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1.
Hashino M Kim S Tachibana M Shimizu T Watarai M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(8):1075-1077
The mechanisms of abortion and sterility induced by bacterial infection are largely unknown. In the present study, we found that Brucella abortus, a causative agent of brucellosis and facultative intracellular pathogen, caused sterility in pregnant mice. We have recently established a mouse model for abortion induced by B. abortus infection and high rates of abortion are observed for bacterial infection on day 4.5 of gestation, but not for other days. Infected newborn (first generation) mice showed poor growth compared with uninfected newborn mice and bacterial replication in the spleen of the former was observed over a long period. When infected first generation female mice were mated to infected first generation male mice, the number of fetuses was significantly less than that in uninfected first generation mice. These infected second generation mice also showed poor growth. These results suggest that vertical transmission of B. abostus causes sterility in pregnant mice and our mouse model would be useful for the investigating of brucellosis. 相似文献
2.
Influence of surface charge on viscosity behavior of cellulose microcrystal suspension 总被引：3，自引：0，他引：3
Microcrystalline cellulose with minimal surface charge was prepared from softwood kraft pulp via hydrolysis by 4N hydrochloric acid instead of sulfuric acid. To this material, sulfate ester groups as surface charge were introduced by treating with 55% (w/w) sulfuric acid. A treatment at 60°C for 2h gave nearly the same level of surface charge as that of the H2SO4 -hydrolyzed microcrystal. The number of sulfate groups were controlled by changing the H2SO4 treatment conditions. Although the microscopic size and shape of the microcrystalline particles were the same irrespective of the preparation method, the introduction of surface charge drastically reduced the viscosity and removed its time dependence. These changes in viscosity behavior are considered to result from charge-induced dispersion of loose aggregates existing in the initial charge-free microcrystals prepared by HCl hydrolysis.Part of this report was presented at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998 相似文献
3.
Ibuki M Kovacs-Nolan J Fukui K Kanatani H Mine Y 《Veterinary immunology and immunopathology》2011,139(2-4):289-295
Salmonella spp. is one of the major causes of food-borne illness in humans, and Salmonella enteritidis (SE) infection in commercial poultry is a world-wide problem. Here we have investigated the in vitro immune-modulating effects of β 1-4 mannobiose (MNB), which was previously found to prevent SE infection in vivo in chickens, using chicken macrophage (MQ-MCSU) cells. Treatment of MQ-NCSU cells with MNB dose-dependently increased both phagocytic activity and Salmonella-killing activity of macrophages, with the highest reduction in SE viability observed at a concentration of 40 μg/ml at 48 h post-infection. Likewise, both hydrogen peroxide (H(2)O(2)) and nitric oxide (NO) production were increased in a dose-dependent manner by MNB. Gene expression analysis of MNB-treated macrophages revealed significant increases in the expression of iNOS, NOX-1, IFN-γ, NRAMP1, and LITAF, genes critical for host defense and antimicrobial activity, when compared to untreated cells. This data confirms that MNB possesses potent innate immune-modulating activities and can up-regulate antibacterial defenses in chicken macrophages. 相似文献
4.
Kim S Asakura H Kuri A Watarai M Shirahata T Takeshi K Tsukamoto T Makino S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(10):927-931
To investigate a long-term shedding of Shiga toxin (Stx)-producing Escherichia coli (STEC) from sheep, a fifteen-month study for STEC isolation from a sheep, which had yielded STEC before, was attempted. The sheep continued to shed STEC and 39 STEC were isolated. The number of STEC in the feces was estimated at 1.7 x 10(3) per gram. In addition, although Stx1-negative O157 and stx2-encoding bacteriophage were experimentally infected to the sheep, Stx-positive O157 or Stx2- producing bacterial cells were not detected. The genetical and biochemical characterization of those 39 STEC strains showed that all STEC strains produced Shiga toxin 1 (Stx1) and were divided into three classes (I to III). From phylogenetic analysis of their amino acid sequences, class-I STEC was classified as group 1 comprising mainly human STEC, and classes II/III were as group 2 comprising sheep STEC. Our results suggest that STEC easily colonized in sheep and that the sheep continued to shed STEC, showing that sheep might be an important reservoir for human STEC infection. 相似文献
5.
Watanabe K Iwai N Tachibana M Furuoka H Suzuki H Watarai M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(7):681-686
Brucella abortus (B. abortus) is a facultative intracellular pathogen that can survive inside macrophages and trophoblast giant cells, and the causative agent of brucellosis. In the present study, we found that production of regulated upon activation normal T-cell expressed and secreted (RANTES) due to B. abortus infection contributes to abortion in pregnant mice. B. abortus infected pregnant interferon-gamma (IFN-gamma) knockout mice died within 15 days of infection, but non-pregnant IFN-gamma knockout mice were still alive. With infection by wild type B. abortus, a large amount of RANTES production was observed in pregnant IFN-gamma knockout mice, and induction of RANTES was also observed in normal pregnant mice infected with the wild type, but not in those infected with the intracellular replication-defective mutant. Production of RANTES and IFN-gamma were inhibited in mice inoculated with the respective RANTES or IFN-gamma antibody. Neutralization of RANTES, induced by B. abortus infection, served to prevent abortion. These results indicate that the production and function of RANTES are correlated with IFN-gamma in pregnant mice infected with B. abortus. 相似文献
6.
Kim S Watanabe K Shirahata T Watarai M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(9):1059-1063
Brucella spp. are facultative intracellular pathogens that have the ability to survive and multiply in professional and nonprofessional phagocytes, and cause abortion in domestic animals and undulant fever in humans. The mechanism and factors of virulence are not fully understood. High-affinity zinc uptake system protein mutant (znuA mutant) showed reduced growth in zinc chelated medium, and failed to replicate in HeLa cells and mouse bone marrow-derived macrophages. Transformation of znuA mutant with a shuttle vector pBBR1MCS-4 containing znuA gene restored the growth in zinc chelated medium and intracellular replication in HeLa cells and macrophages to a level comparable to that of wild-type strain. Bacterial internalization into HeLa cells and macrophages and co-localization with either late endosomes or lysosomes of znuA mutant were not different from those of wild-type strain. These results suggest that znuA does not contribute to intracellular trafficking of B. abortus, but contributes to utilization of zinc required for intracellular growth. 相似文献
7.
Patricia Rodríguez Freddy Gonzlez-Mujica Jairo Bermúdez Masahisa Hasegawa 《Fitoterapia》2010,81(8):1220-1223
Glucose intestinal absorption (GIA) is one of the factors that increase glycemia. Its reduction could be an important factor in decreasing hyperglycemia in diabetic patients. It has been shown that the aqueous extract of Bauhinia megalandra leaves inhibits GIA. In the present study we identified a compound present in the extract of B. megalandra responsible for the biological effect. The methanol extract of B. megalandra leaves was fractionated using different solvents, and high-speed counter-current chromatography yielding two pure compounds identified by 1H NMR and 13C NMR as kaempferol 3-O-α-rhamnoside and quercetin 3-O-α-rhamnoside. The first one increased the KM without changes in the VMAX of GIA. In addition it exerted an additive inhibitory effect, on GIA, when combined with phlorizin. We suggest that kaempferol 3-O-α-rhamnoside is a competitive inhibitor of intestinal SGLT1 cotransporter. 相似文献
8.
Watarai M Yamato Y Murakata K Kim S Omata Y Furuoka H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(4):449-451
Lawsonia intracellularis is an obligate intracellular pathogenic bacterium that causes proliferative enteropathy in various animals. The detection of L. intracellularis in clinical and environmental samples is necessary for the diagnosis of infection and epidemiological investigations. For the detection of L. intracellularis in fecal samples, we have developed an immunological method using immunomagnetic separation and ATP bioluminescence. Magnetic beads were coated with an anti-Lawsonia surface antigen (LsaA) antibody in order to capture the L. intracellularis in fecal samples from infected rabbits and the bacteria captured by the immunomagnetic beads were assayed by means of ATP bioluminescence. Our results showed that L. intracelluraris was detected by immunomagnetic separation of bacteria-holding magnetic beads and ATP-based bioluminescence, suggesting that our methods could be useful for the diagnosis of proliferative enteropathy. 相似文献
9.
Watarai M Yoshiya M Sato A Furuoka H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(7):731-733
Lawsonia intracellularis is an obligate intracellular pathogenic bacterium that causes proliferative enteropathy in domestic and experimental animals. In this study, we improved the in vitro cultivation method of L. intracellularis to increase the passage efficiency and showed that L. intracellularis isolated from a rabbit and a pig have different antigenic properties. Bacteria should be recovered from infected cells before cell death due to infection to obtain higher bacterial passage efficiency, and measurement of LDH activity in the cell culture medium was useful for determining the timing of bacterial passage. L. intracellularis isolated from the rabbit and pig showed different band patterns in immunoblotting. Our results should be helpful in the development of serological diagnosis and epidemiological investigation methods. 相似文献
10.
Kim S Lee DS Suzuki H Watarai M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(6):615-618
Brucella canis and Leptospira interrogans are pathogenic bacteria that cause brucellosis and leptospirosis in dogs around the world. Both diseases can be diagnosed serologically, but the direct detection of these organisms in canine semen is needed when it is used for artificial reproduction. We have been attempting the artificial reproduction of guide dogs for greater breeding efficiency and for this purpose have developed a multiplex nested PCR technique for the detection of B. canis and L. interrogans in the semen and cryoprotective agent (CPA). Our results demonstrated the high sensitivity and simplicity of this technique in the detection of these organisms in canine semen and that will be useful in routine diagnosis. Since they have been found to stay alive in canine semen and CPA up to 48 hr, canine semen for breeding purposes should be checked for contamination by the PCR assay. 相似文献