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OBJECTIVE: A paucity of data exists on the role of the interview day in programs and applicants’ final rank list. The objective of our study was to investigate the impact interview day has on our programs and our interviewees’ final rank list. METHODS: For the 2020 appointment year, our program used an Electronic Residency Application System Application Scoring Tool and Interview Scoring Tool to generate the preliminary rank list for our pulmonary and critical care fellowship applicants. The final rank list was decided after interviewers’ discussion during the program’s rank list meeting. We aimed to correlate the preliminary and final lists. We also surveyed applicants on the importance of interview day in generating their rank list. RESULTS: The final and the preliminary rank lists were strongly correlated (r(s)(47) = 0.87, P < 0.001). There was a stronger correlation between the final rank and the rank based on the application score (r(s)(47) = 0.84, P < 0.001) than the rank based on the interview score (r(s)(47) = 0.64, P < 0.001). For the postinterview survey, 48 applicants were surveyed—20 replied with a response rate of 42% and 18 respondents (90%) rated the interview experience as important or very important in their rank list decisions. CONCLUSIONS: The programs rank list correlated more with the candidates’ written application than their interview day performance; however, interview experience greatly influenced the applicants’ rank lists. In the coronavirus disease 2019 pandemic, in which all interviews are virtual, programs should make diligent efforts to construct virtual interview days, given their importance to applicants in generating their final rank list for the match.

BACKGROUND: Many persons with a history of smoking tobacco have clinically significant respiratory symptoms despite an absence of airflow obstruction as assessed by spirometry. They are often treated with medications for chronic obstructive pulmonary disease (COPD), but supporting evidence for this treatment is lacking. METHODS: We randomly assigned persons who had a tobacco-smoking history of at least 10 pack-years, respiratory symptoms as defined by a COPD Assessment Test score of at least 10 (scores range from 0 to 40, with higher scores indicating worse symptoms), and preserved lung function on spirometry (ratio of forced expiratory volume in 1 second [FEV(1)] to forced vital capacity [FVC] ≥0.70 and FVC ≥70% of the predicted value after bronchodilator use) to receive either indacaterol (27.5 μg) plus glycopyrrolate (15.6 μg) or placebo twice daily for 12 weeks. The primary outcome was at least a 4-point decrease (i.e., improvement) in the St. George’s Respiratory Questionnaire (SGRQ) score (scores range from 0 to 100, with higher scores indicating worse health status) after 12 weeks without treatment failure (defined as an increase in lower respiratory symptoms treated with a long-acting inhaled bronchodilator, glucocorticoid, or antibiotic agent). RESULTS: A total of 535 participants underwent randomization. In the modified intention-to-treat population (471 participants), 128 of 227 participants (56.4%) in the treatment group and 144 of 244 (59.0%) in the placebo group had at least a 4-point decrease in the SGRQ score (difference, −2.6 percentage points; 95% confidence interval [CI], −11.6 to 6.3; adjusted odds ratio, 0.91; 95% CI, 0.60 to 1.37; P=0.65). The mean change in the percent of predicted FEV(1) was 2.48 percentage points (95% CI, 1.49 to 3.47) in the treatment group and −0.09 percentage points (95% CI, −1.06 to 0.89) in the placebo group, and the mean change in the inspiratory capacity was 0.12 liters (95% CI, 0.07 to 0.18) in the treatment group and 0.02 liters (95% CI, −0.03 to 0.08) in the placebo group. Four serious adverse events occurred in the treatment group, and 11 occurred in the placebo group; none were deemed potentially related to the treatment or placebo. CONCLUSIONS: Inhaled dual bronchodilator therapy did not decrease respiratory symptoms in symptomatic, tobacco-exposed persons with preserved lung function as assessed by spirometry. (Funded by the National Heart, Lung, and Blood Institute and others; RETHINC ClinicalTrials.gov number, NCT02867761.)

Home environmental exposures are a primary source of asthma exacerbation. There is a gap in decision support models that efficiently aggregate the home exposure assessment scores for focused and tailored interventions. Three development methods of a home environment allergen exposure scale for persons with asthma (weighted by dimension reduction, unweighted, precision biomarker-based) were compared, and racial disparity tested.Baseline measures from a longitudinal cohort of 187 older adults with asthma were analyzed using humidity and particulate matter sensors, allergy testing, and a home environment checklist. Weights for the dimension reduction scale were obtained from factor analysis, applied for loadings 0.35. Scales were tested in linear regression models with asthma control and asthma quality of life outcomes. Racial disparities were tested using t tests. Scale performance was tested using unadjusted regression analyses with asthma control and asthma quality of life outcomes, separately.The 7-item empirically weighted scale demonstrated best performance with asthma control associations (F = 4.65, p = 0.03, RThe Home Environment Allergen Exposure Scale scores were associated with racial disparities. Replicating these methods in populations residing in high-risk/low-income housing may generate a clinically meaningful, tailored assessment of asthma triggers. Further consideration for variables that address allergic reactivity and biomarker results is indicated to enhance the potential for a precision prevention score.RéSUMé: OBJECTIFS: Les expositions environnementales à domicile sont une source principale d’exacerbation de l’asthme. Il existe une lacune dans les modèles de soutien à la décision qui regroupent efficacement les scores d’évaluation de l’exposition à domicile pour des interventions ciblées et adaptées. Trois méthodes de développement d’une échelle d’exposition aux allergènes de l’environnement domestique pour les personnes atteints d’asthme (pondérée par réduction de dimension, non pondérée, basée sur un biomarqueur de précision) ont été comparées et la disparité raciale testée. MéTHODES: Les mesures de base d’une cohorte longitudinale de 187 personnes âgées asthmatiques ont été analysées à l’aide de capteurs d’humidité et de particules, de tests d’allergie et d’une liste de contrôle de l’environnement domestique. Les poids pour l’échelle de réduction des dimensions ont été obtenus à partir de l’analyse factorielle, appliquée aux charges0,35. Les échelles ont été testées dans des modèles de régression linéaire avec contrôle de l’asthme et résultats de la qualité de vie avec asthme. Les disparités raciales ont été testées à l’aide de tests t. La performance de l’échelle a été testée à l’aide d’analyses de régression non pondérées avec contrôle de l’asthme et résultats de la qualité de vie avec asthme, séparément. RéSULTATS: L’échelle pondérée empiriquement en 7 éléments a démontré les meilleures performances avec les associations de contrôle de l’asthme (F = 4,65, p = 0,03, R

BACKGROUND: Asthma is common in older adults and is confirmed by demonstration of variable expiratory air-flow limitations, typically evaluated by spirometric assessment of bronchodilator responsiveness. However, many patients with clinically suspected asthma and documented air-flow obstruction do not exhibit a post-bronchodilator response that meets or exceeds current established guidelines. We investigated if extending the time from bronchodilator administration to assessment of bronchodilator response increases the yield of spirometry for the diagnosis of asthma in older adults. METHODS: This was a cross-sectional study. The subjects were non-smokers, ≥ 60 y old, and with suspected asthma. Subjects were characterized as (1) those with a positive bronchodilator response on the 30-min post-bronchodilator spirometry, (2) those with a positive bronchodilator response on the 60-min post-bronchodilator spirometry, and (3) those without a positive bronchodilator response but with a positive methacholine challenge test. Factors associated with a late response to bronchodilator were evaluated by using bivariate analysis and by multivariate analysis by using a logistic regression model. RESULTS: This study enrolled 165 subjects. Of these, 81 (49.1%) had a positive bronchodilator response on 30-min post-bronchodilator spirometry; 25 (15.2%) had a positive bronchodilator response on the 1-h post-bronchodilator spirometry; and 59 (35.8%) had no positive bronchodilator response but had a positive methacholine challenge test. On multivariable regression analysis, those with a higher baseline percentage of predicted FEV1, higher scores on a standard asthma control test, and wheezing and/or cough after exercise were more likely to either have a late bronchodilator response or no bronchodilator response. CONCLUSIONS: Our study showed that a late positive response to bronchodilator use was more common than previously presumed in older subjects with suspected asthma. Pulmonary function testing laboratories should consider routinely reassessing spirometry at 1 h after bronchodilator use if the earlier assessment did not reveal a significant response.

Many wearables allow physiological data acquisition in sleep and enable clinicians to assess sleep outside of sleep labs. Belun Sleep Platform (BSP) is a novel neural network-based home sleep apnea testing system utilizing a wearable ring device to detect obstructive sleep apnea (OSA). The objective of the study is to assess the performance of BSP for the evaluation of OSA. Subjects who take heart rate-affecting medications and those with non-arrhythmic comorbidities were included in this cohort. Polysomnography (PSG) studies were performed simultaneously with the Belun Ring in individuals who were referred to the sleep lab for an overnight sleep study. The sleep studies were manually scored using the American Academy of Sleep Medicine Scoring Manual (version 2.4) with 4% desaturation hypopnea criteria. A total of 78 subjects were recruited. Of these, 45% had AHI < 5; 18% had AHI 5–15; 19% had AHI 15–30; 18% had AHI ≥ 30. The Belun apnea-hypopnea index (bAHI) correlated well with the PSG-AHI (r = 0.888, P < 0.001). The Belun total sleep time (bTST) and PSG-TST had a high correlation coefficient (r = 0.967, P < 0.001). The accuracy, sensitivity, specificity in categorizing AHI ≥ 15 were 0.808 [95% CI, 0.703–0.888], 0.931 [95% CI, 0.772–0.992], and 0.735 [95% CI, 0.589–0.850], respectively. The use of beta-blocker/calcium-receptor antagonist and the presence of comorbidities did not negatively affect the sensitivity and specificity of BSP in predicting OSA. A diagnostic algorithm combining STOP-Bang cutoff of 5 and bAHI cutoff of 15 events/h demonstrated an accuracy, sensitivity, specificity of 0.938 [95% CI, 0.828–0.987], 0.944 [95% CI, 0.727–0.999], and 0.933 [95% CI, 0.779–0.992], respectively, for the diagnosis of moderate to severe OSA. BSP is a promising testing tool for OSA assessment and can potentially be incorporated into clinical practices for the identification of OSA. Trial registration: ClinicalTrial.org NCT03997916 https://clinicaltrials.gov/ct2/show/NCT03997916?term=belun+ring&draw=2&rank=1

STUDY OBJECTIVES: The objective of the study is to validate the performance of Belun Ring Platform, a novel home sleep apnea testing system using a patented pulse oximeter sensor and a proprietary cloud-based neural networks algorithm. METHODS: The Belun Ring captures oxygen saturation, photoplethysmography, and accelerometer signals. The Belun Ring total sleep time is derived from features extracted from accelerometer, oxygen saturation, and photoplethysmography signals. The Belun Ring respiratory event index is derived from Belun Ring total sleep time and features extracted from heart rate variability and oxygen saturation changes. A total of 50 adults without significant cardiopulmonary or neuromuscular comorbidities and heart rate affecting medications were evaluated. In-lab sleep studies were performed simultaneously with the Ring and the studies were manually scored using the American Academy of Sleep Medicine Scoring Manual 4% desaturation criteria. RESULTS: The Belun Ring respiratory event index correlated well with the polysomnography-apnea-hypopnea index (AHI; r = .894, P < .001). The sensitivity and specificity in categorizing AHI ≥ 15 events/h were 0.85 and 0.87, respectively, and the positive predictive value and negative predictive value were 0.88 and 0.83, respectively. The Belun Ring total sleep time also correlated well with the polysomnography-total sleep time (r = .945, P < .001). Although the Belun Ring Platform has a good overall performance, it tends to overestimate AHI in individuals with AHI under 15 events/h and underestimate AHI in those with AHI over 15 events/h. Conclusions: In this proof-of-concept study, the Belun Ring Platform demonstrated a reasonable accuracy in predicting AHI and total sleep time in patients without significant comorbidities and heart rate-affecting medications. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Validation of a Novel Device for Screening Patients With Symptoms of Obstructive Sleep Apnea; URL: https://clinicaltrials.gov/ct2/show/NCT04121923; Identifier: NCT04121923. CITATION: Gu W, Leung L, Kwok KC, Wu I-C, Folz RJ, Chiang AA. Belun Ring Platform: a novel home sleep apnea testing system for assessment of obstructive sleep apnea. J Clin Sleep Med. 2020;16(9):1611–1617.

Success in testing research outcomes requires identification of effective recruitment strategies in the targeted population. In this paper, we present the protocol for our NIH-funded study as well as success rates for the various recruitment strategies employed. This longitudinal observational study is: developing a phenotyping algorithm for asthma in older adults, exploring the effects of the asthma phenotype and of volatile organic compounds on asthma control, and developing a predictive model of asthma quality of life. A sub-aim is to characterize barriers to successful medication management in older adults with asthma. Individuals are eligible if they are ≥60 years, have a positive response to at least 1 of 6 asthma screening questions, non-smokers, and demonstrate bronchodilator reversibility or a positive bronchial challenge test with methacholine. Exclusion criteria are smokers who quit 20 pack year smoking history, and those having other chronic pulmonary diseases. Participants (N=190) complete baseline pulmonary function testing, questionnaires, sputum induction, skin prick testing, and have blood drawn for Vitamin D and Immunoglobulin E. Home environmental assessments are completed including 24-hour particulate and volatile organic compound measurements. At 9-months post-baseline, home spirometry, medication assessment, and assessment of asthma quality of life and asthma control are assessed. At 18-months post-baseline, home spirometry, completion of baseline questionnaires, and a home environmental assessment are completed. We have employed multiple recruitment efforts including referrals from clinical offices, no-cost media events, flyers, and ads. The most successful efforts have been referrals from clinical offices and media events.

Burtch, AR, Ogle, BT, Sims, PA, Harms, CA, Symons, TB, Folz, RJ, and Zavorsky, GS. Controlled frequency breathing reduces inspiratory muscle fatigue. J Strength Cond Res 31(5): 1273-1281, 2017-Controlled frequency breathing (CFB) is a common swim training modality involving holding one's breath for approximately 7-10 strokes before taking another breath. We sought to examine the effects of CFB training on reducing respiratory muscle fatigue. Competitive college swimmers were randomly divided into either the CFB group that breathed every 7-10 strokes or a control group that breathed every 3-4 strokes. Twenty swimmers completed the study. The training intervention included 5-6 weeks (16 sessions) of 12 × 50-m repetitions with breathing 8-10 breaths per 50-m (control group) or 2-3 breaths per 50-m (CFB group). Inspiratory muscle fatigue was defined as the decrease in maximal inspiratory pressure (MIP) between rest and 46 seconds after a 200-yard freestyle swimming race (115 seconds [SD 7]). Aerobic capacity, pulmonary diffusing capacity, and running economy were also measured pre- and posttraining. Pooled results demonstrated a 12% decrease in MIP at 46 seconds post-race (-15 [SD 14] cm H2O, effect size = -0.48, p0.01). After 4 weeks of training, only the CFB group prevented a decline in MIP values before to 46 seconds after race (-2 [13] cm H2O, p0.05). However, swimming performance, aerobic capacity, pulmonary diffusing capacity, and running economy did not improve (p0.05) posttraining in either group. In conclusion, CFB training appears to prevent inspiratory muscle fatigue; yet, no difference was found in performance outcomes.

Infectious bronchitis virus, otherwise known as coronavirus, can cause mild upper respiratory tract illnesses in children and adults. Rarely has coronavirus been linked, either by serology or nasal wash, to pneumonia. We report a case of a young woman who, following treatment for stage IIIA breast cancer using a high-dose chemotherapy regimen followed by autologous bone marrow and stem cell transplantation, developed respiratory failure and was found to have coronavirus pneumonia as diagnosed by electron microscopy from BAL fluid. We propose that coronavirus should be considered in the differential diagnosis of acute respiratory failure in cancer patients who have undergone high-dose chemotherapy and autologous hematopoietic support.

Background The diagnosis of asthma is not always straightforward and can be even more challenging in older adults. Asthma is ideally confirmed by demonstration of variable expiratory airflow limitation. However, many patients with asthma do not demonstrate airflow obstruction nor show bronchodilator reversibility. We aimed to investigate predictors for a positive bronchial challenge test with methacholine in older adults being evaluated for asthma. Methods This is a diagnostic accuracy study with a cross-sectional design. Participants ≥60 years with suspected asthma and a negative postbronchodilator response on spirometry were included. All participants underwent a methacholine challenge test (MCT). We assessed the value of standard asthma screening questions and additional clinical questions to predict the MCT results. A multivariable logistic regression model was developed to assess the variables independently impacting the odds of a positive MCT result. Results Our study included 71 participants. The majority were female (n = 52, 73.2%) and the average age was 67.0 years. Those with a positive MCT (n = 55, 77.5%) were more likely to have wheezing or coughing due to allergens (n = 51, 92.7% vs. n = 12, 75.0%; P = 0.004) and difficulty walking several blocks (n = 14, 25.5% vs. n = 1, 6.3%, P = 0.009). After adjustment, having wheezing or coughing due to allergens (OR = 4.2, 95% CI 1.7–7.8, P = 0.012) remained the only significant independent predictor of a positive MCT. Conclusions In older adults with suspected asthma, questioning about wheezing or coughing due to allergens provides a modest independent value to predict a MCT result in those who previously had a negative postbronchodilator response on spirometry.

An imbalance between oxidants and antioxidants is considered a major factor in the development of pulmonary vascular diseases. Oxidative stress seen in pulmonary vascular cells is regulated by increased expression of prooxidant enzymes (e.g., nicotinamide adenine dinucleotide phosphate reduced oxidases) and/or decreased production of antioxidants and antioxidant enzymes (e.g., superoxide dismutases). We and others have shown that expression of antioxidant genes in pulmonary artery cells is regulated by epigenetic mechanisms. In this study, we investigate the regulation of oxidative stress in pulmonary artery cells using inhibitors of histone deacetylases (HDACs). Human pulmonary artery endothelial cells (HPAECs) and human pulmonary artery smooth muscle cells were exposed to an array of HDAC inhibitors followed by analysis of anti- and prooxidant gene expression using quantitative RT-PCR and quantitative RT-PCR array. We found that exposure of HPAECs to scriptaid, N-[4-[(hydroxyamino)carbonyl]phenyl]-α-(1-methylethyl)-benzeneacetamide, and trichostatin A for 24 hours induced expression of extracellular superoxide dismutase (EC-SOD) up to 10-fold, whereas expression of the prooxidant gene NADPH oxidase 4 was decreased by more than 95%. We also found that this differential regulation of anti- and prooxidant gene expression resulted in significant attenuation in the cellular levels of reactive oxygen species. Induction of EC-SOD expression was attenuated by the Janus kinase 2 protein kinase inhibitor AG490 and by silencing Janus kinase 2 expression. Augmentation of EC-SOD expression using scriptaid was associated with increased histone H3 (Lys27) acetylation and H3 (Lys4) trimethylation at the gene promoter. We have determined that oxidative stress in pulmonary endothelial cells is regulated by epigenetic mechanisms and can be modulated using HDAC inhibitors.

BackgroundDespite current therapies, diffuse cutaneous systemic sclerosis (scleroderma) often has a devastating outcome. We compared myeloablative CD34+ selected autologous hematopoietic stem-cell transplantation with immunosuppression by means of 12 monthly infusions of cyclophosphamide in patients with scleroderma.MethodsWe randomly assigned adults (18 to 69 years of age) with severe scleroderma to undergo myeloablative autologous stem-cell transplantation (36 participants) or to receive cyclophosphamide (39 participants). The primary end point was a global rank composite score comparing participants with each other on the basis of a hierarchy of disease features assessed at 54 months: death, event-free survival (survival without respiratory, renal, or cardiac failure), forced vital capacity, the score on the Disability Index of the Health Assessment Questionnaire, and the modified Rodnan skin score.ResultsIn the intention-to-treat population, global rank composite scores at 54 months showed the superiority of transplantation (67% of 1404 pairwise comparisons favored transplantation and 33% favored cyclophosphamide, P=0.01). In the per-protocol population (participants who received a transplant or completed ≥9 doses of cyclophosphamide), the rate of event-free survival at 54 months was 79% in the transplantation group and 50% in the cyclophosphamide group (P=0.02). At 72 months, Kaplan-Meier estimates of event-free survival (74% vs. 47%) and overall survival (86% vs. 51%) also favored transplantation (P=0.03 and 0.02, respectively). A total of 9% of the participants in the transplantation group had initiated disease-modifying antirheumatic drugs (DMARDs) by 54 months, as compared with 44% of those in the cyclophosphamide group (P=0.001). Treatment-related mortality in the transplantation group was 3% at 54 months and 6% at 72 months, as compared with 0% in the cyclophosphamide group.ConclusionsMyeloablative autologous hematopoietic stem-cell transplantation achieved long-term benefits in patients with scleroderma, including improved event-free and overall survival, at a cost of increased expected toxicity. Rates of treatment-related death and post-transplantation use of DMARDs were lower than those in previous reports of nonmyeloablative transplantation. (Funded by the National Institute of Allergy and Infectious Diseases and the National Institutes of Health; ClinicalTrials.gov number, NCT00114530 .).

Allergy skin prick testing (SPT) is commonly performed during the work-up of allergic asthma. We examined a cohort of older asthmatics who underwent allergy SPT following a standardized medication hold protocol in use at the University of Louisville. The protocol attempts to address the impact concurrent medication use has on skin prick test outcomes and are aimed at medications with anti-histaminic or anti-inflammatory activity. It is well documented that immune-senescence is common with advanced age. We were surprised to find a disproportionately low number of subjects with positive skin prick tests in our older aged asthmatics. This led us to explore the idea that additional medications which were not withheld by protocol (e.g., not typically recognized as suppressing immune function or allergy reactions) may effect skin prick interpretations. In one case, for example, a muscle relaxant related to amitriptyline was not held, although amitriptyline itself is typically withheld for 5 days prior to testing. Also, opioids and benzodiazepines have some immunosuppressive activity, yet are not singled out for withholding per SPT protocol. Given that older adults tend to have higher rates of both intra and inter-class polypharmacy that aim to treat comorbid conditions outside of asthma and allergy, we have looked at the potential role these medications play with this surprisingly low rate of negative allergy testing results. Our findings suggest that additional studies are needed to further understand the potential role additional classes of medications commonly used in older adults may play with interfering with skin prick testing protocols.

This case-controlled clinical study was undertaken to investigate to what extent pulmonary function in individuals with chronic Spinal Cord Injury (SCI) is affected by posture. Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), Maximal Inspiratory Pressure (PImax) and Maximal Expiratory Pressure (PEmax) were obtained from 27 individuals with chronic motor-complete (n=13, complete group) and motor-incomplete (n=14, incomplete group) C2-T12 SCI in both seated and supine positions. Seated-to-supine changes in spirometrical (FVC and FEV1) and airway pressure (PImax and PEmax) outcome measures had different dynamics when compared in complete and incomplete groups. Patients with motor-complete SCI had tendency to increase spirometrical outcomes in supine position showing significant increase in FVC (p=.007), whereas patients in incomplete group exhibited decrease in these values with significant decreases in FEV1 (p=.002). At the same time, the airway pressure values were decreased in supine position in both groups with significant decrease in PEmax (p=.031) in complete group and significant decrease in PImax (p=.042) in incomplete group. In addition, seated-to-supine percent change of PImax was strongly correlated with neurological level of motor-complete SCI (ρ= −.77, p=.002). These results indicate that postural effects on respiratory performance in patients with SCI can depend on severity and neurological level of SCI, and that these effects differ depending on respiratory tasks. Further studies with adequate sample size are needed to investigate these effects in clinically specific groups and to study the mechanisms of such effects on specific respiratory outcome measures.

Asthma, of all chronic diseases, has the highest disease burden attributed to environmental exposures. Few studies have attempted to characterize the prevalence of co-existing auto-inflammatory disease and asthma, or to link environmental exposure as a factor that may increase asthmatic lung obstruction and racial disparity with auto-inflammatory comorbidity. While there is an increased risk for asthma development and severity linked to certain autoimmune diseases, there is a known racial disparity in the prevalence of these autoimmune diseases. Racial and ethnic differences in the link between environmental exposures and auto-immune comorbid asthma as a potential common trigger of inflammation is not well understood. This talk will focus on developing a model to longitudinally predict asthma control and quality of life associated with home environmental triggers and volatile organic chemical (VOC) exposure in older adults and investigate the direct and indirect effect of autoimmune disease in racial disparities of the longitudinal relationships of home environmental asthma triggers on airway obstruction and functional status in older adults with asthma.

a b s t r a c t This prospective case-controlled clinical study was undertaken to investigate to what extent the manu- ally assisted treadmill stepping locomotor training with body weight support (LT) can change respiratory function in individuals with chronic spinal cord injury (SCI). Pulmonary function outcomes (forced vital capacity /FVC/, forced expiratory volume one second /FEV1/, maximum inspiratory pressure /PImax/, maximum expiratory pressure /PEmax/) and surface electromyographic (sEMG) measures of respiratory muscles activity during respiratory tasks were obtained from eight individuals with chronic C3-T12 SCI before and after 62 ± 10 (mean ± SD) sessions of the LT. FVC, FEV1, PImax, PEmax, amount of overall sEMG activity and rate of motor unit recruitment were significantly increased after LT (p < 0.05). These results suggest that these improvements induced by the LT are likely the result of neuroplastic changes in spinal neural circuitry responsible for the activation of respiratory muscles preserved after injury. © 2013 Elsevier B.V. All rights reserved.

The purpose of this study determined if oral supplementation of Protandim® (a nutraceutical) for 90 days improved 5-km running performance and reduced serum thiobarbituric acid-reacting substances (TBARS) at rest, an indicator of oxidative stress. Secondary objectives were to measure whole blood superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GPX), at rest and 10 minutes after completion of the race before and after supplementation as well as quality of life. In a double-blind, randomized, placebo controlled trial, 38 runners [mean (SD) = 34 (7) yrs; BMI = 22 (2) kg/m2] received either 90 days of Protandim® [1 pill a day, n = 19)] or placebo (n = 19). Randomization was done in blocks of two controlling for sex and 5-km baseline performance. A 5-km race was performed at baseline and after 90 days of supplementation, with blood samples taken before and 10-min after each race. Fasting blood samples were acquired at baseline, after 30, 60, and 90 days of supplementation. TBARS, SOD, GPX, and GSH were assayed in an out-of-state accredited lab. Running performance was not altered by Protandim® or placebo [20.3 (2.1) minutes, with an -8 (33) seconds change in 5-km time regardless of group]. There was no change in TBARS, SOD, or GPX (at rest) after three months of Protandim® supplementation compared to placebo. However, in a subgroup ≥ 35 years of age, there was a 2-fold higher increase in SOD in those taking Protandim® for three months compared to those on placebo (p = 0.038). The mean post-race change in TBARS (compared to pre-race) increased by about 20% in half of the subjects, but was not altered between groups, even after three months of supplementation. Quality of life was also not different between the two conditions. In conclusion, Protandim® did not (1) alter 5-km running time, (2) lower TBARS at rest (3) raise antioxidant enzyme concentrations compared to placebo (with exception of SOD in those ≥ 35 years old) or, (4) affect quality of life compared to placebo. Trial Registration: ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT02172625","term_id":"NCT02172625"}}NCT02172625

To assess factors associated with severe pulmonary toxicity after myeloablative conditioning using total body irradiation (TBI) followed by allogeneic stem cell transplantation.A total of 101 adult patients who underwent TBI-based myeloablative conditioning for hematologic malignancies at Duke University between 1998 and 2008 were reviewed. TBI was combined with high-dose cyclophosphamide, melphalan, fludarabine, or etoposide, depending on the underlying disease. Acute pulmonary toxicity, occurring within 90 days of transplantation, was scored using Common Terminology Criteria for Adverse Events version 3.0. Actuarial overall survival and the cumulative incidence of acute pulmonary toxicity were calculated via the Kaplan-Meier method and compared using a log-rank test. A binary logistic regression analysis was performed to assess factors independently associated with acute severe pulmonary toxicity.The 90-day actuarial risk of developing severe (Grade 3-5) pulmonary toxicity was 33%. Actuarial survival at 90 days was 49% in patients with severe pulmonary toxicity vs. 94% in patients without (p0.001). On multivariate analysis, the number of prior chemotherapy regimens was the only factor independently associated with development of severe pulmonary toxicity (odds ratio, 2.7 per regimen).Severe acute pulmonary toxicity is prevalent after TBI-based myeloablative conditioning regimens, occurring in approximately 33% of patients. The number of prior chemotherapy regimens appears to be an important risk factor.

Extracellular superoxide dismutase (EC-SOD) is the major antioxidant enzyme present in the vascular wall, and is responsible for both the protection of vessels from oxidative stress and for the modulation of vascular tone. Concentrations of EC-SOD in human pulmonary arteries are very high relative to other tissues, and the expression of EC-SOD appears highly restricted to smooth muscle. The molecular basis for this smooth muscle-specific expression of EC-SOD is not known. Here we assessed the role of epigenetic factors in regulating the cell-specific and IFN-γ-inducible expression of EC-SOD in human pulmonary artery cells. The analysis of CpG site methylation within the promoter and coding regions of the EC-SOD gene demonstrated higher levels of DNA methylation within the distal promoter region in endothelial cells compared with smooth muscle cells. Exposure of both cell types to DNA demethylation agents reactivated the transcription of EC-SOD in endothelial cells alone. However, exposure to the histone deacetylase inhibitor trichostatin A (TSA) significantly induced EC-SOD gene expression in both endothelial cells and smooth muscle cells. Concentrations of EC-SOD mRNA were also induced up to 45-fold by IFN-γ in smooth muscle cells, but not in endothelial cells. The IFN-γ-dependent expression of EC-SOD was regulated by the Janus tyrosine kinase/signal transducers and activators of transcription proteins signaling pathway. Simultaneous exposure to TSA and IFN-γ produced a synergistic effect on the induction of EC-SOD gene expression, but only in endothelial cells. These findings provide strong evidence that EC-SOD cell-specific and IFN-γ-inducible expression in pulmonary artery cells is regulated, to a major degree, by epigenetic mechanisms that include histone acetylation and DNA methylation.

Pulmonary complications associated with persistent respiratory muscle weakness, paralysis, and spasticity are among the most important problems faced by patients with spinal cord injury when lack of muscle strength and disorganization of reciprocal respiratory muscle control lead to breathing insufficiency. This review describes the mechanisms of the respiratory motor control and its change in individuals with spinal cord injury, methods by which respiratory function is measured, and rehabilitative treatment used to restore respiratory function in those who have experienced such injury.

Acute lung dysfunction of noninfectious etiology, known as idiopathic pneumonia syndrome (IPS), is a severe complication following hematopoietic stem cell transplantation (HSCT). Several mouse models have been recently developed to determine the underlying causes of IPS. A cohesive interpretation of experimental data and their relationship to the findings of clinical research studies in humans is needed to better understand the basis for current and future clinical trials for the prevention/treatment of IPS.Our goal was to perform a comprehensive review of the preclinical (i.e., murine models) and clinical research on IPS.An ATS committee performed PubMed and OVID searches for published, peer-reviewed articles using the keywords "idiopathic pneumonia syndrome" or "lung injury" or "pulmonary complications" AND "bone marrow transplant" or "hematopoietic stem cell transplant." No specific inclusion or exclusion criteria were determined a priori for this review.Experimental models that reproduce the various patterns of lung injury observed after HSCT have identified that both soluble and cellular inflammatory mediators contribute to the inflammation engendered during the development of IPS. To date, 10 preclinical murine models of the IPS spectrum have been established using various donor and host strain combinations used to study graft-versus-host disease (GVHD). This, as well as the demonstrated T cell dependency of IPS development in these models, supports the concept that the lung is a target of immune-mediated attack after HSCT. The most developed therapeutic strategy for IPS involves blocking TNF signaling with etanercept, which is currently being evaluated in clinical trials.IPS remains a frequently fatal complication that limits the broader use of allogeneic HSCT as a successful treatment modality. Faced with the clinical syndrome of IPS, one can categorize the disease entity with the appropriate tools, although cases of unclassifiable IPS will remain. Significant research efforts have resulted in a paradigm shift away from identifying noninfectious lung injury after HSCT solely as an idiopathic clinical syndrome and toward understanding IPS as a process involving aspects of both the adaptive and the innate immune response. Importantly, new laboratory insights are currently being translated to the clinic and will likely prove important to the development of future strategies to prevent or treat this serious disorder.

Extracellular superoxide dismutase (EC-SOD) plays an important role in maintaining normal redox homeostasis in the lung. It is expressed at very high levels in pulmonary fibroblasts, alveolar type II epithelial cells, and smooth muscle cells. The molecular mechanisms governing this cell-specific expression of EC-SOD are mostly unknown. In our previous studies we showed that EC-SOD cell-specific expression was not attributable to differential transcriptional regulation, suggesting that other, possibly epigenetic, mechanisms are involved in regulation of its expression. In this paper, we show high levels of promoter methylation in A549 cells and correspondingly low levels of methylation in MRC5 cells. Inhibition of DNA methyltransferase activity by 5-azacytidine in A549 cells reactivated EC-SOD transcription (2.75+/-0.16-fold, P

Extracellular superoxide dismutase (SOD3), a secretory copper-containing antioxidant enzyme, plays an important role in various oxidative stress-dependent cardiovascular diseases. Although cofactor copper is required for SOD3 activity, it remains unknown whether it can regulate SOD3 transcription. We previously demonstrated that SOD3 activity requires the copper chaperone antioxidant-1 (Atox1), involved in copper delivery to SOD3 at the trans-Golgi network (TGN). Here we show that copper treatment in mouse fibroblasts significantly increases mRNA and protein levels of SOD3, but not SOD1, which is abolished in Atox1-deficient cells. Copper promotes Atox1 translocation to the nucleus. Promoter deletion analysis identifies copper- and Atox1-response elements (REs) at the SOD3 promoter. Gel-shift and ChIP assays reveal that Atox1 directly binds to the Atox1 RE in a copper-dependent manner in vitro and in vivo. Adenovirus-mediated reexpression in Atox1(-/-) cells of nucleus-targeted Atox1 (Atox1-NLS), but not TGN-targeted Atox1 (Atox1-TGN), increases SOD3 transcription without affecting SOD3 activity. Importantly, reexpression of both Atox1-NLS and Atox1-TGN together, but not either alone, in Atox1(-/-) cells increases SOD3 activity. SOD3 transcription is positively regulated by copper through the transcription factor function of Atox1, whereas the full activity of SOD3 requires both the copper chaperone and the transcription factor functions of Atox1. Thus, Atox1 is a potential therapeutic target for oxidant stress-dependent cardiovascular disease.

The objective of this study was to examine the feasibility of a full-scale investigation of the neurophysiological mechanisms of COPD-induced respiratory neuromuscular control deficits. Characterization of respiratory single- and multi-muscle activation patterns using surface electromyography (sEMG) were assessed along with functional measures at baseline and following 21±2 (mean±SD) sessions of respiratory motor training (RMT) performed during a one-month period in four patients with GOLD stage II or III COPD. Pre-training, the individuals with COPD showed significantly increased (p0.05) overall respiratory muscle activity and disorganized multi-muscle activation patterns in association with lowered spirometrical measures and decreased fast- and slow-twitch fiber activity as compared to healthy controls (N=4). Following RMT, functional and respiratory sEMG activation outcomes during quite breathing and forced expiratory efforts were improved suggesting that functional improvements, induced by task-specific RMT, are evidence respiratory neuromuscular networks re-organization.

Purpose: To assess the utility of the 6-minute walk test (6MWT) as a predictor of symptomatic radiation-induced pneumonitis (RP). Methods: As part of a prospective trial to study radiation-induced lung injury, 53 patients receiving thoracic radiotherapy (RT) underwent a pre-RT 6MWT, pulmonary function tests (PFTs), and had ≥3-month follow-up for prospective assessment of Grade 2 or worse RP (requiring medications or worse). Dosimetric parameters ( e.g. , the percentage of lung receiving ≥30 Gy) were extracted from the lung dose–volume histogram. The correlations between the 6MWT and PFT results were assessed using Pearson's correlation. The receiver operating characteristic technique was used in patient subgroups to evaluate the predictive capacities for RP of the dosimetric parameters, 6MWT results, and PFT results, or the combination (using discriminant analysis) of all three metrics. ROCKIT software was used to compare the receiver operating characteristic areas between each predictive model. The association of the decline in 6MWT with the development of RP was evaluated using Fisher's exact test. Results: The pre-RT PFT and 6MWT results correlated weakly ( r = 0.44–0.57, p ≤ 0.001), suggesting that they measure somewhat different physiologic functions. Of the 53 patients, 9 (17%) developed RP. The dose–volume histogram-based dosimetric parameters were the best single-metric model for predicting RP ( e.g. , percentage of lung receiving ≥30 Gy, receiver operating characteristic area 0.73, p = 0.03). Including the PFT or 6MWT results with the percentage of lung receiving ≥30 Gy did not improve the predictions. The predictive abilities of dosimetric-based models improved when the analysis was restricted to those patients whose tumors were not causing regional lung dysfunction. No correlation was found between the decline in the 6MWT result and the RP rate ( p = 0.6). Conclusion: Although the PFTs and 6MWT are related to each other, the correlation coefficients were weak, suggesting that they could be measuring different physiologic functions. In the present data set, the addition of the PFTs or 6MWT did not increase the ability of the dosimetric parameters to predict for acute symptomatic RP. Additional work is needed to better understand the interaction among the PFT results, exercise tolerance (6MWT), and the risk of RT-induced lung dysfunction.

Purpose: Clinical and 3D dosimetric parameters are associated with symptomatic radiation pneumonitis rates in retrospective studies. Such parameters include: mean lung dose (MLD), radiation (RT) dose to perfused lung (via SPECT), and pre-RT lung function. Based on prior publications, we defined pre-RT criteria hypothesized to be predictive for later development of pneumonitis. We herein prospectively test the predictive abilities of these dosimetric/functional parameters on 2 cohorts of patients from Duke and The Netherlands Cancer Institute (NKI). Methods and Materials: For the Duke cohort, 55 eligible patients treated between 1999 and 2005 on a prospective IRB-approved study to monitor RT-induced lung injury were analyzed. A similar group of patients treated at the NKI between 1996 and 2002 were identified. Patients believed to be at high and low risk for pneumonitis were defined based on: ( 1 ) MLD; ( 2 ) OpRP (sum of predicted perfusion reduction based on regional dose-response curve); and ( 3 ) pre-RT DLCO. All doses reflected tissue density heterogeneity. The rates of grade ≥2 pneumonitis in the "presumed" high and low risk groups were compared using Fisher's exact test. Results: In the Duke group, pneumonitis rates in patients prospectively deemed to be at "high" vs. "low" risk are 7 of 20 and 9 of 35, respectively; p = 0.33 one-tailed Fisher's. Similarly, comparable rates for the NKI group are 4 of 21 and 6 of 44, respectively, p = 0.41 one-tailed Fisher's. Conclusion: The prospective model appears unable to accurately segregate patients into high vs. low risk groups. However, considered retrospectively, these data are consistent with prior studies suggesting that dosimetric ( e.g. , MLD) and functional ( e.g. , PFTs or SPECT) parameters are predictive for RT-induced pneumonitis. Additional work is needed to better identify, and prospectively assess, predictors of RT-induced lung injury.

Diffuse alveolar hemorrhage (DAH) after allogeneic hematopoietic stem cell transplantation (HSCT) is often fatal. Standard therapy with high-dose corticosteroid is not always effective. There is paucity of data in the literature about other potentially useful agents, such as aminocaproic acid (Amicar) in the post-transplantation setting. We retrospectively reviewed our data on 115 consecutive patients who underwent HSCT and had pulmonary complications, with the aim of determining the overall clinical outcome in recipients of allogeneic transplants and in the subgroup of these patients who were treated with concomitant Solu-Medrol and aminocaproic acid. Aminocaproic acid was added at the discretion of the attending physician. We identified 14 allogeneic transplant recipients (median age, 41 years) with 15 episodes of DAH who were treated with Solu-Medrol (250 mg to 1 g intravenously per day). Of these, 8 patients also received concomitant aminocaproic acid at 1000 mg intravenously every 6 hours. Failure to improve was the most common reason for adding aminocaproic acid. The incidence of DAH was 12.2% (10.3% in myeloablative versus 1.9% in nonmyeloablative recipients). The overall 100-day DAH mortality and median transplantation survival were 60% and 99 days, respectively. Among the subset of patients treated with the combination of Solu-Medrol and aminocaproic acid, we observed a 100-day DAH mortality and median transplantation survival of 44% and 167 days, respectively, compared with 83% and 96.5 days in those treated with Solu-Medrol alone. The median time to DAH was 40.5 days, and the median time to death was 53 days in the combined treatment group compared with 29.5 days in those treated with steroid alone. There were no significant differences in coagulation parameters between subsets. Infections (yeast, respiratory syncytial virus, herpes simplex virus, and parainfluenza) were isolated and treated from 6 diagnostic bronchial alveolar lavage samples and were more common in the subgroup treated with Solu-Medrol only. Respiratory failure was the documented cause of death in 89% of patients. There were no clinically significant side effects from aminocaproic acid. Although these historically lower DAH outcomes are intriguing, prospective studies are needed to confirm the role of aminocaproic acid in DAH occurring in the allogeneic transplantation setting.

Summary The single exhalation analysis of carbon monoxide, acetylene, and methane allows the determination of intrabreath (regional) DL, pulmonary capillary blood flow and ventilation inhomogeneities during rest and exercise. We reasoned that this technique might be more sensitive in detecting regional pulmonary capillary abnormalities than resting single breath DL (DL sb ). We selected a group of breast cancer patients in high-dose chemotherapy (HDCT) protocols who were at risk for pulmonary injury. We grouped the patients into pre-HDCT and post-HDCT, and used resting DL sb to further categorize the latter into those with and without pulmonary injury. We found that exercise DL increases were blunted in post-HDCT patients with low resting DL sb . More importantly, even in post-HDCT patients with normal resting DL sb , exercise DL response was reduced in the slowest emptying lung units along with evidence for ventilation inhomogeneities (increased methane slope). We conclude that exercise assessments of DL at low lung volumes and gas mixing properties may be sensitive indicators of lung injury.

This study investigates the role of extracellular SOD (EC-SOD), the major extracellular antioxidant enzyme, in skeletal muscle ischemia and reperfusion (I/R) injury. Pedicled cremaster muscle flaps from homozygous EC-SOD knockout (EC-SOD−/−) and wild-type (WT) mice were subjected to 4.5-h ischemia and 90-min reperfusion followed by functional and molecular analyses. Our results revealed that EC-SOD−/−mice showed significantly profound I/R injury compared with WT littermates. In particular, there was a delayed and incomplete recovery of arterial spasm and blood flow during reperfusion, and more severe acute inflammatory reaction and muscle damage were noted in EC-SOD−/−mice. After 90-min reperfusion, intracellular SOD [copper- and zinc-containing SOD (CuZn-SOD) and manganese-containing (Mn-SOD)] mRNA levels decreased similarly in both groups. EC-SOD mRNA levels increased in WT mice, whereas EC-SOD mRNA was undetectable, as expected, in EC-SOD−/−mice. In both groups of animals, CuZn-SOD protein levels decreased and Mn-SOD protein levels remained unchanged. EC-SOD protein levels decreased in WT mice. Histological analysis showed diffuse edema and inflammation around muscle fibers, which was more pronounced in EC-SOD−/−mice. In conclusion, our data suggest that EC-SOD plays an important role in the protection from skeletal muscle I/R injury caused by excessive generation of reactive oxygen species.

Purpose: To assess the 6-minute walk test (6MWT) as a predictor of radiation therapy–induced lung injury (RTLI). Methods and Materials: The 6MWT is a simple, economical, and reproducible test that measures both how far a person can walk in 6 min and any associated changes in vital signs. As part of a prospective trial to study RTLI, a pre-RT 6MWT was performed in 41 patients. The predictive capacities of pre-RT 6MWT, forced expiratory volume in 1 s (FEV1), and single-breath diffusing capacity for carbon monoxide (DLCO) for the development of RTLI were assessed with receiver operating curve (ROC) techniques. To evaluate the 6MWT, alone or with mean lung dose (MLD) of radiation, as a predictor of RTLI, the rates of RTLI in patient subgroups defined by 6MWT results were compared by using Fisher's exact test. Results: Thirty-one patients with ≥3 months' follow-up were evaluable. The median baseline 6MWT result was 1400 ft. Of 31 patients, 7 developed Grade ≥2 RTLI. Of 15 patients with an MLD >18 Gy (the median), 5 developed RTLI, compared with 2 of 16 with MLD ≤18 Gy ( p = 0.22). Among those with an MLD ≤18 Gy, the RTLI rates were 0 of 8 and 2 of 8 for 6MWT results ≥1400 ft or p = 0.46. The ROC area under the curve for individual metrics was as follows: FEV1 0.66, MLD 0.70, DLCO 0.61, and 6MWT 0.47. Combining FEV1 with 6MWT increased the ROC to 0.71, suggesting that the ratio might be a better predictor than the individual values. Patients with a high 6MWT/FEV1 ratio had a lower rate of RTLI than those with a relatively low ratio. Conclusions: The 6MWT might provide prognostic information beyond pulmonary function tests and dosimetric parameters in predicting RTLI. Additional work is needed to better assess the utility of these functional metrics.

Purpose: To assess the difficulty of assigning a definitive clinical diagnosis of radiation (RT)-induced lung injury in patients irradiated for lung cancer. Methods: Between 1991 and 2003, 318 patients were enrolled in a prospective study to evaluate RT-induced lung injury. Only patients with lung cancer who had a longer than 6-month follow-up (251 patients) were considered in the current analysis. Of these, 47 of 251 patients had Grade ≥2 (treated with steroids) increasing shortness of breath after RT, thought possibly consistent with pneumonitis/fibrosis. The treating physician, and one to three additional reviewing physicians, evaluated the patients or their medical records, or both. The presence or absence of confounding clinical factors that made the diagnosis of RT-induced uncertain lung injury were recorded. Results: Thirty-one of 47 patients (66%) with shortness of breath had “classic” pneumonitis, i.e., they responded to steroids and had a definitive diagnosis of pneumonitis. In 13 of 47 patients (28%), the diagnosis of RT-induced toxicity was confounded by possible infection; exacerbation of preexisting lung disease (chronic obstructive pulmonary disease); tumor regrowth/progression; and cardiac disease in 6, 8, 5, and 1 patients, respectively (some of the patients had multiple confounding factors and were counted more than once). An additional 3 patients (6%) had progressive shortness of breath and an overall clinical course more consistent with fibrosis. All 3 had evidence of bronchial stenosis by bronchoscopy. Conclusions: Scoring of radiation pneumonitis was challenging in 28% of patients treated for lung cancer owing to confounding medical conditions. Recognition of this uncertainty is needed and may limit our ability to understand RT-induced lung injury.

The ability to optimize treatments for cancer on the basis of relative risks for normal tissue injury has important implications in oncology, because higher doses of radiation might, in some diseases, improve both local control and survival. To achieve this goal, a thorough understanding of the molecular mechanisms responsible for radiation-induced toxicity will be essential. Recent research has demonstrated that ionizing radiation triggers a series of genetic and molecular events, which might lead to chronic persistent alterations in the microenvironment and an aberrant wound-healing response. Disrupted epithelial-stromal cell communication might also be important. With the application of a better understanding of fundamental biology to clinical practice, new approaches to treating and preventing normal tissue injury can focus on correcting these disturbed molecular processes.

Previous work suggests that superoxide mediates hypoxia/reoxygenation (H/R)-induced constriction of isolated mouse coronary arteries (CA). To determine the source of superoxide overproduction during H/R we studied CA obtained from transgenic (Tg) mice overexpressing human CuZn-superoxide dismutase (SOD) and mice lacking gp91phox using an in vitro vascular ring bioassay. We found that under normoxic conditions CA isolated from wild type (wt) mice, CuZn-SOD Tg mice and gp91phox knock-out mice had similar contractile responses to U46619 and hypoxia and similar dilation responses to acetylcholine. In wt CA, 30 min of hypoxia (1% O2) followed by reoxygenation (16% O2) resulted in further coronary vasoconstriction (internal diameter from 105 ± 11 to 84.5 ± 17.9 μm), whereas this response was completely blocked in both CuZn-SOD Tg and gp91phox knock-out CA (104.3 ± 10.5 to 120.7 ± 14 μm and 143.3 ± 15.3 to 172.7 ± 12.5 μm, respectively, p < 0.01). Furthermore, we show that H/R enhances the generation of superoxide radicals in wt CA (25.8 ± 0.7 relative light units per second (RLU/s)), whereas CuZn-SOD Tg CA (12.2 ± 0.8 RLU/s, p < 0.01) and gp91phox CA (12.5 ± 0.9 RLU/s, p < 0.01) show reduced levels. These results demonstrate that H/R-induced vasoconstriction is mediated by intracellular superoxide overproduction via endothelial NADPH oxidase gp91phox. Therefore, increasing endogenous levels of CuZn-SOD in CA may provide a novel cardioprotective strategy for maintaining coronary perfusion under conditions of H/R.

Purpose The purpose of this study was to determine if radiation-induced lung injury is associated with prolonged oxidative stress, and whether chronic overexpression of extracellular superoxide dismutase (EC-SOD) in the lung of transgenic mice protects against radiation-induced lung injury. Methods and materials Whole-lung radiation was delivered to EC-SOD overexpressing B6C3 transgenic (XRT-TG) mice and wild-type littermates (XRT-WT). Pulmonary function was assessed by breathing frequency. Right lung wet weight was used as a gross indicator of lung damage. Histopathology was used to assess collagen deposition and tissue fibrosis according to an established grading system. Immunohistochemistry was used to stain and quantify the number of macrophages. ELISA was used to measure activated TGF-β1. Oxidative stress was assessed by measuring lipid oxidation products (malondialic acid) by HPLC. Results Four of six XRT-WT mice required euthanasia at 15–19 weeks postradiation because of respiratory distress, whereas no XRT-TG mouse developed distress. All assessments of lung damage at 15–20 weeks postradiation were higher for XRT-WT mice compared with the XRT-TG mice, including breathing frequency (380 vs. 286 bpm, p ≤ 0.0004), right lung weight (228 vs. 113 mg, p ≤ 0.06), macrophage count (48 vs. 5 per 40× field, p ≤ 0.06), and percent activated TGF-β1 (37 vs. 11%, p ≤ 0.06). Semiquantitative measures, including fibrosis and collagen deposition, were also higher for XRT-WT mice, with an exact Fisher p value of ≤0.03 for both variables. In addition, malondialic acid was elevated in XRT-WT mice 15–20 weeks after radiation delivery, and levels were lower in the XRT-TG mice (624 vs. 323 pmol/mg protein, p ≤ 0.06). Conclusions After radiation therapy, oxidative stress is present at 15–20 weeks after initial exposure, which correlates with the delayed clinical onset of radiation-induced lung damage. Overexpression of EC-SOD in transgenic mice appears to confer protection against this radiation-induced lung injury, with a corresponding decrease in oxidative stress. EC-SOD may be a potential therapeutic agent for radioprotection in the treatment of thoracic malignancies. Further investigation is needed to confirm and expand on the current results.

Radiation therapy (RT) for thoracic-region tumors often causes lung injury. The incidence of lung toxicity depends on the method of assessment (eg, radiographs, patient's symptoms, or functional endpoints such as pulmonary function tests). Three-dimensional (3D) treatment planning tools provide dosimetric predictors for the risk of symptomatic RT-induced lung injury and allow for beams to be selected to minimize these risks. A variety of cytokines have been implicated as indicators/mediators of lung injury. Recent work suggests that injury-associated tissue hypoxia perpetuates further injury. Sophisticated planning/delivery methods, such as intensity modulation, plus radioprotectors such as amifostine, hold promise to reduce the incidence of RT-induced lung injury.

We tested the hypothesis that targeted transgenic overexpression of human extracellular superoxide dismutase (EC-SOD) would preserve alveolar development in hyperoxia-exposed newborn mice. We exposed newborn transgenic and wild-type mice to 95% oxygen (O2) or air x 7 days and measured bronchoalveolar lavage cell counts, and lung homogenate EC-SOD, oxidized and reduced glutathione, and myeloperoxidase. We found that total EC-SOD activity in transgenic newborn mice was approximately 2.5x the wild-type activity. Hyperoxia-exposed transgenic mice had less pulmonary neutrophil influx and oxidized glutathione than wild-type littermates at 7 days. We measured alveolar surface and volume density in animals exposed to 14 days more of air or 60% O2. Hyperoxia-exposed transgenic EC-SOD mice had significant preservation of alveolar surface and volume density compared with wild-type littermates. After 7 days 95% O2 + 14 days 60% O2, lung inflammation measured as myeloperoxidase activity was reduced to control levels in all treatment groups.

Extracellular superoxide dismutase (EC-SOD or SOD3) is an important protective enzyme against the toxicity of superoxide radicals that are produced under both physiological and pathophysiological conditions. We have isolated and characterized over 11kb of the mouse EC-SOD gene and its 5′- and 3′-flanking regions. The gene consists of two exons, with the entire coding region located within exon 2. In order to study the mechanism of cell-specific gene regulation for mouse EC-SOD, we characterized 2500bp of its 5′-flanking region using cultured cells derived from mouse lung fibroblasts (MLg), kidney medulla (mIMCD3) and hepatocytes (Hepa 1-6). Real-time PCR showed that basal expression of EC-SOD was considerably higher in MLg cells compared with the other cell types. Reporter-gene assays revealed that the proximal promoter region was sufficient to support this high expression in MLg cells. Although no obvious TATA box was identified, our results show that a highly purine-rich region from −208 to +104 contains active binding sites for both the Kruppel-like and Ets families of transcription factors. Using electrophoretic mobility shift, DNase footprinting and reporter gene assays, we identified myeloid zinc finger 1 and gut-enriched Kruppel-like-factor-like nuclear transcription factors as repressors of EC-SOD expression, whereas nuclear transcription factors from the Ets family, such as Elf-1 and GA-binding protein α and β, were potent activators of EC-SOD transcription. We propose a model that highlights competition between Ets activators and Kruppel-like repressors within the proximal promoter region that determines the level of EC-SOD expression in a particular cell type.

Excessive production and/or inadequate removal of reactive oxygen species, especially superoxide anion (O(2)(*-)), have been implicated in the pathogenesis of many cardiovascular diseases, including atherosclerosis, hypertension, diabetes, and in endothelial dysfunction by decreasing nitric oxide (NO) bioactivity. Since the vascular levels of O(2)(*-) are regulated by the superoxide dismutase (SOD) enzymes, a role of SOD in the cardiovascular disease is of substantial interest. Particularly, a major form of SOD in the vessel wall is the extracellular SOD (ecSOD). This review will discuss the characteristics of ecSOD and the role of ecSOD in cardiovascular diseases.

Delayed pulmonary toxicity syndrome after high-dose chemotherapy (HDC) and autologous hematopoietic support occurs in up to 64% of women with advanced-stage breast cancer. Using a similar, but nonmyeloablative, HDC treatment regimen in mice, we found both immediate and persistent lung injury, coincident with marked decreases in lung tissue glutathione reductase activity and accompanied by increases in lung oxidized glutathione, bronchoalveolar lavage (BAL) lipid peroxidation, and BAL total cell counts. Most interestingly, at 6 wk, BAL total cell counts had increased fourfold, with lymphocyte cell counts increasing >11-fold. A single supplemental dose of glutathione prevented early lung injury at 48 h but showed no lung-protective effects at 6 wk, whereas single doses of other thiol-sparing agents (Ethyol and glutathione monoethyl ester) showed no benefit. These data suggest that this HDC regimen results in acute and persistent lung toxicity, induced in part by oxidative stress, that culminates with an acute lung cellular inflammatory response. Continuous glutathione supplementation and/or attenuation of the delayed pulmonary inflammatory response may prove beneficial in preventing lung toxicity after the use of these chemotherapeutic agents.

The mechanism of tissue injury after exposure to air pollution particles is not known. The biological effect has been postulated to be mediated via an oxidative stress catalyzed by metals present in particulate matter (PM). We utilized a transgenic (Tg) mouse model that overexpresses extracellular superoxide dismutase (EC-SOD) to test the hypothesis that lung injury after exposure to PM results from an oxidative stress in the lower respiratory tract. Wild-type (Wt) and Tg mice were intratracheally instilled with either saline or 50 μg of residual oil fly ash (ROFA). Twenty-four hours later, specimens were obtained and included bronchoalveolar lavage (BAL) and lung for both homogenization and light histopathology. After ROFA exposure, EC-SOD Tg mice showed a significant reduction in BAL total cell counts (composed primarily of neutrophils) and BAL total protein compared with Wt. EC-SOD animals also demonstrated diminished concentrations of inflammatory mediators in BAL. There was no statistically significant difference in BAL lipid peroxidation; however, EC-SOD mice had lower concentrations of oxidized glutathione in the BAL. We conclude that enhanced EC-SOD expression decreased both lung inflammation and damage after exposure to ROFA. This supports a participation of oxidative stress in the inflammatory injury after PM exposure rather than reflecting a response to metals alone.

BACKGROUND To study the predictive value of serial pulmonary function testing (PFT) for toxicity in patients who have received high-dose chemotherapy (HDCT) and stem-cell rescue for breast carcinoma. These patients are at risk of developing therapy-related pneumonitis (TRP) during or after radiotherapy (RT). METHODS Sixty-eight patients who received induction chemotherapy (CT) and consolidation HDCT (cyclophosphamide, cisplatin, carmustine) underwent serial PFTs before induction CT, after HDCT, and before locoregional RT. The rate of TRP, i.e., pulmonary complications of Grade 2 or higher (World Health Organization classification), was studied during and 2 months after RT. We analyzed the time-course of changes in the diffusing capacity of carbon monoxide (DLCO) and forced expiratory volume at one second (FEV1) and studied the differences between patients who developed TRP and those who did not. RESULTS The incidence of TRP was 46%. There were marked reductions in DLCO and FEV1 at the time of RT compared with baseline (Wilcoxon signed rank test: P < 0.001). However, pre-RT PFT values did not predict subsequent development of TRP. Instead, the ratio of pre-RT DLCO to the minimum post- HDCT DLCO, i.e., trend of improvement, predicted the development of TRP in patients (logistic regression analysis: P = 0.048). At a cutoff level of 1, the positive and negative predictive values for this ratio were 61% and 87%, respectively. There was an association between this ratio and a longer interval between HDCT and RT (Spearman rank correlation: P = 0.002). CONCLUSIONS The results suggest that the directional trend of DLCO after HDCT, i.e., no recovery from nadir values, is a predictor for TRP. TRP patients have a shorter median interval between HDCT and RT than asymptomatic patients. To minimize the occurrence of TRP, one should consider either delaying RT beyond 2 months following carmustine-based HDCT to allow the PFTs to partly recover, or confirm apositive directional trend for improvement of DLCO at the start of RT compared to the post-HDCT nadir value. Cancer 2002;94:2821–9. © 2002 American Cancer Society. DOI 10.1002/cncr.10573