• Title/Summary/Keyword: antigen analysis

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Detection of antibodies in swine serum to Aujeszky's disease virus using agar-gel immunodiffusion test (Agar-gel immunodiffusion test를 이용한 돼지 혈청중 Aujeszky's disease virus 항체 검출에 관한 연구)

  • Cho, Hyo-gueon;Jun, Moo-hyung
    • Korean Journal of Veterinary Research
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    • v.30 no.3
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    • pp.297-307
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    • 1990
  • To establish an agar-gel immunodiffusion (AGID) test for detection of antibodies to Aujeszky's disease virus(ADV) in swine, the precipitating antigens were prepared by four procedures using the Aujeszky's disease virus, NYJ-1-87 strain isolated from the affected piglets in Korea. The optimal condition for AGID test and the properties of the antigens were investigated. To determine the optimal concentration of antigens, four antigens were experimentally prepared by concentrating the viral fluids by 1/30 to 1/200. It was proved that the antigen precipitated with ammonium sulfate at concentration of 1/100 was the most efficient to detect ADV antibodies by AGID test. When the relationship between the concentration of the antigens and the size of precipitating in radial immunodiffusion test was investigated, a high correlation coefficiency at r=0.95 (y=0.23x+23.4) was estimated, In study on the effects of various buffered salt solutions and agars on the sensitivity of AGID test by using the experimental ADV antigens, it was found that 0.05M tris buffer without sodium chloride at pH 7.2 induced the most distinctive precipitating lines, and that there was no significant differences in the sensitivity between the agarose and Noble's special agar. When the efficiency of AGID test was compared with serum neutralization(SN) test, the sensitivity of AGID test was 100% in SN titer over 1 : 16, 91.7% in SN titer of 1 : 8 and 57.1% in SN titer of 1 : 4. The specificity of AGID test compared with the sera with SN titer under 1 : 2 was 98.4%. Protein analysis of the antigens by SDS-PAGE indicated that antigen I and antigen III showed a specific band of polypeptides with molecular weight of 116 K in comparison with the control antigen. Antigen IV, treated with tween-80 and ammonium sulfate, revealed specific polypeptides bands at the molecular weights 45K, 98K and 150 K.

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Identification of surface antigen of Trichomonas vaginalis (질편모충의 표면항원 분석)

  • 민득영;임미혜
    • Parasites, Hosts and Diseases
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    • v.32 no.4
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    • pp.243-248
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    • 1994
  • Plasma membrane proteins of a Korean isolate of Trichomonus vofinalis HY-1 were fractionated for antigen analysis. Homogenates of T. vaginalis were fractionated by the differential centrifugation using sucrose step-gradient method. The interface layer from the 25%/45% sucrose was collected as a plasma membrane fraction and its purity was examined by transmission electron microscopy. The antigenicity of plasma membrane fraction was analysed by enzyme-linked immunoelectrotransfer blot technique with immune rabbit serum and compared with surface antigen labelled with N. hydroxysuccinimide-biotin. The fluffy fraction of 25%/45% sucrose interface was homogeneous and membrane particles were present as extended sheet and concentric vesicles showing typical trilamellar appearance under transmission electron microscope. Seven fractions at 40, 50, 60, 110, 130, 140 and 150 kDa were identified as the antigenic membrane proteins in EITB with anti HY-1 rabbit serum. The common band at 60 kDa was detected both in antigenic fractions of plasma membrane and surface protein labelled with NHS-biotin. This result indicates that this protein is considered as a major surface antigen of T. vaginalis. The role of this surface antigen at 60 kDa should be studied further.

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Modulatory Effect of Kaempferitrin, a 3,7-Diglycosylflavone, on the LPS-Mediated Up-regulation of Surface Co-stimulatory Molecules and CD29-Mediated Cell-cell Adhesion in Monocytic- and Macrophage-like Cells (활성화된 단핵구 및 대식세포의 항원제시기능에 대한 Kaempferitrin의 조절 효과)

  • Kim, Byung-Hun;Cho, Dong-Ha;Cho, Jae-Youl
    • YAKHAK HOEJI
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    • v.51 no.6
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    • pp.482-489
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    • 2007
  • Kaempferitrin, isolated from Kenaf (Hibiscus cannabinus), was examined to evaluate its modulatory effects on antigen-presenting cell functions of macrophages/monocytes such as phagocytosis of foreign materials, up-regulation of costimulatory molecules (CD40, CD80 and CD86), adhesion molecule activation, and antigen processing and presentation. Kaempferitrin strongly blocked up-regulation of CD40, CD80 and CD86, but not pattern recognition receptor (PRR) (e.g., TLR2). It also suppressed functional activation of CD29 (${\beta}1$-integrins), as assessed by cell-cell adhesion assay, required for T cell-antigen-presenting cell (APC) interaction. Furthermore, this compound did not block a simple activation of CD29, as assessed by cell-fibronectin adhesion assay. However, the compound did not diminish phagocytic uptake, an initial step for antigen processing, and ROS generation in RAW264.7 cells. In particular, to understand molecular mechanism of kaempferitrin-mediated inhibition, the regulatory role of LPS-induced signaling events was examined using immunoblotting analysis. Interestingly, this compound dose dependently suppressed the phosphorylation of $I{\kappa}B{\alpha}$, Src, Akt and Syk, demonstrating that it can negatively modulate the activation of these signaling enzymes. Therefore, our data suggested that kaempferitrin may be involved in regulating APC function-relevant immune responses of macrophages and monocytes by regulating intracellular signaling.

An Engineered Outer Membrane-Defective Escherichia coli Secreting Protective Antigens against Streptococcus suis via the Twin-Arginine Translocation Pathway as a Vaccine

  • Li, Wenyu;Yin, Fan;Bu, Zixuan;Liu, Yuying;Zhang, Yongqing;Chen, Xiabing;Li, Shaowen;Li, Lu;Zhou, Rui;Huang, Qi
    • Journal of Microbiology and Biotechnology
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    • v.32 no.3
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    • pp.278-286
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    • 2022
  • Live bacterial vector vaccines are one of the most promising vaccine types and have the advantages of low cost, flexibility, and good safety. Meanwhile, protein secretion systems have been reported as useful tools to facilitate the release of heterologous antigen proteins from bacterial vectors. The twin-arginine translocation (Tat) system is an important protein export system that transports fully folded proteins in a signal peptide-dependent manner. In this study, we constructed a live vector vaccine using an engineered commensal Escherichia coli strain in which amiA and amiC genes were deleted, resulting in a leaky outer membrane that allows the release of periplasmic proteins to the extracellular environment. The protective antigen proteins SLY, enolase, and Sbp against Streptococcus suis were targeted to the Tat pathway by fusing a Tat signal peptide. Our results showed that by exploiting the Tat pathway and the outer membrane-defective E. coli strain, the antigen proteins were successfully secreted. The strains secreting the antigen proteins were used to vaccinate mice. After S. suis challenge, the vaccinated group showed significantly higher survival and milder clinical symptoms compared with the vector group. Further analysis showed that the mice in the vaccinated group had lower burdens of bacteria load and slighter pathological changes. Our study reports a novel live bacterial vector vaccine that uses the Tat system and provides a new alternative for developing S. suis vaccine.

The Value of Postoperative Serum Carcinoembryonic Antigen and Carbohydrate Antigen 19-9 Levels for the Early Detection of Gastric Cancer Recurrence after Curative Resection

  • Lee, Eung-Chang;Yang, Jun-Young;Lee, Kyung-Goo;Oh, Seung-Young;Suh, Yun-Suhk;Kong, Seong-Ho;Yang, Han-Kwang;Lee, Hyuk-Joon
    • Journal of Gastric Cancer
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    • v.14 no.4
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    • pp.221-228
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    • 2014
  • Purpose: This study aimed to evaluate the value of serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels to detect gastric cancer recurrence. Materials and Methods: We retrospectively reviewed 154 patients who developed recurrence within 2 years after curative gastric cancer surgery and analyzed the relationship between postoperative CEA and CA19-9 levels and recurrence. We readjusted the cut-off values to improve the detection of recurrence. Subgroup analysis according to clinicopathologic variables was performed to further investigate the relationship between recurrence and CEA and CA19-9 levels. Results: The sensitivity and specificity for elevated CEA levels to detect recurrence were 40.6% and 89.5%, respectively, and those for CA19-9 were 34.2% and 93.6%, respectively. The sensitivity and specificity for elevation of either tumor marker were 54.3% and 84.0%, respectively; those for elevation of both tumor markers were 19.2% and 98.4%, respectively. By readjusting the cut-off values from 5.0 ng/ml to 5.2 ng/ml for CEA and from 37.00 U/ml to 30.0 U/ml for CA19-9, the sensitivity was increased from 34.2% to 40.2% for CA19-9, while there was no increase in sensitivity for CEA. In subgroup analysis, the sensitivity of CEA was higher in patients with elevated preoperative CEA levels than in patients with normal preoperative CEA levels (86.7% versus 33.7%; P<0.001). Furthermore, the sensitivity of CA19-9 was higher in patients with elevated preoperative CA19-9 levels than in patients with normal preoperative CA19-9 levels (82.61% versus 26.83%; P<0.001). Conclusions: CEA and/or CA19-9 measurement with the readjusted cut-off values allows for more effective detection of gastric cancer recurrence.

Fusion Analytical Sensitivity of Rapid Influenza Antigen Limit of Detection Tests for Human Influenza virus (인플루엔자 바이러스에 대한 신속 항원 검출 검사 검출한계의 융합적 분석)

  • Song, Chang-Sub;Sung, Hyun-Ho;Kim, Jung-Hyun;Kim, Dae-Eun;Park, Chang-Eun;Yoon, Joong-Soo
    • Journal of the Korea Convergence Society
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    • v.9 no.3
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    • pp.165-171
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    • 2018
  • In this study, to analyze the detection of limit for sensitivity of the influenza rapid antigen test kit, the positive detection of limits were analyzed by serial dilution of influenza virus A and B type for five influenza rapid antigen test kits in Korea. As a result of analysis, visual measurement of type A were up to 1:8192 for the Wellsbio product and up to 1:4096 for the II product, up to 1:512 for the I and III products, and only 1:128 for the IV product, and type B were positive for up to 1:8192 for the Wellsbio product, up to 1: 4096 for the II product and up to 1:1024 for the I, III and IV products. For instrument readings with the same specimen, both A and B types were found to be positive for up to 1:8192 for the Wellsbio product, up to 1: 4096 for the II product, and up to 1:2048 for the I product. The sensitivity of the rapid antigen test for influenza differs greatly depending on the sampling area of the patient, infection period, specimen volume, etc. Therefore, it is necessary to observe exactly the collection timing and method of the specimen. And it is necessary further study to improve the sensitivity for influenza rapid antigen test.

Genetic diversity analysis in Chinese miniature pigs using swine leukocyte antigen complex microsatellites

  • Wu, Jinhua;Liu, Ronghui;Li, Hua;Yu, Hui;Yang, Yalan
    • Animal Bioscience
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    • v.34 no.11
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    • pp.1757-1765
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    • 2021
  • Objective: The swine leukocyte antigen (SLA) gene group, which is closely linked and highly polymorphic, has important biomedical significance in the protection and utilization of germplasm resources. However, genetic polymorphism analyses of SLA microsatellite markers in Chinese miniature pigs are limited. Methods: Eighteen pairs of microsatellite primers were used to amplify the SLA regions of seven miniature pig breeds and three wild boar breeds (n = 346) from different regions of China. The indexes of genetic polymorphism, including expected heterozygosity (He), polymorphic information content (PIC), and haplotype, were analyzed. The genetic differentiation coefficient (Fst) and neighbor-joining methods were used for cluster analysis of the breeds. Results: In miniature pigs, the SLA I region had the highest numbers of polymorphisms, followed by the SLA II and SLA III regions; the region near the centromere had the lowest number of polymorphisms. Among the seven miniature pig breeds, Diannan small-ear pigs had the highest genetic diversity (PIC value = 0.6396), whereas the genetic diversity of the Hebao pig was the lowest (PIC value = 0.4330). The Fst values in the Mingguang small-ear, Diannan small-ear, and Yunnan wild boars were less than 0.05. According to phylogenetic cluster analysis, the South-China-type miniature pigs clustered into one group, among which Mingguang small-ear pigs clustered with Diannan small-ear pigs. Haplotype analysis revealed that the SLA I, II, and III regions could be constructed into 13, 7, and 11 common haplotypes, respectively. Conclusion: This study validates the high genetic diversity of the Chinese miniature pig. Mingguang small-ear pigs have close kinship with Diannan small-ear pigs, implying that they may have similar genetic backgrounds and originate from the same population. This study also provides a foundation for genetic breeding, genetic resource protection, and classification of Chinese miniature pigs.

Determination of Monoclonal Antibodies Capable of Recognizing the Native Protein Using Surface Plasmon Resonance

  • Kim, Deok-Ryong
    • BMB Reports
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    • v.34 no.5
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    • pp.452-456
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    • 2001
  • Surface plasmon resonance has been used for a biospecific interaction analysis between two macromolecules in real time. Determination of an antibody that is capable of specifically interacting with the native form of antigen is very useful for many biological and medical applications. Twenty monoclonal antibodies against the $\alpha$ subunit of E. coli DNA polymerase III were screened for specifically recognizing the native form of protein using surface plasmon resonance. Only four monoclonal antibodies among them specifically recognized the native $\alpha$ protein, although all of the antibodies were able to specifically interact with the denatured $\alpha$ subunit. These antibodies failed to interfere with the interaction between the $\tau$ and $\alpha$ subunits that were required for dimerization of the two polymerases at the DNA replication fork. This real-time analysis using surface plasmon resonance provides an easy method to screen antibodies that are capable of binding to the native form of the antigen molecule and determine the biological interaction between the two molecules.

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Prognostic Factors on Overall Survival in Lymph Node Negative Gastric Cancer Patients Who Underwent Curative Resection

  • Jeong, Ji Yun;Kim, Min Gyu;Ha, Tae Kyung;Kwon, Sung Joon
    • Journal of Gastric Cancer
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    • v.12 no.4
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    • pp.210-216
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    • 2012
  • Purpose: To assess independent prognostic factors for lymph node-negative metastatic gastric cancer patients following curative resection is valuable for more effective follow-up strategies. Materials and Methods: Among 1,874 gastric cancer patients who received curative resection, 967 patients were lymph node-negative. Independent prognostic factors for overall survival in lymph node-negative gastric cancer patients grouped by tumor invasion depth (early gastric cancer versus advanced gastric cancer) were explored with univariate and multivariate analyses. Results: There was a significant difference in the distribution of recurrence pattern between lymph node-negative and lymph nodepositive group. In the lymph node-negative group, the recurrence pattern differed by the depth of tumor invasion. In univariate analysis for overall survival of the early gastric cancer group, age, macroscopic appearance, histologic type, venous invasion, lymphatic invasion, and carcinoembryonic antigen level were significant prognostic factors. Multivariate analysis for these factors showed that venous invasion (hazard ratio, 6.695), age (${\geq}59$, hazard ratio, 2.882), and carcinoembryonic antigen level (${\geq}5$ ng/dl, hazard ratio, 3.938) were significant prognostic factors. Multivariate analysis of advanced gastric cancer group showed that depth of tumor invasion (T2 versus T3, hazard ratio, 2.809), and age (hazard ratio, 2.319) were prognostic factors on overall survival. Conclusions: Based on our results, independent prognostic factors such as venous permeation, carcinoembryonic antigen level, and age, depth of tumor invasion on overall survival were different between early gastric cancer and advanced gastric cancer group in lymph node-negative gastric cancer patients. Therefore, we are confident that our results will contribute to planning follow-up strategies.

Prognostic role of preoperative carcinoembryonic antigen levels in colorectal cancer: propensity score matching

  • Kim, Cho Shin;Kim, Sohyun
    • Journal of Yeungnam Medical Science
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    • v.34 no.2
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    • pp.216-221
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    • 2017
  • Background: This study was conducted to investigate preoperative carcinoembryonic antigen (CEA) as a prognostic factor in colorectal cancer. Methods: Between January 2000 and July 2011, 1298 patients with primary adenocarcinoma colorectal cancer without metastasis, who underwent curative resection were retrospectively identified. The patients were divided into two groups according to serum CEA level at primary diagnosis: a high CEA (HCEA) group (serum CEA ${\geq}6ng/mL$) and a normal CEA (NCEA) group (serum CEA <6 ng/mL). A 1:1 propensity score matching analysis was applied to reduce bias. Finally, 364 patients were enrolled in this study. Matched variables were age, gender, preoperative chemoradiotherapy, tumor site, cell differentiation and pathologic stage. Results: The clinicopathological characteristics of the two groups did not differ significantly difference. The systemic metastasis rate was 16.5% (30/182) and 25.3% (46/182) in the NCEA and HCEA groups, respectively (p=0.039). There were no significant differences in local recurrence or metastatic sites between groups. The 5-year disease-free survival (DFS) rate of the HCEA group was worse than that of the NCEA group; however, there was no significant difference in overall survival between the two groups. Conclusion: Elevated preoperative CEA was related to frequent systemic recurrence and low DFS. Therefore, elevated preoperative CEA could be considered a prognostic factor for worse clinical outcomes in patients with colorectal cancer.