bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relaxation of proximal and distal isolated human bronchi by halothane, isoflurane and desflurane
Authors: Mercier F.J. , Naline E. , Bardou M. , Georges O. , Denjean A. , Benhamou D. , Advenier C. 
Published: October 2002

Volatile anaesthetics relax airway smooth musclein vitro. The amount of relaxation might depend on the type and concentration of volatile anaesthetics, the calibre and precontraction level of the bronchi, and also on the species considered. These effects were investigated on isolated human bronchi.Isometric relaxations produced by halothane, isoflurane and desflurane bubbled on human bronchial rings precontracted with carbachol were recorded and compared with time controls.Volatile anaesthetics induced a concentration-dependent relaxation at 0.66, 1.33 and 2 minimum alveolar concentration (MAC). The relaxation was greater in mildly (carbachol 3×10−7 M) than in highly (carbachol 2×10−6 M) precontracted bronchi. Halothane was more potent in relaxing distal as compared to proximal bronchi; this differential effect was less pronounced with isoflurane and not observed with desflurane. While the three volatile anaesthetics induced similar relaxation on proximal bronchi, halothane was significantly more potent than desflurane on distal bronchi, with isoflurane being intermediate. The relaxation induced by 1.33 MAC of halothane, isoflurane and desflurane on moderately precontracted distal bronchi (carbachol 1×10−6 M) was attenuated by pretreatment with glibenclamide 1×10−5 M.In conclusion, halothane, isoflurane and desflurane exert direct but differential relaxant effects on human isolated bronchial smooth muscle. This may provide supplemental bronchodilation during anaesthesia. Although adenosine triphosphate-sensitive K+channels are involved in these relaxant effects, they are unlikely to explain the observed differences between the three volatile anaesthetics.
Sepsis and hyperoxia effects on the pulmonary surfactant system in wild-type and iNOS knockout mice
Authors: Bailey T.C. , Cavanagh C. , Mehta S. , Lewis J.F. , Veldhuizen R.A.W. 
Published: October 2002

Alterations of pulmonary surfactant and increases in inducible nitric oxide synthase (iNOS) have been implicated in the pathophysiology of acute lung injury. It was hypothesised that these two observations are related and that alterations of the endogenous surfactant, due to either sepsis or hyperoxia, would be reduced in mice lacking the iNOS gene compared to wild-type mice.Wild-type and iNOS (−/−) mice were randomised into sham or sepsis, and in a separate experiment animals were randomised to normoxia or hyperoxia exposure for 48 h. Lungs were lavaged and analysed for total surfactant levels and surfactant subfractions (large (LA) and small (SA) aggregates).Both sepsis groups had decreased SA compared to sham groups with no significant difference between the two genotypes. Mice exposed to hyperoxia had a decreased amount of total surfactant when compared to normoxia controls and there was no significant difference between the two genotypes.It is concluded that inducible nitric oxide synthase does not influence the amount of pulmonary surfactant or surfactant subfractions recovered in lavage after 18 h of sepsis or 48 h of hyperoxia.
Pertechnegas lung clearance in different forms of interstitial lung disease
Authors: Thomeer M.J. , Dehaes B. , Mortelmans L. , Demedts M. 
Published: October 2002

Interstitial lung diseases (ILD) are characterized by an acute or chronic inflammation of the alveolar capillary membrane, which affects the permeability of this membrane. A possible way to measure the permeability of the membrane is by radionuclide aerosol imaging. Pertechnegas, a gas composed of technetium-labelled carbon particles, has recently been proposed as a new ventilation agent to measure this lung clearance.The clearance by pertechnegas in the four most common forms of ILD (eight patients with connective tissue disease, 10 with hypersensitivity pneumonitis, nine with idiopathic interstitial pneumonia and 10 with sarcoidosis) was measured and compared with 10 nonactive smoking controls. Because forced vital capacity (FVC), total lung capacity (TLC) and carbon monoxide diffusing capacity of the lung (DL,CO) are used in the assessment of functional severity of the ILD, the pertechnegas clearance was correlated with these lung-function indices.It was found that the time to half clearance of pertechnegas of the lung is significantly decreased in idiopathic interstitial pneumonia (p<0.0001), hypersensitivity pneumonitis (p=0.0005) and connective tissue disease (p=0.002) but not in sarcoidosis when compared with 10 nonsmoking controls. A significant correlation is also found between time to half clearance and FVC (r=0.76; p<0.0001), TLC (r=0.63; p<0.0001) andDL,CO(r=0.75; p<0.0001) for all groups together. For all subjects as a group, the time to half clearance is shorter in the upper lung zones than in the lower zones (p<0.0001) and the ratio between both zones is not significantly different between the different types of disease.These results indicate that pertechnegas clearance is increased in idiopathic interstitial pneumonia, hypersensitivity pneumonitis and connective tissue disease, but not in sarcoidosis and is related to the functional severity of the disease.
A portable forced oscillation device for respiratory home monitoring
Authors: Rigau J. , Farré R. , Roca J. , Marco S. , Herms A. , Navajas D. 
Published: October 2002

The increase in the prevalence of chronic respiratory diseases has resulted in a rise in health services provided at home. The forced oscillation technique (FOT) proves to be a useful tool when it is desired to assess lung function noninvasively, and particularly for patients in whom spirometry cannot be applied. As no portable FOT device is currently available, the aim of this study was to design and test a portable FOT system for ambulatory and home care applications.The system devised is based on a microprocessor, which allows online computation of respiratory resistance (Rrs) and reactance (Xrs) and reliability indices. The portable device was compared with a conventional FOT system by using signals from 14 patients with chronic respiratory disease.This device has the same computation capabilities and flexibility as conventional FOT systems and meets the requirements for home application.Rrs(14.2±6.0 cmH2O·s·L−1, mean±sd) andXrs(−5.3±2.7 cmH2O·s·L−1) measured at 5 Hz by the portable system virtually coincided with those computed with the reference conventional FOT system: mean differences±sd were 0.074±0.025 and 0.005±0.009 cmH2O·s·L−1, respectively.This portable forced oscillation technique device could be a useful tool for monitoring respiratory mechanics in ambulatory and home care applications.
Adenosine-receptor subtypes: their relevance to adenosine-mediated responses in asthma and chronic obstructive pulmonary disease
Authors: Polosa R. 
Published: October 2002

Adenosine administration by inhalation elicits concentration-related bronchoconstriction in subjects with asthma and chronic obstructive pulmonary disease (COPD). The mechanisms of adenosine-induced bronchoconstriction appear to involve a selective interaction with activated mast cells with subsequent release of preformed and newly-formed mediators. Further evidence linking adenosine signalling to asthma and COPD comes from the finding that many cell types that play important roles in the exacerbation of these conditions express adenosine receptors and demonstrate relevant effects through stimulation of these receptors.Therefore, blockade of these receptors may be a valuable approach to the treatment of asthma and chronic obstructive pulmonary disease. Promising adenosine-receptor targets for novel therapeutics of asthma and chronic obstructive pulmonary disease have recently been identified in a number of inflammatory cell types, including mast cells, eosinophils, lymphocytes, neutrophils, and macrophages. The recent characterisation of the A2Breceptors indicates the human lung mast cell as one of the most strategic cellular targets.
Interval training as an alternative modality to continuous exercise in patients with COPD
Authors: Vogiatzis I. , Nanas S. , Roussos C. 
Published: October 2002

Understanding of what constitutes a training load adequate to induce training effects in patients with chronic obstructive pulmonary disease (COPD) is still evolving. The present study investigated whether interval training (IT) is effective in terms of inducing measurable improvements in physiological response and compared its effects on exercise tolerance (ET) and quality of life to those of continuous training (CT).Thirty-six COPD patients, with a forced expiratory volume in one second of 45±4% of the predicted value (mean±sem), were randomly assigned to CT (exercise at 50% of baseline peak work-rate) or IT (work for 30 s at 100% of peak work-rate alternating with 30‐s rest intervals) groups that cycled 40 min·day−1and 2 days·week−1for 12 weeks.After training, both groups showed significantly improved ET (IT, 57±6 to 71±8 W; CT, 57±5 to 70±6 W) and total quality-of-life score of the Chronic Respiratory Disease Questionnaire (IT, 77±3 to 88±2; CT, 78±3 to 93±2). At identical levels of exercise, minute ventilation was significantly reduced (IT, 35.8±2.5 to 31.7±2.5 L·min−1; CT, 36.4±2.7 to 32.5±2.7 L·min−1). The magnitude of improvement in these variables was not significantly different among groups.The present data expand on the principles of exercise prescription for chronic obstructive pulmonary disease patients by demonstrating that interval training elicits substantial training effects, which are similar in magnitude to those produced by continuous training at half the exercise intensity but double the exercise time.
Screening for α1‐Pi deficiency in patients with lung diseases
Authors: Wencker M. , Marx A. , Konietzko N. , Schaefer B. , Campbell E.J. 
Published: October 2002

In patients with pulmonary emphysema, studies have reported 2–3% of individuals with severe α1‐Pi deficiency. The aims of this study were to evaluate the accuracy of a new method for quantifying α1‐Pi through phenotyping from dried blood spots (DBS) and to test the hypothesis that the screening of a population at risk increases the detection rate for severe α1‐Pi deficiency.The accuracy of phenotyping results from DBS was compared to conventional methods in a total of 555 individuals. In a prospective study 1,060 patients with chronic lung disease were screened for α1‐Pi deficiency using DBS.The validation of the phenotyping method from DBS showed an accuracy of 100%. Out of 1,060 tested patients, none had a severe PiZ deficiency and only 3 had PiSZ, whilst 36 (3.34%) individuals were identified as heterozygous for PiMS and 39 (3.68%) for PiMZ.No patients with severe α1‐Pi deficiency could be detected in this population and the frequency of PiMS or PiMZ detected was similar to that of the normal population. Thus, the screening of an unselected population of chronic obstructive pulmonary disease and asthma patients may not detect a large number of individuals with severe α1‐Pi deficiency.
Estimating anisotropy parameters and traveltimes in the τ‐pdomain
Authors: van der Baan Mirko , Kendall J. Michael 
Published: October 2002

The presence of anisotropy influences many aspects of seismic wave propagation and has therefore implications for conventional processing schemes. To estimate the anisotropy, we need both forward modelling and inversion tools. Exact forward modelling in anisotropic media is generally done by raytracing. However, we present a new and fast method, using the τ‐p transform, to calculate exact P and SV reflection moveout curves in stratified, laterally homogeneous, anisotropic media which requires no ray tracing. Results are exact even if the SV‐waves display cusps. In addition, we show how the same method can be used for parameter estimation.Since inversion for anisotropic parameters is very nonunique, we develop expressions requiring only a reduced number of parameters. Nevertheless, predictions using these expressions are more accurate than Taylor series expansions and are also able to handle cusps in the SV traveltime curves. In addition, layer stripping is a linear process. Therefore, both effective (average) and local (interval) estimates can be obtained.
Detection of reservoirs from normalized full gradient of gravity anomalies and its application to Shengli oil field, east China
Authors: Zeng Hualin , Meng Xiaohong , Yao Changli , Li Xiaomeng , Lou Hai , Guang Zhining , Li Zhiping 
Published: October 2002

We present how to detect reservoirs by the 3‐D normalized full gradient (NFG) of gravity anomalies constrained by seismic and drilling data. The normalized full gradient represents the full gradient of the gravity anomaly at a point divided by the average of the full gradient at the datum. The closed minima on an NFG map indicate the occurrence and horizontal locations of the centers of mass of density anomalies related to oil reservoirs. This information can be used to select well locations in an oil field. On a cross‐section, the closed minima can be used to estimate the depth to centers of mass of possible hydrocarbon reservoirs. Some characteristics of the NFG are calculated for a hypothetical case of an anticline saturated with oil and gas. The relationship of these characteristics to the geometry and physical parameters of the anticline is studied. Modeling studies show that the NFG largely depends on the number of terms in the Fourier series used to calculate it, and it closely related to the length of the gravity profile or the size of the study area. Applying the NFG method to the Shengli oil field, i.e., using closed minima of NFG alongside drilling data, showed an effectiveness of up to 70%. These results were used to select well locations with the result that some high‐production gas‐bearing strata were discovered by drilling.
Migration velocity analysis from locally coherent events in 2‐D laterally heterogeneous media, Part II: Applications on synthetic and real data
Authors: Chauris Hervé , Noble Mark S. , Lambaré Gilles , Podvin Pascal 
Published: October 2002

We demonstrate a method for estimating 2‐D velocity models from synthetic and real seismic reflection data in the framework of migration velocity analysis (MVA). No assumption is required on the reflector geometry or on the unknown background velocity field, provided that the data only contain primary reflections/diffractions. In the prestack depth‐migrated volume, locations where the reflectivity exhibits local coherency are automatically picked without interpretation in two panels: common image gathers (CIGs) and common offset gathers (COGs). They are characterized by both their positions and two slopes. The velocity is estimated by minimizing all slopes picked in the CIGs.We test the applicability of the method on a real data set, showing the possibility of an efficient inversion using (1) the migration of selected CIGs and COGs, (2) automatic picking on prior uncorrelated locally coherent events, (3) efficient computation of the gradient of the cost function via paraxial ray tracing from the picked events to the surface, and (4) a gradient‐type optimization algorithm for convergence.
3‐D eikonal solvers: First‐arrival traveltimes
Authors: Kim Seongjai 
Published: October 2002

The article is concerned with the development and comparison of three different algorithms for the computation of first‐arrival traveltimes: the fast marching method (FMM), the group marching method (GMM), and a second‐order finite‐difference eikonal solver. GMM is introduced as a variant of FMM. It proceeds the solution by advancing a selected group of grid points at a time, rather than sorting the solution in the narrow band to march forward a single grid point. The second‐order eikonal solver studied in the article is an expanding‐box, essentially nonoscillatory scheme for which the stability is enforced by the introduction of a down ‘n’ out marching and a post‐sweeping iteration.Techniques such as the maximum angle condition, the average normal velocity, and cache‐based implementation are introduced for the algorithms to improve the numerical accuracy and efficiency. The algorithms are implemented for solving the eikonal equation in 3‐D isotropic media, and their performances are compared. GMM is numerically verified to be faster than FMM. However, the second‐order algorithm turns out to be superior to these first‐order level‐set methods in both accuracy and efficiency; the incorporation of average normal velocity improves accuracy dramatically for the second‐order scheme.
Thought and Language Index: an instrument for assessing thought and language in schizophrenia
Authors: Liddle Peter F. , Ngan Elton T. C. , Caissie Stephanie L. , Anderson Cameron M. , Bates Alan T. , Quested Digby J. , White Richard , Weg Rowena 
Published: October 2002

BackgroundSubtle formal thought disorders are difficult to quantify. Their relationship to florid thought disorder is unknown.AimsTo assess the interrater reliability, sensitivity and factor structure of a new assessment instrument, the Thought and Language Index (TLI), and to determine if minor aberrations detectable in the speech of healthy individuals are related to the more severe formal thought disorders characteristic of schizophrenia.MethodInterrater reliability was evaluated by determining the intraclass correlation for the ratings by five assessors. Factor analysis of the TLI scores of 87 patients was performed, and TLI scores in matched patients and controls were compared.ResultsThe intraclass correlation was good for individual TLI items, and excellent for sub-scale scores. Factor analysis identified three groups of approximately orthogonal disorders. Mild speech aberrations were observed in healthy participants and in patients with schizophrenia. The prevalence of mild aberrations was correlated with the prevalence of definite formal thought disorders.ConclusionsThe TLI is reliable and capable of detecting subtle disorders. Some mild aberrations occurring in the speech of healthy individuals appear to be attenuated forms of the florid disorders characteristic of schizophrenia.
Dropping out of care: inappropriate terminations of contact with community-based psychiatric services
Authors: Rossi Alberto , Amaddeo Francesco , Bisoffi Giulia , Ruggeri Mirella , Thornicroft Graham , Tansella Michele 
Published: October 2002

BackgroundFew studies have investigated factors which predict inappropriate terminations (drop-out) of clinical contact with mental health services.AimsTo identify patient and treatment characteristics associated with dropping out of contact with community-based psychiatric services (CPS).MethodA 3-month cohort of patients attending the CPS was followed up for 2 years, to identify drop-outs.ResultsWe identified 495 patients who had had at least one psychiatric contact of whom 261 had complete ratings for the Global Assessment of Functioning and the Verona Service Satisfaction Scale. In the year after the index contact, 70 terminated contact with the CPS; of these, 44 were rated as having inappropriate terminations (the ‘drop-out’ group) and 26 had appropriate terminations of contact. Drop-outs were younger, less likely to be married and their previous length of contact with services was shorter. No drop-outs had a diagnosis of schizophrenia. Multivariate analysis revealed predictors of dropping out.ConclusionsIn a CPS targeted to patients with severe mental illnesses, those who drop out of care are younger patients without psychoses who are generally satisfied with their treatment.
Small‐volume Resuscitation with HBOC‐201: Effects on Cardiovascular Parameters and Brain Tissue Oxygen Tension in an Out‐of‐hospital Model of Hemorrhage in Swine
Authors: Morabito Diane , Hemphill J. Claude , Erickson Vanessa , Holcroft John J. , Derugin Nikita , Knudson M. Margaret , Manley Geoffrey T. , Lee Seong K. 
Published: October 2002

Abstract Objective: Hemoglobin‐based oxygen carriers, such as HBOC‐201, offer several potential advantages over conventional resuscitation solutions or banked blood in the acute treatment of hemorrhagic shock. While previous studies with some hemoglobin solutions revealed vasoactive effects resulting in decreased oxygen delivery, these investigations were performed without directly measuring vital tissue oxygenation. The authors tested the hypothesis that a small‐volume bolus of HBOC‐201 would improve and sustain brain tissue oxygen tension (PbrO 2) without adverse effects on cardiovascular end‐points, when used in an acute out‐of‐hospital hemorrhage model. Methods: Male Yorkshire swine (n = 7) were hemorrhaged to a mean arterial pressure (MAP) of 40 mm Hg while monitoring standard hemodynamic parameters. In addition, Clark‐type polarographic probes were directly inserted into brain tissue to measure PbrO2. Following institution of high‐flow oxygen (FiO2= 1.0), resuscitation was performed with a bolus infusion of HBOC‐201 (6 mL/kg). Swine were observed for two hours. Results: Cardiac output (CO), MAP, pulmonary artery diastolic pressure (PAD), and PbrO2 all decreased significantly with hemorrhage (p < 0.05). Immediately following resuscitation with HBOC‐201 (mean volume = 239 mL), MAP and CO were restored to 83% and 84% of baseline levels, respectively. PbrO2 increased significantly after treatment with HBOC‐201, surpassing baseline levels by 66%. PAD rose above baseline levels during observation, but this increase was not significantly different from baseline levels (24.0 mm ± 4.1 vs. 22.7 mm ± 7.4). Conclusions: Small‐volume resuscitation with HBOC‐201 rapidly restored hemodynamic parameters and PbrO2 following severe hemorrhage without detrimental vasoactive effects and without compromise to directly monitored brain tissue oxygenation. The results of this preliminary study demonstrate that HBOC‐201 could potentially improve current resuscitation measures and that further investigations with HBOC‐201 are warranted.
The Effects of a High‐potency Topical Steroid on Cutaneous Healing of Burns in Pigs
Authors: Singer Adam J. , McClain Steve A. 
Published: October 2002

Abstract Objective: Burns are dynamic injuries that tend to progress over the course of several days. Steroids inhibit the formation of vasoconstrictive prostanoids that may contribute to this progression of injury. The authors hypothesized that adding topical steroids to a standard antimicrobial agent would reduce the progression of burns and accelerate reepithelialization without increasing infection rates. Methods: This was a prospective, blinded, controlled, experimental trial. Forty‐eight standardized second‐degree burns were created by applying an aluminum bar preheated to 80°C to the flanks of isoflurane‐anesthetized young pigs for 20 seconds. Three equal sets of 16 burns were randomly treated with silver sulfadiazine cream (SSD), clobetasol propionate 0.05% (CP), or both (SSD+CP). Daily dressing changes were performed for 14 days. Full‐thickness biopsies were taken after injury and at one, two, seven, ten, and 14 days for blinded histopathological evaluation using hematoxylin and eosin (H&E) staining. The primary outcome was the % reepithelialization (REP) calculated by dividing the length of the neoepidermis by the section's total length (interobserver correlation = 0.99). Depth of injury was measured for each dermal element (collagen; epithelial, mesenchymal, and vascular cells; and vessel thrombosis). Comparisons across groups were performed using oneway analysis of variance (ANOVA). A repeated‐measures ANOVA was used to compare injury depths over time. This study had 80% power to detect a 33‐percentage point difference in REP across groups (two‐tailed alpha = 0.05). Results: Pretreatment burn depths were similar across groups. While burn depth changed over time, there was no difference between the groups in burn injury progression. There was no difference across the groups in REP or infection rates at all times. Conclusions: Addition of a potent topical steroid to standard antimicrobial topical agents does not reduce burn depth or accelerate reepithelialization after burns.