Time-to-positivity in patients with Escherichia coli bacteraemia

The time from the start of incubation to a positive reading of blood cultures (time-to-positivity; TTP) is related to the concentration of bacteria in blood. Information concerning the correlation of TTP with clinical parameters, and its usefulness as a prognostic factor in patients with Escherichia coli bacteraemia, is limited. To investigate the relationship of TTP to clinical parameters, 459 cases of monomicrobial E. coli bloodstream infections from a single institution between 1997 and 2005 were reviewed. All cases involved patients who were not undergoing antibiotic treatment at the time of blood sampling. The in-hospital mortality rate was 6.3%. Median TTP was significantly shorter for patients who died than for those who survived (9.7 h, inter-quartile range 7.85-11.05 h vs. 11.2 h, inter-quartile range 10.1-11.4 h; p <0.001). Patients with TTP in the lowest quartile were more likely to be female, to have a non-urinary tract or an unknown origin of bacteraemia, to have severe sepsis or shock, and to subsequently die. In a multivariable Cox regression model, the hazard ratio for death from any cause for patients with a short TTP was 3.13 (95% CI 1.28-7.64; p 0.01). TTP in patients with E. coli bacteraemia provides prognostic information beyond that provided by the presence of haematological illness, a Charlson score > or =3, a non-urinary tract origin of bacteraemia, and the presence of severe sepsis or shock.

Body mass index and weight change are associated with adult lung function trajectories: the prospective ECRHS study

BACKGROUND

Previous studies have reported an association between weight increase and excess lung function decline in young adults followed for short periods. We aimed to estimate lung function trajectories during adulthood from 20-year weight change profiles using data from the population-based European Community Respiratory Health Survey (ECRHS).

METHODS

We included 3673 participants recruited at age 20-44 years with repeated measurements of weight and lung function (forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1)) in three study waves (1991-93, 1999-2003, 2010-14) until they were 39-67 years of age. We classified subjects into weight change profiles according to baseline body mass index (BMI) categories and weight change over 20 years. We estimated trajectories of lung function over time as a function of weight change profiles using population-averaged generalised estimating equations.

RESULTS

In individuals with normal BMI, overweight and obesity at baseline, moderate (0.25-1 kg/year) and high weight gain (>1 kg/year) during follow-up were associated with accelerated FVC and FEV1 declines. Compared with participants with baseline normal BMI and stable weight (±0.25 kg/year), obese individuals with high weight gain during follow-up had -1011 mL (95% CI -1.259 to -763) lower estimated FVC at 65 years despite similar estimated FVC levels at 25 years. Obese individuals at baseline who lost weight (<-0.25 kg/year) exhibited an attenuation of FVC and FEV1 declines. We found no association between weight change profiles and FEV1/FVC decline.

CONCLUSION

Moderate and high weight gain over 20 years was associated with accelerated lung function decline, while weight loss was related to its attenuation. Control of weight gain is important for maintaining good lung function in adult life.

Childhood Body Composition Trajectories and Adolescent Lung Function. Findings from the ALSPAC study

Rationale: Body composition changes throughout life may explain the inconsistent associations reported between body mass index and lung function in children. Objectives: To assess the associations of body weight and composition trajectories from 7 to 15 years with lung function at 15 years and lung function growth between 8 and 15 years. Methods: Sex-specific body mass index, lean body mass index, and fat mass index trajectories were developed using Group-Based Trajectory Modeling on data collected at least twice between 7 and 15 years from 6,964 children (49% boys) in the UK Avon Longitudinal Study of Parents and Children birth cohort. Associations of these trajectories with post-bronchodilation lung function parameters at 15 years and with lung function growth rates from 8 to 15 years were assessed using multivariable linear regression models, stratified by sex, in a subgroup with lung function data (n = 3,575). Measurements and Main Results: For all body mass measures we identified parallel trajectories that increased with age. There was no consistent evidence of an association between the body mass index trajectories and lung function measures. Higher lean body mass index trajectories were associated with higher levels and growth rates of FVC, FEV1, and forced expiratory flow, midexpiratory phase in both sexes (e.g., boys in the highest lean body mass index trajectory had on average a 0.62 L [95% confidence interval, 0.44-0.79; P trend < 0.0001] higher FVC at 15 yr than boys in the lowest trajectory). Increasing fat mass index trajectories were associated with lower levels and growth rates of FEV1 and forced expiratory flow, midexpiratory phase only in boys and lower levels of FEV1/FVC in both sexes. Conclusions: Higher lean body mass during childhood and adolescence is consistently associated with higher lung function at 15 years in both sexes, whereas higher fat mass is associated with lower levels of only some lung function parameters.

Risk factors for bacteremia in patients with limb cellulitis

The aim of this study was to identify the risk factors for bacteremia in patients with limb cellulitis. Using the administrative and microbiology laboratory databases of a community teaching hospital, a review was conducted of all cases of community-acquired limb cellulitis that occurred during the period 1997-2004 and in which blood cultures had been performed. A comparison of demographical, clinical, and analytical data of patients with bacteremia versus patients without bacteremia was performed by univariate and multivariate analyses. Of 2,678 patients with cellulitis who presented to the hospital's emergency department, 308 were diagnosed with limb cellulitis and had blood cultures. Of these, 57 (18.5%) had bacteremia. In 24 of the 57 (42.1%) patients with bacteremia, the microorganism isolated in blood cultures was non-group-A beta-hemolytic Streptococcus, and in another 14 (24.6%), the microorganism identified was a gram-negative bacterium. Staphylococcus aureus was determined as the cause of bacteremia in just 6 (10.5%) patients and group A Streptococcus in 2 (3.5%). By logistic regression analysis, the following factors were associated with bacteremia: absence of previous antibiotic treatment (OR 5.3, 95% CI 1.4-20.3), presence of two or more comorbid factors simultaneously (OR 4.3, 95% CI 1.6-11.7), length of illness<2 days OR 2.44, 95% CI 1.07-5.56), and proximal limb involvement (OR 6, 95% CI 3.03-12.04). Patients with limb cellulitis who exhibit any of these characteristics are at increased risk of bacteremia. In such patients, it is imperative that blood cultures be performed.

Physical activity and lung function-Cause or consequence?

Concerns exist that the positive association of physical activity with better lung function, which has been suggested in previous longitudinal studies in smokers, is due to reverse causation. To investigate this, we applied structural equation modeling (SEM), an exploratory approach, and marginal structural modeling (MSM), an approach from the causal inference framework that corrects for reverse causation and time-dependent confounding and estimates causal effects, on data from participants in the European Community Respiratory Health Survey (ECRHS, a multicentre European cohort study initiated in 1991–1993 with ECRHS I, and with two follow-ups: ECRHS II in 1999–2003, and ECRHS III in 2010–2014). 753 subjects who reported current smoking at ECRHS II, with repeated data on lung function at ECRHS I, II and III, physical activity at ECRHS II and III, and potential confounders at ECRHS I and II, were included in the analyses. SEM showed positive associations between physical activity and lung function in both directions. MSM suggested a protective causal effect of physical activity on lung function (overall difference in mean β (95% CI), comparing active versus non-active individuals: 58 mL (21–95) for forced expiratory volume in one second and 83 mL (36–130) for forced vital capacity). Our results suggest bi-directional causation and support a true protective effect of physical activity on lung function in smokers, after accounting for reverse causation and time-dependent confounding.

Physical-activity trajectories during childhood and lung function at 15 years: findings from the ALSPAC cohort

Background

Although physical activity has many known health benefits, its association with lung function in childhood/adolescence remains unclear. We examined the association of physical-activity trajectories between 11 and 15 years with lung function at 15 years in 2266 adolescents.

Methods

A population-based cohort of 14 305 singleton births alive at 1 year was recruited in the UK population-based Avon Longitudinal Study of Parents and Children cohort. Physical activity (counts/minute and moderate-to-vigorous physical activity) was assessed for 7 days using an accelerometer at 11, 13 and 15 years. We identified sex-specific physical-activity trajectories applying K-means for longitudinal data in children with at least two accelerometer measurements (n = 3584). We then estimated the sex-specific associations of these trajectories with post-bronchodilation lung-function parameters using multivariable linear-regression models (n = 2266, 45% boys).

Results

Fewer than 7% of participants met the WHO physical-activity recommendations (i.e. daily average of at least 60 minutes of moderate-to-vigorous physical activity). Boys were substantially more active than girls. In both sexes, we identified three distinct physical-activity trajectories (‘low’: 39.8% boys, 45.8% girls; ‘moderate’: 42.9% boys, 41.4% girls; and ‘high’ physical activity: 17.3% boys, 12.8% girls). Girls in the moderate and high physical-activity trajectories had 0.11 L [95% confidence interval (CI): 0.04–0.19] and 0.15 L (95% CI: 0.03–0.26) higher forced vital capacity than their less-active peers. No association was observed in boys.

Conclusions

Higher childhood physical activity relates to higher lung-function levels in adolescent girls. A better understanding of the mechanisms underlying this association should be pursued.

Surveillance of Acute SARS-CoV-2 Infections in School Children and Point-Prevalence During a Time of High Community Transmission in Switzerland

Background: Switzerland had one of the highest incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in Europe during the second wave. Schools were open as in most of Europe with specific preventive measures in place. However, the frequency and transmission of acute unrecognized, asymptomatic or oligosymptomatic infections in schools during this time of high community transmission is unknown. Thereof, our aim was to pilot a surveillance system that detects acute SARS-CoV-2 infections in schools and possible transmission within classes. Methods: Fourteen out of the randomly selected sample of the Ciao Corona cohort study participated between December 1 and 11, a time when incidence rate for SARS-CoV-2 infections was high for the canton of Zurich. We determined point-prevalence of acute SARS-CoV-2 infections of school children attending primary and secondary school. A buccal swab for polymerase chain reaction (PCR) and a rapid diagnostic test (RDT) to detect SARS-CoV-2 were taken twice 1 week apart (T1 and T2) in a cohort of children from randomly selected classes. A questionnaire assessed demographics and symptoms compatible with a SARS-CoV-2 infection during the past 5 days. Results: Out of 1,299 invited children, 641 (49%) 6- to 16-year-old children and 66 teachers from 14 schools and 67 classes participated in at least one of two testings. None of the teachers but one child had a positive PCR at T1, corresponding to a point-prevalence in children of 0.2% (95% CI 0.0-1.1%), and no positive PCR was detected at T2. The child with positive PCR at T1 was negative on the RDT at T1 and both tests were negative at T2. There were 7 (0.6%) false positive RDTs in children and 2 (1.7%) false positive RDTs in teachers at T1 or T2 among 5 schools (overall prevalence 0.7%). All 9 initially positive RDTs were negative in a new buccal sample taken 2 h to 2 days later, also confirmed by PCR. Thirty-five percent of children and 8% of teachers reported mild symptoms during the 5 days prior to testing. Conclusion: In a setting of high incidence of SARS-CoV-2 infections, unrecognized virus spread within schools was very low. Schools appear to be safe with the protective measures in place (e.g., clearly symptomatic children have to stay at home, prompt contact tracing with individual and class-level quarantine, and structured infection prevention measures in school). Specificity of the RDT was within the lower boundary of performance and needs further evaluation for its use in schools. Given the low point prevalence even in a setting of very high incidence, a targeted test, track, isolate and quarantine (TTIQ) strategy for symptomatic children and school personnel adapted to school settings is likely more suitable approach than surveillance on entire classes and schools. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT04448717, ClinicalTrials.gov NCT04448717.

The morphometric acclimation to depth explains the long-term resilience of the seagrass Cymodocea nodosa in a shallow tidal lagoon

Cadiz Bay is a shallow mesotidal lagoon with extensive populations of the seagrass Cymodocea nodosa at intertidal and shallow subtidal elevations. This work aims to understand the mechanisms behind the resilience of this species to gradual sea level rise by studying its acclimation capacity to depth along the shallow littoral, and therefore, to gradual variations in the light environment. To address this objective, these populations have been monitored seasonally over a 10 year period, representing the longest seasonal database available in the literature for this species. The monitoring included populations at 0.4, -0.08 and -0.5 m LAT. The results show that C. nodosa has a strong seasonality for demographic and shoot dynamic properties - with longer shoots and larger growth in summer (high temperature) than in winter (low temperature), but also some losses. Moreover, shoots have different leaf morphometry depending on depth, with small and dense shoots in the intertidal areas (0.4 m) and sparse large shoots in the subtidal ones (-0.08 and 0.5 m). These differences in morphometry and shoot dynamic properties, combined with the differences in shoot density, explain the lack of differences in meadow production balance (i.e. meadow growth - meadow losses) between the intertidal (0.4 m) and the deepest population (-0.5 m), supporting the long term resilience of Cymodocea nodosa in Cadiz Bay. This study contributes to the understanding of the mechanisms behind seagrass stability and resilience, which is particularly important towards predicting the effects of climate change on these key coastal ecosystems, and also highlights the value of continuous long-term monitoring efforts to evaluate seagrass trajectories.

Characteristics and prognostic value of morning dipping of peak expiratory flow rate in stable asthmatic subjects

Characteristics and prognostic relevance of morning dip of peak expiratory flow rate (PEFR) were evaluated in stable asthmatic subjects. Among 246 outpatients monitored four times daily for two weeks, 38 (group A) showed a significant difference between morning reading of PEFR and each of the others; they were compared to 38 randomly selected patients (group B) not showing morning dip in PEFR. Less frequent seasonal course, extrinsic pathogenesis, and sensitization to mites characterized group A; starting airflow limitation was more severe in those with morning dip, but no significant difference between mean PEFR measured throughout two weeks was found. At 6 to 12 weeks, morning dip was not found in 19 of 38 subjects in group A and appeared in seven of 38 subjects in group B, with no clearcut relationship to treatment being evident. At 25 to 104 weeks, no significant difference between therapeutic requirements and the forced expiratory volume in one second was detected; therefore, unlike the short-term, morning dip is not a risk factor for worse long-term prognosis.

Pollen limitation may be a common Allee effect in marine hydrophilous plants: implications for decline and recovery in seagrasses

Pollen limitation may be an important factor in accelerated decline of sparse or fragmented populations. Little is known whether hydrophilous plants (pollen transport by water) suffer from an Allee effect due to pollen limitation or not. Hydrophilous pollination is a typical trait of marine angiosperms or seagrasses. Although seagrass flowers usually have high pollen production, floral densities are highly variable. We evaluated pollen limitation for intertidal populations of the seagrass Zostera noltei in The Netherlands and found a significant positive relation between flowering spathe density and fruit-set, which was suboptimal at <1200 flowering spathes m(-2) (corresponding to <600 reproductive shoots m(-2)). A fragmented population had ≈35 % lower fruit-set at similar reproductive density than a continuous population. 75 % of all European populations studied over a large latitudinal gradient had flowering spathe densities below that required for optimal fruit-set, particularly in Southern countries. Literature review of the reproductive output of hydrophilous pollinated plants revealed that seed- or fruit-set of marine hydrophilous plants is generally low, as compared to hydrophilous freshwater and wind-pollinated plants. We conclude that pollen limitation as found in Z. noltei may be a common Allee effect for seagrasses, potentially accelerating decline and impairing recovery even after environmental conditions have improved substantially.

Variability of peak expiratory flow rate as a prognostic index in asymptomatic asthma

The prognostic relevance of an enhanced variability of peak expiratory flow rate (PEFR) throughout the day was evaluated in asthmatics in remission: it was expressed as the coefficient of variation (CV) of values recorded 4 times daily for 2 weeks. Outcome at 3, 6, and 12 months was assessed in 2 groups of 16 patients each, differing because of a CV respectively higher (group A) and lower (group B) than 8%. A significantly higher frequency of abnormal PEFR values during the subsequent 3 months was recorded in patients of group A, and found as correlated to the magnitude of CV; in the same group a significantly worse clinical status--scored on the basis of response to treatment--was pointed out. Therefore, a high CV of PEFR may be assumed as a reliable indicator of the risk of exacerbation--not otherwise predictable--both in a short and a longer term; on this basis home monitoring of PEFR may be recommended as a useful tool in the evaluation of all the cases of asthma in remission.

Preventive effects of hyperbaric oxygen in cluster headache

The effect of a 2-week course of hyperbaric oxygen on both the duration and frequency of cluster headache attacks was tested in four patients suffering from chronic cluster headache with no clear response to pharmacological treatments. Two patients (two courses in one case) dramatically improved while on hyperbaric oxygen treatment, this positive response remaining for 2 and 31 days posttreatment. Case 3 only improved in frequency, while the remaining patient showed no benefit. These findings suggest that daily hyperbaric oxygen treatment can be used as a transient preventive treatment for desperate cluster headache sufferers.

Early-life and health behaviour influences on lung function in early adulthood

RATIONALE

Early-life exposures may influence lung function at different stages of the life course. However, the relative importance of characteristics at different stages of infancy and childhood are unclear.

OBJECTIVES

To examine the associations and relative importance of early-life events on lung function at age 24 years.

METHODS

We followed 7545 children from the Avon Longitudinal Study of Parents and Children from birth to 24 years. Using previous knowledge, we classified an extensive list of putative risk factors for low lung function, covering sociodemographic, environmental, lifestyle and physiological characteristics, according to timing of exposure: 1) demographic, maternal and child; 2) perinatal; 3) postnatal; 4) early childhood; and 5) adolescence characteristics. Lung function measurements (forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), FEV₁/FVC and forced expiratory flow at 25-75% of FVC) were standardised for sex, age and height. The proportion of the remaining variance explained by each characteristic was calculated. The association and relative importance (RI) of each characteristic for each lung function measure was estimated using linear regression, adjusted for other characteristics in the same and previous categories.

RESULTS

Lower maternal perinatal body mass index (BMI), lower birthweight, lower lean mass and higher fat mass in childhood had the largest RI (0.5-7.7%) for decreased FVC. Having no siblings, lower birthweight, lower lean mass and higher fat mass were associated with decreased FEV₁ (RI 0.5-4.6%). Higher lean mass and childhood asthma were associated with decreased FEV₁/FVC (RI 0.6-0.8%).

CONCLUSIONS

Maternal perinatal BMI, birthweight, childhood lean and fat mass and early-onset asthma are the factors in infancy and childhood that have the greatest influence on early-adult lung function.

Early childhood growth is associated with lung function at 7 years: a prospective population-based study

Previous studies have related early postnatal growth with later lung function but their interpretation is limited by the methods used to assess a child's growth. We aimed to assess the association of early childhood growth, measured by body mass index (BMI) trajectories up to 4 years, with lung function at 7 years.We included 1257 children from the Spanish Infancia y Medio Ambiente population-based birth cohort. Early childhood growth was classified into five categories based on BMI trajectories up to 4 years previously identified using latent class growth analysis. These trajectories differed in birth size ("lower", "average", "higher") and in BMI gain velocity ("slower", "accelerated"). We related these trajectories to lung function (forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), FEV₁/FVC and forced expiratory flow at 25%-75% of FVC (FEF_25-75%)) at 7 years, using multivariable mixed regression.Compared to children with average birth size and slower BMI gain (reference), children with higher birth size and accelerated BMI gain had a higher FVC % pred (3.3%, 95% CI 1.0%-5.6%) and a lower FEV₁/FVC % pred (-1.5%, 95% CI -2.9%--0.1%) at 7 years. Similar associations were observed for children with lower birth size and accelerated BMI gain. Children with lower birth size and slower BMI gain had lower FVC % pred at 7 years. No association was found for FEF_25-75%Independently of birth size, children with accelerated BMI gain in early childhood had higher lung function at 7 years but showed airflow limitation. Children with lower birth size and slower BMI gain in early childhood had lower lung function at 7 years.

Lifestyle Behaviours of Children and Adolescents During the First Two Waves of the COVID-19 Pandemic in Switzerland and Their Relation to Well-Being: An Observational Study

Objectives: To describe changes in adherence to recommendations for physical activity (PA), screen time (ST), and sleep duration over the first two waves of the pandemic in Switzerland, and to assess the associations of these lifestyle behaviours with life satisfaction and overall health as well-being indicators. Methods: In this observational study, we included 2,534 participants (5-16 years) from four Swiss cantons. Participants, or their parents, completed repeated questionnaires and reported on their (child's) lifestyle and well-being, between June 2020 and April 2021. We used linear and logistic regression models to assess the associations between lifestyle and well-being. Results: The percentage of children meeting the recommendations for PA and ST decreased from the pre-pandemic period to the first wave, with a slight recovery during the second wave. Participants meeting all three recommendations during the second wave were more likely to report excellent health (OR: 1.65 [95% CI: 1.00-2.76]) and higher life satisfaction (β: 0.46 [0.16-0.77]) in early 2021 than participants not meeting any recommendation. Conclusion: We showed a substantial impact of the COVID-19 pandemic on children's and adolescents' lifestyle, and a positive association between meeting lifestyle recommendations and well-being.

Respiratory morbidity in preschool and school-age children born very preterm and its association with parents' health-related quality of life and family functioning

The purpose of this study is to describe the prevalence and severity of respiratory symptoms in children born very preterm and to assess their association with parents' health-related quality of life (HRQoL) and family functioning. We conducted a cross-sectional study and recruited children born less than 32 weeks' gestation between January 2006 and December 2019, in the greater Zurich area, Switzerland. Between May and December 2021, parents were invited to complete an online survey for their preterm child and for a control term born (≥ 37 weeks' gestation) sibling aged 1 to 18 years. We used a validated questionnaire to assess respiratory symptoms and the Pediatrics Quality of Life Family Impact Module (PedsQL FIM) to assess parents' HRQoL and family functioning. The survey was completed for 616 very preterm children (99 with bronchopulmonary dysplasia (BPD)) and 180 controls. Girls made up 45% (46% in controls) of the sample, and 63% (60% in controls) of participants were aged 6 to 18 years (school-age). Very preterm children reported a higher risk of respiratory symptoms than controls, especially preschoolers and those with moderate-to-severe BPD. Parents of children with "mild" and "moderate-severe" respiratory symptoms had on average -3.9 (95%CI: -6.6 to -1.1) and -8.2 (-11.2 to -5.2) lower PedsQL FIM total score, respectively, than parents of children with no symptoms. The same pattern was observed after stratifying by age categories.  Conclusions: Our study suggests that respiratory morbidity in very preterm children has a negative impact on parents' HRQoL and family functioning, even beyond the first years of life. What is Known: • The burden of respiratory morbidity associated with very premature birth is high and last far beyond the neonatal period. • Respiratory morbidity contributes to lower health-related quality of life (HRQoL) in parents of very preterm children in early infancy. What is New: • Respiratory morbidity in very preterm children has a negative impact on parents' HRQoL and family functioning beyond the first years of life. • Parents of very preterm children with moderate and severe respiratory symptoms are the ones who report lower scores, both for preschool and school-age children.

Apical leakage in canals filled with glass ionomer sealer and gutta-percha after dentin conditioning

This study assessed in vitro apical leakage in root canals filled with gutta-percha and Ketac-Endo using different dentin conditioning and filling techniques. The root canals of 63 single-rooted teeth were instrumented and randomly divided into the following four groups: group A--canals were irrigated with 25% tannic acid and filled with Ketac-Endo and a standardized gutta-percha cone; group B--canals were irrigated with 1% NaOCl and filled as in group A; group C--canals were irrigated with 25% tannic acid and filled with Ketac-Endo and a chloroform-softened gutta-percha cone adapted to the canal walls; group D--canals were irrigated with 1% NaOCl and filled with Grossman's sealer and laterally condensed gutta-percha. After storage for 72 hours at 37 degrees C and 100% humidity, the gutta-percha was removed to a level 4 mm short of the working length, using a Peeso reamer. Teeth were immersed in India ink for 48 hours and cleared, and the coronal extent of dye penetration examined under a binocular dissecting microscope at x 15 magnification. The mean value of leakage for group A was 0.86 mm, for group B 2.23 mm, for group C 2.34 mm, and for group D 0.56 mm. Tukey's multiple comparison test disclosed significant differences (P < 0.05) between group A and groups B and C, and between group D and groups B and C. Differences between groups A and D, as well as between groups B and C, were not significant.

Comparison of the effect of oxitropium bromide and of slow-release theophylline on nocturnal asthma

The effects of a new inhaled antimuscarinic drug, oxitropium bromide, and of a slow-release theophylline preparation upon nocturnal asthma were compared in a placebo-controlled double-blind study. Two samples were studied: 12 patients received oxitropium at 600 micrograms (6 subjects) or at 400 micrograms t.i.d. (6 subjects) whereas 11 received theophylline at 300 mg b.i.d. Morning dipping, assessed by the fall in peak flow overnight, was significantly reduced in the periods when either active drug was taken, whereas no difference was noticed during the placebo administration. No significant difference was noticed between results obtained with either active drug, as well as with either dosage of oxitropium. No subject reported side effects of oxitropium, as compared to three subjects reporting nausea, vomiting and tremors after theophylline. Oxitropium proves to be a valuable alternative to theophylline in nocturnal asthma, since it is equally potent, safer and does not require the titration of dosage.

Effects of intertidal seagrass habitat fragmentation on turbulent diffusion and retention time of solutes

An in-depth knowledge of solutes advection and turbulent diffusion is crucial to estimate dispersion area and retention time (t(R)) of pollutants within seagrass habitats. However, there is little knowledge on the influence of seagrass habitat fragmentation on such mechanisms. A set of dye tracer experiments and acoustic Doppler velocimeter measurements (ADV) were conducted. Solute transport conditions were compared in between fragmented (FM) vs homogeneous (HM) intertidal meadows, and in vertical gradients (canopy vs overlaying flow). Results showed the highest horizontal diffusion coefficient (K(y), c.a. 10(-3)m(2)s(-1)) on FM and at the canopy-water column interface, whereas t(R) (2.6-5.6 min) was not affected by fragmentation. It suggests that (1) FM are more vulnerable to pollution events in terms of dispersion area and (2) at low tide, advection rather than turbulent diffusion determines t(R). Furthermore, Taylor's theorem is revealed as a powerful tool to analyze vertical gradients on K(y) within seagrass canopies.

Parents' Working Conditions in the Early COVID-19 Pandemic and Children's Health-Related Quality of Life: The Ciao Corona Study

Objective: To assess the associations between parents' working conditions during the lockdown period (March-May 2020) and children's health-related quality of life (HRQOL) over the first year of the COVID-19 pandemic in Zurich, Switzerland. Methods: We included 2211 children (6-16 years) and their parents from the prospective study Ciao Corona. Parents reported their employment status and working conditions during the lockdown. Children's HRQOL was assessed in June-July 2020, January and March 2021 using the parents-report of the KINDL®. We used mixed models to assess the associations between parents' working conditions and children's HRQOL at the three time points. Results: Children from families in which at least one parent changed their working conditions during the lockdown showed lower HRQOL in June-July 2020, than children from families in which neither parent experienced changes. Children from families in which at least one parent had to work remotely continued to show lower HRQOL in January and March 2021. Conclusion: Changes in parents' working conditions during lockdown were negatively associated with children's HRQOL. Public health policies aiming to support families susceptible to adverse changes are needed.

Health-Related Quality of Life and Adherence to Physical Activity and Screen Time Recommendations in Schoolchildren: Longitudinal Cohort Ciao Corona

Objectives: We investigated changes in adherence to physical activity (PA) and screen time (ST) recommendations of children and adolescents throughout the pandemic, and their association with health-related quality of life (HRQOL). Methods: 1,769 primary (PS, grades 1-6) and secondary (SS, 7-9) school children from Ciao Corona, a school-based cohort study in Zurich, Switzerland, with five questionnaires 2020-2022. HRQOL was assessed using the KINDL questionnaire. PA (≥60 min/day moderate-to-vigorous PA) and ST (≤2 h/day ST) recommendations followed WHO guidelines. Results: Adherence to PA recommendations dropped in 2020 (83%-59% PS, 77%-52% SS), but returned to pre-pandemic levels by 2022 (79%, 66%). Fewer children met ST recommendations in 2020 (74% PS, 29% SS) and 2021 (82%, 37%) than pre-pandemic (95%, 68%). HRQOL decreased 3 points between 2020 and 2022, and was 9.7 points higher (95% CI 3.0-16.3) in March 2021 in children who met both versus no recommendations. Conclusion: Adherence to WHO guidelines on PA and ST during the pandemic had a consistent association with HRQOL despite longitudinal changes in behavior.

The combination of fenoterol and ipratropium bromide in bronchial asthma: comparison of the acute effects of two different dosages

Combinations of beta-stimulant and anticholinergic drugs have been advocated as a potentially useful tool in the treatment of reversible airway obstruction. We investigated the effectiveness and safety of a metered aerosol preparation delivering fenoterol 100 micrograms and ipratropium bromide 40 micrograms per puff: two dosages (2 puffs and 4 puffs) were used in 16 asthmatic patients, and their acute effects (up to 420 min) were investigated in a double-blind randomized trial. The results point out a reasonably good response to both dosages, with no notable difference between them as far as vital capacity, FEV 1, MMEF and Vmax75 are concerned. This finding indicates the possibility of achieving a satisfactory bronchodilation at beta-stimulant dosages far lower than the standard ones commonly used and therefore minimizing the risk of untoward cardiovascular effects.

Role of DNA methylation in the association of lung function with body mass index: a two-step epigenetic Mendelian randomisation study

BACKGROUND

Low lung function has been associated with increased body mass index (BMI). The aim of this study was to investigate whether the effect of BMI on lung function is mediated by DNA methylation.

METHODS

We used individual data from 285,495 participants in four population-based cohorts: the European Community Respiratory Health Survey, the Northern Finland Birth Cohort 1966, the Swiss Study on Air Pollution and Lung Disease in Adults, and the UK Biobank. We carried out Mendelian randomisation (MR) analyses in two steps using a two-sample approach with SNPs as instrumental variables (IVs) in each step. In step 1 MR, we estimated the causal effect of BMI on peripheral blood DNA methylation (measured at genome-wide level) using 95 BMI-associated SNPs as IVs. In step 2 MR, we estimated the causal effect of DNA methylation on FEV1, FVC, and FEV1/FVC using two SNPs acting as methQTLs occurring close (in cis) to CpGs identified in the first step. These analyses were conducted after exclusion of weak IVs (F statistic < 10) and MR estimates were derived using the Wald ratio, with standard error from the delta method. Individuals whose data were used in step 1 were not included in step 2.

RESULTS

In step 1, we found that BMI might have a small causal effect on DNA methylation levels (less than 1% change in methylation per 1 kg/m2 increase in BMI) at two CpGs (cg09046979 and cg12580248). In step 2, we found no evidence of a causal effect of DNA methylation at cg09046979 on lung function. We could not estimate the causal effect of DNA methylation at cg12580248 on lung function as we could not find publicly available data on the association of this CpG with SNPs.

CONCLUSIONS

To our knowledge, this is the first paper to report the use of a two-step MR approach to assess the role of DNA methylation in mediating the effect of a non-genetic factor on lung function. Our findings do not support a mediating effect of DNA methylation in the association of lung function with BMI.