Nasal oxidative stress mediating the effects of colder temperature exposure on pediatric asthma symptoms

BACKGROUND

Colder temperature exposure is a known trigger for pediatric asthma exacerbation. The induction of oxidative stress is a known pathophysiologic pathway for asthma exacerbation. However, the role of oxidative stress in linking colder temperature exposure and worsened pediatric asthma symptoms is poorly understood.

METHODS

In a panel study involving 43 children with asthma, aged 5-13 years old, each child was visited 4 times with a 2-week interval. At each visit, nasal fluid, urine, and saliva samples were obtained and measured for biomarkers of oxidative stress in the nasal cavity (nasal malondialdehyde [MDA]), the circulatory system (urinary MDA), and the oral cavity (salivary MDA). Childhood Asthma-Control Test (CACT) was used to assess asthma symptoms.

RESULTS

When ambient daily-average temperature ranged from 7 to 18 °C, a 2 °C decrement in personal temperature exposures were significantly associated with higher nasal MDA and urinary MDA concentrations by 47-77% and 6-14%, respectively. We estimated that, of the decrease in child-reported CACT scores (indicating worsened asthma symptoms and asthma control) associated with colder temperature exposure, 14-57% were mediated by nasal MDA.

CONCLUSION

These results suggest a plausible pathway that colder temperature exposure worsens pediatric asthma symptoms partly via inducing nasal oxidative stress.

IMPACT

The role of oxidative stress in linking colder temperature exposure and worsened asthma symptoms is still poorly understood. Lower temperature exposure in a colder season was associated with higher nasal and systemic oxidative stress in children with asthma. Nasal MDA, a biomarker of nasal oxidative stress, mediated the associations between colder temperature exposures and pediatric asthma symptoms. The results firstly suggest a plausible pathway that colder temperature exposure worsens pediatric asthma symptoms partly via inducing oxidative stress in the nasal cavity.

Associations between personal apparent temperature exposures and asthma symptoms in children with asthma

Ambient temperature and relative humidity can affect asthma symptoms. Apparent temperature is a measure of temperature perceived by humans that takes into account the effect of humidity. However, the potential link between personal exposures to apparent temperature and asthma symptoms has not been investigated. We conducted a panel study of 37 asthmatic children, aged 5-11 years, during an early spring season (average daily ambient temperature: 14°C, range: 7-18°C). Asthma symptoms were measured 4 times for each participant with a 2-week interval between consecutive measurements using the Childhood Asthma-Control Test (C-ACT). Average, minimum, and maximum personal apparent temperature exposures, apparent temperature exposure variability (TV), and average ambient temperature were calculated for the 12 hours, 24 hours, week, and 2 weeks prior to each visit. We found that a 10°C lower in 1-week and 2-week average & minimum personal apparent temperature exposures, TV, and average ambient temperature exposures were significantly associated with lower total C-ACT scores by up to 2.2, 1.4, 3.3, and 1.4 points, respectively, indicating worsened asthma symptoms. Our results support that personal apparent temperature exposure is potentially a stronger driver than ambient temperature exposures for the variability in asthma symptom scores. Maintaining a proper personal apparent temperature exposure could be an effective strategy for personalized asthma management.

Oral cavity response to air pollutant exposure and association with pulmonary inflammation and symptoms in asthmatic children

Exposure to fine particulate matter (PM_2.5) and ozone (O₃) may lead to inflammation and oxidative damage in the oral cavity, which is hypothesized to contribute to the worsening of airway inflammation and asthma symptoms. In this panel study of 43 asthmatic children aged 5-13 years old, each child had 4 clinic visits with a 2-week interval between two consecutive visits. At each visit, saliva samples were collected and subsequently analyzed for interleukin 6 (IL-6) and eosinophil cationic protein (ECP) as biomarkers of inflammation and malondialdehyde (MDA) as a biomarker of oxidative stress in the oral cavity. At each visit, children were measured for fractional exhaled nitric oxide (FeNO) as a marker of pulmonary inflammation. Asthma symptoms of these children were measured using the Childhood Asthma Control Test (C-ACT). We found that an interquartile range (IQR) increase in 24-h average personal exposure to PM_2.5 measured 1 and 2 days prior was associated with increased salivary IL-6 concentration by 3.0% (95%CI: 0.2%-6.0%) and 4.2% (0.7%-8.0%), respectively. However, we did not find a clear association between personal O₃ exposure and any of the salivary biomarkers, except for a negative association between salivary MDA and O₃ exposure measured 1 day prior. An IQR increase in salivary IL-6 concentration was associated with significantly increased FeNO by 28.8% (4.3%-53.4%). In addition, we found that increasing salivary IL-6 concentrations were associated with decreased individual and total C-ACT scores, indicating the worsening of asthma symptoms. We estimated that 13.2%-22.2% of the associations of PM_2.5 exposure measured 1 day prior with FeNO and C-ACT scores were mediated by salivary IL-6. These findings suggest that the induction of inflammation in the oral cavity may have played a role in linking air pollution exposure with the worsening of airway inflammation and asthma symptoms.

767The hospital frailty risk score (HFRS) predicts complications in older surgical patients

Background

Frailty increases the risk of post-operative complications in older patients, however clinical assessment of frailty is not routinely undertaken. We aimed to evaluate whether the Hospital Frailty Risk Score (HFRS), calculated using data available from ICD-10 coded electronic records at time of admission, could be used to identify patients at risk of complications.

Methods

Hospital and death data for individuals aged >50 years, admitted for surgery to all hospitals in NSW, Australia 2016-2017 were linked. Hospital-acquired complications (HACs) were identified using 16 categories. Logistic regression models were used to quantify influence of explanatory variables; age, sex, comorbidity, urgency of admission and HFRS on risk of HACs, and model performance assessed.

Results

Of the 150,355 hospitalisations, 12.3% resulted in a complication. Infections (6.1%) and delirium (3.3%) were the most common complications. 30-day mortality was higher following complication (12.5% vs 1.8%, p < 0.0001). Emergency surgery was the strongest predictor for >1 complication (OR 2.67, 95%CI 2.57-2.78), followed by multimorbidity (OR 1.90, 95%CI 1.78-2.02) and high HFRS (OR 1.57, 95%CI 1.48-1.66). The fully-fitted model provided acceptable discrimination (AUC 0.72, 95%CI 0.72-0.73).

Conclusions

The HFRS was strongly associated with complications following surgery. Used in conjunction with age, sex, urgency and comorbidity the HFRS predicted complications with 72% accuracy.

Key messages

This is the first study to validate the use of HFRS as a screening tool to identify frail patients at risk of developing complications following surgery. The HFRS provides hospitals with an inexpensive, systematic method to screen for high-risk patients at time of admission.

Role of endogenous melatonin in pathophysiologic and oxidative stress responses to personal air pollutant exposures in asthmatic children

BACKGROUND

Heightening oxidative stress and inflammation is an important pathophysiological mechanism underlying air pollution health effects in people with asthma. Melatonin can suppress oxidative stress and inflammation in pulmonary and circulatory systems. However, the role of melatonin in the oxidative stress and physiological responses to air pollution exposure has not been examined in children with asthma.

METHODS

In this panel study of 43 asthmatic children (5-13 years old), each child had 4 clinic visits with a 2-week interval between two consecutive visits. At each visit, urine samples were collected and subsequently analyzed for 6-sulfatoxymelatonin (aMT6s) as a surrogate of circulating melatonin and for malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) as two biomarkers of systemic oxidative stress. At each clinic visit, children were measured for pulmonary function and fractional exhaled nitric oxide (FeNO, a marker of pulmonary inflammation). None of the children reported to have taking melatonin supplementation. Concentrations of indoor and ambient PM_2.5 and ozone (O₃) were combined with individual time-activity data to calculate personal air pollutant exposures.

RESULTS

We found that interquartile range increases in urinary MDA and 8-OHdG concentrations were associated with significantly increased urinary aMT6s concentrations by 73.4% (95% CI: 52.6% to 97.0%) and 41.7% (22.8% to 63.4%), respectively. Increases in daily personal exposure to O₃ and to PM_2.5 were each associated with increased urinary aMT6s concentrations. Increasing urinary aMT6s concentrations were associated with decreased FeNO and resonant frequency, indicating improved airway inflammation and lung elasticity, respectively.

CONCLUSION

The results suggest that systemic oxidative stress heightened by air pollution exposure may stimulate melatonin excretion as a defense mechanism to alleviate the adverse effects.

Does identifying frailty from ICD-10 coded data on hospital admission improve prediction of adverse outcomes in older surgical patients? A population-based study

BACKGROUND

frailty is a major contributor to poor health outcomes in older people, separate from age, sex and comorbidities. This population-based validation study evaluated the performance of the International Classification of Diseases, 10th revision, coded Hospital Frailty Risk Score (HFRS) in the prediction of adverse outcomes in an older surgical population and compared its performance against the commonly used Charlson Comorbidity Index (CCI).

METHODS

hospitalisation and death data for all individuals aged ≥50 admitted for surgery to New South Wales hospitals (2013-17) were linked. HFRS and CCI scores were calculated using both 2- and 5-year lookback periods. To determine the influence of individual explanatory variables, several logistic regression models were fitted for each outcome of interest (30-day mortality, prolonged length of stay (LOS) and 28-day readmission). Area under the receiving operator curve (AUC) and Akaike information criterion (AIC) were assessed.

RESULTS

of the 487,197 patients, 6.8% were classified as high HFRS, and 18.3% as high CCI. Although all models performed better than base model (age and sex) for prediction of 30-day mortality, there was little difference between CCI and HFRS in model discrimination (AUC 0.76 versus 0.75), although CCI provided better model fit (AIC 79,020 versus 79,910). All models had poor ability to predict prolonged LOS (AUC range 0.62-0.63) or readmission (AUC range 0.62-0.65). Using a 5-year lookback period did not improve model discrimination over the 2-year period.

CONCLUSIONS

adjusting for HFRS did not improve prediction of 30-mortality over that achieved by the CCI. Neither HFRS nor CCI were useful for predicting prolonged LOS or 28-day unplanned readmission.

Care of Older People in Surgery for general surgery: a single centre experience

BACKGROUND

Older patients undergoing emergency surgery experience higher mortality and morbidity. 'Care of Older People in Surgery' (COPS) is a comprehensive geriatric care model developed for acute surgical units (ASU) to improve clinical outcomes in older general surgical patients. This study aimed to evaluate the impact of COPS on clinical and health service outcomes in an Australian hospital.

METHODS

The before-and-after study was conducted in the ASU, at Nepean Hospital. Data from patients ≥75 years admitted for >24 h into the ASU during the intervention period between April 2017 and March 2018 were compared to patients admitted in the previous year (April 2016 to March 2017) prior to the COPS intervention (n = 212). Health service outcomes measured include the average stay length, medical emergency team response, unplanned intensive care unit admission and 28-day readmission rates.

RESULTS

The COPS group (n = 214) suffered significantly fewer medical complications, including less acute kidney injuries, arrhythmias and urinary tract infections compared to the pre-intervention cohort (n = 212). Medical emergency team activation was significantly reduced after COPS model implementation and the average length of stay decreased. However, the incidence of postoperative delirium and acute coronary syndrome were higher in COPS cohort.

CONCLUSION

Our study demonstrated that comprehensive geriatric assessment and care delivered through a shared model of care in older general surgical patients improved clinical outcome and patient safety measures.

Personal Exposure to PM2.5 Oxidative Potential in Association with Pulmonary Pathophysiologic Outcomes in Children with Asthma

Fine particulate matter (PM_2.5) with a higher oxidative potential has been thought to be more detrimental to pulmonary health. We aim to investigate the associations between personal exposure to PM_2.5 oxidative potential and pulmonary outcomes in asthmatic children. We measured each of the 43 asthmatic children 4 times for airway mechanics, lung function, airway inflammation, and asthma symptom scores. Coupling measured indoor and outdoor concentrations of PM_2.5 mass, constituents, and oxidative potential with individual time-activity data, we calculated 24 h average personal exposures 0-3 days prior to a health outcome measurement. We found that increases in daily personal exposure to PM_2.5 oxidative potential were significantly associated with increased small, large, and total airway resistance, increased airway impedance, decreased lung function, and worsened scores of individual asthma symptoms and the total symptom score. Among the PM_2.5 constituents, organic matters largely of indoor origin contributed the greatest to PM_2.5 oxidative potential. Given that the variability in PM_2.5 oxidative potential was a stronger driver than PM_2.5 mass for the variability in the respiratory health outcomes, it is suggested to reduce PM_2.5 oxidative potential, particularly by reducing the organic matter constituent of indoor PM_2.5, as a targeted source control strategy in asthma management.

Real-time measurements of PM2.5 and ozone to assess the effectiveness of residential indoor air filtration in Shanghai homes

Portable air cleaners are increasingly used in polluted areas in an attempt to reduce human exposure; however, there has been limited work characterizing their effectiveness at reducing exposure. With this in mind, we recruited forty-three children with asthma from suburban Shanghai and deployed air cleaners (with HEPA and activated carbon filters) in their bedrooms. During both 2-week filtration and non-filtration periods, low-cost PM_2.5 and O₃ air monitors were used to measure pollutants indoors, outdoors, and for personal exposure. Indoor PM_2.5 concentrations were reduced substantially with the use of air cleaners, from 34 ± 17 to 10 ± 8 µg/m³ , with roughly 80% of indoor PM_2.5 estimated to come from outdoor sources. Personal exposure to PM_2.5 was reduced from 40 ± 17 to 25 ± 14 µg/m³ . The more modest reductions in personal exposure and high contribution of outdoor PM_2.5 to indoor concentrations highlight the need to reduce outdoor PM_2.5 and/or to clean indoor air in multiple locations. Indoor O₃ concentrations were generally low (mean = 8±4 ppb), and no significant difference was seen by filtration status. The concentrations of pollutants and the air cleaner effectiveness were highly variable over time and across homes, highlighting the usefulness of real-time air monitors for understanding individual exposure reduction strategies.

Children's microenvironmental exposure to PM2.5 and ozone and the impact of indoor air filtration

BACKGROUND

In highly polluted urban areas, personal exposure to PM_2.5 and O₃ occur daily in various microenvironments. Identifying which microenvironments contribute most to exposure can pinpoint effective exposure reduction strategies and mitigate adverse health impacts.

METHODS

This work uses real-time sensors to assess the exposures of children with asthma (N = 39) in Shanghai, quantifying microenvironmental exposure to PM_2.5 and O₃. An air cleaner was deployed in participants' bedrooms where we hypothesized exposure could be most efficiently reduced. Monitoring occurred for two 48-h periods: one with bedroom filtration (portable air cleaner with HEPA and activated carbon filters) and the other without.

RESULTS

Children spent 91% of their time indoors with the majority spent in their bedroom (47%). Without filtration, the bedroom and classroom environments were the largest contributors to PM_2.5 exposure. With filtration, bedroom PM_2.5 exposure was reduced by 75% (45% of total exposure). Although filtration status did not impact O₃, the largest contribution of O₃ exposure also came from the bedroom.

CONCLUSIONS

Actions taken to reduce bedroom PM_2.5 and O₃ concentrations can most efficiently reduce total exposure. As real-time pollutant monitors become more accessible, similar analyses can be used to evaluate new interventions and optimize exposure reductions for a variety of populations.

Malondialdehyde in Nasal Fluid: A Biomarker for Monitoring Asthma Control in Relation to Air Pollution Exposure

Fine particulate matter (PM_2.5) and ozone (O₃) may exert oxidative damage in the nose, which is hypothesized to be associated with worsened asthma symptoms. This study, hence, is to explore whether an oxidative stress biomarker, malondialdehyde (MDA) in the nasal fluid, has the potential to aid personalized asthma control. In a panel study of 43 asthmatic children, 5-13 years old, each child was measured 4 times with a 2-week interval between consecutive clinic visits. At each visit, nasal fluid and urine samples were collected, and fractional exhaled nitric oxide (FeNO) was measured as a biomarker of pulmonary inflammation. In addition to nasal MDA, urinary MDA and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were measured as biomarkers of systemic oxidative stress. We also assessed asthma symptoms using the Childhood Asthma-Control Test (C-ACT). We found that interquartile range (IQR) increases in 24 h average personal PM_2.5 exposure (22.2-33.5 μg/m³), estimated 0 to 5 days prior to a clinic visit, were associated with increased nasal MDA concentrations by 38.6-54.9%. Similarly, IQR increases in 24 h average personal O₃ exposure (7.7-8.2 ppb) estimated 2 to 4 days prior were associated with increased nasal MDA by 22.1-69.4%. Only increased PM_2.5 exposure was associated with increased FeNO. Increased nasal MDA concentration was associated with decreased total and individual C-ACT scores, indicating worsening of asthma symptoms. However, no significant associations were observed between urinary MDA or 8-OHdG and C-ACT scores. The results confirm that oxidative stress plays an important role in linking air pollution exposure and adverse respiratory health effects. These findings support that MDA in the nasal fluid may serve as a useful biomarker for monitoring asthma status, especially in relation to PM_2.5 and O₃ exposures, two known risk factors of asthma exacerbation.

Associations of personal exposure to air pollutants with airway mechanics in children with asthma

BACKGROUND

The importance of airway mechanics has been increasingly recognized in pediatric asthma. However, no studies have examined responses of airway mechanics to air pollution exposure in asthmatic children.

METHODS

In this panel study involving indoor air filtration manipulation that created a large gradient of personal exposure to PM_2.5, the airway mechanics and lung function of 43 asthmatic children 5-13 years old in a suburb of Shanghai were measured four times within 3 consecutive months. Concentrations of indoor and outdoor PM_2.5 and ozone were coupled with individual time-activity data to calculate personal exposures. Linear mixed effects models were used to examine the relationships of personal exposure with indicators of airway mechanics and lung function, respectively.

RESULTS

An interquartile range (IQR) increase in 24-hour average PM_2.5 personal exposure (30.3 µg/m³) in the prior day was associated with significant increases in small airway resistance (R₅-R₂₀) of 15.8%, total airway resistance (R₅) of 6.3%, and airway inflammation (FeNO) of 9.6%. These associations were stronger in children with lower blood eosinophil counts (<450/µL). No significant associations were found between personal PM_2.5 exposure and lung function. Low-level ozone exposure (daily maximum 8-hour exposure range 1.1-56.4 ppb) was not significantly associated with any of the outcomes.

CONCLUSION

Changes in personal PM_2.5 exposure, partly enhanced by air filtration, were associated with significant changes in airway resistance and inflammation in children with asthma. These findings suggest the importance of reducing PM_2.5 exposure, via personal air quality management, in improving airflow limitation in the airways, especially the small airways.

The impact of household air cleaners on the oxidative potential of PM2.5 and the role of metals and sources associated with indoor and outdoor exposure

The health effects associated with human exposure to airborne fine particulate matter (PM_2.5) have been linked to the ability of PM_2.5 to facilitate the production of excess cellular reactive oxygen species (oxidative potential). Concern about the adverse human health impacts of PM_2.5 has led to the increased use of indoor air cleaners to improve indoor air quality, which can be an important environment for PM_2.5 exposure. However, the degree to which the oxidative potential of indoor and personal PM_2.5 can be influenced by an indoor air cleaner remains unclear. In this study we enrolled 43 children with physician diagnosed asthma in suburban Shanghai, China and collected two paired-sets of 48-h indoor, outdoor, and personal PM_2.5 exposure samples. One set of samples was collected under "real filtration" during which a functioning air cleaner was installed in the child's bedroom, and the other ("false filtration") with an air cleaner without internal filters. The PM_2.5 samples were characterized by inductively coupled plasma mass spectroscopy for elements, and by an alveolar macrophage assay for oxidative potential. The sources of metals contributing to our samples were determined by the EPA Positive Matrix Factorization model. The oxidative potential was lower under real filtration compared to sham for indoor (median real/sham ratio: 0.260) and personal exposure (0.813) samples. Additionally, the sources of elements in PM_2.5 that were reduced indoors and personal exposure samples by the air cleaner (e.g. regional aerosol and roadway emissions) were found by univariate multiple regression models to be among those contributing to the oxidative potential of the samples. An IQR increase in the regional aerosol and roadway emissions sources was associated with a 107% (95% CI: 80.1-138%) and 38.1% (17.6-62.1%) increase in measured oxidative potential respectively. Our results indicate that indoor air cleaners can reduce the oxidative potential of indoor and personal exposure to PM_2.5, which may lead to improved human health.

Using low-cost sensors to monitor indoor, outdoor, and personal ozone concentrations in Beijing, China

High concentrations of ground-level ozone (O₃) have been measured outdoors across China but there are limited measurements of O₃ in microenvironments, including in homes, and for personal exposure. This highlights the need for cheaper methods to accurately make these measurements and to better capture fine-scale spatial variability in O₃ across cities. With this in mind, we conducted a pilot study at six homes in Beijing, China, over 12 days to evaluate the use of portable, low-cost, time-resolved monitors for measuring O₃ indoors and outdoors. We also assessed personal exposure for one adult in each home for two 48 hour periods using backpack-mounted monitors. Prior to and following sampling we collocated all monitors with a reference analyzer; we used data from these colocations to generate linear calibrations which we applied to all monitor data. Calibration slopes did not change significantly over the study although some intercepts differed. The average limit of detection (LOD) was 7.0 ppb, average root mean square error was 16.7 ppb, mean absolute error was 13.3 ppb and normalized root mean square error was 33%. Performance varied substantially between sensors, underscoring the importance of monitor-specific calibrations and determinations of measurement error. Outdoor concentrations varied spatially, with home-specific peak hourly averages of 32-165 ppb; indoor concentrations ranged from below the LOD to 15 ppb. Hour-averaged personal exposure was generally higher than O₃ indoors, and at times exceeded ambient O₃ indicating contributions to personal exposure from ambient sources of O₃ away from the home. This work illustrates the feasibility of using these monitors to characterize distributions of O₃ spatially and temporally when differences in concentrations are large, and outlines considerations for using these monitors to measure personal exposure.

Evaluation of the Assurance GDS™ for E. coli O157:H7 Method and Assurance GDS for Shigatoxin Genes Method in Selected Foods: Collaborative Study

A multilaboratory collaborative study was conducted to compare the Assurance GDS™ for E. coli O157:H7 method and the reference culture methods for the detection of E. coli O157:H7 in orange juice, raw ground beef, and fresh lettuce. A separate companion assay, the Assurance GDS for Shigatoxin Genes method was also evaluated with the same test portions. Fifteen laboratories participated in the study. A Chi square analysis of each of the 3 food types at the high, low, and uninoculated control levels was performed. For all foods, the Assurance GDS for E. coli O157:H7 method and the Assurance GDS for Shigatoxin Genes method were equivalent to or better than the reference methods.

The impact of household air cleaners on the chemical composition and children's exposure to PM2.5 metal sources in suburban Shanghai

Increased public awareness of the health impacts of atmospheric fine particulate matter (PM_2.5) has led to increased demand and deployment of indoor air cleaners. Yet, questions still remain about the effectiveness of indoor air cleaners on indoor PM_2.5 concentrations and personal exposure to potentially hazardous components of PM_2.5. Metals in PM_2.5 have been associated with adverse health outcomes, so knowledge of their sources in urban indoor and outdoor areas and how exposures are influenced by indoor air cleaners would be beneficial for public health interventions. We collected 48-h indoor, outdoor, and personal PM_2.5 exposure samples for 43 homes with asthmatic children in suburban Shanghai, China during the spring months. Two sets of samples were collected for each household, one set with a functioning air filter placed in the bedroom ("true filtration") and the other with a non-functioning ("sham") air cleaner. PM_2.5 samples were analyzed for elements, elemental carbon, and organic carbon. The major sources of metals in PM_2.5 were determined by Positive Matrix Factorization (PMF) to be regional aerosol, resuspended dust, residual oil combustion, roadway emissions, alloy steel abrasion, and a lanthanum (La) and cerium (Ce) source. Under true filtration, the median indoor to outdoor percent removal across all elements increased from 31% to 78% and from 46% to 88% across all sources. Our findings suggest that indoor air cleaners are an effective strategy for reducing indoor concentrations of PM_2.5 metals from most sources, which could translate into improved health outcomes for some populations.

Sources of volatile organic compounds in suburban homes in Shanghai, China, and the impact of air filtration on compound concentrations

Air pollution in China is an ongoing concern, with subsets of the population (e.g., asthmatic children) especially susceptible to the associated health effects. In addition, people spend the majority of their time indoors, where pollutant composition may differ from the better characterized ambient environment. Although volatile organic compounds (VOCs) present health risks and have high concentrations indoors, their sources have not been thoroughly quantified in typical homes in suburban China. Similarly lacking is an understanding of how well a purifier with high efficiency particulate air and activated carbon filters can remove VOCs in a real-world setting in China. In this study, we a) quantified total VOCs (TVOC) and 900 + individual VOCs in 20 homes in China, b) identified potential sources of VOCs, and c) evaluated impacts of filtration. We used non-negative matrix factorization, a variable reduction technique, to identify sources. TVOC and individual compounds had higher concentrations indoors than outdoors (mean [range] indoors, filtration with pre-filter only: 302 [56-793] μg m-3; outdoors, entire study: 92 [26-629] μg m-3), indicating prevalent sources indoors. Many compounds detected have not, to our knowledge, been measured in homes in China. Some compounds (e.g., octanal, heptanal, ⍺-cedrene) were specific to the indoor environment, a few were ubiquitous (e.g., acetaldehyde, formaldehyde), and others were detected infrequently. These compounds may originate from consumer products, solvents, vehicle emissions, a hexane source, wooden products, and cooking. Filtration may improve air quality indoors by lowering concentrations of some VOCs, and, specifically, contributions related to solvents and consumer products.

The influence of air cleaners on indoor particulate matter components and oxidative potential in residential households in Beijing

In many developing regions with poor air quality, the use of air filtration devices to clean indoor air is growing rapidly. In this study, we collected indoor, outdoor and personal exposure filter-based samples of fine particulate matter (PM_2.5) with both properly operating, and sham air cleaners in six Beijing residences from July 24th to August 17th, 2016. Mass concentrations of PM_2.5 and several health relevant components of PM_2.5 including organic carbon, elemental carbon, sulfate, nitrate, ammonium, and 21 selected metals, were analyzed to evaluate the effectiveness of air cleaners. The effect of air purification on PM_2.5 reactive oxygen species (ROS) activity, a metric of the oxidative potential of the aerosol, was also evaluated. The average indoor PM_2.5 concentration during true filtration was 8.47μg/m³, compared to 49.0μg/m³ during sham filtration; thus, air cleaners can significantly reduce the indoor PM_2.5 concentration to well below WHO guideline levels and significantly lower all major components of PM_2.5. However, the utility of air cleaners in reducing overall personal exposure to PM_2.5 and its components was marginal in this study: the average personal exposure PM_2.5 concentration was 67.8 and 51.1μg/m³ during true and sham filtration respectively, and it is likely due to the activity patterns of the subjects. Short-term exposure contributions from environments with high PM_2.5 concentrations, including exposure to traffic related emissions as well as uncharacterized indoor microenvironments, likely add substantially to the total PM_2.5 exposure burden. The toxicity assay indicates that the air cleaners can also significantly reduce ROS activity in the indoor environment; however, this decrease did not translate to a reduction in personal exposure. Elemental carbon, lead, and arsenic were well-correlated with the ROS activity, thus adding to the knowledge base of drivers for ROS activity.

Abstract P6-13-08: A novel comparative analysis approach to personalize chemotherapy dose in early breast cancer

Background: Worldwide, body surface area [BSA] is used to calculate chemotherapy dose. The BSA formula was originally developed in 1916, derived from height and weight, with no consideration of other patient characteristics. Most chemotherapy agents have a narrow therapeutic index and are distributed in lean body mass [LBM], leading to under- or over-dosing and deleterious effects to major organs when body composition is not considered. To date, while experts worldwide acknowledge the limitations and risks of BSA dosing, no practical approach to personalizing chemotherapy dose has been developed. Ideally, body composition would be assessed by tests already routinely performed, avoiding unnecessary radiation exposure, clinic visits, discomfort to the patient, and cost. The majority of patients undergo cardiac imaging prior to chemotherapy. We hypothesized that clinical parameters routinely performed prior to chemotherapy could predict LBM in early breast cancer patients.

Method: Early stage breast cancer patients (n = 45) enrolled in the Multidisciplinary Team Intervention in Cardio-Oncology (TITAN) study underwent pre-treatment cardiac MRI, body composition (iDEXA) and laboratory (complete blood cell count and chemistry). Cardiac MRI and iDEXA are considered 'gold standard' imaging modalities, the accuracy of which allow for significantly reduced sample size.

Our modeling approach, which is novel in this area, aimed to select the best combination of parameters with the most predictive ability of total lean mass (iDEXA). The parameters included in study are: cardiac MRI metrics (LV mass, cardiac output), and laboratory parameters associated with major organ function (albumin, creatinine, bilirubin). All parameters were tested using univariate, multivariate and subset selection approach. Akaike's Information Criterion (AIC) was used to measure model quality, with lower AIC values indicating closer prediction.

Results: The univariate analysis of each parameter independently showed LV mass is most predictive with AIC 857.8, while combination of all parameter in multivariate fashion show improvement in prediction with AIC 851. The subset selection approach shows, Adjusted R2 with 4 parameters had AIC 849.14, Schwartz's information criterion (BIC) with 2 parameters had AIC 849.66 and Mallows' C Selection (Cp) model with 3 parameters had the least AIC 848.71 value (P &lt; 0.001).

Conclusion: Our comparative analysis showed that the Cp model with 3 parameters (LV mass, cardiac output and bilirubin) has high prediction ability of LBM. This model will form the basis of a personalized formula for chemotherapy dose calculation. We expect this work to result in optimal cancer-specific outcomes while reducing short and long-term toxicities associated with necessary chemotherapy.

Citation Format: Perri MD, Singhal S, Hegadoren K, Norris C, Mackey J, Paterson I, Pituskin E. A novel comparative analysis approach to personalize chemotherapy dose in early breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-13-08.

Assessing Exposure to Household Air Pollution: A Systematic Review and Pooled Analysis of Carbon Monoxide as a Surrogate Measure of Particulate Matter

BACKGROUND

Household air pollution from solid fuel burning is a leading contributor to disease burden globally. Fine particulate matter (PM_2.5) is thought to be responsible for many of these health impacts. A co-pollutant, carbon monoxide (CO) has been widely used as a surrogate measure of PM_2.5 in studies of household air pollution.

OBJECTIVE

The goal was to evaluate the validity of exposure to CO as a surrogate of exposure to PM_2.5 in studies of household air pollution and the consistency of the PM_2.5-CO relationship across different study settings and conditions.

METHODS

We conducted a systematic review of studies with exposure and/or cooking area PM_2.5 and CO measurements and assembled 2,048 PM_2.5 and CO measurements from a subset of studies (18 cooking area studies and 9 personal exposure studies) retained in the systematic review. We conducted pooled multivariate analyses of PM_2.5-CO associations, evaluating fuels, urbanicity, season, study, and CO methods as covariates and effect modifiers.

RESULTS

We retained 61 of 70 studies for review, representing 27 countries. Reported PM_2.5-CO correlations (r) were lower for personal exposure (range: 0.22-0.97; median=0.57) than for cooking areas (range: 0.10-0.96; median=0.71). In the pooled analyses of personal exposure and cooking area concentrations, the variation in ln(CO) explained 13% and 48% of the variation in ln(PM_2.5), respectively.

CONCLUSIONS

Our results suggest that exposure to CO is not a consistently valid surrogate measure of exposure to PM_2.5. Studies measuring CO exposure as a surrogate measure of PM exposure should conduct local validation studies for different stove/fuel types and seasons. https://doi.org/10.1289/EHP767.

A panel study of the acute effects of personal exposure to household air pollution on ambulatory blood pressure in rural Indian women

BACKGROUND

Almost half the world's population is exposed to household air pollution from biomass and coal combustion. The acute effects of household air pollution on the cardiovascular system are poorly characterized. We conducted a panel study of rural Indian women to assess whether personal exposures to black carbon during cooking were associated with acute changes in blood pressure.

METHODS

We enrolled 45 women (ages 25-66 years) who cooked with biomass fuels. During cooking sessions in winter and summer, we simultaneously measured their personal real-time exposure to black carbon and conducted ambulatory blood pressure measurements every 10min. We recorded ambient temperature and participants' activities while cooking. We assessed body mass index, socioeconomic status, and salt intake. Multivariate mixed effects regression models with random intercepts were used to estimate the associations between blood pressure and black carbon exposure, e.g., average exposure in the minutes preceding blood pressure measurement, and average exposure over an entire cooking session.

RESULTS

Women's geometric mean (GM) exposure to black carbon during cooking sessions was lower in winter (GM: 40μg/m(3); 95% CI: 30, 53) than in summer (GM: 56μg/m(3); 95% CI: 42, 76). Interquartile range increases in black carbon were associated with changes in systolic blood pressure from -0.4mm Hg (95% CI: -2.3, 1.5) to 1.9mm Hg (95% CI: -0.8, 4.7), with associations increasing in magnitude as black carbon values were assessed over greater time periods preceding blood pressure measurement. Interquartile range increases in black carbon were associated with small decreases in diastolic blood pressure from -0.9mm Hg (95% CI: -1.7, -0.1) to -0.4mm Hg (95% CI: -1.6, 0.8). Associations of a similar magnitude were estimated for cooking session-averaged values.

CONCLUSIONS

We found some evidence of an association between exposure to black carbon and acute increases in systolic blood pressure in Indian women cooking with biomass fuels, which may have implications for the development of cardiovascular diseases.

A population-based comparison of the use of acute healthcare services by older adults with and without mental illness diagnoses

Older adults with mental illness (MI) are a highly vulnerable population and need to be provided healthcare services in a timely and thorough way. Compared with older adults without MI, older adults with MI spend a great deal of time being hospitalized and hence costing millions of dollars because the care they need is often overlooked and/or not provided. While they end up spending too much time in hospital, in the emergency department and getting readmitted to hospital because of their MI, this could have been prevented or lessened if an adequate assessment and treatment regime was done by clinicians who were well informed on the topic of older adults' mental health. Older adults with MI are also more likely to leave hospital for long-term care settings, to die and to have more sickness compared with older adults who do not have MI. Further, they are also more likely to be admitted to hospital on an urgent, unplanned basis. How older adults with MI use acute hospitals is important for psychiatric nurses to know and understand, as they can help to provide the care needed so they do not have to be in hospital for long periods of time. Psychiatric nurses can share much support and information on making sure older adults with MI are accurately care for when needed. To explore and compare predictors of hospital length of stay (LOS), acute LOS (ALOS), emergency room (ER) wait times, rate of readmission (ROR) and costs of inpatient hospital care for older adults with and without mental illness (MI) diagnoses in the province of Newfoundland and Labrador (NL). This descriptive-comparative study used aggregate population level data of 12,283 people aged 65 years and older admitted to an acute care hospital in the province of NL. A total of 8.3% of hospitalized older adults had MI diagnoses. Older adults with MI diagnoses had a significantly longer LOS, ALOS, ROR, ER wait time and costs compared with older adults without MI diagnoses, after controlling for medical co-morbidities. Key variables such as patient demographics, admission indicators, discharge indicators and other medical co-morbidities had differential impacts on observed service use. While only a small percentage of hospitalized older adults had MI diagnoses, the use and cost of acute hospitalizations was significantly greater than that of older adults without MI diagnoses.

Elevated phenylacetic acid levels do not correlate with adverse events in patients with urea cycle disorders or hepatic encephalopathy and can be predicted based on the plasma PAA to PAGN ratio

BACKGROUND

Phenylacetic acid (PAA) is the active moiety in sodium phenylbutyrate (NaPBA) and glycerol phenylbutyrate (GPB, HPN-100). Both are approved for treatment of urea cycle disorders (UCDs) - rare genetic disorders characterized by hyperammonemia. PAA is conjugated with glutamine in the liver to form phenylacetyleglutamine (PAGN), which is excreted in urine. PAA plasma levels ≥ 500 μg/dL have been reported to be associated with reversible neurological adverse events (AEs) in cancer patients receiving PAA intravenously. Therefore, we have investigated the relationship between PAA levels and neurological AEs in patients treated with these PAA pro-drugs as well as approaches to identifying patients most likely to experience high PAA levels.

METHODS

The relationship between nervous system AEs, PAA levels and the ratio of plasma PAA to PAGN were examined in 4683 blood samples taken serially from: [1] healthy adults [2], UCD patients of ≥ 2 months of age, and [3] patients with cirrhosis and hepatic encephalopathy (HE). The plasma ratio of PAA to PAGN was analyzed with respect to its utility in identifying patients at risk of high PAA values.

RESULTS

Only 0.2% (11) of 4683 samples exceeded 500 μg/ml. There was no relationship between neurological AEs and PAA levels in UCD or HE patients, but transient AEs including headache and nausea that correlated with PAA levels were observed in healthy adults. Irrespective of population, a curvilinear relationship was observed between PAA levels and the plasma PAA:PAGN ratio, and a ratio>2.5 (both in μg/mL) in a random blood draw identified patients at risk for PAA levels>500 μg/ml.

CONCLUSIONS

The presence of a relationship between PAA levels and reversible AEs in healthy adults but not in UCD or HE patients may reflect intrinsic differences among the populations and/or metabolic adaptation with continued dosing. The plasma PAA:PAGN ratio is a functional measure of the rate of PAA metabolism and represents a useful dosing biomarker.

A STUDY OF PNEUMOCOCCI AND ALLIED ORGANISMS IN HUMAN MOUTHS AND LUNGS AFTER DEATH

THE FOLLOWING CONCLUSIONS MAY BE DRAWN, BASED UPON THE RESULT OF OUR RESEARCHES: 1. Organisms of the pneumococcus or streptococcus group are present in the lungs of practically all cases, whether normal or showing a variety of lesions; strictly speaking, they were found by us in forty out of forty-two cases, or in 95% of our series. 2. The pneumococci and the streptococci were obtained in practically similar percentages-that is, in 50 % of the cases. 3. Pneumococci were not obtained more frequently in the small series of patients exposed for some time to hospital atmosphere; our tables show the contrary to obtain. The number of cases examined were, however, insufficient, and the findings may thus be accidental, and hence of no value. 4. Test micro-organisms, namely, small portions-half a drachm or less-of B. prodigiosus, introduced into the human mouth after death, were conveyed to and recovered from the lungs by culture in a little over half of the cases in which this experiment was tried. The test micro-organisms are, we believe, conveyed to the lungs with the fluid which collects in mouths of persons after death, and which in many cases collects just before death. The numerous manipulations entailed in the removal of the body from the wards to the morgue greatly facilitate the entrance of any fluid from the pharynx and buccal cavity into the lungs. It follows logically, from the results obtained in this experiment, that the cultural findings after death are no guide to the bacterial contents of the lungs during life, and that any deductions made from such findings are unreliable and deceptive. Granted that our explanation be correct, there is every reason to believe that any of the micro-organisms present in the mouths and pharynx and in many cases in the stomach contents may enter the lungs and, if the conditions be suitable, increase in numbers, during the time between death and the examination of the lungs. There exists, perhaps, more frequently than has hitherto been suspected, a series of diplococci, intermediate between the typical pneumococci and streptococci. The diplococci of this type have been found in forty (40) per cent. of our cases. The differential diagnosis of these atypical diplococci from the pneumococci and streptococci is a difficult one, depending, as it does, upon general cultural characteristics. No single character, such as the presence of capsules or the fermentation of inulin, virulence, etc., has been found to be a certain criterion. The few agglutinative reactions we have made seem to show that these intermediate diplococci, those of Groups II, III, and IV, have no or only slight agglutinative affinities to the typical pneumococcus. Further tests must, however, be made with the various methods at our disposal before this statement can be accepted as final. These diplococci are of interest from the fact that they have been found in the blood during life, and in the pial exudate of cases of meningitis, endocarditis, etc. 6. Our studies have thrown no light whatever upon the conditions which determine the onset of lobar pneumonia in apparently healthy persons. Moreover, we have been unable to draw conclusions as to the presence of pneumococci in the lungs during life, or as to the channels by which they gain access thereto.

"RED-LEG"-AN INFECTIOUS DISEASE OF FROGS

The epidemics we have observed, were due to the presence and growth in the frogs of Bacillus hydrophilus fuscus. This was proved by recovering the bacillus in pure culture from the body fluids of frogs sick or dead of the disease, and the inoculation of healthy frogs with an emulsion of the pure culture, and by obtaining the same clinical picture and pathological findings as in the original diseased frogs; and, finally, by recovering the bacillus in pure culture from frogs inoculated and sick or dying as a result of the inoculation. The disease is widely distributed throughout North America and Europe, and in this country and Canada is known as "red-leg." It has been observed by us chiefly in the warm weather of September and October. The disease is characterized by congestion of the ventral surfaces of the body, with more or less ulceration in, and hæmorrhage beneath, the skin, bloating due to serous exudation into the lymph sacs, gradual failure to respond to stimuli, which symptoms are followed by coma and death, the last being occasionally preceded by tetanic seizures. After death hæmorrhages into the muscles and degenerative changes in the muscles, spleen, liver, and, to a slight degree, in the intestinal tract, are found. The blood shows an advanced degree of anæmia and leucocytosis. Predisposing causes of the disease are lesions of the skin, which seem to be the usual portal of entry of the infection, and lowered resistance from heat and from anæmia. By a series of controlled experiments with inoculated frogs we have shown that, while temperatures a little above freezing have no harmful effect upon the frogs, they completely control all manifestations of the disease in inoculated or diseased frogs, if the frogs are left in the cold for a period as long as seven days; and, further, that even short periods in the cold chamber will bring about a delay of the fatal results in diseased or inoculated frogs. The anæmia so often found in apparently healthy frogs seems in many cases to be due to the presence in the lungs of the frog of a parasite, the Distomum cylindraceum, which, occurring in sufficiently large numbers in an individual frog, is capable of materially diminishing the available supply of red corpuscles. Severe laking of the blood, the presence of numerous isolated red-cell nuclei, and great diminution in the number, or almost total absence of the red cells in the diseased frogs, are in proportion to the severity of the infection and due to bacterial action. The presence of the hæmatozoan parasite, the Drepanidium, does not play any part as a predisposing or exciting cause of the disease. The ascarid Rhabdomena nigrovenosum, although frequently present as a parasite in the lungs of the frogs, plays no part in causing or promoting the disease.

Rapeseed cytoplasm gives advantage in wild relatives and complicates genetically modified crop biocontainment

Biocontainment methods for genetically modified crops closest to commercial reality (chloroplast transformation, male sterility) would be compromised (in absolute terms) by seed-mediated gene flow leading to chloroplast capture. Even in these circumstances, however, it can be argued that biocontainment still represses transgene movement, with the efficacy depending on the relative frequency of seed- and pollen-mediated gene flow. In this study, we screened for crop-specific chloroplast markers from rapeseed (Brassica napus) amongst sympatric and allopatric populations of wild B. oleracea in natural cliff-top populations and B. rapa in riverside and weedy populations. We found only modest crop chloroplast presence in wild B. oleracea and in weedy B. rapa, but a surprisingly high incidence in sympatric (but not in allopatric) riverside B. rapa populations. Chloroplast inheritance models indicate that elevated crop chloroplast acquisition is best explained if crop cytoplasm confers selective advantage in riverside B. rapa populations. Our results therefore imply that chloroplast transformation may slow transgene recruitment in two settings, but actually accelerate transgene spread in a third. This finding suggests that the appropriateness of chloroplast transformation for biocontainment policy depends on both context and geographical location.

Swallowing function after intensity modulated radiotherapy (IMRT) and chemotherapy for head and neck cancer

6046

Background: To evaluate the swallowing function of patients treated with intensity modulated radiation therapy (IMRT) + chemotherapy (CT) for HNSCC. Methods: Patients completing RT between 9/04 and 8/06 at the DFCI/BWH were evaluated with IRB approval. All patients had formal swallowing evaluation following the completion of therapy; patients with swallowing difficulty underwent video swallow and both stricture and aspiration were scored. Variables examined for correlation with swallowing pathology were: age, race, gender, smoking and alcohol history, primary site, LVI, PNI, RT intention (primary, postop) and use of induction CT. All variables were analyzed via two-sided t-test. Results: 96 patients were evaluated. Median follow-up 10 mos. 75% of the pts were given definitive RT and 25% received postop RT. 72% stage IV, 24% stage III. Primary sites: oropharynx-43, hypopharynx/larynx-17, oral cavity-13, nasopharynx-11, maxillary sinus-2 and unknown primary-10 pts. All pts received once daily IMRT. 9 pts received RT alone, 28 pts received sequential induction and concurrent (CT) and 59 pts received concurrent CT. 31 pts (32%) had some aspiration after therapy; 36 pts (37%) had evidence of a stricture following RT. All but 5 patients had percutaneous endoscopic gastrostomy placed prophylactically RT. Smoking history was the only significant factor found on univariate analysis to correlate with stricture (p=0.05) but not aspiration. Induction CT was not a significant factor in causing aspiration or stricture. 22 of the strictures (71%) resolved after dilation. RT doses to swallowing structures are under evaluation and will be presented. Conclusions: Aspiration and stricture are common side effects after radical treatment with IMRT and CT for HNSCC. Smoking has a significant negative impact on functional outcome.

No significant financial relationships to disclose.