• Research in Plant Disease
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• v.12 no.2
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• pp.108-114
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• 2006

This study was conducted to elucidate the interactions among soil microorganisms in a special field where one, two or three of N, P, K fertilizers were continuously not applied for 29 years. Crop yield (barley, soybean), soil chemical properties and microflora and microfauna including nematodes, nematophagous fungi, actinomycetes, bacteria, and fungi were examined for two years. Tylenchorhynchus sp. was the most important plant-parasitic nematode (range $11{\sim}642/300 cm^3$ soil) followed by Pratylenchus sp. and Helicotylenchus sp. Among nematophagous fungi, Monacrosporium spp. was the most frequently found followed by Harposporium sp. and Cystopage sp. In general, plots treated with phosphate fertilizer yielded more, had more nematodes, bacteria and actinomycetes. In contrast, total fungal population densities including nematophagous fungi, Cystopage sp. and Harposporium sp. were in reverse; they were more abundant in the plots with lower phosphate contents. Phosphate and pH are positively correlated and two most important determining factors for the population density of soil organisms under investigation. According to correlation analysis, Ca, Mg, and $SiO_2$ contents in soil and population densities of Tylenchorhynchus sp., saprophitic nematodes, actinomycetes, and bacteria were positively correlated with pH, but were negatively correlated with fungal population densities. We hope that the study will add an additional knowledges to understand our mysterious underworld.

• Parasites, Hosts and Diseases
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• v.58 no.4
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• pp.413-419
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• 2020

Eosinophilia occurs commonly in many diseases including allergic diseases and helminthic infections. Toxocariasis has been suggested as one cause of eosinophilia. The present study was undertaken to examine the prevalence of toxocariasis in patients with eosinophilia and to identify the risk factors for toxocariasis. This prospective cohort study recruited a total of 81 patients with eosinophilia (34 males and 47 females) who visited the outpatient clinic at Seoul National University Hospital from January 2017 to February 2018 and agreed to participate in this study. The prevalence of toxocariasis was examined by T. canis-specific ELISA, and the various risk factors for toxocariasis were evaluated by a questionnaire survey. Among 81 patients with eosinophilia, 18 were positive for anti-T. canis antibodies (22.2%); 88.9% were male (16/18) and 11.1% were female (2/18). Multivariate statistical analysis revealed that males (OR 21.876, 95% CI: 1.667-287.144) with a history of consuming the raw meat or livers of animals (OR 5.899, 95% CI: 1.004-34.669) and a heavy alcohol-drinking habit (OR 8.767, 95% CI: 1.018-75.497) were at higher risk of toxocariasis in patients with eosinophilia. Toxocariasis should be considered a potential cause of eosinophilia when the patient has a history of eating the raw meat or livers of animals in Korea. A single course of albendazole is recommended to reduce the migration of Toxocara larvae in serologically positive cases with eosinophilia.

• Journal of Life Science
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• v.31 no.12
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• pp.1066-1071
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• 2021

The aim of this study was to examine the metabolic adjustment of lactate dehydrogenase (EC 1.1.1.27, LDH) isozymes to a change in dissolved oxygen (DO) in bluegill (Lepomis macrochirus). After bluegills were adapted to a constant environment in an aquarium, the DO was changed to investigate the activity of LDH isozyme and the relative ratio of subunits A, B, and C for each tissue. When the DO was decreased from 18 ppm to 6 ppm, LDH in skeletal muscle, heart, and brain tissues recovered to the level of control activity within 12, 12, and 6 hr, respectively. LDH activity changed in accordance with a change in DO. The compensation was performed rapidly and is thought to be an important function of LDH in enabling bluegills to adapt to their environment. In bluegill heart, eye, and brain tissues, the relative ratio of subunit A increased and showed a tendency to recover similarly to the subunit ratio of control groups up to 12 hr. It is thought that the anaerobic metabolism using subunit A was increased in the initial stage when DO was changed. In addition, the results revealed that subunit C was more similar to subunit A than subunit B. In bluegills, subunits A and C of LDH seem to be evolutionarily similar. LDH isozymes, mainly containing subunits A and C, are likely responsible for the function of pyruvate reductase, which plays a role in making the bluegill adapt to a hypoxic environment through anaerobic metabolism.

• Research in Plant Disease
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• v.25 no.3
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• pp.124-130
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• 2019

The study was conducted to investigate the infestation and distribution of plant-parasitic nematodes on Chinese yam (Dioscorea batatas) in Andong, Korea. Root-knot nematodes, Meloidogyne incognita was the most prevalent nematode species which is found from 43 yam fields (81.1%) with high population densities (average of 450 juveniles/$300cm^3$). Other nematodes, root-lesion nematode (Pratylenchus spp.) and pin nematode (Paratylenchus spp.) were less problematic. Density of juveniles (J2) of M. incognita was $10\;J2/300cm^3$ by August, then increased to 274 in September and 624 in October. The highest J2 density was found at the soil depth between 40 and 50 cm ($1,840\;J2/300cm^3$). M. incognita was able to infest yam tuber down to a depth of 70 cm and developed galls outside and brown spots inside. The highest number of females were found at 40-50 cm (79 females/10 cm piece) tuber from the top.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.93-112
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• 2019

Calf diarrhea is a common disease in young claves and is still a major cause of productivity and economic loss in livestock farms. Fecal samples from Korean native cattle (n=100) with diarrhea from 64 farms in Gwangju area, Korea from september 2017 to December 2018 were examined for shedding of important protozoan parasitic, viral and bacterial pathogens using culture, rapid test kit and PCR methods. Of 57 (89.1%) of the 64 Korean native cattle farms examined had samples infected with at least one of the investigated pathogens. Among 100 fecal samples, 88 samples were positive for at least one the twelve pathogens and 51 samples were simultaneously positive for two or more pathogens by culture and PCR assay. Bovine group A rotavirus (BRV) was the most common pathogen, found in 43/100 (43.0%) samples on 32/64 (50.0%) farms. Subsequently, kobuvirus (30.0%), pathogenic E. coli (29.0%), bovine parvovirus (17.0%), Giardia spp. (13.0%), Eimeria spp. (10.0%), Clostridium perfringens type A (8.0%), bovine torovirus (8.0%), bovine viral diarrhea virus (6.0%), bovine coronavirus (5.0%), bovine norovirus (2.0%) and Cryptosporidium spp. (2.0%) were detected. Nebovirus, kırklareli virus, bovine adenovirus, Salmonella spp. and intestinal parasites were not detected. Of the 72 calves sampled in this age group, 64 (88.9%) samples were positive for at least one enteropathogen. BRV was identified in 34/72 (47.2%) samples from 27/48 (56.3%) farms. Subsequently, pathogenic E. coli (30.6%), kobuvirus (29.2%), BPaV (22.2%), Giardia spp. (15.3%), Eimeria spp. (9.7%), BVDV (6.9%), Cl. perfringens type A (6.9%), BCoV (4.6%) and Cryptosporidium spp. (2.8%) were detected in fecal samples. A total of ninety-six strains of E. coli were isolated from one hundred fecal samples collected from Korean native cattle with diarrhea. The presence of stx1, stx2, eaeA, LT, STa, STb, ehxA, saa, F4, F5(K99), F6, F17, F18 and F41 genes in the isolates was investigated by PCR. Out of ninety-six E. coli isolates screened for specific genes, 30 strains E. coli were identified to harbor shiga toxin-producing E. coli (STEC) 7 (7.3%), enterohemorrhagic E. coli (EHEC) 8 (8.3%), enteropathogenic E. coli (EPEC) 6 (6.3%), enterotoxigenic E. coli (ETEC) 2 (2.1%) and STEC/ETEC hybrid 7 (7.3%). This study provides epidemiological estimates of the prevalence of Korean native cattle's enteropathogens in Gwangju area, Korea, which would be used for cattle farmers and veterinarians to select appropriate therapeutic method.

• Journal of fish pathology
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• v.35 no.1
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• pp.113-120
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• 2022

Scuticociliatosis caused by Miamiensis avidus is a very important parasitic disease in olive flounder farming industry. The aim of this study was to determine effect of combined treatment with blue LED (light-emitting diode) illumination and formalin on olive flounder (Paralichthys olivaceus) infected with M. avidus. Different intensity of 405 nm LED (20, 40, and 60 μmol·m^-2·s^-1) was illuminated on 2.2×10⁴ cells/well of M. avidus in a 24 well microplate for 24 h. Also, 2.4×10⁴ cells/well of M. avidus were exposed to varying combinations of 60 μmol·m^-2·s^-1 of 405 nm LED and serial 10-fold dilutions of formalin (from 10 to 100 ppm) for 15, 30, 45, and 60 min. Surviving M. avidus were counted using a hemocytometer. For in vivo test, flounder acclimatized at 11-12 practical salinity unit (psu) were challenged with 2×10⁶ cells/ml of M. avidus by immersion method for 1 h. Then, fish were moved and divided into four groups; "F" group, treated with formalin at 50 ppm; "L" group, treated with 60 μmol·m^-2·s^-1 of 405 nm LED; "C" group, treated with combination of the two methods; and the control group. After treatment for 30 min, fish were transferred to new tanks (salinity = 11-12 psu) and observed for 3 weeks. As a result, illumination of 405 nm LED at 60 μmol·m^-2·s^-1 killed 100% of M. avidus after 12 h, while 67% and 90% of the scuticociliate died at 20 and 40 μmol·m^-2·s^-1, respectively, after 24 h exposure. One hundred percent of M. avidus was killed at 90, 80, 80 and 70 ppm after exposure to formalin for 15, 30, 45 and 60 min, respectively. However, combined method (e.g., 60 μmol·m^-2·s^-1 of 405 nm-LED plus 50 ppm formalin) killed the parasite within 30 min. From in vivo test, similarly, survival rates of fish challenged with M. avidus were 100%, 43%, 29% and 0% in the C, F, L, and control groups, respectively. Results obtained in this study demonstrates that the combined treatment method has clear synergistic effect on scuticociliatosis in fish.

• Korean journal of applied entomology
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• v.59 no.3
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• pp.233-241
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• 2020

Several hard tick species in Ixodidae are medically important pests that transmit infectious disease including severe fever with thrombocytopenia syndrome (SFTS). In Korea, the number of SFTS patients continues to steadily increase since its first report in 2013, and Gyeongsangbuk-do (province) is the second most frequent area of SFTS patient occurrence. In order to investigate the distribution of ticks in Sangju city, we collected ticks using the flagging method from 26 sites comprising urban green area, vulnerable area of management, and rural area, and examined SFTS virus from the collected ticks in 2019. Based on Collection Index (CI = tick number / 1 h / 2 people), CI 143 ticks, including Haemaphysalis longicornis, Haemaphysalis flava, and Ixodes nipponensis, were collected; the most abundant species among the three tick species was H. longicornis (CI 138, 96.5%). Ninety two percent (CI 131) of ticks were collected in vulnerable area of management, where people cannot easily enter and are not managed by city hall, whereas only 8.4% (CI 12) were collected in the urban green area and rural area. Regarding SFTS virus detection, virus was not investigated from 26 pools containing CI 143 ticks. The results of this study are expected to be used as a recommendation for ensuring the safety of local residents from tick-borne diseases.

• Journal of agricultural medicine and community health
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• v.25 no.2
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• pp.231-244
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• 2000

Classification and research trends were studied to analyze a total of 240 original articles that have been published in 34 volumes of The Korean Journal of Rural Medicine from 1976 to 1999. The results were as follows: 1. A total of 337 articles were published. Among them, 240(71.2%) articles were classified as original articles. This number has been increasing significantly over the years as the number of the articles was 13 in the 1970s, 73 in the 1980s, and 154 in the 1990s. 2. There were 10 authors in the original articles and 55(22.9%) of them were written by 3 of them. There were five research institutions involved in the articles, and 106(44.2%) of the articles were done by one research group. 3. In the original articles. 24(10.0%) were noted to be done using research funds, and only 6(2.5%) were written in English. 4. In the view of the research styles of the original articles, 115(47.9%) used analytical study, 92(38.3%) used technical study, 21(9.2%) used experimental study, and 6(2.5%) used case reports. In the 1970s, 13(100.0%) articles used technical study, and in the 1980s, 47(64.4%) used technical studies and 19(26.0%) used analytical studies. However, in the 1990s, 96(62.8%) articles used analytical studies and 32(20.9%) used technical studies. The statistical methods most commonly used in the articles were technical statistics, the ${\chi}^2$-test, and the t-test respectively. 5. On the classification into three different research fields, 105(43.8%) articles were classified as health management, 96(40.0%) as disease epidemiology, and 39(16.3%) as rural environment and rural occupational disorders. In the 1970s, 12 (92.3 %) of the articles were on disease epidemiology and 1(7.7%) on health management were published. In the 1980s, 33(45.2%) articles on disease epidemiology, 29(39.7%) on health control, and 11(15.1%) on rural environment and rural occupational disorders were recorded. In the 1990s, however, 75(48.7%) articles were on health control, 51(33.1%) on disease control, and 28(18.2%) on the rural environment and rural occupational disorders. 6. According to the research subjects in each research field, the 39 articles in rural environment and rural occupational disorders were composed of 8(20.5%) articles on pesticide intoxication, 7(17,9%) on farmer's diseases, 7(17.9%) on vinyl-house diseases, and 6(15.4%) on accidents. From a total of 96 articles in disease epidemiology 56(58.3%) articles were on parasites, 16(16.7%) on non-infectious diseases, 12(12.5) on infectious diseases. From 105 articles in health control 25(23.8%) articles were on medical care utilization patterns, 18(17.1%) on the health care delivery system, and 13(12.4%) on maternal and child health. In the analysis of the 10 most prevalent subjects dealt in the above articles, 6(46.2%) articles were on parasites and 4(30.8%) on non-infectious diseases were recorded in the 1970s. In the 1980s, 28(38.4%) were on parasites. 9(12.3%) on the health care system, 7(9.6%) on medical care utilization patterns, 5(6.8%) on maternal and child health, and 4(5.5%) were on pesticide intoxication. In the 1990s, 22(14.3%) articles were on parasites. 18(11.7%) on medical care utilization patterns, 16(10.4%) on senile health, 14(9.1%) on the health care system, 10(6.5%) on infectious diseases, arid 10(6.5%) were on non-infectious diseases. In conclusion, the research activity on rural health has been strengthened in this country because the original articles in The Korean Journal of Rural Medicine have significantly increased in the past 24 years. In the 1970s and 1980s, research on disease epidemiology was most prevalent, but in the 1990s papers on health care were most popular. In addition, the articles on parasites were most frequently published in the 1970s, 1980s, and 1990s, showing that parasitic problem was the main theme in those eras. However, in the 1990s, it was evident that the articles on parasites were decreasing and articles on the subject of medical care utilization patterns and senile health increased. Hereafter it was expected that research on health care would be more common in rural health in Korea.

• Journal of Preventive Medicine and Public Health
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• v.18 no.1
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• pp.99-112
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• 1985

It was measured to check the state of health education by the survey of the items related to the health with the first grade of students in middle school who mastered elementary courses. Totally 50 questions, which were selected from Standard and Dong-A reference books, were given to teachers and have got answered by the students who were totally 959(491 from urban areas and 468 from rural areas). It's done just after they entered middle school for a month, from April 10 to may 10, 1984. There were totally 782 items of health in all subjects of all grades. In contents, the most cases were about mental and emotional health(17.7%), exercise and rest (15.1%), environmental health, health life, personal health care, nutrition and foods, social health and organization, physiology and anatomy, statistics of public health population problem, disease and care, food sanitation, school health, parasitic and communicable disease control, eugenics and heredity(0.4%), etc were followed. In subjects, Korean language had 44.7% of mental and emotional health in 114 cases, arithmetics 46.4% of statistics of public health in 26, sociology, 23.1% of environmental health in 118, natural science, 60.1% of physiology and anatomy in 30, ethics, 40.3% of mental and emotional health in 176, music, 21.8% of mental and emotional health and accidents in 23, art, 42.9% of exercise and rest in 28, physical education, 38.6% of exercise and rest in 201, practical course, 36.2% of nutrition and foods in 61, and there was nothing but only one case in Korean history. Subjects in total cases of health informing items are below: Physical education 25.8, ethics 22.5%, sociology 15.1%, Korean language 14.6%, practical course 7.8%, natural science 3.8%, art 3.6%, arithmetics 3.3%, music 2.9%, Korean history 0.6%. Grades in total cases of health informing items are belows: the sixth grade 29.1%, the fourth grade 21.2%, the fifth grade 18.9%, the third grade 11.6%, the first grade 11.5%, the second grade 7.7%. The sections related to health matters were average 35.4%. According to the grades, the fourth and the sixth grade were 38.2% each other, the highest, and the second grade was 29.3%, the lowest. All scetions in physical education included them. The acceptability to the knowledge for health was belows: 56.3% in urban students and 53.9% in rural students. There was some difference in acceptability between two parties (p<0.005).

• Journal of Veterinary Clinics
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• v.27 no.6
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• pp.640-646
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• 2010

Neosporosis is a widespread parasitic disease caused by Neospora caninum, an intracellular protozoan parasite. It causes economic losses due to reproductive failure. The potential relationship between pregnancy outcomes and levels of IFN${\gamma}$, hormones, and antibodies in naturally N. caninum-infected cows was examined in the blood samples collected every 2 or 4 weeks in 26 pregnant cows from 4 different farms. The mean S/P value of seropositive nonaborting animals (n = 14) reached peak levels 15 weeks prior to parturition, and declined thereafter to parturition. The S/P value 13 weeks prior to abortion in seropositive aborting cows (n=3) remained at high levels, and abortions occurred at 20 (142 days), 26 (185 days), and 28 weeks (199 days) after artificial insemination. IFN${\gamma}$ levels in the seropositive non-aborting group varied by individuals and gestational periods; IFN${\gamma}$ levels stayed at elevated levels or increased abruptly close to abortion in seropositive aborting cows. IFN${\gamma}$ level patterns in the seronegative group (n = 9) were similar to the seropositive non-aborting group, although IFN${\gamma}$ amounts were lower than the seropositive group. The mean progesterone levels in the seropositive non-aborting and seronegative groups decreased markedly 7 weeks prior to parturition. The mean progesterone levels 5 and 7 weeks prior to abortion were lower than the other groups 5 and 7 weeks prior to parturition. The mean 17${\beta}$-estradiol levels in the seropositive aborting cows increased close to abortion; the produced amounts were lower than those of seropositive non-aborting and seronegative groups close to parturition. These results suggested that lower levels of progesterone and ${\beta}$-estradiol in Neospora-infected cows may lead to increases in IFN${\gamma}$ production and in turn may result in abortion.