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| Registros recuperados: 31 | |
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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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| Altangerel, Khukhuu; Sivakumar, Thillaiampalam; Inpankaew, Tawin; Jittapalapong, Sathaporn; Terkawi, Mohamad Alaa; Ueno, Akio; Xuan, Xuenan; Igarashi, Ikuo; Yokoyama, Naoaki; 玄, 学南; 五十嵐, 郁男; 横山, 直明. |
| Here we report on an epidemiological study regarding the molecular prevalence of different genotypes of Theileria orientalis present among domestic cattle and water buffalo populations bred in Thailand. A phylogenetic analysis based on the parasitic gene encoding a major piroplasm surface protein revealed the presence of 5 genotypes (Types 1, 3, 5, 7, and N-3) in cattle and 7 genotypes (Types 1, 3, 4, 5, 7, N-2, and N-3) in water buffaloes. Types 4, 7, and N-3 of T. orientalis were reported for the first time in water buffaloes. The previously reported C and Thai types from Thailand clustered as types 7 and 6, respectively, in the present analysis. Great similarities were observed among nucleotide sequences of isolates of the same genotype from cattle and... |
| Ano: 2011 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3592 |
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| Bork, Sabine; Yokoyama, Naoaki; Okamura, Masashi; Igarashi, Ikuo; 横山, 直明; 五十嵐, 郁男. |
| Recently，we reported the in vitro growth inhibitory effects of the imidazole derivatives，clotrimazole(CLT) and ketoconazole (KC)，and the herbicide，clodinafop-propargyl(CP)，against bovine and equine Babesia parasites. Additionally，in the bovine species，several combined applications of the CLT，KC，and CP were reported to significantly increase the inhibitory effects. In this study，similar combination tests were carried out in order to confirm possible synergistic effects in the equine species，Babesia caballi and Babesia equi. Combinations of CLT/KC， CLT/CP，and CLT/KC/CP exerted a significantly enhanced growth inhibitory efficacy in B. caballi，in contrast to B. equi，where no synergistic effects were observed in any of the combinations. Our results suggest that... |
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Palavras-chave: In vitro; Babesia; Clotrimazole; Ketoconazole; Clodinafop-propargyl. |
| Ano: 2003 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/637 |
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| Fujii, Kei; Yokoyama, Naoaki; Takabatake, Noriyuki; Suzuki, Hiroshi; Xuan, Xuenan; Igarashi, Ikuo; 横山, 直明; 鈴木, 宏志; 玄, 学南; 五十嵐, 郁男. |
| In hemoprotozoa，gene transfer technology provides an important tool to aid in the functional study of parasite genes. In this study，a transfer vector containing the enhanced green fluorescent protein (EGFP) gene laid between the Toxoplasma gondii GRAI promoter region and the GRA2 polyA signal region was constructed and transfected into the in vitro culture of Babesia boνis by the electroporation method.On the first and second days post-transfection，clear positive fluorescences were detected in some parasite bodies， indicating the successful expression of the EGFP gene controlled by the GRA-1 promoter in B. bovis. However， the positive parasites were not ubiquitous and finally disappeared until the forth day post-transfection. This is the first time that... |
| Ano: 2003 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/631 |
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| Fukumoto, Shinya; Sekine, Yukiko; Kimbita, Elikira; Huang, Xiaohong; Xuan, Xuenan; Inoue, Noboru; Yokoyama, Naoaki; Igarashi, Ikuo; Fujisaki, Kozo; Sugimoto, Chihiro; Nagasawa, Hideyuki; Mikami, Takeshi; Suzuki, Hiroshi; 福本, 晋也; 玄, 学南; 井上, 昇; 横山, 直明; 五十嵐, 郁男; 鈴木, 宏志. |
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Palavras-chave: Babesia gibsoni; Babesia canis; CDNA library; ELISA; P30 gene. |
| Ano: 2002 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/624 |
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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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| 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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| Ishizaki, Takahiro; Sivakumar, Thillaiampalam; Hayashida, Kyoko; Tuvshintulga, Bumduuren; Igarashi, Ikuo; Yokoyama, Naoaki. |
| Babesia bovis is an apicomplexan hemoprotozoan that can invade bovine red blood cells (RBCs), where it multiplies asexually. RBC invasion assays using free viable merozoites are now routinely used to understand the invasion mechanism of B. bovis, and to evaluate the efficacy of chemicals and antibodies that potentially inhibit RBC invasion by the parasite. The application of high-voltage pulses (high-voltage electroporation), a commonly used method to isolate free merozoites from infected RBCs, reduces the viability of the merozoites. Recently, a cold treatment of B. bovis in vitro culture was found to induce an effective release of merozoites from the infected RBCs. In the present study, we incubated in vitro cultures of B. bovis in an ice bath to... |
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Palavras-chave: Babesia bovis; Cold treatment; Invasion-inhibition assay; Merozoite isolation; RBC invasion. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4488 |
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| Kamiya, Shiho; Takabatake, Noriyuki; Fujii, Kei; Okamura, Masashi; Iseki, Hiroshi; Yokoyama, Naoaki; Igarashi, Ikuo. |
| Babesia spp. are major hemoprotozoan parasites in animals. Exoantigens, which are soluble antigens released by the parasites during their asexual development, have been successfully applied for the development of a vaccine against babesiosis. In this study, we examined the ability of exoantigens to induce protective immunity in mice against a rodent Babesia parasite, Babesia rodhaini. The BALB/c mice immunized with the blood plasma fraction of B. rodhaini-infected mice (B. rodhaini exoantigens) showed a significant decrease in the lethal rate when challenged with B. rodhaini. Western blot analysis with anti-B. rodhaini exoantigen immune serum specifically detected at least eleven proteins in the lysate of B. rodhaini-infected erythrocytes. Next, a cDNA... |
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Palavras-chave: Babesiosis; Babesia rodhaini; Exoantigen; Protective effect; Mice. |
| Ano: 2005 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/149 |
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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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| 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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| 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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| 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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| 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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| 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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| 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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| Okubo, Kazuhiro; Yokoyama, Naoaki; Govind, Yadav; Alhassan, Andy; Igarashi, Ikuo. |
| In the present study, we examined the effects of four kinds of cysteine protease inhibitors (E64, E64d, leupeptin, and ALLN) on the in vitro asexual growth of Babesia bovis. Of these, only the lipophilic inhibitors, E64d and ALLN, were found to effectively inhibit the growth of B. bovis. In further experiments, E64d, but not ALLN, significantly suppressed the parasite’s invasion of host erythrocytes, while both chemicals, especially ALLN, inhibited the parasite’s replication within the infected erythrocytes. These data suggested the presence of cysteine protease(s) derived from B. bovis, in which the protease(s) would play important roles in the erythrocyte invasion and/or replication processes of the parasite. |
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Palavras-chave: Babesia bovis; Cysteine protease; Inhibitor; Invasion; Replication. |
| Ano: 2007 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/1041 |
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| Sivakumar, T; Aboulaila, M. R. A.; Khukhuu, A; Iseki, H; Alhassan, A; Yokoyama, Naoaki; Igarashi, Ikuo; 横山, 直明; 五十嵐, 郁男. |
| The in vitro inhibitory effect of fosmidomycin was evaluated against the asexual growth of bovine Babesia parasites (Babesia bovis and Babesia bigemina). In the cultures with these parasites, severe reduction of parasite growth was observed by the addition of 1.25 μg/ml of the final drug concentration. Under these conditions, B. bigemina was completely cleared until the third day of cultivation. On the other hand, B. bovis was completely eliminated on the fourth day when the concentration was 6.25 μg/ml in the culture. These parasites failed to grow again when a drug-free medium was substituted for the subsequent cultivation. The IC50 values of fosmidomycin against B. bovis were determined as 0.88 and 0.63 μg/ml in the in vitro cultures with... |
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Palavras-chave: Fosmidomycin; Babesia bovis; Babesia bigemina; Asexual growth; In vitro culture. |
| Ano: 2008 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2235 |
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| Registros recuperados: 31 | |
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