Tirapazamine (3-amino-1,2,4-benzotriazine 1,4-dioxide) is a heterocyclic di-N-oxide that undergoes enzymatic deoxygenation selectively in the oxygen-poor (hypoxic) cells found in solid tumors to generate a mono-N-oxide metabolite. This work explored the idea that the electronic changes resulting from the metabolic deoxygenation of tirapazamine analogues might be exploited to activate a DNA-alky...

In contrast to the Moon, Mars is rich in carbon, nitrogen, hydrogen and oxygen, all in biologically readily accessible forms such as carbon dioxide gas, nitrogen gas, and water ice and permafrost. Carbon, nitrogen, and hydrogen are only present on the Moon in parts per million quantities, much like gold in seawater. Oxygen is abundant on the Moon, but only in tightly bound oxides such as silico...

Measurement of pulmonary gas uptake and elimination is often performed, using nitrogen as marker gas to measure gas flow, by applying the Haldane transformation. Because of the inability to measure nitrogen with conventional equipment, measurement is difficult during inhalational anesthesia. A new method is described, which is compatible with any inspired gas mixture, in which fresh gas and exh...

Nitrogen oxide (NO) is well known as an atmospheric pollutant, which is contained in automobile exhaust fumes and cigarette smoke. Over the past 20 years, since the numerous biological functions of NO have become known, this gas has been studied in healthy individuals and in the presence of pathology. Nitrogen oxide was discovered during an experiment to activate gyanylate cyclase to form cycli...

The effect of maintaining pulmonary nitrogenation on venous admixture during halothane anaesthesia and on postoperative hypoxaemia was studied in patients undergoing either abdominal surgery or the removal of varicose veins. In both groups venous admixture was greater when nitrogen replaced nitrous oxide in the anaesthetic gas mixture. In the varicose vein group hypoxaemia was more severe in th...

Deemed the worlds largest environmental health issue, air pollution has been shown to be a more potent danger than previously thought. Increasing concern regarding major gas pollutants nitrogen dioxide (NO2), ammonia (NH3), and ozone (O3) has sparked research in the field of gas adsorption as a method to remove these gases from the atmosphere. Using first principles calculations based on the De...

The nitrovasodilators are a diverse group of pharmacological agents that produce vascular relaxation by releasing nitric oxide. The mechanisms by which these compounds release nitric oxide vary, depending on their chemical structure. Compounds with lower oxidation states of nitrogen such as nitroprusside, nitrosamines, and nitrosothiols release nitric oxide nonenzymatically. In the case of nitr...

Successful pathogens must be able to protect themselves against reactive nitrogen species generated either as part of host defense mechanisms or as products of their own metabolism. The regulatory protein NsrR (a member of the Rrf2 family of transcription factors) plays key roles in this stress response. Microarray analysis revealed that NsrR represses nine operons encoding 20 genes in Escheric...