1.Use of MAVRIC-SL for metal artifact reduction in postoperative canine stifle MRI
Sojin KIM ; Youngmin KIM ; Jae-Pung HAN ; Sunghoon JEON ; Gonhyung KIM ; Sang-Hwan HYUN ; Dongwoo CHANG ; Namsoon LEE
Journal of Veterinary Science 2026;27(2):e21-
Objective:
This study aimed to determine whether a multiacquisition variable-resonance image combination-selective (MAVRIC-SL) sequence, which reduces susceptibility artifacts, is useful for postoperative evaluation.
Methods:
MRI was performed on four dogs that underwent CCLR correction using metallic implants. Imaging was performed with MAVRIC-SL and two-dimensional fast spin echo (2D-FSE) sequences, including proton density (PD), PD fat-suppressed (F/S), and T2-weighted F/S. The artifact area for each sequence was quantitatively analyzed. A four-level qualitative image analysis was performed to assess image artifacts, cartilage delineation, and visualization of the cranial cruciate ligament and bone.
Results:
The artifact area was significantly reduced with MAVRIC-SL than with 2D-FSE, regardless of the metal materials used. In addition, the amount of artifact, cartilage delineation, and visualization of the bone were significantly improved with MAVRIC-SL compared with 2D-FSE.
Conclusions
and Relevance: In this preliminary study, the MAVRIC-SL sequence improves postoperative MRI evaluation by reducing susceptibility artifacts in dogs with CCLR treated with metallic implants.
2.Myelopathy secondary to generalized thoracic caudal articular process aplasia in a non-brachycephalic breed dog: a case report
Youngmin KIM ; Byoungho AN ; Gonhyung KIM ; Dongwoo CHANG ; Namsoon LEE
Korean Journal of Veterinary Research 2025;65(4):e25-
A 5-month-old mixed-breed dog was presented with progressive ambulatory paraparesis. Neurological examination was consistent with thoracolumbar myelopathy. Magnetic resonance imaging (MRI) revealed a spinal (sub)arachnoid diverticulum (SAD) at T8–T9 with spinal cord compression associated with central canal dilation and intramedullary edema. Computed tomography (CT) showed generalized caudal articular process dysplasia (CAPD) from T2 to T9 vertebras. Considering diagnostic imaging results, symptoms were strongly suspected to be due to spinal cord compression associated with CAPD-induced SAD. Surgery was performed and cystic structure was detached. One month after the surgery, no progression of clinical symptoms was observed. To the best of our knowledge, this is the first reported case of SAD causing thoracolumbar myelopathy in a non-brachycephalic dog with generalized CAPD. These findings highlight the potential role of CAPD as a contributing factor to SAD formation. A combination of CT and MRI is recommended for thorough evaluation of vertebral structures and alignment in similar cases.
3.A renal oncocytoma in a Maltese dog with renal cysts
Jong uk KIM ; Jinsung PARK ; Gonhyung KIM ; Dongwoo CHANG ; Byeongwoo AHN
Korean Journal of Veterinary Research 2019;59(1):47-49
A renal oncocytoma was diagnosed in an 8-year-old female Maltese dog with a history of renal cysts. Tumor cells were not detected until six months after observation of renal cysts. Nephrectomy was performed to treat the neoplasia. Tumor-like masses with numerous nodules were observed in the inner surface of cysts present in the caudal part of the left kidney. Histologically, the tumor consisted of cells with abundant eosinophilic cytoplasm. The diagnosis was based on histological features, periodic acid-Schiff reaction, and immunohistochemical cytokeratin staining. Based on a literature review, this is the first canine renal oncocytoma case reported in Korea.
4.A renal oncocytoma in a Maltese dog with renal cysts
Jong uk KIM ; Jinsung PARK ; Gonhyung KIM ; Dongwoo CHANG ; Byeongwoo AHN
Korean Journal of Veterinary Research 2019;59(1):47-49
A renal oncocytoma was diagnosed in an 8-year-old female Maltese dog with a history of renal cysts. Tumor cells were not detected until six months after observation of renal cysts. Nephrectomy was performed to treat the neoplasia. Tumor-like masses with numerous nodules were observed in the inner surface of cysts present in the caudal part of the left kidney. Histologically, the tumor consisted of cells with abundant eosinophilic cytoplasm. The diagnosis was based on histological features, periodic acid-Schiff reaction, and immunohistochemical cytokeratin staining. Based on a literature review, this is the first canine renal oncocytoma case reported in Korea.
Adenoma, Oxyphilic
;
Animals
;
Child
;
Cytoplasm
;
Diagnosis
;
Dogs
;
Eosinophils
;
Female
;
Humans
;
Keratins
;
Kidney
;
Korea
;
Nephrectomy
;
Periodic Acid-Schiff Reaction
5. In vitro antiproliferative and apoptosis inducing effect of a methanolic extract of Azadirachta indica oil on selected cancerous and noncancerous cell lines
Muhammad KASHIF ; Dongwook KIM ; Gonhyung KIM
Asian Pacific Journal of Tropical Medicine 2018;11(10):555-561
Objective: To find the cytotoxic and apoptotic effects of neem oil extract on the selected cancerous (A-549, PC-3 and DU-145) and noncancerous (NIH3T3 and CCD-18Co) cell lines. Methods: Viability and cytotoxic effect induced by the extract was measured by using MTT assay and apoptotic effect of the extract was evaluated by using Hoechst 33342 and propidium iodide dual staining through a fluorescent microscope and activity of caspases 3, 8 and 9 through colorimetric assay kits. Results: The results showed that neem oil extract significantly reduced the viability in all selected cancer cells treated with varying concentrations of extract as compared with untreated cells and had less effect on noncancerous cell lines. It significantly increased the percentage of necrotic and apoptotic cells, and caspases 3, 8 and 9 activities in all cancer cells treated with extract as compared with untreated cells whereas no effect on noncancerous cell lines. It suggested that neem oil extract exerted a higher cytotoxic effect on cancer cells than normal cells and lower concentration induced apoptosis only in cancer cells. One of the apoptosis-inducing mechanism was through the activation of caspases signaling pathways. Conclusion: Conclusively, it implies that neem oil extract may contain one or more potential agents that can be used as a safe and effective anticancer therapy.
6.Effects of neural stem cells and 5-fluorocytosine in canine metastatic lung tumor.
Yawon HWANG ; Dongwook KIM ; Dongwoo CHANG ; Byeongwoo AHN ; Yun Bae KIM ; Gonhyung KIM
Journal of Veterinary Science 2017;18(2):257-260
This is the first case report to describe the tumor regressive effect of systemic human neural stem cell (NSC)/5-fluorocytosine (5-FC) therapy on canine metastatic lung tumor. The therapeutic effects appeared approximately two weeks after 5-FC administration. Thoracic radiographs revealed a reduced number of lung nodules and decreased nodule size. However, there were no significant antitumor effects on primary lesions in abdominal organs. In conclusion, human NSC/5-FC prodrug therapy can secure patient quality of life with the same or more therapeutic effects and fewer side effects than other recommended chemotherapies.
Drug Therapy
;
Flucytosine*
;
Genetic Therapy
;
Humans
;
Lung*
;
Neural Stem Cells*
;
Quality of Life
;
Therapeutic Uses
7.Persistent left cranial vena cava with congenital heart defect in two dogs.
Yawon HWANG ; Hyejong OH ; Dongwoo CHANG ; Gonhyung KIM
Korean Journal of Veterinary Research 2016;56(3):193-195
The purpose of this report is to introduce persistent left cranial vena cava (PLCVC) with persistent right aortic arch (PRAA) and patent ductus arteriosus (PDA). Case 1 was a Cocker Spaniel with PRAA and case 2 was a Maltese with PDA. PLCVC was enclosed at the sites of PRAA and PDA surgery; therefore, it was lifted dorsally during PDA and PRAA surgery. Surgery to repair congenital heart defects including PRAA and PDA is recommended for dogs that do not die of PLCVC at a young age.
Animals
;
Aorta, Thoracic
;
Dogs*
;
Ductus Arteriosus, Patent
;
Heart Defects, Congenital*
;
Thoracotomy
8.Evaluation of stability and biocompatibility of PHEMA-PMMA keratoprosthesis by penetrating keratoplasty in rabbits.
Laboratory Animal Research 2016;32(4):181-186
Artificial corneas have been developed as an alternative to natural donor tissue to replace damaged or diseased corneas. This study was conducted to evaluate the stability and biocompatibility of PHEMA-PMMA [poly (2-hydroxyl methacrylate)-poly (methyl methacrylate)] keratoprostheses in rabbits following penetrating keratoplasty. Sixteen male New Zealand White rabbits aged 16 weeks were divided into three groups. Group I and group II contained six rabbits each, while the control group had four rabbits. Experimental surgery was conducted under general anesthesia. The cornea was penetrated using an 8 mm diameter biopsy punch. In group I (core 5 mm & skirt 3 mm) and group II (core 6 mm & skirt 2 mm), the keratoprosthesis was placed into the recipient full thickness bed and sutured into position with double-layer continuous. In the control group, corneal transplantation using normal allogenic corneal tissue was performed with the same suture method. After four and eight weeks, keratoprosthesis devices were evaluated by histopathological analysis of gross lesions. Post-operative complications were observed, such as extrusion and infection in experimental groups. Most corneas were maintained in the defect site by double-layer continuous suture materials for 4 weeks and kept good light transmission. However, most artificial cornea were extruded before 8 weeks. Overall, combined PHEMA and PMMA appears to have sufficient advantages for production of artificial corneas because of its optical transparency, flexibility and other mechanical features. However, the stability and biocompatibility were not sufficient to enable application in humans and animals at the present time using penetrating keratoplasty. Further studies are essential to improve the stability and biocompatibility with or without other types of keratoplasty.
Anesthesia, General
;
Animals
;
Biopsy
;
Cornea
;
Corneal Transplantation
;
Humans
;
Keratoplasty, Penetrating*
;
Male
;
Methods
;
Pliability
;
Polyhydroxyethyl Methacrylate
;
Polymethyl Methacrylate
;
Rabbits*
;
Sutures
;
Tissue Donors
9.Comparable bone healing capacity of different bone graft matrices in a rabbit segmental defect model.
Jong Min KIM ; Myoung Hwan KIM ; Seong Soo KANG ; Gonhyung KIM ; Seok Hwa CHOI
Journal of Veterinary Science 2014;15(2):289-295
We compared the bone healing capacity of three different demineralized bone matrix (DBM) products applied using different carrier molecules (hyaluronic acid [HA] vs. carboxymethylcellulose [CMC]) or bone compositions (cortical bone vs. cortical bone and cancellous bone) in a rabbit segmental defect model. Overall, 15-mm segmental defects in the left and right radiuses were created in 36 New Zealand White rabbits and filled with HA-based demineralized cortical bone matrix (DBX), CMC-based demineralized cortical bone matrix (DB) or CMC-based demineralized cortical bone with cancellous bone (NDDB), and the wound area was evaluated at 4, 8, and 12 weeks post-implantation. DBX showed significantly lower radiopacity, bone volume fraction, and bone mineral density than DB and NDDB before implantation. However, bone healing score, bone volume fraction, bone mineral density, and residual bone area at 4, 8, and 12 weeks post-implantation revealed no significant differences in bone healing capacity. Overall, three DBM products with different carrier molecules or bone compositions showed similar bone healing capacity.
Animals
;
Bone Matrix/*physiology
;
Bone Transplantation
;
Carboxymethylcellulose Sodium/*pharmacology
;
Histology
;
Hyaluronic Acid/*pharmacology
;
Rabbits
;
*Wound Healing
;
X-Ray Microtomography
;
X-Rays
10.Male pseudohermaphroditism in a Maltese/poodle mixed dog.
Seok Jin JANG ; Young Jae KIM ; Gonhyung KIM ; Seok Hwa CHOI
Journal of Biomedical Research 2014;15(1):36-39
Male pseudohermaphroditism is not commonly reported in veterinary medicine. Here, a 3-year-old Maltese/poodle mixed dog presented with malformed external genitalia and episodic hematuria. Inspection and palpation of the external genitals showed a malformed penis, shortened prepuce, external urethral orifice, and cryptorchidism. There was no urethral meatus at the tip of the penis. The urethral opening was situated between the prepuce and the penis. The anterior half of the prepuce was absent, and the penis was free and exposed to both trauma and licking. Plain radiographic examination showed absence of an os penis in the penis. A double-contrast cystograph showed the suspected uterus as well as the cystic calculi. A hypoechoic space was seen at the dorsal portion of the urinary bladder. The space was suspected to be the uterus. A sagital ultrasonograph showed cystic calculi in the urinary bladder. During surgery to remove cystic calculi, hypoplastic testes as well as the uterus were observed. Histological examination of the testes showed the seminiferous tubules and interstitial cells. The sertoli cells and spermatogonia were adjacent to the basement membrane. No evidence of spermatogenesis was found. Striated squamous epithelial cells and smooth muscle cells were found in the uterus. This dog had vestigial oviducts as well as a uterus with male-appearing external genitals.
46, XY Disorders of Sex Development*
;
Animals
;
Basement Membrane
;
Calculi
;
Child, Preschool
;
Cryptorchidism
;
Disorders of Sex Development
;
Dogs*
;
Epithelial Cells
;
Genitalia
;
Hematuria
;
Humans
;
Male
;
Myocytes, Smooth Muscle
;
Oviducts
;
Palpation
;
Penis
;
Seminiferous Tubules
;
Sertoli Cells
;
Spermatogenesis
;
Spermatogonia
;
Testis
;
Urinary Bladder
;
Uterus
;
Veterinary Medicine

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