bluuebunny/crossref_metadata_2025 huggingface dataset:
Hot-Melt Application for Functional Compounds on Technical Textiles
Authors: Glawe Andrea , Reuscher Regina , Koppe Regina , Kolbusch Thomas
Published: October 2003

Application of hot-melt products for the production of functional technical textiles is increasing rapidly. The system in comparison to the wet lamination process is able to run at high speeds. Increasing fields of application are realised, such as for the automotive industry, for interlinings, medical textiles, and other clothing applications. The coating machinery industry and suppliers of special hot melt adhesives are responsible for developing of new solutions and systems for the required fields. A close cooperation between all partners, machinery as well as chemical suppliers, is important for perfect customer solutions. The complete solution includes the chemical solution, test of different hot-melt products for their material, and the optimal application method. Close cooperation between all responsible partners with great experience is of outstanding importance to meet the high demand on technical textiles for the protection of human, environment, and machinery, as well for special textiles for functional applications such as roofing systems, geotextiles, building textiles, and textiles for airplanes.
Nonwoven Protective Garments with Thermo-Regulating Properties
Authors: Pause Barbara
Published: October 2003

Nonwoven protective garments possess a poor thermo-physiological wearing comfort due to their insufficient breathability. The problem can be solved by applying phase change material (PCM) to the fabrics that the garment consists of PCM is a highly-productive thermal storage medium, which can be used to absorb excessive heat released by the human body under strenuous activities. The heat absorption by the PCM results in a delay in the microclimate temperature increase and hence a substantial decrease of the skin's moisture release. Both lead to an overall enhancement of the thermo-physiological wearing comfort and a prevention of heat stress situations as a serious health risk. Furthermore, the wearing times of nonwoven protective garments can be extended, resulting in an increased productivity.
New Discovery in the Properties of Composites Reinforced with Natural Fibers
Authors: Mueller Dieter H. , Krobjilowski Andreas
Published: October 2003

Composite materials with thermoplastic matrices and a reinforcement of natural fibers are increasingly regarded as an alternative to glass fiber-reinforced composites. The substitution of the traditionally used reinforcing glass fibers by natural fibers such as flax, kenaf, or cotton can lead to a reduction of the component's weight and furthermore to a significant improvement of specific properties like impact strength, crash behaviour, or sound absorption. One of the major fields of application for such materials can be found in structural components for the automotive industry. Product examples are door trim panels, headliners, or back panels. At present the processing of such materials into structural parts usually takes place by thermal compression molding. Semiproducts (so-called hybrid fleeces) are employed, which are generated by carding or air-laid processes and subsequent mechanical bonding. This paper presents a survey and latest developments on the material, processing technologies, and fields of applications. Furthermore, acoustical investigations on cotton-based composite materials are presented.
Real time seam tracking system for automated fusion arc welding
Authors: De A. , Parle D.
Published: October 2003

The demand for a simple and inexpensive yet flexible real time seam tracking system for automated fusion arc welding processes is ever increasing. To date, few techniques have been implemented in industry on a commercial basis, employing mostly thermovision devices, e.g. infrared vision cameras, infrared scanning radiometers, etc. or laser illuminated seam tracking systems. From the literature it appears that the use of simple vision sensors such as charge coupled device (CCD) cameras, which can monitor the surface temperature gradients as well as seam tracking operation in real time economically and reliably, has not yet been fully explored. It is thus conceived that further work is required in investigating real time seam tracking and adaptive control using image processing techniques and CCD cameras as they are inexpensive and robust as well as being sufficiently flexible. This highlights the importance of the present work, in which an attempt is made to extract geometrical parameters of the welding arc and to locate the weld seam ahead of the welding torch using images sensed by a simple CCD monochrome camera. The developed system has been tested successfully for fusion arc welding of butt joints with arc offsets, which are induced intentionally during experimentation.
Vorticity based turbulence model for thermofluids modelling of welds
Authors: Hong K. , Weckman D. C. , Strong A. B. , Zheng W.
Published: October 2003

A comprehensive thermofluids model of stationary gas tungsten arc welding (GTAW) has been developed and used to examine the effects of thermofluids phenomena on the predicted temperatures and flow field in the weld pool, as well as their impact on the resultant weld pool dimensions in 304 stainless steel and 6061 aluminium plates. A dynamic numerical grid remapping technique was used within the finite element based model to model the geometry of the solid/liquid interface and free surface of the weld pool. Initial work showed that correlation between experimental and predicted weld pool dimensions was only possible provided that the effects of turbulence were modelled using a well posed k - ∊ turbulence model. However, the two-equation k - ∊ turbulence model introduces additional complexity and requires considerable additional computational effort. To overcome these shortcomings, a simpler vorticity based turbulence model has been developed in which the turbulent viscosity and thermal conductivity are based upon the magnitude of the vorticity in the flow field as predicted through solution of the continuity, momentum and energy equations. Excellent correlation was obtained between the weld pool dimensions predicted by the vorticity based turbulence model, the predictions from the k - ∊ turbulence model and the experimental data from welds made in 304 stainless steel with three different sulphur impurity concentrations and in 6061 aluminium. The advantage of the vorticity based turbulence model is that it is significantly less computationally intensive than the standard k - ∊ turbulence model and has, therefore, the potential of providing tractable and practical computations of fully three-dimensional welding processes.
Mechanical characteristics of resistance multispot welded joints
Authors: Bang H.-S. , Bang H.-S. , Joo S.-M. , Kim J.-M. , Chang W.-S.
Published: October 2003

In the present study, three-dimensional thermal elastoplastic analysis has been carried out in order to clarify the mechanical phenomena of the thermal elastoplastic behaviour of multispot welded joints. As the shape of multispot welded joints is not axisymmetrical, unlike single spot welded joints, the solution domain for simulation should be three-dimensional. Therefore, the present study first developed three-dimensional heat conduction and thermal elastoplastic programs using the isoparametric finite element method. Second, from the results analysed by the developed programs, thermal and mechanical characteristics and their production mechanisms on single and multispot welded joints were clarified. Moreover, effects of pitch length on the temperature distribution, welding residual stresses and plastic strain of multispot welded joints were evaluated, indicating that a pitch of 30 mm was more advantageous compared to a pitch of 15 mm.
Finite element simulation of laser spot welding
Authors: De A. , Maiti S. K. , Walsh C. A. , Bhadeshia H. K. D. H.
Published: October 2003

The present work reports on a two-dimensional axisymmetric finite element analysis of heat flow during laser spot welding, taking into account the temperature dependence of the physical properties and latent heat of transformations. An analysis based on conduction heat transfer alone, but using the ‘double ellipsoidal’ representation of the laser beam, seems to be sufficient to estimate the transition to keyhole formation during laser spot welding, although the ‘double ellipsoidal’ representation requires an a priori knowledge of the expected weld pool dimensions. Transient temperature isotherms and the weld pool dimensions are predicted using the model; the latter are found to compare well with measurements of weld bead dimensions. The results show that the keyhole mode is stimulated using either a high laser power and low on-time or a low laser power and high on-time. The outcomes are found to be sensitive to the assumed absorptivity and the assumed weld pool depth used to define the ‘double ellipsoidal’ heat source.
Analysis of friction stir welds using thermocouple measurements
Authors: Lambrakos S. G. , Fonda R. W. , Milewski J. O. , Mitchell J. E.
Published: October 2003

The friction stir welding process is analysed via an inverse problem approach, using experimentally obtained thermocouple information to constrain the thermal field of the model. Using this approach, the thermal field is described by a convenient parametric representation, which is constrained in a self-consistent manner according to data from the outer regions of the weld (e.g. the heat affected zone). The thermal field is scaled using thermocouple measurements acquired during friction stir welding, and is then compared with the thermocouple measurements acquired at different locations. Various aspects of this inverse problem approach relevant to its application to friction stir welds using thermocouple measurements are discussed.
Comparison of multiple regression and back propagation neural network approaches in modelling top bead height of multipass gas metal arc welds
Authors: Kim I. S. , Lee S. H. , Yarlagadda P. K. D. V.
Published: October 2003

With the advanced developments and automation of the welding process, the use of process optimisation techniques has increased. The objective of the present paper is to describe process optimisation techniques for the gas metal arc (GMA) welding process, based on experimental results generated by the process. Back propagation (BP) neural network and multiple regression methods are employed to study relationships between process parameters and top bead height for robotic multipass welding process, and to select a suitable model that provides the weld final configuration and properties as output and employs the process parameters as input. The process parameters, namely pass number, arc current, welding voltage and welding speed are optimised to produce the required top bead height. These techniques have achieved good agreement with the experimental data and yielded satisfactory results. Also, the BP neural network that was developed was compared to the empirical equations for predicting top bead height through additional experiments, and it was evident that the BP neural network was considerably more accurate than multiple regression techniques.
Predicting persistent disease among children who wheeze during early life
Authors: Kurukulaaratchy R.J. , Matthews S. , Holgate S.T. , Arshad S.H.
Published: October 2003

This study sought to determine factors influencing the persistence of early life wheezing up to the age of 10 yrs and to create a score identifying those with the highest risk of persistent disease.

Children were seen at birth, 1, 2, 4 and 10 yrs in a whole population birth cohort study (n=1,456). Information was collected prospectively on wheeze prevalence and subjects were classified into wheezing phenotypes. Early life genetic and environmental risk factors were recorded and skin-prick testing (SPT) was performed at 4 yrs. Independently significant factors for persisting wheeze were identified at logistic regression and used to create a score for persistence.

Wheezing persistence from the first 4 yrs to the age of 10 yrs occurred in 37% of early life wheezers. Independent significance for persistence was associated with asthmatic family history, atopic SPT at 4 yrs and recurrent chest infections at 2 yrs, whilst recurrent nasal symptoms at 1 yr conferred reduced risk. A cumulative risk score using these factors identified wheezing persistence in 83% scoring 4 and transience in 80% scoring 0.

Thus, a combination of genetic predisposition, early life atopy and recurrent chest infections favours the persistence of early life wheezing. Risk scores using such knowledge could provide prognostic guidance on the outcome of early wheeze.
Dietary factors associated with wheezing and allergic rhinitis in children
Authors: Farchi S. , Forastiere F. , Agabiti N. , Corbo G. , Pistelli R. , Fortes C. , Dell'Orco V. , Perucci C.A.
Published: October 2003

The effect of dietary factors on asthma is controversial. This study examined food consumption and the use of fats in relation to wheezing and allergic rhinitis in children.

Baseline questionnaire data on individual and family characteristics were recorded by parents of 5,257 children aged 6–7 yrs living in central Italy participating in the International Study on Asthma and Allergies in Childhood study. A total of 4,104 children (78.1%) were reinvestigated after 1 yr using a second parental questionnaire to record occurrence of respiratory symptoms over the intervening 12 months. Consumption of foods rich in antioxidants, such as vitamins C and E, animal fats, and food containing omega‐3 fatty acids were investigated using a food-frequency questionnaire. Frequency of use of fats was also evaluated. Wheezing, shortness of breath with wheeze, and symptoms of allergic rhinitis in the past 12 months were considered.

Intake of cooked vegetables, tomatoes, and fruit were protective factors for any wheeze in the last 12 months and shortness of breath with wheeze. Consumption of citrus fruit had a protective role for shortness of breath with wheeze. Consumption of bread and margarine was associated with an increased risk of wheeze, while bread and butter was associated with shortness of breath with wheeze.

Dietary antioxidants in vegetables may reduce wheezing symptoms in childhood, whereas both butter and margarine may increase the occurrence of such symptoms.
Short-term effects of air pollution on daily asthma emergency room admissions
Authors: Galán I. , Tobías A. , Banegas J.R. , Aránguez E.
Published: October 2003

Many time-series studies have shown positive associations between air pollutants and asthma morbidity. However, few studies have included pollen as a potential confounder when examining this relationship.

This study analysed the short-term association between air pollutants (sulphur dioxide (SO2), particles measured with a median aerodynamic diameter of <10 µm (PM10), nitrogen dioxide (NO2) and ozone (O3)) and asthma emergency room admissions in Madrid, Spain, in 1995–1998, adjusting for four types of pollen with allergenic potential (Olea europaea,Plantago sp., Poaceae and Urticaceae). Data were analysed using autoregressive Poisson regression and generalised additive models (GAM).

The strongest associations were observed at 1 day lag for O3, and 3 days lag for the remaining pollutants. Using Poisson regression, a single-pollutant model showed that a 10‐µg·m−3rise in pollutant level led to relative risks of: 1.039 for PM10; 1.029 for SO2; 1.033 for NO2; and 1.045 for O3. Adjustment for the different types of pollen led to no substantial variation in these associations. In the multipollutant models for cold-season pollutants (including PM10, SO2and the four types of pollen) and photochemical pollutants (including NO2, O3and the four types of pollen) the associations for PM10, NO2and O3held, but no relationship with SO2was evident. GAM analysis yielded the same results, both in terms of lags and of quantification of the effect for all pollutants.

In conclusion, the usual air pollution levels in Madrid were associated with an increase in asthma emergency room admissions, and this association remained controlling for the presence of ambient pollen.
Multidrug-resistant tuberculosis: eight years of surveillance in France
Authors: Robert J. , Trystram D. , Truffot-Pernot C. , Jarlier V.
Published: October 2003

The aim of this study was to evaluate the annual prevalence of multidrug-resistant tuberculosis (MDRTB) and to describe the characteristics of the patients with MDRTB in France.

Annual questionnaire surveys from 1992–1999 were mailed to all French microbiological laboratories performing mycobacterial cultures. A total of 264 distinct patients were reported to the National Reference Centre for Resistance of Mycobacteria to Antituberculosis Drugs during the 8‐yr surveillance period resulting in a mean annual prevalence of MDRTB of 0.6%.

A mean of 16% of the MDRTB patients were reported over several subsequent years. The majority of patients were male (69.7%), foreign-born (55.7%), with a previous history of treatment (65.9%), and pulmonary involvement (92.8%) with smear-positive results (59.1%). Human immunodeficiency virus (HIV) coinfection was present in 20.8% of the patients. Strains were resistant only to isoniazid and rifampin in 37.9% of the cases, and additional resistance to both streptomycin and ethambutol was present in 25.8%. HIV coinfection and female status were statistically associated with primary resistance, whereas smear-positive results were associated with secondary resistance. Foreign-birth and smear-positive results were associated with a chronic status.

The prevalence of multidrug-resistant tuberculosis is low in France (<1%). However, a substantial proportion of patients remain positive for several years, suggesting nonoptimal management. Therefore, as recommended by the World Health Organization, a few reference teams, working in collaboration with national associations of physicians and microbiologists, should be established to improve the outcome of multidrug-resistant tuberculosis.
Increased serum concentration of urinary trypsin inhibitor with asthma exacerbation
Authors: Yasui K. , Kanda H. , Iwanami T. , Komiyama A.
Published: October 2003

The aim of the study was to determine whether the amount of urinary trypsin inhibitor (UTI) in serum, a degenerate induced by neutrophil elastase (NE), reflects the degree of bronchial inflammation in children with acute asthma exacerbation.

The involvement of neutrophil-mediated inflammation plays as important a role as eosinophil-mediated inflammation in the pathogenesis of acute asthma exacerbation. However, no measurable marker is sensitive enough to assess neutrophil-mediated inflammation in the airways. The pre‐α‐/inter‐α‐trypsin inhibitors are assumed to be precursors of UTI. NE degrades pre‐α‐/inter‐α‐trypsin inhibitors to liberate UTI. UTI concentrations in 25 childhood patients admitted with asthma exacerbation and 15 control subjects were measured by means of one-step sandwich-type enzyme immunoassay.

Serum UTI concentrations in the patients at admission were significantly higher than control values (10.597±0.649 and 6.136±0.303 U·mL−1, respectively (mean±sem)). These levels returned to baseline values with improvement in the asthmatic symptoms. However, serum NE and α1antitrypsin concentrations were not significantly different between patients and controls, even during acute exacerbation in the former.

The findings suggest that neutrophil-mediated inflammatory events are involved in exacerbation of childhood asthma. The monitoring of urinary trypsin inhibitor concentrations might be useful for evaluating the neutrophil-mediated inflammation in childhood asthma attack.
Assessment of tidal breathing parameters in infants with cystic fibrosis
Authors: Ranganathan S.C. , Goetz I. , Hoo A-F. , Lum S. , Castle R. , Stocks J. ,   and the London Collaborative Cystic Fibrosis Group
Published: October 2003

Simple methods are needed to assess lung function in infants with cystic fibrosis (CF). This study determined the relationship between simple measurements obtained from tidal breathing with those from more complicated forced expiratory manoeuvres.

Healthy infants and infants with CF were recruited from two maternity units and five specialist CF hospitals, respectively. Respiratory rate, tidal volume, minute ventilation and the tidal breathing ratio (TPTEF:TE) were measured in sedated infants and compared with forced expiratory volume in 0.4 seconds (FEV0.4) measured by the raised volume technique.

Altogether, 95 healthy infants and 47 infants with CF of similar age, sex, ethnicity and proportion exposed to maternal smoking were recruited. There was no difference in TPTEF:TEand tidal volume between healthy infants and those with CF. Minute ventilation was significantly greater in infants with CF due to a mean (95% confidence interval) increase in respiratory rate of 5.8 (3.2–8.4) min−1. Thirteen (28%) infants with CF had a respiratory rate elevated by >2 sd. However, no association between respiratory rate and FEV0.4could be identified.

Tidal breathing ratio was not useful in identifying diminished airway function in infants with cystic fibrosis. An elevated respiratory rate may be due in part to ventilation heterogeneity but is poorly predictive of diminished airway function measured by forced expiration.
Indications, patient selection and timing of referral for lung transplantation
Authors: Glanville A.R. , Estenne M.
Published: October 2003

Lung transplantation (LTx) is now generally accepted as a useful modality of care for patients with severe life-threatening respiratory diseases that are refractory to other medical or surgical therapies. With the huge development of LTx over the last 15 yrs, the disparity between the number of potential recipients and the number of donor organs available has become a major constraint, with many patients dying on the waiting lists. Therefore, it is of primary importance to control and optimise the use of this limited organ resource by weighting the risks and benefits of transplantation in individual patients, and to identify those patients who have a better chance of having a favourable outcome with transplantation.

This article discusses the selection process of potential candidates and the currently accepted absolute and relative contraindications, and proposes general and disease-specific recommendations for optimising the timing of referral. Early referral for consideration of lung transplantation is highly desirable as it enhances the patient's chance of surviving to transplant and allows the transplant team to actively manage identified comorbidities during the waiting period.
Effects of a comprehensive self-management programme in patients with chronic obstructive pulmonary disease
Authors: Monninkhof E. , van der Valk P. , van der Palen J. , van Herwaarden C. , Zielhuis G.
Published: October 2003

The aim of this study was to assess the effects of a comprehensive self-management intervention on health-related quality of life (HRQoL), symptoms and walking distance in patients with stable moderately severe chronic obstructive pulmonary disease (COPD).

This study was part of the overall COPD study of the Dept of Pulmonary Medicine,Enschede, which consisted of an inhaled corticosteroid (ICS) trial and a self-management trial. After the ICS trial, all patients were randomised again to a self-management and a control group. The self-management intervention consisted of askill-oriented patient education programme and a near-home fitness programme, on top of usual care. The control group received usual care by the treating chest physician. HRQoL was measured by the St George’s Respiratory Questionnaire (SGRQ) and walking distance by the 6‐min walking test. Patients recorded their symptoms in diaries and graded their health status from 1–10 in a weekly report.

Altogether, 248 COPD patients were randomly allocated to either an intervention (127) or control (121) group. No differences in the SGRQ scores within and between both groups were observed over 1 yr. Similarly, no differences in symptom scores and 6‐min walking distance were found within and between groups. The intervention group reported more exacerbations than the control group. The majority (69%) of the exacerbations in the intervention group were self-treated at home.

This study failed to show positive effects of a self-management programme among moderately severe chronic obstructive pulmonary disease patients.
Collagen phagocytosis by lung alveolar macrophages in animal models of emphysema
Authors: Lucattelli M. , Cavarra E. , M. de Santi M. , Tetley T.D. , Martorana P.A. , Lungarella G.
Published: October 2003

Under steady state conditions the intracellular pathway is the major route of collagen catabolism in tissues characterised by rapid collagen turnover. In the lung, the collagen is subject to continuous remodelling and turnover however, the intracellular pathway of collagen degradation is unusual under physiological conditions.

The current authors previously described crystalloid inclusions in alveolar macrophages of mice with genetic emphysema at the time of septal disruption. Using an immunogold technique these inclusions were identified as collagen-derived products and related to intracytoplasmic collagen degradation. To examine whether a different degree of protease burden in lung interstitium may influence the route of intracellular collagen degradation, collagen phagocytosis by alveolar macrophages was studied in various mouse models of emphysema at the time when emphysema develops.

Evident collagen by-products in alveolar macrophages were observed in destructive processes characterising spontaneous models of emphysema either with negligible (blotchy mouse) or moderate (pallid mouse) elastase burden. On the other hand, intracellular collagen by-products were appreciated only in a few macrophages from tight-skin mice with high elastolytic burden and could not be observed in mice with a very severe burden after elastase instillation. In conclusion, the interstitial level of proteases burden can affect the way by which the collagen is cleared (intracellularlyversusextracellularly).
Effect of nasal or oral breathing route on upper airway resistance during sleep
Authors: Fitzpatrick M.F. , McLean H. , Urton A.M. , Tan A. , O'Donnell D. , Driver H.S.
Published: October 2003

Healthy subjects with normal nasal resistance breathe almost exclusively through the nose during sleep. This study tested the hypothesis that a mechanical advantage might explain this preponderance of nasal over oral breathing during sleep.

A randomised, single-blind, crossover design was used to compare upper airway resistance during sleep in the nasal and oral breathing conditions in 12 (seven male) healthy subjects with normal nasal resistance, aged 30±4 (mean±sem) yrs, and with a body mass index of 23±1 kg·m2.

During wakefulness, upper airway resistance was similar between the oral and nasal breathing routes. However, during sleep (supine, stage two) upper airway resistance was much higher while breathing orally (median 12.4 cmH2O·L−1·s−1, range 4.5–40.2) than nasally (5.2 cmH2O·L−1·s−1, 1.7–10.8). In addition, obstructive (but not central) apnoeas and hypopnoeas were profoundly more frequent when breathing orally (apnoea-hypopnoea index 43±6) than nasally (1.5±0.5).

Upper airway resistance during sleep and the propensity to obstructive sleep apnoea are significantly lower while breathing nasally rather than orally. This mechanical advantage may explain the preponderance of nasal breathing during sleep in normal subjects.
The approach to the surgical management of cancer in four European countries
Authors: Connolly C.K. , Van Schil P.E.Y. , Milroy R. , Braendli O. , Prescott R.J.
Published: October 2003

Outcome of lung cancer appears poorer in the UK than elsewhere in Europe. This may be due to a less aggressive approach in treatment. This study investigated whether clinicians' perceptions of their approach differed between European countries.

A questionnaire was circulated to cancer specialists in four countries (Belgium, Greece, Switzerland and the UK) asking about management. An aggression score was calculated using the proportion of standard cases that would proceed to operation at different ages and levels of pulmonary function.

The principle problems suggested by most of the 314 respondents were inoperability before symptoms (particularly in the UK) and confounding effects of comorbidity. Surgeons particularly blamed delay in referral. The aggression scores (Belgium 54%, UK 49%, Switzerland 47% and Greece 37%) did not suggest the UK is an outlier, but the UK was more conservative in its approach to N2 disease and isolated cerebral metastasis. The aggression scores of surgeons were greater than those of the others (51%versus42%).

Lung cancer was felt to present late with potentially confounding symptoms, but delay in the clinical process was thought to be less important. Although the UK was more conservative with special cases, its approach to typical cases could account for differences in patient survival.
Formoterol as relief medication in asthma: a worldwide safety and effectiveness trial
Authors: Pauwels R.A. , Sears M.R. , Campbell M. , Villasante C. , Huang S. , Lindh A. , Petermann W. , Aubier M. , Schwabe G. , Bengtsson T.
Published: October 2003

The aim of the study was to compare the safety and effectiveness of as-needed formoterol with salbutamol in a large international real-life asthma study.

Children and adults (n=18,124) were randomised to 6 months as-needed treatment with open-label formoterol 4.5 µg Turbuhaler® or salbutamol 200 µg pressurised metered dose inhaler or equivalent. Primary safety variables were asthma-related and nonasthma-related serious adverse events (SAE)s and adverse events (AE)s resulting in discontinuation (DAE)s. The primary efficacy variable was time to first asthma exacerbation.

The incidences of AEs, SAEs and DAEs arising from SAEs were not significantly different between treatments. DAEs for nonserious AEs were higher with formoterol. Asthma-related AEs decreased with formoterol (1,098 (12.3%)versus1,206 (13.5%)), asthma-related SAEs were similar (108 (1.2%)versus121 (1.4%)) but more asthma-related DAEs occurred in the formoterol group (89 (1.0%)versus48 (0.5%)). Time to first exacerbation was prolonged (hazard ratio 0.86) and less as-needed and maintenance medication was used with formoterol. Reductions of exacerbations with as-needed formoterolversussalbutamol increased with increasing age and asthma medication level.

This real-life study demonstrates that formoterol as-needed has a similar safety profile to salbutamol, and its use as a reliever therapy is associated with fewer asthma symptoms and exacerbations.
Cost analysis of video-assisted thoracic surgeryversusthoracotomy: critical review
Authors: Van Schil P.
Published: October 2003

Cost containment has become an important issue in thoracic surgery. Applying the principles of evidence-based medicine a literature search was performed to determine whether video-assisted thoracic surgery (VATS) has an advantage over thoracotomy concerning total cost.

Only eight studies specifically looked at cost; all but one were retrospective. Lung biopsy by VATS yielded higher operating room costs compared with limited thoracotomy. The cost of VATS wedge resection of lung nodules was competitive with open techniques. In a prospective study regarding the treatment of pneumothorax by VATS, no advantages were demonstrated compared with axillary minithoracotomy. In two retrospective studies the total economic cost of VATS was lower but not all relevant factors were considered. Lung volume reduction surgery by VATS had a lower total inpatient cost compared with sternotomy but no specific details were provided. Finally, VATS treatment of lung cancer yielded conflicting results regarding total hospital charges.

From these studies it is clear that video-assisted thoracic surgery has a higher initial cost. Whether this is offset by a more rapid discharge remains to be proven. There is a definite need for high-quality prospective randomised studies.
Angiotensin-converting enzyme genotype and the ventilatory responseto exertional hypoxia
Authors: Patel S. , Woods D.R. , Macleod N.J. , Brown A. , Patel K.R. , Montgomery H.E. , Peacock A.J.
Published: October 2003

The “insertion” (I) rather than “deletion” (D) variant of the human angiotensin-converting enzyme (ACE) gene is associated with both lower tissue ACE activity and elite performance at high altitude. Three genotypes, II, ID and DD, are thus represented in the population. The authors examined whether an improved ventilatory response to hypoxic exercise may contribute to this effect.

Subjects (n=60; 37 male, mean±sem age 23.6±0.6 yrs, 14 II, 30 ID, 16 DD) underwent incremental cardiopulmonary exercise testing to establish maximal oxygen uptake and ventilatory threshold (VT). Four hours later, subjects exercised for 6 mins at 50% of the workload at VT. The protocol was repeated 15 mins later while breathing 12.5±0.5% oxygen in nitrogen.

All subject characteristics were independent of genotype, as were data during normoxic exercise. However, the hypoxia-induced rise in minute ventilation was significantly greater among those of II genotype (39.6±4.1%versus27.9±2.0%versus28.4±2.2% for IIversusIDversusDD, respectively). These data are supported by a significantly greater decrease in end tidal carbon dioxide (consistent with an increase in alveolar ventilation) among those homozygous for the I allele (II −18.7±1.3%, ID −15.7±0.4%, DD −15.1%±1.1).

The ventilatory response to hypoxic exercise is influenced by angiotensin-converting enzyme genotype. Potential implications concern high altitude performance and the pathogenesis and management of hypoxic lung disease.
Health consequences associated with frequent wheezing in adolescents without asthma diagnosis
Authors: Yeatts K. , Johnston Davis K. , Peden D. , Shy C.
Published: October 2003

Using questions from the International Study of Asthma and Allergies in Childhood, this study evaluated the association between undiagnosed frequent wheezing and health consequences in adolescents.

The North Carolina School Asthma Survey provided self-reported questionnaire data on respiratory health from 122,829 children aged 12–14 yrs. The frequency of health consequences were compared among undiagnosed frequent wheezers, diagnosed asthmatics, and children with no wheezing symptoms or diagnosed asthma.

The odds of wheezing-related sleep disturbances, limited activities, and missed school were higher among undiagnosed frequent wheezers, relative to diagnosed asthmatics. The frequency of emergency room visits and hospitalisations did not differ substantially between the undiagnosed wheezing and diagnosed asthma groups, though the undiagnosed group was less likely to have visited a physician for wheezing in the past year.

Children with frequent wheezing symptoms but no asthma diagnosis experience substantial illness-related morbidity similar to that of diagnosed asthmatics. Undiagnosed frequent wheezers require more recognition from primary care physicians and need active disease management to reduce health consequences.
Effect of age and asthma duration upon elastase and α1-antitrypsin levels in adult asthmatics
Authors: Vignola A.M. , Bonanno A. , Profita M. , Riccobono L. , Scichilone N. , Spatafora M. , Bousquet J. , Bonsignore G. , Bellia V.
Published: October 2003

In asthmatic subjects an imbalance between elastase and α1‐antitrypsin (α1‐PI) exists. This study aims to evaluate whether ageingper seaffects the levels of elastase.

Both young and elderly asthmatics with comparable severity and duration of disease, as well as young and elderly healthy subjects, underwent an induced sputum procedure to measure levels of elastase and α1‐PI.

The percentage of sputum neutrophils and eosinophils was higher in young and elderly asthmatics than in young and elderly controls. The levels of both total and active elastase were significantly higher in young and elderly asthmatics than in young and elderly controls, and directly correlated with the percentage of neutrophils. In addition, in both young and elderly asthmatics the levels of total and active elastase were negatively correlated with forced expiratory volume in one second values, but positively correlated with the duration of the disease.

This study indicates that ageingper sedoes not necessarily lead to a progressive elastase/α1‐antitrypsin imbalance in asthma, and suggests that an important variable in the development of airway remodelling in both young and elderly asthmatics is represented by the duration of the disease.
The prevention of occupational asthma
Authors: Cullinan P. , Tarlo S. , Nemery B.
Published: October 2003

There is sufficient understanding of the causation of occupational asthma for preventive action to be appropriate. To date, attempts appear to have been largely unsuccessful and this appears to be largely due to nonscientific/technical obstacles. These include the fragmented nature of the disease, its low public and industrial profile, and its comparative rarity in single workplaces. Nonetheless the disease has high individual and societal costs.

Prevention strategies should be concentrated on workplace-exposure controls, accompanied by intense educational and managerial improvements. Methods of secondary prevention appear to be successful but require considerable refinement. Screening (out) of potential new employees is inefficient and likely to remain so; and in any case is beset by difficult ethical and legal issues.

There are only a handful of published studies reporting evaluations of preventive programmes. None is entirely rigorous but each suggests that primary and secondary prevention are both feasible and highly effective. The evaluation of preventive strategies is difficult, not only because of the low incidence of the disease in individual workplaces but also because of the failure of many epidemiologists to engage in this work. Considerably more cooperation between scientists in the field, regulatory authorities and industry is required.
Interaction of Pseudomonas aeruginosa with human respiratory mucosa in vitro
Authors: Tsang KW , Rutman A , Tanaka E , Lund V , Dewar A , Cole PJ , Wilson R
Published: October 2003

Pseudomonas aeruginosa commonly infects the airways of patients with cystic fibrosis and bronchiectasis. It produces several toxins that slow ciliary beat, stimulate mucus production and damage epithelium. It adheres to epithelial cells, damaged mucosa (in animal models), and mucus. However, little is known of the interaction of P. aeruginosa with intact human respiratory mucosa. We have studied the interactions of a nonmucoid clinical isolate of P. aeruginosa with adenoid tissue in a novel organ culture model with an air-mucosal interphase P. aeruginosa (5.9 +/- 0.9 x 10(6) colony-forming units (cfu)) was pipetted onto the organ culture surface, and incubated for 15 min, 1, 2, 4, 8, 12, 16, and 24 h, at 37 degrees C in 5% CO2 in a humidified atmosphere. Assessment has been made by transmission and scanning electron microscopy. Transmission electron microscopy (TEM) showed that uninfected organ cultures had normal ultrastructure. TEM of infected organ cultures at 8 h showed significant epithelial damage: 43.9 +/- 10% of cells extruding from the epithelial surface, 17.7 +/- 3% of cells with loss of cilia, 32.9 +/- 10.2% of cells with mitochondrial damage, and 11.6 +/- 3% of cells with cytoplasmic blebbing. P. aeruginosa only infrequently adhered to normal epithelium, but adhered to areas of epithelial damage and to basement membrane. Scanning electron microscopy (SEM) of organ cultures up to 2 h found P. aeruginosa only infrequently associated with mucus. SEM at 4 h revealed P. aeruginosa predominantly associated with mucus and extruded damaged epithelial cells, but also occasionally associated with cilia, and very occasionally with unciliated cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Pseudomonas aeruginosa exotoxin A induces pulmonary endothelial cytotoxicity: protection by dibutyryl-cAMP
Authors: Bourke WJ , O'Connor CM , FitzGerald MX , McDonnell TJ
Published: October 2003

In pseudomonal septicaemia, serum levels of antibody to exotoxin A have been demonstrated to be an important independent predictor of survival. Previously, we have demonstrated that exotoxin A directly injures pulmonary endothelial cells, and that dibutyryl-cyclic adenosine monophosphate (Db-cAMP) can attenuate this injury. The object of this study was to examine the mechanisms of this pulmonary endothelial cell injury and the mechanism of Db-cAMP protection. The effects of differing duration of exposure to exotoxin A and a reduction in temperature on endothelial cell injury were examined. In addition, the effect of post-treatment with Db-cAMP on exotoxin A-induced endothelial cell injury was studied. A brief, 5 min, exposure to exotoxin resulted in maximum injury comparable to that produced by 18 h exposure. This injury did not occur at low temperatures, which would inhibit receptor-mediated endocytosis. Db-cAMP protected endothelial cells, even when added up to one hour after exotoxin exposure. These results suggest that, in this model, exotoxin A-induced injury of endothelial cells is receptor-mediated. Furthermore, this injury may be attenuated even after exotoxin A internalization has taken place.
Bacterial adhesion to oropharyngeal and bronchial epithelial cells in smokers with chronic bronchitis and in healthy nonsmokers
Authors: Riise GC , Larsson S , Andersson BA
Published: October 2003

Bacterial adhesion is probably a prerequisite for colonization of mucous membranes, but adhesion to the bronchial mucosa has not been studied in detail. We investigated adhesion of respiratory pathogens to bronchial epithelial cells, and asked whether chronic bronchitis had an influence on bacterial adhesion. Oropharyngeal and bronchial cells were collected during bronchoscopy from 14 healthy nonsmokers, 22 smokers with nonobstructive chronic bronchitis, and 19 smokers with chronic bronchitis and chronic obstructive pulmonary disease (COPD). Patients with a forced expiratory volume in one second (FEV1) less than 50% predicted were excluded. Adhesion of highly adherent test strains of H. influenzae and S. pneumoniae to these cells were studied. The test strains of H. influenzae and S. pneumoniae were found to adhere well to both oropharyngeal and bronchial cells. H. influenzae showed a higher degree of adhesion both to ciliated and goblet cells from the patients with nonobstructive bronchitis than to cells from the healthy nonsmokers. No corresponding difference was found for S. pneumoniae. The patients with COPD did not differ from the controls in their adhesion values. Our results indicate that bacterial adhesion is of importance for the colonization and retention of H. influenzae in the human airways. For S. pneumoniae the role of adhesion is more uncertain.
Hand-scoring of MESAM 4 recordings is more accurate than automatic analysis in screening for obstructive sleep apnoea
Authors: Koziej M , Cieslicki JK , Gorzelak K , Sliwinski P , Zielinski J
Published: October 2003

The MESAM 4 system, developed to monitor breathing sounds, heart rate, arterial oxygen saturation (Sao2) and body position, was proposed as a screening method for obstructive sleep apnoea (OSA). The aim of the study was to assess the accuracy of hand-scoring versus automatic-scoring in screening for obstructive sleep apnoea. The study population consisted of 56 patients, 51 males, and 5 females, mean age 47 +/- 10 yrs, suspected of having obstructive sleep apnoea. Full polysomnography and MESAM 4 recordings were performed simultaneously. The apnoea+hypopnoea index was hand-scored in polysomnography and in MESAM 4. The hand-scoring in MESAM 4 was based on analysis of breathing sounds, heart rate and Sao2 changes taken together. The automatic-scoring system of MESAM 4 calculated oxygen desaturation index, heart rate variation index and intermittent snoring index. The diagnosis of obstructive sleep apnoea (apnoea+hypopnoea index > or = 10) was established by polysomnography in 37 patients. Sensitivity and specificity of hand-scored MESAM 4 diagnosis were 100 and 63%, respectively. Sensitivity and specificity of MESAM 4 diagnosis with automatic-scoring were: from oxygen desaturation index 100 and 27%; from heart rate variation index 81 and 74%; and from intermittent snoring index 92 and 16%, respectively. We suggest that hand-scoring of MESAM 4 is more accurate than automatic-scoring in screening for obstructive sleep apnoea.
Required levels of nasal continuous positive airway pressure during treatment of obstructive sleep apnoea
Authors: Series F , Marc I , Cormier Y , La Forge J
Published: October 2003

The improvement in the severity of obstructive sleep-related breathing disorders during nasal continuous positive airway pressure (NCPAP) therapy can account for the decrease in the required NCPAP level with time. The aim of this study was to prospectively quantify the changes in the required NCPAP level over time of use in sleep apnoea-hypopnoea syndrome (SAHS). Forty sleep apnoea-hypopnoea patients were evaluated before and during the time course of NCPAP therapy. The effective NCPAP level was defined as the positive pressure level that abolished apnoeic and hypopnoeic events and snoring in all sleep stages and sleep positions. This pressure level was determined within 2 weeks after baseline diagnostic sleep study. Sleep studies with NCPAP and NCPAP titration were performed after 2 (n = 40), 8 (n = 40), and 20 (n = 24) months of NCPAP therapy. The initial effective NCPAP level was 9.6 +/- 0.4 cmH2O. It progressively decreased to 8.8 +/- 0.4, 7.9 +/- 0.4 and 7.7 +/- 0.5 after 2, 8 and 20 months, respectively; the difference being significant between the first three NCPAP nights. There was a poor relationship between the changes in the effective NCPAP and changes in weight recorded at the different visits. There was a weak negative relationship between the changes in NCPAP and the previous NCPAP level. In 13 patients, the apnoea-hypopnoea index (AHI) remained > 10 n.h-1 at the first NCPAP trial because the effective NCPAP level was not tolerated. Despite a suboptimal NCPAP level, their sleep architecture improved, and they all reported a subjective improvement in diurnal hypersomnolence.(ABSTRACT TRUNCATED AT 250 WORDS)
Lung function, CT-scan and X-ray in upper airway obstruction due to thyroid goitre
Authors: Melissant CF , Smith SJ , Perlberger R , Verschakelen J , Lammers JW , Demedts M
Published: October 2003

The purpose of this study was to assess the clinical reliability and to compare routine lung function tests (maximal flows and resistance) and radiological images (computed tomography (CT)-scan and X-ray) in upper airway obstruction. We, therefore, performed these examinations prospectively in 28 female patients (aged 68 +/- 13 yrs) with a goitre and without pulmonary disorders. Lung function measurements consisted of maximum expiratory and inspiratory flow-volume curves and of airway resistance. CT-scans and X-rays were performed during apnoea at functional residual capacity (FRC). Peak expiratory flow was 3.6 +/- 1.3 l.s-1 (i.e. 62 +/- 21% predicted); airway resistance was 0.38 +/- 0.14 kPa (i.e. 149 +/- 58% pred); and specific conductance was 1.0 +/- 0.3 kPa (i.e. 70 +/- 24% pred). Almost all lung function tests were significantly correlated with each other. On CT-scan the tracheal cross-sectional area at the zone of tracheal narrowing could be evaluated in 26 patients and was 58 +/- 17% (CT1/2) of the control area 2 cm above the carina (CT2). On X-ray the sagittal and coronal tracheal diameters at the zone of narrowing could only be measured in 16 subjects and were 60 +/- 17% (X-dia1/2) of the diameter at the control level. CT1/2 and X-dia1/2 were significantly correlated to each other. No correlation was found between the lung function tests and the radiological indices except airway resistance and CT2. Routine lung function and CT-scan do not provide comparable information on the degree of airway obstruction due to a goitre.(ABSTRACT TRUNCATED AT 250 WORDS)