PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (514939)

Clipboard (0)
None

Related Articles

1.  The glucocorticoid receptor N363S polymorphism and steroid response in Duchenne dystrophy 
Background
Steroid administration is beneficial in Duchenne muscular dystrophy (DMD), but the response, incidence, and the severity of side effects are variable.
Aims
To investigate whether glucocorticoid receptor (GRL) gene polymorphisms may be responsible for glucocorticoid sensitivity in DMD.
Methods
Forty eight DMD patients treated either with prednisone or deflazacort were subjected to genetic analyses of the GRL gene.
Results
Mutation studies revealed an heterozygous A to G mutation at GRL cDNA position 1220 in three DMD patients resulting in an asparagine to serine amino acid change at amino acid position 363 (N363S). The N363S carrier DMD patients showed a trend towards a later age at loss of ambulation in comparison with non‐carrier patients.
Conclusions
These data suggest that the N363S GRL polymorphism may be implicated in the long term response to glucocorticoids.
doi:10.1136/jnnp.2005.078345
PMCID: PMC2077532  PMID: 16980656
Duchenne muscular dystrophy; glucocorticoid receptor; SNP; steroid therapy
2.  The Canadian experience with long term deflazacort treatment in Duchenne muscular dystrophy 
Acta Myologica  2012;31(1):16-20.
Deflazacort is the most commonly prescribed corticosteroid for the treatment of Duchenne muscular dystrophy in Canada. We review the long term experience with deflazacort treatment at two centers in Canada; Montreal and Toronto. Deflazacort has benefitted both cohorts by prolonged ambulation, preserved cardiac and respiratory function, less scoliosis and improved survival. Common side effects in both cohorts include weight gain, decreased height and cataract formation. The Canadian experience supports the use of deflazacort in treating boys with Duchenne muscular dystrophy.
PMCID: PMC3440807  PMID: 22655512
Deflazacort; Duchenne Muscular Dystrophy; Canada
3.  Randomized, blinded trial of weekend vs daily prednisone in Duchenne muscular dystrophy 
Neurology  2011;77(5):444-452.
Objective:
To perform a double-blind, randomized study comparing efficacy and safety of daily and weekend prednisone in boys with Duchenne muscular dystrophy (DMD).
Methods:
A total of 64 boys with DMD who were between 4 and 10 years of age were randomized at 1 of 12 centers of the Cooperative International Neuromuscular Research Group. Efficacy and safety of 2 prednisone schedules (daily 0.75 mg/kg/day and weekend 10 mg/kg/wk) were evaluated over 12 months.
Results:
Equivalence was met for weekend and daily dosing of prednisone for the primary outcomes of quantitative muscle testing (QMT) arm score and QMT leg score. Secondary strength scores for QMT elbow flexors also showed equivalence between the 2 treatment groups. Overall side effect profiles of height and weight, bone density, cataract formation, blood pressure, and behavior, analyzed at 12 months, did not differ between weekend and daily dosing of prednisone.
Conclusions:
Weekend dosing of prednisone is equally beneficial to the standard daily dosing of prednisone. Analysis of side effect profiles demonstrated overall tolerability of both dosing regimens.
Classification of evidence:
This study provides Class I evidence that weekend prednisone dosing is as safe and effective as daily prednisone in preserving muscle strength and preventing body mass index increases in boys with DMD over a 12-month period.
doi:10.1212/WNL.0b013e318227b164
PMCID: PMC3146308  PMID: 21753160
4.  Treatment of dysferlinopathy with deflazacort: a double-blind, placebo-controlled clinical trial 
Background
Dysferlinopathies are autosomal recessive disorders caused by mutations in the dysferlin (DYSF) gene encoding the dysferlin protein. DYSF mutations lead to a wide range of muscular phenotypes, with the most prominent being Miyoshi myopathy (MM) and limb girdle muscular dystrophy type 2B (LGMD2B).
Methods
We assessed the one-year-natural course of dysferlinopathy, and the safety and efficacy of deflazacort treatment in a double-blind, placebo-controlled cross-over trial. After one year of natural course without intervention, 25 patients with genetically defined dysferlinopathy were randomized to receive deflazacort and placebo for six months each (1 mg/kg/day in month one, 1 mg/kg every 2nd day during months two to six) in one of two treatment sequences.
Results
During one year of natural course, muscle strength declined about 2% as measured by CIDD (Clinical Investigation of Duchenne Dystrophy) score, and 76 Newton as measured by hand-held dynamometry. Deflazacort did not improve muscle strength. In contrast, there is a trend of worsening muscle strength under deflazacort treatment, which recovers after discontinuation of the study drug. During deflazacort treatment, patients showed a broad spectrum of steroid side effects.
Conclusion
Deflazacort is not an effective therapy for dysferlinopathies, and off-label use is not warranted. This is an important finding, since steroid treatment should not be administered in patients with dysferlinopathy, who may be often misdiagnosed as polymyositis.
Trial registration
This clinical trial was registered at http://www.ClincalTrials.gov, identifier: NCT00527228, and was always freely accessible to the public.
doi:10.1186/1750-1172-8-26
PMCID: PMC3617000  PMID: 23406536
Limb girdle muscular dystrophy (LGMD); Dysferlinopathy; Therapy; Deflazacort; Muscle strength; Steroids
5.  Prednisolone improves walking in Japanese Duchenne muscular dystrophy patients 
Journal of Neurology  2013;260:3023-3029.
We evaluated the long-term efficacy of prednisolone (PSL) therapy for prolonging ambulation in Japanese patients with genetically confirmed Duchenne muscular dystrophy (DMD). There were clinical trials have shown a short-term positive effect of high-dose and daily PSL on ambulation, whereas a few study showed a long-term effect. Especially in Japan, “real-life” observation was lacking. We utilized the national registry of muscular dystrophy in Japan for our retrospective study. We compared the age at loss of ambulation (LOA) between patients in PSL group and those in without-PSL group. Out of 791 patients’ in the Remudy DMD/BMD registry from July 2009 to June 2012, 560 were matched with inclusion criteria. Of the 560, all were genetically confirmed DMD patients, 245 (43.8 %) of whom were treated with PSL and 315 (56.2 %) without PSL. There was no difference between the two groups regarding their mutational profile. The age at LOA was significantly greater (11 month on average) in the PSL group than in the without-PSL group (median, 132 vs. 121 months; p = 0.0002). Although strictly controlled clinical trials have shown that corticosteroid therapies achieved a marked improvement in ambulation, discontinuation of the drug due to intolerable side effects led to exclusion of clinical trial participants, which is considered as unavoidable. In our study, patients were not excluded from the PSL group, even if they discontinued the medication shortly after starting it. The results of our study may provide evidence to formulate recommendations and provide a basis for realistic expectations for PSL treatment of DMD patients in Japan, even there are certain limitations due to the retrospectively captured data in the registry.
doi:10.1007/s00415-013-7104-y
PMCID: PMC3843366  PMID: 24057148
Duchenne muscular dystrophy; Prednisolone; Walking; National registry; Natural history
6.  Long term treatment of polymyalgia rheumatica with deflazacort. 
Annals of the Rheumatic Diseases  1994;53(5):331-333.
OBJECTIVES--To evaluate the long term efficacy and tolerability of deflazacort, a corticosteroid reputed to have only minor side effects, in the treatment of polymyalgia rheumatica (PMR). METHODS--In a prospective open study, deflazacort was administered at an average initial dose of 21.8 mg/day for a mean period of 19 months in 40 patients with PMR. RESULTS--A highly significant improvement of clinical and laboratory parameters occurred one month after therapy onset. This improvement persisted for the whole study period. Laboratory parameters of tolerability did not change during the study. Mild to moderate steroid-related side effects occurred in 57.9% of the patients. CONCLUSIONS--Deflazacort is effective in the treatment of PMR. Its long term safety profile may be superior to that of other corticosteroids.
PMCID: PMC1005333  PMID: 8017988
7.  Emerging Drugs for Duchenne Muscular Dystrophy 
Expert opinion on emerging drugs  2012;17(2):261-277.
Introduction
Duchenne muscular dystrophy (DMD) is the most common, severe childhood form of muscular dystrophy. Treatment is limited to glucocorticoids that have the benefit of prolonging ambulation by approximately 2 years and preventing scoliosis. Finding a more satisfactory treatment should focus on maintaining long-term efficacy with a minimal side effect profile.
Areas covered
Authors discuss different therapeutic strategies that have been used in pre-clinical and clinical settings.
Expert opinion
Multiple treatment approaches have emerged. Most attractive are molecular-based therapies that can express the missing dystrophin protein (exon skipping or mutation suppression) or a surrogate gene product (utrophin). Other approaches include increasing the strength of muscles (myostatin inhibitors), reducing muscle fibrosis, and decreasing oxidative stress. Additional targets include inhibiting NF-κB to reduce inflammation, or promoting skeletal muscle blood flow and muscle contractility using phosphodiesterase inhibitors or nitric oxide (NO) donors. The potential for each of these treatment strategies to enter clinical trials is a central theme of discussion. The review emphasizes that the goal of treatment should be to find a product at least as good as glucocorticoids with a lower side effect profile or with a significant glucocorticoid sparing effect.
doi:10.1517/14728214.2012.691965
PMCID: PMC3486431  PMID: 22632414
Duchenne muscular dystrophy; exon skipping; mutation suppression; stop codon readthrough; utrophin; myostatin inhibition; nitric oxide; phosphodiesterase inhibitors; NF-κB inhibition
8.  Lack of Functional Benefit with Glutamine versus Placebo in Duchenne Muscular Dystrophy: A Randomized Crossover Trial 
PLoS ONE  2009;4(5):e5448.
Background
Oral glutamine decreases whole body protein breakdown in Duchenne muscular dystrophy (DMD). We evaluated the functional benefit of 4 months oral glutamine in DMD.
Methodology/Principal Findings
30 ambulant DMD boys were included in this double-blind, randomized crossover trial with 2 intervention periods: glutamine (0.5 g/kg/d) and placebo, 4 months each, separated by a 1-month wash-out, at 3 outpatient clinical investigation centers in France. Functional benefit was tested by comparing glutamine versus placebo on change in walking speed at 4 months. Secondary outcome measures were: 2-minute walk test, work, power, muscle mass (urinary creatinine), markers of myofibrillar protein breakdown (urinary 3-methyl-histidine/creatinine), serum creatine phospho-kinase, body composition (fat free mass, fat mass percentage), safety and oral nutrient intake. There was no improvement in the primary end point (walking speed) or in secondary measures of muscle function (2-minute walk test, work, power) in the glutamine group compared with placebo. However, subjects receiving glutamine or placebo showed no deterioration in functional measures over the course of the 9-month trial. No differences in muscle mass, markers of protein breakdown or serum creatine phosho-kinase were observed, except for a blunted increase in fat free mass in the glutamine group which led to a greater increase in fat mass percentage. Glutamine was safe and well-tolerated.
Conclusions
This trial did not identify additional benefit of 4 months oral glutamine over placebo on muscle mass or function in ambulatory DMD boys. Although apparently safe, current data cannot support routine supplementation in this population as a whole, until further research proves otherwise.
Trial Registration
ClinicalTrials.gov NCT00296621
doi:10.1371/journal.pone.0005448
PMCID: PMC2673684  PMID: 19421321
9.  Andrographolide attenuates skeletal muscle dystrophy in mdx mice and increases efficiency of cell therapy by reducing fibrosis 
Skeletal Muscle  2014;4:6.
Background
Duchenne muscular dystrophy (DMD) is characterized by the absence of the cytoskeletal protein dystrophin, muscle wasting, increased transforming growth factor type beta (TGF-β) signaling, and fibrosis. At the present time, the only clinically validated treatments for DMD are glucocorticoids. These drugs prolong muscle strength and ambulation of patients for a short term only and have severe adverse effects. Andrographolide, a bicyclic diterpenoid lactone, has traditionally been used for the treatment of colds, fever, laryngitis, and other infections with no or minimal side effects. We determined whether andrographolide treatment of mdx mice, an animal model for DMD, affects muscle damage, physiology, fibrosis, and efficiency of cell therapy.
Methods
mdx mice were treated with andrographolide for three months and skeletal muscle histology, creatine kinase activity, and permeability of muscle fibers were evaluated. Fibrosis and TGF-β signaling were evaluated by indirect immunofluorescence and Western blot analyses. Muscle strength was determined in isolated skeletal muscles and by a running test. Efficiency of cell therapy was determined by grafting isolated skeletal muscle satellite cells onto the tibialis anterior of mdx mice.
Results
mdx mice treated with andrographolide exhibited less severe muscular dystrophy than untreated dystrophic mice. They performed better in an exercise endurance test and had improved muscle strength in isolated muscles, reduced skeletal muscle impairment, diminished fibrosis and a significant reduction in TGF-β signaling. Moreover, andrographolide treatment of mdx mice improved grafting efficiency upon intramuscular injection of dystrophin-positive satellite cells.
Conclusions
These results suggest that andrographolide could be used to improve quality of life in individuals with DMD.
doi:10.1186/2044-5040-4-6
PMCID: PMC4021597  PMID: 24655808
Andrographolide; mdx; DMD; Fibrosis; Skeletal muscle; Cell therapy
10.  Insights into bone health in Duchenne muscular dystrophy 
BoneKEy reports  2012;1:9.
Poor bone health is a significant problem for patients with Duchenne muscular dystrophy (DMD), a progressive, disabling disease. Although the primary focus of DMD disease pathogenesis is degeneration of striated muscle, impairment of bone health likely has a role in the disease that has only been superficially examined to date. Deficiency of bone mineral density and increased incidence of bone fractures are well-recognized clinical components of the DMD phenotype. Furthermore, therapy with corticosteroids, an approved treatment for DMD that prolongs ambulation, may have multiple effects on bone health in DMD patients. This review examines the evidence in preclinical models and in human DMD disease that provides insight into the role performed by bone in the disease pathogenesis and phenotype of DMD. The information reviewed here points toward the need for mechanistic and therapeutic studies to optimize bone health in DMD patients.
doi:10.1038/bonekey.2012.5
PMCID: PMC3727795  PMID: 23951421
11.  Percent-Predicted 6-Minute Walk Distance in Duchenne Muscular Dystrophy to Account for Maturational Influences 
PLoS Currents  2012;4:RRN1297.
We recently described a modified version of the 6-minute walk test (6MWT) for Duchenne muscular dystrophy (DMD) based partly on the American Thoracic Society (ATS) guidelines. This measure has shown reliability, validity and utility as a primary outcome measure in DMD clinical trials. Because loss of muscle function in DMD occurs against the background of normal childhood growth and development, younger children with DMD can show increase in distance walked during 6MWT over ~1 year despite progressive muscular impairment. In this study, we compare 6-minute walk distance (6MWD) data from DMD boys (n=17) and typically developing control subjects (n=22) to existing normative data from age- and sex-matched children and adolescents. An age- and height-based equation fitted to normative data by Geiger and colleagues was used to convert 6MWD to a percent-predicted (%-predicted) value in boys with DMD. Analysis of %-predicted 6MWD data represents a method to account for normal growth and development, and shows that gains in function at early ages represents stable rather than improving abilities in boys with DMD. Boys with DMD from 4-7 years of age maintain a stable 6MWD approximately 80% of that of typically developing peers, with the deficit progressing at a variable rate thereafter.
doi:10.1371/currents.RRN1297
PMCID: PMC3269886  PMID: 22306689
12.  Percent-Predicted 6-Minute Walk Distance in Duchenne Muscular Dystrophy to Account for Maturational Influences 
PLoS Currents  2012;4:RRN1297.
We recently described a modified version of the 6-minute walk test (6MWT) for Duchenne muscular dystrophy (DMD) based partly on the American Thoracic Society (ATS) guidelines. This measure has shown reliability, validity and utility as a primary outcome measure in DMD clinical trials. Because loss of muscle function in DMD occurs against the background of normal childhood growth and development, younger children with DMD can show increase in distance walked during 6MWT over ~1 year despite progressive muscular impairment. In this study, we compare 6-minute walk distance (6MWD) data from DMD boys (n=17) and typically developing control subjects (n=22) to existing normative data from age- and sex-matched children and adolescents. An age- and height-based equation fitted to normative data by Geiger and colleagues was used to convert 6MWD to a percent-predicted (%-predicted) value in boys with DMD. Analysis of %-predicted 6MWD data represents a method to account for normal growth and development, and shows that gains in function at early ages represents stable rather than improving abilities in boys with DMD. Boys with DMD from 4-7 years of age maintain a stable 6MWD approximately 80% of that of typically developing peers, with the deficit progressing at a variable rate thereafter.
doi:10.1371/currents.RRN1297
PMCID: PMC3269886  PMID: 22306689
13.  Motor and Cognitive Assessment of Infants and Young Boys with Duchenne Muscular Dystrophy; Results from the Muscular Dystrophy Association DMD Clinical Research Network 
Neuromuscular disorders : NMD  2013;23(7):529-539.
Therapeutic trials in Duchenne Muscular dystrophy (DMD) exclude young boys because traditional outcome measures rely on cooperation. The Bayley-III Scales of Infant and Toddler Development (Bayley-III) have been validated in developing children and those with developmental disorders but have not been studied in DMD. Expanded Hammersmith Functional Motor Scale (HFMSE) and North Star Ambulatory Assessment (NSAA) may also be useful in this young DMD population. Clinical evaluators from the MDA-DMD Clinical Research Network were trained in these assessment tools. Infants and boys with DMD (n=24; 1.9±0.7 years) were assessed. The mean Bayley-III motor composite score was low (82.8 ± 8; p=<.0001)(normal=100 ± 15). Mean gross motor and fine motor function scaled scores were low (both p=<.0001). The mean cognitive comprehensive (p=.0002), receptive language (p=<.0001), and expressive language (p=.0001) were also low compared to normal children. Age was negatively associated with Bayley-III gross motor (r=−0.44 p=.02) but not with fine motor, cognitive, or language scores. HFMSE (n=23) showed a mean score of 31 ± 13. NSAA (n =18 boys; 2.2 ± 0.4years) showed a mean score of 12 ± 5. Outcome assessments of young boys with DMD are feasible and in this multicenter study were best demonstrated using the Bayley-III.
doi:10.1016/j.nmd.2013.04.005
PMCID: PMC3743677  PMID: 23726376
14.  Clinical Heterogeneity of Duchenne Muscular Dystrophy (DMD): Definition of Sub-Phenotypes and Predictive Criteria by Long-Term Follow-Up 
PLoS ONE  2009;4(2):e4347.
Background
To explore clinical heterogeneity of Duchenne muscular dystrophy (DMD), viewed as a major obstacle to the interpretation of therapeutic trials
Methodology/Principal Findings
A retrospective single institution long-term follow-up study was carried out in DMD patients with both complete lack of muscle dystrophin and genotyping. An exploratory series (series 1) was used to assess phenotypic heterogeneity and to identify early criteria predicting future outcome; it included 75 consecutive steroid-free patients, longitudinally evaluated for motor, respiratory, cardiac and cognitive functions (median follow-up: 10.5 yrs). A validation series (series 2) was used to test robustness of the selected predictive criteria; it included 34 more routinely evaluated patients (age>12 yrs). Multivariate analysis of series 1 classified 70/75 patients into 4 clusters with distinctive intellectual and motor outcomes: A (early infantile DMD, 20%): severe intellectual and motor outcomes; B (classical DMD, 28%): intermediate intellectual and poor motor outcome; C (moderate pure motor DMD, 22%): normal intelligence and delayed motor impairment; and D (severe pure motor DMD, 30%): normal intelligence and poor motor outcome. Group A patients had the most severe respiratory and cardiac involvement. Frequency of mutations upstream to exon 30 increased from group A to D, but genotype/phenotype correlations were restricted to cognition (IQ>71: OR 7.7, 95%CI 1.6–20.4, p<0.003). Diagnostic accuracy tests showed that combination of “clinical onset <2 yrs” with “mental retardation” reliably assigned patients to group A (sensitivity 0.93, specificity 0.98). Combination of “lower limb MMT score>6 at 8 yrs” with “normal or borderline mental status” reliably assigned patients to group C (sensitivity: 1, specificity: 0.94). These criteria were also predictive of “early infantile DMD” and “moderate pure motor DMD” in series 2.
Conclusions/Significance
DMD can be divided into 4 sub-phenotypes differing by severity of muscle and brain dysfunction. Simple early criteria can be used to include patients with similar outcomes in future therapeutic trials.
doi:10.1371/journal.pone.0004347
PMCID: PMC2633042  PMID: 19194511
15.  Effects of steroids and angiotensin converting enzyme inhibition on circumferential strain in boys with Duchenne muscular dystrophy: a cross-sectional and longitudinal study utilizing cardiovascular magnetic resonance 
Background
Steroid use has prolonged ambulation in Duchenne muscular dystrophy (DMD) and combined with advances in respiratory care overall management has improved such that cardiac manifestations have become the major cause of death. Unfortunately, there is no consensus for DMD-associated cardiac disease management. Our purpose was to assess effects of steroid use alone or in combination with angiotensin converting enzyme inhibitors (ACEI) or angiotension receptor blocker (ARB) on cardiovascular magnetic resonance (CMR) derived circumferential strain (εcc).
Methods
We used CMR to assess effects of corticosteroids alone (Group A) or in combination with ACEI or ARB (Group B) on heart rate (HR), left ventricular ejection fraction (LVEF), mass (LVM), end diastolic volume (LVEDV) and circumferential strain (εcc) in a cohort of 171 DMD patients >5 years of age. Treatment decisions were made independently by physicians at both our institution and referral centers and not based on CMR results.
Results
Patients in Group A (114 studies) were younger than those in Group B (92 studies)(10 ± 2.4 vs. 12.4 ± 3.2 years, p < 0.0001), but HR, LVEF, LVEDV and LVM were not different. Although εcc magnitude was lower in Group B than Group A (-13.8 ± 1.9 vs. -12.8 ± 2.0, p = 0.0004), age correction using covariance analysis eliminated this effect. In a subset of patients who underwent serial CMR exams with an inter-study time of ~15 months, εcc worsened regardless of treatment group.
Conclusions
These results support the need for prospective clinical trials to identify more effective treatment regimens for DMD associated cardiac disease.
doi:10.1186/1532-429X-13-60
PMCID: PMC3207955  PMID: 22011358
16.  A Randomized, Double-Blind Trial of Lisinopril and Losartan for the Treatment of Cardiomyopathy in Duchenne Muscular Dystrophy 
PLoS Currents  2013;5:ecurrents.md.2cc69a1dae4be7dfe2bcb420024ea865.
Objectives: This study sought to compare the effectiveness and safety of an angiotensin converting enzyme inhibitor (ACE-I) (lisinopril) vs. an angiotensin receptor blocker (ARB) (losartan) for the treatment of cardiomyopathy (CM) in boys with Duchenne muscular dystrophy (DMD). Background: Development of CM is universal in boys with DMD. ACE-I and ARB have both been suggested as effective treatment options. ARBs have been associated with skeletal muscle regeneration in a mouse model of DMD. The question of which, if either, is more effective for CM treatment in DMD remains. The purpose of this multicenter double-blind prospective study was to compare efficacy and safety of lisinopril versus losartan in the treatment of newly diagnosed CM in boys with DMD. Methods: Echocardiographic technician inter- and intraobserver variability were tested on 2 separate days on 2 different boys with DMD CM. Results were compared with paired t-testing. Twenty-two boys with newly diagnosed DMD CM (echocardiographic ejection fraction (EF) 10% EF drop. Three boys in the aCE-I group had 3 visits, due to study funding termination. Two were withdrawn because of low EF. All their data are included in the analysis for as long as they remained in the study. Mean EF’s were similar at baseline (47.5%- ACE-I, 48.4%- ARB). After 1 year each group significantly improved to 54.6% and 55.2% respectively (p=.02). There was no difference between the 2 treatment groups at 1 year. Conclusions: Inter-observer and intra-observer reliability studies showed no differences between echocardiographers on serial examinations. EF improved equally in the two groups. There is no therapeutic difference in EF improvement between lisinopril and losartan over the one-year duration for treatment of boys with DMD-related CM. Trial Registration: ClinicalTrials.gov NCT01982695
doi:10.1371/currents.md.2cc69a1dae4be7dfe2bcb420024ea865
PMCID: PMC3871420  PMID: 24459612
17.  Physical training in boys with Duchenne Muscular Dystrophy: the protocol of the No Use is Disuse study 
BMC Pediatrics  2010;10:55.
Background
"Use it or lose it" is a well known saying which is applicable to boys with Duchenne Muscular Dystrophy (DMD). Besides the direct effects of the muscular dystrophy, the increasing effort to perform activities, the fear of falling and the use of personal aids indirectly impair leg and arm functions as a result of disuse. Physical training could oppose this secondary physical deterioration. The No Use is Disuse (NUD) study is the first study in human subjects with DMD that will examine whether a low-intensity physical training is beneficial in terms of preservation of muscle endurance and functional abilities. The study consists of two training intervention studies: study 1 "Dynamic leg and arm training for ambulant and recently wheelchair-dependent boys with DMD and, study 2 "Functional training with arm support for boys with DMD who have been confined to a wheelchair for several years". This paper describes the hypotheses and methods of the NUD study.
Methods
Study 1 is an explorative randomized controlled trial with multiple baseline measurements. Thirty boys with a DNA-established diagnosis of DMD will be included. The intervention consists of a six-months physical training during which boys train their legs and arms with active and/or assisted cycling training equipment. The primary study outcomes are muscle endurance and functional abilities, assessed with a Six-Minute Bicycle Test and the Motor Function Measure. Study 2 has a within-group repeated measurements design and will include ten boys with DMD who have already been confined to a wheelchair for several years. The six-months physical training program consists of 1) a computer-assisted training and 2) a functional training with an arm support. The primary study outcome is functional abilities of the upper extremity, assessed with the Action Research Arm Test.
Discussion
The NUD study will fill part of the gap in the current knowledge about the possible effects of training in boys with DMD and will increase insight into what type of exercise should be recommended to boys with DMD. The study will finish at the end of 2010 and results are expected in 2011.
Trial registration
The Netherlands National Trial Register1631
doi:10.1186/1471-2431-10-55
PMCID: PMC2929216  PMID: 20691042
18.  Quantitative Assessment of the T2 Relaxation Time of the Gluteus Muscles in Children with Duchenne Muscular Dystrophy: a Comparative Study Before and After Steroid Treatment 
Korean Journal of Radiology  2010;11(3):304-311.
Objective
To determine the feasibility of using T2 mapping as a quantitative method to longitudinally follow the disease activity in children with Duchenne muscular dystrophy (DMD) who are treated with steroids.
Materials and Methods
Eleven boys with DMD (age range: 5-14 years) underwent evaluation with the clinical functional score (CFS), and conventional pelvic MRI and T2 mapping before and during steroid therapy. The gluteus muscle inflammation and fatty infiltration were evaluated on conventional MRI. The histograms and mean T2 relaxation times were obtained from the T2 maps. The CFS, the conventional MRI findings and the T2 values were compared before and during steroid therapy.
Results
None of the patients showed interval change of their CFSs. On conventional MRI, none of the images showed muscle inflammation. During steroid treatment, two boys showed increased fatty infiltration on conventional MRI, and both had an increase of the mean T2 relaxation time (p < 0.05). The remaining nine boys had no increase in fatty infiltration. Of these, three showed an increased mean T2 relaxation time (p < 0.05), two showed no change and four showed a decreased mean T2 relaxation time (p < 0.05).
Conclusion
T2 mapping is a feasible technique to evaluate the longitudinal muscle changes in those children who receive steroid therapy for DMD. The differences of the mean T2 relaxation time may reflect alterations in disease activity, and even when the conventional MRI and CFS remain stable.
doi:10.3348/kjr.2010.11.3.304
PMCID: PMC2864857  PMID: 20461184
Magnetic resonance (MR); Duchenne muscular dystrophy (DMD); Muscle; T2 relaxation time map
19.  Participation and quality of life in children with Duchenne muscular dystrophy using the International Classification of Functioning, Disability, and Health 
Background
Duchenne muscular dystrophy (DMD) is characterized by muscle damage and progressive loss of muscle function in male children. DMD is one of the most devastating genetically linked neuromuscular diseases for which there is currently no cure. Most clinical studies for DMD utilize a standard protocol for measurement exploring pathophysiology, muscle strength and timed tasks. However, we propose that examining broader components of health as emphasized by the International Classification of Functioning, Disability and Health-Children and Youth Version (ICF-CY) may be of great value to children and their families, and important outcomes for future clinical trials.
Methods
Fifty boys with DMD and 25 unaffected age-matched boys completed two self-report measures: the Children’s Assessment of Participation and Enjoyment and the Pediatric Quality of Life InventoryTM 4.0. We investigated differences between the two groups with regard to participation in life activities and perceived quality of life (QoL). Additionally, we compared participation in activities and QoL in both cohorts of younger and older boys.
Results
Participation in physical activities was significantly lower in boys with DMD than unaffected boys. Perceived QoL was markedly diminished in children with DMD relative to unaffected controls, except in the emotional domain. The amount of time boys engage in an activity, as well as participation in social activities, declined for our older boys with DMD but no changes were observed for our older unaffected boys. For both groups, QoL remained constant over time.
Conclusions
The ICF-CY provides a conceptual framework and specific terminology that facilitates investigation of the consequences of impairment in children and youth. Our study is one of the first to explore participation in a cohort of boys with DMD. It was not surprising that activities of choice for boys with DMD were less physical in nature than unaffected boys their age, but the consequences of less social engagement as the boys with DMD age is of great concern. Results from our study underscore the need to further evaluate activities that children elect to participate in, with special emphasis on facilitators and barriers to participation and how participation changes throughout the course of a disease.
doi:10.1186/1477-7525-10-43
PMCID: PMC3358238  PMID: 22545870
Duchenne muscular dystrophy; ICF; Participation; Quality of life
20.  Deflazacort for the treatment of Duchenne Dystrophy: A systematic review 
BMC Neurology  2003;3:7.
Background
To complete a systematic review and meta-analysis based on the clinical question: Is Deflazacort (DFZ), a prednisolone derivative, an effective therapy for improving strength, with acceptable side effects, in children with Duchenne Dystrophy (DD)?
Methods
MEDLINE, EMBASE, Current Contents, Dissertation Abstracts, Health Star, PsychINFO and Cochrane, were searched using the following inclusion criteria: 1) A randomized controlled trial comparing DFZ with placebo or another therapy; 2) Male participants age 2–18 years with DD; 3) Outcomes of (a) any form of strength or functional testing, or (b) any form of side effect.
Results
Fifteen studies of potential relevance were identified, with five meeting the inclusion criteria. These five studies included 291 children and were published in English language journals between 1994 and 2000. Two studies compared DFZ versus placebo, two studies compared DFZ with prednisone and one study had both placebo and prednisone comparisions. Two large trials were identified that have not been published in article format. Due to the heterogeneity in outcome measures and the inconsistent reporting of summary statistics a meta-analytic approach could not be taken.
Conclusions
Examining individual studies it appears that DFZ improves strength and functional outcomes compared to placebo, but it remains unclear if it has a benefit over prednisone on similar outcomes. Two trials found that DFZ causes less weight gain than prednisone.
doi:10.1186/1471-2377-3-7
PMCID: PMC222985  PMID: 12962544
21.  Pentoxifylline as a rescue treatment for DMD 
Neurology  2012;78(12):904-913.
Objective:
To determine whether pentoxifylline (PTX) slows the decline of muscle strength and function in ambulatory boys with Duchenne muscular dystrophy (DMD).
Methods:
This was a multicenter, randomized, double-blinded, controlled trial comparing 12 months of daily treatment with PTX or placebo in corticosteroid-treated boys with DMD using a slow-release PTX formulation (∼20 mg/kg/day). The primary outcome was the change in mean total quantitative muscle testing (QMT) score. Secondary outcomes included changes in QMT subscales, manual muscle strength, pulmonary function, and timed function tests. Outcomes were compared using Student t tests and a linear mixed-effects model. Adverse events (AEs) were compared using the Fisher exact test.
Results:
A total of 64 boys with DMD with a mean age of 9.9 ± 2.9 years were randomly assigned to PTX or placebo in 11 participating Cooperative International Neuromuscular Research Group centers. There was no significant difference between PTX and the placebo group in total QMT scores (p = 0.14) or in most of the secondary outcomes after a 12-month treatment. The use of PTX was associated with mild to moderate gastrointestinal or hematologic AEs.
Conclusion:
The addition of PTX to corticosteroid-treated boys with DMD at a moderate to late ambulatory stage of disease did not improve or halt the deterioration of muscle strength and function over a 12-month study period.
Classification of evidence:
This study provides Class I evidence that treatment with PTX does not prevent deterioration in muscle function or strength in corticosteroid-treated boys with DMD.
doi:10.1212/WNL.0b013e31824c46be
PMCID: PMC3306159  PMID: 22402864
22.  Correlation of clinical and deletion data in Duchenne and Becker muscular dystrophy. 
Journal of Medical Genetics  1989;26(11):682-693.
Cloned cDNA sequences representing exons from the Duchenne/Becker muscular dystrophy (DMD/BMD) gene were used for deletion screening in a population of 287 males males affected with DMD or BMD. The clinical phenotypes of affected boys were classified into three clinical severity groups based on the age at which ambulation was lost. Boys in group 1 had DMD, losing ambulation before their 13th birthday; those in group 2 had disease of intermediate severity, losing ambulation between the ages of 13 and 16 years; and boys in group 3 had BMD, being ambulant beyond 16 years. A fourth group consisted of patients too young to be classified. Clinical group allocation was made without previous knowledge of the DNA results. A gene deletion was found in 124 cases where the clinical severity group of the affected boy was known. The extent of the deletions was delineated using cDNA probes. There were 74 different deletions. Fifty-five of these were unique to individual patients, but the other 19 were found in at least two unrelated patients. The different clinical groups showed generally similar distributions of deletions, and the number of exon bands deleted (that is, deletion size) was independent of phenotype. Some specific deletion types, however, correlated with the clinical severity of the disease. Deletion of exons containing HindIII fragments 33 and 34 and 33 to 35 were associated with BMD and were not found in patients with DMD. Deletions 3 to 7 occurred in four patients with the intermediate phenotype and one patient with BMD. Other shared deletions were associated with DMD, although in four cases patients with disease of intermediate severity apparently shared the same deletion with boys with DMD. The range of phenotypes observed, and the overlap at the genetic level between severe and intermediate and mild and intermediate forms of dystrophy, emphasizes the essential continuity of the clinical spectrum of DMD/BMD. There were no characteristic deletions found in boys with mental retardation or short stature which differed from deletions in affected boys without these features.
Images
PMCID: PMC1015738  PMID: 2585468
23.  Deflazacort in comparison to other steroids for nephrotic syndrome 
Indian Journal of Nephrology  2012;22(4):239-245.
Patients with nephrotic syndrome require steroids for long time and sometimes repeatedly resulting in various adverse effects. Deflazacort (DFZ) had been described as equally effective and with fewer side effects as compared with other steroids. This review evaluates the literature on efficacy and toxicity of DFZ as compared with other therapies for nephrotic syndrome. A systematic review of Pubmed database and Cochrane Central Register of Controlled Trials with last search date of 20th April 2011. Search terms included “nephrotic AND deflazacort” without any limitations. Randomized control trials comparing DFZ vs placebo or other therapies in subjects with nephrotic syndrome were included. Two authors extracted data independently. Three studies meet inclusion criteria and data were synthesized qualitatively. The limited evidence suggested that DFZ appeared to be equally effective in inducing remission or decreasing proteinuria in patients with nephrotic syndrome. It caused significantly less decrease in bone mineral content (BMC) in spine as compared with prednisolone. The results related to weight change, blood pressure change, Cushingoid symptoms, and urinary calcium excretion were inconsistent between included studies. By reviewing the available limited evidence, DFZ appears to be of similar efficacy for nephrotic patients, but there were inconsistent results regarding side effect profile of DFZ as compared with other steroids except for decrease in BMC where DFZ was better. There is need for larger randomized controlled trials to evaluate effectiveness and adverse effect profile of DFZ as compared with other steroids in nephrotic syndrome.
doi:10.4103/0971-4065.101238
PMCID: PMC3495343  PMID: 23162265
Bone mineral content; deflazacort; nephrotic syndrome; prednisolone
24.  A translational approach for limb vascular delivery of the micro-dystrophin gene without high volume or high pressure for treatment of Duchenne muscular dystrophy 
Background
Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder with monogenic mutations setting the stage for successful gene therapy treatment. We have completed a study that directly deals with the following key issues that can be directly adapted to a gene therapy clinical trial using rAAV considering the following criteria: 1) A regional vascular delivery approach that will protect the patient from widespread dissemination of virus; 2) an approach to potentially facilitate safe passage of the virus for efficient skeletal muscle transduction; 3) the use of viral doses to accommodate current limitations imposed by vector production methods; 4) and at the same time, achieve a clinically meaningful outcome by transducing multiple muscles in the lower limb to prolong ambulation.
Methods
The capacity of AAV1, AAV6 or AAV8 to cross the vascular endothelial barrier carrying a micro-dystrophin cDNA was compared under identical conditions with delivery through a catheter placed in the femoral artery of the mdx mouse. Transduction efficiency was assessed by immuno-staining using an antibody (Manex1a) that recognizes the N-terminus of micro-dystrophin. The degree of physiologic correction was assessed by measuring tetanic force and protection from eccentric contraction in the extensor digitorum longus muscle (EDL). The vascular delivery paradigm found successful in the mouse was carried to the non-human primate to test its potential translation to boys with DMD.
Results
Regional vascular delivery resulted in transduction by rAAV8.micro-dystrophin reaching 94.5 ± 0.9 (1 month), 91.3 ± 3.1 (2 months), and 89.6 ± 1.6% (3 months). rAAV6.micro-dystrophin treated animals demonstrated 87.7 ± 6.8 (1 month), 78.9 ± 7.4 (2 months), and 81.2 ± 6.2% (3 months) transduction. In striking contrast, rAAV1 demonstrated very low transduction efficiency [0.9 ± 0.3 (1 month), 2.1 ± 0.8 (2 months), and 2.1 ± 0.7% (3 months)] by vascular delivery. Micro-dystrophin delivered by rAAV8 and rAAV6 through the femoral artery significantly improved tetanic force and protected against eccentric contraction. Mouse studies translated to the hindlimb of cynamologous macaques using a similar vascular delivery paradigm. rAAV8 carrying eGFP in doses proportional to the mouse (5 × 1012 vg/kg in mouse vs 2 × 1012 vg/kg in monkey) demonstrated widespread gene expression [medial gastrocnemius – 63.8 ± 4.9%, lateral gastrocnemius – 66.0 ± 4.5%, EDL – 80.2 ± 3.1%, soleus – 86.4 ± 1.9%, TA – 72.2 ± 4.0%.
Conclusion
These studies demonstrate regional vascular gene delivery with AAV serotype(s) in mouse and non-human primate at doses, pressures and volumes applicable for clinical trials in children with DMD.
doi:10.1186/1479-5876-5-45
PMCID: PMC2082019  PMID: 17892583
25.  Pre-clinical drug tests in the mdx mouse as a model of dystrophinopathies: an overview 
Acta Myologica  2012;31(1):40-47.
Duchenne muscular dystrophy is a lethal X-linked muscle disease affecting 1/3500 live male birth. It results from defects in the subsarcolemmal protein dystrophin, a component of the dystrophinglycoprotein complex (DGC) which links the intracellular cytoskeleton to the extracellular matrix. The absence of dystrophin leads to muscle membrane fragility, muscle necrosis and gradual replacement of skeletal muscle by fat and connective tissue, through a complex and still unclear cascade of interconnecting events. No cure is currently available, with glucocorticoids being the sole drugs in clinical use in spite of their remarkable side effects. A great effort is devoted at performing pre-clinical tests on the mdx mouse, the mostly used homologous animal model for DMD, with the final aim to identify drugs safer than steroids and able to target the pathogenic mechanisms so to delay pathology progression. This review updates the efforts on this topic, focusing on the open issues about the animal model and highlighting the classes of pharmaceuticals that are more promising as diseasemodifiers, while awaiting for more corrective therapies. Although caution is necessary in data transfer from mdx model to DMD patients, the implementation of standard operating procedures and the growing understanding of the pathology may allow a more accurate evaluation of therapeutics, alone or in combination, in pre-clinical settings. A continuous cross-talk with clinicians and patients associations are also crucial points for proper translation of data from mouse to bedside.
PMCID: PMC3440805  PMID: 22655516
Duchenne muscular dystrophy; mdx mouse model; pharmaceuticals; pre-clinical studies; translational research

Results 1-25 (514939)