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Association between the usage of dental floss and interdental brushes and the prevalence of systemic diseases (치실 및 치간칫솔 사용과 전신질환 유병률의 연관성)

  • Seon-Jip Kim;Hye-Jin Kwon;Hyun-Jae Cho
    • Journal of Korean Dental Hygiene Science
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    • v.7 no.1
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    • pp.17-28
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    • 2024
  • Background: Oral health has a significant impact on systemic health, and the close association between oral and systemic diseases has been continuously reported. To prevent oral diseases, the role of oral hygiene products such as dental floss and interdental brushes, in addition to tooth brushing, is becoming increasingly important. This study aims to analyze the effect of using oral hygiene products on the lifetime prevalence of systemic diseases among Korean adults. Methods: This study utilized data from the 7th Korea National Health and Nutrition Examination Survey (2016-2018). The study population consisted of 13,199 adults aged 19 years and older. The independent variable was the use of oral hygiene products, and the dependent variable was the prevalence of systemic diseases diagnosed by a physician. Demographic variables, health status, and behavioral variables were included as covariates, and multivariable logistic regression analysis was performed. Results: The use of dental floss showed no significant association with the prevalence of systemic diseases. However, those who did not use interdental brushes had a 22% lower likelihood of dyslipidemia (OR 0.777, 95% CI 0.660-0.913). Among participants with periodontal disease, those who did not use dental floss had a significantly higher risk of myocardial infarction (OR 11.488, 95% CI 1.438-91.772). Conversely, those who did not use interdental brushes had lower risks of dyslipidemia, myocardial infarction, and angina, particularly among women and individuals under 65 years of age. Conclusion: This study found a low overall association between the use of oral hygiene products and the prevalence of systemic diseases, but there was a notable association with cardiovascular diseases. To reduce the risk of myocardial infarction, the prevention and treatment of periodontal disease, along with proper oral hygiene management, are crucial. Future prospective studies are needed to clearly establish the causal relationship between oral hygiene and systemic diseases.

A Study on the Itch Relief (Barrier Improvement) Effect of Creams containing Siraitia grosvenorii Extract due to Sk in Moisturizing (나한과추출물 함유 크림의 피부 보습에 기인한 가려움 완화(장벽 개선) 효과에 대한 연구)

  • Yoon-Young Sung;Dong-Seon Kim
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.50 no.3
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    • pp.261-270
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    • 2024
  • In this study, the effects of relieving itching and improving the barrier due to moisturizing human skin were evaluated for the cream containing Siraitia grosvenorii extract, which is effective in suppressing histamine and improving skin inflammation in the study subjects with itching. 43 female volunteers aged 21 ~ 59 years old (experimental group: 21 and control group 22) suitable for the purpose of the study were used for 4 weeks on the anterior gourd. The evaluation measured the amount of skin moisture and transepidermal moisture loss (TEWL) in the left or right anterior gourd before and after use of the product, and the visual analogue scale (VAS) evaluation due to skin drying, the efficacy and usability questionnaire evaluation of the product, and skin safety evaluation were conducted. As a result of the analysis, compared to before product use, both the experimental group and the control group showed significant improvement effects according to product use 4 weeks after use on the evaluation items of skin moisture and transepidermal moisture loss and the VAS due to skin dryness. In particular, the experimental group showed a significant improvement effect compared to the control group. As a result of the survey on the efficacy and usability of the product, the subjects of the study in the test group showed higher satisfaction than the control group in the case of the items "relieving itching (suitable)", "moisturizing" and "smoothing" after four weeks of use. In terms of usability, the subjects of the study in the experimental group showed higher satisfaction than the control group in the case of the "scent" and "feeling" items. Based on the above results, it is believed that "cream containing S. grosvenorii extract" has an itch relief (barrier improvement) effect due to skin moisturizing and can be used as a functional product for itching and barrier function improvement.

The Use of Analgesics in the Last 24 hours of Life of Patients with Advanced Cancer : A Comparison of Medical Physicians and Surgeons (말기 암 환자의 마지막 24시간 동안 진통제 사용의 분석 : 내과의사와 외과의사의 비교)

  • Choi, Youn-Seon;Kim, Jong-Min;Lee, Young-Mee;Lim, Jong-Kuk;Lee, Tai-Ho;Hong, Myung-Ho
    • Journal of Hospice and Palliative Care
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    • v.1 no.1
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    • pp.47-55
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    • 1998
  • Background : It is almost important therapy modality to control pain for the terminal cancer patients for the last 24 hours because those terminally illed patient deserved to have pain free and peaceful time before death. Physician who is deal with terminal cancer patients for their last 24 hours does not need to worry about drug addiction or other untoward side reactions of pain medications. The purpose of this study was to evaluate if terminally illed cancer patient was given pain medication properly and sufficiently and if there was any different behavior to control pain of terminal cancer patients between medical physicians and surgeons in terms of type, amount and administration route and frequency. Methods : A retrospective chart audit of analgesic type, amount and administration route was performed on the medical recorders of 160 hospitalized terminal cancer patients who had died in the Korea University Medical Center Anam Hospital during the period of July 1, 1994 to June 30, 1995. Patients were classified into 103 patients were cared for by medical physicians and 57 patients were cared for by surgeons. After then, we analysed the difference of pain control pattern between them. Different types and amount of analgesics were converted to a common standard, an oral morphine equivalents(OME) relative to 1mg of oral morphine. Results : 1) The total number of patients was 160, male 102 cases(63.8%), and the female was 58 cases(36.2%) respectively. 2) The mean age was 56.4(${\pm}14.62$) years old and mean admission period was 27.8 days(${\pm}34.85$). 3) The frequent cancer site was stomach 42 cases(26.315), lung and liver 29 cases(18.1%) each, pancreas 10 cases(6.2%) in order 4) 125 out of 160 subjects (78.13%) complained pain, and 66 out of 103(64.08%) and 31 out of 57(54.39%) were treated with analgesics to relieve pain. 50 out of 97(51.55%) were able to continue on oral medication. 5) 86 cases(53.75%) were well oriented 24 hours prior to death. 6) The frequent analgesics for regular basis were long acting form of oral morphine 34 cases(Medical phsicians 24, Surgeons 10), intravenous morphine 26 cases(Medical physicians 20, Surgeons 6) in order, and the most common p.r.n.(pro re nata) analgesics used was intravenous morphine. 7) The mean amount of analgesics on regular basis was 115.41 OME by medical physicians and 52.7 OME by surseons(P<0.05). The mean amount of p.r.n. analgesics was significantly larger in patients are for by surgeons(66.64 OME) than medical physicians 23.49 OME(P<0.01). 8) The mean frequency of administrated number of p.r.n. analgesics was 0.62 times/day on medical part and 1.88 times/day on surgical part (P<0.001). Conclusion : Of the 97 patients with advanced cancer, 51.55% were able to take oral medications in the last day of life. The parenteral analgesics were more frequently used in the patients cared for by surgeons than medical physicians. Over the half of terminal cancer patients were well oriented in the last day of life. Doctor's knowledge and attitude towards pain is very important to mange the pain, effectively.

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Influence analysis of Internet buzz to corporate performance : Individual stock price prediction using sentiment analysis of online news (온라인 언급이 기업 성과에 미치는 영향 분석 : 뉴스 감성분석을 통한 기업별 주가 예측)

  • Jeong, Ji Seon;Kim, Dong Sung;Kim, Jong Woo
    • Journal of Intelligence and Information Systems
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    • v.21 no.4
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    • pp.37-51
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    • 2015
  • Due to the development of internet technology and the rapid increase of internet data, various studies are actively conducted on how to use and analyze internet data for various purposes. In particular, in recent years, a number of studies have been performed on the applications of text mining techniques in order to overcome the limitations of the current application of structured data. Especially, there are various studies on sentimental analysis to score opinions based on the distribution of polarity such as positivity or negativity of vocabularies or sentences of the texts in documents. As a part of such studies, this study tries to predict ups and downs of stock prices of companies by performing sentimental analysis on news contexts of the particular companies in the Internet. A variety of news on companies is produced online by different economic agents, and it is diffused quickly and accessed easily in the Internet. So, based on inefficient market hypothesis, we can expect that news information of an individual company can be used to predict the fluctuations of stock prices of the company if we apply proper data analysis techniques. However, as the areas of corporate management activity are different, an analysis considering characteristics of each company is required in the analysis of text data based on machine-learning. In addition, since the news including positive or negative information on certain companies have various impacts on other companies or industry fields, an analysis for the prediction of the stock price of each company is necessary. Therefore, this study attempted to predict changes in the stock prices of the individual companies that applied a sentimental analysis of the online news data. Accordingly, this study chose top company in KOSPI 200 as the subjects of the analysis, and collected and analyzed online news data by each company produced for two years on a representative domestic search portal service, Naver. In addition, considering the differences in the meanings of vocabularies for each of the certain economic subjects, it aims to improve performance by building up a lexicon for each individual company and applying that to an analysis. As a result of the analysis, the accuracy of the prediction by each company are different, and the prediction accurate rate turned out to be 56% on average. Comparing the accuracy of the prediction of stock prices on industry sectors, 'energy/chemical', 'consumer goods for living' and 'consumer discretionary' showed a relatively higher accuracy of the prediction of stock prices than other industries, while it was found that the sectors such as 'information technology' and 'shipbuilding/transportation' industry had lower accuracy of prediction. The number of the representative companies in each industry collected was five each, so it is somewhat difficult to generalize, but it could be confirmed that there was a difference in the accuracy of the prediction of stock prices depending on industry sectors. In addition, at the individual company level, the companies such as 'Kangwon Land', 'KT & G' and 'SK Innovation' showed a relatively higher prediction accuracy as compared to other companies, while it showed that the companies such as 'Young Poong', 'LG', 'Samsung Life Insurance', and 'Doosan' had a low prediction accuracy of less than 50%. In this paper, we performed an analysis of the share price performance relative to the prediction of individual companies through the vocabulary of pre-built company to take advantage of the online news information. In this paper, we aim to improve performance of the stock prices prediction, applying online news information, through the stock price prediction of individual companies. Based on this, in the future, it will be possible to find ways to increase the stock price prediction accuracy by complementing the problem of unnecessary words that are added to the sentiment dictionary.

A Study on Food Safety of Distribution Foods in the Northern Gyeonggi Area (경기북부권역에서의 유통식품 안전성 연구)

  • Kang, Jeung-Bok;Bang, Seon-Jae;Kwon, Yeon-Ok;Jang, Mi-Jung;Oh, Sang-Hun;Park, Jeong-Hwa;Hong, Seung-Hee
    • Journal of Food Hygiene and Safety
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    • v.31 no.5
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    • pp.349-355
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    • 2016
  • This study was performed to investigate food safety of 18,446 distribution foods in the northern Gyeongii area from 2010 to 2014 year. Food safety analysis was conducted by using Korean food code and food additives code. Fail determination about standards and specifications was 184 cases of 18,446 distribution foods, which represented about 1.00% fail rate of total cases. In the case of collected by food sanitation inspector, fail determination was 124 cases of 13,706 foods and showed about 0.90% fail rate. In the case of requested for food safety inspection, fail determination was 42 cases of 3,419 foods and showed about 1.23% fail rate. Results of fail determination by years, 61 cases (about 1.66%) detected fail among 3,683 foods in 2010 year, 37 cases (about 0.96%) detected fail among 3,863 foods in 2011 year, 44 cases (about 1.18%) detected fail among 3,721 foods in 2012 year, 25 cases (about 0.68%) detected fail among 3,669 foods in 2013 year, and 17 cases (about 0.48%) detected fail among 3,510 foods in 2014 year. In distribution of fail rate by month, september was showed the highest fail rate at 2.54% compared with other months. Fail determination by type of foods showed that 23 cases of perilla oil detected fail in 204 foods (about 11.27%), 32 cases of sesame oil detected fail in 394 foods (about 8.12%), 9 cases of pickles detected fail in 177 foods (about 5.08%), and 10 cases of red pepper powder detected fail in 283 foods (about 3.53%). For analysis of fail determination by examination items, microorganism was 28 fail cases (15.22%) and that was the highest level among examination items, linolenic acid and acid value were 27 fail cases (14.67%), iodine value was 19 fail cases (10.33%), content amount was 16 fail cases (8.70%), and sulfur dioxide was 9 fail cases (4.89%). In conclusion, the result of this study indicate that various fail determination items were detected of distribution foods on the market during the past five years and it was showed to higher hazard occurrence potential due to food. Therefore, more strict food safety control will be need for improving human health by prevent food health problem and ensure food safety.

A Comparative Analysis of GBEF According to Image Aquisition Method in Hepatobiliary Scan (간담도스캔의 영상수집방법에 따른 담즙배출율의 비교분석)

  • Kim, Yeong-Seon;Seo, Myeong-Deok;Lee, Wan-Kyu;Song, Jae-Beom
    • The Korean Journal of Nuclear Medicine Technology
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    • v.18 no.2
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    • pp.8-16
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    • 2014
  • Purpose The quantitative analysis of gallbladder emptying is very important in diagnosis of motility disorder of gallbladder and in biliary physiology. The GBEF obtain the statics aquisition method or the dynamic acquisition method in two ways. The purpose of this study is to compare the GBEF value of statics acquisition method and the dynamic acquisition method. And we find the best way for calculate GBEF. Materials and Methods The quantitative hepatobiliary scan with $^{99m}Tc$-mebrofenin was performed of 27 patients. Initial images were acquired statically, for 60 min after injection of the radioactive tracer. And if the gallbladder is visualized to 60 min, performed stimulation of gallbladder (1egg, 200 mL milk). After that, started acquisition of dynamic image for 30 min. After that, image of after fatty meal of the statics method were acquired on equal terms with 60 min image. The statics GBEF was calculated using the images of before fatty meal and post fatty meal by the statics method. The dynamic GBEF was calculated using the images of time of maximum bile juice uptake ($T_{max}$) and time of minimum bile juice uptake ($T_{min}$) images from the gallbladder time-activity curve. A bile juice is secreted from gallbladder while eating a fatty meal. that is named early GBEF and that was calculated using before fatty meal image of the statics method and 1 min image of the dynamic method. Results The result saw very big difference between two according to $T_{max}$. The result, were as follows. 1) In case of less than 1 min, the dynamic mean GBEF was $40.1{\pm}21.7%$, the statics mean GBEF was $51.5{\pm}23.6%$ in 16 cases. The early mean GBEF was $14.0{\pm}29.1%$. The GBEF of statics method was higher because that include secreted bile juice while performed stimulation of gallbladder. A difference of GB counts according to acquisition method and the early bile juice counts was $17.6{\pm}14.8%$ and $13.5{\pm}15.3%$. 2) In case of exceed than 1 min, the dynamic mean GBEF was $31.0{\pm}19.7%$, the statics mean GBEF was $21.3{\pm}19.4%$ in 7 cases. The early GBEF was $-6.9{\pm}4.9%$. The GBEF of dynamic method was higher because that include concentrated bile juice to $T_{max}$. A difference of GB counts according to acquisition method and the early bile juice counts was $14.3{\pm}7.3%$ and $5.9{\pm}3.9%$. Conclusion The statics method is very easy and simple, but in case of $T_{max}$ delay, the GBEF can be lower. The dynamic method is able to calculate accurately in case of $T_{max}$ delay, but in case of $T_{max}$ is less than 1 min, the GBEF can be lower because dynamic GBEF exclude secreted bile juice while performed stimulation of gallbladder. The best way to calculate GBEF is to scan with dynamic method preferentially and to choose suitable method between the two way after conform $T_{max}$ on the T-A curve of the dynamic method.

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The Comparison of Results Among Hepatitis B Test Reagents Using National Standard Substance (국가 표준물질을 이용한 B형 간염 검사 시약 간의 결과 비교)

  • Lee, Young-Ji;Sim, Seong-Jae;Back, Song-Ran;Seo, Mee-Hye;Yoo, Seon-Hee;Cho, Shee-Man
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.2
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    • pp.203-207
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    • 2010
  • Purpose: Hepatitis B is infection caused by Hepatitis B virus (HBV). Currently, there are several methods, Kits and equipments for conducting Hepatitis B test. Due to ununiformed methods, it would cause some differences. To manage these differences, it needs process evaluating function of test system and reagent using particular standard substance. The aim of this study is to investigate tendency of RIA method's reagent used in Asan Medical Center through comparing several other test reagents using national standard substance. Materials and Methods: The standard substance in National Institute of Food and Drug Safety Evaluation's biology medicine consists of 5 things, 4 antigens and 1 antibody. We tested reagents using A, B company's Kits according to each test method. All tests are measured repeatedly to obtain accurate results. Results: Test result of "HBs Ag Mixed titer Performance panel" is obtained match rate compared S/CO unit standard with RIA method and EIA 3 reagents, CIA 2 reagents is that company A's reagent is 94.4% (17/18), 83.3% (15/18), B is 88.9% (16/18), 77.8% (14/18). Test result of "HBs Ag Low titer Performance panel" is obtain that EIA 2 reagents is shown 7 posive results, CIA 3 reagents is 11, and RIA method's company A's reagent is 3, B is 2 of 13 in low panel. "HBV surface antigen 86.76 IU/vial" tested dilution. A is obtain positive results to 600 times(0.14 IU/mL), B is 300 times (0.29 IU/mL). Case of "HBV human immunoglobulin 95.45 IU/vial", A is shown positive result to 10,000 times (9.5 mIU/mL) and B is 4,000 times (24 mIU/mL). Test result of "HBs Ag Working Standards 0.02~11.52 IU/mL" is shown that Company A's kit concentration level was 0.38IU/mL, company B was 2.23 IU/mL and higher level of concentration was positive results. Conclusion: When comparing various test reagents and RIA method according to National Standard substances for Hepatitis B test, we recognized that there were no significant trends between reagents. For hepatitis B virus antigen-antibody titers even in parts of the test up to 600 times the antigen, antibodies to 10,000 times the maximum positive results could be obtained. Therefore, we confirmed that results from Asan Medical Center are performed smoothly by reagents and system for hepatitis B virus test.

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A Clinical and Pathological Analysis of Children with Membranoproliferative Glomerulonephritis According to the Clinical Manifestations at Presentation (발견 양상에 따른 소아 막증식성 사구체신염의 임상적 및 병리조직학적분석)

  • Jeon Chang-Ho;Kang Mi-Seon;Chung Woo-Yeong
    • Childhood Kidney Diseases
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    • v.8 no.2
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    • pp.186-194
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    • 2004
  • Purpose: Membranoproliferative glomeulonephritis(MPGN) has been diagnosed in an increasing number of asymptomatic cases. These cases have been detected by school urinary screening test even though the total cases of MPGN show a decreasing trend. We have analyzed the clinical and pathological characteristics of children with MPGN according to the clinical manifestations at the time of disease presentation. Methods: A total of 18 patients who had been diagnosed with idiopathic MPGN by percutaneous renal biopsy from January 1990 to February 2004 were involved in our study. The patients were divided into 2 groups as the school urinary screening(A) group and the symptomatic(S) group according to the clinical manifestations at the time of disease presentation. Results: Out of the total 18 patients, 8(44.4%) were in the S group and 10(55.6%) were in the A group. The mean serum total protein, albumin and $C_3$ levels in the S group were significantly lower than those levels of the A group, respectively($4.9{\pm}1.2\;g/dL,\;vs\;7.0{\pm}0.5\;g/dL\;P=0.002,\;2.8{\pm}0.9\;g/dL\;vs.\;4.1{\pm}0.3\;g/dL\;P=0.002,\;63.9{\pm}36.4\;mg/dL\;vs.\;100.8{\pm}39.5\;g/dL\;P=0.041$). The mean total protein amount of 24 hour collected urine in the S group were significantly higher than that of the A group($3684.0{\pm}2601.3\;mg/m^2\;vs.\;559.4{\pm}4.6.9\;mg/m^2$, respectively, P=0.001). Hypocomplementemia was observed in 11(61.1%) out of 18 patients at the time of disease onset, 7(87.5%) in the S group and 4(40%) in the A group. However the hypocomplementemia was decreased in 6(33.3%) out of 18 patients at the time of final follow-up, 3(37.5%) in the S group and 3(30%) in the A group. According to the pathologic type, hypocomplementemia was observed 8 patients(61.5%) with type I disease, 1 patients (100%) with type II disease, 2 patients(50%) in type III disease at the disease onset, but 4 patients(30.8%) in type I disease, 1 patient(100%) in type II disease, 1 patient(33.3%) with type III disease at the time of last follow-up. The incidence of cellular crescent formation and tubular atropy. as observed on light microscopy, were higher in the S group compared to the A group. Mean grade of capillary wall thickening and, mesangial proliferation were significantly higher in the S group. Conclusion: MPGN, as diagnosed in patients with only asymptomatic urinary abnormalities, has been increasing, it is more frequent in asymptomatic patients than in patients with presenting symptoms. Our result suggests that MPGN should be considered in the renal biopsy diagnosis regardless of serum $C_3$ level when urinary abnormalities are found by school urinary screening test.

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Status and Prospect of Herbicide Resistant Weeds in Rice Field of Korea (한국 논에서 제초제 저항성잡초 발생 현황과 전망)

  • Park, Tae-Seon;Lee, In-Yong;Seong, Ki-Yeong;Cho, Hyeon-Suk;Park, Hong-Kyu;Ko, Jae-Kwon;Kang, Ui-Gum
    • Korean Journal of Weed Science
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    • v.31 no.2
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    • pp.119-133
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    • 2011
  • Sulfonylurea (SU)-resistant weeds include seven annual weeds such as Monochoria vaginalis, Scirpus juncoides and Cyperus difformis, etc., and three perennial weeds of Scirpus planiculmis, Sagittaria pigmaea and Eleocharis acicularis as of 2010 since identification Monochoria korsakowii in the reclaimed rice field in 1998. The Echinochloa oryzoides resistant to acetyl CoA carboxylase (ACCase) and acetolactate synthase (ALS) inhibitors has been confirmed in wet-direct seeding rice field of the southern province, Korea in 2009. In the beginning of occurrence of SU-resistant weeds the M. vaginalis, S. juncoides and C. difformis were rapidly and individually spreaded in different fields, however, theses resistant weeds have been occurring simultaneously in the same filed as time goes by. The resistant biotype by weed species demonstrated about 10- to 1,000-fold resistance, base on $GR_{50}$ (50% growth reduction) values of the SU herbicides tested. And the resistant biotype of E. oryzoides to cyhalofop-butyl, pyriminobac-methyl, and penoxsulam was about 14, 8, and 11 times more resistant than the susceptible biotype base on $GR_{50}$ values. In history of paddy herbicides in Korea, the introduction of SU herbicides including besulfuron-metyl and pyrazosulfuron-ethyl that control many troublesome weeds at low use rates and provide excellent crop safety gave farmers and many workers for herbicide business refreshing jolt. The products and applied area of SU-included herbicides have been rapidly increased, and have accounted for about 69% and 96%, respectively, in Korea. The top ten herbicides by applied area were composed of all SU-included herbicides by 2003. The concentrated and successive treatment of ACCase and ALS inhibitors for control of barnyardgrass in direct-seeded rice led up to the resistance of E. oryzoides. Also, SU-herbicides like pyrazosulfuron-ethyl and imazosulfuron which are effective to barnyardgrass can be bound up with the resistance of E. oryzoides. The ALS activity isolated from the resistant biotype of M. korsakowii to SU-herbicides tested was less sensitive than that of susceptible biotype. The concentration of herbicide required for 50% inhibition of ALS activity ($I_{50}$) of the SU-resistant M. korsakowii was 14- to 76-fold higher as compared to the susceptible biotype. No differences were observed in the rates of [$^{14}C$]bensulfuron uptake and translocation. ALS genes from M. vaginalis resistant and susceptible biotypes against SU-herbicides revealed a single amino acid substitution of proline (CCT), at 197th position based on the M. korsakowii ALS sequence numbering, to serin (TCT) in conserved domain A of the gene. Carfentrazone-ethyl and pyrazolate were used mainly to control SU-resistant M. vaginalis by 2006, the early period, in Korea. However, the alternative herbicides such as benzobicyclone, to be possible to control simultaneously the several resistant weeds, have been developing and using broadly because the several resistant weeds have been occurring simultaneously in the same filed. The top ten herbicides by applied area in Korea have been occupied by products of 3-way mixture type including herbicides with alternative mode of action for the herbicide resistant weeds. Mefenacet, fentrazamide and cafenstrole had excellent controlling effects on the ACCase and ALS inhibitors resistant when they were applied within 2 leaf stage.

Measuring Intracellular Mycobacterial Killing Using a Human Whole Blood Assay (인체 전혈 모델을 이용한 세포내 결핵균 살균력에 관한 연구)

  • Cheon, Seon-Hee;Song, Ho-Yeon;Lee, Eun-Hee;Oh, Hee-Jung;Kang, In-Sook;Cho, Ji-Yoon;Hong, Young-Sun
    • Tuberculosis and Respiratory Diseases
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    • v.53 no.5
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    • pp.497-509
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    • 2002
  • Background : The mechanisms through which cellular activation results in intracellular mycobacterial killing is only partially understood. However, in vitro studies of human immunity to Mycobacterium tuberculosis have been largely modeled on the work reported by Crowle, which is complicated by several factors. The whole blood culture is simple and allows the simultaneous analysis of the relationship between bacterial killing and the effect of effector cells and humoral factors. In this study, we attempted to determine the extent to which M. tuberculosis is killed in a human whole blood culture and to explore the role of the host and microbial factor in this process. Methods : The PPD positive subject were compared to the umbilical cord blood and patients with tuberculosis, diabetes and lung cancer. The culture is performed using heparinized whole blood diluted with a culture medium and infected with a low number of M. avium or M. tuberculosis $H_{37}Ra$ for 4 days by rotating the culture in a $37^{\circ}C$, 5% $CO_2$ incubator. In some experiments, methlprednisolone- or pentoxifyline were used to inhibit the immune response. To assess the role of the T-cell subsets, CD4+, CD8+ T-cells or both were removed from the blood using magnetic beads. The ${\Delta}$ log killing ratio was defined using a CFU assay as the difference in the log number of viable organisms in the completed culture compared to the inoculum. Results : 1. A trend was noted toward the improved killing of mycobacteria in PPD+ subjects comparing to the umbilical cord blood but there was no specific difference in the patients with tuberculosis, diabetes and lung cancer. 2. Methylprednisolone and pentoxifyline adversely affected the killing in the PPD+ subjects umbilical cord blood and patients with tuberculosis. 3. The deletion of CD4+ or CD8+ T-lymphocytes adversely affected the killing of M. avium and M. tuberculosis $H_{37}Ra$ by PPD+ subjects. Deletion of both cell types had an additive effect, particularly in M. tuberculosis $H_{37}Ra$. 4. A significantly improved mycobacterial killing was noted after chemotherapy in patients with tuberculosis and the ${\Delta}$ logKR continuously decreased in a 3 and 4 days of whole blood culture. Conclusion : The in vitro bactericidal assay by human whole blood culture model was settled using a CFU assay. However, the host immunity to M. tuberculosis was not apparent in the human whole blood culture bactericidal assay, and patients with tuberculosis showed markedly improved bacterial killing after anti-tuberculous chemotherapy compared to before. The simplicity of a whole blood culture facilitates its inclusion in a clinical trial and it may have a potential role as a surrogate marker in a TB vaccine trial.