Current trends in flow cytometry automated data analysis software

Automated flow cytometry (FC) data analysis tools for cell population identification and characterization are increasingly being used in academic, biotechnology, pharmaceutical, and clinical laboratories. The development of these computational methods is designed to overcome reproducibility and process bottleneck issues in manual gating, however, the take-up of these tools remains (anecdotally) low. Here, we performed a comprehensive literature survey of state-of-the-art computational tools typically published by research, clinical, and biomanufacturing laboratories for automated FC data analysis and identified popular tools based on literature citation counts. Dimensionality reduction methods ranked highly, such as generic t-distributed stochastic neighbor embedding (t-SNE) and its initial Matlab-based implementation for cytometry data viSNE. Software with graphical user interfaces also ranked highly, including PhenoGraph, SPADE1, FlowSOM, and Citrus, with unsupervised learning methods outnumbering supervised learning methods, and algorithm type popularity spread across K-Means, hierarchical, density-based, model-based, and other classes of clustering algorithms. Additionally, to illustrate the actual use typically within clinical spaces alongside frequent citations, a survey issued by UK NEQAS Leucocyte Immunophenotyping to identify software usage trends among clinical laboratories was completed. The survey revealed 53% of laboratories have not yet taken up automated cell population identification methods, though among those that have, Infinicyt software is the most frequently identified. Survey respondents considered data output quality to be the most important factor when using automated FC data analysis software, followed by software speed and level of technical support. This review found differences in software usage between biomedical institutions, with tools for discovery, data exploration, and visualization more popular in academia, whereas automated tools for specialized targeted analysis that apply supervised learning methods were more used in clinical settings.

Impact of Catheter Ablation on Sleep Quality and Relationship Between Sleep Stability and Recurrence of Paroxysmal Atrial Fibrillation After Successful Ablation: 24-Hour Holter-Based Cardiopulmonary Coupling Analysis

Background

Sleep fragmentation and sleep apnea are common in patients with atrial fibrillation (AF). We investigated the impact of radio‐frequency catheter ablation (RFCA) on sleep quality in patients with paroxysmal AF and the effect of a change in sleep quality on recurrence of AF.

Methods and Results

Of 445 patients who underwent RFCA for paroxysmal AF between October 2007 and January 2017, we analyzed 225 patients who had a 24‐hour Holter test within 6 months before RFCA. Sleep quality was assessed by cardiopulmonary coupling analysis using 24‐hour Holter data. We compared cardiopulmonary coupling parameters (high‐frequency coupling, low‐frequency coupling, very‐low‐frequency coupling) before and after RFCA. Six months after RFCA, the high‐frequency coupling (marker of stable sleep) and very‐low‐frequency coupling (rapid eye movement/wake marker) was significantly increased (29.84%–36.15%; P<0.001; and 26.20%–28.76%; P=0.002, respectively) while low‐frequency coupling (unstable sleep marker) was decreased (41.25%–32.13%; P<0.001). We divided patients into 3 tertiles according to sleep quality before RFCA, and the risk of AF recurrence in each group was compared. The second tertile was used as a reference; patients with unstable sleep (Tertile 3) had a significantly lower risk of AF recurrence (hazard ratio [HR], 0.32; 95% CI, 0.12–0.83 for high‐frequency coupling; and HR, 0.22; 95% CI, 0.09–0.58 for low‐frequency coupling).

Conclusions

Sleep quality improved after RFCA in patients with paroxysmal AF. The recurrence rate was significantly lower in patients who had unstable sleep before RFCA. These results suggest that RFCA can influence sleep quality, and sleep quality assessment before RFCA may provide a risk marker for recurrence after RFCA in patients with paroxysmal AF.

Association of Sleep Electroencephalography-Based Brain Age Index With Dementia

IMPORTANCE

Dementia is an increasing cause of disability and loss of independence in the elderly population yet remains largely underdiagnosed. A biomarker for dementia that can identify individuals with or at risk for developing dementia may help close this diagnostic gap.

OBJECTIVE

To investigate the association between a sleep electroencephalography-based brain age index (BAI), the difference between chronological age and brain age estimated using the sleep electroencephalogram, and dementia.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective cross-sectional study of 9834 polysomnograms, BAI was computed among individuals with previously determined dementia, mild cognitive impairment (MCI), or cognitive symptoms but no diagnosis of MCI or dementia, and among healthy individuals without dementia from August 22, 2008, to June 4, 2018. Data were analyzed from November 15, 2018, to June 24, 2020.

EXPOSURE

Dementia, MCI, and dementia-related symptoms, such as cognitive change and memory impairment.

MAIN OUTCOMES AND MEASURES

The outcome measures were the trend in BAI when moving from groups ranging from healthy, to symptomatic, to MCI, to dementia and pairwise comparisons of BAI among these groups.

FINDINGS

A total of 5144 sleep studies were included in BAI examinations. Patients in these studies had a median (interquartile range) age of 54 (43-65) years, and 3026 (59%) were men. The patients included 88 with dementia, 44 with MCI, 1075 who were symptomatic, and 2336 without dementia. There was a monotonic increase in mean (SE) BAI from the nondementia group to the dementia group (nondementia: 0.20 [0.42]; symptomatic: 0.58 [0.41]; MCI: 1.65 [1.20]; dementia: 4.18 [1.02]; P < .001).

CONCLUSIONS AND RELEVANCE

These findings suggest that a sleep-state electroencephalography-based BAI shows promise as a biomarker associated with progressive brain processes that ultimately result in dementia.

Prevalence of Undiagnosed Sleep Apnea in Patients With Atrial Fibrillation and its Impact on Therapy

OBJECTIVES

This study sought to evaluate the proportion of patients with atrial fibrillation (AF) who also have undiagnosed sleep apnea and examine the impact of its diagnosis on adherence to sleep apnea therapies.

BACKGROUND

Sleep apnea is a modifiable risk factor for AF. However, the proportion of patients with AF who also have undiagnosed sleep apnea and the impact of its diagnosis on therapy have not been well studied.

METHODS

This prospective study included 188 consecutive patients with AF without a prior diagnosis of sleep apnea who were scheduled to undergo AF ablation. Participants underwent home sleep apnea testing, completed a sleep apnea screening questionnaire (STOP-BANG [Snoring; Tiredness, Fatigue, or Sleepiness During the Daytime; Observation of Apnea and/or Choking During Sleep; Hypertension; Body Mass Index >35 kg/m²; Age >50 Years; Neck Circumference >40 cm; and Male Sex]) and were followed for ≥2 years to evaluate the impact of diagnosis on therapy.

RESULTS

Home sleep apnea testing was positive in 155 of 188 patients (82.4%); among those 155, 127 (82%) had a predominant obstructive component and 28 (18%) had mixed sleep apnea with a 15.2 ± 7.4% central component. Sleep apnea severity was mild in 43.8%, moderate in 32.9%, and severe in 23.2%. The sensitivity and specificity of a STOP-BANG questionnaire were 81.2% and 42.4%, respectively. In a multivariate analysis, STOP-BANG was not predictive for sleep apnea (odds ratio: 0.54; 95% confidence interval: 0.17 to 1.76; p = 0.31). Therapy with continuous positive airway pressure ventilators was initiated in 73 of 85 patients (85.9%) with moderate or severe sleep apnea, and 68 of the 73 patients (93.1%) remained complaint after a mean follow-up period of 21 ± 6.2 months.

CONCLUSIONS

Sleep apnea is exceedingly prevalent in patients with AF who are referred for ablation, with a large proportion being undiagnosed due the limited predictive value of sleep apnea symptoms in this AF population. Screening for sleep apnea resulted in high rate of long-term continuous positive airway pressure adherence.

Altered structural brain network resulting from white matter injury in obstructive sleep apnea

STUDY OBJECTIVES

To assess, using fractional anisotropy (FA) analysis, alterations of brain network connectivity in adults with obstructive sleep apnea (OSA). Abnormal networks could mediate clinical functional deficits and reflect brain tissue injury.

METHODS

Structural brain networks were constructed using diffusion tensor imaging (DTI) from 165 healthy (age 57.99 ± 6.02 years, male 27.9%) and 135 OSA participants (age 59.01 ± 5.91 years, male 28.9%) and global network properties (strength, global efficiency, and local efficiency) and regional efficiency were compared between groups. We examined MRI biomarkers of brain tissue injury using FA analysis and its effect on the network properties.

RESULTS

Differences between groups of interest were noted in global network properties (p-value < 0.05, corrected), and regional efficiency (p-value < 0.05, corrected) in the left middle cingulate and paracingulate gyri, right posterior cingulate gyrus, and amygdala. In FA analysis, OSA participants showed lower FA values in white matter (WM) of the right transverse temporal, anterior cingulate and paracingulate gyri, and left postcentral, middle frontal and medial frontal gyri, and the putamen. After culling fiber tracts through WM which showed significant differences in FA, we observed no group difference in network properties.

CONCLUSIONS

Changes in WM integrity and structural connectivity are present in OSA participants. We found that the integrity of WM affected brain network properties. Brain network analysis may improve understanding of neurocognitive deficits in OSA, enable longitudinal tracking, and provides explanations for specific symptoms and recovery kinetics.

1008 Brain Age Based on Sleep Encephalography is Elevated in HIV+ Adults on ART

Introduction

Sleep EEG is a promising tool to measure brain aging in vulnerable populations such as people with HIV, who are high risk of brain aging due to co-morbidities, increased inflammation, and antiretroviral neurotoxicity. Our lab previously developed a machine learning model that estimates age from sleep EEG (brain age, BA), which reliably predicts chronological age (CA) in healthy adults. The difference between BA and CA, the brain age index (BAI), independently predicts mortality, and is increased by cardiovascular co-morbidities. Here, we assessed BAI in HIV+ compared to matched HIV- adults.

Methods

Sleep EEGs from 43 treated HIV+ adults were gathered and matched to controls (HIV-, n=284) by age, gender, race, alcoholism, smoking and substance use history. We compared BAI between groups and used additional causal interference methods to ensure robustness. Individual EEG features that underlie BA prediction were also compared. We performed a sub-analysis of BAI between HIV+ with or without a history of AIDS.

Results

After matching, mean CA of HIV+ vs HIV- adults were 49 and 48 years, respectively (n.s.). The mean HIV+ BAI was 3.04 years higher than HIV- (4.4 vs 1.4 yr; p=0.048). We found consistent and significant results with alternative causal inference methods. Several EEG features predictive of BA were different in the HIV+ and HIV- cohorts. Most notably, non-REM stage 2 sleep (N2) delta power (1-4Hz) was decreased in HIV+ vs. HIV- adults, while theta (4-8Hz) and alpha (8-12Hz) power were increased. Those with AIDS (n=19, BAI=4.40) did not have significantly different BAI than HIV+ without AIDS (n=23, BAI=5.22). HIV+ subjects had higher rates of insomnia (56% vs 29%, p&lt;0.001), obstructive apnea (47% vs 30%, p=0.03), depression (49% vs 23%, p&lt;0.001), and bipolar disorder (19% vs 4%, p&lt;0.001).

Conclusion

HIV+ individuals on ART have excess sleep-EEG based brain age compared to matched controls. This excess brain age is partially due to reduction in delta power during N2, suggesting decreased sleep depth. These results suggest sleep EEG could be a valuable brain aging biomarker for the HIV population.

Support

This research is supported by the Harvard Center for AIDS Research HU CFAR NIH/NIAID 5P30AI060354-16.

0662 Hybrid Therapies to Improve Sleep Apnea Management

Introduction

A one-size fits all approach to sleep apnea management, as is promoted by insurance requirements, pervades the field of sleep medicine but does not address individual differences in disease phenotype or treatment tolerance or attempt to achieve meaningful targets for adherence or disease optimization. Continuous positive airway pressure (CPAP) is considered to be the gold standard treatment for sleep apnea, yet CPAP nonadherence rates remain high (estimates at &gt; 30%) while usage goals (at least 4 hours/night) and therapeutic success targets (machine detected AHI &lt; 5) allow for substantial residual disease to persist. Hybrid therapy, combining mandibular advancement device (MAD) and positive airway pressure (PAP), has demonstrated additive effects on lowering the AHI, ODI, and therapeutic PAP pressure in severe OSA patients with pressure intolerance. This analysis explores the impact of hybrid therapy on treatment adherence and optimization, and identifies patient and data characteristics suggestive of benefit from combined therapies.

Methods

In a retrospective analysis, we reviewed the demographic data, medical histories, home sleep test, diagnostic and therapeutic attended polysomnography results, and PAP device settings and data (including usage, leak, residual event index, and waveforms) pre-and post-hybrid approach, in patients treated with hybrid therapy in our multidisciplinary academic sleep disorders clinic from 2014-2019.

Results

Hybrid therapies utilized include simultaneous (MAD worn together with PAP), alternating (MAD and PAP separately over parts of or on alternating nights), and anchoring (MAD to maintain mouth closure and jaw stability to minimize leak). Preliminary analysis (N=30) shows that hybrid therapy compared to PAP alone improves PAP adherence, lowers residual AHI, minimizes periodic breathing, reduces aerophagia, and lowers therapeutic PAP pressure in these patients. Patient and data characteristics suggestive of benefit include high loop gain sleep apnea, complex apnea, mouth breathing, and position dominance.

Conclusion

Individualizing treatment by combining therapies can result in improved PAP tolerance, usage, and disease control.

Support

 

0758 Quantification of Late REM Periods in Patients With Prolonged Sleep Duration

Introduction

Evaluation of hypersomnia includes polysomnography followed by mean sleep latency testing (MSLT). As consistent with guidelines as applied in most centers, the overnight portion of the study will be terminated to begin sleep latency testing. For patients with prolonged sleep duration, this interruption could result in REM sleep on nap testing that reflects continuation of their biological night, rather than abnormalities in REM sleep pressure/regulation.

Methods

We reviewed 42 consecutive extended (unrestricted) sleep studies for patients with a total sleep time greater than 600 minutes. For studies with sleep onset before midnight, we evaluated for REM period onset after 6AM, the number of REM periods after 6AM and 8AM, and the time of the final REM period onset.

Results

42 hypnograms were reviewed for patients undergoing evaluation of hypersomnia, median age 32 years (range 19-92) with a median total sleep time of 663 minutes (range 602-832), of these 28/42 (67%) had sleep onset before midnight (12 AM) and were included in the analysis. 27/28 (96%) of hypnograms reviewed had REM sleep after 6 AM, 24/28 (86%) had REM sleep after 8 AM, with the onset of the final REM period ranging from 4:46 AM-12:30 PM for patients with sleep onset time before midnight (12 AM).

Conclusion

These data suggest that termination of overnight polysomnography to complete mean sleep latency testing, as is standard in most sleep labs, may influence the presence of REM sleep on MSLT for patients with prolonged total sleep duration. These results may have implications for the interpretation of MSLT for patients with long sleep duration, and may explain why a given individual may test as type II narcolepsy or idiopathic hypersomnia unpredictably on repeat testing.

Support

Sleep Medicine Fellowship at BIDMC

0786 Non-24 Hour Sleep Wake Syndrome: A Cohort Analysis

Introduction

Although commonly described in the blind population, diagnosis in sighted individuals can be difficult due to perceived rarity and underlying co-morbid conditions. Our objective was to identify the characteristics of N24 rhythm individuals, and responses to varied treatments.

Methods

Patients were identified to have non-24-hour sleep wake syndrome (N24) via history, sleep diaries or digital logs, paired melatonin profiling as well as actigraphy through retrospective chart review at the Beth Israel Deaconess Medical Center, Sleep Disorders Clinic.

Results

37 patients were identified from 2007 to 2019 with N24 syndrome, BMI of 28, and 67% male. The mean age of onset was within the teenage years (16), and age at diagnosis of 35 years. Paired melatonin profiles (24-hour salivary melatonin, 3-hourly, separated by 7 days, in the subject’s own home) showed “movement”. Depression and anxiety were seen in 54% and 29% of the cohort respectively. 75% (28) of the patients had a treatment strategy involving light, and 54% (20) included melatonin. The combination of melatonin and light led to a clinical improvement in 41% of individuals under that regimen (17). Low dose lithium (8 subjects) enhanced melatonin/light responses. A strategy of combining the orexin antagonist suvorexant with melatonin or ramelteon (3 subjects) helped stabilize the circadian rhythm. Tasimelteon treatment has been initiated in 4 subjects.

Conclusion

These data suggest that while comorbid psychiatric conditions are prevalent, a significant proportion of the cohort did not have associated psychiatric disease. Patients reported onset of symptoms in the teenage years, however there was significant delay to diagnosis. Besides light/melatonin, orexin antagonism and low dose lithium may have benefits, but require more systematic assessments. Paired melatonin estimations could be considered as a definitive testing strategy.

Support

 

0704 Treatment-emergent Central Sleep Apnea Predicts Residual Respiratory Instability During Cpap Use At 6 Months

Introduction

The prevalence, severity, significance, and predictors of residual sleep apnea during use of continuous positive airway pressure (CPAP) remain uncertain. High loop gain is associated with or induces periodic breathing and central sleep apnea (CSA). Treatment-emergent CSA (TE-CSA) is often considered a transient phenomenon of no long-term clinical significance. Standard polysomnographic features were assessed as risk factors for high residual apnea during compliant CPAP use.

Methods

Patients with sleep apnea (mean AHI 53.6, SD:33/hour of sleep) who underwent split night studies were prospectively entered in a database. They were all treated with positive airway pressure at the Beth Israel Deaconess Medical Center (Boston) and tracked by the EncoreAnywhere system. Machine detected AHI (AHIm) was extracted for a week average at month 6. The manual scored AHI(AHIs) was calculated from the last waveform graph during every month. Logistic regression assessed predictors of elevated automated (5 or greater) or manual (10 or greater) residual events//hour of use.

Results

A total of 69 CPAP compliant (average of at least 4 hours) subjects were analyzed. Age: 59.5 (range 17-81), gender: 47/69 male. 44/69 had an elevated manual AHI, while 20/69 had an elevated autodetected AHI. The only predictors of high residual apnea were TE-CSA (5 or more central apneas and hypopneas/hour of sleep): Odds Ratio 3.6 (CI: 1.07-12-3), p: 0.39. and the treatment component arousal index: Odds Ratio 1.06 (CI: 1.01-1.11), p: 0.018. Machine estimated AHI, which under-detected events by a factor of 3 or more, was not associated with any measure.

Conclusion

Residual apnea is common after 6 months of compliant CPAP use, and the only predictors identified were TE-CSA and treatment component arousal index.

Support

This study is supported by American Academy of Sleep Medicine Foundation, Category-I award to RJT

Dietary intake of broccoli and the risk of cancer in the prostate, lung, colorectal, and ovarian cancer (PCLO) screening trial

e13560

Background: The cruciferous vegetable broccoli, are a good source of vitamins, minerals and fibre, as well as thiol phytochemicals (indole-3-carbinol), glucosinolates (isothiocyanates, its metabolite, sulforaphane), carotenoids (lutein and zeaxanthin) and flavonols (kaempferol). Laboratory and human biopsy studies have found that broccoli intake influenced epigenetic expression of genes via blockage of histone deacetylase which reduce inflammation and cancer growth. Clinically, a randomised control study reported dried broccoli extract (along with three other foods) influenced PSA progression in men with prostate cancer1. However, no preventative intervention studies in humans have been conducted and data from cohort studies are inconsistent for its influence on cancer incidence2,3. Methods: We analysed 49,104 people within the intervention arm of the 155,000 participant PLCO screening trial. Histological confirmed cases of any cancer were reported in 8,263 (16.83%) during the 11.5 year follow up. Broccoli consumption was assessed with a food frequency questionnaire (FFQ). Baseline characteristics were compared between broccoli consumption groups using Chi-square and Kruskal-Wallis tests. Cox regression models were used to assess the association between broccoli intake and cancer incidence. Results: Broccoli consumption was associated with reduced cancer incidence: HR 0.95 (CI 0.93-0.97, p < 0.001). This pattern persisted with adjustments for age, sex, race, education level and family history (HR 0.97, CI 0.96-0.99, p = 0.007) as well as smoking, BMI and alcohol consumption (HR 0.98, CI 0.96-0.99, p = 0.010). Conclusions: The study identified an association between increased broccoli consumption and reduced cancer risk. In practical terms, 15g of broccoli, or more, consumed per day (about a small cup) was associated with a 5% lower risk of cancer. Broccoli should continue to be included in healthy eating advice. This data supports the consideration of future prospective intervention studies investigating the role of broccoli as part of a cancer prevention programme. References 1. Thomas et al. The NCRN Pomi-T RCT. Prostate cancer & prostatic diseases (2014), 2,180. 2. Liu et al Cruciferous vegetables inversely linked with breast cancer: Breast (2013), 22;3,309. 3. Bosetti et al Cruciferous vegetables and cancer risk Ann Oncol (2012) 23(8);2198.

Dietary consumption of tea and the risk of prostate cancer in the prostate, lung, colorectal, and ovarian cancer screening trial

e13559

Background: The popular beverage tea, brewed from infused leaves of camellia sinesis, contains non-phytoestrogenic polyphenols such as flavonoids, anthocyanidins, flavanols (epigallocatechin gallate); phenolic acids (ellagic acid) and stimulants (caffeine, theophylline). Laboratory studies report tea promotes antioxidant enzyme formation, slows cancer cell proliferation and unblocks apoptosis. Clinically, the Pomi-T randomised study reported tea extract (along with three other foods) reduced PSA progression in men with prostate cancer1. Evidence of prostate cancer prevention, however, from prospective cohort data is conflicting with one recent study even implying an increased risk2. Methods: We analysed 25,097 men within the intervention arm of the 155,000 participant PLCO screening trial. Histological confirmed cases of prostate cancer were reported in 3,088 men (12.3%) during the 11.5 year follow up. Tea consumption was assessed with a food frequency questionnaire (FFQ). Baseline characteristics were compared between groups using Chi-square and Kruskal-Wallis tests. Cox regression models were used to assess the association between tea intake and prostate cancer incidence. Results: Overall tea consumption was associated with a significantly lower risk of prostate cancer (p = 0.009). More precisely, the participants in the highest third of consumption group had a significantly lower risk compared to those in the lowest third (HR 1.16 (CI 1.05-1.29, p = 0.004). This pattern persisted with adjustments for age, sex, race and education level (p = 0.034), family history of cancer (p = 0.037). Those who never drank tea, however, had no statistical lower risk of prostate cancer compared to other groups (p = 0.501). Conclusions: Among tea drinkers, this data revealed a positive association between drinking tea and a reduced risk of prostate cancer. This data supports the consideration of future prospective intervention studies investigating the role of tea as part of a prostate cancer prevention programme. 1. Thomas et al. The NCRN Pomi-T RCT. Prostate cancer & prostatic diseases (2014), 2,180. 2. Reger et al. Dietary isoflavones and prostate cancer risk. Int J. Cancer (2017), 142; 4, 719.

First evidence for a latitudinal body mass effect in extant Crocodylia and the relationships of their reproductive characters

Relationships between distribution patterns and body size have been documented in many endothermic taxa. However, the evidence for these trends in ectotherms generally is equivocal, and there have been no studies of effects in crocodylians specifically. Here, we examine the relationship between latitudinal distribution and body mass in 20 extant species of crocodylians, as well as the relationships between seven important reproductive variables. Using phylogenetically independent contrasts to inform generalized linear models, we provide the first evidence of a latitudinal effect on adult female body mass in crocodylians. In addition, we explore the relationships between reproductive variables including egg mass, hatchling mass and clutch size. We report no correlation between egg mass and clutch size, upholding previously reported within-species trends. We also find no evidence of a correlation between measures of latitudinal range and incubation temperature, contrasting with the trends found in turtles.

The pathway to diagnosis and treatment for surgically managed lung cancer patients

BACKGROUND

Most lung cancer is diagnosed at an advanced stage, resulting in poor survival. This study examined diagnostic pathways for patients with operable lung cancer to identify factors contributing to early diagnosis.

METHODS

Surgically treated lung cancer patients (aged ≥40, within 6 months of diagnosis), approached via the population-based Cancer Registry, with their primary care physicians (PCPs) and specialists completed cross-sectional surveys assessing symptoms, diagnostic route (symptomatic or 'investigation' of other problem), tests, key event dates and treatment. Time intervals to diagnosis and treatment were determined, and quantile regression examined differences between the two diagnostic routes. Cox proportional hazard regression analyses examined associations between survival and diagnostic route adjusting for stage, sex and age.

RESULTS

One hundred and ninety-two patients (36% response rate), 107 PCPs and 55 specialists participated. Fifty-eight per cent of patients had a symptomatic diagnostic route reporting an average of 1.6 symptoms, most commonly cough, fatigue or haemoptysis. Symptomatic patients had longer median primary care interval than 'investigation' patients (12 versus 9 days, P < 0.05) and were more likely to report their PCP first-ordered imaging tests. Secondary care interval was shorter for symptomatic (median = 43 days) than investigation (median = 62 days, P < 0.05) patients. However, 56% of all patients waited longer than national recommendations (6 weeks). While survival estimates were better for investigation than symptomatic patients, these differences were not significant.

CONCLUSION

Many operable lung cancer patients are diagnosed incidentally, highlighting the difficulty of symptom-based approaches to diagnosing early stage disease. Longer than recommended secondary care interval suggests the need for improvements in care pathways.

From protocol to product: ventral midbrain dopaminergic neuron differentiation for the treatment of Parkinson's disease

Current cell therapy product limitations include the need for in-depth product understanding to ensure product potency, safety and purity. New technologies require development and validation to address issues of production scale-up to meet clinical need; assays are required for process control, validation and release. Prior to clinical realization, an understanding of production processes is required to implement process changes that are essential for process control. Identification of key parameters forms the basis of process tolerances, allowing for validated, adaptive manufacturing processes. This enables greater process control and yield while withstanding regulatory scrutiny. This report summaries key milestones in specifically for ventral midbrain dopaminergic neuroprogenitor differentiation and key translational considerations and recommendations to enable successful, robust and reproducible current cell therapy product-manufacturing.

Thermal damage thresholds for multiple-pulse porcine skin laser exposures at 1070 nm

As solid-state laser technology continues to mature, high-energy lasers operating in the near-infrared (NIR) band have seen increased utilization in manufacturing, medical, and military applications. Formulations of maximum permissible exposure limits establish guidelines for the safe use of these systems for a given set of laser parameters, based on past experimental and analytical studies of exposure thresholds causing injury to the skin and eyes. The purpose of our study is to characterize the skin response to multiple-pulsed laser exposures at the NIR wavelength of 1070 nm, at a constant beam diameter of 1 cm, using anesthetized Yucatan mini-pig subjects. Our study explores three constant total laser-on times of 0.01, 0.1, and 10 s as single- and multiple-pulse sequences. Exposures consisting of 10, 30, and 100 pulses have identical individual pulse durations but different duty cycles in order to include variable degrees of thermal additivity. A plurality of three observers quantifies skin damage with the minimally visible lesion metric, judged at the 1- and 24-h intervals postexposure. Calculation of the median effective dose (ED₅₀) provides injury thresholds for all exposure conditions, based on varying laser power across subjects. The results of this study will provide a quantitative basis for the incorporation of multiple-pulsed laser exposure into standards and augment data contained in the existing ED₅₀ database.

Using porous iron composite (PIC) material to immobilize rhenium as an analogue for technetium

Technetium (⁹⁹Tc), a uranium-235 (²³⁵U) and plutonium-239 (²³⁹Pu) fission product, is a primary risk driver in low level radioactive liquid waste at U.S. Department of Energy sites. Previous studies have shown success in using Zero Valent Iron (ZVI) to chemically reduce and immobilize redox sensitive groundwater contaminants. Batch and column experiments were performed to assess the ability of a novel porous iron composite material (PIC) to immobilize Tc(VII) in comparison with two commercial Fe oxide sorbents and reagent grade ZVI in the presence and absence of NO₃^-, a competing oxidized species that is often found in high concentrations in liquid nuclear waste. Perrhenate (ReO₄^-) was used as a non-radioactive chemical analogue for pertechnetate (TcO₄^-) under both oxic and anoxic test conditions. The PIC powder was the most effective at immobilizing Re(VII) under all batch test conditions. The presence of nitrate (NO₃^-) slowed the removal of ReO₄^- from solution, presumably through chemical reduction and precipitation. Even so, the PIC and ZVI were effective at removing both Re(VII) and NO₃^- completely from solution. Nitrate was reduced to NH₃ with very little nitrite (NO₂^-) buildup during equilibration. Significant Re immobilization was observed in the column tests containing PIC sorbent, even though inlet solutions were in equilibrium with O₂. The presence of NO₃^- hastened Re breakthrough, while NO₃^- reduction to NH₃ was observed. The results suggest that PIC and ZVI would be the most effective at the removal of TcO₄^- from contaminated groundwater sites.

The Respiratory Signature: A Novel Concept to Leverage Continuous Positive Airway Pressure Therapy as an Early Warning System for Exacerbations of Common Diseases such as Heart Failure

ABSTRACT

Each night millions of patients use continuous positive airway pressure (CPAP) to treat obstructive sleep apnea (OSA). To facilitate monitoring of treatment success, modern CPAP machines routinely record and analyze the respiratory signal in near real-time and submit some of these data to the manufacturer's centralized cloud server. Some of the conditions frequently associated with OSA such as heart failure or chronic obstructive pulmonary disease result in characteristic changes of the respiratory signal ("signatures"), especially during exacerbations. Thus, this infrastructure could be leveraged to detect changes in patients' health status facilitating early interventions. To illustrate this concept, we present and discuss the case of a patient with OSA who showed abrupt changes in his breathing pattern (increase in periodic breathing and machine-detected obstructive apneas) from 10 days prior until 8 days after a hospitalization for acute heart failure exacerbation.

Quantifying statistical uncertainty in metrics of sleep disordered breathing

BACKGROUND

The apnea-hypopnea index (AHI) (or one of its derivatives) is the primary clinical metric for characterizing sleep disordered breathing-the value of which with respect to a threshold determines severity of diagnosis and eligibility for treatment reimbursement. The index value, however, is taken as a perfect point estimate, with no measure of statistical uncertainty. Thus, current practice does not robustly account for variability in diagnosis/eligibility due to chance. In this paper, we quantify the statistical uncertainty associated with respiratory event indices for sleep disordered breathing and the effect of uncertainty on treatment eligibility.

METHODS

We develop an empirical estimate of uncertainty using a non-parametric bootstrap on the interevent times, as well as a theoretical Poisson estimate reflecting the current formulation of the AHI. We then apply these methods to estimate AHI uncertainty for 2049 subjects (954/1095 M/F, age: mean 69 ± 9.1) from the Multi-Ethnic Study of Atherosclerosis (MESA).

RESULTS AND CONCLUSIONS

The mean 95% empirical confidence interval width was 11.500 ± 6.208 events per hour and the mean 95% theoretical Poisson confidence interval width was 5.998 ± 2.897 events per hour, suggesting that uncertainty is likely a major confounding factor within the current diagnostic framework. Of the 278 subjects in the symptomatic population (ESS>10), 27% (76/278) had uncertain diagnoses given the 95% empirical confidence interval. Of the 2049 subjects in the full population, 43% (880/2049) had uncertain diagnoses given the 95% empirical confidence interval. The inclusion of subjects with uncertain diagnoses increases the number of eligible patients by 21.3% for the symptomatic population and by 84.8% for the full population. The exclusion of subjects with uncertain diagnoses given the 95% empirical confidence interval decreases the number of eligible patients by 12.4% for the symptomatic population and by 34.8% for full population. Additional analyses suggest that it is practically infeasible to gain diagnostic statistical significance through additional testing for a broad range of borderline cases. Overall, these results suggest that AHI uncertainty is a vital additional piece of information that would greatly benefit clinical practice, and that the inclusion of uncertainty in epidemiological analysis might help improve the ability for researchers to robustly link AHI with co-morbidities and long-term outcomes.

Prevalence and Characteristics of Restless Legs Syndrome in Korean Adults: A Study in Two Independent Samples of the General Population

BACKGROUND

Restless legs syndrome (RLS) is a common sleep disorder, although it has a low prevalence in Asian populations. However, the reported RLS prevalence in -Korean adults is mostly 4.5-12.1%, which is higher than that reported in other Asian populations. This study aimed to diagnose RLS and exclude mimicking conditions in 2 independent samples of Korean adults, and to compare its prevalence to that from previous studies performed in Asian countries.

METHODS

Study populations included a (1) nationwide stratified random sample (n = 2,824; age 19-79 years) and (2) community-based cohort (n = 2,685; age 47-79 years). We applied the Cambridge-Hopkins diagnostic questionnaire to diagnose RLS and differentiate it from RLS mimics. Sleep-related symptoms, mood, and medical conditions were compared between the RLS and non-RLS groups. Prior studies of the RLS prevalence in Asia were systematically reviewed and compared to our findings.

RESULTS

The adjusted RLS prevalence was 0.4 and 1.3% in populations 1 and 2, respectively. In both populations, subjects with RLS had more depression. The prevalence of RLS mimics was 5.1 and 2.6%, in populations 1 and 2, respectively. The RLS prevalence in Asia was higher when RLS was defined by the presence of essential clinical features and lower when a differential diagnosis was additionally implemented.

CONCLUSIONS

The RLS prevalence in Korean adults considering RLS mimics is comparable to that in adults from other Asian countries (< 2%). The reported RLS prevalence varies depending on the diagnostic method employed.

Suprathreshold laser injuries in excised porcine skin for millisecond exposures at 1070 nm

Skin injury response to near-infrared (NIR) laser radiation between the minimum visible lesion threshold and ablation onset is not well understood. This study utilizes a 1070-nm diode-pumped Yb-fiber laser to explore the response of excised porcine skin to high-energy exposures in the suprathreshold injury region without inducing ablation. Concurrent high-speed videography is employed to determine a dichotomous response for three progressive damage categories: observable surface distortion, surface bubble formation due to contained intracutaneous water vaporization, and surface bubble rupture during exposure. Median effective dose (ED50) values are calculated in these categories for 3- and 100-ms pulses with beam diameters (1  /  e2) of 3 mm (28, 35, and 49  J  /  cm2) and 7 mm (96, 141, and 212  J  /  cm2), respectively. Double-pulse cases are secondarily investigated. Experimental data are compared with the maximum permissible exposure limits and ablation onset simulated by a one-dimensional multiphysics model. Logistic regression analysis predicted injury events with ∼90  %   of accuracy. The distinction of skin response into progressive damage categories expands the current understanding of high-energy laser safety while underlining the unique biophysical effects during induced water phase change in tissue. These results prove to be useful in the diagnosis and treatment of NIR laser injuries.