جستجوی مقالات مرتبط با کلیدواژه "antigens" در نشریات گروه "پزشکی"

Cystic echinococcosis (CE) is an important zoonotic parasitic disease caused by the larval stage or metacestode of the tapeworm Echinococcus granulosus sensu lato. Due to treatment protocols for different liver cysts, diagnosis of cyst stages is very important. Different antigens have been used for CE diagnosis. However, each one is more sensitive and effective for the diagnosis of specific CE stages is not known well. We aimed to compare Native Hydatid Cyst Fluid (HCF), Lyophilized Hydatid Cyst Fluid (LHCF), antigen B (AgB) and Lyophilized antigen B (LAgB) originated from E. granulosus sensu stricto (G1-G3) genotype, for sero- diagnosis of active, transitional and inactive human liver CE using ELISA technique.

The HCF was collected aseptically from liver CE cysts of sheep slaughtered from 2018 to 2019 in Shiraz slaughterhouse, Southern, Iran. The cysts were characterized by PCR and sequencing for genotype specification. Four types of antigens were used: HCF, LHCF, AgB and LAgB originated from E. granulosus sensu stricto (G1-G3) genotype. Thirty-three serum samples from active, transitional, and inactive human cysts were collected. Overall, 48 samples from other parasitic diseases and 60 samples from healthy subjects as negative controls were checked using four antigens by ELISA method.

The best diagnostic sensitivity with 96.97% was observed by anti-LHCF IgG ELISA test. The best specificity with 95.37% was observed in ELISA test using LAgB.

Simultaneous test of sera with anti-LHCF IgG ELISA and anti-LAgB IgG ELISA would be the best in the diagnosis of human liver cystic echinococcosis.

Serological diagnosis of Strongyloides stercoralis (S. stercoralis) is frequently challenging because of cross-reactivity with other parasitic nematodes. Therefore, it is necessary to introduce novel serological tests with high performance to properly diagnose this neglected parasitic infection. The purpose of the current study was to design a multi-epitope construct for the diagnosis of S. stercoralis.

For the purpose of this study, first, highly antigenic segments and potential immunodominant epitopes of S. stercoralis were identified from two antigenic proteins, and then all of the selected parts were linked by an appropriate linker. Next, the physico-chemical features of the designed construct were analyzed. Then, tertiary structures of the construct were built and evaluated to find out the best one. Lastly, the amino acid sequence was reverse-translated and optimized for over-expression in Escherchia coli (E. coli).

The bioinformatic evaluation indicated that the designed protein construct could be hydrophilic, thermostable, and acidic and the estimated half-life was more than 10 hr in E. coli.

According to the results of the study, the designed construct could be used as an efficient antigen in the ELISA system for serological diagnosis of human strongyloidiasis.

In recent decades, the incidence of dengue has increased dramatically. In dengue-endemic countries, changes in dengue virus serotypes, genotypes, and lineages have been reported. This study was designed to detect and characterize the dengue virus isolates circulating in North India by serological and molecular techniques.

This study was conducted at the Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India. NS1 antigen and IgM antibody against dengue were detected by ELISA methods, viral RNA was extracted and amplified by conventional PCR and one-step single-tube multiplex PCR. The purified PCR products were cycle sequenced and a database search was implemented for the confirmation of the sequence product. Phylogenetic analysis was carried out with previously reported sequences.

Among 1509 samples, 205 (13.6%) were found positive for IgM antibodies with the highest number (n=67) among the 21 to 30 years age group with peak positivity during post-monsoon months. Among acute samples, NS1 antigen was positive in 62.9%. Seven patients out of 13 had dengue viral RNA in PCR. It comprised six DENV-2 serotypes and one DENV-3 serotype. On phylogenetic analysis, DENV-2 strains grouped with genotype IV and DENV-3 with genotype III.

Dengue infection was found frequently during post-monsoon season. The positivity rate of the dengue NS1 antigen test was greater than that of the antibody test. The dengue isolates were characterized as genotype IV and genotype III of DENV-2 and DENV-3 respectively.

T-lymphocytes have critical functions in the immune responses against viral and intracellular bacterial infections as well as cancers. Antigen (Ag)-specific T-lymphocyte clones enriched and expanded in vitro are valuable tools in the study of immune responses in animal models and adoptive T-cell therapy of patients with cancer or infection. We described a method for inducing, enriching, and replicating Ag-specific poly-clonal T-cells from BALB/c mice infected with live Bacillus Calmette Guérin (BCG) bacterium. During a 7-8 days procedure, T-lymphocytes were purified from immune cells of lymph nodes stimulated with immunodominant Ag of BCG, TB10.4, and expanded by interleukin -2 cytokine. We evaluated the effect of Ag doses (1, 10, and 100 μg/mL) and exposure method of Ag presenting cells (APCs) to T-cells, on T-cells’ proliferation, viability, and Interferon-gamma (IFN-γ) secretion at 2, 5, and 7 days after Ag stimulation. Increasing Ag concentration increased the average cell division, but at the highest dose of Ag (100 μg/mL), T-cell viability is decreased. Only clones induced by 10 μg/mL Ag produced a desirable amount of IFN-γ. Incubation of Ag and APCs, 24 h before T-lymphocytes addition, increased the proliferation and viability of cells. T cells are in a more favorable condition around day 5 of Ag stimulation in terms of proliferation and survival, and it is the desired time for T cell restimulation. For optimal preparation of specific T-cells for adoptive cell transfer, optimization of Ag dose, the order of APCs and T-cells exposure with Ag, and the duration of initial Ag stimulation, as well as the time for restimulation, is essential.

Human platelet antigens (HPAs) are part of platelet GP complexes have the potential to contribute to the autoantibody production. Moreover, these antigens demonstrate different patterns of distribution on different ethnic groups and variation in some types of diseases. This study was objected to determine the incidence of HPA-1 to -5 and -15 polymorphisms in the Iranians suffering from primary Immune thrombocytopenic purpura (ITP). 

In this case-control investigation, 30 patients by definite primary ITP were randomly selected and enrolled in the study. HPA genotyping was performed implicating by the Single Specific Primer PCR (SSP-PCR). For the control group, data of recently published gene polymorphism among Iranian Blood donors were deployed for comparison. 

The incidence of HPA-1 to -5 and -15 polymorphisms in the Iranian patients with primary ITP was found to be: HPA-1a/1a: 0.933, HPA-1a/1b: 0.067, HPA-2a/2a: 0.133, HPA-2a/2b: 0.867, HPA-3a/3a: 0.2, HPA-3a/3b: 0.533, HPA-3b/3b: 0.267, HPA-4a/4a: 1, HPA-5a/5a: 0.967, HPA-5a/5b: 0.330, HPA-15a/15a: 0.166, HPA-15a/15b: 0.667 & HPA-15b/15b: 0.167.  

This study provides special new data on the distribution of HPA allele among the Iranians ITP patients.Furthermore, it might useful toccharacterize understanding more presizely about ITP and HPA distribution. However, further studies concerning platelet immunology are needed to do help on best practice on management of immune diseases triggered by platelet antibodies.