|
|
Cerebral organoids as a neurodevelopmental model of schizophrenia
Sovíčková, Lucie ; Weissová, Kamila (advisor) ; Olejníková, Lucie (referee)
The neurodevelopmental model of schizophrenia incorporates genetic and environmental factors, which both play a role in the development of this disorder. For example the risk of developing schizophrenia is increased by prenatal stress in a sex-dependant manner. Fibroblast growth factor receptor 1 plays a role in neurodevelopmental abnormalities and has been found to influence cortical development, development of dopaminergic neurons and genes dysregulated in schizophrenia. Circadian, hypothalamic-pituitary-adrenal axis and sleep abnormalities are also common in schizophrenia patients and they might increase susceptibility to psychosis via dopaminergic system. The schizophrenia susceptibility gene Disc1 has been found to play a role in sleep abnormalities and regulation of radial glia cell cycle. Cerebral organoids, which are generated by using human induced pluripotent stem cells, model human brain development and could be used for further studies of neurodevelopmental model of schizophrenia. Cerebral organoids could be improved in the future by vascularization and bioengineering methods. Key words: cerebral organoids, schizophrenia, circadian rhythms, stress, FGFR1, DISC1, glucocorticoids
|
|
|
Photobiological Safety of luminaires and Light Sources
Štěpánek, Jaroslav ; Bendová,, Zdeňka (referee) ; Vik,, Michal (referee) ; Škoda, Jan (advisor)
This doctoral thesis called “Photobiological safety of luminaires and light sources” has focused on an optical radiation and its relation to human body. The thesis describes possible consequences on living tissue during excessive exposure to optical radiation. Among others the work deals with the light source, lamp and optical devices evaluation in dependence of photobiological safety. There is created a method of light source evaluation procedure for photobiological safety in accordance with ČSN EN 62471. The meaning of this procedure is based on its hazard calculation from measured values of irradiation to different photometric distances. Validity of procedure is verified by light source measuring, in which visual angle and photometric distance have been changed. There we can also find an application of this procedure in the UV source evaluation, which helps to determine a safe distance away from UV sources not to create any danger. The evaluated UV sources include a UVA luminaire with a dominant wavelength of 365 nm or an arc of an electric welder. The thesis also describes a method of evaluating light sources for blue light hazard for an aphakic and pseudophakic eye. This method can also help to determine the hazard for the eye without lens or with some implanted lens. Furthermore, there was developed the method of the blue light hazard assessment depending on the age of an exposed person. In terms of the work there was also created a computer programme evaluating photobiological safety resulting from the spectral data having been stored in the library programme or from spectroradiometric measurement data. The work also marginally deals with the topic of circadian rhythms, which are closely related to photobiological manifestation in an human body. Above all the work compares light sources for which equivalent illuminances are calculated, consequently light sources have the same effect on suppressing the melatonin hormone production.
|
|
|
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.
|
|
|
Design of the morning sun simulator
Suský, Stanislav ; Krbal, Michal (referee) ; Štěpánek, Jaroslav (advisor)
This work deals with the introduction of the influence of electromagnetic radiation on circadian rhythms and their influence on the organism. The work describes circadian rhythms and their influence on the organism, the location and description of functions of important organs and the influence of electromagnetic radiation on these organs. There are described light sources and their influence on circadian rhythms.
|
|
|
Chronotypes and Social Jet Lag Related to Obesity
Halászová, Andrea ; Fárková, Eva (advisor) ; Červená, Kateřina (referee)
In nature we can observe plenty of actions which show some kind of regularity as they repeat with a certain period. The circadian rhythm with its period of approximately one day belongs among these. The circadian rhythm is synchronized mainly by light, but there are also many other internal and especially external synchronizers such as the society we live in. In an organism many processes show circadian rhythmicity, but everyone has the rhythm adjusted individualy, thus called chronotype. It's indeed very important to note that living in harmony with the chronotype is essential. Social jet lag is the term for a long-term disbalance and circadian desynchrony as a consequence of the need to adjust this individual circadian preference to the regime set by the society we live in. Many of recent studies support the findings, that social jet lag might have an impact on health and could participate in development of some of the lifestyle diseases such as obesity. Therefore it should be found beneficial to apply those finding in a clinic practise not only in order to help with an efficient treatment of obesity and its consequences but also in preventing it.
|
|
|
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
|
|
|
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.
|
|
|
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...
|
|
|
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.
|
|
|
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
|
guest ::
