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Treatment Of Aortic Heart Valve Conduit With Glutamine And Heat Shock As A Means To Deter The Constituent Cellular Population From Becoming Apoptotic, Alyce Marie Linthurst Jones

Theses and Dissertations in Biomedical Sciences

Cryopreserved allograft heart valves represent the best solution for a patient with a failing heart valve. However, the constituent cells become apoptotic and within months of transplant the heart valve becomes acellular and the recipient's cells do not repopulate the allograft (3, 51). A strategy to prevent this situation would be to minimize or prevent apoptosis from occurring by strategically altering steps during heart valve processing. Recently it has been demonstrated that: 1) Heat shock protein 70 is a negative modulator of the apoptotic cascade; 2) Cells in culture exposed to hypothermic conditions produce heat shock protein 70 upon rewarming; …

Nanosecond Pulsed Electric Field Induction Of Programmed Cell Death Is Cell Type Dependent: An In Vitro Study, Wei Ren

Theses and Dissertations in Biomedical Sciences

Nanosecond pulsed electric fields (nsPEFs) present a novel and effective method for cancer ablation by eradicating the ubiquitous cancer hallmark of apoptosis evasion and enforcing cancer programmed cell death. To develop nsPEFs as an anticancer method, a comprehensive understanding of cell death mechanisms is required. The overall objective of this dissertation is to elucidate molecular mechanisms underlying effects of nsPEFs on E4 murine squamous cell carcinoma and human T-cell Jurkat clones that are wildtype, deficient in FADD (ΔFADD) and deficient in caspase-8 (ACas-8). The overall hypothesis is that nsPEFs eliminate cancer cells through activating caspase-dependent and caspase-independent programmed cell death …

Nanosecond Pulsed Electric Fields Induce A Mitochondria-Independent Apoptosis In B16f10 Melanoma Cells In Vitro, Wentia Elissa Ford

Theses and Dissertations in Biomedical Sciences

Nanosecond pulsed electric fields (nsPEFs) are ultra-short pulses that induce direct electric field and biological effects that initiate apoptosis. Here the application of ten 300ns pulses ranging in electric fields from 12kV/cm-60kV/cm was administered to determine the effects on B16F10 melanoma cells evaluated by in vitro studies. Initial application of nsPEFs demonstrated apoptosis induction in an electric field- and pulse number-dependent manner measured by caspase activation that correlated with decrease in cell viability 24hr post pulse. In addition caspase activity was shown to be independent of calcium mobilization though ions may play a part in other aspects of apoptosis. The …

Nanosecond Pulsed Electric Field Effects On Cell Cycle And Apoptosis, Emily H. Hall

Theses and Dissertations in Biomedical Sciences

Apoptosis, programmed cell death, is a highly regulated and complex pathway essential for embryonic development, immune-system function and maintenance of tissue homeostasis where cells induce their own cell death. Cells undergoing apoptosis exhibit a distinctive phenotype characterized by maintenance of membrane integrity, cell shrinkage, phosphatidylserine (PS) externalization at the plasma membrane, caspase protease activation, DNA fragmentation, release of cytochrome c from the mitochondrion, and membrane blebbing. An important regulatory protein in the apoptotic pathway is p53. The p53 protein functions to modulate the cell cycle by arresting cells in the G1 and G 2 phases to repair DNA damage, and/or …

The Antitumor Agent, Arglabin-Dma, Preferentially Induces Apoptosis In Human Colon Tumor Cells, Sung Wook Kwon

Theses and Dissertations in Biomedical Sciences

Arglabin-DMA, an analog of farnesyl pyrophosphate (FPP), reportedly inhibits farnesyltransferase (FTase) directly by competitively blocking the binding of Ras protein and its posttranslational modification, as suggested in previous studies. But, the mechanisms by which Arglabin-DMA inhibits tumor growth in vivo and in vitro are still relatively poorly characterized. To determine the mechanism by which this drug inhibits tumor growth, the effects of Arglabin-DMA in two human colon tumor cell lines (mutant K-ras HCT 116 and wild-type ras HT-29) were explored on cell proliferation, apoptosis, and cell cycle kinetics in vitro. In cell viability studies, we showed that Arglabin-DMA …

Apoptosis Pathways: Presence And Significance In Ejaculated Human Spermatozoa, Steven Lewis Taylor

Theses and Dissertations in Biomedical Sciences

Ejaculated sperm display markers that are indicative of apoptosis in somatic cells. The question remains as to whether sperm have operative apoptosis mechanisms. The aim of this research was to test the hypothesis that apoptosis markers in sperm and somatic cells are different.

Ejaculated human sperm from patients and donors were separated into high and low motility fractions using Percoll™ gradients. Contaminating cells were removed using anti-CD45 conjugated paramagnetic beads. Fractions were divided into groups: staurosporine, anti-Fas antibody, and hydrogen peroxide treated and control. Direct enzymatic measurement of caspase activity, flow cytometric evaluation of phosphatidylserine translocation, immunoblots, and immunocytochemistry were …