Data interpretation vitro

As many studies submitted to pesticide regulatory jurisdictions use in vivo methodologies, but an increasing number of studies employ in vitro techniques, this section addresses data interpretation challenges with both study types. Discussion... 

The same data-interpretation strategy is applied by Gangl et al. [13] in a study on the metabolism of the HIV-protease inhibitors ritonavir and indinavir (see Figure 10.2c). After the in vitro generation by incubation with human liver microsomes, the metabolites were extracted by means of LLE. Gradient elution LC-MS on an ion-trap instrument was applied to search for possible metabolites, which were subsequently fragmented in time-scheduled triple-quadrapole MS-MS. 

The surface modification of biomaterials is also frequently achieved using plasmas. The physico-chemical properties of the material surface may be modified using plasma discharge in different gases, or a polymer coating may be deposited using plasma polymerization (cf. the section on Data Interpretation Through Simulation). A well-known example of the first approach is tissue-culture polystyrene (TCPS), which is commonly used to culture cells in vitro (Fig. 19). XPS shows that plasma... 

Abstract. Recent years have seen a growing interest in the use of Raman-based spectroscopy as an analytical tool for the chemical analysis of biological samples. Raman spectroscopy has found many applications in cellular and structural biology, biomedicine, and biodetection. Its attractiveness for live biological studies lies mainly in its hi sensitivity to molecular interactions and small molecular scale conformational changes. In addition, the noninvasiveness of this s roach permits both in-vitro and in-vivo studies. This increased interest has been a result of advances in both instrumentation and techniques that have enabled improved data acquisition and data interpretation. This chapter addresses recent advances in Raman-based techniques and highlights their uses in specific biological studies. 

Many of the coagulation factors measured by global coagulation tests have limited stability, and the time and temperature of storage of sample will affect their measurements. Concepts of analyte stability and half-life in plasma extend to markers measured by immunoassay. Markers of platelet activation are affected by artifactual activation in vitro upon collection of the blood specimen. This section will highlight some of the nonanalytical variables that, if uncontrolled, can lead to spurious results and thus affect the interpretation of laboratory data. 

In assessing animal data, careful attention must be paid to the quality of the data, the incidence of spontaneous tumors in the control population, consistency if more than one study is available, and statistical validity. If the exposure route and experimental regimen employed do not agree with the most likely mode(s) of human exposure (e.g., intramuscular injection), the data must be interpreted cautiously. Consideration should be given to data on metabolism of the compound by the animal species tested, as compared with metabolism in humans if this information is known. If only in vitro data are available, only qualitative estimates may be possible because of uncertainties regarding the association between in vitro results and human or animal effects. The availability of associated pharmacokinetic data, however, may allow development of a rough quantitative estimate. 

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