Medicine and Health Sciences Commons^™

Manipulating The Tumor Microenvironment For Therapeutic Benefit, Kate M. Bailey

USF Tampa Graduate Theses and Dissertations

The physical tumor microenvironment contributes significantly to carcinogenesis, cancer progression and metastatic dissemination. Two main components of the tumor microenvironment, hypoxia and acidosis, are present in nearly every solid tumor and act as powerful selection forces against the tumor. Hypoxia and acidosis promote tumor heterogeneity and contribute to chemotherapy and radiotherapy resistance. This dissertation interrogates methods to target the tumor microenvironment including two novel studies describing mechanisms of buffer therapy resistance and targeting tumor hypoxia with vasodilators to enhance the efficacy of a hypoxia activated prodrug, TH-302.

In the first study, mechanisms of buffer therapy resistance were identified and detailed. …

The Effects Of Oxygen On The Electrophysiology Of Co2/H+-Chemosensitive And -Insensitive Neurons Of The Solitary Complex Of The Rat, Michael Patrick Matott

USF Tampa Graduate Theses and Dissertations

This study tested the hypothesis that decreasing the control O₂ level from 95% to 40% (5% CO₂ + 55% N₂) maintains viability in caudal solitary complex (cSC) neurons in transverse slices (~300-400ꝳ) prepared from neonatal rat (P2-22) maintained at 32-34°C. The underlying rationale is to reduce exposure to redox and nitrosative stimuli generated during several hours of exposure to 95% O₂ that produces a tissue O₂ tension throughout the slice which is in excess of 203 kPa (2.0 atmospheres absolute,ATA) oxygen. Whole cell recordings of cSC neurons maintained in 40% O₂ exhibited spontaneous …

Secreted Factors From Human Umbilical Cord Blood Cells Protect Oligodendrocytes From Ischemic Insult, Derrick Rowe

USF Tampa Graduate Theses and Dissertations

Oligodendrocytes (OL)s are the dominant cell type in the white matter and are integral for synaptic transmission essential for proper neuronal communication between brain areas. Previous studies have shown that intravenous administration of the mononuclear fraction of human umbilical cord blood (HUCB) cells in rat models of stroke reduced white matter injury, gray matter injury and behavioral deficits. Yet the mechanisms used by HUCB cells remain unknown in ischemic injury. These studies will investigate both in vitro and in vivo approaches to elucidate this mechanism in OLs. When mature primary OLs were coincubated with HUCB cells, HUCB cells secreted soluble …

Neuroprotection With Anesthetics In Two Models Of Cerebral Ischemia, Rafael Eduardo Chaparro Buitrago

USF Tampa Graduate Theses and Dissertations

Neuroprotection with anesthetics has been studied for many decades; important advances in this field have modified the way Anesthesiologists treat patients in the operating room. Animal models have played an important role in the study of ischemia in the operating room. Recent studies have demonstrated that the effect of anesthetics seems to be different in different animal models. We decided to evaluate anesthetics in a well-known model of cerebral ischemia and also in hypotensive models designed by us. We used a model of cerebral ischemia (MCAO) to test anesthetics neuroprotective effect in a two-week period. Then, we used a model …