Journal of Veterinary Medical Science
Online ISSN : 1347-7439
Print ISSN : 0916-7250
ISSN-L : 0916-7250
最新号
選択された号の論文の17件中1~17を表示しています
Anatomy
  • Shiori KATO, Toshifumi YOKOYAMA, Taisei FUJIKAWA, Yusuke KIRIZUKI, You ...
    2024 年 86 巻 3 号 p. 300-307
    発行日: 2024年
    公開日: 2024/03/16
    [早期公開] 公開日: 2024/01/24
    ジャーナル オープンアクセス
    電子付録

    We previously showed that the anti-Müllerian hormone (AMH), infiltrating from the testis to the mesonephros reaches the cranial and middle regions of the Müllerian duct (MD) and induces their regression using an organ culture in mice. However, it is difficult to maintain structural integrity, such as the length and diameter and normal direction of elongation of the caudal region of the MD, in conventional organ culture systems. Therefore, the pathway of AMH to the caudal MD region remains uncharted. In this study, we established an organ culture method that can maintain the morphology of the caudal region of the MD. The gonad–mesonephros complex, metanephros, and urinary bladder of mouse fetuses at 12.5 dpc attached to the body trunk were cultured on agarose gels for 72 hr. The cultured caudal region of the mesonephros was elongated along the body trunk, and the course of the mesonephros was maintained in many individuals. In males, mesenchymal cells aggregated around the MD after culture. Moreover, the male MD diameter was significantly smaller than the female. Based on these results, it was concluded that the development of the MD was maintained in the present organ culture system. Using this culture system, AMH infiltration to the caudal region of the MD can be examined without the influence of AMH in the blood. This culture system is useful for clarifying the regression mechanism of the caudal region of the MD.

  • Haena YOO, Seyoung LEE, Kwang-Yun SHIN, Jong-pil SEO
    2024 年 86 巻 3 号 p. 308-311
    発行日: 2024年
    公開日: 2024/03/16
    [早期公開] 公開日: 2023/12/29
    ジャーナル オープンアクセス

    This study aimed to describe the computed tomographic (CT) dimensions and the contrast attenuation of the eye in Jeju horses and Thoroughbreds. We evaluated the CT images of 10 Jeju horses and 6 Thoroughbreds without ocular abnormalities to assess the ocular dimensions and contrast attenuation. The following measurements showed significant differences between Jeju horses and Thoroughbreds (P<0.05): the diameters of the lens, globe, posterior segment, orbital fossa, and lateromedial distance of the anterior chamber; and the Hounsfield units of the vitreous body. This study describes the CT anatomical characteristics of Jeju horses and Thoroughbreds and the differences between the two breeds and provides useful information for understanding and evaluating of the eyes of Jeju horses through a CT scan.

Internal Medicine
  • Kazuto KIMURA, Hiroya NAGAKURA, Masaya TSUKAMOTO, Takumi YOSHIDA, Hiro ...
    2024 年 86 巻 3 号 p. 247-257
    発行日: 2024年
    公開日: 2024/03/01
    [早期公開] 公開日: 2024/01/04
    ジャーナル オープンアクセス
    電子付録

    Canine induced pluripotent stem cells (ciPSCs) can provide useful insights into novel therapies in both veterinary and medical fields. However, limited accessibility to the present culture medium and requirement of considerable time, effort, and cost for routine ciPSC maintenance restrict advancement in ciPSC research. In addition, it is unknown whether ciPSC culture conditions influence differentiation propensity. We investigated the availability of the common human pluripotent stem cells (hPSCs) culture systems for ciPSC maintenance and the differentiation propensities of the ciPSCs maintained in these culture systems. StemFlex and mTeSR Plus supported PSC-like colony formation and pluripotency markers expression in ciPSCs even after five passages. Additionally, ciPSCs were maintained under weekend-free culture conditions with a stable growth rate, pluripotency marker expression, and differentiation abilities using vitronectin (VTN-N) and Geltrex. Following maintenance of spontaneously differentiated ciPSCs under various conditions by embryoid body formation, there were few differences in the differentiation propensities of ciPSCs among the tested culture conditions. Thus, ciPSCs were successfully cultured under weekend-free conditions for ciPSC maintenance using StemFlex or mTeSR Plus with VTN-N or Geltrex. The present study offers simpler and more effort-, time-, and cost-saving options for ciPSC culture systems, which may lead to further development in research using ciPSCs.

Pathology
  • Takayuki MINESHIGE, Yusuke TANAKA, Kenichi WATANABE, Michihito TAGAWA, ...
    2024 年 86 巻 3 号 p. 258-265
    発行日: 2024年
    公開日: 2024/03/01
    [早期公開] 公開日: 2024/01/18
    ジャーナル オープンアクセス
    電子付録

    Oral squamous cell carcinoma (oSCC) is a highly invasive malignant neoplasm in cats. Recently, tumor stroma, known as tumor microenvironments, have been considered to play an essential role in tumor progression. However, their role in feline squamous cell carcinoma (SCC) remains unclear. This study aimed to reveal the cancer microenvironment of feline oSCC and evaluate the pathological mechanisms of progression. We used 19 samples from 17 cats with oSCC, which were examined using light microscopy, immunohistochemistry, and in situ hybridization (RNAscope®). Feline oSCCs had two types of stroma, namely fibrotic and myxoid stromal reaction patterns, which were easily distinguished using hematoxylin–eosin staining. The myxoid stroma was rich in hyaluronic acid, which seems to be produced by neoplastic cells. Furthermore, the presence of myxoid stroma was correlated with histological parameters, including the appearance of cancer-associated fibroblasts and tumor budding. Periostin protein expression was also frequently observed in the stroma of feline oSCC and was significantly more common in the myxoid stromal reaction pattern group than in the fibrotic group. Positive signals for periostin mRNA were detected in stromal cancer-associated fibroblasts. This study indicates that the interaction between neoplastic cells and stromal reaction pattern components, such as hyaluronic acid and periostin, may be involved in tumor malignancy. Therefore, we propose that focus be placed not only on the tumor tissue but also on the characterization of the stroma for analyzing feline oSCC.

  • Da-Ye NAM, Seong-Hwan JANG, So-Jeong YIM, Jae-Hoon KIM, Ji-Youl JUNG
    2024 年 86 巻 3 号 p. 312-316
    発行日: 2024年
    公開日: 2024/03/16
    [早期公開] 公開日: 2024/01/31
    ジャーナル オープンアクセス
    電子付録

    A 12-year-old castrated male poodle presented with vomiting and diarrhea. Ultrasonography and computed tomography revealed a protruding mass at the caudal pole of the left kidney. Grossly, the poorly circumscribed abnormal mass was 1.6 × 1.8 × 1.9 cm in size and had multifocal dark-red foci. Microscopically, it was composed of densely or loosely packed variable-sized short spindle or ovoid cells. These neoplastic cells showed high pleomorphism, mitotic figures, and invasive tendency to the adjacent tissue. Immunohistochemically, the neoplastic spindle cells expressed vimentin, S100, neuron-specific enolase, nerve growth factor receptor, and laminin. Therefore, the mass was diagnosed as a malignant peripheral nerve sheath tumor (MPNST). To our knowledge, this is the first report of primary renal MPNST in a dog.

Pharmacology
  • Ting-Wei YU, Haru YAMAMOTO, Shohei MORITA, Ryuji FUKUSHIMA, Mohamed EL ...
    2024 年 86 巻 3 号 p. 317-321
    発行日: 2024年
    公開日: 2024/03/16
    [早期公開] 公開日: 2024/01/29
    ジャーナル オープンアクセス

    Lapatinib is an orally administered tyrosine kinase inhibitor used to treat human epidermal growth factor receptor 2 (HER2) -overexpressing breast cancers in humans. Recently, the potential of lapatinib treatment against canine urothelial carcinoma or feline mammary tumor was investigated. However, the pharmacokinetic studies of lapatinib in dogs and cats are not well-defined. In the present study, the pharmacokinetic characteristics of lapatinib in both cats and dogs after a single oral administration at a dose of 25 mg/kg were compared with each other. Lapatinib was administered orally to four female laboratory cats and four female beagle dogs. Blood samples were collected over time, and the plasma lapatinib concentrations were analyzed by HPLC. Following a single dose of 25 mg/kg, the averaged maximum plasma concentration (Cmax) of lapatinib in cats was 0.47 μg/mL and achieved at 7.1 hr post-administration, while the Cmax in dogs was 1.63 μg/mL and achieved at 9.5 hr post-administration. The mean elimination half-life was 6.5 hr in cats and 7.8 hr in dogs. The average area under the plasma concentration-time curve of dogs (37.2 hr·μg/mL) was significantly higher than that of cats (7.97 hr·μg/mL). These results exhibited slow absorptions of lapatinib in both animals after oral administration. The Cmax observed in cats was significantly lower and the half-life was shorter than those observed in dogs. Based on these results, a larger dose or shorter dosing intervals might be recommended in cats to achieve similar plasma concentration as dogs.

Public Health
  • Takeshi NIWA, Shunsuke IKEUCHI, Thi Hien BUI, Minato OKUMURA, Takahide ...
    2024 年 86 巻 3 号 p. 322-324
    発行日: 2024年
    公開日: 2024/03/16
    [早期公開] 公開日: 2024/01/25
    ジャーナル オープンアクセス

    This study aimed to investigate the prevalence of antibodies against pathogenic Yersinia such as Y. enterocolitica and Y. pseudotuberculosis in domestic pigs. A total of 650 serum samples from pigs in nine regions of the Chiba Prefecture in Japan, were tested using plasmid-encoded Yersinia outer membrane protein (Yops) antigen ELISA. The cutoff value was calculated using 20 pathogenic Yersinia-free pig serum samples. According to the cutoff value, 246 (37.8%) pigs from seven regions were considered seropositive for pathogenic Yersinia during the study period. These results indicate that pathogenic Yersinia is widespread in pigs in Chiba, which may become the source of human yersiniosis in this region.

Surgery
  • Teppei KANDA, Natsuki AKASHI, Nanako KAWAMURA, Yuna NEKI, Miho OSUMI, ...
    2024 年 86 巻 3 号 p. 266-271
    発行日: 2024年
    公開日: 2024/03/01
    [早期公開] 公開日: 2024/01/24
    ジャーナル オープンアクセス

    Propofol is a potential injectable anesthetic agent used in total intravenous anesthesia. However, the sparing effect of fentanyl and medetomidine on the required propofol dose in dogs remains unclear. We aimed to investigate the effect of fentanyl constant-rate infusion (CRI) with or without medetomidine on the minimum infusion rate of propofol required to prevent motor movement (MIRNM) in dogs. Six healthy purpose-bred dogs were anesthetized on three occasions with propofol alone (loading dose [LD], 8 mg/kg to effect; initial infusion rate [IR], 0.70 mg/kg/min); propofol (LD, 6 mg/kg to effect; IR, 0.35 mg/kg/min) and fentanyl (LD, 2 µg/kg; IR, 0.10 µg/kg/min); or propofol (LD, 4 mg/kg to effect; IR, 0.25 mg/kg/min), fentanyl (LD, 2 µg/kg; IR, 0.10 µg/kg/min), and medetomidine (LD, 2 µg/kg; IR, 0.5 µg/kg/hr) under controlled ventilation. The MIRNM was determined by observing the response to a noxious electrical stimulus. Heart rate, blood pressure, and blood gas analyses were performed at 1, 2, 3, and 4 hr after initiating CRI. The MIRNM (mean [range]) was significantly lower in the propofol-fentanyl-medetomidine group (0.16 [0.10–0.27] mg/kg/min) than that in the propofol-alone group (0.63 [0.47–0.82] mg/kg/min) (P=0.0004). Fentanyl combined with medetomidine did not significantly decrease the mean arterial pressure in dogs receiving propofol CRI 1–3 hr after initiating CRI compared with propofol CRI alone (P>0.9999, P=0.1536, and P=0.0596, respectively), despite inducing a significantly lower heart rate.

  • Yusuke SAKAGUCHI, Hidetaka NISHIDA, Hiroshi TANAKA, Masahiko KITAMURA, ...
    2024 年 86 巻 3 号 p. 272-276
    発行日: 2024年
    公開日: 2024/03/01
    [早期公開] 公開日: 2024/01/24
    ジャーナル オープンアクセス

    Some reports have been published on clinical features in dogs with early recurrence of type I thoracolumbar intervertebral disk herniation (TL-IVDH), but there is little understanding of the changes involved. This retrospective study describes the clinical features, including radiographic image results at the time of recurrence, of dogs with type I TL-IVDH that had undergone hemilaminectomy but then suffered early recurrence. Our medical records were searched between June 2007 and December 2022. Nine dogs showed deterioration in neurological signs within 4 to 6 weeks after surgery. All nine were Miniature Dachshunds. Radiographic images at initial onset showed calcification at the affected intervertebral disk space in all 9 dogs. Disk herniations at the initial onset were located between T11-12 and L1-2. After the first surgery, neurological function improved in all dogs. Recurrence occurred at the same site as at initial onset in all dogs. No calcification was observed at the affected intervertebral disk space on images at the time of recurrence. The extruded disk materials were surgically removed, and neurological function improved after the second surgery. In conclusion, calcification at the affected disk space at the time of initial onset is indicative of residual nucleus materials not yet fully extruded, and is a risk factor for early recurrence of type I TL-IVDH.

  • Takeshi SOGAWA, Fumi YAMAGUCHI, Kazuhiro MISUMI, Makoto FUJIKI
    2024 年 86 巻 3 号 p. 325-332
    発行日: 2024年
    公開日: 2024/03/16
    [早期公開] 公開日: 2024/02/05
    ジャーナル オープンアクセス

    This study was performed to evaluate cortical bone strength in dogs using a quantitative ultrasound measurement device. In this study, 16 clinically healthy dogs with no lameness underwent measurement of the ultrasound propagation velocity of cortical bone (namely, speed of sound [SOS]) at the radius and tibia. Additionally, computed tomography examination with a calibration phantom was performed in 10 dogs. We calculated the bone mineral density (BMD) and Young’s modulus from the computed tomography data using bone strength evaluation software. SOS, BMD, and Young’s modulus were statistically compared between the radius and tibia. In addition, we examined the correlation between SOS and BMD and between SOS and Young’s modulus. We also examined the correlation between SOS and age in the 13 dogs whose age was known. BMD and Young’s modulus were not significantly different between the radius and tibia, but SOS was significantly different (P<0.05). Moreover, SOS and BMD showed a positive correlation in both radius and tibia. Similarly, SOS and Young’s modulus showed a positive correlation. In addition, SOS and age showed a strong positive correlation (radius: r=0.77, P<0.05, tibia: r=0.83, P<0.05). Our finding that SOS of the radius and tibia cortical bone was correlated with BMD and Young’s modulus indicates that quantitative ultrasound can be useful for evaluating cortical bone strength in dogs.

Toxicology
  • Sakura YONOICHI, Yukako HARA, Yuya ISHIDA, Asuka SHODA, Mako KIMURA, M ...
    2024 年 86 巻 3 号 p. 277-284
    発行日: 2024年
    公開日: 2024/03/01
    [早期公開] 公開日: 2024/01/23
    ジャーナル オープンアクセス
    電子付録

    The mechanism by which the neonicotinoid pesticide clothianidin (CLO) disrupts the intestinal microbiota of experimental animals is unknown. We focused on α-defensins, which are regulators of the intestinal microbiota. Subchronic exposure to CLO induced dysbiosis and reduced short-chain fatty acid–producing bacteria in the intestinal microbiota of mice. Levels of cryptdin-1 (Crp1, a major α-defensin in mice) in feces and cecal contents were lower in the CLO-exposed groups than in control. In Crp1 immunostaining, Paneth cells in the jejunum and ileum of the no-observed-adverse-effect-level CLO-exposed group showed a stronger positive signal than control, likely due to the suppression of Crp1 release. Our results showed that CLO exposure suppresses α-defensin secretion from Paneth cells as part of the mechanism underlying CLO-induced dysbiosis.

  • Yuya ISHIDA, Sakura YONOICHI, Yukako HARA, Asuka SHODA, Mako KIMURA, M ...
    2024 年 86 巻 3 号 p. 333-339
    発行日: 2024年
    公開日: 2024/03/16
    [早期公開] 公開日: 2024/02/05
    ジャーナル オープンアクセス

    The effects of exposure to clothianidin (CLO), a neonicotinoid pesticide (NN), on the thymus and intestinal microbiota were recently revealed. Immune cells express nicotinic acetylcholine receptors (nAChRs), an NN target, suggesting CLO may disrupt the immune system. However, the relationship between CLO and atopic dermatitis (AD) is unknown. We administered a no-adverse-effect-level (NOAEL) dose of CLO to male NC/Nga mice with induced AD and measured, at three time points, key AD symptom indicators: epidermal thickening, mast cell number, total plasma IgE, and histamine levels. CLO increased total plasma IgE levels but reduced epidermal thickening, mast cell number, and plasma histamine levels in the early stages of AD. This demonstrates for the first time that CLO exposure inhibits AD’s early symptoms.

  • Yukako HARA, Asuka SHODA, Sakura YONOICHI, Yuya ISHIDA, Midori MURATA, ...
    2024 年 86 巻 3 号 p. 340-348
    発行日: 2024年
    公開日: 2024/03/16
    [早期公開] 公開日: 2024/02/05
    ジャーナル オープンアクセス
    電子付録

    Neonicotinoid pesticides (NNs) have been associated with numerous neurobehavioral effects in rodents, raising concerns about their impact on cognitive function. Clothianidin (CLO), a type of NN, was orally administered to male mice (10 weeks old, C57BL/6N) at the no-observed-adverse-effect level (NOAEL) of 50 mg/kg/day as indicated in the pesticide risk assessment report. Behavioral tests (novel location recognition and rotarod tests) evaluated hippocampal memory and cerebellar motor learning. After each test, plasma monoamines (3-methoxytyramine, histamine, serotonin, tryptamine) were measured by LC-ESI/MS/MS (Liquid chromatography-electrospray ionization/tandem mass spectrometry), and cerebellar mRNA expression was quantified by microarray and qRT-PCR analyses. The NOAEL of CLO was found to impair hippocampal memory, leading to decreased spontaneous locomotor activity and motor function. We reported, for the first time, multiple alterations of gene expression in the cerebellum associated with motor dysfunction.

Wildlife Science
  • Naoya MATSUMOTO, Megumi ITOH, Takahito TOYOTOME, Kyogo HAGINO, Sakurak ...
    2024 年 86 巻 3 号 p. 285-289
    発行日: 2024年
    公開日: 2024/03/01
    [早期公開] 公開日: 2024/01/16
    ジャーナル オープンアクセス

    Pulmonary aspergillosis occurring in captive penguins living in zoos and aquariums is a fatal disease owing to its high mortality rate. On conducting computed tomography, two gentoo penguins (Pygoscelis papua) with respiratory clinical signs that were housed at an aquarium in Hokkaido, Japan were found to have a certain amount of fluid in their air sacs. This fluid was collected and cultured for bacteria and fungi, the results of which both came back negative. These results enabled us to rule out bacterial infection or aspergillosis and supported our decision not to administer antibacterial and antifungal drugs. Overall, the combination of computed tomography and air sac fluid examination was useful for ruling out bacterial infection or aspergillosis in penguins with respiratory clinical signs.

  • Yoshikazu SEKI, Keita HARA, Yoshinori MINAMI
    2024 年 86 巻 3 号 p. 290-294
    発行日: 2024年
    公開日: 2024/03/01
    [早期公開] 公開日: 2024/01/23
    ジャーナル オープンアクセス

    Some wildlife species that have expanded their range into urban areas use various anthropogenic structures for breeding and resting. We investigated the use of seismically isolated buildings, with gaps between the structures and ground surface, by urban wildlife in Japan. Camera traps set in a building revealed that masked palm civets (Paguma larvata) continued to use the building for approximately 3 years. Civet feces and footprints were found in two buildings during field sign surveys. To ensure public health, civets should be prevented from invading seismically isolated buildings by covering gaps with elastic materials and avoiding placing pipes that could be used by the animals near these gaps.

  • Kazue OHISHI, Yuko TAJIMA, Erika ABE, Tadasu K YAMADA, Tadashi MARUYAM ...
    2024 年 86 巻 3 号 p. 295-299
    発行日: 2024年
    公開日: 2024/03/01
    [早期公開] 公開日: 2024/01/25
    ジャーナル オープンアクセス
    電子付録

    In the western North Pacific, prominent granulomatous testes have been detected in many Brucella-infected common minke whales (Balaenoptera acutorostrata), but there have been no reports in toothed cetaceans. We found severe orchitis with granulomatous lesions in a rough-toothed dolphin (Steno bredanensis) stranded on the Pacific coast of Japan in 2011. Histopathological examination revealed leukocyte infiltration of the lesions. DNA from the lesion was analyzed by PCR and it showed molecular biological similarities with those of Brucella-infected common minke whales and Brucella ceti of sequence-type 27 (ST27). These results suggest that the type of Brucella ceti that infected the dolphin was ST27, which may have caused severe orchitis. This study adds to our understanding of Brucella infections in marine mammals.

  • Yuga MORI, Atsushi NAKA, Ryosuke KODA, Yuzuru ISHIZUKA, Atsushi HINENO ...
    2024 年 86 巻 3 号 p. 349-353
    発行日: 2024年
    公開日: 2024/03/16
    [早期公開] 公開日: 2024/01/26
    ジャーナル オープンアクセス

    Strongyloides myopotami is an intestinal nematode parasite of nutrias. Identification of S. myopotami is conducted based on the morphological characteristics of adult worms or cultured larvae. To widely and effectively understand the infection in nutrias, it would be preferable to develop the molecular identification using a few grams of the feces. Here, we attempted to identify S. myopotami using DNA extracted from eggs obtained from fecal samples. Among previously reported primer pairs targeting the 18S rRNA gene of Strongyloides spp., most could not be successful. We newly designed primers that successfully amplified the partial sequences in S. myopotami, resulting in being sequenced. Our simple protocol can be useful in nationwide surveys for clarifying the risk of human infection.

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