella enterica subspecies enterica serovar Choleraesuis isolates from diseased pigs in Japan     

Asai T  Namimatsu T  Osumi T  Kojima A  Harada K  Aoki H  Sameshima T  Takahashi T 《Comparative immunology, microbiology and infectious diseases》2010,33(2):109-119

Salmonella enterica serovar Choleraesuis (S. Choleraesuis) isolates derived from diseased pigs in Japan during 2001 and 2005 were analyzed for biotype, based on H(2)S production and dulcitol fermentation, pulsed-field gel electrophoresis (PFGE) profile, and antimicrobial resistance profile. S. Choleraesuis biotype Choleraesuis (biotype Choleraesuis) was classified into one genotype, while varietas Kunzendorf (var. Kunzendorf) was classified into two genotypes. The isolates of var. Kunzendorf belonging to one genotype were isolated in a limited area of Japan. Variation in the antimicrobial resistance pattern was observed in isolates of both biotypes Choleraesuis and var. Kunzendorf. We have also shown that the PFGE profile was associated with the biotype and isolation region of each isolate.  相似文献   

Collaborative non-self recognition system in S-RNase-based self-incompatibility   总被引：6，自引：0，他引：6  

Kubo K  Entani T  Takara A  Wang N  Fields AM  Hua Z  Toyoda M  Kawashima S  Ando T  Isogai A  Kao TH  Takayama S 《Science (New York, N.Y.)》2010,330(6005):796-799

Self-incompatibility in flowering plants prevents inbreeding and promotes outcrossing to generate genetic diversity. In Solanaceae, a multiallelic gene, S-locus F-box (SLF), was previously shown to encode the pollen determinant in self-incompatibility. It was postulated that an SLF allelic product specifically detoxifies its non-self S-ribonucleases (S-RNases), allelic products of the pistil determinant, inside pollen tubes via the ubiquitin-26S-proteasome system, thereby allowing compatible pollinations. However, it remained puzzling how SLF, with much lower allelic sequence diversity than S-RNase, might have the capacity to recognize a large repertoire of non-self S-RNases. We used in vivo functional assays and protein interaction assays to show that in Petunia, at least three types of divergent SLF proteins function as the pollen determinant, each recognizing a subset of non-self S-RNases. Our findings reveal a collaborative non-self recognition system in plants.  相似文献   

Detection of Pythium aphanidermatum in tomato using loop-mediated isothermal amplification (LAMP) with species-specific primers     

Shiro Fukuta  Reiko Takahashi  Satoru Kuroyanagi  Noriyuki Miyake  Hirofumi Nagai  Hirofumi Suzuki  Fujio Hashizume  Tomoko Tsuji  Hiromi Taguchi  Hideki Watanabe  Koji Kageyama 《European journal of plant pathology / European Foundation for Plant Pathology》2013,136(4):689-701

A loop-mediated isothermal amplification (LAMP) reaction with a primer set designed from the rDNA ITS sequence of P. aphanidermatum was developed. Results of a specificity test using 57 strains of Pythium spp. indicated that the LAMP assay gave no cross reactions in other 39 Pythium species, 11 strains of Phytophthora spp. and eight other soil borne pathogens. The detection limit was 10 fg of genomic DNA, which was ten times the sensitivity of the polymerase chain reaction. The LAMP assay was applied to hydroponic solution samples from tomato fields, and the results were compared to those of the conventional plating method. LAMP was observed to be effective for the specific detection of P. aphanidermatum. Furthermore, P. aphanidermatum was detected directly in tomato roots infected with P. aphanidermatum without DNA extraction. The LAMP method established in this study is a simple, sensitive and rapid tool for the detection of P. aphanidermatum.  相似文献   

不同玉米品种萌芽期及苗期抗旱性初步研究   总被引：15，自引：4，他引：15       下载免费PDF全文

胡兴波  曹敏建  王学智  冢田利夫  侯玉慧 《玉米科学》2004,12(3):066-067

对4个玉米杂交种辽单35、丹玉24、沈丹16、沈农87进行萌芽期和苗期的抗旱性研究.结果表明,不同杂交种在抗旱性上存在明显差异,在水分胁迫下,抗旱性强的杂交种仍然保持较高的发芽势和发芽率,苗期叶片气孔导度、蒸腾速率、光合速率下降的幅度较小。  相似文献   

Improvement of paddy field drainage for mechanization   总被引：1，自引：1，他引：1  

Toshio?TabuchiEmail author 《Paddy and Water Environment》2004,2(1):5-10

In Japan, land consolidation and drainage improvement for farm mechanization in paddy fields began during the 1960 s. It was not easy to use big machines in the muddy conditions caused by the clayey soil and heavy rainfall during the harvesting period. A number of investigations were carried out by many researchers, and factors relating to drainage were clarified. Not only surface drainage but also underdrainage was planned. However, drainage was not always sufficient, because the clayey surface soil was impermeable to ponding water. It became clear that underdrainage for a clayey paddy field for the harvest is quite different from underdrainage for an ordinary field. Field and soil characteristics, as well as water conditions, should be examined carefully before planning drainage improvement for farm mechanization.Dr. Toshio Tabuchi is an honorable member of the Japanese Society of Irrigation, Drainage and Reclamation Engineering (JSIDRE), a former Professor of the University of Tokyo, and a former President of JSIDRE  相似文献   

Basal levels and GnRH-induced responses of peripheral testosterone and estrogen in Holstein bulls with poor semen quality     

Devkota B  Takahashi K  Matsuzaki S  Matsui M  Miyamoto A  Yamagishi N  Osawa T  Hashizume T  Izaike Y  Miyake Y 《The Journal of reproduction and development》2011,57(3):373-378

The present study investigated the basal levels and GnRH-induced responses of peripheral testosterone and estrogen in Holstein bulls with poor semen quality. On the basis of semen parameters, bulls (n=5) having poor semen quality were selected as experimental bulls, and good semen quality bulls (n=4) were used as control bulls. Both groups were treated intramuscularly once with GnRH (250 μg of fertirelin acetate). Blood samples were collected at -1 day (d), -30 min and 0 h (treatment) followed by every 30 min for 5 h and 1, 3 and 5 d post-GnRH treatment (PGT), and LH, testosterone and estradiol-17β (E(2)) concentrations were measured. The pretreatment concentrations were used as basal levels. The percentage increments based on the 0-h levels were calculated per bull for each sampling time until 5 h PGT, and differences were compared between the experimental and control groups. The PGT concentrations of testosterone and basal and PGT concentrations of E(2) were significantly lower in the experimental group. The testosterone increment in the experimental group was delayed and significantly lower from 1 to 5 h PGT than those in the control group. It can be suggested that bulls with poor semen quality have delayed and lower GnRH-induced testosterone response and may also have lower estrogen levels.  相似文献   

Anticancer activities of thelephantin O and vialinin A isolated from Thelephora aurantiotincta     

Norikura T  Fujiwara K  Narita T  Yamaguchi S  Morinaga Y  Iwai K  Matsue H 《Journal of agricultural and food chemistry》2011,59(13):6974-6979

Thelephora aurantiotincta is an edible mushroom belonging to the genus Thelephora; it grows in symbiosis with pine trees. Recently, phytochemical investigations have revealed that the genus Thelephora is an abundant source of p-terphenyl derivatives. However, their bioactivity has not yet been well characterized. In screening for natural materials with anticancer activity, a T. aurantiotincta ethanol extract (TAE) was found to decrease cell viability in human hepatocellular carcinoma cells (HepG2). In this study, a new p-terphenyl derivative, thelephantin O, and a known compound, vialinin A, were isolated as the principal bioactive components of TAE. These compounds decreased cell viability in HepG2 and human colonic carcinoma cells (Caco2), but not in noncancerous human hepatocytes. This is the first report of the isolation from T. aurantiotincta of selective cytotoxic agents against cancer cells.  相似文献   

Effects of transforming growth factor-β3 and matrix metalloproteinase-3 on the pathogenesis of chronic mitral valvular disease in dogs     

Obayashi K  Miyagawa-Tomita S  Matsumoto H  Koyama H  Nakanishi T  Hirose H 《American journal of veterinary research》2011,72(2):194-202

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