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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

CD4? T-cell deficiency and dysfunction in HIV patients receiving combination antiretroviral therapy

Fernandez, Sonia January 2007 (has links)
[Truncated abstract] Failure to fully reconstitute the immune system is a common clinical problem in HIV patients who were severely immunodeficient before responding to combination antiretroviral therapy (CART). This can manifest as a deficiency in the number or function of CD4+ T-cells and occurs most often in patients who had a nadir CD4+ T-cell count below 100/μl when CART was commenced. Observational studies of large cohorts of HIV patients, such as the D:A:D study, have demonstrated that patients with low CD4+ T-cell counts have increased rates of death compared with patients who have normal CD4+ T-cell counts. Furthermore, individual case studies suggest that impaired recovery of pathogen-specific immune responses during CART is associated with opportunistic infections or disease progression. This thesis addresses possible causes of deficiencies in CD4+ T-cell number or function in HIV patients who were very immunodeficient prior to treatment and are responding (virologically) to CART. Firstly, the role of the thymus in producing naive CD4+ T-cells and the effects of persistent immune activation on the recovery of CD4+ T-cell numbers were assessed in patients with either low or high CD4+ T-cell counts after long-term CART. ... Proportions of antigen presenting cell (APC) subpopulations were examined in HIV patients with low or high CMV-specific CD4+ T-cell responses after long-term CART. HIV patients had significantly lower proportions of plasmacytoid dendritic cells (pDC) than HIV-negative controls. Furthermore, the proportions of pDC were positively correlated with CMV-specific CD4+ T-cell responses in HIV patients. Proportions of myeloid dendritic cells (mDC) were significantly higher in HIV patients than controls, and were also increased in patients with low CMV-specific CD4+ T-cell responses. Proportions of M-DC8+ dendritic cells or CD14+ monocytes did not differ between patients and controls, nor were they associated with CMV-specific CD4+ T-cell responses. Quantitation of cytokine (interferon-α, tumour necrosis factor-α, interleukin (IL) -12, IL-23, IL-15, IL-18 and IL-10) mRNA in unstimulated, purified populations of the APC described above revealed few significant differences between patients with low or high CD4+ T-cell IFN-γ responses to CMV. The only notable difference was the slight elevation of IL-15 mRNA levels in patients compared to controls. Since patients in the high responder group had the highest levels of IL-15 mRNA, this association may reflect the anti-apoptotic properties of IL-15. These studies provide valuable insights into the causes of persistent CD4+ T-cell deficiency and dysfunction in HIV patients on CART and may lead to better monitoring and treatments.
42

The role of secondary signaling in experimental autoimmune thyroiditis

Peterson, Karin E. January 1998 (has links)
Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves: 190-217). Also available on the Internet.
43

The association of CTLA-4 gene with childhood graves' disease in Hong Kong Chinese.

January 2006 (has links)
Yung Chung Ming Edmund. / Thesis submitted in: September 2005. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 44-54). / Abstracts in English and Chinese. / Title Page / Contents / Abstract / 摘要 / List of Figures and tables / Abbreviations / Text / References / Chapter Chapter 1: --- General Introduction / Chapter 1.1 --- An overview to the study of CTLA-4 gene in childhood Graves' disease (GD) / Chapter 1.1.1 --- "Graves' disease 226}0ؤ features, incidence, aetiology and pathogenesis page" / Chapter 1.1.1.1 --- GD features 226}0ؤ from clinical to laboratory --- p.1 / Chapter 1.1.1.2 --- GD incidence - from adult to children --- p.2 / Chapter 1.1.1.3 --- GD aetiology - from environment to genes --- p.3 / Chapter 1.1.1.4 --- GD pathogenesis - from auto-antigen to autoantibody --- p.4 / Chapter 1.1.2 --- CTLA-4 gene study in Graves' disease --- p.5 / Chapter 1.1.3 --- Conclusion --- p.6 / Chapter 1.2 --- "Objectives, hypothesis and planning of the study" --- p.7 / Chapter 1.2.1 --- Objectives --- p.7 / Chapter 1.2.2 --- Hypothesis --- p.7 / Chapter 1.2.3 --- Planning --- p.7 / Chapter Chapter 2: --- Literature Review --- p.8 / Chapter 2.1 --- The CD28 / CTLA-4: B7 co-stimulatory pathway and Graves' disease --- p.8 / Chapter 2.1.1 --- Overview of co-stimulation and T cell activation --- p.8 / Chapter 2.1.2 --- Overview of the CD28 gene --- p.9 / Chapter 2.1.3 --- Overview of the CTLA-4 gene --- p.10 / Chapter 2.1.4 --- Co-stimulation and Graves' disease --- p.13 / Chapter 2.2 --- The study of CTLA-4 gene polymorphism in Graves' disease --- p.14 / Chapter Chapter 3: --- Methodology --- p.16 / Chapter 3.1 --- Recruitment of subjects --- p.16 / Chapter 3.1.1 --- Recruitment of cases --- p.16 / Chapter 3.1.2 --- Recruitment of controls --- p.16 / Chapter 3.1.3 --- Ethical approval --- p.17 / Chapter 3.2 --- Peripheral blood collection and genomic DNA preparation --- p.17 / Chapter 3.2.1 --- Peripheral blood collection --- p.17 / Chapter 3.2.2 --- White blood cell harvesting --- p.17 / Chapter 3.2.3 --- White blood cell digestion --- p.17 / Chapter 3.2.4 --- DNA extraction --- p.17 / Chapter 3.3 --- Polymerase Chain Reaction (PCR) amplification of CTLA-4 gene exon one --- p.18 / Chapter 3 .4 --- PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) analysis of CTLA-4 gene codon 17 A/G dimorphism --- p.19 / Chapter 3.5 --- PCR-Single Strand Conformational Polymorphism (PCR-SSCP) analysis of of CTLA-4 gene codon 17 A/G dimorphism --- p.21 / Chapter 3.5.1 --- Preparation of SSCP gel and buffer --- p.21 / Chapter 3.5.2 --- ´5ةend labelling of forward PCR primer --- p.21 / Chapter 3.5.3 --- Preparation of PCR fragment for SSCP analysis --- p.21 / Chapter 3.5.4 --- SSCP analysis --- p.22 / Chapter 3.5.5 --- Autoradiography --- p.22 / Chapter 3.6 --- Sequence confirmation of the SSCP fragment by PCR cycle sequencing --- p.22 / Chapter 3.6.1 --- Preparation of sequencing template from SSCP fragment --- p.22 / Chapter 3.6.2 --- PCR cycle sequencing --- p.23 / Chapter 3.6.3 --- Preparation of cycle sequencing products for electrophoresis --- p.23 / Chapter 3.6.4 --- Sequencing by capillary electrophoresis (CE) --- p.24 / Chapter 3.7 --- Statistical analysis --- p.24 / Chapter Chapter 4: --- Results and Data Analysis --- p.26 / Chapter 4.1 --- Results --- p.26 / Chapter 4.1.1 --- Demographic data of case and control subjects --- p.26 / Chapter 4.1.2 --- PCR amplification of CTLA-4 gene exon one --- p.26 / Chapter 4.1.3 --- PCR-RFLP analysis of CTLA-4 gene codon 17 A/G dimorphism locus --- p.26 / Chapter 4.1.4 --- PCR-SSCP analysis of CTLA-4 gene codon 17 A/G dimorphism locus --- p.29 / Chapter 4.1.5 --- PCR cycle sequencing of the SSCP fragments --- p.31 / Chapter 4.2 --- Data analysis --- p.32 / Chapter 4.2.1 --- Overview of data --- p.32 / Chapter 4.2.2 --- CTLA-4 exon one polymorphism analysed with respect to sex --- p.32 / Chapter 4.2.3 --- CTLA-4 exon one polymorphism in patients with Graves' disease and controls --- p.34 / Chapter Chapter 5: --- Discussion --- p.36 / Chapter Chapter 6: --- Summary and Conclusions --- p.42
44

Flow cytometric analysis of leukocyte surface molecule expression in critical illness:comparison between septic and non-septic patients

Jämsä, J. (Joel) 06 June 2017 (has links)
Abstract Sepsis is a common problem in the intensive care unit (ICU) still having a high mortality and causing high costs to health care system. Currently, there is no marker to distinguish sepsis from other causes of systemic inflammation. Leukocyte surface molecules have been proposed as markers of sepsis. The most promising markers have been neutrophil CD64 and CD11b on monocytes and neutrophils and HLA-DR on monocytes. In this thesis, leukocyte surface molecules were investigated using quantitative flow cytometry in critically ill patients with sepsis, non-septic ICU controls, and healthy volunteers. The surface molecules of interest were neutrophil CD11b and CD64, monocyte CD11b, CD14, CD40, CD64, CD80, HLA-DR, and lymphocyte CD69. First, a special emphasize was indicated in methodological aspects of the quantitative flow cytometry. Then, the surface molecule kinetics was investigated in different types of critically ill patients. Finally, the diagnostic performance of the molecules was determined and compared to that of traditionally used sepsis markers. Furthermore, an example of multiple marker analysis was introduced as a diagnostic tool. The optimal circumstances for leukocyte surface molecule analysis were +4°C temperature throughout the collection and preparation of the samples using tubes containing acid citrate dextrose (ACD) as an anticoagulant, followed by flow cytometry within 6 hours from sampling. Monocyte CD11b and CD40, neutrophil CD11b and CD64, and CD69 on CD4+ T cells and natural killer (NK) cells separated sepsis from non-septic ICU controls and healthy volunteers, neutrophil CD64, having the best area under curve. Procalcitonin (PCT) was second best marker. Monocyte CD40 and NK CD69 may predict positive blood culture detection, whereas CD11b may predict early mortality. In multiple marker analysis, combination of positive neutrophil CD64, C-reactive protein (CRP) and PCT increased post-test probability for sepsis. In conclusion, pre-analytical and analytical factors have effects on results of leukocyte surface molecule analysis. Leukocyte surface molecules may improve sepsis diagnostics in ICU setting. Neutrophil CD64 was the most promising marker. Combination of CD64, CRP and PCT increased the detection of sepsis in ICU. / Tiivistelmä Sepsis on yleinen tehohoidon ongelma, johon liittyy korkea kuolleisuus ja suuret hoidolliset kustannukset. Toistaiseksi ei ole laboratoriomerkkiainetta, joka erottaisi sepsistä sairastavat muista kriittisesti sairaista, joilla on yleistynyt tulehdusvaste. Valkosolujen pintamolekyylien käyttöä sepsiksen laboratoriomerkkiaineena on tutkittu. Lupaavimmat näistä molekyyleistä ovat olleet neutrofiilien CD64, monosyyttien ja neutrofiilien CD11b ja monosyyttien HLA-DR. Tässä väitöskirjassa tutkittiin valkosolujen pintamolekyylejä kriittisesti sairailla sepsistä sairastavilla potilailla, niillä tehohoitopotilailla, joilla ei ollut sepsistä, ja terveillä vapaaehtoisilla virtaussytometriaa käyttäen. Mielenkiinnon kohteina olivat neutrofiilien CD11b ja CD64, monosyyttien CD11b, CD14, CD40, CD64, CD80 ja HLA-DR, sekä lymfosyyttien CD69. Ensimmäiseksi tutkittiin kvantitatiivista virtaussytometriaa menetelmänä. Sen jälkeen pintamolekyylien kinetiikkaa tutkittiin eri potilasryhmillä. Lopuksi määritettiin pintamolekyylien diagnostinen tehokkuus ja sitä verrattiin perinteisempiin sepsiksen diagnostiikassa käytettyihin laboratoriomerkkiaineisiin. Lisäksi selvitettiin usean merkkiaineen mallin diagnostista osuvuutta. Parhaat olosuhteet virtaussytometrialle olivat: +4 °C:n lämpötila näytteenoton ja -käsittelyn aikana, näytteiden ottaminen putkiin, joissa on antikoagulanttina hapan sitraatti-dekstroosi (ACD) ja näytteiden analysointi kuuden tunnin kuluessa näytteenotosta. Monosyyttien CD11b ja CD40, neutrofiilien CD11b ja CD64 sekä CD4+ T-solujen ja NK-solujen CD69 erottivat sepsistä sairastavat tehohoitoverrokeista ja terveistä. Neutrofiilien CD64:llä oli paras erottelukyky. Prokalsitoniini (PCT) oli toiseksi paras merkkiaine. Monosyyttien CD40 ja NK-solujen CD69 voivat parantaa positiivisen veriviljelylöydöksen havaitsemista, kun taas CD11b voi ennustaa varhaista potilaan menehtymistä. Usean merkkiaineen mallissa neutrofiilien CD64 paransi C-reaktiivisen proteiinin (CRP) ja PCT:n tehoa sepsiksen diagnostiikassa. Loppupäätelmänä on, että valkosolujen pintamolekyylien analysointivaiheen eri muuttujilla on vaikutusta virtaussytometriatuloksiin. Valkosolujen pintamolekyylien käyttö voi parantaa sepsiksen diagnostiikkaa teho-osastolla. Neutrofiilien CD64 oli lupaavin merkkiaine. Neutrofiilien CD64:n, CRP:n ja PCT:n yhdistelmä paransi sepsiksen diagnostiikkaa teho-osastolla.
45

Charakterizace biologických a funkčních vlastností nového typu lidských CD27- paměťových B lymfocytů / Characterization of biological and functional features of a new type of CD27- memory B lymphocytes.

Bajzíková, Martina January 2011 (has links)
The increased frequencies of two novel B cell populations defined as IgM+ CD19+ CD27- CD21low CD38low CD24+ and IgM+ CD19+ CD27- CD21low CD38low CD24- in peripheral blood of patients with common variable immunodeficiency (CVID) compared to healthy donors were found. The aim was to search for such B cells in patients with rheumatoid arthritis (RA) and their further characterization. The production of immunoglobulin (Ig) mRNA in single B cells was analyzed using flow cytometry, single cell sorting and RT-PCR, IgVH-specific PCR, cycle sequencing and statistical analysis. The study was focused on analysis of variable regions of the heavy chains of Igs and significant differences in the usage of VH, DH and JH gene segments, mutational frequencies, distribution of silent and replacement mutations, length and composition of CDR3 regions, clonal relation and RAG gene expression in above mentioned B cell populations were found. Because of lack of the surface CD27 molecule being regarded as marker of B cells that have undergone antigen-driven germinal reactions, analyzed populations were considered as naive. However, the pattern and type of mutations suggested that these cells could represent a new type of differentiated memory/antigen- experienced B lymphocytes (in CVID less maturated) with the likely role in...

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