Conditional power and information fraction calculations at an interim analysis for random coefficient models

Random coefficient (RC) models are commonly used in clinical trials to estimate the rate of change over time in longitudinal data. Trials utilizing a surrogate endpoint for accelerated approval with a confirmatory longitudinal endpoint to show clinical benefit is a strategy implemented across various therapeutic areas, including immunoglobulin A nephropathy. Understanding conditional power (CP) and information fraction calculations of RC models may help in the design of clinical trials as well as provide support for the confirmatory endpoint at the time of accelerated approval. This paper provides calculation methods, with practical examples, for determining CP at an interim analysis for a RC model with longitudinal data, such as estimated glomerular filtration rate (eGFR) assessments to measure rate of change in eGFR slope.

Drug Resistance Assessment Following Administration of Respiratory Syncytial Virus (RSV) Fusion Inhibitor Presatovir to Participants Experimentally Infected With RSV

BACKGROUND

Presatovir is an oral respiratory syncytial virus (RSV) fusion inhibitor targeting RSV F protein. In a double-blind, placebo-controlled study in healthy adults experimentally infected with RSV (Memphis-37b), presatovir significantly reduced viral load and clinical disease severity in a dose-dependent manner.

METHODS

Viral RNA from nasal wash samples was amplified and the F gene sequenced to monitor presatovir resistance. Effects of identified amino acid substitutions on in vitro susceptibility to presatovir, viral fitness, and clinical outcome were assessed.

RESULTS

Twenty-eight treatment-emergent F substitutions were identified. Of these, 26 were tested in vitro; 2 were not due to lack of recombinant virus recovery. Ten substitutions did not affect presatovir susceptibility, and 16 substitutions reduced RSV susceptibility to presatovir (2.9- to 410-fold). No substitutions altered RSV susceptibility to palivizumab or ribavirin. Frequency of phenotypically resistant substitutions was higher with regimens containing lower presatovir dose and shorter treatment duration. Participants with phenotypic presatovir resistance had significantly higher nasal viral load area under the curve relative to those without, but substitutions did not significantly affect peak viral load or clinical manifestations of RSV disease.

CONCLUSIONS

Emergence of presatovir-resistant RSV occurred during therapy but did not significantly affect clinical efficacy in participants with experimental RSV infection.

Phase 1 First-in-Human, Single- and Multiple-Ascending Dose, and Food Effect Studies to Assess the Safety, Tolerability, and Pharmacokinetics of Presatovir for the Treatment of Respiratory Syncytial Virus Infection

Respiratory syncytial virus (RSV)-associated respiratory tract infection is a leading cause of hospitalizations in infants for which no effective treatment exists. RSV infection is also an important cause of respiratory disease in adults and immunocompromised patients. Presatovir (GS-5806) is an orally bioavailable antiviral agent that inhibits fusion of RSV with host cell membranes. Here, results from 2 phase 1 studies that evaluated safety, tolerability, and pharmacokinetics of presatovir in healthy adults following administration of single and multiple (7 days) once- or twice-daily ascending doses (first-in-human study) and in the presence or absence of food (food effect study) are described. Presatovir exhibited favorable safety and pharmacokinetic profiles that supported once-daily dosing. Presatovir exposure increased in an approximately dose-proportional manner across the evaluated dose range (single doses 25-300 mg; multiple doses 10-75 mg once daily for 7 days). Administration of presatovir with a high-fat meal did not alter exposure, supporting administration without regard to a meal in further clinical studies. These data were subsequently used to inform presatovir dosing regimens in a phase 2a challenge study of adults experimentally infected with RSV. Collectively, results from phase 1 evaluations and a phase 2a challenge study support further clinical investigation of presatovir for the treatment of RSV infection.

A preliminary quality of life questionnaire-bronchiectasis: a patient-reported outcome measure for bronchiectasis

BACKGROUND

The Quality of Life Questionnaire-Bronchiectasis (QOL-B) is the first disease-specific, patient-reported outcome measure for patients with bronchiectasis. Content validity, cognitive testing, responsivity to open-label treatment, and psychometric analyses are presented.

METHODS

Reviews of literature, existing measures, and physician input were used to generate the initial QOL-B. Modifications following preliminary cognitive testing (N = 35 patients with bronchiectasis) generated version (V) 1.0. An open-ended patient interview study (N = 28) provided additional information and was content analyzed to derive saturation matrices, which summarized all disease-related topics mentioned by each participant. This resulted in QOL-B V2.0. Psychometric analyses were carried out using results from an open-label phase 2 trial, in which 89 patients were enrolled and treated with aztreonam for inhalation solution. Responsivity to open-label treatment was observed. Additional analyses generated QOL-B V3.0, with 37 items on eight scales: respiratory symptoms; physical, role, emotional, and social functioning; vitality; health perceptions; and treatment burden. For each scale, scores are standardized on a 0-to-100-point scale; higher scores indicate better health-related quality of life. No total score is calculated. A final cognitive testing study (N = 40) resulted in a minor change to one social functioning scale item (QOL-B V3.1).

RESULTS

Content validity, cognitive testing, responsivity to open-label treatment, and initial psychometric analyses supported QOL-B items and structure.

CONCLUSIONS

This interim QOL-B is a promising tool for evaluating the efficacy of new therapies for patients with bronchiectasis and for measuring symptoms, functioning, and quality of life in these patients on a routine basis. A final psychometric validation study is needed and is forthcoming.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00805025; URL: www.clinicaltrials.gov.

Quality of Life Questionnaire-Bronchiectasis: final psychometric analyses and determination of minimal important difference scores

BACKGROUND

The Quality of Life-Bronchiectasis (QOL-B), a self-administered, patient-reported outcome measure assessing symptoms, functioning and health-related quality of life for patients with non-cystic fibrosis (CF) bronchiectasis, contains 37 items on 8 scales (Respiratory Symptoms, Physical, Role, Emotional and Social Functioning, Vitality, Health Perceptions and Treatment Burden).

METHODS

Psychometric analyses of QOL-B V.3.0 used data from two double-blind, multicentre, randomised, placebo-controlled, phase III trials of aztreonam for inhalation solution (AZLI) in 542 patients with non-CF bronchiectasis and Gram-negative endobronchial infection.

RESULTS

Excellent internal consistency (Cronbach's α ≥0.70) and 2-week test-retest reliability (intraclass correlation coefficients ≥0.72) were demonstrated for each scale. Convergent validity with 6 min walk test was observed for Physical and Role Functioning scores. No floor or ceiling effects (baseline scores of 0 or 100) were found for the Respiratory Symptoms scale (primary endpoint of trials). Baseline Respiratory Symptoms scores discriminated between patients based on baseline FEV₁% predicted in only one trial. The minimal important difference score for the Respiratory Symptoms scale was 8.0 points. AZLI did not show efficacy in the two phase III trials. QOL-B responsivity to treatment was assessed by examining changes from baseline QOL-B scores at study visits at which protocol-defined pulmonary exacerbations were reported. Mean Respiratory Symptoms scores decreased 14.0 and 14.2 points from baseline for placebo-treated and AZLI-treated patients with exacerbations, indicating that worsening respiratory symptoms were reflected in clinically meaningful changes in QOL-B scores.

CONCLUSIONS

Previously established content validity, reliability and responsivity of the QOL-B are confirmed by this final validation study. The QOL-B is available for use in clinical trials and routine clinical practice.

Oral GS-5806 activity in a respiratory syncytial virus challenge study

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of infant hospitalizations and is increasingly recognized as a cause of considerable morbidity and mortality. No accepted antiviral treatment exists.

METHODS

We conducted a double-blind, placebo-controlled study of GS-5806, an oral RSV-entry inhibitor, in healthy adults who received a clinical challenge strain of RSV intranasally. Participants were monitored for 12 days. At the time of a positive test for RSV infection or 5 days after inoculation, whichever occurred first, participants were randomly assigned to receive GS-5806 or placebo in one of seven sequential cohorts. Cohorts 1 to 4 received a first dose of 50 mg of GS-5806 and then 25 mg daily for the next 4 days, cohort 5 received a first dose of 50 mg and then 25 mg daily for the next 2 days, cohort 6 received one 100-mg dose, and cohort 7 received a first dose of 10 mg and then 5 mg daily for the next 4 days. Dose selection for cohorts 5, 6, and 7 occurred after an interim analysis of data for cohorts 1 to 4. The primary end point was the area under the curve (AUC) for the viral load, which was assessed after administration of the first dose through the 12th day after inoculation. Secondary end points were mucus weight and symptom scores.

RESULTS

Among the 54 participants in cohorts 1 to 4 who were infected with RSV, active treatment was associated with a lower viral load (adjusted mean, 250.7 vs. 757.7 log10 plaque-forming-unit equivalents [PFUe] × hours per milliliter; P<0.001), lower total mucus weight (mean, 6.9 g vs. 15.1 g; P=0.03), and a lower AUC for the change from baseline in symptom scores (adjusted mean, -20.2 vs. 204.9 × hours; P=0.005). The results were similar in cohorts 5, 6, and 7. Adverse events, including low neutrophil counts and increased levels of alanine aminotransferase, were more common among participants receiving GS-5806.

CONCLUSIONS

Treatment with GS-5806 reduced the viral load and the severity of clinical disease in a challenge study of healthy adults. (Funded by Gilead Sciences; ClinicalTrials.gov number, NCT01756482.).

Acute hyperkalemia associated with inhalation of a potent ENaC antagonist: Phase 1 trial of GS-9411

BACKGROUND

Inhaled epithelial sodium channel (ENaC) blockers are designed to increase airway surface liquid volume, thereby benefiting cystic fibrosis patients. This study evaluated the safety, tolerability, and pharmacokinetics of multiple doses of ENaC blocker GS-9411, in healthy participants.

METHODS

This randomized, double-blind, placebo-controlled, parallel-group, residential, Phase 1 study evaluated inhaled GS-9411 (2.4, 4.8, and 9.6 mg) or placebo, dosed twice daily for 14 days.

RESULTS AND CONCLUSIONS

GS-9411 was well tolerated; 86.1% of treated participants completed dosing (n=31/36). Cough and dizziness (27.8% participants each; most of mild severity) were the most commonly reported adverse events and occurred in both placebo and GS-9411 treatment groups. Arrhythmias were not observed for GS-9411-treated participants, and electrocardiographic changes were not considered clinically significant. Serum potassium levels exceeded the upper limit of normal (>5 mmol/L), 4 hr after the morning dose in GS-9411 (n=16/24) and placebo (n=4/12) treatment groups (38 incidences total). Retesting revealed levels had returned to normal within 2-3 hr. In urine electrolyte analyses, obtained 0-6 hr after the Day 1 morning dose, mean sodium/potassium ratios significantly increased from values 0-6 hr before dosing. Increased urine sodium/potassium ratios corresponded with high urine concentrations of active GS-9411 metabolites, which inhibited sodium reabsorption in the kidney, leading to the observed transient hyperkalemia in these participants. Inhaled GS-9411 was well tolerated except for the emergence of transient clinically significant hyperkalemia; this finding resulted in termination of further clinical development of this drug and will necessitate development of a new generation of ENaC blockers, which provide a sustained improvement in mucociliary clearance, while reducing renal exposure to ENaC blockade. Transient increases in mean urine sodium/potassium ratios appeared to be the first signal of electrolyte imbalances resulting from drug-induced block of ENaC in the kidney. The results of this study strongly suggest that clinical trials of novel ENaC blockers will require intensive measurement of plasma and urine electrolyte levels.

The alpha- and beta-tubulin folding pathways

The alpha-beta tubulin heterodimer is the subunit from which microtubules are assembled. The pathway leading to correctly folded alpha- and beta-tubulins is unusually complex: it involves cycles of ATP-dependent interaction of newly synthesized tubulin subunits with cytosolic chaperonin, resulting in the production of quasi-native folding intermediates, which must then be acted upon by additional protein cofactors. These cofactors form a supercomplex containing both alpha- and beta-tubulin polypeptides, from which native heterodimer is released in a GTP-dependent reaction. Here, we discuss the current state of our understanding of the function of cytosolic chaperonin and cofactors in tubulin folding.

Inhaled aztreonam lysine vs. inhaled tobramycin in cystic fibrosis: a comparative efficacy trial

BACKGROUND

Open-label, parallel-group, international trial comparing aztreonam for inhalation solution (AZLI) and tobramycin nebulizer solution (TNS) for cystic fibrosis patients with airway Pseudomonas aeruginosa.

METHODS

273 patients (≥ 6 years); randomized to three 28-day courses (AZLI 75 mg [three-times/day] or TNS 300 mg [twice/day]); 28 off-days separated each course.

RESULTS

268 patients were treated (AZLI/TNS: 136/132). Mean baseline FEV1 was 52% predicted. Mean relative changes after 1 course (AZLI: 8.35%; TNS: 0.55%; p<0.001) and mean actual changes across 3 courses (AZLI: 2.05%; TNS: -0.66%; p=0.002) indicated AZLI statistical superiority vs. TNS. AZLI-treated patients had fewer respiratory hospitalizations (p=0.044) and respiratory events requiring additional antipseudomonal antibiotics (p=0.004); both treatments were well tolerated. 133 patients received 1 to 3 courses of AZLI treatment in the open-label extension-period (28-day courses separated by 28 days off-treatment); lung function improvements were comparable regardless of whether patients had received TNS or AZLI in the preceding comparative period.

CONCLUSIONS

AZLI demonstrated statistical superiority in lung function and a reduction in acute pulmonary exacerbations compared to TNS over 3 treatment courses (ClinicalTrials.gov: NCT00757237).

Successful implementation of cognitive interviews in special populations

The cognitive interview, with a focus on debriefing methods, was developed in the 1980s to identify sources of potential response error in surveys or questionnaires. With the release of the final US FDA guidance, titled 'Patient-Reported Outcome Measures: Use in Medical Product Development to Support Labeling Claims', cognitive interviews have gained importance and relevance both for concept elicitation and debriefing purposes in the context of instrument development. This article is intended as a guide for the researcher working with special populations in methods to foster successful cognitive interviews that meet FDA standards. While many of these techniques are broadly applicable, specific recommendations are provided for working with pediatric and cognitively challenged populations, as well as with individuals with communication difficulties.

A natural experiment on the impact of fruit supplementation on asthma symptoms in children

A high fruit intake may reduce the risk of asthma. The English National School Fruit Scheme was introduced in the East Midlands region of the UK in June 2003 and in the Eastern region in September 2004. Questionnaires were distributed to children aged 4-6 yrs in schools in May 2003. This was repeated in May 2004 when those in the East Midlands had received free fruit for 1 yr and those in the Eastern region had not. Responses were obtained in 2004 for 4,971 (53%) and 5,770 (54%) children in the intervention and control regions, respectively. Despite an increase in fruit consumption in the intervention compared with the control region between 2003 and 2004, there was no difference between the two regions in the prevalence or severity of asthma symptoms after 1 yr of fruit supplementation (odds ratio for wheeze in the past 12 months in intervention compared with control region 1.00, 95% confidence interval 0.88-1.14). Providing free fruit at school for 1 yr does not have any immediate effect on prevalence or severity of asthma in young children, although these data do not refute the hypothesis that a higher increase in fruit intake improves measures of asthma control.

Effect of maternal asthma, exacerbations and asthma medication use on congenital malformations in offspring: a UK population-based study

BACKGROUND

Clinical advice to pregnant women with asthma is to maintain optimal therapeutic management; however, potential adverse effects of asthma treatments on fetal development remain uncertain. A study was undertaken to assess the association between maternal asthma and gestational exposure to asthma medications with risk of congenital malformation in offspring.

METHODS

A matched case-control study was performed using The Health Improvement Network primary care database. Children with malformations were matched to control children on birth year, general practice and singleton or twin delivery.

RESULTS

5124 cases of liveborn children with major congenital malformations and 30,053 controls were included in the study. The risk of any malformation in children born to women with asthma was marginally higher than that in children born to women without asthma (adjusted OR 1.10, 95% CI 1.01 to 1.20). However, no association was present in children born to mothers receiving asthma treatment in the year before or during pregnancy (OR 1.06, 95% CI 0.94 to 1.20). In assessing teratogenicity of medications, no increased risk of malformation was found with gestational exposures to short- or long-acting beta agonists, inhaled corticosteroids, oral corticosteroids, other bronchodilators or cromones. These findings were similar for each of 11 system-specific malformation groups, except for an increase in musculo-skeletal system malformation associated with cromone exposure.

CONCLUSIONS

Gestational exposure to commonly used asthma medications was found to be safe overall, although a moderate teratogenic risk of cromones cannot be excluded. There was some evidence of a small increased risk of congenital malformation in children born to women with asthma, but this was not explained by gestational exposure to asthma drugs.

The relation between dietary intake of individual fatty acids, FEV1 and respiratory disease in Dutch adults

BACKGROUND

A reduced dietary intake of n-3 fatty acids, in association with increased n-6 fatty acid intake, has been proposed as a potential aetiological factor for chronic obstructive pulmonary disease (COPD) and asthma. However, the relative importance of individual fatty acids within the n-3 and n-6 categories on this effect has not been widely investigated. We have studied the relation between individual fatty acid intakes, lung function and self-reported respiratory symptoms and diagnoses in a representative sample of more than 13,000 Dutch adults.

METHODS

Intake of individual fatty acids was estimated by a food frequency questionnaire and analysed in relation to measures of forced expiratory volume in 1 s (FEV1) and to questionnaire reported wheeze, asthma and COPD symptoms.

RESULTS

After adjusting for confounding, we found no protective association between individual n-3 fatty acid intakes and FEV1. Higher intakes of some n-6 fatty acids were associated with lower FEV1, this effect being most marked for c22:4 n-6 docosatetraenoic acid (reduction in FEV1 between the highest and lowest quintile of intake 54.5 ml (95% CI -81.6 to -27.4)). Most of the n-6 fatty acid effects interacted significantly with smoking, their effects being strongest in current smokers. Individual n-3 fatty acid intakes were generally associated with a higher risk of wheeze in the past year, but otherwise there was little or no association between fatty acid intake and wheeze, doctor diagnosed asthma or other respiratory symptoms.

CONCLUSIONS

A high intake of n-3 fatty acids does not appear to protect against COPD or asthma, but a high intake of several n-6 fatty acids is associated with a significant reduction in FEV1, particularly in smokers. These findings indicate that high dietary intake of n-6 fatty acids, rather than reduced n-3 intake, may have an adverse effect on lung health.

Does participation in a population-based dietary intervention scheme have a lasting impact on fruit intake in young children?

BACKGROUND

The National Schools Fruit Scheme (NSFS) is intended to improve fruit intake in young children by providing free daily fruit at school.

METHODS

We used a parentally completed questionnaire for three consecutive years to study fruit intake in young children before, during and after participation in the NSFS compared with a control region.

RESULTS

In 2003, 2004 and 2005, a total of 224, 220 and 179 schools, respectively, were studied with responses from 5,606, 5,111 and 3,382 children for each survey. Between 2003 and 2004, individual fruit consumption in the intervention region increased by more (from a median of 7.5 to 14.0 pieces/week) than in the control region (from a median of 9.2-11.0 pieces/week), resulting in a difference (P < 0.001) between the two regions in 2004. However, after ceasing to be eligible for the NSFS, fruit intake in children in the intervention region fell to a median of 12 pieces per week, lower than that in the control region (median value of 14 pieces per week, P = 0.02).

CONCLUSIONS

School-based fruit distribution schemes providing free fruit at school appear to be an effective means of increasing dietary fruit intake in young children, including those who live in relatively socio-economically deprived areas. However, this approach does not influence fruit intake after the provision of free fruit ends, so schemes may need to be sustained to provide the maximum benefit to young children.

Fertility rates in women with asthma, eczema, and hay fever: a general population-based cohort study

The protective association between having older siblings and the risk of subsequent allergic disease may be due to decreased fertility among women with allergic disease. In this study, the authors compared fertility rates among women with asthma, eczema, or hay fever with those in the general female population. Computerized primary-care data from the United Kingdom were used to conduct a cohort analysis of 491,516 women. General fertility rates and age-specific fertility rates for 1994-2004 were estimated. Using Poisson regression, the authors compared fertility rates among women with asthma, eczema, or hay fever with rates in women without these diagnoses. Fertility rates were 53.0 and 52.3 livebirths per 1,000 person-years in women with and without asthma, respectively. The fertility rate ratio for women with asthma compared with women without asthma was 1.02 (95% confidence interval (CI): 1.00, 1.04) after adjustment for age, smoking, body mass index, and socioeconomic status. Equivalent fertility rate ratios for eczema and hay fever were 1.15 (95% CI: 1.13, 1.17) and 1.08 (95% CI: 1.06, 1.10), respectively. The authors found no evidence that the fertility rates of women with asthma, eczema, or hay fever are lower than those of women in the general population.

First Report of Root-Knot Nematode Meloidogyne javanica on Chrysanthemum in Colombia

Severe plant stunting, chlorosis, and extensive root galling were observed on chrysanthemum (Dendrathema grandiflora cv. Yellow Vero) in a commercial cut-flower production facility in Rionegro, Antioquia, northwestern Colombia. Examination of the root samples from selected infected plants revealed the presence of abundant root-knot nematodes. Juveniles, males, and females were extracted for species identification using morphological characteristics. Identification was confirmed by perineal patterns and esterase phenotype analysis of females. All methods of identification were consistent with typical Meloidogyne javanica. No other root-knot nematode species were found on this farm, but the presence of other Meloidogyne species in the region is possible. Root-knot nematodes have been reported to cause economic losses in cut-flower plantations in Colombia (1), but there are no reports of the species involved. M. javanica has an extensive host range and wide distribution. The identification and distribution of M. javanica in chrysanthemum production is relevant because nematode-fungus interactions may depend on the nematode species involved. Only M. javanica, and not M. hapla or M. incognita, has been found to increase the severity of Fusarium wilt on chrysanthemum (2). To our knowledge, this is the first report of M. javanica on chrysanthemum in Colombia. References: (1) G. Arbeláez. Acta Hortic. 482:91, 1999. (2) A. W. Johnson and R. H. Littrell. J. Nematol. 1:122. 1969.

Exposure of the fetus and infant to hens' egg ovalbumin via the placenta and breast milk in relation to maternal intake of dietary egg

BACKGROUND

Maternally derived allergens may be transferred to the developing infant during pregnancy and lactation. However, it is not known how manipulation of environmental allergen levels might impact on this early-life exposure.

OBJECTIVE

To measure dietary egg allergen (ovalbumin (OVA)) in gestation-associated environments, in relation to maternal dietary egg intake.

METHOD

OVA was measured by allergen-specific ELISA in maternal blood collected throughout pregnancy, infant blood at birth (umbilical cord) and in breast milk at 3 months post-partum. Samples derived from pregnant women undergoing diagnostic amniocentesis at 16-18 weeks gestation who were not subject to any dietary intervention, and from pregnant women, with personal or partner atopy, randomized to complete dietary egg exclusion or an unmodified healthy diet before 20 weeks gestation as a primary allergy prevention strategy. Maternal dietary egg intake was monitored closely throughout the study period by diary record and serial measurement of OVA-specific immunoglobulin G concentration.

RESULTS

Circulating OVA was detected throughout pregnancy in 20% of women and correlated with both presence (P<0.001) and concentration (r=0.754, P<0.001) of infant OVA at birth (umbilical cord). At 3 months post-partum OVA was detected in breast milk samples of 35% women, in higher concentrations than measured in blood. Blood and breast milk OVA were not related to maternal dietary intake or atopic pre-disposition.

CONCLUSIONS

Rigorous dietary egg exclusion does not eliminate trans-placental and breast milk egg allergen passage. This early-life exposure could modulate developing immune responses.

Does severity of low-dose, double-blind, placebo-controlled food challenges reflect severity of allergic reactions to peanut in the community?

BACKGROUND

The severity of allergic reactions to food appears to be affected by many interacting factors. It is uncertain whether challenge-based reactions reflect the severity of past reactions or can predict future risk.

OBJECTIVE

To explore the relationship of a subject's clinical history of past reactions to the severity of reaction elicited by a low-dose, double-blind, placebo-controlled food challenge (DBPCFC) with peanut.

METHOD

Cross-sectional questionnaire assessment of community-based allergic reactions and low-dose DBPCFC in self-selected peanut-allergic subjects. Reaction severity was assessed using a novel scoring system, taking account of the dose of allergen ingested.

RESULTS

Forty subjects (15 males, 23 children, 23 asthmatics by history) were studied. Only the most recent community reaction predicted the severity of reaction in the DBPCFC, but even this association was weak (r=0.37, P=0.03). Peanut-specific IgE (PsIgE) and skin prick test (SPT) weal size were not associated with community score but PsIgE level correlated well with the challenge score (r=0.6, P=0.001). Asthma did not affect the eliciting dose or challenge score directly but the association of PsIgE and challenge score was stronger in those without asthma (r=0.72, P=0.001) than in those with asthma (r=0.48, P=0.02).

CONCLUSIONS

The scoring system developed appears to improve the sensitivity of assessment of reactions induced by DBPCFC. This is the first prospective study showing an association between PsIgE levels and clinical reactivity in DBPCFC, an effect that is more pronounced in non-asthmatics. This finding has important implications for the clinical care of subjects with food allergy. There is a poor correlation between the severity of reported reactions in the community and the severity of reaction elicited during low-dose DBPCFC with peanut.

Lung function and blood levels of copper, selenium, vitamin C and vitamin E in the general population

BACKGROUND

Increased dietary intake of antioxidants has been associated with higher lung function, but few studies have used biological markers of antioxidant intake.

OBJECTIVE

This study aimed to determine if antioxidant status, as measured by blood levels, influences lung function.

DESIGN

Using a random subsample of 479 participants, aged 18-65 y old, from a larger cross-sectional observational study, the association of forced expiratory volume in 1 s (FEV1) with plasma copper, vitamin C, vitamin E and serum selenium was assessed.

RESULTS

An s.d. increase in blood copper level was associated with a difference in FEV1 of -48 ml (95% confidence intervals: -95, -2 ml, P = 0.04), vitamin C +49 ml (+4, +94, P = 0.03), vitamin E -15 ml (-62, +32, P = 0.53) and selenium +52 ml (+7, +96, P = 0.02). The sizes of association were not appreciably altered in a mutually adjusted model.

CONCLUSIONS

Higher levels of serum vitamin C and selenium appear to be associated with higher FEV1. The association between higher serum copper and lower FEV1 requires further study in view of the ubiquitous exposure to this mineral.

Validation of the International Study of Asthma and Allergies in Children (ISAAC) and U.K. criteria for atopic eczema in Ethiopian children

BACKGROUND

Reliable diagnostic criteria for atopic eczema (AE) are essential in order to make international comparisons and to identify possible disease risk factors. Little is known about the prevalence of atopic eczema and validity of diagnostic criteria for AE in developing countries where English is not the first language.

OBJECTIVES

We sought to determine the prevalence of AE in an area of urban and rural Ethiopia, and to compare the predictive values of different questionnaire and examination methods for diagnosing AE in this population.

METHODS

We conducted a cross-sectional survey of 7915 children aged 1-5 years living in and around the town of Jimma in southwest Ethiopia. AE prevalence was assessed in two ways: (i) by using the International Study for Asthma and Allergies in Childhood (ISAAC) questionnaire, and (ii) using the U.K. refinement of Hanifin and Rajka's diagnostic criteria. All possible cases identified by screening questions and random samples of controls were then examined by an experienced local paediatrician, who acted as a reference standard to determine the predictive value of the criteria used to diagnose AE.

RESULTS

The overall 1-year period prevalence of AE according to ISAAC and U.K. criteria was 4.4%[95% confidence interval (CI) 3.95-4.85] and 1.8% (95% CI 1.5-2.1), respectively. Corresponding point prevalence estimates (symptoms in the last week) were 1.8% for ISAAC and 1.3% for the U.K. criteria. The positive predictive values of the ISAAC and U.K. criteria questions for AE symptoms still reported to be present (in the last week) at the doctor's examination were 48.8% and 55.5%, respectively. Corresponding negative predictive values were 90.5% and 90.1%, respectively. The sign of visible flexural dermatitis (a component of the U.K. criteria) when used alone had positive and negative predictive values of 57% and 91%, respectively.

CONCLUSIONS

Neither the ISAAC nor U.K. criteria performed especially well in predicting cases of AE in this survey. Possible reasons include problems with questionnaire translation, cultural conceptions of terminology, asking parents rather than the child about symptoms, the transient nature of AE signs, and differences in what a doctor perceives to constitute a typical case of AE. The results do not preclude the use of standardized diagnostic criteria alongside a doctor's examination in future surveys of Ethiopian children, and knowledge of the criteria's limited predictive value should help to interpret study findings that have employed such criteria. Consideration should be given to adopting the sign of visible flexural dermatitis as a standard for estimating the point prevalence of AE throughout the world because it is less susceptible to problems with translation and interpretation.

E-cadherin expression in invasive non-lobular carcinoma of the breast and its prognostic significance

BACKGROUND

E-cadherin is a cell adhesion molecule that is expressed in normal breast tissue and is often considered useful as a phenotypic marker in breast cancer diagnosis, with absence of its expression frequently observed in tumours of lobular subtype. However, the clinicopathological and prognostic value of E-cadherin in the more frequent non-lobular types of breast carcinoma is unclear.

METHODS AND RESULTS

E-cadherin expression was assessed immunohistochemically in a large and well-characterized series of invasive non-lobular breast carcinoma types (n=1665) with long-term clinical follow-up (median 56 months) using tissue microarray technology, to determine the relationship between its expression and primary tumour characteristics and disease outcome. Only membranous expression of E-cadherin was considered in this study and its expression was categorized as normal (H-score>100) or reduced [absent or below the median (score</=100)]. Complete absence of its expression (score=0) was detected in 7.2% of cases. On univariate analysis, reduced E-cadherin expression was associated with a reduced disease-free interval and overall survival and also with indicators of poor prognosis including larger tumour size, higher histological grade, development of distant metastasis and tumours negative for oestrogen receptors. No association between E-cadherin expression and lymph node status was found. On multivariate analysis, E-cadherin was an independent predictor of disease-free interval [hazards ratio (HR) 1.56, 95% confidence intrerval (CI) 1.23, 1.99; P<0.001] and overall survival (HR 1.53, 95% CI 1.09, 2.14; P=0.013) and there was some evidence that the prognostic value was greater in those with positive lymph nodes (P interaction=0.099).

CONCLUSIONS

These results suggest that E-cadherin loss may play a role in progression, development of distant metastasis and recurrence in non-lobular invasive carcinomas of the breast and its assessment by immunohistochemistry may help in the identification of patients with poor outcomes.

The promiscuity of immunoglobulin E binding to peanut allergens, as determined by Western blotting, correlates with the severity of clinical symptoms

BACKGROUND

IgE binding to a specific protein has been shown to be associated with severe anaphylaxis to hazelnuts; however, the relationship between IgE binding to specific peanut allergens and symptom severity is currently unclear.

OBJECTIVE

To determine if the pattern of IgE binding to specific peanut allergens is associated with the severity of clinical symptoms.

METHODS

Forty peanut allergic patients underwent a double-blind placebo-controlled low-dose peanut challenge, during which the severity of the patients' peanut allergy was scored. Serum peanut-specific IgE (psIgE) was measured and IgE binding patterns to peanut proteins analysed.

RESULTS

Seventeen IgE binding bands were identified between 5 and 100 kDa with eight bound by >50% of patients. The total number of bands per patient correlated significantly with challenge score (P=0.001, r=0.505) and psIgE (P<0.001, r=0.820). Cluster analysis failed to reveal any association between a particular protein or pattern of proteins (based on presence/absence) and challenge score. However, two protein bands ( approximately 43 and 41 kDa) had peak intensities that correlated positively with challenge score and a third band ( approximately 48 kDa) that correlated negatively. The bands were identified as subunits of Ara h 3/4 and 1, respectively.

CONCLUSIONS

Promiscuity of IgE binding appears more important than the recognition of individual proteins. This may mean that clinically useful specific immunotherapy for peanut allergy will be difficult to achieve if only selected allergenic proteins are used. Further investigation of Ara h 1 and 3/4 subunits and a possible association with symptom severity are also highlighted by this study.

Serum ovalbumin-specific immunoglobulin G responses during pregnancy reflect maternal intake of dietary egg and relate to the development of allergy in early infancy

BACKGROUND

The value of allergen elimination diets during pregnancy for primary prevention of infant allergy has been questioned. However, dietary compliance may influence effectiveness.

OBJECTIVES

To monitor egg intake during a randomized controlled trial of egg avoidance throughout pregnancy and lactation by serial measurements of serum ovalbumin (OVA) IgG concentration in conjunction with dietary diary record and also, to analyse specific IgG concentrations at birth in relation to infant allergic outcome.

METHODS

Pregnant women, with personal or partner atopy, were randomized to complete dietary egg exclusion or an unmodified healthy diet before 20 weeks gestation. The infants were evaluated for atopy at 6 months of age. Serum food-specific IgG concentrations were determined by ELISA in maternal samples collected at study recruitment and during labour, and in infant samples at birth (umbilical cord).

RESULTS

Serum-specific IgG to OVA, but not the unrelated allergen, cow's milk beta-lactoglobulin, decreased over pregnancy in egg-avoiding women only (P<0.001). Cord OVA IgG concentration correlated with maternal IgG at delivery (r=0.944; P<0.001), and for infants born to atopic women, cord concentration was higher than that of their mother's (P<0.001). Infants with the lowest and highest cord IgG concentrations were the least likely, and those with mid-range concentrations were the most likely, to be atopic by 6 months of age (P=0.008).

CONCLUSION

Serum OVA IgG concentration reflects egg consumption, thereby indicating dietary allergen doses to which the developing immune system might be exposed. Trans-placental maternal IgG must be considered among early life factors that regulate infant atopic programming.

Secondhand smoke, dietary fruit intake, road traffic exposures, and the prevalence of asthma: a cross-sectional study in young children

The authors have investigated the independent effects of exposure to secondhand smoke, road vehicle traffic, and dietary fruit intake in a cross-sectional study of asthma in young children. They surveyed all children aged 4-6 years in 235 schools in the East Midlands and East of England regions of the United Kingdom in 2003. Data on respiratory symptoms, diagnoses and treatment, smoking in the home, and dietary fruit intake were collected by parental questionnaire. A geographic information system was used to map postcodes and determine the distance of the home from the nearest main road. Responses were obtained from 11,562 children. Wheeze in the past year and physician-diagnosed asthma were reported by 14.1% and 18.2%, respectively. Both of these outcomes were more common in children who lived with a smoker, and the prevalence of asthma increased with the number of smokers in the home. Asthma prevalence was not associated with proximity of the home to a main road or with dietary fruit intake. The authors conclude that, of the potential risk factors considered in this study, preventing secondhand smoke exposure may be the most effective way of preventing asthma.

A case-control study of dietary and erythrocyte membrane fatty acids in asthma

BACKGROUND

Epidemiological evidence suggests that increased dietary omega-6 and reduced omega-3 fatty acid intake, may have contributed to the rising prevalence of asthma, but these hypotheses have not been tested in studies comparing both dietary intake and objective measures of polyunsaturated fatty acids.

OBJECTIVE

To assess whether a higher intake of omega-6 or a lower intake of omega-3 fatty acids increases the risk of asthma, by measuring dietary fatty acid intake by a food frequency questionnaire (FFQ) and erythrocyte membrane fatty acids, as an objective biomarker of intake.

METHODS

We have compared individual fatty acid intake estimated by FFQ and by mass spectrometry of fasting erythrocyte cell membranes in 89 cases of asthma and 89 community-matched controls.

RESULTS

The odds of asthma were increased in relation to intake of the omega-3 fatty acids eicosapentaenoic acid (odds ratio (OR) for difference between the 25th and 75th centiles of intake= 1.89, 95% CI 1.15-3.11) and docosahexaenoic acid (OR = 2.11, 95% CI 1.19-3.74). There was no evidence of any difference in erythrocyte membrane levels of omega-3 fatty acids, while the odds of asthma were reduced in relation to linoleic acid (omega-6) membrane levels (OR = 0.45, 95% CI 0.21-0.95).

CONCLUSION

These findings suggest that dietary omega-3 fatty acids do not play a major role in protecting against asthma, and that higher levels of erythrocyte membrane linoleic acid are associated with a lower risk of asthma.

Survival and disease progression in UK patients with lymphangioleiomyomatosis

BACKGROUND

Lymphangioleiomyomatosis (LAM) is a rare and progressive disease of young women with no effective treatment. Previous estimates of 10 year survival, based mostly on case series or patients from tertiary centres, have ranged from 40% to 79%; no data are available on the progression of respiratory disability. In order to provide data for patients and for planning intervention studies, we have looked at the time course of LAM using a national cohort.

METHODS

Time to death, time to MRC dyspnoea grades 2-5, and need for oxygen in patients on the UK LAM database were analysed using Kaplan-Meier analysis and Cox regression.

RESULTS

Fifty seven of 72 patients responded with a median duration of follow up of 12.6 years (range 2.3-37) from the onset of symptoms. Ten year survival was 91% from onset of symptoms but varied widely with 11 patients alive after 20 years. Median time to MRC grade 3 dyspnoea (breathless walking on the flat) was 9.3 years (95% CI 5.1 to 13.4) from onset of symptoms.

CONCLUSIONS

Survival from LAM appears to be better than that reported in early studies. These data should be helpful for patients and for planning clinical trials.

Vitamin E supplements in asthma: a parallel group randomised placebo controlled trial

BACKGROUND

Increased dietary vitamin E intake is associated with a reduced incidence of asthma, and combinations of antioxidant supplements including vitamin E are effective in reducing ozone induced bronchoconstriction. A study was undertaken to investigate the effect of supplementation with vitamin E for 6 weeks on bronchial hyperresponsiveness in atopic adults with asthma.

METHODS

72 participants from a clinical trial register of adults with asthma were randomised to receive 500 mg natural vitamin E or matched placebo for 6 weeks in a placebo controlled, double blind parallel group clinical trial. Inclusion criteria included age 18-60 years, maintenance treatment of at least one dose of inhaled corticosteroid per day, a positive skin prick test to one of three common allergens, and bronchial hyperresponsiveness to methacholine (defined as a dose provoking a 20% fall in forced expiratory volume in 1 second (FEV(1)) (PD(20)) of 12.25 micromol). Secondary outcomes were FEV(1), forced vital capacity, mean morning and evening peak flow, symptom scores, bronchodilator use, and serum immunoglobulin E levels.

RESULTS

In the primary intention to treat analysis the change in PD(20) was similar in the vitamin E and placebo groups with a mean difference of +0.25 doubling doses of methacholine (95% confidence interval -0.67 to +1.16 greater with vitamin E). There was no effect of vitamin E supplementation on any other measure of asthma control, either in the intention to treat or per protocol analysis. There was also no effect of vitamin E supplementation on serum immunoglobulin levels.

CONCLUSION

Dietary supplementation with vitamin E adds no benefit to current standard treatment in adults with mild to moderate asthma.

Prevalence and associated factors of atopic dermatitis symptoms in rural and urban Ethiopia

BACKGROUND

Allergic diseases, including atopic dermatitis (AD), are increasingly becoming a clinical problem in developing countries.

OBJECTIVE

We investigated the prevalence of AD symptoms and the effects of potential environmental aetiologies in rural and urban areas of Jimma in southwestern Ethiopia.

METHODS

Information on allergic disease symptoms and lifestyle factors was gathered in an interviewer-led cross-sectional questionnaire-based population survey of 9844 urban and 3032 rural participants of all ages. A one-in-four subsample underwent skin prick testing for hypersensitivity to Dermatophagoides pteronyssinus, mixed threshings, and aspergillus.

RESULTS

Around 95% of those eligible took part in the survey. Lifetime cumulative prevalence of AD symptoms was generally low with an overall prevalence of 1.2%, but was higher in the urban (1.5%) than in the rural area (0.3%; odds ratio (OR)=4.45 [95% CI 2.34-8.47]). AD symptoms were strongly associated with wheeze (adjusted OR=22.03 [15.45-31.42]) and rhinitis symptoms (61.94 [42.66-89.95]). Of several environmental exposures assessed, residence in a house made of brick (rather than mud) walls with wooden (rather than clay) floor, exposure to cigarette smoke as a child, having lived outside of Jimma in the past, and being of the Tigrean ethnic group were associated with an increased risk of AD symptoms.

CONCLUSION

Although the overall prevalence of AD symptoms was low in this Ethiopian population, a marked urban-rural gradient was evident. Lifestyle factors linked to urbanization were associated with an increased risk of AD symptoms.

Domestic risk factors for wheeze in urban and rural Ethiopian children

BACKGROUND

To identify which environmental exposures underpin the emergence of asthma epidemics, we need to study epidemics as they appear, as is now happening in the Jimma region of Ethiopia. We have previously studied risk factors for asthma in adults in Jimma and have now completed a survey of young children.

AIM

To establish the prevalence of asthma in urban and rural children in Jimma, and to identify locally important risk factors.

DESIGN

Cross-sectional survey.

METHODS

All children aged 1-5 years living in Jimma town and three surrounding rural regions were identified. Data were collected using an interviewer-led questionnaire, and consenting children had skin prick tests to house dust mite and cockroach.

RESULTS

We surveyed 7155 children, of whom 3623 (51%) were female and 4285 (60%) lived in the urban area. The prevalence of wheeze in the last year was 3.4%, and was lower in the rural area (OR 0.47; 95%CI 0.34-0.66). In the urban area, the main risk factors for wheeze were a longer duration of breastfeeding, use of kerosene, and environmental tobacco smoke, while living with animals was protective. In rural children, the main risk factors were a positive skin prick test and living with animals.

DISCUSSION

The prevalence of wheeze in children in the Jimma region is low, particularly in rural children. In addition to having an impact on disease prevalence, place of residence also appears to modify the impact of environmental risk factors for wheeze.

Oral magnesium and vitamin C supplements in asthma: a parallel group randomized placebo-controlled trial

BACKGROUND

Epidemiological studies suggest that higher intakes of dietary vitamin C and magnesium may be associated with a reduced risk of asthma.

OBJECTIVE

To determine whether vitamin C or magnesium supplements improve the clinical control of asthma in primary care patients.

METHODS

A randomized, placebo-controlled, double-blind parallel group trial of 16 weeks supplementation with 1 g/day vitamin C, 450 mg/day magnesium chelate or matched placebo. Three hundred patients aged 18-60 years with physician-diagnosed asthma, controlled with at least one dose of an inhaled corticosteroid daily, were recruited from 24 primary care practices in Nottingham, UK. The main outcome measures were change in forced expiratory volume in 1 s, forced vital capacity, airway responsiveness to methacholine, mean morning and evening peak flow, symptom scores and bronchodilator use, both individually and as a combined summary statistic.

RESULTS

There was no evidence of any beneficial effect of either supplement on any outcome measure of asthma control in the primary intention-to-treat analysis, or in an analysis restricted to participants who completed the study.

CONCLUSIONS

Regular dietary supplementation with vitamin C or magnesium adds no clinical benefit to current standard therapy of asthma in primary care patients.

Effects of volatile organic compounds, damp, and other environmental exposures in the home on wheezing illness in children

BACKGROUND

The effects of indoor exposure to volatile organic compounds (VOCs), including formaldehyde, on respiratory health are not clearly understood. The aim of this study was to determine the independent effects of VOCs and other common environmental exposures in the home on the risk and severity of persistent wheezing illness in children.

METHODS

Total volatile organic compounds, formaldehyde, nitrogen dioxide, damp (on a four category scale of % wood moisture equivalent), and environmental tobacco smoke (from salivary cotinine) were measured objectively in the homes of 193 children with persistent wheezing illness and 223 controls aged 9-11 years in Nottingham, UK.

RESULTS

The risk of wheezing illness was significantly increased only in relation to damp (odds ratio (OR) per increasing category=1.32 (95% confidence interval (CI), 1.00 to 1.75)), and was unrelated to the other exposures measured. Among cases, formaldehyde and damp were associated with more frequent nocturnal symptoms (OR per increasing quartile and category, respectively, 1.45 (1.06 to 1.98) and 1.97 (1.10 to 3.53)), significantly more so in atopic cases, but there was no effect of total volatile organic compounds, nitrogen dioxide, or cotinine.

CONCLUSIONS

Domestic volatile organic compounds are not a major determinant of risk or severity of childhood wheezing illness, though formaldehyde may increase symptom severity. Indoor damp increases both the risk and severity of childhood wheezing illness.

Lymphangioleiomyomatosis: a case-control study of perinatal and early life events

BACKGROUND

Lymphangioleiomyomatosis (LAM), a rare disease affecting women, is caused by somatic mutations in the tuberous sclerosis complex genes.

METHODS

A case-control questionnaire study was carried out examining parental and family history, prenatal events, and early life events to try to shed light on the aetiology of the condition. Forty five patients identified from a national LAM register completed a questionnaire and 31 were compared with 117 age and sex matched control subjects using conditional logistic regression.

RESULTS

No differences were found in perinatal events, childhood infections, and parental or family history, except that patients were more likely to be an only child (odds ratio (OR) 4.3 (95% confidence interval (CI), 1.5 to 11.8)) and have a relative with uterine fibroids (OR 4.2 (1.4 to 13)). Patients with LAM had had fewer pregnancies and fewer children but no differences in miscarriage rates. A non-matched analysis using all 45 cases and 117 controls gave similar results.

CONCLUSIONS

No features in the family history, perinatal events, or early life events were detected that were associated with having LAM. Being more likely to be an only child and having an increased family history of uterine fibroids may, if confirmed, indicate some differences in reproductive function within the families of affected individuals.

Respiratory symptoms in patients with treated hypothyroidism and inflammatory bowel disease

BACKGROUND

Patients with idiopathic chronic cough and unexplained airflow obstruction in non-smokers have been shown to have an increased prevalence of hypothyroidism and other organ specific autoimmune disorders. Whether patients with hypothyroidism have an increased prevalence of respiratory symptoms is unknown.

METHODS

The prevalence of respiratory symptoms was assessed in 124 patients with treated hypothyroidism recruited from primary and secondary care, 64 outpatients with inflammatory bowel disease, and 1346 control adults recruited randomly from the electoral register in a case-control study. Respiratory symptoms and smoking history were assessed by a respiratory symptom questionnaire.

RESULTS

After adjustment for age, sex and smoking, symptoms of breathlessness and sputum production were more prevalent in both patient populations than in controls (odds ratios for hypothyroidism and inflammatory bowel disease; breathlessness: 3.1 (95% CI 2.1 to 4.6) and 3.4 (95% CI 2.0 to 6.0), respectively; sputum production: 2.7 (95% CI 1.6 to 4.5) and 2.5 (95% CI 1.2 to 5.0), respectively). Cough during the day and night was significantly more prevalent in patients with hypothyroidism (1.8 (95% CI 1.2 to 2.9)) and approached significance in those with inflammatory bowel disease (1.8 (95% CI 1.0 to 3.4)). Wheeze and nocturnal cough were no more prevalent in either disease population than in controls.

CONCLUSION

There is a significantly increased prevalence of respiratory symptoms in patients with hypothyroidism or inflammatory bowel disease compared with controls recruited from the general population. Further work is required to determine whether similar differences are seen in comparison with hospital based controls. These findings support the hypothesis that there is a link between autoimmune hypothyroidism and respiratory disease.

Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study

BACKGROUND

In the assessment of severity in community acquired pneumonia (CAP), the modified British Thoracic Society (mBTS) rule identifies patients with severe pneumonia but not patients who might be suitable for home management. A multicentre study was conducted to derive and validate a practical severity assessment model for stratifying adults hospitalised with CAP into different management groups.

METHODS

Data from three prospective studies of CAP conducted in the UK, New Zealand, and the Netherlands were combined. A derivation cohort comprising 80% of the data was used to develop the model. Prognostic variables were identified using multiple logistic regression with 30 day mortality as the outcome measure. The final model was tested against the validation cohort.

RESULTS

1068 patients were studied (mean age 64 years, 51.5% male, 30 day mortality 9%). Age >/=65 years (OR 3.5, 95% CI 1.6 to 8.0) and albumin <30 g/dl (OR 4.7, 95% CI 2.5 to 8.7) were independently associated with mortality over and above the mBTS rule (OR 5.2, 95% CI 2.7 to 10). A six point score, one point for each of Confusion, Urea >7 mmol/l, Respiratory rate >/=30/min, low systolic(<90 mm Hg) or diastolic (</=60 mm Hg) Blood pressure), age >/=65 years (CURB-65 score) based on information available at initial hospital assessment, enabled patients to be stratified according to increasing risk of mortality: score 0, 0.7%; score 1, 3.2%; score 2, 3%; score 3, 17%; score 4, 41.5% and score 5, 57%. The validation cohort confirmed a similar pattern.

CONCLUSIONS

A simple six point score based on confusion, urea, respiratory rate, blood pressure, and age can be used to stratify patients with CAP into different management groups.

Relationship between FEV1 reduction and respiratory symptoms in the general population

Obstructive airways diseases typically present with dyspnoea, cough and wheeze, and are defined by a reduced forced expiratory volume in one second (FEV1/forced vital capacity (FVC) ratio. Traditionally, however, the severity of chronic obstructive pulmonary disease is graded by the FEV1 % predicted rather than the FEV1/FVC ratio, whilst other potentially valid measures of FEV1 impairment, such as the absolute difference of FEV1 from predicted or the absolute level of FEV1, tend not to be used. The authors have therefore explored the relationship between these different measures of FEV1 impairment and chronic respiratory symptoms in a general population sample. FEV1 and FVC were measured and questionnaire data were obtained on cough, wheeze, shortness of breath and general self-reported breathing trouble in a cross-sectional survey of 2,633 adults aged 18-70 yrs from a district of Nottingham, UK. Odds ratios for each symptom were calculated for declining levels of absolute FEV1, FEV1 % pred, absolute difference of FEV1 from predicted, and FEV1/FVC ratio. They were plotted to display the shape and strength of these relationships before and after adjustment for each other measure. The odds of symptoms increased with declining levels of all FEV1 measures, particularly for wheeze and general breathing trouble. Although this study was not sufficiently powerful to detect significant differences between measures, these relationships were consistently strongest, before and after adjustment, for FEV1 % pred, particularly below a threshold of approximately 75%. The authors conclude that forced expiratory volume in one second % predicted appears to be the measure of airflow impairment most closely associated with chronic respiratory symptoms in the general population.

Living near a main road and the risk of wheezing illness in children

The effect of road vehicle traffic pollution on asthma is still not clearly understood. However, any effect is likely to be most marked among those who live within 150 m of a main road, because this is the distance within which concentrations of primary vehicle traffic pollutants are raised above ambient background levels. We have investigated the relation between proximity of the family home to the nearest main road, estimated objectively using geographical information system software, and the risk of wheeze in the past year in a case-control sample of 6,147 primary schoolchildren (age 4 to 11 yr) and a random cross-sectional sample of 3,709 secondary schoolchildren (age 11 to 16 yr) in Nottingham, United Kingdom. Among children living within 150 m of a main road, the risk of wheeze increased with increasing proximity by an odds ratio (OR) of 1.08 (95% confidence interval [CI] 1.00 to 1.16) per 30-m increment in primary schoolchildren, and 1.16 (1.02 to 1.32) in secondary schoolchildren. Most of the increased risk was localized to within 90 m of the roadside. Among primary schoolchildren, effects were stronger in girls than boys (p(interaction) = 0.02). Living within approximately 90 m of a main road is associated with a proximity-related increase in the risk of wheezing illness in children.

Analysis of 1,3-Dichloropropene for Control of Meloidogyne spp. in a Tobacco Pest Management System

1,3-Dichloropropene (1,3-D) and nonfumigant nematicides were evaluated for control of Meloidogyne spp. and soil and foliar insects in a tobacco pest management system. In a field with a high Meloidogyne spp. population density (root gall index 4.0 to 4.5 on a 0 to 10 scale in untreated controls), tobacco yields and crop values increased (482 kg/ha and $1,784/ha for 1, 3-D; 326 kg/ha and $1,206/ha for fenamiphos; 252 kg/ha and $933/ha for ethoprop) with nematicide application over an untreated control. In fields with a low population density of Meloidogyne arenaria or M. incognita (root gall index 2.3 to 2.5 in untreated controls), yields ranged from 1,714 to 2,027 kg/ha and were not altered by fumigant or nonfumigant nematicide application. Carbofuran, a soil-applied nonfumigant nematicide/insecticide, reduced the number of foliar insecticide applications required to keep insect populations below treatment threshold (3.8 vs. 4.5, respectively, for treated vs. untreated). Carbofuran reduced the cost ($23/ha) of foliar insecticide treatments when compared to an untreated control. Although nonfumigant nematicides provided some soil and foliar insect control, the cost of using a fumigant plus a lower insecticidal rate of a soil insecticide/nematicide was comparable to the least expensive non-fumigant nematicide when the cost of foliar insecticide applications was included in the cost estimates. Savings in foliar insecticide cost by use of soil-applied nonfumigant nematicide/insecticides were small ($23/ha) in comparison to potential value reductions by root-knot nematodes when the nonfumigant nematicides fenamiphos or ethoprop ($578/ha and $851/ha, respectively) were used instead of 1,3-D.

Airway responsiveness and peak flow variability in the diagnosis of asthma for epidemiological studies

Airway responsiveness and variability in peak expiratory flow (PEF) are widely used as objective diagnostic measures of asthma, but it is not clear how these variables should be calculated or adjusted to obtain the highest diagnostic validity for physician-diagnosed asthma in the community. Data from a community-based sample of 1,513 adults has been used. Airway responsiveness to methacholine and 7-day PEF data were obtained in 1991, asthma and respiratory symptoms were diagnosed by questionnaires in 1991 and 1999. Airway responsiveness was expressed as the provocative dose causing a 20% fall in forced expiratory volume in one second (PD20), two-point and least-squares regression slopes. PEF variability was expressed as daily amplitude, weekly standard deviation and mean of the two lowest readings. Continuous measures were adjusted for measures of baseline airway calibre by linear regression. Measures of airway responsiveness had greater sensitivity for specificity for self-reported diagnosed asthma than expressions of PEF variability, before and after adjustment for airway calibre. Diagnostic validity was substantially better in adults aged <50 yrs; PD20 provided the best sensitivity for specificity (61% for 95% at 8.3 micromol). In those aged > or =50 yrs, no measure was closely related to diagnosed asthma. In younger age groups, provocative dose causing a 20% fall in forced expiratory volume in one second provides a valuable objective measure of asthma for epidemiological studies, but is unable to distinguish between asthma and chronic obstructive pulmonary disease in older people.

Crop Rotation and Nematicides for Management of Mixed Populations of Meloidogyne spp. on Tobacco

The effects of crop rotation and the nematicides 1,3-dichloropropene (1,3-D), ethoprop, and fenamiphos on the relative frequency of Meloidogyne incognita race 3, M. arenaria race 2, and M. javanica and tobacco yields on a sandy loam soil were determined. Cropping sequences altered the species composition and population densities of Meloidogyne spp. Meloidogyne arenaria and M. incognita predominated when cotton, corn, sorghum, or rye-fallow preceded tobacco. Meloidogyne javanica and M. arenaria predominated when tobacco preceded tobacco. Sorghum, cotton, corn, or rye-fallow preceding tobacco enhanced yields compared to tobacco preceding tobacco in plots containing mixtures of Meloidogyne species. Sorghum supported minimal reproduction of any Meloidogyne spp. Application of 1,3-D increased tobacco yields and reduced root galling when compared to untreated controls. Both fenamiphos and ethoprop treatments were less effective than 1,3-D in controlling Meloidogyne spp. or increasing yields. A rotation crop x nematicide interaction was not observed. In continuous tobacco, use of the M. incognita-resistant tobacco cv. Coker 176 increased tobacco yields when compared to the M. incognita-susceptible cv. Coker 319 when 1,3-D was not applied.

Increased risk of allergy associated with the use of kerosene fuel in the home

Allergic diseases are becoming increasingly prevalent in developing countries, consistent with an environmental etiology associated with affluence or urbanization. We have tested the hypothesis that the risk of allergy is increased by the use of non-biomass fuels (kerosene, gas or electricity) in the home, using data from a survey of the urban population of Jimma, Ethiopia. Questionnaire data on allergic symptoms, domestic fuel use and lifestyle factors were collected from 9844 adults and children, and allergen skin sensitization measured in a subsample of 2372. Use of any non-biomass fuel was reported by 959 individuals (10%), usually in combination with biomass fuel, and was significantly associated with an increased risk of allergic sensitization (age, sex and socio-economic status adjusted odds ratio (95% confidence interval) = 1.78 [1.06 to 2.97]) and wheeze (1.56 [1.07 to 2.26]), rhinitis (2.06 [1.46 to 2.91]) and eczema (2.82 [1.61 to 4.96]) relative to use of biomass fuel only. These effects were predominantly due to kerosene, which was significantly related to all outcomes, and gas, which was strongly related to allergic sensitization. Our findings suggest that domestic combustion of refined fossil fuels increases the risk of allergic sensitization and symptoms, and may have contributed to the increasing prevalence of allergic disease.

Siblings, multiple births, and the incidence of allergic disease: a birth cohort study using the West Midlands general practice research database

BACKGROUND

The presence of older siblings reduces the risk of developing hay fever, eczema and atopy, but findings for asthma have been inconsistent. Whether twins have a reduced risk of allergic disease is also unclear. We have investigated these questions in a birth cohort analysis of the West Midlands General Practice Research Database (GPRD).

METHODS

Our birth cohort included 29,238 children. The incidence of allergic disease was examined according to the number of siblings, multiple births, and parental allergic disease and smoking habit using Cox regression.

RESULTS

There was a dose related decrease in the incidence of eczema and hay fever with increasing number of older siblings (hazard ratio for children with three or more older siblings compared with none 0.70 (95% CI 0.64 to 0.76) for eczema and 0.67 (95% CI 0.52 to 0.86) for hay fever). In contrast, the presence of older siblings increased the incidence of asthma (HR 1.17, 95% CI 1.06 to 1.29), although this effect was strongly dependent on age of diagnosis. For children diagnosed over the age of 2 years the presence of older siblings was protective (HR 0.66, 95% CI 0.52 to 0.82), while below this age the reverse was true (HR 1.38, 95% CI 1.24 to 1.54). Members of a multiple birth had a reduced incidence of all three allergic diseases. Birth order and multiple birth effects were independent of sex, maternal age, consulting behaviour, and parental allergy and smoking habit.

CONCLUSIONS

The presence of older siblings and being a member of a multiple birth appears to protect against the development of eczema, hay fever, and asthma diagnosed after the age of 2. In contrast, the presence of older siblings increases the incidence of early asthma.

Adverse effects of oral corticosteroids in relation to dose in patients with lung disease

BACKGROUND

The adverse effects of oral corticosteroids are widely recognised but there are few quantitative data on which to base advice to patients. In a two part cross sectional study we compared adverse effects in patients with lung disease taking oral corticosteroids and control subjects and related the adverse effects to corticosteroid dose in the patient group.

METHODS

Data on oral corticosteroid use, lifestyle, fractures, and other possible adverse effects were collected by questionnaire and compared between a community based cohort of patients taking continuous or frequent intermittent oral corticosteroids for asthma, chronic obstructive pulmonary disease, or alveolitis and age and sex matched control subjects. Dose related effects were explored in the corticosteroid group using cumulative dose quartiles and multiple logistic regression.

RESULTS

A total of 367 patients (> or = 50 years, 48% female) and 734 control subjects completed the questionnaire. The cumulative incidence of fractures since the time of diagnosis was 23% for patients taking oral corticosteroids and 15% in the control group (odds ratio (OR) 1.8; 95% confidence interval (CI) 1.3 to 2.6). Patients were more likely to have had a fracture of the vertebrae (OR 10; 95% CI 2.9 to 34), hip (OR 6; 95% CI 1.2 to 30), and ribs or sternum (OR 3.2, 95% CI 1.6 to 6.6) than control subjects. They also reported a significant increase in cataracts, use of antacids, muscle weakness, back pain, bruising, oral candidiasis, and having fewer teeth. The effects of oral corticosteroids were dose related: the odds ratio for patients in the highest compared with the lowest cumulative dose quartile (median prednisolone dose 61 g versus 5 g) ranged from 2 for all fractures to 9 for vertebral fractures and bruising.

CONCLUSIONS

By quantifying the morbidity associated with the use of oral corticosteroids, this study should help to rationalise their long term use.

Association of specific allergen sensitization with socioeconomic factors and allergic disease in a population of Boston women

BACKGROUND

Socioeconomic differences in allergic disease prevalence have been reported; asthma has been associated with poverty in the United States and hay fever and eczema with relative affluence elsewhere. It is not yet established to what degree such differences in disease prevalence reflect patterns of sensitization and specific allergen sensitivities.

OBJECTIVE

We analyzed specific and total IgE measurements in a sample of 458 women, enriched for allergic disease, from the metropolitan Boston area to establish the relation of allergen sensitization to markers of socioeconomic status (SES) and to the prevalence and socioeconomic pattern of allergic disease in this community.

METHODS

Total and specific IgE antibodies were measured with the UNICAP System; self-reported allergic disease, household income, education, and race-ethnicity were ascertained with a questionnaire; and a further marker of poverty (percentage living below the poverty level) in the women's area of residence was established on the basis of zip codes. Analysis was performed with SAS statistical software.

RESULTS

Markers of low SES were univariately associated with increases in total IgE, number of allergen sensitizations, and levels of specific IgE. Socioeconomic differences in sensitization to cockroach (35% vs 6% in the highest and lowest poverty areas), animal (44% vs 26%), and ragweed (49% vs 23%) allergens were most marked. Sensitization primarily to indoor inhalant allergens (not ragweed or ryegrass) were associated with an increased risk of asthma, even after adjustment for SES.

CONCLUSION

We have demonstrated a socioeconomic gradient in sensitization that concords with increased rates of asthma in less affluent communities in this population.

Measurement of CP-violating asymmetries in B0 decays to CP eigenstates

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta = 0.34+/-0.20 (stat)+/-0.05 (syst).

Processes involved in the development of latent fingerprints using the cyanoacrylate fuming method

Chemical processes involved in the development of latent fingerprints using the cyanoacrylate fuming method have been studied. Two major types of latent prints have been investigated-clean and oily prints. Scanning electron microscopy (SEM) has been used as a tool for determining the morphology of the polymer developed separately on clean and oily prints after cyanoacrylate fuming. A correlation between the chemical composition of an aged latent fingerprint, prior to development, and the quality of a developed fingerprint has been observed in the morphology. The moisture in the print prior to fuming has been found to be more important than the moisture in the air during fuming for the development of a useful latent print. In addition, the amount of time required to develop a high quality latent print has been found to be within 2 min. The cyanoacrylate polymerization process is extremely rapid. When heat is used to accelerate the fuming process, typically a period of 2 min is required to develop the print. The optimum development time depends upon the concentration of cyanoacrylate vapors within the enclosure.