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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.
21

Immunology of lungworm (Protostrongylus) infections of the Rocky Mountain bighorn sheep

Hudson, Robert John January 1970 (has links)
Protostrongylus stilesi, the parenchymal lungworm, has been attributed an important role in the widespread respiratory diseases of the Rocky Mountain bighorn sheep (Ovis canadensis canadensis). This study was conducted to delineate some of the immunologic and non-specific interactions between parasite and host. A procedure was developed for- the immunochemical quantitation of the ovine immunoglobulins IgG(1), IgG(2) and IgM and for the semi-quantitative analysis of IgA. This technique obviated, the preparation of highly specific antisera required for single radial immunodiffusion. The lungworm did not appear to be a significant part of the total antigenic environment of infected animals since no relationship between immunoglobulin levels and parasite activity was detected. Genetic influences were suggested in the levels of IgG(2) which remained at a relatively constant level characteristic of individual animals. The seromucoids were evaluated as correlates of the inflammatory reaction to parasitism. These proteins were useful in detecting changes in parasite activity and bacterial infection. Gastrointestinal disorders associated with severe scouring were accompanied by the disappearance of circulating orosomucoid (α-1 acid glycoprotein). The loss of this low molecular weight protein appeared to be related to vascular leakage. Lungworm infections induced the appearance of homocytotropic antibodies which could be detected in vitro by their ability to sensitize peripheral polymorphonuclear leucocytes for adherence to the larval cuticle. The elution of this antibody from sensitized cells and the inhibition of the adherence reaction with specific antiserum suggested that the reaction was mediated at least partly by IgG(1). The adherence reaction was used to assay homocytotropic activity of serum from infected animals (washed-cell test). This test was correlated with the ability of sera to sensitize skin for anaphylaxis. The effective hypersensitive response, accounting for both sensitizing and blocking activity, was determined by exposing normal cells to larvae in a medium containing serum (decomplemented-serum test). The results of this test paralleled inflammatory changes in parasitized animals, monitored by the levels of serum orosomucoid. Using this method, levels of homocytotropic and blocking antibodies were measured throughout the annual parasite cycle. Preliminary observations indicated that immunogenic inflammation, associated with the "spring rise" and "self cure," resulted from a shift in a dynamic balance between competing antibodies rather than a proportionate increase in homocytotropic activity. The response of peripheral lymphocytes to the presence of larvae or larval extracts was cursorily examined. Although ovine lymphocytes did not respond well enough in culture to draw definitive conclusions, the presence of larval extracts appeared to have a detrimental effect on cell survival and transformation. Even in the presence of EDTA, minute amounts of antibody sensitized lymphocytes for adherence to the larval cuticle. Sera from a wide variety of sources had an inhibitory effect on this reaction. Treatment of larvae with neuraminidase and high concentrations of NaCl engendered improved adherence. This suggested that Protostrongylus had adopted mechanisms similar to the trophoblast or the neoplastic cell which allegedly evade immunologic recognition with a strongly anionic coat. These aspects are discussed in terms of the possible role of Protostrongylus in respiratory diseases of the bighorn sheep, and the exploitation of molecular mechanisms in the control of parasitic diseases. / Land and Food Systems, Faculty of / Graduate
22

Cord blood dendritic cell populations in atopic-at-risk and not-at-risk infants

Strigul, Olena January 2018 (has links)
Allergic disease encompasses multiple complex syndromes including hayfever, food allergies, eczema and asthma. Atopy is the genetic predisposition towards an IgE-driven immune response in reaction to environmental stimuli, and often serves as a predictor for the development of allergies in the future. While disease etiology is not yet fully understood, many factors including genetics and the environment play a role in the development of allergic disease. Reliable methods for predicting atopic disease development are crucial in emerging therapeutic approaches, which aim to decrease allergic disease severity and clinical progression through early detection and preventative measures. While DCs are emerging as key players in the development of allergic disease, they are challenging to study in vivo due to their low numbers, and ex vivo methods remain relatively unstudied. In this project, receptor expression profiles of atopic-at-risk infants compared to not-atrisk infants were examined in DCs found in cord-blood at birth and CD34+-derived DCs cultured ex vivo. Atopic-at-risks exhibited a higher percentage of ex vivo pDCs expressing TSLPR when compared to not-at-risks. Additionally, an increase of FcεRI expression in atopic-at-risks was found approaching significance in in vivo mDCs. Furthermore, DC differentiation in culture from hematopoietic progenitors and the differences between in vivo and ex vivo DCs were studied. Results indicated a consistent 10-fold increase in the DC population after a 12-day culture compared to cord blood DC numbers. Additionally, a distinct DC population emerged as early as Day 3 with a substantial increase in the percentage of mDCs relative to pDCs. A trend of increased TSLP, CD80, CD86 receptor expression and decreased TLR-5, ST2, FcεRI receptor expression after culture in both mDCs and pDCs was also noted. / Thesis / Master of Science (MSc) / Allergic disease development typically begins in infancy, progressing classically in a series of stages from early life through adulthood. Currently, there is a lack of reliable predictive tests for the development of atopic sensitization and disease. This has slowed efforts to intercept and prevent allergy development at its earliest stages. Dendritic cells (DCs) link innate and adaptive immunity and are thought to be key players in the development of allergic disease. However, the low numbers of DCs in blood make them challenging to study. Methods such as inducing the differentiation of DCs from progenitors are often utilized to obtain a sufficient number of cells. This project investigates whether receptor expression of cord blood-derived DCs grown ex vivo are comparable to the profiles of in vivo DCs at birth. Furthermore, the expression of key receptors on DCs grown in vivo/ex vivo are compared in atopic at-risk, not-at-risk infants.
23

VISCERAL PAIN RESPONSES TO COLORECTAL DISTENTION IN RATS THAT HAVE RECOVERED FROM A BOUT OF COLITIS

Sessenwein, Jessica L. 10 1900 (has links)
<p>Increased visceral pain is often seen in patients with gastrointestinal (GI) inflammation. Some studies, however, have suggested that such pain may persist after resolution of damage or inflammation. Despite the debilitating pain associated with GI inflammation, and its significant impact on affected individuals, few studies have addressed this issue. We hypothesized that altered visceral pain responses would persist after resolution of a bout of colitis in an animal model of colitis. We studied the pain responses to colorectal distention in Wistar rats with dinitrobenzene sulfonic acid (DNBS)-induced colitis, using changes in heart rate as an index of pain. Colonic inflammation had resolved by day 15 after DNBS administration. The assessment of colonic inflammation was based on histological scores, colonic tissue pro-inflammatory cytokine levels and myleoperoxidase activity. Rats examined at 15 days post-DNBS administration exhibited diminished pain responses to colorectal distention as compared to healthy rats. This was associated with significant increases in colonic tissue levels of IL-4 and IL-10 as compared to healthy rats, indicating a possible role for these anti-inflammatory cytokines in counteracting the generation of pain and hyperalgesia. We also studied the effects of hydrogen sulfide (H2S) in our animal model, by administering inhibitors of two of the key enzymes involved in the production of H2S. Our results demonstrated that inhibition of H2S production did not significantly alter the pain responses observed in rats at 15 days post-DNBS administration. In summary, our results demonstrate altered autonomic responses to colorectal distension following resolution of colitis. Further research on the role of anti-inflammatory cytokines and H2S may help to determine the mechanism underlying this effect.</p> / Master of Science (MSc)
24

The Biology of Dendritic Cell Subsets in Allergen-Induced Asthma

Dua, Benny 04 1900 (has links)
<h4> </h4> / <p>Asthma is an inflammatory disorder of the airways, and there has been growing insight into the cellular and molecular mechanisms underlying the inflammatory basis of this disease. Research into the inflammatory mechanisms of asthma has progressively shifted focus from downstream effectors, such as mast cells and eosinophils, up to Th2 lymphocytes and their proallergic cytokines. Even more upstream in the allergic cascade are dendritic cells (DCs), potent APCs that orchestrate immune responses. Evidence supporting a role of DCs in regulating airway allergic inflammation is derived mainly from animal studies. In animal models of asthma, myeloid DCs (mDCs) induce and maintain airway inflammation, while plasmacytoid DCs (pDCs) mediate tolerance and lung homeostasis. It remains uncertain, however, whether this concept of pro-allergic mDCs and anti-allergic pDCs translates from animal to human models. The overall objective of this thesis was to investigate the biology of DC subsets in allergen-induced asthma in asthmatic subjects. Initially, we demonstrate that both mDCs and pDCs increase in the airways of subjects with mild asthma after allergen inhalation. Next, we describe a distinct subpopulation of mDCs, called mDC2s, and demonstrate their association with allergy and asthma severity. Expanding on these findings, we show that mDC2s increase in the airways of mild asthmatics after allergen challenge. Lastly, we explore the potential of pharmacological therapies, anti-OX40L MAb and anti-TSLP MAb, to affect DCs in subjects with mild asthma, and demonstrate no effect of either drug on circulating DC subsets. The studies presented here provide evidence for multiple DC subtypes being involved in the regulation of allergen-induced inflammatory responses, and support continued investigations into the biology of different DC subsets in allergen-induced asthma.</p> / Doctor of Philosophy (Medical Science)
25

Tissue factor expression, regulation, and signaling in human airway cells

Davis, Michael D 01 January 2017 (has links)
Rationale: Tissue Factor (TF) is a transmembrane glycoprotein that canonically functions as the initiator of the coagulation cascade. Increased levels of TF have been associated with inflammatory airway diseases. Since lipopolysaccharide (LPS) is known to elicit and inflammatory response in airway epithelium, we hypothesized that airway epithelial cells release TF when exposed to LPS. Since TF aids in local wound healing, we also hypothesized that inhibition of TF would decrease NHBE growth. The specific aim of this work was to evaluate the effects of LPS exposure on TF production and release from airway epithelia and determine the signaling pathways involved. A secondary aim was to evaluate the effects of TF inhibition on NHBE growth. Methods: Normal human bronchial epithelial cells were grown in submerged cell culture and exposed to LPS as well as several intracellular signaling pathway agonist and inhibitors. Measurements: Tissue Factor mRNA and protein were measured in culture media and cell lysate by reverse-transcriptase polymerize chain reaction and enzyme-linked immunosorbent assay, respectively. Signaling pathways were evaluated using selective agonists and inhibitors. Main results: TF protein levels increased nearly two-fold in cell media after exposure to LPS (p < 0.01). This did not occur in the presence of an MEK/ERK inhibitor (PD98059) or a SMAD inhibitor (SB431542). TF protein levels also increased nearly ten-fold in the presence of TGF-beta (p < 0.05). mRNA of TF and TGF-beta was not altered by LPS or TGF-beta exposure. NHBE grown in the presence of Tissue Factor Pathway Inhibitor grew significantly slower than those grown in standard media (P < 0.05). Conclusions: NHBE release TF when exposed to LPS. This phenomenon is post-translational and may be mediated by an autocrine mechanism involving MEK/ERK signaling that increases TGF-beta which then leads to the release of TF. Our data suggest that this airway epithelium release of TF serves as a local repair function.
26

Mecanismos regulatórios mediados pelos anticorpos maternos na modulação da resposta de hipersensibilidade do tipo I ao alérgeno ovalbumina em camundongos neonatos. / Regulatory mechanisms involved on the offspring type I hypersensitivity response inhibition mediated by maternal immunixation with OVA.

Victor, Jefferson Russo 05 December 2008 (has links)
Avaliamos os mecanismos regulatórios desencadeados pela imunização materna na resposta alérgica da prole OVA. A imunização materna com OVA promoveu alterações como o aumento da expressão dos receptores FcgRIIb nos linfócitos B esplênicos dos neonatos aos 3 dias de idade (d.i.), o que se manteve até os 20 d.i. Com a imunização das proles no período neonatal a imunização materna inibiu a produção de anticorpos IgE anti-OVA. Além disso, foi observado na população de linfócitos B da prole o aumento da expressão dos receptores FcgRIIb e CD44. A transferência passiva de IgG de mães imunes no pós-natal mostrou uma inibição da produção de IgE, e no período pré-natal foi capaz de reduzir a expressão das moléculas CD40 e CD23 nos linfócitos B e a secreção de IL-10 em linfócitos T CD4 na prole no período neonatal. As evidências mostram que a imunização pré-concepcional com OVA induz mecanismos que regulam a resposta IgE da prole imunizada no período neonatal, o que foi parcialmente observado com a transferência passiva de anticorpos IgG durante o período pré e pós-natal. / To evaluate the regulatory mechanisms triggered by maternal immunization in the immune response of the offspring, the effect of preconceptional immunization with OVA was evaluated. Maternal immunization with OVA led to early alteration with increased expression of FcgRIIb in B lymphocytes from 3 days old pups. Offspring from immune mother showed diminished percentage of CD4 T cells IL-4+. The immunization of offspring during neonatal period showed that maternal immunization inhibits the production of anti-OVA IgE antibodies. The evaluation of CD4 T cell population revealed diminished IL-4+ cells. Passive IgG transfer from immune mother during neonatal period showed inhibition in the IgE synthesis, during pregnancy showed capacity to reduce the expression of CD40 molecules in B cells from neonatal pups. These evidences show that maternal OVA immunization down regulates the IgE response of offspring including phenotypic and functional alteration in B and CD4 T cells. These alterations were partially observed with IgG transfer during pregnancy or after birth.
27

Influência dos receptores do tipo Toll 2 e 4 no desenvolvimento da alergia pulmonar experimental induzida por Blomia tropicalis em presença de lipopolissacarídio. / Influence of Toll-like receptors 2 and 4 on the development of experimental allergic airway disease induced by Blomia tropicalis in the presence of lipopolissacharide.

Barboza, Renato 09 December 2010 (has links)
O objetivo deste trabalho foi estudar o efeito da endotoxina durante a sensibilização com extrato de Blomia tropicalis (Bt) Para induzir a alergia pulmonar experimental, camundongos foram sensibilizados s.c. com Bt adsorvido ao alum em presença ou não de LPS e desafiados i.n. com Bt. Os animais sensibilizados e desafiados com de Bt apresentaram intensa inflamação pulmonar eosinofílica, AHR, grande produção de muco, aumento na produção de citocinas do tipo 2 no lavado broncoalveolar (BAL) e aumento de IgE. Quando o LPS foi adicionado, observou-se inibição no influxo de eosinófilos e aumento no influxo de neutrófilos no BAL. O LPS também inibiu IL-4 e IL5 e aumentou IFN<font face=\"Symbol\">g e IL-17. Surpeendentemente, o LPS não afetou a AHR, nem a produção de IgE. Utilizando animais nocautes, verificou-se que a inibição eosinofílica induzida pelo LPS é dependente de IFN<font face=\"Symbol\">g e MyD88 enquanto que o aumento de neutrófilos é independente de IFN<font face=\"Symbol\">g e dependente da sinalização dos TLR2, TLR4 e CD14. Além disso, na ausência de TLR2, TLR4 ou CD14, o LPS suprimiu a alergia pulmonar experimental. Em conclusão, os resultados indicam que camundongos sensibilizados com Bt e LPS co-adsorvidos ao alum desenvolvem um fenótipo de asma não clássico, dependente da sinalização pelos TLR. / The aim of this work was to study the effects of endotoxin during sensitization with Blomia tropicalis extract (Bt). To induce experimental allergic airways, mice were sensitized s.c. with Bt with or without LPS co-adsorbed onto alum, and challenged i.n. with Bt. Wild type mice sensitized and challenged with HDM showed eosinophilic lung inflammation, Arway hyperactivity (AHR), mucus hyperproduction, increased levels of type 2 cytokines in the bronchoalveolar lavage (BAL) fluid, and augmented total IgE. When LPS was added at the sensitization, we observed an inhibition of eosinophil influx and an increase in neutrophil counts in the BAL. Moreover, LPS inhibited IL-4 and IL-5 production and increased IFN-<font face=\"Symbol\">g and IL-17 production. Surprisingly, LPS did not affect AHR or IgE production. Using knockout mice, we found that the eosinophilic inhibition induced by LPS was dependent on IFN<font face=\"Symbol\">g and MyD88, while the neutrophilic increase was independent of IFN<font face=\"Symbol\">g and dependent on TLR2, TLR4 and CD14 signaling. Moreover, in the absence of TLR2, TLR4 or CD14, LPS suppressed AAD. In conclusion, our results indicate that mice sensitized with Bt and LPS co-adsorbed to alum develop a non-classical asthma-like phenotype that is dependent on TLR signaling.
28

YouTube and Food Allergy: An Appraisal of the Educational Quality of Information

Reddy, Keerthi C., Kearns, Mary, Alvarez-Arango, S., Carillo-Martin, L., Cuervo-Pardo, N., Dimov, V., Lang, D., Lopez-Alvarez, S., Schroer, B., Dula, Mark, Zheng, Shimin, Kozinetz, Claudia A. 10 November 2016 (has links)
No description available.
29

The Association of Cancer Development in Patients with Systemic Lupus Erythematosus

Coley, Rose Michelle 01 January 2016 (has links)
The Association of Cancer Development in Patients with Systemic Lupus Erythematosus by Rose Michelle Coley MPH, Walden University, 2011 BS, University of Mount Olive, 2008 Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Public Health Walden University March 2016 Both cancer and autoimmune diseases have been associated with numerous factors that may independently lead to the development of either disease. When these factors overlap the difficulty in assessing association is compounded. The numerous factors that are thought to cause systemic lupus erythematosus (SLE), which leads to the development of cancer, makes the study of an association between the 2 diseases challenging. The purpose of this study was to examine whether the risk of cancer development increased in SLE patients compared to the risk in non-SLE patients. Researchers have not shown consistent relationships of cancer development in patients with SLE; however, consideration of the various factors that contribute to the diseases is necessary to measure an association between the 2 diseases. This study used the Clinical Practice Research database (CPRD), a large, population-based database to test the relationship between SLE and cancer. A matched retrospective cohort study among SLE (n=3025) and non-SLE (n=180555) patients was conducted using the propensity score methodology to help balance the differences between the comparison groups. The propensity score methodology created a similar distribution of observed baseline covariates between the 2 groups. With adjustment for age, the predictor variable of SLE indicates that a patient with SLE is still 2.7 times more likely to develop cancer than is a non-SLE patient. The study outcomes could promote positive social change by reinforcing current recommendations for cancer screenings in persons with SLE, which could enhance the ability to detect cancer early enough to decrease mortality because of cancer in persons with SLE.
30

The DNA methyltransferase inhibitor, guadecitabine, targets tumor-induced myelopoiesis and recovers T cell activity to slow tumor growth

Elkovich, Andrea J 01 January 2019 (has links)
Myeloid Derived Suppressor Cells (MDSC) represent a significant hurdle to cancer immunotherapy because they dampen anti-tumor cytotoxic T cell responses. Previous studies have reported on the myelo-depletive effects of certain chemotherapies. Using guadecitabine, a next-generation DNA methyltransferase inhibitor (DNMTi), we observed significantly reduced tumor burden in the 4T1 murine mammary carcinoma model. Guadecitabine treatment prevents excessive tumor-induced myeloid proliferation and systemic accumulation, and skews remaining MDSCs toward a beneficial antigen-presenting phenotype. Together, this alters the splenic environment to improve T cell activation and interferon-gamma (IFNg) production. Additionally, guadecitabine enhances the therapeutic effect of adoptively transferred antigen-experienced lymphocytes to diminish tumor growth and improve overall survival. Based on these findings, the immune-modulatory effects of guadecitabine can help rescue the anti-tumor immune response and could contribute to the overall effectiveness of current cancer immunotherapies. Allergies and asthma are common ailments that are on the rise around the world. Mast cells play a direct role in the signs and symptoms characteristic in allergic patients. The family of A Disintegrin And Metalloproteinases (ADAMs) are involved in regulating many cellular processes by cleaving surface receptors, ligands, and signaling molecules. We sought to determine the role of ADAM17 in mast cell activity. In studies using ADAM17-deficient mast cells, percent degranulation and cytokines released by IgE-mediated activation were significantly reduced. Interestingly, ionomycin-activation was unchanged, suggesting ADAM17 may be involved in IgE-mediated mast cell activation upstream of calcium release. Additionally, ADAM17MC-/- mice showed protection from IgE-, but not histamine-, mediated passive systemic anaphylaxis (PSA). The underlying mechanism behind the reduced degranulation occurs through signaling deficiencies downstream of Lyn phosphorylation. Together, the data suggest that ADAM17 is required for proper mast cell signaling through its interaction with the Src family kinase, Lyn.

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