Endoluminal Closure of Colon Perforation with Endoscopic Band Ligation: Technical Feasibility and Safety in an In Vivo Canine Model

BACKGROUND/AIMS: Endoscopic band ligation (EBL) is an accepted method in the management of variceal bleeding; however, there is little evidence on the safety and feasibility of EBL for the closure of bowel perforation. In this study, we aimed to evaluate the technical feasibility and efficacy of EBL in iatrogenic colon perforation by using a canine model. METHODS: We established an iatrogenic colon perforation model by using seven beagle dogs. Longitudinal 1.5- to 1.7-cm colon perforations were created with a needle knife and an insulated-tip knife, and the perforation was subsequently closed with EBL. During a 2-week follow-up period, the animals were carefully monitored and then euthanized for pathologic examination. RESULTS: The EBL of iatrogenic colon perforations was successful in all dogs. The mean procedure time for EBL closure with one to three bands was 191.7 seconds, and there were no immediate complications. One animal was euthanized after 3 days because of peritonitis. There were no clinical and laboratory features of sepsis or peritonitis in the remaining six animals. On necropsy, we did not find any fecal peritonitis, pericolonic abscess formation, or transmural dehiscence at the perforation site. Histopathology demonstrated inflamed granulation tissue and scar lesions replaced by fibrosis. CONCLUSIONS: EBL might be a feasible and safe method for the management of iatrogenic colon perforations in an in vivo model.

Evaluation of biocompatibility of alpha-1,3 galactosyltransferase knockout pig bone graft in a rat calvarial defect model / 동물의과학연구지

The current study was conducted to evaluate the biocompatibility of alpha-1,3 galactosyltransferase knockout pig bone graft in a rat calvarial defect model. Porcine cancellous bones were harvested from general and alpha-gal KO pigs and washed with 70% ethanol solution and normal saline. Bone pieces of the alpha-gal KO pig underwent a chemical treatment process to delipidize and deproteinize the bone. Bone graft particles were freeze-dried and stored at -70degrees C until use. Each bone graft was implanted into the rat calvarial defect in a fresh general pig, fresh transgenic pig, and chemical-treated pig bone group. There was no systemic adverse effect on hematology or necropsy findings in all groups at 1 week and 4 weeks. In the microcomputed tomography analysis, bone volume increased significantly in the chemical-treated transgenic pig bone group, whereas bone mineral density decreased significantly in the fresh general pig bone group compared with other groups. Histological evaluation showed cellular infiltration located at the margin of the bone graft particles, especially in the fresh general pig bone group. These results indicate that fresh general pig bone can elicit a greater local inflammatory response than fresh transgenic pig bone. Further, chemical-treated transgenic pig bone graft was less immunogenic than fresh bone graft. In conclusion, transgenic pig bone is a more biocompatible graft material. In addition, chemical treatment can reduce bone graft immunogenicity by delipidizing and deproteinizing bone.

Comparable bone healing capacity of different bone graft matrices in a rabbit segmental defect model

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.

Effects of mesenchymal stem cells treated with BMP-2 and VEGF on regeneration of large bone defects / 동물의과학연구지

This study evaluated the possibility of clinical application using matrigel-based bioceramic/polymer scaffolds treated with bone morphogenetic protein, angiogenic factor, and mesenchymal stem cells (MSCs) for new bone formation. In the in vitro study, bone morphogenetic protein (BMP-2) and vascular endothelial growth factor (VEGF) containing matrigel, which is a basement membrane gel, was injected into HA/PCL scaffolds to estimate the release rates of growth factors. In the in vivo study, BMP-2, VEGF, and MSCs with matrigel-based scaffolds were implanted into rat femoral segmental defects, and new bone formation was evaluated at 4 and 8 weeks. In the results, the release rates of BMP-2 and VEGF explosively increased by day 5. For the in vivo study results, radiological evaluation revealed that the matrigel-based HA/PCL scaffolds with BMP-2 and VEGF grafted (M+B+V) and matrigel-based HA/PCL scaffolds with BMP-2, VEGF, and MSC grafted (MSC) groups showed increased bone volume and bone mineral density. Moreover, in the histological evaluation, large new bone formation was observed in the M+B+V group, and high cellularity in the scaffold was observed in the MSC group. In conclusion, grafted matrigel-based HA/PCL scaffolds with BMP-2, angiogenic factor, and MSCs increased new bone formation, and in clinical cases, it may be effective and useful to enhance healing of delayed fractures.

Male pseudohermaphroditism in a Maltese/poodle mixed dog / 동물의과학연구지

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.

The effect of angiogenic factors with HA/PCL scaffold containing matrigel in a rat calvarial defect model / 동물의과학연구지

The current study was conducted in order to investigate bone formation using matrigel and angiogenic factors with HA and poly epsilon-caprolactone (HA/PCL) in a rat calvarial defect model. Calvarial defect formation was surgically created in Sprague Dawley rats (n=36). Rats in the control group (CD group, n=6) did not receive a graft. The HA/PCL scaffold was grafted with matrigel (M-HA/PCL group, n=6) or without matrigel (HA/PCL group, n=6); and 100 ng of vascular endothelial growth factor with HA/PCL scaffold containing matrigel (VEGF100 group, n=6), 100 ng (PDGF100 group, n=6) and 300 ng (PDGF300 group, n=6) of PDGF with HA/PCL scaffold containing matrigel were grafted in calvarial defects, respectively. Four weeks after surgery, bone formation was evaluated with micro computed tomography (micro CT) scanning, and histologically. According to the results, bone mineral density was significantly increased in the VEGF100, PDGF100, and PDGF300 groups compared to the HA/PCL group, in which angiogenic factors were not applied. In histological evaluation, more new bone formation around scaffolds was observed in the PDGF100 and the PDGF300 groups, compared with the VEGF100 group. Thus, the results indicate that HA/PCL containing matrigel with VEGF and PDGF is an effective grafting material for enhancement of bone formation in critical-sized bone defects. Especially, due to its price and capacity for bone formation, PDGF may be more effective than VEGF.

Efficacy of alcohol-free cetylpyridinium chloride on periodontal disease in beagle dogs via drinking water additive and oral gel / 동물의과학연구지

This study was conducted in order to examine the effects of alcohol-free cetylpyridinium chloride drinking water additive and oral gel on clinical parameters related to periodontal disease in beagle dogs. This study was conducted with healthy 15 beagle dogs. Following a professional teeth cleaning procedure, dogs were divided into three groups. Dogs in the control group received nothing, those in the drinking water additive (DWA) group received 800 ml water with 15 ml of alcohol-free cetylpyridinium chloride drinking water additive daily, and those in the Oral gel (OG) group were treated with oral gel containing alcohol-free cetylpyridinium chloride and 0.05% chlorhexidine gluconate daily. Clinical parameters, including plaque index (PI), calculus index (CI), and gingivitis index (GI) were evaluated at two and four weeks. Dogs in the DWA and OG groups had significantly less plaque than dogs in the control group at two and four weeks (P<0.01, P<0.05). And, at four weeks, CI was significantly lower in the OG group compared to the control group (P<0.05). On GI, similar scores were recorded for all groups during the experimental period. No significant difference was observed between the DWA group and the OG group. The effect of alcohol-free cetylpyridinium chloride drinking water additive was similar to the result for alcohol containing cetylpyridinium chloride mouthwash reported in a previous study. The effect in control of periodontal disease was better in the OG group because of additional chlorhexidine gluconate. However, use of drinking water additive will be more convenient for owners; thus, it will be more effective for achievement of long-term results.

Traumatic and Non-traumatic Osteonecrosis in the Femoral Head of a Rabbit Model / 한국실험동물학회지

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.

Additive Effects of Intra-articular Injection of Growth Hormone and Hyaluronic Acid in Rabbit Model of Collagenase-induced Osteoarthritis

In a rabbit model of collagenase-induced osteoarthritis, the additive effects of intra-articular recombinant human growth hormone (GH) administration to hyaluronic acid (HA) were evaluated. After intra-articular collagenase injection, mature New Zealand white rabbits (n=30) were divided into 3 groups. Group 1 (control rabbits) received once weekly intra-articular saline injections for 4 weeks. Group 2 rabbits received 6 mg HA injections, and group 3 rabbits were injected with 6 mg HA and 3 mg recombinant human GH. These injections were initiated 4 weeks after collagenase injections. Lameness was observed for 9 weeks after collagenase injections. Macroscopic and histopathological knee joint findings were also evaluated at the end of 9 weeks after collagenase injections. Although all animals had lameness after collagenase injections, the duration and severity of lameness were significantly shorter and less severe in group 3 than group 1 and 2 (P<0.01). Macroscopic scores showed that femoral condyles of group 3 rabbits received significantly less cartilage damage than those of groups 1 and 2 rabbits (P<0.01). Histopathological score was also the lowest in group 3 (P<0.01). These results suggest that co-injection of intra-articular HA and recombinant human GH is more effective than HA injections alone in an osteoarthritis model.

Scintigraphic Assessment of Renal Function Using 99mTc-DTPA in Miniature Pigs with Unilateral Ureteral Obstruction / 한국실험동물학회지

This study was performed to investigate the proper method for evaluating renal function in miniature pigs with unilateral ureteral obstruction. Experimental unilateral renal damage was induced after ligation of unilateral right ureter in 3 miniature pigs. On the 3rd post-operative day, scintigraphic images were obtained after 12 mCi of 99mTc-diethylentriamene pertaacetate (DTPA) intravenous injection. Renography showed that radiopharmaceutical uptakes in the right kidney were lower than those of left kidney uptakes as early as at 3 days after surgical operation. The static images of 99mTc-DTPA enabled us to measure the relative renal function in miniature pigs with unilateral ureteral obstruction. In conclusion, renography using 99mTc-DTPA was the useful diagnostic method to evaluate the renal function in miniature pigs.

A case of maloccluded incisor teeth in a beaver: Castor canadensis

A three-year-old female beaver (Castor canadensis) was referred to the Veterinary Teaching Hospital of Chungbuk National University. It had been raised in the Cheong-ju zoo and had a history of malocclusion caused by improper feeding. General anesthesia was induced, and preoperative intraoral dental radiographs of the rostal maxillary and mandibular dentition were taken and lateral and ventrodorsal extraoral radiographs of the cheek teeth were also taken. The radiographs were negative for apical pathology and revealed a normal appearance of the cheek teeth. The lesion was likely to be related to the excessive length of the maxillary and mandibular incisors. Odontoplasty was performed to reduce overgrowth of the crowns of the incisors. Sequential transverse sections were removed until the crown was reduced by approximately its original length. The pulp chamber was not approached during the operation, as confirmed by postoperative intraoral radiographic evaluation of the incisors. Recovery from anesthesia was uneventful and the beaver returned to normal masticatory activities immediately after the operation.

Prophylactic effect of plaster and cataplasm contained ketoprofen in rats with adjuvant arthritis

This study demonstrates that prophylactic effect of plaster and cataplasm contained ketoprofen in adjuvant arthritis therapy by X-ray. Adjuvant arthritis was induced by a single injection of Freund's complete adjuvant. Mature female Sprague-Dawley rats were designated to 3 groups such as nontreated control, plaster-treated (PT) and cataplasm-treated (CT), each of which was composed of ten animals. The PT and the CT groups showed reduced primary paw swelling, but secondary paw swelling was not affected. Bony changes were observed in all regions of the femur and tibia of the nonadjuvant-injected leg and the adjuvant-injected leg. The mean radiographic scores of the PT and the CT groups were significantly lower than those of the control group from day 0 to 7 of the experimental period (p<0.05, p<0.01). The CT rats showed reduced poly-arthritis development than the PT rats. Our results suggest that radiographic assessment of bony changes is more suitable for measuring changes in long bones such as femur or tibia than in vertebrae. The prophylactic effect of CT prominently suppressed edematous swelling and bony changes in arthritic limb compared with PT.

Therapeutic effect of bee venom in sows with hypogalactia syndrome postpartum

The objective of this study was to determine the clincotherapeutic effect of whole bee venom in hypogalactic sows postpartum. Sows after parturition were assigned to treated and nontreated control groups. In the treated group, 22 sows were bee acupunctured once a day for 3 consecutive days. Honeybees (Apis mellifera L.) for bee acupuncture were about 15 days after metamorphosis. One live bee was used to sting the acupoints known as Yang-ming (ST-18, 1.5 cm lateral to the base of the last 2 pairs of teats) and Jiao-chao (GV-1, at the indentation between the base of tail and the anus). In the control group, 20 sows were intramuscularly injected with a standard dosage of penicillin G (400,000 IU/head) once a day for 3 consecutive days. At post-treatment, 85.0% of the drug-treated control and 90.9% of the bee venomtreated group recovered from hypogalactia syndrome. The advantages of apitherapy were that the patients did not have stress because they were not restrained for a long period. The result suggested that apitherapy using bee venom is an effective treatment for sows with hypogalactia syndrome postpartum.