• Journal of Radiation Protection and Research
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• v.47 no.3
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• pp.158-166
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• 2022

Background: The effects of radiation on the health of radiation workers who are constantly susceptible to occupational exposure must be assessed based on an accurate and reliable reconstruction of organ-absorbed doses that can be calculated using personal dosimeter readings measured as H_p(10) and dose conversion coefficients. However, the data used in the dose reconstruction contain significant biases arising from the lack of reality and could result in an inaccurate measure of organ-absorbed doses. Therefore, this study quantified the biases involved in organ dose reconstruction and calculated the bias-corrected H_p(10)-to-organ-absorbed dose coefficients for the use in epidemiological studies of Korean radiation workers. Materials and Methods: Two major biases were considered: (a) the bias in H_p(10) arising from the difference between the dosimeter calibration geometry and the actual exposure geometry, and (b) the bias in air kerma-to-H_p(10) conversion coefficients resulting from geometric differences between the human body and slab phantom. The biases were quantified by implementing personal dosimeters on the slab and human phantoms coupled with a Monte Carlo method and considered to calculate the bias-corrected H_p(10)-to-organ-absorbed dose conversion coefficients. Results and Discussion: The bias in H_p(10) was significant for large incident angles and low energies (e.g., 0.32 for right lateral at 218 keV), whereas the bias in dose coefficients was significant for the posteroanterior (PA) geometry only (e.g., 0.79 at 218 keV). The bias-corrected H_p(10)-to-organ-absorbed dose conversion coefficients derived in this study were up to 3.09- fold greater than those from the International Commission on Radiological Protection publications without considering the biases. Conclusion: The obtained results will aid future studies in assessing the health effects of occupational exposure of Korean radiation workers. The bias-corrected dose coefficients of this study can be used to calculate organ doses for Korean radiation workers based on personal dose records.

• Journal of Microbiology
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• v.41 no.3
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• pp.232-238
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• 2003

Previous phylogenetic studies on human immunodeficiency virus type 1 (HIV-1) isolated from Korean patients suggest that the major subtype of Korean isolate is subtype B. In this subtype, some of the Korean isolates seem to be clustered exclusively of foreign isolates. Presence of this so-called “Korean clade” among Korean isolates is unique but needs verification since the number of Korean isolates used in previous studies was limited. This study aimed to identify the presence of the “Korean clade” by molecular phylogenetic analysis using all the Korean nef gene sequences registered in the NCBI GenBank (N=243) together with 32 reference strains and 77 foreign isolates. Extensive analysis of the nef gene nucleotide sequences by neighbor-joining method revealed the following. Most (83.1 ％) of the Korean isolates belonged to subtype B, and 81.2％ of subtype B were clustered together and excluded foreign isolates (bootstrap value=91.9％ ). Within Korean subtype B cluster, no characteristic subcluster formation was evident since the bootstrap values for the subcluster were very low. Due to limited information, the phylogenetic analysis failed to identify the epidemiological linkage among specific groups such as homosexuals and hemophiliacs within the Korean subtype B cluster. Detailed analysis and epidemiological information are needed to clarify the origin and significance of the Korean subtype B cluster.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3969-3974
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• 2013

The purpose was to provide a descriptive epidemiological assessment of the incidence of cancer of the larynx in Kazakhstan and spatial evaluation with gender characteristics. Thgis retrospective study covered all new cases of laryngeal cancer in 11 years (1999-2009). The total number was 4,967 cases, 4,535 (91.3%) in males and 432 (8.7%) in women, with a ratio of 10.5:1. The higher incidence in men compared to women was evident in all age groups, the differences being statistically significant (p<0.05). At the same time revealed a unimodal growth with age, peaking at 70 years and older both sexes. In the dynamics, incidence rates of laryngeal cancer demonstrated a tendency to decrease, in women (T=-6.7%) this being more pronounced than in men (T=-3.3%). Levels were determined to produce cartograms of cancer of the larynx for male and female populations, clear geographical variation being evidenced. The data are discussed with reference to possible risk factors.

• Journal of Veterinary Clinics
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• v.17 no.1
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• pp.102-108
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• 2000

This study was carried out to investigate the epidemiological prevalence of diseases from birth to weaning in 66 dairy calves which were delivered from three stock farm in Chonbuk area. We examined body weight gain, incidence rate of diseases and population mortality rate in relation to age, season, environmental temperature and rearing management conditions for one year. The results of this experiment were as follows: Birth weight of dairy calves born of primiparae was lower than those of multiparae. But no significant difference in body weight gain was observable between dairy calves born of primiparae and those of multiparae. Body weight gain of diseased calves was lower than normal calves. Of 66 delivered calves, 34 calves(51.5%) were affected with gastronitestinal and/or respiratory diseases. The prevalence of the diseases were gastrointestinal disease(28.7%), respiratory disease(18.2%), and gastronitestinal and respiratory disease(4.6%). The gastronitestinal disease was occurred contrinually regardless of the season. Whereas all of the respiratory disease were occurred in winter and a change of season(December to April). 68.4% of the gastronitestinal disease, and all of the respiratory disease were occurred at atmospheric temperatures below 1$0^{\circ}C$. 89.5% of the gastronitestinal disease were occurred within 3 weeks old, whereas 50% of the respiratory disease were occurred intensively between 3 weeks and 4 weeks old. Of 66 delivered dairy claves, 2 calves were died(3%) with respriratory disease.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.95-102
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• 2003

Because Staphylococcus aureus (S. aureus) has variable number of short sequence repeat region in coagulase gene, it has been used to investigate the relatedness of S. aureus isolates. In this study, we isolated S. aureus strains from 20 dairy farms with bovine mastitis from September 2000 to August 2001. PCR-RFLP analysis of coagulase gene revealed 10 different patterns. Most of the S. aureus isolates showed only one coagulase gene RFLP pattern per farm. However, there were several S. aureus clones spreading between dairy farms. All the farms showed poor management conditions of milking machine and milker, indicating that managements for mastitis control program include use of proper milking matching, premilking sanitation, and segregation in the S. aureus infection herd. Our data suggest that PCR-RFLP analysis of coagulase gene might be applicable for the epidemiological investigations of S. aureus isolated from bovine mastitis cows.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4015-4023
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• 2013

Cancer of the cervix is the third most common cancer in women worldwide, more than 85% of the cases occurring in developing countries such as China. In China, since a national cancer registry is already set up but with geographically limited data generated, the burden of cervical cancer is believed to be underestimated. High-risk human papillomavirus (HR-HPV) prevalence among women attending routine cervical cancer screening programs has been shown to correlate well with cervical cancer incidence rates based on independently obtained HPV prevalence data as well as findings for the worldwide cervical cancer burden. Therefore, reviewing data on HR-HPV prevalence in population-based screening studies and hospital-based case studies will be important in the context of better understanding the cervical cancer burden and for the evaluation of the potential impact of HPV vaccination in the country. With the advent of prophylactic vaccines, significant progress is likely to be made in cervical cancer prevention. This article reviews available data on the HPV epidemiology over a 12-year time period (2001-2012) in mainland China under different epidemiological aspects: by age group of study population, by ethnicity, by geographic area, as well as time period. The authors also review the potential acceptability of HPV vaccination among Chinese women.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.211-215
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• 1984

Forty one male workers employed in an underwater construction field were surveyed in the viewpoints of epidemiological analysis of decompression sickness (caisson's disease). Nineteen out of the entire forty one workers have been, or had been suffering from decompression sickness (as 46.3% of incidence rate) after decompression. The results obtained were as follows: 1. There was a significant relation between duration of work and incidence of disease. 2. Type II (severe type) comprised majority of cases (16 cases, 84.2%) despite any significant correlations were not present between severity types and recompression times. 3. Most frequently cited symptoms were lower limb pain (89.5%), upper limb pain (79.0%), pruritus (68.4%) and so on, however, 10% of patients complained of neurological symptoms. 4. There were not any significant correlations between disease incidence and worker's age or relative body weight.

• Safety and Health at Work
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• v.4 no.3
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• pp.123-135
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• 2013

Exposure to manganese (Mn) is associated with neurobehavioral effects. There is disagreement on whether commonly occurring exposures in welding, ferroalloy, and other industrial processes produce neurologically significant neurobehavioral changes representing parkinsonism. A reviewof methodological issues in the human epidemiological literature onMnidentified: (1) studies focused on idiopathic Parkinson disease without considering manganism, a parkinsonian syndrome; (2) studies with healthy worker effect bias; (3) studies with problematic statistical modeling; and (4) studies arising from case series derived from litigation. Investigations with adequate study design and exposure assessment revealed consistent neurobehavioral effects and attributable subclinical and clinical signs and symptoms of impairment. Twenty-eight studies show an exposure-response relationship between Mn and neurobehavioral effects, including 11 with continuous exposure metrics and six with three or four levels of contrasted exposure. The effects of sustained low-concentration exposures to Mn are consistent with the manifestations of early manganism, i.e., consistent with parkinsonism. This is compelling evidence thatMnis a neurotoxic chemical and there is good evidence that Mn exposures far below the current US standard of $5.0mg/m^3$ are causing impairment.

• Safety and Health at Work
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• v.3 no.2
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• pp.110-116
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• 2012

Establishing a causal relationship between factors at work and disease is difficult for occupational physicians and researchers. This paper seeks to provide arguments for the judgement of evidence of causality in observational studies that relate work factors to disease. I derived criteria for the judgement of evidence of causality from the following sources: the criteria list of Hill, the approach by Rothman, the methods used by International Agency for Research on Cancer (IARC), and methods used by epidemiologists. The criteria are applied to two cases of putative occupational diseases; breast cancer caused by shift work and aerotoxic syndrome. Only three of the Hill criteria can be applied to an actual study. Rothman stresses the importance of confounding and alternative explanations than the putative cause. IARC closely follows Hill, but they also incorporate other than epidemiological evidence. Applied to shift work and breast cancer, these results have found moderate evidence for a causal relationship, but applied to the aerotoxic syndrome, there is an absence of evidence of causality. There are no ready to use algorithms for judgement of evidence of causality. Criteria from different sources lead to similar results and can make a conclusion of causality more or less likely.

• Korean Journal of Veterinary Service
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• v.34 no.3
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• pp.227-234
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• 2011

Brucella (B.) abortus is a facultative intracellular pathogen that infects a wide variety of animal species and human. Brucellosis is the zoonosis and an extremely important disease around the world. Although the eight species can be differentiated by conventional phenotypic tests, these species display a high degree of DNA homology in DNA-DNA hybridization assay (>90%). Various methods have been established for genotyping of Brucella species, but most of analytical methods are lack reproducibility and limited capability to differentiate them. The attempt of this study was to evaluate multiple-locus VNTR analysis (MLVA) for use of epidemiological trace-back analysis in bovine brucellosis. Ninety-four B. abortus isolates from Gyeongbuk province during 2006~2010 were analyzed using 16 VNTR locus. High resolution automatic capillary electrophoresis system was used for more throughput, simpleer, faster, and better discriminable than conventional gel electrophoresis. As a result, 13 different genotypes were identified from 94 B. abortus isolates. MLVA could contribute to epidemiological trace-back analysis of bovine brucellosis.