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Modulation of the JAK/STAT signaling pathway in the suprachiasmatic nucleus of rat hypothalamus
Moravcová, Simona ; Novotný, Jiří (advisor) ; Krulová, Magdaléna (referee) ; Polidarová, Lenka (referee)
Circadian clock in the suprachiasmatic nucleus of the hypothalamus (SCN) regulates daily rhythms in behavior and physiology and is an important part of the mechanisms regulating mammalian homeostasis. SCN are synchronized with a 24hour cycle mainly by light, but they can also be regulated by a variety of nonphotic signals, such as growth factors, opioids, cytokines, or lipopolysaccharide (LPS), which act by inducing the JAK/STAT signaling pathway. STAT family proteins (i.e. signal transducers and activator of transcription) regulate many aspects of cellular physiology, from growth and differentiation to immune response. However, the JAK/STAT signaling pathway has not yet been studied in the SCN and the function of STAT proteins in the SCN has not yet been clarified. In the first part of the thesis, we focused on localization of STAT3 and STAT5 proteins in the rat SCN and determination of rhythm in proteins and mRNA. Our experiments showed the daily rhythm in the levels of STAT3 protein in SCN astrocytes of rat with low but significant amplitude and with maximum in the morning. In addition, we revealed strong but nonrhythmic expression of STAT5A protein in astrocytes and STAT5B protein in nonastrocytic cells of SCN. It was also found that Stat3 mRNA show, similarly to protein, circadian rhythm in...
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Home parenteral nutrition during a day and night regime
Fidlerová, Karolína ; Meisnerová, Eva (advisor) ; Staněk, Ivo (referee)
This diploma thesis deals with home parenteral nutrition in the day and night regime and its effect on patients. Parenteral nutrition is usually administered at night so that patients can do normal daily activities and so that nutrition administered in this way has the least impact on their lives. Parenteral nutrition is not a physiological route of nutrient administration and it is not natural for the human body to process nutrients at night. The first part of the theoretical work presents parenteral nutrition and its composition, indications, contraindications and complications. The next part of the thesis describes home parenteral nutrition and its organisation which is necessary for this form of nutritional support to be implemented. It is necessary to monitor many laboratory values on parenteral nutrition, the theoretical part specifically mentions cholesterol, triacylglycerols, glycemia or liver function tests. One of the important parts is the chapter about circadian rhythms, hormones and metabolic changes in energy intake at night. Qualitative research was chosen for this work, which involved 17 patients on home parenteral nutrition. These patients were getting their nutrition during the night. Their laboratory values such as liver function tests, glycaemia and blood fats was evaluated and...
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SLEEPING OUTDOORS
Bendák, Jan ; Tomalík, Michael (referee) ; Tobola, Ondřej (advisor)
The work deals with the influences acting on humans when staying in the outdoor environment and their effects on our daily rhythm. It focuses closely on the ritual of sleeping outside. It strives for a natural understanding of the laws of nature through exposure to the influences that affect us open air on a daily basis. Seasons, weather, light and other factors are determining elements for the work. The result of understanding and combining these principles are outdoor structures designed to accomodate groups or individuals overnight. The objects should serve as a platform for creating a community that will further develop these principles autonomously. The aim is to present the positives of sleeping outside, delimit against the trend of unsustainable growth and to provide an example of how to deal with this tendency through the perception of nature.
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Circadian rhythm of parathyroid hormone and bone remodeling: implication for the osteoporosis treatment with teriparatide (parathormone [1-34])
Rašková, Mária ; Zikán, Vít (advisor) ; Žofková, Ivana (referee) ; Perlík, František (referee)
Circadian rhythm of parathyroid hormone (PTH) is well documented, but its physiological role is not fully understood. In healthy individuals, biochemical markers of bone remodeling follow a similar circadian rhythm to PTH with a nocturnal rise in bone resorption and formation. The loss of PTH diurnal variation was observed not only in primary hyperparathyroidism, but also in patients with postmenopausal osteoporosis. Continuously elevated concentrations of PTH lead to excessive stimulation of bone resorption, whereas intermittent PTH administration has a strong osteoanabolic effect in patients with osteoporosis. It has not been examined whether the skeletal sensitivity to PTH action depends also on the time of its application. The aim of our study was to verify the hypothesis that the application of teriparatide (TPTD, recombinant human PTH [1-34]) at different times of the day in the context of its diurnal variability affects the physiological circadian rhythm of bone remodeling and also the bone mineral density (BMD) after the long-term TPTD treatment. Fourteen women with postmenopausal osteoporosis treated with 20 micrograms of TPTD daily, applied subcutaneously either in the morning or evening, were included in the first study. The concentration of serum C-terminal telopeptide of type I collagen...
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Circadian sleep regulation and sleep deprivation
Zeithamlová, Barbora ; Weissová, Kamila (advisor) ; Honzlová, Petra (referee)
The circadian system is designed to generate circadian rhythms and serve as the human inner clock. This is achieved through the molecular mechanism of autonomous transcriptional-translational feedback loops, in which so-called clock genes are involved. Circadian rhythms regulate the timing of physiological and behavioral processes, including sleep. Sleep is important for the proper functioning of the human organism. As a result of desynchronization of circadian rhythm, disturbances of sleep arise which threaten the mental and physical state of man. One of the examples is sleep deprivation which is deffined as a lack of necessary amount of sleep. Besides its negative effect on human health, there had been also reported positive effect in the treatment of symptoms in patients with unipolar depression. Other studies suggest that deprivation causes a reset of the circadian system, correcting the abnormal functioning of the internal clock. These effects have only a short duration, but it appears that they could be stabilized by combining sleep deprivation therapy with other therapeutic approaches. However, it is crucial to understand the exact mechanism that causes the positive effect in sleep deprivation therapy.
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Lighting with Tunable Spectral Distribution and Its Influence on Human Physiological Functions
Hanák, Petr ; Bendová,, Zdeňka (referee) ; Baxant, Petr (advisor)
In this diplomat theses are considered the effects of light on human beings, especially on physical performance. The goal of this work was to design a suitable method for evaluation of the effects of light on physical performance. Furthermore, to verify designed methods in laboratory environment and the assessment of collected data. After creating this method several people were tested under different light conditions and collected date evaluated. The results are suggesting that high intensity lighting with low wave lengths leads to an increase of physiological activity in organism and therefore to a potential decreasing physical performance.
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Sleep correlates of early risk of bipolar disorder in children and adolescents.
Šebela, Antonín ; Goetz, Michal (advisor) ; Příhodová, Iva (referee) ; Vevera, Jan (referee)
Background: Reports of subjective sleep impairments have been replicated in adults with bipolar disorder (BD) and young BD patients. Furthermore, circadian rhythm alterations are a core feature of BD. Despite the impairment in circadian rhythms and altered sleep included in various heuristic developmental models of BD, thus far, biomarkers in population at risk for BD have not been sufficiently objectively validated. Thus, we conducted: a) Explorative study of sleep and rest-activity circadian rhythm among offspring of BD parents. b) Study of sleep and rest-activity circadian rhythm among offspring of BD parents without the presence of psychopathology (except depression and anxiety disorders) based on our exploratory findings. Methods: a) 14 days of actigraphic assessment and subjective scales (Pediatric Sleep Questionnaire, PSQ; the Morningness/Eveningness Questionnaire, MEQ; and The General Behavior Inventory Sleep Subscale, GBISS) to assess circadian preference, and to identify sleep impairment symptoms. Psychopathology was assessed using psychiatric interview. b) ≥ 14 days of actigraphic assessment with advanced methods to assess the chronotype, social jet lag and sleep macrostructure, psychiatric interview and subjective psychometric scales to assess the full psychopathology profile. Results:...
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The modulation of the circadian rhythm in melatonin production in human induced by experimental lighting conditions
Skálová, Kateřina ; Bendová, Zdeňka (advisor) ; Jelínková, Dana (referee)
The circadian system controls the timing of most of the physiological functions and behaviour within approximately 24 hours period. The light/dark cycle aligns this circadian period with the exact length of the solar day. Light information is conveyed via ipRGC cells in the retina, with maximum sensitivity in the blue part light (460-480nm wavelength). The information proceeds to the main circadian clocks located in the suprachiasmatic nuclei. This clock regulates the synthesis of neurohormone melatonin in the pineal gland whose high night level can be rapidly downregulated by the light at night. The major aim of this study was to test the effectiveness of the blue or green light-emitting device, potentially utilized in clinical practice, to suppress the night melatonin level and provide thus the first evidence that this device may affect the circadian system. The results show that the light emitted by this device has the potential to lower melatonin levels in most subjects with the higher efficiency in the blue range. Key words: circadian rhythms, melatonin, light pulse, eyelids, blue and green light
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