Medicine and Health Sciences Commons^™

The Role Of The Arched Helicases In Exosome-Mediated Function, A. Alejandra Klauer

Dissertations & Theses (Open Access)

RNA processing and degradation are two important functions that control gene expression and promote RNA fidelity in the cell. A major ribonuclease complex, called the exosome, is involved in both of these processes. The exosome is composed of ten essential proteins with only one catalytically active subunit, called Rrp44. While the same ten essential subunits make up both the nuclear and cytoplasmic exosome, there are nuclear and cytoplasmic exosome cofactors that promote specific exosome functions in each of the cell compartments. To date, it is unclear how the exosome distinguishes between RNA substrates. We hypothesize that compartment specific cofactors may …

Identifying Genetic Variants And Characterizing Their Role In Clubfoot, Katelyn S. Weymouth

Dissertations & Theses (Open Access)

Clubfoot is a common, complex birth defect affecting 4,000 newborns in the United States and 135,000 world-wide each year. The clubfoot deformity is characterized by inward and rigid downward displacement of one or both feet, along with persistent calf muscle hypoplasia. Despite strong evidence for a genetic liability, there is a limited understanding of the genetic and environmental factors contributing to the etiology of clubfoot. The studies described in this dissertation were performed to identify variants and/or genes associated with clubfoot. Genome-wide linkage scan performed on ten multiplex clubfoot families identified seven new chromosomal regions that provide new areas to …

Genetic Analysis Of The Hippo Pathway In Mouse Liver, Li Lu

Dissertations & Theses (Open Access)

Cancer therapy and tumor treatment remain unsolved puzzles. Genetic screening for tumor suppressor genes in Drosophila revealed the Hippo-signaling pathway as a kinase cascade consisting of five core components. Disrupting the pathway by deleting the main component genes breaks the balance of cell proliferation and apoptosis and results in epithelial tissue tumorigenesis. The pathway is therefore believed to be a tumor suppressor pathway. However, a corresponding role in mammals is yet to be determined. Our lab began to investigate the tumor suppression function of the potent mammalian Hippo pathway by putting floxed alleles into the mouse genome flanking the functional-domain-expressing …

Knowledge, Attitudes, And Utilization Of Brca Testing Among Obstetricians And Gynecologists, Salma Nassef

Dissertations & Theses (Open Access)

Hereditary breast and ovarian cancer (HBOC) is an inherited cancer syndrome that is associated with mutations in the BRCA1 and BRCA2 genes. Carriers of BRCA mutations, both men and women, are at an increased risk for developing certain cancers. Carriers are most notably at an increased risk to develop breast and ovarian cancers; however an increased risk for prostate cancer, melanoma, and pancreatic cancers has also been associated with these mutations. In 2009 the American Congress of Obstetricians and Gynecologists (ACOG) released a practice bulletin stating that evaluating a patient’s risk for HBOC should be a routine part of obstetric …

Predictors Of Contralateral Breast Cancer In Brca Negative Women, Ann E. Simmons

Dissertations & Theses (Open Access)

Breast cancer is the most common cancer diagnosis and second leading cause of death in women. Risk factors associated with breast cancer include: increased age, alcohol consumption, cigarette smoking, white race, physical inactivity, benign breast conditions, reproductive and hormonal factors, dietary factors, and family history. Hereditary breast and ovarian cancer syndrome (HBOC) is caused by mutations in the BRCA1 and BRCA2 genes. Women carrying a mutation in these genes are at an increased risk to develop a second breast cancer. Contralateral breast cancer is the most common second primary cancer in patients treated for a first breast cancer. Other risk …

Fzd6, Matn2 And Slc25a32, Possible Candidate Genes In Nonsyndromic Cleft Lip And Palate, Nevena Cvjetkovic

Dissertations & Theses (Open Access)

Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common birth defect with a multifactorial etiology. Despite decades of research, the genetic underpinnings of NSCLP still remain largely unexplained. A genome wide association study (GWAS) of a large NSCLP African American family with seven affected individuals across three generations found evidence for linkage at 8q21.3-24.12 (LOD = 2.98). This region contained three biologically relevant candidate genes: Frizzled-6 (FZD6) (LOD = 2.8), Matrilin-2 (MATN2) (LOD = 2.3), and Solute Carrier Family 25, Member 32 (SLC26A32) (LOD = 1.6). Sequencing of the coding regions and the 5’ and 3’ …

Genetic Predictors Of Hyperglycemia Due To Hydrochlorothiazide Therapy, Jorge L. Del Aguila

Dissertations & Theses (Open Access)

Response to pharmacological treatment is variable among individuals. Some patients respond favorably to a drug while others develop adverse reactions. Early investigations showed evidence of variation in genes that code for drug receptors, drug transporters, and drug metabolizing enzymes; and pharmacogenetics appeared as the science that studies the relationship between drug response and genetic variation.

Thiazide diuretics are the recommended first-line monotherapy for hypertension (i.e. SBP>140 or DBP>90). Even so, diuretics are associated with adverse metabolic side effects, such as hyperglycemia, which increase the risk of developing type 2 diabetes. Published approaches testing variation in candidate genes (e.g. …

Effects Of Thymus Size And Involution On The Contribution Of Recent Thymic Emigrants To The Peripheral T Cell Pool, Michelle L. Bolner

Dissertations & Theses (Open Access)

The contribution of recent thymic emigrants (RTEs) to the peripheral naïve T cell population is necessary to maintain diversity of the T cell receptor (TCR) repertoire and produce immune responses against newly encountered antigens.

The thymus involutes with age, after irradiation or chemotherapy, and due to severe viral infections. Thymus involution results in decreased thymopoiesis and RTE output leading to a reduced diversity of peripheral T cells. This increases susceptibility to disease and impairs immune responsiveness to vaccines. Therefore, studies aimed at maintaining or regenerating thymic function are integral for maintaining and restoring peripheral TCR diversity.

Mice that express a …