No description available.

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 5 uppsatser.

The circadian system provides animals with a means to adapt internal physiology to the constantly changing environmental stimuli that exists on a rotating planet. Light information is translated into molecular timing mechanisms within individual pacemaker cells of the mammalian hypothalamic suprachiasmatic nucleus (SCN) via transcriptionaltranslational feedback loops. Humoral and neural outputs from this master clock result in circadian rhythms of physiology and behavior. The hierarchy of the circadian system involves SCN synchronization of cellular clocks within peripheral tissues so that differential transcriptional profiles in individual organs reflect their specific function. The first step to investigating equine circadian regulation was to identify and isolate the core components of the molecular clock in the horse. Successful isolation and sequencing of equine Bmal1, Per2, Cry1 and Clock cDNAs revealed high sequence homology with their human counterparts. Real Time RT-PCR assays were subsequently designed to quantitatively assess clock gene expression in equine peripheral tissues. Synchronization of equine fibroblasts revealed temporal profiles of clock gene expression identical to those of the SCN and peripheral tissues of other species. However, while clock gene expression varies over time in equine adipose tissue, there was no observable oscillation of clock gene transcripts in equine blood. Spurred by recent reports of immune-circadian interactions, this novel finding prompted an investigation of clock gene expression in equine blood during a systemic inflammatory response. The results demonstrated that acute inflammation upregulates Per2 and Bmal1 in equine blood. Subsequent experiments identified neutrophils as the source of this upregulation and highlighted exciting new immunecircadian interplay during an innate immune response. Finally, the effect of a 6-h phase advance of the light/dark cycle, mimicking an easterly transmeridian journey, on circadian melatonin and core body temperature rhythms was investigated. In contrast to the gradual adaptation observed in other species, these markers of equine circadian phase adapt immediately to a time zone transition. Combined, the results of these experiments highlight important interspecies differences in circadian regulation with practical implications regarding the potential impact of jet lag on equine athletes. Furthermore, the results underline the relevance of chronobiological investigation in a large mammalian species such as the horse.

Thesis (M.A.)--York University, 2005. Graduate Programme in Kinesiology and Health Science. / Typescript. Includes bibliographical references (leaves 32-36). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11750

京都大学 / 新制・課程博士 / 博士(薬学) / 甲第23148号 / 薬博第848号 / 新制||薬||242(附属図書館) / 京都大学大学院薬学研究科薬学専攻 / (主査)教授 土居 雅夫, 教授 中山 和久, 教授 竹島 浩 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-10T00:02:16Z No. of bitstreams: 1 FernandaFernandesKolodiuk_DISSERT.pdf: 12001033 bytes, checksum: 477763b89fc24705d27960971b414f59 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-16T20:20:28Z (GMT) No. of bitstreams: 1 FernandaFernandesKolodiuk_DISSERT.pdf: 12001033 bytes, checksum: 477763b89fc24705d27960971b414f59 (MD5) / Made available in DSpace on 2016-03-16T20:20:28Z (GMT). No. of bitstreams: 1 FernandaFernandesKolodiuk_DISSERT.pdf: 12001033 bytes, checksum: 477763b89fc24705d27960971b414f59 (MD5) Previous issue date: 2015-05-19 / Demanda acad?mica, novo contexto social, novas rotinas e diminui??o do controle dos pais s?o fatores que podem influenciar o padr?o de sono de estudantes que ingressam na universidade. Os discentes de Medicina da Universidade Federal do Rio Grande do Norte (UFRN) apresentam elevada carga hor?ria, conte?do denso nas disciplinas, as aulas do 1o semestre come?am ?s 7 horas da manh? e sua popula??o ? formada por adultos jovens, que ainda sofrem com o atraso de fase de sono comum na adolesc?ncia, o que indica que o hor?rio de aula pode ser inadequado nesta faixa et?ria. A redu??o do sono noturno durante os dias de aula e a tentativa de recupera??o do sono perdido nos dias livres ? Jet lag social (JLS), sugere que j? no primeiro semestre os estudantes sofrem com press?o do sono, o que pode refletir negativamente em tarefas cognitivas e no desempenho acad?mico. Portanto, o objetivo deste trabalho ? avaliar a rela??o entre a press?o do sono e o perfil acad?mico de estudantes de Medicina do primeiro semestre da UFRN, caracterizando sociodemograficamente esta popula??o e investigando poss?veis reflexos no ritmo de atividade-repouso e no desempenho acad?mico. Participaram desta pesquisa 88 estudantes, saud?veis de ambos os sexos, que respoderam aos seguintes question?rios: Qualidade de Sono de Pittsburgh (IQSP), Escala de Sonol?ncia de Epworth (ESE), Cronotipo Horne & Ostberg (HO), Cronotipo Munique (MCTQ) e ?A Sa?de e o Sono?, adaptado. Actimetria foi utilizada em 14 dias para elabora??o de actogramas e obten??o de vari?veis n?o param?tricas do ritmo de atividade-repouso. A nota da disciplina M?dulos Biol?gicos I foi utilizada como desempenho acad?mico. O JLS foi utilizado como medida de press?o do sono e o n?vel de signific?ncia estat?stica foi 95%. A popula??o ? homog?nea em rela??o aos aspectos sociodemogr?ficos e a maioria tem estilo de vida saud?vel, pratica atividade f?sica, locomove-se at? a universidade em carro e leva entre 15 e 30 minutos para realizar tal percurso. Em rela??o ao CSV, grande parte apresentou cronotipo intermedi?rio e vespertino, necessita cochilar durante a semana, sofre sonol?ncia diurna e apresenta m? qualidade de sono. 83% da amostra tem ao menos 1h de JLS, o que nos levou ? divis?o em dois grupos: Grupo < 2h JLS (N=44) e Grupo ? 2h JLS (N=44). Os grupos diferiram apenas no cronotipo, demonstrando que indiv?duos mais vespertinos apresentam mais JLS. Entretanto, n?o encontramos diferen?as em rela??o aos aspectos sociodemogr?ficos, ritmo de atividade-repouso ou desempenho acad?mico. A homogeneidade da amostra possivelmente dificultou a compara??o entre os grupos, todavia, ? alarmante que os estudantes j? apresentem, no primeiro semestre: JLG, qualidade de sono ruim e sonol?ncia diurna excessiva, os quais podem acentuar-se no decorrer do curso, com o in?cio de plant?es noturnos e o aumento da carga hor?ria. Abordar a import?ncia de bons h?bitos de sono e a mudan?a no hor?rio de in?cio da aula s?o estrat?gias que visam ? melhoria na sa?de dos estudantes. / Academic demands, new social context, new routines and decrease of the parental control, are factors that may influence the sleep pattern of freshman students at the University. Medical students from the Federal University of Rio Grande do Norte (UFRN) have a full-time course, subjects with high-level content, and, at the first semester, classes begin at 7 a.m. This group composed by young adults who still suffering with delayed sleep phase, common in adolescence, indicating that this class schedule can be inappropriate at this age. The reduction of nocturnal sleep during school days, and the attempt to recover sleep on free days ? social jet lag (JLS), suggests that in the first semester, students suffer from high sleep pressure. High sleep pressure may reflect on cognitive tasks and performance. Therefore, the aim of this study was to investigate the relationship between sleep pressure and the academic profile of medical students from the first semester of UFRN, characterizing this population socio-demographically and investigating possible impacts on therestactivity rhytm and academic performance. A sample of 88 students, healthy men and women awswered the following questionnaires: Pittsburgh Sleep Quality (PSQI), Epworth Sleepiness Scale (ESS), Horne & Ostberg Chronotype (HO), Munich Chronotype (MCTQ) and ?Health and Sleep? adapted. Actigraphy was used during 14 days to make actogramas and obtain non-parametric variables of the rest-activity rhythm and the grades of the morning schedule were used as academic performance. The JLS was used as a measure of sleep pressure. Statistics significance level was 95%. The population was sociodemographic homogeneous. Most students have healthy lifestyle, practice physical activity, use car to go to the university and take between 15 and 30 minutes for this route. Regarding CSV, most were classify as intermediate (38.6%) and evening (32%) chronotypes, needs to nap during the week, suffer daytime sleepiness and have poor sleep quality. 83% of the sample has at least 1h JLS, which led us to divide into two groups: Group <2h JLS (N = 44) and Group ? 2h JLS (N = 44). The groups have differences only in chronotype, showing that most evening individuals have more JLS, however, no differences were found in relation to sociodemographic aspect, rest-activity rhythm or academic performance. The homogeneity of the sample was limited to compare the groups, however, is alarming that students already present in the first half: JLG, poor sleep quality and excessive daytime sleepiness, which can be accentuated through the university years, with the emergence of night shifts and increased academic demand. Interventionsaddressingthe importance of good sleep habits and the change of the class start time are strategies aimed to improve student?s health.

京都大学 / 0048 / 新制・課程博士 / 博士(薬科学) / 甲第18925号 / 薬科博第39号 / 新制||薬||5(附属図書館) / 31876 / 京都大学大学院薬学研究科医薬創成情報科学専攻 / (主査)教授 岡村 均, 教授 中山 和久, 教授 竹島 浩 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

Circadian rhythms in physiology and behavior are synchronized by a central pacemaker, the suprachiasmatic nuclei (SCN) of the hypothalamus. Shift work, jet lag and sleep disorders can disrupt circadian rhythms, negatively impacting health and well-being. The SCN pacemaker resets rapidly in response to changes in the daily light cycle, however, adjustment of peripheral oscillators to changing time zones or work shifts is more gradual, leading to internal desynchrony. In addition, many diseases can impair the SCN’s ability to adjust to changes in the light cycle. My research investigated whether combined pharmacological inhibition of neuropeptide Y and serotonin could enhance resetting and attenuate transient cycles in locomotor activity following a sudden change in light exposure. I found that simultaneously blocking neuropeptide Y and serotonin receptors potentiated phase shifts during the late subjective night and significantly reduced transient cycles of locomotor activity in hamsters. Development of treatments that enhance the circadian system’s response to light may alleviate some of the negative health consequences experienced by travelers, shift workers and individuals with disease-related circadian desynchrony.

No description available.

The circadian rhythm is a rhythm which permeates all aspects of biological life and follows the hours of the sun. The pace of the rhythm is controlled by a collection of neurons in the hypothalamus, called the suprachiasmatic nucleus (SCN), whose signals affect rhythms throughout the body as can be seen in aspects of life from behavior down to oscillations of proteins in the cells. A disruption of this rhythm such as what happens during jet lag, where the rhythm of the SCN is out of synch with the rhythm of the rest of the body, is something that can have adverse effects on mental and physical health. To realign the SCN and the rhythm of the body, different methods and be implemented. This thesis investigated the effectiveness of glucocorticoids on re-aligning the rhythms of the body following a disruption through a meta-analysis and a qualitative review. The meta-analysis and review incorporated experiments from six articles investigating the hours of circadian rhythm shifts in the mouse model, after administering glucocorticoids. What was found was that the individual experiments presented results with high effect sizes; however, the direction of said effects was not uniform as the rhythms shifted in different directions. The lack of uniform direction caused no significant combined effect size to be found by this meta-analysis (MES=0.11 ± 0.06), showing that a statistical analysis based on hours shifted could not find a significant combined effect. The qualitative review, however, indicates that the administration of glucocorticoids shows an effect in re-entraining the rhythm of the peripheral parts of the body to that of the environmental cues and the SCN. Though no significant statistical effect was found in this analysis, the effect of glucocorticoids should not be discounted and could still prove a promising treatment for circadian disruptions, such as jet lag.