• Proceedings of the Korea Society of Poultry Science Conference
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• 2002.11a
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• pp.64-84
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• 2002

These studies were conducted to evaluate the Properties of lactic acid Producing bacteria(LAB), isolated from broiler and laying hens cecum and select the optimum strains to improve the performance, environment of poultry house, immunity, and intestinal microflora of broiler and laying hens. In experiment I , 23 LAB strains were isolated from broiler and laying hens cecum as a colony form. Six strains were selected by acid tolerance, bile salt tolerance, viability, enzyme release, antagonism, and antibiotics susceptibility. In Experiment II, selected LABs from Ex. 1 were conducted to investigate the effects of feeding various Lactobacillus on performance, nutrients digestibility, intestinal microflora, villi development and observation of epithelium surface, blood chemicals and fecal noxious gas of broiler chicks. One thousand eighty one day old broiler chicks were fed into Lactobacillus crispatus avibrol(LCB), Lactobacillus reuteri avibro2(LRB), Lactobacillus crispatus avihen1(LCH), and Lactobacillus vaginalis avihen2(LVH) at the level of 10$^4$ and 10$\^$7/cfu/g diet. Weight gam of chicks fed Lactobacillus tended to increase from the first week and was higher from 50 to 100g in Lactobacillus treatments than control. Feed intake and feed conversion were not statistically different of all treatments. Dry Matter digestibility of Lactobacillus treatments was prone to improve compared to that of control, but was not significantly different. Protein and Ca digestibility were also tended to improve in Lactobacillus treatments relative that of control. Lactobacillus treatments showed improved tendency in crude ash and fat compared to those of control, whereas phosphorus digestibility was not consistency. Nutrients digestibilities of bird fed LCH were superior to those of other treatments, It showed significantly higher in Ca and P digestibility than control(P〈0.05). Total Lactobacillus spp. of birds fed various Lactobacillus was significantly higher in illeum for five weeks(P〈0.05), but was not different at cecum. Yeast was thought to be not completely attached to intestinal lumen for one week. However, total number of yeast was significantly increased in cecum and illeum of three weeks old chicks (P〈0.05). The number of anaerobes exhibited to tendency the increase in Lactobacillus treatments from one week old of age at both ileum and cecum.

• Journal of the Korean Wood Science and Technology
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• v.2 no.3
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• pp.3-16
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• 1974

One of the disadvantages of. wood and wood products is their hydroscopicity or dimensional instability. This is responsible for the loss of green volume of lumber as seasoning degrade. Dimensional stabilization is needed to substantially reduce seasoning defects and degrades and for increasing the serviceability of wood products. Recently, considerable world-wide attention has been drawn to the so-called Wood-Plastic Composites by irradiation-and heat-catalyst-polymerization methods and many research and developmental works have been reported. Wood-Plastic Composites are the new products having the superior mechanical and physical properties and the combinated characteristics of wood and plastic. The purpose of this experiment was to obtain the basic data for the improvement of wooden materials by manufacturing WPC. The species examined were Mulpurae-Namoo (Fraxinus, rhynchophylla), Sea-Namoo (Carpinus laxiflora), Cheungcheung-Namoo (Cornus controversa), Gorosae-Namoo (Acermono), Karae-Namoo(Juglans mandshurica) and Sanbud-Namoo (Prunus sargentii), used as blocks of type A ($3{\times}3{\times}40cm$) and type B ($5{\times}5{\times}60cm$), and were conditioned to about 10~11% moisture content before impregnation in materials humidity control room. Methyl methacrylate (MMA) as monomer and benzoyl peroxide (BPO) as initiator are used. The monomer containing BPO was impregnated into wood pieces in the vacuum system. After impregnation, the treated samples were polymerized with heat-catalyst methods. The immersed weights of monomer in woods are directly proportionated to the impregnation times. Monomer impregnation properties of Cheungcheung-Namoo, Mulpurae-Namoo and Seo-Namoo are relatively good, but in Karae-Namoo, it is very difficult to impregnate the monomer MMA. Fig. 3 shows the linear relation between polymer retentions in wood and polymerization times; that is, the polymer loadings are increasing with polymerization times. Furthermore species, moisture content, specific gravity and anatomical or conductible structure of wood, bulking solvents and monomers etc have effects on both of impregnation of monomer and polymer retention. Physical properties of treated materials are shown in table 3. Increasing rates of specific gravity are ranged 3 to 24% and volume swelling 3 to 10%. ASE is 20 to 46%, AE 14 to 50% and RWA 18 to 40%. Especially, the ASE in relation to absorption of liquid water increases approximately with increase of polymer content, although the bulking effect of the polymerization of monomer may also be influential. WPCs from Mulpurae-Namoo and Cheungcheung-Namoo have high dimensional stability, while its of Karae-Namoo and Seo-Namoo are-very low. Table 4 shows the mechanical properties of WPCs from 6 species. With its specific gravity and polymer loading increase, all mechanical properties are on the increase. Increasing rate of bending strength is 10 to 40%, compression strength 25 to 70%, ;impact bending absorbed energy 4 to 74% and tensile strength 18 to 56%. Mulpurae-Namoo and Cheungcheung-Namoo with high polymer content have considerable high increasing rate of strengths. But incase of Karae-Namoo with inferior monomer impregnation it is very low. Polymer retention in cell wall is 0.32 to 0.70%. Most of the polymer is accumulated in cell lumen. Effective. of polymer retention is 58.59% for Mulpurae-Namoo, 26.27% for Seo-Namoo, 47.98% for Cheungcheung-Namoo, 25.64% for Korosae-Namoo, 9.96% for Karae-Namoo and 25.84% for Sanbud-Namoo.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.6
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• pp.465-473
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• 2004

Purpose : The essential triad for nerve regeneration is nerve conduit, supporting cell and neurotrophic factor. In order to improve the peripheral nerve regeneration, we used polyglycolic acid(PGA) tube and brain-derived neurotrophic factor(BDNF) gene transfected Schwann cells in sciatic nerve defects of SD rat. Materials and methods : Nerve conduits were made with PGA sheet and outer surface was coated with poly(lactic-co-glycolic acid) for mechanical strength and control the resorption rate. The diameter of conduit was 1.8mm and the length was 17mm Schwann cells were harvested from dorsal root ganglion(DRG) of SD rat aged 1 day. Schwann cells were cultured on the PGA sheet to test the biocompatibility adhesion of Schwann cell. Human BDNF gene was obtained from cDNA library and amplified using PCR. BDNF gene was inserted into E1 deleted region of adenovirus shuttle vector, pAACCMVpARS. BDNF-adenovirus was multiplied in 293 cells and purified. The BDNF-Adenovirus was then infected to the cultured Schwann cells. Left sciatic nerve of SD rat (250g weighing) was exposed and 14mm defects were made. After bridging the defect with PGA conduit, culture medium(MEM), Schwann cells or BDNF-Adenovirus infected Schwann cells were injected into the lumen of conduit, respectively. 12 weeks after operation, gait analysis for sciatic function index, electrophysiology and histomorphometry was performed. Results : Cultured Schwann cells were well adhered to PGA sheet. Sciatic index of BDNF transfected group was $-53.66{\pm}13.43$ which was the best among three groups. The threshold of compound action potential was between 800 to $1000{\mu}A$ in experimental groups which is about 10 times higher than normal sciatic nerve. Conduction velocity and peak voltage of action potential of BDNF group was the highest among experimental groups. The myelin thickness and axonal density of BDNF group was significantly greater than the other groups. Conclusion : BDNF gene transfected Schwann cells could regenerate the sciatic nerve gap(14mm) of rat successfully.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.115-121
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• 2008

Purpose: Aortic Dissection is very dangerous, prognostic disease, which the bloodstream flow out of the true lumen of the aorta by the bursting of aortic intima resulting in a rapid dissociation of inner and outer layer from the media. It is difficult to diagnose aortic dissection clinically by normal X-ray. This study was to investigate the occurrence frequency by age and number of patients who are identified to be aortic dissection by CT (Computed Tomography) scan. Materials and methods: We investigated the trend of yearly fluctuation, gender, age, and department of clinical research of the 112 patients who conducted CT scan in C- University Hospital for two years from January 2005 to December 2006. The MIP and SSD which reconstructed CT image and the VRT image were obtained for the accurate observation. The result was investigated by comparing normal X-ray and CT scan. Results and Conclusion: 1. The yearly check of 112 patients conducted CT scan showed 37 people (41.9%) in 2005, and it was increased to 65 (58.1%) in 2006 by 1.4 times. 2. The gender distribution of patients given a CT scan showed 45 males (40.1%), and female 67 (59.9 %). The aortic dissection patients were 9 (20%) out of 45 males, 21 (31.3%) out of 67 females and women were 1.6 times more than men. Women are also 1.5 times more than men in the number of examinee. 3. The age distribution of patient's who conducted CT scan revealed that there was no patient under 30 years old while 88.3% of all patients were through 41 to 80 years old. The higher the age was, the higher the occurrence of aortic dissection was. The difference in the occurrence frequency of age was statistically significant (p<0.01). 4. The departments that requested CT scan were the emergency department 46 (41.1%), circulatory internal medicine 37 (33.0%), chest surgery 13 (11.6%), and others 6 (14.3%). The combined ratio of emergency medicine and circulatory internal medicine was 74.1% of all. The results show that the aortic dissection is a very dangerous disease whose patients visit mainly via the emergency room. 5. The aortic dissection patients had normal X-ray readings in 22 (73.3%) out of 30, and only 8 (26.7 percent) are abnormal in the X-ray diagnosis. Therefore, the CT scan needs to be enforced in order to assess accurately the disease of aortic dissection.

• Journal of Chest Surgery
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• v.31 no.8
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• pp.739-748
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• 1998

Background: It has been well documented that transient occlusion of the coronary artery causes myocardial ischemia and finally cell death when ischemia is sustained for more than 20 minutes. Extensive studies have revealed that ischemic myocardium cannot recover without reperfusion by adequate restoration of blood flow, however, reperfusion can cause long-lasting cardiac dysfunction and aggravation of structural damage. The author therefore attempted to examine the effect of postischemic reperfusion on myocardial ultrastructure and to determine the rationales for recanalization therapy to salvage ischemic myocardium. Materials and methods: Young Holstein-Friesian cows(130∼140 Kg body weight; n=40) of both sexes, maintained with nutritionally balanced diet and under constant conditions, were used. The left anterior descending coronary artery(LAD) was occluded by ligation with 4-0 silk snare for 20 minutes and recanalized by release of the ligation under continuous intravenous drip anesthesia with sodium pentobarbital(0.15 mg/Kg/min). Drill biopsies of the risk area (antero-lateral wall) were performed at just on reperfusion(5 minutes), 1-, 2-, 3-, 6-, 12-hours after recanalization, and at 1-hour assist(only with mechanical respiration and fluid replacement) after 12-hour recanalization. The materials were subdivided into subepicardial and subendocardial tissues. Tissue samples were examined with a transmission electron microscope (Philips EM 300) at the accelerating voltage of 60 KeV. Results: After a 20-minute ligation of the LAD, myocytes showed slight to moderate degree of ultrastructural changes including subsarcolemmal bleb formation, loss of nuclear matrix, clumping of chromatin and margination, mitochondrial destruction, and contracture of sarcomeres. However, microvascular structures were relatively well preserved. After 1-hour reperfusion, nuclear and mitochondrial matrices reappeared and intravascular plugging by polymorphonuclear leukocytes or platelets was observed. However, nucleoli and intramitochondrial granules reappeared within 3 hours of reperfusion and a large number of myocytes were recovered progressively within 6 hours of reperfusion. Recovery was apparent in the subepicardial myocytes and there were no distinct changes in the ultrastructure except narrowed lumen of the microvessels in the later period of reperfusion. Conclusions: It is likely that the ischemic myocardium could not be salvaged without adequate restoration of coronary flow and that the microvasculature is more resistant to reversible period of ischemia than subendocardium and subepicardium. Therefore, thrombolysis and/or angioplasty may be a rational method of therapy for coronarogenic myocardial ischemia. However, it may take a relatively longer period of time to recover from ischemic insult and reperfusion injury should be considered.

• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.512-517
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• 2005

Purpose : In adults, endoscopic tracheobronchial balloon dilatation and stenting have become valuable methods to establish and maintain an adequate airway lumen when tracheomalacia or neoplastic growth compromise the airways. But in children, only a few cases were reported due to technical problems. We report six children who were treated with stent implantation and describe the use and safety of airway stents. Methods : Six patients with severe airway obstruction were treated. We investigated the underlying medical problems, stenotic site, symptomatic improvement and complications, and the size and location of stent. Results : The median age of the six patients was 21 months. Three of them were mechanically ventilated and one had an endotracheal tube to maintain the patency of airway. Diagnoses were : congenital tracheal stenosis with or without bronchomalacia, granulation tissue formation after right upper lobectomy by bronchial carcinoid or after prolonged intubation, endobronchial tuberculosis, and airway compression by mediastinal undifferentiated sarcoma. Nitinol stents were implanted in the airway guided by bronchoscopy and fluoroscopy simultaneously. Three cases were placed in trachea, the others were in the bronchus. After stent implantation, all patients showed marked improvements of their airway obstructive symptoms. Four patients are doing well, although two expired due to underlying diseases. Four patients had granulation tissue formation around stents, but that was tolerable after removing the stent. Conclusion : We suggest that the use of expandible metallic stent implantation can offer safe therapeutic option even in extremely severe, life threatening and inoperable airway stenosis in children.

• Clinical and Experimental Pediatrics
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• v.46 no.9
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• pp.876-882
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• 2003

Purpose : To find out the myocardial protective effect of cardioxane for the myocardial damage by doxorubicin. Methods : Using Eighteen rabbits(2.0-3.2 kg), doxorubicin($30mg/m^2$) was injected intravenously once a week in group I(12 rabbits) and cardioxane($600mg/m^2$) was injected at 20-30 minutes before doxorubicin administration in group II(6 rabbits). After this, we operated on the rabbits when the total cumulative dose of doxorubicin was reached at 210, 240, 270 and $300mg/m^2$ and observed the degree of myocardial damage with light and electronic microscope. Results : In group I, rabbits with less than $210mg/m^2$ of total cumulative dose of doxorubicin, there was no definite myocardial damage but with $240mg/m^2$, focal degenerative change was observed and with $300mg/m^2$, severe degenerative change was detected with light microscopic examination. With electronic microscope, rabbits with less than $180mg/m^2$ of total cumulative dose of doxorubicin in group I, there was no evidence of myocardial damage. In $210mg/m^2$, focal degenerative change was detected. With $240mg/m^2$, degenerative change was much more advanced and with $300mg/m^2$, severe degenerative change was detected. In group II, no definite myocardial damage was observed even though the total cumulative dose of doxorubicin reached $300mg/m^2$, but with $360mg/m^2$, there was a focal area where myocardial fibers were somewhat decreased, but it's difficult to say whether these decrement were due to adriamycin in the electronic microscopic examination. Conclusion : Cardioxane have a good protective effect for the doxorubicin induced cardiomyopathy and it will be used safely in pediatric cancer patients.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1119-1126
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• 1998

Background: In this study, we investigated the early time course of expression of the major histocompatibility(MHC) antigens, intercellular adhesion molecule-1(ICAM-1), vascular cell adhesion molecule-1(VCAM-1), interleukin-6 and the histopathological changes in the coronary arteries of cardiac allografts exchanged between inbred mice strains that differ in one loci of class I major histocompatibility antigen (B10.BR to B10.A). Material and Method: No immunosuppressive therapy was used. Both allografts and the hearts of the recipients were harvested at 7(group 1, n=6), 15(group 2, n=6), 21(group 3, n=6), and 30(group 4, n=6) days after transplantation. They were examined by immunohistochemistry, microscopy and morphometry. All allografts had contractions at the time of harvest. Result: A strong MHC class I antigen expression was present on the endothelial and medial cells of the coronary arteries in group 1 and remained unchanged in the rest of the groups. However, MHC class II reactivity was none or very little at any time. Mild to moderate ICAM-1 expression was observed on the endothelial cells, but not on the medial cells at any time by 30 days. VCAM-1 expression was strong both on the endothelial and medial cells at any time. Moderate degree expression of interleukin-6 was observed from 7 to 30 day specimens. Histopathologically, percentage of affected vessels(vessels with intimal thickening) was less than 10 % in 7 day group and increased up to 50 % at 30 days. Mean percent narrowing of the lumen of the affected vessels revealed less than 20 % at 7 days and 40 % at 30 days. The area occupied by tropomyosin positive cells in the intimal lesion, graded from 0 to 3, showed gradual increase but remained between grade 0 to 1 by 30 days. Medial integrity was also well preserved at any time. Moderate perivascular mononuclear cell infiltration was observed at 7 days and it was progressively increased upto 30 days. Recipients' heart revealed no positive immunopathologic findings. Conclusion: In this study, the early time course of progression of the transplantation vasculopathy was demonstrated in the murine heterotopic heart transplant model.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.441-446
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• 2009

Background: Side clamping of ascending aorta during proximal graft anastomosis in coronary bypassing surgery in-creases the risk of direct aortic injury as well as embolization of intimal atheroma. Heartstring proximal sealing system (Guidant Corporation, Santa Clara, Calif), developed to avoid aortic side clamping, may minimize risks of such complications. The aim of the current study is to compare the surgical outcomes of the two proximal anastomosis techniquesi.e., Heartstring system versus aortic side clamping in off pump coronary bypassing' surgery (OPCAB). Material and Method: From January 2003 to August 2008, 499 patients underwent OPCAB. Of them, proximal graft anastomosis was performed using Heartstring system in 182 patients (Group I) and conventional manual anastomosis in 317 patients (Group II). The two groups were compared for postoperative major complications and mortality. Result: Two groups showed similar characteristics in terms of preoperative demographic data, left ventricular ejection fraction, renal function and history of diabetes, hypertension and smoking. Although there was no inter-group difference in the history of cerebral ischemia (p=0.48), preoperative brain magnetic resonance angiography revealed greater incidence of severe carotid artery stenosis (>75% of lumen) in the Group I than in the. Group II (44.5% in the Group I and 30.0% in the Group II, p=0.003). There were no inter-group differences in postoperative mortality (p=0.40) and complications (p=0.47) including neurologic events (3 in the Group land 2 in the Group II, p=0.258). Whereas neurologic events all comprised transient ischemic attacks in the Group I, they comprised multiple embolic strokes in the Group II. One patient in the Group II experienced aortic dissection during proximal anastomosis which resulted in ascending aortic replacement. Conclusion: Although proximal anastomosis using Heartstring system did not show statistically significant benefit over aortic side clamping, the. absence of embolic stroke maybe a definite benefit which may be better defined through further studies over a larger cohort.

• Journal of Life Science
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• v.13 no.5
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• pp.596-603
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• 2003

Cells respond to an accumulation of unfolded proteins in the endoplasmic reticulum (ER) by increasing transcription of genes encoding molecular chaperones and folding enzymes. The information is transmitted from the ER lumen to the nucleus by intracellular signaling pathway, called the unfolded protein response (UPR). To obtain genes related to UPR from B. mori, the cDNA library was constructed with mRNA isolated from Bm5 cell lines in which N-glycosylation was inhibited by tunicamycin treatment. From the cDNA library, we selected 40 clones that differentially expressed when cells were treated with tunicamycin. Among these clones, we have isolated ATFC gene showing similarity with Hac1p, encoding a bZIP transcription factor of 5. cerevisiae. Basic-leucine zipper (bZIP) domain in amino acid sequences of ATFC shared homology with yeast Hac1p. Also, ATFC is up-regulated by accumulation of unfolded proteins in the ER through the treatment of ER stress drugs. Therefore we suggest that ATFC represents a major component of the putative transcription factor responsible for the UPR leading to the induction of ER-localized stress proteins.