\left( {\frac{{0 + \beta R_{0} }}{0 + \beta R}\frac{B}{{B_{0} }} - \frac{{\pi_{C} (C)}}{{\pi_{C} (C_{0} )}}\frac{C}{{C_{0} }}} \right) $$\end{document}$$  By definition, the baseline values *B*~0~ and *C*~0~ are related through the equation$$\documentclass[00pt]{minimal}                 \usepackage{amsmath}                 \usepackage{wasysym}                  \usepackage{amsfonts}                  \usepackage{amssymb}                  \usepackage{amsbsy}                 \usepackage{mathrsfs}                 \usepackage{upgreek}                 \setlength{\oddsidemargin}{-00pt}                 \begin{document}$$ D_{C} \frac{{\alpha B_{0} }}{{0 + \beta R_{0} }} - D_{A} \pi_{C} (C_{0} )C_{0} = 0 