Medicine and Health Sciences Commons^™

Characterization Of The Fast Axonally Transported Proteins In The Rat Optic Pathway, Surafel Mulugeta

Theses and Dissertations in Biomedical Sciences

The fast axonally transported proteins represent a subset of neuronal proteins that are conveyed anterogradely as secretory vesicle constituents from the perikarya. Although fast transport displays properties consistent with the general secretory pathway, neuronal structure presents special problems which may require modifications of the general pathway. The elucidation of these special modifications is essential for a more complete understanding of neuronal function both in normal and pathological conditions. In order to characterize the fast transported (FT) proteins and to better understand fast transport trafficking, the FT of radiolabeled retinal ganglion cell (RGC) proteins in the adult rat optic pathway was …

Endothelial Nitric Oxide Synthase And Growth Factor Regulation Of Flow-Mediated Vascular Remodeling, David Anthony Tulis

Theses and Dissertations in Biomedical Sciences

This study was designed to characterize structural remodeling of male Wistar rat mesenteric arteries exposed to elevated blood flow in vivo for 1, 3, or 7 days. A series of arterial ligations induced blood flow increases in ileal and second-order branch arteries compared to same animal control vessels. Neither mean carotid nor local mesenteric arterial pressures changed significantly pre- to post-ligation. The primary flow-mediated force in both vessels was shear stress with possible involvement of acute stretch-induced wall stress in the ileal artery. Significant luminal expansion and medial wall hypertrophy occurred in the ileal and second-order arteries in a time-dependent …

Fluorescence In Situ Hybridization Analysis Of Human Embryos Derived From In Vitro And In Vivo Matured Oocytes, Constance Descisciolo

Theses and Dissertations in Biomedical Sciences

Despite adequate hormonal stimulation, oocytes collected for the purpose of in vitro fertilization and embryo transfer display several levels of nuclear maturity. Preovulatory or mature oocytes, technically those that are Metaphase I or II, are inseminated shortly after aspiration and assessed for fertilization the following day. Prophase I oocytes, also called germinal vesicle-bearing or immature oocytes, require a 24-36 hour period in culture before being exposed to spermatozoa. During this time, the majority of Prophase I oocytes complete nuclear maturation in vitro, progressing from germinal vesicle breakdown through first polar body extrusion. If inseminated, many in vitro matured oocytes fertilize …

The Cellular And Molecular Dynamics Of The Queuosine Modification In Transfer Rna: Definition, Modulation, Deficiencies And Effect Of The Queuosine Modification System, Rana C. Morris

Theses and Dissertations in Biomedical Sciences

The presence of the queuosine modification in the wobble position of tRNA^asn, tRN^asp, tRNA^his, and tRNA^tyr is associated with a decrease in cellular growth rate, an increase in the ability to withstand environmental stress, and differentiation of pleuripotent cells into mature phenotypes. The loss of this normal modification is strongly correlated with neoplastic transformation and tumor progression of a wide variety of cancers.

The "normal" system for formation of the queuosine modification in tRNA was studied in human fibroblast cell cultures and in mouse, rat and human liver tissues. The queuosine modification system …

Differential Endometrial Responses Of Primates Vs Rodents: Screening For Antiproliferative Effects Of Antiprogestins, David Williams Burleigh

Theses and Dissertations in Biomedical Sciences

The antiprogestin, mifepristone, has previously been shown to noncompetitively inhibit estrogen-induced endometrial proliferation in nonhuman primates (van Uem et al., 1989; Wolf et al., 1989b; Neulen et al., 1990; Neulen et al., 1996). For both economical and ethical reasons, we are encouraged to identify comparative laboratory rodent models which can substitute the need to use primate models. In the following study, we compared capabilities of the rat uterine weight bioassay versus a primate uterine bioassay, to identify the noncompetitive antiestrogenic/antiproliferative effects of mifepristone.

Long-term ovariectomized monkeys were exposed to exogenous 17β-estradiol (E2) and mifepristone in doses and regimes already demonstrated …

Axotomy And Regeneration Of The Rat Facial Nerve: A Histomorphometric Study Of The Facial Nucleus, Nerve And Orbicularis Oculi Muscle In An Experimental Model Of Facial Paralysis, Peter Konstantinos Thanos

Theses and Dissertations in Biomedical Sciences

One of the most unsettling sequela of facial paralysis (FP) is the loss of eye sphincter function and the blink response, leading to functional, psychological and aesthetic deficits. A medley of restorative microsurgery approaches have been employed in treating these deficits, however full recovery of function remains elusive. The present research utilized the rat model of facial paralysis, and consisted of three stages. Stage I examined the facial motor neuron (FMN) pool of the eye sphincter (orbicularis oculi muscle=OOM) and identified the facial nerve branch which provides the majority of innervation to the OOM. II. Examined the efficacy of the …