• Parasites, Hosts and Diseases
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• v.58 no.6
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• pp.609-617
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• 2020

Plasmodium vivax reemerged in 1993. It has been sustained for more than 25 years and become one of the important indigenous parasitic diseases in northern and western parts of the Republic of Korea near the demilitarized zone. In particular, relapse is a significant concern for the control of malaria, as short- and long-term incubation periods vary among those infected in Korea. In this study, the prevalence of asymptomatic carriers was examined among residents of high endemic areas of vivax malaria during nonseasonal transmission of mosquitoes. Blood samples from 3 endemic regions in northwestern Korea were evaluated by microscopic examination, rapid diagnostic testing, and nested PCR to identify asymptomatic patients carrying malaria parasites in the community. However, no positive malaria case among residents of endemic areas was detected. Additionally, serological analysis was carried out to measure antibodies against 3 antigenic recombinant proteins of P. vivax, merozoite surface protein 1-19, circumsporozoite surface protein-VK210, and liver-stage antigen (PvLSA-N), by the protein array method. Interestingly, seropositivity of sera between previous exposure and samples without exposure to malaria was significantly higher using the PvLSA-N antigen than the other antigens, suggesting that PvLSA-N can be used as a serological marker to analyze the degree of exposure for malaria transmission in endemic areas. This indicates a very low asymptomatic carrier prevalence during the nonmalaria season in the endemic areas of Korea.

• Journal of Preventive Medicine and Public Health
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• v.30 no.1 s.56
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• pp.103-128
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• 1997

The object of this study is to evaluate the possibility of chemical-induced liver disorder among workers exposed to various chemicals and to classify the the liver function abnormalities by causes and to analyse the risk factors for each liver disorders. A cross-sectional study including questionnaire survey, physical examination, laboratory tests and ultrasonography of liver was conducted on 1,126 workers, 459 workers in a coal chemical plant(company A) and 667 workers in an insulation material manufacturing factory(company B). An industrial hygienist reviewed the chemicals used in both companies and evaluated the work environments to classify the workers by chemical exposure semiquantitatively. The results are as follows: 1. Of 459 workers in company A, 83 workers(18.1%) are classified as nonexposed, group 163(35,5%) as short-term exposure group, 155(33.8%) as intermediately exposed group and 58(12.6%) as long-term exposed group bared on the mean daily exposure to hepatotoxic chemicals evaluated by an industrial hygienist. Of 667 workers in company B, 484(72.6%) workers were classified as nonexposed and 183(35.5%) as exposed group. 2. Workers with SGOT level higher than 40 IU/l were (10.0%) in company A and 77(11.5%) in company 3, and those with SGPT level higher than 35 IU/l were 118(25.7%) in company A and 198(29.7%) in company B. The differences were not significant between companies and between exposure groups(p>0.05). Workers with $\gamma-GT$ level higher than 62 IU/l were 29(6.3%) in company A and 77(11.5%) in company B (p<0.01). The difference between exposure groups was not significant(p>0.05) within companies. Workers with liver function abnormalities(defined as SGOT higher than 40 IU/l or SGPT higher than 35 IU/l) were 338(30.0%) among 1,126 workers. Of 338 workers with live. function abnormalities 139(12.3%) had fatty liver by ultrasonography, 79(7.0%) had alcoholic liver(defined as workers with liver function abnormalities with weekly alcohol consumption greater than 280 g for more than 5 years), 54(4.8%) had hepatitis B, 12(1.1%) had hepatitis C and the other 114(33.7%) was not otherwise classified. Prevalences of alcoholic liver and fatty liver were significantly lower in company A(prevalence ratio 0.24 for alcoholic liver, p<0.001, prevalence ratio 0.76 for fatty liver, p<0.05) but prevalences of liver disorders between exposure groups within companies were not significant(p>0.05). 3. Summary prevalence ratios(SPR) of live. function abnormalities, fatty live. and other liver disorders, adjusted by age and company were not significantly higher in exposed group in any chemicals(p>0.05) but in some chemicals, SPRs were significantly lower. 4. On simple analysis of risk factors for liver function abnormalities, prevalence odds ratio(POR) of those with age between 30 and 39 was 1.54(p<0.01) and those with age ever 40 was 1.51(p<0.01). POR of those with histories of liver disorders and general anesthesia was 1.77(p<0.001) and 4.02 for those with overweight and 6.23 for those with obesity, defined by body mass index(p<0.001). 5. On logistic regression analysis, risk factors of liver function abnormality were fatty liver(POR 2.92 for grade 1, 12.15 for grade 2), presence of hepatitis B surface antigen(POR 3.62) and obesity(POR 5.38 for overweight and 16.52 for obesity). Presence of hepatitis B surface antigen(POR 0.18) was the only preventive facto. of fatty live. Company(POR 0.30) and obesity(POR 2.49 for overweight, 4.52 for obesity) were related to the alcoholic live. Obesity(POR 2.94 for overweight) was the only significant risk factor of hepatitis B and there was no significant risk factor for liver function abnormality not otherwise classified. It is concluded that the evidence of liver disorder related with chemical exposure is not evident in these factories. It is also postulated that fatty liver and alcoholic liver is most common causes of liver function abnormalities among workers and effort for weight control and improvement of life style should be done.

• Journal of Life Science
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• v.11 no.2
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• pp.181-189
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• 2001

Cytokines are hormone-like proteins which mediate and regulast inflammatory and immune responses. Transforming growth factor -$\beta$1(TGF-$\beta$) plays an important role in the control of the immune response and wound healing, and in the development o various tissues and organs, Nitric oxide(NO) is major messenger molecule regulating immune function and blood vessel dilation and serving as a neurotransmitter in the brain and peripheral nervous system. Also, NO is to be a potent mutagen that cause mutation in the p53 tumor suppressor gene in early phases of human gastric carcinogenesis. The purpose of this study was to investigate the effect of Helicobacter phlori lystes, lipopolysaccharide (LPS), and Staphylococcus enterotoxin B(SEB) on production of TGF-$\beta$1 and NO by human fibroblasts. Primary cultured human fibroblasts were incubated with H. pylori lysates(Hp), LPs, SEB, Hp+LPS, Hp+SEB, Hp+LPS+SEB. Cultured supernatants that were collected at 24, 48 and 72 hr were assessed for TGF-$\beta$1 by enzyme-linked immunosorbent assay and NO production by quantification of nitrite ion. TGF-$\beta$1 production in fibroblasts exposed with Hp, LPS or SEB for 48 hrs was enhanced, but for 72 hrs inhibited. Its production by doble exposure such as Hp+LPS, Hp+SEB, Hp+LPS+SEB was lowered in comparison with single exposure of Hp in cases of 24 and 48 hrs incubation, but for 72 hrs decreased in Hp vaculoating toxin(+), increased in Hp vacuolating toxin(-). No production in fibroblasts increaed at all doses of LPS. But its production by exposure of SEB increased or decreased according to dose and incubation time. Also, NO production by Hp vacuolating toxin(+) increased at all doses, but its production by Hp vacuolating toxin(-) decreased. Its production by doble exposure such as Hp+LPS, Hp+SEB, Hp+LPS+SEB decreased in comparison with single exposure Hp Therefore, quantities pf TGB-$\beta$1 and NO released by human fibroblasts shows differences according to kinds of stimulants. Also, in care stimulated with same kinds of stimulants, its productions exhibit quantitative differences according to exposure times. These results suggest that the decreased of TGF-$\beta$1 in fibroblasts by mixed exposure with Hp producing vacuolating toxin and bacterial toxins such as LPS and SEB may effect negatively in healing of host tissue and increased of NO by infection oh H. pylori may related to the increased susceptibility for human gastric carcinogenesis.

• Journal of the Korean Electrochemical Society
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• v.17 no.3
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• pp.172-178
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• 2014

In this work, we describe an electrochemical immunosensor for simple, fast and quantitative detection of a urinary hippuric acid (HA). Urinary HA, of molecular weight 180 DA, is one of the major metabolites and biological indicators in toluene-exposed humans. Simple and ubiquitous monitoring of exposure to toluene is very important in occupational health care. We propose the electrochemical immunoassay based on the dopamine-antigen conjugate for detecting hippuric acid. Our electrochemical immunoassay system employs a conjugate of dopamine (DA) as an electrochemical active molecule and hippuric acid (HA) as an antigen. As an electrochemical aspect, dopamine (DA) containing two hydroxyl group can show excellent redox signal. Also, dopamine-tethered hippuric acid (DA-HA) shows the reversible redox signal in the immunoassay. The competition between HA and DA-HA generated electric signals proportional to HA concentration. The electrochemical immunoassay was performed with DA-HA on the screen printed carbon electrodes (SPCEs), and then applies the mixture antigen (HA) and HA-antibody. The electrical signals were proportional to HA in the range of 0.010~2.500 mg/mL which is enough range to be used for the point-of-care.

• Journal of Ginseng Research
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• v.13 no.2
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• pp.223-228
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• 1989

Natural killer (NK) cells are a heteroguneous subpopulation of lymphocytes that spontaneously exhibit cytotoxic activity against various virus-Infected and neoplastic target cells without prior exposure to a specific antigen. It was thought that NK calls play an important role in immunosurvrillanre against viral agents and tumors, and in prevention of metastasis. Recently, several reports have indicated evidence that ginseng extracts show a significant stimulatory effect on the humoral and cellular immune responses. This evidence gives support to the suggestion that the anticarcinogenic effect of ginseng may be due to the effect of ginseng on the immunological system. Treatment with total, diol, and triol saponin resulted in an increase in NK cytotoxic activity, but no enhancement of the lytic activity due to the natural killer cytotoxic factor (NKCF). Therefore, these results suggest that the augmentation of NK activity by ginseng saponin fractions may not be due to the activation of NKCF lytic activity.

• Childhood Kidney Diseases
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• v.19 no.1
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• pp.39-42
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• 2015

Henoch-Sch$\ddot{o}$nlein purpura can result from exposure to an antigen after infection with several types of organisms. However, Henoch-Sch$\ddot{o}$nlein purpura caused by a primary Epstein-Barr virus infection has been rarely reported. Here, we report the case of a 32-month-old female patient who presented with Henoch-Sch$\ddot{o}$nlein purpura. Based on abnormal liver function test results and positive results for Epstein-Barr virus infection markers, a diagnosis of Epstein-Barr virus hepatitis manifesting as Henoch-Sch$\ddot{o}$nlein purpura was made. Treatment with methyl-prednisolone and hydration improved the symptoms, and a switch to oral steroids was effective in completely alleviating the purpura. No recurrence was noted and no liver function abnormalities were detected during the follow up period.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1216-1221
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• 2006

A protein array was fabricated for a miniaturized immunoassay using microcontact printing ($\mu$CP). A polydimethylsiloxane (PDMS) stamp with a 5 $\mu$m$\times$5 /$\mu$m dimension was molded from a silicon master developed by photolithography. Under optimal fabrication conditions, including the baking, incubation, and exposure time, a silicon master was successfully fabricated with a definite aspect ratio. An antibody fragment was utilized as the ink for the $\mu$CP, and transferred to an Au substrate because of the Au-thiol (-SH) interaction. The immobilization and antibody-antigen interaction were investigated with fluorescence microscopy. When human serum albumin (HSA) was applied to the protein array fabricated with an antibody against HSA, the detection limit was 100 pg/ml of HSA when using a secondary antibody labeled with a fluorescence tag. The fabricated protein array maintained its activity for 14 days.

• Parasites, Hosts and Diseases
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• v.51 no.3
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• pp.375-377
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• 2013

In the present study, we first report the seroprevalence of Dirofilaria immitis in dogs in Shenyang, northeastern China. Sera from 528 randomly selected dogs were examined for D. immitis antigen using SNAP$^{(R)}$4Dx test kit; 12.7% tested showed seropositive. No significant difference of infection was observed in different genders and breeds (P>0.05), but the difference was significant in different age groups and rearing conditions (P<0.05). The result suggested that the risk of exposure to D. immitis in dogs is high in Shenyang, and should be given attention.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.5
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• pp.362-365
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• 2000

A rapid immunochromatographic assay kit using whole blood to screen hepatitis B surface antigen was developed and evaluated by using sera from 240 patients. The reference diagnosis was based on the results obtained with GENEDIA Anti-HBs Rapid kit which is very similar to the above kit except for the use of serum. The test demonstrated a good correlation with the reference immunochromatographic assay kit, that is, the sensitivity and the specificity of the kit was 100%, respectively. The rapid test kit using whole blood should be more convenient and useful for the diagnosis of hepatitis B virus because the kit does not need machines and time to prepare serum. In addition, this kit is safe from inadvertent infection during sample treatment because the blood is sterilized with hydrogen peroxide, eliminates the procedure required to prepare serum and reduces the possibility of exposure to infectious agents.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.441-446
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• 2006

The biological effects of heating and chemical treatment on castor meal were investigated in order to develop a procedure to inactivate its antigenic activity in a way that is suitable for industrial applications. A 1% solution of purified castor bean allergen (CB-1A) was heat-treated with or without exposure to NaOH and NaOCI (250 ppm each). CB-1A exhibited extreme stability when heat-treated alone. In the presence of NaOH and NaOCl, CB-1A showed a drastic decrease in antigenic activity as the temperature surpassed the critical level of $70^{\circ}C$. The gradual disappearance of disc gel electrophoresis bands presumably responsible for the allergenicity of CB-1A, along with the significant losses of the amino acids phenylalanine, methionine, arginine, histidine, and cysteine correlated with the loss of CB-1A activity. CB-1A showed a single symmetrical band in SDS acrylamide gel electrophoresis with an estimated molecular weight of 6,000 daltons. The chemical and heat treatments reduced the disulfide bond content of CB-1A by 9.1% with a coincident increase in sulfhydryl bonds.