No abstract available.
Biological Clocks* ; Periodicity*

A cyclic squint is a rare, interested in ocular motility disturbance. It appears regular and alternate-day rhythmic cycle, most frequently at 48 hours The cyclic squint was reviewed approximately 50 Cases in literatures since it was first reported by Burian in 1958. These all was presented with cyclic ESOTROPIA but authors have not found a description of cyclic EXOTROPIA as described here. The biological clock mechanism which induces a cyclic squint is unknown. This case had recession of the bi-lateral recti and obtained constant orthophoria.
Biological Clocks ; Esotropia ; Exotropia* ; Strabismus

Circadian clocks are the endogenous oscillators that harmonize a variety of physiological processes within the body. Although many urinary functions exhibit clear daily or circadian variation in diurnal humans and nocturnal rodents, the precise mechanisms of these variations are as yet unclear. In this review, we briefly introduce circadian clocks and their organization in mammals. We then summarize known daily or circadian variations in urinary function. Importantly, recent findings by others as well as results obtained by us suggest an active role of circadian clock genes in various urinary functions. Finally, we discuss possible research avenues for the circadian control of urinary function.
Biological Clocks ; Circadian Clocks ; Circadian Rhythm ; Humans ; Mammals ; Physiological Processes ; Rodentia ; Urinary Bladder ; Urination

Cyclic esotropia is a rare condition, first mentioned by Burian in 1958, in which orthophoria is regularly followed by constant deviation on rhythmic pattern. The periodicity would suggest a biologial clock mechanism. Consecutive cyclic esotropia following strabismus surgery is extremely rare. Only three cases of consecutive cyclic esotropia following surgery for intermittent exotropia have been reported We report one case of consecutive cyclic esotropia in an 8-year-old girl who underwent surgery for intermittent exotropia. The periodic esodeviation was treated with bimedial rectus recession. We suggest the overcorrection after surgery for intermittent exotropia would cause the periodicity by biological clock mechanism when the biorhythm of the patient is in an unstable and dangerous state.
Biological Clocks ; Child ; Esotropia* ; Exotropia* ; Female ; Humans ; Periodicity ; Strabismus

Mammals synchronize their circadian activity primarily to the cycles of light and darkness in the environment. Circadian rhythm is controlled by the central clock in the hypothalamic suprachiasmatic nucleus (SCN) and the peripheral clocks in various tissues. More importantly, the central clock can integrate photic/nonphotic signals to generate rhythmic outputs, and then drive the slave oscillators in peripheral tissues through neuroendocrine and behavioral signals. Human reproductive activities, as some other physiological functions, are controlled by the biological clocks. Accumulating lines of epidemiological and genetic evidence indicate that disruption of circadian clock can be directly involved in multiple pathological processes, including infertility. In this review, we mainly discuss the presence of a circadian clock in reproductive tissues and its roles in follicles development, ovulation, spermatogenesis, fertilization and embryo implantation, etc. As the increased shift work and assisted reproductive technologies possibly disrupt circadian rhythmicity to impact reproduction, the importance of circadian rhythms should be highlighted in the regulation of reproductive process.
Animals ; Biological Clocks ; Circadian Rhythm ; Hypothalamus ; Light ; Reproduction ; Suprachiasmatic Nucleus

BACKGROUND: Shift work disturbs workers' biological clocks and this condition can cause various health problems including cardiovascular disease. The elevated albuminuria level has been significantly associated with the risk of the cardiovascular disease even within a normal reference range. Therefore, this study aimed to investigate the association between shift work and microalbuminuria. METHODS: Workers aged over 20 years from the fifth and sixth Korea National Health and Nutrition Examination Survey(KNHANES 2012–2014; n = 3000) were included in this analysis. The multiple logistic regression analysis was performed to determine the association between shift work and microalbuminuria stratified by gender. RESULTS: The prevalence of microalbuminuria in male subjects was higher among day workers, but the difference was not significant. However, the prevalence of microalbuminuria among females was higher in shift workers with statistical significance. For female, the Odds ratio of microalbuminuria in shift workers was significantly higher with 1.86 (95% CI 1.02–3.39) compared with day workers. After dividing into 5 subgroups of the shift work pattern, the odds ratio of microalbuminuria for fixed night shift was significantly higher at 4.68 (95% CI 1.29–17.00) compared with day workers. CONCLUSIONS: This study showed that shift work was associated with microalbuminuria in female workers. Especially we found out the association between fixed night shift and microalbuminuria in female workers.
Albuminuria ; Biological Clocks ; Cardiovascular Diseases ; Female ; Humans ; Korea ; Logistic Models ; Male ; Odds Ratio ; Prevalence ; Reference Values

The cause of cyclic strabismus is not clear but is assumed to be an abnormality of the biological clock mechanism. Secondary factors, combined with surgery or trauma as well as unknown causes stimulate its occurrence and may be followed by the periodicity of strabismus. We report postoperative follow-up results of 4 cases of cyclic esotropia following surgery. Two cases (case 1 and 2), who developed cyclic esotropia after surgery for intermittent exotropia, show good postoperative alignment without periodicity. But in case 3, originally treated for intermittent exotropia after receiving treatment for consecutive esotropia, the patient reverted to original condition. In case 4, originally treated for congenital glaucoma and receiving secondary treatment for cyclic esotropia, the cyclic esotropia was recurred. After surgery for consecutive cyclic strabismus, it is necessary to follow up for a long time.
Biological Clocks ; Esotropia* ; Exotropia ; Follow-Up Studies ; Glaucoma ; Humans ; Periodicity ; Strabismus

BACKGROUND: Short-term measurement of heart rate variability is known to be a non-invasive technique to examine autonomic nerve system. Heart rate variability exhibits circadian rhythm according to work/sleep cycle and biological clock. In primary practice, short-term measurement of heart rate variability is usually used during the day. Therefore the aims of this study were to investigate the possibility of differences in heart rate variability between morning and afternoon and also to examine the relationship among associated factors. METHODS: Sixty-eight healthy volunteers underwent short- term measurement of heart rate variability on two occasions: in the morning (08:30~11:00) and in the afternoon (13:30~16:00). A structured questionnaire was used to access general characteristics, emotion, fatigue and sleeping hours. RESULTS: The mean heart rate was significantly increased and SDNN, RMSSD, TP, HF and VLF were significantly decreased in the afternoon compared to the morning. LF and LF/HF were not changed. The anxiety group, the depression group and the fatigue group showed significantly greater reduction in TP and RMDDS than the control group. CONCLUSION: In the afternoon, parasympathetic activity and total power were decreased significantly compared to the morning. Short-term heart rate variability should be measured in the same time zone and need to consider food intake effect. Those who complained of anxiety, depression or fatigue were related to much decrease in TP and RMSSD in the afternoon.
Anxiety ; Autonomic Pathways ; Biological Clocks ; Circadian Rhythm ; Depression ; Eating ; Fatigue ; Heart ; Heart Rate ; Surveys and Questionnaires

The animal time structure is a basic fact of life, no matter if one wants to study it or not. The time- dependent, mostly rhythmic, and thus to a certain degree predictable, variations of biochemical and physiological functions and of sensitivity and resistance to many environmental agents are often quite large and offer not only new insight into animal physiology and pathology but also diagnostic possibilities and therapeutic advantages. Chronobiology, chronophysiology and its subspecialities, like chronopharmacology and chronotherapy, will certainly play an important role in the clinical medicine of the future. Successful application of chronobiology to veterinary clinical medicine, however, depends critically on a thorough knowledge of its basic principles.
Animals ; Animals, Domestic/*physiology ; Behavior, Animal/*physiology ; Biological Clocks/*physiology ; Circadian Rhythm/*physiology ; Humans ; Photoperiod ; Seasons

Developments of chronobiology abroad are forging ahead in elucidating the cellular and molecular basis and the influential factors of circadian clock such as light, jet lag, pharmaceutical. This article also reviews the influence of circadian system on human physiology and disease occurrence. The circadian-based therapy holds promising future and the research emphasis is on prognosis and prevention.
Biological Clocks ; Chronobiology Phenomena ; Circadian Rhythm ; physiology ; Drug Chronotherapy ; Jet Lag Syndrome