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Circadian system in adolescents and the use of light therapy
Kučerová, Jana ; Červená, Kateřina (advisor) ; Pačesová, Dominika (referee)
Circadian rhythms, as regularly recurring events in living organisms with a period of approximately 24 hours, are an important part of life on Earth. To keep the period of the internal circadian clock of an organism in line with the cycle of the Earth Day, synchronization of this clock is necessary. The most important factor in synchronizing the circadian clock is light, which provides the brain with information about the phase of the Earth Day. The individual setting of the circadian clock, which is manifested in the form of a chronotype, has a profound effect on the life of the individual. Chronotypes change throughout life, and the most significant changes occur during adolescence, when the overall chronotype shifts. This results in adolescents going to bed later even though they have to get up early for school. This is also why they are more likely to suffer from sleep deprivation, be inattentive at school or fall asleep during lessons. Consequently, they experience, often with significant, social jet lag, which is a health risk. Light therapy offers a solution. This paper presents its general use, as well as specific examples of its use with delayed adolescents. However, there are also other ways to improve the situation of adolescents, e.g., delaying the start time of school in the morning,...
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Circadian clock and detoxication processes in the liver
Ludvíková, Tereza ; Pačesová, Dominika (advisor) ; Kolář, David (referee)
The circadian system influences almost all physiological processes in the mammalian body. Among other things, detoxication processes in the liver are under circadian control. Both central and peripheral clock in the liver regulate the expression of genes involved in the detoxication of xenobiotic substances and drugs. The first part of this thesis summarizes the main characteristics of the central and peripheral circadian clocks, including their molecular basis. The second part focuses on the main functions of liver tissue with a focus on detoxification processes. The emphasis of the third section is on circadian rhythms in the expression and activity of enzymes called cytochromes P450, which are the most important system catalyzing phase I detoxication, and also briefly discusses the influence of the circadian system on the expression of nuclear receptors and PAR bZIP transcription factors involved in the regulation of cytochrome P450 transcription. The last section describes the influence of the circadian system on the efficacy and toxicity of selected drugs, on paracetamol metabolism with the main purpose of describing how paracetamol-induced hepatotoxicity is affected by time of administration. Key words: circadian system, liver, detoxication, cytochrome, paracetamol
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The effect of long-term morphine application on clock genes expression in the rat brain
Pačesová, Dominika ; Bendová, Zdeňka (advisor) ; Roubalová, Lenka (referee) ; Polidarová, Lenka (referee)
The circadian and opioid systems are systems involved in maintaining homeostasis in the body. Disruption of the circadian system disturbs the proper timing of physiological processes, which can result in the development or exacerbation of pre-existing pathological conditions, including addiction. One of the factors that can influence the precise synchronization of the circadian system is the use and abuse of opioids. The interrelationship between the circadian and opioid systems is poorly studied. To this end, the present study investigated the effect of morphine and methadone on the rat circadian system in adulthood and during development. The aim of this dissertation was to observe the effect of acute morphine administration on the expression of clock genes in the suprachiasmatic nuclei (SCN) of adult rats, and to investigate the effect of long-term morphine or methadone administration and withdrawal on the expression of clock genes in the SCN and on the activity of the enzyme AA-NAT in the pineal gland of adult rats. Proper development of the circadian clock contributes significantly to the maintenance of health in adulthood and ensures good adaptability of the organism to changes in the external environment. No study to date has focused on examining the effects of opioid administration during...
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Rhythmic function of placenta and the impact of disruption in maternal-placental-fetal axis
Světlíková, Nela ; Sumová, Alena (advisor) ; Pačesová, Dominika (referee)
In mammals, the circadian rhythms result of a complex endogenous system consisting of hierarchically organized oscillators. The system enables the synchronization of the organism's internal processes with the external environment. It consists of the main component, the central clock, located in the suprachiasmatic nuclei in the hypothalamus, and peripheral clocks in other cells, tissues and organs. The placenta is a temporary, specialized mammalian organ that is part of the mother-placenta-fetus axis and exhibits rhythmicity in its functions. The aim of this thesis is to summarize the rhythmic functions of the placenta, such as immunity, protection, and production of hormones and other mediators that play an important role in fetal development and pregnancy. In addition, the thesis also describes rhythmic changes, that occur during pregnancy in the mother-placenta-fetus axis and how these rhythms influence each other. Keywords Placenta, circadian clock, ontogenesis, fetus, maternal synchronization, hormones, enzymes, immunity
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Circadian system of SHR rats
Pačesová, Dominika ; Sumová, Alena (advisor) ; Švandová, Ivana (referee)
The suprachiasmatic nuclei (SCN) harbor the master circadian pacemaker in mammals which is responsible for control and coordination of circadian rhythms throughout the body and ensure optimal functioning of the organism in variable external conditions. The SCN is a heterogeneous structure in its morphology and function. The present thesis focuses on comparison of the SCN and its properties in an animal model of pathological hypertension, i.e. in spontaneously hypertensive rat (SHR), and nonpathological normotensive Wistar rat. To determine selected morphological and functional markers in the SCN between both rat strains, in situ hybridization and immunohistochemistry methods were used. To compare functional properties of the SCN of SHR and Wistar rat, the effect of light pulses on the expression of c-fos and Per1 genes as well as on locomotor activity were studied in both strains. Our results suggest morphological differences in the number of neurons and in the expression of Avp a Vip in the SCN with an apparent tendencies to higher levels of the studied peptides in SHR compared to Wistar rat. Our data further indicate variation in functioning of the SCN in SHR and Wistar rat on the basis of different responses to light pulses administered in the first part of the subjective night, namely in the...
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The role of astrocytes in the formation of brain edema
Heřmanová, Zuzana ; Anděrová, Miroslava (advisor) ; Pačesová, Dominika (referee)
Brain edema is a cause of mortality accompanying number of pathologies such as ischemia, traumatic brain injury, tumors or liver and kidney failure. It is described as a process of osmotic and water flux alterations, which lead to cell volume changes and to an increase in intracranial pressure. Brain edema is usually classified into two types: vasogenic and cytotoxic. Development of vasogenic edema is connected to the blood brain barrier disruption. Water accumulates in the extracellular space and exerts pressure on the cellular compartments of the tissue. The cytotoxic type of edema is characterized by water accumulation within the cells. The process of cellular volume enlargement is termed cellular swelling. Cytotoxic swelling is usually connected to glial cells, namely astrocytes, as these cells represent a part of the blood brain barrier and thus they influence homeostasis inside the brain. Water flows across cytoplasmic membrane through a system of specialized channels - aquaporins. For the brain edema formation, aquaporin 4 is the most important. It is localized on astrocytic membranes and using aquaporin-null mice, it has been shown, that it participates in water clearance in physiological and pathological conditions. Since the water fluxes are passive, the driving force for edema formation...
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Neuroprotective versus apoptotic effect of morphine
Paluba, Michal ; Hejnová, Lucie (advisor) ; Pačesová, Dominika (referee)
Morphine, which is primarily used in medicine as a strong analgesic, has been studied for a long amount of time for its protective effects on neural tissue. Morphine demonstrates its neuroprotective role in ischemic disorders because it induces a higher tolerance to glucose and oxygen deprivation among neurons. However, morphine has a protective influence not only on neurons, but also on neuroglia, especially on astrocytes. Pathological disorders can result in the over-release of neurotransmitters, which include glutamate, which is known for its excitotoxicity at excessive concentration. Morphine even in this case effectively blocks the effect of glutamate, thus preventing apoptosis of cells. However, there is also evidence of an apoptotic effect of morphine on cells, as in some cases it increases the synthesis and activity of proapoptotic factors. However, the apoptotic effect of morphine does not always affect the organism only negatively. There is also evidence of its effect on the regulation of the tumour development by using morphine-induced apoptosis.
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Physiology of Blood Brain Barrier
Kellner, Patrik ; Otáhal, Jakub (advisor) ; Pačesová, Dominika (referee)
This thesis takes on the theme of blood-brain barrier. Blood-brain barrier is a physiological barrier, that divides the circulatory system from brain, in place of their konfrontation. Barriers main task is to maintain homeostasis and regulate the transport of substances in both directions. The most important group of proteins, responsible for transport, are the ABC transporters. Alterations of barrier properties during the pathological states, but also the distribution of medical drugs is subject of futher investigations. Overview of the above mentioned themes will be mediated by this thesis.
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The influence of drugs on prenatal and postnatal development of humans and model organisms.
Adamusová, Tereza ; Hejnová, Lucie (advisor) ; Pačesová, Dominika (referee)
The aim of this bachelors thesis is to summarize the consequences of using opioid substances on a developing organism. This work contains the issues of using illicit drugs heroin and morphine as well as using opioid analgetics and replacement medication during the Opioid Maintenance Treatment, such as buprenorphine or methadon. Examined topics are the characteristis of opioid substances, their metablism and processes by which they affect the organism. In the following parts the thesis describes specific developmental defects, that can be found as a consequence of using opioids.
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The role of astrocytes in the formation of brain edema
Heřmanová, Zuzana ; Anděrová, Miroslava (advisor) ; Pačesová, Dominika (referee)
Brain edema is a cause of mortality accompanying number of pathologies such as ischemia, traumatic brain injury, tumors or liver and kidney failure. It is described as a process of osmotic and water flux alterations, which lead to cell volume changes and to an increase in intracranial pressure. Brain edema is usually classified into two types: vasogenic and cytotoxic. Development of vasogenic edema is connected to the blood brain barrier disruption. Water accumulates in the extracellular space and exerts pressure on the cellular compartments of the tissue. The cytotoxic type of edema is characterized by water accumulation within the cells. The process of cellular volume enlargement is termed cellular swelling. Cytotoxic swelling is usually connected to glial cells, namely astrocytes, as these cells represent a part of the blood brain barrier and thus they influence homeostasis inside the brain. Water flows across cytoplasmic membrane through a system of specialized channels - aquaporins. For the brain edema formation, aquaporin 4 is the most important. It is localized on astrocytic membranes and using aquaporin-null mice, it has been shown, that it participates in water clearance in physiological and pathological conditions. Since the water fluxes are passive, the driving force for edema formation...
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