Thus our intracellular descriptions are parameterized so that they are capable of triggering apoptosis decisions for comparable signals as are seen experimentally. It should be emphasized that most of the essential conclusions drawn Enzalutamide price from this study are not strongly dependent on the particular numerical choice of parameters. Results In this section, numerical results of blood flow are pre sented first, followed by results of drug transport and distribution. The effect of drug examined in terms of tumour cell density distribution by considering both bi stable and irreversible monostable intracellular apoptosis models under various pulse drug injections. In addition, a sensitivity analysis is performed on parameters involved in drug transport.
Results for drug concentration and tumour cell density are presented in the dimensionless form, which are normalised by their corresponding reference values 0. 001 ug/mm3 for vascular and extracellular drug concen trations, 1 ng/105cells for intracellular drug concentration and 106 cells/mm3 for tumour cell density. Blood flow Axial pressure profiles on the lumen and tissue side of the blood vessel wall together with the transmural velocity are presented in Figure 3. It is seen that vascular pressure falls linearly along the flow direction while interstitial fluid Brefeldin_A pressure experiences a sharp rise near the vessel inlet, followed by a gradual reduction. This is due to the entrance effect caused by the discontinuity of pressure conditions imposed at the vessel inlet and the adjacent lower boundary of the interstitium.
The simulation results selleck chem Bosutinib demonstrate that interstitial fluid pressure is strongly coupled to vascular fluid pressure due to elevated hy draulic conductivity normally found in tumour tissues. Since the pressure difference across the capillary wall determines the filtration velocity of blood, the latter experiences a sharp fall near the vessel inlet before declining gradually along the flow direction as the transmural pressure difference diminishes. Drug transport and distribution Drug transport Drugs are transported in tumour tissues by diffusion and convection. The relative importance of diffusion and convection is measured by Peclet number which is defined as where L is the characteristic length, u is a representative velocity, and D is the diffusion coefficient for a given anti cancer drug. Since D is 1. 578 10 10 m2/s for doxorubicin, the corresponding Pe in the blood vessel is on the order of 106, suggesting that intravascular drug transport is dominated by convection. Drugs extravasate into the tumour interstitium by diffu sion and convection, determined by diffusive permeability P and blood filtration velocity JF.