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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.
441

PM2.5 components and respiratory allergy: a series of in vitro studies focusing Asian cities / PM2.5 成分と呼吸器アレルギー:アジア都市のPM2.5 に注目したin vitro 研究

Chowdhury, Pratiti Home 25 September 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20690号 / 工博第4387号 / 新制||工||1682(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 高野 裕久, 教授 米田 稔, 准教授 上田 佳代 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
442

The Chemically Sensitive Individual: Validation by Criterion Group Identification

Henderson, J. Louise 05 1900 (has links)
The purpose of this study was to delineate those variables which are indicative of the patient whose health may be adversely affected by sensitivity to chemicals. In stage One analysis, the files of 10 chemically sensitive and 10 non-chemically sensitive patients were used to establish criterion variables as previously defined by legal proceedings prior to the study. Chemically sensitive and non-chemically sensitive patients were compared on all variables included in the study to empirically determine those variables which demonstrated significant differences by chi square analysis.
443

Atopic diseases in children and adolescents are associated with behavioural difficulties

Keller, Wiebke 12 July 2022 (has links)
Background: Atopic diseases and behavioural difficulties in children have both been on the rise in recent decades. This study seeks to assess associations between atopic diseases and behavioural difficulties, examining the differences considering child age and how behavioural difficulties were reported (via self-report or parent-report). Methods: Data on behavioural difficulties, assessed through the Strengths And Difficulties Questionnaire (SDQ), and on atopic diseases, assessed through the participant’s medical history, were available for 2701 study participants aged 3 to 18 years. Associations between atopic diseases and behavioural difficulties were evaluated using linear regression analyses. We split the study sample into two groups. I: 3-to 10-year-olds/parent-reported SDQ (n=1764), II: 11- to 18-year-olds/parent-reported SDQ (n=937) and self-reported SDQ (n=915). All analyses were adjusted for age, gender, and socioeconomic status. Results: In younger children, atopic dermatitis was strongly associated with higher total difficulties scores, more emotional problems and conduct problems, and more symptoms of hyperactivity/inattention. Parents reported higher total difficulties scores, more emotional problems, and more peer-relationship problems for adolescents with bronchial asthma and other allergies, whereas the adolescents themselves reported more peer relationship problems. Conclusion: In younger children, atopic dermatitis is associated with internalizing and externalizing problems. In adolescents, bronchial asthma and other allergies are associated with a greater level of internalizing problems only. The findings further suggest that parents of adolescents are more likely to perceive associations between atopic diseases and behavioural difficulties than the adolescents themselves.
444

The effect of chemical fragrances on child health and development

Gilton, Katie L. 01 May 2011 (has links)
The American public is bombarded with chemically fragranced products every day, typically in combination with each other. These products can include cosmetics, perfumes, detergents, air fresheners, soaps, and deodorants. Contained in these fragranced products are chemicals that can be harmful to child health and development. Many articles have been published examining the chemicals found in fragranced products and the effects that these chemicals can have on the human body. This integrated literature review examines empirical evidence related to the health and safety of particular chemicals used in these products. Nurses need to be aware of the actual and potential harms from the chemicals used in the self-regulating cosmetic industry and can advocate for public policies that promote a safer environment, therefore protecting the health and wellbeing of children.
445

Correcting for Measurement Error and Misclassification using General Location Models

Kwizera, Muhire Honorine January 2023 (has links)
Measurement error is common in epidemiologic studies and can lead to biased statistical inference. It is well known, for example, that regression analyses involving measurement error in predictors often produce biased model coefficient estimates. The work in this dissertation adds to the existing vast literature on measurement error by proposing a missing data treatment of measurement error through general location models. The focus is on the case in which information about the measurement error model is not obtained from a subsample of the main study data but from separate, external information, namely the external calibration. Methods for handling measurement error in the setting of external calibration are in need with the increase in the availability of external data sources and the popularity of data integration in epidemiologic studies. General location models are well suited for the joint analysis of continuous and discrete variables. They offer direct relationships with the linear and logistic regression models and can be readily implemented using frequentist and Bayesian approaches. We use the general location models to correct for measurement error and misclassification in the context of three practical problems. The first problem concerns measurement error in a continuous variable from a dataset containing both continuous and categorical variables. In the second problem, measurement error in the continuous variable is further complicated by the limit of detection (LOD) of the measurement instrument, resulting in some measures of the error-prone continuous variable undetectable if they are below LOD. The third problem deals with misclassification in a binary treatment variable. We implement the proposed methods using Bayesian approaches for the first two problems and using the Expectation-maximization algorithm for the third problem. For the first problem we propose a Bayesian approach, based on the general location model, to correct measurement error of a continuous variable in a data set with both continuous and categorical variables. We consider the external calibration setting where in addition to the main study data of interest, calibration data are available and provide information on the measurement error but not on the error-free variables. The proposed method uses observed data from both the calibration and main study samples and incorporates relationships among all variables in measurement error adjustment, unlike existing methods that only use the calibration data for model estimation. We assume by strong nondifferential measurement error (sNDME) that the measurement error is independent of all the error-free variables given the true value of the error-prone variable. The sNDME assumption allows us to identify our model parameters. We show through simulations that the proposed method yields reduced bias, smaller mean squared error, and interval coverage closer to the nominal level compared to existing methods in regression settings. Furthermore, this improvement is pronounced with increased measurement error, higher correlation between covariates, and stronger covariate effects. We apply the new method to the New York City Neighborhood Asthma and Allergy Study to examine the association between indoor allergen concentrations and asthma morbidity among urban asthmatic children. The simultaneous occurrence of measurement error and LOD is common particularly in environmental exposures such as measurements of the indoor allergen concentrations mentioned in the first problem. Statistical analyses that do not address these two problems simultaneously could lead to wrong scientific conclusions. To address this second problem, we extend the Bayesian general location models for measurement error adjustment to handle both measurement error and values below LOD in a continuous environmental exposure in a regression setting with mixed continuous and discrete variables. We treat values below LOD as censored. Simulations show that our method yields smaller bias and root mean squared error and the posterior credible interval of our method has coverage closer to the nominal level compared to alternative methods, even when the proportion of data below LOD is moderate. We revisit data from the New York City Neighborhood Asthma and Allergy Study and quantify the effect of indoor allergen concentrations on childhood asthma when over 50% of the measured concentrations are below LOD. We finally look at the third problem of group mean comparison when treatment groups are misclassified. Our motivation comes from the Frequent User Services Engagement (FUSE) study. Researchers wish to compare quantitative health and social outcome measures for frequent jail-and-shelter users who were assigned housing and those who were not housed, and misclassification occurs as a result of noncompliance. The recommended intent-to-treat analysis which is based on initial group assignment is known to underestimate group mean differences. We use the general location model to estimate differences in group means after adjusting for misclassification in the binary grouping variable. Information on the misclassification is available through the sensitivity and specificity. We assume nondifferential misclassification so that misclassification does not depend on the outcome. We use the expectation-maximization algorithm to obtain estimates of the general location model parameters and the group means difference. Simulations show the bias reduction in the estimates of group means difference.
446

Potential Co-Factors of an Intraoral Contact Allergy—A Cross-Sectional Study

Olms, Constanze, Schor, Jana, Yahiaoui-Doktor, Maryam 13 April 2023 (has links)
The aim of this cross-sectional study was to evaluate the frequency of dental allergens and potential co-factors, especially hypothyroidism, for patients with an intraoral contact allergy. From 2015 to 2016, patients with confirmed symptoms of an intraoral contact allergy (study group SG n = 50) were recruited in the dental clinic of the University of Leipzig. The participants of the control group (CG n = 103) were patients without oral diseases or intraoral symptoms of a contact allergy. For the data collection, a new “Allergy questionnaire” was developed. Information on allergies and general diseases were collected. The statistical analysis was carried out with SPSS 23.0. Sensitizations/allergies to metals and composites were higher in SG compared to CG. Of all study participants (n = 148), 14.2% (n = 21) had a nickel allergy. In 18% (n = 8) of the SG a cobalt allergy based on all metal allergens could be seen. In addition, an association between a nickel and cobalt allergy was found. Hypothyroidism occurred significantly more frequently (p = 0.049) in SG than in CG. Sensitizations and allergies can occur to metals in dental alloys. Hypothyroidism increased the risk of having an allergy threefold.
447

Mast cell-mediated intestinal barrier function in homeostasis and disease

Groschwitz, Katherine R. January 2010 (has links)
No description available.
448

Genetic and Functional Analysis of Calpain-14 in Eosinophilic Esophagitis

Davis, Benjamin January 2015 (has links)
No description available.
449

VIRAL-ALLERGEN INTERACTIONS: INSIGHTS INTO THE ORIGINS OF ALLERGIC ASTHMA.

Al-Garawi, Amal 10 1900 (has links)
<p>Asthma is a chronic immune-inflammatory disease of the airways, characterized by reversible airflow obstruction and airway hyperresponsiveness (AHR), and is associated with the development of airway remodeling. While our understanding of the pathophysiology of allergic asthma has increased remarkably in the last few decades, the origins of the disease remain elusive. Indeed, studies indicate that the prevalence of allergic asthma, has increased dramatically over the last 30 years. Within this context, a number of environmental factors including respiratory viral infections have been associated with the onset of this disease but causal evidence is lacking. The work presented in this thesis examines the interactions between a respiratory viral infection, specifically influenza A, and the common aeroallergen house dust mite (HDM) in an experimental murine model. To this end, we investigated the impact of an acute influenza A infection on the exposure to a subclinical dose of HDM (Chapter 2) and addressed potential underlying immune mechanisms using a global, genomic approach (Chapter 3). Our data demonstrate an enhancement of immune inflammatory responses to HDM and reveals multiple immune pathways by which influenza A may enhance the response to subsequent allergen exposure. Collectively these immune pathways are capable of lowering the threshold of HDM responsiveness. Lastly, as allergic asthma develops in most instances during infancy, we investigated the impact of an influenza A infection on allergen responses in infant mice (Chapter 4). In this setting, acute influenza A infection subverts constitutive allergen hyporesponsiveness thus resulting in sensitization, airway inflammation and, ultimately, structural and functional alterations persisting into adulthood.</p> / Doctor of Philosophy (PhD)
450

Function and distribution of neuronal high-affinity IgE receptors (FcεRI)

Song, Jiheon 10 1900 (has links)
<p><strong>Background</strong><strong></strong></p> <p>IgE antibodies have high antigen specificity and are the hallmark biomarkers of allergy. IgE binds to high-affinity IgE receptors, known as FcεRI, which are expressed especially on mast cells and basophils. In allergic individuals, antigen binding to IgE that is associated with FcεRI leads to crosslinking of adjacent receptors and subsequently to cell activation, degranulation and/or secretion of bioactive molecules. These molecules together cause minor local tissue reactions such as oedema or itch, but also can cause major systemic reactions such as hypotension, cardiac and respiratory distress or even laryngeal swelling and death. The role of the nervous system in these reactions is usually thought of as secondary. However, in recent years there have been a number of studies suggesting the expression of FcεRI on neurons, opening the possibility that nerves are directly involved in antigen-specific responses and making a previously unrecognized contribution to allergic disease. <strong></strong></p> <p>Based on these previous observations regarding neuronal FcεRI, the current study employed both <em>in vivo</em> and <em>in vitro</em> approaches with the following objectives:<strong></strong> <ol> <li>To confirm the presence of FcεRI on peripheral nerves and demonstrate that they are functionally active under different conditions of IgE sensitization.</li> <li>To examine the pathways involved in neuronal activation by IgE bound to FcεRI and compare and contrast these to those already established for mast cells and basophils.</li> </ol></p> <p><strong>Methods and Results</strong></p> <p>A potential role of neuronal FcεRI in the IgE-dependent allergen avoidance behaviour of sensitized mice presented with antigen in sucrose solution was assessed based on published evidence for the involvement of peripheral nerves in this response.</p> <p>Chimeric mice with a wild-type nervous system but lacking FcεRI on hematopoietic cells including mast cells and basophils, failed to exhibit aversive behaviour, whereas mice with FcεRI-bearing hematopoietic cells demonstrated the normal aversive response confirming that FcεRI expression on mast cells is necessary for development of allergen avoidance. While immunohistochemical staining could detect IgE bound to mast cells in tissue samples, no IgE was detected on nerves where the nerves were identified by using a pan-neuronal marker, PGP 9.5, in the intestine of either normal or passively sensitized C57BL/6 and BALB/c mice. Similarly, traditional FACS analysis clearly identified FcεRI on cultured mast cells, but these methods provided no evidence for expression of FcεRI or IgE binding on superior cervical ganglion (SCG) and dorsal root ganglion (DRG) neurons in culture.</p> <p>To determine evidence for functional FcεRI on neurons <em>in vitro</em>, intracellular calcium increase was assessed as a measure of cell activation following sensitization and antigen challenge. Using both microscopy and FACS analysis, calcium fluorophore (Fluo-3, AM) increase could be detected in SCG or DRG that were activated with the calcium ionophore A23187 but not following antigen challenge.</p> <p><strong>Summary: </strong>The current study found no evidence for the presence of the FcεRI on neurons <em>in situ</em> or their sensitization by IgE actively or passively using several different approaches both in tissues and cultured SCG or DRG neurons. Possible explanations for the resultant discrepancy with previously published works are discussed.</p> / Master of Science (MSc)

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