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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.
31

Integrated analytics of microarray big data reveals robust gene signature

Liu, Wanting, Peng, Yonghong, Tobin, Desmond J. January 2015 (has links)
No / The advance of high throughput biotechnology enables the generation of large amount of biomedical data. The microarray is increasingly a popular approach for the detection of genome-wide gene expression. Microarray data have thus increased significantly in public accessible database repositories, which provide valuable big data for scientific research. To deal with the challenge of microarray big data collected in different research labs using different experimental set-ups and on different bio-samples, this paper presents a primary study to evaluate the impact of two important factors (the origin of bio-samples and the quality of microarray data) on the integrated analytics of multiple microarray data. The aim is to enable the extraction of reliable and robust gene biomarkers from microarray big data. Our work showed that in order to enhance biomarker discovery from microarray big data (i) it is necessary to treat the microarray data differently in terms of their quality, (ii) it is recommended to stratifying (i.e., sub-group) the data according to the origin of bio-samples in the analytics.
32

The use of acute responses of endocrine and immune biomarkers to highlight overreaching

Leal, Diogo Luis Campos Vaz January 2017 (has links)
The action of overtraining may lead to the different states of overreaching or the overtraining syndrome (OTS). Chronic maladaptation in endocrine and immune mechanisms, and performance decrements occur with the incidence of these states. Circulating cortisol and testosterone have been proposed as endocrine markers of overreaching/OTS. Salivary measurements of these hormones have been used as a non-invasive surrogate for circulating levels. Chapter 4 (study 1) on this Thesis examined the influence of consuming water 10 min, 5 min and 1 min before providing a saliva sample in diluting saliva and consequently providing invalid salivary cortisol and testosterone concentration levels. No trial effect was found. However, exercise-induced salivary cortisol and testosterone significantly elevated in response to the 10 min and 5 min trials only, with lower absolute-changes observed in the 1 min trial. No differences were found in the resting samples. It was suggested that consuming water up to 5 min before providing a saliva sample does not appear to influence the hormone concentrations at rest and during exercise. However, the recommended guidelines for saliva collection have been followed in the subsequent studies. Chapter 5 (study 2) examined the reproducibility of salivary cortisol and testosterone responses to a 30-min cycle named as the 55/80. This test has been proposed as a suitable indicator of hormonal alterations associated with overreaching/OTS. Reproducibility of salivary cortisol and testosterone to the 55/80 was confirmed by determining intra-individual coefficients of variation (CVi). However, the 55/80 is a cycle test and therefore, may not be appropriate for runners. Chapter 6 (study 3) focused on designing a 30-min, running bout (i.e. the RPEtreadmill) to reproduce the effects of the 55/80. The RPEtreadmill is a self-paced test and therefore, will not require aVO2maxtest to determine exercise intensities. An acute elevation of plasma and salivary testosterone, but not cortisol was observed in response to the RPEtreadmill. These responses have been shown to be reproducible. The data from Chapter 6 suggest that the RPEtreadmill may be a suitable tool to indicate hormonal alterations associated with overreaching/OTS. This led to the design of study 4 (Chapter 7). Plasma and salivary cortisol and testosterone responses were examined before and after a 12-day intensified-training period. Immunity markers (specifically salivary immunoglobulin A (SIgA), leucocyte subset proliferation and phagocytic activity) were examined before and after training. Plasma and salivary cortisol were unaffected by acute exercise and training. However, testosterone elevated to the RPEtreadmill Pre-Training, and these responses were reduced Post-Training. Total leucocytes and mucosal immunity were unaffected by exercise and training. However, increased upper respiratory tract infection symptoms were found Post-Training. Baseline phagocytic function was 47% lower Post-Training. This Thesis suggests that testosterone may be a more reliable exercise-stress marker. Moreover, the RPEtreadmill may be a suitable tool to highlight alterations in testosterone when in an overreached state in an attempt to avoid the incidence of OTS, and that this tool may be practically applied in the field of exercise science. Additionally, this Thesis shows that a 12-day intensified-training period induced a marked decrease in phagocytic responses, and therefore using the RPEtreadmill to highlight overreaching may be important to also prevent further impairments in immunity status.
33

Biomarkers of donor kidney quality as predictors of transplantation outcomes

Kaisar, Maria January 2016 (has links)
Kidney transplantation is a lifesaving treatment for end stage kidney disease that offers considerable benefits to recipients in terms of survival and quality of life. The growing demand for transplants to treat conditions stemming from a rising prevalence of end stage renal disease, diabetes and cardiovascular diseases has to be met increasingly with donors who are older with a high incidence of comorbid conditions. Organs obtained from these higher risk donors are more likely to have either suboptimal short and long-term transplant outcomes or even fail to function altogether. Transplant clinicians, who have to balance the risk of patients dying while waiting for a transplant against the uncertainty of outcomes, often decline organs as transplants. These clinical challenges entail difficult decisions, and more refined tools to assess and quantify the risks of marginal donor organs are lacking. Diagnostic markers of donor kidney quality that can predict transplantation outcomes are highly desirable in order to discriminate the suboptimal from those allografts that will recover and have good long-term function. My doctoral research using donor samples collected within the Quality of Organ Donation (QUOD) programme has shown for first time that it is possible, on the basis of a tissue proteomic profile, to discriminate donor kidneys at the time of retrieval that will have suboptimal allograft function from those kidneys that could recover and have good function at three and 12 months post transplantation. Despite AKIN classification and Remuzzi scoring showing no evidence of acute kidney injury or chronic kidney disease in the analysed biopsies, quantitative mass spectrometry and degredomics experiments with a subsequent validation analysis on an independent cohort of biopsy samples confirmed the increased levels of inflammation and pro-fibrotic proteins in the allografts with suboptimal function, while increased levels of cytoprotective proteins were detected in the kidneys that recovered with a good function one year after transplantation. Furthermore, the kidneys with suboptimal function demonstrated enhanced degradation of cytoskeletal proteins that are vital in sustaining the glomerular basement membrane cytoskeleton. In addition, I conducted a pilot study using proteomic analysis of serum and urine of donors whose kidneys either developed delayed graft function or functioned immediately. This study confirmed that is feasible to identify alterations in the blood and urine proteome that are biologically meaningful. In preparation of the discovery and development of diagnostic biomarkers of long-term outcome after kidney transplantation using QUOD plasma samples, I assessed the pre-analytical variability associated with the processing of whole blood during QUOD sample collection in order to identify a baseline proteomic and peptidomic profile against which candidate protein markers relevant for clinical correlates can be selected. Based on the findings reported in this thesis, future work should aim to identify and develop better diagnostic tools that can more reliably predict donor organ quality. In addition, novel intervention strategies can be explored that either attenuate pro-fibrotic and proteolytic activities or enhance antioxidant and cytoprotective mechanisms in deceased donor kidneys prior to transplantation.
34

Evaluating Blood Biomarker Profiles in Adults with New-onset Seizures using Machine Learning

Akel, Sarah January 2022 (has links)
Around 1% of the population worldwide suffer from epilepsy, a condition which is characterized by recurring seizures. The development of reliable biomarkers for both prediction and targeted treatment of seizures is critical, as they can pave the way towards personalized therapy in epilepsy. In addition, sensitive biomarkers can be utilized for the detection of epilepsy in its early stages and allow for early treatment intervention. Various types of biomarkers have been studied in relation to epilepsy, with blood markers emerging as major candidates. Blood biomarkers offer the benefit of being cost and time efficient, in addition to being less invasive to sample in contrast to cerebrospinal fluid markers. Importantly, they can enhance patient diagnosis and prognosis when supplemented with other diagnostic methods, such as EEG. In this pilot study, five blood biomarkers of brain injury are studied in epilepsy, post-stroke epilepsy and single seizure patients. The aim is to analyze whether S100B, NSE, GFAP, NfL and tau are promising indicators of epilepsy after a first seizure in adults. The results present S100B as the most promising biomarker, with potential to predict early epilepsy.
35

Urinary Phthalates as Potential Biomarkers for Attention Deficit Disorder and Proposed Dopaminergic Pathway Interactions

Kissel, Hannah J. January 2015 (has links)
No description available.
36

The comparison of the relationship between urinary flavonoid metabolites and 1, 2 or 3 days of diet records

Pashkova, Anna 27 August 2019 (has links)
No description available.
37

Identification of Molecular Alterations Associated with Loco-regional and Distant Breast Cancer Metastasis

Cawthorn, Thomas 12 January 2010 (has links)
Metastasis initiation is a complex process encompassing numerous steps. To identify molecular alterations associated with early and late stages of metastasis, we used high throughput screening techniques. Early events in metastasis were investigated by differential proteomic analysis of lymph node-negative and positive breast cancer samples. Two candidate biomarkers (DCN and HSP90B1) were discovered and further validated through tissue microarray analyses. To examine late events in metastasis formation, we prospectively evaluated genomic differences between disseminated tumour cells in bone marrow, and metastatic tumour cells obtained from computed tomography guided biopsies of bone metastases. Results indicate that specific subsets of genes are required for breast cancer cells to initiate bone metastases. Discovery of proteomic and genomic alterations specifically associated with metastases may yield biomarkers capable of stratifying patients into different risk categories. Proteins and genes identified in this work may form the foundation of a biomarker panel for metastatic risk assessment.
38

Identification of Molecular Alterations Associated with Loco-regional and Distant Breast Cancer Metastasis

Cawthorn, Thomas 12 January 2010 (has links)
Metastasis initiation is a complex process encompassing numerous steps. To identify molecular alterations associated with early and late stages of metastasis, we used high throughput screening techniques. Early events in metastasis were investigated by differential proteomic analysis of lymph node-negative and positive breast cancer samples. Two candidate biomarkers (DCN and HSP90B1) were discovered and further validated through tissue microarray analyses. To examine late events in metastasis formation, we prospectively evaluated genomic differences between disseminated tumour cells in bone marrow, and metastatic tumour cells obtained from computed tomography guided biopsies of bone metastases. Results indicate that specific subsets of genes are required for breast cancer cells to initiate bone metastases. Discovery of proteomic and genomic alterations specifically associated with metastases may yield biomarkers capable of stratifying patients into different risk categories. Proteins and genes identified in this work may form the foundation of a biomarker panel for metastatic risk assessment.
39

The genetic basis of low levels of PSA in the general population

Al-Ghamdi, Osama Ahmad January 2013 (has links)
No description available.
40

The environmental biogeochemistry of open ocean and partially enclosed marine systems

Dias, Isobelle A. January 1990 (has links)
No description available.

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