Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Comparative analysis of three laboratory based serological assays for SARS-CoV-2 in an Australian cohort

Many unanswered questions remain regarding the role of SARS-CoV-2 serological assays in this unfolding COVID-19 pandemic. These include their utility for the diagnosis of acute SARS-CoV-2 infection, past infection or exposure, correlation with immunity and the effective duration of immunity. This study examined the performance of three laboratory based serological assays, EUROIMMUN Anti-SARS-CoV-2 IgA/IgG, MAGLUMI 2000 Plus 2019-nCov IgM/IgG and EDI Novel Coronavirus (COVID-19) IgM/IgG immunoassays. We evaluated 138 samples from a reference non-infected population and 71 samples from a cohort of 37 patients with SARS-CoV-2 confirmed positive by RT-PCR. The samples were collected at various intervals of 0-45 days post symptoms onset (PSO). Specificity and sensitivity of these assays was 60.9%/71.4% (IgA) and 94.2%/63.3% (IgG) for EUROIMMUN; 98.5%/18.4% (IgM) and 97.8%/53.1% (IgG) for MAGLUMI; and 94.9%/22.5% (IgM) and 93.5%/57.1% (IgG) for EDI, respectively. When samples collected ≥14 days PSO were considered, the sensitivities were 100.0 and 100.0%; 31.0 and 82.8%; 34.5 and 57.1%, respectively. Using estimated population prevalence of 0.1, 1, and 10%, the positive predictive value of all assays remained low. The EUROIMMUN Anti-SARS-CoV-2 IgA lacked specificity for acute diagnosis and all IgM assays offered poor diagnostic utility. Seroconversion can be delayed although all patients had seroconverted at 28 days in our cohort with the EUROIMMUN Anti-SARS-CoV-2 IgG. Despite this, with specificity of only 94% this assay would not be satisfactory for seroprevalence studies in the general Australian population given this is likely to be currently <1%.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Evaluation of femoral head damage during canine total hip replacement

Three types of hip skids and a Hohmann retractor technique were used to facilitate reduction of the prosthesis in cadaveric canine total hip replacement. The degree of damage to the femoral head was evaluated using scanning electron microscopy and optical profilometry. Standard metal and ME-92 coated metal hip skids caused severe regional scratching of the femoral head. Morphologically similar scratch patterns were also identified on femoral heads retrieved from clinical patients. Use of a plastic coated skid or the Hohmann retractor technique had no perceptible effect on surface finish, and therefore either method is acceptable in clinical practice. The use of metal hip skids cannot be recommended for hip reduction as the resultant pattern of femoral head scratching is likely to be associated with early and severe polyethylene wear.

The Effect of MHC Antigen Matching Between Donors and Recipients on Skin Tolerance of Vascularized Composite Allografts

The emergence of skin-containing vascularized composite allografts (VCAs) has provided impetus to understand factors affecting rejection and tolerance of skin. VCA tolerance can be established in miniature swine across haploidentical MHC barriers using mixed chimerism. Because the deceased donor pool for VCAs does not permit MHC antigen matching, clinical VCAs are transplanted across varying MHC disparities. We investigated whether sharing of MHC class I or II antigens between donors and recipients influences VCA skin tolerance. Miniature swine were conditioned nonmyeloablatively and received hematopoietic stem cell transplants and VCAs across MHC class I (n = 3) or class II (n = 3) barriers. In vitro immune responsiveness was assessed, and VCA skin-resident leukocytes were characterized by flow cytometry. Stable mixed chimerism was established in all animals. MHC class II-mismatched chimeras were tolerant of VCAs. MHC class I-mismatched animals, however, rejected VCA skin, characterized by infiltration of recipient-type CD8⁺ lymphocytes. Systemic donor-specific nonresponsiveness was maintained, including after VCA rejection. This study shows that MHC antigen matching influences VCA skin rejection and suggests that local regulation of immune tolerance is critical in long-term acceptance of all VCA components. These results help elucidate novel mechanisms underlying skin tolerance and identify clinically relevant VCA tolerance strategies.

Grafts of Genetically Modified Schwann Cells to the Spinal Cord: Survival, Axon Growth, and Myelination

Schwann cells naturally support axonal regeneration after injury in the peripheral nervous system, and have also shown a significant, albeit limited, ability to support axonal growth and remyelination after grafting to the central nervous system (CNS). It is possible that Schwann cell-induced axonal growth in the CNS could be substantially increased by genetic manipulation to secrete augmented amounts of neurotrophic factors. To test this hypothesis, cultured primary adult rat Schwann cells were genetically modified using retroviral vectors to produce and secrete high levels of human nerve growth factor (NGF). These cells were then grafted to the midthoracic spinal cords of adult rats. Findings were compared to animals that received grafts of nontransduced Schwann cells. Spinal cord lesions were not placed prior to grafting because the primary aim of this study was to examine features of grafted Schwann cell survival, growth, and effects on host axons. In vitro prior to grafting, Schwann cells secreted 1.5 + 0.1 ng human NGF/ml/106 cells/day. Schwann cell transplants readily survived for 2 wk to 1 yr after in vivo placement. Some NGF-transduced grafts slowly increased in size over time compared to nontransduced grafts; the latter remained stable in size. NGF-transduced transplants were densely penetrated by primary sensory nociceptive axons originating from the dorsolateral fasciculus of the spinal cord, whereas control grafts showed significantly fewer penetrating sensory axons. Over time, Schwann cell grafts also became penetrated by TH- and DBH-labeled axons of putative coerulospinal origin, unlike control cell grafts. Ultrastructurally, axons in both graft types were extensively myelinated by Schwann cells. Grafted animals showed no changes in gross locomotor function. In vivo expression of the human NGF transgene was demonstrated for periods of at least 6 m. These findings demonstrate that primary adult Schwann cells 1) can be transduced to secrete augmented levels of neurotrophic factors, 2) survive grafting to the CNS for prolonged time periods, 3) elicit robust growth of host neurotrophin-responsive axons, 4) myelinate CNS axons, and 5) express the transgene for prolonged time periods in vivo. Some grafts slowly enlarge over time, a feature that may be attributable to the propensity of Schwann cells to immortalize after multiple passages. Transduced Schwann cells merit further study as tools for promoting CNS regeneration.

Real-life effectiveness of omalizumab in severe allergic asthma above the recommended dosing range criteria

BACKGROUND

Omalizumab (Xolair) dosing in severe allergic asthma is based on serum IgE and bodyweight. In Australia, patients eligible for omalizumab but exceeding recommended ranges for IgE (30-1500 IU/mL) and bodyweight (30-150 kg) may still receive a ceiling dose of 750 mg/4 weeks. About 62% of patients receiving government-subsidized omalizumab are enrolled in the Australian Xolair Registry (AXR).

OBJECTIVES

To determine whether AXR participants above the recommended dosing ranges benefit from omalizumab and to compare their response to within-range participants.

METHODS

Data were stratified according to dose range status (above-range or within-range). Further sub-analyses were conducted according to the reason for being above the dosing range (IgE only vs. IgE and weight).

RESULTS

Data for 179 participants were analysed. About 55 (31%) were above recommended dosing criteria; other characteristics were similar to within-range participants. Above-range participants had higher baseline IgE [812 (IQR 632, 1747) IU/mL vs. 209 (IQR 134, 306) IU/mL] and received higher doses of omalizumab [750 (IQR 650, 750) mg] compared to within-range participants [450 (IQR, 300, 600) mg]. At 6 months, improvements in Juniper 5-item Asthma Control Questionnaire (ACQ-5, 3.61 down to 2.01 for above-range, 3.47 down to 1.93 for within-range, P < 0.0001 for both) and Asthma Quality of Life Questionnaire (AQLQ mean score (3.22 up to 4.41 for above-range, 3.71 up to 4.88 for within-range, P < 0.0001) were observed in both groups. Forced expiratory volume in one second (FEV₁ ) improved among above-range participants. There was no difference in response between above-range and within-range participants. Above-range participants due to either IgE alone or IgE and weight had similar improvements in ACQ-5, AQLQ and FEV₁ .

CONCLUSIONS AND CLINICAL RELEVANCE

Patients with severe allergic asthma above recommended dosing criteria for omalizumab have significantly improved symptom control, quality of life and lung function to a similar degree to within-range participants, achieved without dose escalation above 750 mg.

Investigating the effects of arctic dietary intake on lung health

BACKGROUND/OBJECTIVE

Preservation of lung health requires understanding the modifiable risk factors of airflow limitation. This study investigates the association between diet and lung function in a population of Greenland Inuit residing in the Arctic (Greenland) or Western Europe (Denmark).

SUBJECTS/METHODS

Two unselected Inuit populations were recruited, one living in Greenland (Urban (Nuuk) n=358; Rural (Uummannaq) n=207) and the other in Denmark (n=539). Lung function was measured using spirometry and diet by a food frequency questionnaire. Factors associated with airflow limitation were assessed using multiple linear regression models.

RESULTS

The dietary composition differed significantly in the two regions, with higher whale, seal and wild meat intake and lower fruit and vegetable intake in the Arctic regions compared with Denmark. Consumption of vegetables (P=0.004) and whale and/or seal (P<0.0001) was significantly and positively associated with FEV1, as well as with FVC (vegetables: P=0.001, whale and/or seal: P=0.002). Regular fruit intake was included in the statistical models; however, it did not reach statistical significance (FEV1: P=0.053; FVC: P=0.055).

CONCLUSIONS

High dietary intake of vegetables as well as intake of arctic marine mammals had independent positive associations with lung function in this cohort of Greenlandic Inuit. These findings suggest an additive role of dietary intake of antioxidants and unsaturated fatty acids in lung health, which warrants prospective evaluation.

Full blood count parameters for the detection of asthma inflammatory phenotypes

BACKGROUND

In asthma, the airway inflammatory phenotype influences clinical characteristics and treatment response. Although induced sputum is the gold standard test for phenotyping asthma, a more accessible method is needed for clinical practice.

OBJECTIVE

To investigate whether white blood cell counts and/or their derived ratios can predict sputum eosinophils or neutrophils in uncontrolled asthma.

METHODS

This cross-sectional study evaluated 164 treated but uncontrolled asthmatic patients with sputum induction and blood collection. Receiver-operating characteristic (ROC) curves were used to assess the relationship between blood and sputum parameters.

RESULTS

There was a significant positive relationship between blood eosinophil parameters and the percentage of sputum eosinophil count. A weak but significant correlation was found between sputum neutrophil percentage and blood neutrophil percentage (r = 0.219, P = 0.005). ROC curve analysis identified that blood eosinophil percentage count was the best predictor for eosinophilic asthma, with an area under the curve (AUC) of 0.907 (P < 0.001). The optimum cut-point for blood eosinophil percentage was 2.7%, and this yielded a sensitivity of 92.2% and a specificity of 75.8%. The absolute blood eosinophil count was also highly predictive with an AUC of 0.898 (P < 0.0001) at a blood eosinophil cut-off of 0.26 × 10(9) /L. The blood eosinophil/lymphocyte ratio (ELR) and eosinophil/neutrophil ratio (ENR) were increased in eosinophilic asthma, and the neutrophil/lymphocyte ratio (NLR) was increased in neutrophilic asthma. Neutrophilic asthma could also be detected by blood neutrophil percentages and NLR, but with less accuracy.

CONCLUSIONS AND CLINICAL RELEVANCE

Blood eosinophil counts and derived ratios (ELR and ENR) can accurately predict eosinophilic asthma in patients with persistent uncontrolled asthma despite treatment. Blood neutrophil parameters are poor surrogates for the proportion of sputum neutrophils. Blood counts may be a useful aid in the monitoring of uncontrolled asthma.

Erratum: The 'Miracle of Childbirth': the Portrayal of Parturient Women in Medieval Miracle Narratives

[This corrects the article DOI: 10.1093/shm/hks019.].

The risk of congenital malformations, perinatal mortality and neonatal hospitalisation among pregnant women with asthma: a systematic review and meta-analysis

BACKGROUND

There is conflicting literature on the effect of maternal asthma on congenital malformations and neonatal outcomes.

OBJECTIVES

This review and meta-analysis sought to determine if maternal asthma is associated with an increased risk of adverse neonatal outcomes.

SEARCH STRATEGY

We searched electronic databases for: (asthma or wheeze) and (pregnan* or perinat* or obstet*).

SELECTION CRITERIA

Cohort studies published between 1975 and March 2012 reporting at least one perinatal outcome of interest (congenital malformations, neonatal complications, perinatal mortality).

DATA COLLECTION AND ANALYSIS

In all, 21 studies met inclusion criteria in pregnant women with and without asthma. Further analysis was conducted on 16 studies where asthmatic women were stratified by exacerbation history, corticosteroid use, bronchodilator use or asthma severity.

MAIN RESULTS

Maternal asthma was associated with a significantly increased risk of congenital malformations (relative risk [RR] 1.11, 95% confidence interval [95% CI] 1.02-1.21, I(2)  = 59.5%), cleft lip with or without cleft palate (RR 1.30, 95% CI 1.01-1.68, I(2)  = 65.6%), neonatal death (RR 1.49, 95% CI 1.11-2.00, I(2)  = 0%), and neonatal hospitalisation (RR 1.50, 95% CI 1.03-2.20, I(2)  = 64.5%). There was no significant effect of asthma on major malformations (RR 1.31, 95% CI 0.57-3.02, I(2)  = 70.9%) or stillbirth (RR 1.06, 95% CI 0.9-1.25, I(2)  = 35%). Exacerbations and use of bronchodilators and inhaled corticosteroids were not associated with congenital malformation risk.

AUTHORS' CONCLUSIONS

Despite limitations related to the observational nature of the primary studies, this review demonstrates a small increased risk of neonatal complications among pregnant women with asthma. Further investigations into mechanisms and potential preventive interventions to improve infant outcomes are required.

A meta-analysis of adverse perinatal outcomes in women with asthma

BACKGROUND

Asthma is a common condition during pregnancy and may be associated with adverse perinatal outcomes.

OBJECTIVE

This meta-analysis sought to establish if maternal asthma is associated with an increased risk of adverse perinatal outcomes, and to determine the size of these effects.

SEARCH STRATEGY

Electronic databases were searched for the following terms: (asthma or wheeze) and (pregnan* or perinat* or obstet*).

SELECTION CRITERIA

Cohort studies published between 1975 and March 2009 were considered for inclusion. Studies were included if they reported at least one perinatal outcome in pregnant women with and without asthma.

DATA COLLECTION AND ANALYSIS

A total of 103 articles were identified, and of these 40 publications involving 1,637,180 subjects were included. Meta-analysis was conducted with subgroup analyses by study design and active asthma management.

MAIN RESULTS

Maternal asthma was associated with an increased risk of low birthweight (RR 1.46, 95% CI 1.22-1.75), small for gestational age (RR 1.22, 95% CI 1.14-1.31), preterm delivery (RR 1.41, 95% CI 1.22-1.61) and pre-eclampsia (RR 1.54, 95% CI 1.32-1.81). The relative risk of preterm delivery and preterm labour were reduced to non-significant levels by active asthma management (RR 1.07, 95% CI 0.91-1.26 for preterm delivery; RR 0.96, 95% CI 0.73-1.26 for preterm labour).

AUTHOR'S CONCLUSIONS

Pregnant women with asthma are at increased risk of perinatal complications, including pre-eclampsia and outcomes that affect the baby's size and timing of birth. Active asthma management with a view to reducing the exacerbation rate may be clinically useful in reducing the risk of perinatal complications, particularly preterm delivery.

Characterization of innate immune signalling receptors in virus-induced acute asthma

BACKGROUND

The role of toll-like receptors (TLRs) and innate immune activation in clinical asthma exacerbations and their relationship to virus infection are unclear.

OBJECTIVE

This study aimed to characterize TLR expression and innate immune activity during virus infection in acute asthma.

METHODS

Subjects with acute asthma, stable asthma and healthy controls were recruited and underwent spirometry and sputum induction with isotonic saline. Selected sputum was dispersed with dithiothreitol and total and differential leucocyte counts were performed. Selected sputum was also used for quantitative real-time PCR for TLR2, TLR3, TLR4, IL-10 and IP-10mRNA expression. Sputum supernatant was used for the measurement of innate immune markers, including IL-8, matrix metalloproteinase-9 and neutrophil elastase activity. Viruses were detected using real-time and gel-based PCR.

RESULTS

Sputum TLR2 mRNA expression was up-regulated in both acute and stable asthma compared with healthy controls and decreased 4-6 weeks after acute exacerbation. Sputum TLR2 mRNA expression was elevated in viral, compared with non-viral, acute asthma. Sputum TLR3 mRNA expression was similar in controls, stable and acute asthma. However, in acute asthma, subjects with virus-induced acute asthma had significantly higher sputum TLR3 mRNA expression. Induced sputum gene expression for IP-10 and IL-10 were increased in viral, compared with non-viral, acute asthma. In virus-induced acute asthma, levels of IP-10 and IL-10 mRNA expression were correlated with the mRNA expression of TLR2 and TLR3.

CONCLUSIONS AND CLINICAL RELEVANCE

Virus-induced acute asthma leads to specific induction of TLR2, TLR3, IP-10 and IL-10, suggesting that signalling via TLRs may play an important role in mediating airway inflammation, via both innate and adaptive pathways, in virus-induced exacerbations. These mediators may provide potential treatment targets for virus-induced asthma. They may also be useful in diagnosing the nature of acute asthma exacerbations and monitoring treatment responses, which would be useful in the clinical management of asthma exacerbations.

Quantitative single point imaging with compressed sensing

A novel approach with respect to single point imaging (SPI), compressed sensing, is presented here that is shown to significantly reduce the loss of accuracy of reconstructed images from under-sampled acquisition data. SPI complements compressed sensing extremely well as it allows unconstrained selection of sampling trajectories. Dynamic processes featuring short T2* NMR signal can thus be more rapidly imaged, in our case the absorption of moisture by a cereal-based wafer material, with minimal loss of image quantification. The absolute moisture content distribution is recovered via a series of images acquired with variable phase encoding times allowing extrapolation to time zero for each image pixel and the effective removal of T2* contrast.

Optimal k-space sampling for single point imaging of transient systems

A novel approach for sampling k-space in a pure phase encoding imaging sequence is presented using the Single Point Imaging (SPI) technique. The sequence is optimised with respect to the achievable Signal-to-Noise ratio (SNR) for a given time interval via selective sparse k-space sampling, dictated by prior knowledge of the overall object of interest's shape. This allows dynamic processes featuring short T(2)( *) NMR signal to be more readily followed, in our case the absorption of moisture by a cereal-based wafer material. Further improvements in image quality are also shown via the use of complete sampling of k-space at the start or end of the series of imaging experiments; followed by subsequent use of this data for un-sampled k-space points as opposed to zero filling.

Long-acting beta2-agonists as an inhaled corticosteroid-sparing agent for chronic asthma in adults and children

BACKGROUND

The addition of a long acting beta agonist (LABA) to inhaled corticosteroid (ICS) therapy can improve asthma symptoms and reduce exacerbations. The addition of LABA may also have an ICS-sparing effect and permit a reduction in ICS maintenance dose.

OBJECTIVES

To determine the efficacy of adding LABA to maintenance ICS therapy in reducing the requirement for ICS while maintaining control of chronic asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group trials register and reference lists of articles. Date of last search: November 2004

SELECTION CRITERIA

Parallel RCTs that compared reduced dose ICS in combination with LABA vs ICS alone in asthmatics requiring daily ICS.

DATA COLLECTION AND ANALYSIS

Trial quality was assessed and data were extracted independently by two reviewers. Study authors were contacted for confirmation. Trials were analysed according to the following ICS dose comparisons: a fixed moderate/high dose or a reduced/tapering dose of the same ICS.

MAIN RESULTS

19 publications describing 10 trials of adults were included in the review. Studies that compared reduced dose (mean 60% reduction) ICS/LABA combination to a fixed moderate/high dose ICS found no significant difference in severe exacerbations requiring oral corticosteroids (RR 1.0, 95%CI 0.76 to 1.32), withdrawal due to worsening asthma (RR 0.82, 95%CI 0.5 to 1.35) or airway inflammation. There were also significant improvements in FEV1 (change from baseline WMD 0.10, 95%CI 0.07 to 0.12), morning & evening PEF and percent rescue free days with LABA. Two studies provided outcomes for a reduced/tapering ICS dose comparison. More participants receiving the LABA/reduced ICS combination achieved a reduction in ICS dose reaching significance in one study. A significant reduction of 253 mcg BDP was achieved in one study.

AUTHORS' CONCLUSIONS

In adults with asthma, using moderate to high maintenance doses of ICS, the addition of LABA has an ICS-sparing effect. The addition ofLABA permits more participants on minimum maintenance ICS to reduce ICS. The precise magnitude of the ICS dose reduction requires further study.

Initial starting dose of inhaled corticosteroids in adults with asthma: a systematic review

BACKGROUND

Asthma guidelines vary in their recommendations for the initial dose of inhaled corticosteroid (ICS) in asthma. A systematic review of the literature was conducted to establish the optimal starting dose of ICS for asthma in adults.

METHODS

Randomised controlled trials comparing two doses of the same ICS in adults with asthma and no concomitant inhaled or oral corticosteroid were assessed. Included trials were analysed according to the following ICS dose comparisons: high (> or =800 microg/day beclomethasone (BDP)) versus moderate (400<800 microg/day BDP) (n = 7); moderate versus low (<400 microg/day BDP) (n = 6); step down versus constant dose (n = 4).

RESULTS

Fourteen publications describing 13 trials were included in the review. Studies (n = 4) that compared a step down approach with a constant moderate/low dose of ICS found no difference in lung function, symptoms, or rescue medications between the two treatment approaches (p>0.05). There was no difference in the change in morning peak flow after treatment with high compared with moderate dose ICS. When compared with low dose ICS, moderate dose ICS significantly improved morning peak flow (change from baseline WMD 11.14 l/min, 95% CI 1.34 to 20.93) and nocturnal symptoms (SMD -0.29, 95% CI -0.53 to -0.06).

CONCLUSIONS

For patients with asthma who require ICS, starting with a moderate dose is equivalent to starting with a high dose and stepping down. The small non-significant benefits of starting with a high ICS dose are not of sufficient clinical benefit to warrant its use. Initial moderate ICS doses appear to be more effective than an initial low ICS dose.

Written action plans for asthma: an evidence-based review of the key components

BACKGROUND

Written action plans for asthma facilitate the early detection and treatment of an asthma exacerbation. Several versions of action plans have been published but the key components have not been determined. A study was undertaken to determine the impact of individual components of written action plans on asthma health outcomes.

METHODS

Randomised controlled trials (n=26) that evaluated asthma action plans as part of asthma self-management education were identified. Action plans were classified as being individualised and complete if they specified when and how to increase treatment (n=17), and as incomplete (n=4) or non-specific (n=5) if they did not include these instructions.

RESULTS

For individualised complete written action plans the use of 2-4 action points and the use of both inhaled (ICS) and oral (OCS) corticosteroid consistently improved asthma outcomes. Action points based on personal best peak expiratory flow (PEF) consistently improved health outcomes while those based on percentage predicted PEF did not. The efficacy of incomplete action plans was inconclusive because of insufficient data. Non-specific action plans led to improvements in knowledge and symptoms.

CONCLUSION

Individualised written action plans based on personal best PEF, using 2-4 action points, and recommending both ICS and OCS for treatment of exacerbations consistently improve asthma health outcomes. Other variations appear less beneficial or require further study. These observations provide a guide to the types of variations possible with written action plans, and strongly support the use of individualised complete written action plans.

Relationship between induced sputum eosinophils and the clinical pattern of childhood asthma

BACKGROUND

The relationship between the clinical pattern of asthma and airway inflammation in childhood asthma is poorly characterised, yet underpins the treatment recommendations in current asthma guidelines. A study was undertaken to examine the relationship between airway inflammation and clinical asthma in children.

METHODS

Children with asthma (n=146) and healthy controls (C, n=37) were recruited from primary and specialist clinics. Sputum induction and hypertonic saline challenge were performed.

RESULTS

As the frequency of asthma episodes in the past 12 months increased, there were significant increases in sputum eosinophils (median; infrequent episodic (IE) 1.5%, frequent episodic (FE) 2.3%, persistent (P) 3.8%, control (C) 1.0%; p=0.002), sputum eosinophil cationic protein (ECP) (IE 113 ng/ml, FE 220, P 375, C 139; p=0.003), and desquamated bronchial epithelial cells (IE 2.0%, FE 6.0%, P 5.0%, C 2.5%; p=0.04). Treatment intensity was also associated with increased sputum eosinophils (p=0.005). The relationships between other severity markers (current symptoms, lung function) were less strong.

CONCLUSION

Children with more frequent episodes of clinical asthma exhibit increasing airway inflammation that is characterised by sputum eosinophilia and bronchial epithelial desquamation. The results support clinical assessment by frequency of wheezing episodes over the past 12 months when determining anti-inflammatory treatment requirements, and indicate that current symptoms are determined by mechanisms in addition to sputum eosinophilia.

Control of virtual environments for young people with learning difficulties

PURPOSE

The objective of this research is to identify the requirements for the selection or development of usable virtual environment (VE) interface devices for young people with learning disabilities.

METHOD

A user-centred design methodology was employed, to produce a design specification for usable VE interface devices. Details of the users' cognitive, physical and perceptual abilities were obtained through observation and normative assessment tests.

CONCLUSIONS

A review of computer interface technology, including virtual reality and assistive devices, was conducted. As there were no devices identified that met all the requirements of the design specification, it was concluded that there is a need for the design and development of new concepts. Future research will involve concept and prototype development and user-based evaluation of the prototypes.