arXiv subjects

Sounak Sadhukhan

Publications and source records attributed to Sounak Sadhukhan.

4 recordsLinked to original sources

arXiv2019

Modeling Tumor Angiogenesis with Cellular Automata

Angiogenesis is the formation of new blood vessels from the existing vessels. During tumour angiogenesis, tumour cells secret a number of chemical substrates called tumour angiogenic factors (TAFs). These factors diffuse through the extracellular matrix (ECM) and degrade the basement membrane of nearby vasculature. The TAFs also disrupt the corresponding endothelial cell receptors and form finger like capillary sprouts. These factors also create a chemical gradient (chemotaxis) between the tumour and the surrounding blood vessels. Due to the chemotactic force, the capillary sprouts migrate towards the tumour. On the other hand, a haptotactic force generated due to fibronectin which is secreted by the endothelial cell, also acts on these sprouts. These sprouts grow through the proliferation of recruited endothelial cells from the parent vessels. Tumour angiogenesis is not fully understood yet. In this paper, we use 2-D cellular automata (CA) model to study the behavior of tumour angiogenesis using both Moore and von-Neumann neighborhood. The CA model also mimics capillary sprout branching and the fusion of two adjacent sprout tips (anastomoses). In this simulation, a couple of important points are noted: a) no two capillary sprouts are generated from adjacent locations; b) as the sprouts approach closer to the tumour, its branching tendency increases; c) chemotaxis is the most effective driving force for angiogenesis.

q-bio.TO↗

arXiv2019

Tumour Induced Angiogenesis and Its Simulation

Due to over-metabolism, the tumour cells become hypoxic. To overcome this situation tumour cells secret several chemical substrates to attract nearby blood vessels towards it (angiogenesis). Transition from avascular to vascular tumour is possible with the initiation of angiogenesis. Angiogenesis also plays a crucial role to spread the cancer cells and its colonization at the distant locations of the body (metastasis). In this paper, we briefly review the processes and factors which directly affect tumour angiogenesis or may get affected by it. A model based on cellular automata is developed to demonstrate this complex process through MATLAB based simulation.

physics.bio-ph↗

arXiv2019

Anomalous Advection-Diffusion Models for Avascular Tumour Growth

In this study, we model avascular tumour growth in epithelial tissue. This can help us to get a macroscopic view of the interaction between the tumour with its surrounding microenvironment and the physical changes within the tumour spheroid. This understanding is likely to assist in the development of better diagnostics, improved therapies and prognostics. In biological systems, most of the diffusive and convective processes are through cellular membranes which are porous in nature. Due to its porous nature, diffusive processes in biological systems are heterogeneous. Fractional advection-diffusion equations are well suited to model heterogeneous biological systems; though most of the early studies did not use this fact. They modelled tumour growth with simple advection-diffusion equation or diffusion equation. We have developed two spherical models based on fractional advection-diffusion equations: one of fixed order and the other of variable order for avascular tumour. These two models are investigated from phenomenological view by measuring some parameters for characterizing avascular tumour growth over time. It is found that both the models offer realistic and insightful information for tumour growth at the macroscopic level, and approximate well the physical phenomena. The fixed-order model always overestimates clinical data like tumour radius, and tumour volume. The cell counts in both the models lie in the clinically established range. As the simulation parameters get modified due to different biochemical and biophysical processes, the robustness of the model is determined. It is found that, the sensitivity of the fixed-order model is low while the variable-order model is moderately sensitive to the parameters.

q-bio.TO↗

arXiv2014

A Solution of Degree Constrained Spanning Tree Using Hybrid GA

In real life, it is always an urge to reach our goal in minimum effort i.e., it should have a minimum constrained path. The path may be shortest route in practical life, either physical or electronic medium. The scenario is to represents the ambiance as a graph and to find a spanning tree with custom design criteria. Here, we have chosen a minimum degree spanning tree, which can be generated in real time with minimum turnaround time. The problem is NP-complete in nature [1, 2]. The solution approach, in general, is approximate. We have used a heuristic approach, namely hybrid genetic algorithm (GA), with motivated criteria of encoded data structures of graph. We compare the experimental result with the existing approximate algorithm and the result is so encouraging that we are interested to use it in our future applications.

cs.NE↗