How &... more How "healthy" do children need to be when selecting reference samples for spirometry? Anthropometry and spirometry were measured in an unselected, multi-ethnic population of school children aged 5-11 years in London, UK, with follow-up assessments 12 months later. Parents provided information on children's birth data and health status. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were adjusted for sex, age, height and ethnicity using the 2012 Global Lungs Initiative equations, and the effects of potential exclusion criteria on the z-score distributions were examined. After exclusions for current and chronic lung disease, acceptable data were available for 1901 children on 2767 occasions. Healthy children were defined as those without prior asthma or hospitalisation for respiratory problems, who were born at full-term with a birthweight ⩾2.5 kg and who were asymptomatic at testing. Mean±sd z-scores for FEV1 and FVC approximated 0±1, indicating the 2012 Global Lungs Initiative equations were appropriate for this healthy population. However, if children born preterm or with low birthweight, children with prior asthma or children mildly symptomatic at testing were included in the reference, overall results were similar to those for healthy children, while increasing the sample size by 25%. With the exception of clear-cut factors, such as current and chronic respiratory disease, paediatric reference samples for spirometry can be relatively inclusive and hence more generalisable to the target population.
American Journal of Respiratory and Critical Care Medicine, Aug 1, 2003
... Monika Gappa a , Janet Stocks b and Peter Merkus c. a Medizinische Hochschule Hannover, Hanno... more ... Monika Gappa a , Janet Stocks b and Peter Merkus c. a Medizinische Hochschule Hannover, Hannover, Germany b Institute of Child Health, London, United Kingdom c Erasmus University, Rotterdam, The Netherlands. REFERENCES. ...
Despite the increasing awareness of the need to identify early pulmonary changes in cystic fibros... more Despite the increasing awareness of the need to identify early pulmonary changes in cystic fibrosis (CF) noninvasively, the role of lung function testing in infancy and early childhood remains less clear than in older children with CF. The aim of this review is to summarize available data, discuss the information gained from these publications, and put this information into perspective with more recent developments of lung function testing in both infants and older children with CF. While some of the available data have been the foundation of the current level of understanding of respiratory physiology in CF, interpretation of other data has been hampered by differences between centers with regard to the methods and equipment used, patient selection, small number of subjects, and lack of appropriate reference data. A structured multicenter approach based on recently published recommendations for the measurement of lung function in infancy, together with pursuit of recent developments such as assessment of raised lung volume flow volume curves and ventilation inhomogeneity may help to more effectively utilize lung function tests in infants in the future.
Test reproducibility is an important consideration when interpreting results and should be set as... more Test reproducibility is an important consideration when interpreting results and should be set as a goal during data collection. Reproducibility criteria may need to be different for different subject groups and are instrument and proce- dure-dependent. Ideally, the within-subject variability for each lung volume and measurement technique used should be established for each laboratory. These values also need to be
How "healthy" do children need to be when selecting reference samples for spirometry? A... more How "healthy" do children need to be when selecting reference samples for spirometry? Anthropometry and spirometry were measured in an unselected, multi-ethnic population of school children aged 5-11 years in London, UK, with follow-up assessments 12 months later. Parents provided information on children's birth data and health status. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were adjusted for sex, age, height and ethnicity using the 2012 Global Lungs Initiative equations, and the effects of potential exclusion criteria on the z-score distributions were examined. After exclusions for current and chronic lung disease, acceptable data were available for 1901 children on 2767 occasions. Healthy children were defined as those without prior asthma or hospitalisation for respiratory problems, who were born at full-term with a birthweight ⩾2.5 kg and who were asymptomatic at testing. Mean±sd z-scores for FEV1 and FVC approximated 0±1, indicating ...
An infant is described who presented a complex cardiopulmonary problem which was evaluated with t... more An infant is described who presented a complex cardiopulmonary problem which was evaluated with the help of new physiological techniques. the infant was born at term after an emergency Caesarian section for fetal distress and was found to have meconium aspiration. He remained persistently tachypnoeic and hypoxic despite high ambient oxygen. Chest radiography suggested cystic lesions at the lung bases, and lung function tests confirmed hyperinflation with delayed nitrogen washout. In addition the child had signs of Fallot's tetralogy, and this diagnosis was confirmed by cardiac catheterization. Because of persistent hypoxia and tachypnoea disproportionate to the cardiac condition, the possibility of localized lung disease was considered. Regional lung function tests were carried out in the neonatal period and again at six months of age useing radioisotopic 13N given by both inhalation and injection. These studies showed gross ventilation/perfusion imbalance in the lungs, particularly marked at the bases, but with enough generalized abnormality to preclude the possibility of surgical intervention. The principles of the measurement of lung mechanics in the newborn by whole-body plethysmography, nitrogen washout, and regional radioisotopic spirometry are outlined. The particular value of these techniques in the evaluation of complex disorders is discussed, especially where both cardiac and pulmonary abnormalities are present.
The prevalence of airway obstruction varies widely with the definition used. To study differences... more The prevalence of airway obstruction varies widely with the definition used. To study differences in the prevalence of airway obstruction when applying four international guidelines to three population samples using four regression equations. We collected predicted values for forced expiratory volume in 1 s/forced vital capacity (FEV(1)/FVC) and its lower limit of normal (LLN) from the literature. FEV(1)/FVC from 40 646 adults (including 13 136 asymptomatic never smokers) aged 17-90+years were available from American, English and Dutch population based surveys. The prevalence of airway obstruction was determined by the LLN for FEV(1)/FVC, and by using the Global Initiative for Chronic Obstructive Lung Disease (GOLD), American Thoracic Society/European Respiratory Society (ATS/ERS) or British Thoracic Society (BTS) guidelines, initially in the healthy subgroup and then in the entire population. The LLN for FEV(1)/FVC varied between prediction equations (57 available for men and 55 for women), and demonstrated marked negative age dependency. Median age at which the LLN fell below 0.70 in healthy subjects was 42 and 48 years in men and women, respectively. When applying the reference equations (Health Survey for England 1995-1996, National Health and Nutrition Examination Survey (NHANES) III, European Community for Coal and Steel (ECCS)/ERS and a Dutch population study) to the selected population samples, the prevalence of airway obstruction in healthy never smokers aged over 60 years varied for each guideline: 17-45% of men and 7-26% of women for GOLD; 0-18% of men and 0-16% of women for ATS/ERS; and 0-9% of men and 0-11% of women for BTS. GOLD guidelines caused false positive rates of up to 60% when applied to entire populations. Airway obstruction should be defined by FEV(1)/FVC and FEV(1) being below the LLN using appropriate reference equations.
Access to reliable birth data (birthweight (BW) and gestational age (GA)) is essential for the id... more Access to reliable birth data (birthweight (BW) and gestational age (GA)) is essential for the identification of individuals who are at subsequent health risk. This study aimed to explore the feasibility of retrospectively collecting birth data for schoolchildren from parental questionnaires (PQ) and general practitioners (GPs) in primary care clinics, in inner city neighbourhoods with high density of ethnic minority and disadvantaged populations. Attempts were made to obtain birth data from parents and GPs for 2,171 London primary schoolchildren (34% White, 29% Black African origin, 25% South Asians, 12% Other) as part of a larger study of respiratory health. Information on BW and/or GA were obtained from parents for 2,052 (95%) children. Almost all parents (2,045) gave consent to access their children's health records held by GPs. On the basis of parental information, GPs of 1,785 children were successfully contacted, and GPs of 1,202 children responded. Birth data were retrieved for only 482 children (22% of 2,052). Missing birth data from GPs were associated with non-white ethnicity, non-UK born, English not the dominant language at home or socioeconomic disadvantage. Paired data were available in 376 children for BW and in 407 children for GA. No significant difference in BW or GA was observed between PQ and GP data, with <5% difference between sources regardless of normal or low birth weight, or term or preterm status. Parental recall of birth data for primary schoolchildren yields high quality and rapid return of data, and it should be considered as a viable alternative in which there is limited access to birth records. It provides the potential to include children with an increased risk of health problems within epidemiological studies.
The study investigated treatment outcomes when respiratory physiotherapy was delivered by non-res... more The study investigated treatment outcomes when respiratory physiotherapy was delivered by non-respiratory on-call physiotherapists, compared with specialist respiratory physiotherapists. Prospective, randomised crossover trial. Paediatric, tertiary care hospital in the United Kingdom. Mechanically ventilated children requiring two physiotherapy interventions during a single day were eligible. Twenty two physiotherapists (10 non-respiratory) and 93 patients were recruited. Patients received one treatment from a non-respiratory physiotherapist and another from a respiratory physiotherapist, in a randomised order. Treatments were individualised to the patients' needs, often including re-positioning followed by manual lung inflations, chest wall vibrations and endotracheal suction. The primary outcome was respiratory compliance. Secondary outcomes included adverse physiological events and clinically important respiratory changes (according to an a priori definition). Treatments delivered to 63 patients were analysed. There were significant improvements to respiratory compliance (mean increase [95% confidence intervals], 0.07 and 0.08ml·cmH2O(-1)·kg(-1) [0.01 to 0.14 and 0.04 to 0.13], p<0.01, for on-call and respiratory physiotherapists' treatments respectively). Case-by-case, there were fewer clinically important improvements following non-respiratory physiotherapists' treatments compared with the respiratory physiotherapists' (n=27 [43%] versus n=40 [63%], p=0.03). Eleven adverse events occurred, eight following non-respiratory physiotherapists' treatments. Significant disparities exist in treatment outcomes when patients are treated by non-respiratory on-call physiotherapists, compared with specialist respiratory physiotherapists. There is an urgent need for targeted training strategies, or alternative service delivery models, to be explored. This should aim to address the quality of respiratory physiotherapy services, both during and outside of normal working hours. Clinicaltrials.gov, NCT01999426.
To investigate differences, if any, in the delivery of respiratory treatments to mechanically ven... more To investigate differences, if any, in the delivery of respiratory treatments to mechanically ventilated children between non-respiratory on-call physiotherapists and specialist respiratory physiotherapists. Paediatric, tertiary care hospital in the United Kingdom. 93 children (aged between 3 days and 16 years), and 22 physiotherapists (10 specialist respiratory physiotherapists) were recruited to the study. Recruited children received two physiotherapy treatments during a single day, one delivered by a non-respiratory physiotherapist, the other by a specialist respiratory physiotherapist in a randomised order. Selection, delivery and effects of techniques were recorded for each treatment. Primary outcomes were selection and application of treatment components. Secondary outcomes included respiratory effects (in terms of changes in flow, volume and pressure) of selected treatment components. Both non-respiratory on-call physiotherapists and specialist respiratory physiotherapists used combinations of saline instillation, manual lung inflations, chest wall vibrations and endotracheal suction during treatments. However specialist respiratory physiotherapists used combinations of chest wall vibrations with suction, and recruitment manoeuvres, significantly more frequently than non-respiratory on-call physiotherapists (92% vs 52%, and 87% vs 46% of treatments respectively, P<0.001). Chest wall vibrations delivered by non-respiratory on-call physiotherapists were 15% less effective at increasing peak expiratory flow. Clinically important differences between non-respiratory and specialist respiratory physiotherapists' treatment outcomes may be related to differences in the selection and application of techniques. This suggests an important training need for non-respiratory on-call physiotherapists, particularly in the effective delivery of physiotherapy techniques. Clinicaltrials.gov NCT01999426.
The 2005 American Thoracic Society (ATS)/European Respiratory Society (ERS) spirometry guidelines... more The 2005 American Thoracic Society (ATS)/European Respiratory Society (ERS) spirometry guidelines define valid tests as having three acceptable blows and a repeatable forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). The aim of this study was to determine how reviewer and computer-determined ATS/ERS quality could affect population reference values for FVC and FEV1. Spirometry results from 7777 normal subjects aged 8-80 years (NHANES (National Health and Nutrition Examination Survey) III) were assigned quality grades A to F for FVC and FEV1 by a computer and one reviewer (reviewer 1). Results from a subgroup of 1466 Caucasian adults (aged 19-80 years) were reviewed by two additional reviewers. Mean deviations from NHANES III predicted for FVC and FEV1 were examined by quality grade (A to F). Reviewer 1 rejected (D and F grade) 5.2% of the 7777 test sessions and the computer rejected ∼16%, primarily due to end-of-test (EOT) failures. Within the subgroup, the comp...
How &... more How "healthy" do children need to be when selecting reference samples for spirometry? Anthropometry and spirometry were measured in an unselected, multi-ethnic population of school children aged 5-11 years in London, UK, with follow-up assessments 12 months later. Parents provided information on children's birth data and health status. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were adjusted for sex, age, height and ethnicity using the 2012 Global Lungs Initiative equations, and the effects of potential exclusion criteria on the z-score distributions were examined. After exclusions for current and chronic lung disease, acceptable data were available for 1901 children on 2767 occasions. Healthy children were defined as those without prior asthma or hospitalisation for respiratory problems, who were born at full-term with a birthweight ⩾2.5 kg and who were asymptomatic at testing. Mean±sd z-scores for FEV1 and FVC approximated 0±1, indicating the 2012 Global Lungs Initiative equations were appropriate for this healthy population. However, if children born preterm or with low birthweight, children with prior asthma or children mildly symptomatic at testing were included in the reference, overall results were similar to those for healthy children, while increasing the sample size by 25%. With the exception of clear-cut factors, such as current and chronic respiratory disease, paediatric reference samples for spirometry can be relatively inclusive and hence more generalisable to the target population.
American Journal of Respiratory and Critical Care Medicine, Aug 1, 2003
... Monika Gappa a , Janet Stocks b and Peter Merkus c. a Medizinische Hochschule Hannover, Hanno... more ... Monika Gappa a , Janet Stocks b and Peter Merkus c. a Medizinische Hochschule Hannover, Hannover, Germany b Institute of Child Health, London, United Kingdom c Erasmus University, Rotterdam, The Netherlands. REFERENCES. ...
Despite the increasing awareness of the need to identify early pulmonary changes in cystic fibros... more Despite the increasing awareness of the need to identify early pulmonary changes in cystic fibrosis (CF) noninvasively, the role of lung function testing in infancy and early childhood remains less clear than in older children with CF. The aim of this review is to summarize available data, discuss the information gained from these publications, and put this information into perspective with more recent developments of lung function testing in both infants and older children with CF. While some of the available data have been the foundation of the current level of understanding of respiratory physiology in CF, interpretation of other data has been hampered by differences between centers with regard to the methods and equipment used, patient selection, small number of subjects, and lack of appropriate reference data. A structured multicenter approach based on recently published recommendations for the measurement of lung function in infancy, together with pursuit of recent developments such as assessment of raised lung volume flow volume curves and ventilation inhomogeneity may help to more effectively utilize lung function tests in infants in the future.
Test reproducibility is an important consideration when interpreting results and should be set as... more Test reproducibility is an important consideration when interpreting results and should be set as a goal during data collection. Reproducibility criteria may need to be different for different subject groups and are instrument and proce- dure-dependent. Ideally, the within-subject variability for each lung volume and measurement technique used should be established for each laboratory. These values also need to be
How "healthy" do children need to be when selecting reference samples for spirometry? A... more How "healthy" do children need to be when selecting reference samples for spirometry? Anthropometry and spirometry were measured in an unselected, multi-ethnic population of school children aged 5-11 years in London, UK, with follow-up assessments 12 months later. Parents provided information on children's birth data and health status. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were adjusted for sex, age, height and ethnicity using the 2012 Global Lungs Initiative equations, and the effects of potential exclusion criteria on the z-score distributions were examined. After exclusions for current and chronic lung disease, acceptable data were available for 1901 children on 2767 occasions. Healthy children were defined as those without prior asthma or hospitalisation for respiratory problems, who were born at full-term with a birthweight ⩾2.5 kg and who were asymptomatic at testing. Mean±sd z-scores for FEV1 and FVC approximated 0±1, indicating ...
An infant is described who presented a complex cardiopulmonary problem which was evaluated with t... more An infant is described who presented a complex cardiopulmonary problem which was evaluated with the help of new physiological techniques. the infant was born at term after an emergency Caesarian section for fetal distress and was found to have meconium aspiration. He remained persistently tachypnoeic and hypoxic despite high ambient oxygen. Chest radiography suggested cystic lesions at the lung bases, and lung function tests confirmed hyperinflation with delayed nitrogen washout. In addition the child had signs of Fallot's tetralogy, and this diagnosis was confirmed by cardiac catheterization. Because of persistent hypoxia and tachypnoea disproportionate to the cardiac condition, the possibility of localized lung disease was considered. Regional lung function tests were carried out in the neonatal period and again at six months of age useing radioisotopic 13N given by both inhalation and injection. These studies showed gross ventilation/perfusion imbalance in the lungs, particularly marked at the bases, but with enough generalized abnormality to preclude the possibility of surgical intervention. The principles of the measurement of lung mechanics in the newborn by whole-body plethysmography, nitrogen washout, and regional radioisotopic spirometry are outlined. The particular value of these techniques in the evaluation of complex disorders is discussed, especially where both cardiac and pulmonary abnormalities are present.
The prevalence of airway obstruction varies widely with the definition used. To study differences... more The prevalence of airway obstruction varies widely with the definition used. To study differences in the prevalence of airway obstruction when applying four international guidelines to three population samples using four regression equations. We collected predicted values for forced expiratory volume in 1 s/forced vital capacity (FEV(1)/FVC) and its lower limit of normal (LLN) from the literature. FEV(1)/FVC from 40 646 adults (including 13 136 asymptomatic never smokers) aged 17-90+years were available from American, English and Dutch population based surveys. The prevalence of airway obstruction was determined by the LLN for FEV(1)/FVC, and by using the Global Initiative for Chronic Obstructive Lung Disease (GOLD), American Thoracic Society/European Respiratory Society (ATS/ERS) or British Thoracic Society (BTS) guidelines, initially in the healthy subgroup and then in the entire population. The LLN for FEV(1)/FVC varied between prediction equations (57 available for men and 55 for women), and demonstrated marked negative age dependency. Median age at which the LLN fell below 0.70 in healthy subjects was 42 and 48 years in men and women, respectively. When applying the reference equations (Health Survey for England 1995-1996, National Health and Nutrition Examination Survey (NHANES) III, European Community for Coal and Steel (ECCS)/ERS and a Dutch population study) to the selected population samples, the prevalence of airway obstruction in healthy never smokers aged over 60 years varied for each guideline: 17-45% of men and 7-26% of women for GOLD; 0-18% of men and 0-16% of women for ATS/ERS; and 0-9% of men and 0-11% of women for BTS. GOLD guidelines caused false positive rates of up to 60% when applied to entire populations. Airway obstruction should be defined by FEV(1)/FVC and FEV(1) being below the LLN using appropriate reference equations.
Access to reliable birth data (birthweight (BW) and gestational age (GA)) is essential for the id... more Access to reliable birth data (birthweight (BW) and gestational age (GA)) is essential for the identification of individuals who are at subsequent health risk. This study aimed to explore the feasibility of retrospectively collecting birth data for schoolchildren from parental questionnaires (PQ) and general practitioners (GPs) in primary care clinics, in inner city neighbourhoods with high density of ethnic minority and disadvantaged populations. Attempts were made to obtain birth data from parents and GPs for 2,171 London primary schoolchildren (34% White, 29% Black African origin, 25% South Asians, 12% Other) as part of a larger study of respiratory health. Information on BW and/or GA were obtained from parents for 2,052 (95%) children. Almost all parents (2,045) gave consent to access their children's health records held by GPs. On the basis of parental information, GPs of 1,785 children were successfully contacted, and GPs of 1,202 children responded. Birth data were retrieved for only 482 children (22% of 2,052). Missing birth data from GPs were associated with non-white ethnicity, non-UK born, English not the dominant language at home or socioeconomic disadvantage. Paired data were available in 376 children for BW and in 407 children for GA. No significant difference in BW or GA was observed between PQ and GP data, with <5% difference between sources regardless of normal or low birth weight, or term or preterm status. Parental recall of birth data for primary schoolchildren yields high quality and rapid return of data, and it should be considered as a viable alternative in which there is limited access to birth records. It provides the potential to include children with an increased risk of health problems within epidemiological studies.
The study investigated treatment outcomes when respiratory physiotherapy was delivered by non-res... more The study investigated treatment outcomes when respiratory physiotherapy was delivered by non-respiratory on-call physiotherapists, compared with specialist respiratory physiotherapists. Prospective, randomised crossover trial. Paediatric, tertiary care hospital in the United Kingdom. Mechanically ventilated children requiring two physiotherapy interventions during a single day were eligible. Twenty two physiotherapists (10 non-respiratory) and 93 patients were recruited. Patients received one treatment from a non-respiratory physiotherapist and another from a respiratory physiotherapist, in a randomised order. Treatments were individualised to the patients' needs, often including re-positioning followed by manual lung inflations, chest wall vibrations and endotracheal suction. The primary outcome was respiratory compliance. Secondary outcomes included adverse physiological events and clinically important respiratory changes (according to an a priori definition). Treatments delivered to 63 patients were analysed. There were significant improvements to respiratory compliance (mean increase [95% confidence intervals], 0.07 and 0.08ml·cmH2O(-1)·kg(-1) [0.01 to 0.14 and 0.04 to 0.13], p<0.01, for on-call and respiratory physiotherapists' treatments respectively). Case-by-case, there were fewer clinically important improvements following non-respiratory physiotherapists' treatments compared with the respiratory physiotherapists' (n=27 [43%] versus n=40 [63%], p=0.03). Eleven adverse events occurred, eight following non-respiratory physiotherapists' treatments. Significant disparities exist in treatment outcomes when patients are treated by non-respiratory on-call physiotherapists, compared with specialist respiratory physiotherapists. There is an urgent need for targeted training strategies, or alternative service delivery models, to be explored. This should aim to address the quality of respiratory physiotherapy services, both during and outside of normal working hours. Clinicaltrials.gov, NCT01999426.
To investigate differences, if any, in the delivery of respiratory treatments to mechanically ven... more To investigate differences, if any, in the delivery of respiratory treatments to mechanically ventilated children between non-respiratory on-call physiotherapists and specialist respiratory physiotherapists. Paediatric, tertiary care hospital in the United Kingdom. 93 children (aged between 3 days and 16 years), and 22 physiotherapists (10 specialist respiratory physiotherapists) were recruited to the study. Recruited children received two physiotherapy treatments during a single day, one delivered by a non-respiratory physiotherapist, the other by a specialist respiratory physiotherapist in a randomised order. Selection, delivery and effects of techniques were recorded for each treatment. Primary outcomes were selection and application of treatment components. Secondary outcomes included respiratory effects (in terms of changes in flow, volume and pressure) of selected treatment components. Both non-respiratory on-call physiotherapists and specialist respiratory physiotherapists used combinations of saline instillation, manual lung inflations, chest wall vibrations and endotracheal suction during treatments. However specialist respiratory physiotherapists used combinations of chest wall vibrations with suction, and recruitment manoeuvres, significantly more frequently than non-respiratory on-call physiotherapists (92% vs 52%, and 87% vs 46% of treatments respectively, P<0.001). Chest wall vibrations delivered by non-respiratory on-call physiotherapists were 15% less effective at increasing peak expiratory flow. Clinically important differences between non-respiratory and specialist respiratory physiotherapists' treatment outcomes may be related to differences in the selection and application of techniques. This suggests an important training need for non-respiratory on-call physiotherapists, particularly in the effective delivery of physiotherapy techniques. Clinicaltrials.gov NCT01999426.
The 2005 American Thoracic Society (ATS)/European Respiratory Society (ERS) spirometry guidelines... more The 2005 American Thoracic Society (ATS)/European Respiratory Society (ERS) spirometry guidelines define valid tests as having three acceptable blows and a repeatable forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). The aim of this study was to determine how reviewer and computer-determined ATS/ERS quality could affect population reference values for FVC and FEV1. Spirometry results from 7777 normal subjects aged 8-80 years (NHANES (National Health and Nutrition Examination Survey) III) were assigned quality grades A to F for FVC and FEV1 by a computer and one reviewer (reviewer 1). Results from a subgroup of 1466 Caucasian adults (aged 19-80 years) were reviewed by two additional reviewers. Mean deviations from NHANES III predicted for FVC and FEV1 were examined by quality grade (A to F). Reviewer 1 rejected (D and F grade) 5.2% of the 7777 test sessions and the computer rejected ∼16%, primarily due to end-of-test (EOT) failures. Within the subgroup, the comp...
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