National Repository of Grey Literature 38 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Chronotype, daily regime and its relationship with socio-demographic characteristics and life style
Cápíková, Markéta ; Sumová, Alena (advisor) ; Sedláčková, Markéta (referee)
This diploma thesis focuses of czech population's description from the perspective of chronotype and its relationship to sociodemographic characteristics and to variables affecting lifestyle. The aim of this thesis is to describe the sample examined in terms of social jetlag. The thesis is based mainly on quantitative methods, specifically I was using individual forms of regression analyzes, which allow to capture the influence of independent variables on the dependent variable. The analytical part data from Qualitas 2016 survey within the AV21 Strategy project are processed. The analysis revealed the existence of an association between chronotype and gender, respectively between chronotype and age. It also turned out that extreme owls consume addictive substances to a greater extent than extreme larks. Owls also generally have higher BMI, lower psychological well-being and more often suffer from social jetlag than those with early circadian preference. However, the social jetlag does not only concern respondents with late circadian preference, but the whole sample analyzed. The average length of social jetlag in the sample is 66 minutes. The analysis also revealed the link between social jetlag and addictive substance abuse.
Synchronization of circadian clock in rat during ontogenesis and in adulthood
Olejníková, Lucie ; Sumová, Alena (advisor) ; Šlamberová, Romana (referee) ; Mareš, Jan (referee)
The circadian system temporally controls behavioral and physiological processes in most organisms so that they change during the day and night with a period of about 24 h. It is an evolutionary adaptation to anticipate periodic changes in environment on the Earth. In mammals, the circadian system consists of the central pacemaker in the suprachiasmatic nuclei (SCN) of hypothalamus and of oscillators located in numerous peripheral organs and tissues. At the molecular level, the circadian clock is based on the rhythmic expression of so called clock genes. The ontogenetic development of the circadian system is a gradual process and the most important changes undergo during the late embryonic and early postnatal stage. Many behavioral, hormonal and metabolic signals provided by the mother are considered to be involved in circadian clock synchronization during early ontogenesis. The mechanisms of the entrainment are not fully known yet. The aim of this thesis was to study the development of the circadian clock and its entrainment via maternal signals and to compare the development of circadian rhythms in two model rat strains - Wistar rat and spontaneously hypertensive rat (SHR). Firstly, we described the ontogenetic maturation of the Wistar rat circadian clock in the colon from the fetal stage until...
Impact of circadian system disruption on development of gastrointestinal disorders
Kubištová, Aneta ; Sumová, Alena (advisor) ; Červená, Kateřina (referee)
The ability to sense 24-hour cycles in external environment and to adapt to them is present in a great array of species living on the Earth. Mammals possess internal time-keeping system which is composed of circadian clocks located in the suprachiasmatic nuclei (SCN) of the hypotalamus and peripheral clocks in various tissues and organs of the body. These clocks are adapting to the changes of external environment, such as light and dark cycles or feeding cycles. Peripheral clocks in the organs of the digestive system are synchronized with the signals derived from the central clock in the SCN and also with signals from food intake. Discordance between these signals may result in development of various diseases of the gastrointestinal tract (GIT) related to insufficient digestion or even in higher risk of developing a cancer. This bachelor thesis is generally aimed at circadian rhythms in the body, with the focus on rhythms in the GIT. It will deal with the importance of the circadian rhythms for correct GIT functions. Furthermore, the thesis is focused on connection between the desynchonization of the circadian clock and GIT disease development, namely of obesity and cancer.
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.
Molecular mechanisms of circadian clock entrainment by daily regime in food intake
Kapoun, Jiří ; Sumová, Alena (advisor) ; Červená, Kateřina (referee)
Circadian clocks form an endogenous time-keeping system present in most organisms, synchronizing physiological and behavioural processes with perodically changing environmental conditions. The system comprises of the master clock in the suprachiasmatic nuclei of the hypothalamus and numerous subsidiary clocks in peripheral tissues. Its molecular design is constituted by the clock genes, which are rhythmically expressed, form a series of transcriptional/translational feedback loops and influence the expression of various other genes involved in metabolic pathways. The peripheral clocks are dependent on the master clock, although they can be entrained with external cues like food intake timing and diet composition. This desynchronization leads to the distruption of clock gene oscillation, which can potentially have serious impact on metabolic processes and increase the risk of metabolic disorders. The aim of this thesis is to summarize current knowledge on the relationship of molecular chronobiology and nutrition with a focus on the molecular mechanisms through which can food, especially its intake timing and composition, influence the crosstalk between clock gene expression and cellular metabolism. The thesis also emphasises the potential effect of circadian clock disruption on the risk of metabolic...
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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