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Tissue Engineering: Applications In Developmental Toxicology, Stephanie N. Thiede, Nimisha Bajaj, Kevin Buno, Sherry L. Voytik-Harbin

The Summer Undergraduate Research Fellowship (SURF) Symposium

In vivo toxicology assays are expensive, low-throughput, and often not predictive of a human response. Three-dimensional in vitro human cell-based tissue systems incorporating cell-cell and cell-matrix interactions have promise to provide high-throughput, physiologically-relevant information on the mechanism of the toxin and a more accurate assessment of the toxicity of a chemical before progression to human trials. Quantification of the disruption of vasculogenesis, the de novo formation of blood vessels from endothelial progenitor cells, can serve as an appropriate indicator of developmental toxicity since vasculogenesis is critical to the early development of the circulatory system. The current routinely used in vitro …

Chemical Profiling And Biological Activity Of Two Tunicate-Associated Marine Bacteria, Lyubina Yankova

Honors Scholar Theses

Marine natural products have recently been an increasingly abundant source of novel antibiotics. Given that there is an increasing resistance to current drug therapies, finding new sources such as marine natural products is essential. Tunicate-associated marine bacteria can be a significant source of antibacterial compounds. Two tunicates of the species Eudistoma were collected from Portobelo National Park on the Salmedina Reef of Panama in the Caribbean Sea. Bacteria associated with the tunicate were isolated, cultured, extracted, and fractionated. Fractions were tested against an array of clinically relevant bacterial pathogens in the BioMAP assay. Two fractions MB0086E and MB0088E demonstrated activity …

Β-Lactam Estrogen Receptor Antagonists And A Dual-Targeting Estrogen Receptor/Tubulin Ligand, Niamh O'Boyle, Jade K. Pollock, Miriam Carr, Andrew Js Knox, Seema M. Nathwani, Shu Wang, Laura Caboni, Daniela M. Zisterer, Mary Meegan

Articles

Twelve novel β-lactams were synthesised and their antiproliferative effects and binding affinity for the predominant isoforms of the estrogen receptor (ER), ERα and ERβ, were determined. β-Lactams 23 and 26 had the strongest binding affinities for ERα (IC₅₀ values: 40 and 8 nM respectively) and ERβ (IC₅₀ values: 19 and 15 nM). β-Lactam 26 was the most potent in antiproliferative assays using MCF-7 breast cancer cells, and further biochemical analysis showed that it caused accumulation of cells in G₂/M phase (mitotic blockade) and depolymerisation of tubulin in MCF-7 cells. Compound 26 also induced apoptosis and downregulation …

Synthesis And Biochemical Activities Of Antiproliferative Amino Acid And Phosphate Derivatives Of Microtubule-Disrupting Beta-Lactam Combretastatins, Niamh M. O'Boyle, Lisa M. Greene, Niall O. Keely, Shu Wang, Tadhg S. Cotter, Daniela M. Zisterer, Mary J. Meegan

Articles

The synthesis and biochemical activities of novel water-soluble β-lactam analogues of combretastatin A-4 are described. The first series of compounds investigated, β-lactam phosphate esters 7a, 8a and 9a, exhibited potent antiproliferative activity and caused microtubule disruption in human breast carcinoma-derived MCF-7 cells. They did not inhibit tubulin polymerisation in vitro, indicating that biotransformation was necessary for their antiproliferative and tubulin binding effects in MCF-7 cells. The second series of compounds, β-lactam amino acid amides (including 10k and 11l) displayed potent antiproliferative activity in MCF-7 cells, disrupted microtubules in MCF-7 cells and also inhibited the polymerisation of …

Increased Geranylgeranylated K-Ras Contributes To Antineoplastic Effects Of Farnesyltransferase Inhibitors., Mandy A. Hall

Dissertations and Theses (Open Access)

The Ras family of small GTPases (N-, H-, and K-Ras) is a group of important signaling mediators. Ras is frequently activated in some cancers, while others maintain low level activity to achieve optimal cell growth. In cells with endogenously low levels of active Ras, increasing Ras signaling through the ERK and p38 MAPK pathways can cause growth arrest or cell death. Ras requires prenylation – the addition of a 15-carbon (farnesyl) or 20-carbon (geranylgeranyl) group – to keep the protein anchored into membranes for effective signaling. N- and K-Ras can be alternatively geranylgeranylated (GG’d) if farnesylation is inhibited but are …

Studies On The Regulation Of Mu Opioid Receptor Mrna Expression In Shsy-5y Human Neuroblastoma Cells, Xin Yu

Seton Hall University Dissertations and Theses (ETDs)

Prolonged exposure to morphine down-regulates mu opioid receptors (MOR) on both undifferentiated and differentiated (retinoic acid or phorbol ester treated) SHSY-5Y cells. However, morphine pretreatment does not alter MOR receptor affinity for morphine. To investigate the molecular basis for MOR regulation after exposure to its selective agonists, we have developed a quantitative competitive reverse transcriptase-polymerase chain reaction (QC-RT PCR) to quantify the expression of MOR in SHSY-SY cells. Differentiation of SHSY-5Y cells with retinoic acid or phorbol ester up regulated MOR mRNA expression by 30 % and 78%, respectively. A 24 hours treatment with morphine (10 µM) down regulated MOR …

A Case For Caution: An Evaluation Of Calabrese And Baldwin's Studies Of Chemical Hormesis, Kevin C. Elliott

RISK: Health, Safety & Environment (1990-2002)

Suggesting a need for more research, Mr. Elliott argues that it is too soon for risk-assessment policy to account for recent challenges to a toxicological linear dose-response assumption.

Policy For Identifying And Assessing The Health Risks Of Toxic Substances, Maine Bureau Of Health

Maine Collection

Policy for Identifying and Assessing the Health Risks of Toxic Substances

by Norman T. Anderson, Environmental Toxicology Program, Division of Disease Control, Bureau of Health (February, 1988).

Contents: Section I: Introduction / Section II: Methods / Section III: Exposure Assessment / Section IV: Hazard Identification / Section V: Hazard Assessment / Section VI: Risk Characterization / List of Figures / List of Tables