Papers - HIRAI Takuya
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Izzati U.Z., Kaneko Y., Kaneko C., Yoshida A., Suwanruengsri M., Okabayashi T., Hirai T., Yamaguchi R.
Journal of Comparative Pathology 188 44 - 51 2021.10
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Comparative Pathology
Following isolation of pseudorabies virus (PRV) from two hunting dogs in Oita prefecture, Japan, we investigated the PRV antigen distribution in the tissues of the infected animals. At necropsy, PRV-associated lesions included facial oedema, tonsillar and meningeal congestion, blotchy haemorrhages on the pericardium and mitral valves, and incomplete splenic contraction in one dog, with less prominent findings in the other dog. Multiple pulmonary nodules were seen in both cases, caused by the diploid form of Paragonimus westermani lung flukes, as confirmed by PCR-restriction fragment length polymorphism and gene sequencing analyses. Histological examination revealed that the PRV infection was associated with lesions of non-suppurative encephalitis in the brainstem. PRV antigen was detected in the cerebrum, cerebellum, brainstem, submucosal and myenteric plexuses, and mononuclear cells, mainly in the bone marrow, lymph nodes, tonsils and spleen tissues. There was evidence of PRV dissemination to the brain via the trigeminal or olfactory routes, in addition to possible spread to lymphoid organs via infected mononuclear cells.
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Mycoplasma bovis May Travel Along the Eustachian Tube to Cause Meningitis in Japanese Black Cattle Reviewed
Suwanruengsri M., Uemura R., Izzati U.Z., Kanda T., Fuke N., Yasuda M., Hirai T., Yamaguchi R.
Journal of Comparative Pathology 188 13 - 20 2021.10
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Comparative Pathology
Mycoplasma bovis (M. bovis) is a common inhabitant of the upper and lower respiratory tracts of cattle and is considered to be the main aetiological agent of otitis media in calves. The eustachian tube appears to be the most common portal for pathogens to enter the middle ear. We investigated the transmission route of M. bovis causing otitis media that progressed to meningitis or meningoencephalitis in Japanese Black cattle. M. bovis was detected in 10 cases by a loop-mediated isothermal amplification method or by immunohistochemistry. One case of caseonecrotic granulomatous meningoencephalitis, one case of caseonecrotic granulomatous meningitis, one case of suppurative meningoencephalitis, eight cases of eustachitis, nine cases of tonsillitis and six cases of suppurative bronchopneumonia were identified by histopathological examination. M. bovis antigen was detected in the eustachian tubes of eight cases. In nine cases, M. bovis was also detected in tonsillar epithelial crypts and lumina, in intraluminal inflammatory cells and in the epithelial cells of minor salivary glands located around the eustachian tubes and tonsils. The results suggest that M. bovis can infect and colonize the tonsils and enter the eustachian tubes, causing otitis media, which, in cases of chronic infection, can progress to meningitis.
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Teh A.P.P., Kitahara G., Izzati U.Z., Mori K., Fuke N., Hirai T., Yamaguchi R.
Journal of Comparative Pathology 187 40 - 51 2021.8
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Comparative Pathology
Granulosa cell tumours (GCTs) are the most common type of bovine ovarian neoplasm. We describe the morphological and immunohistochemical features of GCTs (n = 26) and a thecoma (n = 1) using antibodies to cytokeratin AE1/AE3, vimentin, desmin, nectin-4, anti-Müllerian hormone (AMH), inhibin α, c-erbB-2 oncoprotein and proliferating cell nuclear antigen. The results indicate that, based on the expression similarity of AE1/AE3 and inhibin α, the macrofollicular growth pattern of GCTs derives from highly differentiated granulosa cells (GCs), the Graafian follicle or early atretic follicle. The trabecular growth pattern of GCTs is inferred to be derived from GCs of the atretic follicle in mature animals. AMH is a useful marker for diagnosing bovine sex cord-stromal tumours because it was expressed in all GCT cases and in the single case of thecoma.
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Bursa atrophy at 28 days old caused by variant infectious bursal disease virus has a negative economic impact on broiler farms in Japan Reviewed
Myint O, Suwanruengsri M, Araki K, Izzati UZ, Pornthummawat A, Nueangphuet P, Fuke N, Hirai T, Jackwood DJ, Yamaguchi R.
Avian Pathol 50 ( 1 ) 6 - 17 2021.2
Language：English Publishing type：Research paper (scientific journal)
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Suppurative necrotizing bronchopneumonia caused by Nocardia cyriacigeorgica infection in a stranded striped dolphin (Stenella coeruleoalba) in Japan. Reviewed
Ito S, Hirai T, Hamabe S, Subangkit M, Okabayashi T, Goto Y, Nishida S, Kurita T, Yamaguchi R.
J Vet Med Sci 21 ( 83 ) 146 - 150 2021.1
Language：English Publishing type：Research paper (scientific journal)
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Pathology of the outbreak of subgenotype 2.5 classical swine fever virus in northern Vietnam Reviewed
Izzati U.Z., Hoa N.T., Lan N.T., Diep N.V., Fuke N., Hirai T., Yamaguchi R.
Veterinary Medicine and Science 7 ( 1 ) 164 - 174 2021.1
Language：English Publishing type：Research paper (scientific journal) Publisher：Veterinary Medicine and Science
Classical swine fever (CSF) is an endemic disease in southeastern Asia and is one of the most important swine diseases in Vietnam. This study was conducted to characterize the pathology of natural cases of CSF in northern Vietnam in 2018 and their genetic prevalence. A total of 10 representative pigs were collected from four provinces (Hung Yen, Ha Noi, Quang Ninh and Thai Binh) during five outbreaks and examined pathologically. The gross and histopathological findings showed the disease was expressed as the acute or the subacute to chronic form of CSF, depending on the age of the animals. The most consistently observed lesions associated with infection by the classical swine fever virus (CSFV) included lymphoid depletions in tonsils, lymph node and spleen; histiocytic hyperplasia in spleen; cerebral haemorrhage; perivascular cuffing in the brain; renal erythrodiapedesis; urothelial vacuolation and degeneration and interstitial pneumonia. The immunohistochemical findings showed a ubiquitous CSFV antigen mainly in the monocytes/macrophages and in the epithelial and endothelial cells in various organs. CSFV neurotropism was also found in the small neurons of the cerebrum and the ganglia of the myenteric plexus. Analysis of the full-length envelope protein (E2) genome sequence showed that all strains were genetically clustered into subgenotype 2.5, sharing a nucleotide identity of 94.0%–100.00%. Based on the results of this study, the strain was categorized as a moderately virulent CSFV.
DOI： 10.1002/vms3.339
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Myint O., Suwanruengsri M., Araki K., Izzati U.Z., Pornthummawat A., Nueangphuet P., Fuke N., Hirai T., Jackwood D.J., Yamaguchi R.
Avian Pathology 50 ( 1 ) 6 - 17 2021
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Avian Pathology
Infectious bursal disease (IBD), caused by IBD virus (IBDV), is highly contagious, immunosuppressive and causes a negative economic impact on poultry industry. IBDV-vaccinated broiler farms at south Kyushu, Japan had a bursa-to-bodyweight ratio (BB ratio) reduction at 28 days (d) old, followed by high mortality 30 d later. We analysed the influence of the IBDV on atrophy of the bursa of fabricius (BF) and the subsequent mortality after 30 d. Ten broilers were sampled at each timepoint from the farm with high mortality at 21, 25, 28 and 35 d. A second flock from the same farm was sampled at 14, 21, 25, 28, 35 and 42 d. IBDV was detected in BF samples at 25, 28 and 35 d and at 21, 25, 28 and 35 d in the first and second flocks, respectively, using immunohistochemical staining and RT-PCR. IBDV isolates from both flocks were closely related to the China KM523643 strain. Histopathology and TUNEL assay indicated apoptosis, severe lymphoid depletion, vacuoles within follicles, lymphoid follicle atrophy and fibrosis in the BF. We observed 75% of the polyserositis and 10% of the airsacculitis at 30 D in dead broilers. The antigenic variant IBDV infection was appeared to be the main influencing factor on BF atrophy and BB ratio reduction in the broilers. High mortality in the broilers after 30 d could be due to secondary infection. The disease caused by IBDV had a negative economic impact in the farm. RESEARCH HIGHLIGHTS New variant IBDV caused bursa atrophy and reduced BB ratio in 28-day-old broilers. After vIBDV had infected broilers, at 21 days old they became immunosuppressed. High mortality at 30 days old in broilers was due to secondary infection. New vIBDV has a negative economic impact on broiler farms in Japan.
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Pornthummawat A., Truong Q.L., Hoa N.T., Lan N.T., Izzati U.Z., Suwanruengsri M., Nueangphuet P., Hirai T., Yamaguchi R.
Journal of Veterinary Medical Science 83 ( 11 ) 1653 - 1660 2021
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Veterinary Medical Science
Investigation of the role of animals that have recovered and survived from African swine fever (ASF) in carrying the ASF virus is currently intense and ongoing. However, no clear definition of the carrier stage has been established. The aim of the present study was to establish criteria to elucidate a clear status of survival in naturally ASF-infected domestic pigs in Vietnam. Seroconversion from previous infection was confirmed by serological assay, and the absence of the viral genome in various organs was also assured by molecular analysis of a partial p72 gene. We recognized that histopathological evidence could benefit from further insights into the status and role of the surviving animals; therefore, we performed a histopathological study on four pigs from farms with a history of ASF outbreak. We found fibrotic changes in the reparative process as the main finding in all four pigs. Immunohistochemical detection of viral protein revealed an interesting result. Despite the negative result from viral genome detection, the p30 protein gave a positive signal in the tonsils, lung, and stomach. This raises the possibility of stress-induced viral reactivation in long-term survivors and the risk of further outbreaks from human handling of contaminated carcasses.
DOI： 10.1292/jvms.21-0409
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Severe Degenerative Changes in Cryptorchid Testes in Japanese Black Cattle Reviewed
Fuke N., Kitahara G., Ito S., Van Diep N., Ping Teh A.P., Izzati U.Z., Myint O., Hirai T., Torisu S., Kaneko Y., Sato H., Hidaka Y., Osawa T., Yamaguchi R.
Veterinary Pathology 57 ( 3 ) 418 - 426 2020.5
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Veterinary Pathology
This is a histopathologic and endocrinologic study of 6 calves diagnosed with cryptorchidism. Cases 1–3 were diagnosed as resembling testicular regression syndrome. In cases 1 and 2, the extracted tissue was a small, firm, gray-white mass, and there was lack of obvious testicular tissue in case 3. Histopathologically, the excised tissue in cases 1–3 was a fibrotic testicular remnant with inflammation, mineralization, hemosiderin-laden macrophages or lipofuscin-laden macrophages, and lack of germ cells and interstitial endocrine cells. These findings were compared with cases 4–6, which were diagnosed as testicular hypoplasia due to cryptorchidism. These cases had small but otherwise grossly unremarkable intra-abdominal testicular tissue and histologically had a few germ cells and sustentacular cells with arrested spermatogenesis and an increase in interstitial endocrine cells. Cases 1–3 had more severe degenerative changes compared with cases 4–6. In case 2, the average diameter of the seminiferous tubules was much smaller than in cases 4–6, and there were few tubule cross sections. Anti-Müllerian hormone (214 pg/ml) was detected in the plasma of case 2. Based on the macroscopic and histopathologic findings as well as endocrinologic profiles, the testicular degeneration in cases 1–3 was considered similar to that of testicular regression syndrome. In this condition, it is thought that a normally developing intra-abdominal testis undergoes degeneration due to heat or a vascular disorder such as torsion.
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Severe Degenerative Changes in Cryptorchid Testes in Japanese Black Cattle. Reviewed
Fuke N, Kitahara G, Ito S, Van Diep N, Ping Teh AP, Izzati UZ, Myint O, Hirai T, Torisu S, Kaneko Y, Sato H, Hidaka Y, Osawa T, Yamaguchi R.
Vet Pathol 57 ( 3 ) 418 - 426 2020.2
Language：English Publishing type：Research paper (scientific journal)
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Disseminated Pneumocystosis in a Toy Poodle. Reviewed
Sakashita T, Kaneko Y, Izzati UZ, Hirai T, Fuke N, Torisu S, Yamaguchi R.
J Comp Pathol. 175 85 - 89 2020.2
Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Comparative Pathology
A 1-year and 7-months-old neutered male toy poodle was presented with persistent respiratory distress, gradual weight loss and melaena. Thoracic radiography showed an unstructured interstitial lung pattern. Histopathological examination of tissues collected at necropsy examination revealed disseminated infection by Pneumocystis carinii. The organisms were detected in the lungs, lymph nodes, liver, heart, kidneys, spleen, gastrointestinal tract and pancreas. In the lungs, the organisms were present in the alveolar space and interstitial tissue, and calcified foci containing P. carinii were observed. The presence of the organism in non-thoracic lymph nodes provided evidence of lymphogenous spread. A definitive diagnosis of disseminated pneumocystosis was achieved through the use of Grocott methenamine silver staining, immunohistochemistry (IHC) and polymerase chain reaction for P. carinii. Depletion of cells expressing immunoglobulin (Ig)A and IgG was confirmed by IHC of lymphoid tissue, suggesting possible underlying immunodeficiency.
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Pathological investigation and viral antigen distribution of emerging African swine fever in Vietnam Reviewed
Izzati U.Z., Inanaga M., Hoa N.T., Nueangphuet P., Myint O., Truong Q.L., Lan N.T., Norimine J., Hirai T., Yamaguchi R.
Transboundary and Emerging Diseases 68 ( 4 ) 2039 - 2050 2020
Language：English Publishing type：Research paper (scientific journal) Publisher：Transboundary and Emerging Diseases
African swine fever (ASF) is emerging in Vietnam and poses a continuing severe threat to the swine industry. A histopathological study of clinical samples collected during the May to July 2019 outbreak of ASF was performed to determine the characteristic lesions. We analysed samples from eight ASFV-infected farms. Histopathological results revealed the characteristic lesions of the acute to the subacute clinical form of ASF. Immunohistochemical results showed ASFV viral antigen distribution in mononuclear cells/macrophage in various organs, hepatocytes and renal tubular epithelium. Molecular analysis of partial capsid protein 72 gene revealed that ASFV strain from the eight separate outbreaks belonged to genotype II.
DOI： 10.1111/tbed.13851
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Myint O., Yoshida A., Sekiguchi S., Van Diep N., Fuke N., Izzati U.Z., Hirai T., Yamaguchi R.
BMC Veterinary Research 15 ( 1 ) 2019.11
Language：English Publishing type：Research paper (scientific journal) Publisher：BMC Veterinary Research
Background: Porcine epidemic diarrhea virus (PEDV) infection is a highly contagious infectious disease causing watery diarrhea, vomiting, dehydration and high mortality rate in newborn piglets. PEDV infection can cause high economic losses in pig industry. In Japan, a PEDV outbreak occurred with high mortality from 2013 to 2015. Even though until now, PEDV infection occurs sporadically. For the control and monitoring of PEDV infection, not only symptomatic pigs, but also asymptomatic pigs should be identified. The objective of this study is to develop and optimize novel indirect ELISA as a simple, rapid, sensitive and specific method for the detection of anti-PEDV antibodies and evaluate the efficacy of the assay as a diagnostic method for PED. Results: One hundred sixty-two serum samples, consisting of 81 neutralization test (NT) positive and 81 NT negative sera, were applied to the assay. Indirect ELISA test based on whole virus antigen (NK94P6 strain) derived from Vero cell culture was evaluated by receiver operating characteristic (ROC) analysis with neutralization test (NT) as a reference method, and cut-off value was determined as 0.320 with sensitivity and specificity of 92.6 and 90.1%, respectively. The area under curve (AUC) was 0.949, indicating excellent accuracy of indirect ELISA test. There was significant positive correlation between indirect ELISA and neutralization test (R = 0.815, P < 0.05). Furthermore, the kappa statics showed the excellent agreement between these two tests (kappa value = 0.815). In addition, the sensitivity and specificity of preserved plates with different periods (1 day, 2 weeks, 1, 2, 3, 4, 5 and 6 months) after drying antigen coated plates were 100% and 80-100%, respectively. Conclusions: The developed indirect ELISA test in our study would be useful as a reliable test for serological survey and disease control of PEDV infection, and our pre-antigen coated ELISA plates can be preserved at 4 °C until at least 6 months.
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Ameloblastic Carcinoma Arising from an Amyloid-Producing Odontogenic Tumour in a Reviewed
Izzati UZ, Hidaka Y, Hirai T, Yamaguchi R.
J Comp Pathol 166 54 - 58 2019.1
Language：English Publishing type：Research paper (scientific journal)
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Teh A., Hirai T., Ito S., Hidaka Y., Goto Y., Furukawa H., Sawada J., Yamaguchi R.
Medical Mycology Case Reports 21 37 - 40 2018.9
Language：English Publishing type：Research paper (scientific journal) Publisher：Medical Mycology Case Reports
A 7-month-old female Japanese Black calf developed elongated, nodular mass measuring 30 × 16 cm extended from the retropharyngeal region to mid lateral neck region. Histological examination revealed granulomatous lymphangitis with non-septate fungal hyphae recognized throughout the lesions. Fungal culture, DNA sequencing and molecular phylogenetic tree analysis confirmed the sequence of Lichtheimia corymbifera. The lymphogenous route was speculated to be the main route of fungal spread leading to the characteristic nodular appearance of this case.
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Local extensive granulomatous inflammation of the neck region and lymphangitis Reviewed
Teh APP, Hirai T, Ito S, Hidaka Y, Goto Y, Furukawa H, Sawada J, Yamaguchi R.
Med Mycol Case Rep 17 ( 21 ) 37 - 40 2018.4
Language：English Publishing type：Research paper (scientific journal)
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Van Diep N., Sueyoshi M., Norimine J., Hirai T., Myint O., Teh A.P.P., Izzati U.Z., Fuke N., Yamaguchi R.
BMC Veterinary Research 14 ( 1 ) 2018.3
Language：English Publishing type：Research paper (scientific journal) Publisher：BMC Veterinary Research
Background: Since late 2013, porcine epidemic diarrhea virus (PEDV) has reemerged in Japan and caused severe economic losses to the swine industry. Although PEDV vaccines have been used widely, the disease has swept rapidly across the county, and is commonly observed in PED-vaccinated farms, and has recurred in domestic herds. To better understand PEDVs responsible for the reemerging outbreaks in Japan, full-length spike (S), membrane (M), and nucleocapsid (N) genes of 45 PEDVs collected in Japan during 2013-2016, were sequenced and analyzed. Results: Phylogenetic analysis based on S gene sequences revealed that all the recent field PEDVs were genetically distinct from the classical Japanese strains, and were classified into three genotypes: North American (NA), S INDEL, and Asian non-S INDEL. Our data suggested a possibility that multiple parental PEDV strains were introduced into Japan from abroad at the same time or similar times. The newly identified Japanese strains showed the closest relationship to the US strains. Two sublineages of Japanese strains circulating in Japan were similar to two sublineages identified in the US, suggesting common ancestors for these strains. In comparison with two vaccine strains used in Japan, the field strains had various changes in epitope regions, glycosylation sites, and phosphorylation sites. These substitutions, particularly observed in epitope regions of the S (521, 553, 568, and 570), M (5), and N (123, 252, and 255) proteins, may have affected antigenicity and vaccine efficacy, resulting in an unsuccessful PEDV control. Sequence comparisons between PEDVs collected from primary and secondary outbreaks in three herds revealed that the disease has developed to an endemic stage in which PEDV could persist for nearly two years in the herds or local regions, causing subsequent epidemics. Conclusions: These results elucidate the genetic characteristics, origin, and molecular epidemiology of PEDVs circulating in Japan, as well as the PEDV strains causing recurrent outbreaks. This study provides a better insight into the PEDVs responsible for recent outbreaks in Japan, and could potentially help to develop measures for controlling and preventing the disease.
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Appearance of US-like porcine epidemic diarrhoea virus (PEDV) strains before US outbreaks and genetic heterogeneity of PEDVs collected in Northern Vietnam during 2012-2015. Reviewed
Diep NV, Sueyoshi M, Izzati U, Fuke N, Teh APP, Lan NT, Yamaguchi R
Transboundary and emerging diseases 65 ( 1 ) e83 - e93 2018.2
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Merkel Cell Carcinoma in a Steer Reviewed
Teh A.P.P., Izzati U.Z., Diep N.V., Hirai T., Yamaguchi R.
Journal of Comparative Pathology 158 17 - 21 2018.1
Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Comparative Pathology
Merkel cell carcinoma is a rare and aggressive cutaneous neuroendocrine tumour reported only in man, dogs and cats. A 20-month-old Japanese black fattening steer was presented with necrotic protruding skin masses over the left thoracic area and a 20 × 25 cm subcutaneous mass in the left abdominal area. Microscopical evaluation of the masses revealed cords of small to medium-sized round tumour cells with marked anisocytosis and anisokaryosis and clear and vacuolated cytoplasm, which were separated by a delicate fibrovascular stroma and arranged in a trabecular and nested pattern. Necropsy examination revealed multiple solid white nodular masses in the lungs. Immunohistochemistry (IHC) for cytokeratin (CK) 20 and CKAE1/3 revealed focal perinuclear labelling of tumour cells. IHC for the neuroendocrine markers chromogranin A and neuron specific enolase, the neuroepithelial stem cell marker nestin and the hormonal markers adrenocorticotropic hormone and calcitonin revealed diffuse cytoplasmic labelling of all tumour cells. Ultrastructurally, the tumour cells contained few neurosecretory granules and abundant glycogen pools. The tumours were diagnosed as Merkel cell carcinoma with pulmonary metastases and this case represents the first such diagnosis in cattle.
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TEH Angeline Ping Ping, PRATAKPIRIYA Watanyoo, HIDAKA Yuichi, SATO Hiroyuki, HIRAI Takuya, YAMAGUCHI Ryoji
Journal of Veterinary Medical Science 79 ( 4 ) 714 - 718 2017.4
Language：English Publishing type：Research paper (scientific journal) Publisher：JAPANESE SOCIETY OF VETERINARY SCIENCE
DOI： 10.1292/jvms.16-0501