肠运动昼夜节律及其外科临床意义

肠运动存在昼夜节律，表现为白天活跃，夜间减弱或消失，这是一种内生性的、由时钟基因控制的生物节律。肠运动节律既可与中央节律保持高度一致，也可独立于中央节律而对外周环境刺激做出反馈。外科手术会破坏肠运动的昼夜节律，而围手术期合理使用褪黑素、五羟色胺（5-HT）受体激动剂和非甾体类解热镇痛药等药物则有助于促进此节律的恢复。外科医生了解肠运动节律的机制，有助于加深术后肠麻痹（POI）的认识，再基于时辰药理学，在合适的时机以适宜的剂量给药，或许能进一步缩短POI时间，促进肠运动功能尽早恢复。     

苦寒药与生物钟基因的关系研究进展＊

苦寒类中药善于清热燥湿以改善机体内环境稳态，目前在临床上被广泛应用于糖尿病、肥胖、炎症、菌群失调等慢性或代谢性疾病，而这些疾病往往都伴随着机体生物钟系统的失衡。改善生物钟失衡可能是苦寒药治疗这些疾病的作用机制之一，同时，在生物钟的调控下，机体新陈代谢及内分泌等行为的节律性波动也可能影响苦寒药的药效。既往对苦寒药在临床应用上的研究大部分集中于胃肠动力及激素等基础研究上，从生物钟基因的角度鲜有见到深入的研究与阐述。因此，本文从临床常用苦寒药对生物钟基因的影响及生物钟基因对苦寒药作用的影响两个方面探讨苦寒药的应用，同时分析二者之间的关系和归纳苦寒药影响生物钟基因共同的物质基础，以期为苦寒药作用多靶点以及指导临床合理用药和中药药性物质基础研究提供参考。     

Sundown Syndrome in Older Persons: A Scoping Review

ObjectivesTo map comprehensive investigations of the sundown syndrome (SS), highlighting its key definition and associated characteristics.DesignScoping review of published articles on SS in PubMed, OVID, EMBASE, Scopus, CINAHL, and Science Direct.SettingPost-acute and long-term health care settings.ParticipantsOlder adults aged ≥60 years.MeasuresArticles must present primary data on specific SS behavior, with explicit psychopathological and quantitative outcomes; and/or evening disruptive behavior.ResultsFrom a total number of 460 articles focusing on psychopathology and standardized outcomes of SS, 23 were retained for the final analysis (n = 1210 subjects). The mean age of participants was 63.2 years, and slightly more participants were women. The samples were recruited by convenience from long-term care facilities and tertiary outpatient clinics. The frequency of SS varied from 2% to 82%, without evident difference between genders and race/ethnicity. Generally, the sundown episode occurred during later daytime, when psychomotor alterations and cognitive disturbance manifested repeatedly. The symptomatic manifestations of SS were heterogeneous across the studies. Demographic risk factors were inconsistent. Although some authors have viewed cognitive impairment as a substantive predisposing factor to SS, others supported SS as a predictor of looming cognitive decline. The disrupted circadian rhythm was the most accepted pathophysiology. To date, clinical trials to guide the management of SS with specific pharmacologic and nonpharmacologic approaches are scant.Conclusions and ImplicationsSS can be viewed as a cyclic delirium-like condition affecting the older population around the sunset hour that may last for a few hours. The scarcity of comprehensive studies makes it difficult to determine whether and to what extent it can represent a distinct disease, a prodromal stage of dementia, or an epiphenomenon of incipient or worsening dementia. Extensive gathering of clinical data from multiple health care settings, using uniform measurement tools, is much needed.     

Biohorology and biomarkers of aging: Current state-of-the-art,challenges and opportunities

The aging process results in multiple traceable footprints, which can be quantified and used to estimate an organism's age. Examples of such aging biomarkers include epigenetic changes, telomere attrition, and alterations in gene expression and metabolite concentrations. More than a dozen aging clocks use molecular features to predict an organism's age, each of them utilizing different data types and training procedures. Here, we offer a detailed comparison of existing mouse and human aging clocks, discuss their technological limitations and the underlying machine learning algorithms. We also discuss promising future directions of research in biohorology — the science of measuring the passage of time in living systems. Overall, we expect deep learning, deep neural networks and generative approaches to be the next power tools in this timely and actively developing field.     

Photoacoustic treatment mitigates cognitive dysfunction in a model of sleep-wake rhythm disturbance

Sleep-wake rhythm disturbances,which are characterized by abnormal sleep timing or duration,are associated with cognitive dysfunction.Photoacoustic treatments including light and sound stimulation have been found to be effective in modulating sleep patterns and improving cognitive behavior in abnormal sleep-wake pattern experiments.In this study,we examined whether light and sound interventions could reduce sleep-wake pattern disturbances and memory deficits in a sleep rhythm disturbance model.We established a model of sleep rhythm disturbance in C57 BL/6 J mice via a sleep deprivation method involving manual cage tapping,cage jostling,and nest disturbance.We used a Mini Mitter radio transmitter device to monitor motor activity in the mice and fear conditioning tests to assess cognitive function.Our results indicated that an intervention in which the mice were exposed to blue light(40-Hz flickering frequency)for 1 hour during their subjective daytime significantly improved the 24-hour-acrophase shift and reduced the degree of memory deficit induced by sleep deprivation.However,interventions in which the mice were exposed to a 40-Hz blue light at offset time or subjective night time points,as well as 2 Hz-blue light at 3 intervention time points(subjective day time,subjective night time,and offset time points),had no positive effects on circadian rhythm shift or memory deficits.Additionally,a 2000-Hz sound intervention during subjective day time attenuated the24-hour-acrophase shift and memory decline,while 440-Hz and 4000-Hz sounds had no effect on circadian rhythms.Overall,these results demonstrate that photoacoustic treatment effectively corrected abnormal sleep-wake patterns and cognitive dysfunction associated with sleep-deprivation-induced disturbances in sleep-wake rhythm.All animal experiments were approved by the Experimental Animal Ethics Committee of Drum Tower Hospital Affiliated to the Medical College of Nanjing University,China(approval No.20171102)on November20,2017.     

Pinealectomy interferes with the circadian clock genes expression in white adipose tissue

Melatonin, the main hormone produced by the pineal gland, is secreted in a circadian manner (24‐hr period), and its oscillation influences several circadian biological rhythms, such as the regulation of clock genes expression (chronobiotic effect) and the modulation of several endocrine functions in peripheral tissues. Assuming that the circadian synchronization of clock genes can play a role in the regulation of energy metabolism and it is influenced by melatonin, our study was designed to assess possible alterations as a consequence of melatonin absence on the circadian expression of clock genes in the epididymal adipose tissue of male Wistar rats and the possible metabolic repercussions to this tissue. Our data show that pinealectomy indeed has impacts on molecular events: it abolishes the daily pattern of the expression of Clock, Per2, and Cry1 clock genes and Pparγ expression, significantly increases the amplitude of daily expression of Rev‐erbα, and affects the pattern of and impairs adipokine production, leading to a decrease in leptin levels. However, regarding some metabolic aspects of adipocyte functions, such as its ability to synthesize triacylglycerols from glucose along 24 hr, was not compromised by pinealectomy, although the daily profile of the lipogenic enzymes expression (ATP‐citrate lyase, malic enzyme, fatty acid synthase, and glucose‐6‐phosphate dehydrogenase) was abolished in pinealectomized animals.