Infrared (IR) optical fibers may be defined as fiber optics transmitting radiation with wavelengths greater than approximately 2 μm. The first IR fibers were fabricated in the mid-1960’s from chalcogenide glasses such as arsenic trisulfide with losses in excess of 10 dB/m. During the mid-1970’s, the interest in developing an efficient and reliable IR fiber for short-haul applications increased ...

Title of Document: RESISTANCE TO IONIZING RADIATION AND OXIDATIVE STRESS IN HALOBACTERIUM SALINARUM NRC-1 Courtney Kathryn Robinson, Master of Science, 2009 Directed By: Professor Jonathan Dinman, Department of Cell Biology and Molecular Genetics Oxidative stress results from environmental challenges that cause unchecked production of reactive oxygen species (ROS). We analyzed the cellular dama...

The aim of this study was to determine the effects of vitamin E (VE) and L-carnitine (LC) supplementation, separately or in combination, on radiation-induced oral mucositis and myelosuppression. Group 1 received no treatment (control). Group 2 received 15 Gray of 60Co gamma irradiation as a single dose to total cranium (IR). Group 3, 4, and 5 received irradiation plus 40 mg/kg/day VE (IR+VE) or...

Ionizing radiation (IR) induces the production of reactive oxygen species (ROS), which play an important causative role in radiation damage. -Phenyl-N-t-butylnitrone (PBN) is one of the most widely used spintrapping compounds for investigating the existence of free radicals in biological systems. We investigated the protective role of PBN against IR in U937 cells and mice. On exposure to IR, th...

Current views suggest that apoptosis eliminates genetically damaged cells that may otherwise form tumors. Prior human studies link elevated insulin and reduced apoptosis to risk of colorectal adenomas. We hypothesized that hyperinsulinemia associated with obesity would lead to reduced colon epithelial cell (CEC) apoptosis after radiation and that this effect would be altered by deletion of the ...

Elsewhere, we reported that multiple serial in vivo passage of a squamous cell carcinoma cells (SCC61) concurrent with ionizing radiation (IR) treatment resulted in the selection of radioresistant tumor (nu61) that overexpresses the signal transducer and activator of transcription 1 (Stat1)/IFN-dependent pathway. Here, we report that (a) the Stat1 pathway is induced by IR, (b) constitutive over...

Spaceflight occasionally requires multiple extravehicular activities (EVA) that potentially subject astronauts to repeated changes in ambient oxygen superimposed on those of space radiation exposure. We thus developed a novel in vitro model system to test lung cell damage following repeated exposure to radiation and hyperoxia. Non-tumorigenic murine alveolar type II epithelial cells (C10) were ...

Pancreatic cancer is characterized by very low survival rates because of high intrinsic resistance to conventional therapies. Ionizing radiation (IR)–enhanced tumor invasiveness is emerging as one mechanism responsible for the limited benefit of radiotherapy in pancreatic cancer. In this study, we establish the role of heparanase—the only known mammalian endoglycosidase that cleaves heparan sul...

Pancreatic cancer is characterized by very low survival rates because of high intrinsic resistance to conventional therapies. Ionizing radiation (IR)-enhanced tumor invasiveness is emerging as one mechanism responsible for the limited benefit of radiotherapy in pancreatic cancer. In this study, we establish the role of heparanase-the only known mammalian endoglycosidase that cleaves heparan sul...