• Tuberculosis and Respiratory Diseases
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• v.50 no.1
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• pp.94-105
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• 2001

Background : Examining the biological susceptibility of Mycobacterium tuberculosis to pyrazinamide (PZA) in vitro is very difficult as PZA is inactive under normal culture conditions. The biological susceptibility test, an enzyme assay for Pzase activity, and a genetic test for pncA gene mutations, were performed in order to predict PZA resistance. Methods : 28 cultured clinical isolates of Mycobacterium tuberculosis were tested. The biological susceptibility was performed by the absolute concentration method using Lowenstein-Jensen media. The PZase activity was tested by means of Wayne's method. A 710-bp region includes the entire open reading frame of pncA was amplified and sequenced. Results : All six strains with positive PZase activity exhibited no pncA mutations with one strain showing a false resistance in the biological susceptibility test. Among the 22 strains with no PZase activity, 21 exhibited showed pncA mutations. In the biological susceptibility test, 20 strains were resistant, and one was susceptible, and the other flied to test. The mutation types varied with ten missense, one silent and one nonsense mutation 1 slipped-strand mispairing, and 6 frameshift mutations. Three strains had an adenine to guanine mutation at position -11 upstream of the start codon. Conclusion : The mutation at the pncA promotor region is frequent at -11 upstream position. Automatic sequencing of pncA is a useful tool for rapid and accurate detection of PZA resistant M. tuberculosis, and for demonstrating the epidemiological relatedness of the PZA resistant M. tuberculosis strains.

• Tuberculosis and Respiratory Diseases
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• v.58 no.4
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• pp.392-398
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• 2005

Background : The last national tuberculosis survey was carried out in 1995. In 2000, the KTBS(Korean Tuberculosis Surveillance System) replaced a previous national survey. However, the KTBS does not show some of the important epidemiological indexes such as the prevalence of positive tuberculosis or the drug resistance rate. The aim of this study was to compare the clinical features of pulmonary tuberculosis patients admitted to a national tuberculosis hospital in 1995 and 2002. From this study, the authors expect to estimate the trend of the clinical features of tuberculosis in Korea even though it can not represent the Korean tuberculosis situation as a whole. Method : A cross sectional analysis of the clinical features for 331 pulmonary tuberculosis in-patients admitted to the National Masan Tuberculosis Hospital as of Dec. 2002, was carried out and these results were compared with those reported in 1995. Results : In comparison with the data reported in 1995, the mean age was increased by 3.6 years ($44.1{\pm}14.6$ vs $47.7{\pm}16.4$, p<0.01). The number of past tuberculosis history and used anti-tuberculous drugs prior to admission decreased from $2.0{\pm}1.7$ and $6.1{\pm}2.3$ to $1.7{\pm}1.8$ and $4.6{\pm}3.6$(p<0.05, p<0.001), respectively. While the resistance rate for anti-tuberculous drugs was similar (81.0% vs 77.6%), the initial resistance rate(10.5% vs 21.4%) and initial MDR rate(2.4% vs 16.5%) increased significantly(p=0.012, p=0.001, respectively). In 1995, the public health communities were in charge of approximately 65% of newly diagnosed tuberculosis cases, but this reduced to 40.5% in 2002(p<0.001). Conclusion : The existing national TB program (NTP) needs to be revised and strengthened in order to cope with the unfavorably changing situation of the domestic TB problem because the number of TB patients has not decreased and the initial resistance rate has increased greatly. Furthermore, the public and private sectors should cooperate each other to control the TB problem effectively because the private sector is now managing more than half of the TB patients.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.533-547
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• 1997

In periodontics, much progress was made in the understanding of periodontal disease from 1960s to 1980s and in prevention and management of periodontal disease since the end of 1980s. This presentation will discuss about the prevalence of periodontal disease, treatment need, and provision of periodontal treatment in Korea, and how we could manage the periodontal disease efficiently in the future. According to an epidemiological study in Korea, periodontal disease(including gingivitis) was present in 82% of general population and periodontitis in 30-40% in adult population over 30y and juvenile periodontitis in 0.1% of adolescents. If we consider that at least 17% of these patients may have recurrent or refractory forms, there is obviously an abundance of disease that needs treatment, As a result of increase in life expectancy, senile population over 65 y will be increased from 6% in 1996 to 6.9% in 2000, and tooth retention rate and periodontal treatment need are expected to increase. Periodontists need all the help they can get from the general dentists to control periodontal disease. As for provision, postgraduate course in periodontics started in 1957 in Korea and produced over 700 specialized dentists in periodontics. One report indicated that the periodontists as well as general practitioners did periodontal therapy on only a few periodontal patients, because of specific control by current medical insurance system in Korea. Comprehensive periodontal examination is rarely done in local dental clinic. Therefore, enhancement of periodontal care in medical insurance system and education of simplified periodontal examination such as Periodontal Screening & Recording will make dentists diagnose and manage the management of adult patients is based on the recognition that there are multiple diseases, including gingivitis, chronic adlt periodontitis, and other more aggressive forms of periodontitis, and requires the earliest possible recognition of these three disease categories. In this presentation, we discuss practical approach using PSR to diagnose, manage and refer the patients, to facilitate the separation of the simple from the complex and the predictable from the unpredictable form of periodontal diseases and to integrate diagnostic and therapeutic techniques into private practice today.

• Journal of Life Science
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• v.20 no.7
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• pp.1078-1085
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• 2010

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) are bioaccumulative chemicals that are considered to be toxic contaminants based on several epidemiological studies. These chemicals in colostrum were investigated and estimated for their residual consistencies by maternal characteristics like parity and maternal ages. Test subjects were healthy primipara and multipara mothers with a mean age of 31.5 (S.D=3.6) in 2007. Seven isomers of PCDDs, 10 of PCDFs, 4 of non-orthopolychlorinated biphenyls(non-ortho PCBs) and 8 of mono-orthochlorinated polychlorinated biphenyls (mono-ortho PCBs) were analyzed by HRGC/HRMS. From the analyzed data, the mean level of total WHO-TEQs was 9.41 pg TEQ/g lipid, which is significantly lower than the level found in individuals from other countries. The main contributors to the total WHO-TEQs with increasing percentages were 2,3,4,7,8-PeCDF, 1,2,3,7,8-PeCDD and 3,3',4,4',5-PCB (#126), and they accounted for more than 60% of the total WHO-TEQs. PCDFs concentrations and total WHO-TEQs were negatively associated with parity (p<0.05), and maternal age was positively associated with total WHO-TEQs (p<0.01). However, the associations with body mass index (BMI) and fish intake during pregnancy were not significant. These results were suggested that parity and maternal age are an important factor affecting the concentrations of PCDD/DFs and dl-PCBs in these specimens.

• Journal of Preventive Medicine and Public Health
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• v.9 no.1
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• pp.1-10
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• 1976

This study was conducted in order to observe some descriptive epidemiological findings and causes of life-long labour force loss in the rural population of Korea, and to consider, on the basis of these observations, some principles of the necessary control measures. The total number of subjects in the study was 27,172, all family members of 4,174 households. The study population was located in the 81 counties, out of a total of 138 counties, where the college students conducted service activities during the summer of 1974. In each village area where these service activities were conducted, one household per student interviewer was randomly selected. Student interviewers were instructed on the contents of the questionnaire prior to the survey. The main contents of the questionnaire form included address, name, sex and age of each family members, and present life-long labour force loss, if any, of each family member. In cases of current labour force loss, the age of onset and causes were recorded. Of the total households surveyed, 8.9% had family members (1-4 in number) with life-long labour force loss. Of the total persons surveyed, the crude prevalence rate for life-long labour force loss was 15.1 per 1,000; and the age-standardized prevalence rates for male and female were 16.3 per 1,000 and 13.4 per 1,000, respectively. The rates, in both sexes, were gradually increased as the ages were increased. The prevalence rates per 1,000, in order, for life-long labour force loss by the causes were 10.2 for senility, 2.4 for impairment of extremities, 1.2 for chronic diseases of internal organs, 0.5 for other conditions of muosculoskeletal system, 0.4 for blindness in both eyes, 0.2 for impairment of spine, 0.2 for psychoses, and 0.1 for epilepsy. Among them the causes of impairment of extremities were stroke, poliomyelitis, accidents, arthritis and injury due to war operation, in that order of higher relative frequency. The frequency ratios by age of onset were also observed by the causes and sex.

• Tuberculosis and Respiratory Diseases
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• v.54 no.5
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• pp.485-494
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• 2003

Background : Most previous studies regarding the role of GSTMl and GSTT1 on lung cancer risk have been focused mainly on male smokers. However, epidemiological characteristics, histologic types and risk factors are different in female and male lung cancers, we investigated the association between these genotypes and lung cancer risk in males and females separately. Materials and Methods : The study population consisted of 253 lung cancer (153 males and 100 females) and 243 controls (140 males and 103 females). GSTM1 and GSTT1 genotypes were determined by a multiplex PCR. Results : In the male population, neither GSTM1 nor GSTT1 null genotype showed significant difference between cases and controls. In the female population, the frequencies of GSTM1 null genotype showed no significant difference between cases and controls. However, the frequencies of GSTT1 null genotype was significantly higher in cases (70.3%) than controls (55.3%, odds ratio (OR)=2.18; 95% confidence interval (CI=l.21-3.93). When the female population was stratified by age and smoking status, the ORs for GSTT1 null genotype were significantly higher in subgroups of ${\leq}60$ years (OR=4.82; 95% CI=l.61-14.4) and never-smokers (OR=4.29; 95% CI=1.94-9.48) but not in subgroups of >60 years or smokers. When stratifying the female never-smokers by age, the ORs for GSTT1 null genotype were significantly higher in both age groups of ${\leq}60$ years (OR=7.64; 95% CI=2.00-29.2) and >60 years (OR=2.89; 95% CI=1.05-7.94). Conclusion : We found that GSTT1 null genotype was associated with an increased risk of lung cancer in Korean female never-smokers. This result suggests that GSTT1 null genotype could be used as a biomarker for genetic susceptibility to lung cancer in Korean female never-smokers.

• Tuberculosis and Respiratory Diseases
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• v.58 no.6
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• pp.570-575
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• 2005

Introduction : Diffuse interstitial lung diseases (DILD) comprise of a large group of lung diseases with diverse etiologies. They are classified into four categories based on the etiology and pathological findings. In Korea, epidemiological data on DILD has never been reported in a prospective manner. Method : From May 2002 to April 2004, total 487 patients with DILD were prospectively registered at Samsung Medical Center. The prospective observational analysis of the etiologies, its classification based on 2002 ATS/ERS (American Thoracic Society/European Respiratory Society) guidelines, as well as diagnostic tests and the retrospective analysis of the treatment modalities were carried out. Any infectious and malignant causes were excluded. Results : 1) The patients were classified into idiopathic interstitial pneumonia (IIP) in 269 patients (55.2%), known causes of DILD in 168 patients (34.5%), sarcoidosis in 27 patients (5.5%), other forms of DILD in 14 patients (2.9%), and undetermined DILD in 9 patients (1.9%). 2) The diagnostic test showed that most patients had undergone chest high resolution computed tomography (HRCT) and pulmonary function test (PFT) (97%, 89%). Transbronchial lung biopsy (TBLB) and surgical lung biopsy (SLB) were performed in limited patients (38%, 29%). 3) Among 269 patients with IIP, 220 (82%) had idiopathic pulmonary fibrosis (IPF) while 23 (9%) had nonspecific interstitial pneumonia. SLB was carried out in 36% of patients with IIP. 4) Symptomatic supportive care was given to 67% of IPF, but specific medical treatment including corticosteroids was administered to 89% of non-IPF patients. Conclusion : A nationwide registry of DILD patients is required to determine the annual incidence, etiology, and practice pattern of diagnosis and treatment in Korea.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.386-395
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• 2007

A total of 27 strains of Vibrio parahaemolyticus (18 strains isolated from Korea and 9 strains from Japan) were serotyped and examined for biochemical characteristics, antimicrobial susceptibility patterns, cytotoxicity assay, thermostable direct hemolysin (TDH) production and molecular epidemiology. Using polymerase chain reaction (PCR) method and DNA probe hybridization method, the strains were tested for toxR, tdh, trh and ORF 8 genes. The V. parahaemolyticus isolated from patients were belonged to 8 different serotypes : O3:K6, O1:K38, O3:K57, O4:K9, O4:Kl2, O4:K68, O5:Kl5 and O6:K46. Urease-positive strain possessed the trh gene, and conversely, urease-negative strains lacked the gene, indicating that urease production by V. parahemolyticus strains strongly correlates with the possession of the trh gene. Most strains showed multiple resistant to more than three antibiotics and the antibiogram could be classified into 6 group (I to VI). All of the O3:K6 strains isolated in South Korea and Japan producted TDH at high levels. The TDH titers ranged between 256 and 2.048, and the average titer was 1009. To distinguish the new and increasingly common V. parahaemolyticus strains from clinical isolates, ORF 8 is a useful genetic marker. After Southern hybridization, the HindIII restriction fragment patterns of the tdh gene were grouped one type, respectively. One type showed two bands one of which was 4.3kb and the other was 11.5kb in size. Variation between the O3:K6 serotype are minor when compared to the differences seen with the non O3:K6 strains. The migration patterns of Not I -digested of the total DNA of the O3:K6 strains were similar, and only slight variations were observed between the serotypes. By contrast, the O3:K6 strains and non O3:K6 had markedly different profiles. In conclusion, Random amplified polymorphic DNA (RAPD) profile using appropriate primers was an effective epidemiological marker.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.2
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• pp.99-104
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• 2006

Human Papilloma viruses (HPVs) are etiological agents for cervical cancer and are classified into low- and high-risk categories. The aim of this study was to determine the frequency of the HPV genotype in the HPV screening test of Korean women using PCR-direct sequencing. Consensus primers of L1 legion were used for the amplification of HPV DNA and the PCR products (450 bps) obtained were analyzed by automatic sequencing. Sequences were compared with those in GenBank by using the BLAST program. Cervical swab samples of 3,978 women (20-73 years) were tested and the average age was 37.6 years. In this study, 1,174 samples were HPV positive out of 3,978 cervical swab samples screened (29.5%) and 136 samples (11.6%) showed a double infection. A total of 1,310 HPV genotypes were analyzed. The HPV positive rate was the lowest in the 20 years group (69.5%) and most of the samples of the > 60 years group were found HPV positive. Among thirty seven different HPV types identified by sequencing, 21 were HPV high risk types and 16 HPV low risk types were 69.8% (914/1,310) and 26.0% (340/1,310), respectively. In HPV high-risk types, 16 (13.21%), was the most frequently found. HPV 53 (9.62%) and 58 (9.24%) were also frequently found. This group was followed by HPV types 70 (5.50%), 33 (4.73%), 66 (4.20%), 18 (4.05%), 52 (4.05%), 31 (3.97%) and 56 (3.51%) in descending order of frequency. Among HPV low-risk types, 62 (4.20%), 6 (3.59%), 81 (3.59%), 84 (3.51%), and 11 (2.6%) were frequently found. In conclusion, PCR-direct sequencing could be used for quick and reliable typing of known and novel HPVs from clinical specimens. This data could be useful for epidemiological study of HPV and it also allows type-specific follow-up of women who have been treated for cervical intraepithelial neoplasia.

• Journal of fish pathology
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• v.25 no.3
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• pp.263-270
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• 2012

This study surveyed for the prevalence of parasites, bacteria and viruses in four fish species, olive flounder (Paralichthys olivaceus), red sea bream (Pagrus major), black sea bream (Acathopagrus schlegeli) and black rockfish (Sebastes schlegeli) in 2010. The survey was aimed to compare the pathogens detected from wild and cultured fish for an epidemiological study. Anisakis sp. was predominantly detected from wild olive flounder and red sea bream (58.6% and 41.7% respectively), but not from the cultured fishes, suggesting anisakid infection is rare in cultured fish. The wild fish get in contact with the anisakids through their prey such as small fishes or crustaceans which carry the anisakids; whereas the cultured fish are fed with formulated feed, free of anisakids. Bacterial detection rates from the wild fishes examined in the study were lower than those of cultured fishes. Vibrio sp. dominated among detected bacterial population in cultured olive flounder (18%). Since vibriosis is known as a secondary infection caused by other stressful factors such as parasitic infections, handling and chemical treatment, it seems that cultured olive flounder are exposed to stressful environment. Viruses diagnosed in the study showed difference in distribution between wild and cultured fishes; hirame rhabdovirus (HRV) (0.1%) and lymphocystis disease virus (LCDV) (3.9%) were detected in the cultured olive flounder, but not in the wild fish, and marine birnavirus (MBV) (1.7%) and red sea bream iridovirus (RSIV) (3.2%) were detected from the wild and cultured red sea bream, respectively. From the survey conducted, it can be concluded that even though some pathogens (Trichodina sp., Microcotyle sp., etc.) are detected from both the wild and cultured fish, pathogens such as Anisakis sp., Vibrio sp. and LCDV showed difference in distribution in the wild and cultured host of same fish species and this can be attributed to their environmental condition and feeding.