Journal of Veterinary Medical Science
Online ISSN : 1347-7439
Print ISSN : 0916-7250
ISSN-L : 0916-7250
最新号
June
選択された号の論文の30件中1~30を表示しています
Anatomy
  • Miki KOH, Syunya NOGUCHI, Mami ARAKI, Hirotada OTSUKA, Makoto YOKOSUKA ...
    2020 年 82 巻 6 号 p. 745-753
    発行日: 2020年
    公開日: 2020/06/24
    [早期公開] 公開日: 2020/04/22
    ジャーナル オープンアクセス

    Vascular endothelial growth factor-A (VEGF-A) is a principal regulator of hematopoiesis as well as angiogenesis. However, the functions of VEGF-A and its receptors (VEGFRs) in the differentiation of mast cells (MCs) in the skin remain unclear. The aim of this study was to determine the expression patterns of two VEGFRs (Flk1 and Flt1) in the skin MCs during development and maturation in rats. From the 17th days of embryonic development (E17) to 1 day after birth (Day 1), most of skin MCs were immature cells containing predominant alcian blue (AB)+ rather than safranin O (SO)+ granules (AB>SO MCs). AB>SO MC proportions gradually decreased, while mature AB<SO MC proportions increased from Day 7 to 28. Flk1+ MC proportions increased from E20 and reached to approximately 90% from Day 1 to 21, thereafter decreased to about 10% at Day 60 and 90. Flk1+ MC proportions changed almost in parallel with the numbers of MCs and Ki67+ MC proportions from E17 to Day 90. The proportions of MCs with both nuclear and cytoplasmic Flt1-immunoreactivity were markedly increased at Day 28, when the proportions of nuclear Flk1+, Ki67+, and AB>SO MCs had significantly decreased, and AB<SO MC proportions significantly increased. Considering that the main function of Flt1 is suppression of Flk1 effects, our results indicated that cross-talk between Flk1 and Flt1 regulates the proliferation and maturation of the skin MCs during late embryonic and neonatal development in rats.

  • Tomoyo HORIO, Aisa OZAWA, Junichi KAMIIE, Motoharu SAKAUE
    2020 年 82 巻 6 号 p. 827-835
    発行日: 2020年
    公開日: 2020/06/30
    [早期公開] 公開日: 2020/04/21
    ジャーナル オープンアクセス

    The regulation of glial cells, especially astrocytes and microglia, is important to prevent the exacerbation of a brain injury because over-reactive glial cells promote neuronal death. Acetylcholine (ACh), a neurotransmitter synthesized and hydrolyzed by choline acetyltransferase (ChAT) and acetylcholinesterase (AChE), respectively, in the central nervous system, has the potential to regulate glial cells’ states, i.e., non-reactive and reactive states. However, the expression levels of these ACh-related enzymes in areas containing reactive glial cells are unclear. Herein we immunohistochemically investigated the distributions of AChE and ChAT with reactive glial cells in the cryo-injured brain of mice as a traumatic brain injury model. Immunohistochemistry revealed AChE- and ChAT-immunopositive signals in injured areas at 7 days post-injury. The signals were observed in and around glial fibrillary acidic protein (GFAP)- or CD68-immunopositive cells, and the numbers of cells doubly positive for GFAP/AChE, GFAP/ChAT, CD68/AChE, and CD68/ChAT were significantly increased in injured areas compared to sham-operated areas. Enzyme histochemistry for AChE showed intensely positive signals in injured areas. These results suggest that reactive astrocytes and microglia express and secrete AChE and ChAT in brain-injury areas. These glial cells may adjust the ACh concentration around themselves through the regulation of the expression of ACh-related enzymes in order to control their reactive states.

Bacteriology
Biochemistry
  • Asato SEKIYA, Ken TAKASAWA, Yoshikazu ARAI, Shidow TORISU, Koichiro NI ...
    2020 年 82 巻 6 号 p. 681-689
    発行日: 2020年
    公開日: 2020/06/16
    [早期公開] 公開日: 2020/04/02
    ジャーナル オープンアクセス

    Steroidogenic factor 1 (SF-1) is a nuclear receptor that is important in steroid hormone production, and adrenal and gonad development. The SF-1 gene is highly conserved among most vertebrates. However, dog SF-1 registered in public databases, such as CanFam3.1, lacks the 5’ end compared to other mammals including mouse, human, bovine, and cat. Whether this defect is due to species differences or database error is unclear. Here, we determined the full-length dog SF-1 cDNA sequence and identified the missing 5’ end sequence in the databases. The coding region of the dog SF-1 gene has 1,386 base pairs, and the protein has 461 amino acid residues. Sequence alignment analysis among vertebrates revealed that the 5’ end sequence of dog SF-1 cDNA is highly conserved compared to other vertebrates. The genomic position of the first exon was determined, and its promoter region sequence was analyzed. The DNA methylation state at the basal promoter and the expression of dog SF-1 in steroidogenic tissues and non-steroidogenic cells were examined. CpG sites at the basal promoter displayed methylation kinetics inversely correlated with gene expression. The promoter was hypomethylated and hypermethylated in SF-1 expressing and non-SF-1 expressing tissues, respectively. In conclusion, we identified the true full sequence of dog SF-1 cDNA and determined the genome sequence around the first exon. The gene is under the control of epigenetic regulation, such as DNA methylation, at the promoter.

Clinical Pathology
Immunology
  • Eriko MURATA, Satoi KOZAKI, Tomoaki MURAKAMI, Kaori SHIMIZU, Ayaka OKA ...
    2020 年 82 巻 6 号 p. 764-770
    発行日: 2020年
    公開日: 2020/06/24
    [早期公開] 公開日: 2020/05/01
    ジャーナル オープンアクセス

    Serum amyloid A (SAA) is both an amyloidogenic protein of amyloid A amyloidosis and an acute phase protein in most animal species. Although SAA isoforms, such as SAA1, 2, 3, and 4, have been identified in cattle, their biological functions are not completely understood. Previous studies using mice indicated that SAA3 mRNA expression increased by stimulation with Escherichia coli and lipopolysaccharide (LPS) in colonic epithelial cells, and subsequently the SAA3 protein enhanced the expression of mucin2 (MUC2) mRNA, which is the major component of the colonic mucus layer. These results suggest that SAA3 plays a role in host innate immunity against bacterial infection in the intestine. In this study, a novel anti-bovine SAA3 monoclonal antibody was produced and SAA3 expression levels in bovine epithelia were examined in vitro and in vivo using real-time PCR and immunohistochemistry (IHC). SAA3 mRNA expression, but not that of SAA1, was enhanced by LPS stimulus in bovine small intestinal and mammary glandular epithelial cells in vitro. Moreover, in bovine epithelia (small intestine, mammary gland, lung, and uterus) obtained from four Holstein dairy cows from a slaughterhouse, SAA3 mRNA expression was higher than that of SAA1. Furthermore, using IHC, SAA3 protein expression was observed in bovine epithelia, whereas SAA1 protein was not. These results suggest that in cattle, SAA3 plays an immunological role against bacterial infection in epithelial tissues, including the small intestine, mammary gland, lung, and uterus.

Intermnal Medicine
  • Akiyoshi TANI, Hirotaka TOMIYASU, Aki OHMI, Koichi OHNO, Hajime TSUJIM ...
    2020 年 82 巻 6 号 p. 771-778
    発行日: 2020年
    公開日: 2020/06/24
    [早期公開] 公開日: 2020/04/17
    ジャーナル オープンアクセス

    Non-neoplastic bone marrow disorders such as non-regenerative immune-mediated anemia, pure red cell aplasia, and myelodysplastic syndrome are major causes of non-regenerative anemia in dogs. However, there has been no study on the clinical and clinicopathological features of canine non-neoplastic bone marrow disorders in Japan. Hence, we first investigated the breed disposition of non-neoplastic bone marrow disorders that induce anemia as a retrospective study and found that Miniature Dachshund (MD) was a predisposed breed. Based on this finding, we investigated the clinical and clinicopathological features of non-neoplastic bone marrow disorders in MDs as a preliminary retrospective study, and we compared them between immunosuppressive treatment-responsive and -resistant MDs. We found that treatment-resistant MDs showed thrombocytosis and increased frequencies of dysplastic features in the peripheral blood. These results indicate that bone marrow disorders in treatment-resistant MDs might manifest distinct features compared with those in treatment-sensitive MDs, and sensitivity to immunosuppressive treatments could be predicted based on thrombocytosis and dysplastic features in the peripheral blood. Further studies that examine aberrations in the genome are needed to elucidate the pathophysiology of bone marrow disorders in MDs.

  • Aritada YOSHIMURA, Takahiro OHMORI, Shusaku YAMADA, Takae KAWAGUCHI, M ...
    2020 年 82 巻 6 号 p. 836-845
    発行日: 2020年
    公開日: 2020/06/30
    [早期公開] 公開日: 2020/04/24
    ジャーナル オープンアクセス

    The pancreas is believed to be vulnerable to hypoperfusion. In dogs with acute pancreatitis, pancreatic ischemia due to heart failure can worsen the condition. However, changes in pancreatic blood flow associated with decreased cardiac function have not been previously studied in dogs. Therefore, we aimed to identify and compare changes in pancreatic versus renal blood flow as a result of cardiac dysfunction. Seven dogs were subjected to rapid ventricular pacing to create heart failure models. Noninvasive blood pressure measurement, ultrasonic cardiography, contrast-enhanced ultrasonography for pancreatic blood flow measurement, and para-aminohippuric acid clearance for renal blood flow measurement were performed before starting and at 2 and 4 weeks after starting the pacing. Left ventricular cardiac output and mean blood pressure decreased at 2 and 4 weeks after starting the pacing, and pancreatic blood flow decreased at 2 and 4 weeks after starting the pacing. However, renal blood flow did not change at 2 weeks but decreased 4 weeks after starting the pacing. Overall, this study demonstrated that reduced pancreatic blood flow due to cardiac dysfunction occurs, similar to renal blood flow. This suggests that decreased pancreatic blood flow is not unusual and may frequently occur in dogs with heart failure. The results of this study support the speculation that heart failure can exacerbate acute pancreatitis. Additionally, this study provides useful basic information for designing further studies to study this association.

  • Aya MATSUU, Mihoko YABUKI, Emiko AOKI, Michio IWAHANA
    2020 年 82 巻 6 号 p. 690-694
    発行日: 2020年
    公開日: 2020/06/16
    [早期公開] 公開日: 2020/04/07
    ジャーナル オープンアクセス

    A molecular survey was conducted to understand recent distribution of pathogens associated with canine infectious respiratory disease (CIRD) in Japan. Nasal and/or pharyngeal swabs were collected from asymptomatic dogs and those with CIRD, living in private house or in kennels. PCR-based examination was conducted for detecting nine pathogens. Among private household dogs, 50.8% with CIRD, 11.1% with respiratory disease other than CIRD, and 4.3% asymptomatic were positive for more than one pathogen, whereas in kennel-housed dogs, 42.9% with CIRD and 27.3% asymptomatic were positive. Bordetella bronchiseptica was most frequently detected, followed by canine herpesvirus 1, canine parainfluenza virus, canine pneumovirus, Mycoplasma cynos, and canine adenovirus type 2. In kennel environment, asymptomatic dogs might act as reservoirs carrying the respiratory pathogens.

  • Hitomi ODA, Akihiro MORI, Toshinori SAKO
    2020 年 82 巻 6 号 p. 695-698
    発行日: 2020年
    公開日: 2020/06/16
    [早期公開] 公開日: 2020/04/20
    ジャーナル オープンアクセス

    Insulin degludec (IDeg) is a long-acting basal insulin recently developed for use in humans. This study aimed to investigate the effects of IDeg on glycemic control in diabetic cats. Changes in body weight, IDeg dosage, and glycated albumin (GA) were evaluated at 0, 1, 3, 6, 9, and 12 months following initiation of IDeg. A significant decrease in GA was observed and a mean GA level below 25% was achieved between 3 and 12 months. Furthermore, a significant increase in body weight was observed between 3 and 12 months. The mean IDeg dose was 0.75 ± 0.68 IU/kg/day at 12 months. Taken together, long-term glycemic control was successfully achieved in diabetic cats using IDeg.

  • Yu FURUSAWA, Masashi TAKAHASHI, Tomoko IWANAGA, Akira YABUKI, Rui KANO ...
    2020 年 82 巻 6 号 p. 779-783
    発行日: 2020年
    公開日: 2020/06/24
    [早期公開] 公開日: 2020/05/04
    ジャーナル オープンアクセス

    A 3-years-old male golden retriever was presented for decreased activity (lethargy), anorexia, and titubation. Superficial lymph nodes were enlarged, and arrhythmia and tachycardia were auscultated. Fungal hyphae-like structures were detected in the biopsy samples from an enlarged lymph node and spleen. Nucleotide sequence of the internal transcribed spacer region of the fungi amplified by PCR was highly homologous to that of Inonotus pachyphloeus. The dog was treated with antifungal agents such as itraconazole, fluconazole, and voriconazole. Clinical signs resolved for 325 days but the dog died suddenly, possibly because of arrhythmia. Postmortem examination revealed the presence of a disseminated fungal infection. This report describes the case of canine systemic Inonotus sp. infection treated by an antifungal agent.

  • Jimin YOO, Jaeeun KO, Hakyoung YOON, Kidong EOM, Jaehwan KIM
    2020 年 82 巻 6 号 p. 784-787
    発行日: 2020年
    公開日: 2020/06/24
    [早期公開] 公開日: 2020/05/15
    ジャーナル オープンアクセス

    A seven-month-old cat was referred for evaluation of exercise intolerance and open-mouth breathing. Based on ultrasonographic examination, caudal vena cava (CVC) aneurysm associated with right congestive heart failure resulting from congenital heart disease was diagnosed. Conservative treatment for alleviating pulmonary hypertension mildly improved the clinical signs and decreased the heart size and CVC aneurysm diameter. However, the improvements were transient and four months after initiating therapy, the cat developed dyspnea and uncontrollable seizures and was euthanized.

Parasitology
Pathology
  • Yuki TAKAMI, Takeshi IZAWA, Miyuu TANAKA, Shingo HATOYA, Tomoyo NABETA ...
    2020 年 82 巻 6 号 p. 704-706
    発行日: 2020年
    公開日: 2020/06/16
    [早期公開] 公開日: 2020/04/03
    ジャーナル オープンアクセス
    電子付録

    A 16 years old neutered male Miniature Dachshund with 1-year history of repetitive administration of zonisamide for treatment of epileptic seizure was presented for vomiting, anorexia and diarrhea. Serum biochemistry showed a markedly elevated ALP level. The dog died 6 days after the presentation and a necropsy was performed. Histopathologically, random, focal to extensive necrosis, formation of regenerative hepatocellular nodules surrounded by fibrous septa and proliferation of bile ducts were seen in the liver. From these findings, the hepatic lesion was diagnosed as hepatocellular necrosis with prominent regenerative reactions due to the chronic persistent liver injury. Hepatic lesions were considered to be induced by zonisamide, based on the history of continuous administration, and clinical and histopathological findings.

  • Wen-Ta LI, Ming-Shiuh LEE, Yi-Chia TSENG, Ning-Ya YANG
    2020 年 82 巻 6 号 p. 788-792
    発行日: 2020年
    公開日: 2020/06/24
    [早期公開] 公開日: 2020/05/01
    ジャーナル オープンアクセス

    Reptile-associated nidoviruses (serpentoviruses) have been reported to cause proliferative interstitial pneumonia in pythons and other reptile species. A captive, younger than 2 years old, intact female ball python (Python regius) showed increased oral mucus, wheezing, and audible breathing with weight loss. Gross and microscopic examination revealed large amounts of mucus in the esophagus and proliferative interstitial pneumonia. Serpentovirus genes were detected from the lung tissues by polymerase chain reaction. The current serpentoviruses was phylogenetically grouped with the serpentovirus previously identified in the US. No case of serpentovirus infection has been reported in Asia. The present report provides information of complete genome sequence and global distribution of serpentovirus.

Pharmacology
  • Keisuke IMOTO, Momoko ARATANI, Takahiro KOYAMA, Muneyoshi OKADA, Hidey ...
    2020 年 82 巻 6 号 p. 707-712
    発行日: 2020年
    公開日: 2020/06/16
    [早期公開] 公開日: 2020/04/03
    ジャーナル オープンアクセス

    Expression of thrombospondin-4 (TSP-4), a matricellular protein, is increased in the heart tissue of various cardiac disease models. In dorsal root ganglion neurons, TSP-4 inhibits L-type Ca2+ channel (LTCC) activity. Although TSP-4 might be related to the electrophysiological properties in heart, it remains to be clarified. The present study aimed to clarify the effects of TSP-4 on action potential (AP), LTCC current (ICaL) and voltage-dependent K+ (Kv) channel current (IKv) in rat isolated ventricular myocytes by a patch clamp technique. Ventricular myocytes were isolated from the heart of adult male Wistar rats. The ventricular myocytes were treated with TSP-4 (5 nM) or its vehicle for 4 hr. Then, whole-cell patch clamp technique was performed to measure AP (current-clamp mode) and ICaL and IKv (voltage-clamp mode). The mRNA expression of Kv channels was examined by reverse transcription-polymerase chain reaction. TSP-4 had no effect on the resting membrane potential and peak amplitude of AP. On the other hand, TSP-4 significantly prolonged AP duration (APD) at 50% and 90% repolarization. TSP-4 significantly inhibited the peak amplitudes of ICaL and IKv. TSP-4 had no effect on mRNA expression of Kv channels (Kcna4, Kcna5, Kcnb1, Kcnd2 and Kcnd3). The present study for the first time demonstrated that TSP-4 prolongs APD in rat ventricular myocytes, which is possibly mediated through the suppression of Kv channel activity.

Surgery
  • Harumichi ITOH, Shimpei NISHIKAWA, Kenji TANI, Hiroshi SUNAHARA, Munek ...
    2020 年 82 巻 6 号 p. 713-720
    発行日: 2020年
    公開日: 2020/06/16
    [早期公開] 公開日: 2020/04/09
    ジャーナル オープンアクセス

    Adipose-derived stem cells (ADSCs) are promising cell sources for regenerative medicine due to the simplicity of their harvest and culture; however, their biological properties are not completely understood. Moreover, recent murine and human studies identified several functional subpopulations of ADSCs varying in differentiation potential; however, there is a lack of research on canine ADSCs. Cystine transporter (xCT) is a stem cell marker in gastric and colon cancers that interacts with CD44 to enhance cystine uptake from the cell surface and subsequently accelerates intercellular glutathione levels. In this study, we identified a ~5% functional subpopulation of canine ADSCs with xCT+ expression (xCTHi). Compared with those of the xCT subpopulation (xCTLo), the xCTHi subpopulation showed a significantly higher proliferation rate, higher expression of conventional stem cell markers (SOX2, KLF4, and c-Myc), and higher expression of adipogenic markers (FABP4 and PPARγ). By contrast, the xCTLo subpopulation showed significantly higher expression of osteogenic markers (BMP1 and SPP) than xCTHi cells. These results suggest xCT as a candidate marker for detecting a functional subpopulation of canine ADSCs. Mechanistically, xCT could increase the adipogenic potential while decreasing the osteogenic differentiation potential, which could serve as a valuable target marker in regenerative veterinary medicine.

  • Ekkapol AKARAPHUTIPORN, Takafumi SUNAGA, Eugene C. BWALYA, Ryosuke ECH ...
    2020 年 82 巻 6 号 p. 793-803
    発行日: 2020年
    公開日: 2020/06/24
    [早期公開] 公開日: 2020/04/30
    ジャーナル オープンアクセス

    This study investigated the effects of culture time on phenotype stability of canine articular chondrocytes (CACs) in non-passaged long-term monolayer culture. Third passage (P3) CACs isolated from four cartilage samples were seeded at three different initial seeding densities (0.2 × 104, 1.0 × 104 and 5.0 × 104 cells/cm2) and maintained in monolayer condition up to 8 weeks without undergoing subculture after confluence. The characteristic changes of chondrocytes during the culture period were evaluated based on the cell morphology, cell proliferation, glycosaminoglycans (GAGs) content, DNA quantification, mRNA expression and ultrastructure of chondrocytes. Chondrocytes maintained under post-confluence condition exhibited a capability to grow and proliferate up to 4 weeks. Alcian blue staining and Dimethylmethylene blue (DMMB) assay revealed that the extracellular matrix (ECM) synthesis was increased in a time-dependent manner from 2 to 8 weeks. The chondrocyte mRNA expression profile was dramatically affected by prolonged culture time, with a significant downregulation of collagen type I, whereas the expression of collagen type II, aggrecan, Sox9 and matrix metalloproteinase 13 (MMP-13) were significantly upregulated. In addition, transmission electron microscopy (TEM) result indicated dilation of rough endoplasmic reticulum (RER) in these long-term monolayer cultured chondrocytes. These findings demonstrate that the chondrocytes phenotype could be partially redifferentiated through the spontaneous redifferentiation process in long-term cultures using standard culture medium without the addition of chondrogenic supplements or tissue-culture scaffolds.

  • Daisuke ITO, Naoko SHIOZAWA, Naoki SEKIGUCHI, Chieko ISHIKAWA, Nick D. ...
    2020 年 82 巻 6 号 p. 721-725
    発行日: 2020年
    公開日: 2020/06/16
    [早期公開] 公開日: 2020/04/16
    ジャーナル オープンアクセス

    A 30-month-old Maine Coon presented with progressive proprioceptive ataxia, paraparesis, thoracolumbar pain, and decreased appetite. An extradural mass was detected within the left side of the 13th thoracic vertebral canal that compressed the spinal cord on magnetic resonance (MR) and was considered to be mineralized on computed tomography (CT) images. The resected mass was diagnosed as a vertebral vascular hamartoma. Clinical signs improved, but recurrence was diagnosed by MR and CT imaging at 7 months after surgery. Repeated excisional surgery yielded the same diagnosis and the clinical signs abated. Fifteen months after the second surgery, there was apparent vertebral deformation, but there was no further change on CT images by 29 months.

  • Sho YOSHIMOTO, Daiki KATO, Satoshi KAMOTO, Kie YAMAMOTO, Masaya TSUBOI ...
    2020 年 82 巻 6 号 p. 804-808
    発行日: 2020年
    公開日: 2020/06/24
    [早期公開] 公開日: 2020/04/03
    ジャーナル オープンアクセス
    電子付録

    Human epidermal growth factor receptor 2 (HER2) overexpression has been reported in various human cancers. HER2-targeted therapies showed clinical responses in humans with HER2-positive tumors. The incidence of canine primary lung cancer (cPLC) is increasing, but there are no effective systemic therapies for dogs with late-stage cPLC. HER2-targeted therapy could be an option for cPLC, but HER2 expression in cPLC remains unknown. We evaluated HER2 expression in cPLC. Immunohistochemical analysis revealed that 3 samples (19%) scored 3+; 8 (50%), 2+; 5 (31%); and 1+ and 0 (0%), 0. Of the cPLC tissues, 69% were HER2 positive (scored ≥2+). These data would lead to further evaluation of the role of HER2 in cPLC as a mechanism of malignancy and therapeutic target.

Virology
  • Giang Thi Huong TRAN, Serageldeen SULTAN, Nabila OSMAN, Mohamed Ismail ...
    2020 年 82 巻 6 号 p. 809-816
    発行日: 2020年
    公開日: 2020/06/24
    [早期公開] 公開日: 2020/04/20
    ジャーナル オープンアクセス
    電子付録

    Although intensive vaccination programs have been implemented, Newcastle disease (ND) outbreaks, accompanied by severe economic losses, are still reported in Egypt. The genetic characterization of ND virus (NDV) strains isolated from ND-vaccinated chicken flocks provides essential information for improving ND control strategies. Therefore, here, 38 NDV strains were isolated and identified from outbreaks among vaccinated flocks of broiler chickens located in the provinces of Qena, Luxor, and Aswan of Upper Egypt during 2011–2013. The investigated broiler chicken flocks (aged 28 to 40 days) had high mortality rates of up to 80%. All NDV isolates were genetically analyzed using next-generation DNA sequencing. From these isolates, 10 representative NDV strains were selected for further genetic analyses. Phylogenetic analysis of full-length coding genes revealed that the Egyptian NDV isolates belonged to a single sub-genotype, VII.1.1. These isolates were phylogenetically distant from the vaccine strains, including La Sota or Clone 30 (genotype II), which have been commonly used to vaccinate chicken flocks. Amino acid substitution K78R was observed in the neutralizing epitopes of the F proteins; whereas several mutations were found in the neutralizing epitopes of the hemagglutinin-neuraminidase proteins, notably, E347K. Overall, our results suggested that the occurrence of neutralizing epitope variants may be one of potential reasons for ND outbreaks. Further studies are needed to determine the protective effect of current vaccines against circulating virulent NDV strains.

  • Jinxin LIN, Zhaolong LI, Zhihua FENG, Zhou FANG, Jianghua CHEN, Wengzh ...
    2020 年 82 巻 6 号 p. 846-855
    発行日: 2020年
    公開日: 2020/06/30
    [早期公開] 公開日: 2020/04/24
    ジャーナル オープンアクセス

    The prevalence of an emerging variant of the pseudorabies virus (PRV) has been causing serious losses to farmers in China. Moreover, the commercially available PRV vaccine often fails to provide thorough protection. Therefore, in this study, we generated a PRV-∆gC\gE∆TK strain with defects in gC, gE, and TK of PRV. Compared to the parental PRV strain and the single gene deletion strains (PRV-∆gC, PRV-∆gE, and PRV-∆TK), PRV-∆gC\gE∆TK grew slowly, and exhibited fewer and smaller plaques on swine testis (ST) cells. Furthermore, animal experiment results showed that mice that were immunized intramuscularly with PRV-∆gC\gE∆TK, survived throughout the experiment with no observed clinical symptoms, and were completely protected against PRV challenge. Additionally, deletion of the gC, gE, and TK genes significantly alleviated viral damage in the brain. Furthermore, one-day-old weaned piglets immunized intramuscularly with PRV-∆gC\gE∆TK elicited higher levels of gB antibodies against both the emerging PRV variant and the parental PRV, exhibited full protection against challenge with both variants, and showed neutralization capacity against PRV. These data suggest that PRV-∆gC\gE∆TK is a promising vaccine candidate for the control of pseudorabies.

  • Hirohisa MEKATA, Saori HAMABE, Putu Eka SUDARYATMA, Ikuo KOBAYASHI, To ...
    2020 年 82 巻 6 号 p. 726-730
    発行日: 2020年
    公開日: 2020/06/16
    [早期公開] 公開日: 2020/04/09
    ジャーナル オープンアクセス

    Bovine coronavirus (BCoV) is an etiological agent of bovine respiratory disease (BRD). BRD is a costly illness worldwide; thus, epidemiological surveys of BCoV are important. Here, we conducted a molecular epidemiological survey of BCoV in respiratory-diseased and healthy cattle in Japan from 2016 to 2018. We found that 21.2% (58/273) of the respiratory-diseased cattle were infected with BCoV. The respiratory-diseased cattle had virus amounts 4.7 times higher than those in the asymptomatic cattle. Phylogenetic analyses showed that the BCoV identified in Japan after 2005 formed an individual lineage that was distinct from the strains found in other countries. These results suggest that BCoV is epidemic and has evolved uniquely in Japan.

Wildlife Science
  • Takumi KURIHARA, Akihiro HIRATA, Tsuyoshi YAMAGUCHI, Harue OKADA, Miho ...
    2020 年 82 巻 6 号 p. 817-822
    発行日: 2020年
    公開日: 2020/06/24
    [早期公開] 公開日: 2020/05/01
    ジャーナル オープンアクセス
    電子付録

    Cormorant fishing is a traditional Japanese fishing method using captive Japanese cormorants (Phalacrocorax capillatus). Between June and July 2017, an avian pox outbreak was reported in captive cormorant populations throughout several distant cities in Japan. We examined the lesions obtained from two such affected cormorants, which were raised in distant cities. The affected cormorants were grossly characterized by the development of cutaneous nodules around the base of the beak. Histopathologically, these nodules consisted of marked epidermal hyperplasia with ballooning degeneration of spinous cells and eosinophilic intracytoplasmic inclusions (Bollinger bodies). The lesions displayed 4b core protein (P4b) of Avipoxvirus (APV) and DNA polymerase genes, which were detected by PCR. Moreover, the nucleotide sequences detected from both cormorants were found to be identical. No identical sequence was found in any international database. These findings suggest that both examined cormorants were infected with an identical APV, which has never been previously reported. According to the phylogenetic analysis, the detected sequences were observed to cluster in subclade A3, which consists mainly of the sequences detected from several marine birds, including other cormorant species. This observation suggests that the viruses might be maintained in Japanese cormorants in nature.

  • Yuichi KOSHIISHI, Misuzu UKITA, Michiko MURATA-OKUBO, Shin-ichiro FUJI ...
    2020 年 82 巻 6 号 p. 731-734
    発行日: 2020年
    公開日: 2020/06/16
    [早期公開] 公開日: 2020/04/03
    ジャーナル オープンアクセス

    The emu (Dromaius novaehollandiae) is a new poultry. In this study, we investigated the haplotype composition of mitochondrial DNA among emu populations farmed in Japan. We sequenced the D-loop region in 109 individuals, and detected four substitution sites and three haplotypes (Hap-a, -b, and -c). Hap-a was the most frequently observed haplotype in the Japanese populations. Although Hap-c was a rare haplotype in not only Japanese but also Australian populations, it was detected with high frequency in the Japanese farmed population. The AMOVA indicated that 9% of total variance was “among population”. The FST value was 0.087 and genetic differentiation was significant (P<0.01). These results may contribute to conserving the genetic resources available for the Japanese emu industry.

  • Yoshitsugu OCHIAI, Yuko YOSHIKAWA, Takashi TAKANO, Makoto MORI, Ryo HO ...
    2020 年 82 巻 6 号 p. 735-739
    発行日: 2020年
    公開日: 2020/06/16
    [早期公開] 公開日: 2020/04/09
    ジャーナル オープンアクセス

    A Japanese resident bird, Phalacrocorax carbo hanedae (Japanese name: Kawa-u), was threatened with extinction due to deterioration of its habitat in the 1970s, but the population has since recovered thanks to environmental protection measures. This study analyzed the genetic diversity of 18 Kawa-u individuals living in the basins of the Abe and Warashina rivers in Shizuoka Prefecture, Japan. We obtained seven haplotypes of mitochondrial D-loop sequences and compared them with 49 European P. carbo D-loop haplotypes. We identified four new haplotypes but no clear genetic evidence distinguishing the Kawa-u as a distinct subspecies of P. carbo. Our results suggest the need for further surveillance of the P. carbo genetic lineage, regardless of the geographical distribution.

  • Seiya MAEHARA, Naoya MATSUMOTO, Naoaki TAKIYAMA, Yoshiki ITOH, Yasunar ...
    2020 年 82 巻 6 号 p. 740-744
    発行日: 2020年
    公開日: 2020/06/16
    [早期公開] 公開日: 2020/04/14
    ジャーナル オープンアクセス

    A twenty-year-old male Asiatic black bear (Ursus thibetanus) presented at the Rakuno Gakuen University Animal Medical Center with a 10-year history of bilateral blindness and cataracts. Surgical treatment of bilateral cataracts by extracapsular lensextraction using phacoemulsification and aspiration (PEA) was performed under general anesthesia. An anterior capsulectomy was performed using micro iris scissors and micro anterior lens capsule forceps. The cataract was removed with PEA using the two-handed technique. After surgery, systemic corticosteroids, anti-inflammatory drugs and antibiotics were administered. After cataract removal, the bear had recovered vision, and good quality vision has been maintained to date (15 months). PEA can be a safe and effective treatment for cataracts that impair vision in bears.

  • Kozo TAKASE, Yuko HARAGUCHI, Akira SUZUKI, Takeshi OBI
    2020 年 82 巻 6 号 p. 823-826
    発行日: 2020年
    公開日: 2020/06/24
    [早期公開] 公開日: 2020/05/15
    ジャーナル オープンアクセス

    The Izumi Plain in Kagoshima Prefecture, Japan, is a major wintering ground for wild cranes. Between October 2009 and March 2016, a total of 204 Hooded Cranes Grus monacha and White-naped Cranes G. vipio were found dead or in a weak condition in the plane. Of these, 56 cranes had bone fractures. The rate of incidence of fracture was considered to be higher in White-naped than in Hooded Cranes. Tibia fractures were the most common. The leg and wing fracture numbers were almost equal. Forty six percent of the fracture cases were believed to be caused by collisions with the power line.

  • Nobuhide KIDO, Sohei TANAKA, Tomoko OMIYA, Yuko KAMITE, Kohei SAWADA, ...
    2020 年 82 巻 6 号 p. 856-860
    発行日: 2020年
    公開日: 2020/06/30
    [早期公開] 公開日: 2020/04/17
    ジャーナル オープンアクセス

    Fatal accidents in captive elephants occasionally occur because humans are unable to gauge elephants’ emotions solely by their behavior. The intellectual capacity of elephants makes them capable of understanding circumstantial changes and associated emotions, allowing them to react accordingly. Physiological markers, such as heart rate variability, may be effective in determining an elephant’s emotional state. In this study, a wearable heart rate monitor was used to determine the emotional state of a female Indian captive elephant (Elephas maximus indicus). The average heart rate was higher when the elephant underwent painful treatment than when it underwent non-painful treatment. In addition, the heart rate increased both before and after the treatment, which included radiography and blood collection.

  • Takashi IKEDA, Makoto ASANO, Naotoshi KUNINAGA, Masatsugu SUZUKI
    2020 年 82 巻 6 号 p. 861-865
    発行日: 2020年
    公開日: 2020/06/30
    [早期公開] 公開日: 2020/05/19
    ジャーナル オープンアクセス

    Although the first cases of classical swine fever were reported in 2018, no studies have explored this impact on wild boar populations in Japan. Comparing the relative abundance indices and age ratios in the wild boar population before and after the outbreak, we investigated the impact of classical swine fever virus on wild boar population dynamics in August 2017–December 2019. Relative abundance indices declined from 2017 to 2019 drastically, while there were no significant differences in age ratios throughout the study period. Consequently, wildlife managers should consider that wild boars continue to contract classical swine fever virus, and they should intensively implement countermeasures in agricultural lands and in pig farms, in addition to wild boar population management.

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