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Plasticity of circadian rhythms of the common bed bug
Čejková, Lada ; Balvín, Ondřej (advisor) ; Doležel, David (referee)
Circadian rhythms can be found in all organisms from prokaryotes through plants to animals. They are very plastic, able to adapt to the climatic conditions of the environment and the current availability of food, such differences in conditions led to origin of intraspecific polymorphisms of circadian rhythms. This bachelor thesis summarizes the known data on the circadian rhythm plasticity, managing mechanisms of circadian rhythms and their interdependence. Circadian rhythms were studied only sporadically in the human ectoparasite a bed bug (Cimex lectularius), rhythm reversal can be achieved just by changing the illumination. With knowledge about plasticity of circadian rhythms it shall be possible to identify the changes in the managing mechanisms of circadian rhythms in the bed bug. Key words: circadian rhythms, bed bug, plasticity of circadian rhythm, polymorphism of circadian rhythms
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Examining selected circadian determinant for disabled
JANKOVSKÁ, Alena
Circadian rhytms are rhytmical changes which can be found in numerous functions of human organism at cellular and organ level. For example sleep and vigil, body temperature, hormone release etc. This thesis deals with circardian determinants of Rehabilitation Institute Kladruby clients who have physical disabilites. Practical part is based on standartized questionnaire Circadian typology CIT Harada & Krejčí (2010) which has been filled by 77 Rehabilitation Institute Kladruby clients. In my thesis, I mostly deal with the following topics: what the conditions of quality of sleep in Rehabilitation Institute Kladruby are and whether physical disabilities influence the quality of sleep. The results proved, that Rehabilitation Institute Kladruby clients have rarely problems with falling asleep. Most of the interviewed participants fall asleep within fifteen minutes since lying down. Problems come duing the night when 26 % of men and 41,3 % of women wake up three or more times.
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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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Pineal lesions: clinical presentation, hormone secretion, sleep quality and effect of surgical treatment
Májovský, Martin ; Netuka, David (advisor) ; Šonka, Karel (referee) ; Lipina, Radim (referee)
Introduction: Pineal region is a deep-seated part of the brain surrounded by highly eloquent structures. Differential diagnosis of space-occupying lesions in this region encompasses pineal gland cysts, pineal gland tumours, metastases, germ cell tumours, meningiomas, gliomas, hemangioblastomas and neuroectodermal tumours. In this thesis, I focused mainly on patients with pineal cysts, which is a benign affection of the human pineal gland on the borderline between pathology and normality. The clinical management of patients with a pineal cyst remains controversial, especially when patients present with non-specific symptoms. A melatonin secretion in patients with a pineal cyst before and after a pineal cyst resection has not been studied yet and the effect of surgery on human metabolism is unknown. Materials and Methods: We performed a prospective study between 2000 and 2016. All patients with a pineal cyst larger than 7 mm were included. Epidemiological data, presenting symptoms, surgical results and radiographic and clinical follow-up were documented. We examined melatonin, cortisol and blood glucose secretion profiles perioperatively in a subgroup of 4 patients. The control group was represented by 3 asymptomatic patients with a pineal cyst. For each patient, 24-h circadian secretion curves of...
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Mechanisms of maternal entrainment of the fetal circadian clock
Černá, Barbora ; Sumová, Alena (advisor) ; Balaštík, Martin (referee)
Our body is influenced by many cyclical changes in the environment, such as day and night or seasons. To predict these changes and react to them in time, the organism is equipped with inner clock, which rhythmically influences many physiological processes, such as sleep or metabolic rhythms. Disrupting our inner rhythms at molecular and behavioral levels contributes to many serious disorders. It is necessary that all mechanisms of the inner circadian clock are developed and set up properly. Circadian clocks are set up by the mother, who passes rhythmical information about day and night cycle on to her embryo. Though a great attention is devoted to revealing the nature of this synchronization between the mother and her pup, the mechanisms of this process have not been fully understood yet. The aim of this thesis is to contribute to actual understanding of this synchronization. Experiments, performed in this thesis, relate to studying the ability of maternal signals to synchronize embryos with the environment. Feeding and light regime of pregnant rats was manipulated and the effect of these changes on the neuronal activity within the suprachiasmatic nuclei of 19-day embryos was analyzed.
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Interaction between circadian clock and macrophages in the adipose tissue
Honzlová, Petra ; Sumová, Alena (advisor) ; Horáková, Olga (referee)
Well functioning circadian system is crucial component of healthy organism and its disruption can result in impairment of metabolic functions with consequential development of obesity and type 2 diabetes mellitus. Obesity is in general caused by enhanced migration of pro- inflammatory polarized macrophages (M1) into adipose tissue. We have shown, that interaction of this type of macrophages with adipose tissue had significant effect on rhythmic expression of clock genes in adipocytes. We further investigated effect of high fat diet and diet enriched by omega-3 fatty acids on circadian oscillations in WAT and differently polarized macrophages. This diet affected oscillations in adipose tissue and in M0 and M2 polarized macrophages. These results support previous findings of effect of omega-3 fatty acids on metabolism and suggest their effect on circadian system as well. Key words: circadian rhythms, adipose tissue, macrophages, omega-3 fatty acids, high fat diet
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Interventions of Nurses in Relation to the Prevention of Sleep Deprivation of Patients Hospitalized at the Intensive
Růžičková, Martina ; Jirkovský, Daniel (advisor) ; Vaňková, Milena (referee)
There are many studies about problematic of sleep connected with shift work. However, only few studies devoted to the conditions for good rest and sleep in patients hospitalized in intensive care units. Insufficient or poor quality sleep and relaxation are the most common problems reported by patients that were hospitalized at intensive care units (ICU). Sleep is one of the basic biological needs of human. Sleep deficit can lead to psychical and psychological dysfunction that can affect the healing process. The diploma thesis is dealing with sleeping issues of patients hospitalized especially at intensive care units. The aim of the study is to determining the opinions of nurses that work at intensive care units on meeting the needs relating with sleep and rest of hospitalized patients and mapping, what interventions they use to prevent of occurrence of difficulties in this area. The theoretical part at first describes physiology of sleep and biological rhythms, then sleep disorders, then factors affecting sleep along with the consequences of the lack of sleep and last nursing process for patients with sleep disorder. The empirical part presents the results of questionnaire survey and then results of executed statistical analysis. Established hypothesis not have been assumed in results of survey...
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Circadian regulation of STAT3 protein in the SCN and it's activation by leptin in the SCN, other parts of hypothalamus and the pineal gland
Moníková, Veronika ; Bendová, Zdeňka (advisor) ; Jelínková, Dana (referee)
JAK/STAT signaling pathway is one of the most studied intracellular cascades transmitting signals from the extracellular environment to the cell nucleus in order to affect expression of target genes. Circadian clocks localized in the suprachiasmatic nuclei (SCN) of the hypothalamus are sensitive especially to light but they can respond to non-photic stimuli such as growth factors, opioids, leptin and cytokines that have been demonstrated to perform its function via the JAK/STAT signaling pathway. The recent findings of our laboratory demonstrated that STAT3 protein is highly produced by SCN of rat. Primary aim of our experiments was to test the circadian regulation of STAT3 production in SCN and describe the effect of exogenously administered leptin on STAT3 phosphorylation in the SCN, pineal gland and hypothalamic structures responsible for regulated feeding behavior and energy metabolism. Because activation of leptin receptors may stimulate a number of other signaling cascades, we chose phosphorylated forms of kinase ERK1/2 and GSK-3β as other markers of intracellular changes after administration of leptin in the studied structures. Our results proved rhythmic production of STAT3 protein in SCN of rat and indicated circadian regulation of sensitivity to leptin in hypothalamic structures. The data...
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The influence of endotoxin lipopolysaccharide on the circadian system
Štěrbová, Petra ; Bendová, Zdeňka (advisor) ; Svobodová, Irena (referee)
The biological clock are responsible for entraining of circadian rhytms in many physiological and behavioral functions, including the activity of immune system. In mammals, the biological clock are located in the suprachiasmatic nuclei of the hypothalamus and also on the periphery. The main oscillator in suprachiamatic nuclei synchronizes the phases of the peripheral oscillators in tissues and the other brain areas and it also drives synthesis of melatonin in the pineal gland. Its endogenous period Tau (τ) is being synchronized with external 24-hour day under normal conditions, mostly by the light-dark cycles during the day and night and also by non-photic stimuli. By the application of endotoxin, disruption of normal endogenous conditions in organism causes activation of the immune response, behavioral changes and phase shifts of the circadian rhythmicity. This work examines effect of acute application endotoxin lipopolysaccharid on the cellular signaling cascades in the cells of suprachiasmatic nuclei and pineal gland. Our data indicate, that levels of phosphorylated forms of kinases GSK3β, ERK1/2 and levels of phosphorylated forms transcription factors STAT3 are substantially modificated after administration of lipopolysaccharid in the suprachiasmatic nuclei and especially in the pineal gland of...
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Clock genes in mammalian circadian pacemaker
Cimerová, Veronika ; Bendová, Zdeňka (advisor) ; Polidarová, Lenka (referee)
The behavior of mammals and their physiological processes are dependent on the daily rhythms. These rhythms are controlled by an endogenous circadian clock that responds to light/dark cycles of environment. In mammals, the circadian clocks, are arranged hierarchically, and work in almost all cells and tissues. Suprachiasmatic nuclei (SCN) in the hypothalamus are at the top of the hierarchy and work as a major circadian pacemaker. This work presents the clock genes that have been discovered in the last twenty years in the SCN of mammals. The first chapter focuses on the general mechanism of circadian rhythms and structure of the SCN. The second chapter describes the transcriptional-translational feedback loops that are an essential part of the proper function of the circadian clock, and function of individual genes is briefly introduced in this chapter. The following chapters already include a chronological characterization of Clock, Bmal1, Period and Cryptochrome genes, as they were discovered. If the clock gene expresses different function from the clockwork mechanism, it is briefly introduced in the final paragraph on the chapter. The final chapters deal with other molecules, casein kinases, ROR and REV-ERB receptors that affect its function expression and degradation of circadian genes in the...
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