Phenotyping approaches

Much progress has also been achieved in the phenotypic approach to studies of intra- and interspecific differentiation of fish. It is this approach in the context of a species within its area that has been vigorously explored by ecologists (Volskis, 1973). Each species needs to be regarded as a discrete ecological unit, not an abstract speculation but a distinct component of the biosphere in which it plays a special and versatile part. 

Li J et al (2006) CYP3A Phenotyping approach to predict systemic exposure to EGFR tyrosine kinase inhibitors. J Natl Cancer Inst 98 1714-1723... 

In an attempt to further simplify the caffeine phenotyping test, a trait measure based on the plasma or salivary paraxanthine caffeine concentration ratio between three hours and seven hours after administration of the probe has been suggested (56). High linear correlations (>0.89) have been observed between this trait value and caffeine s oral clearance, and if necessary, a predicted caffeine clearance value may be calculated from the ratio (56). Currently, this phenotyping approach appears to be the simplest and most noninvasive means of readily assessing CYP1A2 activity using caffeine as a probe in addition, the method is reproducible and appears to be robust (56), despite the theoretical dependency of the trait value on the urine flow rate (51). 

An alternative approach involves testing of new drug entities on whole-cell systems and measuring effects on integrated cellular pathways. Favorable phenotypic responses are identified with this approach that may better produce alteration of multicomponent disease processes. 

The ultimate goal of microarray-based expression analysis is to acquire a comprehension of the entire cellular process, in order to exploit and to standardize the multidi-menisional relations between genotype and phenotype. However, an increasingly important parameter, which has not yet been substantially taken into account, is the role of cellular translation. This means that mRNA expression data need to be correlated with the assortment of proteins actually present in the cell. One approach is based on the use of microarrays containing double-stranded DNA probes for the analysis of DNA-protein interaction and, thus, the detection and identification of DNA-binding proteins by means of fluorescence [130] or mass spectrometry analysis [131]. Moreover, substantial efforts are currently under way to develop protein, antibody, or even cell arrays, applicable to the cor-... 

In order to understand current approaches for prevention and control of biofilms, we must first consider the reasons for the failure of conventional antimicrobial protocols. There are thought to be three main reasons as to why biofilm bacteria out-survive their planktonic counterparts during antimicrobial treatments (reviewed by McBain et a/.16).These are i) poor penetration of antimicrobial compounds due to the presence and turn-over of exopolymer slime (glycocalyx) ii) the imposition of extreme nutrient limitation within the depths of the biofilm community and the co-incident expression of metabolically-dormant, recalcitrant phenotypes and (iii) the expression of attachment-specific phenotypes that are radically different and intrinsically less susceptible than unattached ones. 

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