Nonlinear Biomedical Physics Blog

Cancer as a phase transition

Without a theoretical basis experimentalists are wandering around blindly in the dark. Unfortunately, this is often the situation in the medical sciences. That is why interdisciplinary research is so important.

The recent article: ‘Cancer as a dynamical phase transition’ by Davies, Demetrius, and Tuszynski published in Theoretical Biology and Medical Modelling is an excellent example of such research. In their conclusions the authors write: “This new perspective points up certain features that are often ignored in therapeutic approaches. In terms of therapeutic insights that may be gained from the application of the concept of a phase transition, the long-range correlation effect, which is a characteristic property of systems undergoing phase transitions suggests that a truly successful therapy would require a global change of conditions disfavoring the cancer phenotype and not simply a local excision or destruction of cancer cells in their micro-environment. The thermodynamic model of cancer developed in this paper suggests a shift in therapeutic strategy away from radiation and chemotherapy towards novel types of interventions that still need to be identified and tested.”

We fully agree with the authors that “application [of the idea of phase transitions] to the initiation and progression of cancer at a cellular level is novel, and offers a promising approach to the understanding, prevention and control of cancer.” While undergoing a phase transition properties of the system change, not just nonlinearly, but they ‘jump’ in a non-continuous way. Discussing the properties of cancer cells from a perspective based on an analogy with phase transitions in physical systems is really inspiring.

Posted by Wlodzimierz Klonowski at 16:02    Comments (0)

 

Econobiophysics, neuoromarketing, behavioral economics

The Game of Choosing – models and software developed to simulate selection or election processes – has a broad spectrum of applications to both biomedical systems and socio-economical systems; analogous to econophysics it may be called econobiophysics (Klonowski W, Pierzchalski M, Stepien P, and Stepien RA: Econobiophysics - game of choosing. Model of selection or election process with diverse accessible information. Nonlinear Biomedical Physics 2011, 5:7).

If a subject even has an initial slight preference towards a given object then these simulations demonstrate that, if information passed on by a direct or indirect object’s exposition (presentation of the object) exerts a favorable impact on the subject, it is enough to repeat the exposition again and again to cause the subject’s choice of this object, e.g., mating partner, car model, Member of Parliament etc. If information about the object passed on by an exposition exerts an adverse impact then the subject will not choose this object. Initial preferences may be reversed if the impact of subsequent expositions changes due to influences of the environment.

The Game of Choosing may influence current paradigms in neuromarketing (Sanfley AG et al.: The neural basis of economic decision – making in the ultimatum game. Science 2003, 300, 1755-1758) and in behavioral economics (Camerer CF, Loewenstein G, Rabin M (Eds.): Advances in Behavioral Economics, Princeton University Press, 2005) like nonlinear dynamics and chaos theory changed the paradigms of classical physics.

Posted by Wlodzimierz Klonowski at 11:12    Comments (0)

 

Fractal method of assessment of histological images

The fractal method of analysis and assessment of histological images (W.Klonowski, R.Stepien, and  P.Stepien, 2010) can play a very important role in the future diagnostic practice. It may be important also in robotic surgery.

 

Histological images from the border area of the tumor must be now evaluated by an anatomo-pathologist. However, it is very likely that when the automatic analysis achieves more accuracy, the human role in the tissue sample evaluation will become limited. The doctor will always supervise and control the robot surgery and the histological  diagnosis, but the automatic assessment can be more accurate and objective.

 

Contours of a benign mass (a.) and of a malignant breast tumor (b.)

their ‘signatures’ (c. and  d.) and the signatures’ Higuchi’s fractal dimension, D_f  (e. and  f.).

‘Signature’ of a malignant tumor (f.) shows lower value of D_f  than that of a benign mass (e.).

 

 

 

Posted by Wlodzimierz Klonowski at 14:41    Comments (0)

 

From miliseconds to 'till death pulls apart'

 

  W. Klonowski (2004)  put forward the hypothesis that important difference between feelings (emotional processes) and thoughts (rational processes) is in the characteristic time scales of those two kinds of brain processes and that this may be modeled using methods of nonlinear  dynamics. Like any complex dynamical system human brain is characterized in any moment by momentary values of its state variables and so the brain state may be characterized by a point in a multi-dimensional phase space with appropriately defined coordinates. Then psycho-physiological processes in the brain may be represented by some trajectories in this space. Since psychophysical processes occurring in the brain continuously change brain’s phase space, rational processes that are much slower than emotional processes take place in the phase space that in the meantime was modified by emotional processes.

 

      To analyze influence of differences in time-scales both rational and emotional processes were modeled on a two-dimensional lattice and on extremely simplified two-dimensional phase space of the brain. When a stimulus changes emotional state then after a sufficiently long time the state of consciousness may eventually also be changed - the subject becomes alerted (aware of the feeling). For example, falling in love does happen as quickly as an involuntary reflex of hand withdrawal when one touches a very hot surface - only after a while one becomes aware that the touched surface was really hot; similarly, what does reach the consciousness is not the emotion of falling in love but awareness of this emotion (W. Klonowski, 2009).

 

      By reviewing  across a wide range of brain research that used fMRI a team of scientists lead by Stephanie Ortigue (2010) recently revealed that falling in love really takes only about a fifth of a second and that it can elicit not only the same euphoric feeling as using cocaine, but also affects intellectual areas of the brain. When a person falls in love, 12 areas of the brain work in tandem to release euphoria-inducing chemicals such as dopamine, oxytocine, adrenaline vasopressine, and  nerve growth factor (NGF). These results do confirm that popular saying about lovers ‘there is a chemistry between them’ does have a scientific basis and that long-lasting love differs a lot from falling in love. The study also demonstrates that different types of love involve distinct cerebral networks - passionate love is sparked by the reward part of the brain and also associative cognitive brain areas,  while unconditional love, such as that between a mother and a child, is sparked by the common and different brain areas, including the middle of the brain. These results also help in understanding while when love doesn’t work out, it can be a significant cause of emotional stress and depression. By identifying the parts of the brain stimulated by love, doctors and therapists can better understand the pains of love-sick patients. Ortigue’s follow-up study about the speed of love in the human brain is expected to be released soon. 

 

Wlodzimierz Klonowski

Founding Editor Nonlinear Biomedical Physics

 

Posted by Wlodzimierz Klonowski at 09:01    Comments (0)