arXiv subjects

O. G. Isaeva

Publications and source records attributed to O. G. Isaeva.

3 recordsLinked to original sources

arXiv2009

Photodynamic therapy influence on anti-cancer immunity

The system of partial differential equations describing tumor-immune dynamics with angiogenesis taken into account is presented. For spatially homogeneous case, the steady state analysis of the model is carried out. The effects of single photodynamic impact are numerically simulated. In the case of strong immune response we found that the photodynamic therapy (PDT) gives rise to the substantial shrinkage of tumor size which is accompanied by the increase of interleukin-2 concentration. On the contrary, the photodynamic stimulation of weak immune response is shown to be insufficient to reduce the tumor. These findings indicate the important role of anti-cancer immune response in the long-term tumor control after PDT.

q-bio.CB↗

arXiv2008

Different Strategies for Cancer Treatment: Mathematical Modeling

We formulate and analyze a mathematical model describing immune response to avascular tumor under the influence of immunotherapy and chemotherapy and their combinations as well as vaccine treatments. The effect of vaccine therapy is considered as a parametric perturbation of the model. In the case of a weak immune response, neither immunotherapy nor chemotherapy is found to cause tumor regression to a small size, which would be below the clinically detectable threshold. Numerical simulations show that the efficiency of vaccine therapy depends on both the tumor size and the condition of immune system as well as on the response of the organism to vaccination. In particular, we found that vaccine therapy becomes more effective when used without time delay from a prescribed date of vaccination after surgery and is ineffective without preliminary treatment. For a strong immune response, our model predicts the tumor remission under vaccine therapy. Our study of successive chemo/immuno, immuno/chemo and concurrent chemoimmunotherapy shows that the chemo/immuno sequence is more effective while concurrent chemoimmunotherapy is more sparing.

q-bio.CB↗

arXiv2008

Modeling of anti-tumor immune response: immunocorrective effect of weak centimeter electromagnetic waves

We formulate the dynamical model for the anti-tumor immune response based on intercellular cytokine-mediated interactions with the interleukin-2 (IL-2) taken into account. The analysis shows that the expression level of tumor antigens on antigen presenting cells has a distinct influence on the tumor dynamics. At low antigen presentation a progressive tumor growth takes place to the highest possible value. At high antigen presentation there is a decrease in tumor size to some value when the dynamical equilibrium between the tumor and the immune system is reached. In the case of the medium antigen presentation both these regimes can be realized depending on the initial tumor size and the condition of the immune system. A pronounced immunomodulating effect (the suppression of tumor growth and the normalization of IL-2 concentration) is established by considering the influence of low-intensity electromagnetic microwaves as a parametric perturbation of the dynamical system. This finding is in qualitative agreement with the recent experimental results on immunocorrective effects of centimeter electromagnetic waves in tumor-bearing mice.

q-bio.CB↗