TY  - JOUR
AU  - Stanojević, A
AU  - Marković, V M
AU  - Maćešić, Stevan
AU  - Kolar-Anić, Ljiljana
AU  - Vukojević, V
PY  - 2018
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2920
AB  - The sex hormone testosterone (TTS) and the hypothalamic–pituitary–adrenal (HPA) axis mutually control one another’s activity, wherein TTS suppresses corticotrophin releasing hormone (CRH) stimulated HPA axis activity, whereas the activation of HPA axis has an inhibitory effect on TTS secretion. With an intention to explain these phenomena, a network reaction model is developed from the previously postulated stoichiometric models for HPA activity where main dynamic behaviors are controlled by two catalytic steps (one autocatalytic and one autoinhibitory) with respect to cortisol, both found experimentally. The capacity of the model to emulate TTS effects on HPA axis dynamics and its response to acute CRH-induced stress is examined using numerical simulations. Model predictions are compared with empirically obtained results reported in the literature. Thus, the reaction kinetic examinations of nonlinear biochemical transformations that constitute the HPA axis, including the negative feedback effect of TTS on HPA axis activity, recapitulates the well-established fact that TTS dampens HPA axis basal activity, decreasing both cortisol level and the amplitude of ultradian cortisol oscillations. The model also replicates TTS inhibitory action on the HPA axis response to acute environmental challenges, particularly CRH-induced stress. In addition, kinetic modelling revealed that TTS induced reduction in ultradian cortisol amplitude arises because the system moves towards a supercritical Hopf bifurcation as TTS is being increased. © 2017, The Author(s).
PB  - Springer Netherlands
T2  - Reaction Kinetics, Mechanisms and Catalysis
T1  - Kinetic modelling of testosterone-related differences in the hypothalamic–pituitary–adrenal axis response to stress
VL  - 123
IS  - 1
SP  - 17
EP  - 30
DO  - 10.1007/s11144-017-1315-7
ER  - 

@article{
author = "Stanojević, A and Marković, V M and Maćešić, Stevan and Kolar-Anić, Ljiljana and Vukojević, V",
year = "2018",
abstract = "The sex hormone testosterone (TTS) and the hypothalamic–pituitary–adrenal (HPA) axis mutually control one another’s activity, wherein TTS suppresses corticotrophin releasing hormone (CRH) stimulated HPA axis activity, whereas the activation of HPA axis has an inhibitory effect on TTS secretion. With an intention to explain these phenomena, a network reaction model is developed from the previously postulated stoichiometric models for HPA activity where main dynamic behaviors are controlled by two catalytic steps (one autocatalytic and one autoinhibitory) with respect to cortisol, both found experimentally. The capacity of the model to emulate TTS effects on HPA axis dynamics and its response to acute CRH-induced stress is examined using numerical simulations. Model predictions are compared with empirically obtained results reported in the literature. Thus, the reaction kinetic examinations of nonlinear biochemical transformations that constitute the HPA axis, including the negative feedback effect of TTS on HPA axis activity, recapitulates the well-established fact that TTS dampens HPA axis basal activity, decreasing both cortisol level and the amplitude of ultradian cortisol oscillations. The model also replicates TTS inhibitory action on the HPA axis response to acute environmental challenges, particularly CRH-induced stress. In addition, kinetic modelling revealed that TTS induced reduction in ultradian cortisol amplitude arises because the system moves towards a supercritical Hopf bifurcation as TTS is being increased. © 2017, The Author(s).",
publisher = "Springer Netherlands",
journal = "Reaction Kinetics, Mechanisms and Catalysis",
title = "Kinetic modelling of testosterone-related differences in the hypothalamic–pituitary–adrenal axis response to stress",
volume = "123",
number = "1",
pages = "17-30",
doi = "10.1007/s11144-017-1315-7"
}

Stanojević, A., Marković, V. M., Maćešić, S., Kolar-Anić, L.,& Vukojević, V.. (2018). Kinetic modelling of testosterone-related differences in the hypothalamic–pituitary–adrenal axis response to stress. in Reaction Kinetics, Mechanisms and Catalysis
Springer Netherlands., 123(1), 17-30.
https://doi.org/10.1007/s11144-017-1315-7

Stanojević A, Marković VM, Maćešić S, Kolar-Anić L, Vukojević V. Kinetic modelling of testosterone-related differences in the hypothalamic–pituitary–adrenal axis response to stress. in Reaction Kinetics, Mechanisms and Catalysis. 2018;123(1):17-30.
doi:10.1007/s11144-017-1315-7 .

Stanojević, A, Marković, V M, Maćešić, Stevan, Kolar-Anić, Ljiljana, Vukojević, V, "Kinetic modelling of testosterone-related differences in the hypothalamic–pituitary–adrenal axis response to stress" in Reaction Kinetics, Mechanisms and Catalysis, 123, no. 1 (2018):17-30,
https://doi.org/10.1007/s11144-017-1315-7 . .

TY  - JOUR
AU  - Jelić, S.
AU  - Čupić, Željko
AU  - Kolar-Anić, Ljiljana
AU  - Vukojević, V.
PY  - 2009
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/626
AB  - Two methods for dynamic systems analysis, Stoichiometric Network Analysis (SNA) and Quenching of Small Amplitude Oscillations (QA), are used to study the behaviour of a vital biological system. Both methods use geometric approaches for the study of complex reaction systems. In SNA, methods based on convex polytopes geometry are applied for stability analysis and optimization of reaction networks. QA relies on a geometric representation of the concentration phase space, introduces the concept of manifolds and the singular perturbation theory to study the dynamics of complex processes. The analyzed system, the Hypothalamic-Pituitary-Adrenal (HPA) axis, as a major constituent of the neuroendocrine system has a critical role in integrating biological responses in basal conditions and during stress. Self-regulation in the HPA system was modeled through a positive and negative feedback effect of Cortisol. A systematically reduced low-dimensional model of HPA activity in humans was fine-tuned by SNA, until quantitative agreement with experimental findings was achieved. By QA, we revealed an important dynamic regulatory mechanism that is a natural consequence of the intrinsic rhythmicity of the considered system.
T2  - International Journal of Nonlinear Sciences and Numerical Simulation
T1  - Predictive modeling of the hypothalamic-pituitary-adrenal (HPA) function. dynamic systems theory approach by stoichiometric network analysis and quenching small amplitude oscillations
VL  - 10
IS  - 11-12
SP  - 1451
EP  - 1472
UR  - https://hdl.handle.net/21.15107/rcub_cer_626
ER  - 

@article{
author = "Jelić, S. and Čupić, Željko and Kolar-Anić, Ljiljana and Vukojević, V.",
year = "2009",
abstract = "Two methods for dynamic systems analysis, Stoichiometric Network Analysis (SNA) and Quenching of Small Amplitude Oscillations (QA), are used to study the behaviour of a vital biological system. Both methods use geometric approaches for the study of complex reaction systems. In SNA, methods based on convex polytopes geometry are applied for stability analysis and optimization of reaction networks. QA relies on a geometric representation of the concentration phase space, introduces the concept of manifolds and the singular perturbation theory to study the dynamics of complex processes. The analyzed system, the Hypothalamic-Pituitary-Adrenal (HPA) axis, as a major constituent of the neuroendocrine system has a critical role in integrating biological responses in basal conditions and during stress. Self-regulation in the HPA system was modeled through a positive and negative feedback effect of Cortisol. A systematically reduced low-dimensional model of HPA activity in humans was fine-tuned by SNA, until quantitative agreement with experimental findings was achieved. By QA, we revealed an important dynamic regulatory mechanism that is a natural consequence of the intrinsic rhythmicity of the considered system.",
journal = "International Journal of Nonlinear Sciences and Numerical Simulation",
title = "Predictive modeling of the hypothalamic-pituitary-adrenal (HPA) function. dynamic systems theory approach by stoichiometric network analysis and quenching small amplitude oscillations",
volume = "10",
number = "11-12",
pages = "1451-1472",
url = "https://hdl.handle.net/21.15107/rcub_cer_626"
}

Jelić, S., Čupić, Ž., Kolar-Anić, L.,& Vukojević, V.. (2009). Predictive modeling of the hypothalamic-pituitary-adrenal (HPA) function. dynamic systems theory approach by stoichiometric network analysis and quenching small amplitude oscillations. in International Journal of Nonlinear Sciences and Numerical Simulation, 10(11-12), 1451-1472.
https://hdl.handle.net/21.15107/rcub_cer_626

Jelić S, Čupić Ž, Kolar-Anić L, Vukojević V. Predictive modeling of the hypothalamic-pituitary-adrenal (HPA) function. dynamic systems theory approach by stoichiometric network analysis and quenching small amplitude oscillations. in International Journal of Nonlinear Sciences and Numerical Simulation. 2009;10(11-12):1451-1472.
https://hdl.handle.net/21.15107/rcub_cer_626 .

Jelić, S., Čupić, Željko, Kolar-Anić, Ljiljana, Vukojević, V., "Predictive modeling of the hypothalamic-pituitary-adrenal (HPA) function. dynamic systems theory approach by stoichiometric network analysis and quenching small amplitude oscillations" in International Journal of Nonlinear Sciences and Numerical Simulation, 10, no. 11-12 (2009):1451-1472,
https://hdl.handle.net/21.15107/rcub_cer_626 .

TY  - JOUR
AU  - Pejić, Nataša
AU  - Čupić, Željko
AU  - Anić, Slobodan
AU  - Vukojević, V.
AU  - Kolar-Anić, Ljiljana
PY  - 2001
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/39
AB  - The Bray-Liebhafsky (BL) oscillatory reaction, as a reaction where hydrogen peroxide decomposes into the water and oxygen in the presence of iodate and hydrogen ions through a complex mechanism involving a number of intermediates, such as I-, I2, HIO and HIO2, was used as the matrix for analysis of kinetic properties of the catalysts for hydrogen peroxide decomposition. The examined catalysts were enzyme peroxidase (isolated from the horseradish root) and polymeric catalyst (acid form of poly-4-vynil-pyridine functionalized by fericsulfate). The change of kinetic state of the system caused by the presence of added catalyst is reflected in the form of oscillograms, in the time elapsed from the beginning of the reaction to the first oscillation, in the time elapsed from the beginning of the reaction to the end of oscillatory evolution, the number of oscillations, the average period between oscillations and its frequency. Since all these kinetic properties depend on the added amounts of both mentioned catalysts in a complex but analogous manner, a similar reaction mechanism could be expected in both cases.
AB  - Braj-Liebhafski (BL) oscilatorna reakcija, kao reakcija u kojoj se vodonik-peroksid, u prisustvu jodata i vodoničnih jona, razlaže na vodu i kiseonik, po kompleksnom mehanizmu koji uključuje nastanak brojnih intermedijera kao što su I-, I2, HIO i HIO2 je korišćena kao matrica za analizu kinetičkih osobina katalizatora za razlaganje vodonik-peroksida. Ispitivani katalizatori su peroksidaza izolovana iz korena rena i sintetički polimer (kiseli oblik poli-4-vinil-piridina funkcionalizovanog sa ferisulfatom). Promene kinetičkog stanja sistema izazvane prisustvom dodatih količina katalizatora se reflektuju na formu oscilograma, na vreme proteklo od početka reakcije do pojave prve oscilacije, na vreme proteklo od početka reakcije do kraja oscilatorne evolucije, broj oscilacija, srednjeg perioda oscilovanja i njihovu frekvenciju. Kako sva ova kinetička svojstva zavise od dodatih količina katalizatora na kompleksan ali analogan način, sličan reakcioni mehanizam se može očekivati u oba slučaja.
PB  - International Institute for the Science of Sintering, Beograd
T2  - Science of Sintering
T1  - The oscillatory Bray-Liebhafsky reaction as a matrix for analyzing enzyme and polymeric catalysts for hydrogen peroxide
VL  - 33
IS  - 2
SP  - 107
EP  - 115
UR  - https://hdl.handle.net/21.15107/rcub_cer_39
ER  - 

@article{
author = "Pejić, Nataša and Čupić, Željko and Anić, Slobodan and Vukojević, V. and Kolar-Anić, Ljiljana",
year = "2001",
abstract = "The Bray-Liebhafsky (BL) oscillatory reaction, as a reaction where hydrogen peroxide decomposes into the water and oxygen in the presence of iodate and hydrogen ions through a complex mechanism involving a number of intermediates, such as I-, I2, HIO and HIO2, was used as the matrix for analysis of kinetic properties of the catalysts for hydrogen peroxide decomposition. The examined catalysts were enzyme peroxidase (isolated from the horseradish root) and polymeric catalyst (acid form of poly-4-vynil-pyridine functionalized by fericsulfate). The change of kinetic state of the system caused by the presence of added catalyst is reflected in the form of oscillograms, in the time elapsed from the beginning of the reaction to the first oscillation, in the time elapsed from the beginning of the reaction to the end of oscillatory evolution, the number of oscillations, the average period between oscillations and its frequency. Since all these kinetic properties depend on the added amounts of both mentioned catalysts in a complex but analogous manner, a similar reaction mechanism could be expected in both cases., Braj-Liebhafski (BL) oscilatorna reakcija, kao reakcija u kojoj se vodonik-peroksid, u prisustvu jodata i vodoničnih jona, razlaže na vodu i kiseonik, po kompleksnom mehanizmu koji uključuje nastanak brojnih intermedijera kao što su I-, I2, HIO i HIO2 je korišćena kao matrica za analizu kinetičkih osobina katalizatora za razlaganje vodonik-peroksida. Ispitivani katalizatori su peroksidaza izolovana iz korena rena i sintetički polimer (kiseli oblik poli-4-vinil-piridina funkcionalizovanog sa ferisulfatom). Promene kinetičkog stanja sistema izazvane prisustvom dodatih količina katalizatora se reflektuju na formu oscilograma, na vreme proteklo od početka reakcije do pojave prve oscilacije, na vreme proteklo od početka reakcije do kraja oscilatorne evolucije, broj oscilacija, srednjeg perioda oscilovanja i njihovu frekvenciju. Kako sva ova kinetička svojstva zavise od dodatih količina katalizatora na kompleksan ali analogan način, sličan reakcioni mehanizam se može očekivati u oba slučaja.",
publisher = "International Institute for the Science of Sintering, Beograd",
journal = "Science of Sintering",
title = "The oscillatory Bray-Liebhafsky reaction as a matrix for analyzing enzyme and polymeric catalysts for hydrogen peroxide",
volume = "33",
number = "2",
pages = "107-115",
url = "https://hdl.handle.net/21.15107/rcub_cer_39"
}

Pejić, N., Čupić, Ž., Anić, S., Vukojević, V.,& Kolar-Anić, L.. (2001). The oscillatory Bray-Liebhafsky reaction as a matrix for analyzing enzyme and polymeric catalysts for hydrogen peroxide. in Science of Sintering
International Institute for the Science of Sintering, Beograd., 33(2), 107-115.
https://hdl.handle.net/21.15107/rcub_cer_39

Pejić N, Čupić Ž, Anić S, Vukojević V, Kolar-Anić L. The oscillatory Bray-Liebhafsky reaction as a matrix for analyzing enzyme and polymeric catalysts for hydrogen peroxide. in Science of Sintering. 2001;33(2):107-115.
https://hdl.handle.net/21.15107/rcub_cer_39 .

Pejić, Nataša, Čupić, Željko, Anić, Slobodan, Vukojević, V., Kolar-Anić, Ljiljana, "The oscillatory Bray-Liebhafsky reaction as a matrix for analyzing enzyme and polymeric catalysts for hydrogen peroxide" in Science of Sintering, 33, no. 2 (2001):107-115,
https://hdl.handle.net/21.15107/rcub_cer_39 .