bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induced sputum: time from expectoration to processing
Authors: Efthimiadis A. , Jayaram L. , Weston S. , Carruthers S. , Hargreave F.E. 
Published: July 2002

One of the limitations in the use of induced sputum to measure indices of airway inflammation is the perceived need to process the sample within 2 h. Therefore, the authors investigated whether the processing of induced sputum could be delayed.Induced sputum samples obtained from asthmatic subjects (n=30) were examined. Each sample was stored at 4°C. A portion was selected and processed within 2 h and the remaining expectorate (sputum plus saliva) was refrigerated. Later an equal amount was selected and processed at either 9 (n=15) or 18 (n=15) h. The sputum was examined for cell counts and viability, fluid-phase eosinophil cationic protein (ECP), interleukin‐8 (IL‐8) and fibrinogen. Repeatability of measurements was assessed by the interclass correlation coefficient (ICC).Measurements obtained at 9 h did not differ from those made at 2 h and the repeatability was excellent (ICC 0.88–0.99). However, by 18 h the median cell viability was reduced from 65.0% to 43.0% and the ICC was generally lower: 0.10 for total cell count, 0.24 for viability, 0.60 for neutrophils, 0.90 for eosinophils, 0.56 for macrophages, 0.76 for ECP, 0.82 for IL‐8 and 0.84 for fibrinogen.The results indicate that when induced sputum from subjects with asthma is kept at 4°C, examination of cell counts can be delayed for ⩽9 h and for the fluid-phase indices measured for ⩽18 h. Further investigation of this issue is required for spontaneous sputum, other airway diseases and other inflammatory markers.
Obstructive sleep apnoea and urine catecholamines in hypertensive males: a population-based study
Authors: Elmasry A. , Lindberg E. , Hedner J. , Janson C. , Boman G. 
Published: July 2002

Studies addressing the relationship between obstructive sleep apnoea (OSA) and sympathoadrenal activity have been criticized for poor control of factors known to confound sympathetic function, including hypertension. The aim of this study was to investigate the relationship between OSA and urinary catecholamines in a population-based sample of hypertensive males.In 1994, 2,668 males aged 40–79 yrs answered a questionnaire regarding sleep disorders and somatic diseases. Of those who reported hypertension, an age-stratified sample of 116 was selected for monitoring of breathing during sleep and overnight urine analysis.Subjects with OSA, defined as apnoea-hypopnoea index ≥10·h−1, had higher concentrations of urinary normetanephrine (182±57versus141±45 µmol·mol−1creatinine, p<0.001) and metanephrine (70±28versus61±28 µmol·mol−1creatinine, p<0.05) in comparison to subjects without OSA. In a multiple regression analysis, there was an association between variables of sleep-disordered breathing and normetanephrine and metanephrine concentrations, independent of major confounding factors.The authors concluded that, in a population-based sample of hypertensive males, obstructive sleep apnoea is associated with increased urinary concentrations of extraneuronal metabolites of catecholamines independent of major confounding factors, suggesting increased sympathoadrenal activity. Elevated sympathoadrenal activity may explain the increased cardiovascular morbidity associated with obstructive sleep apnoea.
Anti-Chlamydophila immunoglobulin prevalence in sarcoidosis and usual interstitial pneumoniae
Authors: Gaede K.I. , Wilke G. , Brade L. , Brade H. , Schlaak M. , Müller-Quernheim J. 
Published: July 2002

Sarcoidosis and usual interstitial pneumoniae (UIP) are diseases of unknown aetiology affecting the lower respiratory tract. Although there are a number of studies investigating the causal role of these disorders, no micro-organism could be identified as the causal agent. The high incidence ofChlamydophila pneumoniaeinfections associated with lung injury encouraged the present investigations to screen patients with sarcoidosis and with UIP for their Chlamydophila-specific immune response.Thirty-nine patients with sarcoidosis, 26 patients with UIP and 34 controls were tested for the prevalence of Chlamydophila-specific antibodies in bronchoalveolar lavage fluids (BALF) and sera. Samples were tested for the presence of antibodies in a genus-specific test for Chlamydophila-lipopolysaccharide (LPS) and in a species-specific test forC. pneumoniae.This study revealed a significantly higher prevalence of Chlamydophila LPS-specific immunoglobulin (Ig)-G in the BALF of sarcoidosis patients (36.8%) compared to controls (8.8%) and patients with UIP (12.0%). Similar findings were observed in sera. The prevalence ofC. pneumoniae-specific antibodies in BALF was significantly higher in sarcoidosis patients for IgG and IgA (IgG: 74.4%; IgA: 46.2%) and in UIP for IgG (IgG: 50.0%; IgA: 11.5%) compared to controls (IgG: 14.7%; IgA: 14.7%).The elevated prevalence of Chlamydophila-specific antibodies in sarcoidosis patients might implicate Chlamydophila as a causal agent. However, considering the high prevalence of Chlamydophila antibodies in the healthy population, the data presented might reflect Chlamydophila co-infections in pre-injured lungs seen in these patients.
Potential masking effect on dyspnoea perception by short- and long-acting β2-agonists in asthma
Authors: van Schayck C.P. , Bijl-Hofland I.D. , Cloosterman S.G.M. , Folgering H.T.M. , van der Elshout F.J.J. , Van Weel C. 
Published: July 2002

Asthma patients evaluate the effect of medication treatment through the degree of their asthma symptoms, which might be affected by their ability to perceive these symptoms. It has been suggested that β2-agonists may mask the effects of an increase in airway inflammation. This study compared the perception of histamine-induced bronchoconstriction during monotherapy with short- or long-acting β2-agonists.Asthmatic patients (68 male and 60 female, mean age 35±11 yrs, forced expiratory volume in one second (FEV1) 86±15% of the reference value, provocative concentration causing a 20% fall in FEV1(PC20) geometric mean 0.97 mg·mL−1(95% confidence interval (CI): 0.73–1.30)) were selected and randomly allocated to use either a short-acting (salbutamol, n=41) or long-acting β2-agonist (formoterol, n=46) or placebo (n=41) for 12 weeks. Perception of dyspnoea provoked by histamine-induced bronchoconstriction was measured at the start and every 4 weeks thereafter. Subjects quantified their sensation of breathlessness during the challenge tests on a modified Borg scale at the start of the study and every 4 weeks thereafter. The sensitivity to changes in FEV1was analysed by the linear regression slope (α) Borgversus% fall in FEV1. The absolute perceptual magnitude (PS20) was determined by the perception score at the 20% fall in FEV1.Although the geometric mean PC20decreased significantly within the group using short-acting β2-agonists (in the group with initial PC20≥2 mg·mL−1there was a drop from 5.26–1.94 mg·mL−1; p=0.013), repeated measurement analysis showed no difference in the course of time of perception (both slope α and PS20) between the three medication groups.This study showed that chronic use of short- or long-acting β2-agonists in asthmatics for a period of 12 weeks, did not significantly change the perception of histamine-induced bronchoconstriction compared with placebo. Further investigation is required to establish whether this suggests that these drugs do not mask a deterioration of asthma.
Increased soluble CD14 in bronchoalveolar lavage fluid of stable lung transplant recipients
Authors: Ward C. , Walters E.H. , Zheng L. , Whitford H. , Williams T.J. , Snell G.I. 
Published: July 2002

Macrophages, neutrophils and infection have been implicated in the genesis of the bronchiolitis obliterans syndrome (BOS) post lung transplantation. sCD14 is a soluble form of a shed-cell surface protein. It is capable of promoting cytokine-induced inflammation and it's presence in clinically stable lung transplant recipients (LTR) might be important as an early marker of BOS.Bronchalveolar lavage (BAL) and blood samples were taken from 26 stable LTR, at or near their best forced expiratory volume in one second who were free from infection. sCD14 levels were measuredviaenzyme-linked immunosorbent assay. Cell counts were performed on unfiltered BAL.LTR neutrophil count, BAL sCD14 and serum sCD14 levels were higher than controls (median 3.8%versus1.3%, p<0.05; 11.5 ng·mL−1versus6 ng·mL−1, p<0.001; 6.2 µg·mL−1versus2.4 µg·mL−1, p<0.05, respectively). BAL albumin and sCD14 correlated (regression coefficient: 0.77, p<0.001).In this hypothesis-generating, cross-sectional study, the authors have described for the first time soluble CD14 levels in the bronchoalveolar lavage and serum of stable lung transplant recipients, and show that these are elevated compared to controls. This is a practicable candidate marker system, which can be tested for a predictive role in bronchiolitis obliterans syndrome following lung transplantation. The origin of this cellular protein and its temporal relationship to the development of the bronchiolitis obliterans syndrome remains to be elucidated in more definitive longitudinal studies, which should include other measurements potentially relevant to the innate immune system, such as bronchoalveolar lavage endotoxin levels.
Mechanisms and markers of airway inflammation in cystic fibrosis: Fig. 1.—
Authors: De Rose V. 
Published: July 2002

Airway inflammation is now recognized as a major factor in the pathogenesis of lung disease in cystic fibrosis (CF). Its most characteristic feature is a marked and persistent influx into the airways of neutrophils, which damage the lung by releasing noxious mediators, such as reactive oxygen species and proteolytic enzymes.Recent studies suggest that inflammation occurs very early and may even happen in the absence of infection. Furthermore, links between CF transmembrane conductance regulator dysfunction and both infection and inflammation are postulated; dysregulation of cytokine production and abnormal epithelial host defences have been regarded as causes of sustained inflammation.Bronchoalveolar lavage and the evaluation of neutrophils and inflammatory mediators provide the most accurate picture of airway inflammation. Routine bronchoscopy with bronchoalveolar lavage, however, is unpleasant for the patient and usually is of no immediate benefit to the management of individual cases.Therefore, surrogate markers collected by noninvasive procedures would be of great assistance in the follow-up of cystic fibrosis patients. Several markers have been evaluated in the sputum, serum and urine of cystic fibrosis patients and related to the degree of airway inflammation. Long-term studies are needed to confirm their potential clinical utility and specificity, and to determine which can be used clinically to monitor disease outcome and efficacy of treatment.
Effect of chest wall vibration on the canine diaphragm during breathing
Authors: Leduc D. , De Troyer A. 
Published: July 2002

High-frequency mechanical vibration of the ribcage reduces dyspnoea in patients with chronic obstructive pulmonary disease, and the suggestion has been made that this effect might be related to a decrease in central respiratory drive resulting from an increase in afferent inputs from intercostal muscles. In the present studies, the effects of ribcage vibration on central respiratory drive have been assessed without the confounding influence of conscious reactions.The electromyographic (EMG) activity of the diaphragm and the changes in pleural (Ppl) and abdominal (Pab) pressure were measured in six anaesthetized, spontaneously-breathing dogs while the rostral, the middle, or the caudal portion of the ribcage was vibrated at intervals during inspiration. The EMG activity of the external and parasternal intercostals was also measured.Ribcage vibration consistently elicited a marked increase in the inspiratory EMG activity recorded from the external intercostals, thus indicating that the procedure did activate intercostal muscle spindles. However, no alteration in diaphragmatic or parasternal intercostal EMG activity was seen in any animal. Transdiaphragmatic pressure and the relationship between ΔPaband ΔPplduring inspiration were also unaltered.The authors conclude that ribcage vibration and, with it, stimulation of external intercostal muscle spindles has no significant influence on phrenic motoneurones or on medullary inspiratory neurones. It is unlikely, therefore, that the beneficial effect of the procedure on dyspnoea results from a specific reduction in central respiratory drive.
Characterization of pulmonary vascular remodelling in smokers and patients with mild COPD
Authors: Santos S. , Peinado V.I. , Ramírez J. , Melgosa T. , Roca J. , Rodriguez-Roisin R. , Barberà J.A. 
Published: July 2002

Intimal enlargement of pulmonary arteries is an early change in chronic obstructive pulmonary disease (COPD). The cellular and extracellular components that are involved in this enlargement are unknown. The present study was designed to characterize the structural changes occurring in pulmonary muscular arteries in the initial disease stages.Lung specimens from patients with moderate COPD (n=8; forced expiratory volume in one second (FEV1), 66±10% predicted) and smokers without airflow obstruction (n=7; FEV1, 86±6% pred), were investigated by histochemistry to characterize extracellular matrix proteins and by immunohistochemistry to identify intrinsic cells of the vascular wall.In both COPD patients and smokers, the majority of cells present in the enlarged intimas were stained by specific smooth muscle cell (SMC) markers. No staining with endothelial or fibroblast markers was shown. A proportion of SMCs did not stain with desmin, suggesting cellular heterogeneity in this population. Elastin was the most abundant extracellular matrix protein and collagen was seen in a lower proportion. The amount of collagen was related to the intimal thickness (p<0.001).The findings demonstrated smooth muscle cell proliferation, as well as elastin and collagen deposition, in the thickened intimas of pulmonary arteries in moderate chronic obstructive pulmonary disease patients and smokers, suggesting that these abnormalities may originate at an early stage in cigarette smoke-induced respiratory disease.
Free, soluble interleukin-17 protein during severe inflammation in human airways
Authors: Laan M. , Palmberg L. , Larsson K. , Lindén A. 
Published: July 2002

Studies in rodents indicate that the cytokine, interleukin (IL)-17, links the activation of T-lymphocytes to neutrophilic inflammation. The aim of the current study was to determine whether free, soluble IL-17 protein can be released during severe inflammation in human airways.Fifteen healthy subjects were exposed to a swine confinement in order to induce severe inflammation characterized by high neutrophil numbers in the airways. Bronchoalveolar lavage (BAL) fluid was harvested 2 weeks prior to and 24 h after this exposure and the concentration of IL-17 protein was measured using an enzyme-linked immunosorbent assay. Total and cell differential counts were also performed in BAL fluid.Prior to exposure to the swine confinement, the concentration of IL-17 in BAL fluid was low (<7.8 pg·mL−1) in 14 out of 15 subjects. However, exposure to the swine confinement caused an increase in IL-17 in 13 out of 15 subjects (median IL-17 concentration of 26.9 pg·mL−1). This exposure also caused a 51-fold increase in the concentration of neutrophils in BAL fluid.To conclude, free, soluble interleukin-17 protein can be released during severe inflammation characterized by high neutrophil numbers in human airways. The significance of interleukin-17 in inflammatory airway diseases therefore deserves further evaluation.
Effects of lung volume reduction surgery in hamsters with elastase-induced emphysema
Authors: Marchand E. , De Leyn P. , Gayan-Ramirez G. , Palecek F. , Verbeken E. , Decramer M. 
Published: July 2002

Lung volume reduction surgery (LVRS) has been shown to improve respiratory mechanics in selected patients with severe emphysema. This is thought to be due to an improvement in lung elastic recoil. This study was aimed at gaining further understanding about the effects of LVRS on respiratory mechanics and airway function.Control hamsters instilled with saline (Ctrl; n=8) were compared with emphysematous animals that underwent either a sham operation (Sham; n=7) or an LVRS (LVRS; n=7).As expected, there was a significant increase in the static lung volumes in the Sham as compared to the Ctrl group and a significant decrease of these volumes in LVRS as compared to the Sham group. Surprisingly, emphysema was associated with a significant increase and LVRS with a significant decrease in vital capacity. Despite a tendency toward an increase in lung compliance as compared to Sham, indices of maximal expiratory flows tended to decrease with LVRS. As opposed to humans, there was no change in the distribution of airway diameters in Sham compared to Ctrl.These findings appear to be largely explained by the high compliance of the hamster chest wall. This allows for better matching between the emphysematous lung and the chest-wall sizes than in humans.
Multicomponent AVO analysis, Vacuum field, New Mexico
Authors: DeVault Bryan , Davis Thomas L. , Tsvankin Ilya , Verm Richard , Hilterman Fred 
Published: July 2002

Shear‐wave amplitude variation with offset (AVO) analysis can be used to map changes in density, shear‐wave velocity, and fracturing at reservoir scale by allowing the influence of each factor to be separately extracted from the observed seismic response. Weighted least‐squares inversion of the anisotropic reflection coefficients was implemented to find the shear‐wave splitting coefficient and velocity‐contrast parameters. A time‐lapse nine‐component, 4‐D seismic survey acquired over Vacuum field in Lea County, New Mexico, was used to test our methodology of shear‐wave AVO analysis and to compare the results with well production and azimuthal P‐wave AVO analysis.Weighted least‐squares shear‐wave AVO stacks of the splitting parameter were found to be excellent predictors of well fluid‐production performance, implying a strong link between seismically inferred fracturing and reservoir‐scale permeability of the San Andres dolomites at Vacuum field. Analysis of the shear‐wave velocity contrast indicated the presence of a second set of open fractures to the south of a carbon dioxide injector well where a 4‐D anomaly associated with injection had been observed.
Practical applications of uniqueness theorems in gravimetry: Part I—Constructing sound interpretation methods
Authors: Silva João B. C. , Medeiros Walter E. , Barbosa Valéria C. F. 
Published: July 2002

To obtain a unique and stable solution to the gravity inverse problem, a priori information reflecting geological attributes of the gravity source must be used. Mathematical conditions to obtain stable solutions are established in Tikhonov's regularization method, where the a priori information is introduced via a stabilizing functional, which may be suitably designed to incorporate some relevant geological information. However, there is no unifying approach establishing general uniqueness conditions for a gravity inverse problem. Rather, there are many theorems, usually establishing just abstract mathematical conditions and making it difficult to devise the type of geological information needed to guarantee a unique solution. In Part I of these companion papers, we show that translating the mathematical uniqueness conditions into geological constraints is an important step not only in establishing the type of geological setting where a particular method may be applied but also in designing new gravity inversion methods. As an example, we analyze three uniqueness theorems in gravimetry restricted to the class of homogeneous bodies with known density and show that the uniqueness conditions established by them are more probably met if the solution is constrained to be a compact body without curled protrusions at their borders. These conditions, together with stabilizing conditions (assuming a simple shape for the source), form a guideline to construct sound gravity inversion methods. A historical review of the gravity interpretation methods shows that several methods implicitly follow this guideline. In Part II we use synthetic examples to illustrate the theoretical results derived in Part I. We also illustrate that the presented guideline is not the only way to design sound inversion methods for the class of homogeneous bodies. We present an alternative approach which produces good results but whose design requires a good dose of the interpreter's art.
Metalliferous mining geophysics—State of the art in the last decade of the 20th century and the beginning of the new millennium
Authors: Nabighian Misac N. , Asten Michael W. 
Published: July 2002

The downturn in mining activity experienced during the 1990s did not preclude significant new developments in various areas of mining geophysics. The methodology for acquiring and compiling data has kept pace with the latest technological developments, from Global Positioning System navigation to raster displays and parallel computing. Wavelet transforms, principal component analysis, and fractals have begun to find successful applications in both processing and interpretation of geophysical data. Methods of quantitatively interpreting/inverting anomalies in terms of 2‐D and 3‐D models of causative bodies are becoming common.For the first time it is possible to make airborne gravity gradient measurements suitable for use in mineral exploration. Lower transmitter frequencies for airborne time‐domain electromagnetic (EM) systems have enabled surveys in areas where conductive cover previously screened basement conductors. The use of approximation algorithms has allowed the transformation of either time‐domain or frequency‐domain data into conductivity‐depth images (CDIs) which expedite interpretation. Full‐waveform recording and the use of multiple receivers are becoming common for ground EM techniques.In radiometrics it is now common practice to record 256 channels of spectral data which, by using statistical methods, has led to a dramatic reduction of noise in aerial gamma‐ray surveys. Finally, advances in 3‐D oil‐field seismic reflection methods have been introduced into the search for mineral deposits, thereby providing new tools for studying the environment of orebody emplacement as well as detailed geometrical information of value for both exploration and mine‐planning applications.Thus, at the beginning of the 21st century, we find the geophysical techniques used by the mining industry to be at the forefront of the latest technological developments.