1.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
2.Traumatic and Non-traumatic Osteonecrosis in the Femoral Head of a Rabbit Model.
Yawon HWANG ; Jinuk PARK ; Seok Hwa CHOI ; Gonhyung KIM
Laboratory Animal Research 2011;27(2):127-131
Osteonecrosis of the femoral head is an idiopathic, debilitating and progressive disease. A number of traumatic or non-traumatic animal models have been reported for research on osteonecrosis. This study was performed to compare the efficacy of femoral head osteonecrosis in rabbits by traumatic and non-traumatic methods. Twenty-seven New Zealand White rabbits were divided into three experimental groups, nine heads each. Two groups were surgically induced into osteonecrosis; a steel cerclage wire was ligated tightly around the neck of the right femoral head (Group W), and the femoral neck was tied with a cerclage wire in the same way as in the W group, and burned by attachment of an electrode tip to the wire and then the wire was removed (Group B). The other group was induced into osteonecrosis with a single intra-muscular injection of 20 mg/kg methyl-prednisolone acetate single injection (Group M). In the control group, the left femoral head of animals in group W and B was used. After two weeks, rabbits were sacrificed and the femoral head and neck were collected. Osteonecrosis of the femoral head was evaluated by radiography, histology and immunohistology methods. Osteonecrosis lesions in the femoral head were identified in traumatic models of groups W and B. Cartilage degeneration in the superficial layer and TUNEL positive cells in the femoral head were detected more in Group B than in Group W. These findings revealed that short-term induced osteonecrosis of the femoral head was effectively achieved by cautery around the femoral neck.
Animals
;
Burns
;
Cartilage
;
Cautery
;
Electrodes
;
Femur Neck
;
Head
;
In Situ Nick-End Labeling
;
Models, Animal
;
Neck
;
Osteonecrosis
;
Rabbits
;
Steel
3.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
4.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
5.Retrospective study on fractures in dogs.
Maruf MINAR ; Yawon HWANG ; Minhyeok PARK ; Somin KIM ; Cheongjin OH ; Seokhwa CHOI ; Gonhyung KIM
Journal of Biomedical Research 2013;14(3):140-144
Patients referred to the Veterinary Medical Center at Chungbuk National University were analyzed. This study aimed to provide information to clinicians in Korea on the factors affecting fracture incidence in patients adapted to Korean companion animal culture. Eighty cases showing-bone fractures were investigated from January, 2005 to December, 2011. Fractures were mainly observed in miniature dogs such as Yorkshire terrier (12%), Poodle (12%), and Maltese (9%). Almost 50% of all cases were less than 1 year old. Total bone fractures in summer and fall constituted 62%. Fracture incidence was higher in male dogs (54%) than female dogs (46%). Hindlimb fracture (37%) was the most common. Distribution of limb fractures was higher in the femur (19), followed by the tibia/fibula (15), radius/ulna (13), humerus (11), and mandible (8). Pelvic fracture was observed in 19 cases. Simple fracture (84%) was the most common fracture type, followed by comminuted fracture (16%). Distal portion was the most common fracture site in long bones (67%), followed by middle (26%) and proximal bones (7%). Fractures were mainly caused by traffic accidents (43%), whereas 28.5% of fractures were due to falling down. Plate & screw (26%) was the most common method of fracture repair, followed by intramedullary pin (24%), wire (11%), external skeletal fixation (10%), screw (9%), amputation (7%), cross pin (6%), IM pin and wire (5%), and rush pin (1%). Among 80 patients, 79%of patients showed a good prognosis after surgery, whereas 13% patients did not experience a good result. This study shows that miniature dogs are prone to falling and fractures, especially in the distal part of long bones.
Accidents, Traffic
;
Amputation
;
Animals
;
Dogs*
;
Extremities
;
Female
;
Femur
;
Fracture Fixation
;
Fractures, Bone
;
Fractures, Comminuted
;
General Surgery
;
Hindlimb
;
Humans
;
Humerus
;
Incidence
;
Korea
;
Male
;
Mandible
;
Pets
;
Prognosis
;
Retrospective Studies*