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| Registros recuperados: 31 | |
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| Okamura, Masashi; Yokoyama, Naoaki; Takabatake, Noriyuki; Okubo, Kazuhiro; Ikehara, Yuzuru; Igarashi, Ikuo; 横山, 直明; 五十嵐, 郁男. |
| In the present study, the subcellular localization of the host red blood cell (RBC) membrane components, the alpha 2-3-linked sialic acid (SA) residues and the lipid bilayer, was observed during the asexual growth of Babesia bovis using two erythrocyte probes, the SA-specific lectin (MALII) and the lipophilic fluorescent (PKH2) probes, respectively. In confocal laser scanning microscopy with MALII, the SA residues on the surface of parasitized RBCs appeared to accumulate into the intracellular parasites as the parasites matured as well as to remain on the surface of extracellular parasites. Furthermore, when PKH2-labeled RBCs were infected with B. bovis, PKH2 signals were also observed around both the intracellular and the extracellular parasites,... |
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Palavras-chave: Babesia bovis (B. bouis); SA; MALII; RBC; RT; PBS; Babesia equi (B. equi); PV. |
| Ano: 2007 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/1040 |
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| Sivakumar, Thillaiampalam; Kothalawala, Hemal; Weerasooriya, Gayani; Seekkuge Susil Priyantha Silva; Puvanendiran, Sumathy; Munkhjargal, Tserendorj; Igarashi, Ikuo; Yokoyama, Naoaki. |
| Throughout the world, infections with the Babesia and Theileria parasites often result in economically significant clinical disease in cattle. We conducted a longitudinal survey of Babesia and Theileria infections in cattle from the Polonnaruwa (n?=?75; dry zone) and Nuwara Eliya (n?=?161; wet zone) districts of Sri Lanka. DNA from blood samples collected in June, September, and December 2014 and March 2015 was screened for Babesia bovis, Babesia bigemina, Theileria annulata and Theileria orientalis using specific polymerase chain reactions (PCRs). Additionally, serum samples collected from the animals were screened using enzyme-linked immunosorbent assays (ELISAs) to detect B. bovis- and B. bigemina-specific antibodies. All of the animals surveyed in... |
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Palavras-chave: Babesia; Cattle; Longitudinal study; Sri Lanka; Theileria. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4567 |
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| Adrian Patalinghug Ybañez; Rochelle Haidee Daclan Ybañez; Yokoyama, Naoaki; Inokuma, Hisashi. |
| Aim: Anaplasma platys, the causative agent of infectious canine cyclic thrombocytopenia, is a tick-borne pathogen that also has been implicated as potentially zoonotic. To provide molecular evidence on the multiple infections of A. platys variants in Philippine dogs. Materials and Methods: DNA fragments of A. platys from infected dogs in the Philippines were molecularly characterized. For screening, 25 dogs suspected to have canine anaplasmosis were tested using a 16S rRNA-based nested polymerase chain reaction (PCR). Infection was confirmed by sequencing of positive amplicons. Second round PCR targeting a longer 16S rRNA fragment was subsequently performed on the first round PCR amplicons of the positive samples. Further characterization using the... |
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Palavras-chave: Anaplasma platys; Dogs; Philippines; Variants. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4537 |
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| Musinguzi, Simon Peter; Suganuma, Keisuke; Asada, Masahito; Laohasinnarong, Dusit; Sivakumar, Thillaiampalam; Yokoyama, Naoaki; Namangala, Boniface; Sugimoto, Chihiro; Suzuki, Yasuhiko; Xuan, Xuenan; Inoue, Noboru. |
| We screened cattle and goats from the districts of Chama, Monze and Mumbwa in Zambia for animal African trypanosomes, Babesia bigemina and Theileria parva using PCRs; 38.1% of the samples tested positive for at least one of the parasite species. The most common parasite was Trypanosoma vivax (19.8%). Its incidence was significantly higher in goats than in cattle, (P<0.05). B. bigemina was found in samples from all the three areas, making it the most widespread of the parasites in Zambia. Among the tested samples, 12.0% of the positive samples were mixed infections. There were significant differences in the infection rates of T. vivax (Mumbwa had a significantly higher infection rate [39.6%, P<0.0001]), Th. parva (Monze had the only cases... |
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Palavras-chave: Animal African trypanosomosis; Cattle; Goat; Piroplasmosis; Zambia. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4389 |
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| Ihara, Fumiaki; Nishimura, Maki; Muroi, Yoshikage; Furuoka, Hidefumi; Yokoyama, Naoaki; Nishikawa, Yoshifumi. |
| Neospora caninum is an obligate intracellular parasite that causes neurological disorders in dogs and cattle. The majority of host animals are asymptomatic at the chronic stage of infection. However, it remains unclear whether cerebral function is normal in asymptomatic animals. In this study, mice were infected with N. caninum (strain Nc-1) and their brains were examined to understand changes in cerebral function at the chronic stage of infection. Mice infected with N. caninum showed impaired locomotor activity, but no differences in clinical symptoms were observed. In the brains of infected mice, parasites were distributed throughout the brain and histological lesions were observed everywhere except for the cerebellum. Expression levels of... |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4460 |
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| Kuboki, Noritaka; Yokoyama, Naoaki; Namangala, B; Okamura, Masashi; Inoue, Noboru; Takagi, Hideaki; Nakayama, Tomoko; Nishikawa, Yoshifumi; Ikehara, Yuzuru; Kojima, Naoya; 横山, 直明; 井上, 昇; 西川, 義文. |
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Palavras-chave: Adjuvant; African trypanosome; Immunization; Oligomannose-coated liposome(OML). |
| Ano: 2008 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2222 |
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| Matsuo, Tomohide; Yokoyama, Naoaki; Suthisak, Boonchit; Fujisaki, Kozo; Igarashi, Ikuo. |
| We examined the detailed cellular localization of the rhoptry-associated protein-1 (RAP-1) of Babesia bovis merozoites by the post-embedding method of immuno-electron microscopy (IEM) using the anti-RAP-1 monoclonal antibody (mAb) 1C1 in order to substantiate the result in our previous report by an indirect immunofluorescent antibody test and the pre-embedding method of IEM. RAP-1 slightly distributed only in cytoplasm of merozoites, especially around the nucleus, but not in the rhoptry organelle at an early stage after invasion into a red blood cell. Then, the RAP-1 was accumulated in the rhoptry organelle and was also found in the iRBC cytoplasm, which suggests that synthesis and release of RAP-1 may occur in the iRBC. Finally, the RAP-1 was found within... |
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Palavras-chave: Babesia bovis RAP-1 invasion; Escape RBC. |
| Ano: 2005 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/145 |
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| Sivakumar, Thillaiampalam; Igarashi, Ikuo; Yokoyama, Naoaki. |
| Babesia ovata, which is transmitted by Haemaphysalis longicornis, is an intraerythrocytic protozoan parasite of cattle. Based on its morphology, B. ovata is classified as a large-type Babesia. The developmental stages of B. ovata have been described both in cattle and the tick vector. In infected adult female ticks, the parasite is transovarially transmitted to the tick eggs. The sexual reproduction of B. ovata has been demonstrated in the tick midgut. The diagnostic tools that are currently available for the specific detection of B. ovata in cattle include microscopy and polymerase chain reaction assays. The development of improved molecular and serological diagnostic tools has been constrained by the limited availability of genetic data. B. ovata has... |
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Palavras-chave: Babesia ovata; Cattle; Epidemiology; Phylogeny; Taxonomy. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4555 |
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| Ybañez, Adrian Patalinghug; Ybañez, Rochelle Haidee D.; Claveria, Florencia G.; Cruz-Flores, Mary Jane; Xuenan, Xuen; Yokoyama, Naoaki; Inokuma, Hisashi. |
| A total of 658 cattle in 6 provinces in the Philippines were screened for Anaplasma marginale infection by using a diagnostic heat-shock operon (groEL) gene-PCR assay. The screening-positive samples were further tested using the major surface antigen protein 1a (Msp1a) gene-PCR assay. Screening PCR results showed 130 cattle (19.8%) were positive for the A. marginale infection. Subsequent amplification using the Msp1a gene only showed 93 samples (14.1%) to be positive. In addition, 37 tandem-repeat structures, including 20 novel structures, and 41 distinct genotypes were identified. Interestingly, multiple infections of 4 different genotypes were also observed in A. marginale-infected cattle. The present study demonstrated the prevalence and... |
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Palavras-chave: Anaplasma marginale; Cattle; GroEL; Msp1a; Philippines. |
| Ano: 2014 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4011 |
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| Kuboki, Noritaka; Tiwananthagorn, Weerawan; Takagi, Hideaki; Nakayama, Tomoko; Xuan, Xuenan; Inoue, Noboru; Igarashi, Ikuo; Tsujimura, Kunio; Ikehara, Yuzuru; Kojima, Naoya; Yokoyama, Naoaki. |
| The oligomannose-coated liposome (OML) vaccine is known to induce cellular immunity specific for the encapsulated antigen in immunized mice. In the present study, we preliminarily evaluated the effect of the OML vaccine encapsulating the soluble protozoan lysate of Toxoplasma gondii, Trypanosoma brucei gambiense, or Babesia rodhaini on the corresponding protozoan infections in mice. After the challenge of T. gondii, the OML vaccine group avoided the high mortality resulting from acute infection that was dominantly observed in other control groups. During the infectious course, the development of the T. gondii-specific antibody, which is an indicator of humoral immunity, was constantly controlled at a lower level in the surviving mice of the OML vaccine... |
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Palavras-chave: Oligomannose-coated liposome (OML); OML; Soluble protozoan antigen; Antibody responses. |
| Ano: 2007 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/1050 |
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| Munkhjargal, Tserendorj; AbouLaila, Mahmoud; Mohamad Alaa Terkawi; Sivakumar, Thillaiampalam; Ichikawa, Madoka; Davaasuren, Batdorj; Nyamjargal, Tserendorj; Yokoyama, Naoaki; Igarashi, Ikuo; 横山, 直明; 五十嵐, 郁男. |
| We evaluated the inhibitory effects of pepstatin A and mefloquine on the in vitro and in vivo growths of Babesia parasites. The in vitro growth of Babesia bovis, B. bigemina, B. caballi, and B. equi was significantly inhibited (P < 0.05) by micromolar concentrations of pepstatin A (50% inhibitory concentrations = 38.5, 36.5, 17.6, and 18.1 μM, respectively) and mefloquine (50% inhibitory concentrations = 59.7, 56.7, 20.7, and 4 μM, respectively). Furthermore, both reagents either alone at a concentration of 5 mg/kg or in combinations (2.5/2.5 and 5/5 mg/kg) for 10 days significantly inhibited the in vivo growth of B. microti in mice. Mefloquine treatment was highly effective and the combination treatments were less effective than other treatments.... |
| Ano: 2012 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3829 |
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| Tattiyapong, Muncharee; Sivakumar, Thillaiampalam; Takemae, Hitoshi; Simking, Pacharathon; Jittapalapong, Sathaporn; Igarashi, Ikuo; Yokoyama, Naoaki. |
| Babesia bovis, an intraerythrocytic protozoan parasite, causes severe clinical disease in cattle worldwide. The genetic diversity of parasite antigens often results in different immune profiles in infected animals, hindering efforts to develop immune control methodologies against the B. bovis infection. In this study, we analyzed the genetic diversity of the merozoite surface antigen-1 (msa-1) gene using 162 B. bovis-positive blood DNA samples sourced from cattle populations reared in different geographical regions of Thailand. The identity scores shared among 93 msa-1 gene sequences isolated by PCR amplification were 43.5-100%, and the similarity values among the translated amino acid sequences were 42.8-100%. Of 23 total clades detected in our... |
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Palavras-chave: Antigenicity variation; Babesia bovis; Msa-1; Genetic diversity; Thailand. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4490 |
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| Ihara, Fumiaki; Nishimura, Maki; Muroi, Yoshikage; Mahmoud, Motamed Elsayed; Yokoyama, Naoaki; Nagamune, Kisaburo; Nishikawa, Yoshifumi. |
| Chronic infection with Toxoplasma gondii becomes established in tissues of the central nervous system, where parasites may directly or indirectly modulate neuronal function. Epidemiological studies have revealed that chronic infection in humans is a risk factor for developing mental diseases. However, the mechanisms underlying parasite-induced neuronal dysfunction in the brain remain unclear. Here, we examined memory associated with conditioned fear in mice and found that T. gondii infection impairs consolidation of conditioned fear memory. To examine the brain pathology induced by T. gondii infection, we analyzed the parasite load and histopathological changes. T. gondii infects all brain areas, yet the cortex exhibits more severe tissue damage than other... |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4480 |
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| Liyanagunawardena, Nilukshi; Sivakumar, Thillaiampalam; Kothalawala, Hemal; Silva, Seekkuge Susil Priyantha; Battsetseg, Badgar; Dinh Thi Bich Lan; Inoue, Noboru; Igarashi, Ikuo; Yokoyama, Naoaki. |
| Babesia bovis is the most virulent Babesia organism, resulting in a high mortality rate in cattle. The genetic diversity of B. bovis merozoite surface antigens (MSAs), such as MSA-1, MSA-2b, and MSA-2c, might be linked to altered immune profiles in the host animals. The present study aimed to develop type-specific PCR assays for Asian msa-1 genotypes, thereby re-analyzing the genetic diversity of msa-1 in Sri Lanka, Mongolia, and Vietnam. Specific primers were designed for nine Asian msa-1 genotypes, which had been detected based on the phylogeny constructed using msa-1 gene sequences retrieved from the GenBank database. Specificity of the type-specific PCR assays was confirmed using plasmids containing the inserts of msa-1 gene fragments that represent... |
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Palavras-chave: Asia; Babesia bovis; Genetic diversity; Msa-1; Type-specific PCR. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4489 |
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| Registros recuperados: 31 | |
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