55 research outputs found

    Correcting motion induced fluorescence artifacts in two-channel neural imaging

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    Imaging neural activity in a behaving animal presents unique challenges in part because motion from an animal's movement creates artifacts in fluorescence intensity time-series that are difficult to distinguish from neural signals of interest. One approach to mitigating these artifacts is to image two channels; one that captures an activity-dependent fluorophore, such as GCaMP, and another that captures an activity-independent fluorophore such as RFP. Because the activity-independent channel contains the same motion artifacts as the activity-dependent channel, but no neural signals, the two together can be used to remove the artifacts. Existing approaches for this correction, such as taking the ratio of the two channels, do not account for channel independent noise in the measured fluorescence. Moreover, no systematic comparison has been made of existing approaches that use two-channel signals. Here, we present Two-channel Motion Artifact Correction (TMAC), a method which seeks to remove artifacts by specifying a generative model of the fluorescence of the two channels as a function of motion artifact, neural activity, and noise. We further present a novel method for evaluating ground-truth performance of motion correction algorithms by comparing the decodability of behavior from two types of neural recordings; a recording that had both an activity-dependent fluorophore (GCaMP and RFP) and a recording where both fluorophores were activity-independent (GFP and RFP). A successful motion-correction method should decode behavior from the first type of recording, but not the second. We use this metric to systematically compare five methods for removing motion artifacts from fluorescent time traces. We decode locomotion from a GCaMP expressing animal 15x more accurately on average than from control when using TMAC inferred activity and outperform all other methods of motion correction tested.Comment: 11 pages, 3 figure

    Leaning in to Address Sleep Disturbances and Sleep Disorders in Department of Defense and Defense Health Agency

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    Letter to the Editor, Military Medicine, 187, 5/6:155, 202217 USC 105 interim-entered record; under review.The article of record as published may be found at http://dx.doi.org/10.1177/0018720820906050In their article entitled, “Engaging Stakeholders to Optimize Sleep Disorders Management in the U.S. Military: A Qualitative Analysis,” Abdelwadoud and colleagues conducted focus groups of service members, primary care managers (PCMs), and administrative stakeholders about their perceptions, experiences, roles in sleep management, stated education needs, and management of sleep disorders.1 The qualitative methods are rigorous, and the findings reinforce and nuance prior results, especially regarding key requirements from PCMs. We feel compelled, however, to further nuance the authors’ conclusion that “current military sleep management practices are neither satisfactory nor maximally effective” and offer specific examples of actions taken by the Department of Defense (DoD) and Defense Health Agency (DHA) in recognition of the significance of optimal sleep in combat readiness and overall health of service members. We offer here a succinct list of concrete efforts to support and implement substantial clinical, operational, research, or educational efforts by the DoD or DHA to improve sleep in service members and associated clinical challenges in this unique population.Identified in text as U.S. Government work

    Effect of anti-TNF and conventional synthetic disease-modifying anti-rheumatic drug treatment on work disability and clinical outcome in a multicentre observational cohort study of psoriatic arthritis

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    OBJECTIVE: To determine the effect of medical treatment on work disability in patients with active PsA in a real-world setting.METHODS: Four hundred patients with active PsA commencing or switching to anti-TNF or conventional synthetic DMARD (csDMARD) were recruited to a multicentre UK prospective observational cohort study. Work disability was measured using the work productivity and activity-specific health problem instrument and peripheral joint activity was measured with the disease activity in PsA composite measure.RESULTS: Four hundred patients were recruited, of whom 229 (57.25%) were working (of any age). Sixty-two patients of working age (24%) were unemployed. At 6 months there was a 10% improvement in presenteeism (P = 0.007) and a 15% improvement in work productivity (P = 0.001) among working patients commenced on csDMARDs (n = 164) vs a larger and more rapid 30% improvement in presenteeism (P &lt; 0.001) and 40% improvement in work productivity (P &lt; 0.001) among those commenced on anti-TNF therapy (n = 65). Clinical response was poor among patients commenced on a csDMARD (n = 272), with an 8.4 point improvement in disease activity in PsA (P &lt; 0.001) vs those commenced on anti-TNF therapy (n = 121), who had a 36.8 point improvement (P &lt; 0.001).CONCLUSION: We report significant and clinically meaningful improvements in both work disability and clinical outcomes after commencement of anti-TNF therapy in a real-world setting. Improvements in all outcomes among those commencing csDMARDs were slower and of a smaller magnitude.</p

    A randomized controlled trial of high frequency (10 kHz) spinal cord stimulation in painful diabetic neuropathy

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    Importance: Many patients with diabetic peripheral neuropathy experience chronic pain and inadequate relief despite best available medical treatments. Objective: To determine whether 10-kHz spinal cord stimulation (SCS) improves outcomes for patients with refractory painful diabetic neuropathy (PDN). Design, Setting, and Participants: The prospective, multicenter, open-label SENZA-PDN randomized clinical trial compared conventional medical management (CMM) with 10-kHz SCS plus CMM. Participants with PDN for 1 year or more refractory to gabapentinoids and at least 1 other analgesic class, lower limb pain intensity of 5 cm or more on a 10-cm visual analogue scale (VAS), body mass index (calculated as weight in kilograms divided by height in meters squared) of 45 or less, hemoglobin A1c (HbA1c) of 10% or less, daily morphine equivalents of 120 mg or less, and medically appropriate for the procedure were recruited from clinic patient populations and digital advertising. Participants were enrolled from multiple sites across the US, including academic centers and community pain clinics, between August 2017 and August 2019 with 6-month follow-up and optional crossover at 6 months. Screening 430 patients resulted in 214 who were excluded or declined participation and 216 who were randomized. At 6-month follow-up, 187 patients were evaluated. Interventions: Implanted medical device delivering 10-kHz SCS. Main Outcomes and Measures: The prespecified primary end point was percentage of participants with 50% pain relief or more on VAS without worsening of baseline neurological deficits at 3 months. Secondary end points were tested hierarchically, as prespecified in the analysis plan. Measures included pain VAS, neurological examination, health-related quality of life (EuroQol Five-Dimension questionnaire), and HbA1c over 6 months. Results: Of 216 randomized patients, 136 (63.0%) were male, and the mean (SD) age was 60.8 (10.7) years. Additionally, the median (interquartile range) duration of diabetes and peripheral neuropathy were 10.9 (6.3-16.4) years and 5.6 (3.0-10.1) years, respectively. The primary end point assessed in the intention-to-treat population was met by 5 of 94 patients in the CMM group (5%) and 75 of 95 patients in the 10-kHz SCS plus CMM group (79%; difference, 73.6%; 95% CI, 64.2-83.0; P &lt; .001). Infections requiring device explant occurred in 2 patients in the 10-kHz SCS plus CMM group (2%). For the CMM group, the mean pain VAS score was 7.0 cm (95% CI, 6.7-7.3) at baseline and 6.9 cm (95% CI, 6.5-7.3) at 6 months. For the 10-kHz SCS plus CMM group, the mean pain VAS score was 7.6 cm (95% CI, 7.3-7.9) at baseline and 1.7 cm (95% CI, 1.3-2.1) at 6 months. Investigators observed neurological examination improvements for 3 of 92 patients in the CMM group (3%) and 52 of 84 in the 10-kHz SCS plus CMM group (62%) at 6 months (difference, 58.6%; 95% CI, 47.6-69.6; P &lt; .001). Conclusions and Relevance: Substantial pain relief and improved health-related quality of life sustained over 6 months demonstrates 10-kHz SCS can safely and effectively treat patients with refractory PDN. Trial Registration: ClincalTrials.gov Identifier: NCT0322842

    Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

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    BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

    Nightmares in United States Military Personnel With Sleep Disturbances

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    The article of record as published may be found at http://doi.org/10.5664/jcsm.6990The spectrum of sleep disorders in military personnel is varied and complicated by the presence of comorbidities and psychological disorders. Currently, little is known regarding nightmares, especially trauma-related nightmares. Study Impact: This is the first study to report on objective and subjective sleep attributes in a cohort of military personnel, determining the prevalence of nightmares and polysomnographic characteristics associated with nightmares. Clinically, this highlights the need for military and civilian health care providers to evaluate for nightmares in individuals with sleep disturbances after traumatic experiences. From a research perspective, these findings provide the basis to further address nightmares, which are associated with the pressing issues of sleep and behavioral medicine disorders and suicidality in military and veteran populations

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    TMAC reduces decodable motion artifacts in experimental data.

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    A) Top, animal body curvature over time. Middle, GCaMP and RFP fluorescence from a neuron that TMAC estimates to have high signal to noise, recorded from a behaving worm. Bottom, GCaMP and RFP fluorescence from a different neuron in that same recording that TMAC estimates to have large motion artifacts. B) Time trace of animal curvature and predicted behavior, decoded from activity inferred by TMAC in a GCaMP worm. Gray shaded regions were used to train the decoder, white region was held out and used to evaluate decoding performance. C) Ratio of decoding accuracy (ρ2) when decoding GCaMP divided by the median accuracy for a GFP worm across different models (S2 Table). D) Histogram over all neurons of correlation squared between RFP and activity inferred by TMAC from a GFP worm. RFP vs GFP data the same as in Fig 1D and 1E. E) Same as F but in a GCaMP worm.</p
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