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Analysis of Childhood Rapidly Progressive Glomerulonephritis (소아 급속 진행성 사구체신염의 임상적 고찰)

  • Uhm Ji Hyun;Kim Mi Jin;Lee Young-Mock;Kim Ji Hong;Lee Jae Seung;Kim Pyung-Kil;Hong Soon Won;Jeung Hyeun Joo
    • Childhood Kidney Diseases
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    • v.5 no.2
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    • pp.78-86
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    • 2001
  • Purpose: Rapidly progressive glomerulonephritis (RPGN) is characterized by the rapid increase in serum creatitnin and crescents formation involving more than $50\%$ of glomeruli. 10 patients who had been treated for RPGN were studied retrospectively for thier underlying diseases and clinical features Method: Cilinical review was performed on 10 children who were diagnosed with RPGN by clinical features and renal biopsy and followed up at department of pediatrics during tile last 10 years, from May 1990 to May 2000. Result: There were 6 males and 4 females between the ages of 2.1 and 14.3 years (mean $10.9{\pm}3.8$). 3 had Henoch-$Sch{\ddot{o}}nlein$ purpura nephritis; 2, idiopathic rapidly progressive glomerulonephritis; 2, lupus nephritis; 1, hemolytic uremic syndrome; 1, membranous glomerulonephritis and 1, microscopic polyangiitis. The most common chief complaints were gross hematuria and oliguria. Initial clinical features included proteinuria, edema, hypertension, nausea and arthralgia. Mean serum BUN was $74.2{\pm}39.1\;mg/dL$ mean serum creatinin, $3.2{\pm}1.8\;mg/dL$ and mean creatinin clearance, $26.5{\pm}13.2\;mL/min/1.73m^2$. Antineutrophil cytoplasmic antibody was positive only in microscopic polyangiitis. ANA and Anti-DNA antibody were positive in two lupus nephritis patients. Serum complements were decreased in 4 patients. All patients except Hemolytic uremic syndrome received steroid pulse therapy and immunosupressive agents. 3 patients were performed acute peritoneal dialysis and 2 patients were given plasmapheresis. At the last follow up, 1 patient was dead, 4 patients had elevated serum creatinin, 2 of these 4 patients were on chronic ambulatory peritoneal dialysis and 6 patients had normal renal function. Conclusion: Rapidly progressive glomerulonephritis is a medical emergency that requires very rapid diagnosis, classification, and therapy. Appropriate therapy selected on the basis of underlying disease mechanism can substantially improve renal survival. (J. Korean Soc Pediatr Nephrol 2001 ; 5 : 78-86)

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The Impact of Conflict and Influence Strategies Between Local Korean-Products-Selling Retailers and Wholesalers on Performance in Chinese Electronics Distribution Channels: On Moderating Effects of Relational Quality (중국 가전유통경로에서 한국제품 현지 판매업체와 도매업체간 갈등 및 영향전략이 성과에 미치는 영향: 관계 질의 조절효과)

  • Chun, Dal-Young;Kwon, Joo-Hyung;Lee, Guo-Ming
    • Journal of Distribution Research
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    • v.16 no.3
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    • pp.1-32
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    • 2011
  • I. Introduction: In Chinese electronics industry, the local wholesalers are still dominant but power is rapidly swifting from wholesalers to retailers because in recent foreign big retailers and local mass merchandisers are growing fast. During such transient period, conflicts among channel members emerge important issues. For example, when wholesalers who have more power exercise influence strategies to maintain status, conflicts among manufacturer, wholesaler, and retailer will be intensified. Korean electronics companies in China need differentiated channel strategies by dealing with wholesalers and retailers simultaneously to sell more Korean products in competition with foreign firms. For example, Korean electronics firms should utilize 'guanxi' or relational quality to form long-term relationships with whloesalers instead of power and conflict issues. The major purpose of this study is to investigate the impact of conflict, dependency, and influence strategies between local Korean-products-selling retailers and wholesalers on performance in Chinese electronics distribution channels. In particular, this paper proposes effective distribution strategies for Korean electronics companies in China by analyzing moderating effects of 'Guanxi'. II. Literature Review and Hypotheses: The specific purposes of this study are as follows. First, causes of conflicts between local Korean-products-selling retailers and wholesalers are examined from the perspectives of goal incongruence and role ambiguity and then effects of these causes are found out on perceived conflicts of local retailers. Second, the effects of dependency of local retailers upon wholesalers are investigated on local retailers' perceived conflicts. Third, the effects of non-coercive influence strategies such as information exchange and recommendation and coercive strategies such as threats and legalistic pleas exercised by wholesalers are explored on perceived conflicts by local retailers. Fourth, the effects of level of conflicts perceived by local retailers are verified on local retailers' financial performance and satisfaction. Fifth, moderating effects of relational qualities, say, 'quanxi' between wholesalers and retailers are analyzed on the impact of wholesalers' influence strategies on retailers' performances. Finally, moderating effects of relational qualities are examined on the relationship between conflicts and performance. To accomplish above-mentioned research objectives, Figure 1 and the following research hypotheses are proposed and verified. III. Measurement and Data Analysis: To verify the proposed research model and hypotheses, data were collected from 97 retailers who are selling Korean electronic products located around Central and Southern regions in China. Covariance analysis and moderated regression analysis were employed to validate hypotheses. IV. Conclusion: The following results were drawn using structural equation modeling and hierarchical moderated regression. First, goal incongruence perceived by local retailers significantly affected conflict but role ambiguity did not. Second, consistent with conflict spiral theory, the level of conflict decreased when retailers' dependency increased toward wholesalers. Third, noncoercive influence strategies such as information exchange and recommendation implemented by wholesalers had significant effects on retailers' performance such as sales and satisfaction without conflict. On the other hand, coercive influence strategies such as threat and legalistic plea had insignificant effects on performance in spite of increasing the level of conflict. Fourth, 'guanxi', namely, relational quality between local retailers and wholesalers showed unique effects on performance. In case of noncoercive influence strategies, 'guanxi' did not play a role of moderator. Rather, relational quality and noncoercive influence strategies can serve as independent variables to enhance performance. On the other hand, when 'guanxi' was well built due to mutual trust and commitment, relational quality as a moderator can positively function to improve performance even though hostile, coercive influence strategies were implemented. Fifth, 'guanxi' significantly moderated the effects of conflict on performance. Even if conflict arises, local retailers who form solid relational quality can increase performance by dealing with dysfunctional conflict synergistically compared with low 'quanxi' retailers. In conclusion, this study verified the importance of relational quality via 'quanxi' between local retailers and wholesalers in Chinese electronic industry because relational quality could cross out the adverse effects of coercive influence strategies and conflict on performance.

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Mid-Term Results of 292 cases of Coronary Artery Bypass Grafting (관상동맥 우회술 292례의 중기 성적)

  • 김태윤;김응중;이원용;지현근;신윤철;김건일
    • Journal of Chest Surgery
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    • v.35 no.9
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    • pp.643-652
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    • 2002
  • As the prevalence of coronay artery disease is increasing, the surgical treatment has been universalized and operative outcome has been improved. We analyzed the short and mid-term results of 292 CABGs performed in Kangdong Sacred Heart Hospital. Material and Method: From June 1994 to December 2001, 292 patients underwent coronary artery bypass grafting. There were 173 men and 119 women and their ages ranged from 39 to 84 years with a mean of $61.8{\pm}9.1$ years. We analyzed the preoperative risk factors, operative procedures and operative outcome. In addition, we analyzed the recurrence of symptoms, long-term mortality and complications via out-patient follow-up for discharged patients. Result: Preoperative clinical diagnoses were unstable angina in 137(46.9%), stable angina in 34(11.6%), acute myocardial infarction in 40(13.7%), non-Q myocardial infarction in 25(8.6%), postinfarction angina in 22(7.5%), cardiogenic shock in 30(10.3%) and PTCA failure in 4(1.4%) patients. Preoperative angiographic diagnoses were three-vessel disease in 157(53.8%), two-vessel disease in 35 (12.0%), one-vessel disease in 11(3.8%) and left main disease in 89(30.5%) patients. We used saphenous veins in 630, internal thoracic arteries in 257, radial arteries in 50, and right gastoepiploic arteries in 2 distal anastomoses. The mean number of distal anastomoses per patient was $3.2{\pm}1.0$ There were 18 concomitant procedures ; valve replacement in 8(2.7%), left main coronary artery angioplasty in 6(2.1%), patch closure of postinfarction ventricular septal defect(PMI-VSD) in 2(0.7%), replacement of ascending aorta in 1(0.3%) and coronary endarterectomy in 1(0.3%) patient. The mean ACC time was $96.6{\pm}35.3 $ minutes and the mean CPB time was $179.2{\pm}94.6$ minutes. Total early mortality was 8.6%, but it was 3.1% in elective operations. The most common cause of early mortality was low cardiac output syndrome in 6(2.1%) patients. The stastistically significant risk factors for early mortality were hypertension, old age($\geq$ 70 years), poor LV function(EF<40%), congestive heart failure, preoperative intraaortic balloon pump, emergency operation and chronic renal failure. The most common complication was arrhythmia in 52(17.8%) patients. The mean follow-up period was $39.0{\pm}27.0$ months. Most patients were free of symptoms during follow-up. Fourteen patients(5.8 %) had recurrent symptoms and 7 patients(2.9%) died during follow-up period. Follow-up coronary angiography was performed in 13 patients with recurrent symptoms and they were managed by surgical and medical treatment according to the coronary angiographic result. Conclusion: The operative and late results of CABG in our hospital, was acceptable. However, There should be more refinement in operative technique and postoperative management to improve the results.

Professional Speciality of Communication Administration and, Occupational Group and Series Classes of Position in National Public Official Law -for Efficiency of Telecommunication Management- (통신행정의 전문성과 공무원법상 직군렬 - 전기통신의 관리들 중심으로-)

  • 조정현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.3 no.1
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    • pp.26-27
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    • 1978
  • It can be expected that intelligence and knowledge will be the core of the post-industrial society in a near future. Accordingly, the age of intelligence shall be accelerated extensively to find ourselves in an age of 'Communication' service enterprise. The communication actions will increase its efficiency and multiply its utility, indebted to its scientic principles and legal idea. The two basic elements of communication action, that is, communication station and communication men are considered to perform their function when they are properly supported and managed by the government administration. Since the communication action itself is composed of various factors, the elements such as communication stations and officials must be cultivated and managed by specialist or experts with continuous and extensive study practices concerned. With the above mind, this study reviewed our public service officials law with a view to improve it by providing some suggestions for communication experts and researchers to find suitable positions in the framework of government administration. In this study, I would like to suggest 'Occupational Group of Communication' that is consisted of a series of comm, management positions and research positions in parallel to the existing series of comm, technical position. The communication specialist or expert is required to be qualified with necessary scientific knowledge and techniques of communication, as well as prerequisites as government service officials. Communication experts must succeed in the first hand to obtain government licence concerned in with the government law and regulation, and international custom before they can be appointed to the official positions. This system of licence-prior-to-appointment is principally applied in the communication management position. And communication research positions are for those who shall engage themselves to the work of study and research in the field of both management and technical nature. It is hopefully expected that efficient and extensive management of communication activities, as well as scientific and continuous study over than communication enterprise will be upgraded at national dimensions.

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Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy (고 에너지 방사선치료에서 환자의 피폭선량 분포와 생식선의 차폐)

  • Chu, Sung-Sil;Suh, Chang-Ok;Kim, Gwi-Eon
    • Journal of Radiation Protection and Research
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    • v.27 no.1
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    • pp.1-10
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    • 2002
  • High energy photon beams from medical linear accelerators produce large scattered radiation by various components of the treatment head, collimator and walls or objects in the treatment room including the patient. These scattered radiation do not provide therapeutic dose and are considered a hazard from the radiation safety perspective. Scattered dose of therapeutic high energy radiation beams are contributed significant unwanted dose to the patient. ICRP take the position that a dose of 500mGy may cause abortion at any stage of pregnancy and that radiation detriment to the fetus includes risk of mental retardation with a possible threshold in the dose response relationship around 100 mGy for the gestational period. The ICRP principle of as low as reasonably achievable (ALARA) was recommended for protection of occupation upon the linear no-threshold dose response hypothesis for cancer induction. We suggest this ALARA principle be applied to the fetus and testicle in therapeutic treatment. Radiation dose outside a photon treatment filed is mostly due to scattered photons. This scattered dose is a function of the distance from the beam edge, treatment geometry, primary photon energy, and depth in the patient. The need for effective shielding of the fetus and testicle is reinforced when young patients ate treated with external beam radiation therapy and then shielding designed to reduce the scattered photon dose to normal organs have to considered. Irradiation was performed in phantom using high energy photon beams produced by a Varian 2100C/D medical linear accelerator (Varian Oncology Systems, Palo Alto, CA) located at the Yonsei Cancer Center. The composite phantom used was comprised of a commercially available anthropomorphic Rando phantom (Phantom Laboratory Inc., Salem, YN) and a rectangular solid polystyrene phantom of dimensions $30cm{\times}30cm{\times}20cm$. the anthropomorphic Rando phantom represents an average man made from tissue equivalent materials that is transected into transverse 36 slices of 2.5cm thickness. Photon dose was measured using a Capintec PR-06C ionization chamber with Capintec 192 electrometer (Capintec Inc., Ramsey, NJ), TLD( VICTOREEN 5000. LiF) and film dosimetry V-Omat, Kodak). In case of fetus, the dosimeter was placed at a depth of loom in this phantom at 100cm source to axis distance and located centrally 15cm from the inferior edge of the $30cm{\times}30cm^2$ x-ray beam irradiating the Rando phantom chest wall. A acryl bridge of size $40cm{\times}40cm^2$ and a clear space of about 20 cm was fabricated and placed on top of the rectangular polystyrene phantom representing the abdomen of the patient. The leaf pot for testicle shielding was made as various shape, sizes, thickness and supporting stand. The scattered photon with and without shielding were measured at the representative position of the fetus and testicle. Measurement of radiation scattered dose outside fields and critical organs, like fetus position and testicle region, from chest or pelvic irradiation by large fie]d of high energy radiation beam was performed using an ionization chamber and film dosimetry. The scattered doses outside field were measured 5 - 10% of maximum doses in fields and exponentially decrease from field margins. The scattered photon dose received the fetus and testicle from thorax field irradiation was measured about 1 mGy/Gy of photon treatment dose. Shielding construction to reduce this scattered dose was investigated using lead sheet and blocks. Lead pot shield for testicle reduced the scatter dose under 10 mGy when photon beam of 60 Gy was irradiated in abdomen region. The scattered photon dose is reduced when the lead shield was used while the no significant reduction of scattered photon dose was observed and 2-3 mm lead sheets refuted the skin dose under 80% and almost electron contamination. The results indicate that it was possible to improve shielding to reduce scattered photon for fetus and testicle when a young patients were treated with a high energy photon beam.

Multimodality Treatement in Patients with Clinical Stage IIIA NSCLC (임상적 IIIA병기 비소세포폐암의 다각적 치료의 효과)

  • Lee, Yun Seun;Jang, Pil Soon;kang, Hyun Mo;Lee, Jeung Eyun;Kwon, Sun Jung;An, Jin Yong;Jung, Sung Soo;Kim, Ju Ock;Kim, Sun Young
    • Tuberculosis and Respiratory Diseases
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    • v.57 no.6
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    • pp.557-566
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    • 2004
  • Background : To find out effectiveness of multimodality treatments based on induction chemotherapy(CTx) in patients with clinical stage IIIA NSCLC Methods : From 1997 to 2002, 74 patients with clinical stage IIIA NSCLC underwent induction CTx at the hospital of Chungnam National University. Induction CTx included above two cycles of cisplatin-based regimens(ectoposide, gemcitabine, vinorelbine, or taxol) followed by tumor evaluation. In 30 complete resection group, additional 4500-5000cGy radiotherapy(RTx) was delivered in 15 patients with pathologic nodal metastasis. 29 out of 44 patients who were unresectable disease, refusal of operation, and incomplete resection were followed by 60-70Gy RTx in local treatment. Additional 1-3 cycle CTx were done in case of induction CTx responders in both local treatment groups. Results : Induction CTx response rate were 44.6%(complete remission 1.4% & partial response 43.2%) and there was no difference of response rate by regimens(p=0.506). After induction chemotherapy, only 33 out of resectable 55 ones(including initial resectable 37 patients) were performed by surgical treatment because of 13 refusal of surgery by themselves and 9 poor predicted reserve lung function. There were 30(40.5%) patients with complete resection, 2(2.6%) persons with incomplete resection, and 1(1.3%) person with open & closure. Response rate in 27 ones with chest RTx out of non-operation group was 4.8% CR and 11.9% PR. In complete resection group, relapse free interval was 13.6 months and 2 year recur rate was 52%. In non-complete resection(incomplete resection or non-operation) group, disease progression free interval was 11.2 months and 2 year disease progression rate was 66.7%. Median survival time of induction CTx 74 patients with IIIA NSCLC was 25.1months. When compared complete resection group with non-complete resection group, the median survival time was 31.7 and 23.4months(p=0.024) and the 2-year overall survival rate was 80% and 41%. In the complete resection group, adjuvant postoperative RTx subgroup significantly improved the 2-year local control rate(0% vs. 40%, p= 0.007) but did not significantly improve overall survival(32.2months vs. 34.9months, p=0.48). Conculusion : Induction CTx is a possible method in the multimodality treatments, especially followed by complete resection, but overall survival by any local treatment(surgical resection or RTx) was low. Additional studies should be needed to analysis data for appropriate patient selection, new chemotherapy regimens and the time when should RTx be initiated.

Cellular activities of osteoblast-like cells on alkali-treated titanium surface (알칼리 처리된 타이타늄 표면에 대한 골아 유사세포의 세포 활성도)

  • Park, Jin-Woo;Lee, Deog-Hye;Yeo, Shin-Il;Park, Kwang-Bum;Choi, Seok-Kyu;Suh, Jo-Young
    • Journal of Periodontal and Implant Science
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    • v.37 no.sup2
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    • pp.427-445
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    • 2007
  • To improve osseointegration at the boneto-implant interface, several studies have been carried out to modify titanium surface. Variations in surface texture or microtopography may affect the cellular response to an implant. Osteoblast-like cells attach more readily to a rougher titanium surface, and synthesis of extracellular matrix and subsequent mineralization were found to be enhanced on rough or porous coated titanium. However, regarding the effect of roughened surface by physical and mechanical methods, most studies carried out on the reactions of cells to micrometric topography, little work has been performed on the reaction of cells to nanotopography. The purpose of this study was to examme the response of osteoblast-like cell cultured on blasted surfaces and alkali treated surfaces, and to evaluate the influence of surface texture or submicro-scaled surface topography on the cell attachment, cell proliferation and the gene expression of osteoblastic phenotype using ROS 17/2.8 cell lines. In scanning electron micrographs, the blasted, alkali treated and machined surfaces demonstrated microscopic differences in the surface topography. The specimens of alkali treatment had a submicro-scaled porous sur-face with pore size about 200 nm. The blasted surfaces showed irregularities in morphology with small(<10 ${\mu}m$) depression and indentation among flatter-appearing areas of various sizes. Based on profilometry, the blasted surfaces was significantly rougher than the machined and the alkali treated surfaces (p$TiO_2$) were observed on alkali treated surfaces, whereas not observed on machined and blasted surfaces. The attachment morphology of cells according to time was observed by the scanning electron microscope. After 1 hour incubation, the cells were in the process of adhesion and spreading on the prepared surfaces. After 3 hours, the cells on all prepared surfaces were further spreaded and flattened, however on the blasted and alkali treated surfaces, the cells exhibited slightly irregular shapes and some gaps or spaces were seen. After 24 hours incubation, most cells of the all groups had a flattened and polygonal shape, but the cells were more spreaded on the machined surfaces than the blasted and alkali treated surfaces. The MTT assay indicated the increase on machined, alkali treated and blasted surfaces according to time, and the alkali treated and blasted surfaces showed significantly increased in optical density comparing with machined surfaces at 1 day (p<0.01). Gene expression study showed that mRNA expression level of ${\alpha}\;1(I)$ collagen, alkaline phosphatase and osteopontin of the osteoblast-like cells showed a tendency to be higher on blasted and alkali treated surfaces than on the machined surfaces, although no siginificant difference in the mRNA expression level of ${\alpha}\;1(I)$ collagen, alkaline phosphatase and osteopontin was observed among all groups. In conclusion, we suggest that submicroscaled surfaces on osteoblast-like cell response do not over-ride the one of the surface with micro-scaled topography produced by blasting method, although the microscaled and submicro-scaled surfaces can accelerate osteogenic cell attachment and function compared with the machined surfaces.

The Palliative Radiation Therapy in Malignant Extra-Hepatic Biliary Obstruction (간외 폐쇄성 황달 환자에서 고식적 방사선치료의 결과)

  • Kay Chul-Seoung;Jang Hong-Suk;Kim Sung-hwan;Ryu Mi-Ryeong;Kim Yeon-Shil;Chung Su-Mi;Yoon Sei-Chul
    • Radiation Oncology Journal
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    • v.17 no.3
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    • pp.209-216
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    • 1999
  • Purpose : To evaluate the effectiveness of external radiation therapy and the prognostic factors, we retrospectively analyzed therapeutic results of malignant extrahepatic biliary obstruction (EHBO). Methods and Materials : We analyzed the results of the external radiation therapy in 59 patients of inoperable malignant EHBO who had been treated with more than 10 Gy of external radiation therapy from April 1984 to December 1990. There were 21 stomach cancer ($35.6\%$), 12 pancreas cancer ($20.3\%$), 15 extrahepatic biliary cancer ($18.0\%$) and 11 another cancer ($18.0\%$). Their pathologies were confirmed in 31 patients ($52.5\%$). They divided into 27 adenocarcinoma and 4 nonadenocarcinoma. Their chief complaints were jaundice in 47 patients ($79.7\%$) and abdominal pain in 15 patients ($49.2\%$). Twelve patients had slightly increased bilirubin level in liver function test without jaundice. We treated twenty four patients ($40.6\%$) with percutaneous transhepatic biliary drainage (PTBD) and 32 patients ($54\%$) with systemic chemotherapy (CT). We performed external radiation therapy (ERT) upto $10.8\~55.8$ Gy (median 37.8 Gy) with palliative aim. Results : Overall median survival duration was $7.80\pm1.15$ months. The response rates of jaundice were $81.8\%$ in PTBO group and $66.7\%$ in non-PTBD group without statistical significance. The improving rate of jaundice was not significantly different in decreased ratio of total bilirubin level. But abdominal pain was more decreased in CT group than non-CT group (p<0.05). The significant prognostic factors were high performance status (Karnofski Performance Status >70), total radiation dose more than 35 Gy and good response of pain after therapy. There were increased in bacterial cholagitis in PTBD group and gastrointestinal complications in CT group. Conclusion : External radiotheapy could improve jaundice and abdominal pain in malignant EHBO patients, Overall survival duration was prolonged in patients with higher performance status and patients who had been treated with more than 35 Gy of total radiation dose. In the future, we expect not only better palliative role but also the prolongation of survival of using the ERT combined with other treatment method. But to achieve certain conclusion, we need luther study consisted with many kinds of treatment methods including new technologies in RT.

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Results of Definitive Chemoradiotherapy for Unresectable Esophageal Cancer (절제 불가능한 식도암의 근치적 항암화학방사선치료의 성적)

  • Noh, O-Kyu;Je, Hyoung-Uk;Kim, Sung-Bae;Lee, Gin-Hyug;Park, Seung-Il;Lee, Sang-Wook;Song, Si-Yeol;Ahn, Seung-Do;Choi, Eun-Kyung;Kim, Jong-Hoon
    • Radiation Oncology Journal
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    • v.26 no.4
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    • pp.195-203
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    • 2008
  • Purpose: To investigate the treatment outcome and failure patterns after definitive chemoradiation therapy in locally advanced, unresectable esophageal cancer. Materials and Methods: From February 1994 to December 2002, 168 patients with locally advanced unresectable or medically inoperable esophageal cancer were treated by definitive chemoradiation therapy. External beam radiation therapy (EBRT) ($42{\sim}46\;Gy$) was delivered to the region encompassing the primary tumor and involved lymph nodes, while the supraclavicular fossa and celiac area were included in the treatment area as a function of disease location. The administered cone-down radiation dose to the gross tumor went up to $54{\sim}66\;Gy$, while the fraction size of the EBRT was 1.8-2.0 Gy/fraction qd or 1.2 Gy/fraction bid. An optional high dose rate (HDR) intraluminal brachytherapy (BT) boost was also administered (Ir-192, $9{\sim}12\;Gy/3{\sim}4\;fx$). Two cycles of concurrent FP chemotherapy (5-FU $1,000\;mg/m^2$/day, days $2{\sim}6$, $30{\sim}34$, cisplatin $60\;mg/m^2$/day, days 1, 29) were delivered during radiotherapy with the addition of two more cycles. Results: One hundred sixty patients were analyzable for this review [median follow-up time: 10 months (range $1{\sim}149$ months)). The number of patients within AJCC stages I, II, III, and IV was 5 (3.1%), 38 (23.8%), 68 (42.5%), and 49 (30.6%), respectively. A HDR intraluminal BT was performed in 26 patients. The 160 patients had a median EBRT radiation dose of 59.4 Gy (range $44.4{\sim}66$) and a total radiation dose, including BT, of 60 Gy (range $44.4{\sim}72$), while 144 patients received a dose higher than 40 Gy. Despite the treatment, the disease recurrence rate was 101/160 (63.1%). Of these, the patterns of recurrence were local in 20 patients (12.5%), persistent disease and local progression in 61 (38.1%), distant metastasis in 15 (9.4%), and concomitant local and distant failure in 5 (3.1%). The overall survival rate was 31.8% at 2 years and 14.2% at 5 years (median 11.1 months). Disease-free survival was 29.0% at 2 years and 22.7% at 5 years (median 10.4 months). The response to treatment and N-stage were significant factors affecting overall survival. In addition, total radiation dose (${\geq}50\;Gy$ vs. < 50 Gy), BT and fractionation scheme (qd. vs. bid.) were not significant factors for overall survival and disease-free survival. Conclusion: Survival outcome after definitive chemoradiation therapy in unresectable esophageal cancer was comparable to those of other series. The main failure pattern was local recurrence. Survival rate did not improve with increased radiation dose over 50 Gy or the use of brachytherapy or hyperfractionation.

Geochemical Equilibria and Kinetics of the Formation of Brown-Colored Suspended/Precipitated Matter in Groundwater: Suggestion to Proper Pumping and Turbidity Treatment Methods (지하수내 갈색 부유/침전 물질의 생성 반응에 관한 평형 및 반응속도론적 연구: 적정 양수 기법 및 탁도 제거 방안에 대한 제안)

  • 채기탁;윤성택;염승준;김남진;민중혁
    • Journal of the Korean Society of Groundwater Environment
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    • v.7 no.3
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    • pp.103-115
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    • 2000
  • The formation of brown-colored precipitates is one of the serious problems frequently encountered in the development and supply of groundwater in Korea, because by it the water exceeds the drinking water standard in terms of color. taste. turbidity and dissolved iron concentration and of often results in scaling problem within the water supplying system. In groundwaters from the Pajoo area, brown precipitates are typically formed in a few hours after pumping-out. In this paper we examine the process of the brown precipitates' formation using the equilibrium thermodynamic and kinetic approaches, in order to understand the origin and geochemical pathway of the generation of turbidity in groundwater. The results of this study are used to suggest not only the proper pumping technique to minimize the formation of precipitates but also the optimal design of water treatment methods to improve the water quality. The bed-rock groundwater in the Pajoo area belongs to the Ca-$HCO_3$type that was evolved through water/rock (gneiss) interaction. Based on SEM-EDS and XRD analyses, the precipitates are identified as an amorphous, Fe-bearing oxides or hydroxides. By the use of multi-step filtration with pore sizes of 6, 4, 1, 0.45 and 0.2 $\mu\textrm{m}$, the precipitates mostly fall in the colloidal size (1 to 0.45 $\mu\textrm{m}$) but are concentrated (about 81%) in the range of 1 to 6 $\mu\textrm{m}$in teams of mass (weight) distribution. Large amounts of dissolved iron were possibly originated from dissolution of clinochlore in cataclasite which contains high amounts of Fe (up to 3 wt.%). The calculation of saturation index (using a computer code PHREEQC), as well as the examination of pH-Eh stability relations, also indicate that the final precipitates are Fe-oxy-hydroxide that is formed by the change of water chemistry (mainly, oxidation) due to the exposure to oxygen during the pumping-out of Fe(II)-bearing, reduced groundwater. After pumping-out, the groundwater shows the progressive decreases of pH, DO and alkalinity with elapsed time. However, turbidity increases and then decreases with time. The decrease of dissolved Fe concentration as a function of elapsed time after pumping-out is expressed as a regression equation Fe(II)=10.l exp(-0.0009t). The oxidation reaction due to the influx of free oxygen during the pumping and storage of groundwater results in the formation of brown precipitates, which is dependent on time, $Po_2$and pH. In order to obtain drinkable water quality, therefore, the precipitates should be removed by filtering after the stepwise storage and aeration in tanks with sufficient volume for sufficient time. Particle size distribution data also suggest that step-wise filtration would be cost-effective. To minimize the scaling within wells, the continued (if possible) pumping within the optimum pumping rate is recommended because this technique will be most effective for minimizing the mixing between deep Fe(II)-rich water and shallow $O_2$-rich water. The simultaneous pumping of shallow $O_2$-rich water in different wells is also recommended.

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