bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scientific rationale for inhaled combination therapy with long-acting β2-agonists and corticosteroids
Authors: Barnes P.J. 
Published: October 2002

The addition of an inhaled long-acting β2-agonist (LABA) to an inhaled corticosteroid (ICS) gives optimal control of asthma in most patients and two fixed combination inhalers (salmeterol/fluticasone and formoterol/budesonide) are increasingly used as a convenient controller in patients with persistent asthma. There is a strong scientific rationale for the combination of these two drug classes.ICS suppress the chronic inflammation of asthma and reduce airway hyperresponsiveness and this is achieved at low doses in most patients. LABA act on different aspects of the pathophysiology of asthma. In addition to their bronchodilator action, LABA also inhibit mast cell mediator release, plasma exudation and may reduce sensory nerve activation. Thus these two classes of drug address complementary aspects of the pathophysiology of asthma that neither drug class is able to achieve alone.There are several positive interactions between LABA and ICS. Corticosteroids increase the expression of β2-receptors by increasing gene transcription. Experimentally this protects against the loss of β2-receptors in response to long-term exposure to β2-agonists. While this is unlikely to be important in bronchodilator responses to β2-agonists, in view of the large β-receptor reserve, it is probably important in preventing loss of β-agonist effects on the nonbronchodilator actions of LABA discussed earlier. β2-Agonists may potentiate the molecular mechanism of corticosteroid actions, with increased nuclear localization of glucocorticoid receptors and additive or sometimes synergistic suppression of inflammatory mediator release. Thus LABA and ICS may optimize each others beneficial actions in the airways, but the low systemic effects of these drugs do not result in any increase in adverse effects.Long-acting β2-agonists corticosteroid inhaler therapy is therefore a logical advance and results in effective control of asthma in the majority of patients without significant adverse effects. This simplified approach to long-term asthma therapy has a strong scientific rationale.
Evidence of mast-cell activation in a subset of patients with eosinophilic chronic obstructive pulmonary disease
Authors: Louis R.E. , Cataldo D. , Buckley M.G. , Sele J. , Henket M. , Lau L.C. , Bartsch P. , Walls A.F. , Djukanovic R. 
Published: October 2002

Although asthma has been viewed mainly as an eosinophilic disease, and chronic obstructive pulmonary disease (COPD) as a neutrophilic disease, recent studies have shown increased neutrophil counts in severe asthma and sputum eosinophilia in some COPD patients.In an attempt to further characterise these two syndromes according to pathology, the current authors have conducted a study of induced sputum in 15 subjects with COPD, 17 asthmatics, and 17 nonatopic healthy individuals. Sputum was analysed for cytology and levels of eosinophil cationic protein (ECP), albumin, tryptase and soluble intercellular adhesion molecule‐1.The COPD subjects differed from the asthmatics as they had higher sputum neutrophil and lower columnar epithelial cell counts, but there were no differences in any soluble marker studied. When compared to control subjects, both the asthmatic and COPD subjects had raised eosinophil counts and ECP levels. In a subset of COPD subjects with sputum eosinophilia (>3% of total cells), significantly increased levels of tryptase were detected.In conclusion, although chronic obstructive pulmonary disease is a more neutrophilic disease than asthma, the two diseases are difficult to distinguish on the basis of sputum levels of the soluble markers traditionally associated with asthma. However, a subset of patients with chronic obstructive pulmonary disease with airway eosinophilia and mast-cell activation might represent a distinct pathological phenotype.
Ambulatory oxygen improves quality of life of COPD patients: a randomised controlled study
Authors: Eaton T. , Garrett J.E. , Young P. , Fergusson W. , Kolbe J. , Rudkin S. , Whyte K. 
Published: October 2002

It is unknown whether acute response to ambulatory oxygen (O2) predicts longer term improvement in health-related quality of life (HRQL) in chronic obstructive pulmonary disease (COPD) patients.The aims of this study were 1) to assess the short-term clinical impact, as determined by HRQL, of ambulatory O2in a 12-week, double-blind, randomised crossover study of O2(versuscylinder compressed air) of dyspnoeic but not chronically hypoxic COPD patients with exertional desaturation ≤88% (n=41), and 2) to determine whether either baseline characteristics or acute response to O2predicts short-term (12 weeks) response. Primary outcome measures were Chronic Respiratory Questionnaire (CRQ), Hospital Anxiety and Depression scale and the short form (SF)-36.Improvements were seen in all domains of the CRQ for cylinder O2compared with cylinder air. Significant improvements were also noted in anxiety and depression and in certain domains of the SF-36. There were 28 (68%) acute responders to cylinder O2(defined as increase in 6‐min walk ≥54 m or decrease in post-Borg dyspnoea ≥1) and 23 (56%) short-term responders (defined as clinically significant improvement in CRQ). However, acute and short-term responses were not correlated with no predictors of short-term response identified. At study completion, 14 (41%) of acute or short-term responders did not want to continue therapy, with 11 citing poor acceptability or tolerability.Short-term ambulatory oxygen is associated with significant improvements in health-related quality of life. These benefits cannot be predicted by baseline characteristics or acute response. Despite acute or short-term response, a substantial proportion of patients declined ambulatory oxygen.
The public health relevance of air pollution abatement
Authors: Künzli N. 
Published: October 2002

Assuming a causal relationship between current levels of air pollution and morbidity/mortality, it is crucial to estimate the public health relevance of the problem. The derivation of air pollution attributable cases faces inherent uncertainties and requires influential assumptions. Based on the results of the trinational impact assessment study of Austria, France, and Switzerland, where prudent estimates of the air pollution attributable cases (mortality, chronic bronchitis incidence, hospital admissions, acute bronchitis among children, restricted activity days, asthma attacks) have been made, influential uncertainties are quantified in this review.The public health impact of smoking, environmental tobacco smoke, and air pollution on the prevalence of chronic cough/phlegm are outlined. Despite all methodological caveats, impact assessment studies clearly suggest that public health largely benefits from better air quality. The studies are selective underestimates as they are strongly driven by mortality, but do not include full quantification of the impact on morbidity and their consequences on quality of life among the diseased and the caregivers.Air pollution abatement strategies are usually political in nature, targeting at policies, regulation and technology in mobile or stationary sources rather than at individuals. It is of note that key clean air strategies converge into abatement of climate change. In general, energy consumption is very closely related to both air pollution and greenhouse gases. The dominant causes of both problems are the excessive and inefficient combustion of fossil fuel. Thus, for many policy options, the benefit of air pollution abatement will go far beyond what prudent health-impact assessments may derive. From a climate change and air pollution perspective, improved energy efficiency and a strong and decisive departure from the “fossil fuel” combustion society is a science-based must. Health professionals must raise their voices in the political decision process to give strong support for clean air policies, both on a national and international level.
Biochemical markers of cerebrovascular injury in sleep apnoea syndrome
Authors: Jordan W. , Hagedohm J. , Wiltfang J. , Laier-Groeneveld G. , Tumani H. , Rodenbeck A. , Rüther E. , Hajak G. 
Published: October 2002

Sleep apnoea syndrome (SAS) is a known risk factor for vascular diseases and stroke. Structural brain damage, manifesting as an overt neurological deficit or more subtly as cognitive dysfunction, is a frequent symptom in SAS. The presence of a biochemical marker of cerebral injury would be of great benefit in SAS to screen for even small brain damage and to monitor efficiacy of therapy.Therefore, in 10 patients with mild SAS (age 50.8±9.9 yrs, respiratory disturbance index (RDI) 18±3.6, lowest arterial oxygen saturation (minSa,O2) 80.5±4.06%) and nine patients with severe SAS (age 50.3±11.5 yrs, RDI 75.4±21.7, minSa,O256.56±14.58%), serum concentrations of neuron-specific enolase (NSE), S‐100β protein, and β‐trace were measured just before and after sleep using commercially available assays.Only serum levels in the normal range could be found, independent of when the blood was taken or the degree of SAS.Structural cerebral injury caused by sleep apnoea syndrome in patients without neurological symptoms or previous cerebrovascular events may be too small to produce a measurable increase in S‐100β, neuron‐specific enolase and β‐trace serum concentrations or subclinical cerebral damage may be outside the lower detection limits of the analytical methods which were used. There is a need for biochemical markers and more sensitive methods for detecting small cerebral injury in sleep apnoea syndrome.
Association of asthma and total IgE levels with human leucocyte antigen-DR in patients with grass allergy
Authors: Woszczek G. , Kowalski M.L. , Borowiec M. 
Published: October 2002

Exposure to grass pollens during the pollen season, reveals in sensitive patients symptoms of allergic rhinitis, conjunctivitis and/or bronchial asthma. It is not well understood why, in some patients, only symptoms of rhinitis occur while in others similar exposure causes symptoms of asthma and rhinitis.An association study is reported here, where the possible contribution of human leucocyte antigen (HLA)-DR gene polymorphisms to differential phenotypic expression of symptoms in patients with grass-pollen allergy was determined. HLA-DR genotyping was performed by the polymerase chain reaction with the sequence-specific primers method in 82 patients with symptoms of seasonal allergic rhinitis and/or bronchial asthma and 52 healthy nonatopic control subjects.A significant association was found between HLA-DRB1*02, B5* haplotype and asthma phenotype in patients with grass-pollen allergy when compared to patients with rhinitis only. Significantly higher total serum immunoglobulin E levels were observed in patients with HLA-DRB1*01 alleles in comparison to patients without these alleles.The data in this study suggest that human leucocyte antigen-DR locus, or other genes in linkage disequilibrium, may play an important role in asthma phenotype expression in patients with grass-pollen allergy as well as in determining total immunoglobulin E levels in these patients.
Effects of tracheotomy on respiratory mechanics in spontaneously breathing patients
Authors: Moscovici da Cruz V. , Demarzo S.E. , Sobrinho J.B.B. , Amato M.B.P. , Kowalski L.P. , Deheinzelin D. 
Published: October 2002

Tracheotomy is a method of intubating the trachea, which is employed in several clinical settings, including the treatment of head and neck neoplasms. Tracheotomy is believed to facilitate weaning through changes in respiratory mechanics. Existing information concerning functional changes associated with tracheotomy are limited to comparisons with orotracheal intubation.In this study, respiratory mechanics were monitored in seven spontaneously breathing patients, before and after an elective tracheotomy was performed for surgical treatment of cancer. Campbell diagrams were constructed by plotting pressure, obtained with an oesophageal balloon catheter, against volume, obtained from a pneumotachograph placed at the airway opening. Work of breathing was calculated as the internal area of the Campbell diagram and was partitioned into its elastic and inspiratory and expiratory resistive components. Oesophageal pressure was also used to quantify intrinsic positive end-expiratory pressure (PEEPi) and the pressure-time product (PTP), which is considered to be proportional to the oxygen cost of breathing. PTP was divided into its resistive and elastic components.Inspiratory resistive work, PEEPi, inspiratory PTP, as well as its resistive and elastic components were significantly reduced by tracheotomy.Tracheotomy significantly reduces work of breathing and pressure-time product in spontaneously breathing patients.
A proposed polarity standard for multicomponent seismic data
Authors: Brown R. James , Stewart Robert R. , Lawton Don C. 
Published: October 2002

This paper proposes a multicomponent acquisition and preprocessing polarity standard that will apply generally to the three Cartesian geophone components and the hydrophone or microphone components of a 2‐D or 3‐D multicomponent survey on land, at the sea bottom, acquired as a vertical seismic profile, vertical‐cable, or marine streamer survey. We use a four‐component ocean‐bottom data set for purposes of illustration and example. A primary objective is a consistent system of polarity specifications to facilitate consistent horizon correlation among multicomponent data sets and enable determination of correct reflectivity polarity.The basis of this standard is the current SEG polarity standard, first enunciated as a field‐recording standard for vertical geophone data and hydrophone streamer data. It is founded on a right‐handed coordinate system: z positive downward; x positive in the forward line direction in a 2‐D survey, or a specified direction in a 3‐D survey, usually that of the receiver‐cable lines; and y positive in the direction 90° clockwise from x. The polarities of these axes determine the polarity of ground motion in any component direction (e.g., downward ground motion recording as positive values on the vertical‐geophone trace). According also to this SEG standard, a pressure decrease is to be recorded as positive output on the hydrophone trace. We also recommend a cyclic indexing convention, [W, X, Y, Z] or [0, 1, 2, 3], to denote hydrophone or microphone (pressure), inline (radial) geophone, crossline (transverse) geophone, and vertical geophone, respectively.We distinguish among three kinds of polarity standard: acquisition, preprocessing, and final‐display standards. The acquisition standard (summarized in the preceding paragraph) relates instrument output solely to sense of ground motion (geophones) and of pressure change (hydrophones). Polarity considerations beyond this [involving, e.g., source type, wave type (P or S), direction of arrival, anisotropy, tap‐test adjustments, etc.] fall under preprocessing polarity standards. We largely defer any consideration of a display standard.
The potential of fracture imaging using high‐frequency, single‐hole electromagnetic data
Authors: Seol Soon Jee , Suh Jung Hee , Song Yoonho , Kim Hee Joon , Lee Ki Ha 
Published: October 2002

This paper presents an inversion scheme for high‐frequency electromagnetic (EM) data from a single borehole for detection and characterization of fluid‐filled fractures. Water in the fracture zone may be characterized by its high electrical permittivity and, if saline, by high electrical conductivity. High electrical conductivity results in increased attenuation of EM fields, whereas high electrical permittivity reduces the phase velocity of propagating EM fields. Taking advantage of these effects, we use high‐frequency EM fields to detect and characterize fluid‐filled fractures. To demonstrate the feasibility of single‐hole EM imaging, we develop a three‐step inversion scheme to map a fluid‐filled fracture near the borehole and to evaluate its electrical conductivity and permittivity.We assume that a fluid‐filled fracture can be simulated by a conductive thin sheet. To test our inversion scheme, we generated synthetic data using the thin‐sheet integral equation method. A vertical magnetic dipole was used as a source, and the resultant magnetic fields were inverted using a nonlinear least‐squares method. First, the background conductivity and permittivity were obtained using vertical magnetic field data from below and above the transition frequency, at which conduction and displacement current magnitudes are equal. Next, using the phase difference between EM fields at two neighboring frequencies in the wave propagation realm, both the vertical and dipping sheets were successfully mapped using NMO and migration techniques. Electrical properties of the sheet were well resolved by subsequent inversion after having fixed the location of the sheet and host electrical properties.This study shows the potential of imaging the fracture using high‐frequency EM data obtained from single‐hole surveys.
The moments of the impulse response: A new paradigm for the interpretation of transient electromagnetic data
Authors: Smith Richard S. , Lee Terry J. 
Published: October 2002

We define the nth moment of the transient electromagnetic impulse response as the definite integral with respect to time of the “quadrature” magnetic‐field impulse response weighted by time to the nth power. In this context, the quadrature response is defined as the full impulse response with the in‐phase component (i.e., the delta function component at zero time) removed. The low‐order moments are equivalent to familiar quantities: the zeroth moment (n = 0) is numerically equal to the frequency‐domain inductive limit, and the first moment is the resistive‐limit response. The higher order moments can be of particular benefit: successively they put greater emphasis on the late‐time data, and hence can bring out features in the data that are more conductive or deeper.An advantage of calculating moments (and hence the inductive and resistive limit) is that these data are not strongly dependent on any distortion of the waveform from an ideal impulse. Hence, it is not critical to deconvolve the data prior to estimating the moments.If a conductor has a single exponential decay, the nth moment of the decay is proportional to the nth power of the time constant of the exponential. Thus, it is relatively easy to estimate the time constant from the moments. For a conductive sphere model, the expressions for the moments are more complicated, but are still simpler than the full transient solution or the frequency‐domain solution.In a field example, the high‐order moments emphasize local highly conductive features, but also show the noise present in the late‐time data. A discrete feature on the profile evident in moments 3 through 10 has been modeled as a spherical conductor with its center at 90 m depth, a radius of 45 m, and a conductivity of 9.4 S/m.
Performance of a mail-administered version of a stroke-speci” c outcome measure, the Stroke Impact Scale
Authors: Duncan Pamela W , Reker Dean M , Horner Ronnie D , Samsa Gregory P , Hoenig Helen , LaClair Barbara J , Dudley Tara K 
Published: October 2002

Objective: To evaluate the feasibility and concurrent validity of a new, mail-administered, stroke-speci”c outcome measure, the Stroke Impact Scale (SIS). Design: Observational cohort study. Setting and patients: Stroke patients who had lived independently in the community prior to their stroke and who were candidates for post-stroke rehabilitation were recruited from nine, high-volume, Department of Veteran Affairs Medical Centers. Methods: Two hundred and six patients were mailed the SIS after a sixmonth post-stroke telephone interview. Telephone assessments included the Functional Independence Measure, the Lawton IADL and the SF-36. Results: The response rate for the mailed SIS was 63%, with 45% of the responses from proxies. The average rate of missing item level scores per patient was 1.3 (range 0–20) resulting in an average rate of 0.13 missing domain scores per patient (range 0–3). Nonresponders to the mailed SIS had more severe strokes with lower functional status at the time of the survey than responders. Proxies were more likely to complete the survey if the subjects were older, married, cognitively impaired and more functionally limited. The SIS did not exhibit a high rate of ‘oor and ceiling effects, particularly in physical function domains, as did the FIM and the SF-36. Conclusions: The mailed SIS is a feasible means of assessing post-stroke function. Missing items and missing domain scores were extremely low, however, there is a trade-off between the low-cost mail SIS survey on the one hand and the resulting nonresponse bias on the other.
Prevalence of spasticity post stroke
Authors: Watkins C L , Leathley M J , Gregson J M , Moore A P , Smith T L , Sharma A K 
Published: October 2002

Objectives: To establish the prevalence of spasticity 12 months after stroke and examine its relationship with functional ability. Design: A cohort study of prevalence of spasticity at 12 months post stroke. Setting: Initially hospitalized but subsequently community-dwelling stroke survivors in Liverpool, UK. Subjects: One hundred and six consecutively presenting stroke patients surviving to 12 months. Main outcome measures: Muscle tone measured at the elbow using the Modi”ed Ashworth Scale and at several joints, in the arms and legs, using the Tone Assessment Scale; functional ability using the modi”ed Barthel Index. Results: Increased muscle tone (spasticity) was present in 29 (27%) and 38 (36%) of the 106 patients when measured using the Modi”ed Ashworth Scale and Tone Assessment Scale respectively. Combining the results from both scales produced a prevalence of 40 (38%). Those with spasticity had signi”cantly lower Barthel scores at 12 months ( p < 0.0001). Conclusion: When estimating the prevalence of spasticity it is essential to assess both arms and legs, using both scales. Despite measuring tone at several joints, spasticity was demonstrated in only 40 (38%) patients, lower than previous estimates.
The effect of independent practice of motor tasks by stroke patients: a pilot randomized controlled trial
Authors: Pollock Alexandra S , Durward Brian R , Rowe Philip J , Paul John P 
Published: October 2002

Objective: To investigate the effect of independent practice of sitting balance as an addition to standard physiotherapy treatment for patients with stroke. Design: Randomized controlled trial, using blocked randomization procedure with 2:1 ratio. Subjects: Inpatients with diagnosis of stroke, having achieved one minute of independent sitting balance but not yet achieved 10 independent steps, and with no known previous disabilities, pathology or neurological de”cit affecting mobility prior to stroke. Intervention: A four-week regime of independent practice aimed at improving aspects of balance, as an addition to standard physiotherapy treatment based on the Bobath Approach. Main outcome measure: Proportion of patients achieving ‘normal’ symmetry of weight distribution during sitting, standing, rising to stand, sitting down, and reaching. Results: Nineteen subjects were randomized to the control group; nine to the intervention group. There were no clinically signi”cant differences in measured outcome between the groups. Conclusions: The regime of independent practice had no measured bene”cial effect on the balance ability of patients with recently acquired stroke.