• Journal of Periodontal and Implant Science
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• v.43 no.4
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• pp.147-152
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• 2013

Purpose: An animal periodontitis model is essential for research on the pathogenesis and treatment of periodontal disease. In this study, we have introduced a lipopolysaccharide (LPS) of a periodontal pathogen to the alveolar bone defect of experimental animals and investigated its suitability as a periodontitis model. Methods: Alveolar bone defects were made in both sides of the mandibular third premolar region of nine beagle dogs. Then, the animals were divided into the following groups: silk ligature tied on the cervical region of tooth group, Porphyromonas gingivalis LPS (P.g. LPS)-saturated collagen with silk ligature group, and no ligature or P.g. LPS application group as the control. The plaque index and gingival index were measured at 0 and 4 weeks postoperatively. The animals were then euthanized and prepared for histologic evaluation. Results: The silk ligature group and P.g. LPS with silk ligature group showed a significantly higher plaque index at 4 weeks compared to the control (P<0.05). No significant difference was found in the plaque index between the silk ligature group and P.g. LPS with silk ligature group. The P.g. LPS with silk ligature group showed a significantly higher gingival index compared to the silk ligature group or the control at 4 weeks (P<0.05). Histologic examination presented increased inflammatory cell infiltration in the gingival tissue and alveolar bone of the P.g. LPS with silk ligature group. Conclusions: An additional P.g. LPS-saturated collagen with silk ligature ensured periodontal inflammation at 4 weeks. Therefore, P.g. LPS with silk ligature application to surgically created alveolar bone defects may be a candidate model for experimental periodontitis.

• Tuberculosis and Respiratory Diseases
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• v.52 no.1
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• pp.54-61
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• 2002

Background: Tracheal stenosis is an urgent but uncommon disease. Therefore, primary care clinicians have limited clinical experience. Animal models of a tracheal stenosis can be used conveniently for the learning, teaching, and developing new diagnostic and therapeutic modalities for tracheal stenosis. Recently, a canine model of a tracheal stenosis was developed using a Nd-YAG laser. To describe the methods and results of developed animal model, we performed this study. Methods : Six Mongrel dogs were generally anesthetized and the anterior 180 degree of tracheal cartilage of the animal was photo-coagulated using a Nd-YAG laser. The animals were bronchoscopically evaluated every week for 4 weeks and a pathologic evaluation was also made. Results : Two weeks after the laser coagulation, the trachea began to stenose and the stenosis progressed through 4 weeks. All animals suffered from shortness of breath, wheezing, and weight loss in the 3 weeks after the laser treatment, and two died of respiratory failure just before the fourth week. The gross pathologic findings showed the loss of cartilage and a dense fibrosis, which resulted in a fibrous stricture of the trachea. Microscopy also showed that the fibrous granulation tissue replaced destroyed cartilage. Conclusion : The canine model can assist in the understanding and development of new diagnostic and therapeutic modalities for tracheal stenosis.

• Journal of Periodontal and Implant Science
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• v.40 no.5
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• pp.232-238
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• 2010

Purpose: To prolong the degradation time of collagen membranes, various cross-linking techniques have been developed. For cross-linking, chemicals such as formaldehyde and glutaraldehyde are added to collagen membranes, but these chemicals could adversely affect surrounding tissues. The aim of this study is to evaluate the ability of porous non-chemical cross-linking porcine-derived collagen nanofibrous membrane to enhance bone and associated tissue regeneration in one-wall intrabony defects in beagle dogs. Methods: The second and third mandibular premolars and the first molars of 2 adult beagles were extracted bilaterally and the extraction sites were allowed to heal for 10 weeks. One-wall intrabony defects were prepared bilaterally on the mesial and distal side of the fourth mandibular premolars. Among eight defects, four defects were not covered with membrane as controls and the other four defects were covered with membrane as the experimental group. The animals were sacrificed 10 weeks after surgery. Results: Wound healing was generally uneventful. For all parameters evaluating bone regeneration, the experimental group showed significantly superior results compared to the control. In new bone height (NBh), the experimental group exhibited a greater mean value than the control ($3.04{\pm}0.23\;mm/1.57{\pm}0.59$, P=0.003). Also, in new bone area (NBa) and new bone volume (NBv), the experimental group showed superior results compared to the control (NBa, $34.48{\pm}10.21%$ vs. $5.09{\pm}5.76%$, P=0.014; and NBv, $28.04{\pm}12.96$ vs. $1.55{\pm}0.57$, P=0.041). On the other hand, for parameters evaluating periodontal tissue regeneration, including junctional epithelium migration and new cementum height, there were no statistically significant differences between two groups. Conclusions: Within the limitations of this study, this collagen membrane enhanced bone regeneration at one-wall intrabony defects. On the other hand, no influence of this membrane on periodontal tissue regeneration could be ascertained in this study.

• Journal of Periodontal and Implant Science
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• v.37 no.2
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• pp.237-249
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• 2007

This study was performed to evaluate the effect of membrane exposure on new bone formation when guided bone regeneration with perforated titanium membrane on atrophic alveolar ridge. The present study attempted to establish a GBR model for four adult beagle dog premolar. Intra-marrow penetration defects were created on the alveolar ridge(twelve weeks after extraction) on the mandibular premolar teeth in the beagle dogs. Space providing perforated titanium membrane with various graft material were implanted to provide for GBR. The graft material were demineralized bovine bone(DBB), Irradiated cancellous bone(ICB) and demineralized human bone powder(DFDB). The gingival flap were advanced to cover the membranes and sutured. Seven sites experienced wound failure within 2-3weeks postsurgery resulting in membrane exposure. The animals were euthanized at 4 weeks postsurgery for histologic and histometric analysis. The results of this study were as follows: 1. There was little new bone formation at 4 weeks postsurgery. irrespectively of membrane exposure. 2. There was significant relationship between membrane exposure and bone graft resorption(P<0.05), but no relation between membrane exposure and infiltrated connective tissue. 3. There was much bone graft resorption on DFDB than ICB and DBB. 4. The less exposure was on the perforated titanium membrane, the more dense infiltrated connective tissue was filled under the membrane when grafted with ICB and DBB. but there was no relationship between the rate of membrane exposure and the percentage of infiltrated connective tissue area and no relationship between the percentage of the area in the infiltrated connective tissue and in the residual bone graft. Within the above results, bone formation may be inhibited when membrane was exposed and ICB and DBB were more effective than DFDB as a bone graft material when guided bone regeneration.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1112-1118
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• 2006

Bordetella bronchiseptica, the agent of swine atrophic rhinitis and kennel cough in dogs, is a mucosal pathogen and produces the hydroxamate type alcaligin siderophore under iron-limited conditions. Genes involved in alcaligin siderophore biosynthesis are contained in an alcABCDE operon. In order to provide direct evidence for the role of AlcA in alcaligin biosynthesis, we needed a B. bronchiseptica mutant carrying alcA gene deletion. A 0.6 kb alcA 5'-flanking and 0.7kb 3'-flanking DNA fragments were PCR amplified with the use of pCP1.11 as a template DNA. The 5'-and 3'-flanking DNA fragments were joined in a suicide plasmid, resulting in a recombinant suicide plasmid pDM1. After introduction of pDM1 into B. bronchiseptica by conjugation, the allelic exchange technique was performed and a B. bronchiseptica alcA deletion mutant, named B. bronchiseptica H1, was obtained. The mutant strain produced reduced amount of siderophore as expected. When a plasmid containing complete alcA gene was transformed back into the mutant, the complemented mutant recovered ability of siderophore production. These results indicated that AlcA is one of essential components for the alcaligin siderophore biosynthesis. The mutant strains obtained in this study will be used in the further studies for the biochemical function of AlcA.

• Journal of Embryo Transfer
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• v.18 no.1
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• pp.27-33
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• 2003

The study was carried out to investigate the effects of morphology, reproductive cycle, incubation time and activation of oocytes in vitro maturation of canine oocytes and development of canine IVM/IVF embryos. The results were summarized as follows: 1. The developmental rates to 16 cells of fresh, salts and 4$^{\circ}C$-stored oocytes with and without cumulus cells were 14.3%, 5.0% and 7.5%, 2.8% and 5.7%, 0.0%, respectively. The rate of oocytes with cumulus cells(5.7%~14.3%) was higher than that of denuded oocytes(0.0%~5.0%). 2. The developmental rate to If cells of in vitro cultured oocytes recovered from ovaries collected at different stages of the reproductive cycle were 0.0%, 10.7%, 1.5%, respectively. 3. The developmental rate to 16 cells of fresh oocytes with cumulus cell cultured for 24, 32 and 48 hrs in $CO_2$ incubator were 0.0%, 5.3%, 11.8%, respectively. The rate of oocytes cultured for 48 hrs was higher than that oocytes cultured for 24 and 32 hrs. 4. The development to If cells treated activation and non-activation oocytes were 15.0%, 6.7%, respectively. The rate of oocytes treated activation was higher than that oocyte treat non-activation.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.399-422
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• 1995

The purpose of this study was to investigate a fragment of possibility of pulpotomy with the Nd-YAG laser by the observation of pulpal healing process and the fine structural changes of the fibroblasts of the remaining pulpal tissues. Class V cavities on !55 teeth from 4 adult dogs were prepared and the pulp chambers were opened with a sterilized round bur. In the control group(19 teeth), the exposed coronal pulps were excised by a sharp excarvator. After bleeding was controlled with the sterilized cotton pellets, calcium hydroxide powder was applied on the remaining pulpal tissues and the cavities were sealed with Z.O.E. In the experimental group 1 : the pulpotomy with laser-calcium hydroxide powder application group(l9 teeth), the exposed coronal pulps were excised by Nd-YAG laser(10 watts power, 2 psi water, 20 psi air) for 2 or 3 seconds and calcium hydroxide powder was applied on the remaining pulpal tissues and the cavities were sealed with Z.O.E. In the experimental group 2 : the pulpotomy with laser-no calcium hydroxide powder application group(17 teeth), after amputating the coronal pulps with Nd-YAG laser as the experimental group 1, the remaining pulpal tissues were covered with stenilized aluminum foil and the cavities were filled with Z.O.E. The animals were sacrificed at the intervals of 1, 2, 3 and 4 weeks. All the teeth were rouutinely processed and the remaining pulpal tissues were observed by the light microscope and electron microscope. The results were as follows : 1. In light microscopic findings, there was no significant difference of the inflammatory response in the remaining pulpal tissues between the control group and the experimental groups. In both of the experimental group 1 : pulpotomy with laser-calcium hydroxide powder application group and the control group, the dentin bridges were observed after 2 weeks and the structure of the dentin bridge was almost same. In the experimental group 2 : pulpotomy with laser-no calcium hydroxide powder application group, the fibrous layers instead of dentin bridge were observed on the superficial portion of the remaining pulpal tissues after 2 weeks and they were consisted with densely crowded active fibroblasts. 2. In the electronmicroscopic findings, the active fibroblasts in the experimental groups were more frequently observed than in the control group at 1 week. But active fibroblasts were found with same frequency after 2 weeks in all of the control group and the experimental groups. 3. General distortions of the cell such as loss of the cell membrane, vaculoization of the cell etc. were observed at the suberficial layer of the remaining pulpal tissues and the carbonization was found in the dentinal wall in 1 week of the experimental groups. 4. In the experimental group 2 : pulpotomy with laser-no calcium hydroxide powder application group, the activity and the density of the fibroblasts in the fibrous layer were more than those in the deep portion of the remaining pulpal tissues after 2 weeks. 5. In the control group, bacteria such as cocci and bacilli were observed frequently, but in the experimntal groups, they could not be observed.

• Journal of Chest Surgery
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• v.18 no.4
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• pp.732-739
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• 1985

This study was experimentally undertaken to evaluate the effect of the coronary vasodilator-mixed cardioplegic solution on myocardial protection during prolonged aortic cross-clamping. The dogs were divided into two groups: control group A[received hypothermic cardioplegic solution without any additive coronary vasodilator], and comparing group 8[received hypothermic cardioplegic solution, mixed with various coronary vasodilators and Inderal]. Group A further was divided into two subgroups: subgroup A-1[ischemic time, 90 minutes], and subgroup A-2 [ischemic time, 240 minutes]. Group B further was divided into five subgroups: subgroup B-1 [received papaverine mixed hypothermic cardioplegic solution], subgroup B-2[received nitroglycerin mixed hypothermic cardioplegic solution], subgroup B-3 [received nitroprusside mixed hypothermic cardioplegic solution, subgroup B-4[received hydralazine mixed hypothermic cardioplegic solution], and subgroup B-5 [received inderal mixed hypothermic cardioplegic solution]. The specimens from all of the subgroups were studied by electron microscopic examination. The specimens of subgroups [B-l, B-2 8-3, and B-4], received coronary vasodilators mixed hypothermic cardioplegic solutions, were also compared by methylene blue induced staining of the myocardium and coronary vessels. The results obtained were as followings: l. On electron microscopic examination, all of the specimens, including subgroup A-2, showed no irreversible change of the myocardium. But the best result was obtained from the subgroup B-l, treated by papaverine mixed hypothermic cardioplegic solution. The subgroup B-2, treated by nitroglycerin, was next. And the subgroup B-5, treated by Inderal, was agreeable, comparing the electron microscopic finding with control group in the effect of myocardial protection. 2. The distribution in the myocardium of cardioplegic solution was demonstrated with the aid of methylene blue staining in the subgroups of B-l, B-2, B-3, and B-4, and they were the groups treated by papaverine, nitroglycerin, nitroprusside, and hydralazine in their grouping order. The best result was obtained from the subgroup B-1 [papaverine]. The subgroup B-2 [nitroglycerin] was next. The subgroup B-3 [nitroprusside] was moderate in finding of the colorization. The subgroup B-4 [hydralazine] was the poorest in the distribution of the cardioplegic solution in the myocardium. From these results, it appeared that myocardial protection during ischemic arrest for open heart surgery could be enhanced considerably when coronary dilatation was assured.

• Journal of Chest Surgery
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• v.5 no.2
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• pp.87-96
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• 1972

Studies of blood gas and lung histopathology were done in 10 dogs after intrapericardlal aorto-right pulmonary arterial anastomosis with proximal ligation of the right pulmonary antery. Among the 5 expired during or after operation, in 3 cases, the causes of the death were due to surgical bleeding and, in 2 cases, acute cardiopulmonary insufficiency because of large anastomosis stoma measured respectively 7mm and 10mm. In the 5 of survivals, one was sacrificed because of empyema at postoperative 7 days and 2 were at postoperative one month and remained 2 at postoperative 3 month respectively. The following observations were made. 1.In every survival, continuous machinary murmur was auscultated and the angiograms of all long term survivals showed the good patency of the anastomosis stoma. 2.After the ligation of the right pulmonary artery, the values of $PO_2$ and $PCO_2$ in arterial and venous blood were generally decreased comparing with the preoperative values. The mean value of $P_aO_2$ noted $83.30{pm}11.875$[p<0.01]. After the shunts operation with ligation of the right pulmonary artery, the immediate values of PH, $PO_2$ and $PCO_2$showed no significant changes comparing with that of right pulmonary artery ligation only. In the cases of survivals more than one month, the values of $PO_2$ and $PCO_2$ in the arterial and venous blood were generally higher than that of ligation of the right pulmonary artery only. The $P_aO_2$ value noted $103.750{pm}7.395$[p<0.01]. The mean values of $P_aO_2$, $PCO_2$ and PH in the arterial and venous blood almost returned to that of preoperative studies. 3.In the specimens of lung from the cadavors expired due to acute cardiopulmonary insufficiency after the operation, there were massive congestion, hemorrhage in the alveolar spaces and bronchioles. In specimens obtained at postoperative one month, there were dilatation of alveolar spaces with partial rupture, slight congestion, and alveolar wall thickening in the lung parenchyme, but there was no significant changes in pulmonary vasculature except dilation of pulmonary capillaries. In the specimens obtained at postoperative three months, the alveolar walls were more thickened in the lung parenchyme than the finding of the specimens obtained at postoperative one month. In the wall of pulmonary capillaries, there was only slight thickening with connective tissue proliferatlon.

• Journal of Chest Surgery
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• v.34 no.6
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• pp.441-446
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• 2001

Background: Electrical breathing pacing has many advantages over mechanical ventilation. However, clinically permanent diaphragmatic pacing has been applied to limited patients and few temporary pacing has been reported. Our purpose is to investigate the feasibility of temporary electrical diaphragm pacing in explothoracotomy canine cases. Methods: Five dogs were studied under the general anesthesia. Left 5th intercostal space was opened. Self designed temporary pacing leads were placed around the left phrenic nerve and connected to the myostimulator. Chest wall was closed after tube insertion with underwater drainage. Millar catheter was introduced to the aorta and right atrium. Swan-Ganz catheter was introduced to the pulmonary artery. When the self respiration was shallow with deep anesthesia, hemodynamic and tidal volume were measured with the stimulator on. Results: Tidal volume increased from 143.3$\pm$51.3 ml to 272.3$\pm$87.4 ml(p=0.004). Right atrial diastolic pressure decreased from 0.7$\pm$4.0 mmHg to -10.5$\pm$4.7 mmHg(p=0.005). Pulmonary arterial diastolic pressure decreased from 6.1+2.5 mmHg to 1.2$\pm$4.8 mmHg(p<0.001). The height of water level in chest tube to show intrathoracic pressure change was from 10.3$\pm$6.7cmH$_{2}$O to 20.0$\pm$5.3 cmH$_{2}$O. Conclusion: Temporary electrical diaphragmatic pacing is a simple method to assist respiration in explothoracotomy canine cases. Self designed pacing lead is implantable and removable. Negative pressure ventilation has favorable effects on the circulatory system. Therefore, clinical application of temporary breathing pacing is feasible in thoracotomy patients to assist cardiorespiratory function.