• Journal of Chest Surgery
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• v.39 no.11 s.268
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• pp.828-837
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• 2006

Background: Tissue hypoxia is characteristic of many human malignant neoplasm, and hypoxia inducible factor-1(HIF-1) plays a pivotal role in essential adaptive response to hypoxia, and activates a signal pathway for the expression of the hypoxia-regulated genes, resulting in increasing $O_2$ delivery or facilitating metabolic adaptation to hypoxia. Increased level of HIF-$1{\alpha}$ has been reported in many human malignancies, but in non-small cell lung carcinoma the influence of HIF-$1{\alpha}$ on tumor biology, including neovascularization, is not still defined. In present study the relationship of HIF-$1{\alpha}$ expression on angiogenetic factors, relationship between the tumor proliferation and HIF-$1{\alpha}$ expression, interaction of HIF-$1{\alpha}$ expression and p53, and relationship between HIF-$1{\alpha}$ expression and clinico-pathological prognostic parameters were investigated. Material and Method: Archival tissue blocks recruited in this study were retrieved from fifty-nine patients with primary non-small cell lung carcinoma, who underwent pneumonectomy or lobectomy from 1997 to 1999. HIF-$1{\alpha}$, VEGF(vascular endothelial growth factor), and p53 protein expression and Ki-67 labeling index in tumor tissues were evaluated, using a standard avidin-biotin-peroxidase complex(ABC) immunohistochemistry. Relationship between the HIF-$1{\alpha}$ expression and VEGF, p53 overexpression and correlation between the HIF-$1{\alpha}$ expresseion and Ki-67 index were analyzed. Clinico-pathologic prognostic parameters were also analyzed. Result: HIF-$1{\alpha}$ expression in cancer cells was found in 24 of 59 cases of non-small cell lung carcinoma(40.7%). High HIF-$1{\alpha}$ expression was significantly associated with several pathological parameters, such as pathological TMN stage(p=0.004), pT stage(p=0.020), pN stage (p=0.029), and lymphovascular invasion(p=0.019). High HIF-$1{\alpha}$ expression was also significantly associated with VEGF immunoreactivity(p<0.001), and aberrant p53 expression(p=0.040). but was marginally associated with Ki-67 labeling index(p=0.092). The overall 5-year survival rate was 42.3%. The survival curve of patients with a high HIF-$1{\alpha}$ expression was worse than that of patients with low-expression(p=0.002). High HIF-$1{\alpha}$ expression was independent unfavorable factors with a marginal significance in multivariate analysis performed by Cox regression. Conclusion: It is suggested that high HIF-$1{\alpha}$ expression may be associated with intratumoral neovascularization possibly through HIF-VEGF pathway, and high HIF-$1{\alpha}$ expression could be associated with lymph node metastasis and post operative poor prognosis in patients with non-small cell lung carcinoma.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.1
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• pp.31-38
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• 2008

Ad-Hoc network is a network architecture which has no backbone network and is deployed temporarily and rapidly in emergency or war without fixed mobile infrastructures. All communications between network entities are carried in ad-hoc networks over the wireless medium. Due to the radio communications being extremely vulnerable to propagation impairments, connectivity between network nodes is not guaranteed. Therefore, many new algorithms have been studied recently. This study proposes the secondary header approach to the cluster based routing protocol (CBRP). The primary header becomes abnormal status so that the primary header can not participate in the communications between network entities, the secondary header immediately replaces the primary header without selecting process of the new primary header. This improves the routing interruption problem that occurs when a header is moving out from a cluster or in the abnormal status. The performances of proposed algorithm ACBRP(Advanced Cluster Based Routing Protocol) are compared with CBRP. The cost of the primary header reelection of ACBRP is simulated. And results are presented in order to show the effectiveness of the algorithm.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.5 no.2
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• pp.136-142
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• 2002

Purpose: Foreign body swallowing is common in children. Most of foreign bodies passed upper esophagus are removed spontaneously. But recently, therapeutic endoscopy in children is widely used. In this study, we reviewed gastric foreign bodies regarding types, location, interval from swallowing, complications, and treatment or method of removal. Methods: We reviewed medical records of 96 cases with foreign bodies in gastrointestinal tract at Department of Pediatrics in Gyeongsang National University Hospital (GNUH) from Feb 1987 to Feb 2002. Results: The peak age of patients (male=60, female=36) with foreign bodies in gastrointestinal tract was 2 to 5 years of age. Sixty two patients (64.5%) were asymptomatic. The location of foreign bodies in gastrointestinal tract were detected by simple X-ray in eighty one patients (86.0%), barium study (1 case), and gastroduodenoscopy in 37 cases. The most common location was stomach (63.5%). The most common foreign body was coin (41.7%). In thirty seven cases (38.5%), foreign bodies were removed with flexible gastroduodenoscopy. Fifty four patients (56.3%) visited GNUH in 24 hours after swallowing foreign bodies. The long interval (over 24 hours) of swallowing of foreign bodies is related with high frequency of endoscopic removal. Conclusion: The flexible gastroduodenoscopy was effective in diagnosis and removal of foreign bodies. Further studies for indication and validity of endoscopic removal of foreign bodies in upper gastrointestinal tract are needed.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.1
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• pp.22-29
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• 2007

Purpose: Metastatic thyroid cancers with I-131 uptake have been known to show no increase of FDG uptake whereas those without I-131 uptake tend to demonstrate increased uptake on PET. In this study, we evaluated the degree of FDG uptake in primary thyroid cancers of papillary histology before surgery. Material & Methods: Forty FDG PET studies were performed on the patients who had papillary cancer proven by fine needle aspiration. The degree of FDG uptake was visually categorized as positive or negative (positive if the tumor showed discernible FDG; negative if the tumor didn't) and the peak standard uptake value (peak SUV) of the papillary thyroid cancer (PTC) were compared with the size of PTC. Results: The mean size of 26 PTC with positive FDG uptake was $1.9{\pm}1.4\;cm(0.5{\sim}5\;cm)$. In 13 PTC with negative FDG uptake, the mean size of those was $0.5{\pm}0.2\;cm\;(0.2{\sim}0.9\;cm)$. All PTC larger than 1cm ($2.5{\pm}1.4\;cm,\;1{\sim}5\;cm$) have positive FDG uptake (peak $SUV=6.4{\pm}5.7,\;1.7{\sim}22.7$). Among the micropapillary thyroid cancer (microPTC; PTC smaller than 1cm), 8 microPTC show positive FDG uptake(peak $SUV=2.9{\pm}1.3,\;1.7{\sim}5.5$), while 13 microPTC show negative finding(peak $SUV=1.3{\pm}0.2,\;1.1{\sim}1.7$). The size of microPTC with positive FDG uptake is significantly larger than that of microPTC with negative FDG uptake ($0.7{\pm}0.1\;cm$ vs $0.4{\pm}0.2\;cm$, p=0.01). Conclusion: All PTCs larger than 1cm show positive FDG uptake in our study. In other words, thyroid lesions larger than 1cm with negative FDG uptake are unlikely to be PTC. So far, only poorly differentiated thyroid cancers are known to show increased FDG uptake. Our results seem to be contradictory to what is known in the literature. Further study is needed to understand better the significance of increased FDG uptake in PTC in relation to expression of NIS and GLUT.

• Journal of Chest Surgery
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• v.34 no.9
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• pp.662-671
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• 2001

Background: This study was aimed to assess improvement in myocardial perfusion after TMR by measuring regional myocardial blood flow(RMBF) in porcine model of chronic myocardial ischemia. Material and Method: Ameroid ring was placed around the proximal left circumflex coronary artery in fourteen pigs. After 4 weeks, the control group(7 pigs) underwent rethoracotomy only, and the TMR group(7 pigs) underwent Ho:YAG laser TMR at the circumflex territory. After another 4 weeks, the animals were sacrificed for the measurement of RMBF using colored microspheres. The ratio of RMBF between the circumflex territory and the interventricular septum was calculated and compared. Result: At 4 weeks after ameroid constriction, RMBF of the circumflex territory decreased to 46∼89% of RMBF of the interventricular septum. In five of six animals in the TMR group, RMBF of the circumflex territory at 8 weeks after ameroid constriction was higher compared with RMBF at 4 weeks after ameroid constriction. However, the improvement was statistically significant only in two animals. In three of the four animals in the control group, RMBF of the circumflex territory also increased at 8 weeks compared with RMBF at 4 weeks. The degree of increase in RMBF was not different between the control and the TMR groups. Conclusion: In porcine model of chronic myocardial ischemia, the degree of increase in RMBF of the ischemic area after Ho:YAG TMR was not different from the increase by development of native collateral circulation. Perfusion of ischemic myocardium after TMR is not thought to improve to the degree that can be demonstrated by currently available method of assessment such as radioisotope myocardial scintigraphy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.6
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• pp.783-788
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• 2016

Excessive intake of trans fats is a risk factor for cardiovascular diseases. Previously, we showed that green tea extract lowers intestinal absorption of cholesterol and elaidic acid in rats. This study was conducted to investigate a possible role for sorghum extract on lymphatic absorption of trans fat and cholesterol in rats. Adult male rats with lymph cannulae were infused at a rate of 3.0 mL/h for 8 h via a duodenal catheter with a lipid emulsion containing $146.4{\mu}mol$ of trielaidin, $36.8{\mu}mol$ of trilinoelaidin, $452.0{\mu}mol$ of triolein, $1.0{\mu}Ci$ cholesterol labeled with $^{14}C$ ($^{14}C-cholesterol$), $20.7{\mu}mol$ of cholesterol, and $396.0{\mu}mol$ of Na-taurocholate without or with 100.0 mg of sorghum extract in phosphate-buffered saline buffer (pH 6.4). Lymph was collected hourly for 8 h. No significant difference was noted in lymph flow. However, the lymphatic absorption of elaidic acid and linoelaidic acid for 8 h was significantly lower in rats infused with sorghum extract than in those infused with no sorghum extract. Further, lymphatic absorption of $^{14}C-cholesterol$ was reduced by sorghum extract, which was observed previously. These data indicate that sorghum extract has an inhibitory effect on the intestinal absorption of trans fat and cholesterol. The mechanism(s) by which sorghum extract lowers intestinal absorption of trans fat warrants further study.

• Radiation Oncology Journal
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• v.12 no.1
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• pp.1-8
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• 1994

When cells are exposed to low doses of a mutagenic or clastogenic agents. they often become less sensitive to the effects of a higher dose administered subsequently. Such adaptive responses were first described in Escherichia coli and mammalian cells to low doses of an alkylating agent. Since most of the studies have been carried out with human lymphocytes, it is urgently necessary to study this effect in different cellular systems. Its relation with inherent cellular radiosensitivity and underlying mechanism also remain to be answered. In this study, adaptive response by 1 cGy of gamma rays was investigated in three human lymphoblastoid cell lines which were derived from ataxia telangiectasia homozygote, ataxia telangiectasia heterozygote, and normal individual. Experiments were carried out by delivering 1 cGy followed by 50 cGy of gamma radiation and chromatid breaks were scored as an endpoint. The results indicate that prior exposure to 1 cGy of gamma rays reduces the number of chromatid breaks induced by subsequent higher dose (50 cGy), The expression of this adaptive response was similar among three cell lines despite of their different radiosensitivity. When 3-aminobenzamide, an inhibitor of poly (ADP-ribose) polymerase, was added after 50 cGy, adaptive responses were abolished in all the tested cell lines. Therefore it is suggested that the adaptive response can be observed in human lymphoblastoid cell lines, which was first documented through this study. The expression of adaptive response was similar among the cell lines regardless of their radiosensitivity. The elimination of the adaptive response by 3-aminobenzamide is consistent with the proposal that this adaptive response is the result of the induction of a certain chromosomal repair mechanism.

• Journal of Veterinary Clinics
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• v.22 no.1
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• pp.16-20
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• 2005

The purpose of this study was to compare the antiangiogenic effects of As₄O/sub 6/ to those of As₂O₃ on the rat corneal micropocket model induced by VEGF. 20 ng VEGF impregnated pellets were used for angiogenic inducer on the rat cornea micropocket assay in this study. After ophthalmoscopic examination, Sprague-Dawley rats with normal cornea were implanted VEGF pellet. Total 60 eyes were used in this study. Control group only received VEGF pellet, As₂O₃ group followed oral administration of As₂O₃ at a dose of 50 mg/kg per day after VEGF pellet implantation and As₄O/sub 6/ group followed oral administration of As₄O/sub 6/ at a dose of 50 mg/kg per day after VEGF pellet implantation were classified. The eyes were examined under a surgical microscope daily on postoperative from day 3 to day 9 after pellet implantation. The number, length, clock hour of vascularization, and area of vessels in As₄O/sub 6/ group were significantly less evident than those of control group and As₂O₃ group (P < 0.05). In conclusion, As₄O/sub 6/ had better antiangiogenic effects on the new vessel induced by VEGF in the rat cornea.

• Journal of the Korean Regional Science Association
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• v.34 no.2
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• pp.3-19
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• 2018

The objective of this study is to observe the efficiency of clinical performance on the supply and demand of medical resources in Korea. For the empirical analysis, we constructed the dataset on age standardized mortality rate, the number of physician, specialist, surgery, medical institution, ratio of general hospitals of 16 provinces in Korea from 2006 to 2013. The panel probability frontier model is employed as an analysis method and considered heteroscedasticity and autocorrelation of the error in panel data. In addition, the demographic and socioeconomic characteristics of the 16 provinces, unemployment rate, elderly population ratio, GRDP per capita, and ratio of hospitals in comparison to the general hospitals are used to find the effect on the technical efficiency of clinical performance on supply and demand of medical resources. The results are as follows. First, for the clinical performance, the supply side of human resources such as doctors and specialists and the demand side factors such as chronic illness clinic per unit population have a significant influence, respectively. Second, the technical efficiency of clinical performance on the supply and demand of medical resources of each input component was 59-70% in terms of clinical efficiency in each region. Third. estimates of technical efficiency of inputs that affect clinical performance showed a slight increase in all regions during the analysis period, but the increase trend decreased slightly. Fourth, the ratio of the elderly population and GRDP per capita have a positive influence on the technical efficiency of clinical performance on the supply and demand of medical resources. The difference of each efficiency by region is due to the regional differences of the input medical resources and the combination of them and the demographic and socioeconomic characteristics of the region. It is understood that the differences in technological efficiency due to the complexity of supply and demand of medical resources, demographic structure and economic difference affecting clinical performance by region are different.

• Tuberculosis and Respiratory Diseases
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• v.50 no.2
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• pp.205-212
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• 2001

Background : The information on nasal transport and the metabolism of peptides have been obtained from pharmacokinetic investigations in experimental animals. However, there are no transport and metabolic studies of human nasal epithelial cells. In this study, the permeability characteristics and the metabolic properties of in vitro human nasal cell monolayers were investigated. Material and Methods : Normal human inferior nasal conchal tissue samples were obtained from patients undergoing endoscopic nasal cavitary surgery. The specimens were cultured in a transwell using an air-liquid Interface (ALI) culture, and the transepithelial electrical resistance (TEER) value of the blank filter and confluent cell monolayers were measured. To determine the % leakage of mannitol, $4{\mu}mol%$ $^{14}C$-labelled mannitol was added and the % leakage was measured every 10 minute for 1 hour. Result : Human nasal epithelial cells in the primary culture grew to a confluent monolayer within 7 days and expressed microvilli. The tight junction between the cells was confirmed by transmission electron microscopy. The TEER value of the blank filter, fifth day and seventh day reached $108.5\;ohm.cm^2$, $141\;ohm.cm^2$ and $177.5\;ohm.cm^2$, respectively. Transcellular % leakage of the $^{14}$-mannitol at 10, 20, 30, 40, 50 and 60 minutes was $35.67{\pm}5.43$, $34.42{\pm}5.60$, $32.75{\pm}5.71$, $31.76{\pm}4.22$, $30.96{\pm}3.49$ and $29.60{\pm}3.68\;%$, respectively. Conclusion : The human nasal epithelial monolayer using ALI culture techniques is suitable for a transcellular permeability study. The data suggests that human nasal epithelial cells In an ALI culture technique shows some promise for a nasal transport and metabolism study.