bluuebunny/crossref_metadata_2025 huggingface dataset:
Association between lower respiratory tract symptoms and falls in peak expiratory flow in children
Authors: Clough JB , Sly PD
Published: November 2022

Peak expiratory flow (PEF) measurements are increasingly recommended in childhood asthma management. However, few data are available on the temporal relationship between the onset of upper and lower respiratory tract symptoms and significant falls in PEF. We wanted to determine whether falls in PEF constitute a sensitive marker for clinical episodes of respiratory morbidity. We therefore analysed data on daily PEF and respiratory symptom recording from a 12 month longitudinal study in 192 children aged 7 and 8 yrs with current respiratory symptoms. Outcome measures were number of and relationship between: 1) episodes of fall in PEF (defined as a fall in PEF for more than 2 days to < 1.5 SD below individual mean morning PEF); and 2) upper and lower respiratory tract symptom events (defined as a respiratory symptoms score of > 3 units within three consecutive days). One hundred and eight six of the 192 children completed the study. For the group as a whole, the mean number of PEF episodes per subject was 3.5, and the mean number of symptom events 8.9, with 29% of symptom events being temporally associated with a PEF episode, and 40% of PEF episodes not being accompanied by a symptom event. Forty nine percent of PEF episodes were preceded by at least two consecutive days of either upper or lower respiratory symptoms. We conclude that falls in PEF alone were not a sensitive marker for episodes of respiratory morbidity. On almost half of the occasions where PEF did fall, morbidity could have been detected at least 2 days earlier using symptom reporting.(ABSTRACT TRUNCATED AT 250 WORDS)
Air pollution and upper respiratory symptoms in children from East Germany
Authors: von Mutius E , Sherrill DL , Fritzsch C , Martinez FD , Lebowitz MD
Published: November 2022

Whereas evidence of adverse effects of air pollution on lower respiratory tract illnesses in children is increasing, little is known about the effects of high and moderate levels of air pollution on the incidence of upper respiratory illnesses. 9 to 11 year old schoolchildren (n = 1,854) living in Leipzig, East Germany were studied. The presence of upper respiratory symptoms was documented by a physician. Daily mean and maximum concentrations of SO2, particulate matter (PM) and NOx, as well as temperature and humidity, were measured. Furthermore, a self-administered questionnaire was distributed to the parents to assess confounding factors. Parents of 1,500 (81%) children returned the questionnaire. When controlling for paternal education, passive smoke exposure, number of siblings, temperature and humidity, increased risks for the development of upper respiratory symptoms were found in the winter months for SO2 mean concentrations (odds ratio (OR) = 1.72; 95% confidence interval (95% CI) 1.19-2.49). NOx mean concentrations (OR = 1.53; 95% CI 1.01-2.31) and PM maximum values (OR = 1.62; 95% CI 1.08-2.45). In the summer months, only NOx mean concentrations were associated with a significantly increased risk (OR = 1.82; 95% CI 1.21-2.73). A combination of high mean levels of different pollutants resulted in the highest risk (OR = 2.10; 95% CI 1.30-3.37 in the winter, and OR = 2.16; 95% CI 1.23-3.81 in the summer). We conclude that high concentrations of SO2, and moderate levels of particulate matters and NOx are associated with an increased risk of developing upper respiratory symptoms in childhood.(ABSTRACT TRUNCATED AT 250 WORDS)
An exercise challenge for epidemiological studies of childhood asthma: validity and repeatability
Authors: Haby MM , Peat JK , Mellis CM , Anderson SD , Woolcock AJ
Published: November 2022

We assessed the validity, repeatability and practicality of a standardized exercise challenge protocol for measuring airway responsiveness in epidemiological studies of asthma in children aged 8-11 yrs. The construct validity of the exercise challenge was assessed by comparing response to exercise with other measures of asthma, i.e. wheeze frequency, diagnosed asthma, asthma medication use, atopy and urgent doctor visits (n = 802), and by comparison with response to histamine challenge (n = 201). Repeatability was assessed by comparison of responsiveness to two exercise challenges within 3 days (n = 113), and practicality was assessed by measurement of consent, compliance and throughput rates (n = 802). There was a significant relationship between frequency of wheeze attacks and % fall in forced expiratory volume in one second (FEV1) to exercise. The correlation (r) between % fall in FEV1 to exercise challenge and dose-response ratio to histamine challenge was 0.59. The repeatability of the exercise challenge was +/- 12% fall in FEV1. Consent and compliance rates for exercise challenge were 78 and 99%, respectively, and the mean throughput rate was 45 children per school day for a team of seven researchers. In conclusion, this exercise challenge was found to have good validity and to be reliable and practical. Thus, this challenge could be used as a standardized epidemiological tool to investigate the prevalence, aetiology and mechanisms of asthma.
Use and safety of a shortened histamine challenge test in an occupational study
Authors: Kremer AM , Pal TM , Oldenziel M , Kerkhof M , de Monchy JG , Rijcken B
Published: November 2022

A shortened histamine challenge test was used in a study of occupational airway disease. We evaluated the safety, defined as the absence of a decrease in forced expiratory volume in one second (FEV1) of greater than 40%. The occurrence of complaints, the repeatability of test results, and the average amount of time saved were measured. A standard protocol was used comprising 30 s tidal breathing with sequential doubling concentrations from 1 to 32 mg.ml-1 histamine. Subjects with no indication of hyperresponsive airways started at 4 mg.ml-1. If the decrease in FEV1 was < 6%, a concentration step was skipped (fourfold increase in concentration). The test was terminated when the decrease in FEV1 was at least 18%. A total of 697 subjects performed a test. All subjects with a provocative concentration of histamine producing a 20% decrease in FEV1 (PC20) value of < or = 4 mg.ml-1 (n = 16) started at the lowest concentration. Six subjects reached a > or = 20% decrease in FEV1 (range 21-24%) after a fourfold increase in concentration. Five subjects had a decrease in FEV1 of greater than 40%, and this decrease occurred after a doubling concentration. Cough, flushing, and chest tightness were noted in 18% of the subjects. In 56% of the tested subjects, the shortest provocation scheme (phosphate solution followed by 4, 16 and 32 mg.ml-1 histamine) was applied, resulting in a time reduction of nearly 50% per test, and reducing the time needed to complete the study from 5 to 3 months. The shortened test was repeatable within one concentration difference.(ABSTRACT TRUNCATED AT 250 WORDS)
Chronic allergen exposure enhances cholinergic neurotransmission in sensitized guinea-pigs
Authors: Kageyama N , Igarashi A , Ichinose M , Miura M , Yamauchi H , Tomaki M , Ishikawa J , Sasaki Y , Shirato K
Published: November 2022

Airway hyperresponsiveness in asthmatic patients may be related to cholinergic hyperresponsiveness. In this study, we examined whether chronic allergen exposure induces cholinergic hyperresponsiveness in ovalbumin (OA) sensitized guinea-pig airways. Three weeks after active sensitization, ovalbumin (0.03%, for 3 min, challenged group) or saline inhalation (control group) was repeated every day for 4 weeks. Cholinergic responses were assessed by isometric tracheal contraction after electrical field stimulation (EFS) or exogenously applied acetylcholine (ACh). The contractions were expressed as a percentage of the maximum response to ACh (10(-3) M) (AChmax). We calculated the effective frequencies producing 25% of AChmax (EF25) from frequency-response curves. EFS-induced contractile responses were significantly enhanced in the challenged group (logEF25 = 0.66 +/- 0.08 (mean +/- SEM)) compared with the control group (logEF25 = 1.12 +/- 0.16). In contrast, exogenous ACh-mediated contractile tracheal responses were almost the same in both groups. We conclude that repeated allergen inhalation causes cholinergic airway hyperresponsiveness, presumably due to the facilitation of cholinergic neurotransmission. This mechanism may be involved in the airway hyperresponsiveness in asthmatic airways.
Effect of nitric oxide on in vitro responsiveness of bovine bronchus and pulmonary vessels
Authors: Zhao W , Guenard H
Published: November 2022

Experiments were conducted in bovine isolated bronchi and pulmonary vessels to test whether nitric oxide (NO) could reduce carbachol and hypoxia or KCl (120 mM) induced contraction. Segments of bronchus or pulmonary vessels were slipped around a water-filled balloon connected to a pressure transducer, and mounted in 3 ml thermostated chamber filled with Krebs-Henseleit solution equilibrated with different gas mixtures. NO-CO2-N2 mixtures containing 10, 50 or 100 ppm NO were prepared. The effect of methylene blue on intrinsic tone and the bias effect of residual red blood cells were assessed. The results demonstrate that NO has no obvious effect on the intrinsic tone, the force generated by carbachol stimulation, or the spontaneous relaxation after removal of carbachol, in bronchi, with the exception of 100 ppm which increased the relaxing rate in small bronchi. By contrast, 50 and 100 ppm NO caused 53 and 61% decrease in the hypoxia-induced pulmonary arterial contraction, respectively. One hundred ppm NO caused 40, 38, 50 and 66% decrease in the KCl-induced contraction in pulmonary artery (PA), small pulmonary artery (SPA), small pulmonary vein (SPV) and pulmonary vein (PV), respectively. Sodium nitroprusside (10(-5) M) and isoproterenol (10(-5) M) reduced the carbachol-induced increase in bronchial pressure by 80% and nearly 100%, respectively. The residual concentration of haemoglobin in the chamber cannot explain the lack of effect of NO on the bronchi.(ABSTRACT TRUNCATED AT 250 WORDS)
Lung function development in young adults: is there a plateau phase?
Authors: Robbins DR , Enright PL , Sherrill DL
Published: November 2022

Numerous population studies have reported that pulmonary function following the adolescent growth phase appears to be in a steady-state, where there is little or no growth occurring up to 40 yrs of age. We examined longitudinal forced expiratory volume in one second (FEV1), changes using three different statistical approaches to determine which subjects actually have significant trends during this period. Participants, who were employees at a metal processing plant, underwent quarterly spirometry for up to 10 yrs. Test results up to 33 yrs of age were included in the analysis. Each subject's FEV1 data was first analysed using simple linear regression (SLR) to test for a statistically significant linear slope. Next, each subject's data were fitted using bootstrap sampling (BSS) of their original data, to yield reduced estimates of the slope variances and increase the power of detecting a significant trend. And thirdly, we fitted a regression breakpoint (BKPT) model to the data to find those subjects who may have piecewise linear growth or decline in function. All analyses were stratified, based on smoking status. Subjects included 111 nonsmokers and 110 smokers. Among the nonsmokers, 34 subjects had significant slopes using SLR, an additional three using BSS, and only two with BKPT. Among the smokers, 36 had a significant trend using SLR, 7 were added using BSS, and no additional subjects with BKPT. We conclude that in young adult males lung function is not in a steady-state and that as many as 40% have a significant slope, either positive or negative.(ABSTRACT TRUNCATED AT 250 WORDS)
Multimedia presentation of lung sounds as a learning aid for medical students
Authors: Sestini P , Renzoni E , Rossi M , Beltrami V , Vagliasindi M
Published: November 2022

New educational technologies might help to compensate for the decrease in time and emphasis dedicated to physical examination in medical training. This may, in particular, be applicable for improving the skills in auscultation of the chest. We investigated whether a multimedia presentation of acoustic and graphic characteristics of lung sounds could improve the learning of pulmonary auscultation by medical students, in comparison with conventional teaching methods. We studied 48 medical students without clinical experience, who had received conventional formal teaching on chest examination. Chest auscultation skills were evaluated using an inaccuracy score for the student's auscultation report on three patients, selected according to a standardized procedure. After a baseline evaluation, 27 students in groups of 5-10, participated in a multimedia seminar on lung sounds during which digitized lung sounds were played and the corresponding time-expanded waveform and frequency spectrum were commented on and displayed on a computer. The remaining 21 students received conventional bedside training, acting as control group. The following week, all the students underwent a second evaluation of chest auscultation skills. No differences in the inaccuracy score were observed between the two groups in the preliminary test. However, in the second postintervention assessment, the inaccuracy score of the students who had followed the seminar (11.2 +/- 1.3 points) was significantly lower than that of the controls (16.6 +/- 1.6 points). The answers to a feedback questionnaire confirmed that the great majority of the students found the association of the acoustic signals with their visual image to be useful for learning and understanding lung sounds.(ABSTRACT TRUNCATED AT 250 WORDS)
Density dependence of pulmonary resistance: correlation with small airway pathology
Authors: Guillemi S , Wright JL , Hogg JC , Wiggs BR , Macklem PT , Pare PD
Published: November 2022

The density dependence of maximal expiratory flow is not an effective test of the site of airway narrowing in obstructive lung disease. We hypothesized that the density dependence of pulmonary resistance (DD,RL) would be more closely related to the degree of airway narrowing and peripheral airway pathology in smokers. We measured maximal expiratory flow at 50% vital capacity (V'max50) and lung resistance (RL) breathing air and 80% helium-20% oxygen, and calculated density dependence of V'max50 and RL in 40 patients who had moderate airflow obstruction and in 10 normal subjects. We compared the density dependence of RL and V'max50 with the degree of airway obstruction and bronchiolar pathology scores in 27 patients with resected lung specimens. There were no differences in DD of V'max50 or RL between normal subjects and patients, and no relationship between the degree of obstruction or the bronchiolar pathology score and the DD of these measurements. There were significant relationships between V'max50, RL and the bronchiolar pathology scores. In conclusion, lung resistance and maximal expiratory flow are related to the severity of peripheral airway pathology, but there is no relationship between the severity of obstruction or the severity of peripheral airway pathology and the density dependence of maximal expiratory flow or lung resistance.
Evaluation of an ambulatory device, CID 102, in the diagnosis of obstructive sleep apnoea syndrome
Authors: Van Surell C , Lemaigre D , Leroy M , Foucher A , Hagenmuller MP , Raffestin B
Published: November 2022

Diagnosis of obstructive sleep apnoea syndrome (OSAS) is usually performed during overnight polysomnography in the sleep laboratory. In an attempt to simplify the diagnostic strategy, we compared an ambulatory device, CID 102, with polysomnography during the same night in the laboratory in 50 consecutive patients referred for polysomnography. The CID 102 device monitors oxygen saturation, heart rate, body position and tracheal breath sounds. An acoustic pressure sensor is placed on the suprasternal notch. Signals coming from this sensor are amplified and analysed in three different channels, according to their frequency and energy. CID respiratory disturbance index is defined as the number, per hour of analysis time, of apnoeas lasting more than 10 s plus episodes of desaturation by 4% or more associated with pauses lasting from 7-10 s or snores. The polysomnographic data were recorded on paper (Reega 2000, Alvar) and analysed manually. Polysomnographic apnoea-hypopnoea index (AHIp) was defined as the number of apnoeas plus hypopnoeas per hour of sleep. The sensitivity, specificity, positive predictive value and negative predictive value of various CID respiratory disturbance index (> or = 5, > or = 10, > or = 15 and > or = 20 per hour) in diagnosing obstructive sleep apnoea syndrome were determined. When OSAS was diagnosed as AHIp > or = 15, sensitivity and specificity of a CID respiratory disturbance index > or = 5 were 73 and 62%, respectively. Positive predictive value of CID respiratory disturbance index > or = 10 for AHIp > or = 10 was 94%. CID 102 false negative patients had only hypopnoeas without any desaturation.(ABSTRACT TRUNCATED AT 250 WORDS)
Indices from flow-volume curves in relation to cephalometric, ENT- and sleep-O2 saturation variables in snorers with and without obstructive sleep-apnoea
Authors: Bogaard JM , van der Meche FG , Poublon RM , Ginai AZ , Schmitz PI , Bubberman A , Slappendel AM , Boot H
Published: November 2022

In a group of 37 heavy snorers with obstructive sleep apnoea (OSA, Group 1) and a group of 23 heavy snorers without OSA (Group 2) cephalometric indices, ENT indices related to upper airway collapsibility, and nocturnal O2 desaturation indices were related to variables from maximal expiratory and inspiratory flow-volume (MEFV and MIFV) curves. The cephalometric indices used were the length and diameter of the soft palate (spl and spd), the shortest distance between the mandibular plane and the hyoid bone (mph) and the posterior airway space (pas). Collapsibility of the upper airways was observed at the level of the tongue base and soft palate by fibroscopy during a Muller manoeuvre (mtb and msp) and ranked on a five point scale. Sleep indices measured were the mean number of oxygen desaturations of more than 3% per hour preceded by an apnoea or hypopnoea of more than 10 s (desaturation index), maximal sleep oxygen desaturation, baseline arterial oxygen saturation (Sa,O2) and, in the OSA group, percentage of sleep time with Sa,O2 < 90%. The variables obtained from the flow-volume curves were the forced vital capacity (FVC), forced expiratory and inspiratory volume in 1 s (FEV1 and FIV1), peak expiratory and peak inspiratory flows (PEF and PIF), and maximal flow after expiring 50% of the FVC (MEF50). The mean of the flow-volume variables, influenced by upper airway aperture (PEF, FIV1) was significantly greater than predicted.(ABSTRACT TRUNCATED AT 250 WORDS)
Respiratory muscle activity and oxygenation during sleep in patients with muscle weakness
Authors: White JE , Drinnan MJ , Smithson AJ , Griffiths CJ , Gibson GJ
Published: November 2022

Patients with respiratory muscle weakness show nocturnal hypoventilation, with oxygen desaturation particularly during rapid eye movement (REM) sleep, but evidence in individuals with isolated bilateral diaphragmatic paresis (BDP) is conflicting. The effect of sleep on relative activity of the different respiratory muscles of such patients and, consequently, the precise mechanisms causing desaturation have not been clarified. We have studied eight patients, four with generalized muscle weakness and four with isolated BDP during nocturnal sleep with measurements including oxygen saturation and surface electromyographic (EMG) activity of various respiratory muscle groups. Nocturnal oxygenation correlated inversely with postural fall in vital capacity, an index of diaphragmatic strength. During REM sleep, hypopnoea and desaturation occurred particularly during periods of rapid eye movements (phasic REM sleep). In most subjects, such events were "central" in type and associated with marked suppression of intercostal muscle activity, but two subjects had recurrent desaturation due to "obstructive" hypopnoea and/or apnoea. Expiratory activity of the external oblique muscle was present whilst awake and during non-rapid eye movement (NREM) sleep in seven of the eight subjects in the semirecumbent posture. This probably represents an "accessory inspiratory" effect, which aids passive caudal diaphragmatic motion as the abdominal muscles relax at the onset of inspiration. Expiratory abdominal muscle activity was suppressed in phasic REM sleep, suggesting that loss of this "accessory inspiratory" effect may contribute to "central" hypopnoea. We conclude that, in patients with muscle weakness, nocturnal oxygenation correlates with diaphragmatic strength.(ABSTRACT TRUNCATED AT 250 WORDS)
Breathing pattern awake and asleep in patients with myotonic dystrophy
Authors: Veale D , Cooper BG , Gilmartin JJ , Walls TJ , Griffith CJ , Gibson GJ
Published: November 2022

Patients with myotonic dystrophy often have an irregular pattern of breathing at rest, implying abnormality of breathing control. No central medullary defect has been found in such patients. We postulated that irregular breathing in myotonic dystrophy due to abnormal central respiratory output would persist during slow-wave sleep. We examined the patterns of breathing whilst awake and asleep in seven patients with myotonic dystrophy, seven similarly weak nonmyotonic subjects and seven normal controls. Polysomnography was performed, and the coefficients of variation (CoV) of the breath intervals were analysed during different stages of sleep. The myotonic group showed significantly greater variation in breath intervals than the other two groups whilst awake (median CoV 37 vs 18% for nonmyotonics) and during light sleep (31 vs 13%). This difference was not evident during slow-wave sleep (median CoV 12 vs 9% in nonmyotonic). We conclude that irregular breathing in patients with myotonic dystrophy whilst awake and during light sleep, does not persist during slow-wave sleep. These results suggest that "behavioural" influences play a role in the abnormal breathing pattern found in myotonic dystrophy. The source of the irregular breathing is unlikely to be found in the medulla, but may originate from forebrain influences.
Ambulatory oxygen therapy in stable kyphoscoliosis
Authors: Jones DJ , Paul EA , Bell JH , Wedzicha JA
Published: November 2022

Patients with chronic obstructive pulmonary disease (COPD) may benefit from ambulatory oxygen; however, the effect of exercise on arterial oxygen saturation (Sa,O2) in patients with kyphoscoliosis and of correction with ambulatory oxygen have not been previously reported. Twelve patients with stable kyphoscoliosis (mean (SD) Cobb angle 79 (26) degrees) were studied, with mean (SD) arterial oxygen tension (Pa,O2) 8.96 (0.93) kPa, arterial carbon dioxide tension (Pa,CO2) 6.52 (0.66), forced expiratory volume in one second (FEV1) 0.90 (0.15) L, forced vital capacity (FVC) 1.34 (0.46) L. Six-minute walking tests with oximetry and visual analogue scores (VAS) for breathlessness were performed on air (baseline), and with cylinders containing air and oxygen at 2 L-min-1. Cylinder walks were in random order, with patients blinded to cylinder content. Patients showed oxygen desaturation at each stage of the study. At baseline, oxygen desaturation during exercise was correlated with deterioration in VAS breathlessness scores. Ambulatory oxygen produced significant improvements in desaturation, breathlessness scores and recovery time compared to baseline and air cylinder walks. There was no relationship between baseline desaturation and changes in walking distance. Although exercise desaturation, breathlessness and recovery times were significantly improved with ambulatory oxygen at 2 L.min-1, walking distance was unaffected. We conclude that patients with moderate to severe kyphoscoliosis have significant oxygen desaturation on exercise and should thus routinely receive oximetry on exercise and assessment for ambulatory oxygen therapy.
Rat diaphragm contractility and histopathology are affected differently by low dose treatment with methylprednisolone and deflazacort
Authors: Dekhuijzen PN , Gayan-Ramirez G , Bisschop A , de Bock V , Dom R , Bouillon R , Decramer M
Published: November 2022

The extent to which treatment with low doses of the nonfluorinated steroid methylprednisolone affects diaphragm contractility and morphology is unknown. In the present study, we compared the effects of equipotent doses of methylprednisolone and deflazacort, an oxazoline derivate of prednisolone with less systemic side-effects on bone structure and carbohydrate metabolism. Twenty six male adult rats were randomized to receive daily saline (control), methylprednisolone 0.4 mg.kg-1 or deflazacort 0.5 mg.kg-1 i.m. Contractile properties and histopathology were measured after a 6 week treatment period. During treatment, body weight increased in control and methylprednisolone-treated animals, but decreased by 4.2 +/- 1.1% (mean +/- SD) in the deflazacort group. Similarly, diaphragm mass in the deflazacort group was decreased compared to control and methylprednisolone groups. Twitch tension and twitch characteristics of isolated diaphragm bundles were similar in the three groups. Maximal tetanic tension was decreased in the deflazacort group. The force-frequency curve of the deflazacort bundles shifted downwards compared to control. Fatigue occurring during this protocol was greatest in the methylprednisolone- and deflazacort-treated animals. Microscopic examination revealed no gross abnormalities in the three groups. Histochemical analysis after staining for myosin adenosine triphosphatase (ATP-ase) showed that in the deflazacort group cross-sectional area of type I, IIa and IIb fibres were decreased. We conclude that low doses of methylprednisolone caused subtle and negligible changes in rat diaphragm contractile properties without affecting fibre dimensions, while deflazacort at an equipotent dose induced generalized fibre atrophy and changes in diaphragm contractility.
Can computed tomography quantify pulmonary emphysema?
Authors: Gevenois PA , Yernault JC
Published: November 2022

In the last decade, several studies have suggested the possible role of computed tomography (CT) in the detection and the quantification of pulmonary emphysema. In order to verify whether this new method is adequately validated, this article gives an overview of these studies. The review shows that most of the studies used conventional CT and were based on visual scoring. Only a few were based on high resolution CT (HRCT) or concerned objective measurements of computed density. In addition, only a few studies included normal subjects and distinguished centrilobular from panlobular emphysema. The number of scans obtained in each study is extremely variable, whilst the minimum number necessary to provide accurate results remains unknown. Recently, automatic objective procedures which are truly quantitative and are applicable to HRCT have been made available. They should take the place of subjective scoring methods but further studies, based on macroscopic as well as on microscopic comparisons, are needed to validate and to standardize these techniques.
Frequency response of variable orifice type peak flow meters: requirements and testing
Authors: Pedersen OF , Rasmussen TR , Kjaergaard SK , Miller MR , Quanjer PH
Published: November 2022

Little is known about the response of variable orifice peak flow meters to high frequency flow input. The purpose of this study was to define and test dynamic requirements for such peak flow meters. In a population sample we measured peak expiratory flow (PEF), rise time (tr), from 10-90% PEF and the duration of the flow in excess of 97.5, 95 and 90% of PEF, by use of a carefully calibrated Fleisch pneumotachograph with known and adequate frequency response. Three peak flow meters (Mini Wright, Vitalograph and Ferraris) were tested with an explosive decompression calibrator adjusted to values for PEF and tr as close as possible to the 95th and 5th percentile values, respectively, both for males and females, and with peak durations between 5 and more than 100 ms. The 95th percentile values of PEF were 597 L.min-1 for females and 894 L.min-1 for males. The 5th percentile values of tr were, respectively 55 and 45 ms. The duration of flow in excess of 95% PEF was longer than 10 ms in 99% of the subjects. For all meters, the deviation of PEF corrected for alinearity were less than 5% at a peak duration of 10 ms. We conclude that PEF, rise time, and peak duration can be used for description of dynamic properties of variable orifice meters, and that the tested meters had a satisfactory frequency response for recording PEF in mostly normal subjects.
Occupational asthma due to formaldehyde resin dust with and without reaction to formaldehyde gas
Authors: Lemiere C , Desjardins A , Cloutier Y , Drolet D , Perrault G , Cartier A , Malo JL
Published: November 2022

We report the cases of three subjects who developed asthma after being exposed to formaldehyde dust or gas. For two subjects, specific bronchial provocation tests with formaldehyde gas did not cause significant bronchoconstriction, whereas exposure to formaldehyde resin dust did. One subject experienced asthmatic reaction after being exposed to formaldehyde resin dust and gas. These findings suggest that the physical and chemical properties of formaldehyde are relevant to its likelihood of causing asthma.
Nodular amyloidosis of the lung and the breast mimicking breast carcinoma with pulmonary metastasis
Authors: Liaw YS , Kuo SH , Yang PC , Chen CL , Luh KT
Published: November 2022

Nodular amyloidosis of the breast and lung is a rare condition of unknown aetiology. The disease runs a benign course, but offers a diagnostic problem due to nonspecific histological features. We describe the case of a 56 year old woman with a 5 year history of multiple nodules of both lungs and left breast, clinically mimicking breast carcinoma with pulmonary metastasis. To our knowledge, this is the first case of cytologically proven amyloidosis diagnosed by ultrasound-guided percutaneous transthoracic fine-needle aspiration of pulmonary nodules.
Comparison of performance of four instruments in evaluating the effects of salmeterol on asthma quality of life
Authors: Rutten-van Molken MP , Custers F , van Doorslaer EK , Jansen CC , Heurman L , Maesen FP , Smeets JJ , Bommer AM , Raaijmakers JA
Published: November 2022

Quality of life measures are increasingly used as important efficacy endpoints in studies of drugs for asthma. The purpose of this study was to assess both the sensitivity to change and the construct validity of four different quality of life instruments in patients with asthma. In a double-blind, parallel group study, 120 moderate asthma patients, aged between 18-70 yrs, received either inhaled salmeterol 50 micrograms b.i.d. or inhaled salbutamol 400 micrograms b.i.d. In addition to respiratory outcomes, quality of life was measured at a 6 weeks follow-up using: 1) Asthma Quality of Life Questionnaire (AQLQ); 2) Living With Asthma Questionnaire (LWAQ); 3) Sickness Impact Profile (SIP); 4) Rating Scale (RS); and Standard Gamble (SG) utilities. Salmeterol led to significant improvements over salbutamol on virtually all clinical outcomes. Although all the quality of life instruments showed the same trend in favour of salmeterol, only the AQLQ and RS utilities showed significantly greater improvement on salmeterol than on salbutamol. Except for the AQLQ, the correlation between change in lung function and change in quality of life was generally low. Whereas, the AQLQ correlated well with the patient's overall assessment of efficacy (r = 0.64), the LWAQ, SIP and utilities failed to show such a correlation. The AQLQ showed the best correlation with symptom scores. The cross-sectional correlation between the AQLQ and the LWAQ was 0.73, whereas the longitudinal correlation was only 0.29. The SG generally showed poor correlation with other measures, including the RS. In conclusion, patients given salmeterol showed a greater improvement in quality of life compared to patients given salbutamol. Of the disease-specific questionnaires the Asthma Quality of Life Questionnaire was found to be more responsive to change than the Living With Asthma Questionnaire and showed greater validity. Of the generic instruments, the rating scale utilities were most responsive. The Standard Gamble showed poor correlation with other measures.
The psychological factors associated with poor compliance with treatment in asthma
Authors: Bosley CM , Fosbury JA , Cochrane GM
Published: November 2022

Poor patient compliance with inhaled medication is known to cause morbidity and mortality in asthma. The reasons for nonadherence are not fully understood. We wondered whether psychological factors, such as patient attitudes to asthma and its treatment, anxiety, depression, and interpersonal problems, may be related to asthma self-care and compliance. In a prospective study, 102 patients with asthma, aged 18-70 yrs, requiring treatment with regular inhaled corticosteroids and beta-agonists were recruited from a hospital out-patient clinic and four general practices in South East London. They underwent psychological assessment using the Hospital Anxiety and Depression Scale (HADS), the Inventory of Interpersonal Problems (IIP), and a semi-structured interview focusing on patient attitudes, self-care, compliance, social support and treatment beliefs. Patients were given terbutaline and budesonide turbohalers to use twice daily over 12 weeks. Turbohaler Inhalation Computers (TICs) recorded each inhalation, providing a measurement of compliance. Seventy two patients completed the study. Thirty seven took less than 70% of the prescribed dose over the study period or omitted doses for 1 week and were defined as noncompliant. The noncompliant group had a higher mean (SD) score for depression (4.7 (3.3)) than the compliant group (3.2 (2.5)). The sample had a high mean (SD) score for anxiety (8.3 (4.4)), but there was no significant difference between the compliant and noncompliant groups. Patients' self-report and clinicians' impressions of compliance were not good predictors of actual compliance. Using discriminant analysis, a model was obtained from the questionnaires and interview items, which correctly classified 74% of the patients as compliant or non-compliant.(ABSTRACT TRUNCATED AT 250 WORDS)
Inhaled lysine acetylsalicylate (L-ASA) attenuates the bronchoconstrictor response to adenosine 5'-monophosphate (AMP) in asthmatic subjects
Authors: Crimi N , Polosa R , Magri S , Prosperini G , Milazzo VL , Santonocito G , Mistretta A
Published: November 2022

When administered by inhalation, adenosine 5'-monophosphate (AMP) provokes dose-related bronchoconstriction in asthmatic subjects by a mechanism believed to involve mast cell mediator release. However, little is known of the change in airway responsiveness to AMP after cyclo-oxygenase blockade. The aim of this study was to investigate the effect of the potent cyclo-oxygenase inhibitor, lysine acetylsalicylate (L-ASA) administered by inhalation, on AMP-induced bronchoconstriction in a group of nine asthmatic subjects. The subjects studied attended the laboratory on six separate occasions to receive nebulized L-ASA (solution of 90 mg.ml-1) or matched placebo (glycine solution, 30 mg.ml-1) 15 min prior to bronchoprovocation tests with AMP, histamine and methacholine in a randomized, double-blind order. Changes in airway calibre were followed as forced expiratory volume in one second (FEV1) and agonist responsiveness was expressed as the provocative concentration causing a 20% fall in FEV1 from baseline (PC20). Administration of both L-ASA and glycine solution caused a small but significant acute fall in FEV1 from baseline, which returned to normal within 15 min. When compared to placebo, inhaled L-ASA reduced the airway responsiveness to AMP in all the subjects studied, the geometric mean (range) values for PC20 AMP increasing significantly from 36.3 (7.9-250.5) to 101.8 (27.2-1300) mg.ml-1 after placebo and L-ASA, respectively. Moreover, nebulized L-ASA induced a small but significant reduction in airway responsiveness to histamine, the geometric mean (range) PC20 values for histamine increasing from 2.77 (1.05-5.49) to 4.36 (1.69-11.24) mg.ml-1 after placebo and L-ASA, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Increased maximal airway response to methacholine during seasonal allergic rhinitis in nonasthmatic subjects: relationships with airway wall thickness and inflammation
Authors: Boulet LP , Turcotte H , Carrier G , Boutet M , Laviolette M
Published: November 2022

This study was carried out to determine whether the increase in airway responsiveness induced by natural antigenic exposure in nonasthmatic subjects is associated with an increase in maximal bronchoconstrictor response (MBR), and if these changes could be due to an increase in airway wall thickness from allergen-induced increase in airway inflammation. In 11 nonasthmatic subjects with seasonal allergic rhinitis, a methacholine challenge was obtained monthly, during and out of pollen exposure. Each subject had a high-resolution chest tomography in and out of the pollen season, to determine the relative thickness of the right intermediary bronchus over its total diameter (T/D), as well as inflammatory cell counts, apparent basement membrane thickness as an indication of subepithelial fibrosis and epithelial desquamation in bronchial biopsy specimens. In season, the mean provocative concentration of methacholine producing a 20% decrease in forced expiratory volume in one second (PC20) decreased from 51.5 to 25.8 mg.mL-1, and the maximal post-methacholine fall in forced expiratory volume in one second (delta FEV1,max) or forced vital capacity (delta FVC) and the slope of the dose response curve (DRS) increased compared with out of season: delta FEV1,max 44 +/- 5 vs 25 +/- 5%; delta FVC 34 +/- 5 vs 16 +/- 4%; and slope of DRS 14.1 +/- 2.8 vs 6.9 +/- 1.3%/mg.mL-1. No significant change was observed in T/D ratio. The seasonal change in delta FVC was positively correlated with the delta FEV1,max (rs = 0.891) and the change in DRS (rs = 0.909), but not with the change in PC20, nor with changes in bronchial biopsy inflammatory features or T/D ratio.(ABSTRACT TRUNCATED AT 250 WORDS)
Airway and lung elastic fibre is not reduced in asthma nor in asthmatics following corticosteroid treatment
Authors: Godfrey RW , Lorimer S , Majumdar S , Adelroth E , Johnston PW , Rogers AV , Johansson SA , Jeffery PK
Published: November 2022

By morphometric investigation of the relative content of elastic and collagen fibres, we have tested the hypothesis that loss of elastic fibres in the conducting airways and lung parenchyma may reduce tissue elastic recoil, resulting in increased airway maximal closure and apparent increased responsiveness. The study groups comprised: Group A (n = 11) with relatively mild atopic asthma using inhaled bronchodilators prn (i.e. short-term corticosteroids users); Group B (n = 9) with more severe asthma requiring inhaled bronchodilators regularly, and daily inhaled glucocorticosteroids (i.e. longterm corticosteroid users); Group C (n = 12) normal healthy workers. Bronchial biopsy samples were taken from three sites from the left lung. Group A biopsy samples were taken before and after a 4 wk treatment period with inhaled corticosteroids (200 micrograms b.i.d.) and the relative elastic and collagen fibre content of a subepithelial zone was determined from electron micrographs. In a parallel study, the relative proportion of elastic fibre in post mortem lung tissue samples (inner aspect of the bronchial wall, alveolar wall, and points of attachment of surrounding alveoli to intrapulmonary bronchi) from subjects suffering a fatal asthma attack (n = 11), and non-asthmatic suffering sudden death (n = 9), were determined using Miller's elastic and eosin counterstain for light microscopy. In bronchial biopsies of normal subjects, 4.6 (SEM 1.1)% of subepithelial connective tissue was elastic fibre, similar to mild asthmatic subjects, 1.9 (SEM 0.48)%. Neither short-term (4 weeks) inhaled corticosteroid (200 micrograms b.i.d.) nor long-term (< 6 months) treatment with variable doses of inhaled steroids (100-1000 micrograms b.i.d.) significantly altered the elastic or collagen content of the tissue.(ABSTRACT TRUNCATED AT 250 WORDS)
Allergen-induced late-phase airways obstruction in the pig: the role of endogenous cortisol
Authors: Fornhem C , Lundberg JM , Alving K
Published: November 2022

In developing a novel model for studies of the allergen-induced late-phase airways obstruction, by using the pig, the importance of endogenous cortisol levels was examined by the use of metyrapone, a cortisol-synthesis inhibitor. Specific-pathogen free pigs were actively sensitized with Ascaris suum allergen. One group of pigs was treated with a constant infusion of metyrapone in order to maintain low levels of plasma cortisol. Ascaris suum allergen was nebulized into the lower airways and plasma cortisol and catecholamine levels, total lung resistance and dynamic compliance, blood gases and pH, and blood flow in the bronchial circulation were continuously recorded for 8 h. At the time of allergen challenge, the plasma cortisol levels in sensitized pigs were 455 +/- 37 nM and 40.1 +/- 3.8 nM in non-metyrapone-treated and metyrapone-treated pigs, respectively. No difference was seen between the magnitude of the acute bronchoconstrictor response in the two groups. A late airways obstruction, starting at about 4 h, developed only in pigs with low cortisol levels, whereas a late increase in blood flow in the bronchial circulation was seen in both groups, even if a late airways obstruction was absent. Plasma adrenaline did not seem to influence the late-phase reaction. These results suggest that endogenous cortisol levels, but not adrenaline, modify the late response to allergen in the pig. Furthermore, it is suggested that the pig is a suitable model for studies of allergic reactions in the airways, if metyrapone is used to keep plasma cortisol levels within a normal range.
Recombinant human DNase I in cystic fibrosis patients with severe pulmonary disease: a short-term, double-blind study followed by six months open-label treatment
Authors: Shah PI , Bush A , Canny GJ , Colin AA , Fuchs HJ , Geddes DM , Johnson CA , Light MC , Scott SF , Tullis DE , et al.
Published: November 2022

Chronic pulmonary infection is the major cause of morbidity and mortality in cystic fibrosis (CF). Recombinant human deoxyribonuclease (rhDNase) in vitro has been shown to dramatically reduce the viscoelasticity of the sputum from CF patients. Phase II and III clinical trials have shown the drug to be safe, and that patients with a forced vital capacity (FVC) of > 40% predicted show an improvement in pulmonary function when receiving rhDNase. The current study evaluates the safety and efficacy of rhDNase in the most severly ill CF patients (FVC < 40% predicted). A double-blind, randomized, placebo-controlled trial in which patients received either 2.5 mg rhDNase twice daily or placebo for a period of 14 days followed by a 6 month open extension period (OEP) is reported. Seventy patients were recruited for the double-blind study, and 64 entered the OEP of whom 38 completed. During the OEP, all patients received 2.5 mg rhDNase twice daily. In both the double-blind period and the OEP the drug appeared to be safe. During the double-blind study, forced expiratory volume in one second (FEV1) and FVC improved in both groups but there was no statistically significant difference between the groups. In the OEP, there was mean improvement in percentage predicted FEV1 and FVC, 9 and 18%, respectively, for all patients participating. In conclusion, DNase is safe when administered in conjunction with a rigorous regimen of chest physiotherapy to severely ill patients (FVC < 40% predicted) with CF. The double-blind, 14 day study showed no significant improvement in pulmonary function but some patients may have improved after longer administration of rhDNase.
Evolution of resting lung function in the first year after cardiac transplantation
Authors: Bussieres LM , Pflugfelder PW , Ahmad D , Taylor AW , Kostuk WJ
Published: November 2022

The aim of our study was to characterize the time course and magnitude of the changes in lung function in the first year after cardiac transplantation. Resting pulmonary function tests (spirometry, lung volumes and transfer factor) were performed in 14 patients prior to and at 1, 3 and 12 months after surgery. Resting central haemodynamics were also measured serially in the first year post-transplantation. Before transplantation, patients had impaired resting lung function with marked decrease in transfer factor (TL,CO). Although resting central haemodynamics improved markedly within the first week after cardiac transplantation, lung function (forced expiratory volume in one second (FEV1)) was significantly improved only at three months post-transplantation. TL,CO, however, decreased further early after cardiac transplantation. By 12 months, FEV1 and forced vital capacity had increased significantly by 31 and 33%, respectively, while total lung capacity increased by 22%. On the other hand, TL,CO did not increase significantly and remained well below normal at 12 months after cardiac transplantation, at a value equal to 68% of predicted. We conclude that the resting abnormalities in lung function of most patients with heart failure are reversible after cardiac transplantation, except for TL,CO which remains below normal values. Recovery of lung function, however, lags behind the improvement in cardiac function.
The role of transbronchial needle aspiration in the diagnosis of peripheral lung masses or nodules
Authors: Katis K , Inglesos E , Zachariadis E , Palamidas P , Paraskevopoulos I , Sideris G , Tamvakopoulou E , Apostolopoulou F , Rasidakis A
Published: November 2022

The purpose of this study was to evaluate the role of transbronchial needle aspiration (TBNA) in the diagnosis of peripheral lung lesions. We attempted to perform TBNA in 37 patients referred to our hospital for diagnostic evaluation of radiographically evident peripheral masses (23 cases) or nodules (14 cases). None of them had bronchoscopic evidence of endobronchial lesion. The aspirations were performed under fluoroscopic guidance, through a fibreoptic bronchoscope, employing a 21-gauge, 1.3 cm aspirating needle. They were preceded by bronchial brushing and followed by transbronchial biopsy (TBB) of the peripheral lesion. In two cases, the apical nodules were not accessible by any of these procedures. Bronchial washings were also collected immediately after each procedure (brush, TBNA and TBB). TBNA was diagnostic in 23 of 37 patients (62%) rendering the TBNA yield considerably higher than washing (24%), brushing (27%) or TBB (38%). The addition of TBNA to the combination of TBB, brushing and washing, significantly increased the yield of fibreoptic bronchoscopy in our series from 46% to 70%. No significant complications, such as pneumothorax or major bleeding, occurred either with TBNA or TBB. In conclusion, our findings suggest that transbronchial needle aspiration is a safe procedure, that can improve the diagnostic yield of bronchoscopy in the diagnosis of peripheral lung masses or nodules.