The Experts below are selected from a list of 1149 Experts worldwide ranked by ideXlab platform
Ikuo Igarashi - One of the best experts on this subject based on the ideXlab platform.
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Effects of dihydroorotate dehydrogenase (DHODH) inhibitors on the growth of Theileria equi and Babesia caballi in vitro.
Experimental parasitology, 2017Co-Authors: Ketsarin Kamyingkird, Ikuo Igarashi, Naoaki Yokoyama, Shinuo Cao, Yoshifumi Nishikawa, Bumduuren Tuvshintulga, Akram Salama, Ahmed Abdelmoniem Mousa, Artemis Efstratiou, Xuenan XuanAbstract:Theileria equi and Babesia caballi are the causative agents of equine piroplasmosis (EP), which affects equine production in various parts of the world. However, a safe and effective drug is not currently available for treatment of EP. Dihydroorotate dehydrogenase (DHODH) is the fourth enzyme in the de novo pyrimidine synthesis pathway and has been known as a novel drug target for several apicomplexan protozoan parasites. In this study, we evaluated four DHODH inhibitors; atovaquone (ATV), leflunomide (LFN), brequinar (Breq), and 7-hydroxy-5-[1,2,4] triazolo [1,5,a] pyrimidine (TAZ) on the growth of T. equi and B. caballi in vitro and compared them to diminacene aceturate (Di) as the control drug. The growth of T. equi and B. caballi was significantly hindered by all inhibitors except TAZ. The half maximal inhibitory concentration (IC50) of ATV, LFN, Breq and Di against T. equi was approximately 0.028, 109, 11 and 40 μM, respectively, whereas the IC50 of ATV, LFN, Breq and Di against B. caballi was approximately 0.128, 193, 5.2 and 16.2 μM, respectively. Using bioinformatics and Western blot analysis, we showed that TeDHODH was similar to other Babesia parasite DHODHs, and confirmed that targeting DHODHs could be useful for the development of novel chemotherapeutics for treatment of EP.
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SHORT REPORT: MOLECULAR CLONING AND CHARACTERIZATION OF A PUTATIVE BINDING PROTEIN OF Babesia caballi
2015Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Noboru Kudo, Yumi Takamatsu, Ryoko Takashiro, Ayaka Segawa, Takashi OyamadaAbstract:Abstract. A composite 2,206 nucleotide DNA sequence encoding a putative immunoglobulin-binding protein (BiP) was constructed from a sequence obtained from Babesia caballi cDNA library clones. The 1,962 nucleotide open reading frame predicts a 72 kD protein with extensive homology with BiPs from Apicomplexa parasites. The BiP gene had a predicted N-terminal signal sequence of 18 amino acids and a C-terminal tetrapeptide sequence (Ser-Asp-Glu-Leu) for signaling in the endoplasmic reticulum lumen. The recombinant protein expressed in baculovirus showed an apparent mass of 72 kD, which is identical to that of the native B. caballi protein. Monoclonal antibodies (MAbs) against B. caballi BiP reacted strongly with extracellular merozoites, but not in early intraerythrocytic stage. Detailed observation showed that the reaction of MAbs against pear-shaped forms was markedly irregular, with either no reaction, or reaction with one or two brightly fluorescent pear-shaped forms (two parasites) of B. caballi. Babesia caballi is a tick-borne hemoprotozoan parasite with a life cycle that alternates between an ixodid tick host, and mammalian hosts such as horses, in which it causes economi-cally important diseases worldwide.1 It is an obligatory intra-erythrocytic equine parasite belonging to the Apicomplexa. Although members of the Apicomplexa infect different hos
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Immunochromatographic Test for Simultaneous Serodiagnosis of Babesia caballi and B. equi Infections in Horses
Clinical and vaccine immunology : CVI, 2006Co-Authors: Xiaohong Huang, Naoaki Yokoyama, Xuenan Xuan, Shoufa Zhang, Rodolfo A. Verdida, Ikuo IgarashiAbstract:An immunochromatographic test for the simultaneous detection of Babesia caballi- and B. equi-specific antibodies (BceICT) was developed using a recombinant B. caballi 48-kDa rhoptry protein (rBc48) and a recombinant truncated B. equi merozoite antigen 2 (rEMA-2t). An evaluation of the ability of the BceICT to detect antibodies in sera from uninfected horses and experimentally infected horses showed high sensitivities and specificities of 83.3% (10/12 sera) and 92.9% (52/56 sera), respectively, for the anti-B. caballi antibody and 94.1% (16/17 sera) and 88.2% (45/51 sera), respectively, for the anti-B. equi antibody. Results from the detection of antibodies in field-collected sera indicated that the BceICT results corresponded with those of enzyme-linked immunosorbent assays (ELISA), showing 91.8% correspondence (67/73 sera) for B. caballi and 95.9% correspondence (70/73 sera) for B. equi, and that the BceICT results also corresponded with the ICT for B. caballi and for B. equi, both of which were 98.2% (55/56 sera). The comparable results of the ICT and ELISA and the simplicity and rapidity of the performance of the ICT suggest that the BceICT would be a feasible test for the simultaneous serodiagnosis of both agents of equine babesiosis in the field.
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MOLECULAR CLONING AND CHARACTERIZATION OF A PUTATIVE BINDING PROTEIN OF Babesia caballi
The American journal of tropical medicine and hygiene, 2005Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Noboru Kudo, Yumi Takamatsu, Ryoko Takashiro, Ayaka Segawa, Takashi OyamadaAbstract:A composite 2,206 nucleotide DNA sequence encoding a putative immunoglobulin-binding protein (BiP) was constructed from a sequence obtained from Babesia caballi cDNA library clones. The 1,962 nucleotide open reading frame predicts a 72 kD protein with extensive homology with BiPs from Apicomplexa parasites. The BiP gene had a predicted N-terminal signal sequence of 18 amino acids and a C-terminal tetrapeptide sequence (Ser-Asp-Glu-Leu) for signaling in the endoplasmic reticulum lumen. The recombinant protein expressed in baculovirus showed an apparent mass of 72 kD, which is identical to that of the native B. caballi protein. Monoclonal antibodies (MAbs) against B. caballi BiP reacted strongly with extracellular merozoites, but not in early intraerythrocytic stage. Detailed observation showed that the reaction of MAbs against pear-shaped forms was markedly irregular, with either no reaction, or reaction with one or two brightly fluorescent pear-shaped forms (two parasites) of B. caballi.
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Inhibitory effect of lactoferrin on in vitro growth of Babesia caballi.
The American journal of tropical medicine and hygiene, 2005Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Noboru Kudo, Tetsuya Tanaka, Nona Shibahara, Hiroko Tanaka, Aya Matsuu, Kei-ichi Shimazaki, Takashi OyamadaAbstract:Lactoferrin (LF) is an important biologic molecule with many functions, one of which is antimicrobial defense. We evaluated the growth-inhibiting effects of four types of LF (native LF, Fe+3-bound [holo] LF, Fe+3-free [apo] LF, and LF hydrolyzate) on the in vitro growth of Babesia caballi and B. equi. The growth of B. caballi was significantly suppressed in media containing apo LF, but was not inhibited in media containing native LF, holo LF, or LF hydrolyzate. The growth of B. equi was not inhibited by media containing native LF, holo LF, or apo LF. These data indicate that apo LF had the strongest inhibitory effect on B. caballi. This may have been caused by inactivation or inhibition of a growth factor in the culture medium.
Hiromi Ikadai - One of the best experts on this subject based on the ideXlab platform.
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SHORT REPORT: MOLECULAR CLONING AND CHARACTERIZATION OF A PUTATIVE BINDING PROTEIN OF Babesia caballi
2015Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Noboru Kudo, Yumi Takamatsu, Ryoko Takashiro, Ayaka Segawa, Takashi OyamadaAbstract:Abstract. A composite 2,206 nucleotide DNA sequence encoding a putative immunoglobulin-binding protein (BiP) was constructed from a sequence obtained from Babesia caballi cDNA library clones. The 1,962 nucleotide open reading frame predicts a 72 kD protein with extensive homology with BiPs from Apicomplexa parasites. The BiP gene had a predicted N-terminal signal sequence of 18 amino acids and a C-terminal tetrapeptide sequence (Ser-Asp-Glu-Leu) for signaling in the endoplasmic reticulum lumen. The recombinant protein expressed in baculovirus showed an apparent mass of 72 kD, which is identical to that of the native B. caballi protein. Monoclonal antibodies (MAbs) against B. caballi BiP reacted strongly with extracellular merozoites, but not in early intraerythrocytic stage. Detailed observation showed that the reaction of MAbs against pear-shaped forms was markedly irregular, with either no reaction, or reaction with one or two brightly fluorescent pear-shaped forms (two parasites) of B. caballi. Babesia caballi is a tick-borne hemoprotozoan parasite with a life cycle that alternates between an ixodid tick host, and mammalian hosts such as horses, in which it causes economi-cally important diseases worldwide.1 It is an obligatory intra-erythrocytic equine parasite belonging to the Apicomplexa. Although members of the Apicomplexa infect different hos
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MOLECULAR CLONING AND CHARACTERIZATION OF A PUTATIVE BINDING PROTEIN OF Babesia caballi
The American journal of tropical medicine and hygiene, 2005Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Noboru Kudo, Yumi Takamatsu, Ryoko Takashiro, Ayaka Segawa, Takashi OyamadaAbstract:A composite 2,206 nucleotide DNA sequence encoding a putative immunoglobulin-binding protein (BiP) was constructed from a sequence obtained from Babesia caballi cDNA library clones. The 1,962 nucleotide open reading frame predicts a 72 kD protein with extensive homology with BiPs from Apicomplexa parasites. The BiP gene had a predicted N-terminal signal sequence of 18 amino acids and a C-terminal tetrapeptide sequence (Ser-Asp-Glu-Leu) for signaling in the endoplasmic reticulum lumen. The recombinant protein expressed in baculovirus showed an apparent mass of 72 kD, which is identical to that of the native B. caballi protein. Monoclonal antibodies (MAbs) against B. caballi BiP reacted strongly with extracellular merozoites, but not in early intraerythrocytic stage. Detailed observation showed that the reaction of MAbs against pear-shaped forms was markedly irregular, with either no reaction, or reaction with one or two brightly fluorescent pear-shaped forms (two parasites) of B. caballi.
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Inhibitory effect of lactoferrin on in vitro growth of Babesia caballi.
The American journal of tropical medicine and hygiene, 2005Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Noboru Kudo, Tetsuya Tanaka, Nona Shibahara, Hiroko Tanaka, Aya Matsuu, Kei-ichi Shimazaki, Takashi OyamadaAbstract:Lactoferrin (LF) is an important biologic molecule with many functions, one of which is antimicrobial defense. We evaluated the growth-inhibiting effects of four types of LF (native LF, Fe+3-bound [holo] LF, Fe+3-free [apo] LF, and LF hydrolyzate) on the in vitro growth of Babesia caballi and B. equi. The growth of B. caballi was significantly suppressed in media containing apo LF, but was not inhibited in media containing native LF, holo LF, or LF hydrolyzate. The growth of B. equi was not inhibited by media containing native LF, holo LF, or apo LF. These data indicate that apo LF had the strongest inhibitory effect on B. caballi. This may have been caused by inactivation or inhibition of a growth factor in the culture medium.
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Molecular characterization of a putative protein disulfide isomerase from Babesia caballi
Parasitology, 2005Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Noboru Kudo, Ryoko Takashiro, Naoaki Yokoyama, Ryusuke Tsukada, Mizuki Sasaki, Toshifumi OyamadaAbstract:We produced a mAb against the Babesia caballi extracellular merozoite termed mAb 2H2 and used it to screen a cDNA expression library prepared from B. caballi merozoite mRNA for highly expressed proteins. The complete nucleotide sequence of the cloned gene had 1547 nucleotides and contained a 36-nucleotide intron. The 1398 nucleotide open reading frame predicts a 51 kDa protein showing similarity to protein disulfide isomerase (PDI) from other species. The PDI gene had a predicted N-terminal signal sequence of 19 amino acids and a C-terminal tetrapeptide sequence (His-Thr-Glu-Leu; HTEL) for retention in lumen of the endoplasmic reticulum (ER). The recombinant protein expressed in baculovirus showed an apparent mass of 51 kDa, identical to that the native B. caballi protein. Moreover, the ER retention signal site (HTEL) of the recombinant protein retained its function in ER of insect cells. This 51 kDa protein was strongly expressed by extracelluar B. caballi merozoites in indirect immunofluorescence antibody tests, and was not expressed in the early phase of trophozoite development. Interestingly, detailed observation showed that the reaction of anti-P51 antibody and mAb 2H2 against pear-shaped forms was very erratic, some displaying one or two brightly fluorescent patterns.
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Seroepidemiologic Studies on Babesia caballi and Babesia equi Infections in Japan
The Journal of veterinary medical science, 2002Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Takashi Oyamada, Naoyoshi Suzuki, Akiko Nagai, Xuenan Xuan, Tsugihiko Kamio, Naotoshi Tsuji, Kozo FujisakiAbstract:Antibodies to Babesia caballi and Babesia equi were examined on a total of 2,019 horse serum samples that had been collected in 1971-1973 by the National Institute of Animal Health by enzyme-linked immunosorbent assay (ELISA) using recombinant proteins and by Western-blot analysis. Based on the criterion for positivity by ELISA, 5.4% (109/ 2,019) and 2.2% (44/ 2,019) had antibodies against B. caballi and B. equi, respectively. The ELISA-positive sera were further examined by Western blot; 30/ 109 for B. caballi and 2/ 44 for B. equi were positive for native B. caballi or B. equi, but none of them was seropositive for both infections. Based on the results of this study, further investigations should be required to survey horses that have arrived in Japan relatively recently and tick vectors of equine Babesia using ELISA with some recombinant protein, a parasite detection method in an in vitro culture of equine Babesia, and PCR testing.
Takashi Oyamada - One of the best experts on this subject based on the ideXlab platform.
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SHORT REPORT: MOLECULAR CLONING AND CHARACTERIZATION OF A PUTATIVE BINDING PROTEIN OF Babesia caballi
2015Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Noboru Kudo, Yumi Takamatsu, Ryoko Takashiro, Ayaka Segawa, Takashi OyamadaAbstract:Abstract. A composite 2,206 nucleotide DNA sequence encoding a putative immunoglobulin-binding protein (BiP) was constructed from a sequence obtained from Babesia caballi cDNA library clones. The 1,962 nucleotide open reading frame predicts a 72 kD protein with extensive homology with BiPs from Apicomplexa parasites. The BiP gene had a predicted N-terminal signal sequence of 18 amino acids and a C-terminal tetrapeptide sequence (Ser-Asp-Glu-Leu) for signaling in the endoplasmic reticulum lumen. The recombinant protein expressed in baculovirus showed an apparent mass of 72 kD, which is identical to that of the native B. caballi protein. Monoclonal antibodies (MAbs) against B. caballi BiP reacted strongly with extracellular merozoites, but not in early intraerythrocytic stage. Detailed observation showed that the reaction of MAbs against pear-shaped forms was markedly irregular, with either no reaction, or reaction with one or two brightly fluorescent pear-shaped forms (two parasites) of B. caballi. Babesia caballi is a tick-borne hemoprotozoan parasite with a life cycle that alternates between an ixodid tick host, and mammalian hosts such as horses, in which it causes economi-cally important diseases worldwide.1 It is an obligatory intra-erythrocytic equine parasite belonging to the Apicomplexa. Although members of the Apicomplexa infect different hos
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MOLECULAR CLONING AND CHARACTERIZATION OF A PUTATIVE BINDING PROTEIN OF Babesia caballi
The American journal of tropical medicine and hygiene, 2005Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Noboru Kudo, Yumi Takamatsu, Ryoko Takashiro, Ayaka Segawa, Takashi OyamadaAbstract:A composite 2,206 nucleotide DNA sequence encoding a putative immunoglobulin-binding protein (BiP) was constructed from a sequence obtained from Babesia caballi cDNA library clones. The 1,962 nucleotide open reading frame predicts a 72 kD protein with extensive homology with BiPs from Apicomplexa parasites. The BiP gene had a predicted N-terminal signal sequence of 18 amino acids and a C-terminal tetrapeptide sequence (Ser-Asp-Glu-Leu) for signaling in the endoplasmic reticulum lumen. The recombinant protein expressed in baculovirus showed an apparent mass of 72 kD, which is identical to that of the native B. caballi protein. Monoclonal antibodies (MAbs) against B. caballi BiP reacted strongly with extracellular merozoites, but not in early intraerythrocytic stage. Detailed observation showed that the reaction of MAbs against pear-shaped forms was markedly irregular, with either no reaction, or reaction with one or two brightly fluorescent pear-shaped forms (two parasites) of B. caballi.
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Inhibitory effect of lactoferrin on in vitro growth of Babesia caballi.
The American journal of tropical medicine and hygiene, 2005Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Noboru Kudo, Tetsuya Tanaka, Nona Shibahara, Hiroko Tanaka, Aya Matsuu, Kei-ichi Shimazaki, Takashi OyamadaAbstract:Lactoferrin (LF) is an important biologic molecule with many functions, one of which is antimicrobial defense. We evaluated the growth-inhibiting effects of four types of LF (native LF, Fe+3-bound [holo] LF, Fe+3-free [apo] LF, and LF hydrolyzate) on the in vitro growth of Babesia caballi and B. equi. The growth of B. caballi was significantly suppressed in media containing apo LF, but was not inhibited in media containing native LF, holo LF, or LF hydrolyzate. The growth of B. equi was not inhibited by media containing native LF, holo LF, or apo LF. These data indicate that apo LF had the strongest inhibitory effect on B. caballi. This may have been caused by inactivation or inhibition of a growth factor in the culture medium.
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Seroepidemiologic Studies on Babesia caballi and Babesia equi Infections in Japan
The Journal of veterinary medical science, 2002Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Takashi Oyamada, Naoyoshi Suzuki, Akiko Nagai, Xuenan Xuan, Tsugihiko Kamio, Naotoshi Tsuji, Kozo FujisakiAbstract:Antibodies to Babesia caballi and Babesia equi were examined on a total of 2,019 horse serum samples that had been collected in 1971-1973 by the National Institute of Animal Health by enzyme-linked immunosorbent assay (ELISA) using recombinant proteins and by Western-blot analysis. Based on the criterion for positivity by ELISA, 5.4% (109/ 2,019) and 2.2% (44/ 2,019) had antibodies against B. caballi and B. equi, respectively. The ELISA-positive sera were further examined by Western blot; 30/ 109 for B. caballi and 2/ 44 for B. equi were positive for native B. caballi or B. equi, but none of them was seropositive for both infections. Based on the results of this study, further investigations should be required to survey horses that have arrived in Japan relatively recently and tick vectors of equine Babesia using ELISA with some recombinant protein, a parasite detection method in an in vitro culture of equine Babesia, and PCR testing.
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Improved in vitro Cultivation of Babesia caballi
The Journal of veterinary medical science, 1997Co-Authors: A. Avarzed, Ikuo Igarashi, Takumi Kanemaru, Kazuko Hirumi, Yoshitaka Omata, Atsushi Saito, Takashi Oyamada, Hideyuki Nagasawa, Yutaka Toyoda, Naoyoshi SuzukiAbstract:Babesia caballi infected erythrocytes were collected from the blood of an experimentally infected horse and could be continuously cultivated in vitro with parasitemia ranging from 2-4% in RPMI 1640 medium supplemented with 2 mM L-glutamine, 20 mM HEPES and 40% adult horse serum in a low oxygen atmosphere (2% O2, 5% CO2 and 93% N2). All attempts to increase parasitemia failed using other culture media, serum concentrations and culture vessels. However, parasite growth was enhanced by transfer of cultures from a low oxygen to 5% CO2 in air, with parasitemia ranging from 8-10%.
Kozo Fujisaki - One of the best experts on this subject based on the ideXlab platform.
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Development of a single-round and multiplex PCR method for the simultaneous detection of Babesia caballi and Babesia equi in horse blood.
Veterinary parasitology, 2005Co-Authors: Andy Alhassan, Kozo Fujisaki, Naoaki Yokoyama, Haruyuki Hirata, Masashi Okamura, Badgar Battsetseg, Wilawan Pumidonming, Ikuo IgarashiAbstract:With the aim of developing more simple diagnostic alternatives, a differential single-round and multiplex polymerase chain reaction (PCR) method was designed for the simultaneous detection of Babesia caballi and Babesia equi, by targeting 18S ribosomal RNA genes. The multiplex PCR amplified DNA fragments of 540 and 392 bp from B. caballi and B. equi, respectively, in one reaction. The PCR method evaluated on 39 blood samples collected from domestic horses in Mongolia yielded similar results to those obtained from confirmative PCR methods that had been established earlier. Thus, the single-round and multiplex PCR method offers a simple tool for the differential diagnosis of B. caballi and B. equi infections in routine diagnostic laboratory settings as well as in epidemiological studies.
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Molecular Cloning of a Babesia caballi Gene Encoding the 134-Kilodalton Protein and Evaluation of Its Diagnostic Potential in an Enzyme-Linked Immunosorbent Assay
Clinical and diagnostic laboratory immunology, 2004Co-Authors: Yoh Tamaki, Kozo Fujisaki, Naoaki Yokoyama, Sabine Bork, Haruyuki Hirata, Xuenan Xuan, Noriyuki Takabatake, Ikuo IgarashiAbstract:A Babesia caballi gene encoding the 134-kDa (BC134) protein was immunoscreened with B. caballi-infected horse serum. An enzyme-linked immunosorbent assay (ELISA) using recombinant BC134 protein could effectively differentiate B. caballi-infected horse sera from Babesia equi-infected or noninfected control horse sera. These results suggest that the recombinant BC134 protein is a potential diagnostic antigen in the detection of B. caballi infection.
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Growth-Inhibitory Effects of Artesunate, Pyrimethamine, and Pamaquine against Babesia equi and Babesia caballi in In Vitro Cultures
Antimicrobial agents and chemotherapy, 2003Co-Authors: Akiko Nagai, Kozo Fujisaki, Naoaki Yokoyama, Tomohide Matsuo, Sabine Bork, Haruyuki Hirata, Xuenan Xuan, Yinchang Zhu, Florencia G. Claveria, Ikuo IgarashiAbstract:Three antimalarial drugs, artesunate, pyrimethamine, and pamaquine, were evaluated for their growth-inhibitory effects against Babesia equi and Babesia caballi in in vitro culture. B. equi was more resistant to pyrimethamine than B. caballi. B. equi was also found to be more sensitive to artesunate and pamaquine than B. caballi. Of the three compounds, pyrimethamine gave the most promise for in vivo effectiveness.
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Seroepidemiologic Studies on Babesia equi and Babesia caballi Infections in Horses in Jilin Province of China
The Journal of veterinary medical science, 2003Co-Authors: Shoufa Zhang, Ikuo Igarashi, Kozo Fujisaki, Xuenan Xuan, Xiaohong Huang, Chahan Bayin, Hidenori Kabeya, Soichi Maruyama, Takeshi MikamiAbstract:The prevalence of equine piroplasmosis caused by Babesia equi and Babesia caballi in northeast China has remained unknown, although the People's Republic of China is recognized as an endemic country for the diseases. In the present study, we investigated the prevalence of equine piroplasmosis in Jilin province, a part of northeast China. A total of 111 serum samples were taken from horses in eastern Jilin, and examined for diagnosis of B. equi and B. caballi infections by the enzyme-linked immunosorbent assays with recombinant antigens, equi merozoite antigen-1 and P48, respectively. Of the 111 samples, 38 (34%) and 36 (32%) samples were sero-positive for B. equi infection and B. caballi infection, respectively. In addition, 14 (12%) samples were sero-positive for both B. equi and B. caballi infections. These results indicate that equine piroplasmosis is widespread and therefore a cause for serious concern in northeast China.
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Seroepidemiologic Studies on Babesia caballi and Babesia equi Infections in Japan
The Journal of veterinary medical science, 2002Co-Authors: Hiromi Ikadai, Ikuo Igarashi, Takashi Oyamada, Naoyoshi Suzuki, Akiko Nagai, Xuenan Xuan, Tsugihiko Kamio, Naotoshi Tsuji, Kozo FujisakiAbstract:Antibodies to Babesia caballi and Babesia equi were examined on a total of 2,019 horse serum samples that had been collected in 1971-1973 by the National Institute of Animal Health by enzyme-linked immunosorbent assay (ELISA) using recombinant proteins and by Western-blot analysis. Based on the criterion for positivity by ELISA, 5.4% (109/ 2,019) and 2.2% (44/ 2,019) had antibodies against B. caballi and B. equi, respectively. The ELISA-positive sera were further examined by Western blot; 30/ 109 for B. caballi and 2/ 44 for B. equi were positive for native B. caballi or B. equi, but none of them was seropositive for both infections. Based on the results of this study, further investigations should be required to survey horses that have arrived in Japan relatively recently and tick vectors of equine Babesia using ELISA with some recombinant protein, a parasite detection method in an in vitro culture of equine Babesia, and PCR testing.
Xuenan Xuan - One of the best experts on this subject based on the ideXlab platform.
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Effects of dihydroorotate dehydrogenase (DHODH) inhibitors on the growth of Theileria equi and Babesia caballi in vitro.
Experimental parasitology, 2017Co-Authors: Ketsarin Kamyingkird, Ikuo Igarashi, Naoaki Yokoyama, Shinuo Cao, Yoshifumi Nishikawa, Bumduuren Tuvshintulga, Akram Salama, Ahmed Abdelmoniem Mousa, Artemis Efstratiou, Xuenan XuanAbstract:Theileria equi and Babesia caballi are the causative agents of equine piroplasmosis (EP), which affects equine production in various parts of the world. However, a safe and effective drug is not currently available for treatment of EP. Dihydroorotate dehydrogenase (DHODH) is the fourth enzyme in the de novo pyrimidine synthesis pathway and has been known as a novel drug target for several apicomplexan protozoan parasites. In this study, we evaluated four DHODH inhibitors; atovaquone (ATV), leflunomide (LFN), brequinar (Breq), and 7-hydroxy-5-[1,2,4] triazolo [1,5,a] pyrimidine (TAZ) on the growth of T. equi and B. caballi in vitro and compared them to diminacene aceturate (Di) as the control drug. The growth of T. equi and B. caballi was significantly hindered by all inhibitors except TAZ. The half maximal inhibitory concentration (IC50) of ATV, LFN, Breq and Di against T. equi was approximately 0.028, 109, 11 and 40 μM, respectively, whereas the IC50 of ATV, LFN, Breq and Di against B. caballi was approximately 0.128, 193, 5.2 and 16.2 μM, respectively. Using bioinformatics and Western blot analysis, we showed that TeDHODH was similar to other Babesia parasite DHODHs, and confirmed that targeting DHODHs could be useful for the development of novel chemotherapeutics for treatment of EP.
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Immunochromatographic Test for Simultaneous Serodiagnosis of Babesia caballi and B. equi Infections in Horses
Clinical and vaccine immunology : CVI, 2006Co-Authors: Xiaohong Huang, Naoaki Yokoyama, Xuenan Xuan, Shoufa Zhang, Rodolfo A. Verdida, Ikuo IgarashiAbstract:An immunochromatographic test for the simultaneous detection of Babesia caballi- and B. equi-specific antibodies (BceICT) was developed using a recombinant B. caballi 48-kDa rhoptry protein (rBc48) and a recombinant truncated B. equi merozoite antigen 2 (rEMA-2t). An evaluation of the ability of the BceICT to detect antibodies in sera from uninfected horses and experimentally infected horses showed high sensitivities and specificities of 83.3% (10/12 sera) and 92.9% (52/56 sera), respectively, for the anti-B. caballi antibody and 94.1% (16/17 sera) and 88.2% (45/51 sera), respectively, for the anti-B. equi antibody. Results from the detection of antibodies in field-collected sera indicated that the BceICT results corresponded with those of enzyme-linked immunosorbent assays (ELISA), showing 91.8% correspondence (67/73 sera) for B. caballi and 95.9% correspondence (70/73 sera) for B. equi, and that the BceICT results also corresponded with the ICT for B. caballi and for B. equi, both of which were 98.2% (55/56 sera). The comparable results of the ICT and ELISA and the simplicity and rapidity of the performance of the ICT suggest that the BceICT would be a feasible test for the simultaneous serodiagnosis of both agents of equine babesiosis in the field.
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Molecular Cloning of a Babesia caballi Gene Encoding the 134-Kilodalton Protein and Evaluation of Its Diagnostic Potential in an Enzyme-Linked Immunosorbent Assay
Clinical and diagnostic laboratory immunology, 2004Co-Authors: Yoh Tamaki, Kozo Fujisaki, Naoaki Yokoyama, Sabine Bork, Haruyuki Hirata, Xuenan Xuan, Noriyuki Takabatake, Ikuo IgarashiAbstract:A Babesia caballi gene encoding the 134-kDa (BC134) protein was immunoscreened with B. caballi-infected horse serum. An enzyme-linked immunosorbent assay (ELISA) using recombinant BC134 protein could effectively differentiate B. caballi-infected horse sera from Babesia equi-infected or noninfected control horse sera. These results suggest that the recombinant BC134 protein is a potential diagnostic antigen in the detection of B. caballi infection.
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Growth-Inhibitory Effects of Artesunate, Pyrimethamine, and Pamaquine against Babesia equi and Babesia caballi in In Vitro Cultures
Antimicrobial agents and chemotherapy, 2003Co-Authors: Akiko Nagai, Kozo Fujisaki, Naoaki Yokoyama, Tomohide Matsuo, Sabine Bork, Haruyuki Hirata, Xuenan Xuan, Yinchang Zhu, Florencia G. Claveria, Ikuo IgarashiAbstract:Three antimalarial drugs, artesunate, pyrimethamine, and pamaquine, were evaluated for their growth-inhibitory effects against Babesia equi and Babesia caballi in in vitro culture. B. equi was more resistant to pyrimethamine than B. caballi. B. equi was also found to be more sensitive to artesunate and pamaquine than B. caballi. Of the three compounds, pyrimethamine gave the most promise for in vivo effectiveness.
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Seroepidemiologic Studies on Babesia equi and Babesia caballi Infections in Horses in Jilin Province of China
The Journal of veterinary medical science, 2003Co-Authors: Shoufa Zhang, Ikuo Igarashi, Kozo Fujisaki, Xuenan Xuan, Xiaohong Huang, Chahan Bayin, Hidenori Kabeya, Soichi Maruyama, Takeshi MikamiAbstract:The prevalence of equine piroplasmosis caused by Babesia equi and Babesia caballi in northeast China has remained unknown, although the People's Republic of China is recognized as an endemic country for the diseases. In the present study, we investigated the prevalence of equine piroplasmosis in Jilin province, a part of northeast China. A total of 111 serum samples were taken from horses in eastern Jilin, and examined for diagnosis of B. equi and B. caballi infections by the enzyme-linked immunosorbent assays with recombinant antigens, equi merozoite antigen-1 and P48, respectively. Of the 111 samples, 38 (34%) and 36 (32%) samples were sero-positive for B. equi infection and B. caballi infection, respectively. In addition, 14 (12%) samples were sero-positive for both B. equi and B. caballi infections. These results indicate that equine piroplasmosis is widespread and therefore a cause for serious concern in northeast China.
