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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

Translational insights into the genetic etiology of mental health disorders: Examining risk factor models, neuroimaging, and current dissemination practices

Bourdon, Jessica L 01 January 2019 (has links)
Psychiatric genetics is a basic science field that has potential for practical application and effective translation. To date, translational frameworks utilized by this field have been linear (e.g., sequential) in nature, focusing on molecular genetic information. It is proposed that non-linear (e.g., socio-ecological) frameworks are a better way to immediately translate non-molecular genetic information. This dissertation explored the translation of psychiatric genetic information in two ways. First, a survey was sent to academic stakeholders to assess the state of the science regarding the translation of genetic information to the clinical care of mental health disorders. Findings from this indicate a translation-genetic competence gap whereby genetic knowledge reinforces linear frameworks and genetic competence is needed to achieve effective translation in this content area. Second, a new risk factor model for social anxiety was created that incorporated genetic, environmental, and neurophysiological risk factors (behavioral inhibition, parental bonding, emotion reactivity). Findings indicate that genetic etiology is more informative knowledge that can influence risk factor models and possibly prevention and intervention efforts for social anxiety. Overall this dissertation paves the way for examining the translational capacity of psychiatric genetics in a clinical setting. It constitutes the first examination of barriers to and a potential solution for the most effective translation of psychiatric genetic information.
22

Improving smoking cessation data collection via a health visitor community of practice

McCullough, B., Small, Neil A., Prady, S.L. 05 1900 (has links)
A Collaborations for Leadership in Applied Health Research and Care (CLAHRC) funded study engaged health visitors in investigating the ways in which routinely collected data were captured, stored, transferred, analysed and then used to inform clinical practice. This report focuses on the establishment of a community of practice (CoP) to support these activities and then presents the outcome of the CoP's investigations into the collection and use of data on one key area of concern; maternal smoking behaviour. Evidence-based recommendations for clinical practice made by the CoP ranged from simple changes to the daily working practices of health visitors to ensure accurate data collection and dissemination of information, to major changes to processes and procedures relating to data quality and data sharing. The findings of the CoP emphasised the importance of cross-discipline communication and collaboration.
23

EXPLORATION OF FACTORS ASSOCIATED WITH PATIENT ADHERENCE IN UPPER EXTREMITY REHABILITATION: A MIXED-METHODS EMBEDDED DESIGN

Smith-Forbes, Enrique V. 01 January 2015 (has links)
Adherence is considered a prerequisite for the success of exercise programs for musculoskeletal disorders. The negative effects of non-adherence to exercise recommendations impact the cost of care, and also treatment effectiveness, treatment duration, the therapeutic relationship, waiting times, the efficiency of personnel and use of equipment. Adherence to therapeutic exercise intervention is a multifaceted problem. The World Health Organization (WHO) established the multidimensional adherence model (MAM). The MAM describes five interactive dimensions (socioeconomic, healthcare team and system, condition-related, therapy-related, and patient-related factors) that have an effect on patient adherence. The first purpose of this dissertation was to explore the MAM dimension of condition-related factors to determine the Quick Disabilities of the Arm Shoulder and Hand (QDASH) minimal clinical important difference (MCID) for three distal upper extremity conditions. The second purpose was to explore the MAM dimension of personal factors to learn from individuals who expressed incongruence between their QDASH and GROC scores; how they described their perceived change in therapy. The third purpose was to explore the MAM dimension of therapy-related factors to examine the effect of patient-therapist collaborative goal setting on patient adherence to treatment and QDASH outcomes. Results demonstrated in the first study that diagnosis specific MCID’s differed from the global MCID using multiple diagnoses. In the second study results demonstrated that patients expect to have a dedicated therapist who they can trust to work collaboratively with them to establish goals and spend time with them to achieve these goals. In the third study, our first hypothesis was not supported for all three measures of adherence. The median for home exercise program diary adherence was found to trend towards significance by 8.7 percent favoring the experimental group Mann-Whitney U (p < .100). Our second hypothesis was not supported. The experimental group receiving collaborative goal setting intervention had similar QDASH mean change scores 45.9±27.6 compared to the control group 46.1±23.8, Mann-Whitney U (p < .859).
24

META-ANALYSIS OF GENE EXPRESSION STUDIES

Siangphoe, Umaporn 01 January 2015 (has links)
Combining effect sizes from individual studies using random-effects models are commonly applied in high-dimensional gene expression data. However, unknown study heterogeneity can arise from inconsistency of sample qualities and experimental conditions. High heterogeneity of effect sizes can reduce statistical power of the models. We proposed two new methods for random effects estimation and measurements for model variation and strength of the study heterogeneity. We then developed a statistical technique to test for significance of random effects and identify heterogeneous genes. We also proposed another meta-analytic approach that incorporates informative weights in the random effects meta-analysis models. We compared the proposed methods with the standard and existing meta-analytic techniques in the classical and Bayesian frameworks. We demonstrate our results through a series of simulations and application in gene expression neurodegenerative diseases.
25

A Systems Biology Approach to Detect eQTLs Associated with miRNA and mRNA Co-expression Networks in the Nucleus Accumbens of Chronic Alcoholic Patients

Mamdani, Mohammed 01 January 2014 (has links)
Alcohol Dependence (AD) is a chronic substance use disorder with moderate heritability (60%). Linkage and genome-wide association studies (GWAS) have implicated a number of loci; however, the molecular mechanisms underlying AD are unclear. Advances in systems biology allow genome-wide expression data to be integrated with genetic data to detect expression quantitative trait loci (eQTL), polymorphisms that regulate gene expression levels, influence phenotypes and are significantly enriched among validated genetic signals for many commonly studied traits including AD. We integrated genome-wide mRNA and miRNA expression data with genotypic data from the nucleus accumbens (NAc), a major addiction-related brain region, of 36 subjects (18 AD cases, 18 matched controls). We applied weighted gene co-expression network analysis (WGCNA) to identify mRNA and miRNA gene co-expression modules significantly associated with AD. We identified six mRNA modules, two of which were downregulated in AD and were enriched for neuronal marker gene expression. The remaining four modules were upregulated in AD and enriched for astrocyte and microglial marker gene expressions. After performing gene set enrichment analysis (GSEA), we found that neuronal-specific modules enriched for oxidative phosphorylation, mitochondrial dysfunction and MAPK signaling pathways and glial-specific modules enriched for immune related processes, cell adhesion molecules and cell signaling pathways. WGCNA was also applied to miRNA data and identified two downregulated and one upregulated modules in AD. We intersected computationally predicted miRNA:mRNA interactions with miRNA and mRNA expression correlations to identify 481 significant (FDR<0.10) miRNA:mRNA targeting pairs. Over half (54%) of the mRNAs were targeted cooperatively by more than one miRNA suggesting a potentially important cellular mechanism relevant to AD. After integrating our expression and genetic data we identified 591 significant mRNA and 68 significant miRNA cis-eQTLs (<1 megabase) (FDR<0.10). After querying against GWAS data from the Colaborative Study on Genetics of Alcohol and Study of Addiction: Gentics and Environment, eQTLs for neuronatin (NNAT; rs1780705), proteosome subunit type 5 (PSMB5; rs10137082), long non-coding RNA (PKI55; rs13392737), adaptor related protein complex 1 sigma one subunit (AP1S1; rs12079545) and translocation associate membrane protein 1 (TRAM1; rs13277972) were associated with AD or alcohol related phenotypes at p<10-4.
26

Caracterização dos subtipos moleculares do câncer gástrico por expressão gênica e proteica / Characterization of the molecular subtypes of gastric cancer by gene and protein expression

Ramos, Marcus Fernando Kodama Pertille 08 April 2019 (has links)
INTRODUÇÃO: Recentemente, a classificação molecular do câncer gástrico (CG) emergiu como opção promissora para definir subgrupos prognósticos, distinguir o comportamento biológico, além de permitir a identificação de potenciais alvos terapêuticos para drogas específicas. Por meio de técnicas moleculares, o CG foi dividido em 4 subtipos: instabilidade de microssatélites (MSI), vírus Epstein-Barr (EBV)-positivo, genomicamente estável (GS) e instabilidade cromossômica (CIN). Os custos associados à complexidade técnica das metodologias moleculares são ainda um obstáculo para sua implantação na prática de rotina. OBJETIVOS: Determinar os grupos da classificação molecular por meio da expressão proteica de marcadores associados a cada subtipo. Comparar as diferentes classificações moleculares existentes e propor um novo modelo. MÉTODOS: Foram avaliados, retrospectivamente, 287 pacientes com CG submetidos à gastrectomia-D2 curativa, por meio da construção de tissue microarray. A expressão das proteínas de reparo do DNA, E-caderina e p53 foram avaliadas por imuno-histoquímica (IH), determinando os grupos MSI, GS e CIN, respectivamente. O EBV foi detectado por hibridização in situ (ISH). RESULTADOS: Após avaliação histopatológica, 179 (62,4%) pacientes foram classificados como CIN, 58 (20,2%) MSI, 30 (10,5%) EBV e 20 (7%) como GS. Os subtipos associaram-se com características distintas, tais como: gênero masculino (EBV, p=0.101); idade avançada (MSI, p=0,017), menor relação neutrófilo-linfócito (CIN, p=0,029), gastrectomia total (EBV, p < 0,001), localização distal (MSI, p=0,004), Laurén difuso (GS, p < 0,001), e estádio avançado (GS, p=0,014). O subtipo MSI apresentou melhor sobrevida livre de doença (SLD) (82,8%), seguido pelo EBV e CIN (ambos com 70%) e GS (50%) (p=0.005). A sobrevida global (SG) foi maior nos tumores MSI (75,9%), seguido pelo EBV (73,3%), CIN (65.4%) e GS (45%, mediana de 25 meses) (p=0.007). Em análise multivariada, gastrectomia total, pT, pN e os subtipos tumorais foram fatores significativos associados à SLD (MSI p=0,012; EBV p=0,037; CIN p=0,018; GS referência). Do mesmo modo, o tipo de cirurgia, pT, e os subtipos tumorais foram fatores independentes associados a SG (MSI p=0,010; EBV p=0,006; CIN p=0,025; GS referência). Com base no risco de recidiva dos pacientes do estudo, nova classificação, que inclui 5 subtipos, foi proposta. Evidenciou-se que a classificação por risco e cluster tiveram melhor acurácia para identificar recidivas e óbitos respectivamente. CONCLUSÃO: A análise IH/ISH foi capaz de determinar subtipos de CG com características clinicopatológicas e prognósticos distintos, reproduzindo os subtipos obtidos pela classificação molecular / BACKGROUND: Recently, the molecular classification of gastric cancer (CG) emerged as a promising option to define prognostic subgroups, to distinguish biological behavior, and to identify potential therapeutic targets for specific drugs. Through molecular techniques, GC was divided into 4 subtypes: microsatellite instability (MSI), Epstein-Barr virus (EBV) positive, genomically stable (GS) and chromosomal instability (CIN). The costs associated with the technical complexity of the molecular methodologies are still an obstacle to its implementation in routine practice. OBJECTIVES: To determine molecular classification groups by means of protein expression of markers associated with each subtype. To compare the different existing molecular classifications and propose a new model. METHODS: We retrospectively evaluated 287 CG patients submitted to curative D2-gastrectomy through the construction of tissue microarray. Expression of the DNA repair proteins, E-cadherin and p53 were evaluated by immunohistochemistry (IH), determining the MSI, GS and CIN subtypes, respectively. EBV was detected by in situ hybridization (ISH). RESULTS: After the histopathological evaluation, 179 (62.4%) patients were classified as CIN, 58 (20.2%) MSI, 30 (10.5%) EBV and 20 GS (7%) as GS. The subtypes presented associations with distinct characteristics, such as: male gender (EBV, p=0.101); advanced age (MSI, p=0.017), Laurén diffuse type (GS, p < 0.001), lower neutrophil-lymphocyte ratio (CIN, p=0.029), total gastrectomy (EBV, p < 0.001), distal location (MSI, p=0.004), and advanced stage (GS, p=0.014). The MSI subtype presented better disease-free survival (DFS) (82.8%), followed by the EBV and CIN subtypes (both with 70%) and GS (50%) (p=0.005). Overall survival (OS) was higher in MSI tumors (75.9%), followed by EBV (73.3%), CIN (65.4%) and GS (45%, median of 25 months) (p=0.007). In multivariate analysis, total gastrectomy, tumor invasion, lymph node metastasis, and tumor subtypes were significant factors associated with SLD (MSI p=0.012, EBV p=0.037, CIN p=0.018, GS reference). Likewise, type of surgery, pT, and tumor subtypes were independent factors associated with OS (p=0.010, p=0.010, EBV p=0.006, CIN p=0.025, GS reference). Based on the risk of recurrence, a new classification including 5 subtypes was proposed. It was evidenced that the risk classification and cluster had better accuracy to identify recurrences and deaths respectively. CONCLUSION: The IH / ISH analysis was able to determine CG groups with clinicopathological characteristics and distinct prognoses, reproducing the subtypes obtained by the molecular classification
27

Autologous Peripheral Nerve Grafts to the Brain for the Treatment of Parkinson's Disease

Welleford, Andrew 01 January 2019 (has links)
Parkinson’s disease (PD) is a disorder of the nervous system that causes problems with movement (motor symptoms) as well as other problems such as mood disorders, cognitive changes, sleep disorders, constipation, pain, and other non-motor symptoms. The severity of PD symptoms worsens over time as the disease progresses, and while there are treatments for the motor and some non-motor symptoms there is no known cure for PD. Thus there is a high demand for therapies to slow the progressive neurodegeneration observed in PD. Two clinical trials at the University of Kentucky College of Medicine (NCT02369003, NCT01833364) are currently underway that aim to develop a disease-modifying therapy that slows the progression of PD. These clinical trials are evaluating the safety and feasibility of an autologous peripheral nerve graft to the substantia nigra in combination with Deep Brain Stimulation (DBS) for the treatment of PD. By grafting peripheral nerve tissue to the Substantia Nigra, the researchers aim to introduce peripheral nerve tissue, which is capable of functional regeneration after injury, to the degenerating Substantia Nigra of patients with PD. The central hypothesis of these clinical trials is that the grafted tissue will slow degeneration of the target brain region through neural repair actions of Schwann cells as well as other pro-regenerative features of the peripheral nerve tissue. This dissertation details analysis of the peripheral nerve tissue used in the above clinical trials with respect to tissue composition and gene expression, both of injury-naive human peripheral nerve as well as the post-conditioning injury nerve tissue used in the grafting procedure. RNA-seq analysis of sural nerve tissue pre and post-conditioning show significant changes in gene expression corresponding with transdifferentiation of Schwann cells from a myelinating to a repair phenotype, release of growth factors, activation of macrophages and other immune cells, and an increase in anti-apoptotic and neuroprotective gene transcripts. These results reveal in vivo gene expression changes involved in the human peripheral nerve injury repair process, which has relevance beyond this clinical trial to the fields of Schwann cell biology and peripheral nerve repair. To assess the neurobiology of the graft post-implantation we developed an animal model of the grafting procedure, termed Neuro-Avatars, which feature human graft tissue implanted into athymic nude rats. Survival and infiltration of human graft cells into the host brain were shown using immunohistochemistry of Human Nuclear Antigen. Surgical methods and outcomes from the ongoing development of this animal model are reported. To connect the results of these laboratory studies to the clinical trial we compared the severity of motor symptoms before surgery to one year post-surgery in patients who received the analyzed graft tissue. Motor symptom severity was assessed using the Unified Parkinson’s Disease Rating Scale Part III. Finally, the implications and future directions of this research is discussed. In summary, this dissertation advances the translational science cycle by using clinical trial findings and samples to answer basic science questions that will in turn guide future clinical trial design.
28

A BRAIN-COMPUTER INTERFACE FOR CLOSED-LOOP SENSORY STIMULATION DURING MOTOR TRAINING IN PATIENTS WITH TETRAPLEGIA

Thomas, Sarah Helen 01 January 2019 (has links)
Normal movement execution requires proper coupling of motor and sensory activation. An increasing body of literature supports the idea that incorporation of sensory stimulation into motor rehabilitation practices increases its effectiveness. Paired associative stimulation (PAS) studies, in which afferent and efferent pathways are activated in tandem, have brought attention to the importance of well-timed stimulation rather than non-associative (i.e., open-loop) activation. In patients with tetraplegia resulting from spinal cord injury (SCI), varying degrees of upper limb function may remain and could be harnessed for rehabilitation. Incorporating associative sensory stimulation coupled with self-paced motor training would be a means for supplementing sensory deficits and improving functional outcomes. In a motor rehabilitation setting, it seems plausible that sensory feedback stimulation in response to volitional movement execution (to the extent possible), which is not utilized in most PAS protocols, would produce greater benefits. This capability is developed and tested in the present study by implementing a brain-computer interface (BCI) to apply sensory stimulation synchronized with movement execution through the detection of movement intent in real time from electroencephalography (EEG). The results demonstrate that accurate sensory stimulation application in response to movement intent is feasible in SCI patients with chronic motor deficit and often precedes the onset of movement, which is deemed optimal by PAS investigations that do not involve a volitional movement task.
29

EFFECTS OF THE NA-CL CO-TRANSPORTER (NCC) IN WESTERN DIET INDUCED METABOLIC AND CARDIAC DYSFUNCTION

Cutter, Zachary S 01 January 2018 (has links)
Interleukin-18 (IL-18) is a pro-inflammatory cytokine known to be involved in maintaining metabolic homeostasis; however, also capable of inducing cardiac dysfunction. Additionally, IL-18, has been shown to bind to a novel receptor, the Na-Cl Co-transporter (NCC). We hypothesized that NCC mediates IL-18 metabolic and cardiac signaling in mice. Using male C57BL/6J mice, we compared the metabolic and cardiac function changes after at least 8 weeks of high-saturated fat high sugar diet (Western Diet) in NCC knockout (NCCKO), IL-18 knockout (IL-18KO), and wild-type mice. We show that NCCKO mice have significantly increased body weight gain from baseline, no difference in fasting blood glucose, and attenuated cardiac diastolic dysfunction after WD compared to wild-type mice. Collectively, the metabolic and cardiac phenotypes of NCCKO mice resembled that of the IL-18KO mice, indicating that NCC may mediate IL-18 signaling in a mouse model of diet-induced obesity and cardiac dysfunction.
30

Reducing Sepsis Mortality: A Cloud-Based Alert Approach

Zink, Janet A. 01 January 2018 (has links)
The aim of this study is to examine the impact of a cloud-based CDS alerting system for SIRS, a precursor to sepsis, and sepsis itself, on adult patient and process outcomes at VCU Health System. The two main hypotheses are: 1) the implementation of cloud-based SIRS and sepsis alerts will lead to lower sepsis-related mortality and lower average length of stay, and 2) the implementation of cloud-based SIRS and sepsis alerts will lead to more frequent ordering of the Sepsis PowerPlan and more recording of sepsis diagnoses. To measure these outcomes, a pre-post study was conducted. A pre-implementation group diagnosed with sepsis within the year leading up to the alert intervention consisted of 1,551 unique inpatient visits, and the three-year post-implementation sample size was 9,711 visits, for a total cohort of 11,262 visits. Logistic regression and multiple linear regression were used to test the hypotheses. Study results showed that sepsis-related mortality was slightly higher after the implementation of SIRS alerts, but the presence of sepsis alerts did not have a significant relationship to mortality. The average length of stay and the total number of recorded sepsis diagnoses were higher after the implementation of both SIRS and sepsis alerts, while ordering of the Sepsis Initial Resuscitation PowerPlan was lower. There is preliminary evidence from this study that more sepsis diagnoses are made as a result of alert adoption, suggesting that clinicians can consider the implementation of these alerts in order to capture a higher number of sepsis diagnoses.

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