Desensitization initiation

Decomposition Hazards. The main causes of unintended decompositions of organic peroxides are heat energy from heating sources and mechanical shock, eg, impact or friction. In addition, certain contaminants, ie, metal salts, amines, acids, and bases, initiate or accelerate organic peroxide decompositions at temperatures at which the peroxide is normally stable. These reactions also Hberate heat, thus further accelerating the decomposition. Commercial products often contain diluents that desensitize neat peroxides to these hazards. Commercial organic peroxide decompositions are low order deflagrations rather than detonations (279). 

Parenterally administered penicillin is recommended for all stages of syphilis. Alternative agents may be used in allergic individuals and include doxycycline, minocycline, tetracycline, or erythromycin base or stearate. Some patients may not respond favorably to alternative modalities. Therefore, in patients who must be administered penicillin (i.e., patients who are pregnant or have central nervous system [CNS] involvement) or are allergic, desensitization must be performed before the drug is initiated. 

The observed Li+-induced stimulation of corticotropin (ACTH) secretion from cells in culture, requiring extracellular Ca2+, involves a corresponding and apparently associated increase in the concentration of Ins(l)P, indicating some interaction with phosphoinositide metabolism [176], Pretreatment with Li+ desensitizes the cells, reducing this Li+-induced stimulation of ACTH secretion. Li+ initially raises plasma cortisol levels in manic-depressives however the levels are subsequently reduced with chronic Li+ treatment in both patients and controls [177]. This effect is probably secondary to the stimulation and subsequent desensitization of ACTH secretion by Li+, as observed in cultured cells. 

Despite their initial irritant properties, capsaicin and related TRPVI agonists ultimately reduce sensitivity to painful stimuli by desensitizing the receptor. 

Mercury fulminate (C2N202Hg) is one of the most important primary explosives. It is usually found in the form of a gray powder, is sensitive to impact and friction, and is easily detonated by sparks and flames. It is desensitized by the addition of water, but is very sensitive to sunlight. It reacts with metals in moist environments. It is created by treating a solution of mercuric nitrate with alcohol in nitric acid. Its most important explosive property is that it easily detonates after initiation.10... 

Most of the experimental evidence came initially from studies of the frog motor end-plate, where it was shown that the desensitization of the nicotinic receptor caused by continuous short pulses of acetylcholine was associated with a slow-conformational change in that the ion channel remained closed despite the fact that the transmitter was bound to the receptor surface. 

Some patients may be sensitive to treatment with sulfasalazine. Various desensitization-like regimens have been reported to be effective. These regimens suggest starting with a total daily dose of 50 to 250 mg initially, and doubling it every 4 to 7 days until the desired therapeutic level is achieved. If the symptoms of sensitivity recur, discontinue sulfasalazine. Do not attempt desensitization in patients who have a history of agranulocytosis, or who have experienced an anaphylactoid reaction while previously receiving sulfasalazine. 

First, it provides another mechanism of desensitization, in that receptors at the cell surface produce an increase in cAMP via G whereas internalized receptors produce a decrease in cAMP levels via G,. Second, it has been found that Py subunits released from activated G, are capable of stimulating the MAPK cascade. Thus, at least for the P2 receptor, internalization functions not only to temporarily desensitize the receptor to activation of the cAMP pathway but also to initiate signaling to MAPK. Recently, a number of other G protein-coupled receptors have been found to signal to the MAPK pathway via G as well as G and G and many of these receptors seem to require internalization for such signaling to take place. 

R.L. Grant J.E. Tiffany, Detonators Initiating Efficiency by the Miniature-Cartridge Test , USBurMinesTechPaper 677, GovtPtgOff, Washington, DC (1945) (Description of the test and its comparison with Lead-Plate Test, Small Trauzl Lead Block Test, Sand Test, Esop s Test, Desensitized Dynamite Test and TNT-Iron Oxide Insensitive Powder Test)... 

Horse Detonator. The name given to the American M46 fuze because it can initiate much more effectively than standard fuzes, such as the Mark III. The M46 fuze can be used even with the worst exuding shell, where the standard fuzes nearly always fail. It compensates for both desensitized boosters and bursting charges. In all cases, it gives high-order detonations... 

Explosive 808. A British demolition explosive made in paper-wrapped, 4 oz cartridges 3x 1-3/8 inches. The explosive used was " Desensitized Polar Blasting Gelatine , which COilld be initiated by a priEQef... 

G protein-mediated responses to drugs and hormonal agonists often attenuate with time (Figure 2-12, top). After reaching an initial high level, the response (eg, cellular cAMP accumulation, Na+ influx, contractility, etc) diminishes over seconds or minutes, even in the continued presence of the agonist. This "desensitization" is often rapidly reversible a second exposure to agonist, if provided a few minutes after termination of the first exposure, results in a response similar to the initial response. 

---