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The lack of kinetic data concerning the biological effects of reactive oxygen species is slowing down the development of the field of redox signaling. Herein, we deduced and applied equations to estimate kinetic parameters from typical redox signaling experiments. H2O2-sensing mediated by the oxidation of a protein target and the switch-off of this sensor, by being converted back to its reduced form, are the two processes for which kinetic parameters are determined. The experimental data required to apply the equations deduced is the fraction of the H2O2 sensor protein in the reduced or in the oxidized state measured in intact cells or living tissues after exposure to either endogenous or added H2O2. Either non-linear fittings that do not need transformation of the experimental data or linearized plots in which deviations from the equations are easily observed can be used. The equations were shown to be valid by fitting to them virtual time courses simulated with a kinetic model. The good agreement between the kinetic parameters estimated in these fittings and those used to simulate the virtual time courses supported the accuracy of the kinetic equations deduced. Finally, equations were successfully tested with real data taken from published experiments that describe redox signaling mediated by the oxidation of two protein tyrosine phosphatases, PTP1B and SHP-2, which are two of the few H2O2-sensing proteins with known kinetic parameters. Whereas for PTP1B estimated kinetic parameters fitted in general the present knowledge, for SHP-2 results obtained suggest that reactivity towards H2O2 as well as the rate of SHP-2 regeneration back to its reduced form are higher than previously thought. In conclusion, valuable quantitative kinetic data can be estimated from typical redox signaling experiments, thus improving our understanding about the complex processes that underline the interplay between oxidative stress and redox signaling responses.

What is known and Objective Biopharmaceuticals are an important class of drugs for the treatment of autoimmune/inflammatory and oncologic diseases. With patent expiries, biotechnological manufacturers can now develop biosimilar drugs. Due to timeliness of introducing new and more complex biosimilars, the Portuguese Association of Hospital Pharmacists gathered to develop a common positioning on the use of biosimilar monoclonal antibodies. Main issues The European pathway to biosimilar approval was developed to improve affordability and access to biological therapies, but it remains a work in progress because unresolved issues remain. Due to the present reality of biosimilar monoclonal antibodies, hospital pharmacists must play an important role in ensuring the safe, effective and cost-effective use of biosimilars in health systems; and educating healthcare administrators, providers, legislators, policymakers, payors and patients about these products. What is new and conclusion The conclusions presented in this work focused on the proposal for optimal biosimilar prescription criteria, the preparation of original biologics and biosimilars in the pharmacy, the management and selection of suppliers, extrapolation issues, the specific role of pharmacovigilance and risk management for the optimal use of biosimilar monoclonal antibodies. [ABSTRACT FROM AUTHOR]