• Parasites, Hosts and Diseases
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• v.51 no.3
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• pp.363-367
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• 2013

The prevalence of Toxoplasma gondii infection in birds has epidemiological significance because birds are indeed considered as a good indicator of environmental contamination by T. gondii oocysts. In this study, the prevalence of T. gondii in 313 house sparrows in Lanzhou, northwestern China was assayed by the modified agglutination test (MAT). Antibodies to T. gondii were positive in 39 (12.46%) of 313 samples (MAT titer ${\geq}$ 1:5). Tissues of heart, brain, and lung from the 39 seropositive house sparrows were tested for T. gondii DNA, 11 of which were found to be positive for the T. gondii B1 gene by PCR amplification. These positive DNA samples were typed at 9 genetic markers, including 8 nuclear loci, i.e., SAG1, 5'- and 3'-SAG2, alternative SAG2, SAG3, GRA6, L358, PK1, c22-8 and an apicoplast locus Apico. Of them, 4 isolates were genotyped with complete data for all loci, and 2 genotypes (Type II variants; ToxoDB #3 and a new genotype) were identified. These results showed that there is a potential risk for human infection with T. gondii in this region. To our knowledge, this is the first report of T. gondii seroprevalence in house sparrows in China.

• Proceedings of the Korean Society of Toxicology Conference
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• 2006.11a
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• pp.46-54
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• 2006

The methylmercury (MeHg) is a toxic environmental pollutant, causing serious neurological and developmental effects in humans. Recent epidemiological studies have indicated that ingestion of MeHg in fish during pregnancy can result in neuroethological effects in the offspring. However, the mechanism underlying the MeHg-toxicity is not fully understood. To elucidate the mechanisms of toxicity of MeHg and of defense against MeHg, we searched for factors that determine the sensitivity of yeast cells to MeHg, and found that overexpression of Cdc34, a ubiquitin-conjugating enzyme (E2) that is a component of the ubiquitin-proteasome (UP) system, induces a resistance to MeHg toxicity in both yeast and human cells. The UP system is involved in the intracellular degradation of proteins. When Cdc34 is overexpressed in cells, ubiquitination reactions are activated and the degradation of certain proteins by the UP system is enhanced. Therefore, it seems likely that certain as-yet-unidentified proteins that increase MeHg toxicity might exist in cons and that toxicity might be reduced by the enhanced degradation of such proteins, mediated by the UP system, when Cdc34 is overexpressed. SCF ubiquitin-ligase is a component of UP system and consists of Skpl, the scaffold protein Cdc53, the RING-finger protein Hrt1, and one member of the family of F-box proteins. The F-box proteins directly bind to the substrates and are the determinants of substrate specificity of SCF. Therefore, we searched for the f-box protein that cofers resistance to MeHg, and found that overexpression of Hrt3 or Yi1224w induced resistance to MeHg toxicity in yeast cells. Since the protein(5) that enhance toxicity of MeHg might plausibly be induced in substrates of both f-box proteins, we next searched for substrate proteins that are recognized by Hrt3 or Y1r224w using two-hybrid screen. We found that Did3 or Crsl interacts with Hrt3; and Eno2 interacts with Yir224w. The yeast cells that overexpressed each those proteins showed hypersensitivity to MeHg, respectively, indicating that those proteins enhance the MeHg toxicity. Both Dld3 and Eno2 are proteins involved in the synthesis of pyruvate, and overexpression of both proteins might induce increase in interacellular levels of pyruvate. Deletion of Yi1006w that transports pyruvate into the mitochondria induced aresistance to MeHg. These results suggest that the promotion of the pyruvate irdlowinto the mitochondria might enhance MeHg toxicity. This study providesimportant keyfor the elucidauon of the molecular mechanism of MeHg toxicity.

• Toxicological Research
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• v.32 no.1
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• pp.57-64
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• 2016

Recently several studies reported that the renal toxicity of lead (Pb) and cadmium (Cd) may exist in even a low level exposure. In terms of the deterioration of tubular function, it affects the loss of divalent metals and leads to other complications, so renal tubular effect of heavy metals should be well managed. Considering the exposure to heavy metals in reality, it is hard to find the case that human is exposed to only one heavy metal. We designed a cross-sectional study using Korean Research Project on the Integrated Exposure Assessment (KRIEFS) data to investigate the renal effects of multiple metal exposure in general population. We used blood Pb and urinary Cd as exposure measures, and urinary N-acetyl-${\beta}$-D-glucosaminidase (NAG) and ${\beta}_2$-microglobulin (${\beta}_2$-MG) as renal tubular impairment outcome. We conducted linear regression to identify the association between each heavy metal and urinary NAG and ${\beta}_2$-MG. And then, we conducted linear regression including the interaction term. Of 1953 adults in KRIEFS (2010~2011), the geometric mean of blood Pb and urinary Cd concentration was $2.21{\mu}g/dL$ (geometric $SD=1.49{\mu}g/dL$) and $1.08{\mu}g/g\;cr$ (geometric $SD=1.98{\mu}g/g\;cr$), respectively. In urinary Cd, the strength of the association was also high after adjusting (urinary NAG: ${\beta}=0.44$, p < 0.001; urinary ${\beta}_2$-MG: ${\beta}=0.13$, p = 0.002). Finally, we identified the positive interactions for the two renal biomarkers. The interaction effect of the two heavy metals of ${\beta}_2$-MG was greater than that of NAG. It is very important in public health perspective if the low level exposure to multiple heavy metals has an interaction effect on kidney. More epidemiological studies for the interaction and toxicological studies on the mechanism are needed.

• Korean Journal of Veterinary Service
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• v.26 no.2
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• pp.163-184
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• 2003

This study was conducted to survey the farm which suffered from disease similar to classical swine fever(CSF) in Gyeongbuk province. Clinical signs appeared first in a few number of growing pigs which showed specific signs of diarrhea, depression, sleepiness, and reluctance to get up or to eat. Younger piglets may have appeared chilled, shiver and huddle together. As the disease progresses the affected pig's skin went red and purple. In histopathological signs, there were many haemorrhages throughout the body and larger haemorrhages in some organs such as lymph nodes. And there is a precipitous fall in the number of circulating leukocytes in the blood. In spite of insisting of farmer which did not vaccinate to classical swine fever, significant antibody production was detected in these affected pigs at enzyme-linked immuonsorbent assay. According to the above results at first glance, these affected pig suspected with CSF in clinical signs and histopathological lesions only. Because the symptoms and post-mortem picture were very similar to CSF, these false positive results would have been dangerous to diagnostician. But by reverse transcriptase polymerase chain reaction(RT-PCR) and comparative nucleotide sequence analysis, the disease was correctly diagnosed with post-weaning multisystemic wasting syndrome(PMWS) and porcine reproductive and respiratory syndrome(PRRS) compoundly. And the antigen which were detected the lesion similar to CSF virus, was confirmed with LOM vaccine strain of CSF. In most national CSF eradication program and in countries which are free of the CSF virus, vaccination against CSF is not practiced and generally is not allowed. But now in Korea, routine vaccination is practiced because of outbreaking the CSF repeatedly. When CSF is diagnosed the whole herd and other in contact animal are slaughtered continuously.

• Anxiety and mood
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• v.10 no.1
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• pp.59-67
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• 2014

Objective : To obtain the incidence rate of anxiety disorders among the active duty Korean military personnel, who visited the military hospitals from 2011 to 2013, this descriptive epidemiological study was performed. Methods : After acquiring the data for the anxiety disorders from Defense Medical Statistics Information System, the annual incidence rates were analyzed by forces, position status, and specific disease entities. Results : One thousand, nine hundred and thirteen (1,913) active duty male military personnel were diagnosed with any kinds of anxiety disorders in their first visit to the psychiatric outpatient department (OPD). The total OPD visit counts were 7,870 during the same period. Anxiety disorder, NOS was the most frequent disorder, followed by panic disorder. While the incidence rate for anxiety disorder, NOS decreased, panic disorder displayed increasing tendency. Stress-related disorders and obsessive-compulsive disorder were positioned third and fourth, respectively, for the number of first visit and they both showed decreasing tendency in annual incidence rates. Social anxiety disorder, specific phobias, generalized anxiety disorder (GAD) and mixed anxiety-depressive disorder followed next. The annual incidence rates for anxiety disorders showed decreasing tendency, particularly evident in army soldiers. However, naval officers showed higher anxiety disorder incidence rate compared to those of the army and the air forces. Conclusion : Comparing to general population, panic disorder was higher while specific phobias and GAD were lower in the Korean military. It is interesting to observe higher incidence rate for anxiety disorder in naval officers and warrants further evaluation.

• Journal of Food Hygiene and Safety
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• v.32 no.4
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• pp.306-313
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• 2017

This study systemically analyzed the data on the microbial levels in fresh vegetables in Korea to identify the points to control. We scanned the studies published between 2001 and 2015 in peer-reviewed research papers on the microbial levels in fresh vegetables produced in Korea. Plant products were categorized by using the US IFSAC (Interagency Food Safety Analytics Collaboration) category. The most consumed, the non-heat treated, the epidemiological foodborne diseases sources of fresh vegetable in foodservice (KCDC data) were identified by literature review. Articles were screened using National Digital Science Library (NDSL) search engine regarding to microbial hazards in plant products. Based on the total plate count number and coliforms on the 89 data cases from 26 published articles, the total plate count number was high in the order of sprouts, leaf and stem, bulbs and roots, vine-grown, solanaceous, melons, and pome. Escherichia coli was frequently detected in leaf and stem and sprouts products. Focused on the microbial data of leek, lettuce and cabbage, the levels of total plate count, coliforms and Bacillus cereus showed the levels of 4.15~7.69 log CFU/g, 1~6.99 log CFU/g, and 0.51~3.9 log CFU/g, respectively, by 33 published papers. The levels of environmental factors affecting the microbial safety of lettuce and leek before harvest were investigated. Manure, soil, hands, scale, gloves were the major potential microbial contamination points to control. In addition, GAP (good agricultural practice), microbial testing, and improvement of irrigation methods are required to provide the safer fresh produce.

• Journal of Life Science
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• v.21 no.7
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• pp.947-952
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• 2011

A number of epidemiological studies have identified human papillomavirus (HPV) types 1, 2, 3, 4, 7, 10, 27, 57, and 65 in cutaneous common warts. However, identification of the HPV subtype by conventional polymerase chain reaction (PCR) is time consuming with its multi-step laboratory process. In this study, we aim to develop a specific one-step multiplex polymerase chain reaction method which capably identifies six different HPV genotypes related to common warts. By HPV DNA sequence analysis, 6 pairs of specific primers were designed from the intergenic regions of genes L1 to E6, and from genes E2 to L2. DNA sequence analysis with the L1 gene sequence of the sample was performed to measure the specificity of multiplex PCR. HPV-1, -2, -3, -4, -27, and -57 were identified without cross amplification in 109 out of 129 samples. The sensitivity and specificity of our set of primers in detecting HPV were 85% and 99.5%, respectively. For the 20 samples where HPV type was not identifiable by our batch of primer sets, multiplex PCR with an additional set of HPV primers was done, where 7 were found positive for HPV-7 or -65. Our results demonstrate that the newly designed multiplex PCR can rapidly detect the specific HPV subtype involved in common warts with high accuracy.

• Korean journal of food and cookery science
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• v.7 no.3
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• pp.69-76
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• 1991

Recent epidemiological observations suggested beneficial effects of dietary fiber on man's health. The obsective of this study was to obtain the dietary fiber reference data of mushrooms. The dietary fiber contents of six different mushrooms (Cornellus edodes, Auricularia auriculajudae, Gyrophora esculanta, Agaricus bisporus, Pleurotus ostreatus, Collybia velutipes) were analyzed by Southgate method, modified neutral detergent fiber (NDF) method and Food Research Institute (FRI) method. Duplicate sample were used for each determination. The mean values of total dietary fiber by Southgate method, modified NDF method and FRI method were respectively $20.08\pm1.45g$/100g dry weight, $20.24\pm1.85g$/100g dry weight and $21.5\pm2.70g$/100g dry weight. The mean values of all mushroom samples by FRI method were significantly different from the mean values of the samples by modified NDF method and Southgate method. However, there was no difference in the mean values of the samples between modified NDF method and Southgate method. By Southgate method, total dietary fiber of mushrooms composed of 1.7-3.1% soluble fiber, 47.0-66.6% hemicellulose, 28.4-57.7% cellulose and 0.9-3.3% lignin. By modified NDF method, total dietary fiber of mushrooms composed of 61.8-79.1% hemicellulose, 5.4-32.9% cellulose and 4.5- l5.5% lignin. Therefore, dietary fiber contents of mushrooms were mainly hemicellulose. Our values for total dietary fiber for six mushrooms were 2~4 times higher than crude fiber in textbook.

• Korean Journal of Veterinary Service
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• v.31 no.1
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• pp.1-16
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• 2008

Salmonella infections cause the disease in pigs but also some zoonotic Salmonella serotypes can be transmitted to human through swine products, resulting in food poisoning. The objective of this study was to investigate the bacteriological prevalence and detection of invA gene using Salmonella specific polymerase chain reaction (PCR), the epidemiological characteristics related to Salmonella strains cultured from pig samples in Gangwon areas using serotyping, random amplified polymorphic DNA (RAPD) and pulsed field gel electrophoresis (PFGE) methods. During the period of November 2001 through April 2002, 1,174 ileocecal lymph node were collected from the slaughtered pigs raised in 38 farms located in Gangwon province. The samples were submerged in boiling water and macerated in saline and lymph node homogenates were inoculated into Tetrathionate broth with iodine (TTB, Difco, 0.5% iodine was added) for enrichment growth. Then additional tests were performed using several mediums, and suspects were identified by API 20E kit (BioMerieux) and PCR. Of total 1,174 samples from 38 farms, 44 (3.7%) were isolated as Salmonella spp from 13 farms (34.2%). Of 44 isolates, 31 were in Yangyang region, followed by 9 in Goseong, 2 in both Gangneung and Sokcho. However, there was no difference in regional isolation frequency. All isolates have a 521bp amplified product in Salmonella specific PCR with primer invA which encodes in proteins for invasion of epithelial cells. Of 44 recovered serotypes, 23 (52.3%) were S Eingedi, 10 (22.7%) S Schwarzengrund, 9 (20.5%) S Typhimurium, and 2 (4.5%) S Mbandaka. In RAPD analysis, there appeared to be unique bands distinguishing each serotype, although similarities exist between the different serotypes. Four serotypes of 44 Salmonella isolates appeared to fall into 14 different RAPD types. In PFGE analysis, 9 S Typhimurium were tested with XbaI enzyme and SpeI enzyme. The combination of results obtained with two enzymes subdivided the 9 S Typhimurium into 4 PFGE types.

• Biomedical Science Letters
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• v.18 no.1
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• pp.79-82
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• 2012

Acinetobacter infections are of great concern in clinical settings because of multi-drug resistance (MDR) and high mortality of the infected patients. The MDR Acinetobacter baumannii has emerged as a significant infectious agent in hospitals worldwide. The purpose of this study was to determine for molecular characterization of MDR A. baumannii clinical isolates obtained from the Wonju Christian Hospital in Gangwon province of Korea. A total of seventy nonduplicate A. baumannii isolates were collected from the Wonju Christian Hospital in Korea from March to April in 2011. All of the MDR A. baumannii isolates were encoded by $bla_{OXA-23-like}$ gene and all isolates with the $bla_{OXA-23-like}$ gene had the upstream element ISAba1 to promote increased gene expression and subsequent resistance to carbapenem. 16S rRNA methylase gene (armA) was detected in 44 clinical isolates which were resistant to amikacin, and phosphotransferase genes encoding aac(3)-Ia and aac(6')-Ib were the most prevalent. A combination of 16S rRNA methylase and aminoglycoside-modifying enzyme genes (armA, aac(3)-Ia, aac(6')-Ib, and aph(3')-Ia) were found in 31 isolates. The sequencing results for the quinolone resistance-determining region (QRDR) of gyrA and parC revealed the presence of Ser (TCA) 83 Leu (TTA) and Ser (TCG) 80 Leu (TTG) substitutions in the respective enzymes for all MDR. Molecular typing for MDR A. baumannii could be helpful in confirming the identification of a common source or cross-contamination. This is an important step in enabling epidemiological tracing of these strains.