• Journal of Veterinary Clinics
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• v.33 no.2
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• pp.102-106
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• 2016

More than 20 years after the first report of porcine reproductive and respiratory syndrome virus (PRRSV) in Korea, the disease is still having major impact on domestic pig health and relevant industries. Although ELISA tests are commonly used by veterinarians to guide herd management, data on diagnostic performance of the test in field settings are very limited. The objective of this study was to evaluate two commercially available PRRSV ELISA (IDEXX PRRS X3 ELISA and Bionote PRRSV ELISA 4.0) to detect antibodies against PRRSV on serum samples. To this end, a total of 1,108 sera were recruited from 35 swine farms located in Gyeonggi province and tested at the Gyeonggi Province Veterinary Service Center. All tests were performed according to the manufacturer's instructions, by laboratory technicians who routinely perform PRRS testing on blood samples. Samples were collected from two sources of swine populations with different PRRS prevalence; 60 samples (5.4%) were originated from breeding farms and the remaining 1,048 samples (94.6%) were from farrow-to-finish farms. We applied Bayesian latent class model (LCM) for two-tests in the two-population when the accuracy of the gold standard is not available. The model estimated that Bionote ELISA was a bit more specific but slightly less sensitive. The estimated sensitivity and specificity of the IDEXX ELISA were 99.8% (95% CI 98.1-100%) and 86.4% (95% CI 81.4-96.5%), respectively. Sensitivity, specificity, positive predictive value and negative predictive value for Bionote kit were 98.7% (95% CI 92.8-100%), 89.8% (95% CI 86.2-93.1%), 93.8% (95% CI 91.5-96.0%), and 97.8% (95% CI 87.1-100%), respectively. Based on the Bayesian 95% credible intervals, the sensitivity and specificity of the two ELISAs were not significantly different each other when assuming that two kits were imperfect, indicating that two kits performed equally well in terms of sensitivity and specificity in our filed setting.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.991-996
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• 2000

Enzyme-linked immunosorbent assay was developed for the analysis of soy protein in foods. Competitive indirect ELISA (ciELISA) was established by using specific antibodies against the heat-stable acidic subunits (AS) of glycinin. Soy proteins in each sample used in this study were solublized in the presence of urea and DTT and boiled at $100^{\circ}C$ for 1hr and then were renatured with a cystine-containing solution. After these treatments, each isolated soy protein (ISP) heated at 60, 70, 80, $90^{\circ}C$ for 10 minutes showed almost the same curve as unheated one in the ciELISA. The detection limit of ISP was 0.3 ${\mu}g/mL$. Anti-AS antibodies have very low reactivities less than 0.1% toward non-meat proteins such as skim milk and casein and did not show any reactivities toward egg white powder and ovalbumin. When laboratory-made sausages containing ISP of $0.5{\sim}3%$ were assayed by ciELISA, the mean recovery was about 83% (C.V., 19%). In addition, the average content of soy protein in commercial sausages was 1.27%.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.3 no.2
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• pp.175-180
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• 2000

Purpose: Leptin is an adipocyte-derived blood-borne satiety factor that acts on its cognate leptin receptor in the hypothalamus, thereby regulating food intake and energy expenditure. We measured the leptin concentrations in serum of normal and obese children with human leptin ELISA kit, unlike previous study with leptin RIA kit and investigated the relationship between leptin concentrations and body mass index, gender, and age. Methods: We measured serum concentrations of leptin in 67 children who were visited to the Department of Pediatrics, Chungnam National University Hospital during the period of 5 months from February, 1999 to June, 1999. Height, weight, obesity index, and body mass index were measured in 67 subjects. Leptin values in serum were measured by sandwich ELISA method. Data analysis was done according to the obesity, body mass index, gender and age. Results: The mean concentration of leptin was $7.69{\pm}8.83\;ng/ml$ in normal children group and $36.34{\pm}18.57\;ng/ml$ in obese group. Serum leptin concentrations were significant correlation with the body mass index (p<0.01). Serum leptin concentration was significant higher in the group of over 10 years of age (p<0.01). Leptin levels showed no significant difference by gender. Conclusion: Serum leptin levels were significantly higher in obesity group than in control one, and they were correlated with body mass index and age. Measurements of leptin value by sandwich ELISA method are very useful and easily applicable to determine obesity.

• Parasites, Hosts and Diseases
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• v.29 no.3
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• pp.293-310
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• 1991

Clonorchis sinensis is a common parasite of man in Korea. Researches on the specific antigens of C. sinensis would be valuable not only because those elucidate the molecular characteristics of this fluke but also because it is applicable to immunodiagnosis. Although many monoclonal antibodies have been used in the field of parasite immunology, few articles on monoclonal antibodies against C. sinensis have been published so far. The aim of this study was to analyse C. sinensis antigens recognized by monoclonal antibodies, and to set up ELISA-inhibition test using C. sinensis specific monoclonal antibodies for improved specificity of immunodiagnostic tests. By fusion between spleen cells of the mice immunized with C. sinensis water-soluble crude adult worm antigens and plasmacytoma cells of mouse origin, 29 hybridoma clones secreting anti-C. sinensis monoclonal antibodies were made, and 8 clones among those were found specific. After cell cloning, isotypes of 6 selected specific monoclonal anti- bodies were determined to be IgGl, IgG2b and IgA. Four exposed antigenic determinants of natural infection were recognized by different specific monoclonal antibodies. By enzyme-immunoelectrotransfer blot, 10 KD, 34 KD antigenic determinants were found to be reacted with CsHyb 0714-20, CsHyb 0605-10 monoclonal antibodies, respectively, The antigenic determinant recognized by CsHyb 0714-20 monoclonal antibody was revealed to be located at the surface and parenchyme of a parasite by indirect immunoauorescent antibody technique, and those reacted with CsHyb 0605-10, CsHyb 0714-25 monoclonal antibodies were found at the parenchyme and intestine. The antigenic determinant reacted with CsHyb 0605-23 monoclonal antibody was found mainly around the uterine eggs. Four antigenic determinants recognized by specific monoclonal antibodies were all found to be present in the early eluted fractions of C. sinensis antigens separated by Sephadex G-200 gel filtration. By conventional ELISA, 75% of clonorchiasis cases were found positive, but 7.1% of normal controls and 37.5% of paragonimiasis cases showed false positives. However, by ELISA-inhibition test using C. sinensis specific monoclonal antibody (CsHyb 0605-23), 77.1% of clonorchiasis cases were found positive, and there were no false positives in normal controls or paragonimiasis cases, indicating 100% specificity. The ELISA- inhibition test using monoclonal antibodies was found to have same sensitivity and definitely high specificity in comparison with conventional ELISA for serodiagnosis of human clonorchiasis.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1997.11a
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• pp.153-153
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• 1997

• Parasites, Hosts and Diseases
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• v.50 no.1
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• pp.15-21
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• 2012

In Iran, $Plasmodium$ $vivax$ is responsible for more than 80% of the infected cases of malaria per year. Control interventions for vivax malaria in humans rely mainly on developed diagnostic methods. Recombinant $P.$ $vivax$ apical membrane antigen-1 (rPvAMA-1) has been reported to achieve designing rapid, sensitive, and specific molecular diagnosis. This study aimed to perform isolation and expression of a rPvAMA-1, derived from Iranian patients residing in an endemic area. Then, the diagnostic efficiency of the characterized Iranian PvAMA-1 was assessed using an indirect ELISA method. For this purpose, a partial region of AMA-1 gene was amplified, cloned, and expressed in pET32a plasmid. The recombinant $His-tagged$ protein was purified and used to coat the ELISA plate. Antibody detection was assessed by indirect ELISA using rPvAMA-1. The validity of the ELISA method for detection of anti-$P.$ $vivax$ antibodies in the field was compared to light microscopy on 84 confirmed $P.$ $vivax$ patients and compared to 84 non-$P.$ $vivax$ infected individuals. The ELISA cut-off value was calculated as the mean+2SD of OD values of the people living in malaria endemic areas from a south part of Iran. We found a cut-off point of OD=0.311 that showed the best correlation between the sera confirmed with $P.$ $vivax$ infection and healthy control sera. A sensitivity of 81.0% and specificity of 84.5% were found at this cut off titer. A good degree of statistical agreement was found between ELISA using rPvAMA-1 and light microscopy (0.827) by Kappa analysis.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.793-802
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• 1998

Salmonellosis caused by a number of serotypes of Salmonella is an infectious, acute or chronic, zoonotic disease and characterized by enteritis and diarrhea, septicemia in animal. In these studies we investigated the prevalent serotypes of Salmonella causing animal salmonellosis in Korea and the 71 strains of Salmonella spp. were isolated from materials such as mesenteric lymph nodes, fecal samples from slaughtered animal. With the identification test results, the most prevalent serotypes were, in order, S stanley 31 strains (43.7%), S typhimurium 19 strains (26.8%) and S montevideo 11 strains (15.5%), respectively. And we could establish the method for detection of antibodies to broad variety of Salmonella serotypes. Lipopolysaccharide(LPS) antigen extracted from Salmonella was more sensitive and specific than outer membrane protein antigen from that for detection of Salmonella antibody by using an indirect ELISA. The optimal concentration of antigen was 100ng/ml of LPS, the dilutions of conjugate and serum were 1 : 1,000~2,000 and 1 : 200~400, respectively. The mix LPS-ELISA which was used by mixing LPS from S typhimurium (group B), S choleraesuis (group C) and S enteritidis (group D) were more rapid and effective than that used LPS from individual strain for detection of Salmonella serogroup O4, O7 and O9 antibody at the same time. We could obtain the high values of optical density ($0.73{\pm}0.32$) by mix LPS-ELISA on the farm which had occurred salmonellosis, but very low values of $0.17{\pm}0.06$ on the negative farm of salmonellosis. So, the mix LPS-ELISA may be used to monitor the serological surveillance for the presence of infection with a number of serotypes of Salmonella and would be useful for prevention and control of salmonellosis in animal.

• Korean Journal of Poultry Science
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• v.45 no.1
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• pp.17-28
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• 2018

Infectious bronchitis virus (IBV) is an economically important disease in the poultry industry worldwide. This disease commonly manifests respiratory signs, poor egg quality, and decline in egg production. Since IBV is a RNA virus, the emergence of new variant strains is continuously reported and the immunization of susceptible chickens with only one antigenic type of the virus has been shown to induce partial or no protection against other unrelated types. Therefore, it is difficult to diagnose IBV due to variants serotypes. In this study, we collected serum from various ages of Broiler GP (Grandparent) to Layer CC (Commercial chick) and performed detectability comparison test between domestic company and multinational company manufacturing ELISA kit. Results of this experiment suggest that domestic company manufacturing ELISA kit is more sensitive to infectious bronchitis antibody than that of the multinational company. Our findings also suggest that antibody's change trends after infectious bronchitis vaccination. Thus, the use of appropriate kit for domestic situations is important.

• IMMUNE NETWORK
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• v.5 no.2
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• pp.124-129
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• 2005

Background: CM1 (centrocyte/-blast marker 1) is originally defined as a germinal center B cell marker. It is known that CM1 plays a critical role on B cell development in germinal center. In addition, we have found that CM1 is expressed on lymphoma cell lines, such as Raji, Ramos and IM-9. This means that CM1 might be served as a tumor marker as well. In the present study, we examined the expression of CM1 on the surface of the other tumors and the possibility of the development of tumor screening ELISA kit by using CM1. Methods: First, we have examined the expression of CM1 on stomach cancer and hepatoma, which are predominantly (discovered) occurred in Korean, by flow cytometry analysis. After purifying of CM1 antigen from Raji and Ramos, the optimal ELISA condition was determined. And then we compared the level of CM1 between normal individuals and cancer patients by ELISA. To decrease the non-specific binding of anti-CM1 mAb with serum components except CM1 and to enhance the diagnostic accuracy, albumin depletion spin column was used. Results: CM1 was highly expressed on stomach cancer and hepatoma cell lines. In addition, we have also confirmed the increased CM1 expression on cancer patients. The difference of CM1 expression between normal individuals and cancer patients were more clearly observed, after deletion of serum albumin by using albumin depletion spin column. Conclusion: Based on the results from this study, CM1 might be a useful molecule for the early diagnosis of cancer. In addition, further studies for the increase of ELISA sensitivity and appropriate albumin depletion methods should be needed.

• Biomedical Science Letters
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• v.2 no.1
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• pp.121-126
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• 1996

Specific monoclonal antibodies(mAbs) against bis-indole alkaloids related to vinblastine were established to develop a simple and specific immunoassay system for the quantitation of Vinca alkaloids. Vinca alkaloids were extracted from tissue cultured cells of periwinkle plant (Vinca rosea L.). Spleen cells from Balb/c mice immunized with vinblastine-bovine serum albumin(VBL-BSA) conjugate as immunogen were fused with myeloma cells(Sp2/0-Ag.14) in the presence of polyethylene glycol. In the preliminary experiments, 32 clones which highly reacted with VBL-BSA conjugate were selected by ELISA(Enzyme-linked immunosorbent assay).These clones were further analyzed by inhibition assay of ELISA. The results obtained with two typical monoclonal antibodies, KN-1 and KN-2, were described. KN-1 exhibited considerable reactivities with soluble dimeric bis-indole alkaloids, whereas no cross reacted with monomeric bis-indole alkaloids. However KN-2 showed cross reactivity with mono- and di-meric bis-indole alkaloids. Furthermore, KN-1 was applied to the immunoassay system for determining the VBL amounts of in vitro cultured cell extracts. This assay system could detect dimeric vinca alkaloid as low as 0.05 nM.