Pathogenicity of H5N1 influenza A viruses isolated in Vietnam between late 2003 and 2005   总被引：3，自引：0，他引：3  

Muramoto Y  Le TQ  Phuong LS  Nguyen T  Nguyen TH  Sakai-Tagawa Y  Horimoto T  Kida H  Kawaoka Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(7):735-737

Since late 2003, highly pathogenic H5N1 influenza A viruses have spread among poultry and wild aquatic birds in Asian countries. Transmission of these viruses to humans can be lethal. Most human cases of infection with H5N1 viruses have occurred in Vietnam. Therefore, to understand the pathogenicity in mammals of these H5N1 viruses, we took viruses isolated from poultry (5 strains) and humans (2 strains) in Vietnam and tested their virulence in mice. The results showed that the H5N1 viruses from humans were pathogenic in mice and that one avian isolate was also pathogenic. These findings suggested that the H5N1 viruses circulating in poultry adapted during replication in humans or that strains pathogenic in mice were transmitted directly to humans.  相似文献   

Molecular characterization of the hemagglutinin and neuraminidase genes of H5N1 influenza A viruses isolated from poultry in Vietnam from 2004 to 2005   总被引：4，自引：0，他引：4  

Muramoto Y  Le TQ  Phuong LS  Nguyen T  Nguyen TH  Sakai-Tagawa Y  Iwatsuki-Horimoto K  Horimoto T  Kida H  Kawaoka Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(5):527-531

Highly pathogenic H5N1 avian influenza A viruses have been spreading among domestic poultry, wild aquatic birds, and humans in many Asian countries since 2003. The largest number of patients, to date, infected with the H5N1 viruses are in Vietnam, where these viruses continue to cause outbreaks in domestic poultry. Here, we molecularly characterized the hemagglutinin and neuraminidase genes of nine H5N1 viruses isolated between January 2004 and August 2005 from domestic poultry in Vietnam. We found that several groups of highly pathogenic H5N1 avian influenza viruses are circulating among these birds, which suggests that H5N1 viruses of different lineages have been introduced into Vietnam multiple times.  相似文献   

Immunological characteristics and response to lipopolysaccharide of mouse lines selectively bred with natural and acquired immunities     

Hiroki NARAHARA  Eri SAKAI  Masafumi KATAYAMA  Yukiko OHTOMO  Kanako YAMAMOTO  Miki TAKEMOTO  Hisashi ASO  Shyuichi OHWADA  Yasuaki MOHRI  Katsuhiko NISHIMORI  Emiko ISOGAI  Takahiro YAMAGUCHI  Tomokazu FUKUDA 《Animal Science Journal》2012,83(5):367-374

Genetic improvement of resistance to infectious diseases is a challenging goal in animal breeding. Infection resistance involves multiple immunological characteristics, including natural and acquired immunity. In the present study, we developed an experimental model based on genetic selection, to improve immunological phenotypes. We selectively established three mouse lines based on phagocytic activity, antibody production and the combination of these two phenotypes. We analyzed the immunological characteristics of these lines using a lipopolysaccharide (LPS), which is one of the main components of Gram‐negative bacteria. An intense immunological reaction was induced in each of the three mouse lines. Severe loss of body weight and liver damage were observed, and a high level of cytokine messenger RNA was detected in the liver tissue. The mouse line established using a combination of the two selection standards showed unique characteristics relative to the mouse lines selected on the basis of a single phenotype. Our results indicate that genetic selection and breeding is effective, even for immunological phenotypes with a relatively low heritability. Thus, it may be possible to improve resistance to infectious diseases by means of genetic selection.  相似文献   

Role of sulphide reduction by magnesium hydroxide on the sediment of the eutrophic closed bay          下载免费PDF全文

Dong Xia  Katsumi Okada  Kunio Watanabe  Yukiko Miura  Rameshprabu Ramaraj  Niwooti Wangchai  Kanda Wangchai  Tomoaki Itayama 《Aquaculture Research》2018,49(1):462-470

This study was focused on the effect of magnesium hydroxide (Mg(OH)₂) for improving the sediment of aquaculture field and eutrophic closed estuaries. Sediment samples were collected from Omura Bay, Nagasaki, Japan. The change in pH, acid volatile sulphides (AVS) and dissolved organic carbon (DOC) in interstitial water of the sediment samples were measured before and after 20‐day incubation under the condition of overlapping seawater at 25°C with 0.3–0.4 mg/L of dissolved oxygen (DO). Hydrogen sulphide (H₂S) and the dsrA gene copy number of Grp3 sulphate‐reducing bacteria (SRB) in the sediment samples were also measured at 7‐day incubation under the same condition. The pH of Mg(OH)₂ treatment group was significantly increased from 7.43 to 8.25; it was higher compared to the control group which pH was maintained around 7.6. Meanwhile, the AVS content of Mg(OH)₂ treatment group was significantly reduced and the value was lower than the control group after the 20‐day incubation. Each concentration of interstitial water DOC in the treatment group and the control group increased after the incubation from initial value of 15.4–40.1 and 29.0  mg/L respectively. Furthermore, simultaneous decrease in H₂S and the dsrA gene copy number of Grp3 SRB was observed at the end of the 7‐day incubation by adding Mg(OH)₂. It is concluded that the loss of activity of SRB was strongly related to the decrease in sulphide (H₂S and AVS) and the increase in DOC was due to the alkalization of the sediment by adding Mg(OH)₂.  相似文献   

Prevalence of porcine endogenous retrovirus in domestic pigs in Japan and its potential infection in dogs xenotransplanted with porcine pancreatic islet cells     

Edamura K  Nasu K  Iwami Y  Nishimura R  Ogawa H  Sasaki N  Ohgawara H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(2):129-135

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New method to detect oxolinic acid-resistant <Emphasis Type="Italic">Burkholderia glumae</Emphasis> infesting rice seeds using a mismatch amplification mutation assay polymerase chain reaction     

Yukiko?Maeda  Akinori?Kiba  Kouhei?Ohnishi  Yasufumi?HikichiEmail author 《Journal of General Plant Pathology》2004,70(4):215-217

Bacterial seedling rot and grain rot of rice caused by Burkholderia glumae are seed-borne diseases, traditionally controlled with oxolinic acid (OA). Ser83Arg and Ser83Ile substitutions in GyrA protein are commonly responsible for moderate and high resistance to OA, respectively, in field isolates of B. glumae. To detect OA-resistant B. glumae infesting rice seeds, a mismatch amplification mutation assay polymerase chain reaction protocol was developed using DNA from bacteria incubated in modified S-PG medium and primers based on the amino acid substitutions at position 83 in GyrA.  相似文献   

Neospora caninum antigens recognized by mouse IgG at different stages of infection including recrudescence     

Tomioka Y  Sawada M  Ochiai K  Umemura T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(6):745-747

Western blotting was performed to analyze Neospora caninum tachyzoite antigens recognized by mouse IgG at different stages of infection including recrudescence. At the early stage of infection, a 36-38 kDa antigen was clearly recognized by the mouse antisera. After day 48 postinoculation, the signal of the 36-38 kDa antigen gradually weakened. Meanwhile, a 43 kDa antigen was intensely and continuously recognized from 48 to 125 days postinoculation. This 43 kDa antigen was clearly detectable with the antisera from the mice under immunosuppression. Sera from naturally infected cattle strongly reacted with the 43 kDa antigen. Therefore, the 43 kDa antigen may be useful for immunological reactions to detect infected animals except in the early stage of the infection.  相似文献   

Capsule thickness and amounts of a 39 kDa capsular protein of avian Pasteurella multocida type A strains correlate with their pathogenicity for chickens   总被引：2，自引：0，他引：2  

Borrathybay E  Sawada T  Kataoka Y  Okiyama E  Kawamoto E  Amao H 《Veterinary microbiology》2003,97(3-4):215-227

Capsule thickness of avian Pasteurella multocida type A strains was determined by transmission electron microscopy after labeling with polycationic ferritin and compared with their pathogenicity for chickens. The capsule thickness of P. multocida strains Pm-18 and X-73 was 81.4 and 50.1 nm on average, respectively. These strains were highly virulent for chicken, whereas the less virulent strains Pm-1 and Pm-3 had a thin and irregular capsule, 21.0 and 29.8 nm on average, respectively. However, the thickest capsule was observed in strain P-1059, 101.2 nm on average, and the strain revealed moderate virulence. The noncapsulated variant P-1059B, which was derived from strain P-1059, revealed low virulence. The six P. multocida strains were examined with regard to protein content on the capsule of organisms. Amounts of total proteins of crude capsular extract (CCE) from capsulated strains were approximately twice those of the noncapsulated strains. The amount of an antigenic 39 kDa protein in the CCE were found to correlate with the capsule thickness, since heavily capsulated strains exhibited the greatest amount, whereas noncapsulated strains including noncapsulated and low virulent variant P-1059B possessed little 39 kDa protein. The results demonstrated that the capsule thickness and the quantity of a 39 kDa capsular protein of avian P. multocida type A strains correlated with their pathogenicity for chickens.  相似文献   

Analysis of sources of oxolinic acid-resistant field strains of <Emphasis Type="Italic">Burkholderia glumae</Emphasis> based on rep-PCR analysis and nucleotide sequences of <Emphasis Type="Italic">gyrB</Emphasis> and <Emphasis Type="Italic">rpoD</Emphasis>     

Yukiko Maeda  Mitsuo Horita  Hirosuke Shinohara  Akinori Kiba  Kouhei Ohnishi  Seiya Tsushima  Yasufumi Hikichi 《Journal of General Plant Pathology》2007,73(1):46-52

Repetitive sequence-based polymerase chain reaction (rep-PCR) analysis using BOX and ERIC as primers showed a highly divergent phylogeny among field strains of Burkholderia glumae. To elucidate the sources of oxolinic acid (OA) resistance in field strains of B. glumae isolated from rice seedlings cultivated in Mie, Toyama, and Iwate prefectures, Japan, the amino acid at position 83 of GyrA (GyrA83), which is involved in OA resistance, and the DNA patterns from the rep-PCR and the partial nucleotide sequences of gyrB and rpoD from various strains were analyzed. The ten Mie strains, in which GyrA83 was isoleucine (Ile), were divided into two groups based on the band patterns in rep-PCR analysis, although the nucleotide sequences of gyrB and rpoD were identical among the strains. Based on the band patterns in the rep-PCR analysis and the gyrB and rpoD sequences, two highly OA-resistant Toyama strains, Pg-13 and Pg-14, for which GyrA83 was serine (Ser) and Ile, respectively, were in the same lineage. This suggests that the bacteria might acquire OA resistance faster than phylogenic diversity as determined with the repetitive sequences BOX and ERIC and with gyrB and rpoD. Furthermore, three Iwate strains (H95, H101, and H104), isolated from seedlings of different cultivars grown in different years and having Ile at GyrA83, are probably in the same lineage, suggesting that OA-resistant bacteria might be transferred among different cultivars.  相似文献   

Effects of dopamine infusion on cardiac and renal blood flows in dogs     

Furukawa S  Nagashima Y  Hoshi K  Hirao H  Tanaka R  Maruo K  Yamane Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(1):41-44

In veterinary medicine, dopamine is currently being administered clinically by infusion for treatment of kidney disorders at low doses (< or = 3 microg/kg/min) and for assessment of hemodynamics at high doses (> or = 5 microg/kg/min). However, since high doses of dopamine cause peripheral vasoconstriction due to its effect on alpha adrenoceptors, high doses have no longer been recommended. The present study was conducted to explore possible regimens for the use of dopamine infusion in dogs. The regional (renal and cardiac) blood flow for 60 min was measured by using colored microspheres at three doses (3, 10 and 20 microg/kg/min) of dopamine infusion in healthy anesthetized mongrel dogs. The effects on kidney and peripheral hemodynamics at each dose and the resultant cardiac output, mean arterial blood pressure and total peripheral resistance were determined. Renal blood flow increased markedly at 3 microg/kg/min dopamine. Improvement in hemodynamics indicated by marked increase in cardiac blood flow, cardiac output and mean arterial blood pressure and decreased total peripheral resistance was observed at higher doses (10 and 20 microg/kg/min). At 10 microg/kg/min, in addition to the satisfactory increase in cardiac blood flow, there was also a stable satisfactory increase in renal blood flow. However, at 20 microg/kg/min, increased myocardial oxygen consumption (manifested by marked increased in cardiac output), arrythmia and irregular increase in renal blood flow were detected. This study suggests that the clinical use of dopamine infusion in dogs could be safely expanded to moderately higher doses.  相似文献