Co-repressors AtSDR4L and DIG1 interact with transcription factor VAL2 and promote Arabidopsis seed-to-seedling transition

Two transcriptional co-repressors physically interact with a transcription factor that is known to recruit a multi-protein complex, which promotes the repression of seed maturation genes by depositing trimethylation marks on lysine 27 of the histone 3 tails.

Toward targeted treatments for silicosis

PURPOSE OF REVIEW

There has been a rapid increase in silicosis cases, particularly related to artificial stone. The key to management is avoidance of silica exposure. Despite this, many develop progressive disease and there are no routinely recommended treatments. This review provides a summary of the literature pertaining to pharmacological therapies for silicosis and examines the plausibility of success of such treatments given the disease pathogenesis.

RECENT FINDINGS

In-vitro and in-vivo models demonstrate potential efficacy for drugs, which target inflammasomes, cytokines, effector cells, fibrosis, autophagy, and oxidation.

SUMMARY

There is some evidence for potential therapeutic targets in silicosis but limited translation into human studies. Treatment of silicosis likely requires a multimodal approach, and there is considerable cross-talk between pathways; agents that modulate both inflammation, fibrosis, autophagy, and ROS production are likely to be most efficacious.

Homeostasis of Arabidopsis R protein RPS2 is negatively regulated by the RING-type E3 ligase MUSE16

The homeostasis of resistance (R) proteins in plants must be tightly regulated to ensure precise activation of plant immune responses upon pathogen infection, while avoiding autoimmunity and growth defects when plants are uninfected. It is known that CPR1, an F-box protein in the SCF E3 complex, functions as a negative regulator of plant immunity through targeting the resistance (R) proteins SNC1 and RPS2 for degradation. However, whether these R proteins are also targeted by other E3 ligases is unclear. Here, we isolated Arabidopsis MUSE16, which encodes a RING-type E3 ligase, from a forward genetic screen and suggest that it is a negative regulator of plant immunity. Unlike CPR1, knocking out MUSE16 alone in Arabidopsis is not enough to result in defense-related dwarfism, since only RPS2 out of the tested R proteins accumulated in the muse16 mutants. Thus, our study identifies a novel E3 ligase involved in the degradation of nucleotide-binding and leucine-rich repeat (NLR) R proteins, support the idea that ubiquitin-mediated degradation is a fine-tuned mechanism for regulating the turnover of R proteins in plants, and that the same R protein can be targeted by different E3 ligases for regulation of its homeostasis.

The transcriptional co-repressor SEED DORMANCY 4-LIKE (AtSDR4L) promotes the embryonic-to-vegetative transition in Arabidopsis thaliana

Repression of embryonic traits during the seed-to-seedling phase transition requires the inactivation of master transcription factors associated with embryogenesis. How the timing of such inactivation is controlled is unclear. Here, we report on a novel transcriptional co-repressor, Arabidopsis thaliana SDR4L, that forms a feedback inhibition loop with the master transcription factors LEC1 and ABI3 to repress embryonic traits post-imbibition. LEC1 and ABI3 regulate their own expression by inducing AtSDR4L during mid to late embryogenesis. AtSDR4L binds to sites upstream of LEC1 and ABI4, and these transcripts are upregulated in Atsdr4l seedlings. Atsdr4l seedlings phenocopy a LEC1 overexpressor. The embryonic traits of Atsdr4l can be partially rescued by impairing LEC1 or ABI3. The penetrance and expressivity of the Atsdr4l phenotypes depend on both developmental and external cues, demonstrating the importance of AtSDR4L in seedling establishment under suboptimal conditions.

Predictors of psychological stress in silica-exposed workers in the artificial stone benchtop industry

Background and objective

Artificial stone benchtops are a popular kitchen product, but dust from their preparation and installation contains respirable crystalline silica, which causes silicosis. Silicosis is a preventable, permanent lung disease. The aim of this study was to assess mental health in workers from the artificial stone benchtop industry at risk of silicosis.

Methods

Workers from the artificial stone benchtop industry undergoing assessment for silica‐associated disease were included. Information on demographics; occupational, medical and smoking history; modified Medical Research Council dyspnoea scale; Perceived Stress Scale (PSS‐10) questionnaire; spirometry; and chest x‐ray was collected. Univariate and multivariate regression analyses were conducted.

Results

Of the 547 participants, the majority were men, aged under 45 years, in the industry for less than 10 years. With each increase of dyspnoea score, PSS‐10 scores increased. Higher PSS‐10 scores were also observed in those no longer in the industry, with a history of anxiety or depression, attending assessment early in the programme and a medium exposure duration. Participants who used an interpreter reported lower stress. No difference was observed across job title, age, sex, smoking, spirometry or chest x‐ray categories after multivariate analysis.

Conclusion

This study identified workers with dyspnoea as likely to report higher stress. Other factors, such as leaving the industry, early attendance and a history of anxiety or depression, are also helpful in identifying workers at risk of poorer mental health outcomes.

This study describes psychological stress scores in silica‐exposed workers from the artificial stone benchtop industry and identifies predictors of elevated stress.

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A Forward Genetic Screen in Sclerotinia sclerotiorum Revealed the Transcriptional Regulation of Its Sclerotial Melanization Pathway

Most plant fungal pathogens that cause worldwide crop losses are understudied, due to various technical challenges. With the increasing availability of sequenced whole genomes of these non-model fungi, effective genetic analysis methods are highly desirable. Here, we describe a newly developed pipeline, which combines forward genetic screening with high-throughput next-generation sequencing to enable quick gene discovery. We applied this pipeline in the notorious soilborne phytopathogen Sclerotinia sclerotiorum and identified 32 mutants with various developmental and growth deficiencies. Detailed molecular studies of three melanization-deficient mutants provide a proof of concept for the effectiveness of our method. A master transcription factor was found to regulate melanization of sclerotia through the DHN (1,8-dihydroxynaphthalene) melanin biosynthesis pathway. In addition, these mutants revealed that sclerotial melanization is important for sclerotia survival under abiotic stresses, sclerotial surface structure, and sexual reproduction. Foreseeably, this pipeline can be applied to facilitate efficient in-depth studies of other non-model fungal species in the future.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

The impact of the Hazelwood coal mine fire smoke exposure on asthma

OBJECTIVE

In 2014, a fire at an open cut coal mine in South-eastern Australia burned for about 6 weeks. Residents of the adjacent town were exposed to high levels of fine particulate matter (PM2.5) during this period. Three and a half years after the event, this study aimed to investigate potential long-term impacts of short-term exposure to coal mine fire smoke on asthma.

METHODS

A cross-sectional analysis was undertaken in a group of exposed participants with asthma from Morwell (n = 165) and a group of unexposed participants with asthma from the control town of Sale (n = 64). Exposure was determined by modeled PM2.5 data for the mine fire period. Respiratory symptoms were assessed with a validated respiratory health questionnaire and symptom severity score. Asthma control was assessed with a validated questionnaire. Lung function testing included spirometry, bronchodilator response, and fraction of exhaled nitric oxide.

RESULTS

There was no evidence that exposed participants had more severe asthma symptoms, worse lung function, or more eosinophilic airway inflammation than unexposed participants. However, there was some evidence that Morwell participants had more uncontrolled than well-controlled asthma, compared to the participants from Sale (adjusted relative risk ratio 2.71 95% CI: 1.02, 7.21, p = .046).

CONCLUSION

Three and a half years after exposure, coal mine fire smoke did not appear to be associated with more severe asthma symptoms or worse lung function but might be associated with poorer asthma control.

Diagnostic and Therapeutic Outcomes Following Systematic Assessment of Patients with Concurrent Suspected Vocal Cord Dysfunction and Asthma

BACKGROUND

Vocal cord dysfunction (VCD) is present in 25% to 50% of patients with asthma. When both diagnoses are suspected, accurate diagnosis and targeted management represent a clinical challenge.

OBJECTIVE

To evaluate diagnostic and therapeutic outcomes following systematic assessment for patients with concurrent suspected VCD and asthma.

METHODS

Patients underwent systematic evaluation by clinical assessment and validated questionnaires, followed by multidisciplinary management. VCD was confirmed by visualization of paradoxical vocal fold motion at baseline or following provocation. Asthma was confirmed by demonstrating variable airflow obstruction. Asthma medications were deescalated in those with low clinical probability of asthma and no variable airflow obstruction. Response to 2 or more sessions of speech pathology was assessed by subjective report and standardized questionnaires.

RESULTS

Among 212 consecutive patients, 62 (29%) patients had both VCD and asthma, 54 (26%) had VCD alone, 51 (24%) had asthma alone, and 45 (21%) had neither. Clinician assessment and the Laryngeal Hypersensitivity Questionnaire both predicted laryngoscopy-confirmed VCD. Deescalation or discontinuation of asthma therapy was possible in 37 of 59 (63%) patients without variable airflow obstruction, and was most successful (odds ratio, 5.5) in the presence of laryngoscopy-confirmed VCD (25 of 31, or 81%) Patients with VCD responded subjectively to 2 or more sessions of speech pathology, but laryngeal questionnaire scores did not improve.

CONCLUSIONS

Expert clinician assessment and the Laryngeal Hypersensitivity Questionnaire predict the presence of laryngoscopy-confirmed VCD. Systematic assessment for both VCD and asthma facilitates deescalation or discontinuation of unnecessary asthma medications. Subjective symptom improvement following speech pathology was not paralleled by laryngeal questionnaire scores in this cohort.

Team effort: Combinatorial control of seed maturation by transcription factors

Seed development is under tight spatiotemporal regulation. Here, we summarize how transcriptional regulation helps shape the major traits during seed maturation, which include storage reserve accumulation, dormancy, desiccation tolerance, and longevity. The regulation is rarely a solo task by an individual transcription factor (TF). Rather, it often involves coordinated recruitment or replacement of multiple TFs to achieve combinatorial regulation. We highlight recent progress on the transcriptional integration of activation and repression of seed maturation genes, and discuss potential research directions to further understand the TF networks of seed maturation.

A review of physiotherapy practice for people with bronchiectasis

People with bronchiectasis experience chronic productive cough and acute exacerbations, which are linked to poorer quality of life and a higher rate of disease progression. The clinical guidelines for bronchiectasis management recommend physiotherapy [1, 2]. These guidelines advise the prescription of airway clearance techniques (ACTs) to improve sputum clearance and reduce symptoms [1, 2]. Mucoactive agents may be cautiously considered when required [1, 2]. Individuals with reduced exercise tolerance are recommended to engage in pulmonary rehabilitation or undertake exercise or physical activity [1, 2]. Surveys of physiotherapy management for people with bronchiectasis have described commonly applied ACTs [3, 4] but have not alluded to technique combinations, a strategy considered a key approach towards personalising therapy [3–5]. Other audits have highlighted that ACTs were applied in only 49% and 52% of people with bronchiectasis in Europe and Australia respectively, reflecting a potential underuse of this therapeutic approach [6, 7]. Low referral rates to pulmonary rehabilitation have been noted [3, 7], and the prescription of exercise and physical activity beyond pulmonary rehabilitation is unknown [3].

A combination of airway clearance techniques are applied for people with bronchiectasis, together with recommendations for exercise and suggestions for management of common comorbiditieshttps://bit.ly/2U3c99H

Respiratory surveillance for coal mine dust and artificial stone exposed workers in Australia and New Zealand: A position statement from the Thoracic Society of Australia and New Zealand

Coal mine lung dust disease (CMDLD) and artificial stone (AS) silicosis are preventable diseases which have occurred in serious outbreaks in Australia recently. This has prompted a TSANZ review of Australia's approach to respiratory periodic health surveillance. While regulating respirable dust exposure remains the foundation of primary and secondary prevention, identification of workers with early disease assists with control of further exposure, and with the aims of preserving lung function and decreasing respiratory morbidity in those affected. Prompt detection of an abnormality also allows for ongoing respiratory specialist clinical management. This review outlines a medical framework for improvements in respiratory surveillance to detect CMDLD and AS silicosis in Australia. This includes appropriate referral, improved data collection and interpretation, enhanced surveillance, the establishment of a nationwide Occupational Lung Disease Registry and an independent advisory group. These measures are designed to improve health outcomes for workers in the coal mining, AS and other dust-exposed and mining industries.

Work-related asthma: A position paper from the Thoracic Society of Australia and New Zealand and the National Asthma Council Australia

Work-related asthma (WRA) is one of the most common occupational respiratory conditions, and includes asthma specifically caused by occupational exposures (OA) and asthma that is worsened by conditions at work (WEA). WRA should be considered in all adults with asthma, but especially those with new-onset or difficult to control asthma. Improvement in asthma symptoms when away from work is suggestive of WRA. Clinical history alone is insufficient to diagnose WRA; therefore, objective investigations are required to confirm the presence of asthma and the association of asthma with work activities. Management of WRA requires pharmacotherapy similar to that of non-WRA, however, also needs to take into account control of the causative workplace exposure. Ongoing exposure will likely lead to decline in lung function and worsening asthma control. WRA is a preventable condition but this does rely on increased awareness of WRA and thorough identification and control of all potential occupational respiratory hazards.

Paradoxical Vocal Fold Motion in Difficult Asthma Is Associated with Dysfunctional Breathing and Preserved Lung Function

BACKGROUND

Many patients with difficult asthma also have coexisting vocal cord dysfunction (VCD), evident by paradoxical vocal fold motion (PVFM) on laryngoscopy.

OBJECTIVE

Among patients with difficult asthma, we sought to identify clinical features associated with laryngoscopy-diagnosed PVFM.

METHODS

Consecutive patients with "difficult asthma" referred by respiratory specialists underwent systematic assessment in this observational study. Those with a high clinical suspicion for VCD were referred for laryngoscopy, either at rest or after mannitol provocation. Statistical analyses were performed to identify clinical factors associated with PVFM, and a multivariate logistic regression model was fitted to control for confounders.

RESULTS

Of 169 patients with difficult asthma, 63 (37.3%) had a high clinical probability of VCD. Of 42 who underwent laryngoscopy, 32 had PVFM confirmed. Patients with PVFM more likely had preserved lung function (prebronchodilator forced expiratory ratio 74% ± 11 vs 62% ± 16, P < .001); physiotherapist-confirmed dysfunctional breathing (odds ratio [OR] = 5.52, 95% confidence interval [CI]: 2.4-12.7, P < .001), gastro-oesophageal reflux (OR = 2.6, 95% CI: 1.16-5.8, P = .02), and a lower peripheral eosinophil count (0.09 vs 0.23, P = .004). On multivariate logistic regression, independent predictors for PVFM were dysfunctional breathing (OR = 4.93, 95% CI: 2-12, P < .001) and preserved lung function (OR = 1.07, 95% CI: 1.028-1.106, P < .001).

CONCLUSION

Among specialist-referred patients with difficult asthma, VCD pathogenesis may overlap with dysfunctional breathing but is not associated with severe airflow obstruction. Dysfunctional breathing and preserved lung function may serve as clinical clues for the presence of VCD.

Plant NLRs: The Whistleblowers of Plant Immunity

The study of plant diseases is almost as old as agriculture itself. Advancements in molecular biology have given us much more insight into the plant immune system and how it detects the many pathogens plants may encounter. Members of the primary family of plant resistance (R) proteins, NLRs, contain three distinct domains, and appear to use several different mechanisms to recognize pathogen effectors and trigger immunity. Understanding the molecular process of NLR recognition and activation has been greatly aided by advancements in structural studies, with ZAR1 recently becoming the first full-length NLR to be visualized. Genetic and biochemical analysis identified many critical components for NLR activation and homeostasis control. The increased study of helper NLRs has also provided insights into the downstream signaling pathways of NLRs. This review summarizes the progress in the last decades on plant NLR research, focusing on the mechanistic understanding that has been achieved.

The Notorious Soilborne Pathogenic Fungus Sclerotinia sclerotiorum: An Update on Genes Studied with Mutant Analysis

Ascomycete Sclerotinia sclerotiorum (Lib.) de Bary is one of the most damaging soilborne fungal pathogens affecting hundreds of plant hosts, including many economically important crops. Its genomic sequence has been available for less than a decade, and it was recently updated with higher completion and better gene annotation. Here, we review key molecular findings on the unique biology and pathogenesis process of S. sclerotiorum, focusing on genes that have been studied in depth using mutant analysis. Analyses of these genes have revealed critical players in the basic biological processes of this unique pathogen, including mycelial growth, appressorium establishment, sclerotial formation, apothecial and ascospore development, and virulence. Additionally, the synthesis has uncovered gaps in the current knowledge regarding this fungus. We hope that this review will serve to build a better current understanding of the biology of this under-studied notorious soilborne pathogenic fungus.

Artificial stone-associated silicosis: clinical-pathological-radiological correlates of disease

Occupational lung disease secondary to inhalation of silica particles is variable and potentially life-threatening. As the artificial stone industry has grown over the last two decades, the development of silicosis has been seen to accelerate and behave differently to chronic silicosis. In this case report, we present two patients who underwent lung transplantation for silicosis at the Alfred Hospital, both with predominantly artificial stone masonry exposure. We have identified the presence of both fibrotic/nodular silicosis and conspicuous alveolar proteinosis within the same lung parenchyma of both patients. We then demonstrate the radiological and histopathological correlates of disease; the first time this has been shown clearly in the literature.

Silica-associated lung disease: An old-world exposure in modern industries

Despite silica dust exposure being one of the earliest recognized causes of lung disease, Australia, USA, Israel, Turkey and other countries around the world have recently experienced significant outbreaks of silicosis. These outbreaks have occurred in modern industries such as denim jean production, domestic benchtop fabrication and jewellery polishing, where silica has been introduced without recognition and control of the hazard. Much of our understanding of silica-related lung disease is derived from traditional occupations such as mining, whereby workers may develop slowly progressive chronic silicosis. However, workers in modern industries are developing acute and accelerated silicosis over a short period of time, due to high-intensity silica concentrations, oxidative stress from freshly fractured silica and a rapid pro-inflammatory and pro-fibrotic response. Appropriate methods of screening and diagnosis remain unclear in these workers, and a significant proportion may go on to develop respiratory failure and death. There are no current effective treatments for silicosis. For those with near fatal respiratory failure, lung transplantation remains the only option. Strategies to reduce high-intensity silica dust exposure, enforced screening programmes and the identification of new treatments are urgently required.

Factors Associated with Dysfunctional Breathing in Patients with Difficult to Treat Asthma

BACKGROUND

Understanding of dysfunctional breathing in patients with difficult asthma who remain symptomatic despite maximal inhaler therapy is limited.

OBJECTIVE

We characterized the pattern of dysfunctional breathing in patients with difficult asthma and identified possible contributory factors.

METHODS

Dysfunctional breathing was identified in patients with difficult asthma using the Nijmegen Questionnaire (score >23). Demographic characteristics, asthma variables, and comorbidities were assessed. Multivariate logistic regression was performed for dysfunctional breathing, adjusted for age, sex, body mass index, and airflow obstruction.

RESULTS

Of 157 patients with difficult asthma, 73 (47%) had dysfunctional breathing. Compared with patients without dysfunctional breathing, those with dysfunctional breathing experienced poorer asthma status (symptom control, quality of life, and exacerbation rates) and greater unemployment. In addition, more frequently they had elevated sino-nasal outcome test scores, anxiety, depression, sleep apnea, and gastroesophageal reflux. On multivariate analysis, anxiety (odds ratio [OR], 3.26; 95% CI, 1.18-9.01; P = .02), depression (OR, 2.8; 95% CI, 1.14-6.9; P = .03), and 22-item sino-nasal outcome test score (OR, 1.03; 95% CI, 1.003-1.05; P = .03) were independent risk factors for dysfunctional breathing.

CONCLUSIONS

Dysfunctional breathing is common in difficult asthma and associated with worse asthma status and unemployment. The independent association with psychological disorders and nasal obstruction highlight an important interaction between comorbid treatable traits in difficult asthma.

Diagnosis of concomitant inducible laryngeal obstruction and asthma

BACKGROUND

Inducible laryngeal obstruction, an induced, inappropriate narrowing of the larynx, leading to symptomatic upper airway obstruction, can coexist with asthma. Accurate classification has been challenging because of overlapping symptoms and the absence of sensitive diagnostic criteria for either condition.

OBJECTIVE

To evaluate patients with concomitant clinical suspicion for inducible laryngeal obstruction and asthma. We used a multidisciplinary protocol incorporating objective diagnostic criteria to determine whether asthma, inducible laryngeal obstruction, both, or neither diagnosis was present.

METHODS

Consecutive patients were prospectively assessed by a laryngologist, speech pathologist and respiratory physician. Inducible laryngeal obstruction was diagnosed by visualizing paradoxical vocal fold motion either at baseline or following mannitol provocation. Asthma was diagnosed by physician assessment with objective variable airflow obstruction. Validated questionnaires for laryngeal dysfunction and relevant comorbidities were administered.

RESULTS

Of 69 patients, 15 had asthma alone, 11 had inducible laryngeal obstruction alone and 14 had neither objectively demonstrated. Twenty-nine patients had both diagnoses. In 19 patients, inducible laryngeal obstruction was only seen following provocation. Among patients with inducible laryngeal obstruction, chest tightness was more frequent with concurrent asthma. Among patients with asthma, stridor was more frequent with concurrent inducible laryngeal obstruction. Cough was more frequently found in asthma alone, whereas difficulty with inspiration and symptoms triggered by psychological stress were more frequently found in inducible laryngeal obstruction alone. Patients with asthma alone had greater airflow obstruction. Relevant comorbidities were frequent (rhinitis in 85%, gastro-oesophageal reflux in 65%), and questionnaire scores for laryngeal dysfunction were abnormal. However, neither comorbidities nor questionnaires differentiated patients with or without inducible laryngeal obstruction.

CONCLUSIONS AND CLINICAL RELEVANCE

In this cohort with suspected inducible laryngeal obstruction and asthma, 42% had objective evidence of both conditions. Clinical assessment, questionnaire scores and comorbidity burden were not sufficiently discriminatory for diagnosis, highlighting the necessity of objective diagnostic testing.

Nonadherence in the era of severe asthma biologics and thermoplasty

Nonadherence to inhaled preventers impairs asthma control. Electronic monitoring devices (EMDs) can objectively measure adherence. Their use has not been reported in difficult asthma patients potentially suitable for novel therapies, i.e. biologics and bronchial thermoplasty.Consecutive patients with difficult asthma were assessed for eligibility for novel therapies. Medication adherence, defined as taking >75% of prescribed doses, was assessed by EMD and compared with standardised clinician assessment over an 8-week period.Among 69 difficult asthma patients, adherence could not be analysed in 13, due to device incompatibility or malfunction. Nonadherence was confirmed in 20 out of 45 (44.4%) patients. Clinical assessment of nonadherence was insensitive (physician 15%, nurse 28%). Serum eosinophils were higher in nonadherent patients. Including 11 patients with possible nonadherence (device refused or not returned) increased the nonadherence rate to 31 out of 56 (55%) patients. Severe asthma criteria were fulfilled by 59 out of 69 patients. 47 were eligible for novel therapies, with confirmed nonadherence in 16 out of 32 (50%) patients with EMD data; including seven patients with possible nonadherence increased the nonadherence rate to 23 out of 39 (59%).At least half the patients eligible for novel therapies were nonadherent to preventers. Nonadherence was often undetectable by clinical assessments. Preventer adherence must be confirmed objectively before employing novel severe asthma therapies.

A Structured Approach to Specialist-referred Difficult Asthma Patients Improves Control of Comorbidities and Enhances Asthma Outcomes

BACKGROUND

Systematic evaluation is advocated for difficult asthma, but how best to deliver such care is unclear and outcome data are scarce.

OBJECTIVE

We describe our institution's structured approach to difficult asthma management and report on the outcomes of such an approach.

METHODS

Eighty-two consecutive patients with difficult asthma referred to our clinic from respiratory specialists were evaluated in 3 key areas: diagnostic confirmation, comorbidity detection, and inflammatory phenotyping. We then optimized treatment including relevant comorbidity interventions. The outpatient protocol was supported by comorbidity questionnaires, an electronic clinic template, and standardized panel discussion. Asthma outcomes were assessed at 6 months.

RESULTS

Sixty-eight patients completed follow-up. Asthma diagnosis was refuted in 3 patients and the remaining 65 patients were included in the study analysis. There was no overall escalation of inhaled or oral corticosteroids. Patients had a median of 3 comorbidities, and a median of 3 comorbidity interventions. Control of chronic rhinosinusitis and dysfunctional breathing improved among patients with these diagnoses (22-item Sino-Nasal Outcome Test score from 47 ± 20 to 37 ± 22, P = .017; Nijmegen score from 32 ± 6 to 25 ± 9, P = .003). There were overall improvements in the Asthma Control Test score (from 14 ± 5 to 16 ± 6, P < .001), the Asthma Quality of Life Questionnaire (from 4.29 ± 1.4 to 4.65 ± 1.5, P = .073), and the frequency of exacerbations over 6 months (from 2 [interquartile range, 0-4] to 0 [interquartile range, 0-2], P < .001).

CONCLUSIONS

In patients referred with difficult asthma from respiratory specialists, a structured approach coupled with targeted comorbidity interventions improved control of key comorbidities and enhanced asthma outcomes.

Validated questionnaires heighten detection of difficult asthma comorbidities

OBJECTIVE

Multiple extra-pulmonary comorbidities contribute to difficult asthma, but their diagnosis can be challenging and time consuming. Previous data on comorbidity detection have focused on clinical assessment, which may miss certain conditions. We aimed to locate relevant validated screening questionnaires to identify extra-pulmonary comorbidities that contribute to difficult asthma, and evaluate their performance during a difficult asthma evaluation.

METHODS

MEDLINE was searched to identify key extra-pulmonary comorbidities that contribute to difficult asthma. Screening questionnaires were chosen based on ease of use, presence of a cut-off score, and adequate validation to help systematically identify comorbidities. In a consecutive series of 86 patients referred for systematic evaluation of difficult asthma, questionnaires were administered prior to clinical consultation.

RESULTS

Six difficult asthma comorbidities and corresponding screening questionnaires were found: sinonasal disease (allergic rhinitis and chronic rhinosinusitis), vocal cord dysfunction, dysfunctional breathing, obstructive sleep apnea, anxiety and depression, and gastro-oesophageal reflux disease. When the questionnaires were added to the referring clinician's impression, the detection of all six comorbidities was significantly enhanced. The average time for questionnaire administration was approximately 40 minutes.

CONCLUSIONS

The use of validated screening questionnaires heightens detection of comorbidities in difficult asthma. The availability of data from a battery of questionnaires prior to consultation can save time and allow clinicians to systematically assess difficult asthma patients and to focus on areas of particular concern. Such an approach would ensure that all contributing comorbidities have been addressed before significant treatment escalation is considered.

Inhaled Mannitol as a Laryngeal and Bronchial Provocation Test

OBJECTIVES

Timely diagnosis of vocal cord dysfunction (VCD), more recently termed "inducible laryngeal obstruction," is important because VCD is often misdiagnosed as asthma, resulting in delayed diagnosis and inappropriate treatment. Visualization of paradoxical vocal cord movement on laryngoscopy is the gold standard for diagnosis, but is limited by poor test sensitivity. Provocation tests may improve the diagnosis of VCD, but the diagnostic performance of current tests is less than ideal. Alternative provocation tests are required. This pilot study demonstrates the feasibility of using inhaled mannitol for concurrent investigation of laryngeal and bronchial hyperresponsiveness.

METHODS

Consecutive patients with suspected VCD seen at our institution's asthma clinic underwent flexible laryngoscopy at baseline and following mannitol challenge. VCD was diagnosed on laryngoscopy based on inspiratory adduction, or >50% expiratory adduction of the vocal cords. Bronchial hyperresponsiveness after mannitol challenge was also assessed. We evaluated the interrater agreement of postmannitol laryngoscopy between respiratory specialists and laryngologists.

RESULTS

Fourteen patients with suspected VCD in the context of asthma evaluation were included in the study. Mannitol provocation demonstrated VCD in three of the seven patients with normal baseline laryngoscopy (42.9%). Only two patients had bronchial hyperresponsiveness. There was substantial interrater agreement between respiratory specialists and laryngologists, kappa = 0.696 (95% confidence interval: 0.324-1) (P = 0.006).

CONCLUSION

Inhaled mannitol can be used to induce VCD. It is well tolerated and can evaluate laryngeal and bronchial hyperresponsiveness at the same setting.

Population-wide preventive interventions for reducing the burden of chronic respiratory disease

Chronic obstructive pulmonary disease and asthma impose a substantial burden of disease. This narrative review focuses on potential population-wide interventions that are likely to have an impact on these diseases. The developmental origins of adult disease commence in utero, with maternal nutrition being of particular interest. However, to date, trials of maternal allergen avoidance, dietary supplementation or probiotics have not shown consistent protective effects against asthma. Poor indoor air quality, especially from biomass fuels as well as second-hand tobacco smoke, is a well-recognised risk factor for chronic respiratory diseases. This can be modified by cleaner fuels, cooking stoves or heaters, and improved ventilation. Although allergens are a risk factor for childhood asthma, the results of interventions to reduce exposures have been disappointing. Traffic-related air pollution is associated with an increased incidence of asthma in children. Primary prevention of the adverse effects of air pollution has focused on the development of ambient air quality guidelines, but enforcement remains a challenge in many countries. Occupational asthma may be induced by sensitisers or irritants in the workplace. Prevention involves eliminating the agent or reducing exposure as far as possible, which is more effective than respiratory protective equipment. Smoking cessation remains a key proven preventive strategy for chronic respiratory diseases. There is now an international framework for tobacco control, and recent innovations include plain packaging of tobacco. Chronic respiratory diseases can be substantially prevented by the above population-wide interventions.

Mushroom bodies of vespid wasps

Mushroom bodies are higher centers in the brains of insects. Studies on honey bees and species of ants suggest that these centers are particularly prominent in social insects. The present study confirms the presence of large mushroom bodies in five subfamilies of vespid wasps, while at the same time showing significant departures from the mushroom body organization that typifies bees and ants. Although the basic organizational plan of the insect mushroom body into calyces, peduncle, and lobes is maintained, as is the arrangement of axons of intrinsic neurons, the size and arrangements of the vespid mushroom body lobes differ markedly from those known from other Hymenoptera. Furthermore, considerable variation is found both between and within vespid subfamilies. The present results are discussed with respect to current hypotheses about functional attributes of mushroom bodies and the phylogeny of the Vespidae.

Chunk versus point sampling: visual imaging in a small insect

The eyes of strepsipteran insects are very unusual among living insects. In their anatomical organization they may form a modern counterpart to the structural plan proposed for the eyes of some trilobites. Externally they differ from the usual "insect plan" by presenting far fewer but much larger lenses. Beneath each lens is its own independent retina. Anatomical and optical measurements indicate that each of these units is image-forming, so that the visual field is subdivided into and represented by "chunks," unlike the conventional insect compound eye that decomposes the visual image in a pointwise manner. This results in profound changes in the neural centers for vision and implies major evolutionary changes.

Healthcare in Kenya: learning from a Third World country

Kenya's healthcare problems are exacerbated by illiteracy, widespread communities, poor sanitation in some areas, and tribal customs and traditions. This article gives an overview of Kenya's healthcare system that was gained by the author during a study tour to Kenya in March 1991.

The neuroethology of acoustic startle and escape in flying insects

The acoustic startle/escape response is a phylogenetically widespread behavioral act, provoked by an intense, unexpected sound. At least six orders of insects have evolved tympanate ears that serve acoustic behavior that ranges from sexual communication to predator detection. Insects that fly at night are vulnerable to predation by insectivorous bats that detect and locate their prey by using biosonar signals. Of the six orders of insects that possess tympanate hearing organs, four contain species that fly at night and, in these, hearing is sensitive to a range of ultrasonic frequencies found in the biosonar signals of bats. Laboratory and field studies have shown that these insects (including some orthopterans, lepidopterans, neuropterans and dictyopterans), when engaged in flight behavior, respond to ultrasound by suddenly altering their flight, showing acoustic startle or negative phonotaxis, which serve as bat-avoidance behavior. A neural analysis of ultrasound-mediated escape behavior was undertaken in the field cricket Telegryllus oceanicus. An identified thoracic interneuron, int-1, was shown to trigger the escape response, but only when the cell was driven (synaptically or electrically) at high spike rates, and only when the insect was performing flight behavior; avoidance steering only occurs in the appropriate behavioral context: flight. Thus, significant constraints operate upon the ability of int-1 to trigger the escape response. The integration of auditory input and flight central pattern generator output occurs in the brain. It is found that neural activity descending from the brain in response to stimulation by ultrasound is increased when the insect is flying compared to when it is not. Although the behavioral act of avoidance steering may appear to be a simple reflex act, further analysis shows it to be anything but simple.

An evaluation of a high resolution closed-circuit television link in a hospital radiology department

We have installed and developed a high resolution closed-circuit television system for transmission of radiographic film images from the emergency room in our hospital to the reading room in our radiology department. Using this system, the radiologist can consult promptly on all films and he has increased efficiency. To transmit high detail images, our television system uses a high resolution vidicon camera with a scan rate of 1029 lines and with a limiting resolution of 1200 TV lines. To further increase the overall diagnostic value of our system, we have added remote controls for changing the magnification, illumination and position of the film. In a preliminary clinical trial, seven radiologists were each shown 27 patient film sets transmitted through the television system and then viewed directly on a conventional view box. An analysis of variance of the accuracy rates in each method showed a statistical difference in methods. Even though the error rate was slightly higher using closed-circuit system, radiologist performance was of acceptable accuracy when considering the advantages of the system. In addition, many of the factors reducing the TV system performance have been eliminated or controlled, and further experiments should reflect an even smaller difference between the two methods.