bluuebunny/crossref_metadata_2025 huggingface dataset:
Tec3, a New Developmentally Eliminated DNA Element in
Euplotes crassus
Authors: Jacobs Mary Ellen , Sánchez-Blanco Adolfo , Katz Laura A. , Klobutcher Lawrence A.
Published: February 2003

More than 100,000 interstitial segments of DNA (internal eliminated sequences [IESs]) are excised from the genome during the formation of a new macronucleus in
Euplotes crassus
. IESs include unique sequence DNA as well as two related families of transposable elements, Tec1 and Tec2. Here we describe a new class of
E. crassus
transposons, Tec3, which is present in 20 to 30 copies in the micronuclear genome. Tec3 elements have long inverted terminal repeats and contain a degenerate open reading frame encoding a tyrosine-type recombinase. One characterized copy of Tec3 (Tec3-1) is 4.48 kbp long, has 1.23-kbp inverted terminal repeats, and resides within the micronuclear copy of the ribosomal protein L29 gene (
RPL29
). The 23 bp at the extreme ends of this element are very similar to those in other
E. crassus
IESs and, like these other IESs, Tec3-1 is excised during the polytene chromosome stage of macronuclear development to generate a free circular form with an unusual junction structure. In contrast, a second cloned element, Tec3-2, is quite similar to Tec3-1 but lacks the terminal 258 bp of the inverted repeats, so that its ends do not resemble the other
E. crassus
IES termini. The Tec3-2 element appears to reside in a large segment of the micronuclear genome that is subject to developmental elimination. Models for the origins of these two types of Tec3 elements are presented, along with a discussion of how some members of this new transposon family may have come to be excised by the same machinery that removes other
E. crassus
IESs.
NONCOMMUTATIVE DIPOLE QED
Authors: SADOOGHI NÉDA , SOROUSH MASOUD
Published: January 2003

The noncommutative dipole QED is studied in detail for the matter fields in the adjoint representation. The axial anomaly of this theory is calculated in two and four dimensions using various regularization methods. The Ward–Takahashi identity is proved by making use of a nonperturbative path integral method. The one-loop β-function of the theory is calculated explicitly. It turns out that the value of the β-function depends on the direction of the dipole length L, which defines the noncommutativity. Finally using a semiclassical approximation a nonperturbative definition of the form factors is presented and the anomalous magnetic moment of this theory at one-loop order is computed.
GLUON CORRELATORS IN THE KOGAN–KOVNER MODEL
Authors: GRIPAIOS B. M.
Published: January 2003

The Lorentz-invariant gluon correlation functions  and [Formula: see text], corresponding to scalar and pseudoscalar glueballs, are calculated for Kogan's and Kovner's variational ansatz for the pure SU (N) Yang–Mills wave functional.

One expects only one dynamical mass scale should be present in QCD; the ansatz generates the expected scale for both glueballs, as well as an additional scale for the scalar glueball coming from the correlator of the color electric field. The additional mass scale must therefore vanish, or be close to the expected one. This is shown to constrain the nature of the phase transition in the Kogan–Kovner ansatz.
FRACTIONAL STATISTICS IN TERMS OF THE r-GENERALIZED FIBONACCI SEQUENCES
Authors: RACHIDI M. , SAIDI E. H. , ZEROUAOUI J.
Published: January 2003

We develop a method to approach quantum gases of quasiparticles with generalized statistics. This way is based on Fibonacci hierarchies and offers an alternative issue to the Haldane–Wu method. We give the statistical weights densities ρM of gases of quasiparticles with s = 1/M : mod (1), M ≥ 2, using the combinatorial aspects of M-generalized Fibonacci series. This is a remarkable feature which envelopes naturally the Fermi and Bose statistics.
EXACT SOLUTIONS AND THE COSMOLOGICAL CONSTANT PROBLEM IN DILATONIC-DOMAIN-WALL HIGHER-CURVATURE STRING GRAVITY
Authors: MAVROMATOS NICK E. , RIZOS JOHN
Published: January 2003

In this paper, we extend the previous work by the authors, and elaborate further on the structure of the general solution to the graviton and dilaton equations of motion in brane world scenaria, in the context of five-dimensional effective actions with [Formula: see text] higher-curvature corrections, compatible with bulk string-amplitude calculations. We consider (multi)brane scenaria, dividing the bulk space into regions, in which one matches two classes of general solutions, a linear Randall–Sundrum solution and a (logarithmic) dilatonic domain wall (bulk naked singularity). We pay particular attention to examining the possibility of resolving the mass hierarchy problem together with the vanishing of the vacuum energy on the observable world, which is taken to be a positive tension brane. The appearance of naked dilatonic domain walls provides a dynamical restriction of the bulk space–time. Of particular interest is a dilatonic-wall solution, which after appropriate coordinate transformation, results in a linear dilaton conformal field theory. The latter may provide a holographic resolution of the naked singularity problem. All the string-inspired models involved have the generic feature that the brane tensions are proportional to the string coupling gs; it remains a challenge for string theory, therefore, to show whether microscopic models respecting this feature can be constructed.
DOUBLY SPECIAL RELATIVITY VERSUS κ-DEFORMATION OF RELATIVISTIC KINEMATICS
Authors: LUKIERSKI JERZY , NOWICKI ANATOL
Published: January 2003

We argue that the so-called doubly special relativity (DSR), recently proposed by Amelino-Camelia et al.1,2 with deformed boost transformations identical with the formulae for κ-deformed kinematics in bicrossproduct basis is classical special relativity in nonlinear disguise. The choice of symmetric composition law for deformed four-momenta as advocated in Refs. 1 and 2 implies that DSR is obtained by considering the nonlinear four-momenta basis of classical Poincaré algebra and it does not lead to noncommutative space–time. We also show how to construct two large classes of doubly special relativity theories — generalizing the choice in Refs. 1 and 2 and the one presented by Magueijo and Smolin.3 The older version of deformed relativistic kinematics, differing essentially from classical theory in the coalgebra sector and leading to noncommutative κ-deformed Minkowski space is provided by quantum κ-deformation of Poincaré symmetries.
ON SPATIAL ASYMMETRIC GAMES
Authors: AHMED E. , HEGAZI A. S. , ELGAZZAR A. S.
Published: January 2003

The stability of some spatial asymmetric games is discussed. Both linear and nonlinear asymptotic stability of asymmetric hawk-dove and prisoner's dilemma are studied. Telegraph reaction diffusion equations for the asymmetric spatial games are presented. Asymmetric games of parental investment is studied in the presence of both ordinary and cross diffusions.
PACKET TRANSPORT ON SCALE-FREE NETWORKS
Authors: TADIĆ BOSILJKA , RODGERS G. J.
Published: January 2003

We introduce a model of information packet transport on networks in which the packets are posted by a given rate and move in parallel according to a local search algorithm. By performing a number of simulations we investigate the major kinetic properties of the transport as a function of the network geometry, the packet input rate and the buffer size. We find long-range correlations in the power spectra of arriving packet density and the network's activity bursts. The packet transit time distribution shows a power-law dependence with average transit time increasing with network size. This implies dynamic queuing on the network, in which many interacting queues are mutually driven by temporally correlated packet streams.
APPLYING THE PRODUCT PARTITION MODEL TO THE IDENTIFICATION OF MULTIPLE CHANGE POINTS
Authors: LOSCHI R. H. , CRUZ F. R. B.
Published: January 2003

The multiple change point identification problem may be encountered in many subject areas, including disease mapping, medical diagnosis, industrial control, and finance. One appealing way of tackling the problem is through the product partition model (PPM), a Bayesian approach. Nowadays, practical applications of Bayesian methods have attracted attention perhaps because of the generalized use of powerful and inexpensive personal computers. A Gibbs sampling scheme, simple and easy to implement, is used to obtain the estimates. We apply the algorithm to the analysis of two important stock market data in Brazil. The results show that the method is efficient and effective in analyzing change point problems.
Aerosolized surfactant inhibits acetylcholine-induced airway obstruction in rats
Authors: Hohlfeld J , Hoymann HG , Molthan J , Fabel H , Heinrich U
Published: January 2003

Exogenous surfactant treatment inhibits antigen-induced airway obstruction in sensitized guinea-pigs. Aerosolized surfactant also improves respiratory function in asthmatic patients. The aim of the present study was to determine whether aerosolized surfactant inhibits nonallergic airway obstruction induced by acetylcholine. Anaesthetized Wistar rats were treated by aerosol with the beta2-adrenoceptor agonist terbutaline, surfactant (Alveofact), a surfactant-terbutaline combination, or vehicle (control). Animals were then challenged by aerosolized acetylcholine to elicit receptor-mediated airway obstruction. A second group of animals was challenged with intravenous acetylcholine. Respiratory function variables were measured by body plethysmography before and after treatment, and after the acetylcholine challenge. Baseline lung function values before and after treatment were similar in all groups. Acetylcholine challenge by aerosol increased lung resistance by 64% in control animals. Pretreatment with terbutaline and surfactant significantly limited the increase of lung resistance to +36 and +34%, respectively. Simultaneous aerosolization of surfactant and terbutaline also inhibited airway obstruction but their effects were not additive. By contrast, terbutaline treatment inhibited the effects of intravenous acetylcholine, but surfactant did not. In conclusion, we suggest that surfactant aerosol may prevent acetylcholine and other pharmacological agents from reaching the airway smooth muscle from the airway lumen but not via the bloodstream.
Effect of 1 year daily treatment with 400 microg budesonide (Pulmicort Turbuhaler) in newly diagnosed asthmatics
Authors: Osterman K , Carlholm M , Ekelund J , Kiviloog J , Nikander K , Nilholm L , Salomonsson P , Strand V , Venge P , Zetterstrom O
Published: January 2003

The aim of this study was to investigate whether treatment with a low daily dose of 400 microg inhaled budesonide (Pulmicort Turbuhaler) in newly diagnosed asthmatics could influence the course of asthma. Seventy five adult patients, mostly with mild asthma, diagnosed during the previous year and bronchial hyperresponsiveness, participated in a double-blind, randomized, parallel-group multicentre study. They were treated with budesonide 200 microg b.i.d. or placebo, delivered via Turbuhaler for 12 months and followed-up for another 6 months without inhaled steroid treatment. Airway function, symptom scores, reactivity to histamine and inflammatory indices in blood were assessed. The mean increase in morning peak expiratory flow (PEF) was 28 L x min(-1) after budesonide treatment compared with no increase in the placebo group (p=0.011). The provocative dose of histamine causing a 20% fall in forced expiratory volume in one second (PD20) (geometric mean) increased in the budesonide group by approximately two doubling dose steps, but not in the placebo group (p=0.0003). The difference between groups with regard to improvement in asthma symptom scores and inflammatory indices did not reach statistical significance. During the 6 month follow-up, the PEF values of the patients who had previously been treated with budesonide decreased by 18 L x min(-1) while the PD20 decreased by approximately one doubling dose step. In conclusion, early treatment with a low dose of budesonide improves airway function and decreases bronchial responsiveness, but the improvements are short-lasting without continued treatment.
Investigation of the effect of short-term change in dietary magnesium intake in asthma
Authors: Hill J , Micklewright A , Lewis S , Britton J
Published: January 2003

Epidemiological evidence suggests that a low dietary intake of magnesium is associated with impaired lung function, bronchial hyperreactivity and wheezing. This study was designed to investigate whether short-term alterations of dietary magnesium intake have an effect on the clinical control of asthma. In a randomized, double-blind, placebo-controlled, cross-over study, 17 asthmatic subjects adhered to a low magnesium diet for two periods of 3 weeks, preceded and separated by a 1 week run-in/wash-out, in which they took either placebo or magnesium (400 mg x day(-1)) tablet supplementation. Forced expiratory volume in one second (FEV1) and the provocative dose of methacholine required to cause a 20% fall in FEV1 from baseline (PD20,FEV1) were measured at the beginning and end of each treatment period, and variation in peak expiratory flow (PEF) rate, bronchodilator use and symptom scores recorded throughout. Asthma symptom scores were significantly lower during the magnesium treatment period, the median (95% confidence interval) difference from placebo being 3.8 (0.5-7.0) symptom points per 7 days (p=0.02). However, there was no significant improvement in FEV1, PD20,FEV1, log amplitude percentage mean PEF variation or bronchodilator use during magnesium supplementation. A high magnesium intake was associated with improvement in symptom scores, though not in objective measures of airflow or airway reactivity, in these stable asthmatic subjects.
Sustained protection against distilled water provocation by a single dose of salmeterol in patients with asthma
Authors: Bootsma GP , Dekhuijzen PN , Festen J , Lammers JW , Mulder PG , van Herwaarden CL
Published: January 2003

The long-acting beta2-agonist salmeterol inhibits in vitro the release of inflammatory mediators up to 20 h. These mediators are involved in ultrasonically nebulized distilled water (UNDW)-induced bronchoconstriction. We investigated whether salmeterol provides prolonged protection against UNDW provocation and whether this effect was paralleled by its bronchodilator effects. Nineteen asthmatic patients (mean forced expiratory volume in one second (FEV1) 84.8% predicted, mean provocative concentration of histamine producing a 20% decrease in FEV1 0.65 mg x mL(-1)) participated in this randomized, double-blind, placebo-controlled crossover trial. After measuring baseline FEV1, patients inhaled 50 microg salmeterol or placebo by metered-dose inhaler. FEV1 was measured after 20 and 40 min, and UNDW provocations and FEV1 measurements were performed after 10, 20 and 34 h. Compared to placebo, salmeterol caused marked bronchodilatation from 20 min up to 20 h after inhalation. Salmeterol also provided more than 20 h of protection against UNDW provocation (still more than one doubling dose). Protection beyond the period of bronchodilatation did not occur. Eleven subjects had a significant reduction in provocative dose of UNDW causing a 20% fall in FEV1 (PD20,UNDW) values between 10 and 20 h, at a time when there was still persistent bronchodilation. No correlation existed between changes in FEV1 and changes in PD20,UNDW. From the equations of regression lines between FEV1 and corresponding PD20,UNDW values, it was calculated that only approximately 25% of the afforded protection was explained by bronchodilatation. In conclusion, a single dose of salmeterol induces both bronchodilatation and protection independently of this bronchodilation against a physiological bronchoconstrictor stimulus for more than 20 h.
A guinea-pig model of ultrasonically nebulized distilled water-induced bronchoconstriction
Authors: Fujimura M , Amemiya M , Myou S , Mizuguchi M , Matsuda T
Published: January 2003

Ultrasonically nebulized distilled water-induced bronchoconstriction (UNDW-IB) is specific to asthma. The mechanisms underlying UNDW-IB are not fully understood, and no reproducible animal model has been reported. The purpose of this study was to develop a guinea-pig model of UNDW-IB. Ultrasonically nebulized distilled water (UNDW) was inhaled 20 min after an aerosolized antigen challenge in passively sensitized and artificially ventilated guinea-pigs. UNDW was also inhaled 5 and 20 min after 0.1 mg x mL(-1) methacholine inhalation in nonsensitized animals. In addition, 0.1 mg x kg(-1) S-1452, a thromboxane A2 antagonist, or saline was given intravenously 5 min before UNDW inhalation in sensitized animals. The inhalation of UNDW caused bronchoconstriction, when inhaled 20 min after an antigen challenge in sensitized guinea-pigs. UNDW inhalation did not produce bronchoconstriction after saline inhalation in nonsensitized or sensitized guinea-pigs, or after antigen inhalation in nonsensitized animals. Methacholine-induced bronchoconstriction did not evoke UNDW-IB. Neither did S-1452 reduce the UNDW-IB. In conclusion, the guinea-pig model of ultrasonically nebulized distilled water-induced bronchoconstriction developed in this study suggests that allergic reaction, but not bronchoconstriction, can induce bronchial hyperresponsiveness to ultrasonically nebulized distilled water, and that thromboxane A2 is not involved in ultrasonically nebulized distilled water-induced bronchoconstriction.
The diagnostic capacity of forced oscillation and forced expiration techniques in identifying asthma by isocapnic hyperpnoea of cold air
Authors: Schmekel B , Smith HJ
Published: January 2003

The measurement of forced expiratory volume in one second (FEV1) is often used to assess the effect of bronchial provocations, and deep inspiration is required beforehand. This may briefly alter the bronchial tone in a variable way in some subjects. The forced oscillation technique (FOT) is a test used to characterize the mechanical impedance of the respiratory system, and prior deep inspiration is not required. We tested the hypothesis that measurable bronchoconstriction would occur in all asthmatic subjects stimulated with isocapnic hyperventilation of dry cold air (IHCA). Twenty patients with mild asthma and nine healthy controls were exposed to IHCA, at 70% of their maximal voluntary ventilatory capacity for 4 min and the results were assessed both by applying the FOT and by measuring FEV1. Optimal cut-off levels were defined by receiver operating characteristic (ROC) curve analyses of the changes in respiratory resistance and reactance at 5-35 Hz, resonant frequency (fres) and FEV1. A positive result was present in the asthmatics when measured by FOT, and using ROC analyses the discriminative capacity to correctly diagnose asthma was greatest for responses in fres; the sensitivity was 89% and the specificity 100%. The sensitivity of FEV1 to correctly diagnose asthma was only 73%, and the specificity 88%. In conclusion, the results of this study suggest that the use of forced expiratory volume in one second for bronchial provocation tests by isocapnic hyperventilation of dry cold air may be misleading and that the bronchoconstriction thus elicited is measured with greater sensitivity and specificity by the forced oscillation technique than by forced expiratory volume in one second.
Gastro-oesophageal reflux prevalence and relationship with bronchial reactivity in asthma
Authors: Vincent D , Cohen-Jonathan AM , Leport J , Merrouche M , Geronimi A , Pradalier A , Soule JC
Published: January 2003

The relationship between asthma and gastro-oesophageal reflux (GER) is controversial. In an allergy department, GER prevalence was evaluated in asthmatics, with a view to judging the potential influence of GER on asthma. One hundred and five asthmatics were recruited and co-investigated for GER and lung function. Descriptive analysis was performed, patients with (GER+) and without (GER-) GER were then compared, and finally, stepwise regression analysis was used. GER prevalence was 32%. Lung parameters did not differ between GER+ and GER- patients. When restricting analysis to GER+ patients, bronchial reactivity was closely correlated to the number of reflux episodes (NRE) (r=0.983; p=0.001). When comparing patients with more than 15 reflux episodes x day(-1) (n=50), with those having less (n=43), no differences were found in lung function and GER parameters. However, there was a positive correlation between the provocative dose of methacholine causing forced expiration volume to fall 20% from the baseline and NRE in patients with NRE>15 (r=0.561; p=0.05). In conclusion, gastro-oesophageal reflux was observed in a third of the asthma patients studied. These data do not support a firm aetiological relationship between gastro-oesophageal reflux and asthma, but do suggest an association between the number of reflux episodes and bronchial hyperresponsiveness.
Lack of effect of high doses of inhaled morphine on exercise endurance in chronic obstructive pulmonary disease
Authors: Jankelson D , Hosseini K , Mather LE , Seale JP , Young IH
Published: January 2003

Systemic opiates may relieve dyspnoea and improve exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). Small doses of inhaled opiates may have similar effects; however, recent studies have shown no benefit. We studied higher doses of inhaled morphine and measured systemic absorption to determine whether any beneficial actions are local or systemic. Twenty and 40 mg doses and 0.9% saline were nebulized in a randomized, double-blind study of 16 patients with stable COPD. Patients performed 6 min walk tests immediately after the nebulized test solution (Walk 1) and again 60 min later (Walk 2). Arterial oxygen saturation (Sa,O2), modified Borg dyspnoea score and cardiac frequency were recorded during each walk. There was no difference between placebo and either dose of nebulized morphine on these measurements. The higher dose of nebulized morphine achieved a higher plasma concentration. The highest plasma concentration was measured immediately after nebulization, and this decreased steadily in the hour thereafter (p<0.002). There was no correlation between the change in walk distance and the change in plasma morphine concentration after either dose of nebulized morphine. We conclude that higher doses of nebulized morphine do not improve exercise endurance or relieve dyspnoea in patients with chronic obstructive pulmonary disease, and that morphine is rapidly absorbed systemically after inhalation.
Traffic-related NO2 and the prevalence of asthma and respiratory symptoms in seven year olds
Authors: Studnicka M , Hackl E , Pischinger J , Fangmeyer C , Haschke N , Kuhr J , Urbanek R , Neumann M , Frischer T
Published: January 2003

The aim of this study was to determine whether outdoor nitrogen dioxide (NO2) was associated with the prevalence of asthma and respiratory symptoms. In eight nonurban communities, 843 children resident for a minimum of 2 yrs were studied. Since industrial sources of air pollution were at least 20 km away from the study communities, NO2 was considered to primarily indicate traffic-related air pollution. NO2 was recorded at central monitors, and the 3 yr mean exposure was calculated. Asthma and respiratory symptoms were assessed according to the International Study on Asthma and Allergy in Childhood. Prevalence of asthma at some time ("ever asthma") was associated with long-term NO2. In parallel with increasing levels of NO2 (community specific 3 yr mean 6.0-17.0 parts per billion (ppb)), asthma prevalence was 2.5, 1.4, 1.6, 2.3, 3.4, 3.6, 7.6 and 8.5%, respectively (p=0.002 for trend). The prevalence odds ratios (PORs) for "ever asthma", following adjustment for gender, age, parental education, passive smoke exposure, type of indoor heating, and parental asthma, were 1.28 (95% confidence interval (95% CI) 0.20-7.98), 2.14 (95% CI 0.40-11.3) and 5.81 (95% CI 1.27-26.5), when each of two communities with low, regular and high NO2, respectively, were compared with the two communities with very low NO2. For symptoms "wheeze" (adjusted PORs for increased NO2: 1.47, 1.23 and 2.27) and "cough apart from colds" (adjusted PORs for increased NO2: 1.49, 1.93 and 2.07), a similar trend was seen. In this study a significant relationship was observed between traffic-related nitrogen dioxide and the prevalence of asthma and symptoms. Whether this association is causal has to be tested in longitudinal studies.
Changing prevalence of asthma among schoolchildren in Israel
Authors: Goren AI , Hellmann S
Published: January 2003

This survey was part of a health monitoring system operated in the vicinity of a new power plant in Israel. The aim of this analysis was to determine whether a temporal trend of increased prevalence of asthma can be observed among cohorts of same-aged children, between 1980 and 1989. Schoolchildren were followed up between 1980 and 1989. They performed pulmonary function tests (PFTs), and their parents filled out American Thoracic Society-National Heart and Lung Institute (ATS-NHLI) health questionnaires. This report deals with the changes in the prevalence of asthma, related respiratory conditions and PFT in four cross-sectional data sets gathered among eighth-grade schoolchildren (aged 13-14 yrs). A highly significant (p=0.0005) increase in the prevalence of asthma (from 5.6% in 1980 to 11.2% in 1989), and of wheezing accompanied by shortness of breath (p=0.0009) could be observed. A similar trend could not be found for the prevalence of bronchitis among these children. PFTs of children suffering from asthma or from wheeze accompanied by shortness of breath were lower than those of healthy children. Changes in prevalence of background variables over time could not explain these findings. The significant rise in the prevalence of asthma coupled with reduced pulmonary function test results among asthmatic children, seems to reflect a true increase in morbidity. Temporal changes in the prevalence of background variables as well as proximity to the power plant could not explain this trend.
Minimum skills required by children to complete health-related quality of life instruments for asthma: comparison of measurement properties
Authors: Juniper EF , Guyatt GH , Feeny DH , Griffith LE , Ferrie PJ
Published: January 2003

To gain a complete picture of a child's health-status, measurement of health-related quality of life (HRQL) is necessary. Since parents do not accurately perceive children's HRQL, information must be obtained from the children themselves. The aim of this study was to determine the minimum age and reading skills required by children to complete competently the Paediatric Asthma Quality of Life Questionnaire (PAQLQ), the Health Utilities Index (HUI), the Feeling Thermometer and the Standard Gamble, and to evaluate the validity of each for measuring HRQL in children with asthma. Fifty two children (age 7-17 yrs) with symptomatic asthma participated in a 9 week single cohort study with HRQL and clinical asthma control assessed every 4 weeks. All children provided very reliable data for the PAQLQ and the HUI but they needed > or = grade 6 reading skills to complete the Standard Gamble and > or = grade 2 skills for the Feeling Thermometer. In those children who were able to provide reliable data, the PAQLQ had the best discriminative and evaluative measurement properties, followed closely by the Feeling Thermometer. Measurement properties in the Standard Gamble were weaker and although the HUI was very reliable it was not actually measuring asthma-specific HRQL. The Paediatric Asthma Quality of Life Questionnaire may be used with confidence in clinical studies and practice to provide a profile of children's day-to-day experiences. In those children with adequate skills to complete the test reliably, the Feeling Thermometer provides a good estimate of the value that children place on their asthma health status.
Short-term effects of regular salmeterol treatment on adult cystic fibrosis patients
Authors: Bargon J , Viel K , Dauletbaev N , Wiewrodt R , Buhl R
Published: January 2003

Cystic fibrosis (CF) is characterized by chronic lung inflammation leading to airways obstruction. Bronchodilators, particularly short-acting beta2-agonists, are, therefore, often used by CF patients. The aim of this study was to evaluate, prospectively, the effects of the long-acting beta2-agonist salmeterol in adult CF patients. Twenty six patients with CF (10 males and 16 females; mean age (+/-SEM) 28+/-2 yrs) with mild-to-moderate airways obstruction (baseline forced expiratory volume in one second/forced vital capacity (FEV1/FVC) 56+/-2%) were monitored in an open, cross-over trial for 4 weeks by means of peak expiratory flow rates (PEFR), self-recorded symptom scores and body plethysmography. During a 2 week run-in period, all patients continued their treatment, including regular short-acting beta2-agonists. In weeks 3 and 4, short-acting beta2-agonists were replaced by the long-acting beta2-agonist, salmeterol (50 microg b.i.d.). Salmeterol produced a significant increase in PEFR compared to the run-in period (morning 375+/-23 vs 332+/-23 L x min(-1), deltaPEFR +15.1+/-3.1%, p<0.003; evening 384+/-24 vs 349+/-24 L x min(-1), deltaPEFR +11.7+/-2.4%, p<0.04). Similarly, patients reported lower symptom scores, e.g. less dyspnoea during the day, fewer nocturnal awakenings, less intense cough, and fewer unscheduled puffs of short-acting beta2-agonists. Thus, the long-acting beta2-agonist salmeterol provided clinical benefit to a majority of adult cystic fibrosis patients with airways obstruction. These short-term results are promising enough to set up long-term controlled studies.
Iron-binding proteins in sputum of chronic bronchitis patients with Haemophilus influenzae infections
Authors: Vogel L , Schoonbrood D , Geluk F , Hoek F , Bresser P , Out T , Jansen H , Dankert J , van Alphen L
Published: January 2003

Airway inflammation during infection is associated with increased transudation of serum proteins and increased production of protein by the airway epithelium. We therefore, assessed whether Haemophilus influenzae infections in patients with chronic bronchitis are associated with increased levels of transferrin and lactoferrin in the sputum compared to uninfected patients. Sputum sol phase and serum samples from 14 infected and 13 uninfected patients with chronic bronchitis and from 12 bronchial asthma patients were included in the study. The median Q-values (the concentration in sputum sol phase/the concentration in serum) x 10(3) of transferrin appeared increased in chronic bronchitis patients with an H. influenzae infection (26.0, n=13) compared to uninfected controls (9.5, n=11) and bronchial asthma patients (4.5, n=6). The ratio of the Q(transferrin)/Q(albumin) was >1 in infected chronic bronchitis patients, indicating local production of transferrin. Growth of H. influenzae was stimulated more in sputum from infected and uninfected patients with chronic bronchitis than in sputum from patients with bronchial asthma. The concentrations of lactoferrin were not significantly different in infected (n=14) and uninfected (n=13) chronic bronchitis patients and bronchial asthma patients (n=12) (median 137.4, 84.6, 87.1 mg x L(-1), respectively). We conclude that in patients with chronic bronchitis with Haemophilus influenzae infections, the levels of transferrin are increased and the levels of lactoferrin are not associated with infections.
Lung and chest wall mechanics in patients with acquired immunodeficiency syndrome and severe Pneumocystis carinii pneumonia
Authors: D'Angelo E , Calderini E , Robatto FM , Puccio P , Milic-Emili J
Published: January 2003

The aim of this study was to assess the mechanical characteristics of the respiratory system in patients with acquired immune deficiency syndrome (AIDS) and acute respiratory distress syndrome (ARDS) caused by Pneumocystis carinii pneumonia (PCP). In 12 mechanically ventilated patients, total respiratory system mechanics was assessed using the technique of rapid airway occlusion during constant flow inflation, and was partitioned into lung and chest wall components using the oesophageal balloon technique. We measured interrupter resistance (Rint), which mainly reflects airway resistance, additional resistance (deltaR) due to viscoelastic behaviour and time constant inequalities, and static elastance (Est). In addition, the static inflation volume-pressure (V-P) curve was assessed. In eight patients, computed tomography scans were performed within 2 days of the assessment of respiratory mechanics. Compared to values reported in the literature for normal subjects, Est and deltaR were markedly increased in AIDS patients with PCP, whilst Rint exhibited a relatively smaller increase. These changes, which involved only the lung and airways, were mainly due to the reduction of ventilated lung units, but additional factors were involved to cause independent modifications of lung stiffness, airway calibre, and viscoelastic properties. The changes in Rint, deltaR, and Est were similar to those observed in other studies on patients with ARDS of different aetiologies. At variance with common observations in the latter patients, none of the AIDS patients with PCP exhibited an inflection point on the static inflation V-P curve, suggesting little or no alveolar recruitment during lung inflation. This finding could be related to the distinctive histopathology of Pneumocystis carinii pneumonia. Indeed, computed tomography revealed homogeneous diffuse interstitial and alveolar infiltration rather than the dense, dependent opacities observed in other studies on acute respiratory distress syndrome of different aetiologies.
Apoptosis and Fas/Fas ligand mRNA expression in acute immune complex alveolitis in mice
Authors: Nomoto Y , Kuwano K , Hagimoto N , Kunitake R , Kawasaki M , Hara N
Published: January 2003

Deoxyribonucleic acid (DNA) strand breaks as a characteristic of apoptosis, and Fas antigen (Fas)/Fas ligand (FasL) expression may participate in acute immune complex alveolitis in mice. Male Institute for Cancer Research (ICR) mice were injected intravenously with immunoglobulin G (IgG) antibodies against ovalbumin and inhaled an aerosolized oval albumin (OA) solution. They were killed at 4, 6, 12, 24, 48 h and 7 days after aerosolization. We assessed DNA fragmentation by agarose gel electrophoresis and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end-labelling (TUNEL). The expression of Fas and FasL messenger ribonucleic acid (mRNA) in lung tissues was assessed by reverse transcriptase (RT) polymerase chain reaction, and by in situ hybridization (ISH) to localize Fas mRNA, and RT in situ polymerase chain reaction to localize FasL mRNA. The fragmentation of DNA extracted from lung tissue was found 6-24 h after OA inhalation. TUNEL detected positive signals in bronchial and alveolar epithelial, endothelial and inflammatory cells in the lung tissue. These positive signals had disappeared 7 days after OA inhalation. TUNEL also detected positive signals in apoptotic neutrophils in bronchoalveolar lavage fluid at 6-12 h. Fas mRNA was expressed in the alveolar epithelial and inflammatory cells, while the expression of FasL mRNA appeared to be upregulated in infiltrating inflammatory cells at 6-24 h. These results suggest that apoptosis may be associated with the resolution of inflammation and with tissue repair and also suggest the involvement of the Fas antigen/Fas ligand pathway in acute immune complex alveolitis in mice.
Dependence of forced vital capacity manoeuvre on time course of preceding inspiration in patients with restrictive lung disease
Authors: Koulouris NG , Rapakoulias P , Rassidakis A , Dimitroulis J , Gaga M , Milic-Emili J , Jordanoglou J
Published: January 2003

In normal subjects and patients with airway obstruction, flows during a forced vital capacity (FVC) manoeuvre are higher after a fast inspiration without an end-inspiratory pause (manoeuvre 1) as compared to a slow inspiration with an end-expiratory pause of approximately 5 s (manoeuvre 2). In this study, we investigated the influence of these manoeuvres on maximal expiratory volume-time and flow-volume curves in patients with restrictive lung disease. Eleven patients with restrictive lung disease were studied. Their average (+/-SD) lung function test results were: FVC=55+/-12% predicted value, forced expiratory volume in one second (FEV1) 52+/-20% pred, FEV1/FVC 85+/-6%, total lung capacity 55+/-8% pred, and carbon monoxide transfer factor 47+/-18% pred. The patients performed the two FVC manoeuvres in random order. We compared the ensuing spirograms and maximal expiratory flow-volume curves from which peak expiratory flow, FEV1, FEV1/FVC, maximal mid-expiratory flow, and maximal flows were computed. All spirometric indices were significantly higher with manoeuvre 1 than 2. Maximal expiratory flows at the same lung volume were also significantly higher with manoeuvre 1 than 2, in all patients. Routine spirometric indices, obtained during a forced vital capacity manoeuvre depend on the time course of the preceding inspiration in patients with restrictive lung disease. Therefore, the forced vital capacity manoeuvre should be standardized if used in clinical, epidemiological and research studies.
Comparison of helium dilution and plethysmographic lung volumes in pregnant women
Authors: Garcia-Rio F , Pino-Garcia JM , Serrano S , Racionero MA , Terreros-Caro JG , Alvarez-Sala R , Villasante C , Villamor J
Published: January 2003

The multibreath helium equilibration method is the technique recommended for routine measurement of static lung volumes in normal subjects. However, pregnancy could be an exception to this general rule, due to airway closure during the second half of gestation. The aim of this study was to compare the measurements of lung volumes by plethysmography and helium dilution during pregnancy. Twenty three healthy women were studied at 12, 24 and 36 weeks of pregnancy, and 4 months postpartum. Total lung capacity (TLC), functional residual capacity (FRC) and residual volume (RV) were measured by multibreath helium equilibration (TLCHe, FRCHe and RVHe) and by plethysmography (TLCbox, FRCbox and RVbox). Only at 36 weeks were there differences between the two methods. RVbox was significantly larger than RVHe (1.01+/-0.18 vs 0.77+/-0.21 L; p<0.001). FRCbox was larger than FRCHe (1.95+/-0.32 vs 1.60+/-0.32 L; p<0.001) and TLCbox was larger than TLCHe (4.83+/-0.52 vs 4.45+/-0.51 L; p<0.05). The 95% limits of agreement for differences between lung volumes measured by the two techniques (helium dilution - plethysmography) at 36 weeks were: -0.42 to -0.06 L for RV; -0.54 to -0.17 L for FRC; and -0.66 to -0.11 L for TLC. We conclude that using the multibreath helium equilibration method to measure lung volumes in at-term pregnant women results in underestimation of functional residual capacity and total lung capacity.
Assessment of exposure to environmental tobacco smoke
Authors: Jaakkola MS , Jaakkola JJ
Published: January 2003

We present a theoretical framework for assessment of exposure to environmental tobacco smoke (ETS), and review current methods in order to provide guidelines for different types of studies. Exposure assessment should include both a quantitative dimension and consideration of time-specificity of exposure. The ultimate aim is to measure the concentrations of ETS encountered by an individual for different time periods in various microenvironments. The first step is to identify an indicator of ETS. Personal monitoring of air nicotine and respirable suspended particulates (RSPs) are the most direct assessment methods. Indirect assessment methods include stationary measurements of tobacco smoke constituents in different microenvironments and/or questionnaire-derived information, modelled with time-activity information. Biomarkers, such as nicotine and/or cotinine in body fluids or hair, can be used as surrogate measures of dose, although they are usually affected by individual processes in the body after exposure. The best approach to assess ETS exposure will depend on the aim of the study, the health outcome, and the resources. Personal monitoring of nicotine or RSPs is the best method in studies of short-term health effects with small study samples. Stationary measurements of indoor air nicotine or RSPs are suitable for overall monitoring of ETS in different microenvironments over time. Questionnaires and interviews are suitable when studying health outcomes with a long latency period and rare diseases requiring large study populations. Cotinine in body fluids and nicotine concentration in hair can be used to assess cumulative exposure over days or months, respectively. A combination of different methods is often the best approach.
Myosin gene expression in the respiratory muscles
Authors: Gea JG
Published: January 2003

Myosin is one of the basic structural components of skeletal muscles. Its interaction with actin results in muscle contraction. The myosin molecule is composed of two heavy (MyHC) and two light chains (MyLC) that, together with the adenosine triphosphatase (ATPase) activity, determine the functional characteristics of the fibre. Both MyHC and MyLC present different isoforms. The main MyHC isoforms in adult mammals are the slow MyHC (MyHC-I) and fast MyHCs (MyHC-IIa, MyHC-IIb and MyHC-IIx). Muscle fibres can express only one isoform or coexpress different forms. The muscle phenotype is the product of genome plus environmental stimuli. The family of genes that codifies the MyHC isoforms is located in two different clusters, each isoform being encoded by a separate gene. The gene corresponding to slow MyHC is located in chromosome 14, both in humans and in mice. The other genes are positioned in chromosome 17 in humans, and in chromosome 11 in mice. The transcriptional and translational mechanisms that control the expression of MyHC isoforms are not well known, although it is believed that the main regulation is dependent on mechanical signals. These signals are probably mediated by a biochemical messenger. As a general rule, fast MyHC genes seem to be expressed "by default", whereas the slow MyHC gene would be expressed as a response to changes in load. So far, few studies have analysed the in vivo regulation of MyHC gene expression in respiratory muscles. It has recently been reported that breathing against moderate levels of inspiratory resistance quickly induces an increase in the genetic expression of slow MyHC in the diaphragm. This suggests the possibility of eliciting a phenotypic adaptation of respiratory muscles using specific training protocols.
Immunobiology of pleural inflammation: potential implications for pathogenesis, diagnosis and therapy
Authors: Kroegel C , Antony VB
Published: January 2003

Although infectious, inflammatory and neoplastic diseases frequently involve the pleural space and walls, little is known about the immunological and molecular mechanisms underlying pleural disorders. This article provides an overview of recent insights into immunobiological processes likely to play a role in the pathogenesis of pleural disorders. Pleural involvement in certain diseases is associated with the infiltration of a number of different types of immune cells, such as neutrophils, eosinophils or lymphocytes, in various proportions depending on both the course and the aetiology of the underlying disease. In addition to infiltrating cells, mesothelial cells have been demonstrated to actively participate in pleural inflammation via release of various mediators and proteins, including platelet-derived growth factor (PDGF), interleukin-8, monocyte chemotactic peptide (MCP-1), nitric oxide (NO), collagen, antioxidant enzymes and the plasminogen activation inhibitor (PAI). Furthermore, several inflammatory mediators have been detected at increased concentrations within pleural effusions, including lipid mediators, cytokines and proteins (adenosine deaminase, lysosyme, eosinophil-derived cationic proteins, and products of the coagulation cascade). The presence of these mediators underline the concept of pleural inflammation, and certain cytokines seem to characterize a specific aetiology of pleurisy. The understanding of these processes and the sequence of events leading to pleural loculation, pleural adhesion or repair are likely to provide the basis for early therapeutic intervention and reduce pleural-associated morbidity.
Pneumococcal spherical pneumonia multiply distributed in one lung
Authors: Katsumura Y , Shirakami K , Satoh S
Published: January 2003

Spherical pneumonia, which is seen more frequently in children than in adults, is usually manifested as a solitary nodule. We report the case of a middle-aged man with small spherical pneumonia, with multiple distribution in the right lung, caused by Streptococcus pneumoniae. This type of pneumonia is very unusual and should be included in the differential diagnosis of multiple nodular densities of the lung.
Measurement of absolute lung volumes by imaging techniques
Authors: Clausen J
Published: January 2003

In this paper, the techniques available for estimating total lung capacities from standard chest radiographs in children and infants as well as adults are reviewed. These techniques include manual measurements using ellipsoid and planimetry techniques as well as computerized systems. Techniques are also available for making radiographic lung volume measurements from portable chest radiographs. There are inadequate data in the literature to support recommending one specific technique over another. Though measurements of lung volumes by radiographic, plethysmographic, gas dilution or washout techniques result in remarkably similar mean results when groups of normal subjects are tested, in patients with disease, the results of these different basic measurement techniques can differ significantly. Computed tomographic and magnetic resonance techniques can also be used to measure absolute lung volumes and offer the theoretical advantages that the results in individual subjects are less affected by variances of thoracic shape than are measurements made using conventional chest radiographs.