Deciphering Alveolo-Capillary Gas Transfer Disturbances in Patients Recovering from COVID-19 Lung Disease.

Impaired lung gas exchange is commonly seen in patients with pulmonary involvement related to SARS-CoV-2 acute infection or post-acute COVID-19 syndrome (PACS). The primary aim of our study was to assess lung gas transfer, measuring the pulmonary diffusion capacity for nitric oxide (DLNO) and carbon monoxide (DLCO) in all COVID-19 patients. Our secondary aim was to decipher the respective roles of perturbed lung membrane conductance (DM) and reduced pulmonary capillary volume (VC) in patients with impaired lung gas exchange. From May to October 2020, we measured DLNO-DLCO in 118 patients during their post-COVID-19 period (4.6 months after infection) to decipher alveolo-capillary gas transfer disturbances. DLNO-DLCO measurement was also performed in 28 healthy non-smokers as controls. Patients were classified into three groups according to the severity (mild, moderate, and severe) of acute COVID-19 infection. Patients with mild COVID-19 had normal lung volumes and airways expiratory flows but impaired pulmonary gas exchange, as shown by the significant decreases in DLNO, DLCO, DM, and VC as compared with controls. VC was significantly impaired and the DLNO/DLCO ratio was increased in patients with moderate (n = 4, 11%) and severe COVID-19 (n = 23, 49%). Abnormal membrane conductance was also seen in all three groups of post-COVID-19 patients. These findings suggest a persistent alveolo-capillary gas transfer defect, implying not only reduced membrane conductance but also abnormal pulmonary vascular capacitance in all PACS patients, even those with a milder form of COVID-19 infection.

Cautious Gait during Navigational Tasks in People with Hemiparesis: An Observational Study.

Locomotor and balance disorders are major limitations for subjects with hemiparesis. The Timed Up and Go (TUG) test is a complex navigational task involving oriented walking and obstacle circumvention. We hypothesized that subjects with hemiparesis adopt a cautious gait during complex locomotor tasks. The primary aim was to compare spatio-temporal gait parameters, indicators of cautious gait, between the locomotor subtasks of the TUG (Go, Turn, Return) and a Straight-line walk in people with hemiparesis. Our secondary aim was to analyze the relationships between TUG performance and balance measures, compare spatio-temporal gait parameters between fallers and non-fallers, and identify the biomechanical determinants of TUG performance. Biomechanical parameters during the TUG and Straight-line walk were analyzed using a motion capture system. A repeated measures ANOVA and two stepwise ascending multiple regressions (with performance variables and biomechanical variables) were conducted. Gait speed, step length, and % single support phase (SSP) of the 29 participants were reduced during Turn compared to Go and Return and the Straight-line walk, and step width and % double support phase were increased. TUG performance was related to several balance measures. Turn performance (R2 = 63%) and Turn trajectory deviation followed by % SSP on the paretic side and the vertical center of mass velocity during Go (R2 = 71%) determined TUG performance time. People with hemiparesis adopt a cautious gait during complex navigation at the expense of performance.

Improving Assessment of Adherence Behaviors and Drivers: Targeted Literature Review and Concept Elicitation Interviews in Multiple Countries and Disease Populations.

Purpose: Medication adherence is crucial for achieving clinical goals. Medication adherence drivers and behaviors were explored across multiple conditions, countries, and medication schedules/modalities to develop a conceptual model of medication adherence, which could later be used to support development of a patient-reported outcome (PRO) measure of adherence. Patients and Methods: Targeted review of qualitative literature identified important medication adherence concepts. Fifty-seven qualitative concept elicitation interviews were conducted (USA n=21, Spain n=18, Germany n=18). Participants were prescribed medication for: hypertension (n=9), asthma (n=8), multiple myeloma (n=8), psoriasis (n=8), diabetes (n=7), depression (n=7), multiple sclerosis (n=7), and/or schizophrenia (n=6). Thematic analysis of verbatim transcripts was performed. Expert clinicians (n=3) provided input throughout. Results: Nine qualitative articles were selected for review from 2168 screened abstracts. Forty-two medication adherence concepts were reported and grouped into 10 domains. Eight forms of medication adherence were reported during interviews, along with 27 drivers of non-adherence, all of which were incorporated into a conceptual model. Participants reported skipping medication doses (n=36/57; 63.2%) or taking medication later in the day than prescribed (n=29/57; 50.9%). Common drivers of non-adherence included forgetfulness (n=35/57; 61.4%), being out of the usual routine (n=31/57; 54.4%) and being busy (n=22/57; 38.6%). US participants were more likely to report non-adherence due to low perceived efficacy (n=6/21, 28.6%) and cost (n=5/21, 23.8%) than German (n=1/18, 5.6%; n=0/18, 0.0%) or Spanish (n=2/18, 11.1%; n=1/18, 5.6%) participants. Conclusion: Findings highlight the diverse forms and drivers of medication non-adherence, informing the development of a comprehensive conceptual model of medication adherence. The conceptual model builds on and advances previous models of medication adherence and can be used by healthcare professionals to understand and interpret barriers to medication adherence and how best to support patients in taking their medication as intended.

Medication adherence is the extent to which a patient takes their medication as prescribed. This paper describes a literature review and concept elicitation interviews to identify forms and drivers of medication adherence across a diverse sample of participants. Forms of non-adherence identified included: deviating from the prescription, skipping a dose, taking a different amount, and taking medication at a different time. Behaviours and drivers can vary by condition, treatment modality, and dosing schedule.This research highlights the variation in the prevalence of medication non-adherence, and the different forms and drivers of non-adherence, based on individuals' demographic and clinical characteristics. The conceptual model developed advances previous models of medication adherence and may support healthcare professionals in the management of patients and how they can be supported to take medication as intended. The research ultimately informed the development of the Adelphi Adherence Questionnaire (ADAQ^©), a novel generic patient-reported outcome measure.

Influenza and pneumococcal vaccination in patients with COPD from 3 French cohorts: Insufficient coverage and associated factors.

BACKGROUND: Low vaccination rates against influenza and Streptococcus (S.) pneumoniae infections in COPD could impair outcomes. Understanding underlying factors could help improving implementation. OBJECTIVES: To describe vaccination rates at inclusion in COPD cohorts and analyze associated factors. METHODS: Between 2012 and 2018, 5927 patients with sufficient data available were recruited in 3 French COPD cohorts (2566 in COLIBRI-COPD, 2653 in PALOMB and 708 in Initiatives BPCO). Data at inclusion were pooled to describe vaccination rates and analyze associated factors. RESULTS: Mean age was 66 years, 34 % were women, 35 % were current smokers, mean FEV1 was 58 % predicted, 22 % reported ≥2 exacerbations in the year prior to inclusion, mMRC dyspnea grade was ≥2 in 59 %, 52 % had cardiovascular comorbidities and 9 % a history of asthma. Vaccinations rates in the year prior to study entry were 34.4 % for influenza + S. pneumoniae, 17.5 % for influenza alone and 8.9 % for S. pneumoniae alone. In multivariate analyses, influenza vaccination rate was greater in older age, smoking status, low FEV1, exacerbation history, mMRC dyspnea>2, asthma history, hypertension, diabetes mellitus, and the year of inclusion. SP vaccination was associated with type of practice of the respiratory physician, age, smoking status, FEV1, exacerbation history, dyspnea grade, asthma history and the year of inclusion. CONCLUSION: Rates of vaccination against influenza and S. pneumoniae infection at inclusion in COPD cohorts remain insufficient and vaccination appears restricted to patients with specific features especially regarding severity and comorbidities, which is not consistent with current recommendations.

Hospitalizations for Chronic Obstructive Pulmonary Disease Exacerbation During COVID-19.

This cross-sectional study investigates changes in the number of chronic obstructive pulmonary disease (COPD)­related admissions before, during, and after the COVID-19 pandemic in France.

Porous activated carbons derived from waste Moroccan pine cones for high-performance adsorption of bisphenol A from water.

Porous-activated carbons (ACs) derived from Moroccan pine cones (PC) were synthesised by a two step-chemical activation/carbonisation method using phosphoric acid (PC-H) and zinc chloride (PC-Z) as activating agents and used for the adsorption of bisphenol A (BPA) from water. Several techniques (TGA/DTA, FT-IR, XRD, SEM and BET) were used to determine the surface area and pore characterisation and variations during the preparation of the adsorbents. The modification significantly increased the surface area of both ACs, resulting in values of 1369.03 m2 g-1 and 1018.86 m2 g-1 for PC-H and PC-Z, respectively. Subsequent adsorption tests were carried out, varying parameters including adsorbent dosage, pH, initial BPA concentration, and contact time. Therefore, the highest adsorption capacity was observed when the BPA molecules were in their neutral form. High pH values were found to be unfavourable for the removal of bisphenol A from water. The results showed that BPA adsorption kinetics and isotherms followed pseudo-second-order and Langmuir models. Thermodynamic studies indicated that the adsorption was spontaneous and endothermic. Besides, the regeneration of spent adsorbents demonstrated their reusability. The adsorption mechanisms can be attributed to physical adsorption, hydrogen bonds, electrostatic forces, hydrophobic interactions, and π-π intermolecular forces.

Relevance of individual bronchial symptoms for asthma diagnosis and control in patients with rhinitis: A MASK-air study.

RATIONALE: It is unclear how each individual asthma symptom is associated with asthma diagnosis or control. OBJECTIVES: To assess the performance of individual asthma symptoms in the identification of patients with asthma and their association with asthma control. METHODS: In this cross-sectional study, we assessed real-world data using the MASK-air® app. We compared the frequency of occurrence of five asthma symptoms (dyspnea, wheezing, chest tightness, fatigue and night symptoms, as assessed by the Control of Allergic Rhinitis and Asthma Test [CARAT] questionnaire) in patients with probable, possible or no current asthma. We calculated the sensitivity, specificity and predictive values of each symptom, and assessed the association between each symptom and asthma control (measured using the e-DASTHMA score). Results were validated in a sample of patients with a physician-established diagnosis of asthma. MEASUREMENT AND MAIN RESULTS: We included 951 patients (2153 CARAT assessments), with 468 having probable asthma, 166 possible asthma and 317 no evidence of asthma. Wheezing displayed the highest specificity (90.5%) and positive predictive value (90.8%). In patients with probable asthma, dyspnea and chest tightness were more strongly associated with asthma control than other symptoms. Dyspnea was the symptom with the highest sensitivity (76.1%) and the one consistently associated with the control of asthma as assessed by e-DASTHMA. Consistent results were observed when assessing patients with a physician-made diagnosis of asthma. CONCLUSIONS: Wheezing and chest tightness were the asthma symptoms with the highest specificity for asthma diagnosis, while dyspnea displayed the highest sensitivity and strongest association with asthma control.

A network meta-analysis of the association between patient traits and response to regular dosing with ICS plus short-acting ß2-agonist reliever or ICS/formoterol reliever only in mild asthma.

INTRODUCTION/BACKGROUND: Mild asthma treatment recommendations include intermittent inhaled corticosteroid (ICS)/formoterol dosing or regular ICS dosing with short-acting ß2-agonist reliever. Due to the heterogeneity of asthma, identification of traits associated with improved outcomes to specific treatments would be clinically beneficial. AIMS/OBJECTIVES: To assess the impact of patient traits on treatment outcomes of regular ICS dosing compared with intermittent ICS/formoterol dosing, a systematic literature review (SLR) and network meta-analysis (NMA) was conducted. Searches identified randomised controlled trials (RCTs) of patients with asthma aged ≥12 years, containing ≥1 regular ICS dosing or intermittent ICS/formoterol dosing treatment arm, reporting traits and outcomes of interest. RESULTS: The SLR identified 11 RCTs of mild asthma, of 14,516 patients. A total of 11 traits and 11 outcomes of interest were identified. Of these, a feasibility assessment indicated possible assessment of three traits (age, baseline lung function, smoking history) and two outcomes (exacerbation rate, change in lung function). The NMA found no significant association of any trait with any outcome with regular ICS dosing relative to intermittent ICS/formoterol dosing. Inconsistent reporting of traits and outcomes between RCTs limited analysis. CONCLUSIONS: This is the first systematic analysis of associations between patient traits and differential treatment outcomes in mild asthma. Although the traits analysed were not found to significantly interact with relative treatment response, inconsistent reporting from the RCTs prevented assessment of some of the most clinically relevant traits and outcomes, such as adherence. More consistent reporting of respiratory RCTs would provide more comparable data and aid future analyses.

[COPD: diagnostic and severity assessment]. / Diagnostic et évaluation de la gravité de la BPCO.

COPD: DIAGNOSTIC AND SEVERITY ASSESSMENT. Chronic obstructive pulmonary disease (COPD) is a frequent and underdiagnosed respiratory disease and a leading cause of morbidity and mortality. It should be suspected in patients aged 40 and over presenting with persistent respiratory symptoms (cough, sputum, shortness of breath, recurrent respiratory tract infections) and a history of exposure to risk factors for the disease (smoking, occupational or domestic exposure to noxious particles). Spirometry is required to confirm the diagnosis of COPD, showing persistent airflow limitation with a post-bronchodilator FEV1/FCV inférieur 0.7. COPD assessment includes: classification of airflow limitation severity with post-bronchodilator FEV1 measurement (GOLD score from 1 to 4), clinical severity assessment (intensity of dyspnea, number and severity of acute exacerbations, impaired quality of life) and evaluation of associated complications (chronic respiratory failure, hypercapnia, pulmonary hypertension). Comorbidities are frequent and should be carefully sought: lung cancer, cardiovascular diseases, metabolic syndrome, skeletal muscle dysfunction, sleep apnea syndrome, osteoporosis, anxiety and depression.

Next-Gen GWAS: full 2D epistatic interaction maps retrieve part of missing heritability and improve phenotypic prediction.

The problem of missing heritability requires the consideration of genetic interactions among different loci, called epistasis. Current GWAS statistical models require years to assess the entire combinatorial epistatic space for a single phenotype. We propose Next-Gen GWAS (NGG) that evaluates over 60 billion single nucleotide polymorphism combinatorial first-order interactions within hours. We apply NGG to Arabidopsis thaliana providing two-dimensional epistatic maps at gene resolution. We demonstrate on several phenotypes that a large proportion of the missing heritability can be retrieved, that it indeed lies in epistatic interactions, and that it can be used to improve phenotype prediction.

Prevalence and disparities in influenza vaccination among patients with COPD: A French nationwide population study.

INTRODUCTION: Despite concordant international recommendations, many surveys found disappointing rates of influenza vaccination in at-risk populations, ranging from 23% in overall COPD population to more than 70% in more severe COPD subjects. Therefore, we assessed the proportion of French COPD patients non-vaccinated for influenza and their clinical and socio-demographic factors. MATERIEL AND METHODS: This was a national retrospective study based on the French health insurance database. We identified "diagnosed COPD", defined as subjects hospitalized at least once in 2017 with a principal or associated diagnosis of COPD, and "suspected COPD" as those who were prescribed at least thrice long-acting bronchodilators (LAB), after exclusion of patients with a principal diagnosis or secondary associated diagnosis of asthma or cystic fibrosis, patients deceased before the influenza season and patients hospitalized in long-term or in palliative care unit. Multivariate logistic regression was used to assess the association between patients' characteristics and the lack of influenza vaccination. RESULTS: From the national database, 1 474 396 subjects were identified as "suspected COPD" of whom 528 114 were excluded because of previous diagnosis of asthma or cystic fibrosis, and 350 566 as "diagnosed COPD". Among the 1 296 848 patients included, 646 687 patients (53.3%) were vaccinated against influenza. Non-vaccinated subjects were significantly younger (62.1 vs 71.6 years old), more often women (47.9% vs 43.1%) and had fewer comorbidities assessed by Charlson's index (3.0 ± 2.2 vs 4.3 ± 2.1). Lack of vaccination was also associated with a lower LAB usage. Also, non-vaccinated subjects neither had severe exacerbation during the study period. Besides there was a significant heterogeneity in vaccination rate by geographic region, from 47% to 57%. In multivariate analysis, variables independently associated with the lack of influenza vaccination were female gender, younger age, fewer comorbidities and lower socio-economic level. CONCLUSIONS: This study using the French exhaustive health insurance database shows that influenza vaccination among COPD patients remains dramatically low and must become a high-priority public-health strategy.

[PAL-PRAT study: Healthcare workers' knowledge and perception of palliative practices in a Cancer Center]. / Quelle connaissance et quelle perception ont les professionnels de santé d'un Centre de lutte contre le cancer à propos des pratiques palliatives encadrées par la loi Claeys-Leonetti : étude PAL PRAT.

INTRODUCTION: The issue of end-of-life care is the subject of a sensitive debate in French society, particularly regarding the possibility for certain patients to have access to medical assistance in dying. The aim of this study was to assess the knowledge and opinion of healthcare providers on the care practices for patients at the end of life, as well as to highlight any specificities in their discourse. METHOD: A survey of healthcare providers' opinions, composed of closed and open questions, that were analyzed using a lexicometric approach, was distributed in a cancer center. RESULTS: The results of the study reveal a good knowledge of the different procedures. Professionals considered that advance directives should be systematically collected; a majority of them differentiated euthanasia from deep continuous sedation and perceived the latter as a means of relieving patients' suffering without inducing death. The different procedures related to the active assistance in dying were known by a majority of professionals and the survey did not identify a dominant trend concerning the will to practice euthanasia if the legal framework allowed it. Half of the participants considered their training insufficient, indicating the need to fill this gap. DISCUSSION: This survey underlines the importance of training and support for the professionals caring for patients in palliative situation and their relatives in France.

Chronic occupational exposures to irritants and asthma in the CONSTANCES cohort.

OBJECTIVES: The impact of chronic occupational exposures to irritants on asthma remains discussed. We studied the associations between occupational exposures and asthma, with specific interest for chronic exposure to irritants, including disinfectants and cleaning products (DCPs) and solvents. METHODS: Cross-sectional analyses included 115 540 adults (55% women, mean age 43 years, 10% current asthma) working at inclusion in the French population-based CONSTANCES cohort (2012-2020). Current asthma was defined by ever asthma with symptoms, medication or asthma attacks (past 12 months), and the asthma symptom score by the sum of 5 respiratory symptoms (past 12 months). Both lifetime and current occupational exposures were assessed by the Occupational Asthma-specific Job-Exposure Matrix. Associations were evaluated by gender using logistic and binomial negative regressions adjusted for age, smoking status and body mass index. RESULTS: In women, associations were observed between current asthma and lifetime exposure to irritants (OR 1.05, 95% CI 1.00 to 1.11), DCPs (1.06, 95% CI 1.00 to 1.12) and solvents (1.06, 95% CI 0.98 to 1.14). In men, only lifetime exposure to DCPs (1.10, 95% CI 1.01 to 1.20) was associated with current asthma. Lifetime exposure to irritants was associated with higher asthma symptom score both in women (mean score ratio: 1.08, 95% CI 1.05 to 1.11) and men (1.11, 95% CI 1.07 to 1.15), especially for DCPs (women: 1.09, 95% CI 1.06 to 1.13, men: 1.21, 95% CI 1.15 to 1.27) and solvents (women 1.14, 95% CI 1.10 to 1.19, men: 1.10, 95% CI 1.05 to 1.15). For current exposures, no consistent associations were observed with current asthma and asthma symptom score. CONCLUSIONS: Lifetime occupational exposures to irritants were associated with current asthma and higher asthma symptom score. These exposures should be carefully considered in asthma management.

Adsorption of anti-inflammatory and analgesic drugs traces in water on clay minerals.

The aim of this study was to assess the adsorption of four non-steroidal anti-inflammatory drugs (NSAIDs), namely Paracetamol (PRC), Diclofenac (DIC), Ibuprofen (IBU), and Ketoprofen (KET), using both batch and continuous experiments with clay. Various analytical techniques, including XRD, FTIR, SEM coupled to EDX, and Zeta potential, were employed to characterize both raw and calcined clay. XRD and FTIR analyses confirmed the kaolinite nature of the clay. SEM data revealed a lamellar structure formed in the clay after calcination at 550 °C. Adsorption tests were conducted to determine the optimal adsorption conditions. Batch kinetics of adsorption demonstrated rapid adsorption of all four NSAIDs, with the highest adsorption occurring at pH 4 (DIC, IBU, and KET) and pH 6 for PRC, using a concentration of 20 mg L-1 of calcined clay. Additionally, the pseudo-second-order model provided the best fit for all NSAIDs adsorption processes. Maximum adsorption capacities, as determined by the Langmuir model, were 80 mg g-1 for PRC, 238 mg -1g for DIC, 138 mg g-1 for IBU, and 245 mg g-1 for KET. In fixed bed column studies, three dynamic models (Thomas, Adams-Bohart, and Yoon-Nelson) were utilized to describe the breakthrough curves, with linear regression used to identify key characteristics for process design. The fixed bed column adsorption study revealed that DIC exhibited the highest removal efficiency at 98%, while KET, IBU, and PRC were more persistent, with removal efficiencies of 77.1%, 76.7%, and 67.1%, respectively. The Thomas model was deemed appropriate for describing the breakthrough curve. These findings offer valuable insights into the interactions between clay and pharmaceuticals with varying physicochemical properties. They also provide information on the adsorption models, saturation, and adsorption capacities of various pharmaceuticals on natural clays, which can be crucial for further research and environmental remediation efforts.

Risk of Pneumonia in Patients with COPD Initiating Fixed Dose Inhaled Corticosteroid (ICS) / Long-Acting Bronchodilator (LABD) Formulations Containing Extrafine Beclometasone Dipropionate versus Patients Initiating LABD Without ICS.

Background: Combined ICS and long-acting bronchodilators (LABD) more effectively reduce COPD exacerbations than LABD therapy alone. Corticosteroid-related adverse effects, including pneumonia, limit ICS use. Previous data suggest this risk is lower for extrafine beclometasone (ef-BDP). We compared pneumonia risk among new users of fixed dose ICS/LABD formulations containing ef-BDP, versus patients initiating LABD without any ICS. Methods: A propensity-matched historical cohort study design used data from OPCRD. COPD patients with ≥1 year of continuous data who initiated LABD or ICS/LABD formulations containing ef-BDP were matched. Primary outcome was time to pneumonia event, as treated, using either sensitive (physician diagnosed) or specific (physician diagnosed and x-ray or hospital admission confirmed) definitions, with non-inferiority boundary of 15%. Results: 23,898 COPD patients were matched, who were 68±11 years, 54.3% male and 56% current-smokers, while 43% were former-smokers. Initiation of ef-BDP/LABD was not associated with an increased risk of pneumonia versus LABD, for either a sensitive 0.89 (0.78-1.02), P = 0.08 or a specific 0.91 (0.78-1.05), P = 0.18 definition of pneumonia. The probability of remaining pneumonia free 1-year after ef-BDP/LABD was 98.4%, which was comparable to LABD at 97.7%, and was sustained up to 6 years of observation; non-inferiority criterion was met for both definitions. Initiation of ef-BDP/LABD was also associated with a reduced risk of developing LRTIs in the propensity matched cohort. Conclusion: Risk of pneumonia when using ICS for the management of COPD reported in several randomised controlled trials may not be relevant with ef-BDP in a diverse real-world clinical population.

Criterion validity of the spatial exploration test of upper limb mobility to evaluate the active horizontal workspace of children with spinal muscular atrophy.

PURPOSE: To determine the criterion validity of the SET-ULM (Spatial Exploration Test of Upper Limb Mobility), a functional workspace test. MATERIALS AND METHODS: A prospective study from July 2017 to November 2018 in 30 children with SMA type 1 or 2. All children underwent assessment with the SET-ULM and the Motor Function Measure (MFM). RESULTS: We included 30 children. Median (Q1; Q3) MFM D1 (standing ability, ambulation and transfers), D2 (axial and proximal motor function), D3 (distal motor function) scores, Total MFM and Total SET-ULM active score were respectively 2.6% (2.6-3.8); 45.8% (19.9-65.3); 57.7% (36.9-80.9); 35.4% (16.7-43.2) and 70.2% (49.7-97.9). Total SET-ULM active score was strongly correlated with the MFM D2 dimension score (rho 0.82; p < 001), with the D3 dimension (rho 0.86; p < 0.001) and with the Total MFM score (rho 0.89; p < 0.005). Total SET-ULM active score differed between SMA types (p < 0.01). CONCLUSION: The SET-ULM has good criterion validity for the evaluation of available horizontal active upper limb workspace in children with SMA1 and SMA2. Future studies should evaluate reliability and sensitivity to change during a longitudinal follow-up study, as well as in a longitudinal trial of therapeutic effectiveness. CLINICAL TRIALS: NCT03223051IMPLICATIONS FOR REHABILITATIONThe Spatial Exploration Test for Upper Limb Mobility is a useful adjunct to the Motor Function Measure.It provides a precise evaluation of horizontal reaching ability.The Spatial Exploration Test for Upper Limb Mobility will be of great clinical utility for the evaluation of the effects of treatments for spinal muscular atrophy.