Irrelevance between the induction of anti-Campylobacter humoral response by a bacterin and the lack of protection against homologous challenge in Japanese Jidori chickens     

Okamura M  Tominaga A  Ueda M  Ohshima R  Kobayashi M  Tsukada M  Yokoyama E  Takehara K  Deguchi K  Honda T  Nakamura M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(1):75-78

On-farm vaccination of chickens against Campylobacter jejuni is considered a potentially effective countermeasure to decrease campylobacteriosis via consumption of contaminated chicken meat, but is not yet available. In this study, 2 groups of Jidori chicks were immunized subcutaneously with a formalin-killed C. jejuni with 2 different adjuvants. Other chicks served as the unvaccinated control group. Both vaccines induced high levels of anti-Campylobacter IgG but did not decrease bacterial excretion in cecal droppings and bacterial load in the liver and spleen after oral challenge with 10(5) CFU of the homologous strain. Further study is needed to address the observed irrelevance and to develop a novel effective vaccine against C. jejuni.  相似文献   

Efficacy of soluble recombinant FliC protein from Salmonella enterica serovar enteritidis as a potential vaccine candidate against homologous challenge in chickens     

Okamura M  Matsumoto W  Seike F  Tanaka Y  Teratani C  Tozuka M  Kashimoto T  Takehara K  Nakamura M  Yoshikawa Y 《Avian diseases》2012,56(2):354-358

FliC, the flagellin antigen of Salmonella Enteritidis, was tested as a vaccine candidate for protective effect against a homologous challenge in chickens. After immunization with recombinant FliC (rFliC) or administration of phosphate-buffered saline (PBS) at 56 days old, the chickens were challenged with 10(9) colony-forming units of Salmonella Enteritidis at 76 days old. The vaccinated birds showed significantly decreased bacterial counts in the liver and cecal contents compared to those administered PBS at 7 days postchallenge, but the protection was partial. The replication experiment also showed a similar result. In both experiments, vaccination induced an increased level of serum anti-rFliC IgG, which was also reactive to the native flagella. The intestinal IgA level was slightly higher in the vaccinated birds than in the control. However, neither the proliferative response nor interferon-gamma secretion of splenic cells upon stimulation with rFliC was induced. Therefore, the effect of rFliC as a vaccine is limited, and further improvement is needed.  相似文献   

Proliferation of equine bone marrow-derived mesenchymal stem cells in gelatin/β-tricalcium phosphate sponges     

Seo JP  Tsuzuki N  Haneda S  Yamada K  Furuoka H  Tabata Y  Sasaki N 《Research in veterinary science》2012,93(3):1481-1486

A three dimensional scaffold is essential in mesenchymal stem cells (MSCs) delivery in cell-based therapy for facilitating cell adherence, migration, proliferation, and differentiation. The objectives of this study were to evaluate the possibility of β-tricalcium phosphate incorporated gelatin sponges (Gelatin/β-TCP sponge) as scaffolds for equine MSCs and to examine the effects of seeding density and seeding method on the proliferation of equine MSCs in the Gelatin/β-TCP sponges. Mononuclear cells and MSCs isolated from bone marrow were seeded into Gelatin/β-TCP sponges at different densities by different seeding methods-static or agitated methods. Proliferation of the MSCs in Gelatin/β-TCP was assessed using the Cell Counting Kit-8 assay and histological examination. Distribution and proliferation of MSCs in the Gelatin/β-TCP sponge were observed, and the Gelatin/β-TCP sponge supported limited growth when seeded at high density. We also found that the agitated seeding method enhanced the proliferation of MSCs. This study demonstrated the suitability of Gelatin/β-TCP sponges for the proliferation and maintenance of equine MSCs. These results contribute to the application of MSC-seeded Gelatin/β-TCP sponges in equine medicine.  相似文献   

Establishment rate of direct-seeded rice in the relay-intercropping system in Kanto region of Japan     

Natsumi Okamura  Satoko Yasumoto  Makoto Kojima  Masaki Okamura  Yasuo Ohshita 《Plant Production Science》2018,21(3):278-285

The relay intercropping system for cultivating direct-seeding rice and winter cereal is a low-cost method particularly for double cropping, because it eliminates the steps of raising seedlings, paddling, and transplanting. However, in this system, the seedling establishment rate (SER) of rice is low and unstable. The objective of this study was to identify the factors affecting SER to highlight the ways to improve SER. Experiments were conducted in experimental fields in Tsukuba City, Ibaraki Prefecture in 2015 and 2016. To determine the time of rice seed death and to calculate seed survival rates, ‘Akidawara’ seeds were embedded in soil (depth: 3 cm) and dug up after defined periods. We then analyzed the correlation between SER and meteorological factors at two sites (Ibaraki Prefecture and Gunma Prefecture) over the same two years. Based on mean air temperature (MT), we divided the period from seeding to June 20 (when irrigation had been initiated in almost all the fields) into four phases. In Phase 1, the number of days with rainfall (≥5 mm) and soil-wetting days (water potential ≥ ?100 kPa) were significantly and negatively correlated with SER. We found that most of the seed deaths occurred after germination, and the germination rates were presumably affected by water absorption during the low temperature phase. Further investigations are needed to understand the occurrences during the seedling emergence period. This study contributes to a better understanding of the factors affecting variations in the SER of direct-seeded rice grown in the relay-intercropping system.

List of Abbreviations: DSR: direct-seeded rice; SER: seedling establishment rate; TT: thiuram treatment; SSR: seed survival rate; DS: dead seeds; AGS: already germinated seeds; DSRI: direct-seeding of rice in the inter-row spaces of winter cereals; VWC: volume water content; WP: water potential  相似文献   

Thiazole orange positive platelets in a dog with Evans' syndrome     

Michimoto T  Okamura T  Suzuki K  Watari T  Kano R  Hasegawa A 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(10):1305-1306

We examined transition for the percentage of reticulated platelets (RP%) and platelet count in a canine case of Evans' syndrome. The result demonstrated that measurement of the RP% can be useful in evaluating platelet production in the bone marrow and response to treatment.  相似文献   

Body growth and plasma concentrations of metabolites and metabolic hormones during the pubertal period in female Shiba goats     

Sakurai K  Ohkura S  Matsuyama S  Katoh K  Obara Y  Okamura H 《The Journal of reproduction and development》2004,50(2):197-205

It has been shown in various species that the onset of puberty is closely associated with body growth and nutritional state rather than age. The present study was conducted to determine the timing of puberty and to clarify body growth and metabolic changes around the pubertal period in female Shiba goats. Blood samples were collected between 10 to 38 weeks of age from 12 female goats, and plasma concentrations of progesterone, metabolites (glucose, nonesterified fatty acid, ketone body and acetic acid) and metabolic hormones (insulin and insulin-like growth factor-I (IGF-I)) were analyzed. Physical parameters (body weight, withers height and body length) were also measured at the blood sampling. The week when plasma progesterone concentrations first exceeded 1.0 ng/ml was designated as the onset of puberty. The results showed that the average age of the onset of puberty was 27.0 +/- 0.9 (mean +/- SEM) weeks in female Shiba goats. When the goats reached puberty, the average values of body weight and goat body mass index ((body weight (kg)/withers height (cm)/body length (cm)) x 10(3)) were 12.2 +/- 0.5 kg and 5.7 +/- 0.2, respectively. No particular change associated with puberty was apparent for plasma concentrations of the metabolites examined. Plasma insulin concentrations were maintained at lower levels until the onset of puberty, and then they began to gradually increase. Plasma IGF-I concentrations began to gradually increase 1 to 4 weeks before the onset of puberty and this increase continued throughout the peripubertal period. These results imply that IGF-I acts as a peripheral nutritional signal to trigger the onset of puberty in Shiba goats.  相似文献   

The relationship between cellular radiosensitivity and radiation-induced DNA damage measured by the comet assay   总被引：4，自引：0，他引：4  

Wada S  Kurahayashi H  Kobayashi Y  Funayama T  Yamamoto K  Natsuhori M  Ito N 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(4):471-477

The relationship between deoxyribonucleic acid (DNA) damage and the cell death induced by gamma-irradiation was examined in three kinds of cells, Chinese hamster ovary fibroblast CHO-K1, human melanoma HMV-II and mouse leukemia L5178Y. Cell survival was determined by a clonogenic assay. The induction and rejoining of DNA strand breaks induced by radiation were measured by the alkaline and neutral comet assays. L5178Y cells were the most radiosensitive, while CHO-K1 cells and HMV-II cells were radioresistant. There was an inverse relationship between the survival fraction at 2 Gy (SF2) and the yield of initial DNA strand breaks per unit dose under the alkaline condition for the comet assay, and also a relationship between SF2 and the residual DNA strand breaks (for 4 hr after irradiation) under the neutral condition for the comet assay, the latter being generally considered to be relative to cellular radiosensitivity. In the present analysis, it was considered that the alkaline condition for the comet assay was optimal for evaluating the initial DNA strand breaks, while the neutral condition was optimal for evaluating the residual DNA strand breaks. Since the comet assay is simpler and more rapid than other methods for detecting radiation-induced DNA damage, this assay appears to be a useful predictive assay for evaluating cellular clonogenic radiosensitivity of tumor cells.  相似文献   

Molecular cloning of canine RCAS1 cDNA     

Okamura Y  Ma Z  Khatlani TS  Okuda M  Une S  Nakaichi M  Taura Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(8):913-915

Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) is a novel cancer cell-surface antigen, strongly expressed in invasive cancers. RCAS1 inhibited the in vitro growth of immunocytes, and induced apoptotic cell death. The cloning of canine RCAS1 cDNA was carried out and identified from the mammary gland tumor of a dog. A canine RCAS1 cDNA of 864 bp in length has an open reading frame of 642 bp nucleotides encoding a protein of 213 deduced amino acids. The predicted amino acid sequence of canine RCAS1 showed 96.2% and 96.7% homologies with those of human and mouse RCAS1 respectively. Canine RCAS1 has an N-terminal transmembrane segment and a coiled-coil structure in the C-terminal protein, which are highly conserved in mouse and human RCAS1.  相似文献   

Antigen-specific lymphocyte proliferation and interleukin production in chickens immunized with killed Salmonella enteritidis vaccine or experimental subunit vaccines     

Okamura M  Lillehoj HS  Raybourne RB  Babu U  Heckert R 《Avian diseases》2003,47(4):1331-1338

Lymphocyte proliferation and interleukin (IL)-2 and IL-6 levels in serum were measured as indicators of cell-mediated immunity after immunization of chickens with a commercial killed Salmonella enteritidis (SE) vaccine or experimental subunit vaccines of crude protein (CP) extract or the outer membrane protein (OMP). Significantly increased proliferative responses to SE flagella, but not lipopolysaccharide, porin, CP, or OMP, were observed at 1 wk postimmunizarion in the three vaccination groups. The responses to flagella were specific because flagella-induced proliferation was not seen in chickens immunized with adjuvant alone. Of the three immunization protocols, use of the killed SE vaccine appeared most effective because it induced higher flagella-stimulated lymphocyte proliferation at 1 and 2 wk postvaccination compared with the CP- and OMP-vaccinated groups. Significantly increased IL-2 and IL-6 levels in serum were seen at 1 wk postimmunization in the three vaccination groups compared with adjuvant alone, but there were no differences between the killed vaccine and the subunit vaccines at this time, and the levels of both lymphokines returned to baseline at 2 wk postimmunization. We conclude that cell-mediated immunity to SE after vaccination with the killed bacterial vaccine or subunit vaccines is transient and mainly limited to flagella.  相似文献   

Differential responses of macrophages to Salmonella enterica serovars Enteritidis and Typhimurium   总被引：1，自引：0，他引：1  

Okamura M  Lillehoj HS  Raybourne RB  Babu US  Heckert RA  Tani H  Sasai K  Baba E  Lillehoj EP 《Veterinary immunology and immunopathology》2005,107(3-4):327-335

Macrophages are major effectors against Salmonella infection, and also transport bacteria between host tissues and provide a protected site for intracellular bacterial replication. We hypothesized that differences in chicken macrophage responses to Salmonella enterica serovar Enteritidis (SE) and serovar Typhimurium (ST) played a role in preferential infection of eggs by SE compared with ST. To test this hypothesis, we determined bacterial phagocytosis and intracellular viability and macrophage nitric oxide (NO) production following in vitro infection with SE or ST in the presence or absence of interferon-gamma (IFN-gamma). The effects of bacterial components, lipopolysaccharide (LPS), outer membrane proteins (OMP) and flagella, on NO production were also assessed. Our results showed: (1) in the presence or absence of IFN-gamma, the percentage macrophages phagocytizing SE and ST was similar; (2) the number of intracellular viable SE was significantly reduced compared with ST in the presence or absence of IFN-gamma; (3) increased macrophage necrosis was seen in the presence of IFN-gamma and ST; (4) Salmonella infection acted synergistically with IFN-gamma in induction of nitric oxide production; and (5) in the absence of IFN-gamma, macrophages produced significantly greater NO following treatment with SE outer membrane protein or flagella compared with ST OMP or flagella, while in the presence of IFN-gamma significantly less NO was produced following treatment with SE-LPS compared with ST-LPS. These results suggest that differential responses of chicken macrophages to SE versus ST may result in increased macrophage death with ST, which could result in an increased inflammatory response as compared to SE.  相似文献