Reaction phenotyping protein concentration

Step 2 involves an assessment of whether metabolite formation is proportional to incubation time and protein concentration under conditions that will be used for subsequent reaction phenotyping experiments. The goal is to establish in vitro... 

The metabolism of the drug candidate is not measured under initial rate conditions. Prior to initiating reaction phenotyping studies, a pool of human liver microsomes should always be used to establish initial rate conditions (i.e., conditions under which metabolite formation is proportional to protein concentration and incubation time), and total amount of substrate consumed should be less than 10%. 

Metal ions released from metal implants by osteoclastic bio-corrosion are distributed through- out the body and are eventually taken up by dendritic cells, the most potent anti-gen-presenting cells [14, 15, 18]. Besides changing phenotypic and functional properties of dendritic cells [18], metal ions complex with cellular proteins and peptides. In case of titanium, the ions form complexes with phosphorus-containing proteins and peptides (usually signaling molecules), nucleotides (DNA in the nuclease and RNA in the cytoplasm) and lipids (phospholipids of the cellular membranes) [15]. The new antigenic metal-peptides are presented by dendritic cells to specific T-lymphocytes that react and are activated [15]. The dendritic cells and activated T-lymphocytes accumulate in tissues with high metal concentrations, usually close to the metal implant, and form inflammatory reactions [7] that include secretion of inflammatory cytokines, such as TNF-a, TGF-b, interleukin-6 and interleukin-lb [19]. Most important is secretion of RANK-L by the activated T-lymphocytes, an essential factor for maturation, survival and function of osteoclasts [19]. 

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