Early supplementation with Lactobacillus rhamnosus HN001 reduces eczema prevalence to 6 years: does it also reduce atopic sensitization?

BACKGROUND

The role of probiotics in prevention of allergic disease is still not clear; efficacy may depend on the timing, dose, duration, and specific probiotic used. Using a double-blind randomized placebo-controlled trial (Australian New Zealand Clinical Trials Registry: ACTRN12607000518460), we have shown that in a high-risk birth cohort, maternal supplementation from 35 weeks gestation until 6 months if breastfeeding and infant supplementation from birth until 2 years with Lactobacillus rhamnosus HN001 (HN001) (6 × 10(9) cfu/day) halved the cumulative prevalence of eczema at 2 and 4 years. Bifidobacterium animalis subsp lactis HN019 (HN019) (9 × 10(9) cfu/day) had no significant effect.

OBJECTIVE

To determine whether differences in effects of HN001 and HN019 on eczema persist to age 6 years, and to investigate effects on sensitization.

METHODS

Standard procedures were used to assess eczema (The UK Working Party's Criteria), eczema severity (SCORAD), atopic sensitization [skin prick tests (SPT), total and specific IgE] and standard questions used for asthma, wheeze, and rhinoconjunctivitis.

RESULTS

HN001 was associated with significantly lower cumulative prevalence of eczema (HR = 0.56, 95% CI 0.39-0.80), SCORAD ≥ 10 (HR = 0.69, 0.49-0.98) and SPT sensitization (HR = 0.69, 95% CI 0.48-0.99). The point prevalence of eczema (RR = 0.66, 95% CI 0.44-1.00), SCORAD ≥ 10 (RR = 0.62, 95% CI 0.38-1.01) and SPT sensitization (RR = 0.72, 95% CI 0.53-1.00) were also reduced among children taking HN001. HN019 had no significant effect on any outcome.

CONCLUSION AND CLINICAL RELEVANCE

This study provides evidence for the efficacy of the probiotic L. rhamnosus HN001 in preventing the development of eczema and possibly also atopic sensitization in high risk infants to age 6 years. The absence of a similar effect for HN019 indicates that benefits may be species specific.

Coherent anti-Stokes Raman scattering and spontaneous Raman spectroscopy and microscopy of microalgae with nitrogen depletion

Microalgae are extensively researched as potential feedstocks for biofuel production. Energy-rich compounds in microalgae, such as lipids, require efficient characterization techniques to investigate the metabolic pathways and the environmental factors influencing their accumulation. The model green alga Coccomyxa accumulates significant amounts of triacylglycerols (TAGs) under nitrogen depletion (N-depletion). To monitor the growth of TAGs (lipid) in microalgal cells, a study of microalgal cells (Coccomyxa sp. C169) using both spontaneous Raman and coherent anti-Stokes Raman scattering (CARS) spectroscopy and microscopy were carried out. Spontaneous Raman spectroscopy was conducted to analyze the components in the algal cells, while CARS was carried out to monitor the distribution of lipid droplets in the cells. Raman signals of carotenoid are greater in control microalgae compared to N-depleted cells. Raman signals of lipid droplets appear after N-depletion and its distribution can be clearly observed in the CARS microscopy. Both spontaneous Raman spectroscopy and CARS microscopy were found to be suitable analysis tools for microalgae.

Surface-enhanced Raman spectroscopy using gold-coated horizontally aligned carbon nanotubes

Gold-coated horizontally aligned carbon nanotube (Au-HA-CNT) substrates were fabricated for surface-enhanced Raman spectroscopy (SERS). The Au-HA-CNT substrates, which are granular in nature, are easy-to-prepare with large SERS-active area. Enhancement factors (EFs) of ∼10(7) were achieved using the Au-HA-CNTs as substrates for rhodamine 6G (R6G) molecules. Maximum enhancement was found when the polarization direction (E-field) of the incident laser beam was parallel to the aligned direction of the HA-CNTs. Simulations using the finite-difference time-domain (FDTD) method were carried out for the granular Au-HA-CNT samples. Enhancement mechanisms and determination of EFs were analyzed. Biological samples, including (13)C- and deuterium (D)-labeled fatty acids and Coccomyxa sp. c-169 microalgae cells, were also measured using this SERS substrate. The limits of detection (LODs) of D- and (13)C-labeled fatty acids on the SERS substrate were measured to be around 10 nM and 20 nM, respectively. Significantly enhanced Raman signals from the microalgae cells were acquired using the SERS substrate.

Chromosome 4q31 locus in COPD is also associated with lung cancer

Chronic obstructive pulmonary disease (COPD) is the single greatest risk factor for lung cancer in smokers and is found in 50-90% of lung cancer cases. The link between COPD and lung cancer may stem in part from the matrix remodelling and repair processes underlying COPD, and the development of epithelial-mesenchymal transition (EMT) that underlies lung carcinogenesis. The Hedgehog-interacting protein (HHIP), which mediates the epithelial response (EMT) to smoking, has been implicated in COPD and lung cancer. Recent genome-wide and candidate gene studies of COPD implicate genetic variants on the chromosomal 4q31 (HHIP/glycophorin A (GYPA)) locus. In a case-control study of smokers with normal lung function, COPD and lung cancer (subphenotyped for COPD), we show the GG genotype of the rs 1489759 HHIP single-nucleotide polymorphism (SNP) and the CC genotype of the rs 2202507 GYPA SNP confers a "protective" effect on COPD (OR 0.59, p = 0.006 for HHIP and OR = 0.65, p = 0.006 for GYPA) and lung cancer (OR = 0.70 (p = 0.05) for HHIP and OR 0.70 (p = 0.02) for GYPA). This study suggests that, in smokers, genetic variants of the 4q31 locus conferring a protective effect for COPD are also protective in lung cancer. We conclude that genetic susceptibility to lung cancer includes COPD-related gene variants.

A gene-based risk score for lung cancer susceptibility in smokers and ex-smokers

BACKGROUND

Epidemiological and family studies suggest that lung cancer results from the combined effects of age, smoking and genetic factors. Chronic obstructive pulmonary disease (COPD) is also an independent risk factor for lung cancer and coexists in 40-60% of lung cancer cases.

METHODS

In a two-stage case-control association study, genetic markers associated with either susceptibility or protection against lung cancer were identified. In a test cohort of 439 Caucasian smokers or ex-smokers, consisting of healthy smokers and lung cancer cases, 157 candidate single nucleotide polymorphisms (SNPs) were screened. From this, 30 SNPs were identified, the genotypes (codominant or recessive model) of which were associated with either the healthy smokers (protective) or lung cancer (susceptibility) phenotype. After genotyping of this 30-SNP panel in a second validation cohort of 491 subjects and using the same protective and susceptibility genotypes from our test cohort, a 20-SNP panel was selected on the basis of independent univariate analyses.

RESULTS

Using multivariate logistic regression, including the 20 SNPs, it was also found that age, history of COPD, family history of lung cancer and gender were significantly and independently associated with lung cancer.

CONCLUSIONS

When numeric scores were assigned to both the SNP and demographic data, and sequentially combined by a simple algorithm in a risk model, the composite score was found to be linearly related to lung cancer risk with a bimodal distribution. Genetic data may therefore be combined with other risk variables from smokers or ex-smokers to identify individuals who are most susceptible to developing lung cancer.

Falling asleep: the determinants of sleep latency

BACKGROUND

Difficulty falling asleep (prolonged sleep latency) is a frequently reported problem in school-aged children.

AIMS

This study aimed to describe the distribution of sleep latency and factors that influence its duration.

METHODS

871 children of European mothers were recruited at birth. 591 (67.9%) children took part in the follow-up at 7 years of age. Sleep and daytime activity were measured objectively by an actigraph worn for 24 h.

RESULTS

Complete sleep data were available for 519 children (87.8%) with a mean age of 7.3 years (SD 0.2). Median sleep latency was 26 minutes (interquartile range 13-42). Higher mean daytime activity counts were associated with a decrease in sleep latency (-1.2 minutes per 102 movement count per minute, p = 0.05). Time spent in sedentary activity was associated with an increase in sleep latency (3.1 minutes per hour of sedentary activity, p = 0.01).

CONCLUSIONS

These findings emphasise the importance of physical activity for children, not only for fitness, cardiovascular health and weight control, but also for promoting good sleep.

Lung cancer gene associated with COPD: triple whammy or possible confounding effect?

Recently, several large genome-wide association studies have identified a putative "lung cancer" locus in the nicotinic acetylcholine receptor subunit genes (nAChR) on 15q25. However, these findings may be confounded by the presence of chronic obstructive pulmonary disease (COPD), which is also strongly associated with smoking exposure and lung cancer. This is likely as the prevalence of COPD in lung cancer cohorts is as much as two-fold greater than that reported in smoking control populations (50 versus 20%). The present authors compared the genotype frequencies of the most strongly associated single nucleotide polymorphism (rs16969968) in the alpha5 subunit of the nAChR gene cluster between three matched smoking cohorts. The AA genotype was found to be more frequent and was seen in 437 (16%) lung cancer cases and 445 (14%) COPD cases compared with 475 (9%) healthy smoking controls. More importantly, when 429 lung cancer cases were divided according to spirometry results (performed within 3 months of diagnosis, prior to surgery and in the absence of effusions or collapse), the AA genotype was present in 19 and 11% of cases with and without COPD, respectively. These findings suggest that the association between the alpha5 subunit nicotinic acetylcholine receptor single nucleotide polymorphism and lung cancer may, in part, be confounded by chronic obstructive pulmonary disease.

COPD prevalence is increased in lung cancer, independent of age, sex and smoking history

Chronic obstructive pulmonary disease (COPD) is a common comorbid disease in lung cancer, estimated to affect 40-70% of lung cancer patients, depending on diagnostic criteria. As smoking exposure is found in 85-90% of those diagnosed with either COPD or lung cancer, coexisting disease could merely reflect a shared smoking exposure. Potential confounding by age, sex and pack-yr smoking history, and/or by the possible effects of lung cancer on spirometry, may result in over-diagnosis of COPD prevalence. In the present study, the prevalence of COPD (pre-bronchodilator Global Initiative for Chronic Obstructive Lung Disease 2+ criteria) in patients diagnosed with lung cancer was 50% compared with 8% in a randomly recruited community control group, matched for age, sex and pack-yr smoking exposure (n = 602, odds ratio 11.6; p<0.0001). In a subgroup analysis of those with lung cancer and lung function measured prior to the diagnosis of lung cancer (n = 127), we found a nonsignificant increase in COPD prevalence following diagnosis (56-61%; p = 0.45). After controlling for important variables, the prevalence of COPD in newly diagnosed lung cancer cases was six-fold greater than in matched smokers; this is much greater than previously reported. We conclude that COPD is both a common and important independent risk factor for lung cancer.

Supplementation with Lactobacillus rhamnosus or Bifidobacterium lactis probiotics in pregnancy increases cord blood interferon-gamma and breast milk transforming growth factor-beta and immunoglobin A detection

BACKGROUND

This study explored the effects of maternal probiotic supplementation on immune markers in cord blood (CB) and breast milk.

METHODS

CB plasma and breast milk samples were collected from a cohort of women who had received daily supplements of either 6 x 10(9) CFU/day Lactobacillus rhamnosus HN001 (n=34), 9 x 10(9) CFU/day Bifidobacterium lactis HN019 (n=35) or a placebo (n=36) beginning 2-5 weeks before delivery and continuing for 6 months in lactating women. CB plasma and breast milk (collected at 3-7 days, 3 months and 6 months postpartum) were assayed for cytokines (IL-13, IFN-gamma, IL-6, TNF-alpha, IL-10, TGF-beta1) and sCD14. Breast milk samples were also assayed for total IgA.

RESULTS

Neonates of mothers who received a probiotic had higher CB IFN-gamma levels (P=0.026), and a higher proportion had detectable blood IFN-gamma levels, compared with the placebo group (P=0.034), although levels were undetectable in many infants. While this pattern was evident for both probiotics, when examined separately only the L. rhamnosus HN001 group showed statistically significant higher IFN-gamma levels (P=0.030) compared with the placebo group. TGF-beta1 levels were higher in early breast milk (week 1) from the probiotic groups (P=0.028). This was evident for the B. lactis HN019 group (P=0.041) with a parallel trend in the L. rhamnosus HN001 group (P=0.075). Similar patterns were seen for breast milk IgA, which was more readily detected in breast milk from both the B. lactis HN019 (P=0.008) and the L. rhamnosus HN001 group (P=0.011). Neonatal plasma sCD14 levels were lower in the B. lactis HN019 group compared with the placebo group (P=0.041).

CONCLUSION

The findings suggest that supplementation with probiotics in pregnancy has the potential to influence fetal immune parameters as well as immunomodulatory factors in breast milk.

Changes in elastic fibres in the small airways and alveoli in COPD

Small airways are the major site of airflow obstruction in chronic obstructive pulmonary disease (COPD). This is attributed to loss of elastin in alveoli and fibrosis in small airways. In the present study, it was hypothesised that changes to elastic fibres in alveoli might be paralleled by a similar reduction in elastic fibres in small airways. Tissue blocks from patients who had lobectomy for bronchial carcinoma were studied. Patients were classified as COPD (forced expiratory volume in one second (FEV(1)) < 80% predicted, FEV(1)/forced vital capacity (FVC) < 0.7) or controls (FEV(1) > or = 80% pred, FEV(1)/FVC > or = 0.7). Elastic fibres were visualised using Elastic van Gieson staining and the volume fraction (v/f) of elastic fibres was determined as a percentage of tissue volume using point counting. Elastic fibre networks were also visualised by confocal microscopy. The v/f for elastic fibres in alveoli was 18.6% for COPD and 32.8% in controls. In the airways the v/f was 14.6% for COPD and 25.5% in controls. FEV(1)% predicted was correlated with v/f in both alveoli and small airways. The volume fraction of elastic fibres was reduced to a similar extent in small airways and alveoli in chronic obstructive pulmonary disease and both were correlated with the extent of airflow obstruction. Loss of elastic fibres in small airways may contribute to the development of airflow obstruction in chronic obstructive pulmonary disease.

Risk factors for asthma at 3.5 and 7 years of age

BACKGROUND

It has been suggested that factors in early life including exposure to allergens and microbes may influence the development of asthma.

OBJECTIVE

To identify risk factors for asthma in early childhood. Methods Eight-hundred and seventy-one children of European mothers were enrolled at birth, of whom 385 (44.2%) were born small for gestational age (SGA) and 486 were appropriate for gestational age (AGA). Data were collected at birth, 12 months, 3.5 years of age (y) and 7 y. The outcome of interest (current wheeze) was defined as a positive response to the question: 'Has your child had wheezing or whistling in the chest in the last 12 months?'

RESULTS

Participation rate was 85.4% at 1 y, 63.1% at 3.5 y and 68.0% at 7 y. The prevalence of asthma was 23.8% at 3.5 y and 18.1% at 7 y. Antibiotic use in the first year of life and day care in the first year of life were associated with increased risk of wheeze at 7 y [odds ratio (OR)=4.3 95% confidence interval (CI) (1.8-10.1) and OR=2.8 95% CI (1.2-6.5), respectively], but not at 3.5 y. Exposure to dogs was a risk factor for asthma at both ages [OR=2.1 95% CI (1.1-3.8)] as was sleeping on a used cot mattress in the first year of life [OR=1.8 95% CI (1.0-3.2)].

CONCLUSIONS

There was a significant association between antibiotic use and day care in the first year of life and wheezing at 7 y but not at 3.5 y. This strengthens the argument that these factors increase the risk of asthma. We have also made the novel observation that sleeping on a used mattress in the first year of life is a risk factor for wheezing at 3.5 and 7 y. Capsule summary This prospective study of 871 children made the novel observation that sleeping on a used mattress in the first year of life was a risk factor for wheezing at 3.5 and 7 y.

Inhaled corticosteroids for stable chronic obstructive pulmonary disease

BACKGROUND

The role of inhaled corticosteroids (ICS) in chronic obstructive pulmonary disease (COPD) has been the subject of much controversy. Major international guidelines recommend selective use of ICS. Recently published meta-analyses have reported conflicting findings on the effects of inhaled steroid therapy in COPD.

OBJECTIVES

The objective of the review is to determine the efficacy of regular use of inhaled corticosteroids in patients with stable COPD.

SEARCH STRATEGY

A pre-defined search strategy was used to search the Cochrane Airways Group specialised register for relevant literature. Searches are current as of October 2006.

SELECTION CRITERIA

We selected randomised trials comparing any dose of any type of inhaled steroid with a placebo control in patients with COPD. Acute bronchodilator reversibility to short term beta2-agonists and bronchial hyperresponsiveness were not exclusion criteria. The a priori primary outcome was change in lung function. Data on mortality, exacerbations, quality of life and symptoms, rescue bronchodilator use, exercise capacity, biomarkers and safety were also analysed.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

Forty-seven primary studies with 13,139 participants met the inclusion criteria. Medium term use of ICS (> two months and up to six months) resulted in a small improvement in FEV1 in some studies. Long term use of ICS (> six months) did not significantly reduce the rate of decline in FEV1 in COPD patients (weighted mean difference (WMD) 5.80 ml/year with ICS over placebo, 95% CI -0.28 to 11.88, 2333 participants). There was no statistically significant effect on mortality in COPD patients (OR 0.98, 95% CI 0.83 to 1.16, 8390 participants). Long term use of ICS reduced the mean rate of exacerbations in those studies where pooling of data was possible (WMD -0.26 exacerbations per patient per year, 95% CI -0.37 to -0.14, 2586 participants). ICS slowed the rate of decline in quality of life, as measured by the St George's Respiratory Questionnaire (WMD -1.22 units/year, 95% CI -1.83 to -0.60, 2507 participants). Response to ICS was not predicted by oral steroid response, bronchodilator reversibility or bronchial hyper-responsiveness in COPD patients. There was an increased risk of oropharyngeal candidiasis (OR 2.49, 95% CI 1.78 to 3.49, 4380 participants) and hoarseness. The few long term studies that measured bone effects generally showed no major effect on fractures and bone mineral density over 3 years.

AUTHORS' CONCLUSIONS

Patients and clinicians should balance the potential benefits of inhaled steroids in COPD (reduced rate of exacerbations, reduced rate of decline in quality of life), against the known increase in local side effects (oropharyngeal candidiasis and hoarseness). The risk of long term adverse effects is unknown.

Mucolytic agents for chronic bronchitis or chronic obstructive pulmonary disease

BACKGROUND

Individuals with chronic bronchitis or chronic obstructive pulmonary disease (COPD) may suffer recurrent exacerbations with an increase in volume and/or purulence of sputum. Because of the personal and healthcare costs associated with exacerbations, any therapy that reduces the number of exacerbations is useful. There is a marked difference between countries in terms of prescribing of mucolytics depending on whether or not they are perceived to be effective.

OBJECTIVES

To assess the effects of oral mucolytics in adults with stable chronic bronchitis or COPD.

SEARCH STRATEGY

We have searched the Cochrane Airways Group Specialised Register and reference lists of articles on four separate occasions, the most recent being in June 2005. This is the third major update.

SELECTION CRITERIA

Randomised trials that compared oral mucolytic therapy with placebo for at least two months in adults with chronic bronchitis or COPD. Studies of people with asthma and cystic fibrosis were excluded.

DATA COLLECTION AND ANALYSIS

One reviewer extracted data. Study authors and drug companies were contacted for missing information.

MAIN RESULTS

Twenty six trials were included (7335 participants). Compared with placebo, there was a significant reduction in the number of exacerbations per patient with oral mucolytics (weighted mean difference (WMD) -0.05 per month, 95% confidence interval -0.05, -0.04). Using the annualised rate of exacerbations in the control patients of 2.6 per year, this is a 20% reduction. The number of days of disability also fell (WMD -0.56, 95% confidence interval -0.77, -0.35). A recent study has shown that the benefit may apply only to those patients not already receiving inhaled corticosteroids. The number of patients who remained exacerbation-free was greater in the mucolytic group (OR 2.13 (95% CI 1.86 to 2.42)). There was no difference in lung function or in adverse effects reported between the treatments.

AUTHORS' CONCLUSIONS

In subjects with chronic bronchitis or COPD, treatment with mucolytics was associated with a small reduction in acute exacerbations and a reduction in total number of days of disability. Benefit may be greater in individuals who have frequent or prolonged exacerbations, or those who are repeatedly admitted to hospital with exacerbations with COPD. They should be considered for use, through the winter months at least, in patients with moderate or severe COPD in whom inhaled corticosteroids (ICS) are not prescribed.

Once-daily dosing with budesonide/formoterol compared with twice-daily budesonide/formoterol and once-daily budesonide in adults with mild to moderate asthma

Adherence to maintenance therapy is often poor in patients with asthma. Simplifying dosing regimens has the potential to improve both adherence and asthma-related morbidity. In this 12-week, randomized, double-blind, double-dummy, parallel-group study, 617 patients with mild to moderate persistent asthma (mean forced expiratory volume in 1s [FEV1] 78.5% predicted) who were not optimally controlled on inhaled corticosteroids (200-500 microg/day) were randomized to once-daily budesonide/formoterol (80/4.5 microg, 2 inhalations in the evening), twice-daily budesonide/formoterol (80/4.5 microg, 1 inhalation), or a corresponding dose of budesonide once-daily (200 microg, 1 inhalation in the evening). All patients received budesonide (100 microg twice daily) during a 2-week run-in. Changes in mean morning peak expiratory flow (PEF) were similar for od budesonide/formoterol (23.4 l/min) and twice-daily budesonide/formoterol (24.1 l/min), and both were greater than with budesonide (5.5 l/min; both P<0.001). Evening PEF, symptom-free days, reliever-free days, and asthma control days were improved with budesonide/formoterol therapy vs. budesonide (P<0.05 vs. budesonide for all variables). All treatments were well tolerated. Budesonide/formoterol administered once daily in the evening is a convenient treatment regimen that is as effective in improving asthma control as twice-daily dosing in patients with mild to moderate persistent asthma.

Accuracy of information on medicines in hospital discharge summaries

BACKGROUND

At Auckland Hospital, patients have been given handwritten summaries on discharge from hospital with a copy posted to the general practitioner. A typed summary is often not completed so the list of medicines on the handwritten summary needs to be accurate and complete.

METHODS

We selected 100 patient charts from the general medical service and 100 charts from the general surgical service and recorded the medicines on admission, on the inpatient medication chart and on the discharge summary. We noted errors in the recording of medicines on the discharge summary and rated the severity of errors.

RESULTS

Surgical patients were discharged on 7.88 (95% confidence interval (CI) 7.40-8.64) medicines and medical patients on 8.58 (95% CI 7.87-9.29) medicines. During the admission there were 0.59 (95% CI 0.38-0.80) changes to the medicines for the surgical patients and 1.70 (95% CI 1.39-2.01) for the medical patients (P < 0.0001). There were 0.81 (95% CI 0.65-1.02) errors per surgical discharge summary and 1.42 (95% CI 1.20-1.67) errors per medical summary (P = 0.006). Four errors were graded as having the potential to cause readmission to hospital, 24 as potentially serious, 83 as potentially troublesome and 111 as minor.

DISCUSSION

Error rates were high and although the majority were minor, a number of them had the potential to cause serious consequences. There were more medication changes in the medical patients and this may contribute to higher error rates in this group. There is a need to improve the accuracy of recording medicines on discharge summaries. Strategies to improve this problem are discussed.

Functional variants of antioxidant genes in smokers with COPD and in those with normal lung function

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is predominantly the consequence of chronic smoking exposure, but its development may be influenced by genetic variants that affect lung remodelling, inflammation, and defence from oxidant stress. A study was undertaken to determine whether genetic variants within genes encoding the antioxidant enzymes superoxide dismutase (SOD) and catalase may be associated with the development of impaired lung function.

METHODS

In a case-control study, the allele and genotype frequencies of functional polymorphisms from SOD1 (CuZnSOD), SOD2 (MnSOD), SOD3 (extracellular SOD), and catalase (CAT) were compared in chronic smokers with normal lung function (resistant smokers) and in those with COPD.

RESULTS

Significantly higher frequencies of the G allele and CG/GG genotype of the 213 SOD3 polymorphism were found in resistant smokers (odds ratios (ORs) 4.3 (95% CI 1.5 to 13.3) and 4.2, 95% CI 1.4 to 13.3), Bonferroni corrected p = 0.02 and p = 0.02, respectively) than in those with COPD. There were no differences between the COPD and resistant smokers for the SOD1, SOD2, or CAT polymorphisms tested.

CONCLUSIONS

The 213Gly variant of the SOD3 gene may, through antioxidant or anti-inflammatory effects, confer a degree of resistance in some smokers to the development of COPD.

Physical training for asthma

BACKGROUND

Physical training programmes have been designed for asthmatic subjects with the aim of improving physical fitness, neuromuscular coordination and self-confidence. Habitual physical activity increases physical fitness and lowers ventilation during mild and moderate exercise thereby reducing the likelihood of provoking exercise induced asthma. Exercise training may also reduce the perception of breathlessness through a number of mechanisms including strengthening respiratory muscles. Subjectively, many asthmatics report that they are symptomatically better when fit, but results from trials have varied and have been difficult to compare because of different designs and training protocols.

OBJECTIVES

The purpose of this review was to assess evidence for the efficacy and effectiveness of physical training in asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group Specialised Register, SportDiscus and the Science Citation Index up to May 2005.

SELECTION CRITERIA

Randomised trials in asthmatic subjects undertaking physical training. Subjects had to be eight years and older. Physical training had to be undertaken for at least 20 to 30 minutes, two to three times a week, over a minimum of four weeks.

DATA COLLECTION AND ANALYSIS

Eligibility for inclusion and quality of trials were assessed independently by two reviewers.

MAIN RESULTS

Thirteen studies (455 participants) were included in this review. Physical training had no effect on resting lung function or the number of days of wheeze. The results of this review have shown that lung function and wheeze is not worsened by physical training in patients with asthma. Physical training improved cardiopulmonary fitness as measured by an increase in maximum oxygen uptake of 5.4 ml/kg/min (95% confidence interval 4.2 to 6.6) and maximum expiratory ventilation 6.0 L/min (95% confidence interval 1.5 to 10.4). There were no data concerning quality of life measurements.

AUTHORS' CONCLUSIONS

In people with asthma, physical training can improve cardiopulmonary fitness without changing lung function. It is not known whether improved fitness is translated into improved quality of life. It is comforting to know that physical training does not have an adverse effect on lung function and wheeze in patients with asthma. Therefore, there is no reason why patients with asthma should not participate in regular physical activity.

Risk factors for atopic dermatitis in New Zealand children at 3.5 years of age

BACKGROUND

The prevalence of atopic dermatitis (AD) is increasing in Western societies. The hygiene hypothesis proposes that this is due to reduced exposure to environmental allergens and infections during early life.

OBJECTIVES

To examine factors associated with a diagnosis of AD at 3.5 years of age, especially those factors implicated by the hygiene hypothesis.

METHODS

The Auckland Birthweight Collaborative study is a case-control study of risk factors for small for gestational age babies. Cases were born at term with birthweight < or = 10th centile; controls were appropriate for gestational age, with birthweight > 10th centile. The infants were assessed at birth, 1 year and 3.5 years of age. Data were collected by parental interview and examination of the child. AD was defined as the presence of an itchy rash in the past 12 months with three or more of the following: history of flexural involvement; history of generally dry skin; history of atopic disease in parents or siblings; and visible flexural dermatitis as per photographic protocol. Statistical analyses took into account the disproportionate sampling of the study population.

RESULTS

Analysis was restricted to European subjects. Eight hundred and seventy-one children were enrolled at birth, 744 (85.4%) participated at 1 year, and 550 (63.2%) at 3.5 years. AD was diagnosed in 87 (15.8%) children seen at 3.5 years. The prevalence of AD did not differ by birthweight. AD at 3.5 years was associated with raised serum IgE > 200 kU L(-1), and wheezing, asthma, rash or eczema at 1 year. In multivariate analysis, adjusted for parental atopy and breastfeeding, AD at 3.5 years was associated with atopic disease in the parents: maternal atopy only, adjusted odds ratio (OR) 3.83, 95% confidence interval (CI) 1.20-12.23; paternal atopy only, adjusted OR 3.59, 95% CI 1.09-11.75; both parents atopic, adjusted OR 6.12, 95% CI 2.02-18.50. There was a higher risk of AD with longer duration of breastfeeding: < 6 months, adjusted OR 6.13, 95% CI 1.45-25.86; > or = 6 months, adjusted OR 9.70, 95% CI 2.47-38.15 compared with never breastfed. These findings remained significant after adjusting for environmental factors and a personal history of atopy. AD at 3.5 years was associated with owning a cat at 3.5 years (adjusted OR 0.45, 95% CI 0.21-0.97) but not with owning a dog at 3.5 years, pets at 1 year, nor with older siblings. Furthermore, AD at 3.5 years was not associated with gender, socioeconomic status, maternal smoking, parity, damp, mould, immunizations, body mass index or antibiotic use in first year of life.

CONCLUSIONS

A personal and a parental history of atopic disease are risk factors for AD at 3.5 years. Duration of breastfeeding was associated with an increased risk of AD. No association was found with those factors implicated by the hygiene hypothesis. This study suggests that breastfeeding should not be recommended for the prevention of AD.

Comparison of the effects of nebulised and inhaled salbutamol on breathlessness in severe COPD

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) often report greater relief of breathlessness with nebulised bronchodilators than with the same medicine administered from a metered dose inhaler (MDI). This suggests that the nebulised medicines may have an effect on breathlessness over and above changes in lung function resulting from bronchodilatation.

METHODS

Twenty-four subjects with COPD and breathlessness at rest participated in this randomised, crossover trial. The mean age was 72 years and the mean FEV(1) was 26% of predicted. Subjects were studied on four separate days. On two days they were treated with nebulised salbutamol and on the other 2 days with salbutamol from an MDI and spacer. With each method of delivery, local anaesthetic cream was applied to the face on one day and to the back of the hand on the other.

RESULTS

Five minutes after administration of salbutamol the subjects were significantly less breathless with nebulised salbutamol but by 45 min both treatments resulted in equivalent relief. There was no difference between the treatments in the change in FEV(1) or VC and application of local anaesthetic to the face did not influence the response.

CONCLUSION

There was a small early benefit with nebulised salbutamol but this was not sustained and was not affected by topical anaesthesia. The benefit of nebulisation does not appear to be large enough to warrant the routine, widespread use of nebulised bronchodilators for the treatment of stable COPD.

Does atopy protect against enteric infections?

Allergic sensitization to inhaled allergens and foods is common and is linked to the development of asthma, allergic rhinitis and eczema. In view of the morbidity associated with these diseases it is not clear why the genetic predisposition to atopy is so common. Children who are atopic are less likely to develop oral tolerance to ingested foods and as a result are more likely to have manifestations of food allergy including wheezing, skin rashes and gastrointestinal symptoms. Oral tolerance also develops to micro-organisms in the gastrointestinal tract. Children who are atopic may be protected against enteric infections in early childhood because they are less likely to be tolerant of these organisms. This may explain why individuals who are atopic are less likely to have evidence of previous infection with hepatitis A and other enteric organisms although they are just as likely to have been infected with respiratory pathogens.

Use of a preprinted sticker to improve the prescribing of prophylactic antibiotics for hip fracture surgery

PROBLEM

Antibiotic prophylaxis has been shown to reduce the number of postoperative infections following surgery for hip fracture. At Auckland Hospital the policy for antibiotic prophylaxis for hip fracture surgery is for the patient to receive the first dose of antibiotic at the induction of anaesthesia followed by two more doses at 8 hour intervals. A previous audit found that patients often received too many doses of antibiotic. A retrospective audit was performed of 100 patients undergoing surgery for a hip fracture. The primary problem was over-prescribing; 68 patients (68%) received more than three doses. The number of patients who received three doses according to the guidelines was 29 (29%, 95% CI 21 to 40).

SETTING

Auckland Hospital which provides acute orthopaedic services for a population of 500,000.

STRATEGY FOR CHANGE

A sticker was introduced with the prescription printed on it. The sticker was applied to the medication chart by the anaesthetist when the initial dose of antibiotic was given. Charts of a further 100 patients were reviewed after the introduction of the sticker and compared with those from another hospital in Auckland where the sticker was not used.

EFFECTS OF CHANGE

The number of patients who received three doses, in accordance with the guidelines, improved to 74 (74%, 95% CI 64 to 82, p<0.001). These changes were observed even though the sticker was only used in 44 patients (44%, 95% CI 34 to 54). At the other hospital the number of patients who received three doses was 10 (20%, 95% CI 10 to 42) and 13 (26%, 95% CI 15 to 40, p = 0.37) for the same two periods.

LESSONS LEARNT

The use of a preprinted sticker is a simple intervention which improves the use of antibiotic prophylaxis at the time of surgery. This improvement occurred even though the sticker was used in slightly fewer than half the cases.

Use of a preprinted sticker to improve the prescribing of prophylactic antibiotics for hip fracture surgery

PROBLEM

Antibiotic prophylaxis has been shown to reduce the number of postoperative infections following surgery for hip fracture. At Auckland Hospital the policy for antibiotic prophylaxis for hip fracture surgery is for the patient to receive the first dose of antibiotic at the induction of anaesthesia followed by two more doses at 8 hour intervals. A previous audit found that patients often received too many doses of antibiotic. A retrospective audit was performed of 100 patients undergoing surgery for a hip fracture. The primary problem was over-prescribing; 68 patients (68%) received more than three doses. The number of patients who received three doses according to the guidelines was 29 (29%, 95% CI 21 to 40).

SETTING

Auckland Hospital which provides acute orthopaedic services for a population of 500,000.

STRATEGY FOR CHANGE

A sticker was introduced with the prescription printed on it. The sticker was applied to the medication chart by the anaesthetist when the initial dose of antibiotic was given. Charts of a further 100 patients were reviewed after the introduction of the sticker and compared with those from another hospital in Auckland where the sticker was not used.

EFFECTS OF CHANGE

The number of patients who received three doses, in accordance with the guidelines, improved to 74 (74%, 95% CI 64 to 82, p<0.001). These changes were observed even though the sticker was only used in 44 patients (44%, 95% CI 34 to 54). At the other hospital the number of patients who received three doses was 10 (20%, 95% CI 10 to 42) and 13 (26%, 95% CI 15 to 40, p = 0.37) for the same two periods.

LESSONS LEARNT

The use of a preprinted sticker is a simple intervention which improves the use of antibiotic prophylaxis at the time of surgery. This improvement occurred even though the sticker was used in slightly fewer than half the cases.

Transforming growth factor-beta1 genotype and susceptibility to chronic obstructive pulmonary disease

BACKGROUND

Only a few long term smokers develop symptomatic chronic obstructive pulmonary disease (COPD) and this may be due, at least in part, to genetic susceptibility to the disease. Transforming growth factor beta1 (TGF-beta1) has a number of actions that make it a candidate for a role in the pathogenesis of COPD. We have investigated a single nucleotide polymorphism at exon 1 nucleotide position 29 (T-->C) of the TGF-beta1 gene that produces a substitution at codon 10 (Leu-->Pro).

METHODS

The frequency of this polymorphism was determined in 165 subjects with COPD, 140 healthy blood donors, and 76 smokers with normal lung function (resistant smokers) using the polymerase chain reaction and restriction enzyme fragment length polymorphism.

RESULTS

The distribution of genotypes was Leu-Leu (41.8%), Leu-Pro (50.3%), and Pro-Pro (7.9%) for subjects with COPD, which was significantly different from the control subjects (blood donors: Leu-Leu (29.3%), Leu-Pro (52.1%) and Pro-Pro (18.6%), p=0.006; resistant smokers: Leu-Leu (28.9%), Leu-Pro (51.3%) and Pro-Pro (19.7%), p=0.02). The Pro10 allele was less common in subjects with COPD (33%) than in blood donors (45%; OR=0.62, 95% CI 0.45 to 0.86, p=0.005) and resistant smokers (45%; OR=0.59, 95% CI 0.40 to 0.88, p=0.01).

CONCLUSIONS

The proline allele at codon 10 of the TGF-beta1 gene occurs more commonly in control subjects than in individuals with COPD. This allele is associated with increased production of TGF-beta1 which raises the possibility that TGF-beta1 has a protective role in COPD.

Mucolytic agents for chronic bronchitis or chronic obstructive pulmonary disease

BACKGROUND

Individuals with chronic bronchitis or chronic obstructive pulmonary disease (COPD) may suffer recurrent exacerbations with an increase in volume and/or purulence of sputum and any therapy that reduced the number of exacerbations would be useful. There is a marked difference between countries in terms of prescribing of mucolytics depending on whether or not they are perceived to be effective.

OBJECTIVES

To assess the effects of oral mucolytics in adults with stable chronic bronchitis or COPD.

SEARCH STRATEGY

We have searched the Cochrane Airways Group trials register and reference lists of articles, on three separate occasions.

SELECTION CRITERIA

Randomised trials that compared oral mucolytic therapy with placebo for at least two months in adults with chronic bronchitis or COPD. Studies of people with asthma and cystic fibrosis were excluded.

DATA COLLECTION AND ANALYSIS

One reviewer extracted data. Study authors and drug companies were contacted for missing information.

MAIN RESULTS

Twenty three trials were included. Compared with placebo, there was a significant reduction in the number of exacerbations per patient with oral mucolytics (weighted mean difference (WMD) -0.066 per month, 95% confidence interval -0.077, -0.054, p<0.001). Using the annualised rate of exacerbations in the control patients of 2.7 per year, this is a 29% reduction. The number of days of disability also fell (WMD -0.56, 95% confidence interval -0.77, -0.35, p<0.001). The number of patients who remained exacerbation-free was greater in the mucolytic group (OR 2.22, 95% confidence interval 1.93, 2.54, p<0.001). There was no difference in lung function or in adverse effects reported between treatments.

REVIEWER'S CONCLUSIONS

In subjects with chronic bronchitis or COPD, treatment with mucolytics was associated with a small reduction in acute exacerbations and a somewhat greater reduction in total number of days of disability.

Prophylactic antibiotic therapy for chronic bronchitis

BACKGROUND

The use of prophylactic antibiotics to reduce the frequency and severity of acute exacerbations of chronic bronchitis is controversial.

OBJECTIVES

To determine if prophylactic antibiotics reduce the frequency of exacerbations and/or days of disability in subjects with chronic bronchitis.

SEARCH STRATEGY

We searched the Cochrane Airways Group Register of Clinical Trials and the bibliographies of relevant articles.

SELECTION CRITERIA

Randomised controlled trials of prophylactic antibiotics in patients with chronic bronchitis and/or COPD were selected.

DATA COLLECTION AND ANALYSIS

The eligibility of studies for inclusion was evaluated by three independent reviewers.

MAIN RESULTS

Nine trials involving 1055 subjects were included in the analysis. All were performed before 1970. Concealment of allocation was assessed as clearly adequate in only 3 studies. The likelihood of having a exacerbation at any time during the course of the study was decreased with treatment (Relative Risk 0.91, 95% Confidence Intervals (CI) 0.84, 0.99). There was a small reduction in the number of exacerbations per patient per year with prophylactic antibiotics but this was not statistically significant ( Weighted Mean Difference (WMD) -0.15, 95%CI -0.34, 0.04 ). There was a modest but significant reduction of 22% in the number of days of disability per patient per month treated ( WMD -0.95, 95%CI -1.89 to - 0.01 ). A parallel reduction in the days of disability for each exacerbation (WMD -2.08, 95% CI -4.08 to -0.07) was seen. There was a small increase in adverse effects with antibiotics.

REVIEWER'S CONCLUSIONS

Prophylactic antibiotics in chronic bronchitis / COPD have a small but statistically significant effect in reducing the days of illness due to exacerbations of chronic bronchitis. They do not have a place in routine treatment because of concerns about the development of antibiotic resistance and the possibility of adverse effects. The available data are over 30 years old, so the pattern of antibiotic sensitivity may have changed and there is a wider range of antibiotics in use.

The Acyl-CoA synthetases encoded within FAA1 and FAA4 in Saccharomyces cerevisiae function as components of the fatty acid transport system linking import, activation, and intracellular Utilization

Exogenous long-chain fatty acids are activated to coenzyme A derivatives prior to metabolic utilization. In the yeast Saccharomyces cerevisiae, the activation of these compounds prior to metabolic utilization proceeds through the fatty acyl-CoA synthetases Faa1p and Faa4p. Faa1p or Faa4p are essential for long-chain fatty acid import, suggesting that one or both of these enzymes are components of the fatty acid transport system, which also includes Fat1p. By monitoring the intracellular accumulation of the fluorescent long-chain fatty acid analogue 4,4-difluoro-5-methyl-4-bora-3a,4a-diaza-s-indacene-3-dodecanoic acid, long-chain fatty acid transport was shown to be severely restricted in a faa1 Delta faa4 Delta strain. These data established for the first time a mechanistic linkage between the import and activation of exogenous fatty acids in yeast. To investigate this linkage further, oleoyl CoA levels were defined following incubation of wild type and mutant cells with limiting concentrations of exogenous oleate. These studies demonstrated oleoyl CoA levels were reduced to less than 10% wild-type levels in faa1 Delta and faa1 Delta faa4 Delta strains. Defects in metabolic utilization and intracellular trafficking were also found in the fatty acyl-CoA synthetase-deficient strains. The faa1 Delta faa4 Delta strain had a marked reduction in endogenous acyl-CoA pools, suggesting these enzymes play a role in maintenance of endogenous acyl-CoA pools, metabolism and trafficking. In addition, this strain had levels of in vivo beta-oxidation of exogenous oleate reduced 3-fold when compared with the isogenic parent. Northern analyses demonstrated an additional defect in fatty acid trafficking as FAA1 or FAA4 were required for the transcriptional regulation of the genes encoding the peroxisomal enzymes acyl-CoA oxidase (POX1) and medium-chain acyl-CoA synthetase (FAA2). These data support the hypothesis that fatty acyl-CoA synthetase (Faa1p or Faa4p) functions as a component of the fatty acid import system by linking import and activation of exogenous fatty acids to intracellular utilization and signaling.

Trial of roxithromycin in subjects with asthma and serological evidence of infection with Chlamydia pneumoniae

An association has been reported between chronic infection with Chlamydia pneumoniae and the severity of asthma, and uncontrolled observations have suggested that treatment with antibiotics active against C. pneumoniae leads to an improvement in asthma control. We studied the effect of roxithromycin in subjects with asthma and immunoglobulin G (IgG) antibodies to C. pneumoniae > or = 1:64 and/or IgA antibodies > or = 1:16. A total of 232 subjects, from Australia, New Zealand, Italy, or Argentina, were randomized to 6 wk of treatment with roxithromycin 150 mg twice a day or placebo. At the end of 6 wk, the increase from baseline in evening peak expiratory flow (PEF) was 15 L/min with roxithromycin and 3 L/min with placebo (p = 0.02). With morning PEF, the increase was 14 L/min with roxithromycin and 8 L/min with placebo (NS). In the Australasian population, the increase in morning PEF was 18 L/min and 4 L/min, respectively (p = 0.04). At 3 mo and 6 mo after the end of treatment, differences between the two groups were smaller and not significant. Six weeks of treatment with roxithromycin led to improvements in asthma control but the benefit was not sustained. Further studies are necessary to determine whether the lack of sustained benefit is due to failure to eradicate C. pneumoniae.

Oral mucolytic drugs for exacerbations of chronic obstructive pulmonary disease: systematic review

OBJECTIVE

To assess the effects of oral mucolytics in adults with stable chronic bronchitis and chronic obstructive pulmonary disease.

DESIGN

Systematic review of randomised controlled trials that compared at least two months of regular oral mucolytic drugs with placebo.

STUDIES

Twenty three randomised controlled trials in outpatients in Europe and United States.

MAIN OUTCOME MEASURES

Exacerbations, days of illness, lung function, adverse events.

RESULTS

Compared with placebo, the number of exacerbations was significantly reduced in subjects taking oral mucolytics (weighted mean difference -0.07 per month, 95% confidence interval -0.08 to -0.05, P<0.0001). Based on the annualised rate of exacerbations in the control subjects of 2.7 a year, this is a 29% reduction. The number needed to treat for one subject to have no exacerbation in the study period would be 6. Days of illness also fell (weighted mean difference -0.56, -0.77 to -0.35, P<0.0001). The number of subjects who had no exacerbations in the study period was greater in the mucolytic group (odds ratio 2.22, 95% confidence interval 1.93 to 2.54, P<0.0001). There was no difference in lung function or in adverse events reported between treatments.

CONCLUSIONS

In chronic bronchitis and chronic obstructive pulmonary disease, treatment with mucolytics is associated with a reduction in acute exacerbations and days of illness. As these drugs have to be taken long term, they could be most useful in patients who have repeated, prolonged, or severe exacerbations of chronic obstructive pulmonary disease.

Case management may reduce length of hospital stay in patients with recurrent admissions for chronic obstructive pulmonary disease

OBJECTIVES

The aim of the study was to determine whether the case management of patients with recurrent hospital admissions for chronic obstructive pulmonary disease (COPD) can reduce hospital days without reducing quality of life.

METHODOLOGY

Sixteen subjects (mean forced expiratory volume in 1 second; FEV1 0.64 L) with at least four admissions for COPD in the previous 2 years were case managed by a clinical nurse specialist. Admissions and hospital bed days were recorded before and after the introduction of case management, and compared with data for 16 controls at another hospital who received usual care. Quality of life was measured serially in the case-managed group.

RESULTS

In the first year of case management, the number of hospital bed days fell to eight per patient from 22 per patient in the previous year. This was mainly due to a reduction in the length of stay from 5.6 to 3.5 days. In the control group length of stay did not change. Admissions in both groups declined. Case-managed patients had a significant improvement in their quality-of-life scores.

CONCLUSIONS

In a group of patients with severe COPD and recurrent admissions, case management reduced the number of days in hospital while improving the quality of life. These findings need to be confirmed in a randomized, controlled trial.

Affinity labeling fatty acyl-CoA synthetase with 9-p-azidophenoxy nonanoic acid and the identification of the fatty acid-binding site

Fatty acyl-CoA synthetase (FACS, fatty acid:CoA ligase, AMP-forming, EC ) catalyzes the esterification of fatty acids to CoA thioesters for further metabolism and is hypothesized to play a pivotal role in the coupled transport and activation of exogenous long-chain fatty acids in Escherichia coli. Previous work on the bacterial enzyme identified a highly conserved region (FACS signature motif) common to long- and medium-chain acyl-CoA synthetases, which appears to contribute to the fatty acid binding pocket. In an effort to further define the fatty acid-binding domain within this enzyme, we employed the affinity labeled long-chain fatty acid [(3)H]9-p-azidophenoxy nonanoic acid (APNA) to specifically modify the E. coli FACS. [(3)H]APNA labeling of the purified enzyme was saturable and specific for long-chain fatty acids as shown by the inhibition of modification with increasing concentrations of palmitate. The site of APNA modification was identified by digestion of [(3)H]APNA cross-linked FACS with trypsin and separation and purification of the resultant peptides using reverse phase high performance liquid chromatography. One specific (3)H-labeled peptide, T33, was identified and following purification subjected to NH(2)-terminal sequence analysis. This approach yielded the peptide sequence PDATDEIIK, which corresponded to residues 422 to 430 of FACS. This peptide is immediately adjacent to the region of the enzyme that contains the FACS signature motif (residues 431-455). This work represents the first direct identification of the carboxyl-containing substrate-binding domain within the adenylate-forming family of enzymes. The structural model for the E. coli FACS predicts this motif lies within a cleft separating two distinct domains of the enzyme and is adjacent to a region that contains the AMP/ATP signature motif, which together are likely to represent the catalytic core of the enzyme.

Immunohistochemical staining for Chlamydia pneumoniae is increased in lung tissue from subjects with chronic obstructive pulmonary disease

The seroprevalence of Chlamydia pneumoniae is increased in chronic obstructive pulmonary disease (COPD), and subjects with COPD are more likely to have a positive polymerase chain reaction for C. pneumoniae in their sputum. It has been suggested that C. pneumoniae may have a role in the pathogenesis of COPD. We undertook immunohistochemistical staining for C. pneumoniae in archival tissue from subjects who had undergone lobectomy for bronchial carcinoma. There were 16 subjects with COPD (FEV(1) = 64 +/- 8% [mean +/- SD] predicted) and 21 subjects with normal lung function (FEV(1) = 95 +/- 11% predicted). There was no difference between the two groups in age or smoking history. Tissues from all of the subjects stained positively for C. pneumoniae, but in the subjects with COPD there were 14.5 positive cells per field (magnification x400), as compared with 9.3 cells per field in the control subjects (p = 0.02). Fifty-four percent of the macrophages from the subjects with COPD stained positively for C. pneumoniae, as compared with 29% from the control subjects (p < 0.001). A second control group consisted of 18 younger individuals (mean age: 32 yr) who died accidentally. Only 44% of these subjects had positive staining for C. pneumoniae, and the mean number of cells per field was 0.4. These findings suggest that persistent infection with C. pneumoniae is common, and that there is increased immunostaining for C. pneumoniae in COPD. Further studies are necessary to determine whether chronic infection with C. pneumoniae is important in the pathogenesis of COPD.

Differences in the potencies of inhaled steroids are not reflected in the doses prescribed in primary care in New Zealand

OBJECTIVE

To determine whether the average doses of inhaled beclomethasone, fluticasone and budesonide prescribed in primary care reflect the relative potencies of these medicines.

METHODS

Retrospective analysis of 95,540 prescriptions for inhaled steroids written by 293 general practitioners in Auckland, New Zealand, between November 1995 and June 1998. In addition, 177 general practitioners were presented with two case histories describing patients with uncontrolled asthma who were not on treatment with inhaled steroids. They were asked which medicine they would prescribe and in what dose.

RESULTS

The average daily doses prescribed were 600 microg for fluticasone, 747 microg for beclomethasone and 1184 microg for budesonide. The average dose of fluticasone was 80% of that for beclomethasone. In May 1997, when 4.5% of the prescriptions for inhaled steroids were for fluticasone, the average doses of fluticasone and beclomethasone were 632 microg and 760 microg, respectively. By May 1998, when 23% of prescriptions were for fluticasone, the average doses of fluticasone and beclomethasone were little changed at 610 microg and 726 microg, respectively. In response to the two case histories, the average doses of fluticasone chosen were 71% and 77% of the doses of beclomethasone.

CONCLUSIONS

The average prescribed dose of fluticasone was 80% of that for beclomethasone, even though fluticasone is at least twice as potent as beclomethasone. Similar findings were observed when the general practitioners responded to the case histories. The high doses of fluticasone prescribed may be due to a failure to appreciate that fluticasone is twice as potent as beclomethasone and to the availability of high strength preparations of fluticasone, i.e. 250 microg per actuation.

Murine FATP alleviates growth and biochemical deficiencies of yeast fat1Delta strains

Saccharomyces cerevisiae is an ideal model eukaryote for studying fatty-acid transport. Yeast are auxotrophic for unsaturated fatty acids when grown under hypoxic conditions or when the fatty-acid synthase inhibitor cerulenin is included in the growth media. The FAT1 gene encodes a protein, Fat1p, which is required for maximal levels of fatty-acid import and has an acyl CoA synthetase activity specific for very-long-chain fatty acids suggesting this protein plays a pivotal role in fatty-acid trafficking. In the present work, we present evidence that Fat1p and the murine fatty-acid transport protein (FATP) are functional homologues. FAT1 is essential for growth under hypoxic conditions and when cerulenin was included in the culture media in the presence or absence of unsaturated fatty acids. FAT1 disruptants (fat1Delta) fail to accumulate the fluorescent long-chain fatty acid fatty-acid analogue 4, 4-difluoro-5-methyl-4-bora-3a,4a-diaza-s-indacene-3-do decanoic acid (C1-BODIPY-C12), have a greatly diminished capacity to transport exogenous long-chain fatty acids, and have very long-chain acyl CoA synthetase activities that were 40% wild-type. The depression in very long-chain acyl CoA synthetase activities were not apparent in cells grown in the presence of oleate. Additionally, beta-oxidation of exogenous long-chain fatty acids is depressed to 30% wild-type levels. The reduction of beta-oxidation was correlated with a depression of intracellular oleoyl CoA levels in the fat1Delta strain following incubation of the cells with exogenous oleate. Expression of either Fat1p or murine FATP from a plasmid in a fat1Delta strain restored these phenotypic and biochemical deficiencies. Fat1p and FATP restored growth of fat1Delta cells in the presence of cerulenin and under hypoxic conditions. Furthermore, fatty-acid transport was restored and was found to be chain length specific: octanoate, a medium-chain fatty acid was transported in a Fat1p- and FATP-independent manner while the long-chain fatty acids myristate, palmitate, and oleate required either Fat1p or FATP for maximal levels of transport. Lignoceryl CoA synthetase activities were restored to wild-type levels in fat1Delta strains expressing either Fat1p or FATP. Fat1p or FATP also restored wild-type levels of beta-oxidation of exogenous long-chain fatty acids. These data show that Fat1p and FATP are functionally equivalent when expressed in yeast and play a central role in fatty-acid trafficking.

Effects of physical training in asthma: a systematic review

OBJECTIVES

To assess the evidence for the effects of physical training on pulmonary function, symptoms, cardiopulmonary fitness, and quality of life in subjects with asthma.

METHODS

A search was conducted for randomised controlled trials of subjects with asthma undertaking physical training using the Cochrane Airways Group register of controlled clinical trials, Medline, Embase, Sportdiscus, Science citation index, and Current contents index. Studies were included in the review if the subjects had asthma, were 8 years of age or older, and had undertaken physical training for at least 20 minutes per session, twice a week, for a minimum of four weeks. The eligibility of trials for inclusion in the review and the quality of the trials were independently assessed by two reviewers.

RESULTS

Eight studies with a total of 226 subjects met the inclusion criteria for this review. Physical training had no effect on resting lung function but led to an improvement in cardiopulmonary fitness as measured by an increase in maximum oxygen uptake of 5.6 ml/kg/min (95% confidence interval 3.9 to 7.2). None of the studies measured quality of life.

CONCLUSIONS

Physical training improves cardiopulmonary fitness without changing lung function. It is not clear if the improvement in fitness translates into a reduction in symptoms or an improvement in the quality of life. There is a need for further randomised controlled trials of the effects of physical training in the management of asthma.

The amino-terminal region of the long-chain fatty acid transport protein FadL contains an externally exposed domain required for bacteriophage T2 binding

The fatty acid transport protein FadL from Escherichia coli is predicted to be rich in beta-structure and span the outer membrane multiple times to form a long-chain fatty acid specific channel. Proteolysis of FadL within whole cells, total membranes, and isolated outer membranes identified two trypsin-sensitive sites, both predicted to be in externally exposed loops of FadL. Amino acid sequence analysis of the proteolytic fragments determined that the first followed R93 and yielded a peptide beginning with 94S-L-K-A-D-N-I-A-P-T-A104 while the second followed R384 and yielded a peptide beginning with 385S-I-S-I-P-D-Q-D-R-F-W395. Proteolysis using trypsin eliminated the bacteriophage T2 binding activity associated with FadL, suggesting the T2 binding domain within FadL requires elements within one of these extracellular loops. A peptide corresponding to the amino-terminal region of FadL (FadL28-160) was purified and shown to inactivate bacteriophage T2 in a concentration-dependent manner, supporting the hypothesis that the amino-proximal extracellular loop of the protein confers T2 binding activity. Using an artificial neural network (NN) topology prediction method in combination with Gibbs motif sampling, a predicted topology of FadL within the outer membrane was developed. According to this model, FadL spans the outer membrane 20 times as antiparallel beta-strands. The 20 antiparallel beta-strands are presumed to form a beta-barrel specific for long-chain fatty acids. On the basis of our previous studies evaluating the function of FadL using site-specific mutagenesis of the fadL gene, proteolysis of FadL within outer membranes, and studies using the FadL28-160 peptide, the predicted extracellular regions between beta-strands 1 and 2 and beta-strands 3 and 4 are expected to contribute to a domain of the protein required for long-chain fatty acid and bacteriophage T2 binding. The first trypsin-sensitive site (R93) lies between predicted beta-strands 3 and 4 while the second (R384) is between beta-strands 17 and 18. The trypsin-resistant region of FadL is predicted to contain 13 antiparallel beta-strands and contribute to the long-chain fatty acid specific channel.

Sensitivity to fungal allergens is a risk factor for life-threatening asthma

BACKGROUND

Previous studies have suggested that sensitivity to Alternaria and Cladosporium may be risk factors for life-threatening asthma. We have investigated this by studying the relationship between skin tests for fungal spores and admission to an intensive care unit (ICU) for asthma.

METHODS

Skin prick tests for fungal spores (Alternaria tenuis, Cladosporium cladosporoides, Helminthosporium maydis, and Epicoccum nigrum), cat dander, house-dust mite (Dermatophagoides pteronyssinus), and a seven-grass mix were performed in three groups of patients: patients admitted to an ICU with an attack of asthma; those who had received emergency treatment for asthma but had not been admitted to an ICU, and those who had never required emergency treatment for their asthma.

RESULTS

Twenty of 37 patients (54%) admitted to the ICU had a positive skin test for one or more fungal allergens compared with 15/50 patients (30%) in each of the other groups (P=0.005). The ICU patients were no more likely to have positive skin tests for the grass mix, cat dander, or house-dust mite than the other patients.

CONCLUSIONS

A positive skin test for fungal allergens is a risk factor for admission to an ICU with an acute attack of asthma.

Serological evidence of infection with Chlamydia pneumoniae is related to the severity of asthma

There is evidence that infection with Chlamydia pneumoniae is associated with asthma of recent onset and that it can influence the severity of asthma. This has led to the suggestion that macrolide antibiotics may be useful in the treatment of asthma in subjects infected with C. pneumoniae. This study examined the association between immunoglobulin (Ig)G and IgA titres to C. pneumoniae and the severity of asthma. IgG and IgA antibodies to C. pneumoniae were measured in 619 subjects with asthma (18-60 yrs), using the microimmunofluoresence method. Subjects were asked about their use of asthma medicines, symptoms, previous hospitalization for asthma, smoking status and age of onset of asthma. In subjects with IgG titres of > or =1:64 and/or IgA titres > or =1:16 (n=212), spirometry was performed and peak expiratory flow rate (PEFR) and symptoms were recorded twice daily for 4 weeks on a diary card. The use of high dose inhaled steroids was associated with an increase of 74.1% in the titre of IgG antibodies (p=0.04) and an increase of 70.6% in the titre of IgA antibodies (p=0.0001) when compared with the use of low dose inhaled steroids. There was an inverse association between IgG antibodies and forced expiratory volume in one second (FEV1) as a percentage of predicted in those subjects with elevated IgG and/or IgA (p=0.04). In this group IgA antibodies were also associated with a higher daytime symptom score (p=0.04). Higher titres of antibodies to Chlamydia pneumoniae appears to be associated with markers of asthma severity. This raises the possibility that chronic infection with Chlamydia pneumoniae leads to an increase in the severity of asthma. Studies aimed at eradicating chronic infection with Chlamydia pneumoniae are necessary to determine whether or not this is the case.

Long-chain acyl-CoA-dependent regulation of gene expression in bacteria, yeast and mammals

Fatty acyl-CoA thioesters are essential intermediates in lipid metabolism. For many years there have been numerous conflicting reports concerning the possibility that these compounds also serve regulatory functions. In this review, we examine the evidence that long-chain acyl-CoA is a regulatory signal that modulates gene expression. In the bacteria Escherichia coli, long-chain fatty acyl-CoA bind directly to the transcription factor FadR. Acyl-CoA binding renders the protein incapable of binding DNA, thus preventing transcription activation and repression of many genes and operons. In the yeast Saccharomyces cerevisiae, genes encoding peroxisomal proteins are activated in response to exogenously supplied fatty acids. In contrast, growth of yeast cells in media containing exogenous fatty acids results in repression of a number of genes, including that encoding the delta9-fatty acid desaturase (OLE1). Both repression and activation are dependent upon the function of either of the acyl-CoA synthetases Faa1p or Faa4p. In mammals, purified hepatocyte nuclear transcription factor 4alpha (HNF-4alpha) like E. coli FadR, binds long chain acyl-CoA directly. Coexpression of HNF-4alpha and acyl-CoA synthetase increases the activation of transcription of a fatty acid-responsive promoter, whereas coexpression with thioesterase decreases the fatty acid-mediated response. Conflicting data exist in support of the notion that fatty acyl-CoA are natural ligands for peroxisomal proliferator-activated receptor alpha (PPARalpha).

Physical training for asthma

BACKGROUND

Physical training programmes have been designed for asthmatic subjects with the aim of improving physical fitness, neuromuscular coordination and self-confidence. Habitual physical activity increases physical fitness and lowers ventilation during mild and moderate exercise thereby reducing the likelihood of provoking exercise -induced asthma. Exercise training may also reduce the perception of breathlessness through a number of mechanisms including strengthening respiratory muscles. Subjectively, many asthmatics report that they are symptomatically better when fit, but results from trials have varied and have been difficult to compare because of different designs and training protocols.

OBJECTIVES

The purpose of this review was to assess evidence for the efficacy and effectiveness of physical training in asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group trials register, Sportdiscus and Science citation index.

SELECTION CRITERIA

Randomised trials in asthmatic subjects undertaking physical training. Subjects had to be 8 years and older. Physical training had to be undertaken for at least 20 to 30 minutes, 2 to 3 times a week, over a minimum of four weeks.

DATA COLLECTION AND ANALYSIS

Eligibility for inclusion and quality of trials were assessed independently by two reviewers.

MAIN RESULTS

Eight studies could be included in this review. Physical training had no effect on resting lung function or the number of days of wheeze. Physical training improved cardiopulmonary fitness as measured by an increase in maximum oxygen uptake of 5.6 ml/kg/min (95% confidence interval 3. 9 to 7.2). There were no data concerning quality of life measurements.

REVIEWER'S CONCLUSIONS

In people with asthma, physical training can improve cardiopulmonary fitness without changing lung function. It is not known whether improved fitness is translated into improved quality of life.

Energetics underlying the process of long-chain fatty acid transport

The gram negative bacterium Escherichia coli has evolved a highly specific system for the transport of exogenous long-chain fatty acids (C12-C18) across the cell envelope that requires the outer membrane protein FadL and the inner membrane associated fatty acyl CoA synthetase. The transport of oleate (C18:1) across the cell envelop responds to metabolic energy. In order to define the source of metabolic energy which drives this process, oleate transport was measured in wild-type and ATP synthase-defective (Deltaatp) strains which were (i) subjected to osmotic shock and (ii) starved and energized with glucose or d-lactate in the presence of different metabolic inhibitors. Osmotic shock did not eliminate transport but rather reduced the rate to 33-55% of wild-type levels. These results suggested a periplasmic protein may participate in this process or that osmotic shock disrupts the energized state of the cell which in turn reduces the rate of oleate transport. Transport systems which are osmotically sensitive also require ATP. The process of long-chain fatty acid transport requires ATP generated either by substrate-level or oxidative phosphorylation. Following starvation, the basal rate of transport for wild-type cells was 340.4 pmol/min/mg protein compared to 172.0 pmol/min/mg protein for the Deltaatp cells. When cells are energized with glucose, the rates of transport were increased and comparable (1242.6 and 1293.8 pmol/min/mg protein, respectively). This was in contrast to cells energized with d-lactate in which only the wild-type cells were responsive. The role of ATP is likely due to the ATP requirement of fatty acyl CoA synthetase for catalytic activity. The process of oleate transport is also influenced by the energized state of the inner membrane. In the presence of carbonyl cyanide-m-chlorophenylhydrazone oleate transport is depressed to 30-50% of wild-type levels in wild-type and Deltaatp strains under starvation conditions. These results are mirrored in cells energized with glucose and d-lactate, indicating that an energized membrane is required for optimal levels of oleate transport. These data support the hypothesis that the fatty acid transport system of E. coli responds to both intracellular pools of ATP and an energized membrane for maximal proficiency.

Long-chain fatty acid transport in bacteria and yeast. Paradigms for defining the mechanism underlying this protein-mediated process

Protein-mediated transport of exogenous long-chain fatty acids across the membrane has been defined in a number of different systems. Central to understanding the mechanism underlying this process is the development of the appropriate experimental systems which can be manipulated using the tools of molecular genetics. Escherichia coli and Saccharomyces cerevisiae are ideally suited as model systems to study this process in that both [1] exhibit saturable long-chain fatty acid transport at low ligand concentration; [2] have specific membrane-bound and membrane-associated proteins that are components of the transport apparatus; and [3] can be easily manipulated using the tools of molecular genetics. In E. coli, this process requires the outer membrane-bound fatty acid transport protein FadL and the inner membrane associated fatty acyl CoA synthetase (FACS). FadL appears to represent a substrate specific channel for long-chain fatty acids while FACS activates these compounds to CoA thioesters thereby rendering this process unidirectional. This process requires both ATP generated from either substrate-level or oxidative phosphorylation and the proton electrochemical gradient across the inner membrane. In S. cerevisiae, the process of long-chain fatty acid transport requires at least the membrane-bound protein Fat1p. Exogenously supplied fatty acids are activated by the fatty acyl CoA synthetases Faa1p and Faa4p but unlike the case in E. coli, there is not a tight linkage between transport and activation. Studies evaluating the growth parameters in the presence of long-chain fatty acids and long-chain fatty acid transport profiles of a fat1delta strain support the hypothesis that Fatlp is required for optimal levels of long-chain fatty acid transport.

The effect of sustained-release morphine on breathlessness and quality of life in severe chronic obstructive pulmonary disease

Morphine has been proposed as a treatment for breathlessness in patients with severe chronic obstructive pulmonary disease (COPD), but there is uncertainty as to whether or not it is effective. Orally administered sustained-release morphine was compared with placebo in a randomized, double-blind, crossover trial with two 6-wk treatment periods separated by a 2-wk washout period. The primary end point was quality of life measured using the Chronic Respiratory Disease Questionnaire (CRQ). Secondary end points included 6-min walk (6MW), distance, and breathlessness scores. Sixteen subjects with a mean age 70.7 yr, FEV1 of 0.6 L, and VC of 1.90 L were studied. There was no change in the total CRQ score with either treatment, but the score on the Mastery subscale was significantly worse with morphine (p = 0.02). The 6MW distance increased by 21 m from the beginning to the end of the placebo treatment period, but it decreased by 35 m with morphine (p = 0.04). There were no differences between treatments in breathlessness scored on daily diary cards or on the Dyspnea subscale of the CRQ. Almost all the subjects experienced adverse effects related to morphine. Sustained-release morphine was not a useful treatment for breathlessness in these patients with severe COPD.

The effects of nebulised isotonic saline and terbutaline on breathlessness in severe chronic obstructive pulmonary disease (COPD)

BACKGROUND

There is anecdotal evidence that nebulised saline relieves breathlessness at rest in patients with severe chronic obstructive pulmonary disease (COPD). It is unclear whether nebulised beta agonists are any more effective than nebulised saline in relieving breathlessness at rest in these individuals.

AIM

To compare the effects of nebulised saline and nebulised terbutaline on breathlessness at rest in patients with severe COPD.

METHODS

We studied 18 patients with severe COPD with a mean age of 71.1 years, forced expiratory volume in 1 second (FEV1) of 0.58 L and vital capacity (VC) of 1.59 L, in a randomised, double-blind, crossover trial. The subjects received three doses of nebulised saline on one study day, and three doses of nebulised terbutaline (cumulative dose 10 mg) on the other. Breathlessness was measured using Likert and Visual Analogue Scales (VAS).

RESULTS

Both treatments led to a significant improvement in breathlessness on VAS and Likert scales but there was no significant difference in breathlessness scores for saline compared with terbutaline. There was a small but significant increase in FEV1 with terbutaline of 74 mL, but no change with saline.

CONCLUSIONS

A saline aerosol has no effect on lung function but reduces breathlessness at rest in subjects with severe COPD. Nebulised saline may be considered as an adjunct to the use of nebulised bronchodilators for the treatment of breathlessness in patients with COPD.