獣医学科

原 康

ハラ ヤスシ  (Yasushi Hara)

基本情報

所属
日本獣医生命科学大学 獣医学部 獣医学科 教授 (小動物外科設立専門医)
獣医外科学研究室 教授
学位
獣医学修士(日本獣医生命科学大学)
獣医学博士(日本獣医生命科学大学)

J-GLOBAL ID
200901007028918014
researchmap会員ID
1000093611

受賞

 8

論文

 153
  • Norihiro Muroi, Nobuo Kanno, Yasuji Harada, Yasushi Hara
    Veterinary and comparative orthopaedics and traumatology : V.C.O.T 2024年8月29日  
    OBJECTIVE:  The aim of this study was to identify risk factors for refracture after radial union in small-breed dogs. STUDY DESIGN:  In our retrospective study, medical records of radial-ulnar fracture cases in small dogs treated with plates and screws were reviewed. General information and postoperative course (days until confirmed radial fracture healing, with or without ulnar union, time to final follow-up, with or without plate removal and refracture) were recorded. The fracture line location, screw positions, radial thickness and width, and pixel values throughout the postoperative periods were obtained from the radiographs. The affected limbs were classified into non-plate removal (P) and plate removal (R) groups. RESULTS:  Refracture occurred in 5 of the 141 limbs at the most distal screw in the P group and 5 of the 40 limbs at the same site as the initial fracture in the R group. Multivariate analysis indicated that refracture was linked to the amount of relative change with growth in the position of the most distal screw in the P group, with pixel value and radial thickness ratios at the same site as the initial fracture in the R group. CONCLUSION:  Reducing the screw diameter relative to the radial width to the appropriate extent may be considered in cases where the screw positioned at the most distal end of the radius is expected to be relatively proximal as the distal radius grows; not removing the plate may be considered in cases with a decreased radial thickness or bone mineral density beneath the plate during plate removal.
  • Tomokazu Nagashima, Shohei Tsumoto, Daisuke Yazawa, Miki Omura, Kazuhiko Ochiai, Karin Yoshida, Kayoko Sugibayashi, Yukino Machida, Ryoichi Suzuki, Koh Igarashi, Koichi Makimura, Yasushi Hara, Masaki Michishita
    Journal of comparative pathology 213 73-77 2024年8月  査読有り
    A 10-year-old spayed mixed breed dog presented with severe neurological signs. Computed tomography revealed a cranial mediastinal mass, osteolysis of the right second rib and second thoracic vertebra, tracheobronchial and mesenteric lymph node enlargement, pneumonia and pleural effusion. Magnetic resonance imaging detected lesions in the white matter of the right frontal lobe and left cerebral hemisphere with contrast-enhanced T1-weighted images showing demarcated enhancement. On cut section, the surface of the right cerebral frontal lobe and left cerebral hemisphere corticomedullary junctions were indistinct and the white matter was discoloured. Microscopically, multicentric granulomatous inflammation was seen in the brain, cranial mediastinal mass, masses on the right second rib, tracheobronchial and mesenteric lymph nodes, heart, kidneys, lungs and oesophagus. Necrosis and hyaline fungal structures were frequently observed in the centre of the granulomas. These fungi had septae, Y-shaped branching and were 2-3 μm in width. Sequence analysis of DNA from formalin-fixed paraffin-embedded samples identified the fungi as Schizophyllum commune. Based on these findings, this case was diagnosed as disseminated S. commune infection. This is the first report of granulomatous encephalitis caused by S. commune in a dog.
  • Norihiro Muroi, Sawako Murakami, Nobuo Kanno, Yasuji Harada, Yasushi Hara
    Veterinary and comparative orthopaedics and traumatology : V.C.O.T 2024年3月6日  
    OBJECTIVE:  The aim of this study was to evaluate the stress changes in the radii beneath the locking plates (LP) of dogs implanted with LP using finite element analysis (FEA). STUDY DESIGN:  The study included radii harvested from eight dogs. After computed tomography (CT) scans of the forelimb, the articular surface of the radius was fixed using resin. Material tests were conducted to identify the yield and fracture points and for verification with FEA. The CT data of the radius were imported into FEA software. The radii were classified into three groups based on the placement of the LP (nonplate placement, intact group; 1 mm above the radial surface, LP + 1 mm group; 3 mm above the radial surface, LP + 3 mm group). Equivalent, maximum, and minimum principal stresses and minimum principal strain were measured after FEA at the radial diaphysis beneath the plate. RESULTS:  In shell elements, the LP + 1 mm and LP + 3 mm groups showed a significantly lower maximum principal stress compared with the intact group. In solid elements, the LP + 1 mm and LP + 3 mm groups showed a significantly higher equivalent stress and a significantly lower maximum principal stress compared with the intact group. CONCLUSION:  When an axial load is applied to the radius, LP placement reduces the tension stress on the cortical bone of the radius beneath the plate, possibly related to implant-induced osteoporosis and bone formation in the cortical bone beneath the plate.
  • Masakazu Shimada, Chenxu Huang, Satoshi Yamakawa, Hiromichi Fujie, Sawako Murakami, Nobuo Kanno, Yasushi Hara
    BMC Veterinary Research 20(1) 2024年2月24日  
    Abstract Background Cranial closing wedge osteotomy (CCWO) is a functional stabilisation technique for cranial cruciate ligament (CrCL) ruptures. This biomechanical study aimed to evaluate the influence of CCWO on the stability of the stifle joint. Eighteen Beagle stifle joints were divided into two groups: control and CCWO. The stifle joints were analyzed using a six-degree-of-freedom robotic joint biomechanical testing system. The joints were subjected to 30 N in the craniocaudal (CrCd) drawer and proximal compression tests and 1 Nm in the internal–external (IE) rotation test. Each test was performed with an extension position, 135°, and 120° of joint angle. Results The stifle joints were tested while the CrCLs were intact and then transected. In the drawer test, the CCWO procedure, CrCL transection, and stifle joint flexion increased CrCd displacement. The CCWO procedure and CrCL transection showed an interaction effect. In the compression test, the CCWO procedure decreased and CrCL transection and stifle joint flexion increased displacement. In the IE rotation test, CCWO, CrCL transection, and stifle joint flexion increased the range of motion. Conclusions CCWO was expected to provide stability against compressive force but does not contribute to stability in the drawer or rotational tests. In the CCWO-treated stifle joint, instability during the drawer test worsened with CrCL transection. In other words, performing the CCWO procedure when the CrCL function is present is desirable for stabilizing the stifle joint.
  • Daisuke YAZAWA, Masakazu SHIMADA, Nobuo KANNO, Shuji SUZUKI, Takuya YOGO, Yasuji HARADA, Yasushi HARA
    Journal of Veterinary Medical Science 2024年  

MISC

 453

書籍等出版物

 34

講演・口頭発表等

 41

担当経験のある科目(授業)

 3

共同研究・競争的資金等の研究課題

 15