bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exercise tolerance in children with cystic fibrosis undergoing lung transplantation assessment
Authors: Aurora P. , Prasad S.A. , Balfour-Lynn I.M. , Slade G. , Whitehead B. , Dinwiddie R. 
Published: July 2002

The aim of this study was to compare the 6-min walk test against the recently developed 3-min step test, as measures of exercise tolerance in children with moderate to severe cystic fibrosis (CF) lung disease referred for lung transplantation assessment.Twenty-eight children with CF (16 girls, 12 boys), with a mean age of 13.7 yrs (range 7.2–17.8 yrs) and mean forced expiratory volume in one second of 34% predicted (range 17%–67%) were recruited. All subjects performed both the 6-min walk and 3-min step-tests. Outcome measures were maximum rise in heart rate (HR), and maximum fall in arterial oxygen saturation (Sa,O2).There was no significant difference in resting HR orSa,O2prior to starting the two tests. Both step and walk tests produced significant rises in median HR (from 114–149 min−1, p<0.0005, and 119–138 min−1, p<0.0005, respectively) and significant falls inSa,O2(both from 94–92%, p<0.0005). The step test produced a significantly greater percentage rise in HR (30%versus18%, p<0.0005) and a significantly greater percentage fall inSa,O2(4%versus2%, p=0.002). Bland-Altman analysis gave wide 95% limits of agreement (10.7–29.3% for rise in HR, −2.1–4.6% for fall inSa,O2). The step test was well tolerated.The 3-min step test produced a greater fall inSa,O2and a greater rise in HR than the 6-min walk test in children with moderate to severe CF lung disease. It may be of value when assessing a child's suitability for lung transplantation.
Increased frequency dependence of specific airway resistance in patients with laryngeal hemiplegia
Authors: Fasano V. , Raiteri L. , Bucchioni E. , Guerra S. , Cantarella G. , Massari M.G. , Cesana B.M. , Allegra L. 
Published: July 2002

The aim of this study was to investigate whether patients with laryngeal hemiplegia (LH) show a frequency-dependent increase in specific airway resistance (sRaw), measured by body plethysmography.In addition to the flow-volume loop, usually considered in the functional evaluation of upper airway obstructions, variations in sRawat respiratory frequencies of 30±5 (=0.5 Hz), 60±5 (=1 Hz) and 90±5 breaths·min−1(=1.5 Hz) in 21 never-smoking patients (LH group, mean age±sd 55±12.09 yrs; 17 females) whose unilateral vocal-cord paralysis was documented by laryngoscopy and who had no signs or symptoms of other respiratory diseases studied. They were compared to 21 healthy control subjects (C group: 50.1±15.44 yrs; 10 females).The sRawvalues at 30±5 breaths·min−1were similar in the two groups (5.54±1.88versus5.68±1.06 cmH2O·s−1; p=ns), but at increasing frequencies (30±5, 60±5 and 90±5 breaths·min−1), they progressively and significantly increased in the LH patients (from 5.54±1.88 to 6.63±1.96 and 8.05±2.6 cmH2O·s−1; p<0.0005), and not significantly in controls (5.68±1.06, 5.85±0.95 and 5.9±1.12 cmH2O·s; p=ns). Linear discriminant analysis using ΔsRaw(sRawat 1.5 Hz-sRawat 0.5 Hz) and forced inspiratory flow at 50% of the vital capacity made it possible to correctly classify all of the controls and 19 of the 21 patients.In conclusion, the multiple, rapid and noninvasive plethysmographical testing of frequency-dependent increase in specific airway resistance with the flow-volume loop, allows the sufficiently satisfactory discrimination of laryngeal hemiplegia patients from controls.
Influence of setting on unattended respiratory monitoring in the sleep apnoea/hypopnoea syndrome
Authors: Lloberes P. , Sampol G. , Levy G. , Aristizabal D. , Sagales T. , De la Calzada M. , Roca A. , Cañas I. , Morell F. 
Published: July 2002

The high demand for full polysomnography and the better quality of sleep at home are the main reasons for performing home sleep studies. Home respiratory monitoring has been evaluated in several studies, but the influence of setting on the results of unattended respiratory monitoring has not been assessed to date.Unattended monitoring of respiratory variables at home and in the sleep laboratory was conducted in 35 consecutive patients with suspected sleep apnoea/hypopnoea syndrome. Respiratory variables during sleep, rate of successful studies and patient preference were compared.The data acquisition failure rate was 2.8% in the sleep laboratory and 5.7% at home. The mean difference between apnoea/hypopnoea indices (AHI) obtained from home and laboratory studies was −0.21±8 (95% confidence interval 3.27–2.84). Using the method comparison approach of Bland and Altman, the limits of agreement of the mean difference between AHI home and AHI laboratory were −16.7 and 17.1. No difference was observed between the studies in time spent in different body positions. When patients were asked where they would prefer to repeat the sleep study, 53% replied at home, 28% in hospital and 19% showed no preference.It was concluded that the setting of unattended respiratory monitoring (home or sleep laboratory) influences neither the number of valid studies nor the results of the respiratory parameters measured; most patients, however, preferred home studies.
Response of nitric oxide pathway to l-arginine infusion at the altitude of 4,350 m
Authors: Schneider J-C. , Blazy I. , Déchaux M. , Rabier D. , Mason N.P. , Richalet J-P. 
Published: July 2002

It was hypothesized that hypoxia may inhibit nitric oxide (NO) production by reducing the availability of endothelial NO synthase (NOS III) substrate.To evaluate the effect of l-arginine on the NO release in high altitude, 11 subjects were infused with l-arginine (0.5 g·kg−1) during 30 min in normoxia and after 36 h at 4,350 m (hypoxia). The l-citrulline and cyclic guanosine monophosphate (cGMP) concentrations were measured to investigate NO synthesis and guanylyl cyclase activity respectively. l-citrulline concentration, arterial oxygen saturation (Sa,O2), systemic blood pressure, heart rate and acute mountain sickness (AMS) score were measured at rest and 15, 30 and 45 min after starting infusion.The results showed that baseline l-citrulline was lower in hypoxia (p<0.05). l-arginine infusion increased l-citrulline concentration in both conditions. However, in hypoxia l-citrulline concentration remained lower than in normoxia (p<0.05). The concentration of cGMP was lower in hypoxia (p<0.05). In hypoxia,Sa,O2increased from 15 min after the start of the infusion to 45 min (p<0.05). Blood pressure and heart rate were not affected by l-arginine infusion.Subjects who experienced symptoms of AMS showed a slight decrease in AMS score with l-arginine.The decreased l-citrulline suggests a hypoxia-induced impairment of nitric oxide synthase III or a decrease in l-arginine availability. The improvement of arterial oxygen saturation by pretreatment with l-arginine could be ascribed to an enhancement of the ventilation/perfusion ratio. Collectively, these results are consistent with a decrease in nitric oxide production in hypoxia that could be antagonized by supplying nitric oxide synthase cosubstrate.
A new asthma severity index: a predictor of near-fatal asthma?
Authors: Lee P. , Abisheganaden J. , Chee C.B.E. , Wang Y.T. 
Published: July 2002

Bronchial hyperresponsiveness (BHR), measured as the provocative dose of inhaled histamine or methacholine required to produce a 20% fall in forced expiratory volume in one second (FEV1) (PD20), is widely used as one of the indices of asthma severity. Excessive bronchoconstriction, reflected by the maximal percentage fall in forced vital capacity (FVC) at PD20(ΔFVC %) during BHR testing, is considered to be the most important pathophysiological determinant in fatal asthma. The present study hypothesized that an index which combines both the ease of airway narrowing and excessive bronchoconstriction, ΔFVC %/log(PD20), may be better in assessing asthma severity, especially in those at risk of near-fatal attacks.The dose-response curves of 46 asthmatics who underwent methacholine challenge testing were studied. Group 1 (n=14) patients had mild disease, Group 2 (n=21) had moderate disease and Group 3 (n=11) had severe disease, as classified according to the Global Initiative for Asthma. Nine patients had prior intubation for near-fatal asthma.ΔFVC %/log (PD20) was better than ΔFVC % and PD20in categorizing patients into the three severity groups (p<0.0001), but more importantly, it was able to discriminate patients with previous intubation from those without (p=0.04). It also correlated better with FEV1(% predicted), frequency of symptoms and inhaled steroid requirement than either index alone.It is concluded that the percentage fall in forced vital capacity/log of the provocative dose causing a 20% fall in forced expiratory volume in one second combines information on the ease and excessive degrees of airway narrowing in asthma. This new index may be better at assessing asthma severity and in discriminating those at risk of near-fatal attacks.
Chronic intermittent hypercapnic hypoxia increases pulmonary arterial pressure and haematocrit in rats
Authors: McGuire M. , Bradford A. 
Published: July 2002

Sleep-disordered breathing is associated with pulmonary hypertension and raised haematocrit. The multiple episodes of apnoea in this condition cause chronic intermittent hypoxia and hypercapnia but the effects of such blood gas changes on pulmonary pressure or haematocrit are unknown. The present investigation tests the hypothesis that chronic intermittent hypercapnic hypoxia causes increased pulmonary arterial pressure and erythropoiesis.Rats were treated with alternating periods of normoxia and hypercapnic hypoxia every 30 s for 8 h per day for 5 days per week for 5 weeks, as a model of the intermittent blood gas changes which occur in sleep-disordered breathing in humans. Haematocrit, red blood cell count and haemoglobin concentration were measured each week and systemic and pulmonary arterial blood pressure and heart weight were measured after 5 weeks.In relation to control, chronic intermittent hypercapnic hypoxia caused a significant increase in systemic (104.3±4.7 mmHgversus121.0±10.4 mmHg) and pulmonary arterial pressure (20.7±6.8 mmHgversus31.3±7.2 mmHg), right ventricular weight (expressed as ratios) and haematocrit (45.2±1.0%versus51.5±1.5%).It is concluded that the pulmonary hypertension and elevated haematocrit associated with sleep-disordered breathing is caused by chronic intermittent hypercapnic hypoxia.
Changes in xylosyltransferase activity and in proteoglycan deposition in bleomycin-induced lung injury in rat
Authors: Koslowski R. , Pfeil U. , Fehrenbach H. , Kasper M. , Skutelsky E. , Wenzel K-W. 
Published: July 2002

Several lines of evidence support the hypothesis of the involvement of altered proteoglycan deposition in the development of lung diseases. UDP-d-xylose: core protein β-d-xylosyltransferase (UDP-xylosyltransferase; EC 2.4.2.26) is a key enzyme for the glycosylation of proteoglycan core proteins. This study examined the catalytic activity of UDP-xylosyltransferase in lung tissue and in isolated fibroblasts, as well as the deposition of the proteoglycans versican, biglycan and decorin in rat lung tissue during bleomycin-induced lung injury.Rats were given, endotracheally, a single dose of bleomycin. Deposition of proteoglycans in lung tissue was assessed by immunohistochemistry and the catalytic activity of xylosyltransferase was determined with an acceptor peptide of the sequence Q-E-E-E-G-S-G-G-G-Q-G-G as a substrate.The results show coincidence of increasing xylosyltransferase activities in lung tissue with accumulation of versican at alveolar entrance rings and in fibrotic regions in close proximity to α-smooth muscle actin-positive cells. In contrast, no changes in biglycan and decorin deposition in fibrotic lungs were observed, except for decorin in alveolar type II pneumocytes and alveolar macrophages. Bleomycin treatment of isolated rat lung fibroblasts resulted in a concentration-dependent increase of xylosyltransferase activity up to 2 mU bleomycin·mL−1.The data suggest a participation of myofibroblasts with increased xylosyltransferase activities in accumulation of versican in fibrotic foci of injured lung tissue at the early stages of development of lung fibrosis.
The repeatability of nonbronchoscopic bronchoalveolar lavage differential cell counts
Authors: Warke T.J. , Kamath S. , Fitch P.S. , Brown V. , Shields M.D. , Ennis M. 
Published: July 2002

Airway inflammation in children can be assessed by nonbronchoscopic bronchoalveolar lavage (BAL). Little is known about the repeatability of cell counts in the BAL obtained.Children (n=43) attending for elective surgery were studied. Cell counts were obtained following a nonbronchoscopic lavage. Two samples were obtained with either: 1) the catheter wedged in the same position (n=21) or 2) the catheter reinserted and wedged again (n=22). Slides (n=30) from nonbronchoscopic lavage samples were selected at random and two independent observers counted 500 cells on each slide on two occasions. The repeatability of the lavage sampling and cell counting was assessed for different cell types.The inter- and intra-observer repeatability for the differential cell counting demonstrated that there was good repeatability for all cell types except lymphocytes (interobserver: Lin's concordance coefficient 0.42; repeatability coefficient 0.66). Quantification of eosinophil (%) was highly repeatable using either method (Lin's concordance coefficient 1) 0.99, 2) 0.95; repeatability coefficient 1) 0.58, 2) 1.36).Nonbronchoscopic lavage is a repeatable technique for the quantification of eosinophils. Variation in the sampling method can be reduced by taking two separate samples and averaging the differential cell counts. Furthermore, increasing the number of cells counted should ensure accurate quantification of lymphocytes.
The European Community Respiratory Health Survey: what are the main results so far?
Authors: Janson C. , Anto J. , Burney P. , Chinn S. , de Marco R. , Heinrich J. , Jarvis D. , Kuenzli N. , Leynaert B. , Luczynska C. , Neukirch F. , Svanes C. , Sunyer J. , Wjst M. 
Published: July 2002

The European Community Respiratory Heath Survey (ECRHS) was the first study to assess the geographical variation in asthma and allergy in adults using the same instruments and definitions. The database of the ECRHS includes information from ∼140,000 individuals from 22 countries. The aim of this review is to summarize the results of the ECRHS to date.The ECRHS has shown that there are large geographical differences in the prevalence of asthma, atopy and bronchial responsiveness, with high prevalence rates in English speaking countries and low prevalence rates in the Mediterranean region and Eastern Europe. Analyses of risk factors have highlighted the importance of occupational exposure for asthma in adulthood. The association between sensitization to individual allergens and bronchial responsiveness was strongest for indoor allergens (mite and cat). Analysis of treatment practices has confirmed that the treatment of asthma varies widely between countries and that asthma is often undertreated.In conclusion, the European Community Respiratory Health Survey has shown that the prevalence of asthma varies widely. The fact that the geographical pattern is consistent with the distribution of atopy and bronchial responsiveness supports the conclusion that the geographical variations in the prevalence of asthma are true and most likely due to environmental factors.
“Haemoxygenase-1 induction and exhaled markers of oxidative stress in lung diseases”, summary of the ERS Research Seminar in Budapest, Hungary, September, 1999
Authors: Horváth I. , MacNee W. , Kelly F.J. , Dekhuijzen P.N.R. , Phillips M. , Döring G. , Choi A.M.K. , Yamaya M. , Bach F.H. , Willis D. , Donnelly L.E. , Chung K.F. , Barnes P.J. 
Published: July 2002

In recent years, there has been increasing interest in noninvasive monitoring of airway inflammation and oxidative stress. Several volatile and nonvolatile substances can be measured in exhaled breath and have been suggested as potential biomarkers of these events.Exhaled gases, including carbon monoxide (CO), alkanes (ethane, pentane), and substances measured in breath condensate, such as hydrogen peroxide (H2O2) and isoprostanes were all suggested as potential markers of oxidative stress in the lung.A European Respiratory Society (ERS) International Research Seminar entitled “Haemoxygenase-1 induction and exhaled markers of oxidative stress in lung diseases” was organized by the Airway Regulation and Provocation Group of the Clinical Allergy and Immunology Assembly in Budapest, Hungary in September, 1999 to integrate the latest knowledge on these issues and accelerate further improvement in this area. During this 2-day event several issues were raised about: the use and standardization of measurements in exhaled breath; problems of measuring expired H2O2and other mediators in breath condensate; role and regulation of haemoxygenase (HO)-1 in the lung; and conditions and factors influencing exhaled CO.This report is a summary of the main presentations at the seminar, together with the current areas of research in this rapidly expanding field.
Quantitative computed tomography assessment of lung structure and function in pulmonary emphysema
Authors: Madani A. , Keyzer C. , Gevenois P.A. 
Published: July 2002

Accurate diagnosis and quantification of pulmonary emphysema during life is important to understand the natural history of the disease, to assess the extent of the disease, and to evaluate and follow-up therapeutic interventions.Since pulmonary emphysema is defined through pathological criteria, new methods of diagnosis and quantification should be validated by comparisons against histological references.Recent studies have addressed the capability of computed tomography (CT) to quantify pulmonary emphysema accurately. The studies reviewed in this article have been based on CT scans obtained after deep inspiration or expiration, on subjective visual grading and on objective measurements of attenuation values. Especially dedicated software was used for this purpose, which provided numerical data, on both two- and three-dimensional approaches, and compared CT data with pulmonary function tests.More recently, fractal and textural analyses were applied to computed tomography scans to assess the presence, the extent, and the types of emphysema. Quantitative computed tomography has already been used in patient selection for surgical treatment of pulmonary emphysema and in pharmacotherapeutical trials. However, despite numerous and extensive studies, this technique has not yet been standardized and important questions about how best to use computed tomography for the quantification of pulmonary emphysema are still unsolved.
Long-term treatment of pulmonary hypertension with aerosolized iloprost
Authors: Machherndl S. , Kneussl M. , Baumgartner H. , Schneider B. , Petkov V. , Schenk P. , Lang I.M. 
Published: July 2002

Pulmonary arterial hypertension (PAH), defined as elevated pulmonary arterial pressure and pulmonary vascular resistance, is an end-point of a variety of conditions. The only therapy that has been shown to improve both quality of life and survival is intravenous prostacyclin (prostaglandin I2(PGI2), epoprostenol).The effect of long-term aerosolized iloprost (Ilomedin, Schering, Berlin, Germany and Vienna, Austria), a stable prostacyclin analogue and potent vasodilator, on haemodynamics and functional status was investigated in 12 patients with severe pulmonary hypertension. Haemodynamic measurements and vasodilator testing by right heart catheterization were performed prior to and after long-term iloprost inhalation therapy.Haemodynamic improvement or increased exercise tolerance was not observed in any of the patients. After a mean±sd treatment period of 10±5 months, mean±sd pulmonary vascular resistance had increased from 11±3 Wood Units (mmHg·L−1·min) to 13±4 Wood Units, with unchanged arterial oxygen saturation (92±4%versus91±4%). Within the study period, three patients went into right heart failure and had to be placed on intravenous epoprostenol.The authors conclude that inhaled iloprost in addition to conventional therapy in the presently recommended dose of 100 µg·day−1delivered in 8–10 2 h portions, is not an efficient vasodilator therapy in severe pulmonary hypertension. It remains to be shown whether dose increases and/or combination protocols will be effective, or whether inhalation of iloprost may be safe for selected cases of pulmonary hypertension.
Methacholine inhalation challenge: a shorter, cheaper and safe approach
Authors: Izbicki G. , Bar-Yishay E. 
Published: July 2002

Increased nonspecific bronchial hyperresponsiveness to pharmacological agents such as histamine or methacholine (MCh) is a hallmark of asthma. The measurement of airway reactivity is quite sensitive but testing is tedious, and time and money consuming. The present aim was, therefore, to design the shortest possible, yet safe inhalation challenge protocol applicable for a lung function referral centre.All records of studies performed in our institution during 1996 were analyzed retrospectively with a baseline ratio (bl) of forced expiratory volume in one second/forced vital capacity (FEV1/FVC) ≥0.7 (n=449). It was questioned what the initial dose should be, and whether some inhalation steps could have been skipped without losing pertinent information and/or causing an adverse response (a fall in FEV1>40%). When unavailable, provocative dose causing a 20% fall in FEV1(PD20) values were obtained by linear inter- or extrapolation of the existing data.The present study showed that three-fold concentration steps could have been employed with minimal change in outcome. Only 15/449 patients (3.3%) would have experienced a severe response. Five subjects (of 169, 3.0%) with FEV1/FVCbl0.7–0.8 reacted to inhalation up to 0.073 µmol. Four subjects (of 280, 1.4%) with FEV1/FVCbl≥0.8 reacted to inhalation up to 0.219 µmol.The authors suggest that: 1) an initial dose of 0.219 µmol (initial concentration=0.21 mg·mL−1) may be used when the baseline ratio of forced expiratory volume in one second to forced vital capacity ≥0.8 and 0.073 µmol (initial concentration=0.07 mg·mL−1) when the baseline ratio is <0.8; 2) a tripling dose protocol is easier to perform, cheaper and 30.2% faster, yet just as safe; and 3) other abbreviated protocols used in epidemiologic settings may not be applicable in a referral centre setting.