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"Gordon, Christopher J."
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Efficacy of melatonin with behavioural sleep-wake scheduling for delayed sleep-wake phase disorder: A double-blind, randomised clinical trial
by
Lack, Leon C.
,
Rajaratnam, Shantha M. W.
,
Gordon, Christopher J.
in
Actigraphy
,
Adolescent
,
Adult
2018
Delayed Sleep-Wake Phase Disorder (DSWPD) is characterised by sleep initiation insomnia when attempting sleep at conventional times and difficulty waking at the required time for daytime commitments. Although there are published therapeutic guidelines for the administration of melatonin for DSWPD, to our knowledge, randomised controlled trials are lacking. This trial tested the efficacy of 0.5 mg melatonin, combined with behavioural sleep-wake scheduling, for improving sleep initiation in clinically diagnosed DSWPD patients with a delayed endogenous melatonin rhythm relative to patient-desired (or -required) bedtime (DBT).
This randomised, placebo-controlled, double-blind clinical trial was conducted in an Australian outpatient DSWPD population. Following 1-wk baseline, clinically diagnosed DSWPD patients with delayed melatonin rhythm relative to DBT (salivary dim light melatonin onset [DLMO] after or within 30 min before DBT) were randomised to 4-wk treatment with 0.5 mg fast-release melatonin or placebo 1 h before DBT for at least 5 consecutive nights per week. All patients received behavioural sleep-wake scheduling, consisting of bedtime scheduled at DBT. The primary outcome was actigraphic sleep onset time. Secondary outcomes were sleep efficiency in the first third of time in bed (SE T1) on treatment nights, subjective sleep-related daytime impairment (Patient Reported Outcomes Measurement Information System [PROMIS]), PROMIS sleep disturbance, measures of daytime sleepiness, clinician-rated change in illness severity, and DLMO time.
Between September 13, 2012 and September 1, 2014, 307 participants were registered; 116 were randomised to treatment (intention-to-treat n = 116; n = 62 males; mean age, 29.0 y). Relative to baseline and compared to placebo, sleep onset occurred 34 min earlier (95% confidence interval [CI] -60 to -8) in the melatonin group. SE T1 increased; PROMIS sleep-related impairment, PROMIS sleep disturbance, insomnia severity, and functional disability decreased; and a greater proportion of patients showed more than minimal clinician-rated improvement following melatonin treatment (52.8%) compared to placebo (24.0%) (P < 0.05). The groups did not differ in the number of nights treatment was taken per protocol. Post-treatment DLMO assessed in a subset of patients (n = 43) was not significantly different between groups. Adverse events included light-headedness, daytime sleepiness, and decreased libido, although rates were similar between treatment groups. The clinical benefits or safety of melatonin with long-term treatment were not assessed, and it remains unknown whether the same treatment regime would benefit patients experiencing DSWPD sleep symptomology without a delay in the endogenous melatonin rhythm.
In this study, melatonin treatment 1 h prior to DBT combined with behavioural sleep-wake scheduling was efficacious for improving objective and subjective measures of sleep disturbances and sleep-related impairments in DSWPD patients with delayed circadian phase relative to DBT. Improvements were achieved largely through the sleep-promoting effects of melatonin, combined with behavioural sleep-wake scheduling.
This trial was registered with the Australian New Zealand Clinical Trials Registry, ACTRN12612000425897.
Journal Article
Heat or Insulation: Behavioral Titration of Mouse Preference for Warmth or Access to a Nest
by
Garner, Joseph P.
,
Gaskill, Brianna N.
,
Lucas, Jeffrey R.
in
Adaptation, Physiological - physiology
,
Agriculture
,
Analysis of Variance
2012
In laboratories, mice are housed at 20-24°C, which is below their lower critical temperature (≈30°C). This increased thermal stress has the potential to alter scientific outcomes. Nesting material should allow for improved behavioral thermoregulation and thus alleviate this thermal stress. Nesting behavior should change with temperature and material, and the choice between nesting or thermotaxis (movement in response to temperature) should also depend on the balance of these factors, such that mice titrate nesting material against temperature. Naïve CD-1, BALB/c, and C57BL/6 mice (36 male and 36 female/strain in groups of 3) were housed in a set of 2 connected cages, each maintained at a different temperature using a water bath. One cage in each set was 20°C (Nesting cage; NC) while the other was one of 6 temperatures (Temperature cage; TC: 20, 23, 26, 29, 32, or 35°C). The NC contained one of 6 nesting provisions (0, 2, 4, 6, 8, or 10g), changed daily. Food intake and nest scores were measured in both cages. As the difference in temperature between paired cages increased, feed consumption in NC increased. Nesting provision altered differences in nest scores between the 2 paired temperatures. Nest scores in NC increased with increasing provision. In addition, temperature pairings altered the difference in nest scores with the smallest difference between locations at 26°C and 29°C. Mice transferred material from NC to TC but the likelihood of transfer decreased with increasing provision. Overall, mice of different strains and sexes prefer temperatures between 26-29°C and the shift from thermotaxis to nest building is seen between 6 and 10 g of material. Our results suggest that under normal laboratory temperatures, mice should be provided with no less than 6 grams of nesting material, but up to 10 grams may be needed to alleviate thermal distress under typical temperatures.
Journal Article
Baseline tumor growth and immune control in laboratory mice are significantly influenced by subthermoneutral housing temperature
by
Repasky, Elizabeth A.
,
Lee, Chen-Ting
,
Sexton, Sandra
in
adaptive immunity
,
Ambient temperature
,
Analysis of Variance
2013
We show here that fundamental aspects of antitumor immunity in mice are significantly influenced by ambient housing temperature. Standard housing temperature for laboratory mice in research facilities is mandated to be between 20–26 °C; however, these subthermoneutral temperatures cause mild chronic cold stress, activating thermogenesis to maintain normal body temperature. When stress is alleviated by housing at thermoneutral ambient temperature (30–31 °C), we observe a striking reduction in tumor formation, growth rate and metastasis. This improved control of tumor growth is dependent upon the adaptive immune system. We observe significantly increased numbers of antigen-specific CD8 ⁺ T lymphocytes and CD8 ⁺ T cells with an activated phenotype in the tumor microenvironment at thermoneutrality. At the same time there is a significant reduction in numbers of immunosuppressive MDSCs and regulatory T lymphocytes. Notably, in temperature preference studies, tumor-bearing mice select a higher ambient temperature than non-tumor-bearing mice, suggesting that tumor-bearing mice experience a greater degree of cold-stress. Overall, our data raise the hypothesis that suppression of antitumor immunity is an outcome of cold stress-induced thermogenesis. Therefore, the common approach of studying immunity against tumors in mice housed only at standard room temperature may be limiting our understanding of the full potential of the antitumor immune response.
Journal Article
Simulation-based assessments in health professional education: a systematic review
2016
The use of simulation in health professional education has increased rapidly over the past 2 decades. While simulation has predominantly been used to train health professionals and students for a variety of clinically related situations, there is an increasing trend to use simulation as an assessment tool, especially for the development of technical-based skills required during clinical practice. However, there is a lack of evidence about the effectiveness of using simulation for the assessment of competency. Therefore, the aim of this systematic review was to examine simulation as an assessment tool of technical skills across health professional education.
A systematic review of Cumulative Index to Nursing and Allied Health Literature (CINAHL), Education Resources Information Center (ERIC), Medical Literature Analysis and Retrieval System Online (Medline), and Web of Science databases was used to identify research studies published in English between 2000 and 2015 reporting on measures of validity, reliability, or feasibility of simulation as an assessment tool. The McMasters Critical Review for quantitative studies was used to determine methodological value on all full-text reviewed articles. Simulation techniques using human patient simulators, standardized patients, task trainers, and virtual reality were included.
A total of 1,064 articles were identified using search criteria, and 67 full-text articles were screened for eligibility. Twenty-one articles were included in the final review. The findings indicated that simulation was more robust when used as an assessment in combination with other assessment tools and when more than one simulation scenario was used. Limitations of the research papers included small participant numbers, poor methodological quality, and predominance of studies from medicine, which preclude any definite conclusions.
Simulation has now been embedded across a range of health professional education and it appears that simulation-based assessments can be used effectively. However, the effectiveness as a stand-alone assessment tool requires further research.
Journal Article
Acceptability, tolerability, and potential efficacy of cognitive behavioural therapy for Insomnia Disorder subtypes defined by polysomnography: A retrospective cohort study
by
Bartlett, Delwyn J.
,
Grunstein, Ronald R.
,
Gordon, Christopher J.
in
692/308/409
,
692/308/575
,
Behavior modification
2018
In this retrospective cohort study, we describe acceptability, tolerability and potential efficacy of cognitive behavioural therapy (CBT) in Insomnia Disorder subtypes, derived from polysomnography (PSG): insomnia with normal-sleep duration (I-NSD) and insomnia with short-sleep duration (I-SSD). All research volunteers were offered access to digital CBT, single component sleep restriction therapy and face-to-face group CBT. Follow-up occurred at three months post-treatment using the insomnia severity index (ISI). 96 participants (61 females, mean age of 41 years) were grouped into either normal-sleep (n = 53) or short-sleep (n = 43). CBT was acceptable to 63% of participants (normal-sleep = 31, short-sleep = 29), with 28 completing therapy (tolerability: normal-sleep = 11, short-sleep = 17). For potential efficacy, 39 (normal-sleep = 20, short-sleep = 19) out of 96 participants (41%) completed a follow-up ISI assessment. In this reduced sample, mean (SD) ISI scores decreased across both groups (normal-sleep: 18.0 (4.0) to 10.7 (4.6); short-sleep: 16.5 (5.5) to 11.0 (6.3); both P < 0.01). Those with normal-sleep were more likely to respond (≥6-point ISI reduction) to CBT compared to short-sleep (70%, n = 14/20 vs. 37%, n = 7/19 respectively, P = 0.038). In this cohort, 60 (63%) of participants attempted CBT and of those 28 (47%) completed therapy. Results may be comparable to clinical participants with implications for the successful translation of CBT for insomnia.
Journal Article
Video-based peer assessment of collaborative teamwork in a large-scale interprofessional learning activity
by
Roberts, Chris
,
Haq, Inam
,
Nisbet, Gillian
in
Advancing healthcare systems with interprofessional education and collaboration
,
Allied Health Occupations Education
,
Beliefs, opinions and attitudes
2024
Background
The assessment of team performance within large-scale Interprofessional Learning (IPL) initiatives is an important but underexplored area. It is essential for demonstrating the effectiveness of collaborative learning outcomes in preparing students for professional practice. Using Kane’s validity framework, we investigated whether peer assessment of student-produced videos depicting collaborative teamwork in an IPL activity was sufficiently valid for decision-making about team performance, and where the sources of error might lie to optimise future iterations of the assessment.
Methods
A large cohort of health professional students (
n
= 1218) of 8 differing professions was divided into teams containing 5–6 students. Each team collaborated on producing a short video to evidence their management of one of 12 complex patient cases. Students from two other teams, who had worked on the same case, individually rated each video using a previously developed assessment scale. A generalisability study quantified sources of error that impacted the reliability of peer assessment of collaborative teamwork. A decision study modeled the impact of differing numbers of raters. A modified Angoff determined the pass/fail mark.
Results
Within a large-scale learning activity, peer assessment of collaborative teamwork was reliable (G = 0.71) based on scoring by students from two teams (
n
= 10–12) for each video. The main sources of variation were the stringency and subjectivity of fellow student assessors. Whilst professions marked with differing stringency, and individual student assessors had different views of the quality of a particular video, none of that individual assessor variance was attributable to the assessors’ profession. Teams performed similarly across the 12 cases overall, and no particular professions marked differently on any particular case.
Conclusion
A peer assessment of a student-produced video depicting interprofessional collaborative teamwork around the management of complex patient cases can be valid for decision-making about student team performance. Further refining marking rubrics and student assessor training could potentially modify assessor subjectivity. The impact of professions on assessing individual peers and the case-specificity of team performances in IPL settings need further exploration. This innovative approach to assessment offers a promising avenue for enhancing the measurement of collaborative learning outcomes in large-scale Interprofessional learning initiatives.
Journal Article
Insomnia subtypes characterised by objective sleep duration and NREM spectral power and the effect of acute sleep restriction: an exploratory analysis
by
Bartlett, Delwyn
,
Kim, Jong-Won
,
Gordon, Christopher J.
in
631/443/376
,
692/617/375/1816
,
692/700/139/1449/1450
2021
Insomnia disorder (ID) is a heterogeneous disorder with proposed subtypes based on objective sleep duration. We speculated that insomnia subtyping with additional power spectral analysis and measurement of response to acute sleep restriction may be informative in overall assessment of ID. To explore alternative classifications of ID subtypes, insomnia patients (n = 99) underwent two consecutive overnight sleep studies: (i) habitual sleep opportunity (polysomnography, PSG) and, (ii) two hours less sleep opportunity (electroencephalography, EEG), with the first night compared to healthy controls (n = 25). ID subtypes were derived from data-driven classification of PSG, EEG spectral power and interhemispheric EEG asymmetry index. Three insomnia subtypes with different sleep duration and NREM spectral power were identified. One subtype (n = 26) had shorter sleep duration and lower NREM delta power than healthy controls (short-sleep delta-deficient; SSDD), the second subtype (n = 51) had normal sleep duration but lower NREM delta power than healthy controls (normal-sleep delta-deficient; NSDD) and a third subtype showed (n = 22) no difference in sleep duration or delta power from healthy controls (normal neurophysiological sleep; NNS). Acute sleep restriction improved multiple objective sleep measures across all insomnia subtypes including increased delta power in SSDD and NSDD, and improvements in subjective sleep quality for SSDD (
p
= 0.03), with a trend observed for NSDD (
p
= 0.057). These exploratory results suggest evidence of novel neurophysiological insomnia subtypes that may inform sleep state misperception in ID and with further research, may provide pathways for personalised care.
Journal Article
Altered heart rate variability during sleep in mild cognitive impairment
by
Hoyos, Camilla M
,
Duffy, Shantel L
,
Naismith, Sharon L
in
Aged
,
Autonomic Nervous System
,
Cognitive ability
2021
Abstract
Study Objectives
Cardiovascular autonomic dysfunction, as measured by short-term diurnal heart rate variability (HRV), has been reported in older adults with mild cognitive impairment (MCI). However, it is unclear whether this impairment also exists during sleep in this group. We, therefore, compared overnight HRV during sleep in older adults with MCI and those with subjective cognitive impairment (SCI).
Methods
Older adults (n = 210) underwent overnight polysomnography. Eligible participants were characterized as multi-domain MCI or SCI. The multi-domain MCI group was comprised of amnestic and non-amnestic subtypes. Power spectral analysis of HRV was conducted on the overnight electrocardiogram during non-rapid eye movement (NREM), rapid eye movement (REM), N1, N2, N3 sleep stages, and wake periods. High-frequency HRV (HF-HRV) was employed as the primary measure to estimate parasympathetic function.
Results
The MCI group showed reduced HF-HRV during NREM sleep (p = 0.018), but not during wake or REM sleep (p > 0.05) compared to the SCI group. Participants with aMCI compared to SCI had the most pronounced reduction in HF-HRV across all NREM sleep stages—N1, N2, and N3, but not during wake or REM sleep. The naMCI sub-group did not show any significant differences in HF-HRV during any sleep stage compared to SCI.
Conclusions
Our study showed that amnestic MCI participants had greater reductions in HF-HRV during NREM sleep, relative to those with SCI, suggesting potential vulnerability to sleep-related parasympathetic dysfunction. HF-HRV, especially during NREM sleep, may be an early biomarker for dementia detection.
Journal Article
Cannabinol (CBN; 30 and 300 mg) effects on sleep and next-day function in insomnia disorder (‘CUPID’ study): protocol for a randomised, double-blind, placebo-controlled, cross-over, three-arm, proof-of-concept trial
by
Saini, Bandana
,
Suraev, Anastasia
,
Hoyos, Camilla M
in
Cannabinol
,
Clinical trials
,
Double-blind studies
2023
ObjectiveInsomnia is the most prevalent sleep disorder, with few effective pharmacotherapies. Anecdotal reports and recent preclinical research suggest that cannabinol (CBN), a constituent of Cannabis sativa derived from delta-9-tetrahydrocannabinol, could be an effective treatment. Despite this, the isolated effects of CBN on sleep have yet to be systematically studied in humans.MethodsThe present protocol paper describes a randomised, double-blind, placebo-controlled, single-dose, three-arm, cross-over, proof-of-concept study which investigates the effects of CBN on sleep and next-day function in 20 participants with clinician-diagnosed insomnia disorder and an Insomnia Severity Index Score ≥15. Participants receive a single fixed oral liquid dose of 30 mg CBN, 300 mg CBN and matched placebo, in random order on three treatment nights; each separated by a 2-week wash-out period. Participants undergo overnight sleep assessment using in-laboratory polysomnography and next-day neurobehavioural function tests. The primary outcome is wake after sleep onset minutes. Secondary outcomes include changes to traditional sleep staging, sleep-onset latency and absolute spectral power during non-rapid eye movement (NREM) sleep. Tertiary outcomes include changes to sleep spindles during NREM sleep, arousal indices, absolute spectral power during REM sleep and subjective sleep quality. Safety-related and exploratory outcomes include changes to next-day simulated driving performance, subjective mood and drug effects, postural sway, alertness and reaction time, overnight memory consolidation, pre and post-sleep subjective and objective sleepiness; and plasma, urinary, and salivary cannabinoid concentrations. The study will provide novel preliminary data on CBN efficacy and safety in insomnia disorder, which will inform larger clinical trials.Ethics and disseminationHuman Research Ethics Committee approval has been granted by Bellberry (2021-08-907). Study findings will be disseminated in a peer-reviewed journal and at academic conferences.Trial registration numberNCT05344170.
Journal Article
Physiological Markers of Arousal Change with Psychological Treatment for Insomnia: A Preliminary Investigation
by
Mullins, Anna E.
,
Gordon, Christopher J.
,
Miller, Christopher B.
in
Adult
,
Arousal
,
Biomarkers - blood
2015
The aim of this preliminary study was to evaluate if Sleep Restriction Therapy for insomnia is associated with modifications to physiological arousal, indexed through overnight measures of plasma cortisol concentrations and core body temperature.
In a pre-to-post open label study design, eleven patients with chronic and severe Psychophysiological Insomnia underwent 5 weeks of Sleep Restriction Therapy.
Eight (73%) patients out of 11 consented completed therapy and showed a decrease in insomnia severity pre-to-post treatment (mean (SD): 18.1 (2.8) versus 8.4 (4.8); p = .001). Six patients were analyzed with pre-to-post overnight measures of temperature and cortisol. Contrary to our hypothesis, significantly higher levels of plasma cortisol concentrations were found during the early morning at post-treatment compared to baseline (p < .01), while no change was observed in the pre-sleep phase or early part of the night. Core body temperature during sleep was however reduced significantly (overall mean [95% CI]: 36.54 (°C) [36.3, 36.8] versus 36.45 [36.2, 36.7]; p < .05).
Sleep Restriction Therapy therefore was associated with increased early morning cortisol concentrations and decreased core body temperature, supporting the premise of physiological changes in functioning after effective therapy. Future work should evaluate change in physiological variables associated with clinical treatment response.
Australian New Zealand Clinical Trials Registry ANZCTR 12612000049875.
Journal Article