• Journal of Veterinary Clinics
• /
• v.28 no.5
• /
• pp.486-496
• /
• 2011

A special mesenchymal tissue layer called perichondrium has a chondrogenic capacity and is a candidate tissue for engineering of cartilage. To overcome limited potential for chondrocyte proliferation and re-absorption, we studied a method of cartilage tissue engineering comprising chondrocyte-hydrogel pluronic complex (CPC) and cultured perichondrial cell sheet (cPCs) which entirely cover CPC. For effective cartilage regeneration, cell-sheet engineering technique of high-density culture was used for fabrication of cPCs. Hydrogel pluronic as a biomimetic cell carrier used for stable and maintains the chondrocytes. The human cPCs was cultured as a single layer and entirely covered CPC. The tissue engineered constructs were implanted into the dorsal subcutaneous tissue pocket on nude mice (n = 6). CPC without cPCs were used as a controls (N = 6). Engineered cartilage specimens were harvested at 12 weeks after implantation and evaluated with gross morphology and histological examination. Biological analysis was also performed for glycosaminoglycan (GAG) and type II collagen. Indeed, we performed additional in vivo studies of cartilage regeneration using canine large fullthickness chondrial defect model. The dogs were allocated to the experimental groups as treated chondrocyte sheets with perichondrial cell sheet group (n = 4), and chondrocyte sheets only group (n = 4). The histological and biochemical studies performed 12 weeks later as same manners as nude mouse but additional immunofluorescence study. Grossly, the size of cartilage specimen of cPCs covered group was larger than that of the control. On histological examination, the specimen of cPCs covered group showed typical characteristics of cartilage tissue. The contents of GAG and type II collagen were higher in cPCs covered group than that of the control. These studies demonstrated the potential of such CPC/cPCs constructs to support chondrogenesis in vivo. In conclusion, the method of cartilage tissue engineering using cPCs supposed to be an effective method with higher cartilage tissue gain. We suggest a new method of cartilage tissue engineering using cultured perichondrial cell sheet as a promising strategy for cartilage tissue reconstruction.

• Journal of Chest Surgery
• /
• v.37 no.2
• /
• pp.119-130
• /
• 2004

Decrease in cardiac function after open heart surgery is due to an ischemia induced myocardial damage during surgery, and ischemic preconditioning, a condition in which the myocardial damage does not accumulate after repeated episodes of ischemia but protects itself from damage after prolonged ischemia due to myocytes tolerating the ischemia, is known to diminish myocardial damage, which also helps the recovery of myocardium after reperfusion, and decreases incidences of arrythmia. Our study is performed to display the ischemic preconditioning and show the myocardial protective effect by applying cardioplegic solution to the heart removed from rat. Material and Method: Sprague-Dawley male rats were used, They were fixed on a modified isolated working heart model after cannulation. The reperfusion process was according to non-working and working heart methods and the working method was executed for 20 minutes in which the heart rate, aortic pressure, aortic flow and coronary flow were measured and recorded. The control group is the group which the extracted heart was fixed on the isolated working heart model, recovered by reperfusion 60 minutes after infusion and preserved in the cardioplegic solution 20 minutes after the working heart perfusion and aortic cross clamp, The thesis groups were divided into group I, which ischemic hearts that were hypoxia induced were perfused by cardioplegic solution and preserved for 60 minutes; group II, the cardioplegic solution was infused 45 seconds (II-1), 1 minutes (II-2), 3 minutes (II-3), after the ischemia induction, 20 minutes after working heart perfusion and aortic cross clamp; and group III, hearts were executed on working heart perfusion for 20 minutes and aortic cross clamp was performed for 45 seconds (III-1), 1minute (III-2), 3 minutes (III-3), reperfused for 2 minutes to recover the heart, and then aortic cross clamping was repeated for reperfusion, all the groups were compared based on hemodynamic performance after reperfusion of the heart after preservation for 60 minutes. Result: The recovery time until spontaneous heart beat was longer in groups I, II-3, III-2 and III-3 to control group (p<0.01). Group III-1 (p<0.05) had better results in terms of recovery in number of heart rates compared to control group, and recovered better compared to II-1 (p<0.05). The recovery of aortic blood pressure favored group III-1 (p<0.05) and had better outcomes compared with II-1 (p<0.01). Group III-1 also showed best results in terms of cardiac output (p<0.05) and group III-2 was better compared to II-2 (p<0.05). Group I (p<0.01) and II-3 (p<0.05) showed more cardiac edema than control group. Conclusion: When the effects of other organs are dismissed, protecting the heart by infusion of cardioplegic solution after enforcing ischemia for a short period of time before the onset of abnormal heart beats for preconditioning has a better recovery effect in the cardioplegic group with preconditioning compared to the cardioplegic solution itself. we believe that further study is needed to find a more effective method of preconditioning.

• Journal of Chest Surgery
• /
• v.36 no.8
• /
• pp.545-558
• /
• 2003

Adult respiratory distress syndrome (ARDS) is of particular interest because of its severity of the associated lung injury and its high mortality. However, the pathophysiologies of ARDS in infant and childhood groups are still not well clarified inspite of many previous investigations. To investigate the time course of pathophysiology of ARDS in infant and childhood groups, this study was designed with experimental endotoxin-induced ARDS model using young rabbits (8 week-old). Material and Method: Rabbits were divided into the control group (n=8) and the endotoxin-treated group (n=32). The endotoxin group was subdivided into 4 groups by the sampling times as 3, 6, 12 and 24 hr-groups (G- $E_{3,6,12,24,}$ each n=8). The experimental ARDS was made by a bolus injection of endotoxin (Escherichia coli serotype 055 : B5, 0.50 mg/kg) via rabbit ear vein. For evaluation of the hematologic and inflammatory markers, and superoxide dismutase (SOD) concentrations, the blood samples were taken from the heart. The bronchoalveolar lavage fluid (BALF) were obtained for analysis of the leukocytes and protein concentration. With biopsy of the lung, histopathologic changes of the lung were also evaluated. Result: In the endotoxin groups, significant leukopenia (owing to pancytopenia) occurred in 3 and 6-hr groups, which was followed by significant leukocytosis (owing to neutrophilia) in the 12 and 24-hr groups (p<0.05). Serum levels of tumor necrosis factor-$\alpha$ (TNF-$\alpha$) and interleukin-1 $\beta$ (IL-1 $\beta$) in the endotoxin groups were higher than those of control group (p<0.05). Serum levels of superoxide dismutase (SOD) of G- $E_{3}$ and G- $E_{6}$ were higher than those of control group, whereas those of G- $E_{12}$ were lower than those of control groups (p<0.05). Total leukocyte counts and protein con-centrations in BALF were significantly elevated in the endotoxin groups compared to the control group (p < 0.05). The hemorrhagic pattern of BALF showed occurred in the endotoxin groups. The endotoxin groups (in G- $E_{6}$) had severe infiltration of inflammatory cells (lymphocyte and monocyte) in the pulmonary interstitium and parenchyma, migrations of neutrophil and eosinophil into alveolar spaces and interstitial widening, which are the evidences of acute lung injury. In the endotoxin groups, there were significant positive correlations between the BALF findings and the immunologic markers (TNF-$\alpha$, IL-1$\beta$, SOD) (p<0.05). Conclusion: Severe acute lung injury occurred in all the endotoxin-treated rabbits. The pathophysiologic findings were so progressive until 6-hr by time dependant pattern, and then recovered slowly, Variable hematologic, immuno-logic, and pathologic factors were well correlated in the development and progression of endoxin-induced lung injury. The pathophysiologic responses were sensitive and rapid in young rabbit Young rabbit seemed to be a useful experimental animal model for infant and childhood groups.roups.

• The Journal of Korean Academy of Prosthodontics
• /
• v.52 no.4
• /
• pp.305-311
• /
• 2014

Purpose: When the full veneer crown was treated in the tooth with abfraction lesion due to various causes, the prognosis of it may be compromised according to the location of the finish line, but there is few study about the location of its buccal finish line. The purpose of this study was to investigate the effect of location of the finish line of the full veneer crown on stress distribution of the tooth with abfraction lesion. Materials and methods: The two dimensional finite element model was developed to express tooth, surrounding tissue and full veneer crown. The stress distribution under eccentric 144 N occlusal load was analyzed using finite element analysis. The location of finish line was set just at the lower border of the lesion (Group 0), 1 mm (Group 1) and 2 mm (Group 2) below the lower border of the lesion. Results: In the Group 0, von Mises stress was concentrated at the finish line and the apex of the lesion. Also, the stress at the bucal finish line propagated to the lingual side. In the Group 1 and Group 2, stress distribution was similar each other. Stress was concentrated at the apex of lesion, but the stress at the buccal finish line did not propagate to the lingual side. That implied decrease of the possibility of horizontal crown fracture. Conclusion: Full veneer crown alleviated the stress concentrated at the apex of the abfraction lesion, when the finish line of full veneer crown was set below the lower border of abfraction lesion.

• Journal of Chest Surgery
• /
• v.36 no.7
• /
• pp.489-496
• /
• 2003

To clarify the prognostic implication of the location and number of the metastatic mediastinal nodes in resected stage IIIA N2 non-small cell lung cancer. Material and Method: One hundred and seventy-four patients with resected non-small cell lung cancer who eventually proved to have pathologic stage IIIA N2 disease were studied. Patients who received preoperative induction therapy, non-curative operation or defined as operative mortality were excluded from this study. Result: In upper lobe tumors, there was no difference in 5-year survival according to the involvement of lower mediastinal nodes (32.3% vs 25.6%, p＝0.86). In lower lobe tumors, no difference was found in 5-year survival according to the involvement of upper mediastinal nodes (25.1% vs 14.1%, p＝0.33). There was no significant difference in 5-year survival between patients with or without metastatic subcarinal node (20.9% vs 25.6%, p＝0.364). In terms of the number of metastatic mediastinal nodes, 5-year survival was better in single station group (26.3%) than multiple station group (18.3%) (p＝0.048). In multiple station N2 group, the patients who received postoperative chemotherapy and radiation therapy had better 5-year survival (34.2%) (p＝0.01). Cox's proportional hazards model revealed that the age $\geq$60 (O.R: 1.682, p＝.006), multiple station N2 (O.R: 1.503. p＝0.021), pneumonectomy (O.R: 1.562, p＝0.018), postoperative chemotherapy and radiation therapy (O.R: 0.625, p＝0.012) were the factors affecting the postoperative survival. Conclusion: Multiple station N2 disease was the important prognostic factor for postoperative survival in resected stage IIIA N2 non-small cell lung cancer. Postoperative chemotherapy and radiotherapy were thought to improve the survival in case of multiple station N2 disease.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.1
• /
• pp.33-39
• /
• 2013

Menopause is often associated with several chronic diseases, including osteoporosis, cardiovascular disease, and obesity. In this study, we investigated the ability of Eisenia bicyclis (EB) to prevent bone loss in ovariectomized rats, a model for postmenopausal osteoporosis. Extracts from EB obtained using ethanol or hot water were analyzed for total polyphenol content and osteoporosis effects in vivo. Total polyphenol content was higher with extraction by hot water compared to ethanol extraction. Fifty 8-week-old female Sprague-Dawley rats were randomly assigned to four groups: the group were sham-operated rats (SHAM), ovariectomized rats (OVX-CON), and ovariectomized rats that were treated with EB at 50 mg/kg body weight (OVX-EB50) and 200 mg/kg body weight (OVX-EB200), respectively. The diets were fed to rats for 6 weeks after their operation. We found that the alkaline phosphatase (ALP) activity was lower in the EB extract group compared to the OVX-CON group. Collagen and pyridinoline content, in bone and cartilage, were reduced by ovariectomy, but the supplemented EB extract groups exhibited higher concentrations in their bones. These results suggest that EB can be used for the industrial development of foods with therapeutic functions.

• Journal of Chest Surgery
• /
• v.9 no.1
• /
• pp.1-9
• /
• 1976

The present. study reports four cases of congenital heart diseases, who received open heart surgery by the Sarn's Heart-Lung-Machine in the department of Thoracic Surgery, Hanyang University Hospital during the period between July 1975 and May 1976. The Heart-Lung-Machine consisted of the Sarn's five head roller pump motor system (model 5000), heat exchanger, bubble trap, the Rygg-Kyvsgaard oxygenator, and monitors. The priming of pump oxygenator was carried out by the hemodilution method using Hartman's solution and whole blood. Of the four cases of the heart diseases, three whose body weight were below 30kg, received the partial hemodilution priming and the remaining one whose body weight was 52kg received the total hemodilution priming with Hartman's solution alone. The rate of hemodilution was in the average of 60.5ml/kg. Extracorporeal circulation was performed at the perfusion flow rate of the average 94.0ml/kg/min, and at the moderate hypothermia between 35'5"C and 30'5"C of the rectal temperature. In the total cardiopulmonary bypass, arterial blood pressure was anged between 30 mmHg and 85 mmHg, generally maintaining over 60 mmHg and venous pressure was measured between 4 and $23cmH_2O$, generally maintaining below $10cmH_2O$. The first case: The patient, a nine year old girl having the symptoms and physical signs typical to cardiac anomaly was definitely diagnosed as isolated pulmonary stenosis through the cardiac catheterization. There was, however, no cyanosis, no pathological finding by X-ray and E.C.G. tracings. The valvulotomy was performed through the arteriotomy of pulmouary artery under the total cardiopulmonary bypass. Postoperative course of the patient was uneventful, and murmur and the clinical symptoms disappeared. The second case: A 12 year old boy with congenital heart anomaly was positively identified as having ventricular septal defect through the cardiac catheterization. As in the case with the first case, the patient exhibited the symptoms and physical signs typical to cardiac anomaly, but no pathological abnormality by X-ray and E.C.G. tracings. The septal defect was localized on atrioventricular canal and was 2 by 10 mm in size. The septal defect was closed by direct simple sutures under the cardiopulmonary bypass. Postoperative hemodynamic study revealed that the pressure of the right ventricle and pulmonary artery were decreased satisfactory. Postoperative course of the patient was uneventful, and murmur and the clinical symptoms disappeared. The third case: The patient, a 19 year old girl had been experienced the clinical symptoms typical to cardiac anomaly for 16 years. The pink tetralogy of Fallot was definitey diagnosed through the cardiac catheterization. The patient was placed on an ablolute bed rest prior to the operation because of severe exertional dyspnea, fatigability, and frequent syncopal attacks. However, she exhibited very slight cyanosis. Positive findings were noted on E.C.G. tracings and blood picture, but no evidence of pathological abnormality on X-ray was observed. All of the four surgical approaches such as Teflon patch closure (3 by 4cm in size) of ventricular septal defect, myocardial resection of right ventricular outflow tract, valvulotomy of pulmonary valvular stenosis, and pericardial patch closing of ventriculotomy wound were performed in 95 minutes under the cardiopulmonary bypass. Postoperative hemodynamic study revealed that the pressure of the right ventricle was decreased and pulmonary artery was increased satisfactorily. Postoperative course of the patient was uneventful, and murmur and the clinical symptoms disappeared. The fourth case: The patient, a 7 1/4 year old girl had the symptoms of cardiac anomaly for only three years prior to the operation. She was positively identified as having acyanotic tetralogy of Fallot by open heart surgery. The patient showed positive findings by X-ray and E.C.G. tracings, but exhibited no cyanosis and normal blood picture. All of the three surgical approaches, such a myocardial resection of hypertrophic sight ventricular outflow tract, direct suture closing of ventricular septal defect and pericardial patch closing of ventriculotomy wound were carried out in 110 minutes under the cardiopulmonary bypass. Postoperative hemodynamic study revealed that the pressure of the right ventricle was decreased and pulmonary artery was increased satisfactorily. Postoperative course of the patient was uneventful, and the symptoms disappeared.

• Journal of Chest Surgery
• /
• v.34 no.11
• /
• pp.823-830
• /
• 2001

Background: Paraplegia is a serious complication of thoracic or thoracoabdominal aortic operations, which is related to ischemic injury of the spinal cord induced by low perfusion pressure during cross clamping of the aorta. Ischemic preconditioning of heart or brain with reversible sublethal ischemic injury induces resistance to subsequent lethal ischemia. The aim of this study is to investigate whether ischemic tolerance could be induced by the preconditioning of the spinal cord using swine model. Material and Method: The animals were randomly assigned to three groups: sham group(n=3), control group(n=6) and pre-conditioning group(n=8). In the sham group, we performed the left thoracotomy only without any ischemic injury. In the preconditioning group, the swine received reversible spinal cord ischemic injury by aortic clamping for 20 minutes, whereas control group had no previous aortic cross- clamping. Forty-eight hours later, the aorta was clamped for 30 minutes in both groups. Neurological examination was done 24 hours later, then the animals were euthanized for histopathology and malonedialdehyde(MDA) spectrophotometry assay of the spinal cord. Result: Statistically significant difference in neurological outcome was observed between the control and preconditioning groups at 24 hours after ischemic injury. The incidence of paraplegia and severe paresis was 100% in the control group, and 62.5% in the preconditing group(p=0.028). There was no statistically significant difference in histopathology and MDA assay of the ischemic spinal cord between these two groups with borderline statistical difference in MDA assay(p=0.0745). Conclusion: In the present swine study, ischemic preconditioning could induce tolerance against 30 minute ischemic insult of the spinal cord, although the animals did not completely recover(stand-up or walk). We expect that combining this preconditioning with other currently existing protection methods might lead to a synergistic effect, which warrants further investigation.

• Journal of Chest Surgery
• /
• v.32 no.7
• /
• pp.637-647
• /
• 1999

Background: Ischemia-reperfusion injury is one of the major contributing causes of early graft failure in lung transplantation. It has been suggested that triiodothyronine (T3) may ameliorate ischemia-reperfusion injury to various organs in vivo and in vitro. Predicting its beneficial effect for ischemic lung injury, we set out to demonstrate it by administering T3 into the in situ canine ischemia-reperfusion model. Material and Method: Sixteen adult mongrel dogs were randomly allocated into group A and B. T3 $(3.6\mug/kg)$ was administered before the initiation of single lung ischemia in group B, whereas the same amount of saline was administered in group A. Ischemia was induced in the left lung by clamping the left hilum for 100 minutes. After reperfusion, various hemodynamic parameters and blood gases were analyzed for 4 hours while intermittently clamping the right hilum in order to allow observation of the injured left lung function. Result: Arterial oxygen partial pressure $(PaO_2)$ decreased 30 minutes after reperfusion and recovered gradually thereafter in both groups. In group B the decrease of $PaO_2$ was less marked than in group A. The recovery of $PaO_2$ was faster in group B than in group A. The differences between the two groups were statistically significant from 30 minutes after reperfusion $(125\pm34$ mmHg and $252\pm44$ mmHg, p<0.05) until the end of the experiment $(178\pm42$mmHg and $330\pm37$ mmHg, p<0.05). The differences in the arterial carbon dioxide pressure, airway pressure and lung compliance showed no statistical significance. The malondialdehyde (MDA) level, measured from the tissue obtained 240 minutes after reperfusion, was lower in group B $(0.40\pm0.04\mu$M) than in group A $(0.53\pm0.05\mu$M, p<0.05). The ATP level of group B $(0.69\pm0.07\mu$M/g) was significantly higher than that of group A $(0.48\pm0.07\mu$M/g, p<0.05). The microscopic exami nation revealed varying degrees of injury such as perivascular neutrophil infiltration, capillary hemorrhage and interstitial congestion. There were no differences in the microscopic findings between the two groups. CONCLUSION T3 has beneficial effects on the ischemic canine lung injury including preservation of oxygenation capacity, less production of lipid peroxidation products and a higher level of tissue ATP. These results suggest that T3 is effective in pulmonary allograft preservation.

• Journal of Chest Surgery
• /
• v.32 no.5
• /
• pp.413-421
• /
• 1999

Background: Ischemia reperfusion injury is known to contribute to the major causes of the early graft failure in lung transplantation. Triiodothyronine (T3) has been suggested to ameliorate ischemia reperfusion injury from both in vivo and in vitro experiments of various organs. Prospecting its beneficial effect for pulmonary allograft preservation, we made a new solution by adding T3 into the extracellular type dextran solution. Material and Method: Twelve adult mongrel dogs underwent left lung allotransplantation. Six donor dogs were flushed with the new solution(Group 1, n=6), and the remaining six were flushed with Euro-Collins solution to serve as controls(Group 2, n=6). Allografts were stored in each preservation solution for 20 hours at 4$^{\circ}C$. Left single lung transplantations were performed. The right pulmonary artery and the right main bronchus were clamped at 15 minutes after the reperfusion and maintained throughout the experiment to evaluate the transplanted left lung function. Result: Arterial carbon dioxide tension was better in group 1 than in group 2 throughout the experiment period and the difference was statistically significant at 2 hours after reperfusion(28.0${\pm}$3.0 mmHg and 53.1${\pm}$17.4 mmHg, p<0.05). The differences of arterial oxygen partial pressure, peak airway pressure and pulmonary vascular resistance showed no statistical significance. The malondialdehyde(MDA) level, measured from tissue obtained at 120 minutes after reperfusion showed no statistically significant difference. The tissue wet/dry ratio of group 1(649${\pm}$27 %) was significantly lower than that of group 2(686${\pm}$71 %, p<0.05). The microscopic examination revealed varying degrees of injury represented mainly by findings such as perivascular neutrophil infiltration, capillary hemorrhage and interstitial congestion. These findings were less severe in group 1 than those in group 2. Conclusion: The new solution demonstrated superior allograft preservation after 20 hour ischemia compared to Euro-Collins solution in canine single left lung transplantation model, these results suggest that T3 might be a promising agent for pulmonary allograft preservation.