• The Journal of Natural Sciences
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• v.14 no.1
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• pp.83-121
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• 2004

This study was carried out to examine how solid the production foundation of rice in Chung-Nam Province is, and, if not, to probe alternative measures through the size of farms specializing in rice, of which direction would be a pivot of rice industry-oriented policy. The results obtained can be summarized as follows : 1. The amount of rice production in Chung-Nam Province is highest in Korea and the size of paddy field area is the second largest : This implying that the probability that rice production in Chung-Nam Province would be severely influenced by a global trend of market conditions. The number of farms specializing in rice becoming the core group of rice farming account for 7.7 percent of the total number of farm household in Korea. Average field area financial support which had been input to farm household by Government had a noticeable effect on the improvement of the policy of farm-size program. 2. Farm-size program in Chung-Nam Province established from 1980 to 2002 in creased the cultivation size of paddy field to 19,484 hectares, and this program enhanced the buying and selling of farmland and the number of farmland bargain reached 6,431 household and 16,517 hectares, respectively, in 1995-2002. Meanwhile, long-term letting and hiring of farmland appeared so active that the bargain acreage reached 6,970 hectares, and farm involved was 7,059 households, however, the farm-exchange-and-unity program did not satisfy our expectation, because the retirement farm operators reluctantly participated to sell their farms. Another reason that had delayed the bargain of farms rested on the general category of social complication attendant upon the exchange and unity operation for scattered farm. Such difficulties would work negative effects out to carry on the target of farm-size work in general. 3. The following measures were presented to propel the farm-size promotion program : a. Occupation shift project, followed by the social security program for retirement and elderly farm operators, should be promptly established and also a number of types of incentives for promoting the letting and hiring work and farm-exchange-and-unity program would also be set up. b. To establish the effective key system of rice production, all the farm operators should increase the unit area yield of rice and lower the production cost. To do so, a great deal of production teams of rice equipped with managerial techniques and capabilities need to be organized. And, also, there should be appropriate arrays of facilities including information system. This plan is desirable to be in line with a diversity of the structural implement of regional integration based on farm system building. c. To extend the size of farm and to improve farm management, we have to devise the enlargement of individual size of farm for maximized management and the utilization of farm-size grouping method. In conclusion, it can be said that the farm-size project in Chung-Nam Province which has continued since the 1980s was satisfactorily achieved. However, we still have a lot of problems to be solved to break down the barrier for attainment of the desirable farm-size operation work.. Farm-size project has fairly close relation with farm specialization in rice and, thus, the positive support for farm household including the integrated program for both retirement farmers and off-farm operators should be considered to pursue the progressive development of the farm-size program, which is key means to successful achievement of rice farming enforcement in Chung-Nam Province.

• Korean journal of applied entomology
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• v.14 no.3 s.24
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• pp.97-109
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• 1975

In an attempt to develop an effective integrated system of controlling blast disease of rice caused by Pyricularia oryzae Cav., the possibility of minimizing the disease incidence by proper application of fertilizers has been investigated. Thus the effect of silicate, nitrogen, phosphorus and potassium fertilizers on the development of blast disease as well as the correlation between the rice varieties an4 strains of P. oryzae were studied. The experiments were made in 1971 and 1973 by artificial inoculation and under natural development of the blast disease on rice plants. The results obtained are summarized as follows. 1. Application of silicate fertilizer resulted in the increase of silicate as well as total sugar and potassium content but decrease of total nitrogen and phosphorus in tile leaf blades of rice plants. 2. The ratios of total C/total N. $ SiO_2/total$ N, and $K_2O/total$ N in leaf blades of rice plants increased by the application of silicate fertilizers. There was high level of negative correlation between the ratios mentioned above and the incidence of rice blast disease. 3. Application of silicate fertilizer reduced the incidence of rice blast disease. 4. The over dressing of nitrogen fertilizer resulted in the increase of total nitrogen and decrease of silicate and total sugar content in leaf blades, thus disposing the rice plants more susceptible to blast disease. 5. Over dressing of phosphorus fertilizer resulted in the increase of both total nitrogen and Phosphorus, and decrease of silicate content in the leaf blades inducing the rice plants to become more susceptible to blast disease. 6. Increased dressing of potash resulted in the increase of silicate content and $K_2O/total$ N ratio but decrease of total nitrogen content in leaf blades. When potassium content is low in the leaf blades of rice plants, the additional dressing of potash to rice plant contributed to the increase of resistance to blast disease. However, there was no significant correlation between additional potassium application and the resistance to blast disease when the potassium content is already high in the leaf blades. 7. When four rice varieties were artificially inoculated with three strains of P. oryzae, the incidence of blast disease was most severe on Pungok, least severe on Jinheung and moderate on Pungkwang and Paltal varieties. 8. Disease incidence was most severe on the second leaf from top and less sever on top and there leaf regardless of the fertilizer application when 5-6 leaf stage rice seedlings of four rice varieties were artificially inoculated with three strains of P. oryzae. 9. The pathogenicity of three strains of P. oryzae was in the order of $P_1,\;P_2,\;and\;P_3$ in their virulence when inoculated to Jinheung, Paltal, Pungkwang varieties but not with Pungok. The interaction between strains of P. oryzae and rice varieties was significant.

• Journal of agricultural medicine and community health
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• v.26 no.1
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• pp.37-56
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• 2001

This study was conducted to analyze the degree of changes in knowledge and attitude toward smoking and to examine the factors affecting knowledge and attitude for smoking after providing a smoking prevention program based on social influence model for a year to middle school students. Study population consists of 665 subjects of middle school students(aged 14 years) in Gumi city in Kyeongsangbukdo Province. Among them three-hundred sixty-seven students(intervention group) were educated to a smoking prevention program for 1 year from April 1999 to April 2000. School-based four-class program to prevent smoking was developed. The program provides instruction about short and long-term negative physiologic and social consequences of smoking and also discussed the health hazards of smoking, social pressure to smoke, peer norms regarding tobacco use, and refusal skill. A 45-item self-administered structured questionnaire was designed to evaluate the change of knowledge, attitude, smoking rate and the amount of smoking. The instrument was comprised of 11 knowledge items, thirteen attitude item and demographic items. Each scales were created by summing responses to each items within each scales and high scores on the knowledge, attitude, and smoking behavioral intention scales indicated positive responses. Based on the changes before and after the implementation of smoking prevention program between intervention and control group, the change of scores on knowledge were significantly different between the control group and the intervention group(p<0.05) and the change of scores on the attitude toward smoking was significantly different between intervention and control group. The change of smoking rate were not showing a significant difference between two groups but the amount of smoking were significantly reduced in intervention group than control group. In multiple regression analysis on changes of knowledge about smoking, the variables of smoking prevention program education, previous knowledge on smoking and students' school performance were selected the significant variables. In multiple regression to analysis of the factors influencing changes in attitude toward smoking, the variables of smoking prevention program education, previous knowledge on smoking were shown to be significant. The smoking prevention program was effective on change of knowledge and attitude of middle school students. In considering that the policy should be needed to extent of implementation of school-based health education curricula based on social influence model and it would contribute to reduce smoking of students.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.2
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• pp.189-217
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• 2017

Declaration of Air Defense and Identification Zones started with the United States in 1950, which was followed by declaration of KADIZ by the Republic of Korea in 1951. Initial ADIZ were solely linked with air defense missions, but their roles have changed as nations around the globe manifested a tendency to expand their influence over maritime resources and rights. In particular, China declared ADIZ over the East China Sea in October 2013 and forced all passing aircraft to submit flight plan to ATC or military authority, saying failure of submission will be followed by armed engagement. China announced it would declare another zone over the South China Sea despite the ongoing conflict in the area, clearly showing ADIZ's direct connection with territorial claim and EEZ and that it serves as a zone within which a nation can execute its rights. The expanded KADIZ, which was expanded in Dec 15, 2013 in response to Chinese actions, overlaps with the Chinese ADIZ over the East China Sea and the Japanese ADIZ. The overlapping zone is an airspace over waters where not only the Republic of Korea but also of China and Japan argue to be covering their continental shelf and EEZ. Military conventions were signed to prevent contingencies among the neighboring nations while conducting identifications in KADIZ, including the overlapping zone. If such military conventions and practice of air defense identification continue to be respected among states, it is under the process of turning into a regional customary law, although ADIZ is not yet recognized by international law or customary law. Moreover, identification within ADIZ is carried out by military authorities of states, and misguided customary procedures may cause serious negative consequences for national security since it may negatively impact neighboring countries in marking the maritime border, which calls for formulation of operation rules that account for other state activities and military talks among regional stake holders. Legal frameworks need to be in place to guarantee freedom of flights over international seas which UN Maritime Law protects, and laws regarding military aircraft operation need to be supplemented to not make it a requirement to submit flight plan if the aircraft does not invade sovereign airspace. Organizational instructions that require approval of Chairman of Joint Chiefs of Staff for entrance and exit of ADIZ for military aircraft need to be amended to change the authority to Minister of National Defense or be promoted to a law to be applicable for commercial aircraft. Moreover, in regards to operation and management of ADIZ, transfer of authority should be prohibited to account for its evolution into a regional customary law in South East Asia. In particular, since ADIZ is set over EEZ, military conventions that yield authority related to national security should never be condoned. Among Korea, China, Japan and Russia, there are military conventions that discuss operation and management of ADIZ in place or under negotiation, meaning that ADIZ is becoming a regional customary law in North East Asia region.

• Tuberculosis and Respiratory Diseases
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• v.44 no.3
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• pp.559-573
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• 1997

Background : Asthma causes recurrent episodes of wheezing, breathlessness, chest tightness, and cough. These symptoms are usually associated with widespread but variable airflow limitation that is partly reversible either spontaneously or with treatment. The inflammation also causes an associated increase in airway responsiveness to a variety of stimuli. Method : Of the 403 adult bronchial asthma patients enrolled from March 1992 to March 1994 in Allergy Clinics of Severance Hospital in Yonsei University, this study reviewed the 97 cases to evaluate the treatment effects and to analyse prognostic factors. The patients were classified to five groups according to treatment responses ; group 1 (non control group) : patients who were not controlled during following up, group 2 (high step treatment group) : patients who were controlled longer than 3 months by step 3 or 4 treatment of "Global initiative for asthma, Global strategy for asthma management and prevention" (NHLBI/WHO) with PFR(%) larger than 80%, group 3 (short term control group) : patients who were controlled less than 1 year by step 1 or 2 treatment of NHLBI/WHO, group 4 (intermediate term control group) : patients who were controlled for more than 1 year but less than 2 years by step 1 or 2 treatment of NHLBI/WHO, group 5 (long term control group) : patients who were controlled for more than 2 years by step 1 or 2 treatment of NHLBI/WHO. Especially the patients who were controlled more than 1 year with negatively converted methacholine test and no eosinophil in sputum were classified to methacholine negative conversion group. We reviewed patients' history, atopy score, total IgE, specific IgE, methacholine PC20 and peripheral blood eosinophil count, pulmonary function test, steroid doses and aggrevation numbers after treatment. Results : On analysis of 98 patients, 20 cases(20.6%) were classified to group 1, 26 cases(26.8%) to group 2, 23 cases(23.7%) to group 3, 15 cases(15.5%) to group 4, and 13 cases(13.4%) to groups 5. There were no differences of sex, asthma type, family history, smoking history, allergic rhinitis and aspirin allergy among the groups. In long term control group, asthma onset age was younger, symptom duration was shorter, and initial pulmonary function was better. The long term control group required lower amounts of oral steroid. had less aggrevation during first 3months after starting treatment and shorter duration from enrollment to control Atopy, allergic skin test, sputum and blood eosinophil, total IgE, nonspecific bronchial responsiveness was not significantly different among the groups. Seven out of 28 patients who were controlled more than 1 years showed negatively converted methachloine test and no eosinophils in the sputum. The mean control duration was $20.3{\pm}9.7$ months and relapse did not occur. Conclusion : Patients who had asthma of onset age younger, shorter symptom duration, better PFT, lower treatment initial steps, lower amounts of steroid needs and less aggravation numbers after starting treatment were classified in the long term control groups compared to the others.

• Tuberculosis and Respiratory Diseases
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• v.45 no.2
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• pp.290-300
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• 1998

Background: CYFRA 21-1 is a tumor marker which measures a fragment of cytokeratin 19 expressed by epithelial cells in bronchus. It is known that cytokeratin 19 is abundant in squamous epithelial cell cancer of the lung. However, if the incidence of elevated serum CYFRA 21-1 level in patients with benign lung diseases or pulmonary tuberculosis with severe parenchymal damage is high the specificity of CYFRA 21-1 could be decreased. The purpose of this study is to investigate the changes of serum CYFRA 21-1 according to the degree of parenchymal damage and the usefulness of CYFRA 21-1 for diagnosing possibly combined lung cancer in patients with pulmonary tuberculosis. Method: We studied the changes of serum CYFRA 21-1 according to the sputum AFB stain, radiologic manifestation and history of treatment in 81 patients with pulmonary tuberculosis, and 20 healthy persons, 25 patients with lung cancer, as a control group. CYFRA 21-1 concentration in serum was quantified by the immunoradiometry assay(Centocor$^{(R)}$). Result: The results were as follow; Serum CYFRA 21-1 level was significantly lower in patients with pulmonary tuberculosis($1.54{\pm}1.19ng/mL$, p<0.01) as compared to patients with lung cancer($12.25{\pm}15.97ng/mL$), and was slightly higher than the level in heathy persons($0.90{\pm}0.49ng/mL$) but there was no significant difference. Serum CYFRA 21-1 level was below the cut-off value of 3.3ng/mL in 95 percent of patients with pulmonary tuberculosis but it was above the cut-off value in 64 percent of patients with lung cancer. Serum CYFRA 21-1 level was significantly higher in the initial treatment group($1.91{\pm}1.55ng/mL$, p<0.05) as compared to the treatment. failure group ($0.92{\pm}0.30ng/mL$). According to the sputum AFB smear, serum CYFRA 21-1 level in patients with negative result was slightly higher than the level in patients with positive result but there was no significant difference. According to the radiologic manifestation, serum CYFRA 21-1 level was significantly higher in patients with infiltrative lesion ($2.15{\pm}1.63ng/mL$, p<0.01) as compared to patients with destructive lesion ($l.04{\pm}0.54ng/mL$). As the size of cavity or destructive lesion was larger, the level was significantly lower(p<0.05). Conclusion: As serum CYFRA 21-1 level was significantly higher in the initial treatment group and patients with infiltrative lesion, it suppose to be closely related with the degree of parenchymal damage of the lung of the pulmonary tuberculosis. However CYFRA 21-1 could be useful method for diagnosing lung cancer even in patients with pulmonary tuberculosis combined with lung cancer because of the fact that it was below the cutoff value of 3.3ng/mL in 95 percent of patients with pulmonary tuberculosis.

• Journal of The Korean Association For Science Education
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• v.16 no.4
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• pp.376-388
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• 1996

The first and the second "Discussion Contest of Scientific Investigation" was evaluated in this study. This contest was a part of 'Korean Youth Science Festival' held in 1993 and 1994. The evaluation was based on the data collected from the middle school students of final teams, their teachers, a large number of middle school students and college students who were audience of the final competition. Questionnaires, interviews, reports of final teams, and video tape of final competition were used to collect data. The study focussed on three research questions. The first was about the preparation and the research process of students of final teams. The second was about the format and the proceeding of the Contest. The third was whether participating the Contest was useful experience for the students and the teachers of the final teams. The first area, the preparation and the research process of students, were investigated in three aspects. One was the level of cooperation, participation, support and the role of teachers. The second was the information search and experiment, and the third was the report writing. The students of the final teams from both years, had positive opinion about the cooperation, students' active involvement, and support from family and school. Students considered their teachers to be a guide or a counsellor, showing their level of active participation. On the other hand, the interview of 1993 participants showed that there were times that teachers took strong leading role. Therefore one can conclude that students took active roles most of the time while the room for improvement still exists. To search the information they need during the period of the preparation, student visited various places such as libraries, bookstores, universities, and research institutes. Their search was not limited to reading the books, although the books were primary source of information. Students also learned how to organize the information they found and considered leaning of organizing skill useful and fun. Variety of experiments was an important part of preparation and students had positive opinion about it. Understanding related theory was considered most difficult and important, while designing and building proper equipments was considered difficult but not important. This reflects the students' school experience where the equipments were all set in advance and students were asked to confirm the theories presented in the previous class hours. About the reports recording the research process, students recognize the importance and the necessity of the report but had difficulty in writing it. Their reports showed tendency to list everything they did without clear connection to the problem to be solved. Most of the reports did not record the references and some of them confused report writing with story telling. Therefore most of them need training in writing the reports. It is also desirable to describe the process of student learning when theory or mathematics that are beyond the level of middle school curriculum were used because it is part of their investigation. The second area of evaluation was about the format and the proceeding of the Contest, the problems given to students, and the process of student discussion. The format of the Contests, which consisted of four parts, presentation, refutation, debate and review, received good evaluation from students because it made students think more and gave more difficult time but was meaningful and helped to remember longer time according to students. On the other hand, students said the time given to each part of the contest was too short. The problems given to students were short and open ended to stimulate students' imagination and to offer various possible routes to the solution. This type of problem was very unfamiliar and gave a lot of difficulty to students. Student had positive opinion about the research process they experienced but did not recognize the fact that such a process was possible because of the oneness of the task. The level of the problems was rated as too difficult by teachers and college students but as appropriate by the middle school students in audience and participating students. This suggests that it is possible for student to convert the problems to be challengeable and intellectually satisfactory appropriate for their level of understanding even when the problems were difficult for middle school students. During the process of student discussion, a few problems were observed. Some problems were related to the technics of the discussion, such as inappropriate behavior for the role he/she was taking, mismatching answers to the questions. Some problems were related to thinking. For example, students thinking was off balanced toward deductive reasoning, and reasoning based on experimental data was weak. The last area of evaluation was the effect of the Contest. It was measured through the change of the attitude toward science and science classes, and willingness to attend the next Contest. According to the result of the questionnaire, no meaningful change in attitude was observed. However, through the interview several students were observed to have significant positive change in attitude while no student with negative change was observed. Most of the students participated in Contest said they would participate again or recommend their friend to participate. Most of the teachers agreed that the Contest should continue and they would recommend their colleagues or students to participate. As described above, the "Discussion Contest of Scientific Investigation", which was developed and tried as a new science contest, had positive response from participating students and teachers, and the audience. Two among the list of results especially demonstrated that the goal of the Contest, "active and cooperative science learning experience", was reached. One is the fact that students recognized the experience of cooperation, discussion, information search, variety of experiments to be fun and valuable. The other is the fact that the students recognized the format of the contest consisting of presentation, refutation, discussion and review, required more thinking and was challenging, but was more meaningful. Despite a few problems such as, unfamiliarity with the technics of discussion, weakness in inductive and/or experiment based reasoning, and difficulty in report writing, The Contest demonstrated the possibility of new science learning environment and science contest by offering the chance to challenge open tasks by utilizing student science knowledge and ability to inquire and to discuss rationally and critically with other students.

• Journal of Preventive Medicine and Public Health
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• v.30 no.2 s.57
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• pp.308-326
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• 1997

Many studies have led to the notion that essential hypertension in adults is the result of a process that starts early in life: investigation of blood pressure(BP) in children and adolescents can therefore contribute to knowledge of the etiology of the condition. A unique longitudinal study on BP in Korea, known as Kangwha Children's Blood Pressure(KCBP) Study was initiated in 1986 to investigate changes in BP in children. This study is a part of the KCBP study. The purposes of this study are to show changes in BP and to determine factors affecting to BP level and change in Korean adolescents during age period 12 to 16 years. A total of 710 students(335 males, 375 females) who were in the first grade at junior high school(12 years old) in 1992 in Kangwha County, Korea have been followed to measure BP and related factors(anthropometric, serologic and dietary factors) annually up to 1996. A total of 562 students(242 males, 320 females) completed all five annual examinations. The main results are as follows: 1. For males, mean systolic and diastolic BP at age 12 and 16 years old were 108.7 mmHg and 118.1 mmHg(systolic), and 69.5 mmHg and 73.4 mmHg(diastolic), respectively. BP level was the highest when students were at 15 years old. For females, mean systolic and diastolic BP at age 12 and 16 years were 114.4 mmHg and 113.5 mmHg(systolic) and 75.2 mmHg and 72.1 mmHg(diastolic), respectively. BP level reached the highest point when they were 13-14 years old. 2. Anthropometric variables(height, weight and body mass index, etc) increased constantly during the study period for males. However, the rate of increase was decreased for females after age 15 years. Serum total cholesterol decreased and triglyceride increased according to age for males, but they did not show any significant trend fer females. Total fat intake increased at age 16 years compared with that at age 14 years. Compositions of carbohydrate, protein and fat among total energy intake were 66.2:12.0:19.4, 64.1:12.1:21.8 at age 14 and 16 years, respectively. 3. Most of anthropometric measures, especially, height, body mass index(BMI) and triceps skinfold thickness showed a significant correlation with BP level in both sexes. When BMI was adjusted, serum total cholesterol showed a significant negative correlation with systolic BP at age 12 years in males, but at age 14 years the direction of correlation changed to positive. In females serum total cholesterol was negatively correlated with diastolic BP at age 15 and 16 years. Triglyceride and creatinine showed positive correlation with systolic and diastolic BP in males, but they did not show any correlation in females. There was no consistent findings between nutrient intake and BP level. However, protein intake correlated positively with diastolic BP level in males. 4. Blood pressure change was positively associated with changes in BMI and serum total cholesterol in both sexes. Change in creatinine was associated with BP change positively in males and negatively in females. Students whose sodium intake was high showed higher systolic and diastolic BP in males, and students whose total fat intake was high maintained lower level of BP in females. The major determinants on BP change was BMI in both sexes.

• Tuberculosis and Respiratory Diseases
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• v.54 no.5
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• pp.551-562
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• 2003

Background : NF-${\kappa}B$ is a characteristic transcriptional factor which has been shown to regulate production of acute inflammatory mediators and to be involved in the pathogenesis of many inflammatory lung diseases. There has been some evidence that PI3K/Akt pathway could activate NF-${\kappa}B$ in human cell lines. However, the effect of PI3K/Akt pathway on the activation of NF-${\kappa}B$ varied depending on the cell lines used in the experiments. In this study we evaluated the effect of PI3K/Akt pathway on the activation of NF-${\kappa}B$ in human respiratory epithelial cell lines. Methods : BEAS-2B, A549 and NCI-H157 cell lines were used in this experiment. To evaluate the activation of Akt activation and I${\kappa}B$ degradation, cells were analysed by western blot assay using phospho-specific Akt Ab and $I{\kappa}B$ Ab. To block PI3K/Akt pathway, cells were pretreated with wortmannin or LY294002 and transfected with dominant negative Akt (DN-Akt). For IKK activity, immune complex kinase assay was performed. To evaluate the DNA binding affinity and transcriptional activity of NF-${\kappa}B$, electrophoretic mobility shift assay (EMSA) and luciferase assay were performed, respectively. Results : In BEAS-2B, A549 and NCI-H157 cell lines, Akt was activated by TNF-$\alpha$ and insulin. Activation of Akt by insulin did not induce $I{\kappa}B{\alpha}$ degradation. Blocking of PI3K/Akt pathway via wortmannin/LY294002 or DN-Akt did not inhibit TNF-$\alpha$-induced $I{\kappa}B{\alpha}$ degradation or IKK activation. Inhibition of PI3K/Akt did not affect TNF-$\alpha$-induced NF-${\kappa}B$ activation. Overexpression of DN-Akt did not block TNF-$\alpha$-induced transcriptional activation of NF-${\kappa}B$, but wortmannin enhanced TNF-$\alpha$-induced in NF-${\kappa}B$ transcriptional activity. Conclusion : PI3K/Akt was not involved in TNF-$\alpha$-induced $I{\kappa}B{\alpha}$ degradation or transcriptional activity of NF-${\kappa}B$ in human respiratory epithelial cell lines.

• The Korean Journal of Nuclear Medicine
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• v.38 no.6
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• pp.486-491
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• 2004

Purpose: factor analysis and independent component analysis (ICA) has been used for handling dynamic image sequences. Theoretical advantages of a newly suggested ICA method, ensemble ICA, leaded us to consider applying this method to the analysis of dynamic myocardial $H_2^{15}O$ PET data. In this study, we quantified patients' blood flow using the ensemble ICA method. Materials and Methods: Twenty subjects underwent $H_2^{15}O$ PET scans using ECAT EXACT 47 scanner and myocardial perfusion SPECT using Vertex scanner. After transmission scanning, dynamic emission scans were initiated simultaneously with the injection of $555{\sim}740$ MBq $H_2^{15}O$. Hidden independent components can be extracted from the observed mixed data (PET image) by means of ICA algorithms. Ensemble learning is a variational Bayesian method that provides an analytical approximation to the parameter posterior using a tractable distribution. Variational approximation forms a lower bound on the ensemble likelihood and the maximization of the lower bound is achieved through minimizing the Kullback-Leibler divergence between the true posterior and the variational posterior. In this study, posterior pdf was approximated by a rectified Gaussian distribution to incorporate non-negativity constraint, which is suitable to dynamic images in nuclear medicine. Blood flow was measured in 9 regions - apex, four areas in mid wall, and four areas in base wall. Myocardial perfusion SPECT score and angiography results were compared with the regional blood flow. Results: Major cardiac components were separated successfully by the ensemble ICA method and blood flow could be estimated in 15 among 20 patients. Mean myocardial blood flow was $1.2{\pm}0.40$ ml/min/g in rest, $1.85{\pm}1.12$ ml/min/g in stress state. Blood flow values obtained by an operator in two different occasion were highly correlated (r=0.99). In myocardium component image, the image contrast between left ventricle and myocardium was 1:2.7 in average. Perfusion reserve was significantly different between the regions with and without stenosis detected by the coronary angiography (P<0.01). In 66 segment with stenosis confirmed by angiography, the segments with reversible perfusion decrease in perfusion SPECT showed lower perfusion reserve values in $H_2^{15}O$ PET. Conclusions: Myocardial blood flow could be estimated using an ICA method with ensemble learning. We suggest that the ensemble ICA incorporating non-negative constraint is a feasible method to handle dynamic image sequence obtained by the nuclear medicine techniques.