Biofeedback Training to Increase P co2 in Asthma With Elevated Anxiety: A One-Stop Treatment of Both Conditions?

OBJECTIVE: Anxiety is highly prevalent in individuals with asthma. Asthma symptoms and medication can exacerbate anxiety, and vice versa. Unfortunately, treatments of comorbid anxiety and asthma are largely lacking. A problematic feature common to both conditions is hyperventilation. It adversely affects lung function and symptoms in asthma and anxiety. We examined whether a treatment to reduce hyperventilation, shown to improve asthma symptoms, also improves anxiety in asthma patients with high anxiety. METHOD: One hundred twenty English- or Spanish-speaking adult patients with asthma were randomly assigned to either Capnometry-Assisted Respiratory Training (CART) to raise P co2 or feedback to slow respiratory rate (SLOW). Although anxiety was not an inclusion criterion, 21.7% met clinically relevant anxiety levels on the Hospital Anxiety and Depression Scale (HADS). Anxiety (HADS-A) and depression (HADS-D) scales, anxiety sensitivity (Anxiety Sensitivity Index [ASI]), and negative affect (Negative Affect Scale of the Positive Affect Negative Affect Schedule) were assessed at baseline, posttreatment, 1-month follow-up, and 6-month follow-up. RESULTS: In this secondary analysis, asthma patients with high baseline anxiety showed greater reductions in ASI and PANAS-N in CART than in SLOW ( p values ≤ .005, Cohen d values ≥ 0.58). Furthermore, at 6-month follow-up, these patients also had lower ASI, PANAS-N, and HADS-D in CART than in SLOW ( p values ≤ .012, Cohen d values ≥ 0.54). Patients with low baseline anxiety did not have differential outcomes in CART than in SLOW. CONCLUSIONS: For asthma patients with high anxiety, our brief training designed to raise P co2 resulted in significant and sustained reductions in anxiety sensitivity and negative affect compared with slow-breathing training. The findings lend support for P co2 as a potential physiological target for anxiety reduction in asthma. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT00975273 .

Retrospective observational study of asthma and chronic obstructive pulmonary disease prevalence and associated healthcare resource utilization in a large, integrated healthcare system.

Limited data exist on asthma and chronic obstructive pulmonary disease (COPD) management-major drivers of healthcare resource utilization (HCRU) in the USA. We describe prevalence and exacerbation rates, therapeutic interventions, and HCRU for asthma and/or COPD within a large, integrated healthcare system. Patients with asthma, COPD, and asthma + COPD were identified from retrospective electronic health record data (2016-2018) of >1.7 million patients. Descriptive analysis of disease prevalence and exacerbation frequencies, pharmacotherapies, and HCRU was performed. Time-to-event analysis of time to first exacerbation was performed in patients with asthma and/or COPD. Exacerbation rates, pharmacotherapies, and HCRU were examined by exploratory analysis in an outpatient subset. Overall, 149,086 unique patients (8.6%) had encounters for asthma, COPD, or asthma + COPD. Acute care utilization was high, including emergency department visits (asthma, 52.9%; COPD, 35.1%) and hospitalizations (asthma, 26.7%; COPD, 65.7%). Many patients were prescribed short-acting therapies (asthma, 45.3%; COPD, 40.0%; asthma + COPD, 54.7%). Prescription rates for maintenance therapies were low (17.1%, 20.8%, 31.7%) and annual exacerbation rates were 0.65, 0.80, and 1.33. This analysis showed a substantive prevalence of pulmonary disease, variability between documented prescriptions and pharmacotherapy guidelines, and high HCRU. Appropriate tailoring of pharmacotherapies and management of asthma and COPD over a continuum are opportunities to improve patient care.

Dectin-1 Controls TSLP-Induced Th2 Response by Regulating STAT3, STAT6, and p50-RelB Activities in Dendritic Cells.

The epithelium-associated cytokine thymic stromal lymphopoietin (TSLP) can induce OX40L and CCL17 expression by myeloid dendritic cells (mDCs), which contributes to aberrant Th2-type immune responses. Herein, we report that such TSLP-induced Th2-type immune response can be effectively controlled by Dectin-1, a C-type lectin receptor expressed by mDCs. Dectin-1 stimulation induced STAT3 activation and decreased the transcriptional activity of p50-RelB, both of which resulted in reduced OX40L expression on TSLP-activated mDCs. Dectin-1 stimulation also suppressed TSLP-induced STAT6 activation, resulting in decreased expression of the Th2 chemoattractant CCL17. We further demonstrated that Dectin-1 activation was capable of suppressing ragweed allergen (Amb a 1)-specific Th2-type T cell response in allergy patients ex vivo and house dust mite allergen (Der p 1)-specific IgE response in non-human primates in vivo. Collectively, this study provides a molecular explanation of Dectin-1-mediated suppression of Th2-type inflammatory responses and suggests Dectin-1 as a target for controlling Th2-type inflammation.

Whole blood transcriptional variations between responders and non-responders in asthma patients receiving omalizumab.

BACKGROUND: Anti-IgE (omalizumab) has been used for the treatment of moderate-to-severe asthma that is not controlled by inhaled steroids. Despite its success, it does not always provide patients with significant clinical benefits. OBJECTIVE: To investigate the transcriptional variations between omalizumab responders and non-responders and to study the mechanisms of action of omalizumab. METHODS: The whole blood transcriptomes of moderate-to-severe adult asthma patients (N = 45:34 responders and 11 non-responders) were analysed over the course of omalizumab treatment. Non-asthmatic healthy controls (N = 17) were used as controls. RESULTS: Transcriptome variations between responders and non-responders were identified using the genes significant (FDR < 0.05) in at least one comparison of each patient response status and time point compared with control subjects. Using gene ontology and network analysis, eight clusters of genes were identified. Longitudinal analyses of individual clusters revealed that responders could maintain changes induced with omalizumab treatment and become more similar to the control subjects, while non-responders tend to remain more similar to their pre-treatment baseline. Further analysis of an inflammatory gene cluster revealed that genes associated with neutrophil/eosinophil activities were up-regulated in non-responders and, more importantly, omalizumab did not significantly alter their expression levels. The application of modular analysis supported our findings and further revealed variations between responders and non-responders. CONCLUSION AND CLINICAL RELEVANCE: This study provides not only transcriptional variations between omalizumab responders and non-responders, but also molecular insights for controlling asthma by omalizumab.

Usefulness of harmonica playing to improve outcomes in patients with chronic obstructive pulmonary disease.

Pulmonary rehabilitation in chronic obstructive pulmonary disease (COPD) includes a multidisciplinary approach of exercise and pursed-lip diaphragmatic breathing. Pursed-lip diaphragmatic breathing reduces alveolar collapse during exhalation, and diaphragmatic breathing improves inspiratory pressures. Harmonica playing has maneuvers similar to those taught in pursed-lip diaphragmatic breathing, with diaphragmatic breathing to create musical tones. Hence, we designed a trial to determine whether patients with COPD would benefit from harmonica playing. COPD patients who completed pulmonary rehabilitation at least 6 months prior were eligible for this trial. Patients attended 12 weeks of harmonica training sessions for 2 hours a week and were encouraged to practice at home. Participants completed pre- and postspirometry testing, maximum inspired and expired pressure (PImax, PEmax) testing, and 6-minute walk tests. Eleven of the 14 participants completed the 12-week trial. PImax and PEmax increased by an average of 15.4 ± 12.0 cm H2O (P = 0.0017) and 14.4 ± 14.0 cm H2O (P = 0.0061), respectively. Additionally, 6-minute walk distance increased by approximately 60 m (61 ± 78, P = 0.03). This pilot study showed that a 12-week harmonica program significantly improved PImax, PEmax, and 6-minute walk distance in COPD patients after rehabilitation. Larger-scale harmonica studies are warranted to evaluate this program's adjunctive potential benefit to formal pulmonary rehabilitation.

Dominance Effects and Functional Enrichments Improve Prediction of Agronomic Traits in Hybrid Maize.

Single-cross hybrids have been critical to the improvement of maize (Zea mays L.), but the characterization of their genetic architectures remains challenging. Previous studies of hybrid maize have shown the contribution of within-locus complementation effects (dominance) and their differential importance across functional classes of loci. However, they have generally considered panels of limited genetic diversity, and have shown little benefit from genomic prediction based on dominance or functional enrichments. This study investigates the relevance of dominance and functional classes of variants in genomic models for agronomic traits in diverse populations of hybrid maize. We based our analyses on a diverse panel of inbred lines crossed with two testers representative of the major heterotic groups in the U.S. (1106 hybrids), as well as a collection of 24 biparental populations crossed with a single tester (1640 hybrids). We investigated three agronomic traits: days to silking (DTS), plant height (PH), and grain yield (GY). Our results point to the presence of dominance for all traits, but also among-locus complementation (epistasis) for DTS and genotype-by-environment interactions for GY. Consistently, dominance improved genomic prediction for PH only. In addition, we assessed enrichment of genetic effects in classes defined by genic regions (gene annotation), structural features (recombination rate and chromatin openness), and evolutionary features (minor allele frequency and evolutionary constraint). We found support for enrichment in genic regions and subsequent improvement of genomic prediction for all traits. Our results suggest that dominance and gene annotations improve genomic prediction across diverse populations in hybrid maize.

Phenotypic and functional alterations of regulatory B cell subsets in adult allergic asthma patients.

BACKGROUND: IL-10-producing regulatory B cells (Bregs) are widely ascribed immune regulatory functions. However, Breg subsets in human asthma have not been fully investigated. OBJECTIVE: We studied Breg subsets in adult allergic asthma patients by assessing two major parameters, frequency and IL-10 expression. We then investigated factors that affect these two parameters in patients. METHODS: Peripheral blood mononuclear cells (PBMCs) of adult allergic asthma patients (N = 26) and non-asthmatic controls (N = 28) were used to assess the frequency of five subsets of transitional B cells (TBs), three subsets of CD24high CD27+ B cells and B1 cells. In addition to clinical data, IL-10 expression by individual Breg subsets was assessed by flow cytometry. RESULTS: Asthma patients had decreases of CD5+ and CD1d+ CD5+ , but an increase of CD27+ TBs which was significant in patients with moderate asthma (60 < FEV1 < 80). Regardless of asthma severity, there was no significant alteration in the frequencies of 6 other Breg subsets tested. However, we found that oral corticosteroid (OCS) significantly affected the frequency of Bregs in Breg subset-specific manners. OCS decreased CD5+ and CD1d+ CD5+ TBs, but increased CD27+ TBs and CD10+ CD24high CD27+ cells. Furthermore, OCS decreased IL-10 expression by CD27+ TBs, all 3 CD24high CD27+ B cell subsets (CD5+ , CD10+ and CD1d+ ) and B1 cells. OCS-mediated inhibition of IL-10 expression was not observed in the other Breg subsets tested. CONCLUSION & CLINICAL RELEVANCE: Alterations in the frequency of Bregs and their ability to express IL-10 are Breg subset-specific. OCS treatment significantly affects the frequency as well as their ability to express IL-10 in Breg subset-specific manners.

Towards an assessment of perceived COPD exacerbation triggers: Initial development and validation of a questionnaire.

BACKGROUND AND OBJECTIVE: Prevention of exacerbations in chronic obstructive pulmonary disease (COPD) is important to decrease overall declines in functioning and improve quality of life. The present study sought to develop a psychometrically valid measure of perceived triggers of exacerbations in COPD patients, the COPD Exacerbation Trigger Inventory (CETI). METHODS: Participants (n = 192) were recruited through local clinics and online to complete surveys of the CETI, demographic information, disease-specific information and the COPD Assessment Test (CAT). The CETI included a free response section on patients' individual top triggers, combined with ratings of their controllability. RESULTS: Exploratory principal component analyses identified a stable 5-factor structure (33 items), from which trigger subscales for weather/climate, air pollution/irritants, exercise, infection/illness and psychological factors were formed (internal consistency Cronbach's α = 0.90-0.94). Trigger factors were associated with COPD functional status, exacerbation frequency and healthcare utilization. Participants found personal triggers related to dust, air pollution, smoking and physical activity to be the most easily controlled, whereas those related to psychological factors, climate, infection, respiratory symptoms and sleep to be more difficult to control. Greater perceived controllability of triggers was associated with lower CAT scores, indicating better health status and less impact of the disease on functioning. CONCLUSION: The CETI is a psychometrically valid measure of perceived exacerbation triggers in patients with COPD. Perceived triggers are associated with clinical outcomes. Assessment of trigger classes and their controllability may prove useful in both research and clinical settings with COPD patients and to further our knowledge in prevention and disease management.

Clinical implications of CD4+ T cell subsets in adult atopic asthma patients.

BACKGROUND: T cells play a central role in chronic inflammation in asthma. However, the roles of individual subsets of T cells in the pathology of asthma in patients remain to be better understood. METHODS: We investigated the potential signatures of T cell subset phenotypes in asthma using fresh whole blood from adult atopic asthma patients (n = 43) and non-asthmatic control subjects (n = 22). We further assessed their potential clinical implications by correlating asthma severity. RESULTS: We report four major features of CD4+ T cells in the blood of atopic asthma patients. First, patients had a profound increase of CCR7+ memory CD4+ T cells, but not CCR7- memory CD4+ T cells. Second, an increase in CCR4+ CD4+ T cells in patients was mainly attributed to the increase of CCR7+ memory CD4+ T cells. Accordingly, the frequency of CCR4+CCR7+ memory CD4+ T cells correlated with asthma severity. Current common asthma therapeutics (including corticosteroids) were not able to affect the frequency of CCR4+CCR7+ memory CD4+ T cell subsets. Third, patients had an increase of Tregs, as assessed by measuring CD25, Foxp3, IL-10 and CTLA-4 expression. However, asthma severity was inversely correlated only with the frequency of CTLA-4+ CD4+ T cells. Lastly, patients and control subjects have similar frequencies of CD4+ T cells that express CCR5, CCR6, CXCR3, CXCR5, CD11a, or α4 integrin. However, the frequency of α4+ CD4+ T cells in patients correlated with asthma severity. CONCLUSIONS: CCR4+CCR7+ memory, but not CCR4+CCR7- memory, α4+, and CTLA4+ CD4+ T cells in patients show significant clinical implications in atopic asthma. Current common therapeutics cannot alter the frequency of such CD4+ T cell subsets in adult atopic asthma patients.

Asthmatic granulomatosis as a rare variant of uncontrolled severe asthma.

Asthmatic granulomatosis (AG) is a variant of severe asthma, first described in 2012, that consists of small airway changes compatible with asthma as well as interstitial nonnecrotizing granulomas. Treatment of AG requires immunosuppression as opposed to the traditional asthma therapy of inhaled steroids. We describe a 5-year course of a patient with AG that has shown no improvement with immunosuppression or other standards of therapy.

Controlling asthma by training of Capnometry-Assisted Hypoventilation (CATCH) vs slow breathing: a randomized controlled trial.

BACKGROUND: Hyperventilation has been associated with adverse effects on lung function, symptoms, and well-being in asthma. We examined whether raising end-tidal CO2 levels (ie, Pco2) compared with slow breathing is associated with improvements in asthma control, including peak flow variability. METHODS: One hundred twenty patients with asthma were randomly assigned to capnometry-assisted respiratory training (CART) for raising Pco2 or slow breathing and awareness training (SLOW) for slowing respiratory rate. Patients received five weekly sessions and completed bid homework exercises over 4 weeks. Blinded assessments at baseline, posttreatment, 1- and 6-month follow-up of asthma control, Pco2, and diurnal peak flow variability were primary outcome measures. Additionally, we measured pulmonary function (spirometry, forced oscillation, exhaled nitric oxide, and methacholine challenge), symptoms, quality of life, and bronchodilator use. Because the control group received active treatment, we expected improvements in asthma control in both groups but more pronounced benefits from CART. RESULTS: Improvements were seen in 17 of 21 clinical indexes (81.0%) in both interventions, including the primary outcome variables asthma control (d = 0.81), peak flow variability (d = 0.54), quality of life, bronchodilator use, lung function, and airway hyperreactivity. Most improvements were sustained across the 6-month follow-up. Compared with slow breathing, CART showed greater increases in Pco2 (d = 1.45 vs 0.64 for CART vs SLOW, respectively) and greater reductions in respiratory impedance during treatment, less distress during methacholine challenge, and greater reduction in asthma symptoms at follow-up (P < .05). CONCLUSIONS: Brief interventions aimed at raising Pco2 or slowing respiratory rate provide significant, sustained, and clinically meaningful improvements in asthma control. Raising Pco2 was associated with greater benefits in aspects of lung function and long-term symptoms. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT00975273; URL: www.clinicaltrials.gov.

Validation of Rules of Two™ as a paradigm for assessing asthma control.

Assessing asthma control at each patient encounter is an essential task to determine pharmacologic requirements. Rules of Two (Ro2) was created from the original 1991 National Asthma Education Program guidelines to determine the need for controller therapy. This study determined the degree of agreement between Ro2 and the Expert Panel Report (EPR-3) definition of "in control" asthma and compared that value with the Asthma Control Test (ACT) in a group of asthmatics for the purpose of validating this tool. Patients with documented asthma were randomized to complete Ro2 or ACT prior to being assessed for asthma control by certified asthma educators using an EPR-3 template. Assessments occurred in either a specialty asthma clinic or at a local health fair. Patients were also queried for their personal assessment of asthma control. The primary statistical methodology employed was the degree of agreement (kappa) between each survey tool and the EPR-3 template. Of 150 patients, 72% did not have their asthma in control, based on the EPR-3 template. Ro2 identified 58% of patients not in control of their asthma, whereas ACT identified 36%, with kappa scores of 0.41 for Ro2 and 0.37 for ACT compared with the EPR-3 template. These were not significantly different. Of the 150 patients, 75% considered their asthma in control based on self-assessments, with a kappa of 0.23. In 14 of 73 ACT questionnaires, scores were not added or were misadded. Eliminating evaluation of static lung function significantly improved both kappa scores of Ro2 and ACT. In conclusion, Ro2 identifies patients with uncontrolled asthma as well as ACT and may be useful to the primary assessing clinician in determining asthma control.

The genetic architecture of maize height.

Height is one of the most heritable and easily measured traits in maize (Zea mays L.). Given a pedigree or estimates of the genomic identity-by-state among related plants, height is also accurately predictable. But, mapping alleles explaining natural variation in maize height remains a formidable challenge. To address this challenge, we measured the plant height, ear height, flowering time, and node counts of plants grown in >64,500 plots across 13 environments. These plots contained >7300 inbreds representing most publically available maize inbreds in the United States and families of the maize Nested Association Mapping (NAM) panel. Joint-linkage mapping of quantitative trait loci (QTL), fine mapping in near isogenic lines (NILs), genome-wide association studies (GWAS), and genomic best linear unbiased prediction (GBLUP) were performed. The heritability of maize height was estimated to be >90%. Mapping NAM family-nested QTL revealed the largest explained 2.1 ± 0.9% of height variation. The effects of two tropical alleles at this QTL were independently validated by fine mapping in NIL families. Several significant associations found by GWAS colocalized with established height loci, including brassinosteroid-deficient dwarf1, dwarf plant1, and semi-dwarf2. GBLUP explained >80% of height variation in the panels and outperformed bootstrap aggregation of family-nested QTL models in evaluations of prediction accuracy. These results revealed maize height was under strong genetic control and had a highly polygenic genetic architecture. They also showed that multiple models of genetic architecture differing in polygenicity and effect sizes can plausibly explain a population's variation in maize height, but they may vary in predictive efficacy.

Comprehensive genotyping of the USA national maize inbred seed bank.

BACKGROUND: Genotyping by sequencing, a new low-cost, high-throughput sequencing technology was used to genotype 2,815 maize inbred accessions, preserved mostly at the National Plant Germplasm System in the USA. The collection includes inbred lines from breeding programs all over the world. RESULTS: The method produced 681,257 single-nucleotide polymorphism (SNP) markers distributed across the entire genome, with the ability to detect rare alleles at high confidence levels. More than half of the SNPs in the collection are rare. Although most rare alleles have been incorporated into public temperate breeding programs, only a modest amount of the available diversity is present in the commercial germplasm. Analysis of genetic distances shows population stratification, including a small number of large clusters centered on key lines. Nevertheless, an average fixation index of 0.06 indicates moderate differentiation between the three major maize subpopulations. Linkage disequilibrium (LD) decays very rapidly, but the extent of LD is highly dependent on the particular group of germplasm and region of the genome. The utility of these data for performing genome-wide association studies was tested with two simply inherited traits and one complex trait. We identified trait associations at SNPs very close to known candidate genes for kernel color, sweet corn, and flowering time; however, results suggest that more SNPs are needed to better explore the genetic architecture of complex traits. CONCLUSIONS: The genotypic information described here allows this publicly available panel to be exploited by researchers facing the challenges of sustainable agriculture through better knowledge of the nature of genetic diversity.

Discrepancies between lung function and asthma control: asthma perception and association with demographics and anxiety.

Understanding asthma symptom perception is necessary for reducing unnecessary costs both for asthma sufferers and society and will contribute to improving asthma management. The primary aim of this study was to develop and test a standardized method for classification of asthma perceiver categories into under-, normal, and overperceiver groups based on the comparison between self-report and lung function components of asthma control. Additionally, the degree to which demographic variables and anxiety contributed to the classification of patients into perceiver groups was examined. Patients underwent methacholine or reversibility testing to confirm asthma diagnosis. Next, participants completed lung function testing over 3 days before their next appointment. Finally, patients filled out demographic and self-report measures including the Asthma Control Test (ACT). Each self-report category of control assessed by the ACT (interference, shortness of breath, nighttime awakenings, rescue inhaler usage, and a composite total score) was compared with lung function measurements using a modified version of the asthma risk grid. Using the modified asthma risk grid to determine perceiver categorization, this sample included 14 underperceivers, 29 normal perceivers, and 36 overperceivers. A discriminant analysis was performed that indicated that a majority of underperceivers were characterized by being African American and having low asthma-specific anxiety. Normal perceivers in this sample tended to be older. Overperceivers tended to be female. Our findings encourage further research using the reported method of classifying asthma patients into perceiver categories.

Approaches to chronic disease management for asthma and chronic obstructive pulmonary disease: strategies through the continuum of care.

Investigator-initiated research in both asthma and chronic obstructive pulmonary disease conducted at the Baylor Martha Foster Lung Care Center has sought to improve management throughout the continuum of respiratory care using a multidisciplinary approach. Respiratory care therapists employed in the primary care setting were shown to improve the quality of asthma care: rescue inhaler use decreased by 75% and respiratory symptom score decreased by 49% in patients who were seen by this midlevel specialty provider. In addition to similar results in a geriatric population, patients' diagnosis was changed in 48% of cases and treatment was changed in 76% of cases after the intervention. For pulmonary rehabilitation, an activity of daily living assessment form was created, and rehabilitation-whether traditional or water-based-was shown to improve patients' ability to perform activities of daily living and improve quality of life scores. The Rules of Two((R)), developed by Baylor University Medical Center at Dallas to simplify understanding of good asthma control, continues to be taught, and patient education has also been offered through asthma summer camps for children. Finally, a multidisciplinary team worked to develop a protocol for treatment of asthma patients in the emergency department and, through this effort, was able to reduce length of stay from an average of 278 minutes to an average of 168 minutes. These efforts aim to overcome the gap between recommended care and actual practice, so that patients benefit from evidence-based medicine and continuing refinements to diagnosis and treatment.

Children with asthma miss more school: fact or fiction?

BACKGROUND: It is widely believed that children with asthma miss considerably more school than children without asthma. Previous surveys have indicated that 49% of children with asthma miss school (Asthma in America, 1998), but only a few studies have attempted to quantify the amount of school missed. Understanding the role of asthma in school attendance will help direct limited health-care resources to the children who need them most. METHODS: We investigated school absence rates in fourth- through sixth-grade students in 19 inner-city schools in the Dallas Independent School District (DISD). The sample consisted of 353 students who were identified as possibly having asthma based on responses to a modified Brief Pediatric Screen instrument and who underwent spirometry and/or exercise challenge (EC) testing to confirm the diagnosis of asthma: 25 students were excluded for FEV(1) < 70% and without bronchodilator response, while 157 students had EC-positive test results, and 171 students had EC-negative test results. We compared yearly absences for these students with each other, with all fourth- through sixth-grade students in the 19 study schools, and with all fourth- through sixth-grade students in the district. We also tabulated data from a separate database that included asthma patients identified by the school registered nurse (RN). Absence data by school and by grade level were provided by the school district for the 2002-2003 school year. RESULTS: Absence rates were as follows: 2.54% (EC positive), 2.12% (EC negative), 2.59% (abnormal FEV(1)), 2.86% (RN identified), 2.85% (all fourth- through sixth-grade students in study schools), and 2.95% (all fourth- through sixth-grade students in the DISD). CONCLUSION: Students with asthma in the DISD miss no more school their classmates without asthma.

Screening Two Lycopersicon peruvianum Collections for Resistance to Tomato spotted wilt virus.

The United States Department of Agriculture (USDA) Research Service and the Tomato Genetics Resource Center (TGRC) Lycopersicon peruvianum germplasm collections (16,335 plants from 285 accessions) were screened with the Tomato spotted wilt virus (TSWV) isolates TSWV6 from Hawaii, and Anwa-1 from Western Australia. Using TSWV6 to screen for resistance, 10,634 L. peruvianum plants from 280 accessions were screened for resistance, resulting in 168 (60%) accessions with 1,437 (14%) plants indicating resistance, with all 1,404 89S (Sw-5+/Sw-5+) and 1,456 89R (Sw-5/Sw-5) controls infected. When using Anwa-1 for screening, 864 (15%) of 5,701 L. peruvianum plants were uninfected from 106 of the 181 accessions tested, and 472 (95%) of the 495 89S and 421 (73%) of the 574 89R controls were infected. Of the 172 accessions tested with both isolates, 54 were resistant to one isolate but not the other. Additionally, more accessions from the USDA than from the TGRC collection indicated resistance. TSWV-resistant accessions were somewhat equally distributed throughout the L. peruvianum geographic range, with an observation that northern Chile and southern Peru seemed to have an unusually high portion of accession indicating resistance. The value of Sw-5 is discussed in relationship to potential additional sources of TSWV resistance.