Effectiveness spectra, action

The straightforward step used to form the ring system means that the chemistry involved in the preparation of the scores of barbiturates that have been used clinically in fact devolves on the syntheses of the various malonic esters. It should be noted that little success has been achieved in changing the side effect spectrum of these dmgs. The main differences between the various agents involve their pharmacokinetic properties these in turn are manifested as variations in bioavailablity by parenteral and oral routes as well as in time to the onset and duration of action. 

In many kinds of skin diseases a therapy with UV-light is applied the same lamps are used for cosmetic tanning. Therefore, the different action spectra should be known with high accuracy to avoid unwanted effects. Such action spectra of medical interest are the erythema curve (the action spectrum of sunburn) and action spectra after oral or local administration of photosensitizers. 

Figure 2.4 Erythemal response (sunburn) action spectrum, the midday solar spectrum, and the resultant erythemal effectiveness spectrum. (Parrish, J.A. et al., UV-A- Biological Effects of Ultraviolet Radiation with Emphasis on Human Responses to Long-Wave Ultraviolet, p. 121. New York Plenum Press, 1978.)...

The phototoxic effects of chlorpromazine may be partly due to its metabolites (see references in Harber et al., 1982). Photodynamic and nonphotodynamic processes have been demonstrated for this drug. Stable photoproducts of the drug may account for some of its effects. The action spectrum for chlorpromazine phototoxicity is red-shifted (max at 330 nm) compared with its absorption spectrum (max at 305 nm). This may be due to the shape of the penetration spectrum of light into tissue and/or... 

This definition is based on incident photons (radiation incident on the surface of a solid polymer or on the surface of a cell carrying a solution of the polymer). No corrections are made for scattering losses, back reflection, absorbance, or internal reflection effects. The action spectrum, therefore, depends on absorption characteristics of the polymer as well as on the quantum yield of the degradation process studied. 

The occurrence of an erythema is determined by the spectrum of solar irradiance and the reaction of the skin, the erythemal action spectrum. The product of these two spectra results in the erythemal effectiveness spectrum depicted in Fig. 13. It is assumed that the skin type does not matter in the determination of the SPF, as the MED and MEDp have always to be... 

Since there was some evidence that these compounds owe their action to interference with the action of histamine, this class has earned the soubriquet "antihistamines." This class of drugs is further characterized by a spectrum of side effects which occur to a greater or lesser degree in various members. These include antispasmodic action, sedative action, analgesia, and antiemetic effects. The side effects of some of these agents are sufficiently pronounced so that the compounds are prescribed for that effect proper. Antihistamines, for example, are used as the sedative-hypnotic component in some over-the-counter sleeping pills. 

The addition of a secondary solute or wavelength shifter can serve to offset much if not all of the action of tagged nitrocompds in reducing counting efficiency. For expl nitrocompds, a shift of the emission spectrum considerably into the visible region where absorption effects are not so pronounced is clearly indicated. The secondary solute POPOP has been found to be most efficient for this purpose (Ref 2). This enhanced effect on the scintillation process is illustrated in Fig 2 for p-Nitrotoluene... 

What is important to emphasize is that, given the range of known EDCs, their potential to act with more than one mechanism of action, and ability of some chemicals to mediate effects via mnltiple tissues, no single effective test exists for an endocrine disrnpter rather, a snite of approaches is reqnired to capture the spectrum of possible effects. 

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