Equivalent responses

Patients who present with symptomatic disease will be started on therapy. Two regimens used are VAD and melphalan and prednisone (MP). VAD like chemotherapy regimens are used most often in transplant candidates because it avoids the alkylating agent melphalan, thus minimizing damage to the stem cell compartment. These two regimens produce equivalent response rates of approximately 50% to 70% in previously untreated patients with myeloma (see Table 93-4).35>36... 

The factor by which the agonist concentration must be increased when in the presence of a competitive antagonist to produce an equivalent response ... 

Nonetheless, methylmercury production can be proportional to Hg concentration (83, 89) and may be limited in lakes by the flux of reactive Hg(II) species across the sediment-water interface (52). Thus an increase in total Hg deposition could produce an equivalent response in Hg bioaccumulation, all other factors being equal. It may be significant in this regard that the average rate of increase in Hg residues in fish in Minnesota is of the same magnitude as that calculated here for atmospheric loading, roughly 3% annually since 1930 (19). 

Before the quantitative information contained in a chromatographic peak can be used, the purity of the peak should be confirmed. Only after we are sure that no coeluting impurity was present, which could have contributed to the peak response, can we convert the peak s area or height into quantitative information based on the equivalent response of a pure standard. This peak purity analysis can be based on the comparison of the various spectra recorded during the elution of the peak. If the peak is pure, then, apart from concentration differences, the spectra taken at several points during a peak s elution should all be identical and the match scores obtained should be very close to the perfect match scores. If significant deviations are encountered, this can be seen as an indication of impurity. 

Comparison of the nasal route with other routes has been made in some instances. Desmopressin (l-desamino-8-D-arginine vasopressin) administered as a 20 pg dose elicits a response equivalent to approximately 2 pg administered by i.v. injection. Also, a greater dose of vims is required to obtain an equivalent response to a nasal vaccine than when administered by other routes. 

The sample should be as pure as possible, but standards have been used where the major constituent is approximately 85% of the mixture, as long as the remainder is made up of known compounds. Suggestions to use mixtures as reference standards have been made to reduce the number of assays run and the number of samples handled. This is clearly the case for a racemic mixture in an achiral HPLC assay, where both enantiomers have the same retention and detector response. It can also be beneficial to use known mixtures of diastereomers as a standard, provided there is sound reasoning that they give equivalent response to the method of detection. 

Taste receptor cells within taste buds in different areas of the tongue respond to the sweet, sour, bitter, or salty flavor molecules. One soporous unit of fructose (C(,H]20, the sweetest kind of sugor, forms hydrogen bonds with the receptor site on the sweet toste buds. Saccharin contains a similar soporous unit (shaded area) and therefore evokes an equivalent response from the sweet taste receptor cells. 

Pyridazinone effects on phospholipids also provide information relative to phospholipid biosynthesis. The similarity in fatty acid composition of PC and PE in the absence of BASF 13 338 and their equivalent response to treatment suggest that the biosynthesis of phospholipids in wheat roots is not specific with respect to acyl chains. 

First, potential and current ramps have been replaced by staircases, which may or may not give an equivalent response depending on the step size. Secondly, the response is sampled, which may lead to an increase in noise. Both these problems and the strategy adopted in order to circumvent them win be discussed during the course of the chapter. Further details on analog and digital instrumentation can be found in Chapter 1.2. 

Effects data applicable for QSAR analyses are reported in terms of a constant equivalent response - that is, isoeffective concentrations that correspond to the number of moles of the compounds evoking the same effect. Activity measures such as toxicity parameters should be based on a dose-response curve, not only on a single point determination. Various factors act as determinants in dose-response relationships, such as route of exposure, duration of exposure and species sensitivity (Figure 2.8). 

Figure 4.3.1. A schematic of a typical a) EIS sensor and b) an analogous MOS capacitor, (c) The capacitance of a MOS capacitor as a function of gate voltage for a j -type substrate, and d) the equivalent response for an n-type substrate.

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