No description available.

Background: Haematotoxicity of conventional chemotherapies often results in delays of treatment or reduction of chemotherapy dose. To ameliorate these side-effects, patients are routinely treated with blood transfusions or haematopoietic growth factors such as erythropoietin (EPO) or granulocyte colony-stimulating factor (G-CSF). For the latter ones, pharmaceutical derivatives are available, which differ in absorption kinetics, pharmacokinetic and -dynamic properties. Due to the complex interaction of cytotoxic effects of chemotherapy and the stimulating effects of different growth factor derivatives, optimal treatment is a non-trivial task. In the past, we developed mathematical models of thrombopoiesis, granulopoiesis and erythropoiesis under chemotherapy and growth-factor applications which can be used to perform clinically relevant predictions regarding the feasibility of chemotherapy schedules and cytopenia prophylaxis with haematopoietic growth factors. However, interactions of lineages and growth-factors were ignored so far. Results: To close this gap, we constructed a hybrid model of human granulopoiesis and erythropoiesis under conventional chemotherapy, G-CSF and EPO applications. This was achieved by combining our single lineage models of human erythropoiesis and granulopoiesis with a common stem cell model. G-CSF effects on erythropoiesis were also implemented. Pharmacodynamic models are based on ordinary differential equations describing proliferation and maturation of haematopoietic cells. The system is regulated by feedback loops partly mediated by endogenous and exogenous EPO and G-CSF. Chemotherapy is modelled by depletion of cells. Unknown model parameters were determined by fitting the model predictions to time series data of blood counts and cytokine profiles. Data were extracted from literature or received from cooperating clinical study groups. Our model explains dynamics of mature blood cells and cytokines after growth-factor applications in healthy volunteers. Moreover, we modelled 15 different chemotherapeutic drugs by estimating their bone marrow toxicity. Taking into account different growth-factor schedules, this adds up to 33 different chemotherapy regimens explained by the model. Conclusions: We conclude that we established a comprehensive biomathematical model to explain the dynamics of granulopoiesis and erythropoiesis under combined chemotherapy, G-CSF, and EPO applications. We demonstrate how it can be used to make predictions regarding haematotoxicity of yet untested chemotherapy and growth-factor schedules.

Neurorehabilitation is a multidisciplinary rehabilitation process used in patients with neurological diseases. These patients have not only movement disorders but also cognitive and neurobehavioral problems as well as aphasias. Their rehabilitation is a long term process and the results are often unsatisfactory. Neuroplasticity - physiological basis for neurorehabilitation induces functional restitution or recovery after secondary brain damage. Various neuroprotective substances (e.g. erythropoietin - EPO) are tested to empower mechanisms of plasticity after brain injury. Preclinical studies testing efficacy of those substances in animal brain damage models are essential to prepare clinical trials. The aim of the study was to reveal the influence of EPO combined with rehabilitation on functional outcomes after global cerebral hypoxia. FIM (Functional independence measure) test was used for functional evaluation and Meilli test for visual memory of the patients who attended special program for rehabilitation in clinical part. Patients who came earlier had better prognosis than patients who came later. In experimental part three-months old male Wistar albino rats were exposed to hypobaric hypoxia for 60 minutes in an experimental chamber, simulating an altitude of 8000 m. Half of the animals received...

Neurorehabilitation is a multidisciplinary rehabilitation process used in patients with neurological diseases. These patients have not only movement disorders but also cognitive and neurobehavioral problems as well as aphasias. Their rehabilitation is a long term process and the results are often unsatisfactory. Neuroplasticity - physiological basis for neurorehabilitation induces functional restitution or recovery after secondary brain damage. Various neuroprotective substances (e.g. erythropoietin - EPO) are tested to empower mechanisms of plasticity after brain injury. Preclinical studies testing efficacy of those substances in animal brain damage models are essential to prepare clinical trials. The aim of the study was to reveal the influence of EPO combined with rehabilitation on functional outcomes after global cerebral hypoxia. FIM (Functional independence measure) test was used for functional evaluation and Meilli test for visual memory of the patients who attended special program for rehabilitation in clinical part. Patients who came earlier had better prognosis than patients who came later. In experimental part three-months old male Wistar albino rats were exposed to hypobaric hypoxia for 60 minutes in an experimental chamber, simulating an altitude of 8000 m. Half of the animals received...

No description available.

Background: Haematotoxicity of conventional chemotherapies often results in delays of treatment or reduction of chemotherapy dose. To ameliorate these side-effects, patients are routinely treated with blood transfusions or haematopoietic growth factors such as erythropoietin (EPO) or granulocyte colony-stimulating factor (G-CSF). For the latter ones, pharmaceutical derivatives are available, which differ in absorption kinetics, pharmacokinetic and -dynamic properties. Due to the complex interaction of cytotoxic effects of chemotherapy and the stimulating effects of different growth factor derivatives, optimal treatment is a non-trivial task. In the past, we developed mathematical models of thrombopoiesis, granulopoiesis and erythropoiesis under chemotherapy and growth-factor applications which can be used to perform clinically relevant predictions regarding the feasibility of chemotherapy schedules and cytopenia prophylaxis with haematopoietic growth factors. However, interactions of lineages and growth-factors were ignored so far. Results: To close this gap, we constructed a hybrid model of human granulopoiesis and erythropoiesis under conventional chemotherapy, G-CSF and EPO applications. This was achieved by combining our single lineage models of human erythropoiesis and granulopoiesis with a common stem cell model. G-CSF effects on erythropoiesis were also implemented. Pharmacodynamic models are based on ordinary differential equations describing proliferation and maturation of haematopoietic cells. The system is regulated by feedback loops partly mediated by endogenous and exogenous EPO and G-CSF. Chemotherapy is modelled by depletion of cells. Unknown model parameters were determined by fitting the model predictions to time series data of blood counts and cytokine profiles. Data were extracted from literature or received from cooperating clinical study groups. Our model explains dynamics of mature blood cells and cytokines after growth-factor applications in healthy volunteers. Moreover, we modelled 15 different chemotherapeutic drugs by estimating their bone marrow toxicity. Taking into account different growth-factor schedules, this adds up to 33 different chemotherapy regimens explained by the model. Conclusions: We conclude that we established a comprehensive biomathematical model to explain the dynamics of granulopoiesis and erythropoiesis under combined chemotherapy, G-CSF, and EPO applications. We demonstrate how it can be used to make predictions regarding haematotoxicity of yet untested chemotherapy and growth-factor schedules.:Background; Methods; Results; Model predictions; Discussion; Conclusions