bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nerve growth factor levels and localisation in human asthmatic bronchi
Authors: Olgart Höglund C. , de Blay F. , Oster J-P. , Duvernelle C. , Kassel O. , Pauli G. , Frossard N. 
Published: November 2002

Nerve growth factor (NGF) has recently been suggested to be an important mediator of inflammation. In support of this, serum levels of NGF have been shown to be enhanced in asthmatics. However, it has not yet been shown whether the levels of NGF are also altered locally in asthmatic airways, when compared with healthy subjects, and the localisation of potential sources of NGF in the human bronchus have not yet been described. The aim of the present study was to assess NGF levels in bronchoalveolar lavage fluid (BALF) from asthmatics and to compare them to those of control subjects. Furthermore, the authors wanted to localise potential sources of NGF in bronchial tissue, and to number NGF-immunopositive infiltrating cells in the bronchial submucosa.BALF and bronchial biopsies were obtained from seven control subjects and seven asthmatic patients by fibreoptic bronchoscopy. NGF protein levels were quantified by enzyme-linked immunosorbent assay in BALF. NGF localisation was examined by immunohistochemistry on bronchial biopsy sections.The asthmatics exhibited significantly enhanced NGF levels in BALF. Intense NGF-immunoreactivity was observed in bronchial epithelium, smooth muscle cells and infiltrating inflammatory cells in the submucosa, and to a lesser extent in the connective tissue. The asthmatics exhibited a higher number of NGF-immunoreactive infiltrating cells in the bronchial submucosa than control subjects.This study provides evidence that nerve growth factor is locally produced in the airways, and shows that this production is enhanced in asthmatics. These findings suggest that nerve growth factor is produced by both structural cells and infiltrating inflammatory cells in human bronchusin vivo, and the authors suggest that the increase in nerve growth factor protein in bronchoalveolar lavage fluid observed in asthmatic patients may originate both from structural cells, producing increased nerve growth factor levels in inflammatory conditons, and from the increase in nerve growth factor-immunopositive cells determined in the bronchial submucosa.
Asbestos bodies in the sputum of asbestos workers: correlation with occupational exposure
Authors: Paris C. , Galateau-Salle F. , Creveuil C. , Morello R. , Raffaelli C. , Gillon J.C. , Billon-Galland M.A. , Pairon J.C. , Chevreau L. , Letourneux M. 
Published: November 2002

A cross-sectional medical survey including collection of three consecutive sputum samples was carried out among 270 retired workers of a textile and friction materials factory, in order to investigate the relationship between asbestos body identification and asbestos exposure.The individual cumulative asbestos exposure, determined by means of a plant-specific job-exposure matrix based on asbestos air measurements in the workshops, proved to be heavy with a mean cumulative exposure of 217 fibres·mL−1×yr. Macrophages and asbestos bodies were identified in sputum samples by light microscopy.The lung origin of the sputum, suggested by the presence of macrophages and/or asbestos bodies, was confirmed in 82.6% of subjects, and 53% of these samples were positive for asbestos bodies. The prevalence of asbestos bodies was not related to sex, smoking status or latency. Conversely, multivariate analysis showed a positive relationship with cumulative exposure, duration and intensity of exposure to asbestos, as well as age and time since retirement.These findings suggest that sputum analysis for asbestos bodies may remain a relevant and noninvasive marker of heavy occupational exposure to asbestos, even years after retirement. Owing to the new perspectives in lung cancer screening, it might contribute to the identification of high-risk subjects.
Murine gammaherpes virus as a cofactor in the development of pulmonary fibrosis in bleomycin resistant mice
Authors: Lok S.S. , Haider Y. , Howell D. , Stewart J.P. , Hasleton P.S. , Egan J.J. 
Published: November 2002

Studies of human tissue have suggested an association between productive Epstein Barr virus and idiopathic pulmonary fibrosis (IPF). However, a pathogenic role for the virus has not been established. This study was undertaken to develop an animal model, which would explore the association between viral infection and pulmonary fibrosis.BALB/c mice (n=30), resistant to bleomycin, were primed with murine gammaherpesvirus 68 and then given intraperitoneal bleomycin. The mice were sacrificed at 28 days after bleomycin and their lungs assessed histologically and biochemically. Lung pathology was scored 0–3 for fibrotic and inflammatory change.BALB/c mice given virus and bleomycin showed more lung fibrosis (median score 2.2) compared to those given bleomycin alone (median 0), virus alone (median 0.2) or phosphate-buffered saline (PBS) control (median 0). Similarly mice given both virus and bleomycin showed more lung inflammation (median score 1.9) compared to those given bleomycin (median 0.5), virus (median 0.8), or PBS control (median 0.2). There was a significant difference in collagen content between the bleomycin and virus group (mean 1.86 mg) compared to the belomycin alone group (mean 1.52 mg).These results suggest that virus alone does not result in pulmonary fibrosis but that replicating virus in the presence of an exogenous injury may promote the development of pulmonary fibrosis.
Dose reduction of inhaled corticosteroids under concomitant medication with montelukast in patients with asthma
Authors: Kanniess F. , Richter K. , Janicki S. , Schleiss M.B. , Jörres R.A. , Magnussen H. 
Published: November 2002

The present study aimed at comparing the effects of a dose reduction of inhaled corticosteroids on lung function, indirect measures of airway inflammation and clinical scores during treatment with a leucotriene receptor antagonist.In 50 patients (mean forced expiratory volume in one second (FEV1) 94% predicted), steroid doses (800 µg beclomethasone dipropionate) were first reduced to 50% and then to 25%, for 6 weeks each. One group received a placebo and the other group received montelukast (10 mg).The first reduction did not cause significant effects. During the second, FEV1and peak expiratory flow decreased in both groups (p<0.001). Daytime symptoms were not altered with placebo but were reduced by montelukast (p<0.05). Night-time symptoms were slightly elevated with placebo (p<0.05) but not montelukast, as well as the use of supplemental salbutamol. Changes in provocative concentration of methacholine causing a 20% fall in FEV1(PC20), sputum eosinophils and exhaled nitric oxide were mostly nonsignificant for both placebo and montelukast.These data demonstrate that a 75% reduction in the dose of steroid given to patients with asthma led to a deterioration in lung function not prevented by montelukast, whereas changes in clinical state seemed to favour montelukast treatment. It therefore appears that potential effects of montelukast, in the presence of low-dose steroids, could not be attributed to single indices of lung function or airway inflammation.
Factors associated with unknown aetiology in patients with community-acquired pneumonia
Authors: Ewig S. , Torres A. , Ángeles Marcos M. , Angrill J. , Rañó A. , de Roux A. , Mensa J. , Martínez J.A. , de la Bellacasa J.P. , Bauer T. 
Published: November 2002

Despite comprehensive diagnostic work-up, the aetiology of community-acquired pneumonia (CAP) remains undetermined in 30–60% of cases. The authors studied factors associated with undiagnosed pneumonia.Patients hospitalised with CAP and being evaluated by two blood cultures, at least one valid lower respiratory tract sample, and serology on admission were prospectively recorded. Patients who had received antimicrobial pretreatment were excluded. Patients with definite or probable aetiology were compared to those with undetermined aetiology by uni- and multivariable analysis.A total 204 patients were eligible for the study. The aetiology remained undetermined in 82 (40%) patients, whereas a definite aetiology could be established in 89 (44%) and a probable one in 33 (16%). In multivariable analysis, factors associated with undetermined aetiology included age >70 yrs, renal and cardiac comorbidity, and nonalveolar infiltrates on the chest radiograph. There was no association of undiagnosed pneumonia with mortality.Age and host factors were associated with unknown aetiology of community-acquired pneumonia. Some of these cases may also represent fluid volume overload mimicking pneumonia.
Serum levels of CC16, SP-A and SP-B reflect tobacco-smoke exposure in asymptomatic subjects
Authors: Robin M. , Dong P. , Hermans C. , Bernard A. , Bersten A.D. , Doyle I.R. 
Published: November 2002

Since the 16-kDa bronchiolar Clara cell protein (CC16) and the alveolar surfactant-associated proteins (SP)-A and -B leak into the circulation when parenchymal health is disturbed, the aim of this study was to determine whether their serum levels could serve as early peripheral markers of tobacco smoke-induced epithelial injury.Sixty-nine (51 yrs (32–54) median (25–75th percentile)) nonsmokers and 54 (42 yrs (31–53)) asymptomatic smokers were enrolled in the study.Serum levels of SP-A did not differ between subjects (270 (208–389)versus259 (168–392) µg·L−1), however, CC16 levels decreased (10.6 (8.7–14.6)versus7.6 (6.0–11.2) µg·L−1) and SP-B levels increased (2,529 (2,091–2,943)versus3,053 (2,613–4,188) µg·L−1) in the smokers. When tobacco smoke exposure, serum creatinine (renal index), age and sex were used as independent variables, CC16 was negatively influenced by cumulative smoking and positively influenced by age. SP-A and -B were negatively influenced by creatinine and positively influenced by cumulative smoking. Serum SP-B was inversely correlated with forced expiratory volume in one second/vital capacity, suggesting an association between obstructive disease and parenchymal lung health.The authors suggest that serum surfactant-associated proteins-A and -B reflect increased alveolocapillary leakage whereas Clara cell secretory protein 16 reflects tobacco smoke-induced Clara cell toxicity. Their evaluation may allow the effects of tobacco smoke on different levels of the respiratory tract, cellular toxicity and epithelial leakage to be distinguished.
Parameter selection by an artificial neural network for a laser bending process
Authors: Casalino G , Ludovico A D 
Published: November 2002

Based on thermally induced plastic deformations produced by laser irradiation, metal sheet laser bending can be a valid alternative to dies for rapid prototyping and manufacturing. Some numerical models have been built in order to improve the understanding and prediction of mechanisms. Drawbacks entailed with those models have been found. Finite element model simulation has proved to be time and CPU (central processing unit) memory consuming. The analytical models have been cumbersome and unsatisfactory. Nowadays, it is possible to build a neural network model for process modelling directly from data collected during the experiments. In this paper a feed-forward neural network with a back-propagation learning function has been designed and its performances have been evaluated for metal sheet laser bending. This technique has proved to be effective and efficient, providing the process parameters that are necessary to achieve a desired bending angle.
An implementation of the business process modelling approach in the automotive industry
Authors: Monfared R P , West A A , Harrison R , Weston R H 
Published: November 2002

The development and application of a business process modelling approach to comprehend, formalize, simulate and assess a particular domain within the automotive industry are described in this paper. Within an ongoing project carried out by Loughborough University, the design and implementation of a new generation of component-based machine control systems are being investigated. As part of this project, impacts of business and technical aspects of the new control systems on existing practices are also being examined using enterprise modelling methods and tools. The modelling has been applied to the production and assembly of a machine for a new engine project in the automotive industry. The modelling approach has been based on the CIMOSA modelling architecture and complementary simulation and analysis tools, mainly ithink™ and Excel. The lessons learned from the implementation of the modelling approach and the assessment of the component-based machine control systems are also discussed in this paper. The criteria of this assessment were considered primarily as cost and time, although other factors that ultimately impact on the business processes are also discussed.
Numerical study of a Sahelian synoptic weather system: Initiation and mature stages of convection and its interactions with the large‐scale dynamics
Authors: Diongue A. , Lafore J.‐P. , Redelsperger J.‐L. , Roca R. 
Published: November 2002

AbstractA 24 h multi‐scale simulation of the life cycle of a Sahelian squall line is presented. The initial and coupling fields have been taken from the European Centre for Medium‐Range Weather Forecasts re‐analysis (ERA‐15) after humidity corrections to avoid spurious absolute and conditional convective instabilities. Comparisons of model‐synthetic and Meteosat infra‐red radiances indicate that the simulated scenario of convection development and structure are realistic, though differences are found concerning the size of the squall line with a delay of 2–3 h. The simulated arc‐shaped structure and surface signature fit well with radar and ground station observations, respectively.The mature stage of the simulated squall line presents a cross‐line structure similar to conceptual models. An intense rear‐to‐front flow is generated below the trailing stratiform part. An acceleration of the African easterly jet (AEJ) is simulated behind the system, occurring across its full width. This leads to the generation of a dipole of counter‐rotating vortices. The resulting potential‐vorticity signature leads to local reinforcement of the barotropic instability on the north flank of the AEJ.This simulation is used to analyse the impact of the convection at synoptic‐scales and to compare it with ERA‐15. It suggests that the convection contributes to reinforce the monsoon at least up to 500 km. The monsoon inflow moves eastward and westward with time‐scales shorter and longer than 24 h, respectively. The tropical easterly jet intensifies to the south‐west of the convection area up to 700 km away. The AEJ is strongly intensified ahead of the trough where active convection occurs. Organized convection developing in the vicinity of the AEJ core induces weakening of the AEJ ahead of the squall line and strengthening behind it. A common result in the simulation and in ERA‐15 is that the AEJ core moves westward faster due to the convective activity. Copyright © 2002 Royal Meteorological Society
Improvement of surface flux parametrizations with a turbulence‐related length
Authors: Yang K. , Koike T. , Fujii H. , Tamagawa K. , Hirose N. 
Published: November 2002

AbstractIn surface flux parametrizations, aerodynamic roughness length zm0, and thermal roughness length zh0, are used to account for different resistances for momentum transfer and heat transfer. This paper introduces a turbulence‐related length hT and parametrizes the quantity kA−1=ln(hT/zh0) in order to estimate zh0. Based on data at three sites on the Tibetan Plateau, a general formula for kA−1 is obtained for the surfaces covered by bare soil or partially covered by very short vegetation. A surface flux parametrization with this formula provides better estimates of heat flux than either profile flux parametrization or surface flux parametrization with kB−1 (i.e. ln(zm0/zh0)). Therefore, the use of a reasonable length to scale zh0 can contribute to the improvement of surface flux parametrizations. Copyright © 2002 Royal Meteorological Society
In vitro toxicity of several dithiocarbamates and structure–activity relationships
Authors: Segovia N. , Crovetto G. , Lardelli P. , Espigares M. 
Published: November 2002

AbstractDithiocarbamates (DTCs) are chemicals featuring a great chelating capacity. The toxicological study of DTCs is very important in view of their relatively simple synthesis and wide array of sanitary and industrial applications. In this study, the toxicity of some of the more recently synthesized DTCs is determined using an extremely simple bioassay, described in previous studies, based on the inhibition of growth of Escherichia coli (IGEC). The lowest‐observed‐effect concentration (LOEC), the median effective concentration (EC50) and no‐observed‐effect concentration (NOEC) of the following sodium dithiocarbamates was determined: N‐benzyl‐N‐methyldithiocarbamate·2H2O, N‐benzyl‐N‐isopropyldithiocarbamate·3H2O, N‐benzyl‐N‐ethyldithiocarbamate·2H2O, N‐butyl‐N‐methyldithiocarbamate·2H2O, N,N‐dibenzyldithiocarbamate·2H2O and N‐benzyl‐2‐phenethyldithiocarbamate·4H2O. Our results showed N,N‐dibenzyl‐DTC to be the least toxic of the tested substances, with an EC50 value of 1269.9 µg ml−1, whereas N‐butyl‐N‐methyl‐DTC and N‐benzyl‐N‐methyl‐DTC, with respective EC50 values of 14.9 µg ml−1 and 23.5 µg ml−1, were the most toxic. Regression analysis showed, through exponential models, that the degree of toxicity of this group of substances correlated with the molecular weight of the compound, the molecular weight of the smallest chemical radical linked to the dithiocarbamate group and the number of benzene rings present in the molecule. The consideration of these models allows us to establish that in general terms the toxicity of DTCs decreases exponentially with a greater molecular weight and the number of benzene rings. Copyright © 2002 John Wiley & Sons, Ltd.
Haematological, hepatic and renal alterations after repeated oral or intraperitoneal administration of monoisoamyl DMSA. I. Changes in male rats
Authors: Mehta Ashish , Kannan G. M. , Dube S. N. , Pant B. P. , Pant S. C. , Flora S. J. S. 
Published: November 2002

AbstractMonoisoamyl 2,3‐dimercaptosuccinic acid (MiADMSA), a vicinal thiol chelator, is gaining recognition recently as a better chelator than meso 2,3‐dimercaptosuccinic acid (DMSA) in decreasing heavy metal burden in tissues because of its lipophilic character. There is, however, little information available on the toxicological properties of this chelator after repeated administration in animals. In the present study, we investigated the dose‐dependent effect of MiADMSA on various biochemical parameters suggestive of alterations in haem biosynthesis and hepatic, renal and brain oxidative stress after 21 days of repeated intraperitoneal (i.p.) or oral (p.o.) administration to rats. The concentration of essential metals in blood and soft tissues was determined along with histopathological observations of hepatic and renal tissues.The results suggest that MiADMSA administration had no effect on blood δ‐aminolevulinic acid dehydratase activity. However, an increase in zinc protoporphyrin and a decrease in haemoglobin levels were noted in animals given MiADMSA i.p. A moderate increase in serum alkaline phosphatase suggested mild hepatotoxicity at the highest dose (100 mg kg−1, i.p.). This was confirmed by histopathological examinations, which identified basophilic stippling, granulation of the cytoplasm, haemorrhage and congestion. At the highest dose, levels of hepatic thiobarbituric acid reactive substance and oxidized glutathione were increased above those of control values. Levels of hepatic reduced glutathione were decreased. Taken together, these observations point to oxidative stress. In animals administered MiADMSA i.p. there was an increase in the brain malondialdehyde levels at the two higher doses (50 and 100 mg kg−1). Essential metal status revealed a significant effect of MiADMSA (p.o.) in increasing blood zinc while significantly decreasing the kidney zinc level. The most significant adverse effect of MiADMSA was on copper concentration, which showed significant depletion from almost all major organs. Magnesium levels in blood decreased but increased in liver of MiADMSA‐administered rats. Histopathological observations of liver and kidneys suggest few moderate lesions.It can be concluded that repeated administration of MiADMSA is compromised with some mild toxic effect, particularly the loss of copper. The effects during oral administration are comparatively less pronounced than by the i.p. route. Copyright © 2002 John Wiley & Sons, Ltd.
Responses in the respiratory tract of rats following exposure to sulphuric acid aerosols for 5 or 28 days
Authors: Kilgour Joanne D. , Foster John , Soames Anthony , Farrar David G. , Hext Paul M. 
Published: November 2002

AbstractSulphuric acid mists have been classified by the International Agency for Research on Cancer as being carcinogenic to humans based on epidemiological findings of respiratory tract tumours. To determine if early changes in the respiratory tract following exposure to sulphuric acid (H2SO4) aerosols are consistent with the possible development of tumours after extended periods of exposure, groups of female rats were exposed to respirable aerosols of H2SO4 at target concentrations of 0, 0.2, 1.0 or 5.0 mg m−3 for 6 h per day for either 5 days or for 5 days a week over a 28‐day period. Additional groups exposed to 0 or 5.0 mg m−3 over the 28‐day period were retained after exposure for 4 or 8 weeks to assess recovery. Histopathological examinations and quantitative cell proliferation measurements were conducted on the nasal passages, larynx and lung. Achieved concentrations were 0.3, 1.38 and 5.52 mg m−3 H2SO4. Histological and cell proliferative changes were confined to the larynx and no effects were seen in the nasal passages or lungs. At the two highest concentrations, squamous metaplasia accompanied by significant cell proliferation was apparent after 5 and 28 days of exposure and there was a reduction in the severity of the pathological changes following the recovery periods. No effects were seen at 0.3 mg m−3 after 5 days of exposure and only minimal metaplastic change was seen after 28 days in a few animals and was not accompanied by cell proliferation. The toxicological relevance of these findings is discussed. Copyright © 2002 John Wiley & Sons, Ltd.