Search results for " complex"
showing 10 items of 3391 documents
Hepatitis B surface antigen presentation and HLA-DRB1*– lessons from twins and peptide binding studies
2005
Summary The aim of this study was to investigate the underlying mechanisms of the genetic association between certain HLA-DRB1* alleles and the immune response to HBsAg vaccination. Therefore, HBsAg peptide binding to HLA-DR molecules was measured in vitro by peptide binding ELISAs. Additionally, HBsAg-specific T cell reaction and cytokine profile of immune response were analysed ex vivo in ELISPOT assays and DR-restriction of T-cell proliferative responses was investigated with HBsAg specific T cell clones. In addition, we compared HBsAg specific T cell responses of 24 monozygotic and 3 dizygotic twin pairs after HBsAg vaccination. Our results showed that the peptide binding assays did not…
The influence of major histocompatibility complex class II genes and T-cell Vbeta repertoire on response to immunization with HBsAg.
1998
Nonresponsiveness to HBsAg vaccination is observed in 5-10% of vaccine recipients and is possibly caused by a defect in the T helper cell compartment. The immune response to HBsAg is influenced by genes of the major histocompatibility complex. We have investigated MHC class I and class II antigens in 53 adult responders and 73 nonresponders. Results obtained in this first study were tested in a second study with 56 responders and 62 nonresponders from an infant vaccination trial. In addition, the peripheral Vbeta-chain T-cell receptor repertoire was investigated using monoclonal antibodies and flow-cytometry in 26 adult responders and 38 nonresponders. As previously reported, nonresponsiven…
HLA-DRB1*1301 AND *1302 protect against chronic hepatitis B
1997
Abstract Background/Aims: The outcome of acute hepatitis B infection may be influenced by host factors like the major histocompatibility complex (MHC). We have investigated MHC class I and class II antigens in patients with chronic hepatitis B compared to a healthy control population. To confirm the findings of this first study we performed a second study in a group of subjects who had spontaneously recovered from acute hepatitis B infection. Methods: Frequencies of MHC class I and class II antigens were analyzed in patients with chronic hepatitis B virus infection and in control subjects. MHC class I typing was done by standard microlymphocytotoxicity assays. DRB1 and DQA1 genotypes were d…
Evidence that the interaction between circulating IgA and fibronectin is a normal process enhanced in primary IgA nephropathy
1991
A solid-phase ELISA was set up to measure the direct binding capacity (BC) of different, commercially available, purified human IgA preparations to plates coated with human fibronectin (FN). It was found that secretory, polymeric, and, to a much lesser extent, monomeric IgA exhibited elevated FN-BC as compared to their BC to plates coated with bovine serum albumin. This binding was specific since not observed with human IgG or IgM antibodies. In addition, we noted that this interaction was dose dependent, Ca2+ dependent, saturable, and not covalent, was inhibited by soluble FN, but not by a prior incubation of FN-coated plates with anti-human fibronectin antibodies, and appeared to involve …
Vitamin D as an effective treatment in human uterine leiomyomas independent of mediator complex subunit 12 mutation.
2021
Objective To study whether vitamin D (VitD) inhibits cell proliferation and Wnt/β-catenin and transforming growth factor−β (TGFβ) signaling pathways in uterine leiomyomas independent of mediator complex subunit 12 (MED12) mutation status. Design Prospective study comparing leiomyoma vs. myometrial tissues and human uterine leiomyoma primary (HULP) cells treated with or without VitD and analyzed by MED12 mutation status. Setting Hospital and university laboratories. Patient(s) Women with uterine leiomyoma without any treatment (n = 37). Intervention(s) Uterine leiomyoma and myometrium samples were collected from women undergoing surgery because of symptomatic leiomyoma pathology. Main Outcom…
Performance characteristics of the new Abbott Real Time MTB assay for detection of Mycobacterium tuberculosis complex in respiratory specimens
2015
The performance of the Abbott Real Time MTB assay for detection of Mycobacterium tuberculosis complex in respiratory specimens was evaluated using a standard culture as the reference. The overall concordance between both methods was 0.95. The assay displayed an excellent sensitivity (100% for smear-positive/92.3% for smear-negative specimens) and specificity (100%).
Performance of a Highly Sensitive Mycobacterium tuberculosis Complex Real-Time PCR Assay for Diagnosis of Pulmonary Tuberculosis in a Low-Prevalence …
2018
ABSTRACT The potential impact of routine real-time PCR testing of respiratory specimens from patients with presumptive tuberculosis in terms of diagnostic accuracy and time to tuberculosis treatment inception in low-prevalence settings remains largely unexplored. We conducted a prospective intervention cohort study. Respiratory specimens from 1,020 patients were examined by acid-fast bacillus smear microscopy, tested by a real-time Mycobacterium tuberculosis complex PCR assay (Abbott RealTi me MTB PCR), and cultured in mycobacterial media. Seventeen patients tested positive by PCR (5 were acid-fast bacillus smear positive and 12 acid-fast bacillus smear negative), and Mycobacterium tubercul…
Role of p16INK4a and BMI-1 in oxidative stress-induced premature senescence in human dental pulp stem cells
2017
Human dental pulp stem cells (hDPSCs) are a source for cell therapy. Before implantation, an in vitro expansion step is necessary, with the inconvenience that hDPSCs undergo senescence following a certain number of passages, loosing their stemness properties. Long-term in vitro culture of hDPSCs at 21% (ambient oxygen tension) compared with 3–6% oxygen tension (physiological oxygen tension) caused an oxidative stress-related premature senescence, as evidenced by increased β-galactosidase activity and increased lysil oxidase expression, which is mediated by p16INK4a pathway. Furthermore, hDPSCs cultured at 21% oxygen tension underwent a downregulation of OCT4, SOX2, KLF4 and c-MYC factors, w…
Autoreactive liver-infiltrating T cells in primary biliary cirrhosis recognize inner mitochondrial epitopes and the pyruvate dehydrogenase complex.
1993
Primary biliary cirrhosis (PBC) is characterized by lymphoid infiltrates in the portal tracts of the liver and the occurrence of antimitochondrial autoantibodies in serum directed against components of the pyruvate dehydrogenase complex and the other alpha-keto acid dehydrogenase complexes. These enzymes are located on the inner mitochondrial membrane. The destruction of the biliary tract in PBC is thought to be mediated by autoreactive liver-infiltrating T cells exerting cytotoxic activity or releasing certain lymphokines. In this study the reactivity of liver infiltrating T cells was shown to a bovine pyruvate dehydrogenase complex (PDH), a purified E2 subunit (PDH-E2) and a crude prepara…
A new set of 299 pictures for psycholinguistic studies : French norms for name agreement, image agreement, conceptual familiarity, visual complexity,…
2003
Pictures are often used as stimuli in studies of perception, language, and memory. Since performances on different sets of pictures are generally contrasted, stimulus selection requires the use of standardized material to match pictures across different variables. Unfortunately, the number of standardized pictures available for empirical research is rather limited. The aim of the present study is to provide French normative data for a new set of 299 black-and-white drawings. Alario and Ferrand (1999) were closely followed in that the pictures were standardized on six variables: name agreement, image agreement, conceptual familiarity, visual complexity, image variability, and age of acquisit…