Congenital, Hereditary, and Neonatal Diseases and Abnormalities Commons^™

Monitoring Intraventricular Hemorrhage In Preterm Infants, Lilian Mn Kebaya

Electronic Thesis and Dissertation Repository

Germinal Matrix-Intraventricular hemorrhage (GMH-IVH) remains a significant cause of adverse neurodevelopmental outcomes in preterm infants. Current management options for GMH-IVH rely on serial 2-dimensional cranial ultrasound (2D cUS) ventricular measurements and clinical signs. A need exists for reliable biomarkers to aid in the early detection of posthemorrhagic ventricular dilatation (PHVD) and cerebral palsy (CP). We incorporated 3-dimensional cranial US (3D cUS) and functional infrared spectroscopy (fNIRS) to monitor ventricle volumes (VV) and spontaneous functional connectivity (sFC) in preterm infants with GMH-IVH. Infants with severe GMH-IVH who underwent cerebrospinal fluid diversion showed larger VV, which correlated with decreased sFC. Our findings …

Trna Regulation In Humans: The Cellular Effect Of A Pathological Hars Y454s Mutation, Rosan Kenana

Electronic Thesis and Dissertation Repository

tRNAs are the adapter molecules involved in translating the genetic code into functional protein in a living cell. tRNAs are charged with their cognate amino acids - by aminoacyl-tRNA synthetases (aaRS or ARS) - which are then transferred to a growing peptide in a process called mRNA translation. The efficiency of translation is dependent on the ratio of ARS enzymes to their cognate tRNAs and the availability of correctly amino acylated tRNAs. Disruptions of this process, caused by mutations in ARS genes, in particular, have been linked to complex inherited diseases. USH3B syndrome, a recessively inherited disorder among consanguineous families …

The Effects Of Maternal Delta-9-Tetrahydrocannabinol And Cannabidiol Exposure On Fetal Heart Development In Mice, Gregory Robinson

Electronic Thesis and Dissertation Repository

Up to 22.6% of pregnant women consume cannabis during pregnancy despite the uncertainty of teratogenicity of the main ingredients in cannabis, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). This study tested the hypothesis that gestational THC and CBD exposure leads to heart abnormalities. Daily, oral THC exposure induced heart abnormalities in 68% of offspring with three main phenotypes including thickened semilunar valves, ventricular myocardial hypertrophy and hypoplastic coronary arteries in fetuses, and postnatal cardiac dysfunction. Altered gene expression of key cardiogenic regulators, increased proliferation, and reduced epicardial epithelial-to-mesenchymal-transition were demonstrated implicating potential mechanisms responsible for these abnormalities. Also, maternal CBD exposure resulted …

Nutrient Sensing Pathways Mediating Igfbp1 Phosphorylation In Fgr, Shapnil Bhuiyan

Electronic Thesis and Dissertation Repository

Impairment of fetal oxygen levels and nutrient delivery contributes to fetal growth restriction (FGR), which affects 20% of pregnancies. Such cellular stress induces hepatic Insulin-like Growth Factor Binding Protein 1 (IGFBP1) phosphorylation, which sequesters Insulin-like Growth Factor 1 (IGF-I) and markedly reduces fetal growth signaling. IGFBP1 hyperphosphoryaltion in hypoxia is mediated through the mTOR signaling pathway and through the Amino Acid Response (AAR) pathway during amino acid deprivation. Hypoxia stimulates upstream mTORC1 regulators, AMPK and REDD1 which are well-established upstream regulators of one of the two mTOR complexes, mTORC1. The molecular mechanisms by which upstream mTORC1-driven processes regulate IGFBP1 phosphorylation …

Atypical Structural Connectivity And Integrity In Children With Hydrocephalus And Its Relation To Executive Function, Daamoon Ghahari

Electronic Thesis and Dissertation Repository

Infants with hydrocephalus are a high-risk group for adverse neurodevelopmental outcomes, including impairments in executive functions such as goal-directed behaviour, focusing, and shifting attention. The current pilot study aimed to profile white matter and executive dysfunction in school-aged children with ventriculoperitoneal (VP) shunted hydrocephalus and age-matched healthy controls using the Behaviour Rating Inventory for Executive Functions and diffusion tensor imaging. To assess the degree of similarity between patient structural networks and controls, probabilistic streamlines between striatal and cortical regions and their respective diffusivity metrics were assessed. For a number of patients with hydrocephalus, white matter in the striatal-executive network showed …

Effects Of Increased Sulfatide In Schwann And Mesenchymal Stromal Cells In Metachromatic Leukodystrophy, Srinitya Gannavarapu

Electronic Thesis and Dissertation Repository

Metachromatic leukodystrophy (MLD) is an inherited lysosomal storage disease caused by deficient arylsulfatase A (ARSA) activity, resulting in intra-lysosomal accumulation of sulfatide. Sulfatide is integral for proper maintenance of myelin in the central and peripheral nervous systems. This study characterized mitochondrial morphology, cytokine secretion and phagocytic activity in Schwann and mesenchymal cells isolated from ARSA^-/- mice. Cells were treated with different, increasing concentrations of sulfatide for a period of 24 hours. ARSA^-/- cells presented with persistent, increased fragmented mitochondrial structures suggestive of prolonged mitochondrial fission. Sulfatide treatments increased secretion of pro-inflammatory cytokines TNF-α and IL-1β in ARSA^{-/- …}

Neurodevelopmental Outcomes Of Infantile Hydrocephalus: An Fmri Case Study, Ikhlas Ahmed Hashi

Electronic Thesis and Dissertation Repository

Ventricle dilatation caused by infantile hydrocephalus may result in extensive damage of the posterior cortex (parietal and occipital lobes). We hypothesize that pathological changes in the development of the posterior cortex can be linked to non-verbal learning disabilities in children with previous infantile hydrocephalus. This case study will investigate the neurodevelopmental outcomes of 3 treated hydrocephalus patients, when compared to a group of healthy control children (n = 12). Within the hydrocephalus group, patients displayed differences in non-verbal test performance as well as parietal brain activation during an fMRI number comparison task. We associated these differences with clinical variables such …

Maternal Nicotine Exposure Induces Congenital Heart Defects In The Offspring Of Mice, Elizabeth Greco

Electronic Thesis and Dissertation Repository

Congenital heart defects are the most prevalent birth defect, and maternal cigarette smoking is a known risk factor. Nicotine replacement therapies are recommended to pregnant women who smoke to aid in smoking cessation, as this alternative is thought to be much safer compared to cigarette smoking. However, these products contain nicotine, and the safety of nicotine on the developing heart is not well known. In this thesis, a mouse model was used to test the hypothesis that maternal nicotine exposure (MNE) during pregnancy leads to congenital heart defects and coronary artery defects in the offspring of mice. MNE resulted in …

The Effects Of Tracheal Occlusion On Wnt Signaling In A Rabbit Model Of Congenital Diaphragmatic Hernia, Martina M. Mudri

Electronic Thesis and Dissertation Repository

Purpose: Tracheal occlusion (TO) reverses pulmonary hypoplasia (PH) in congenital diaphragmatic hernia (CDH), but its effect on epithelial-mesenchymal transition (EMT) in lung development remains poorly understood. The purpose of this study was to a) confirm the CDH rabbit model produced PH which was reversed by TO and b) determine the effects of CDH +/- TO on EMT pathways.

Methods: CDH was created at 23 days, TO at 28 days and lung collection at 31 days gestation in fetal rabbits. Lung body weight ratio (LBWR), mean terminal bronchiole density (MTBD), and expression of mRNA and micro-RNA was determined.

Results: Fifteen CDH, …

Computational Modelling Of Human Transcriptional Regulation By An Information Theory-Based Approach, Ruipeng Lu

Electronic Thesis and Dissertation Repository

ChIP-seq experiments can identify the genome-wide binding site motifs of a transcription factor (TF) and determine its sequence specificity. Multiple algorithms were developed to derive TF binding site (TFBS) motifs from ChIP-seq data, including the entropy minimization-based Bipad that can derive both contiguous and bipartite motifs. Prior studies applying these algorithms to ChIP-seq data only analyzed a small number of top peaks with the highest signal strengths, biasing their resultant position weight matrices (PWMs) towards consensus-like, strong binding sites; nor did they derive bipartite motifs, disabling the accurate modelling of binding behavior of dimeric TFs.

This thesis presents a novel …

Characterization Of Hemangioma-Initiating Stem Cells, Natalie Montwill

Electronic Thesis and Dissertation Repository

Infantile hemangioma (IH) is the most common vascular tumour of infancy. IH undergoes a unique life cycle consisting of robust endothelial cell proliferation and vessel formation in the proliferating phase, followed by spontaneous regression in the involuting phase. Our laboratory has shown that IH arises from multipotential stem cells termed hemangioma stem cells (HemSCs). However, the phenotype of HemSCs has not been fully elucidated. Here, I examined HemSCs and compared these lesion-derived cells to a panel of normal counterparts. My results show that HemSCs share similar gene expression profiles with human fetal liver-derived stem cells (FLSCs) and postnatal bone marrow …

Molecular Mechanisms Linking Amino Acid (Leucine) Deprivation To Igfbp-1 Hyperphosphorylation In Fetal Growth Restriction, Niyati M. Malkani

Electronic Thesis and Dissertation Repository

In this study, we explore the molecular mechanisms linking amino acid (leucine) deprivation to IGFBP-1 hyperphosphorylation in vitro. During pregnancy, a maladaptive fetal response to in utero amino acid deprivation leads to Fetal Growth Restriction (FGR). FGR infants display elevated phosphorylated IGFBP-1, which is associated with decreased IGF-I bioavailability. Leucine deprivation inhibits mechanistic target of rapamycin (mTOR) signaling and stimulates the amino acid response (AAR). Using HepG2 cells, a model for fetal hepatocytes, we demonstrate that in leucine deprivation, the AAR modulates total and phosphorylated IGFBP-1 while mTOR mediates total IGFBP-1 secretion only. We also reveal that protein kinases …

A Pilot Trial Comparing The Effects Of Onabotulinumtoxina And Standard Oxybutynin Therapy As First Line Treatment For The Poorly Compliant Pediatric Neurogenic Bladder, Sumit Dave

Electronic Thesis and Dissertation Repository

Research question

Is it feasible to conduct a phase III RCT to compare OnabotulinumtoxinA injections to oxybutynin as primary therapy in pediatric neurogenic bladder?

Methods

Patients on a stable oxybutynin regimen were recruited for a pilot RCT and underwent randomization to either OnabotulinumtoxinA or continuation of oxybutynin. Primary outcomes included an a priori defined feasibility and acceptability assessment. Secondary outcomes included continence, urodynamic parameters, side effects and QOL.

Results

The study enrolled 8 subjects in the OnabotulinumtoxinA group and 6 in the oxybutynin group. The recruitment rate was 75 % and the dropout rate was 6.6 %. There were 2 …