Compare the marginal effects for environmental exposure and biomonitoring data with repeated measurements and values below the limit of detection

BACKGROUND

Environmental exposure and biomonitoring data with repeated measurements from environmental and occupational studies are commonly right-skewed and in the presence of limits of detection (LOD). However, existing model has not been discussed for small-sample properties and highly skewed data with non-detects and repeated measurements.

OBJECTIVE

Marginal modeling provides an alternative to analyzing longitudinal and cluster data, in which the parameter interpretations are with respect to marginal or population-averaged means.

METHODS

We outlined the theories of three marginal models, i.e., generalized estimating equations (GEE), quadratic inference functions (QIF), and generalized method of moments (GMM). With these approaches, we proposed to incorporate the fill-in methods, including single and multiple value imputation techniques, such that any measurements less than the limit of detection are assigned values.

RESULTS

We demonstrated that the GEE method works well in terms of estimating the regression parameters in small sample sizes, while the QIF and GMM outperform in large-sample settings, as parameter estimates are consistent and have relatively smaller mean squared error. No specific fill-in method can be deemed superior as each has its own merits.

IMPACT

Marginal modeling is firstly employed to analyze repeated measures data with non-detects, in which only the mean structure needs to be correctly provided to obtain consistent parameter estimates. After replacing non-detects through substitution methods and utilizing small-sample bias corrections, in a simulation study we found that the estimating approaches used in the marginal models have corresponding advantages under a wide range of sample sizes. We also applied the models to longitudinal and cluster working examples.

Comparative study of arterial and venous grafting for pedicle lengthening in head and neck microvascular reconstruction

BACKGROUND

In the field of head and neck microvascular reconstruction, no previous study has compared arterial and venous grafting as methods of anterolateral thigh (ALT) pedicle lengthening. Therefore, we conducted this comparative study to compare the outcomes between the two pedicle lengthening techniques.

METHODS

We performed comparative effectiveness research by conducting a retrospective chart review from January 2012 to December 2021 to identify patients who underwent head and neck reconstruction with non-descending branch ALT perforator flaps using either the in situ pedicle lengthening (ISPL) technique or the vein graft (VG) technique. A total of 26 patients were analyzed, including 14 who underwent ISPL, and 12 who underwent VG. The collected data, including patient demographics, surgical indications, history of prior free flap, prior neck dissection, radiation therapy, chemotherapy, graft length, and flap outcomes, were analyzed. The flap outcomes were categorized as total flap loss, partial flap loss, flap compromise that required operating room visits, or minor issues, including infection or dehiscence. The flap characteristics and postoperative outcomes were compared between the two groups.

RESULTS

The VG group had two flap losses, whereas the ISPL group had none. Although the failure rate was higher in the VG group than that in the ISPL group, the difference was not statistically significant (0% vs. 16.7%, p = 0.203). Additionally, there were no significant differences in flap take-back (14.3% vs. 16.7%, p = 1) and minor complications between the two groups (35.7% vs. 33.3%, p = 1).

CONCLUSIONS

If pedicle lengthening with vessel graft is inevitable in head and neck reconstruction, arterial graft may provide a reliable outcome and may be considered an effective alternative when compared to vein grafts.

Comparisons of characteristics and outcome between abusive head trauma and non-abusive head trauma in a pediatric intensive care unit

BACKGROUND

Abusive head trauma (AHT) is the leading cause of death in infants with traumatic brain injury (TBI). Early recognition of AHT is important for improving outcomes, but it can be challenging due to its similar presentations with non-abusive head trauma (nAHT). This study aims to compare clinical presentations and outcomes between infants with AHT and nAHT, and to identify the risk factors for poor outcomes of AHT.

METHODS

We retrospectively analyzed infants of TBI in our pediatric intensive care unit from January 2014 to December 2020. Clinical manifestations and outcomes were compared between patients with AHT and nAHT. Risk factors for poor outcomes in AHT patients were also analyzed.

RESULTS

60 patients were enrolled for this analysis, including 18 of AHT (30%) and 42 of nAHT (70%). Compared with those with nAHT, patients with AHT were more likely to have conscious change, seizures, limb weakness, and respiratory failure, but with a fewer incidence of skull fractures. Additionally, clinical outcomes of AHT patients were worse, with more cases undergoing neurosurgery, higher Pediatric Overall Performance Category score at discharge, and more anti-epileptic drug (AED) use after discharge. For AHT patients, conscious change is an independent risk factor for a composite poor outcome of mortality, ventilator dependence, or AED use (OR = 21.9, P = 0.04) CONCLUSION: AHT has a worse outcome than nAHT. Conscious change, seizures and limb weaknesses but not skull fractures are more common in AHT. Conscious change is both an early reminder of AHT and a risk factor for its poor outcomes.

Kurarinone exerts anti-inflammatory effect via reducing ROS production, suppressing NLRP3 inflammasome, and protecting against LPS-induced sepsis

Kurarinone, a major lavandulyl flavanone found in the roots of Sophora flavescens aiton, has been reported to exhibit anti-inflammatory and anti-oxidative activities in lipopolysaccharide (LPS)-induced macrophages; however, the effects of kurarinone on the activation of NLRP3 inflammasome and the protective effects against sepsis have not been well investigated. In this study, we aimed to investigate the impacts of kurarinone on NLRP3 inflammasome activation in lipopolysaccharide (LPS)-induced macrophages and its protective effects against sepsis in vivo. Secretion of pro-inflammatory cytokines, activation of MAPKs and NF-κB signaling pathways, formation of NLRP3 inflammasome, and production of reactive oxygen species (ROS) by LPS-induced macrophages were examined; additionally, in vivo LPS-induced endotoxemia model was used to investigate the protective effects of kurarinone in sepsis-induced damages. Our experimental results demonstrated that kurarinone inhibited the expression of iNOS and COX-2, suppressed the phosphorylation of MAPKs, attenuated the production of TNF-α, IL-6, nitric oxide (NO) and ROS, repressed the activation of the NLRP3 inflammasome, and impeded the maturation and secretion of IL-1β and caspase-1. Furthermore, the administration of kurarinone attenuated the infiltration of neutrophils in the lung, kidneys and liver, reduced the expression of organ damage markers, and increased the survival rate in LPS-challenged mice. Collectively, our study demonstrated that kurarinone can protect against LPS-induced sepsis damage and exert anti-inflammatory effects via inhibiting MAPK/NF-κB pathways, attenuating NLRP3 inflammasome formation, and preventing intracellular ROS accumulation, suggesting that kurarinone might have potential for treating sepsis and inflammation-related diseases.

Dual task measures in older adults with and without cognitive impairment: response to simultaneous cognitive-exercise training and minimal clinically important difference estimates

BACKGROUND

Responsiveness and minimal clinically important difference (MCID) are critical indices to understand whether observed improvement represents a meaningful improvement after intervention. Although simultaneous cognitive-exercise training (SCET; e.g., performing memory tasks while cycling) has been suggested to enhance the cognitive function of older adults, responsiveness and MCID have not been established. Hence, we aimed to estimate responsiveness and MCIDs of two dual task performance involving cognition and hand function in older adults with and without cognitive impairment and to compare the differences in responsiveness and MCIDs of the two dual task performance between older adults with and without cognitive impairment.

METHODS

A total of 106 older adults completed the Montreal Cognitive Assessment and two dual tasks before and after SCET. One dual task was a combination of Serial Sevens Test and Box and Block Test (BBT), and the other included frequency discrimination and BBT. We used effect size and standardized response mean to indicate responsiveness and used anchor- and distribution-based approaches to estimating MCID ranges. When conducting data analysis, all participants were classified into two cognitive groups, cognitively healthy (Montreal Cognitive Assessment ≥ 26) and cognitively impaired (Montreal Cognitive Assessment < 26) groups, based on the scores of the Montreal Cognitive Assessment before SCET.

RESULTS

In the cognitively healthy group, Serial Seven Test performance when tasked with BBT and BBT performance when tasked with Serial Seven Test were responsive to SCET (effect size = 0.18-0.29; standardized response mean = 0.25-0.37). MCIDs of Serial Seven Test performance when tasked with BBT ranged 2.09-2.36, and MCIDs of BBT performance when tasked with Serial Seven Test ranged 3.77-5.85. In the cognitively impaired group, only frequency discrimination performance when tasked with BBT was responsive to SCET (effect size = 0.37; standardized response mean = 0.47). MCIDs of frequency discrimination performance when tasked with BBT ranged 1.47-2.18, and MCIDs of BBT performance when tasked with frequency discrimination ranged 1.13-7.62.

CONCLUSIONS

Current findings suggest that a change in Serial Seven Test performance when tasked with BBT between 2.09 and 2.36 corrected number (correct responses - incorrect responses) should be considered a meaningful change for older adults who are cognitively healthy, and a change in frequency discrimination performance when tasked with BBT between 1.47 and 2.18 corrected number (correct responses - incorrect responses) should be considered a meaningful change for older adults who are cognitively impaired. Clinical practitioners may use these established MCIDs of dual tasks involving cognition and hand function to interpret changes following SCET for older adults with and without cognitive impairment.

TRIAL REGISTRATION

NCT04689776, 30/12/2020.

Maternal occupational exposure to selected organic and chlorinated solvents and delivery of small-for-gestational age or preterm infants

BACKGROUND

Potential reproductive effects of organic solvent exposure during pregnancy remain unclear. We investigated the association between maternal occupational exposure during pregnancy to six chlorinated solvents, three aromatic solvents, and Stoddard solvent, and delivery of preterm infants or those born small-for-gestational age (SGA).

METHODS

In this case-control study of SGA and preterm birth (PTB) nested within the National Birth Defects Prevention Study (NBDPS) from 1997 to 2011, we analyzed data from 7504 singleton live births without major birth defects and their mothers. Self-reported information on jobs held in the periconceptional period was assessed for solvent exposure. Unconditional logistic regression was used to estimate the association between maternal occupational exposure (any, none) during early pregnancy to organic solvents and PTB and SGA. Linear regression was used to examine changes in mean birthweight potentially associated with maternal occupational solvent exposure.

RESULTS

Maternal occupational exposure to any organic solvents overall was not associated with an increased odds of PTB (adjusted odds ratio [aOR] = 0.94; 95% confidence interval [CI] 0.67-1.33) or SGA (aOR = 0.93; 95% CI 0.65-1.34). Point estimates increased modestly for higher estimated exposure versus lower, but confidence intervals were wide and not statistically significant. Maternal exposure to solvents was not associated with a statistically significant change in term birthweight among infants.

CONCLUSIONS

Occupational exposure to organic solvents at the frequency and intensity levels found in a population-based sample of pregnant workers was not associated with PTB or SGA; however, we cannot rule out any effects among pregnant workers with uncommonly high exposure to organic solvents.

A sequential mediation model of perceived social support, mindfulness, perceived hope, and mental health literacy: An empirical study on Taiwanese university students

This study explored the mediation of mindfulness and perceived hope between perceived social support and mental health literacy in university students. Of 568 students (205 males, 363 females, average age 20.97) from 70 Taiwanese universities, tools like the Perceived Social Support Scale, General Health Questionnaire, Mindful Attention Awareness Scale, and State Hope Scale were used, adapted to Traditional Chinese through back-translation. Confirmatory factor analysis affirmed model validity. Hayes' PROCESS Model 6 analyzed the data. The results showed an indirect effect of social support on mental health literacy via mindfulness and hope (B = 0.091, 95 % CI: 0.0613 to 0.1258). Three mediation paths were: (1) mindfulness (B = 0.035); (2) hope (B = 0.052); and (3) a combined effect (B = 0.003). A direct effect of social support on mental health literacy was significant (B = 0.120). The model explained 33.9 % of the variance in mental health literacy. The research underscores the link between social support, mindfulness, hope, and mental health literacy, identifying mindfulness and hope as mediators. It stresses the mediation impact and suggests strategies to boost mental health literacy in university students. Future research should expand to cross-cultural studies, further examine the evolving dynamics of social support, and incorporate both qualitative and experimental methodologies. The inclusion of factors such as alienation, well-being, and resilience can enrich the theoretical framework.

Regulatory Cues in Pulmonary Fibrosis-With Emphasis on the AIM2 Inflammasome

Pulmonary fibrosis (PF) is a chronic lung disorder characterized by the presence of scarred and thickened lung tissues. Although the Food and Drug Administration approved two antifibrotic drugs, pirfenidone, and nintedanib, that are currently utilized for treating idiopathic PF (IPF), the clinical therapeutic efficacy remains unsatisfactory. It is crucial to develop new drugs or treatment schemes that combine pirfenidone or nintedanib to achieve more effective outcomes for PF patients. Understanding the complex mechanisms underlying PF could potentially facilitate drug discovery. Previous studies have found that the activation of inflammasomes, including nucleotide-binding and oligomerization domain (NOD)-like receptor protein (NLRP)1, NLRP3, NOD-like receptor C4, and absent in melanoma (AIM)2, contributes to lung inflammation and fibrosis. This article aims to summarize the cellular and molecular regulatory cues that contribute to PF with a particular emphasis on the role of AIM2 inflammasome in mediating pathophysiologic events during PF development. The insights gained from this research may pave the way for the development of more effective strategies for the prevention and treatment of PF.

Psychometric properties of novel instrument for evaluating ambient air pollution health literacy in adults

We aimed to develop and validate a comprehensive ambient air pollution health literacy instrument. We developed items covering 12 constructs, four information competencies within three health domains. In this population-based telephone interview study, probability proportional to size sampling and random digit dialing were used to determine participants. We conducted confirmatory factor analysis to analyze model fits and used content validity indices and Cronbach's alpha to measure content validity and internal consistency reliability. Twenty-four items were generated, and a total of 1,297 participants were recruited. A theoretically conceived 12-factor model was supported (root mean square error of approximation [RMSEA] = 0.068, comparative fit index [CFI] = 0.039, standardized root mean square residual [SRMR] = 0.934, normed fit index [NFI] = 0.914, Tucker-Lewis index [TLI] = 0.902). Content validity indices for relevance, importance, and unambiguity were 0.97, 0.99, and 0.94, respectively. Internal consistency reliability assessed by Cronbach's alpha was 0.93. The ambient air pollution health literacy instrument is valid and reliable and can be used in community residents. The novel instrument can guide the stakeholders and the authority to tailor and implement effective and appropriate interventions and actions, empowering the public to manage hazardous exposure and improving AAPHL of the public.

Evaluating Exposure to VOCs and Naphthalene for Firefighters Wearing Different PPE Configurations through Measures in Air, Exhaled Breath, and Urine

Firefighters are at an increased risk of cancer due to their occupational exposure to combustion byproducts, especially when those compounds penetrate the firefighter personal protective equipment (PPE) ensemble. This has led to questions about the impact of base layers (i.e., shorts vs. pants) under PPE ensembles. This study asked 23 firefighters to perform firefighting activities while wearing one of three different PPE ensembles with varying degrees of protection. Additionally, half of the firefighters unzipped their jackets after the scenario while the other half kept their jackets zipped for five additional minutes. Several volatile organic compound (VOC) and naphthalene air concentrations outside and inside of hoods, turnout jackets, and turnout pants were evaluated; biological (urinary and exhaled breath) samples were also collected. VOCs and naphthalene penetrated the three sampling areas (hoods, jackets, pants). Significant (p-value < 0.05) increases from pre- to post-fire for some metabolites of VOCs (e.g., benzene, toluene) and naphthalene were found. Firefighters wearing shorts and short sleeves absorbed higher amounts of certain compounds (p-value < 0.05), and the PPE designed with enhanced interface control features appeared to provide more protection from some compounds. These results suggest that firefighters can dermally absorb VOCs and naphthalene that penetrate the PPE ensemble.

Indirect causal path from motor function to quality of life through daily use of the affected arm poststroke after task-specific training: a longitudinal mediation analysis

PURPOSE

Task-specific training generally targets motor function, with the ultimate goal of improving quality of life (QoL). This study aimed to determine whether motor function indirectly affects QoL through daily use of the affected arm and activities of daily living (ADL) in patients with chronic stroke.

METHODS

This was a retrospective cohort study of 155 patients who received training for 90-120 min/session, 3-5 sessions/week, for 4-6 weeks. The training involved specific mirror or robot-assisted therapy, followed by functional task practice for 15-30 min in each session. Patients were assessed before and after the intervention.

RESULTS

At both pre-test and post-test, significant indirect effects of motor function on QoL through daily use of the affect arm and ADL were observed (β = 0.087-0.124). When the change scores of the measures between the pre-test and post-test were used, significant mediating effects of daily arm use on the relationship between motor function and QoL were identified (β = 0.094-0.103).

CONCLUSIONS

Enhanced motor function after intervention may lead to an increase in arm use for daily activities and subsequently result in an improvement in QoL. These results highlight the critical role of daily arm use in task-specific training aimed at improving QoL.IMPLICATIONS FOR REHABILITATIONTask-specific training may improve motor function, daily arm use, activities of daily living, and quality of life in patients with mild-to-moderate arm hemiparesis.To improve quality of life in task-specific training, clinicians may work in sequence from motor function to daily arm use and then to activities of daily living.Emphasizing the use of the affected arm in daily life is critical to improve quality of life in task-specific training.

Clinical predictors of early surgical intervention in patients with venomous snakebites

BACKGROUND

Venomous snakebites induce tissue destruction and secondary infection; however, the optimal timing of surgical intervention for these complications remains unknown. This study assessed the clinical predictors of early surgical intervention in patients with snakebites.

METHODS

This retrospective study included 63 patients (45 men and 18 women) with venomous snakebites. In addition to the snake species, the demographics, affected body parts, clinical characteristics, and ultrasound findings of the patients in the surgical (32 patients) and nonsurgical (31 patients) groups were analyzed and compared.

RESULTS

A higher incidence of acute compartment syndrome, local ecchymosis, skin necrosis, bullae, blisters, and fever was found in the surgical group than in the nonsurgical group, and ultrasound findings of the absence of Doppler flow were more frequently noted in the surgical group than in the nonsurgical group. After adjustment using a multivariate logistic regression model, only advanced age, Naja atra bite, local ecchymosis, and bulla or blister formation remained significant factors for surgical intervention. Furthermore, comparison of the outcomes of patients who received early (≤ 24 h) and late (> 24 h) surgical intervention revealed that the duration of continuous negative pressure wound therapy (6 vs. 15 days; P = 0.006), duration of hospital stay (13 vs. 26 days; P = 0.002), and duration of outpatient follow-up (15 vs. 36 days; P < 0.001) were significantly lower in patients who received early surgical intervention. The final reconstructive surgery was simple among the patients who received surgical intervention within 24 h of being bitten (P = 0.028).

CONCLUSION

In patients with snakebites, advanced age, high-risk clinical manifestations (e.g., local ecchymosis and bulla or blister formation), and Naja atra envenomation are predictors of surgical intervention within 24 h.

The effects of high versus low frequency of combined physical and cognitive training on cognitive function in older adults with cognitive decline: a quasi-experimental study

BACKGROUND

The effects of combined training can be affected by training characteristics such as frequency, session length, and duration. No empirical studies to date have directly compared how combined physical and cognitive training offered at different training frequencies affects cognitive function for older adults with cognitive decline. This study investigated the impact of training frequency on cognitive outcomes after combined physical and cognitive training for older adults with cognitive decline.

METHODS

A quasi-experimental study was conducted in community facilities and day care centers. The study assigned 89 older adults with cognitive decline into high-frequency (HF) or low-frequency (LF) training groups. The participants received 90- to 105-min training sessions, one (LF) or three (HF) times a week, for 12 weeks. Outcome measures were the Montreal Cognitive Assessment, Word List subtest of the Wechsler Memory Scale, Digit Symbol Substitution Test (DSST), and Stroop Color Word Test.

RESULTS

The HF group demonstrated greater improvement in immediate memory measured by the WL-IM (F = 8.7, P = 0.004) and in executive function measured by the SCWT (F = 5.89, P = 0.017) than the LF group. Compared with the HF group, the LF group showed a great improvement in delayed memory measured by the WL-DM (F = 9.62, P = 0.003). The HF and LF groups both increased in processing speed and global cognitive function.

CONCLUSIONS

Our study indicated that the different training frequency of combined physical and cognitive training may result in benefits on different cognitive functions in older adults with cognitive decline. These findings may assist clinical practitioners in choosing appropriate training frequencies based on various intervention purposes for the elderly with cognitive decline.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT03619577 (08/08/2018).

Use of Preliminary Exposure Reduction Practices or Laundering to Mitigate Polycyclic Aromatic Hydrocarbon Contamination on Firefighter Personal Protective Equipment Ensembles

Chronic health risks associated with firefighting continue to be documented and studied, however, the complexity of occupational exposures and the relationship between occupational exposure and contaminated personal protective equipment (PPE) remains unknown. Recent work has revealed that common PPE cleaning practices, which are becoming increasingly more common in the fire service, are not effective in removing certain contaminants, such as polycyclic aromatic hydrocarbons (PAHs), from PPE. To better understand the relationship between contaminated firefighter PPE and potential exposure to PAHs, and to gain further understanding of the efficacy of cleaning practices, we used a standardized fire exposure simulator that created repeatable conditions and measured PPE surface contamination levels via wipe sampling and filters attached to firefighter gear worn by standing mannequins. This study examined the effects of repeated (40 cycles) PPE cleaning (laundering and on-scene preliminary exposure reduction (PER) techniques) and repeated exposures on PAH concentration on different surfaces. Further exploration included examination of contamination breakthrough of turnout jackets (comparing outer shell and interior liner) and evaluation of off-gassing PAHs from used gear after different cleaning treatments. When compared by jacket closure type (zipper and hook and dee), total PAH concentration wiped from gear after exposure and cleanings showed no significant differences. Regression analysis indicated that there was no effect of repeated exposures on PAH contamination levels (all sampling sites combined; before fire 10, 20, and 40; after fire 1, 10, 20, and 40; p-value > 0.05). Both laundering and on-scene PER significantly reduced contamination levels on the exterior pants and helmets and were effective at reducing PAH contamination. The jacket outer shell had significantly higher PAH contamination than the jacket liner. Both laundering and wet soap PER methods (post-fire) are effective in reducing surface contamination and appear to prevent accumulation of contamination after repeated exposures. Semi-volatile PAHs deep within the fibers of bulky PPE are not effectively reduced via PER or machine laundering, therefore, permitting continued off-gassing of these compounds. Further research is needed to identify the most effective laundering methods for firefighter turnout gear that considers the broad spectrum of common contaminants.

Sustaining Improvements of Surgical Site Infections by Six Sigma DMAIC Approach

SSIs (surgical site infections) are associated with increased rates of morbidity and mortality. The traditional quality improvement strategies focusing on individual performance did not achieve sustainable improvement. This study aimed to implement the Six Sigma DMAIC method to reduce SSIs and to sustain improvements in surgical quality. The surgical procedures, clinical data, and surgical site infections were collected among 42,233 hospitalized surgical patients from 1 January 2019 to 31 December 2020. Following strengthening leadership and empowering a multidisciplinary SSI prevention team, DMAIC (Define, Measure, Analyze, Improve, and Control) was used as the performance improvement model. An evidence-based prevention bundle for reduction of SSI was adopted as performance measures. Environmental monitoring and antimicrobial stewardship programs were strengthened to prevent the transmission of multi-drug resistant microorganisms. Process change was integrated into a clinical pathway information system. Improvement cycles by corrective actions for the risk events of SSIs were implemented to ensure sustaining improvements. We have reached the targets of the prevention bundle elements in the post-intervention period in 2020. The carbapenem resistance rates of Enterobacteriaceae and P. aeruginosa were lower than 10%. A significant 22.2% decline in SSI rates has been achieved, from 0.9% for the pre-intervention period in 2019 to 0.7% for the post-intervention period in 2020 (p = 0.004). Application of the Six Sigma DMAIC approach could significantly reduce the SSI rates. It also could help hospital administrators and quality management personnel to create a culture of patient safety.

The role of vein grafts in reconstructive head and neck microsurgery

OBJECTIVE

Free tissue transfer is widely used for head and neck reconstruction. In certain circumstances, vein grafting is required to elongate free flap pedicles to connect them to appropriate recipient vessels. Because of controversy regarding the use of interposition vein grafts in free tissue reconstruction, this paper reports vein graft indications, techniques, safety, and outcomes for head and neck microvascular surgery.

METHODS

Twenty-six patients (23 men and 3 women) who underwent interposition vein grafting concurrent with free tissue transfer were included in this study. The most common reason for head and neck reconstruction with vein graft was tumor recurrence, followed by flap salvage. The interposition vein grafts were applied in two manners as temporary arteriovenous (A-V) loop and conduit to extend the length of the free flap for venous drainage.

RESULTS

The most common reconstructions were anterolateral thigh flaps (15 cases), followed by vastus lateralis myocutaneous (3 cases) and radial forearm (2 cases) flaps. The common recipient vessels were superior thyroid artery, superficial temporal artery and external jugular vein. The free flap loss rate was 7.7% with vein grafts and 4.9 without vein grafts (p = 0.380). The free flap complication rate was 50.0% and 16.8% in patients with and without vein grafts, respectively (p < 0.001). Radiation therapy, chemotherapy, prior neck dissection, and prior free flap transfer were more common in the vein graft group (all p < 0.001). The hospital stay was significantly longer for the vein graft group than for the non-vein graft group (29.5 vs. 19.0 days; p = 0.001).

CONCLUSION

Overall free flap survival rates of 92.3% and 95.1% in the vein and non-vein graft groups, respectively - indicating the reliability of the vein grafts in challenging head and neck reconstructions, particularly in salvage cases and patients with multiple reconstructions.

LEVEL OF EVIDENCE

Level 3.

Congenital Surfactant C Deficiency with Pulmonary Hypertension-A Case Report

Interstitial lung diseases in children are a diverse group in terms of etiology and pathogenesis. With advances in genetic testing, mutations in surfactant protein have now been identified as the etiology for childhood interstitial lung disease of variable onset and severity, ranging from fatal acute respiratory distress syndrome (RDS) in neonates to chronic lung disease in adults. We presented an 11-month-old girl with surfactant protein C deficiency and secondary pulmonary hypertension, successfully treated with hydroxychloroquine, and provided a detailed discussion of the clinical and diagnostic approach and management.

Case report: Transcatheter closure of a giant and tortuous right coronary artery to right ventricle fistula in an infant

Congenital coronary artery fistulas (CAFs) are an uncommon congenital anomaly. While most patients are asymptomatic, life-threatening events including sudden death, myocardial ischemia, heart failure, infective endocarditis, and rupture of aneurysm may occur. Surgical ligation was once the standard choice of management of CAFs in the past. However, transcatheter closure of CAFs has become an emerging alternative to surgery in patients with suitable anatomy. We reported a 7-month-old infant with a giant and tortuous CAF that originated from the distal right coronary artery and drained into the right ventricle, and was successfully treated by transcatheter closure with an Amplatzer ductus occluder.

Reliability and validity of an employer-completed safety hazard and management assessment questionnaire

INTRODUCTION

Managing and improving occupational safety and health requires evaluating performance. Organizations are encouraged to use both lagging indicators (such as injury rates and costs) and leading indicators (such as questionnaire-assessed safety hazards and management practices) for this purpose, but the association between types of indicators over time can be complex. Longitudinal data can assist in clarifying these associations and increasing indicator utility.

METHOD

Employer data were used to evaluate the reliability and predictive validity of a safety management questionnaire. Employers' longitudinal questionnaire responses and workers' compensation (WC) claims data were analyzed using a marginal model with time-dependent covariates. Multivariable Poisson and linear regression analyses with claim rate and logarithmic cost, respectively, as dependent variables were carried out after adjusting for industry sector and size. Questionnaire data were used to evaluate questionnaire scaling properties and to assess generalizability of results.

RESULTS

One safety management scale was associated with a better WC outcome as predicted and two scales were unexpectedly associated with poorer WC claim outcomes. Analyses assisted in interpreting the latter results, suggesting that WC outcomes were a stimulus for change in some cases. Twelve hazards assessed on the questionnaire were associated with poorer WC claim outcomes as predicted.

CONCLUSIONS

This study extends leading indicator research using longitudinal questionnaire and WC claims data from employers. Analyses provided insight into associations between leading and lagging indicators, emphasizing the importance of both for safety improvement. Safety management questionnaire scales were predictive of WC claim outcomes, although support for hazard assessments as leading indicators was stronger.

PRACTICAL APPLICATIONS

This study supports the use of employer-completed hazard assessment questionnaires for targeting and prioritizing improvement efforts. Employer-completed safety management scales may be useful for directing improvement efforts, although the conditions under which they are completed, including submission to insurers, require additional consideration.

Firefighters' urinary concentrations of VOC metabolites after controlled-residential and training fire responses

INTRODUCTION

Firefighters are exposed to volatile organic compounds (VOCs) during structural fire responses and training fires, several of which (e.g., benzene, acrolein, styrene) are known or probable carcinogens. Exposure studies have found that firefighters can absorb chemicals like benzene even when self-contained breathing apparatus (SCBA) are worn, suggesting that dermal absorption contributes to potentially harmful exposures. However, few studies have characterized VOC metabolites in urine from firefighters.

OBJECTIVES

We quantified VOC metabolites in firefighters' urine following live firefighting activity across two field studies.

METHODS

In two separate controlled field studies, spot urine was collected before and 3 h after firefighters and firefighter students responded to simulated residential and training fires. Urine was also collected from instructors from the training fire study before the first and 3 h after the last training scenario for each day (instructors led three training scenarios per day). Samples were analyzed for metabolites of VOCs to which firefighters may be exposed.

RESULTS

In the residential fire study, urinary metabolites of xylenes (2MHA), toluene (BzMA), and styrene (MADA) increased significantly (at 0.05 level) from pre- to post-fire. In the training fire study, MADA concentrations increased significantly from pre- to post-fire for both firefighter students and instructors. Urinary concentrations of benzene metabolites (MUCA and PhMA) increased significantly from pre- to post-fire for instructors, while metabolites of xylenes (3MHA+4MHA) and acrolein (3HPMA) increased significantly for firefighter students. The two highest MUCA concentrations measured post-shift from instructors exceeded the BEI of 500 μg/g creatinine.

CONCLUSIONS

Some of the metabolites that were significantly elevated post-fire are known or probable human carcinogens (benzene, styrene, acrolein); thus, exposure to these compounds should be eliminated or reduced as much as possible through the hierarchy of controls. Given stringent use of SCBA, it appears that dermal exposure contributes in part to the levels measured here.

Exposure assessment of polycyclic aromatic hydrocarbons in refined coal tar sealant applications

BACKGROUND

Refined coal tar sealant (RCTS) emulsions are used to seal the surface of asphalt pavement. Nine of the 22 polycyclic aromatic hydrocarbons (PAHs) evaluated in this study are classified as known, probable, or possible human carcinogens. Exposure assessment research for RCTS workers has not been published previously.

OBJECTIVES

The overall objective of this study was to develop a representative occupational exposure assessment of PAH exposure for RCTS workers based on worksite surveys. The specific aims were to: 1) quantify full-shift airborne occupational exposures to PAHs among RCTS workers; 2) quantify workers' dermal exposures to PAHs; 3) quantify biomarkers of PAH exposure in workers' urine; 4) identify specific job titles associated with RCTS exposure; and 5) apply these results to a biological exposure index to assess risk of potential genotoxicity from occupational exposures.

METHODS

A total of twenty-one RCTS workers were recruited from three companies. Personal and area air samples were collected using a modification of NIOSH Method 5515. Dermal exposure was assessed by hand and neck wipes before and after shifts. Twenty-two PAHs were quantified via gas chromatography-mass spectrometry selected ion monitoring. Internal dose was estimated by quantifying select PAH metabolites in pre- and post-shift urine samples using on-line solid phase extraction-high performance liquid chromatography-tandem mass spectrometry.

RESULTS

PAH levels in the worker breathing zones were highest for naphthalene, acenaphthene, and phenanthrene, with geometric means of 52.1, 11.4, and 9.8 μg/m3, respectively. Hand wipe levels of phenanthrene, fluoranthene and pyrene were the highest among the 22 PAHs with geometric means of 7.9, 7.7, and 5.5 μg/cm2, respectively. Urinary PAH biomarkers for naphthalene, fluorene, phenanthrene, and pyrene were detected in all workers and were higher for post-shift samples than those collected pre-shift. Urinary concentrations of the metabolite 1-hydroxypyrene were greater than the American Conference of Governmental Industrial Hygienists (ACGIH) Biological Exposure Index (BEI) for this metabolite in 89 percent of post-shift samples collected on the final day of the work week or field survey. Statistically significances were found between concentrations of fluorene, naphthalene, and phenanthrene in the breathing zone of workers and their corresponding urinary PAH biomarkers. Workers were placed in two work place exposure groups: applicators and non-applicators. Applicators had higher total PAH concentrations in personal breathing zone (PBZ) air samples than non-applicators and were more likely to have post-shift hand wipe concentrations significantly higher than pre-shift concentrations. Concentrations of post-shift urinary biomarkers were higher, albeit not significantly, for applicators than non-applicators.

CONCLUSIONS

The exposure results from RCTS worker samples cannot be explained by proximal factors such as nearby restaurants or construction. Air and skin concentration levels were substantially higher for RCTS workers than previously published levels among asphalt workers for all PAHs. PAH profiles on skin wipes were more consistent with RCTS sealant product than air samples. Last day post-shift urinary concentrations of 1-hydroxypyrene greatly exceeded the ACGIH BEI benchmark of 2.5 μg/L in 25 of 26 samples, which suggests occupational exposure and risk of genotoxicity. When pyrene and benzo[a]pyrene were both detected, concentration ratios from personal exposure samples were used to calculate the adjusted BEI. Concentrations of 1-hydroxypyrene exceeded the adjusted BEIs for air, hand wipes, and neck wipes in most cases. These results indicate the need to increase safety controls and exposure mitigation for RCTS workers.

Plasmon Tuning of Liquid Gallium Nanoparticles through Surface Anodization

In this work, tunable plasmonic liquid gallium nanoparticles (Ga NPs) were prepared through surface anodizing of the particles. Shape deformation of the Ga NPs accompanied with dimpled surface topographies could be induced during electrochemical anodization, and the formation of the anodic oxide shell helps maintain the resulting change in the particle shape. The nanoscale dimple-like textures led to changes in the localized surface plasmon resonance (LSPR) wavelength. A maximal LSPR red-shift of ~77 nm was preliminarily achieved using an anodization voltage of 0.7 V. The experimental results showed that an increase in the oxide shell thickness yielded a negligible difference in the observed LSPR, and finite-difference time-domain (FDTD) simulations also suggested that the LSPR tunability was primarily determined by the shape of the deformed particles. The extent of particle deformation could be adjusted in a very short period of anodization time (~7 s), which offers an efficient way to tune the LSPR response of Ga NPs.

Characterizing exposure to benzene, toluene, and naphthalene in firefighters wearing different types of new or laundered PPE

The fire service has become more aware of the potential for adverse health outcomes due to occupational exposure to hazardous combustion byproducts. Because of these concerns, personal protective equipment (PPE) manufacturers have developed new protection concepts like particulate-blocking hoods to reduce firefighters' exposures. Additionally, fire departments have implemented exposure reduction interventions like routine laundering of PPE after fire responses. This study utilized a fireground exposure simulator (FES) with 24 firefighters performing firefighting activities on three consecutive days wearing one of three PPE ensembles (stratified by hood design and treatment of PPE): 1) new knit hood, new turnout jacket and new turnout pants 2) new particulate-blocking hood, new turnout jacket and new turnout pants or 3) laundered particulate-blocking hood, laundered turnout jacket and laundered turnout pants. As firefighters performed the firefighting activities, personal air sampling on the outside and inside the turnout jacket was conducted to quantify exposures to volatile organic compounds (VOCs) and naphthalene. Pre- and immediately post-fire exhaled breath samples were collected to characterize the absorption of VOCs. Benzene, toluene, and naphthalene were found to diffuse through and/or around the turnout jacket, as inside jacket benzene concentrations were often near levels reported outside the turnout jacket (9.7-11.7% median benzene reduction from outside the jacket to inside the jacket). The PPE ensemble did not appear to affect the level of contamination found inside the jacket for the compounds evaluated here. Benzene concentrations in exhaled breath increased significantly from pre to post-fire for all three groups (p-values < 0.05). The difference of pre-to post-fire benzene exhaled breath concentrations were positively associated with inside jacket and outside jacket benzene concentrations, even though self-contained breathing apparatus (SCBA) were worn during each response. This suggests the firefighters can absorb these compounds via the dermal route.

A Rare Complication During Transcatheter Closure of Double Atrial Septal Defects With Incomplete Cor Triatriatum Dexter: A Case Report

The cor triatiatum dexter is an embryologic remnant derived from the right atrium and totally separate from the right atrium. An incomplete cor triatiatum dexter (iCTD) means a partially obstructive remnant at the right atrium. It is usually formed by a remnant of the Eustachian valve (EV), Thebesian valve (ThV), or Chiari network (CN). This anatomic variant is usually asymptomatic but is often associated with other heart abnormalities including atrial septal defects (ASDs), and has the potential to hamper percutaneous heart procedures such as electrophysiological study or ASD closure. Herein, we report a rare complication, transient heart ischemia, in transcatheter closure of double ASDs in a 55-year-old woman with EV. This rare complication was thought to be caused by coronary sinus obstruction during device placement. The ischemic change was resolved spontaneously after we withdrew the device. For a second attempt, we adjusted the position of the device to avoid coronary sinus obstruction under transesophageal echocardiogram guidance and the device was smoothly deployed in a good position with a minimal residual shunt. This case suggests that anatomy details in percutaneous heart procedures are important, and this rare and dangerous complication, heart ischemia, should be identified immediately during the procedure.

Laboratory study of physical barrier efficiency for worker protection against SARS-CoV-2 while standing or sitting

Transparent barriers were installed as a response to the SARS-COV-2 pandemic in many customer-facing industries. Transparent barriers are an engineering control that intercept particles traveling between customers and workers. Information on the effectiveness of these barriers against aerosols is limited. In this study, a cough simulator was used to represent a cough from a customer. Two optical particle counters were used (one on each side of the barrier, labeled customer and worker) to determine the number of particles that migrated around a transparent barrier. Ten configurations were tested with six replicates for both sitting and standing scenarios, representing nail salons and grocery stores, respectively. Barrier efficiency was calculated using a ratio of the particle count results (customer/worker). Barriers had better efficiency (up to 93%) when its top was 9 to 39 cm above cough height and its width was at least 91 cm. Barriers that extended 91 cm above table height for both scenarios blocked 71% or more of the particles between 0.35-0.725 μm and 68% for particles between 1 to 3 μm. A barrier that blocked an initial cough was effective at reducing particle counts. While the width of the barriers was not as significant as the height in determining barrier efficiency it is important that a barrier be placed where interactions between customers and workers are most frequent. Bystander exposure was not taken into consideration along with other limitations.

Maternal occupation as a nail technician or hairdresser during pregnancy and birth defects, National Birth Defects Prevention Study, 1997-2011

OBJECTIVE

Nail technicians and hairdressers may be exposed to chemicals with potential reproductive effects. While studies have examined birth defects in children of hairdressers, those in children of nail technicians have not been evaluated. We investigated associations between selected birth defects and maternal occupation as a nail technician or hairdresser versus a non-cosmetology occupation during pregnancy.

METHODS

We analysed population-based case-control data from the multisite National Birth Defects Prevention Study, 1997-2011. Cases were fetuses or infants with major structural birth defects; controls were live-born infants without major birth defects. Expert raters classified self-reported maternal jobs as nail technician, combination nail technician-hairdresser, hairdresser, other cosmetology work or non-cosmetology work. We used logistic regression to calculate adjusted ORs and 95% CIs for associations between occupation during pregnancy and birth defects, controlling for age, smoking, education and race/ethnicity.

RESULTS

Sixty-one mothers worked as nail technicians, 196 as hairdressers, 39 as combination nail technician-hairdressers and 42 810 as non-cosmetologists. The strongest associations among nail technicians included seven congenital heart defect (CHD) groups (ORs ranging from 2.7 to 3.5) and neural tube defects (OR=2.6, CI=0.8 to 8.4). Birth defects most strongly associated with hairdressing included anotia/microtia (OR=2.1, CI=0.6 to 6.9) and cleft lip with cleft palate (OR=2.0, CI=1.1 to 3.7). All oral cleft groups were associated with combination nail technician-hairdresser work (ORs ranging from 4.2 to 5.3).

CONCLUSIONS

Small samples resulted in wide CIs. Still, results suggest associations between maternal nail technician work during pregnancy and CHDs and between hairdressing work and oral clefts.

Glycan Masking of Epitopes in the NTD and RBD of the Spike Protein Elicits Broadly Neutralizing Antibodies Against SARS-CoV-2 Variants

Glycan-masking the vaccine antigen by mutating the undesired antigenic sites with an additional N-linked glycosylation motif can refocus B-cell responses to desired epitopes, without affecting the antigen's overall-folded structure. This study examined the impact of glycan-masking mutants of the N-terminal domain (NTD) and receptor-binding domain (RBD) of SARS-CoV-2, and found that the antigenic design of the S protein increases the neutralizing antibody titers against the Wuhan-Hu-1 ancestral strain and the recently emerged SARS-CoV-2 variants Alpha (B.1.1.7), Beta (B.1.351), and Delta (B.1.617.2). Our results demonstrated that the use of glycan-masking Ad-S-R158N/Y160T in the NTD elicited a 2.8-fold, 6.5-fold, and 4.6-fold increase in the IC-50 NT titer against the Alpha (B.1.1.7), Beta (B.1.351) and Delta (B.1.617.2) variants, respectively. Glycan-masking of Ad-S-D428N in the RBD resulted in a 3.0-fold and 2.0-fold increase in the IC-50 neutralization titer against the Alpha (B.1.1.7) and Beta (B.1.351) variants, respectively. The use of glycan-masking in Ad-S-R158N/Y160T and Ad-S-D428N antigen design may help develop universal COVID-19 vaccines against current and future emerging SARS-CoV-2 variants.

Novel Healthy Eating Index to Examine Daily Food Guides Adherence and Frailty in Older Taiwanese

This study was conducted to investigate the adherence of Daily Food Guides (DFGs) among older Taiwanese, and the relationship of dietary quality and frailty. 154 functional independent older adults who were retirement home residents or community dwellers involved in congregate meal services were recruited. DFGs adherence was measured using a novel Taiwanese Healthy Index (T-HEI). Dietary quality was further assessed using Dietary Approach to Stop Hypertension (DASH) and Mediterranean Diet Score (MDS). Frailty was defined using modified Fried’s criteria. Of the total participants, 12.3% were considered non-frail individuals, while 77.3% were prefrail, and 10.4% were frail. Compared to non-frail participants, prefrail and frail individuals indicated significantly lower adherence to DFGs (p_trend = 0.025). Intake of dark or orange vegetables (p_trend = 0.010), whole grains (p_trend = 0.007), as well as nuts and seeds (p_trend = 0.029) by non-frail individuals were significantly higher than the levels by prefrail and frail individuals. Linear regression model adjusted for age, gender, and functional ability showed that T-HEI was inversely associated with frailty status (β = −0.16 ± 0, p = 0.047), but additional adjustment for nutritional status attenuated the association (β = −0.14 ± 0, p = 0.103). A similar relationship was observed for DASH but not MDS (DASH: β = −0.18 ± 0.01, p = 0.024; MDS: β = −0.06 ± 0.02, p = 0.465). After adjustment for confounders, the association was not observed. However, the distribution of whole grains component in both DASH and MDS was significantly higher in non-frail than prefrail and frail individuals, indicating the importance of whole grains intake in frailty prevention. In conclusion, higher adherence to DFGs and better dietary quality were associated with a lower prevalence of frailty. Higher nutrient-dense foods intake such as whole grains, dark or orange vegetables, nuts, and seeds mark a watershed in frailty prevention.

Quantile regression for exposure data with repeated measures in the presence of non-detects

BACKGROUND

Exposure data with repeated measures from occupational studies are frequently right-skewed and left-censored. To address right-skewed data, data are generally log-transformed and analyses modeling the geometric mean operate under the assumption the data are log-normally distributed. However, modeling the mean of exposure may lead to bias and loss of efficiency if the transformed data do not follow a known distribution. In addition, left censoring occurs when measurements are below the limit of detection (LOD).

OBJECTIVE

To present a complete illustration of the entire conditional distribution of an exposure outcome by examining different quantiles, rather than modeling the mean.

METHODS

We propose an approach combining the quantile regression model, which does not require any specified error distributions, with the substitution method for skewed data with repeated measurements and non-detects.

RESULTS

In a simulation study and application example, we demonstrate that this method performs well, particularly for highly right-skewed data, as parameter estimates are consistent and have smaller mean squared error relative to existing approaches.

SIGNIFICANCE

The proposed approach provides an alternative insight into the conditional distribution of an exposure outcome for repeated measures models.

Experience with outreach services of a multidisciplinary team for child abuse identification

BACKGROUND/PURPOSE

Identifying child abuse is sometimes challenging due to its various presentations. To facilitate timely identification of critical or complex cases of physical abuse outside our child protection center, we established an outreach multidisciplinary team (OMDT) to support Kaohsiung City Government in 2014. The objective of this study was to describe our experience of OMDT services during a 6-year period and examine its role in assisting law enforcement.

METHODS

We retrospectively analyzed all OMDT cases from January 2014 to January 2020. Clinical characteristics and OMDT reports were reviewed. After inspection by our OMDT, cases were determined as indicating either a high risk or low risk of child abuse. Associations among clinical characteristics, radiographic findings, OMDT decisions and case outcomes including law enforcement and prosecution were examined.

RESULTS

Thirty-two cases (22 [68.8%] males and 10 [31.2%] females; mean age 24.2 months) received OMDT service, of whom 28 (87.5%) were admitted to the pediatric intensive care unit. The victims had an average of 2.2 types of wounds in 3.4 locations. The most common finding on radiography was subdural hemorrhage (18, 56.3%), followed by subarachnoid hemorrhage (31, 31.3%). Law enforcement was activated in 20 (64.5%) cases, and was only associated with the high-risk group as determined by the OMDT (p < 0.05) but not with any other variables.

CONCLUSION

Our experience indicates that an OMDT can play an important role in child protection and activating law enforcement for children with complex or critical physical abuse. We suggest that in Taiwan, OMDT services should be incorporated into child protection centers, National Health Insurance system and governmental child protection policies.

In situ pedicle lengthening and perforator shifting technique for overcoming the perforator variation of the anterolateral thigh free flap during head and neck reconstruction

BACKGROUND

Anterolateral thigh (ALT) free flap is one of the most popular options for surgeons when reconstructing head and neck defects. When the recipient vessels are located in a remote site, a flap with adequate pedicle length is essential. The conventional methods of either pedicle elongation or fabricating combined flap increase the total surgical time. We present the experience on the use of what in situ pedicle lengthening and perforator shifting technique to overcome these problems.

METHODS

Fifteen patients with an age range of 38-65 years underwent in situ vascular transposition microsurgery of the ALT free flap harvest during head and neck reconstruction. Fourteen patients were male and one was female. Indications for reconstruction were malignant neoplasm in 14 patients and osteoradionecrosis in one patient. In this series, the descending branch of the lateral circumflex femoral vessels was used for interposition grafts. If the pedicle length was insufficient, the interposition grafts were used to lengthen the pedicle. The interposition grafts could also bridge different perforasomes in the thigh region in complex head and neck reconstruction.

RESULTS

Of the 15 patients, 11 received the in situ pedicle lengthening technique, while four patients received in situ fabricated combined techniques. After surgery, all of the patients were followed up for at least 3 months. Two partial wounds involving poor healing occurred but finally healed after debridement. There were two major complications: one case involved venous thrombosis of the anastomosis and the other suffered from hematoma. Both cases were salvaged. All of the 15 free ALT flaps were successful.

CONCLUSIONS

The alternative method employed in this series was able to solve the ALT flap perforator variation. Although the enrolled cases were confined to only head and neck reconstruction in the series, the in situ technique of the ALT flaps could be administered during reconstruction in other regions.

Exposure to Particulate Matter and Estimation of Volatile Organic Compounds across Wildland Firefighter Job Tasks

Wildland firefighters are exposed to smoke-containing particulate matter (PM) and volatile organic compounds (VOCs) while suppressing wildfires. From 2015 to 2017, the U.S. Forest Service conducted a field study collecting breathing zone measurements of PM₄ (particulate matter with aerodynamic diameter ≤4 μm) on wildland firefighters from different crew types and while performing various fire suppression tasks on wildfires. Emission ratios of VOC (parts per billion; ppb): PM₁ (particulate matter with aerodynamic diameter ≤1 μm; mg/m³) were calculated using data from a separate field study conducted in summer 2018, the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE-CAN) Campaign. These emission ratios were used to estimate wildland firefighter exposure to acrolein, benzene, and formaldehyde. Results of this field sampling campaign reported that exposure to PM₄ and VOC varied across wildland firefighter crew type and job task. Type 1 crews had greater exposures to both PM₄ and VOCs than type 2 or type 2 initial attack crews, and wildland firefighters performing direct suppression had statistically higher exposures than those performing staging and other tasks (mean differences = 0.82 and 0.75 mg/m³; 95% confidence intervals = 0.38-1.26 and 0.41-1.08 mg/m³, respectively). Of the 81 personal exposure samples collected, 19% of measured PM₄ exposures exceeded the recommended National Wildland Fire Coordinating Group occupational exposure limit (0.7 mg/m³). Wildland fire management should continue to find strategies to reduce smoke exposures for wildland firefighters.

A national survey of ambient air pollution health literacy among adult residents of Taiwan

OBJECTIVE

To investigate the level of and covariates associated with ambient air pollution health literacy (AAPHL) among adult residents of Taiwan.

METHODS

With a cross-sectional study design, we conducted telephone interviews using a Chinese version AAPHL scale, which consisted of 24 items assessing 12 subdomains of AAPHL formed by 4 information processing competence matrices (i.e., access, understand, appraise, and apply) and 3 health contexts (i.e., healthcare, disease prevention, and health promotion). The AAPHL was with the lowest and highest score at 1 to 4, respectively. Between September and November 2020, a sample of 1017 and 280 adults was successfully interviewed via home phones and mobile phones, respectively. We employed multiple linear regression models to identify covariates significantly associated with overall and 4 matric-specific AAPHL scores.

RESULTS

The mean and standard deviation (±SD) of overall AAPHL score was considered as moderate at 2.90 (±0.56), with the highest and lowest metric-specific score for "apply" (3.07 ± 0.59) and "appraise" (2.75 ± 0.66). Lower education was significantly associated with a lower overall score; and living with children < 12 years and single were both significantly associated with higher overall scores. We also noted a significant geographic variation in overall score in which people living in the east/remote islands had highest scores.

CONCLUSIONS

People in Taiwan had only moderate level of AAPHL; and covariates including education, living arrangement, marital status, and area of living were significantly associated with AAPHL. These covariates should be considered in future educational interventions aiming to improve the AAPHL in the community.

Characterizing exposures to flame retardants, dioxins, and furans among firefighters responding to controlled residential fires

Firefighters may encounter items containing flame retardants (FRs), including organophosphate flame retardants (OPFRs) and polybrominated diphenyl ethers (PBDEs), during structure fires. This study utilized biological monitoring to characterize FR exposures in 36 firefighters assigned to interior, exterior, and overhaul job assignments, before and after responding to controlled residential fire scenarios. Firefighters provided four urine samples (pre-fire and 3-h, 6-h, and 12-h post-fire) and two serum samples (pre-fire and approximately 23-h post-fire). Urine samples were analyzed for OPFR metabolites, while serum samples were analyzed for PBDEs, brominated and chlorinated furans, and chlorinated dioxins. Urinary concentrations of diphenyl phosphate (DPhP), a metabolite of triphenyl phosphate (TPhP), bis(1,3-dichloro-2-propyl) phosphate (BDCPP), a metabolite of tris(1,3-dichloro-2-propyl) phosphate (TDCPP), and bis(2-chloroethyl) phosphate (BCEtP), a metabolite of tris(2-chloroethyl) phosphate (TCEP), increased from pre-fire to 3-hr and 6-hr post-fire collection, but only the DPhP increase was statistically significant at a 0.05 level. The 3-hr and 6-hr post-fire concentrations of DPhP and BDCPP, as well as the pre-fire concentration of BDCPP, were statistically significantly higher than general population levels. BDCPP pre-fire concentrations were statistically significantly higher in firefighters who previously participated in a scenario (within the past 12 days) than those who were responding to their first scenario as part of the study. Similarly, firefighters previously assigned to interior job assignments had higher pre-fire concentrations of BDCPP than those previously assigned to exterior job assignments. Pre-fire serum concentrations of 2,3,4,7,8-pentachlorodibenzofuran (23478-PeCDF), a known human carcinogen, were also statistically significantly above the general population levels. Of the PBDEs quantified, only decabromodiphenyl ether (BDE-209) pre- and post-fire serum concentrations were statistically significantly higher than the general population. These results suggest firefighters absorbed certain FRs while responding to fire scenarios.

Sociopolitical values and social institutions: Studying work and health equity through the lens of political economy

Work contributes to health and health inequity in complex ways. The traditional exposure-disease framework used in occupational health research is not equipped to address societal contexts in which work is embedded. The political economy approach to public health directly examines macro-level societal contexts, but the attention to work in this literature is mostly on unemployment. As a result, we have limited understanding of work as a social determinant of health and health inequity. To fill this gap, we propose a conceptual framework that facilitates research on work, health, and health equity in institutional contexts. As an illustration of different social institutions creating different work-related health, we present characteristics of work and health in the United States and the European Union using the 2015 Working Conditions Surveys data. The results also highlight limitations of the traditional exposure-disease approach used in occupational health research. Applying the proposed framework, we discuss how work and health could be investigated from a broader perspective that involves multiple social institutions and the sociopolitical values that underpin them. Such investigations would inform policy interventions that are congruent with existing social institutions and thus have the potential for being adopted and effective. Further, we clarify the role of research in generating knowledge that would contribute to institutional change in support of population health and health equity.

Effects of firefighting hood design, laundering and doffing on smoke protection, heat stress and wearability

Firefighter hoods must provide protection from elevated temperatures and products of combustion (e.g. particulate) while simultaneously being wearable (comfortable and not interfering with firefighting activities). The purpose of this study was to quantify the impact of (1) hood design (traditional knit hood vs particulate-blocking hood), (2) repeated laundering, and (3) hood removal method (traditional vs overhead doffing) on (a) protection from soot contamination on the neck, (b) heat stress and (c) wearability measures. Using a fireground exposure simulator, 24 firefighters performed firefighting activities in realistic smoke and heat conditions using a new knit hood, new particulate-blocking hood and laundered particulate-blocking hood. Overall, soot contamination levels measured from neck skin were lower when wearing the laundered particulate-blocking hoods compared to new knit hoods, and when using the overhead hood removal process. No significant differences in skin temperature, core temperature, heart rate or wearability measures were found between the hood conditions. Practitioner Summary: The addition of a particulate-blocking layer to firefighters' traditional two-ply hood was found to reduce the PAH contamination reaching the neck but did not affect heat stress measurements or thermal perceptions. Modifying the process for hood removal resulted in a larger reduction in neck skin contamination than design modification. Abbreviations: ANOVA: analysis of variance; B: new particulate-blocking hood and PPE (PPE configuration); FES: fireground exposure simulator; GI: gastrointestinal; K: new knit hood and PPE (PPE configuration); L: laundered particulate-blocking hood and PPE (PPE configuration); LOD: limit of detection; MLE: maximum likelihood estimation; NFPA: National fire protection association; PAH: polycyclic aromatic hydrocarbon; PPE: personal protective equipment; SCBA: self-contained breathing apparatus; THL: total heat loss; TPP: thermal protective performance.

Recipient vessel selection for multiple free flap transfers in head and neck reconstruction at different periods

BACKGROUND

Treatment decisions can be challenging in patients undergoing multiple oropharyngeal microsurgical reconstructions at different periods by various causes. We, retrospectively, reviewed patients with at least three consecutive free flap reconstructions to determine the optimal strategy for selecting recipient vessels.

METHODS

Then, 36 patients (33 men and 3 women) who underwent at least 3 microsurgical reconstructions with a total of 51 free flap transfers for head and neck defects were included in this report. The most common reason for multiple microsurgical reconstructions was recurrent disease. For reconstructions, recipient vessel candidates on the same side of the head and neck were prioritized; if ipsilateral vessels were unavailable, contralateral recipient vessels, which might necessitate vein grafts, were used.

RESULTS

The most common reconstructions were anterolateral thigh flaps (19 cases). The most commonly used contralateral recipient vessels were the superior thyroid artery, facial artery, and external jugular vein. All vessel anastomoses were performed using the end-to-end method. Postoperative complications occurred at the sites of 26 free flap reconstructions. The overall flap reconstruction success rate in patients with at least three surgeries was 90.2%. The median follow-up duration was 25.8 months. During follow-up, 26 patients survived until the end of follow-up.

CONCLUSIONS

In patients undergoing multiple free flap reconstructions, recipient vessels on the ipsilateral side that have not been subjected to radiation should be selected first. Recipient vessels contralateral to the reconstruction side can then be selected; however, they may require vein grafts. Finally, distant healthy recipient vessels can be selected through vein grafting.

Zerumbone Suppresses the LPS-Induced Inflammatory Response and Represses Activation of the NLRP3 Inflammasome in Macrophages

Zerumbone is a natural product isolated from the pinecone or shampoo ginger, Zingiber zerumbet (L.) Smith, which has a wide range of pharmacological activities, including anti-inflammatory effects. However, the effects of zerumbone on activation of the NLRP3 inflammasome in macrophages have not been examined. This study aimed to examine the effects of zerumbone on LPS-induced inflammatory responses and NLRP3 inflammasome activation using murine J774A.1 cells, murine peritoneal macrophages, and murine bone marrow-derived macrophages. Cells were treated with zerumbone following LPS or LPS/ATP treatment. Production of nitric oxide (NO) was measured by Griess reagent assay. The levels of IL-6, TNF-α, and IL-1β secretion were analyzed by ELISA. Western blotting analysis was performed to determine the expression of inducible NO synthase (iNOS), COX-2, MAPKs, and NLRP3 inflammasome-associated proteins. The activity of NF-κB was determined by a promoter reporter assay. The assembly of NLRP3 was examined by immunofluorescence staining and observed by confocal laser microscopy. Our experimental results indicated that zerumbone inhibited the production of NO, PGE₂ and IL-6, suppressed the expression of iNOS and COX-2, repressed the phosphorylation of ERK, and decreased the activity of NF-κB in LPS-activated J774A.1 cells. In addition, zerumbone suppressed the production of IL-1β and inhibited the activity of NLRP3 inflammasome in LPS/ATP- and LPS/nigericin-activated J774A.1 cells. On the other hand, we also found that zerumbone repressed the production of NO and proinflammatory cytokines in LPS-activated murine peritoneal macrophages and bone marrow-derived macrophages. In conclusion, our experimental results demonstrate that zerumbone effectively attenuates the LPS-induced inflammatory response in macrophages both in vitro and ex vivo by suppressing the activation of the ERK-MAPK and NF-κB signaling pathways as well as blocking the activation of the NLRP3 inflammasome. These results imply that zerumbone may be beneficial for treating sepsis and inflammasome-related diseases.

Angiotensin-Converting Enzyme 2 Activator Ameliorates Severe Pulmonary Hypertension in a Rat Model of Left Pneumonectomy Combined With VEGF Inhibition

Background: Pulmonary arterial hypertension (PAH) is a life-threatening and deteriorating disease with no promising therapy available currently due to its diversity and complexity. An imbalance between vasoconstriction and vasodilation has been proposed as the mechanism of PAH. Angiotensin-converting enzyme 2 (ACE2), which catalyzes the hydrolysis of the vasoconstrictor angiotensin (Ang) II into the vasodilator Ang-(1-7), has been shown to be an important regulator of blood pressure and cardiovascular diseases. Herein we hypothesized diminazene aceturate (DIZE), an ACE2 activator, could ameliorate the development of PAH and pulmonary vascular remodeling.

Methods: A murine model of PAH was established using left pneumonectomy (PNx) on day 0 followed by injection of a single dose of the VEGF receptor-2 inhibitor SU5416 (25 mg/kg) subcutaneously on day 1. All hemodynamic and biochemical measurements were done at the end of the study on day 42. Animals were divided into 4 groups (n = 6–8/group): (1) sham-operated group, (2) vehicle-treatment group (SuPNx₄₂), (3) early treatment group (SuPNx₄₂/DIZE₁₋₄₂) with DIZE at 15 mg/kg/day, subcutaneously from day 1 to day 42, and (4) late treatment group (SuPNx₄₂/DIZE₂₉₋₄₂) with DIZE from days 29–42.

Results: In both the early and late treatment groups, DIZE significantly attenuated the mean pulmonary artery pressure, pulmonary arteriolar remodeling, and right ventricle brain natriuretic peptide (BNP), as well as reversed the overexpression of ACE while up-regulating the expression of Ang-(1-7) when compared with the vehicle-treatment group. In addition, the early treatment group also significantly decreased plasma BNP and increased the expression of eNOS.

Conclusions: ACE2 activator has therapeutic potentials for preventing and attenuating the development of PAH in an animal model of left pneumonectomy combined with VEGF inhibition. Activation of ACE2 may thus be a useful therapeutic strategy for the treatment of human PAH.

Case Report: Low Dose of Valsartan/Sacubitril Leads to Successful Reversal of Acute Heart Failure in Chemotherapy-Induced Cardiomyopathy

Valsartan/sacubitril is a new agent approved for the treatment of chronic heart failure in adults, with a combination of angiotensin receptor inhibitor and neprilysin inhibitor. However, the benefit of valsartan/sacubitril in pediatric patients is unknown. We herein report its clinical benefit in a case of acute decompensated heart failure in chemotherapy-induced cardiomyopathy. This case suggests that in children with acute heart failure refractory to conventional medications, low dose of sacubitril/valsartan may be an effective therapy.

Marginal quantile regression for longitudinal data analysis in the presence of time-dependent covariates

When observations are correlated, modeling the within-subject correlation structure using quantile regression for longitudinal data can be difficult unless a working independence structure is utilized. Although this approach ensures consistent estimators of the regression coefficients, it may result in less efficient regression parameter estimation when data are highly correlated. Therefore, several marginal quantile regression methods have been proposed to improve parameter estimation. In a longitudinal study some of the covariates may change their values over time, and the topic of time-dependent covariate has not been explored in the marginal quantile literature. As a result, we propose an approach for marginal quantile regression in the presence of time-dependent covariates, which includes a strategy to select a working type of time-dependency. In this manuscript, we demonstrate that our proposed method has the potential to improve power relative to the independence estimating equations approach due to the reduction of mean squared error.

Flame retardants, dioxins, and furans in air and on firefighters' protective ensembles during controlled residential firefighting

INTRODUCTION

Structure fires that involve modern furnishings may emit brominated flame retardants (BFRs) and organophosphate flame retardants (OPFRs), as well as brominated and chlorinated dioxins and furans, into the environment.

OBJECTIVES

The goal of this study was to quantify the airborne and personal protective equipment (PPE) contamination levels of these compounds during controlled residential fires in the U.S., and to evaluate gross-decontamination measures.

METHODS

Bulk-sampling was done to confirm the presence of flame retardants (FRs) in the furnishings used in 12 controlled residential structure fires. Area air samples were collected during the fires and PPE wipe samples were collected from the firefighters' turnout jackets and gloves after firefighting. For each fire, half of the jackets were decontaminated and the other half were not.

RESULTS

Of the BFRs and OPFRs measured in air during the fire period, decabromodiphenyl ether (BDE-209) and triphenyl phosphate (TPP) were the most abundant, with medians of 15.6 and 408 µg/m³, respectively, and were also detected during overhaul. These and several other BFRs and OPFRs were measured on PPE. Some gloves had contaminant levels exceeding 100 ng/cm² and were generally more contaminated than jackets. Air and surface levels of the brominated furans appeared to be higher than the chlorinated dioxins and furans. Routine gross decontamination appeared to reduce many of the BFR contaminants, but results for the OPFRs were mixed.

CONCLUSIONS

Structure fires are likely to result in a variety of FRs, dioxins, and furans into the environment, leading to PPE contamination for those working on the fireground. Firefighters should wear self-contained breathing apparatus during all phases of the response and launder or decontaminate their PPE (including gloves) after fire events.

Combined noninvasive ventilation and mechanical insufflator-exsufflator for acute respiratory failure in patients with neuromuscular disease: effectiveness and outcome predictors

Background:

To determine the effectiveness of combined noninvasive ventilation (NIV) and mechanical insufflator-exsufflator (MI-E) for acute respiratory failure (ARF) in patients with neuromuscular disease (NMD), and outcome predictors.

Methods:

A prospectively observational study of patients with ARF was conducted in a pediatric intensive care unit (PICU). All received combined NIV/MI-E during PICU stays between 2007 and 2017. Pertinent clinical variables of heart rate (HR), respiratory rate (RR), pH, PaCO₂, and PaO₂/FiO₂ ratio were collected at baseline and at 2 h, 4-8 h, and 12-24 h after initiating use of NIV/MI-E. Treatment success was defined as avoiding intubation.

Results:

A total of 62 ARF episodes in 56 patients with NMD (median age, 13 years) were enrolled. The most frequent underlying NMD was spinal muscular atrophy (32/62, 52%). ARF was primarily due to pneumonia (65%). The treatment success rate was 86%. PICU stay and hospitalization were shorter in the success group (9.4 ± 6.1 vs. 21.9 ± 13.9 days and 16.3 ± 7.8 vs. 33.6 ± 17.9 days, respectively; both p < 0.05). HR, RR, pH, and PaCO₂ showed a progressive improvement, particularly after 4 h following successful NIV/MI-E treatment. RR decrease at 4 h, and pH increase and PaCO₂ decrease at 4-8 h might predict success of NIV/MI-E treatment. The multivariate analysis identified PaCO₂ at 4-8 h of 58.0 mmHg as an outcome predictor of NIV/MI-E treatment.

Conclusions:

Applying combined NIV/MI-E in the acute care setting is an efficient means of averting intubation in NMD patients with ARF. Clinical features within 8 h of the institution may predict treatment outcome.

The reviews of this paper are available via the supplemental material section.

Fabrication of local micro-contacts to silicon solar cells by dewetting of ultrathin polymer films

A local contact patterning process based on dewetting of 50 nm-thick polystyrene (PS) films has been developed for fabrication of silicon PERC (Passivated Emitter and Rear Cell) solar cells. Holey PS films with a random pattern of holes were prepared on dielectric passivated silicon wafers through the dewetting process, and then served as etch masks for selective plasma etching of dielectric passivation layers, in doing so metal contact patterns could be generated. The impact of local back contact formation on cell performance was studied as a function of the metallization fraction. This chemical-based patterning process, which broadens the applications of dewetting of polymer films, offers an interesting alternative to laser-based approaches as it may avoid silicon surface damage and lower the manufacturing costs. The application of this patterning technique to PERC fabrication could result in a preliminary efficiency of 13.5% with a V _oc = 655 mV and a J _sc = 38.4 mA cm^-2. An apparent gain in conversion efficiency of 0.6% could be achieved compared to the full-area aluminum back surface field reference cell.

Worker exposure to flame retardants in manufacturing, construction and service industries

Workers in several industries are occupationally exposed to flame retardants. This study characterizes flame retardant exposure for nine industries through air and hand wipe measures for 105 workers. Specifically, we analyzed 24 analytes from three chemical classes: organophosphate flame retardants (OFRs), polybrominated diphenyl ethers (PBDEs), and non-PBDE brominated flame retardants (NPBFRs). The industries were: carpet installation, chemical manufacturing, foam manufacturing, electronic scrap, gymnastics, rigid board installation, nail salons, roofing, and spray polyurethane foam. Workers wore personal air samplers for two entire workdays and provided hand wipe samples before and after the second work day. Bulk products were also analyzed. The air, hand wipe and bulk samples were evaluated for relevant flame retardants. Spray polyurethane foam workers' tris(1-chloro-2-propyl) phosphate air (geometric mean = 48,500 ng/m³) and hand wipe (geometric mean = 83,500 ng per sample) concentrations had the highest mean industry concentration of any flame retardant analyzed in this study, followed by triphenyl phosphate air concentration and tris(1,3-dichloro-2-propyl) phosphate hand wipe concentration from chemical manufacturers. Overall, OFR air and hand wipe concentrations were higher and more prevalent than PBDEs or non-PBDE brominated flame retardants. Some industries including spray polyurethane foam application, chemical manufacturing, foam manufacturing, nail salons, roofing, and rigid polyiso board installation had high potential for both air and hand exposure to OFRs. Carpet installers, electronic scrap workers, and gymnastic workers had exposures to all three classes of flame retardants including PBDEs, which were phased out of production in 2013. Air and dermal exposures to OFRs are prevalent in many industries and are replacing PBDEs in some industries.

Association between maternal occupational exposure to polycyclic aromatic hydrocarbons and rare birth defects of the face and central nervous system

BACKGROUND

Previous studies suggested associations between maternal smoking, a source of exposure to polycyclic aromatic hydrocarbons (PAHs) and other chemicals, and central nervous system and face birth defects; however, no previous studies have evaluated maternal occupational PAH exposure itself.

METHODS

Jobs held in the periconceptional period were retrospectively assigned for occupational PAH exposures. Associations between maternal occupational PAH exposure and selected rare defects of the face (cataracts, microphthalmia, glaucoma, microtia, and choanal atresia) and central nervous system (holoprosencephaly, hydrocephaly, cerebellar hypoplasia, and Dandy-Walker malformation) were evaluated using data from the National Birth Defects Prevention Study, a population-based case-control study in the United States. Crude and adjusted odds ratios (ORs) with 95% confidence intervals were calculated to estimate associations between each evaluated defect and PAH exposure using multivariable logistic regression.

RESULTS

Food and beverage serving, as well as cooks and food preparation occupations, were among the most frequent jobs held by exposed mothers. Cataracts, microtia, microphthalmia, and holoprosencephaly were significantly associated with PAH exposure with evidence of dose-response (P-values for trend ≤.05). Hydrocephaly was associated with any PAH exposure, but not significant for trend. Sensitivity analyses that reduced possible sources of exposure misclassification tended to strengthen associations.

CONCLUSIONS

This is the first population-based case-control study to evaluate associations between maternal occupational PAH exposures and these rare birth defects of the central nervous system and face.