Abstract: To gain a better understanding of brain tumor angiogenesis, new techniques for isolating brain endothelial cells (ECs) and evaluating gene expression patterns were developed. When transcripts from brain ECs derived from normal and malignant colorectal tissues were compared with transcripts from non-endothelial cells, genes predominantly expressed in the endothelium were identified. Comparison between normal- and tumor-derived endothelium revealed genes that were specifically elevated in tumor-associated brain endothelium. These results confirm that neoplastic and normal endothelium in human brains are distinct at the molecular level, and have significant implications for the development of anti-angiogenic therapies in the future.

Abstract: The heater shutdown circuit is connected between an electric current source and a heating element in an electric heater and is operable to shut off the flow of current to the heating element when the heating element reaches a predetermined temperature and to maintain the flow of current shut off after the heating element cools to a temperature below the predetermined temperature. The heater shutdown circuit will maintain the electric current shut off until the heater shutdown circuit is disconnected from the current source for a predetermined period of time after which the heater shutdown circuit can be re-energized. The heater shutdown circuit includes a control circuit connected to the current source, a switching circuit coupled between the control circuit and the heating element, and a current sensing circuit coupled between the heating element and the junction between the control circuit and the switching circuit.