Nadeem Khan

..Furthermore, EPR oximetry could be potentially used to enhance the outcome of chemoradiation by scheduling treatments at times of increase in glioma pO(2)...

..3 Gy of radiation and carbogen inhalation on orthotopic 9L and C6 gliomas and on the contralateral brain pO(2) in rats using a new and potentially widely useful method, multisite in vivo electron paramagnetic resonance oximetry...

..We report repeated measurements of orthotopic F98 tumor pO(2) and relate this to the effect of carbogen inhalation on tumor growth when combined with hypofractionated radiotherapy...

..This multimodal approach could be used to enhance the outcome of radiotherapy. Furthermore, tumor pO2 could be a potential marker of therapeutic response...

..The active ester nitroxide showed approximately 6% intracellular localization and low cytotoxicity. The EPR spectra of TMAO nitroxide indicated an increased rigidity in the nitroxide ring, due to dibenzo-annulation...

..The information on the dynamics of tumor pO(2) after efaproxiral administration illustrates the ability of efaproxiral to increase intracranial tumor oxygenation...

..This is the first study to demonstrate the ability of efaproxiral to increase tumor oxygenation and to increase the tumor growth inhibition of radiotherapy over 5 days of treatment...

..We report a recently developed electron paramagnetic resonance (EPR) oximetry approach with multiple probe implantable resonators (IRs) that allow repeated measurements of oxygen in tissue at depths of greater than 10mm...

..Repeated tumor pO(2) measurements by EPR oximetry can provide temporal information that could be used to improve therapeutic outcomes by scheduling doses at times of improved tumor oxygenation...

..It then should be feasible to select the spin trap(s) best suited for the proposed study...

..The results are consistent with our earlier findings suggesting that such oxygen gradients may be a general phenomenon found in most or all cell systems under appropriate conditions...

..In vivo EPR oximetry is currently being tested for repeated pO(2) measurements in patients with superficial tumors...

..This vital information could also be used to schedule radiotherapy to enhance therapeutic outcome...

..To investigate the temporal effects of single or fractionated radiotherapy on subcutaneous RIF-1 tumor pO(2) and to determine the therapeutic outcomes when the timing of fractionations is guided by tumor pO(2)...

..These studies demonstrate the feasibility of EPR oximetry in a clinical setting and the potential for more widespread use in the treatment of these and other oxygen-dependent diseases...

..The dynamics of tumor pO(2) after RSR13 administration may be useful for the design of clinical protocols using allosteric hemoglobin effectors...

..This should significantly expand the ability to use spin trapping in biology and medicine...

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..26 to 0.95 (carbogen) were similar by the two methods and (4) in some rats breathing carbogen, absolute values of PtO(2) were above the sensitive range of the OxyLite method...

..5% BN formulation led to a significant growth inhibition. EPR oximetry provided dynamic information on the changes in tumor pO(2), which could be used to identify responders and non-responders and schedule therapy during the experiments...

..We are confident that in vivo EPR oximetry will play a crucial role in the understanding and clinical management of various pathologies in the years to come...

..In addition, the ability to simultaneously measure the pO(2) in several areas of the brain provides important information that could potentially help differentiate the pO(2) changes that can occur due to global or local mechanisms...

..The results indicate that the concentration of cholesterol in the plasma membrane can be an important factor for the magnitude of the oxygen gradient observed across the cell membrane...

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..We propose that the repeated measurement of the oxygen levels in the tumors during radiotherapy can be used to identify responders and to design tumor oxygen guided treatment plans to improve the outcome...

..It seems likely that the use of in vivo EPR to measure redox processes will become an increasingly utilized and valuable tool...

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..To assess the importance of genetic background for collateral artery development...

..This approach can be potentially used to enhance radiotherapeutic outcome by scheduling radiation doses when an increase in tumor pO(2) is observed after topical applications of BN formulations...

..In this chapter, we describe the procedure for in vivo pO(2) and redox measurements in animal models...

..The current state of the art for these and other measurements is discussed, especially in relationship to experiments that are likely to be useful for studies of reactive oxygen species (ROS) and/or reactive nitrogen species (RNS)...

..If the promise of these techniques is fulfilled, clinicians will have a new powerful tool for management of peripheral vascular disease, based on fundamental pathophysiology. ..

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..The proposed approach to modulate tumor hypoxia will avoid possible complications and toxicity arising due to oral or injections of drugs. If successful, this approach potentially could be immediately extended for clinical applications. ..

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