Organic sensitization

When the poisons and the organs sensitive to it do not come into contact, or when sensitiveness of the organs does not exist, there can be no action. 

AGRICULTURAL CROPS Irrigation water, tolerated level AQUATIC LIFE Freshwater organisms Sensitive species, tolerated level <15,000 pg/L 1... 

Sanjuan, A., Alvaro, M., Corma, A. and Garcia, H. (1999). An organic sensitizer within Ti-zeolites as photocatalyst for the selective oxidation of olefins using oxygen and water as reagents. Chem. Commun. 1641-1642... 

The selective oxidation and, more generally, the activation of the C-H bond in alkanes is a topic of continuous interest. Most methods are based on the use of strong electrophiles, but photocatalytic methods offer an interesting alternative in view of the mild conditions, which may increase selectivity. These include electron or hydrogen transfer to excited organic sensitizers, such as aryl nitriles or ketones, to metal complexes or POMs. The use of a solid photocatalyst, such as the suspension of a metal oxide, is an attractive possibility in view of the simplified work up. Oxidation of the... 

If disease is mediated by non-specific activation of the alternative pathway, it does not explain why some mill workers, who are presumably exposed to equal dust levels, do not develop symptoms. One possible explanation is that there is host factor variability, such as end-organ sensitivity. It has also been proposed that pre-existing, non-specific bronchial hyperreactivity may be Important in development of byssinosis (51), but, to date, there is little evidence for this hypothesis (52- ). 

The variation in sensitivity may be based on pharmacokinetic differences (same dose different plasma levels) or on differences in target organ sensitivity ( same plasma level - different effects). 

In the absence of definitive human data, risk assessment may have to depend on the results of cancer bioassays in laboratory animals, short-term tests, or other experimental methods. Hence the following issues must be addressed under such circumstances the ability of the test system to predict risks for man (quantitatively as well as qualitatively) the reproducibility of test results the influence of species differences in pharmacokinetics, metabolism, homeostasis, repair rates, life span, organ sensitivity, and baseline cancer rates extrapolation across dose and dose rates, and routes of exposure the significance of benign tumors fitting models to the data in order to characterize dose-incidence relationships and the significance of negative results. 

Research on dye sensitizers is mainly focused on transition metal complexes, but considerable work is now directed toward the optimization of organic sensitizers and of natural sensitizers extracted from fruits. 

Ling N, Hickey CW, Burton GA. 1998. Are Antarctic marine organisms sensitive to anthropogenic pollutants NZ Nat Sci 23 106. 

Besides the direct photoreactions reported to date (see Figure 6.6), coordination entities also undergo the photosensitized modes in which they play the role of non-absorbing substrate. The application is usually connected with solving some mechanistic problems, as in the early study of cobalt(III) complexes with organic sensitizers, such as biacetyl, benzophenone, benzaldehyde, and naphthalene, which provided valuable mechanistic information about the excited states responsible for the photophysical, photoredox, and photosubstitution processes observed in cases of these complexes [105],... 

Photosensitized oxidations involve either organic dyes or transition metal complexes as sensitizers. Most organic sensitizers operate in their triplet states, as they are relatively longer lived than the singlet states. 

Regardless of whether the pharmacokinetics of a drug is altered or not, the response to sedative drugs may be increased in patients with liver disease, perhaps as a result of increased end-organ sensitivity. Opioids should therefore be used cautiously, ensuring the patient is closely monitored. 

End-organ sensitivity to opioids may be increased in liver disease, in terms of both analgesic properties and adverse effects, meaning that even if the pharmacokinetics of an opioid are not altered, the dose requirement in a patient with liver disease may be less. 

Increased end-organ responsiveness to glucocorticoids, mineralocorti-coids, and aldosterone (Section 9.3.3). Oversecretion of (and presumably also enhanced sensitivity to) any of these hormones can result in hypertension. Vitamin Bg supplementation would be expected to reduce end-organ sensitivity to these hormones, and thus might have a hypotensive action. 

CA 35, 8299(1941) [Blasting expls consisting of AN sensitized with inorganic sensitizers (such as Al, Mg, Sb, Zt, ferro-silicon, Ca silicide, S etc) or organic sensitizers (such as DPhA, hexamethylenetetramine, acid amides,nitrocompds, ales, nitrates, sugars, etc). These substances ate dispersed in AN soln prior to crystn] H)A. J. 

Swift, C.G. Pharmacodynamics changes in homeostatic mechanisms, receptor and target organ sensitivity in the elderly. Br. Med. Bull. 1990, 46, 36-52. 

All psychotropics prescribed to elderly patients should begin with small doses and be titrated slowly. In addition, maintenance doses may sometimes be 30 to 50 percent lower than in younger patients. The aging person may demonstrate increased receptor or organ sensitivity to medications and there is an age-associated decrease in albumin, resulting in more free (active) drug available. 

Organism sensitivity studies minimum inhibitory concentration see text) define the minimum effective concentration. 

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