• Title/Summary/Keyword: Antigen process

Search Result 128, Processing Time 0.031 seconds

Degradation and Conversion of Blood Group Antigens in Saliva (혈액형 항원의 분해와 변환에 관한 연구)

  • Lim, Sang-Wook;Park, Hee-Kyung;Jung, Seung-Eun;Kho, Hong-Seop;Kim, Young-Ku
    • Journal of Oral Medicine and Pain
    • /
    • v.30 no.1
    • /
    • pp.15-23
    • /
    • 2005
  • Mucin glycoproteins are the primary carriers of the oligosaccharide moieties that constitute the blood group substances in human saliva. The aim of this study was to determine whether or not the conversion of either the A or B blood group antigens to the H antigen can occur during the degradation process of stored saliva samples. Forty subjects (20 subjects in each A and B blood group) identified as secretors were enrolled in this study. Fresh whole saliva samples and their clarified supernatants were stored at room temperature for 1 week. The conversion of the blood group antigens was detected by SDS-PAGE and immunoblotting. Among the subjects showing the conversion in whole saliva, glandular saliva samples were obtained from 8 subjects (4 subjects in each A and B blood group). Submandibular-sublingual saliva (SMSL) and a mixture of SMSL and parotid saliva (PS) were stored at room temperature for 1 week. The conversion of the blood group antigens was detected by the same method. The obtained results were as follows: 1. In the clarified samples of whole saliva, the A antigen was detected as being either intact (5%) or degraded molecules (95%) after the 1 week period. Conversion of the A antigen to the H antigen was detected in 5 subjects (25%). In the unclarified samples, the A antigen was either detected as degraded molecules (90%) or was not detected (10%). Conversion of the antigen had occurred in 4 subjects (20%). 2. In the clarified samples of whole saliva, the B antigen was detected as intact (20%) or as degraded molecules (65%) or was not detected (15%) after the 1 week period. Conversion of the B antigen to the H antigen was detected in 7 subjects (35%). In the unclarified samples, the B antigen was detected as intact (5%) or as degraded molecules (65%), or was not detected (30%). Conversion of the antigen was observed in 2 subjects (10%). 3. In the glandular saliva samples, only one of the four subjects displayed an antigenic conversion from the A to H antigen or from the B to H antigen. The conversion had occurred in both the SMSL samples and the SMSL and PS mixture. No degradation of the antigens was detected in the other three samples of the A or B blood groups, nor was there any conversion. The results demonstrated that conversion of the blood group antigens could occur in saliva, and suggested that the enzymes responsible for the conversion are present in saliva. Further studies on the origin and activity of the specific glycosidases in saliva as well as quantitative measurements of the antigenic conversion will be needed.

The PSA Testing Debate in the U.S and Flexible Evidence-Based Medicine (미국의 PSA 진단검사 논쟁과 유연한 근거중심의학)

  • Hyun, Jae Hwan
    • Journal of Science and Technology Studies
    • /
    • v.13 no.1
    • /
    • pp.77-109
    • /
    • 2013
  • The global diffusion of Evidence-Based Medicine (EBM) is changing the landscape of medicine and the healthcare system. STS scholars have shown how EBM works when put into practice. In continuing to add to the literature of previous scholars, this paper traces the historical process and debate over Prostate-Specific Antigen (PSA) testing as an early screening test for prostate cancer in the U.S. This study will reveal that both pros and cons of the testing using EBM as a crucial resources of the debate, and in the process both 'flexibly' interpret and mobilize the hierarchy of scientific evidence for EBM despite the fact the hierarchy is imagined to being scientific criteria that is rigid. Furthermore, this paper will argue that this phenomenon, for which EBM currently seems to support the cons side of PSA screening, was constructed in the context of appraisal of the value 'quality of life' in the EBM system. This case study proposes that those who study the debate of medical technology in the EBM era should contextualize and analyze EBM as part of this debate rather than simply taking EBM for granted.

  • PDF

Epigenetic Changes within the Promoter Regions of Antigen Processing Machinery Family Genes in Kazakh Primary Esophageal Squamous Cell Carcinoma

  • Sheyhidin, Ilyar;Hasim, Ayshamgul;Zheng, Feng;Ma, Hong
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.23
    • /
    • pp.10299-10306
    • /
    • 2015
  • The esophageal squamous cell carcinoma (ESCC) is thought to develop through a multi-stage process. Epigenetic gene silencing constitutes an alternative or complementary mechanism to mutational events in tumorigenesis. Posttranscriptional regulation of human leukocyte antigen class I (HLA-I) and antigen processing machinery (APM) proteins expression may be associated with novel epigenetic modifications in cancer development. In the present study, we determined the expression levels of HLA-I antigen and APM components by immunohistochemistry. Then by a bisulfite-sequencing PCR (BSP) approach, we identified target CpG islands methylated at the gene promoter region of APM family genes in a ESCC cell line (ECa109), and further quantitative analysis of CpG site specific methylation of these genes in cases of Kazakh primary ESCCs with corresponding non-cancerous esophageal tissues using the Sequenom MassARRAY platform. Here we showed that the development of ESCCs was accompanied by partial or total loss of protein expression of HLA-B, TAP2, LMP7, tapasin and ERp57. The results demonstrated that although no statistical significance was found of global target CpG fragment methylation level sof HLA-B, TAP2, tapasin and ERp57 genes between ESCC and corresponding non-cancerous esophageal tissues, there was significant differences in the methylation level of several single sites between the two groups. Of thesse only the global methylation level of LMP7 gene target fragments was statistically higher ($0.0517{\pm}0.0357$) in Kazakh esophageal cancer than in neighboring normal tissues ($0.0380{\pm}0.0214$, p<0.05). Our results suggest that multiple CpG sites, but not methylation of every site leads to down regulation or deletion of gene expression. Only some of them result in genetic transcription, and silencing of HLA-B, ERp57, and LMP7 expression through hypermethylation of the promoters or other mechanisms may contribute to mechanisms of tumor escape from immune surveillance in Kazakh esophageal carcinogenesis.

A NON-MARKOVIAN EVOLUTION MODEL OF HIV POPULATION WITH BUNCHING BEHAVIOUR

  • Sridharan, V.;Jayshree, P.R.
    • Journal of applied mathematics & informatics
    • /
    • v.5 no.3
    • /
    • pp.785-796
    • /
    • 1998
  • In this paper we propose a model of HIv population through method of phases with non-Markovian evolution of immi-gration. The analysis leads to an explicit differnetial equations for the generating functions of the total population size. The detection process of antibodies (against the antigen of virus) is analysed and an explicit expression for the correlation functions are provided. A measure of bunching is also introduced for some particular choice of parameters.

Current Trends in Cancer Vaccines - a Bioinformatics Perspective

  • Sankar, Shanju;Nayanar, Sangeetha K.;Balasubramanian, Satheesan
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.7
    • /
    • pp.4041-4047
    • /
    • 2013
  • Cancer vaccine development is in the process of becoming reality in future, due to successful phase II/III clinical trials. However, there are still problems due to the specificity of tumor antigens and weakness of tumor associated antigens in eliciting an effective immune response. Computational models to assess the vaccine efficacy have helped to improve and understand what is necessary for personalized treatment. Further research is needed to elucidate the mechanisms of activation of antigen specific cytotoxic T lymphocytes, decreased TREG number functionality and antigen cascade, so that overall improvement in vaccine efficacy and disease free survival can be attained. T cell epitomic based in sillico approaches might be very effective for the design and development of novel cancer vaccines.

Allograft Immune Reaction of Kidney Transplantation Part 1. Mechanism of Allograft Rejection (신이식 후 면역반응의 이해 - 1부. 이식 거부 반응의 기전 -)

  • Kang, Hee-Gyung
    • Childhood Kidney Diseases
    • /
    • v.12 no.1
    • /
    • pp.23-29
    • /
    • 2008
  • Kidney allograft transplantation is the most effective method of renal replacement for end stage renal disease patients. Still, it is another kind of 'disease', requiring immunosuppression to keep the allograft from rejection(allograft immune reaction). Immune system of the allograft recipient recognizes the graft as a 'pathogen (foreign or danger)', and the allograft-recognizing commanderin-chief of adaptive immune system, T cell, recruits all the components of immune system for attacking the graft. Proper activation and proliferation of T cell require signals from recognizing proper epitope(processed antigen by antigen presenting cell) via T cell receptor, costimulatory stimuli, and cytokines(IL-2). Thus, most of the immunosuppressive agents suppress the process of T cell activation and proliferation.

  • PDF

Current Diagnosis and Management of Hypersensitivity Pneumonitis

  • Leone, Paolo Maria;Richeldi, Luca
    • Tuberculosis and Respiratory Diseases
    • /
    • v.83 no.2
    • /
    • pp.122-131
    • /
    • 2020
  • Hypersensitivity Pneumonitis (HP) one of the most common interstitial lung diseases (ILDs) is characterized by exposure to an inhaled inciting antigen that leads to a host immunologic reaction determining interstitial inflammation and architectural distortion. The underlying pathogenetic mechanisms are unclear. The absence of international shared diagnostic guidelines and the lack of a "gold-standard" test for HP combined with the presence of several clinical and radiologic overlapping features makes it particularly challenging to differentiate HP from other ILDs, also in expert contests. Radiology is playing a more crucial role in this process; recently the headcheese sign was recognized as a more specific for chronic-HP than the extensive mosaic attenuation. Several classification proposals and diagnostic models have been advanced by different groups, with no prospective validation. Therapeutic options for HP have been limited to antigen avoidance and immunosuppressant drugs over the last decades. Several questions about this condition remain unanswered and there is a need for more studies.

ANALYSIS OF FLUIDIC BEAD CUBE EMBEDDED PORTABLE CMOS SENSING SYSTEM FOR IMMUNO REACTION MONITORING (유체소자가 집적화된 면역검사용 휴대용 CMOS 바이오칩의 분석)

  • Jeong, Yong-Won;Park, Se-Wan;Kim, Jin-Seok;Kim, Hyeon-Cheol;Chun, Kuk-Jin
    • Proceedings of the IEEK Conference
    • /
    • 2005.11a
    • /
    • pp.755-758
    • /
    • 2005
  • This paper describes the novel immunoassay sensing system for a portable clinical diagnosis system. It consists of a bead cage reactor and a CMOS integrated biosensor. It showed the simple and easy antibody coating method on beads by flow-through avidin biotin complex technology in a microfluidic device. It showed just 90 nL sample consumption and good result for the application of alpha feto protein. The bead cage reactor has the role of the antibody coating, antigen binding and enzyme linking for the electrochemical sensing method. The CMOS biosensor consists of ISFET (ion selective field effect transistor) biosensor and temperature sensor for detecting pH that is the byproduct of enzyme reaction. The sensitivity is 8 $kHz/^{\circ}C$ in a temperature sensor and 33 mV/pH in a pH sensor. After filling the 15 um polystyrene beads in bead cage, antibody flowed and reacted to beads. Subsequently, the biotinylated antigen flowed and bound to the antibody and GOD (glucose oxidase)-avidin conjugate flowed and reacted to the biotin of the biotinylated antigen. After this reaction process, glucose solution flowed and reacted to the GOD on beads. The hydrogen was generated by glucose-GOD reaction. And it was detected by the pH sensor.

  • PDF

Multilevel Precision-Based Rational Design of Chemical Inhibitors Targeting the Hydrophobic Cleft of Toxoplasma gondii Apical Membrane Antigen 1 (AMA1)

  • Vetrivel, Umashankar;Muralikumar, Shalini;Mahalakshmi, B;K, Lily Therese;HN, Madhavan;Alameen, Mohamed;Thirumudi, Indhuja
    • Genomics & Informatics
    • /
    • v.14 no.2
    • /
    • pp.53-61
    • /
    • 2016
  • Toxoplasma gondii is an intracellular Apicomplexan parasite and a causative agent of toxoplasmosis in human. It causes encephalitis, uveitis, chorioretinitis, and congenital infection. T. gondii invades the host cell by forming a moving junction (MJ) complex. This complex formation is initiated by intermolecular interactions between the two secretory parasitic proteins-namely, apical membrane antigen 1 (AMA1) and rhoptry neck protein 2 (RON2) and is critically essential for the host invasion process. By this study, we propose two potential leads, NSC95522 and NSC179676 that can efficiently target the AMA1 hydrophobic cleft, which is a hotspot for targeting MJ complex formation. The proposed leads are the result of an exhaustive conformational search-based virtual screen with multilevel precision scoring of the docking affinities. These two compounds surpassed all the precision levels of docking and also the stringent post docking and cumulative molecular dynamics evaluations. Moreover, the backbone flexibility of hotspot residues in the hydrophobic cleft, which has been previously reported to be essential for accommodative binding of RON2 to AMA1, was also highly perturbed by these compounds. Furthermore, binding free energy calculations of these two compounds also revealed a significant affinity to AMA1. Machine learning approaches also predicted these two compounds to possess more relevant activities. Hence, these two leads, NSC95522 and NSC179676, may prove to be potential inhibitors targeting AMA1-RON2 complex formation towards combating toxoplasmosis.