• Title/Summary/Keyword: cohort

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Quantitative CT Analysis Based on Smoking Habits and Chronic Obstructive Pulmonary Disease in Patients with Normal Chest CT (정상 흉부 단층촬영 검사에서 흡연 및 폐쇄성 폐질환 유무에 따른 정량화 검사 분석)

  • Jung Hee Byon;Gong Yong Jin;Young Min Han;Eun Jung Choi;Kum Ju Chae;Eun Hae Park
    • Journal of the Korean Society of Radiology
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    • v.84 no.4
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    • pp.900-910
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    • 2023
  • Purpose To assess normal CT scans with quantitative CT (QCT) analysis based on smoking habits and chronic obstructive pulmonary disease (COPD). Materials and Methods From January 2013 to December 2014, 90 male patients with normal chest CT and quantification analysis results were enrolled in our study [non-COPD never-smokers (n = 38) and smokers (n = 45), COPD smokers (n = 7)]. In addition, an age-matched cohort study was performed for seven smokers with COPD. The square root of the wall area of a hypothetical bronchus of internal perimeter 10 mm (Pi10), skewness, kurtosis, mean lung attenuation (MLA), and percentage of low attenuation area (%LAA) were evaluated. Results Among patients without COPD, the Pi10 of smokers (4.176 ± 0.282) was about 0.1 mm thicker than that of never-smokers (4.070 ± 0.191, p = 0.047), and skewness and kurtosis of smokers (2.628 ± 0.484 and 6.448 ± 3.427) were lower than never-smokers (2.884 ± 0.624, p = 0.038 and 8.594 ± 4.944, p = 0.02). The Pi10 of COPD smokers (4.429 ± 0.435, n = 7) was about 0.4 mm thicker than never-smokers without COPD (3.996 ± 0.115, n = 14, p = 0.005). There were no significant differences in MLA and %LAA between groups (p > 0.05). Conclusion Even on normal CT scans, QCT showed that the airway walls of smokers are thicker than never-smokers regardless of COPD and it preceded lung parenchymal changes.

Do some patients receive unnecessary parenteral nutrition after pancreatoduodenectomy? Results from an international multicentre study

  • Thomas B. Russell;Peter L. Labib;Paula Murphy;Fabio Ausania;Elizabeth Pando;Keith J. Roberts;Ambareen Kausar;Vasileios K. Mavroeidis;Gabriele Marangoni;Sarah C. Thomasset;Adam E. Frampton;Pavlos Lykoudis;Manuel Maglione;Nassir Alhaboob;Hassaan Bari;Andrew M. Smith;Duncan Spalding;Parthi Srinivasan;Brian R. Davidson;Ricky H. Bhogal;Daniel Croagh;Ismael Dominguez;Rohan Thakkar;Dhanny Gomez;Michael A. Silva;Pierfrancesco Lapolla;Andrea Mingoli;Alberto Porcu;Nehal S. Shah;Zaed Z. R. Hamady;Bilal Al-Sarrieh;Alejandro Serrablo;Somaiah Aroori
    • Annals of Hepato-Biliary-Pancreatic Surgery
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    • v.28 no.1
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    • pp.70-79
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    • 2024
  • Backgrounds/Aims: After pancreatoduodenectomy (PD), an early oral diet is recommended; however, the postoperative nutritional management of PD patients is known to be highly variable, with some centers still routinely providing parenteral nutrition (PN). Some patients who receive PN experience clinically significant complications, underscoring its judicious use. Using a large cohort, this study aimed to determine the proportion of PD patients who received postoperative nutritional support (NS), describe the nature of this support, and investigate whether receiving PN correlated with adverse perioperative outcomes. Methods: Data were extracted from the Recurrence After Whipple's study, a retrospective multicenter study of PD outcomes. Results: In total, 1,323 patients (89%) had data on their postoperative NS status available. Of these, 45% received postoperative NS, which was "enteral only," "parenteral only," and "enteral and parenteral" in 44%, 35%, and 21% of cases, respectively. Body mass index < 18.5 kg/m2 (p = 0.03), absence of preoperative biliary stenting (p = 0.009), and serum albumin < 36 g/L (p = 0.009) all correlated with receiving postoperative NS. Among those who did not develop a serious postoperative complication, i.e., those who had a relatively uneventful recovery, 20% received PN. Conclusions: A considerable number of patients who had an uneventful recovery received PN. PN is not without risk, and should be reserved for those who are unable to take an oral diet. PD patients should undergo pre- and postoperative assessment by nutrition professionals to ensure they are managed appropriately, and to optimize perioperative outcomes.

Stock Identification of Todarodes pacificus in Northwest Pacific (북서태평양에 서식하는 살오징어(Todarodes pacificus) 계군 분석에 대한 고찰)

  • Kim, Jeong-Yun;Moon, Chang-Ho;Yoon, Moon-Geun;Kang, Chang-Keun;Kim, Kyung-Ryul;Na, Taehee;Choy, Eun Jung;Lee, Chung Il
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.17 no.4
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    • pp.292-302
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    • 2012
  • This paper reviews comparison analysis of current and latest application for stock identification methods of Todarodes pacificus, and the pros and cons of each method and consideration of how to compensate for each other. Todarodes pacificus which migrates wide areas in western North Pacific is important fishery resource ecologically and commercially. Todarodes pacificus is also considered as 'biological indicator' of ocean environmental changes. And changes in its short and long term catch and distribution area occur along with environmental changes. For example, while the catch of pollack, a cold water fish, has dramatically decreased until today after the climate regime shift in 1987/1988, the catch of Todarodes pacificus has been dramatically increased. Regarding the decrease in pollack catch, overfishing and climate changes were considered as the main causes, but there has been no definite reason until today. One of the reasons why there is no definite answer is related with no proper analysis about ecological and environmental aspects based on stock identification. Subpopulation is a group sharing the same gene pool through sexual reproduction process within limited boundaries having similar ecological characteristics. Each individual with same stock might be affected by different environment in temporal and spatial during the process of spawning, recruitment and then reproduction. Thereby, accurate stock analysis about the species can play an efficient alternative to comply with effective resource management and rapid changes. Four main stock analysis were applied to Todarodes pacificus: Morphologic Method, Ecological Method, Tagging Method, Genetic Method. Ecological method is studies for analysis of differences in spawning grounds by analysing the individual ecological change, distribution, migration status, parasitic state of parasite, kinds of parasite and parasite infection rate etc. Currently the method has been studying lively can identify the group in the similar environment. However It is difficult to know to identify the same genetic group in each other. Tagging Method is direct method. It can analyse cohort's migration, distribution and location of spawning, but it is very difficult to recapture tagged squids and hard to tag juveniles. Genetic method, which is for useful fishery resource stock analysis has provided the basic information regarding resource management study. Genetic method for stock analysis is determined according to markers' sensitivity and need to select high multiform of genetic markers. For stock identification, isozyme multiform has been used for genetic markers. Recently there is increase in use of makers with high range variability among DNA sequencing like mitochondria, microsatellite. Even the current morphologic method, tagging method and ecological method played important rolls through finding Todarodes pacificus' life cycle, migration route and changes in spawning grounds, it is still difficult to analyze the stock of Todarodes pacificus as those are distributed in difference seas. Lately, by taking advantages of each stock analysis method, more complicated method is being applied. If based on such analysis and genetic method for improvement are played, there will be much advance in management system for the resource fluctuation of Todarodes pacificus.

Modeling Brand Equity for Lifestyle Brand Extensions: A Strategic Approach into Generation Y vs. Baby Boomer (생활방식품패확장적품패자산건모(生活方式品牌扩张的品牌资产建模): 침대Y세대화영인조소비자적전략로경(针对Y世代和婴儿潮消费者的战略路径))

  • Kim, Eun-Young;Brandon, Lynn
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.1
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    • pp.35-48
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    • 2010
  • Today, the fashion market challenged by a maturing retail market needs a new paradigm in the "evolution of brand" to improve their comparative advantages. An important issue in fashion marketing is lifestyle brand extension with a specific aim to meet consumers' specific needs for their changing lifestyle. For fashion brand extensions into lifestyle product categories, Gen Y and Baby Boomer are emerging as "prospects"-Baby Boomers who are renovating their lifestyle, and generation Y experiencing changes in their life stage-with demands for buying new products. Therefore, it is imperative that apparel companies pay special attention to the consumer cohort for brand extension to create and manage their brand equity in a new product category. The purposes of this study are to (a) evaluate brand equity between parent and extension brands; (b) identify consumers' perceived marketing elements for brand extension; and (c) estimate a structural equation model for examining causative relationship between marketing elements and brand equity for brand extensions in lifestyle product category including home fashion items for the selected two groups (e.g., Gen Y, and Baby boomer). For theoretical frameworks, this study focused on the traditional marketing 4P's mix to identify what marketing element is more importantly related to brand extension equity for this study. It is assumed that comparable marketing capability can be critical to establish "brand extension equity", leads to successfully entering the new categories. Drawing from the relevant literature, this study developed research hypotheses incorporating brand equity factors and marketing elements by focusing on the selected consumers (e.g., Gen Y, Baby Boomer). In the context of brand extension in the lifestyle products, constructs of brand equity consist of brand awareness/association, brand perceptions (e.g., perceived quality, emotional value) and brand resonance adapted from CBBE factors (Keller, 2001). It is postulated that the marketing elements create brand extension equity in terms of brand awareness/association, brand perceptions by the brand extension into lifestyle products, which in turn influence brand resonance. For data collection, the sample was comprised of Korean female consumers in Gen Y and Baby Boomer consumer categories who have a high demand for lifestyle products due to changing their lifecycles. A total of 651 usable questionnaires were obtained from female consumers of Gen Y (n=326) and Baby Boomer (n=325) in South Korea. Structural and measurement models using a correlation matrix was estimated using LISREL 8.8. Findings indicated that perceived marketing elements for brand extension consisted of three factors: price/store image, product, and advertising. In the model of Gen Y consumers, price/store image had a positive effect on brand equity factors (e.g., brand awareness/association, perceived quality), while product had positive effect on emotional value in the brand extensions; and the brand awareness/association was likely to increase the perceived quality and emotional value, leading to brand resonance for brand extensions in the lifestyle products. In the model of Baby Boomer consumers, price/store image had a positive effect on perceived quality, which created brand resonance of brand extension; and product had a positive effect on perceived quality and emotional value, which leads to brand resonance for brand extension in the lifestyle products. However, advertising was negatively related to brand equity for both groups. This study provides an insight for fashion marketers in developing a successful brand extension strategy, leading to a sustainable competitive advantage. This study complements and extends prior works in the brand extension through critical factors of marketing efforts that affect brand extension success. Findings support a synergy effect on leveraging of fashion brand extensions (Aaker and Keller, 1990; Tauber, 1988; Shine et al., 2007; Pitta and Katsanis, 1995) in conjunction with marketing actions for entering into the new product category. Thus, it is recommended that marketers targeting both Gen Y and Baby Boomer can reduce marketing cost for entering the new product category (e.g., home furnishings) by standardized marketing efforts; fashion marketers can (a) offer extension lines with premium ranges of price; (b) place an emphasis on upscale features of store image positioning by a retail channel (e.g., specialty department store) in Korea, and (c) combine apparel with lifestyle product assortments including innovative style and designer’s limited editions. With respect to brand equity, a key to successful brand extension is consumers’ brand awareness or association that ensures brand identity with new product category. It is imperative for marketers to have knowledge of what contributes to more concrete associations in a market entry into new product categories. For fashion brands, a second key of brand extension can be a "luxury" lifestyle approach into new product categories, in that higher price or store image had impact on perceived quality that established brand resonance. More importantly, this study increases the theoretical understanding of brand extension and suggests directions for marketers as they establish marketing program at Gen Y and Baby Boomers.

Comparative Study on the Regimens with Pyrazinamide or Ofloxacin in the retreatment of pulmonary tuberculosis (폐결핵 재치료에서 Pyrazinamide 복합처방과 Ofloxacin 복합처방의 효과에 관한 비교 연구)

  • Choi, In Hwan;Park, Seung Kyu;Kim, Kyeong Ho;Kim, Jin Ho;Kim, Cheon Tae;Song, Sun Dae
    • Tuberculosis and Respiratory Diseases
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    • v.43 no.6
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    • pp.871-881
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    • 1996
  • Objective: In the early short-term therapy of pulmonary tuberculosis, PZA is used for the first two months on 6EHRZ therapy but PZA is not effective in the case of long-tenn use PZA for retreatment in the sensitive relapse or acquired drug resistance for PZA. But in the endemic area as Korea, if we can't use PZA in the retreatment of pulmonary tuberculosis, we can't expect the success for retreatment of pulmonary tuberculosis, therefore we need new drugs substituting for PZA. In these days, 4 - fluoroquinolone derivatives were investigated and only ofloxacin and ciprofloxacin of derivatives were known to be effective but the effectiveness was also not certain because the result was experimental or combined with other bacteriocidal drugs and datas on effectiveness of pulmonary tuberculosis were so little. Therefore these drugs should be use with other two or three strong-acting drugs in the last period of retreatment of pulmonary tuberculosis. The ofloxacin or ciprofloxacin is used in some area in Korea but randomly and needed more study. We did this study for proving the effectiveness of these drugs and establishment of retreatment regimen for pulmonary tuberculosis. Methods: Retrospective cohort study of 83 drug-resistant pulmonary tuberculosis patients at National Masan Tuberculosis Hospital from Jan. 1994 to dec. 1995 was made. All the patients taken medicine for 2nd ami-tuberculosis regimens for the first lime. We separated the patients by two groups.(Group I : OFX+ PTA + CS+PAS + Injection, Group II: PZA + PTA+ CS + PAS + Injection). We compared the difference between two groups and tested the confidence limit about results after treatment by $\chi$2-test and T-test. Results : 1. The age distribution was most frequent in fourth decade(29.2% in Group I, 37.1% in Group II) and the mean age was 43.9 year in Group I, and 39.0 year in Group II, but had no significant difference between two groups. The sex distribution was more frequent in the males(68.8% in Group I, 85.7% in Group II), but had no significant difference. 2. Family history was 29.2% in Group I, 28.6% in Group II, but had no significant difference. 3. In the respect of extent of disease, far-advanced stare was 60.4% in Group I, 74.3% in Group II, but had no significant difference. 4. The side effects for drugs showed in 58.3% in Group I and 65.7% in Group II, and the gastrointestinal trouble showed 25.0% in Group and arthralgia 34.3% in Group II predominantly respectively and had the significant difference(p<0.05). 5. The negative conversion rate on sputum AFB smear was 87.5% in Group I and 80.0% in Group II, but had no significant difference. But the negative conversion rate on sputum AFB culture was 83.3% in Group I and 57.1 % in Group II and had the significant difference(p<0.05). 6. The success rate of treatment was 87.5 % in Group I and 83.3 % in Group II but had no significant difference. Conclusion : In the retreatment of pulmonary tuberculosis, ofloxacin is useful drug for the patients who are not available to use PZA and can be use effectively substituting for PZA.

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Trend of Medical Care Utilization and Medical Expenditure of the Elderly Cohort (노인 코호트의 의료이용 및 입원진료비 변화 추이 -공.교 의료보험 대상자를 대상으로-)

  • Lee, Kyeong-Soo;Kang, Pock-Soo
    • Journal of Preventive Medicine and Public Health
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    • v.30 no.2 s.57
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    • pp.437-461
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    • 1997
  • Because of a significant improvement in the economic situation and development of scientific techniques in Korea during the last 30 years, the life expectancy of the Korean people has lengthened considerably and as a result, the number of the elderly has markedly increased. Such an increase of the number of aged population brought about many social, economic, and medical problems which were never seriously considered before. This study was conducted to assess the trend of medical care utilization and medical expenditure of the elderly. The data of each patient in the study were taken from computer database maintained for administrative purpose by the Korea Medical Insurance Corporation. The study population was 132,670 who were 60 years old or more and registered in Korean Medical Insurance Corporation from 1989 to 1993. The study subjects were predominantly female(56.3%) and 10,000-20,000 Won premium group(50.6%). The following are summaries of findings : The total increase of the number of inpatient cases was 40.5% from 1989 through 1993. The average annual increase was 3.7% in inpatient medical expenditures per case, 4.4% in inpatient medical expenditures per day and 0.08% in length of stay per case from 1989 through 1993. Cataract was the most prevalent disease of 10 leading frequent diseases in all ages from 1989 through 1993. The case mix in 1993 compared to 1989 revealed that cataract and ischemic cerebral disease were increased whereas essential hypertension and pulmonary tuberculosis were decreased . The average annual increase of medical expenditures was 3.8% in general hospitals, 6.3% in hospitals and 2.4% in clinics. From 1989 through 1993, medical expenditures used by high-cost patients accounted for about 14% to 20% of all expenditures for inpatient care, while they represented less than 2.5% of the elderly population. Time series analysis revealed that total medical expenditures and doctor's fee for inpatient will be progressively increased whereas drug expenditures for inpatient will be decreased. And there will be no change in length of stay. Based on the above results, the factors increasing medical cost and utilization should be identified and the method of cost containment for the elderly health care should be developed systematically.

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Cohort Observation of Blood Lead Concentration of Storage Battery Workers (축전지공장 근로자들의 혈중 연농도에 대한 코호트 관찰)

  • Kim, Chang-Yoon;Kim, Jung-Man;Han, Gu-Wung;Park, Jung-Han
    • Journal of Preventive Medicine and Public Health
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    • v.23 no.3 s.31
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    • pp.324-337
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    • 1990
  • To assess the effectiveness of the interventions in working environment and personal hygiene for the occupational exposure to the lead, 156 workers (116 exposed subjects and 40 controls) of a newly established battery factory were examined for their blood lead concentration (Pb-B) in every 3 months up to 18 months. Air lead concentration (Pb-A) of the workplaces was also checked for 3 times in 6 months interval from August 1987. Environmental intervention included the local exhaust ventilation and vacuum cleaning of the floor. Intervention of the personal hygiene included the daily change of clothes, compulsory shower after work and hand washing before meal, prohibition of cigarette smoking and food consumption at the work site and wearing mask. Mean Pb-B of the controls was $21.97{\pm}3.36{\mu}g/dl$ at the preemployment examination and slightly increased to $22.75{\pm}3.38{\mu}g/dl$ after 6 months. Mean Pb-B of the workers who were employed before the factory was in operation (Group A) was $20.49{\pm}3.84{\mu}g/dl$ on employment and it was increased to $23.90{\pm}5.30{\mu}g/dl$ after 3 months (p<0.01). Pb-B was increased to $28.84{\pm}5.76{\mu}g/dl$ 6 months after the employment which was 1 month after the initiation of intervention program. It did not increase thereafter and ranged between $26.83{\mu}g/dl\;and\;28.28{\mu}g/dl$ in the subsequent 4 tests. Mean Pb-B of the workers who were employed after the factory had been in operation but before the intervention program was initiated (Group B) was $16.58{\pm}4/53{\mu}g/dl$ before the exposure and it was increased to $28.82{\pm}5.66{\mu}g/dl$(P<0.01) in 3 months later (1 month after the intervention). The values of subsequent 4 tests remained between 26.46 and $28.54{\mu}g/dl$. Mean Pb-B of the workers who were employed after intervention program had been started (Group C) was $19.45{\pm}3.44{\mu}g/dl$ at the preemployment examination and gradually increased to $22.70{\pm}4.55{\mu}g/dl$ after 3 months(P<0.01), $23.68{\pm}4.18{\mu}g/dl$ after 6 months, and $24.42{\pm}3.60{\mu}g/dl$ after 9 months. Work stations were classified into 4 parts according to Pb-A. The Pb-A of part I, the highest areas, were $0.365mg/m^3$, and after the intervention the levels were decreased to $0.216mg/m^3\;and\;0.208mg/m^3$ in follow-up tests. The Pb-A of part II was decreased from $0.232mg/m^3\;to\;0.148mg/m^3,\;and\;0.120mg/m^3$ after the intervention. Pb-A of part III and W was tested only after intervention and the Pb-A of part III were $0.124mg/m^3$ in Jannuary 1988 and $0.081mg/m^3$ in August 1988. The Pb-A of part IV not stationed at one place but moving around, was $0.110mg/m^3$ in August 1988. There was no consistent relationship between Pb-B and Pb-A. Pb-B of the group A and B workers in the part of the highest Pb-A were lower than those of the workers in the parts of lower Pb-A. Pb-B of the workers in the part of the lowest Pb-A incerased more rapidly. Pb-B of group C workers was the highest in part I and the lowest in part IV. These findings suggest that Pb-B is more valid method than Pb-A for monitoring the health of lead workers and intervention in personal hygiene is more effective than environmental intervention.

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A cohort study on blood zinc protoporphyrin concentration of workers in storage battery factory (축전지 공장 근로자들의 혈중 Zinc Protoporphyrin에 대한 코호트 연구)

  • Jeon, Man-Joong;Lee, Joong-Jeong;SaKong, Joon;Kim, Chang-Yoon;Kim, Jung-Man;Chung, Jong-Hak
    • Journal of Preventive Medicine and Public Health
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    • v.31 no.1 s.60
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    • pp.112-126
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    • 1998
  • To investigate the effectiveness of the interventions in working environment and personal hygiene for the occupational exposure to the lead, the blood zinc protoporphyrin (ZPP) concentrations of 131 workers (100 exposed subjects and 31 controls) of a newly established battery factory were analyzed. They were measured in every 3 months up to 18 months. Ai. lead concentration (Pb-A) of the workplaces was also checked for 3 times in 6 months interval from August 1987. Environmental intervention included the local exhaust ventilation and vacuum cleaning of the floor. Intervention of the personal hygiene included the daily change of clothes, compulsory shower after work and hand washing before meal, prohibition of cigarette smoking and food consumption at the work site and wearing mask. Mean blood ZPP concentration of the controls was $16.45{\pm}4.83{\mu}g/d\ell$ at the preemployment examination and slightly increased to $17.77{\pm}5.59{\mu}g/d\ell$ after 6 months. Mean blood ZPP concentration of the exposed subjects who were employed before the factory was in operation (Group A) was $17.36{\pm}5.20{\mu}g/d\ell$ on employment and it was increased to $23.00{\pm}13.06{\mu}g/d\ell$ after 3 months. The blood ZPP concentration was increased to $27.25{\pm}6.40{\mu}g/d\ell$ on 6 months (p<0.01) after the employment which was 1 month after the initiation of intervention program. It did not increase thereafter and ranged between $25.48{\mu}g/d\ell$ and $26.61{\mu}g/d\ell$ in the subsequent 4 results. Mean blood ZPP concentration of the exposed subjects who were employed after the factory had been in operation but before the intervention program was initiated (Group B) was $14.34{\pm}6.10{\mu}g/d\ell$ on employment and it was increased to $28.97{\pm}7.14{\mu}g/d\ell$ (p<0.01) in 3 months later(1 month after the intervention). The values of subsequent 4 tests were maintained between $26.96{\mu}g/d\ell$and $27.96{\mu}g/d\ell$. Mean blood ZPP concentration of the exposed subjects who were employed after intervention program had been started (Group C) was$21.34{\pm}5.25{\mu}g/d\ell$ on employment and it was gradually increased to $23.37{\pm}3.86{\mu}g/d\ell$ (p<0.01) after 3 months, $23.93{\pm}3.64{\mu}g/d\ell$ after 6 months, $25.50{\pm}3.01{\mu}g/d\ell$ after 9 months, and $25.50{\pm}3.10{\mu}g/d\ell$ after 12 months. Workplaces were classified into 4 parts according to Pb-A. The Pb-A of part I, the highest areas, were $0.365mg/m^3$, and after the intervention the levels were decreased to $0.216mg/m^3$ and$0.208mg/m^3$ in follow-up test. The Pb-A of part II which was resulted in lowe. value than part I was decreased from $0.232mg/m^3$ to $0.148mg/m^3$, and $0.120mg/m^3$ after the intervention. The Pb-A of part III was tested after the intervention and resulted in $0.124mg/m^3$ in January 1988 and $0.181mg/m^3$ in August 1988. The Pb-A of part IV was also tested after the intervention and resulted in $0.110mg/m^3$ in August 1988. There was no consistent relationship between Pb-A and blood ZPP concentration. The blood ZPP concentration of the group A and B workers in the part of the highest Pb-A were lower than those of the workers in the parts of lower Pb-A. The blood ZPP concentration of the workers in the part of the lowest Pb-A increased more rapidly. The blood ZPP concentration of the group C workers was the highest in part III. These findings suggest that the intervention in personal hygiene is more effective than environmental intervention, and it should be carried out from the first day of employment and to both the exposed subjects, blue color workers and the controls, white color workers.

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Optimum Radiotherapy Schedule for Uterine Cervical Cancer based-on the Detailed Information of Dose Fractionation and Radiotherapy Technique (처방선량 및 치료기법별 치료성적 분석 결과에 기반한 자궁경부암 환자의 최적 방사선치료 스케줄)

  • Cho, Jae-Ho;Kim, Hyun-Chang;Suh, Chang-Ok;Lee, Chang-Geol;Keum, Ki-Chang;Cho, Nam-Hoon;Lee, Ik-Jae;Shim, Su-Jung;Suh, Yang-Kwon;Seong, Jinsil;Kim, Gwi-Eon
    • Radiation Oncology Journal
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    • v.23 no.3
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    • pp.143-156
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    • 2005
  • Background: The best dose-fractionation regimen of the definitive radiotherapy for cervix cancer remains to be clearly determined. It seems to be partially attributed to the complexity of the affecting factors and the lack of detailed information on external and intra-cavitary fractionation. To find optimal practice guidelines, our experiences of the combination of external beam radiotherapy (EBRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT) were reviewed with detailed information of the various treatment parameters obtained from a large cohort of women treated homogeneously at a single institute. Materials and Methods: The subjects were 743 cervical cancer patients (Stage IB 198, IIA 77, IIB 364, IIIA 7, IIIB 89 and IVA 8) treated by radiotherapy alone, between 1990 and 1996. A total external beam radiotherapy (EBRT) dose of $23.4\~59.4$ Gy (Median 45.0) was delivered to the whole pelvis. High-dose-rate intracavitary brachytherapy (HDR-IBT) was also peformed using various fractionation schemes. A Midline block (MLB) was initiated after the delivery of $14.4\~43.2$ Gy (Median 36.0) of EBRT in 495 patients, while In the other 248 patients EBRT could not be used due to slow tumor regression or the huge initial bulk of tumor. The point A, actual bladder & rectal doses were individually assessed in all patients. The biologically effective dose (BED) to the tumor ($\alpha/\beta$=10) and late-responding tissues ($\alpha/\beta$=3) for both EBRT and HDR-ICBT were calculated. The total BED values to point A, the actual bladder and rectal reference points were the summation of the EBRT and HDR-ICBT. In addition to all the details on dose-fractionation, the other factors (i.e. the overall treatment time, physicians preference) that can affect the schedule of the definitive radiotherapy were also thoroughly analyzed. The association between MD-BED $Gy_3$ and the risk of complication was assessed using serial multiple logistic regression models. The associations between R-BED $Gy_3$ and rectal complications and between V-BED $Gy_3$ and bladder complications were assessed using multiple logistic regression models after adjustment for age, stage, tumor size and treatment duration. Serial Coxs proportional hazard regression models were used to estimate the relative risks of recurrence due to MD-BED $Gy_{10}$, and the treatment duration. Results: The overall complication rate for RTOG Grades $1\~4$ toxicities was $33.1\%$. The 5-year actuarial pelvic control rate for ail 743 patients was $83\%$. The midline cumulative BED dose, which is the sum of external midline BED and HDR-ICBT point A BED, ranged from 62.0 to 121.9 $Gy_{10}$ (median 93.0) for tumors and from 93.6 to 187.3 $Gy_3$ (median 137.6) for late responding tissues. The median cumulative values of actual rectal (R-BED $Gy_3$) and bladder Point BED (V-BED $Gy_3$) were 118.7 $Gy_3$ (range $48.8\~265.2$) and 126.1 $Gy_3$ (range: $54.9\~267.5$), respectively. MD-BED $Gy_3$ showed a good correlation with rectal (p=0.003), but not with bladder complications (p=0.095). R-BED $Gy_3$ had a very strong association (p=<0.0001), and was more predictive of rectal complications than A-BED $Gy_3$. B-BED $Gy_3$ also showed significance in the prediction of bladder complications in a trend test (p=0.0298). No statistically significant dose-response relationship for pelvic control was observed. The Sandwich and Continuous techniques, which differ according to when the ICR was inserted during the EBRT and due to the physicians preference, showed no differences in the local control and complication rates; there were also no differences in the 3 vs. 5 Gy fraction size of HDR-ICBT. Conclusion: The main reasons optimal dose-fractionation guidelines are not easily established is due to the absence of a dose-response relationship for tumor control as a result of the high-dose gradient of HDR-ICBT, individual differences In tumor responses to radiation therapy and the complexity of affecting factors. Therefore, in our opinion, there is a necessity for individualized tailored therapy, along with general guidelines, in the definitive radiation treatment for cervix cancer. This study also demonstrated the strong predictive value of actual rectal and bladder reference dosing therefore, vaginal gauze packing might be very Important. To maintain the BED dose to less than the threshold resulting in complication, early midline shielding, the HDR-ICBT total dose and fractional dose reduction should be considered.