Adaptation to chronic hypoxia increases myocardial resistance to acute ischemia/reperfusion (I/R) injury, similarly to application of exogenous erythropoietin (EPO). Nevertheless, it is not known if EPO induced by chronic hypoxia plays a role in its cardioprotective mechanism. The aim of this study was to find out if protective effect of exogenous EPO adds up to protection offered by chronic hypoxia. Adult male mice (ICR) were adapted to intermittent hypobaric hypoxia 8 hours per day, 5 days per week for 5 weeks. The degree of hypoxia corresponded to 7000 metres. Control animals were housed for the same time in normoxic environment. Resistance to I/R injury was assessed according to size of myocardial infarction induced by 45-min global ischemia and 1-h reperfusion of the heart in vitro. Animals were treated 24 h before the experiment with 200 or 5000 U/kg EPO. Treatment with 200 U/kg EPO was sufficient to significantly limit infarct size in normoxic animals (33,56 ± 2,93 % vs. 25,71 ± 2,29 %). Hypoxic adaptation decreased infarct area to 23,49 ± 2,30%, but additive effect of EPO in hypoxic group was not detected. The results indicate that exogenous EPO employs the same cardioprotective mechanisms as adaptation to chronic intermittent hypoxia. Preliminary results indicate that repeated application of EPO...

Proefschrift Universiteit Maastricht. / Met bibliogr. - Met lit. opg. - Met een samenvatting in het Nederlands.

This work is focused on fractal dimension utilization for heart rate variability analysis. Both the theory of heart rate variability and the methods of HRV analysis in time domain and using the fractal dimesion are summarized. Short comparsion of time domain and fractal dimension method is presented.

Opioids are considered as a dangerous addictive substances which are widely used in medicine for their strong analgetic effects. Opioids (such as morphine and methadon) may nevertheless play an important role in the resistance of the heart to ischemia by reducing the rate of cell damage. This protective effect is well understood about morphine but we don't know almost nothing about effects of methadone on the myocardium. The main aim of this thesis was to find out how chronic methadone treatment affects ischemic tolerance of rat hearts. For our experiments we used Wistar rats in two series. In the first series we administered morphine (10 mg/kg/day, i.m.) or methadone (2 mg/kg/day, i.m.) for 10 days. In the second experiment series we administered methadon for 28 days (2 mg/kg/day, i.m.). For analysis of the ischemic heart tolerance we used the isolated perfused heart method. Incidence and severity of ischemia and reperfusion arrhythmias were analyzed during the 50 min of ischemia and early reperfusion. Infarct size was analyzed histochemically, using tetrazolium salts and KMnO4 1 h after reperfusion and was determined by planimetric method. In the first series of experiments analyzing the effect of 10-day administration of both opioids on the resistance of the heart to ischemia we did not find a...

NG2-glia, a fourth major glial cell population, were shown to posses wide proliferation and differentiation potential in vitro and in vivo, therefore the aim of this study was to compare the rate of proliferation and differentiation potential of NG2-glia after different types of brain injuries, such as global and focal cerebral ischemia (GCI, FCI) or stab wound (SW), as well as during aging. Moreover, we aimed to determine the role of Sonic hedgehog (Shh) in NG2-glia proliferation/differentiation after FCI. We used transgenic mice, in which tamoxifen triggers the expression of red fluorescent protein (tdTomato) in NG2-glia and cells derived therefrom. Proliferation and differentiation potential of tdTomato+ cells in sham operated animals (controls) and those after injury were determined by immunohistochemistry employing antibodies against proliferating cell nuclear antigen and glial fibrillary acidic protein. FCI was induced by middle cerebral artery occlusion, GCI by carotid occlusion with hypotension and SW by sagittal cortical cut. Shh signaling in vivo was activated or inhibited by Smoothened agonist or Cyclopamine, respectively. Compared to controls, the proliferation rate of tdTomato+ cells was increased after all types of injuries, while it declined in aged mice (15-18- months-old) after...

Astrocytes posses a wide range of functions within the brain. In response to ischemic conditions they swell due to increased uptake of osmolytes and they are mainly responsible for cytotoxic edema formation. However, they are also able to regulate their volume by releasing osmolytes together with water via the process of regulatory volume decrease (RVD). The Aquaporin 4 (AQP4) channel and Transient receptor potential vanilloid 4 (TRPV4) channel are suspected to be strongly involved in these processes of astrocytic volume regulation. The goal of the present diploma thesis was to clarify the role of both channels in astrocytic swelling in situ. For our experiments we used a subpopulation of green fluorescent protein-labelled astrocytes from AQP4-deficient (AQP4-/- ), TRPV4-deficient (TRPV4-/- ) and control (Ctrl) mice. Cell volume alterations were induced in acute brain slices by hypoosmotic stress or by oxygen-glucose deprivation (OGD). Data were quantified using fluorescence intensity-based approach in the whole cells and in astrocytic endfeet. Our results indicate, that there is no difference in astrocytic swelling or cell volume recovery between astrocytes from AQP4-/- , TRPV4-/- and control mice when exposed to hypoosmotic stress. On the contrary, volume changes induced by OGD varied...

The aim of present project was to uncover the effect of pharmacological increase in acute and chronic nitric oxide (NO) production on cardioprotective effect of chronic hypoxia. We studied the effect of NO donor molsidomine on hemodynamic conditions and ischemia - induced myocardium injury. Male Wistar rats were exposed to continual hypoxia in a normobaric chamber (10 % O2, 4 weeks). Rats received molsidomine either chronically (15 mg/kg/day) in drinking water or acutely (10 mg/kg) in saline infused 30 min before ischemia. Control rats were kept under normoxia and treated in a corresponding manner. Adaptation to chronic hypoxia resulted in development of pulmonary hypertension. Chronic treatment with molsidomine slightly reduced these consequences of chronic hypoxia but it had no effect on increased cardiac ischemic tolerance in chronically hypoxic rats. On the other hand acute treatment with molsidomine significantly reduced infarct size and increased the number of arrhythmias in both normoxic and chronically hypoxic animals. In conclusion, our data suggests that acute increase in availability of NO is cardioprotective in both normoxic and chronically hypoxic rats contrary to its chronic increase which seems to have no protective contribution.

Objectives: Hematopoietic stem cell transplantation (HSCT) is a widely used method for treatment of hematological disorders and some other diseases. However, sometimes a suitable donor of hematopoietic stem cells (HSC) is not found for a patient. Because HSC have been described as cells with low proliferative and metabolic activity, their tolerance to the lack of oxygen or metabolic substrates may be assumed. In this study, we explored cadaveric bone marrow as an alternative source of HSC for HSCT, using a mouse experimental model. In addition, the effect of in vitro metabolic inhibition and short-term in vitro storage (1 - 4 days) on functional properties of mouse HSC was investigated. Methods: C57Bl/6 mice (wild-type or p53-/- ) were used in the experiments. To explore cadaveric HSC, bone marrow (BM) was left in intact femurs at 37řC, 20řC and 4řC under the conditions of ischemia. The bone marrow cells were harvested after defined time periods ranging 0 - 48 hours. For metabolic inhibition, the electron transport chain inhibitor potassium cyanide (KCN) and inhibitor of glycolysis 2-deoxy-D-glucose (2-DG) were used in vitro. To determine the impact of ischemia, metabolic inhibition, or in vitro storage on transplantability of HSC, the competitive repopulation assay using Ly5.1/Ly5.2 congenic model...

Peripheral arterial disease (PAD) is a disease which may cause gradual narrowing and possibly congestion of arteries that are responsible for nourishing the lower limbs. Most often this condition develops consequently with atherosclerosis. The most advanced stage of PAD is called critical limb ischemia. The changes induced by atherosclerosis affect not only the lower limb arteries, but at the time of the diagnosis of PAD all arteries in the body are already affected. Therefore PAD belongs among cardiovascular diseases and its diagnosis is a negative prognostic factor of the overall cardiovascular risk. The aim of treatment interventions is to reduce complications that accompany this ailment and their impact on the patient's life. The aim of the thesis was to find out to what extend the patients are informed about the causes of PAD, options of its treatment and the impact of prevention and life style on the overall prognosis of the disease. The first objective of the thesis is to find out if patients are aware of the risks of PAD treatment, one of which is leg amputation. The second objective is to find out whether the patients are sufficiently informed about their condition. The third objective is to evaluate whether patients follow the prescribed treatment. The fourth objective is to find out whether patients are willing to change their life style in order to eliminate the risk of lower limb amputation. A part of interviews with patients was to educate them about their condition, the necessity of following the treatment regimen and the impact of lifestyle on the affected leg prognosis. At the end, the interviewed received educational handouts with information about the most important suggested procedures to follow. The practical part of the thesis is based on qualitative research. The data was collected in semi-structured interviews. The interviews were conducted in two steps. The first step was to educate patients about PAD and distribute informational handouts. The second round of interviews took place intentionally several months after the first ones. Their purpose was to assess the impact of education on patients' compliance with treatment and regimen. The research shows the majority of the interviewed were well-informed about the crucial aspects of their condition and treatment procedures. The participants understood the given information and considered it satisfactory. However, it was surprising that patients had not looked for information themselves. Simultaneously, it was ascertained that most of the respondents were aware of the prognosis and risks related to the treatment. The two-step interviews showed some respondents were not aware of the causes of their disease. It can be therefore assumed that their ignorance of the risk factors and their impact on the development of the disease is the reason why patients do not give enough importance to the suggested treatment regimen. Furthermore, it was found out that they had not look for a substitute solution if they are not able to follow the recommended treatment regimen. The results of this thesis show that although the elimination of the risk factors is crucial for patients' future they do not pay enough attention to them. There are two aspects to it; either patients trivialize the potential risks or are apathetic or are not sufficiently informed. It is hard to have some impact on patients' apathy and trivialization of their condition. Nevertheless, it is possible to influence the second aspect, which is the subject of the final part of the thesis and the educational handout. As was discovered during the interviews, the information provided by doctors during ambulatory treatment is not thorough and does not include practical advice how to follow treatment regimen. Patients should be informed by nurse either personally or during the sessions. In this way the patient should be also selfmotivated in their treatment.

Heart rate variability analysis can be used for a diagnosis of the cardiac diseases. The HRV analysis methods are divided into linear and nonlinear methods. Time-domain method is one of the simplest method and belongs to linear methods. Detrended fluctuation analysis DFA is nonlinear method made relatively recently. In this paper, it has been done the comparison of these two methods based on the changes detection in HRV caused by an ischemia.