Use of MFM-20 to monitor SMA types 1 and 2 patients treated with nusinersen.

OBJECTIVE: To evaluate sensitivity to change and discriminant validity of the 20-item Motor Function Measure (MFM-20) in 2-7-year-old patients with spinal muscular atrophy types 1 (SMA1) or 2 (SMA2) treated with nusinersen. METHODS: Children aged 2 to 7 years old with SMA1 or SMA2 treated with nusinersen were assessed at least three times using the MFM-20 over an average follow-up time of 17 months. Evolution of 4-month-standardized MFM-20 scores was calculated for each MFM-20 domain (D1 standing and transfers, D2 axial and proximal, D3 distal) and for the total score (TS). RESULTS: Included in the study were 22 SMA1 subjects and 19 SMA2 subjects. Baseline MFM scores were significantly lower in patients with SMA1 than SMA2 (TS 29.5% vs. 48.3%, D1 4.5% vs. 10.6%, D2 43.6% vs. 72.6%, D3 51.2% vs. 75.0%). When considering the mean change during nusinersen treatment, standardized over a 4-month period, TS was improved for both SMA1 (+ 4.1%, SRM 1.5) and SMA2 (+ 2.8%, SRM 0.89) patients. For SMA1 patients, considerable changes were observed in D2 (+ 6.2%, SRM 0.89) and D3 (+ 6.0%, SRM 0.72), whereas the change in D1 was small (+ 0.5%, SRM 0.44). In SMA2 2 subjects, D3 was improved to a larger extent (+ 4.2%, SRM 0.53) than D1 (+ 1.8% SRM 0.63) or D2 (+ 3.2%, SRM 0.69). CONCLUSION: Our results validate use of MFM-20 to monitor function of young SMA1 and SMA2 subjects treated with nusinersen. Significant motor function improvements following treatment were observed in both SMA1 and SMA2 patients.

Scoring People With Spinal Muscular Atrophy on the Motor Function Measure Using the Microsoft Kinect.

PURPOSE: Assess the ability of the Kinect to capture movement and posture of people with spinal muscular atrophy (SMA) during completion of 14 items of the Motor Function Measure, a validated functional rating scale for people with neuromuscular diseases. METHODS: Multicenter feasibility study in which Motor Function Measure items were scored as usual by the participant's therapist during the completion (Score-T) while another therapist scored items based only on the visualization of digital data collected using the Kinect (Score-D). Agreement and disagreement were investigated. RESULTS: Twenty people with SMA type 2 or 3 were participants; 142 items were recorded and analyzed. There was 31.7% agreement between Score-T and Score-D for participants with SMA type 2, and 76.2% for those with SMA type 3. CONCLUSIONS: The results prevent us from considering the use of Kinect capture to deduce an automated scoring, but this device may be of interest to highlight potential compensations.

Determining the Interrater Reliability of the SOFMER Activity Score (version 2) for Individuals in Rehabilitation Centers.

OBJECTIVE: To assess the interrater reliability of the SOFMER Activity Score (SAS) (version 2 [v2], an 8-item [4 motor and 4 cognitive] and 5-level scale) and improve its scoring system before conducting further validation steps. DESIGN: Cross-sectional, prospective, observational, noninterventional, and multicentric study. SETTING: The study was conducted between November 2018 and September 2019 in 4 French rehabilitation centers (2 public university hospitals for adults and 2 private not-for-profit rehabilitation centers for children). PARTICIPANTS: The study included 101 participants (N=101; mean age, 44.5±25.4 years; 28.7% younger than 18 and 18.8% older than 65 years). The female/male sex ratio was 0.6. The causes for admission to the center were mainly neurologic (65%) or orthopedic (24%). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Activity limitation was rated with the SAS the same day by 2 independent multidisciplinary teams. The interrater reliabilities of the score items were assessed using weighted kappa coefficients. RESULTS: All weighted kappa coefficients ranged between 0.83 and 0.92, indicating "good" to "excellent" interrater reliability. Interteam score disagreements occurred in 227 of 808 scores (28%). The reason for most disagreements was unnoticed human or material aid during the observation period. CONCLUSIONS: The results demonstrate the high interrater reliability of the SASv2 and allow carrying out further validation steps after minor changes to item scoring instructions and clearer definitions of some items that help improving scoring standardization. The SASv2 may then become a consistent measure of activity level for clinical research or burden of care investigations.

Responsiveness and Minimal Clinically Important Difference of the Motor Function Measure in Collagen VI-Related Dystrophies and Laminin Alpha2-Related Muscular Dystrophy.

OBJECTIVES: To investigate the responsiveness of the motor function measure (MFM) and determine the minimal clinically important difference (MCID) in individuals with 2 common types of congenital muscular dystrophy (CMD). DESIGN: Observational, prospective, single center, cohort study. SETTING: National Institute of Neurological Disorders and Stroke (NINDS) of the National Institutes of Health (NIH). PARTICIPANTS: Individuals (N=44) with collagen VI-related dystrophies (COL6-RD, n=23) and 21 individuals laminin alpha2-related muscular dystrophy (LAMA2-RD, n=21) enrolled in a 4-year longitudinal natural history study. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Responsiveness of the MFM-32 and the Rasch-scaled MFM-25 and the MCID of the MFM-32 determined from a patient-reported anchor with 2 different methods, within-patient and between-patient. RESULTS: The original MFM-32 and Rasch-scaled MFM-25 performed similarly overall in both the COL6-RD and LAMA2-RD populations, with all subscores (D1, standing and transfers; D2, axial and proximal; D3, distal) showing a significant decrease over time, except MFM D1 and D3 for LAMA2-RD. The MFM D1 subscore was the most sensitive to change for ambulant individuals, whereas the MFM D2 subscore was the most sensitive to change for nonambulant individuals. The MCID for the MFM-32 total score was calculated as 2.5 and 3.9 percentage points according to 2 different methods. CONCLUSIONS: The MFM showed strong responsiveness in individuals with LAMA2-RD and COL6-RD. Because a floor effect was identified more prominently with the Rasch-Scaled MFM-25, the use of the original MFM-32 as a quantitative variable with the assumption of scale linearity appears to be a good compromise. When designing clinical trials in congenital muscular dystrophies, the use of MCID for MFM should be considered to determine if a given intervention effects show not only a statistically significant change but also a clinically meaningful change.

Corticosteroids in Duchenne muscular dystrophy: impact on the motor function measure sensitivity to change and implications for clinical trials.

AIM: To monitor the evolution of the motor function of ambulatory patients with Duchenne muscular dystrophy (DMD) treated by corticosteroids for 2 years in comparison with untreated patients. METHOD: This observational, multicentre cohort study explores the evolution of the motor function measure (MFM) over a 24-month period for 29 ambulant corticosteroids-treated and 45 ambulant untreated patients with DMD. RESULTS: Significant differences were found between mean MFM scores in corticosteroids-treated and untreated groups for domain 1 of the MFM (standing position and transfers; D1), domain 2 of the MFM (axial and proximal motor function; D2), and domain 3 of the MFM (distal motor function; D3). Subscores were between 0 months and 6 months, and 0 months and 24 months. For the D1 subscore specifically, there was a significant increase in the corticosteroids-treated group (mean±standard deviation [SD] slope of change=12.6±15.5%/y), while a decrease was observed in the untreated group (-17.8±17.7%/y) between 0 months and 6 months (p<0.001). Sensitivity to change as assessed by standardized response means was high between 12 months and 24 months for D1 of both corticosteroids-treated and untreated groups (1.0 and 1.2 respectively), and low for D2 and D3 of both treated and untreated groups. INTERPRETATION: Patients with DMD treated by corticosteroids present a different course of the disease as assessed by MFM, confirming the sensitivity to change of the MFM in this population. WHAT THIS PAPER ADDS: Corticosteroids have a quantitative impact on muscle strength 6 to 24 months after starting treatment. Motor function measure is a valid outcome measure in Duchenne muscular dystrophy patients under corticosteroid treatment.

Is Going Beyond Rasch Analysis Necessary to Assess the Construct Validity of a Motor Function Scale?

OBJECTIVE: To examine whether a Rasch analysis is sufficient to establish the construct validity of the Motor Function Measure (MFM) and discuss whether weighting the MFM item scores would improve the MFM construct validity. DESIGN: Observational cross-sectional multicenter study. SETTING: Twenty-three physical medicine departments, neurology departments, or reference centers for neuromuscular diseases. PARTICIPANTS: Patients (N=911) aged 6 to 60 years with Charcot-Marie-Tooth disease (CMT), facioscapulohumeral dystrophy (FSHD), or myotonic dystrophy type 1 (DM1). INTERVENTIONS: None. MAIN OUTCOME MEASURE(S): Comparison of the goodness-of-fit of the confirmatory factor analysis (CFA) model vs that of a modified multidimensional Rasch model on MFM item scores in each considered disease. RESULTS: The CFA model showed good fit to the data and significantly better goodness of fit than the modified multidimensional Rasch model regardless of the disease (P<.001). Statistically significant differences in item standardized factor loadings were found between DM1, CMT, and FSHD in only 6 of 32 items (items 6, 27, 2, 7, 9 and 17). CONCLUSIONS: For multidimensional scales designed to measure patient abilities in various diseases, a Rasch analysis might not be the most convenient, whereas a CFA is able to establish the scale construct validity and provide weights to adapt the item scores to a specific disease.

English cross-cultural translation and validation of the neuromuscular score: a system for motor function classification in patients with neuromuscular diseases.

OBJECTIVE: To develop and validate an English version of the Neuromuscular (NM)-Score, a classification for patients with NM diseases in each of the 3 motor function domains: D1, standing and transfers; D2, axial and proximal motor function; and D3, distal motor function. DESIGN: Validation survey. SETTING: Patients seen at a medical research center between June and September 2013. PARTICIPANTS: Consecutive patients (N=42) aged 5 to 19 years with a confirmed or suspected diagnosis of congenital muscular dystrophy. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: An English version of the NM-Score was developed by a 9-person expert panel that assessed its content validity and semantic equivalence. Its concurrent validity was tested against criterion standards (Brooke Scale, Motor Function Measure [MFM], activity limitations for patients with upper and/or lower limb impairments [ACTIVLIM], Jebsen Test, and myometry measurements). Informant agreement between patient/caregiver (P/C)-reported and medical doctor (MD)-reported NM scores was measured by weighted kappa. RESULTS: Significant correlation coefficients were found between NM scores and criterion standards. The highest correlations were found between NM-score D1 and MFM score D1 (ρ=-.944, P<.0001), ACTIVLIM (ρ=-.895, P<.0001), and hip abduction strength by myometry (ρ=-.811, P<.0001). Informant agreement between P/C-reported and MD-reported NM scores was high for D1 (κ=.801; 95% confidence interval [CI], .701-.914) but moderate for D2 (κ=.592; 95% CI, .412-.773) and D3 (κ=.485; 95% CI, .290-.680). Correlation coefficients between the NM scores and the criterion standards did not significantly differ between P/C-reported and MD-reported NM scores. CONCLUSIONS: Patients and physicians completed the English NM-Score easily and accurately. The English version is a reliable and valid instrument that can be used in clinical practice and research to describe the functional abilities of patients with NM diseases.

Rasch analysis of the motor function measure in patients with congenital muscle dystrophy and congenital myopathy.

OBJECTIVES: To monitor treatment effects in patients with congenital myopathies and congenital muscular dystrophies, valid outcome measures are necessary. The Motor Function Measure (MFM) was examined for robustness, and changes are proposed for better adequacy. DESIGN: Observational study based on data previously collected from several cohorts. SETTING: Nineteen departments of physical medicine or neuromuscular consultation in France, Belgium, and the United States. PARTICIPANTS: Patients (N=289) aged 5 to 77 years. INTERVENTIONS: None. MAIN OUTCOME MEASURES: A Rasch analysis examined the robustness of the MFM across the disease spectrum. The 3 domains of the scale (standing position and transfers, axial and proximal motor function, and distal motor function) were independently examined with a partial credit model. RESULTS: The original 32-item MFM did not sufficiently fit the Rasch model expectations in either of its domains. Switching from a 4- to a 3-category response scale in 18 items restored response order in 16. Various additional checks suggested the removal of 7 items. The resulting Rasch-scaled Motor Function Measure with 25 items for congenital disorders of the muscle (Rs-MFM25(CDM)) demonstrated a good fit to the Rasch model. Domain 1 was well targeted to the whole severity spectrum-close mean locations for items and persons (0 vs 0.316)-whereas domains 2 and 3 were better targeted to severe cases. The reliability coefficients of the Rs-MFM25(CDM) suggested sufficient ability for each summed score to distinguish between patient groups (0.9, 0.8, and 0.7 for domains 1, 2, and 3, respectively). A sufficient agreement was found between results of the Rasch analysis and physical therapists' opinions. CONCLUSIONS: The Rs-MFM25(CDM) can be considered a clinically relevant linear scale in each of its 3 domains and may be soon reliably used for assessment in congenital disorders of the muscle.

Motor function measure: validation of a short form for young children with neuromuscular diseases.

OBJECTIVE: To validate a useful version of the Motor Function Measure (MFM) in children with neuromuscular diseases aged <7 years old. DESIGN: Two prospective cohort studies that documented the MFM completion of children aged between 2 and 7 years old. SETTING: French-speaking rehabilitation departments from France, Belgium, and Switzerland. PARTICIPANTS: Healthy children (n=194) and children with a neuromuscular disease (n=88). INTERVENTIONS: Patients were rated by the MFM either once or twice by trained medical professionals, with a delay between the 2 MFMs ranging between 8 and 30 days. MAIN OUTCOME MEASURE: Intra- and interrater reliability of the MFM. RESULTS: The subtests making up the MFM-32, a scale monitoring severity and progression of motor function in patients with a neuromuscular disease in 3 functional domains, were carried out in healthy children aged 2 to 7 years. Twenty items of the MFM-32 were successfully completed by these children and were used to constitute the MFM-20. Principal component analysis of the MFM-20 confirmed the 3 functional domains. Inter- and intrarater reliability of the 3 subscores and total score were high (intraclass correlation coefficient >.90), and discriminant validity was good. CONCLUSIONS: The MFM-20 can be used as an outcome measure for assessment of motor function in young children with neuromuscular disease.

Psychometric Characteristics of the Motor Function Measure in Neuromuscular Diseases: A Systematic Review1.

BACKGROUND: Recent pharmaceutical breakthroughs in neuromuscular diseases may considerably change the prognosis and natural history these diseases. The ability to measure clinically relevant outcomes such as motor function is critical for the assessment of therapeutics and the follow up of individuals. The Motor Function Measure (MFM) is a quantitative scale designed to measure motor function in adult and children with neuromuscular disease (NMD). OBJECTIVE: The objective of this study is to assess the quality and level of evidence of the MFM's published measurement properties by completing a systematic review of the validation and responsiveness studies of the MFM20 (a 20-item version of MFM adapted for children 2 to 6 years of age) and the MFM32 (the original 32 item version), in all NMDs and in specific diseases. METHODS: A search for MFM responsiveness and MFM validation studies was completed in February 2023 in EMBASE, MEDLINE, SCOPUS and Web of Science databases. The PRISMA guidelines and the COSMIN manual for systematic reviews were followed for databases searches, articles screening and selection, study quality and measurement properties evaluation. RESULTS: 49 studies were included in analysis. In studies including individuals with all NMDs, MFM's internal consistency, reliability, convergent validity, construct validity and responsiveness were rated as sufficient with a high quality of evidence. Structural validity was rated sufficient with a moderate quality of evidence In SMA in particular, MFM's reliability, internal consistency, convergent validity, discriminant validity and responsiveness are sufficient with a high quality of evidence. More studies would be required to assess specific measurement properties in different diseases. MFM32's minimal clinically relevant difference has been defined between 2 and 6%. CONCLUSION: MFM's structural validity, internal consistency, reliability, construct validity, convergent validity and responsiveness have been verified with moderate to high level of evidence.

Implementation of Motor Function Measure score percentile curves - Predicting motor function loss in Duchenne muscular dystrophy.

The Motor Function Measure is a standardized scoring system to evaluate motor function and monitor disease progression in neuromuscular diseases such as Duchenne muscular dystrophy. There are no available reference percentile curves for this measure. The aim of this analysis was to generate Motor Function Measure percentile curves for ambulant and non-ambulant patients affected by Duchenne Muscular Dystrophy, providing the opportunity to better evaluate the status and progression of an individual patient compared to other patients in the same age group. Data of patients aged between 6 and 15 years (819 measurements) was obtained from the international Motor Function Measure database. Age-dependent percentile curves were estimated using a "Generalized additive model for location, scale and shape" as suggested by the World Health Organisation Multicentre Growth Reference Study Group. Percentile curves for the Motor Function Measure total score and its sub-scores for patients with and without treatment with glucocorticoids are presented. Mean scores decline with age. Patients treated with glucocorticoids have higher mean values compared to glucocorticoid-naïve patients at the same age. The percentile curves with the online tool extend the clinical utility of the Motor Function Measure by facilitating the interpretation of individual standing and disease progression.

Detection of ISUP ≥2 prostate cancers using multiparametric MRI: prospective multicentre assessment of the non-inferiority of an artificial intelligence system as compared to the PI-RADS V.2.1 score (CHANGE study).

INTRODUCTION: Prostate multiparametric MRI (mpMRI) has shown good sensitivity in detecting cancers with an International Society of Urological Pathology (ISUP) grade of ≥2. However, it lacks specificity, and its inter-reader reproducibility remains moderate. Biomarkers, such as the Prostate Health Index (PHI), may help select patients for prostate biopsy. Computer-aided diagnosis/detection (CAD) systems may also improve mpMRI interpretation. Different prototypes of CAD systems are currently developed under the Recherche Hospitalo-Universitaire en Santé / Personalized Focused Ultrasound Surgery of Localized Prostate Cancer (RHU PERFUSE) research programme, tackling challenging issues such as robustness across imaging protocols and magnetic resonance (MR) vendors, and ability to characterise cancer aggressiveness. The study primary objective is to evaluate the non-inferiority of the area under the receiver operating characteristic curve of the final CAD system as compared with the Prostate Imaging-Reporting and Data System V.2.1 (PI-RADS V.2.1) in predicting the presence of ISUP ≥2 prostate cancer in patients undergoing prostate biopsy. METHODS: This prospective, multicentre, non-inferiority trial will include 420 men with suspected prostate cancer, a prostate-specific antigen level of ≤30 ng/mL and a clinical stage ≤T2 c. Included men will undergo prostate mpMRI that will be interpreted using the PI-RADS V.2.1 score. Then, they will undergo systematic and targeted biopsy. PHI will be assessed before biopsy. At the end of patient inclusion, MR images will be assessed by the final version of the CAD system developed under the RHU PERFUSE programme. Key secondary outcomes include the prediction of ISUP grade ≥2 prostate cancer during a 3-year follow-up, and the number of biopsy procedures saved and ISUP grade ≥2 cancers missed by several diagnostic pathways combining PHI and MRI findings. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Comité de Protection des Personnes Nord Ouest III (ID-RCB: 2020-A02785-34). After publication of the results, access to MR images will be possible for testing other CAD systems. TRIAL REGISTRATION NUMBER: NCT04732156.

Impact of a multifaceted program to prevent postoperative delirium in the elderly: the CONFUCIUS stepped wedge protocol.

BACKGROUND: Postoperative delirium is common in the elderly and is associated with a significant increase in mortality, complications, length of hospital stay and admission in long care facility. Although several interventions have proved their effectiveness to prevent it, the Cochrane advises an assessment of multifaceted intervention using rigorous methodology based on randomized study design. Our purpose is to present the methodology and expected results of the CONFUCIUS trial, which aims to measure the impact of a multifaceted program on the prevention of postoperative delirium in elderly. METHOD/DESIGN: Study design is a stepped wedge cluster randomized trial within 3 surgical wards of three French university hospitals. All patients aged 75 and older, and admitted for scheduled surgery will be included. The multifaceted program will be conducted by mobile geriatric team, including geriatric preoperative consultation, training of the surgical staff and implementation of the Hospital Elder Life Program, and morbidity and mortality conference related to delirium cases. The primary outcome is based on postoperative delirium rate within 7 days after surgery. This program is planned to be implemented along four successive time periods within all the surgical wards. Each one will be affected successively to the control arm and to the intervention arm of the trial and the order of program introduction within each surgical ward will be randomly assigned. Based on a 20% reduction of postoperative delirium rate (ICC = 0.25, α = 0.05, ß = 0.1), three hundred sixty patients will be included i.e. thirty patients per service and per time period. Endpoints comparison between intervention and control arms of the trial will be performed by considering the cluster and time effects. DISCUSSION: Better prevention of delirium is expected from the multifaceted program, including a decrease of postoperative delirium, and its consequences (mortality, morbidity, postoperative complications and length of hospital stay) among elderly patients. This study should allow better diagnosis of delirium and strengthen the collaboration between surgical and mobile geriatric teams. Should the program have a substantial impact on the prevention of postoperative delirium in elderly, it could be extended to other facilities. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01316965.

Additional validation study and French cross-cultural adaptation of the Pediatric Stroke Outcome Measure-Summary of Impressions (PSOM-SOI).

BACKGROUND: The Pediatric Stroke Outcome Measure-Summary of Impressions (PSOM-SOI) measures neurological function across right and left sensorimotor domains (Item A), language production (Item B), language comprehension (Item C), and cognition/behaviour (Item D). OBJECTIVE: This study was a cross-cultural adaptation into French of the PSOM-SOI and an assessment of its reliability and limitations of use. MATERIAL AND METHODS: The translation and adaptation of the PSOM-SOI was followed by the assessment of its reliability in a cohort of 69 children with diagnosed acute neonatal arterial ischemic stroke. Three independent raters retrospectively scored the PSOM-SOI based on data from in-person neurological examination and results of standardized tests performed at age 7 in the cohort database. Comparison 1 (C1) involved a less experienced rater and an experienced rater and comparison 2 (C2) involved 2 experienced raters. Inter-rater reliability (IRR) was measured with Kappa coefficients. RESULTS: The cross-cultural adaptation was easily performed, and no rater had difficulties using the French PSOM-SOI. The IRR was better in C1 than C2. For Item A, the agreement in C1 (κ=0.47) and C2 (κ=0.44) was moderate. The C1 agreement was substantial for Items B (κ=0.71) and C (κ=0.70); the C2 agreement was fair for Item B (κ=0.23) and slight for Item C (κ=0.16). For Item D, the agreement was moderate in C1 (κ=0.52) and fair in C2 (κ=0.35). In all but one comparison, agreement or minor disagreement (≤0.5 points) was obtained for more than 90% of the item scores. Regarding the total score, agreement for normal function (≤0.5) versus abnormal function (>0.5) was achieved for 90% in C1 and 67% in C2. CONCLUSION: The IRR of the French PSOM-SOI gave variable results depending on the item and rater's experience, but the extent of disagreements was minor for individual items and total score. Additional prospective validation studies using the French PSOM-Short Neurological Exam to score the PSOM-SOI are needed. A dichotomised total score (cut-off≤0.5) could be used to define normal function versus poor outcome.

Development and Validation of a Predictive Model of Hypovitaminosis D in General Adult Population: SCOPYD Study.

The worldwide global increase in serum 25-hydroxyvitamin D (25(OH)D) measurements has led some countries to restrict reimbursement for certain clinical situations only. Another approach could consist in providing physicians with screening tools in order to better target blood test prescription. The objective of the SCOPYD study was to identify the best combination of predictors of serum VitD concentration among adults aged 18-70 years. Potential risk factors for VitD deficiency were collected using a comprehensive self-administered questionnaire. A multivariable linear regression was used to build a predictive model of serum 25(OH)D concentration. Among 2488 participants, 1080 (43.4%) had VitD deficiency (<50 nmol/L) and 195 (7.8%) had severe deficiency (<25 nmol/L). The final model included sunlight exposure in the preceding week and during the last holidays, month of blood sampling, age, sex, body mass index, skin phototype, employment, smoking, sport practice, latitude, and VitD supplementation in preceding year. The area under the curve was 0.82 (95% CI (0.78; 0.85)) for severe deficiency. The model predicted severe deficiency with a sensitivity of 77.9% (95% CI (69.1; 85.7)) and a specificity of 68.3% (95% CI (64.8; 71.9)). We identified a set of predictors of severe VitD deficiency that are easy to collect in routine that may help to better target patients for serum 25(OH)D concentration determination.

Biochemical characterization and crystal structure of Synechocystis arogenate dehydrogenase provide insights into catalytic reaction.

The extreme diversity in substrate specificity, and in the regulation mechanism of arogenate/prephenate dehydrogenase enzymes in nature, makes a comparative structural study of these enzymes of great interest. We report here on the biochemical and structural characterization of arogenate dehydrogenase from Synechocystis sp. (TyrAsy). This work paves the way for the understanding of the structural determinants leading to diversity in substrate specificity, and of the regulation mechanisms of arogenate/prephenate dehydrogenases. The overall structure of TyrAsy in complex with NADP was refined to 1.6 A. The asymmetric unit contains two TyrAsy homodimers, with each monomer consisting of a nucleotide binding N-terminal domain and a particularly unique alpha-helical C-terminal dimerization domain. The substrate arogenate was modeled into the active site. The model of the ternary complex enzyme-NADP-arogenate nicely reveals at the atomic level the concerted mechanism of the arogenate/prephenate dehydrogenase reaction.

Use and tolerability of a side pole static ankle foot orthosis in children with neurological disorders.

BACKGROUND: Transverse-plane foot deformities are a frequently encountered issue in children with neurological disorders. They are the source of many symptoms, such as pain and walking difficulties, making their prevention very important. OBJECTIVES: We aim to describe the use and tolerability of a side pole static ankle foot orthosis used to prevent transverse-plane foot deformities in children with neurologic disorders. STUDY DESIGN: Monocentric, retrospective, observational study. METHODS: Medical data were collected from 103 children with transverse-plane foot deformities in one or both feet caused by a neurological impairment. All children were braced between 2001 and 2010. RESULTS: Unilateral orthosis was prescribed for 32 children and bilateral orthosis for 71. Transverse-plane foot deformities were varus in 66% of the cases and an equinus was associated in 59.2% of the cases. Mean age for the first prescription was 8.6 years. For the 23 patients present at the 4-year visit, 84.8% still wore the orthosis daily, and 64.7% wore the orthosis more than 6 h per day. The rate of permanent discontinuation of wearing the orthosis was 14.7%. CONCLUSION: The side pole static ankle foot orthosis is well tolerated with very few side effects, which promotes regular wearing and observance. Clinical relevance Side pole static ankle foot orthoses are well tolerated and can be safely used for children with foot abnormalities in the frontal plane that have a neurological pathology origin.

Influence of a two-year steroid treatment on body composition as measured by dual X-ray absorptiometry in boys with Duchenne muscular dystrophy.

Steroids are nowadays routinely used as a long-term treatment in Duchenne muscular dystrophy (DMD). Their effects on body composition were assessed using dual X-ray absorptiometry. The study followed over 2 years 29 genetically confirmed DMD patients: 21 in the steroid-treated group and 8 in the steroid-naïve group. After 2 years of steroid treatment, the lean tissue mass values increased significantly (p<0.0001), the percentage of body fat mass remained practically constant (p=0.94) in comparison with the initial visit. In the steroid-naïve patients, there were no significant increases in the lean tissue mass but deterioration in body composition confirmed by a significant increase in the percentage of body fat mass. Besides, significant negative correlations were found between the percentage of body fat mass and the MFM total score (R=-0.79, n=76, p<0.0001). A 2-year steroid treatment improves significantly body composition of boys with DMD through a significant increase in lean tissue mass. We suggest that a thorough check of body composition should be carried out before steroid treatment discontinuation in case of overweight gain.

Tyrosine and phenylalanine are synthesized within the plastids in Arabidopsis.

While the presence of a complete shikimate pathway within plant plastids is definitively established, the existence of a cytosolic postchorismate portion of the pathway is still debated. This question is alimented by the presence of a chorismate mutase (CM) within the cytosol. Until now, the only known destiny of prephenate, the product of CM, is incorporation into tyrosine (Tyr) and/or phenylalanine (Phe). Therefore, the presence of a cytosolic CM suggests that enzymes involved downstream of CM in Tyr or Phe biosynthesis could be present within the cytosol of plant cells. It was thus of particular interest to clarify the subcellular localization of arogenate dehydrogenases (TYRAs) and arogenate dehydratases (ADTs), which catalyze the ultimate steps in Tyr and Phe biosynthesis, respectively. The aim of this study was to address this question in Arabidopsis (Arabidopsis thaliana) by analysis of the subcellular localization of the two TYRAAts and the six AtADTs. This article excludes the occurrence of a spliced TYRAAt1 transcript encoding a cytosolic TYRA protein. Transient expression analyses of TYRA- and ADT-green fluorescent protein fusions reveal that the two Arabidopsis TYRA proteins and the six ADT proteins are all targeted within the plastid. Accordingly, TYRA and ADT proteins were both immunodetected in the chloroplast soluble protein fraction (stroma) of Arabidopsis. No TYRA or ADT proteins were immunodetected in the cytosol of Arabidopsis cells. Taken together, all our data exclude the possibility of Tyr and/or Phe synthesis within the cytosol, at least in green leaves and Arabidopsis cultured cells.