Sleep deprivation increases mortality in female mice bearing Ehrlich ascitic tumor

Sleep in the intensive and intermediate care units: Exploring related factors of delirium, benzodiazepine use and mortality

AIM OF THE STUDY

The primary purpose was to examine sleep difficulties and delirium in the Intensive and Intermediate Care Unit. Secondarily, factors impacting night-time sleep duration and quality, mortality, and the impact of benzodiazepine use on sleep outcomes were investigated.

MATERIALS AND METHODS

This retrospective study encompassed data from 323 intensive and intermediate care unit admissions collected in the Netherlands, spanning from November 2018 to May 2020. Sleep quality was measured using the Richards-Campbell Sleep Questionnaire. Night-time sleep duration was nurse-reported. We investigated associations of these sleep outcomes with age, sex, length-of-stay, natural daylight, disease severity, mechanical ventilation, benzodiazepine use, and delirium using Generalized Estimating Equations models. Associations with one-year post-discharge mortality were analyzed using Cox regression.

RESULTS

Night-time sleep duration was short (median 4.5 hours) and sleep quality poor (mean score 4.9/10). Benzodiazepine use was common (24 % of included nights) and was negatively associated with night-time sleep duration and quality (B = -0.558 and -0.533, p <.001). Delirium and overnight transfers were negatively associated with sleep quality (B = -0.716 and -1.831, p <.05). The day-to-night sleep ratio was higher in the three days before delirium onset than in non-delirious individuals (p <.05). Age, disease severity and female sex were associated with increased one-year mortality. Sleep quality was negatively, but not-significantly, associated with mortality (p =.070).

CONCLUSIONS

Night-time sleep in the critical care environment has a short duration and poor quality. Benzodiazepine use was not associated with improved sleep. Sleep patterns change ahead of delirium onset.

IMPLICATIONS FOR CLINICAL PRACTICE

Consistent sleep monitoring should be part of routine nursing practice, using a validated instrument like the Richards-Campbell Sleep Questionnaire. Given the lack of proven efficacy of benzodiazepines in promoting sleep in critical care settings, it is vital to develop more effective sleep treatments that include non-benzodiazepine medication and sleep hygiene strategies.

Euphorbia grantii Oliv. standardized extract and its fraction ameliorate doxorubicin-induced cardiomyopathy in Ehrlich carcinoma bearing mice

ETHNOPHARMACOLOGICAL RELEVANCE

Euphorbia plants have long been used as traditional medicine in China, Europe, America, Turkey, India, Africa, Iran, and Pakistan because of its high medicinal value and health advantages especially as a remedy for several types of cancer.

AIM OF THE STUDY

Doxorubicin (DOX) is one of the most frequently prescribed drugs in cancer chemotherapy, with dose-limiting cardiotoxicity. The development of medicinal approaches to attenuate drug's toxicity represents an area of great concern in cancer research. Because research on this topic is still disputed and limited, we aim to investigate the potential of supplementation with Euphorbia grantii Oliv. on DOX-induced cardiomyopathy in Ehrlich carcinoma bearing mice.

MATERIALS AND METHODS

The high-performance thin layer chromatography (HPTLC) analysis of total methanolic extract (TE), and its bioactive dichloromethane fraction (DCMF) was applied for the determination of friedelin. Male BALB/c mice were used to keep the Ehrlich ascites tumor cells. The experiment was performed for a 2-weeks period.

RESULTS

A good linearity relationship was found to be with correlation coefficient (r2) value of 0.9924 for the isolated friedelin. Limit of detection (LOD) and limit of quantitation (LOQ) was found to be 0.00179, and 0.000537 ng/band respectively for friedelin. The amount of friedelin in the TE and DCMF were determined by using calibration curve of standard as 106.32 ± 5.69 μg, and 159.2 ± 4.24 μg friedelin/mg extract, respectively. DOX-induced cardiomyopathy by decreasing the ejection fraction (EF) compared to the Ehrlich and negative control groups. It resulted in a decrease in the EF by 30 and 39% compared to the other groups. High and low doses of the TE and DCMF did not result in significantly different ejection fractions compared to the Ehrlich group. Co-administration of DCMF with DOX ameliorated the alteration in the serum CKMB and LDH levels. As revealed from histopathological study, DOX impairs viability of cardiac myocytes and DCMF could effectively and extensively counteract this action of DOX and potentially protect the heart from severe toxicity of DOX.

CONCLUSIONS

Finally, our results indicated that Euphorbia grantii Oliv. would be the best option to reduce DOX adverse effects.

Sleep Disruption and Cancer: Chicken or the Egg?

Sleep is a nearly ubiquitous phenomenon across the phylogenetic tree, highlighting its essential role in ensuring fitness across evolutionary time. Consequently, chronic disruption of the duration, timing, or structure of sleep can cause widespread problems in multiple physiological systems, including those that regulate energy balance, immune function, and cognitive capacity, among others. Many, if not all these systems, become altered throughout the course of cancer initiation, growth, metastatic spread, treatment, and recurrence. Recent work has demonstrated how changes in sleep influence the development of chronic diseases, including cancer, in both humans and animal models. A common finding is that for some cancers (e.g., breast), chronic disruption of sleep/wake states prior to disease onset is associated with an increased risk for cancer development. Additionally, sleep disruption after cancer initiation is often associated with worse outcomes. Recently, evidence suggesting that cancer itself can affect neuronal circuits controlling sleep and wakefulness has accumulated. Patients with cancer often report difficulty falling asleep, difficulty staying asleep, and severe fatigue, during and even years after treatment. In addition to the psychological stress associated with cancer, cancer itself may alter sleep homeostasis through changes to host physiology and via currently undefined mechanisms. Moreover, cancer treatments (e.g., chemotherapy, radiation, hormonal, and surgical) may further worsen sleep problems through complex biological processes yet to be fully understood. This results in a “chicken or the egg” phenomenon, where it is unclear whether sleep disruption promotes cancer or cancer reciprocally disrupts sleep. This review will discuss existing evidence for both hypotheses and present a framework through which the interactions between sleep and cancer can be dissociated and causally investigated.

Role of sleep deprivation in immune-related disease risk and outcomes

Modern societies are experiencing an increasing trend of reduced sleep duration, with nocturnal sleeping time below the recommended ranges for health. Epidemiological and laboratory studies have demonstrated detrimental effects of sleep deprivation on health. Sleep exerts an immune-supportive function, promoting host defense against infection and inflammatory insults. Sleep deprivation has been associated with alterations of innate and adaptive immune parameters, leading to a chronic inflammatory state and an increased risk for infectious/inflammatory pathologies, including cardiometabolic, neoplastic, autoimmune and neurodegenerative diseases. Here, we review recent advancements on the immune responses to sleep deprivation as evidenced by experimental and epidemiological studies, the pathophysiology, and the role for the sleep deprivation-induced immune changes in increasing the risk for chronic diseases. Gaps in knowledge and methodological pitfalls still remain. Further understanding of the causal relationship between sleep deprivation and immune deregulation would help to identify individuals at risk for disease and to prevent adverse health outcomes.

Sleep Deprivation Disturbs Immune Surveillance and Promotes the Progression of Hepatocellular Carcinoma

Sleep disturbance is common in patients with cancer and is associated with poor prognosis. However, the effects of sleep deprivation (SD) on immune surveillance during the development of hepatocellular carcinoma (HC) and the underlying mechanisms are not known. This was investigated in the present study using mouse models of SD and tumorigenesis. We determined that acute and chronic sleep deprivation (CSD) altered the relative proportions of various immune cell types in blood and peripheral organs. CSD increased tumor volume and weight, an effect that was enhanced with increasing CSD time. Expression of the cell proliferation marker Ki-67 was elevated in tumor tissues, and tumor cell infiltration into adjacent muscles was enhanced by CSD. Multicolor flow cytometry analysis revealed that CSD significantly reduced the numbers of antitumor CD3+ T cells and natural killer (NK) cells and increased that of immunosuppressive CD11b+ cells infiltrating into the tumor microenvironment from the spleen via the peripheral blood. These results indicate that CSD impairs immune surveillance mechanisms and promotes immunosuppression in the tumor microenvironment to accelerate tumor growth, underscoring the importance of alleviating sleep disturbance in HC patients in order to prevent HC progression.

Genes, Environments, and Phenotypic Plasticity in Immunology

For most of its history, immunology has sought to control environmental variation to establish genetic causality. As with all biological traits though, variation among individuals arises by three broad pathways: genetic (G), environmental (E), and the interactive between the two (GxE); and immunity is no different. Here, we review the value of applying the evolutionary frameworks of phenotypic plasticity and reaction norms to immunology. Because standardized laboratory environments are vastly different from the conditions under which populations evolved, we hypothesize that immunology might presently be missing important phenotypic variation and even focusing on dysregulated molecular and cellular processes. Modest adjustments to study designs could make model organism immunology more productive, reproducible, and reflective of human physiology.

The Sleep-Immune Crosstalk in Health and Disease

Sleep and immunity are bidirectionally linked. Immune system activation alters sleep, and sleep in turn affects the innate and adaptive arm of our body's defense system. Stimulation of the immune system by microbial challenges triggers an inflammatory response, which, depending on its magnitude and time course, can induce an increase in sleep duration and intensity, but also a disruption of sleep. Enhancement of sleep during an infection is assumed to feedback to the immune system to promote host defense. Indeed, sleep affects various immune parameters, is associated with a reduced infection risk, and can improve infection outcome and vaccination responses. The induction of a hormonal constellation that supports immune functions is one likely mechanism underlying the immune-supporting effects of sleep. In the absence of an infectious challenge, sleep appears to promote inflammatory homeostasis through effects on several inflammatory mediators, such as cytokines. This notion is supported by findings that prolonged sleep deficiency (e.g., short sleep duration, sleep disturbance) can lead to chronic, systemic low-grade inflammation and is associated with various diseases that have an inflammatory component, like diabetes, atherosclerosis, and neurodegeneration. Here, we review available data on this regulatory sleep-immune crosstalk, point out methodological challenges, and suggest questions open for future research.

Sleep influences the immune response and the rejection process alters sleep pattern: Evidence from a skin allograft model in mice

INTRODUCTION

Sleep generally regulates immune functions in a supportive manner and can affect parameters that are directly involved in the rejection process.

STUDY OBJECTIVES

The first objective was to assess whether sleep deprivation (SD) or sleep restriction (SR) affects the allograft rejection process in mice. The second objective was to investigate whether the rejection process itself modulates the sleep pattern of allografted mice.

DESIGN

Adult BALB/c and C57BL/6J male mice were used as the donors and recipients, respectively, except for the syngeneic group (ISOTX), which received skin from mice of the same strain (C57BL/6J). The recipients were randomly assigned to either one of two control groups - TX (allogenic) or ISOTX (syngeneic) - which underwent stereotaxic surgery to enable sleep recording prior to the allograft but were not sleep deprived; one of two paradoxical sleep deprived groups - SDTX and TXSD - which underwent 72h of continuous SD either before or after the allograft respectively, and one of two sleep restricted groups - SRTX and TXSR - which underwent 21h of SD and 3h of sleep for 15days either before or after the allograft respectively.

INTERVENTIONS

The skin allograft was inspected daily to determine the survival time, expected as 8.0±0.4days in this transplant model under no treatment. The sleep pattern was controlled throughout the rejection process in the SD and SR groups. Draining lymph nodes, spleen, blood and skin grafts were harvested on the 5th day after transplantation for evaluation of the immune parameters related to allograft rejection.

MEASUREMENTS AND RESULTS

In the control groups, we observed a reduction in paradoxical sleep throughout the entire allograft rejection process. Acute and chronic experimental sleep loss in the SD and SR groups produced marked alterations in the immune response. Both SD and SR prolonged allograft survival compared to the non-sleep-deprived group. There were reductions in the following parameters involved in the allograft rejection under sleep loss: CD4⁺ and CD8⁺ T cell subpopulations in the peripheral lymph organs and spleen, circulating sIL-2R levels, graft-infiltrating CD4⁺ T cells and skin allograft global gene expression.

CONCLUSIONS

We provide, as far as we are aware, the first evidence in vivo that the immune response can alter the normal sleep pattern, and that sleep loss can conversely affect the immune response related to graft rejection.

Pre-diagnostic Sleep Duration and Sleep Quality in Relation to Subsequent Cancer Survival

STUDY OBJECTIVES

Poor sleep quality and short sleep duration have been associated with elevated risk for several cancer types; however, the relationship between sleep and cancer outcomes has not been well characterized. We assessed the association between pre-diagnostic sleep attributes and subsequent cancer survival within the Women's Health Initiative (WHI).

METHODS

We identified WHI participants in whom a first primary invasive cancer had been diagnosed during follow-up (n = 21,230). Participants provided information on sleep characteristics at enrollment. Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between these pre-diagnostic sleep characteristics and cancer-specific survival for all cancers combined and separately for common cancers. Analyses were adjusted for age, study arm, cancer site, marital status, income, smoking, physical activity, and time to diagnosis.

RESULTS

No individual pre-diagnostic sleep characteristics were found to be significantly associated with cancer survival in analyses of all cancer sites combined; however, women who reported short sleep duration (≤ 6 h sleep/night) combined with frequent snoring (≥ 5 nights/w experienced significantly poorer cancer-specific survival than those who reported 7-8 h of sleep/night and no snoring (HR = 1.32, 95% CI: 1.14-1.54). Short sleep duration (HR = 1.46, 95% CI: 1.07-1.99) and frequent snoring (HR = 1.34, 95% CI: 0.98-1.85) were each associated with poorer breast cancer survival; those reporting short sleep combined with frequent snoring combined had substantially poorer breast cancer survival than those reporting neither (HR = 2.14, 95% CI: 1.47-3.13).

CONCLUSIONS

Short sleep duration combined with frequent snoring reported prior to cancer diagnosis may influence subsequent cancer survival, particularly breast cancer survival.

Sleep-deprivation reduces NK cell number and function mediated by β-adrenergic signalling

Reduction of sleep time triggers a stress response, leading to augmented levels of glucocorticoids and adrenaline. These hormones regulate components of the innate immune system such as natural killer (NK) and NKT cells. In the present study, we sought to investigate whether and how stress hormones could alter the population and function of NK and NKT cells of mice submitted to different lengths of paradoxical sleep deprivation (PSD, from 24 to 72 h). Results showed that 72h of PSD decreased not only NK and NKT cell counts, but also their cytotoxic activity against B16F10 melanoma cells in vitro. Propranolol treatment during PSD reversed these effects, indicating a major inhibitory role of beta-adrenergic receptors (β-AR) on NK cells function. Moreover, both corticosterone plasma levels and expression of beta 2-adrenergic receptors (β2-AR) in NK cells increased by 48 h of PSD. In vitro incubation of NK cells with dexamethasone augmented the level of β2-AR in the cell surface, suggesting that glucocorticoids could induce β2-AR expression. In summary, we propose that reduction of NK and NKT cell number and cytotoxic activity appears to be mediated by glucocorticoids-induced increased expression of β2-AR in these cells.

Paradoxical sleep deprivation impairs mouse survival after infection with malaria parasites

Background

Parasitic diseases like malaria are a major public health problem in many countries and disrupted sleep patterns are an increasingly common part of modern life. The aim of this study was to assess the effects of paradoxical sleep deprivation (PSD) and sleep rebound (RB) on malarial parasite infection in mice.

Methods

After PSD, one group was immediately infected with parasites (PSD). The two other PSD rebound groups were allowed to sleep normally for either 24 h (24 h RB) or 48 h (48 h RB). After the recovery periods, mice were inoculated with parasites.

Results

The PSD group was the most affected by parasites presenting the higher death rate (0.02), higher number of infected cells (p < 0.01), and decrease in body weight (p < 0.04) compared to control and 48 h RB groups. The 24 h RB group was also different from control group in survival (p < 0.03), number of infected cells (p < 0.05) and body weight (p < 0.04). After 48 hours of sleep rebound animals were allowed to restore their response to parasitic infection similar to normal sleep animals.

Conclusions

These results suggest that PSD is damaging to the immune system and leads to an increased infection severity of malaria parasites; only 48 hours of recovery sleep was sufficient to return the mice infection response to baseline values.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-015-0690-7) contains supplementary material, which is available to authorized users.

Relationship Between Sleep Apnea and Cancer

In the light of relationships reported between hypoxemia (tissue hypoxia) and cancer, Abrams et al. concluded in 2008 that sleep apnea-hypopnea syndrome (SAHS) and its main consequence, intermittent hypoxia, could be related with increased susceptibility to cancer or poorer prognosis of a pre-existing tumor. This pathophysiological association was confirmed in animal studies. Two large independent historical cohort studies subsequently found that the degree of nocturnal hypoxia in patients with SAHS was associated with higher cancer incidence and mortality. This finding has been confirmed in almost all subsequent studies, although the retrospective nature of some requires that they be considered as hypothesis-generating only. The relationship between sleep apnea and cancer, and the pathophysiological mechanisms governing it, could be clarified in the near future in a currently on-going study in a large group of melanoma patients.

Sleeping on a problem: the impact of sleep disturbance on intensive care patients - a clinical review

Sleep disturbance is commonly encountered amongst intensive care patients and has significant psychophysiological effects, which protract recovery and increases mortality. Bio-physiological monitoring of intensive care patients reveal alterations in sleep architecture, with reduced sleep quality and continuity. The etiological causes of sleep disturbance are considered to be multifactorial, although environmental stressors namely, noise, light and clinical care interactions have been frequently cited in both subjective and objective studies. As a result, interventions are targeted towards modifiable factors to ameliorate their impact. This paper reviews normal sleep physiology and the impact that sleep disturbance has on patient psychophysiological recovery, and the contribution that the clinical environment has on intensive care patients' sleep.