• Journal of Microbiology and Biotechnology
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• v.28 no.2
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• pp.338-346
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• 2018

Two molecular epidemiologic methods, IS6110 restriction fragment length polymorphism (IS6110-RFLP) and 24-locus mycobacterial interspersed repetitive unit-variable-number tandem repeat (MIRU-VNTR), are used worldwide in studies of Mycobacterium tuberculosis (MTB). Conversely, because of its poor resolution, pulsed-field gel electrophoresis (PFGE) is not widely used for MTB. In this study, we improved the 24-locus MIRU-VNTR and PFGE protocols and compared the effectiveness of these approaches for the molecular typing of MTB using 75 clinical isolates obtained from a cohort investigation of high-risk populations infected with MTB. The 24-locus MIRU-VNTR method demonstrated superior discriminatory ability, followed by PFGE and IS6110-RFLP. Next, we analyzed six isolates with clear epidemiologic connections; that is, isolates from patients who attended the same school. IS6110-RFLP and PFGE identified these samples as the same type. By contrast, according to MIRU-VNTR, two isolates differed from four other isolates at one locus each; one isolate was identified as Mtub29 and the other as QUB-26. In summary, the 24-locus MIRU-VNTR assay was the most useful molecular typing method among the three methods investigated due to its discriminatory power, short time required, and availability as an epidemiologic investigation tool. PFGE was the second-best method. Compared with the other loci assessed in the 24-locus MIRU-VNTR assay, the Mtub29 and QUB-26 loci appeared to exhibit greater variability during transmission.

• Journal of Preventive Medicine and Public Health
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• v.35 no.1
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• pp.65-71
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• 2002

Objective : To estimate the status of HIV infection and AIDS incidence using a back-calculation model in Korea. Methods : Back-calculation is a method for estimating the past infection rate using AIDS incidence data. The method has been useful for obtaining short-term projections of AIDS incidence and estimating previous HIV prevalence. If the density of the incubation periods is known, together with the AIDS incidence, we can estimate historical HIV infections and forecast AIDS incidence in any time period up to time t. In this paper, we estimated the number of HIV infections and AIDS incidence according to the distribution of various incubation periods Results : The cumulative numbers of HIV infection from 1991 to 1996 were $708{\sim}1,426$ in Weibull distribution and $918{\sim}1,980$ in Gamma distribution. The projected AIDS incidence in 1997 was $16{\sim}25$ in Weibull distribution and $13{\sim}26$ in Gamma distribution. Conclusions : The estimated cumulative HIV infections from 1991 to 1996 were $1.4{\sim}4.0$ times more than notified cumulative HIV infections. Additionally, the projected AIDS incidence in 1997 was less than the notified AIDS cases. The reason for this underestimation derives from the very low level of HIV prevalence in Korea, further research is required for the distribution of the incubation period of HIV infection in Korea, particularly for the effects of combination treatments.

• Korean Journal of Community Nutrition
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• v.3 no.2
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• pp.273-280
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• 1998

This study was designed to estimate the improvement of Validity for food frequency questionnaire(FFQ) by offering multiple choice portion size in developing a questionnaire. Validity of the two methods(food frequency questionnaire I=FFQ I & Food frequency questionnaire II=FFQ II) was tested in comparison with reference method of the 7-day weighed record(7DWR). Dietary consumption data of the three methods(FFQ I, FFQ II & 7DWR) were collected from 101 female university students for the analysis. Validity was measured in two categories : One was the nutrient intake value from the three methods, the other was the identification of between individual variation within the group. Spearman's rank order correlation test and distribution graphs were used for the analysis. The result showed that individual intake value of the FFQII was closer to that of the 7DWR than that of the FFQ I.Spearman's rank order correlation between the FFQII and the 7DWR did not show any improved correlation. The distribution graphs of nutrient intake derived from both the FFQ I and the FFQII were different from that of the 7DWR. Therefore, it could be suggested that single one portion size food frequency questionnaire is an equally efficient method as a multiple choice food frequency questionnaire to be adopted in epidemiologic studies.

• Toxicological Research
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• v.30 no.1
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• pp.7-11
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• 2014

Malondialdehyde (MDA), used as an oxidative stress marker, is commonly assayed by measuring the thiobarbituric acid reactive substances (TBARS) using HPLC, as an indicator of the MDA concentration. Since the HPLC method, though highly specific, is time-consuming and expensive, usually it is not suitable for the rapid test in large-scale environmental epidemiologic surveys. The purpose of this study is to develop a simple and rapid method for estimating TBARS levels by using a multiple regression equation that includes TBARS levels measured with a microplate reader as an independent variable. Twelve hour urine samples were obtained from 715 subjects. The concentration of TBARS was measured at three different wavelengths (fluorescence: ${\lambda}-_{ex}$ 530 nm and ${\lambda}-_{em}$ 550 nm; ${\lambda}-_{ex}$ 515 nm and ${\lambda}-_{em}$ 553 nm; and absorbance: 532 nm) using microplate reader as well as HPLC. 500 samples were used to develop a regression equation, and the remaining 215 samples were used to evaluate the validity of the regression analysis. The induced multiple regression equation is as follows: TBARS level (${\mu}M$) = -0.282 + 1.830 ${\times}$ (TBARS level measured with a microplate reader at the fluorescence wavelengths ${\lambda}-_{ex}$ 530 nm and ${\lambda}-_{em}$ 550 nm, ${\mu}M$) -0.685 ${\times}$ (TBARS level measured with a microplate reader at the fluorescence wavelengths ${\lambda}-_{ex}$ 515 nm and ${\lambda}-_{em}$ 553 nm, ${\mu}M$) + 0.035 ${\times}$ (TBARS level measured with a microplate reader at the absorbance wavelength 532 nm, ${\mu}M$). The estimated TBARS levels showed a better correlation with, and are closer to, the corresponding TBARS levels measured by HPLC compared to the values obtained by the microplate method. The TBARS estimation method reported here is simple and rapid, and that is generally in concordance with HPLC measurements. This method might be a useful tool for monitoring of urinary TBARS level in environmental epidemiologic surveys with large sample sizes.

• Journal of Trauma and Injury
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• v.18 no.2
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• pp.94-100
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• 2005

Background: Although trauma has been the major cause of death in korea, there are few reports describing the epidemiologic characteristics of trauma victims according to age-group. Thus, this study aimed to describe the epidemiologic characteristics of trauma victims visiting an urban emergency medical center in Korea. Method: This study was conducted with all trauma victims who visited the emergency departments of Asan Medical Center from April 11, 2005 to May 10, 2005. After the subjects were divided into three groups such as child (${\leq}14$ years old), adult(15-64 years old) and elderly(${\geq}65$ years old), the prehospital courses, injury mechanisms, injury severities and clinical results were compared. Result: Among total 5,927 patients who visited the emergency medical center, 896(15.1%) patients were trauma victims. Although child under the age of 15 comprised 28.7% of the total trauma victims, less severe injuries(injury severity score < 9) accounted for 97.7% of the cases. The hospitalization rate for injury among child was 21.5%. however, although elderly aged 65 comprised only 5.9% of the total trauma victims, more severe injuries(injury severity score ${\geq}9$) accounted for 30.2% of the cases. The hospitalization rate for injury among elderly was 56.4%. Conclusion: Patterns of injury and clinical results by age-group were considerably different. less severe and non-hospitalized injuries were more common in child than other age-groups. while severe and hospitalized injuries were common in elderly.

• Journal of Nutrition and Health
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• v.26 no.9
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• pp.1129-1137
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• 1993

This study was carried out to analyze the effects of dietary and life-style factors on the prevalence of depression in Korea. Epidemiologic data from a nation-wide sample of 2,000 adults who were selected with the stratified random sampling method in Korea were interviewed by trained interviewers. Data were presented on the CES-D, a 20-items self-report depression symptom scale developed by the Center for Epidemiologic Studies in U.S.A. The prevalence of depression among all the respondents was 13.5%, with 13.1% in urban samples and 15.5% in rural samples. The prevalence was higher in females(15.3%) than in males(11.7%). There were highly marked differences in the prevalence of depression by sex(p<0.05), age(p<0.0001), education(p<0.001) and income(p<0.01). Respondents of 60 years and over group, the less educated group(below elementary school graduated), and the less income group(less than 400,000 won/month) reported the highest rate of depression. However subjects' occupation and residence had little relation with the prevalence of depression. Drinking and smoking habit appeared to be highly associated with depression in females(p<0.0001) but not in males. The prevalence of depression and eating behavior were highly related(p<0.005). Male respondents below 20 years, 20-29, and 60 years and over depressed group reported significantly lower energy and protein intakes compared to that of the normal group. However, in the female respondents 20-29 years and 60 years and over depressed groups showed the significantly lower energy and protein intakes compared to those of the normal groups(p<0.05), it can be concluded that the various ecological factors such as epidemiological, dietary, and health factors may affect the prevalence of depression among Korean.

• Communications for Statistical Applications and Methods
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• v.21 no.6
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• pp.487-500
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• 2014

A new method to calculate the transmittable prevalence of an epidemic disease is proposed based on a back-calculation formula. We calculated the probabilities of reactivation and of parasitemia as well as transmittable prevalence (the number of persons with parasitemia in the incubation period) of malaria in South Korea using incidence of 12 years(2001-2012). For this computation, a new probability function of transmittable condition is obtained. The probability of reactivation is estimated by the least squares method for the back-calculated longterm incubation period. The probability of parasitemia is calculated by a convolution of the survival function of the short-term incubation function and the probability of reactivation. Transmittable prevalence is computed by a convolution of the infected numbers and the probabilities of transmission. Confidence intervals are calculated using the parametric bootstrap method. The method proposed is applicable to other epidemic diseases in other countries where incidence and a long incubation period are available. We found the estimated transmittable prevalence in South Korea was concentrated in the summer with 276 cases on a peak at the $31^{st}$ week and with about a 60% reduction in the peak from the naive prevalence. The statistics of transmittable prevalence can be used for malaria prevention programs and to select blood transfusion donors.

• Journal of Korean Academy of Nursing
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• v.31 no.3
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• pp.391-400
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• 2001

Purpose: The purpose of this study was to examine depression in order to identify and improve health care policies promoting health among Korean women. Method: There were 329 participants, all older than 18 years old, and staying in Kyungki-Do, city. The data was collected from July to September 1999. The instrument used for this study was the CES-D (Center for Epidemiologic Studies Depression Scale) to evaluate depression. The collected data was analyzed with frequency, percentage, t-test, ANOVA, $\chi$2-test and Multiple logistic Analysis. Result: The result of this study are as follows: 1. Among the participants, 90.6% had normal to mild depression and 9.4% had severe depression. 2. For general characteristics, there were significant difference in the degree of depression according to age(P=0.0001), and marital status(P=0.0001). As for health related characteristics, the depression scores were affected by health perception(P= 0.0001), menopause(P=0.0005), stress (P= 0.0001) and sexual activity(P=0.0001). 3. There was a significant relationship between marital status and stress. Conclusion: This study suggests that a replicate study is needed. The results are also is useful in developing various nursing intervention programs.

• Journal of Biomedical Engineering Research
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• v.9 no.2
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• pp.159-164
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• 1988

This thesis investigates the Quantitative aspect of epidemic phenomena utilizing the analytical method of discrete time systeMs based on the theory of Markov processes. In particular, the pattern on the epidemic character of turberculosis controlled by prophylaxis and BCG vaccinatioll was analyzed by the markovian model of tuberculosis system which is derived according to the ecologic relationship between nine epidemiologic states of individuals. The quantitative aspects of the model were characterized by digital computer simulations.

• The korean journal of orthodontics
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• v.14 no.1
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• pp.33-37
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• 1984

The prevalence of normal occlusion and malocclusion was assessed by Angle's Classification method for 8989 school students at 7-22 years in Seoul. The occurrence of malocclusion and the need-for orthodontic treatment was 61 per cent among them. Results indicated no significant differences between the sexes for the occlusal relationships of the mandible to the maxille. The prevalence of Class I, Class II, and Class III malocclusion in all malocclusion was shown to be Class I, 45.7 per cent; Class II, 7.6 per cent; and Class III, 7.9 per cent. Class II Division 1 was observed to occur four times frequently compared to Class II Division 2 in Class II malocclusions. Class III malocclusion was shown to occur more frequently compared that of Caucasians.