著者

Fumitaka TAKAHASHI Shigenori KOUNO Shinya YAMAGUCHI Yasushi HARA

出版者

JAPANESE SOCIETY OF VETERINARY SCIENCE

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.17-0553, (Released:2018-12-24)

被引用文献数

1

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This study investigated cerebral ventricle size and concurrent craniocervical junction abnormality in relation to atlantooccipital overlapping (AOO) in dogs with atlantoaxial instability (AAI). A total of 61 dogs were treated with atlantoaxial ventral fixation. Medical records of each dog, including magnetic resonance (MR) and computed tomography (CT) images, were retrospectively reviewed. CT images were assessed for the presence of AOO and the dogs were then assigned to either an AOO group or a non-AOO group accordingly. CT images were also evaluated to determine the foramen magnum (FM) index. Syringomyelia, cerebellar compression, dorsal compression, and the degree of enlargement of each cerebral ventricle were evaluated using MR images. Of the 61 dogs, 23 had AOO and 38 did not. Furthermore, the ventricle/brain height ratio, the fourth ventricle height/cerebellum length ratio, and the fourth ventricle width/cerebellum length ratio were significantly higher in the AOO group than in the non-AOO group. However, the FM index, third ventricle/brain height ratio, and incidence of syringomyelia did not differ significantly between the two groups. Dogs with concurrent AOO exhibited significantly more dilatation of the lateral and fourth ventricles.

著者

Masahiro TAGAWA Yasushi HARA Hiroyasu EJIMA Shinobu KOMORI Toru R. SAITO Kazuaki W. TAKAHASHI Kyoji HIOKI Susumu EBUKURO

出版者

Japanese Association for Laboratory Animal Science

雑誌

Experimental Animals (ISSN:13411357)

巻号頁・発行日

vol.44, no.1, pp.49-55, 1995 (Released:2003-12-23)

参考文献数

19

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This study was undertaken to evaluate the sedative effect of medetomidine, an α2-adrenoceptor agonist, and the counteractive effect of atipamezole, an antagonist to medetomidine, in house musk shrews (Suncus murinus). Two hundred, 300, 400, or 600 μg/kg of medetomidine was intraperitoneal injected into 89 house musk shrews. A sedative effect was produced in one to two minutes after injection. The dose-dependent prolongation of the sedative duration and the dose-dependent appearance of a hypothermic effect were demonstrated. With 200 μg/kg of medetomidine, the sedative effect obtained was not adequate in some of the animals. With 300 μg/kg and above, a stable sedative state was induced in all the animals. The duration of sedation in the house musk shrews was much longer (p<0.01) in males than in females. This suggested the higher susceptibility of male house musk shrews to this drug. The sedative effect and hypothermia obtained with 400 μg/kg of medetomidine were completely counteracted by more than 2.0 mg/kg of atipamezole. With 0.5 and 1.0 mg/kg of atipamezole, only a partial antagonistic action was produced. Transient vomiting appeared in 4.5% of the house musk shrews at approximately one minute after injection of medetomidine. This side-effect had occurred before the sedative effect was obtained, and was not serious enough to be a problem. None of the 89 house musk shrews died in this experiment. The above results show that the combination of medetomidine and atipamezole is a highly effective and safe anesthetic treatment which permits easy handling of house musk shrews.

著者

Fumitaka TAKAHASHI Takaharu HAKOZAKI Nobuo KANNO Shuji SUZUKI Yasuji HARADA Satoshi SOETA Shinichi NAKAMURA Shinya YAMAGUCHI Yasushi HARA

出版者

JAPANESE SOCIETY OF VETERINARY SCIENCE

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.21-0315, (Released:2022-04-05)

被引用文献数

1

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We evaluated the completeness of bony fusion of the atlantoaxial joint (AAJ) through polymethylmethacrylate fixation (PMF) and atlantoaxial plate fixation (APF) using six canine models with dens partial resection. In both groups, the hydroxyapatite content at the AAJ was measured up to 7 months postoperatively using quantitative computed tomography. Histological assessment revealed fibrous fusion in the PMF group. Meanwhile, in the APF group, only one dog achieved fibrous fusion, whereas the remaining three showed bony fusion. To our knowledge, this study was the first to evaluate AAJ fusion histologically after PMF and APF. The present study demonstrates that PMF and APF may stabilize the AAJ without clinical complications. Therefore, PMF and APF are clinically useful fixation methods for atlantoaxial instability.

著者

Musubu Takahashi Ruri Iwai Ryoko Takasawa Tsuyoshi Nakano Tomoya Fujie Takato Hara Yasushi Hara Chika Yamamoto Toshiyuki Kaji

出版者

The Japanese Society of Toxicology

雑誌

The Journal of Toxicological Sciences (ISSN:03881350)

巻号頁・発行日

vol.46, no.7, pp.341-344, 2021 (Released:2021-07-01)

参考文献数

11

被引用文献数

3

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Reactive sulfur species (RSS) include biological persulfide molecules that protect cells against oxidative stress and heavy metal toxicity. Vascular endothelial cells regulate blood coagulation and fibrinolytic activity, and prevent vascular disorders such as atherosclerosis. We hypothesized that RSS protect vascular endothelial cells not only from nonspecific cell damage but also from specific functional damage through regulation of specific cell functions. In the present study, cultured bovine aortic endothelial cells were treated with sodium trisulfide, a sulfane sulfur donor, and both [3H]thymidine incorporation and effects on cell cycle were analyzed. These results suggest that RSS stimulate vascular endothelial cell proliferation. RSS may reduce the functional cytotoxicity of antiproliferative agents.

著者

Sawako MURAKAMI Yasuji HARADA Yasushi HARA

出版者

JAPANESE SOCIETY OF VETERINARY SCIENCE

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.20-0249, (Released:2020-12-14)

被引用文献数

2

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This study aimed to evaluate changes in the vertical and fore-aft force generation of the hindlimbs in dogs with stifle orthoses. Custom-made orthoses were used on the right stifle joint. Force plate and marker data from four beagle dogs in trials without orthoses, with fixed orthoses, and with unfixed orthoses were collected. The vertical ground reaction force of the right side was decreased with fixed orthoses and increased with unfixed orthoses compared to that of gait without orthoses. When compared to that of gait without orthoses, the fore-aft ground reaction force changed with fixed orthoses but not with unfixed orthoses. It is suggested that the level of constraint of the orthosis affected the ground reaction force pattern.

著者

Sachiyo TANAKA Hitomi SHIBUYA Shuji SUZUKI Nobuo KANNO Yasuji HARADA Asaka SATO Satoshi SOETA Yasushi HARA

出版者

JAPANESE SOCIETY OF VETERINARY SCIENCE

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.20-0401, (Released:2020-12-02)

被引用文献数

7

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This study aimed to assess the structural and functional effects of long-term hyperglucocorticoidemia on canine myocardium and compare these parameters with histopathological changes. Twelve healthy male beagle dogs were enrolled and assigned to the high-dose prednisolone (P; n=6) and control (C; n=6) groups. The P group was treated with 2 mg/kg of prednisolone BID for 84 days. Clinical parameters were measured using echocardiography and non-invasive systolic blood pressure (SBP) measured before the initiation of synthetic corticosteroids and at 7, 28, 56, and 84 days after the start of medication. For histological evaluation, cardiovascular tissue was harvested from dogs in groups P (at the end of the medication period) and C (scheduled to be euthanized for unrelated reasons). In the P group, clinical changes including thickening of the left ventricular free wall (LVFW) and interventricular septum (IVS), decreased left ventricular (LV) diastolic function, and increased SBP were observed after the start of medication. During histological evaluation, fibrosis was observed in the LVFW and IVS in the P group. Furthermore, decreased glucocorticoid receptor (GCR) levels were observed in the LVFW, right ventricular free wall (RVFW), and IVS and increased mineralocorticoid receptor (MCR) levels were observed in the LVFW and RVFW in the P group compared with those in the C group. In conclusion, fibrosis may cause LV structural and functional abnormalities in dogs with hyperadrenocorticism. Furthermore, GCR downregulation and upregulated MCR might influence the myocardial fibrosis.

著者

Masakazu SHIMADA Nichika MIZOKAMI Tom ICHINOHE Nobuo KANNO Shuji SUZUKI Takuya YOGO Yasuji HARADA Yasushi HARA

出版者

JAPANESE SOCIETY OF VETERINARY SCIENCE

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.19-0613, (Released:2020-05-25)

被引用文献数

16

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The object of this study is to evaluate the long-term outcome of hind limb weight-bearing function and progression of stifle osteoarthritis (OA) after tibial plateau leveling osteotomy (TPLO). Groups were classified by the degree of cranial cruciate ligament (CrCL) damage and presence or absence of medial meniscus damage as macroscopically evaluated during surgery. Weight-bearing function was assessed via the peak vertical force (PVF), and OA progression was assessed via the radiographic OA score (OAS) preoperatively and 1, 3, 6, 12, 18, 24, and 36 months postoperatively. In all stifles, PVF was significantly higher within 6 months postoperatively than preoperatively, and this high ratio was maintained for 36 months. The OAS was significantly higher 24 months postoperatively than preoperatively in stifles with a partial CrCL tear, and significantly increased at each timepoint after 3 months postoperatively in stifles with complete CrCL rupture. The OAS remained consistently lower in stifles with a partial CrCL tear and no treatment of the medial meniscus than in stifles with complete rupture. Thus, after TPLO, the weight-bearing function improved in the early postoperative period and was maintained for as long as 36 months. Although OA progressed over time after TPLO, the progression was more gradual in stifles with partial tears than in those with complete rupture. Canine patients would benefit from earlier surgical intervention through development of technology that enables early detection of ligament degeneration.

著者

Tom ICHINOHE Nobuo KANNO Yasuji HARADA Yukihiro FUJITA Hiromichi FUJIE Yasushi HARA

出版者

JAPANESE SOCIETY OF VETERINARY SCIENCE

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.18-0501, (Released:2019-12-13)

被引用文献数

3

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The aim of this study was to evaluate the normal range of motion of the canine tibiofemoral joint and the movement of the tibia relative to the femur, especially the internal/external rotation under flexion. Right stifle joints were harvested from eight skeletally mature Beagle dogs, which were euthanized for reasons unrelated to this study. All muscle tissue was removed from the limbs prior to testing. Flexion and extension tests were conducted using a robotic manipulator with six degrees-of-freedom. Cranial/caudal and medial/lateral displacement and varus/valgus and internal/external rotation were measured at various degrees of flexion. We observed that the tibia rotated internally at an increasing flexion angle with mean peak internal and external rotations of 20.0° ± 13.8° and 4.5° ± 3.6°, respectively. The tibia also tended to displace cranially at an increasing flexion angle, with a mean peak cranial displacement of 8.9 ± 4.4 mm; there was minimal medial displacement when increasing the flexion angle. Valgus rotation also tended to occur at an increasing flexion angle. During the flexion of the canine stifle joint, approximately 20° of internal tibial rotation occurred around the longitudinal axis, along with a rollback motion involving the cranial displacement of the tibia.

著者

Fumitaka TAKAHASHI Takaharu HAKOZAKI Shigenori KOUNO Shuji SUZUKI Asaka SATO Nobuo KANNO Yasuji HARADA Shinya YAMAGUCHI Yasushi HARA

出版者

JAPANESE SOCIETY OF VETERINARY SCIENCE

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.17-0438, (Released:2018-02-05)

被引用文献数

5

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We compared clinical outcomes after ventral fixation in dogs with atlantoaxial instability (AAI) on the basis of the presence or absence of atlantooccipital overlapping (AOO). Of 41 dogs diagnosed with AAI and treated ventral fixation, 12 exhibited AOO (AOO group), whereas 29 did not (non-AOO group). The AOO group had significantly higher neurological scores before (P=0.024) and 1 month after (P=0.033) surgery compared with the non-AOO group; however, no significant differences were observed between the groups 2 months after surgery. The presence of complicating AOO affected the clinical signs for dogs with AAI, but did not directly affect the outcome of surgical stabilization of AAI.

著者

Fumitaka TAKAHASHI Takaharu HAKOZAKI Nobuo KANNO Yasuji HARADA Shinya YAMAGUCHI Yasushi HARA

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.16-0160, (Released:2016-09-04)

被引用文献数

2

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We evaluated comparatively the mechanical strength in three kinds of surgical fixation techniques for canine atlantoaxial joint. Atlantoaxial plate fixation (APF), polymethylmethacrylate (PMMA) fixation (PMF) and transarticular fixation (TAF) were applied to the atlas and axis harvested from healthy beagle dogs, and then the specimens were tested. The PMF group had significantly higher resistance to flexion than the APF group (P=0.030) and the TAF group (P=0.004). There were no significant differences in resistance to torsion between the APF group and the PMF group, while the APF group had significantly higher resistance to torsion than the TAF group (P=0.037). Considering the possible drawbacks of using PMMA, the APF method is proposed as an alternative to the PMF method.

著者

Tom ICHINOHE Nobuo KANNO Yasuji HARADA Takuya YOGO Masahiro TAGAWA Satoshi SOETA Hajime AMASAKI Yasushi HARA

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.14-0383, (Released:2015-02-17)

被引用文献数

12

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Degenerative cranial cruciate ligament (CCL) rupture is characterized histologically by degenerating extracellular matrix (ECM) and chondroid metaplasia. Here, we describe the progression of chondroid metaplasia and the changes in the expression of ECM components in canine CCL rupture (CCLR). CCLs from 26 stifle joints with CCLR (CCLR group) and normal CCLs from 12 young beagles (control group) were examined histologically and immunohistochemically for expression of type I (COLI), type II (COLII), type III collagen (COLIII) and Sry-type HMG box 9 (SOX9). Cell density and morphology of CCLs were quantified using hematoxylin–eosin staining. The percentage of round cells was higher in the CCLR group than in controls. COLI-positive areas were seen extensively in the connecting fibers, but weakly represented in the cytoplasm of normal CCLs. In the CCLR group, there were fewer COLI-positive areas, but many COLI-positive cells. The percentages of COLII-, COLIII- and SOX9-positive cells were higher in the CCLR group than in controls. The number of spindle cells with perinuclear halo was high in the CCLR group, and most of these cells were SOX9-positive. Deposition of COLI, the main ECM component of ligaments, decreased with increased COLIII expression in degenerated CCL tissue, which shows that the deposition of the ECM is changed in CCLR. On the contrary, expression of SOX9 increased, which may contribute to the synthesis of cartilage matrix. The expression of COLII and SOX9 in ligamentocytes showed that these cells tend to differentiate into chondrocytes.

著者

Kunihiko TERAKADO TAKUYA YOGO Yoshinori NEZU Yasuji HARADA Yasushi HARA Masahiro TAGAWA

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.12-0363, (Released:2013-06-18)

被引用文献数

1 5

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To determine the efficacy of a colorimetric pupil light reflex (PLR) device (Melan-100®, U.S.A.) in dogs of sudden acquired retinal degeneration syndrome (SARDS; 16 cases), progressive retinal atrophy (PRA; 10 cases) and optic pathway disease (6 cases). The colorimetric device detected PLR abnormality in 32, 16, and 9 eyes with SARDS, PRA and optic pathway disease, respectively, whereas white light detected PLR abnormality in 18, 11 and 9 eyes with SARDS, PRA and optic pathway disease, respectively. SARDS dogs displayed miosis, while optic pathway disease dogs displayed mydriasis by blue light examination. Thus, colorimetric PLR may be a useful method for determining whether electroretinography (ERG) or magnetic resonance imaging (MRI) should be performed for dogs with acute blindness.

著者

Takuma MIYATA Takanori KODAMA Rie HONMA Yoshinori NEZU Yasuji HARADA Takuya YOGO Yasushi HARA Masahiro TAGAWA

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.12-0436, (Released:2013-02-28)

被引用文献数

5 25

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To investigate influence of general anesthesia on immunological anti-tumor activity, the natural killer (NK) cytotoxic activity of peripheral lymphocytes (PBLs) was measured in 7 dogs anesthetized for 3 hr with isoflurane following propofol-induction (anesthesia group) and 6 dogs without anesthesia (control group). Blood samples were collected before (baseline) and 24, 120 and 192 hr after the anesthesia. The PBLs were isolated via centrifugation with Ficoll-Hypaque solution (density, 1.073), and adherent cells were removed. The NK cytotoxic activity of the isolated PBLs against canine thyroid cancer cells was detected by the colorimetric rose Bengal assay. Significant decrease in the NK cytotoxic activity was observed at 24 hr after the anesthesia, compared with the baseline values and the control group. The NK cytotoxic activities were recovered to the baseline values until 120 hr after the anesthesia. The general anesthesia with isoflurane following propofol-induction decreased the NK cytotoxic activities of PBLs in dogs. This finding has a clinical relevance to the risk of tumor recurrence or metastasis induced by the suppression of immunological anti-tumor activity after general anesthesia in dogs. The results further emphasized the importance of the need to evaluate immune suppression following general anesthesia in animals.

著者

Yasushi HARA Takahiro TESHIMA Takahiro TAODA Hirokazu ISHINO Yoshinori NEZU Yasuji HARADA Takuya YOGO Hiroyuki MASUDA Akira TERAMOTO Masahiro TAGAWA

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

vol.72, no.4, pp.397-404, 2010 (Released:2010-05-03)

参考文献数

53

被引用文献数

4 13

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Postoperative changes in endocrinological status and serum chemistry during the 4 years after transsphenoidal surgery (TSS) in 25 dogs with Cushing's disease were investigated in a prospective study. In all 25 dogs, Cushing's disease was diagnosed from resected pituitary tissues as a corticotroph adenoma in the anterior lobe of the pituitary. Prior to TSS, all 25 dogs showed hypercortisolemia. After TSS, the ACTH stimulation test showed continued low serum cortisol concentrations in 21 dogs (84%). In addition, the serum thyroid stimulating hormone concentrations decreased sequentially, while the serum T4 concentrations tended to increase due to the postoperative hormone substitution therapy utilized to avoid secondary hypothyroidism. In regard to serum chemistry, alkaline phosphatase (ALP), alanine aminotransferase (ALT) and total cholesterol are commonly increased in canine Cushing's disease. In this study, ALP, ALT and total cholesterol were increased in 23 cases (92%), 19 cases (76%) and 20 cases (80%), respectively. However, postoperatively, these concentrations gradually decreased. The postoperative serum concentrations of ALP at 1 year, that of ALT at six months to 2 years and that of total cholesterol over the course of the 4 years decreased significantly compared with the concentrations before TSS. These results show that TSS is an effective treatment for canine Cushing's disease and for long-term improvement of hypercortisolemia. Moreover, TSS is effective in improvement of hypercortisolism, such as increased concentrations of serum ALP, ALT and total cholesterol.

著者

Takahiro TESHIMA Yasushi HARA Kae SHIGIHARA Susumu TAKEKOSHI Yoshinori NEZU Yasuji HARADA Takuya YOGO Akira TERAMOTO Robert Y. OSAMURA Masahiro TAGAWA

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

vol.71, no.1, pp.93-98, 2009 (Released:2009-02-05)

参考文献数

36

被引用文献数

5 8 1

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Pituitary thyrotroph hyperplasia results from prolonged primary hypothyroidism in humans, mice and rats. In dogs with Cushing's disease, many cases have low serum thyroid hormones concentrations due to euthyroid sick syndrome. A 6-year-old castrated male Beagle diagnosed with Cushing's disease had a high serum thyroid stimulating hormone (TSH) concentration that was treated by hypophysectomy. On histological examination, the resected pituitary gland contained both a corticotroph adenoma and thyrotroph hyperplasia. The TSH-positive cell ratio in this case was greater than that of healthy Beagles. In the present case, the pituitary thyrotroph hyperplasia was probably caused by primary hypothyroidism. In conclusion, this Beagle is the first histological confirmation of the coexistence of a corticotroph adenoma and thyrotroph hyperplasia.