Considerable evidence suggests that the time of day at which calories are consumed markedly impacts body weight gain and adiposity. However, a precise quantification of energy balance parameters ...during controlled animal studies enforcing time-of-day-restricted feeding is currently lacking in the absence of direct human interaction.
The purpose of the present study was therefore to quantify the effects of restricted feeding during the light (sleep)-phase in a fully-automated, computer-controlled comprehensive laboratory animal monitoring system (CLAMS) designed to modulate food access in a time-of-day-dependent manner. Energy balance, gene expression (within metabolically relevant tissues), humoral factors and body weight were assessed.
We report that relative to mice fed only during the dark (active)-phase, light (sleep)-phase fed mice: (1) consume a large meal upon initiation of food availability; (2) consume greater total calories per day; (3) exhibit a higher respiratory exchange ratio (indicative of decreased reliance on lipid/fatty acid oxidation); (4) exhibit tissue-specific alterations in the phases and amplitudes of circadian clock and metabolic genes in metabolically active tissues (greatest phase differences observed in the liver and diminution of amplitudes in epididymal fat, gastrocnemius muscle and heart); (5) exhibit diminished amplitude in humoral factor diurnal variations (for example, corticosterone); and (6) exhibit greater weight gain within 9 days of restricted feeding.
Collectively, these data suggest that weight gain following light (sleep)-phase restricted feeding is associated with significant alterations in energy balance, as well as dyssynchrony between metabolically active organs.
Highlights ► Mice with constitutively active GSK3α/β (KI) exhibit disrupted circadian behavior. ► GSK3α/β KI mice show dampened and fragmented wheel-running activity rhythms. ► Chronic activation of ...GSK3α or β alone did not produce the same altered phenotype. ► SCN neurons from GSK3α/β KI have elevated neuronal activity during the night. ► Chronic GSK3α/β activity results in the loss of typical SCN firing rate rhythms.
Currently, prognostic and therapeutic determinations for canine cutaneous mast cell tumors (MCTs) are primarily based on histologic grade. However, the use of different grading systems by veterinary ...pathologists and institutional modifications make the prognostic value of histologic grading highly questionable. To evaluate the consistency of microscopic grading among veterinary pathologists and the prognostic significance of the Patnaik grading system, 95 cutaneous MCTs from 95 dogs were graded in a blinded study by 28 veterinary pathologists from 16 institutions. Concordance among veterinary pathologists was 75% for the diagnosis of grade 3 MCTs and less than 64% for the diagnosis of grade 1 and 2 MCTs. To improve concordance among pathologists and to provide better prognostic significance, a 2-tier histologic grading system was devised. The diagnosis of high-grade MCTs is based on the presence of any one of the following criteria: at least 7 mitotic figures in 10 high-power fields (hpf); at least 3 multinucleated (3 or more nuclei) cells in 10 hpf; at least 3 bizarre nuclei in 10 hpf; karyomegaly (ie, nuclear diameters of at least 10% of neoplastic cells vary by at least two-fold). Fields with the highest mitotic activity or with the highest degree of anisokaryosis were selected to assess the different parameters. According to the novel grading system, high-grade MCTs were significantly associated with shorter time to metastasis or new tumor development, and with shorter survival time. The median survival time was less than 4 months for high-grade MCTs but more than 2 years for low-grade MCTs.
Aim
To examine the patient characteristics associated with early initiation of insulin after a diagnosis of Type 2 diabetes.
Methods
We analysed cross‐sectional data from the 2012 Canadian Community ...Health Survey conducted by Statistics Canada. Multivariable logistic regression was used to explore the association between patient sociodemographic and health status characteristics and initiating insulin within 1 year of a diagnosis of Type 2 diabetes (early insulin use).
Results
Weighted estimates for the Canadian population showed that 32% of patients with Type 2 diabetes initiated insulin within 1 year of their diagnosis. Of the insulin initiators, 52% were female and 68% were aged ≥60 years. Factors strongly associated with early initiation of insulin were age (60–69 years: adjusted odds ratio 1.89, 95% CI 1.84–1.94; ≥ 70 years, odds ratio 2.08, 95% CI 2.01–2.15, both vs 40–49 years); smoking (smoker vs never: odds ratio 2.39, 95% CI 2.32–2.46); geography (Western Canada: odds ratio 2.75, 95% CI 2.69–2.81; Quebec: odds ratio 2.20, 95% CI 2.13–2.27, both vs Ontario); mental health (poor vs excellent: odds ratio 1.98, 95% CI 1.92–2.04); BMI (overweight vs normal/underweight: odds ratio 1.63, 95% CI 1.58–1.67); oral antidiabetic medication use (yes vs no: odds ratio 0.66, 95% CI 0.65–0.68); and alcohol use (regular vs non‐drinker: odds ratio 0.66, 95% CI 0.65–0.68).
Conclusion
One‐third of the study population with Type 2 diabetes initiated insulin within their first year of diagnosis. Age, smoking status, geographical location, mental health, BMI, education, oral antidiabetic medication use, employment, physical activity, language, doctor visits and alcohol consumption were associated with timing of insulin initiation.
What's new?
In a cross‐sectional study using a 2012 Canadian health survey, we evaluated the association between several patient characteristics and early use of insulin in patients with Type 2 diabetes.
We found that approximately one‐third of Canadians with Type 2 diabetes who reported using insulin, initiated insulin within their first year of diagnosis.
Older age, smoking, geographical location, poor mental health and being overweight were strongly associated with early initiation of insulin, whereas current use of oral antidiabetic medication and regular alcohol consumption were associated with later use of insulin.
Huntington Disease (HD) is a devastating neurological disorder characterized by progressive deterioration of psychiatric, motor, and cognitive function. Purkinje cells (PCs), the output neurons of ...the cerebellar cortex, have been found to be vulnerable in multiple CAG repeat disorders, but little is known about the involvement of PC dysfunction in HD. To investigate possible PC abnormalities, we performed quantitative real time PCR, Western blot analysis, and immunohistochemistry experiments to explore the changes in PC markers in the R6/2 mouse model of severe HD. There were reductions in the transcript and protein levels of the calcium-binding proteins parvalbumin and calbindin, as well as the enzyme glutamic acid decarboxylase 67. Immunohistochemistry supported these results, with the most substantial changes occurring in the PC layer. To determine whether the reductions in PC marker expression were due to cell loss, we performed stereology on both presymptomatic and end-stage R6/2 mice. Stereological counts indicated a significant reduction in PC number by end-stage but no change in presymptomatic animals (4weeks of age). To assess cellular function prior to cell loss and symptom onset, we measured spontaneous firing in PCs from 4-week old animals and found a striking deficit in PC firing as indicated by a 57% decrease in spike rate. Interestingly, huntingtin inclusions were not widely observed in PCs until 12weeks of age, indicating that soluble huntingtin and/or abnormalities in other cell types may contribute to PC dysfunction. Considering the roles for PCs in motor control, these data suggest that early PC dysfunction potentially contributes to motor impairment in this model of HD.
► It is not known how Purkinje cells (PCs) are affected in Huntington Disease (HD). ► PCs are lost in R6/2 mice as evidenced by lost transcripts, protein, and cell number. ► Electrophysiological abnormalities are present in PCs before overt motor symptoms. ► Firing abnormalities are present before the appearance of htt inclusions within PCs. ► This early PC dysfunction potentially contributes to motor impairment in HD.
ULTRASPEC is a high-speed imaging photometer mounted permanently at one of the Nasmyth focii of the 2.4-m Thai National Telescope (TNT) on Doi Inthanon, Thailand's highest mountain. ULTRASPEC employs ...a 1024 × 1024 pixel frame-transfer, electron-multiplying CCD (EMCCD) in conjunction with re-imaging optics to image a field of 7.7 × 7.7 arcmin2 at (windowed) frame rates of up to ∼200 Hz. The EMCCD has two outputs – a normal output that provides a readout noise of 2.3 e− and an avalanche output that can provide essentially zero readout noise. A six-position filter wheel enables narrow-band and broad-band imaging over the wavelength range 330–1000 nm. The instrument saw first light on the TNT in 2013 November and will be used to study rapid variability in the Universe. In this paper we describe the scientific motivation behind ULTRASPEC, present an outline of its design and report on its measured performance on the TNT.
Serotonin i.e., 5-hydroxytryptamine (5-HT)-targeted antidepressants are in wide use for the treatment of mood disorders, although many patients do not show a response or experience unpleasant side ...effects. Psychostimulants, such as cocaine and 3,4-methylenedioxymethamphetamine (i.e., "ecstasy"), also impact 5-HT signaling. To help dissect the contribution of 5-HT signaling to the actions of these and other agents, we developed transgenic mice in which high-affinity recognition of multiple antidepressants and cocaine is eliminated. Our animals possess a modified copy of the 5-HT transporter (i.e., SERT, slc6a4) that bears a single amino acid substitution, I172M, proximal to the 5-HT binding site. Although the M172 substitution does not impact the recognition of 5-HT, this mutation disrupts high-affinity binding of many competitive antagonists in transfected cells. Here, we demonstrate that, in M172 knock-in mice, basal SERT protein levels, 5-HT transport rates, and 5-HT levels are normal. However, SERT M172 mice display a substantial loss of sensitivity to the selective 5-HT reuptake inhibitors fluoxetine and citalopram, as well as to cocaine. Through a series of biochemical, electrophysiological, and behavioral assays, we demonstrate the unique properties of this model and establish directly that SERT is the sole protein responsible for selective 5-HT reuptake inhibitor-mediated alterations in 5-HT clearance, in 5-HT1A autoreceptor modulation of raphe neuron firing, and in behaviors used to predict the utility of antidepressants.
Key points
Many time‐of‐day cues are mediated by G protein‐coupled signals within the clock centre (the suprachiasmatic nucleus, SCN) of the mammalian brain.
The role of G protein‐coupled inwardly ...rectifying potassium (GIRK) channels in SCN function and entrainment has yet to be determined.
GIRK channels are necessary for proper day‐time SCN neuronal resting membrane potential, neuropeptide Y signalling, and re‐entrainment to phase advances of the light–dark (LD) cycle.
GIRK channel activation is sufficient to mimic non‐photic phase shifts of the molecular clock.
GIRK channels act as an essential part of the non‐photic entrainment system, and could play a critical role in diseases such as epilepsy or addiction that have strong circadian comorbidities.
G protein signalling within the central circadian oscillator, the suprachiasmatic nucleus (SCN), is essential for conveying time‐of‐day information. We sought to determine whether G protein‐coupled inwardly rectifying potassium channels (GIRKs) modulate SCN physiology and circadian behaviour. We show that GIRK current and GIRK2 protein expression are greater during the day. Pharmacological inhibition of GIRKs and genetic loss of GIRK2 depolarized the day‐time resting membrane potential of SCN neurons compared to controls. Behaviourally, GIRK2 knockout (KO) mice failed to shorten free running period in response to wheel access in constant darkness and entrained more rapidly to a 6 h advance of a 12 h:12 h light–dark (LD) cycle than wild‐type (WT) littermate controls. We next examined whether these effects were due to disrupted signalling of neuropeptide Y (NPY), which is known to mediate non‐photic phase shifts, attenuate photic phase shifts and activate GIRKs. Indeed, GIRK2 KO SCN slices had significantly fewer silent cells in response to NPY, likely contributing to the absence of NPY‐induced phase advances of PER2::LUC rhythms in organotypic SCN cultures from GIRK2 KO mice. Finally, GIRK channel activation is sufficient to cause a non‐photic‐like phase advance of PER2::LUC rhythms on a Per2Luc+/− background. These results suggest that rhythmic regulation of GIRK2 protein and channel function in the SCN contributes to day‐time resting membrane potential, providing a mechanism for the fine tuning responses to non‐photic and photic stimuli. Further investigation could provide insight into disorders with circadian disruption comorbidities such as epilepsy and addiction, in which GIRK channels have been implicated.
Solving complex problems such as preventing chronic diseases introduces unique challenges for the creation and application of knowledge, or knowledge to action (KTA). KTA approaches that apply ...principles of systems thinking are thought to hold promise, but practical strategies for their application are not well understood. In this paper we report the results of a scan of systems approaches to KTA with a goal to identify how to optimize their implementation and impact.
A 5-person advisory group purposefully selected 9 initiatives to achieve diversity on issues addressed and organizational forms. Information on each case was gathered from documents and through telephone interviews with primary contacts within each organization. Following verification of case descriptions, an inductive analysis was conducted within and across cases.
The cases revealed 5 guidelines for moving from conceiving KTA systems to implementing them: (1) establish and nurture relationships, (2) co-produce and curate knowledge, (3) create feedback loops, (4) frame as systems interventions rather than projects, and (5) consider variations across time and place.
Results from the environmental scan are a modest start to translating systems concepts for KTA into practice. Use of the strategies revealed in the scan may improve KTA for solving complex public health problems. The strategies themselves will benefit from the development of a science that aims to understand adaptation and ongoing learning from policy and practice interventions, strengthens enduring relationships, and fills system gaps in addition to evidence gaps. Systems approaches to KTA will also benefit from robust evaluations.
Background
RCTs in surgery are challenging owing to well established methodological issues. Well designed pilot and feasibility studies (PFS) may help overcome such issues to inform successful main ...trial design and conduct. This study aimed to analyse protocols of UK‐funded studies to explore current use of PFS in surgery and identify areas for practice improvement.
Methods
PFS of surgical interventions funded by UK National Institute for Health Research programmes from 2005 to 2015 were identified, and original study protocols and associated publications sourced. Data extracted included study design characteristics, reasons for performing the work including perceived uncertainties around conducting a definitive main trial, and whether the studies had been published.
Results
Thirty‐five surgical studies were identified, of which 29 were randomized, and over half (15 of 29) included additional methodological components (such as qualitative work examining recruitment, and participant surveys studying current interventions). Most studies focused on uncertainties around recruitment (32 of 35), with far fewer tackling uncertainties specific to surgery, such as intervention stability, implementation or delivery (10 of 35). Only half (19 of 35) had made their results available publicly, to date.
Conclusion
The full potential of pretrial work to inform and optimize definitive surgical studies is not being realized.
This 10‐year review of UK National Institute for Health Research (NIHR)‐funded surgical pilot/feasibility study protocols shows that the full potential of pretrial work to address the uncertainties and challenges of undertaking surgical trials is yet to be realized. Misunderstanding of the application and value of pilot/feasibility work persists, with poor dissemination of work, and consequent missed opportunities for learning, study adaptation and the prevention of research waste. Future work will build on existing broad recommendations, to offer focused comprehensive guidance for clinical and trial teams designing and submitting funding applications for surgical pilot/feasibility studies. RfBP, Research for Patient Benefit; CI, chief investigator.
Room for better guidance
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