Hypoxic

Phosphorothioates generally protect normal tissues more than tumors. Tumor protection reported in some animal studies can pardy be explained by physiological effects of the particular dmgs, which are specific to rodents (4). WR-2721 does not appear to protect human and most animal tumors, apparentiy because of the low availabiUty of the dmg to tumor cells (4). Many tumors appear to have a reduced capillary density (44), which may mean that these tumors have altered levels of alkaline phosphatase, the enzyme that converts WR-2721 to WR-1065. A reduced abiUty of thiols to protect the hypoxic cells characteristic of many tumors may also contribute to their selectivity for normal tissues. The observation that WR-1065 protects cultured normal human fibroblasts, but not fibrosarcoma tumor cells, suggests that additional factors may contribute to the selectivity of radioprotection by WR-2721 m vivo (18). 

The eye has its own hydraulic system, and disturbances in it may cau.se serious damage to the eye. The normal eye pressure is 22 mm Hg, but when the pressure increases to 28-30 mm Hg, the optic nerve is squeezed and becomes hypoxic. This increase in the eye pressure may be due to acids or alkali causing inflammation in the anterior chamber of the eye, blocking the outflow of aqueous humor back into the systemic circulation. 

Following the action of extraordinary stimulants (hypoxic hypoxia, hypoxia + hyperoxia, hypodynamia + hyperthermia), animals demonstrate an accumulation of malonic dialdehyde with a simultaneous fall of antiradical activity of the liver tissue. A preliminary introduction to rats of acetylene amine 3,4,5-tris(morpho-linopropynyl)-l-methylpyrazole 103 and also of tocopherol antioxidant and gutumine antihypoxant averts activation of the lipid peroxidation processes. The inhibition of peroxidation with this agent is mediated by stabilization of ly-zosomal and mitochondrial membranes. Unsaturated amines prevent destruction of the organelle membranes provoked by UV irradiation and incubation at 37°C (pH4.7)(78MIl). 

The acetylene aminopyrazole 103 was capable of inhibiting the processes of lipid peroxidation both in the enzymatic and nonenzymatic peroxidation system (76MI2). Finally, 4-[3-(l-methyl-l//-pyrazol-3-yl)-prop-2-ynyl]morpholine hydrochloride 104 was patented as a compound with high hypoxic activity (93MIP1). 

S100B Sensitive marker of hypoxic brain damage in infants and children undergoing open-heart surgery... 

Hypoxic-ischemic encephalopathy in asphyxiated full-term infants... 

Succinylcholine-induced rhabdomyolysis Hypoxic encephalopathy Intrathecal administration of constant agents Defective temperature-monitoring devices Stimulation during light anesthesia... 

Niimberg GK (2002) Quantification of oxygen depletion in lakes and reservoirs with the hypoxic factor. Lake Reserv Manage 18 299-306... 

Roberts, J.K.M., Callis, J., Wemmer, D., Walbot, V. Jardetzky, O. (1984). Mechanisms of cytoplasmic pH regulation in hypoxic maize root tips and its role in survival under hypoxia. Proceedings of the National Academy of Sciences, USA, 81, 3379-83. 

Tissues That Function Under Hypoxic Circumstances Tend to Produce Lactate (Figure 17-2)... 

Kukor JJ, RH Olsen (1996) Catechol 2,3-dioxygenases functional in oxygen-limited hypoxic environments. Appl Environ Microbiol 62 1728-1740. 

Bfx Fx 126 Hypoxic selective cytotoxicity compound 126 DNA-interaction was studied showing poor affinity for this biomolecule [219-222]... 

Merry, P., Grootveld, M., Lunec, J. and Blake, D.R (1991). Oxidative damage to lipids within the inflamed human joint provides evidence of radical-mediated hypoxic-reperfusion injury. Am. J. Clin. Nutr. 53, 362S-369S. 

Jones, D.P. (1985) The role of oxygen concentration in oxidative stress hypoxic and hyperoxic models. In Oxidative Stress (ed. H. Sies) pp. 151-195. Academic Press, London. 

Webb, S.C., Fleetwcxjd, G. and Montgomery, R. (1983). Absence of a relationship between extracellular potassium accumulation and contractile failure in the ischaemic or hypoxic rabbit heart. J. Mol. Cell. Cardiol. 15, 27. 

Imaizumi, S., Kayama, T, and Suzuki, J. (1984). Chemiluminescence in hypoxic brain. The first report correlation between energy metabolism and free radical reaction. Stroke 15, 1061 -1065. 

The release of iron from intracellular ferritin stores is thought to involve the reduction of Fe to Fe " (Funk et al., 1985) and one would expect this reduction to be fecilitated by the low oxygen tension, increased levels of reducing species and the low pH shown by nuclear magnetic resonance (NM to be as low as 6.9 after only 6 h of cold storage (Fuller et al., 1988). Exogenous redox-active quinones such as adriamycin have been shown to catalyse lipid peroxidation in the presence of ferritin under hypoxic conditions (Vile and Winterbourne, 1988), and lipid peroxidation is stimulated in micro-somes in the presence of purified ferritin and flavin... 

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