2002 NEWS 2003 NEWS 2004 NEWS 2005 NEWS
DECEMBER - 2006
28 - 2006 Top Ten: Advances in Pharmacological Approach in DMD (my personal opinion)
25 - Duchenne Muscular Dystrophy: Summary of important research results between July and December 2006 - Guenter Scheuerbrandt report
20 - (IN PRESS: PNAS 2007, 104(1):264-9) Nitric oxide release combined with nonsteroidal antiinflammatory activity prevents muscular dystrophy pathology and enhances stem cell therapy
Silvia Brunelli, Clara Sciorati, Giuseppe D’Antona, Anna Innocenzi, Diego Covarello, Beatriz G. Galvez, Cristiana Perrotta, Angela Monopoli, Francesca Sanvito, Roberto Bottinelli, Ennio Ongini, Giulio Cossu and Emilio Clementi - Italy
Duchenne muscular dystrophy is a relatively common disease that affects skeletal muscle, leading to progressive paralysis and death. There is currently no resolutive therapy. We have developed a treatment in which we combined the effects of nitric oxide with nonsteroidal antiinflammatory activity by using HCT 1026, a nitric oxide-releasing derivative of flurbiprofen. Here, we report the results of long-term (1-year) oral treatment with HCT 1026 of two murine models for limb girdle and Duchenne muscular dystrophies (alpha-sarcoglycan-null and mdx mice). In both models, HCT 1026 significantly ameliorated the morphological, biochemical, and functional phenotype in the absence of secondary effects, efficiently slowing down disease progression. HCT 1026 acted by reducing inflammation, preventing muscle damage, and preserving the number and function of satellite cells. HCT 1026 was significantly more effective than the corticosteroid prednisolone, which was analyzed in parallel. As an additional beneficial effect, HCT 1026 enhanced the therapeutic efficacy of arterially delivered donor stem cells, by increasing 4-fold their ability to migrate and reconstitute muscle fibers. The therapeutic strategy we propose is not selective for a subset of mutations; it provides ground for immediate clinical experimentation with HCT 1026 alone, which is approved for use in humans; and it sets the stage for combined therapies with donor or autologous, genetically corrected stem cells.
ADDITIONAL INFORMATIONS:
"HCT 1026, a derivative of flurbiprofen, one of the most potent nonsteroidal antiinflammatory drugs, that releases NO and does not have the severe side effects of corticosteroids. Of importance for an immediate testing in the clinic is the fact that HCT 1026 is safe at the gastrointestinal level, and it has been approved for use in humans; it is effective on oral administration, and it is thus suited for long-term treatment."
"Two decades after the identification of the molecular defect responsible for Duchenne muscular dystrophy, there are still no effective cures for the disease. The failure of all previous pharmacological treatments has left corticosteroids as the only available drug treatment. Therapy with corticosteroids, despite current attempts to ameliorate the protocols of administration, is still of limited clinical benefits, and it is accompanied by severe side effects. The treatment we tested here meets several criteria for an effective therapy, including the ability to block or at least significantly delay the progress of the disease, produce little or no side toxicity, be cost-effective, and, eventually, resolve the underlying genetic defect. In particular, the administration of HCT 1026 was sufficient on its own to delay significantly and persistently the progression of muscular dystrophy in two different models relevant to muscular dystrophy in humans. The drug was effective in correcting biochemical and morphological alterations and in limiting inflammation. Most importantly, the drug increased muscle strength and significantly increased the ability of animals to perform on different motility tests. This functional amelioration was persistent after 12 months of treatment, when disease in untreated animal was severe, clearly demonstrating the efficacy of the treatment in slowing disease progression. Long-term beneficial effects have not been reported for any of the experimental treatments of muscular dystrophy investigated so far."
12 - (IN PRESS: J Dev Behav Pediatr 27:470- 476, 2006) Social Behavior Problems in Boys with Duchenne Muscular Dystrophy
Veronica J. Hilton, Nancy E Nereo, Robert J Fee, Shana E Cyrulnik - USA
Duchenne muscular dystrophy (DMD) is a chronic, progressive pediatric disease that affects both muscle and brain. The objectives of the study were to examine parent reported behavior in children with DMD, investigate the influence of chronic illness, intellectual ability and etiology on behavior, and determine whether a specific behavioral profile is associated with DMD. Parental ratings of boys with DMD (n = 181) on the Child Behavior Checklist behavior scales were examined and compared to reported findings of children with other chronic illnesses, unaffected siblings of boys with DMD (n = 86), and children with cerebral palsy (CP) (n = 42). Increased ratings of general behavior problems were reported, and neither physical progression nor intellectual level contributed to behavioral ratings. Among the children with DMD, the Social Problem behavior scale had the greatest number of ‘‘clinically significant’’ ratings (34%). Between-group comparisons showed significantly more boys with DMD were rated as having social behavior problems than either the sibling or CP comparison groups. In addition to the increase in reported behavioral problems likely related to the effects of chronic illness, boys with DMD may be at heightened risk for specific social behavior problems. The specificity of the findings of the behavior profile in DMD may be partially due to the lack of dystrophin isoforms in the central nervous system, and not solely a reactive response to the illness.
11 - (IN PRESS: Journal of Cell Science 2006; 119: 5114-5123) Ex vivo treatment with nitric oxide increases mesoangioblast therapeutic efficacy in muscular dystrophy
Muscular dystrophies are characterized by primary wasting
of skeletal muscle for which no satisfactory therapy is available.
Studies in animal models have shown that stem cell-based therapies
may improve the outcome of the disease, and that mesoangioblasts
are promising stem cells in this respect. The efficacy of mesoangioblasts
in yielding extensive muscle repair is, however, still limited.
We found that mesoangioblasts treated with nitric oxide (NO) donors
and injected intra-arterially in
-sarcoglycan-null
dystrophic mice have a significantly enhanced ability to migrate to
dystrophic muscles, to resist their apoptogenic environment and
engraft into them, yielding a significant recovery of
-sarcolgycan
expression. In vitro NO-treated mesoangioblasts displayed an enhanced
chemotactic response to myotubes, cytokines and growth factors
generated by the dystrophic muscle. In addition, they displayed an
increased ability to fuse with myotubes and differentiating myoblasts
and to survive when exposed to cytotoxic stimuli similar to
those present in the dystrophic muscle. All the effects of NO were
cyclic GMP-dependent since they were mimicked by treatment with the
membrane permeant cyclic-GMP analogue 8-bromo-cGMP and prevented by
inhibiting guanylate cyclase. We conclude that NO donors exert
multiple beneficial effects on mesoangioblasts that may be used to
increase their efficacy in cell therapy of muscular dystrophies.
11 - (IN PRESS: Pediatric Neurology 2007; 36(1):1-7) Pathophysiology of Duchenne Muscular Dystrophy: Current Hypotheses
Nicolas Deconinck and Bernard Dan - Belgium
Duchenne muscular dystrophy is a
devastating inherited neuromuscular disorder that affects one in 3300 live male
births. Although the responsible gene and its product, dystrophin, have been
characterized for more than 15 years, and a mouse model (mdx) has been
developed, comprehensive understanding of the mechanism leading from the absence
of dystrophin to the muscular degeneration is still debated. First, dystrophin
is considered a key structural element in the muscle fiber, and the primary
function of the dystrophin-associated protein complex is to stabilize plasma
membrane, although a role of signaling is still possible. Mechanically induced
damage through eccentric contractions puts a high stress on fragile membranes
and provokes micro-lesions that could eventually lead to loss of calcium
homeostasis, and cell death. Altered regeneration, inflammation, impaired
vascular adaptation, and fibrosis are probably downstream events that take part
in the muscular dystrophy and that probably vary a lot
along species (i.e., mdx mice), probands within families, stressing the
importance of epigenic factors. Because no etiologic therapy is available for
Duchenne muscular dystrophy, a better understanding of
the primary and downstream mechanisms could prove useful for producing new
adjuvant treatments. All pathophysiologic mechanisms are reviewed together with
perspectives on management.
9 - (IN
PRESS: Chest 2006; 130:1879-1886) Recent
Advances in Respiratory Care for Neuromuscular Disease
Anita K. Simonds - UK
The impact of ventilatory support on the natural history of neuromuscular disease (NMD) has become clearer over the last 2 decades as techniques have been more widely applied. Noninvasive ventilation (NIV) allows some patients with nonprogressive pathology to live to nearly normal life expectancy, extends survival by many years in patients with other conditions (eg, Duchenne muscular dystrophy), and in those patients with rapidly deteriorating disease (eg, amyotrophic lateral sclerosis) survival may be increased, but symptoms can be palliated even if mortality is not reduced. A growing number of children with NMD are surviving to adulthood with the aid of ventilatory support. The combination of NIV with cough-assist techniques decreases pulmonary morbidity and hospital admissions. Trials have confirmed that NIV works in part by enhancing chemosensitivity, and in patients with many different neuromuscular conditions the most effective time to introduce NIV is when symptomatic sleep-disordered breathing develops.
4 - (IN PRESS: Neuromuscular Disorders, 2006) First test of a ‘‘high-density injection’’ protocol for myogenic cell transplantation throughout large volumes of muscles in a Duchenne muscular dystrophy patient: eighteen months follow-up
Daniel Skuk, Marlyne Goulet, Brigitte Roy, Vincent Piette, Claude H. Cote,Pierre Chapdelaine , Jean-Yves Hogrel, Martin Paradis, Jean-Pierre Bouchard, Michel Sylvain, Jean-Guy Lachance, Jacques P. Tremblay - Canada
A 26-years old Duchenne muscular dystrophy (DMD) patient received normal muscle-precursor cells, proliferated in vitro and implanted in a thenar eminence, biceps brachii, and in a portion of a gastrocnemius by injections placed 1 mm from each other or less. Saline was injected in the contralateral gastrocnemius. The patient was immunosuppressed with tacrolimus. The protocol of cell transplantation was well tolerated and did not cause permanent sequels. Some injected sites were biopsied at 1, 14 and 18 months post-transplantation. Muscles were replaced by fat and fibrosis. In the cell-grafted site of the gastrocnemius, 27.5% of the myofiber profiles expressed donor-derived dystrophin 1 month post-transplantation and 34.5% 18 months post-transplantation. The contralateral gastrocnemius was dystrophin-negative. Myofibers were virtually absent in the biceps brachii, where only two dystrophin-positive myofibers were observed. In conclusion, a ‘‘high-density injection’’ protocol was feasible for intramuscular cell-transplantation in a DMD patient and long-term expression of donor-derived dystrophin was observed.
NOVEMBER - 2006
29- (IN PRESS: Neuromuscular Disorders, 2006) Low dose formoterol administration improves muscle function in dystrophic mdx mice without increasing fatigue
Leah J. Harcourt, Jonathan D. Schertzer, James G. Ryall, Gordon S. Lynch - Australia
The β2-adrenoceptor agonist (β2-agonist), formoterol, has been shown to cause muscle hypertrophy in rats even when administered at the micromolar dose of 25 μg/kg/day. We investigated whether a similar low dose of formoterol could improve muscle function in the dystrophic mdx mouse. Ten-week-old male mdx and wild-type (C57BL/10) mice were administered formoterol (25 μg/kg/day, i.p.) for 4 weeks. Formoterol treatment increased extensor digitorum longus (EDL) and soleus muscle mass, increased median muscle fibre size in diaphragm, EDL, and soleus muscles, and increased maximum force producing capacity in skeletal muscles of both wild-type and mdx mice. In contrast to other studies where β2-agonists have been administered to mice and rats, generally at higher doses, low dose formoterol treatment did not increase the fatiguability of EDL, soleus or diaphragm muscles. Although others have found formoterol can decrease ubiquitin mRNA and proteasome activity when administered to tumour bearing rats at high doses (2 mg/kg/day), in the present study low dose formoterol treatment did not alter ubiquitin or the E1 and E3 ubiquitin ligases in diaphragm muscles of wild-type or mdx mice, but it did reduce the level of ubiquitinated proteins in diaphragm of wild-type mice. The findings indicate that formoterol has considerably more powerful anabolic effects on skeletal muscle than older generation β2-agonists (like clenbuterol and albuterol), and has considerable therapeutic potential for muscular dystrophies and other neuromuscular disorders where muscle wasting is indicated.
16 - (IN PRESS: Nature, 2006) A move in the right direction
Jeffrey S. Chamberlain - USA
The potential of stem-cell technologies to revolutionize medical care is causing great excitement among biologists and the general public. Recent studies on embryonic and adult stem cells, coupled with advances in our understanding of how they can be coaxed into forming particular cell types and tissues, have improved the prospects for addressing a host of untreatable diseases. Bone-marrow transplants to renew blood stem cells are now routine, but significant technological hurdles must still be overcome before the power of stem cells can be harnessed to regenerate solid organs such as muscle................ Cossu and colleagues’ results provide compelling evidence that this method should be developed further for testing in patients. That will take several years, and may need many rounds of refinement in animals before any human trials can take place. Importantly, the corrected mesoangioblast approach could have widespread application to a variety of other muscle diseases besides Duchenne muscular dystrophy.......... Perhaps these conditions will be among the first for which the promise of stem-cell technology for degenerative disorders can be realized.
15 - (IN PRESS: Nature, 2006) Mesoangioblast stem cells ameliorate muscle function in dystrophic dogs
Maurilio Sampaolesi, Stephane Blot, Giuseppe D’Antona, Nicolas Granger, Rossana Tonlorenzi, Anna Innocenzi, Paolo Mognol, Jean-Laurent Thibaud, Beatriz G. Galvez, Ines Barthelemy, Laura Perani, Sara Mantero, Maria Guttinger, Orietta Pansarasa, Chiara Rinaldi, M. Gabriella Cusella De Angelis, Yvan Torrente, Claudio Bordignon, Roberto Bottinelli
& Giulio Cossu - Italy and FranceDuchenne muscular dystrophy remains an untreatable genetic disease that severely limits motility and life expectancy in affected children. The only animal model specifically reproducing the alterations in the dystrophin gene and the full spectrum of human pathology is the golden retriever dog model. Affected animals present a single mutation in intron 6, resulting in complete absence of the dystrophin protein, and early and severemuscle degeneration with nearly complete loss of motility and walking ability. Death usually occurs at about 1 year of age as a result of failure of respiratory muscles. Here we report that intra-arterial delivery of wild-type canine mesoangioblasts (vessel-associated stem cells) results in an extensive recovery of dystrophin expression, normal muscle morphology and function (confirmed by measurement of contraction force on single fibres). The outcome is a remarkable clinical amelioration and preservation of active motility. These data qualify mesoangioblasts as candidates for future stem cell therapy for Duchenne patients.
Stem cell tests offer muscular dystrophy hope
11 - (IN PRESS: J.Appl.Physiol., 2006)The role of free radicals in muscular dystrophy
Null mutation of members of the dystrophin protein complex can cause progressive, and possibly fatal, muscle wasting. Although these muscular dystrophies arise from mutation of a single gene that is expressed primarily in muscle, the resulting pathology is complex and multi-systemic. Prior to the identification of the deficient proteins that underlie muscular dystrophies such as Duchenne muscular dystrophy (DMD), oxidative stress was proposed as a major cause of the disease. Now, current knowledge indicates that interactions between the primary genetic defect and disruptions in the production of free radicals contribute these diseases. In this review, we focus on the pathophysiology of dystrophin-deficiency in humans with DMD and the mdx mouse model of DMD. Current evidence indicates three routes through which free radical production can be disrupted in dystrophin-deficiency and promote pathology. First, constitutive differences in free radical production can disrupt signaling in muscle and other tissues and exacerbate pathology. Second, tissue responses to the pathology can shift free radical production to promote cellular injury and dysfunction. Finally, behavioral differences in the affected individual can cause changes in the production free radicals and contribute to disease. Unfortunately, the complexity of the free radical mediated processes that are perturbed in muscular dystrophy makes it difficult to develop therapies founded on systemic administration of anti-oxidants. More mechanistic knowledge of the specific disruptions of free radicals that underlie major features of muscular dystrophy is needed to develop more targeted therapeutic approaches.
11 - (IN PRESS: British Journal of Anaesthesia, 2006 97(6):851-7) Spinal fusion surgery in children with non-idiopathic scoliosis: is there a need for routine postoperative ventilation?
Background. The perioperative management of children with non-idiopathic scoliosis undergoing spinal deformity surgery has not been standardized and the current practice is to routinely ventilate these patients in the postoperative period. This study reports the experience from a single institution and evaluates the need and reasons for postoperative ventilation. Details of ventilated patients are presented.
Methods. All patients undergoing spinal fusion surgery for non-idiopathic scoliosis were recorded prospectively (2003–4). Patients were anaesthetized according to a standardized technique. Physical characteristics, cardiopulmonary function, intraoperative blood loss and fluid requirement, postoperative need for ventilation and all perioperative adverse events were recorded on a computer database.
Results. A total of 76.2% of patients were safely extubated at the end of surgery without any further complications or need for re-ventilation; 23.8% of patients required postoperative ventilation with half of the cases being planned before operation and 40% of all patients with Duchenne muscular dystrophy (DMD) required postoperative ventilation. There were no specific factors that could predict the need for postoperative ventilation, although an increased tendency for children with DMD and those with a preoperative forced vital capacity <30% towards requiring postoperative ventilation was observed.
Conclusions. Early extubation can be safely performed after spinal deformity surgery for non-idiopathic scoliosis. The use of short-acting anaesthetics, drugs to reduce blood loss, experienced spinal anaesthetists and the availability of intensive care support are all essential for a good outcome in patients with neuromuscular disease and cardiopulmonary co-morbidity.
OCTOBER - 2006
31 - (IN PRESS:International Journal of Cardiology, 2006) B-type natriuretic peptide and cardiac dysfunction in Duchenne muscular dystrophy - Letter to the Editor
Tayyab Mohyuddin, Irwin B. Jacobs, Robert C. Bahler - USA
Serum levels of B-type natriuretic peptide have moderate utility for detection of early ventricular dysfunction in adults and in experimental muscular dystrophy. To determine if B-type natriuretic peptide levels are useful in the detection of early left ventricular dysfunction in Duchenne muscular dystrophy patients, measurements were obtained in 21 patients being evaluated by echocardiography for left ventricular dysfunction. Two patients with clinical evidence of heart failure were excluded (mean B-type natriuretic peptide level of 352 pg/ml). Age range of the remaining 19 patients was 9–21 yrs. Fractional shortening was abnormal (<30%) in 14/19 and early diastolic tissue Doppler velocities were abnormal in 13/16. In these patients B-type natriuretic peptide levels were clearly normal (<30 pg/ml) in 15/19 and only mildly elevated (30–80 pg/ml) in 4/19. The 4 patients with mildly elevated B-type natriuretic peptide had significantly lower fractional shortening (12.6±5.9 versus 19.8±5.3, p<0.05). In conclusion, B-type natriuretic peptide levels are normal in the majority of Duchenne muscular dystrophy patients with asymptomatic left ventricular dysfunction and only mildly elevated when fractional shortening is markedly reduced.
29 - Curcumin Attenuates Dystrophic
Pathology in mdx Mice through Inhibiting NF-κB Activation
M. S. Zhu, C. Chen, Y. L. Hu, S. Chen - China
The dystrophin-glycoprotein complex has emerged as a scaffold responsible for
the membrane docking of signaling proteins. There is no definitive cure
available currently. In dystrophin-deficient muscular dystrophy, abnormal
activation of signal pathways may play important roles in dystrophic
pathogenesis. In this report, we found a natural botanical gradient, curcumin,
capable of attenuating dystrophic pathology significantly and the mechanism
underlying was involved in NF-κB inhibition. After treating X-linked muscular
dystrophy (mdx) mice with 1 to 10 mg of curcumin, the sarcolemmic
integrity assessed by Evans blue staining and muscle strength determined both by
grip strength test and traction test were improved significantly. Histological
analysis demonstrated that curcumin reduced severity of myofibril necrosis and
extent of regenerating fibers as well as the variability in size of fibers.
Creatine kinase level and the expressions of tumor necrosis factor alpha,
interleukine-1 beta and inducible nitric oxide synthase were decreased also
after curcumin treatment. Consistently, elevated NF-κB activity in muscle fibers
of mdx mice decreased after curcumin administration. Since curcumin is a
non-toxic compound derived from C.longa, which was widely used in
healthy food. The possible effect of curcumin may be worth studying in Duchenne
muscular dystrophy therapy.
(46th Annual Meeting American Society for Cell Biology - San Diego, December
2006)
SOUTH PLAINFIELD, NJ – October 21, 2006 -
PTC Therapeutics, Inc. (PTC), a biopharmaceutical company focused on the
discovery and development of small-molecule drugs targeting post-transcriptional
control processes, today announced encouraging data from a Phase 2 clinical
trial of PTC124 in patients with Duchenne muscular dystrophy (DMD) due to a
nonsense mutation. The results imply pharmacological activity based on
preliminary data that suggest increases in dystrophin in muscle biopsies in a
number of patients and statistically significant improvements in muscle enzymes
in serum. The preliminary data were presented today at the PPUK 4th
International DMD Conference in London, England.
“These results are the first example of an oral therapy addressing the
underlying cause of DMD by restoring dystrophin production,” said Dr. Richard
Finkel, Director of the Neuromuscular Program, Children’s Hospital of
Philadelphia, PA, one of the trial’s lead investigators. “There are limited
therapeutic options for patients living with DMD, and these data strongly
indicate PTC124 warrants further clinical investigation in this patient
population, which has a great unmet medical need.”
Langdon Miller, M.D., Chief Medical Officer,
PTC, stated, “These preliminary results in patients with DMD provide
confirmation of proof of concept that PTC124 can induce ribosomal readthrough of
nonsense mutations as an approach to treating genetic disorders. Given that
PTC124 was very well-tolerated and activity was observed at lower-than-expected
plasma concentrations, we are amending this trial to evaluate higher dose levels
and the potential to further increase dystrophin expression.”
“In the first half of 2007, we expect to present the final data set from this
Phase 2 clinical trial and meet with regulatory authorities to determine the
next steps for further clinical development of PTC124. Following these
discussions, we hope to initiate longer-term clinical trials for PTC124 in
2007,” said Dr. Miller.
Patients with DMD who lack dystrophin, a protein that is critical to the
structural stability of muscle fibers. This Phase 2 multi-site, open-label,
dose-ranging clinical trial is evaluating muscle dystrophin expression in
patients with nonsense-mutation-mediated DMD. Blood levels of muscle-derived
creatine kinase are being measured as assessments of muscle integrity. PTC124
safety, compliance, and pharmacokinetics are also being evaluated.
Patients included in the interim analysis
were enrolled at three clinical sites in the United States: Children's Hospital
of Philadelphia, Philadelphia, Pennsylvania; Cincinnati Children's Hospital
Medical Center, Cincinnati, Ohio; and the University of Utah, Salt Lake City,
Utah. In the study, patients received 28 days of PTC124 treatment at one of two
dose levels. All patients were boys with a nonsense mutation in the dystrophin
gene, substantially elevated serum creatine kinase, and symptoms associated with
DMD.
Assessment of the in vitro effects of PTC124 on dystrophin expression showed
dose-dependent production of full-length dystrophin in myocytes obtained from
multiple study subjects; these data suggest the potential for response across of
range of early to late nonsense mutations within the dystrophin gene. Evaluation
of the in vivo effects of PTC124 over the 28-day treatment course suggest an
increase in dystrophin expression in muscle biopsies in a number of the boys
participating in the trial, although quantitative analysis is not yet complete.
Statistically significant reductions in the concentrations of muscle-derived
creatine kinase levels in the blood were observed during PTC124 treatment.
Although no formal questionnaire was used to collect data on changes in
DMD-related symptoms, several parents and teachers reported that boys
participating in the study had improvements in terms of greater activity level
and increased endurance during treatment.
PTC124 was well tolerated among the 26 patients included in the study.
Potentially drug-related adverse events were infrequent, mild to moderate in
severity, did not result in therapy interruptions or discontinuations, and were
reversible. There were no safety concerns based on physical examinations, vital
sign measurements, electrocardiograms, or laboratory parameters. Compliance was
excellent at both dose levels.
“These preliminary results are very encouraging and add to the growing body of
clinical evidence supporting the potential of PTC124 as a treatment for genetic
disorders due to a nonsense mutation,” said Stuart W. Peltz, Ph.D., President
and Chief Executive Officer of PTC Therapeutics. “The findings in the DMD trials
are consistent with the results observed in Phase 2 clinical trials of PTC124 in
patients with cystic fibrosis. We intend to extend this concept into other
nonsense-mediated genetic disorders.
20 -
FDA AWARDS PTC THERAPEUTICS
ORPHAN PRODUCTS DEVELOPMENT GRANT FOR THE DEVELOPMENT OF PTC124 IN DUCHENNE
MUSCULAR DYSTROPHY - Preliminary Data to be Presented at Parent Project UK
Muscular Dystrophy Conference
17 - Readthrough strategies for stop codons in Duchenne muscular dystrophy
16 - (IN PRESS:Lancet Neurology. 5(11):906, 2006) Deacetylase inhibitors aid recovery in muscular dystrophy
Ian Anderson
In a mouse model of muscular dystrophy, deacetylase inhibitors promote the recovery of dystrophic muscles, according to a new study (Nat Med 2006). Interventions that increase myofibre size have previously been shown to counteract the decline in function seen in dystrophic muscle tissue.
“I think the evidence that a pharmacological intervention counters myofibre degeneration by enhancing regeneration in dystrophic muscles, without restoring dystrophin expression, is remarkable”, said study author Lorenzo Puri (Institute of Cell Biology and Tissue Engineering, Rome, Italy, and Burnham Institute, California, USA).
The researchers gave a 3 month course of the deacetylase inhibitor trichostatin A (TSA) to dystrophin-deficient (MDX) mice and observed its effects on dystrophic muscle strength and exercise tolerance. The team also histologically examined the myofibre cross-sectional area and the sarcolemma integrity (sarcolemma instability being a pathogenic feature of the muscular dystrophy model) at the end of the study period. TSA was selected following a small pilot study, which found it to be well tolerated, having no noticeable side-effects of increased mortality.
The force of contraction per cross-sectional square metre among MDX mice was shown to be lower than that of the controls, a deficit that was restored following treatment with TSA. On treadmill testing, MDX mice became exhausted faster than did the control group, but TSA-treated mice showed a full recovery of exercise performance. Sarcolemma integrity was shown to be greater in TSA-treated MDX mice than in untreated MDX mice. Histological analysis of myofibre size showed that the cross-sectional area of TSA-treated MDX mice myofibres was nearly twice that of the untreated MDX group.
Discussing the implications of the study, Puri added: “Deacetylase inhibitors are already used in clinical practice and can therefore be a suitable strategy for a pharmacological treatment of muscular dystrophy.”
“One should be extremely careful in proposing a clinical relevance for humans from the findings presented in this paper”, commented Helge Amthor (University Hospital of Essen, Essen, Germany), adding: “The drugs used are potentially very toxic in humans when given in high doses and the therapeutic strategy should be tested in the dystrophic dog before entering human trials.”
14 - (IN PRESS:CHEST, 130(4) Supplement. October 2006)
LUNG FUNCTION IMPAIRMENT AND REHABILITATION STRATEGY FOR PATIENTS WITH MUSCULAR DYSTROPHY
PURPOSE: To compare the characteristics of lung function impairment in three groups of patients with Becker’s Muscular Dystrophy(BMD) and Duchenne’s Muscular Dystrophy(DMD) and try to approach the rehabilitation strategy.
METHODS: Lung function were measured and compared among three groups of Muscular Dystrophy patients. Patients in Group A suffered from BMD. Patients in Group B were those with DMD and insisted on long-term rehabilitation exercise, while patients in Group C were those with DMD and nearly never had rehabilitation exercise.
RESULTS:Lung function parameters of Group A were in normal range as the following: FVC% was 82±15%, FEV1% was 91±18%•MVV% was 98±32%. Lung function was impaired in both Group B and Group C. In Group B, FVC% was 64±11%•FEV1% was 74±13%•MVV% was 82±19%. In Group C, FVC% was 37±12%•FEV1% was 43±15%•MVV% was 52±19%. There were statistically significant differences among the three groups in FVC%, FEV1% and MVV% (P<0.05), while no significant differences in FEV1/FVC (P>0.05).
CONCLUSION: Although the main lung function parameters of BMD patients were in normal range, the abnormally increased FEV1/FVC in both BMD and DMD patients demonstrated that restrictive ventilation disorder was common characteristic in patients with muscular dystrophy.
CLINICAL IMPLICATIONS:Rehabilitation exercise might be helpful for slowing the lung function deterioration, while rehabilitation exercise specifically aiming at respiratory muscles might be more helpful in that it could improve the restrictive ventilation disorder in muscular dystrophy patients.
MAJOR NONCARDIOPULMONARY COMPLICATIONS AMONG PATIENTS WITH DUCHENNE MUSCULAR DYSTROPHY WHO EXPERIENCE PROLONGED SURVIVAL THROUGH ASSISTED VENTILATION
PURPOSE: Survival among patients with Duchenne muscular dystrophy (DMD) has increased due to improved cardiopulmonary management. However, due to prolonged survival, patients are now exposed to the risk of developing major medical complications. In this report, we describe the frequency and nature of major non-cardiopulmonary complications in patients with DMD and prolonged survival due to use of assisted ventilation.
METHODS: Retrospective chart review of all pts with DMD in our clinic who are alive and over 20 years of age. Prolonged survival was attributed to assisted ventilation if the pt lived for > 5 years after vital capacity fell below 1 liter (Phillips et al AJRCCM, 2001).
RESULTS: 27 pts in our clinic are alive and > 20 yrs old. Complications: 15 pts have malnutrition/dysphagia requiring gastrostomy tube placement; 6 pts have renal calculi; 2 pts have diabetes and use insulin; 2 pts have deep venous thrombosis and were anti-coagulated; 1 pt has gallstones; 1 pt has inflammatory bowel disease. Of the 19 pts with one or more of these complications, 16 use noninvasive positive pressure ventilation (NPPV) and 2 are ventilated via tracheostomy. The 18 pts using assisted ventilation have thusfar survived a mean (+/- SD) of 6.5 +/- 4.3 yrs after their vital capacity fell below one liter (with 12 of 18 pts surviving > 5 years past the fall below one liter). Their mean survival thusfar after starting assisted ventilation is 7.6 +/- 3.8 yrs. Twelve of the 18 pts are ventilated 24 hrs/day.
CONCLUSION: Our pts with DMD who achieve prolonged survival through the use of assisted ventilation experience a high incidence of major non-cardiopulmonary medical complications. Therapy for these complications, such as gastrostomy placement, urologic procedures, anti-coagulation and insulin use, imposes additional risks.
CLINICAL IMPLICATIONS: These findings have significant implications regarding potential morbidities, burden of care and medical management in pts with DMD whose survival is prolonged by long-term mechanical ventilation.
BENEFIT OF THE PEDIATRIC INTENSIVE CARE UNIT TO INITIATE LONG-TERM NONINVASIVE VENTILATION IN PATIENTS WITH MUSCULAR DYSTROPHY: AN EXAMPLE OF FORWARD-DIRECTED ICU CARE (FDIC)
PURPOSE: Acute medical care is the primary goal of the pediatric intensive care unit (PICU). Another potential benefit of admission to the PICU for patients (pts) with chronic diseases is the initiation of long-term therapies which may improve survival. We call this use of the ICU to initiate beneficial chronic therapies “forward-directed ICU care” (FDIC). We hypothesized that pts with severe Duchenne muscular dystrophy (DMD) who start long-term noninvasive positive pressure ventilation (NPPV) during acute respiratory illness in the PICU may benefit by prolonged survival (an example of FDIC).
METHODS: Retrospective chart review of all pts with DMD who had NPPV initiated in our PICU during the time period 9/93 to 3/01. Definition of prolonged survival: survival for > 5 yrs after fall in vital capacity below 1 liter (Phillips et al, AJRCCM, 2001).
RESULTS: 9 pts with DMD started NPPV in the PICU during the time period. Reason for admission: pneumonia (7 pts), acute respiratory failure (2 pts). Age at NPPV initiation: 18.0 +/- 4.6 yrs (all data mean +/- SD). 8 of 9 pts are alive and 7 pts still use NPPV, 5 of them 24 hrs/day. One pt required tracheostomy after 5.6 yrs on NPPV. Current age of survivors: 27.2 +/- 5.4 yrs. Duration of NPPV use (to current date for 7 pts; to date of tracheostomy or death for 1 pt each): 8.9 +/- 2.7 yrs. Mean survival with NPPV after vital capacity fell below 1 liter: 7.4 +/- 4.1 yrs (with 6 of 9 pts thusfar surviving > 5 yrs after v.c. fell below 1 liter).
CONCLUSION: Initiation of NPPV during acute illness in the PICU resulted in prolonged survival for most of our 9 pts with severe DMD, and the majority of them now use NPPV 24 hrs/day.
CLINICAL IMPLICATIONS: This use of the acute care setting of the PICU to initiate a therapy with long-term benefit is an example of forward-directed ICU care or FDIC, a concept with potential applications to many chronic illnesses.
11- (IN PRESS:International Journal of Biochemistry & Cell Biology, 2006) Duchenne Muscular Dystrophy: Focus on pharmaceutical and nutritional interventions
Radley H.G., De Luca A., Lynch G.S., Grounds M.D. - Australia and Italy
Duchenne muscular dystrophy is a lethal X-linked muscle disease resulting from a defect in the muscle membrane protein dystrophin. The absence of dystrophin leads to muscle membrane fragility, muscle death (necrosis) and eventual replacement of skeletal muscle by fat and fibrous connective tissue. Extensive muscle wasting and respiratory failure results in premature death often by the early 20s. This short review evaluates drug and nutritional interventions designed to reduce the severity of muscular dystrophy, while awaiting the outcome of research into therapies to correct the fundamental gene defect. Dietary supplementation with amino-acids such as creatine in combination with specific anti-inflammatory drugs might have immediate realistic clinical benefits although rigorous research is required to determine optimal combinations of such interventions.
10 - (IN PRESS:European Journal of Paediatrics Neurology, 2006) Feeding problems and weight gain in Duchenne muscular dystrophy
Marika Pane, Isabella Vasta, Sonia Messina, Domenica Sorleti, Annie Aloysius, Federico Sciarra, Fortunato Mangiola, Maria Kinali, Enzo Ricci and Eugenio Mercuri - Italy
The aim of the study was to conduct a survey using a dedicated questionnaire to estimate feeding difficulties, gastrointestinal involvement and weight gain in a population of 118 Duchenne muscular dystrophy (DMD) patients (age range 13.80–35.8 years). All the answers were entered in a database and the data analysed subdividing the cohort into age groups (3–9, 9–13, 13–18, 18–24, 24–30, 30–36 years). The results indicate that chewing difficulties are frequent and become increasingly present with age, associated with a progressive increase of the duration of meals. Episodes of choking or other clinical signs of swallowing difficulties are in contrast much less frequent even after age 18. Aspiration pneumonia were also not very frequent and only occurred in 7/118. Clinical signs of gastroesophageal reflux requiring treatment were only found in 5 while 43/118 complained of constipation requiring treatment. Very few of our patients had their weight above 2 SD (n=4) and this was always found in patients between 9 and 18 years while after this age there was an increasing number of patients with weight below 2 SD. The results of our survey suggest that although choking is one of the most feared complications in patients with DMD, clinical signs of swallowing abnormalities are infrequent when collecting clinical information retrospectively. Further studies using an objective evaluation such as videofluoroscopy are needed to identify minor signs that may not be obvious on clinical examination.
9 - (IN PRESS:Molecular Therapy.14(5):724-734, 2006) The Mouse Dystrophin Muscle Promoter/Enhancer Drives Expression of Mini-dystrophin in Transgenic mdx Mice and Rescues the Dystrophy in These Mice
Carrie L. Anderson, Yves De Repentigny, Carlo Cifelli, Philip Marshall, Jean-Marc Renaud, Ronald G. Worton and Rashmi Kothary - Canada
Successful gene therapy for Duchenne muscular dystrophy (DMD) requires the restoration of dystrophin protein in skeletal muscles. To achieve this goal, appropriate regulatory elements that impart tissue-specific transgene expression need to be identified. Currently, most muscle-directed gene therapy studies utilize the muscle creatine kinase promoter. We have previously described a muscle enhancer element (mDME-1) derived from the mouse dystrophin gene that increases transcription from the mouse dystrophin muscle promoter. Here, we explore the use of this native mouse dystrophin muscle promoter/enhancer to drive expression of a human dystrophin minigene in transgenic mice. We show that the dystrophin promoter can provide tissue-specific transgene expression and that the mini-dystrophin protein is expressed at the sarcolemma of skeletal muscles from mdx mice, where it restores the dystrophin-associated glycoprotein complex. The level of transgene expression obtained is sufficient to protect mdx muscles from the morphological and physiological symptoms of muscular dystrophy, as well as from exercise-induced damage. Therefore, the dystrophin muscle promoter/enhancer sequence represents an alternative for use in gene therapy vectors for the treatment of DMD
9 - (IN PRESS:Journal of Prosthetics & Orthotics. 18(4):111-19, 2006) Lower Limb Orthotic Management of Duchenne Muscular Dystrophy: A Literature Review.
Phillip M. - USA
Although currently incurable, Duchenne
muscular
dystrophy remains treatable. The
characteristic gradual loss of functional muscle and the concurrent developments
of progressive contracture are often indications for orthotic interventions. As
the disease progresses through the abbreviated life of the young man, he will
encounter three functional stages: independent ambulation, assisted ambulation,
and wheelchair mobility. Although controversy continues as to the appropriate
role of orthoses during each of these stages, some generalities may be gleaned
from a review of published literature. Specific patterns of weakness,
accommodation, and contracture development characterize the initial stage of
independent ambulation. Orthotic intervention is often confined to nighttime
splints to slow the development of equinus contracture. As weakness and
contracture progress, balance becomes increasingly precarious, and independent
ambulation is ultimately precluded. Many authors have suggested that a degree of
ambulation may be maintained during this phase by combinations of surgery,
knee-ankle-foot orthoses and aggressive rehabilitation. The popularity of such
procedures has declined since its peak in the 1970s and 1980s. Appropriate
timing, patient selection, and rehabilitation appear to be essential in
obtaining optimal outcomes. Weakness and contracture continue to progress until
even assisted ambulation is precluded and wheelchair confinement ensues. Some
authors have suggested a limited role of orthotic intervention in the form of
postoperative positional ankle-foot orthoses to prevent recurrence of
deformities. The relevance of corticosteroids, fracture incidence, and cognitive
ability are also discussed.
7 - Correction of neuromuscular scoliosis in patients with preexisting respiratory failure
5 - Drug may help treat muscular dystrophy
Angiotensin II Type 1 Receptor Blockade Improves TGFb-induced Failure of Muscle Regeneration in the mdx Mouse Model of Duchenne Muscular Dystrophy.
R.D. Cohn, J.P. Habashi, B.L. Loeys, E.C. Klein, M. Gamradt, T.M. Holm, D.P. Judge, H.C. Dietz USA
We have previously shown that increased TGFb activity causes abnormal muscle regeneration and myopathy in fibrillin-1 deficient mice, a model of Marfan syndrome. Systemic antagonism of TGFb via administration of TGFb-neutralizing antibody or the angiotensin II type 1 receptor (AT1) blocker losartan restores abnormal muscle regeneration and prevents subsequent development of myopathic features. Impaired satellite cell performance and muscle repair has also been shown to play a significant role in the disease progression of various forms of muscular dystrophy. Here we demonstrate that myopathic changes in the dystrophin-deficient mdx mouse model of Duchenne muscular dystrophy associates with excessive TGFb signaling, as evidenced by increased phosphorylation of pSmad2/3. Systemic TGFb antagonism via losartan improves the satellite cell response to toxin induced-injury in the mdx mouse. Losartan treated mdx mice have improved steady-state muscle architecture and a near-normal amount of actively regenerating, neonatal myosin positive fibers four days after induced injury. After 18 days, losartan-treated mdx mice show only minimal amount of fibrosis, as demonstrated by vimentin expression, when compared to placebo-treated mice. Moreover, long-term administration of losartan leads to improved functional performance as demonstrated by increased muscle grip strength and decreased muscle fatigue in mdx mice. Together, our data demonstrate that treatment with the FDA approved medication losartan attenuates TGFb-induced failure of muscle regeneration and represents a promising therapeutic strategy for the treatment of Duchenne muscular dystrophy. Given that losartan is widely used to treat hypertension and has an exceptional tolerance profile in all age groups, we propose that a clinical trial using losartan is warranted.
SEPTEMBER - 2006
29 - Duchenne research report - Guenter Scheuerbrandt report
29 - (IN PRESS:Journal of Clinical Neuromuscular Disease 8(1):1-6, 2006) Assessment of Bone Mineral Density in Duchenne Muscular Dystrophy Using the Lateral Distal Femur
Harcke, H Theodore; Kecskemethy, Heidi H RD; Conklin, Dolores BA; Scavina, Mena; Mackenzie, William G; McKay, Charles P - USA
Objectives: To document lateral
distal femur (LDF) bone mineral density (BMD) values in children with Duchenne
muscular
dystrophy (DMD) and to examine the
potential for these measures to aid in their care.
Methods: Forty-seven boys with DMD had a total of 82 studies of BMD at
multiple sites (whole body, lumbar spine, distal femur). Measures were converted
to age-adjusted z-scores and analyzed for ambulatory status, steroid use, and
fracture history.
Results: Bone mineral density z-scores were significantly lower in the
whole body and LDF in children who were partially ambulatory and nonambulatory
when compared with children who were always ambulatory. With a positive history
of fracture, mean LDF z-scores were significantly lower when compared with mean
z-scores of children with no fractures. Lateral distal femur BMD correlated with
ambulation and fracture better than whole body and lumbar spine BMD.
Conclusions: The LDF is recommended as a more sensitive alternative to
lumbar spine for measure of BMD in children with DMD.
29 - (IN PRESS:Neuromuscular Disorders, 2006) Outpatient continuous inotrope infusion as an adjunct to heart failure therapy in Duchenne muscular dystrophy
Linda H. Cripe, Brent J. Barber, Robert L. Spicer , Brenda L. Wong ,Norbert Weidner , D. Woodrow Benson , Larry W. Markham - USA
We report the use of continuous intravenous inotrope infusion as a palliative management strategy for the treatment of symptomatic, refractory, end stage cardiac dysfunction in patients with Duchenne muscular dystrophy. Milrinone and/or dobutamine administered by continuous intravenous infusion provided symptomatic and objective cardiovascular improvement up to 30 months in 3 individuals with Duchenne muscular dystrophy and severe dilated cardiomyopathy. Continuous inotrope infusion should be considered a practical treatment strategy for end stage cardiac dysfunction in Duchenne muscular dystrophy patients when cardiac transplantation is not a viable option.
18 - Experimental cancer drugs counter muscle deterioration seen in muscular dystrophy
Pharmacological
interventions that increase myofiber size counter the functional decline of
dystrophic muscles. We show that deacetylase inhibitors increase the size of
myofibers in dystrophin-deficient (MDX) and
-sarcoglycan
(-SG)–deficient
mice by inducing the expression of the myostatin antagonist follistatin in
satellite cells. Deacetylase inhibitor treatment conferred on dystrophic muscles
resistance to contraction-coupled degeneration and alleviated both morphological
and functional consequences of the primary genetic defect. These results provide
a rationale for using deacetylase inhibitors in the pharmacological therapy of
muscular dystrophies.
16 -
Weekly oral prednisolone improves survival and strength in male mdx mice
16 - (IN PRESS:Journal of Neurology, Neurosurgery, and Psychiatry 2006;77:1177-1179) 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.
16 - Reliable surrogate outcome measures in multicenter clinical trials of duchenne muscular dystrophy
AUGUST - 2006
26 - Knee-ankle-foot orthosis in children with duchenne muscular dystrophy: User views and adjustment
22 - Abstracts from 11th International Congress of World Muscle Society - Bruges, Belgium, October 2006
1) A phase I/II clinical trial in Duchenne muscular dystrophy using IM and IV delivered antisense oligonucleotides: The MDEX consortium
2) Gene expression profiling to monitor therapeutic and adverse effects of antisense-induced exon skipping for Duchenne muscular dystrophy
3) Towards safe and efficient full-body delivery of antisense oligonucleotides for the treatment of Duchenne muscular dystrophy
4) Antisense oligonucleotide design for therapeutic antisense-mediated exon skipping for Duchenne muscular dystrophy
5) Improvement of muscle mass after injection of AAV vectors expressing either myostatin shRNA or Activin receptor IIb shRNA
6) Autologous transplantation of muscle-derived AC133+ stem cells
7) NT-proBNP is not associated with dilated cardiomyopathy in Becker and Duchenne muscular dystrophies
8) Revising the cardiac phenotype of Duchenne muscular dystrophy
9) Impaired platelet adhesion on collagen surfaces and secretion defect in Duchenne muscular dystrophy patients
10) The therapeutic effect of myostatin-blockade on muscular dystrophic mice and gene expression analysis of the treated muscles
11) The effects of prednisone on exercised-induced muscle damage in mdx mice
12) Quantitative ultrasound measurements of bone density DMD and SMA patients
13) Bone health in Duchenne muscular dystrophy
14) Functional ability monitoring in Duchenne muscular dystrophy using posture and walking time recording in a home environment
15) Is there a relationship between hamstring length and function in ambulant boys with Duchenne muscular dystrophy?
16) Predictive factors for the development of scoliosis in Duchenne muscular dystrophy
17) Does deflazacort treatment impact the surgical outcomes for boys with Duchenne muscular dystrophy?
18) CINRG pilot trial of oxatomide in steroid-naive Duchenne muscular dystrophy
19) Lower urinary tract symptoms in patients with Duchenne muscular dystrophy
20) Depression and functional evaluation in Duchenne muscular dystrophy according to family functionality
21) Protease inhibitors as potential treatment strategy for muscular dystrophies
22) Antisense-induced exon skipping in Duchenne muscular dystrophy patients
23) Rescue of dystrophin in the GRMD dog by multi-exon skipping using engineered U7 snRNAs
24) Vascular endothelial growth factor gene transfer using adeno-associated viral vectors stimulates skeletal muscle regeneration and enhances muscle function in mdx mice
21 - (IN PRESS:Neuromuscular Disorders, 2006) Induced dystrophin exon skipping in human muscle explants
G. McClorey, A.M. Fall, H.M. Moulton, P.L. Iversen, J.E. Rasko, M. Ryan, S. Fletcher, S.D. Wilton - Australia
Antisense oligonucleotide (AO) manipulation of pre-mRNA splicing of the dystrophin gene is showing promise in overcoming Duchenne muscular dystrophy (DMD)-causing mutations. To date, this approach has been limited to studies using animal models or cultured human muscle cells, and evidence that AOs can induce exon skipping in human muscle has yet to be shown. In this study, we used different AO analogues to induce exon skipping in muscle explants derived from normal and DMD human tissue. We propose that inducing exon skipping in human muscle explants is closer to in vivo conditions than cells in monolayer cultures, and may minimize the numbers of participants in Phase I clinical studies to demonstrate proof of principle of exon skipping in human muscle.
21 - (IN PRESS:Neuromuscular Disorders, 2006) Exercise improves the success of myoblast transplantation in mdx mice
Manaf Bouchentouf, Basma F. Benabdallah, Philippe Mills, Jacques P. Tremblay - Canada
Transplantation of normal muscle precursor cells is a potential approach to restore dystrophin expression within dystrophin [deficient] mdx mice, a model of Duchenne Muscular Dystrophy. This study aims to evaluate whether exercise could improve graft success and hybrid fiber distribution within mdx muscle. eGFP+ Muscle precursor cells were transplanted into tibialis anterior muscles of mdx mice using a single injection trajectory. During the following weeks, muscle fiber breaks were induced by making mdx mice swim. To evaluate fiber damage, Evans blue solution was injected intraperitoneally to mice 16 h before their sacrifice. Tibialis anterior muscles were then harvested and eGFP, dystrophin and Evans blue labeling were analyzed by fluorescent microscopy. Twenty minutes of exercise (i.e., swimming) were used to induce damage in about 30% of TA muscle fibers. Graft success, evaluated as the percentage of hybrid fibers which are eGFP+, was improved by 1.9-fold after swimming 3 times per week during 4 weeks and by 1.8-fold after daily swimming. Hybrid muscle fiber transversal and longitudinal distribution were also increased after repeated physical efforts. Exercise induced fiber breaks, which improved MPC recruitment and fusion and increased long-term graft success and also transverse and longitudinal distribution of hybrid fibers.
19 - 2006 Annual Conference Powerpoint Presentations
11 - USP advances in the treatment of muscular dystrophy
Sao Paulo - Scientists of Genome Human of Research Center of the University of Sao Paulo (USP) are getting important advances in the research of adult stem cell (not embryonic) gotten of a little conventional source: the residual fat of the techniques of lipoaspiration in clinics of plastic surgery. Adult stem cells from lipid tissue had been transformed into producing muscle cells of distrophin, an essential protein for patients with Duchenne muscular dystrophy, a genetic illness that cause degeneration of the muscles. According Natássia Vieira stem cell of lipid tissue can be so versatile than bone marrow stem cell. “Perhaps they are until more. I am trying to demonstrate this.” In this experiments in vitro they cast muscle cells of patients with stem cells from lipid tissue. This "treated cells" had started to produce dystrophin normally. “The expression levels had been compatible with healthful person”, said Natássia. The experiments had been made only in vitro, and many studies still are necessary until the technique can be tested in human. “It is only one first step, but an important step”, observes Mayana Zatz. The next ones are tests in mice and dogs. In Portuguese: http://www.estadao.com.br/saude/noticias/materias/2006/ago/11/45.htm
3 - (IN PRESS:THE AMERICAN JOURNAL OF CARDIOLOGY, 2006) Left Ventricular Function and Response to Enalapril in Patients With Duchenne Muscular Dystrophy During the Second Decade of Life
Claudio
Ramaciotti, Lisa C. Heistein, Melanie Coursey , Matthew S. Lemler, Reenu S.
Eapen, Susan T. Iannaccone and William A. Scott - Texas
The role of angiotensin-converting enzyme inhibitors in the
management of cardiomyopathy related to Duchenne muscular dystrophy has
not been completely defined. The purposes of this study were to describe the
response to enalapril and its relation to dystrophin mutation type, ventricular
size, or age at the onset of left ventricular (LV) systolic dysfunction. Serial
clinical and echocardiographic data from 50 patients with Duchenne muscular
dystrophy (aged 10 to 20 years) were retrospectively reviewed. Twenty-seven
patients (46%) developed LV systolic dysfunction (mean age 13.2 ± 2.4 years).
Ten (43%) responded to enalapril with the normalization of function. Responders
and nonresponders developed LV systolic dysfunction at similar ages (p = 0.91).
At the onset of LV systolic dysfunction, only 2 patients (1 responder, 1
nonresponder) had dilated left ventricles. The positive response to enalapril
was sustained in 7 patients (median follow-up 23 months, range 5 to 58). No
specific mutation was associated with the response to enalapril (p = 0.66) or
predictive of the development of LV systolic dysfunction (p = 0.8). In
conclusion, 10 of 26 patients (43%) with Duchenne muscular dystrophy responded
to the use of enalapril with normalization of the shortening fraction. Age at
the onset of LV systolic dysfunction and the type of mutation were not
predictors of response to enalapril
JULY - 2006
29 - Therapeutic restoration of dystrophin expression in Duchenne muscular dystrophy
26 - (IN PRESS: European Respiratory Journal, 2006) Diurnal ventilation via mouthpiece: survival in end-stage Duchenne patients
26 - Beta-blocker therapy for cardiac dysfunction in patients with muscular dystrophy
24 - (IN PRESS: Biochemical and Biophysical Research Communications , Jul 2006) Nitric oxide synthase is up-regulated in muscle fibers in muscular dystrophy
Karla Punkt, Stefan Schering, Sabine Löffler, Evgeny A. Minin, Vera E Samoilova, Martin Hasselblatt, Werner Paulus, Ursula Müller-Werdan, Uta Demus, Gabriele Koehler, Werner Boecker and Igor B. Buchwalow - Germany
Nitric oxide (NO) mediates fundamental physiological actions on skeletal muscle. The neuronal NO synthase isoform (NOS1) was reported to be located exclusively in the sarcolemma. Its loss from the sarcolemma was associated with development of Duchenne muscular dystrophy (DMD). However, new studies evidence that all three NOS isoforms—NOS1, NOS2, and NOS3—are co-expressed in the sarcoplasm both in normal and in DMD skeletal muscles. To address this controversy, we assayed NOS expression in DMD myofibers in situ cytophotometrically and found NOS expression in DMD myofibers up-regulated. These results support the hypothesis that NO deficiency with consequent muscle degeneration in DMD results from NO scavenging by superoxides rather than from reduced NOS expression.
23 - Dystrophin expression in mdx mice after bone marrow stem cells transplantation
23 - Myocardial strain changes in Duchenne muscular dystrophy without overt cardiomyopathy
10 -
(IN
PRESS: J. Cell Biol.,
Jul 2006)
Complete repair of dystrophic skeletal muscle by
mesoangioblasts with enhanced migration ability
Efficient delivery of cells to target tissues is a major problem
in cell therapy. We report that enhancing delivery of mesoangioblasts
leads to a complete reconstitution of downstream skeletal muscles
in a mouse model of severe muscular dystrophy (
-sarcoglycan
ko). Mesoangioblasts, vessel-associated stem cells, were exposed
to several cytokines, among which stromal- derived factor (SDF)
1 or tumor necrosis factor (TNF)
were the most potent in enhancing transmigration in vitro and
migration into dystrophic muscle in vivo. Transient expression of
4
integrins or L-selectin also increased several fold migration both in
vitro and in vivo. Therefore, combined pretreatment with SDF-1 or TNF-
and expression of
4
integrin leads to massive colonization (>50%) followed by
reconstitution of >80% of
-sarcoglycan–expressing
fibers, with a fivefold increase in efficiency in comparison
with control cells. This study defines the requirements for efficient
engraftment of mesoangioblasts and offers a new potent tool to
optimize future cell therapy protocols for muscular dystrophies.
10 - (IN PRESS: Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, 2006) Current Treatment of Adult Duchenne Muscular Dystrophy
Kathryn R. Wagner, Noah Lechtzin
and Daniel P. Judge - USAPatients with Duchenne muscular dystrophy (DMD) are living longer into adulthood due to a variety of improvements in health care practices. This growing patient population presents new therapeutic challenges. In this article, we review the literature on current treatment of adult DMD as well as our own experience as a multidisciplinary team actively caring for 23 men ages 19 -38 years of age. Approximately one quarter of our adult DMD patients have remained on moderate dose corticosteroids. Daily stretching exercises are recommended, particularly of the distal upper extremities. Cardiomyopathy is anticipated, detected, and treated early with afterload reduction. Oxygen saturation monitoring, noninvasive positive pressure ventilation and cough assist devices are routinely used. Other medical issues such as osteoporosis, gastrointestinal and urinary symptoms are addressed. Current and future therapies directed at prolonging the lifespan of those with DMD will result in further increases in this adult population with special needs and concerns. These needs are best addressed in a multidisciplinary clinic.
7 - (IN PRESS: J. Cell Sci., Jul 2006; 119: 2945 - 2952) Myogenic potential of adipose-tissue-derived cells
Adipose-tissue-derived mesenchymal stem cells can be directed towards a myogenic phenotype in vitro by the addition of specific inductive media. However, the ability of these or other adipose-tissue-associated cells to respond to `natural' myogenic cues such as a myogenic environment has never been investigated in detail. Here, we provide evidence that a restricted subpopulation of freshly harvested adipose-tissue-derived cells possesses an intrinsic myogenic potential and can spontaneously differentiate into skeletal muscle. Conversion of adipose-tissue-derived cells to a myogenic phenotype is enhanced by co-culture with primary myoblasts in the absence of cell contact and is maximal when the two cell types are co-cultured in the same plate. Conversely, in vitro expanded adipose-tissuederived mesenchymal stem cells require direct contact with muscle cells to generate skeletal myotubes. Finally, we show that uncultured adipose-tissue-associated cells have a high regenerative capacity in vivo since they can be incorporated into muscle fibers following ischemia and can restore significantly dystrophin expression in mdx mice.
5 - rAAV6-microdystrophin preserves muscle function and extends lifespan in severely dystrophic mice
JUNE - 2006
29 - (IN PRESS: Molecular Therapy, 2006) The Mouse Dystrophin Muscle Promoter/Enhancer Drives Expression of Mini-dystrophin in Transgenic mdx Mice and Rescues the Dystrophy in These Mice
Carrie L. Anderson, Yves De Repentigny, Carlo Cifelli, Philip Marshall, Jean-Marc Renaud, Ronald G. Worton, and Rashmi Kothary - Canada
Successful gene therapy for Duchenne muscular dystrophy (DMD) requires the restoration of dystrophin protein in skeletal muscles. To achieve this goal, appropriate regulatory elements that impart tissue-specific transgene expression need to be identified. Currently, most muscle-directed gene therapy studies utilize the muscle creatine kinase promoter. We have previously described a muscle enhancer element (mDME-1) derived from the mouse dystrophin gene that increases transcription from the mouse dystrophin muscle promoter. Here, we explore the use of this native mouse dystrophin muscle promoter/enhancer to drive expression of a human dystrophin minigene in transgenic mice. We show that the dystrophin promoter can provide tissue-specific transgene expression and that the mini-dystrophin protein is expressed at the sarcolemma of skeletal muscles from mdx mice, where it restores the dystrophin-associated glycoprotein complex. The level of transgene expression obtained is sufficient to protect mdx muscles from the morphological and physiological symptoms of muscular dystrophy, as well as from exercise-induced damage. Therefore, the dystrophin muscle promoter/enhancer sequence represents an alternative for use in gene therapy vectors for the treatment of DMD.
24 - (IN PRESS: Neurobiology of the Disease, 2006) Cromolyn administration (to block mast cell degranulation) reduces necrosis of dystrophic muscle in mdx mice
Hannah G. Radley and Miranda D. Grounds - Australia
7 - (IN PRESS: Molecular Therapy, 2006) Exploring the Frontiers of Therapeutic Exon Skipping for Duchenne Muscular Dystrophy by Double Targeting within One or Multiple Exons
Annemieke Aartsma-Rus, Wendy E. Kaman, Rudie Weij, Johan T. den Dunnen, Gert-Jan. B. van Ommen, and Judith C.T. van Deutekom - The Netherlands
Through antisense-induced single-, double-, and multiexon skipping, we have previously demonstrated restoration of dystrophin expression in Duchenne muscular dystrophy (DMD) patientderived muscle cells in vitro. In this study we further explored the frontiers of this strategy by using specific combinations of 2'-O-methyl phosphorothioate antisense oligonucleotides (AONs) targeting either one or multiple exons. We show that skipping efficiencies may indeed be improved by targeting two putative splicing regulatory sequences within one exon. In particular, such double targeting was effective for the thus far
"unskippable" exons 47 and 57. We previously reported the feasibility of multiexon skipping spanning exon 45 to exon 51, using a combination of AONs targeting both outer exons (45 and 51). This would be applicable to 13% of all DMD patients. We here explored the frontiers of multiexon skipping both to increase the number of patients that can be treated with the same set of AONs and to mimic large deletions found in relatively mildly affected BMD patients. We aimed at inducing larger multiexon-skipping stretches, such as exons 17–51, exons 42–55, and exons 45–59. However, this appeared complicated and may be dependent on cotranscriptional splicing and the size of the flanking introns.MAY - 2006
26 - Induction of revertant fibres in the mdx mouse using antisense oligonucleotides
17 - Management of scoliosis in Duchenne muscular dystrophy: a large 10-year retrospective study
13 - (IN PRESS: Clinica Chimica Acta, 2006) Altered expression, Intracellular distribution and activity of lymphocyte Calpain II in duchenne muscular dystrophy
Sundaram J. Shanmuga, Rao V. Mohana, Meena AK, Anandaraj MPJS, - Hyderabad
Background: Calpain II is an calcium dependent cysteine protease involved in essential regulatory or processing functions of the cell, mediated by physiological concentrations of Ca2+. However, in an environment of abnormal intracellular calcium in Duchenne muscular dystrophy (DMD), calpain is suggested to cause membrane alterations. Methods: Twelve individuals with dystrophin gene deletion and an equal number of age and sex matched controls were chosen for the study. The expression pattern of calpain II (both at RNA and protein levels), its cellular location upon activation and its activity in lymphocytes were specifically assessed to know if our earlier report of increased calpain activity in DMD lymphocytes is a result of de novo synthesis or is due to basic defect in calcium handling. Results: We found a significant increase in the expression, alteration in calpain II distribution and increased activity of this enzyme. Conclusion: Membrane abnormalities and altered signaling pathways observed in DMD lymphocytes may be due to increased association of calpain II onto membrane and cytosol.
11- (IN PRESS: Journal of Neuropathology & Experimental Neurology.65(4): 371-386, April 2006) Dystrophin Expression in Muscles of Duchenne Muscular Dystrophy Patients After High-Density Injections of Normal Myogenic Cells
Skuk, Daniel ; Goulet, Marlyne; Roy, Brigitte;
Chapdelaine,
Pierre; Bouchard, Jean-Pierre ; Roy, Raynald ; Dugre, Francine J. ; Sylvain, Michel ; Lachance, Jean-Guy ; Deschenes, Louise ;
Senay, Helene; Tremblay, Jacques P. - Canada
A clinical trial was conducted to test a new protocol of normal muscle precursor cell (MPC) allotransplantation in skeletal muscles of patients with Duchenne muscular dystrophy (DMD). Cultured MPCs obtained from one of the patient's parents were implanted in 0.25 or 1 cm3 of a Tibialis anterior in 9 patients with DMD. MPC injections were placed 1 to 2 mm from each other, and a similar pattern of saline injections was done in the contralateral muscle. The patients were immunosuppressed with tacrolimus. Muscle biopsies were performed at the injected sites 4 weeks later. In the biopsies of the cell-grafted sites, there were myofibers expressing donor's dystrophin in 8 patients. The percentage of myofibers expressing donor's dystrophin varied from 3.5% to 26%. Evidence of small myofiber neoformation was observed in some patients. Donor-derived dystrophin transcripts were detected by reverse transcriptase-polymerase chain reaction in the cell-grafted sites in all patients. The protocol of immunosuppression was sufficient to obtain these results, although it is not certain whether acute rejection was efficiently controlled in all the cases. In conclusion, intramuscular allotransplantation of normal MPCs can induce the expression of donor-derived dystrophin in skeletal muscles of patients with DMD, although this expression is restricted to the sites of MPC injection.
6 - (IN PRESS: Pediatrics, 2006;117) Controversy in cardiac evaluation and treatment in Duchenne Muscular Dystrophy - two comments about this article: Cardiovascular health supervision for individuals affected by Duchenne or Becker muscular dystrophy (December/03/2006)
1) Therapeutic Nihilism in Duchenne Cardiomyopathy
To the Editor.—
The recent American Academy of Pediatrics clinical report on cardiovascular supervision in Duchenne muscular dystrophy was overly nihilistic. Advances in diagnostic and therapeutic interventions were dismissed or ignored. The authors call for early recognition of cardiac dysfunction and acknowledge the limitations of echocardiography in scoliotic patients but do not mention B type natriuretic peptide. Assay of serum B-type natriuretic peptide is widely available and may identify patients with cardiac involvement even before symptoms develop. Several studies, including some cited in their report, suggest the possibility of significant benefit from both angiotensin-converting enzyme (ACE) inhibition and beta blockade in the treatment of Duchenne cardiomyopathy. There are no reports of significant unanticipated risk from these therapies. Unfortunately, optimal studies have not been conducted and may never be. The toll of cardiac disease on patients with muscular dystrophy is high, however, and safe, rational, and apparently effective modalities for evaluating and treating these patients are readily available. We should not dismiss their use out of hand.
Jeffrey Rein, MD, FAAP - El Rio Neighborhood Health Center - Tucson, AZ
2) In Reply.—
The Section on Cardiology and Cardiac Surgery appreciates the comments of Dr Rein in response to the American Academy of Pediatrics clinical report “Cardiovascular Health Supervision for Individuals Affected by Duchenne or Becker Muscular Dystrophy.” We believe the report is not “overly nihilistic” but provides cautious optimism to a group of patients who experience significant morbidity and mortality from the cardiomyopathy associated with their disease. As stated, the report provides “recommendations for optimal cardiovascular evaluation to health care specialists caring” for those with muscular dystrophy. The intent of the report was to alert the health care community to the need for earlier diagnosis and treatment and to provide minimum guidelines for cardiovascular care. Unfortunately, in many areas of this country, patients with Duchenne muscular dystrophy (DMD)/Becker muscular dystrophy (BMD) do not come to the attention of the cardiologist until they are approaching end-stage cardiomyopathy. At that point, traditional heart failure therapies are used although this approach has failed to alter the natural history of the disease. Until a cure is found, we are optimistic that early recognition can change DMD from a fatal to a chronic disease. The challenge lies in finding sensitive and specific markers to detect early cardiac dysfunction. Unfortunately, studies have not shown brain natriuretic peptide (BNP) elevation in DMD to meet the criteria as an early screening test. BNP levels become elevated in DMD relatively late in the disease process. In the article by Mori et al (cited by Rein), BNP elevation was minimal, with a shortening fraction as low as 15%. Individuals with shortening fractions < 15% did have dramatic increases in BNP. Demachi et al compared BNP levels between subjects with DMD/BMD and idiopathic dilated cardiomyopathy and ejection fraction < 50%. The study revealed dramatically lower BNP levels in subjects with DMD/BMD for a similar degree of dysfunction, leading the authors to conclude that “plasma BNP may underestimate the degree of systolic dysfunction in patients with muscular dystrophy.” This suggests that BNP is unlikely to be an ideal screening test for the presence of cardiac dysfunction in DMD/BMD. It is interesting to note that cardiovascular risk is inferred on the basis of genetic diagnosis, potentially allowing treatment to be initiated before the onset of clinical symptoms. In the absence of adequate clinical trials, cardiologists and families are left with only a handful of cited case series and reports to direct therapy. Although angiotensin-converting enzyme (ACE) inhibitor use is gaining attention in the presymptomatic patient with DMD/BMD, no multicenter prospective clinical trial exists regarding its efficacy at this time. Given the number of patients followed at each center in this country, a nationwide collaborative effort is required to obtain suitable evidence for inclusion of other therapies into official guidelines. A clinical report such as this leading to improved awareness is the first step to early cardiovascular evaluation and, ultimately, treatment.
Linda Cripe, MD and Larry Markham, MD - Division of Pediatric Cardiology Comprehensive Neuromuscular Care Program Cincinnati Children’s Hospital Medical Center - Cincinnati
APRIL - 2006
29 - Being the next of kin of an adult person with muscular dystrophy
29 - Respiratory muscle strength and cough capacity in patients with duchenne muscular dystrophy
27 - (IN PRESS: Journal of Neuroimmunology 2006) Immunomodulation of TGF-beta1 in mdx mouse inhibits connective tissue proliferation in diaphragm but increases inflammatory response: Implications for antifibrotic therapy
Francesca Andreetta, Pia Bernasconi, Fulvio Baggi, Paolo Ferro, Laura Oliva, Elisa Arnoldi, Ferdinando Cornelio, Renato Mantegazza, Paolo Confalonieri - Italy
Irreversible connective tissue proliferation in muscle is a pathological hallmark of Duchenne muscular dystrophy (DMD), a genetic degenerative muscle disease due to lack of the sarcolemmal protein dystrophin. Focal release of transforming growth factor-beta1 (TGF-h1) is involved in fibrosis development. Murine muscular dystrophy (mdx) is genetically homologous to DMD and histopathological alterations comparable to those in DMD muscles occur in diaphragm of older mdx mice. To investigate the early development of fibrosis and TGF-h1 involvement, we assessed diaphragms in 6–36-week-old mdx and C57/BL6 (control) mice for fibrosis, and used real-time PCR and ELISA to determine TGF-h1 expression. Significantly greater fibrosis and TGF-h1 expression were found in mdx from the 6th week. Mice treated with neutralizing antibody against TGF-h1 had lower levels of TGF-h1 protein, reduced fibrosis, unchanged muscles fiber degeneration/ regeneration, but increased inflammatory cells (CD4+lymphocytes). These data demonstrate early and progressive fibrosis in mdx diaphragm accompanied by TGF-h1 upregulation. Reduction of TGF-h1 appears promising as a therapeutic approach to muscle fibrosis, but further studies are required to evaluate long term effects of TGF-h1 immunomodulation on the immune system.
25 - Muscle engraftment of myogenic progenitor cells following intraarterial transplantation
25 - (IN PRESS: Gene Therapy 2006;13(9):744-51) Restoration of all dystrophin protein interactions by functional domains in trans does not rescue dystrophy
Gardner, K L; Kearney, J A; Edwards, J D ; Rafael-Fortney, J A - USA
Rescue of dystrophic
skeletal muscle in mdx and utrophin/dystrophin-deficient (dko) mouse models by
reintroduction of dystrophin has validated gene therapy as a potential
therapeutic approach for Duchenne muscular
dystrophy. However, the size of the
dystrophin gene exceeds the capacity of adeno-associated viral (AAV) vectors.
Dystrophin provides a mechanical link at the muscle membrane by direct binding
of its amino-terminal and cysteine-rich domains to actin and a transmembrane
protein complex, respectively. It has not been investigated whether restoration
of these two tethering functions by two separate dystrophin molecules is
sufficient to prevent dystrophic pathologies. We examine the effect of
coexpression of the amino-terminal and cysteine-rich domains from separate
dystrophin transgenes, [DELTA]cys and Dp71, on the dystrophic phenotype.
Expression of individual dystrophin domains from multiple vectors would
effectively expand AAV capacity. Although both [DELTA]cys and Dp71 colocalize at
the membrane, there is no improvement of dystrophic pathology. The fiber-type
and neuromuscular junction
abnormalities of dko mice that are ameliorated by the [DELTA]cys transgene are
not further improved or disrupted by Dp71. Separate truncated dystrophins, which
together restore all protein interactions and scaffolding for signaling
molecules, are not sufficient to ameliorate the dystrophic phenotype and
therefore dystrophin domains in trans cannot be used to increase the effective
cloning capacity for AAV-mediated gene therapy.
22 -
(IN
PRESS:
Pediatr Neurol 2006;34:296-300)
Are Males With Duchenne Muscular
Dystrophy at Risk for Reading Disabilities?
Jos G.M. Hendriksen, and Johan S.H. Vles, PhD - The Netherlands
Males with Duchenne muscular dystrophy have subaverage cognitive capacities and may manifest more specifically language-related deficits. In the current study, the information-processing capacity, reading performance, and behavioral functioning of 25 Dutch males with Duchenne muscular dystrophy (mean age 10.1 years) were systematically assessed. This study relied on the use of a new battery of tests to explore more precisely reading disabilities in males with Duchenne muscular dystrophy. Five of the males had serious reading problems and another five had moderate reading problems, which indicates that reading problems are significantly more common in males with Duchenne muscular dystrophy than in males from a normal population. These reading problems were independent of the level of information processing and behavioral functioning. Implications of these findings and possible directions for future research are discussed, especially with regard to the early detection and treatment of reading problems in males with Duchenne muscular dystrophy.
20 - (IN PRESS: Am J Physiol Endocrinol Metab - April 18, 2006) Systemic administration of IGF-I enhances oxidative status and reduces contraction-induced injury in skeletal muscles of mdx dystrophic mice
The absence of dystrophin and resultant disruption of the dystrophin glycoprotein complex renders skeletal muscles of dystrophic patients and dystrophic mdx mice susceptible to contraction-induced injury. Strategies to reduce contraction-induced injury are of critical importance because this mode of damage contributes to the etiology of myofiber breakdown in the dystrophic pathology. Transgenic over-expression of insulin-like growth factor-I (IGF-I) causes myofiber hypertrophy, increases force production, and can improve the dystrophic pathology in mdx mice. In contrast, the predominant effect of continuous exogenous administration of IGF-I to mdx mice at a low dose (1.0-1.5 mg/kg/day) is a shift in muscle phenotype from fast glycolytic toward a more oxidative, fatigue resistant, slow muscle without alterations in myofiber cross sectional area, muscle mass or maximum force producing capacity. We found that exogenous administration of IGF-I to mdx mice increased myofiber succinate dehydrogenase activity, shifted the overall myosin heavy chain isoform composition toward a slower phenotype, and most importantly, reduced contraction-induced damage in tibialis anterior (TA) muscles. The deficit in force producing capacity after two damaging lengthening contractions was reduced significantly in TA muscles of IGF-I treated (53 ± 4%) compared with untreated mdx mice (70 ± 5%, P < 0.05). The results provide further evidence that IGF-I administration can enhance the functional properties of dystrophic skeletal muscle and, when compared to results in transgenic mice or viral-mediated over-expression, highlight the disparities in different models of endocrine factor delivery.
15 - (IN PRESS: Journal of Bone and Joint Surgery - British Volume, Orthopaedic Proceedings Vol 88-B, Issue SUPP II, 228, 2006) SCOLIOSIS SURGERY IN DUCHENNE MUSCULAR DYSTROPHY: THE EFFECT ON RESPIRATORY FUNCTION
Background: There are conflicting reports regarding the effect of scoliosis surgery on respiratory function in Duchenne Muscular Dystrophy (DMD)1,2. Galasko et al2 found that the Percentage Predicted Forced Vital Capacity (%PFVC), remained static for thirty six months following surgery, in patients with DMD that underwent spinal stabilisation for scoliosis. The aim of the current study was to support or refute the above finding in a large series of patients with DMD.
Methods: A retrospective analysis of data on 55 consecutive patients with DMD that underwent single stage posterior surgical correction for scoliosis. We analysed the data of 55 boys with DMD who underwent scoliosis surgery between 1990 and 2002. Age at surgery, pre-operative Cobb angles, pre-operative %PFVC, and post-operative %PFVC at 6 months, 12-18 months and 2–3 years were collected. We documented the pre-operative Cobb angle ± SD to assess the difficulty level of our surgical cases. Percentage PFVC was used as our outcome measure to assess respiratory function. The mean pre-operative %PFVC was compared to the post –operative mean %PFVC at three different time intervals; at 6 months, 12 to 18 months and at 2 to 3 years.
Results: The mean age was 14.6 years (range 11.2–18yrs). The mean pre-operative Cobb angle was 65.4 degrees ± 14.8. The mean %PFVC pre-operatively was 33.9 ± 10.4. The mean post-operative %PFVC’s were: 6 months (29.1 ± 10.4), 12 to 18 months (27.6 ± 12.1) and 2 to 3 years (25.4 ± 8.7). Therefore the mean % PFVC following surgery at 6 months, 12 to 18 months and 2 to 3 years decreased from the mean pre-operative % PFVC by 4.8%, 6.3% and 8.5% respectively.
Conclusion: The natural history of patients with DMD is a gradual decline in respiratory function. In the current study the mean post –operative %PFVC was less than the mean pre-operative %PFVC at 6 months, 12 to 18 months and at 2 to 3 years post surgery. Our series would suggest that respiratory function declines post-operatively, even in the short term, in patients with DMD that undergo spinal stabilisation. The decline in respiratory function in our study was progressive over the 3 year follow up period.
15 - (IN PRESS: Journal of Bone and Joint Surgery - British Volume, Orthopaedic Proceedings Vol 88-B, Issue SUPP II, 232, 2006) BONE DENSITOMETRY IN PATIENTS WITH DIFFERENT TYPES SCOLIOSIS
Background: To evaluate bone mineral density in patients with scoliosis of different causes and compare it to the expected values for the age, gender and body mass.
Methods: A Prospective, observational case series. From October 2003 to December 2004, Bone Mineral Density (BMD) of patients with different types of Scoliosis was recorded. Patients listed for corrective spinal surgery in our institute were included in the study (Total of 68 patients). BMD on lumbar spine and whole body was measured by DXA scan and recorded in form of Z-scores. Z-scores = number of Standard Deviations (SD) above or below age matched norms; it is age and gender specific standard deviation scores. Data collected using the same DXA scan equipment and software.
There were 29 patients with Adolescent Idiopathic Scoliosis and 7 patients with congenital or infantile scoliosis. Z-scores from patients with neuromuscular scoliosis also included, 10 patients with cerebral palsy and 11 with muscular dystrophies (mainly Duchenne MD). There were also 3 patients with Neurofbromatosis and 8 patients with other conditions (miscellaneous). Outcome measures were bone mineral density in patients with different types of scoliosis in form of Z-scores.
Results: Bone mineral density was significantly lower than normal for the age, gender and body mass in all patients with neuromuscular scoliosis; whole body z-score in group with cerebral palsy was –1.00 and –1.30 in muscular dystrophies group. Lumbar spine BMD was even lower in lumbar spine, mean z-score, – 4.51 in cerebral palsy and –2.36 in muscular dystrophies (mainly Duchenne MD). In idiopathic Scoliosis group mean BMD was markedly lower than normal for the age, gender and body mass, mean z-score = – 1.87, however whole body BMD was within the normal range, mean z-score = +0.124. Similar results were found in congenital and infantile scoliosis group, mean lumber z-score= – 1.36 and whole body z-score, – 0.30. In patients with neurofibromatosis, there were low BMD on spine, mean z-score was –1.19 while whole body z-score was + 0.19. In group of patients with other miscellaneous causes of scoliosis or syndromic scoliosis lumbar mean z-score= –2.22 and whole body mean z-score was –1.67.
Conclusion: This study showed that BMD on spine was lower than normal for the age, gender and body mass in all patients with scoliosis and the condition was even worse in neuromuscular and sydromic scoliosis. There was no correlation between spine BMD and whole body BMD. Spine BMD was lower than normal in almost all patients even when whole body BMD was within normal range. Thus we believe that DXA scan is a useful adjunct in the preoperative assessment of scoliotic patients prior to spinal surgery
15 - (IN PRESS: Journal of Bone and Joint Surgery - British Volume, Orthopaedic Proceedings Vol 88-B, Issue SUPP II, 269, 2006) EVALUATION OF SINGLE ROD FUSION TECHNIQUE FOR SCOLIOSIS SECONDARY TO DUCHENNE MUSCULAR DYSTROPHY.
Introduction: Duchenne’s Muscular Dystrophy (DMD) is a progressive sex linked recessive disease, predominantly involving skeletal muscle. Scoliosis is almost universal in patients with DMD. Surgical stabilization carries a significant risks and complications with peroperative mortality of <6%. Cardiopulmonary complications along with severe intraoperative blood loss requiring massive blood transfusion are the major cause of morbidity
Aim: To evaluate the efficacy of single rod fusion technique in reducing the peroperative and post operative complications especially blood loss, duration of surgery and progression of curve
Material & Methods: Retrospective review – 14 patients with scoliosis secondary to DMD with an average age of 14.5 years (range, 11–17) underwent single rod fusion technique using Isola rod system and pelvic was not included in fixation. Blood loss was measured directly from the peroperative suction and post operative drainage, indirectly by weighing the swabs. Vapour free hypotensive anesthesia was used in all case. Progression of curve was monitored over a period of five years.
Results: The mean operative time was 110 min (range, 80 – 180). The average blood loss was 1.6L (range, 0.7 – 5). The mean follow up was 32 months (range, 4 – 60). There was no progression noticed in the curve on follow up. Two patients develop complications, one had loosening & migration of the rod, required revision and superficial wound infection treated with intravenous antibiotics.
Conclusion: In our experience, single rod stabilization is a safe and quick method of stabilizing the spine in DMD with less blood loss and complications compared to traditional methods.
6 - (IN PRESS: The American Journal of Clinical Nutrition, 2006) Oral glutamine and amino acid supplementation inhibit whole-body protein degradation in children with Duchenne muscular dystrophy
Background: Glutamine has been shown to acutely decrease whole-body protein degradation in Duchenne muscular dystrophy (DMD).
Objective: To improve nutritional support in DMD, we tested whether oral supplementation with glutamine for 10 d decreased whole-body protein degradation significantly more than did an isonitrogenous amino acid control mixture.
Design: Twenty-six boys with DMD were included in this randomized, double-blind parallel study; they received an oral supplement of either glutamine (0.5 g · kg–1 · d–1) or an isonitrogenous, nonspecific amino acid mixture (0.8 g · kg–1 · d–1) for 10 d. The subjects in each group were not clinically different at entry. Leucine and glutamine metabolisms were estimated in the postabsorptive state by using a primed continuous intravenous infusion of [1-13C]leucine and [2-15N]glutamine before and 10 d after supplementation.
Results: A significant effect of time was observed on estimates of whole-body protein degradation. A significant (P < 0.05) decrease in the rate of leucine appearance (an index of whole-body protein degradation) was observed after both glutamine and isonitrogenous amino acid supplementation [x ±SEM: 136 ± 9 to 124 ± 6 µmol · kg fat-free mass (FFM)–1 · h–1 for glutamine and 136 ± 6 to 131 ± 8 µmol · kg FFM–1 · h–1 for amino acids]. A significant (P < 0.05) decrease in endogenous glutamine due to protein breakdown was also observed (91 ± 6 to 83 ± 4 µmol · kg FFM–1 · h–1 for glutamine and 91 ± 4 to 88 ± 5 µmol · kg FFM–1 · h–1 for amino acids). The decrease in the estimates of whole-body protein degradation did not differ significantly between the 2 supplemental groups.
Conclusion: Oral glutamine or amino acid supplementation over 10 d equally inhibits whole-body protein degradation in DMD
6 - (IN PRESS: Human Molecular Genetics, 2006) Naturally occurring utrophin correlates with disease severity in Duchenne Muscular Dystrophy
Kleopas A. Kleopa,
Eleni Mavrikiou, Annita Ormiston, Anthi Drousiotou, and Theodoros Kyriakides - CyprusAlthough there is good experimental data that utrophin, the autosomal analogue of dystrophin, can ameliorate the phenotype in dystrophinopathies, there is scant evidence from human data to support this hypothesis. We investigated in diagnostic muscle biopsies from 16 patients with DMD the level of utrophin expression using quantitative immunoblot analysis. In 13 of 16 patients, in whom there was adequate follow up data, utrophin expression was correlated to two clinical endpoints; age at reaching Hammersmith score of 30/40 and age at becoming wheelchair bound. We found that utrophin expression increases with age in DMD and that there is a significant positive correlation between the quantity of utrophin at initial biopsy and time to becoming wheelchair bound.
3 - Abstract submissions to News Directions in Biology and Disease of Skeletal Muscle, April 23-26, Dallas, Texas ( http://www.med.upenn.edu/muscle )
Gene Expression Profiling to Monitor Therapeutic and Adverse Effects of Antisense Therapies for Duchenne Muscular Dystrophy
Towards Clinical Studies on Antisense-mediated Exon Skipping in Duchenne Muscular Dystrophy
Viral expression of IGF-IB drives proliferation at the expense of hypertrophy in mdx skeletal muscle
Designing oligonucleotides containing CpG modifications to recruit specific repair mechanisms leads to improved gene correction efficiency in skeletal muscles of mdx mice
Improved Quality of Life and Reduced Health Care Needs for Boys with Duchenne Muscular Dystrophy treated with Long-term Deflazacort
Evaluation of the olopatadine effect in the dystrophinopathy progression in mdx mice submitted to physical activity - from Brazilian Research Center
Association between AKT signaling and hypertrophic response of Duchenne and limb-girdle muscular dystrophies
Muscle-derived nitric oxide modulates adult neurogenesis in the brains of mdx mice
AAV-mediated Microdystrophin Expression Reduces Muscular Dystrophy in Symptomatic Utrophin/dystrophin Double Knock-out Mice
Increased cytokines, chemokines, and extracellular matrix proteins in 21-day mdx and mdx:utrophin-/- serum and diaphragm muscles
Systemic rAAV6-microdystrophin administration enhances skeletal muscle function and extends lifespan in the dystrophin-/utrophin- mouse model of severe muscular dystrophy
Anti-inflammatory drugs, or increased IGF-1 expression, reduce necrosis of dystrophic muscle
Mechanisms for dystrophin expression in BMD patients with premature stop codons and frameshift mutations in DMD exon 1
Genetic Modifiers of Muscular Dystrophy
NKT cells and Osteopontin Correspond with the Inflammatory Response in Mdx Muscular Dystrophy
Body-wide restoration of functional levels of dystrophin by intravenous delivery of antisense oligonucleotides alleviates pathology in dystrophic mice
Overcoming Immune Rejection in Myoblast Transplant Therapy through Hematopoietic Cell Transplantation
Aberrant Golgi Complex Organization in Dystrophin-Deficient Skeletal Muscle Fibers
Chronic treatment with the beta-adrenoceptor agonist formoterol deleteriously affects cardiac function in rats
Dystrophin and utrophin: sequence homologues with distinct functional mechanisms
Eosinophilia, a mediator of fibrosis in dystrophin-deficient muscle
Transplantation of SM/C-2.6+ satellite cells transduced with micro-dystrophin CS1 cDNA by lentiviral vector into mdx mice
Systemic gene delivery of of micro-dystrophin prevents acute heart failure in mdx mice
Local calcium release events in wildtype and dystrophic adult myofibers
Prevention of Lethal Muscular Dystrophy in a Severe DMD Mouse Model via Human Retinal Dystrophin Transgene: Implications for DMD Gene Therapy
Nanopolymer-oligonucleotides for the induction of dystrophin expression in mdx mice
Passive mechanical properties of maturing EDL are not affected by lack of dystrophin
MARCH - 2006
29- First clinical trial of gene therapy for muscular dystrophy now under way
Boy, 8, is pioneer for gene therapy
27 - (IN PRESS: Molecular Therapy, 2006) C-Terminal-Truncated Microdystrophin Recruits Dystrobrevin and Syntrophin to the Dystrophin-Associated Glycoprotein Complex and Reduces Muscular Dystrophy in Symptomatic Utrophin/Dystrophin Double-Knockout Mice
Yongping Yue, Mingju Liu, and Dongsheng Duany - USA
C-terminal-truncated (DC) microdystrophin is being developed for Duchenne muscular dystrophy gene therapy. Encouraging results have been achieved in the mdx mouse model. Unfortunately, mdx mice do not display the same phenotype as human patients. Evaluating DC microdystrophin in a symptomatic model will be of significant relevance to human trials. Utrophin/dystrophin doubleknockout (u-dko) mice were developed to model severe dystrophic changes in human patients. In this study we evaluated the therapeutic effect of the DR4-R23/DC microdystrophin gene (DR4/DC) after serotype-6 adeno-associated virus-mediated gene transfer in neonatal u-dko muscle. At 2 months after gene transfer, the percentage of centrally nucleated myofiber was reduced from 89.2 to 3.4% and muscle weight was normalized. Furthermore, we have demonstrated for the first time that DC microdystrophin can eliminate interstitial fibrosis and macrophage infiltration and restore dystrobrevin and syntrophin to the dystrophin-associated glycoprotein complex. Interestingly neuronal nitric oxide synthase was not restored. The most impressive results were achieved in muscle force measurement. Neonatal gene therapy increased twitch- and tetanic-specific force. It also brought the response to eccentric contraction-induced injury to the normal range. In summary, our results suggest that the DR4/DC microgene holds great promise in preventing muscular dystrophy.
23 - (IN PRESS: NeuroRX,3(2):225-34, 2006) Therapeutics in Duchenne Muscular Dystrophy - Review article
Jonathan B. Strober - USA
Duchenne muscular dystrophy (DMD) is a fatal disorder affecting approximately 1 in 3500 live born males, characterized by progressive muscle weakness. Several different strategies are being investigated in developing a cure for this disorder. Until a cure is found, therapeutic and supportive care is essential in preventing complications and improving the afflicted child’s quality of life. Currently, corticosteroids are the only class of drug that has been extensively studied in this condition, with controversy existing over the use of these drugs, especially in light of the multiple side effects that may occur. The use of nutritional supplements has expanded in recent years as researchers improve our abilities to use gene and stem cell therapies, which will hopefully lead to a cure soon. This article discusses the importance of therapeutic interventions in children with DMD, the current debate over the use of corticosteroids to treat this disease, the growing use of natural supplements as a new means of treating these boys and provides an update on the current state of gene and stem cell therapies.
23 - Santhera develops drugs for the treatment of Duchenne muscular dystrophy: An interview with Thomas Meier, PhD, Chief Scientific Officer at Santhera Pharmaceuticals Ltd. in Liestal near Basel, Switzerland.
22 - (IN PRESS: Pediatric Research, 2006) Intravenous Infusion of an Antisense Oligonucleotide Results in Exon Skipping in Muscle Dystrophin mRNA of Duchenne Muscular Dystrophy
TAKESHIMA, YASUHIRO; YAGI, MARIKO; WADA, HIROKO; ISHIBASHI, KAZUTO; NISHIYAMA, ATUSHI; SAKAEDA, MIKIO KAKUMOTO TOSHIYUKI; SAURA, RYUICHI; OKUMURA, KATSUHIKO; MATSUO, MASAFUMI - Japan
Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease that is characterized by muscle dystrophin deficiency. We report that intravenous (IV) infusion of an antisense oligonucleotide created an in-frame dystrophin mRNA from an out-of-frame DMD mutation (via exon skipping) which led to muscle dystrophin expression. A 10-year-old DMD patient possessing an out-of-frame, exon 20 deletion of the dystrophin gene received a 0.5 mg/kg IV infusion of an antisense 31-mer phosphorothioate oligonucleotide against the splicing enhancer sequence of exon 19. This antisense construct was administered at one-week intervals for 4 wk. No side effects attributable to infusion were observed. Exon 19 skipping appeared in a portion of the dystrophin mRNA in peripheral lymphocytes after the infusion. In a muscle biopsy one week after the final infusion, the novel in-frame mRNA lacking both exons 19 and 20 was identified and found to represent approximately 6% of the total reverse transcription PCR product. Dystrophin was identified histochemically in the sarcolemma of muscle cells after oligonucleotide treatment. These findings demonstrate that phosphorothioate oligonucleotides may be administered safely to children with DMD, and that a simple IV infusion is an effective delivery mechanism for oligonucleotides that lead to exon skipping in DMD skeletal muscles.
21 - Transfection and in vitro expression of human microdystrophin gene in rat mesenchymal stem cells
20 - (IN PRESS: Neuromuscular Disorders, 2006) Long-term benefits of deflazacort treatment for boys with Duchenne muscular dystrophy in their second decade
W.D. Biggar, V.A. Harris, L. Eliasoph, B. Alman - Canada
We compare the clinical course of 74 boys 10–18 years of age with Duchenne muscular dystrophy (DMD) treated (40) and not treated (34) with deflazacort. Treated boys were able to rise from supine to standing, climb stairs and walk 10 m without aids, 3–5 years longer than boys not treated. After 10 years of age, treated boys had significantly better pulmonary function than boys not treated and after15 years of age, 8 of 17 boys not treated required nocturnal ventilation (treated 0 of 40). For boys over 15 years of age, 11 of 17 boys not treated required assistance with feeding compared to none of the treated boys. By 18 years, 30 of 34 boys not treated had a spinal curve greater than 20o compared to 4 of 40 treated boys. By 18 years, 7 of 34 boys not treated had lost 25% or more of their body weight (treated 0 of 40) and 4 of those 7 boys required a gastric feeding tube. By 18 years, 20 of 34 boys not treated had cardiac left ventricular ejection fractions less than 45% compared to 4 of 40 treated boys and 12 of 34 died in their second decade (mean 17.6+1.7 years) primarily of cardiorespiratory complications. Two of 40 boys treated with deflazacort died at 13 and 18 years of age from cardiac failure. The treated boys were significantly shorter, did not have excessive weight gain and 22 of 40 had asymptomatic cataracts. Long bone fractures occurred in 25% of boys in both the treated and not treated groups. This longer-term study demonstrates that deflazacort has a very significant impact on health, quality of life and health care costs for boys with DMD and their families, and is associated with few side effects.
16 - Creatine monohydrate as a therapeutic aid in muscular dystrophy
16 - (IN PRESS: Neuromuscular Disorders, 2006) First evaluation of the potential effectiveness in muscular dystrophy of a novel chimeric compound, BN 82270, acting as calpain-inhibitor and anti-oxidant
Rosa Burdi, Maria Paola Didonna, Bernadette Pignol, Beatrice Nico, Domenica Mangieri , Jean-Francois Rolland, Claudia Camerino, Alberta Zallone , Paolo Ferro , Francesca Andreetta, Paolo Confalonieri, Annamaria De Luca - Italy
BN 82270 is a membrane-permeable prodrug of a chimeric compound (BN 82204) dually acting as calpain inhibitor and anti-oxidant. Acute in vivo injection of dystrophic mdx mice (30 mg/kg, s.c.) fully counteracted calpain overactivity in diaphragm. A chronic 4–6 weeks administration significantly prevented in vivo the fore limb force drop occurring in mdx mice exercised on treadmill. Ex vivo electrophysiological recordings showed that BN 82270 treatment contrasted the decrease in chloride channel function (gCl) in diaphragm, an index of spontaneous degeneration, while it was less effective on both exercise-impaired gCl and calcium-dependent mechanical threshold of the hind limb extensor digitorum longus (EDL) muscle fibres. The BN 82270 treated mdx mice showed a marked reduction of plasma creatine kinase and of the pro-fibrotic cytokine TGF-b1 in both hind limb muscles and diaphragm; however, the histopathological profile of gastrocnemious muscle was poorly ameliorated. In hind limb muscles of treated mice, the active form was detected by HPLC in the low therapeutic concentration range. In vitro exposure to 100 mM BN 82270 led to higher active form in diaphragm than in EDL muscle. This is the first demonstration that this class of chimeric compounds, dually targeting pathology-related events, exerts beneficial effects in muscular dystrophy. The drug/prodrug system may require posology adjustment to produce wider beneficial effects on all muscle types.
FEBRUARY - 2006
28 - (IN PRESS: American Journal of Pathology 2006;168:918-26) Lipid Peroxidation Inhibition Blunts Nuclear Factor-B Activation, Reduces Skeletal Muscle Degeneration, and Enhances Muscle Function in mdx Mice
Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disease resulting from lack of the sarcolemmal protein dystrophin. However, the mechanism leading to the final disease status is not fully understood. Several lines of evidence suggest a role for nuclear factor (NF)-B in muscle degeneration as well as regeneration in DMD patients and mdx mice. We investigated the effects of blocking NF-B by inhibition of oxidative stress/lipid peroxidation on the dystrophic process in mdx mice. Five-week-old mdx mice received three times a week for 5 weeks either IRFI-042 (20 mg/kg), a strong antioxidant and lipid peroxidation inhibitor, or its vehicle. IRFI-042 treatment increased forelimb strength (+22%, p < 0.05) and strength normalized to weight (+23%, p < 0.05) and decreased fatigue (–45%, p < 0.05). It also reduced serum creatine kinase levels (p < 0.01) and reduced muscle-conjugated diene content and augmented muscle-reduced glutathione (p < 0.01). IRFI-042 blunted NF-B DNA-binding activity and tumor necrosis factor- alpha expression in the dystrophic muscles (p < 0.01), reducing muscle necrosis (p < 0.01) and enhancing regeneration (p < 0.05). Our data suggest that oxidative stress/lipid peroxidation represents one of the mechanisms activating NF-B and the consequent pathogenetic cascade in mdx muscles. Most importantly, these new findings may have clinical implications for the pharmacological treatment of patients with DMD.
28 - Pentoxifylline fails to attenuate fibrosis in dystrophic (mdx) diaphragm muscle
1) A CINRG Pilot Trial of Oxatomide in Steroid-Naive Duchenne Muscular Dystrophy
2) Adenovirus-Mediated Utrophin Gene Delivery as a Therapy for Duchenne Muscular Dystrophy
3) CINRG Open Label Pilot Clinical Trial of Coenzyme Q10 in Steroid Treated Duchenne Muscular Dystrophy
4) Biological Effects of a Potent, Muscle-Targeted, Orally Bioavailable Calpain Inhibitor (C101) for Duchenne Muscular Dystrophy (DMD)
5) Haploinsufficiency of Utrophin Gene Worsens Diaphragm and Quadriceps Muscle Dystrophy in Mdx Mice
6) Recombinant AAV and Corticosteroid Therapy in mdx Mice: In Consideration for Clinical Trials
7) Absence of T-Cells and B-Cells Does Not Improve Functional Outcome in mdx Mice
24 - (IN PRESS: Neuromuscular Disorders, 2006) Muscular Dystrophy Campaign Funded Workshop on Managementof Scoliosis in Duchenne Muscular Dystrophy 24 January 2005, London, UK
Francesco Muntoni, Kate Bushby, Adnan Y. Manzur
Consensus statements
A. Is spinal surgery viable in DMD?
There are many years of experience and published case series confirming that spinal surgery is a safe and effective way to manage progressive scoliosis in DMD when it is carried out in experienced centres with multidisciplinary support. Mortality and complication rates in experienced centres and in patients managed by multidisciplinary teams are low and satisfaction levels high.
B. What is the aim of spinal surgery in DMD?
The primary aim of spinal surgery in DMD is to correct scoliosis and prevent further progression of spinal deformity. Long-term objectives of the surgery are to achieve a good sitting posture, comfort and quality of life by avoiding the complications of progressive scoliosis.
C. What is the optimum surveillance for the development of scoliosis in DMD?
Between 75 and 90% of children with DMD develop a scoliosis and when present this has a significant tendency to progress. Awareness of scoliosis as an issue in DMD is needed both for the medical team and for the families even in the ambulant phase (when scoliosis is however, unlikely to be clinically significant). A multidisciplinary approach involving the paediatrician/paediatric neurologists, orthopaedic surgeons are essential. The muscle clinic team should monitor for the development of scoliosis in all children with DMD before and after loss of independent ambulation. When there is a clinically detectable scoliosis sitting X-rays, usually every 6 months, are indicated under the guidance of the team who will be responsible for the management of the scoliosis.
D. When should surgery be considered?
This depends on several factors (degree of spinal curvature, respiratory function and cardiac status). The decision on when to perform surgery should be taken in partnership with the whole multidisciplinary team, the affected boy and his family. With respect to the spinal curve, there are three main variables—Cobb angle, progression and flexibility of the spine. Pubertal growth spurt plays an essential role as rapid progression is most likely during this period. Progression of scoliosis is less of an issue after skeletal maturity is achieved. From a surgical perspective, the best time for surgery is likely to be when there is a progressive deterioration but the curve is still flexible. The optimum range of Cobb angle for the decision process to perform surgery is likely to be around 20–408. Forced vital capacity falls during the teenage years in DMD. Scoliosis surgery should optimally be performed when respiratory reserve is not too compromised (FVCO30). However, FVC below 30% is not an absolute contraindication to surgery and has been done safely in patients with FVC between 20 and 30% as improved supportive care and peri-operative nasal mask ventilation in experienced hands may make surgery possible and the rate of complications not dissimilar from stronger patients. These patients need however, to be individually assessed by an experienced anaesthetists and respiratory physician as they clearly are more fragile compared to stronger patients. A full pre-operative assessment is essential (within 3 months of surgery) and should include forced vital capacity, peak cough flow and overnight oximetry. In the presence of significant respiratory impairment, for example, if there is evidence of nocturnal hypoventilation or recurrent severe chest infections, then the patient should be familiarised with non-invasive ventilation and cough augmentation techniques before surgery as this may ameliorate post-operative recovery. The nutritional status of the patients should be carefully considered and caloric supplemented initiated, in patients who are failing to thrive, at least 6 months prior to surgery. Occasionally, a pre-spinal surgery gastrostomy might be required. All patients with DMD are at risk of cardiomyopathy, though they are rarely symptomatic. The importance of cardiac status in DMD has become much better recognised in recent years. Existing guidelines recommend that cardiac status in DMD should be monitored every year from the age of 10 by echocardiography and ECG [54]. Assessment should in addition be performed within 3 months of surgery. It is already established that progressive abnormalities on echocardiography are an indication for treatment with ACE inhibition and beta blockade. Patients who have stabilised on such treatment should not represent an absolute contraindication to surgery, but such patients need to be considered and monitored carefully. Risks increase dramatically with fractional shortening of !25% and the benefits of surgery need to be balanced against the overall prognosis. Deteriorating cardiac failure on treatment is a poor prognostic factor irrespective of surgery. It is important to recognise that cardiac problems may develop during the stress of surgery even with normal pre-operative assessment. Significant stress factors that are known to be associated with increased peri-operative morbidity are the duration of surgery and the amount of blood loss. All efforts should therefore be put in trying to reduce both the operative time and blood loss.
E. Is there a role for spinal bracing in the management of scoliosis in DMD?
Spinal bracing is part of the total postural management of the child which includes the provision of appropriate wheelchair seating. There is no evidence that spinal bracing treats or slows the progression of scoliosis. Bracing can improve posture and comfort in sitting in patients in whom spinal surgery is contraindicated or refused. Comfortable seating in tilt in space chairs with appropriate adjustment for change in posture following surgery is an essential part of the process of planning for and rehabilitation following surgery so local physiotherapy, seating and wheelchair services should be involved in the planning process.
F. Who should be performing scoliosis surgery in patients with DMD?
Detailed guidelines for summarising the requirements for individual centres involved in scoliosis surgery have been published (BOA guidelines 2001, http://www.boa.ac.uk/BSS/) and have been recently subjected to significance revisions to take into account the complexity of this procedure in a high-risk population such as patients with neuromuscular diseases (BOA guidelines in preparation). Surgeons operating on patients with DMD and other paediatric neuromuscular diseases should be working with all members of the neuromuscular multidisciplinary team and have regular experience in operating on this patient group.
G. Is there a consensus on what kind of surgery should be performed?
The choice of surgical intervention depends on the clinical indication in an individual case. The more recent instrumentation systems have an advantage compared to the previous Luque or Harrington rods technique and should therefore be preferred. Regarding the issue of fixation to the pelvis, there are significant variations in the clinical practice of individual centres. In many centres were surgery is performed very early on minimal or mild curvatures, the choice is that of not fixing the pelvis and in most instances medium term followup indicates that this choice is correct. In centres or cases in which the scoliosis is more significant, and there is significant (208 or more) pelvic obliquity present at the time of surgery, fixation to the pelvis is indicated. Longer term follow-up data are needed on functional and postural results of these different approaches.
H. How are patients and their families best prepared for surgery?
Pre-operative issues that need to be addressed should include an assessment of the impact of surgery on seating, housing, hoisting, mobility, school and other functional issues. There needs to be a full exploration with the patient of the best and worst possible outcomes, and where possible a chance to see the unit and the intensive therapy unit prior to admission. Written information should be available to the patient and the family. The MDC has produced two information leaflets, a general one on scoliosis and a more recent one on surgical management of scoliosis. Both are available at the MDC website: http://www.musculardystrophy.org/information_resources/factsheets/medical_issues_factsheets/surgical.html. Generation of more condition specific literature may also be appropriate in the future.
24 - Body-wide gene therapy of Duchenne muscular dystrophy in the mdx mouse model
24 - Mini-dystrophin efficiently incorporates into the dystrophin protein complex in living cells
21 - (IN PRESS: Neuromuscular Disorders, 2006) Diaphragmatic function in advanced Duchenne muscular dystrophy
Jennifer Becka, Jan Weinbergb, Carl-Hugo Hamnega°rdc, Jadranka Spahijad, Jan Olofsonc, Gunnar Grimbye, Christer Sinderbyf - Canada and Sweden
The aim of this study was to assess diaphragm electrical activation and diaphragm strength in patients with advanced Duchenne muscular dystrophy during resting conditions. Eight patients with advanced Duchenne muscular dystrophy (age of 25+2 years) were studied during tidal breathing, maximal inspiratory capacity, maximal sniff inhalations, and magnetic stimulation of the phrenic nerves. Six patients were prescribed home mechanical ventilation (five non-invasive and one tracheotomy). Transdiaphragmatic pressure and diaphragm electrical activation were measured using an esophageal catheter. During tidal breathing (tidal volume 198+83 ml, breathing frequency 25+7), inspiratory diaphragm electrical activation was clearly detectable in seven out of eight patients and was 12+7 times above the noise level, and represented 45+19% of the maximum diaphragm electrical activation. Mean inspiratory transdiaphragmatic pressure during tidal breathing was 1.5+1.2 cmH2O, and during maximal sniff was 7.6+3.6 cmH2O. Twitch transdiaphragmatic pressure deflections could not be detected. This study shows that despite near complete loss of diaphragm strength in advanced Duchenne muscular dystrophy, diaphragm electrical activation measured with an esophageal electrode array remains clearly detectable in all but one patient.
21 - (IN PRESS: Molecular Therapy, 2006) Induction of Dystrophin Expression by Exon Skipping in mdx Mice Following Intramuscular Injection of Antisense Oligonucleotides Complexed with PEG–PEI Copolymers
Jason H. Williams, Shashank R. Sirsi, Daniel R. Latta, and Gordon J. Lutz - USA
Antisense oligonucleotides (AOs) with 2-O-methyl modifications can circumvent dystrophin mutations via exon skipping and, it is hoped, can become drugs for treatment of Duchenne muscular dystrophy (DMD). However, AO-based approaches are hindered by a lack of effective carriers to facilitate delivery of AOs to myonuclei. We examined whether copolymers composed of cationic poly(ethylene imine) (PEI) and polyethylene glycol (PEG) can enhance AO transfection in skeletal muscle of mdx mice. Single intramuscular injections of AO complexed with low Mw PEI2000(PEG550) copolymers into TA muscles of mdx mice resulted in widespread distribution of dystrophin-positive fibers at 3 weeks after injection, with no apparent cytotoxicity. Overall, injections of these low Mw polyplexes, which formed 250-nm aggregate particles, resulted in about sixfold more dystrophin-positive fibers than AO alone. Western analysis confirmed the dystrophin expression in these muscles. Surprisingly, injections of AO complexed with high Mw PEI25000 (PEG5000) copolymers, which formed smaller nonaggregated particles, produced about threefold fewer dystrophin-positive fibers than injections of the low Mw polyplexes. We conclude that low Mw PEI2000(PEG550) copolymers function as high-capacity, nontoxic AO carriers suitable for in vivo transfection of skeletal muscle and are promising compounds for potential use in molecular therapy of DMD.
20 - FDA Approvals: SmartVest Trimline
http://www.electromed-usa.com/
Feb. 17, 2006 — The US Food and Drug Administration (FDA)
has approved a respiratory vest system for use in patients requiring percussive
therapy to enhance mucus transport.
Powered Percussor System (SmartVest Trimline) Promotes Airway Clearance
On December 1, 2005, the FDA approved a powered airway clearance system (SmartVest
Trimline, made by Electromed, Inc) for use in patients requiring percussive
therapy to enhance mucus transport. Applications include cystic fibrosis,
bronchiectasis, obstructive pulmonary conditions and other diseases such as
multiple sclerosis and muscular dystrophy. The system consists of a
compact, portable generator that produces oscillating pressurized air pulses
that are delivered through a hose to an inflatable vest, causing it to rapidly
inflate and deflate against the patient's chest wall. Delivery of high-frequency
chest wall oscillation serves to mobilize bronchial secretions, thereby
improving airway clearance and improving bronchial drainage.
The system can be programmed with up to 3 individual patient therapy
prescriptions and fits into a 2-wheeled case sized to fit under airplane seats
or in overhead bins for convenience. The vest is available in a wide range of
sizes to fit patients aged as young as 18 months to large adults, and is made of
washable fabric rather than plastic to reduce perspiration and itching.
18 -
(IN
PRESS:
Neuromuscular Disorders, 2006)
Improvement in survival and muscle function in an mdx/utrn−/−
double mutant mouse using a human retinal dystrophin transgene
Roger Gaedigk, Douglas J. Law, Kathleen M. Fitzgerald-Gustafson, Steven G. McNulty, Ndona N. Nsumu, Ann C. Modrcin, Robert J. Rinaldi, David Pinson, Stephen C. Fowler, Mehmet Bilgen, Joanne Burns, Stephen D. Hauschka and Robert A. White - USA
Duchenne muscular dystrophy is a progressive muscle
disease characterized by increasing muscle weakness and death by the third
decade. mdx mice exhibit the underlying muscle disease but appear
physically normal with ordinary lifespans, possibly due to compensatory
expression of utrophin. In contrast, double mutant mice (mdx/utrn−/−),
deficient for both dystrophin and utrophin die by
3
months and suffer from severe muscle weakness, growth retardation, and severe
spinal curvature. The capacity of human retinal dystrophin (Dp260) to compensate
for the missing 427 kDa muscle dystrophin was tested in mdx/utrn−/−
mice. Functional outcomes were assessed by histology, EMG, MRI, mobility, weight
and longevity. MCK-driven transgenic expression of Dp260 in mdx/utrn−/−
mice converts their disease course from a severe, lethal muscular dystrophy
to a viable, mild myopathic phenotype. This finding is relevant to the design of
exon-skipping therapeutic strategies since Dp260 lacks dystrophin exons 1-29.
18 - Cardiac monitoring and treatment for children and adolescents with neuromuscular disorders
Treatment of the heart in Duchenne muscular dystrophy
11 - Interleukin-4 improves the migration of human myogenic precursor cells in vitro and in vivo
4 - PPMD Antiinflammatory Conference
4 -
Report of the
Monaco Round Table January 14th 2006 Translation of Exon Skipping
JANUARY - 2006
28- (IN PRESS: Trends in Molecular Medicine, 2006) Utrophin upregulation for treating Duchenne or Becker muscular dystrophy: how close are we?
Pedro Miura and Bernard J. Jasmin - Canada
Duchenne muscular dystrophy (DMD) is a severe muscle-wasting disorder for which there is currently no effective treatment. This disorder is caused by mutations or deletions in the gene encoding dystrophin that prevent expression of dystrophin at the sarcolemma. A promising pharmacological treatment for DMD aims to increase levels of utrophin, a homolog of dystrophin, in muscle fibers of affected patients to compensate for the absence of dystrophin. Here, we review recent developments in our understanding of the regulatory pathways that govern utrophin expression, and highlight studies that have used activators of these pathways to alleviate the dystrophic symptoms in DMD animal models. The results of these preclinical studies are promising and bring us closer to implementing appropriate utrophin-based drug therapies for DMD patients.
28 - Somitic origin of limb muscle satellite and side population cells
28 - (IN PRESS: Molecular Therapy, 2006) Transduction of Myogenic Cells by Retargeted Dual High-Capacity Hybrid Viral Vectors: Robust Dystrophin Synthesis in Duchenne Muscular Dystrophy Muscle Cells
Manuel A. F. V. Goncalves, Maarten Holkers, Christophe Cudre-Mauroux, Gijsbert P. van Nierop, Shoshan Knaa¨n-Shanzer, Ietje van der Velde, Dinko Valerio, and Antoine A. F. de Vries -The Netherlands and Switzerland
Duchenne muscular dystrophy (DMD) is caused by mutations in the dystrophin gene (DMD), making it amenable to gene- or cell-based therapies. Another possible treatment entails the combination of both principles by transplantation of autologous myogenic cells after their genetic complementation. This approach requires efficient and stable transduction of these cells with recombinant DMD. Recently, we generated a dual high-capacity (hc) adenovirus (Ad)–adeno-associated virus (AAV) hybrid vector (HV) that can deliver two full-length dystrophin-encoding modules into target cells. We showed that HV transduction of human cells containing AAV Rep proteins leads to the insertion of foreign DNA into the AAVS1 locus. Here, we improved HV entry into muscle cells from DMD patients. After having verified that these cells barely express the coxsackie B virus and Ad receptor (CAR), which constitutes the attachment molecule for Ad serotype 5 (Ad5) fibers, we equipped dual hcAd/ AAV HV particles with Ad serotype 50 fiber domains to achieve CAR-independent uptake. These retargeted vectors complemented much more efficiently the genetic defect of dystrophin-defective myoblasts and myotubes than their isogenic counterparts with conventional Ad5 fibers. Importantly, the accumulation of B-dystroglycan along the membranes of vector-treated DMD myotubes indicated proper assembly of dystrophin-associated glycoprotein complexes.
24 - VASTox announces positive DMD preclinical news
21 - (IN PRESS: Am J Phys Med Rehabil 2006;85:105–111) Expiratory Flow Maneuvers in Patients with Neuromuscular Diseases
Bach JR, Goncalves MR, Paez S, Winck JC, Leitao S, Abreu P - USA and Portugal
Objectives: To compare cough peak flows (CPF), peak expiratory flows (PEF), and potentially confounding flows obtained by lip and tongue propulsion (dart flows, DF) for normal subjects and for patients with neuromuscular disease/restrictive pulmonary syndrome and to correlate them with vital capacity and maximum insufflation capacity.
Design: A cross-sectional analytic study of 125 stable patients and 52 normal subjects in which CPF, PEF, and DF were measured by peak flow meter and vital capacity and maximum insufflation capacity by spirometer.
Results: In normal subjects and in patients, the DF significantly exceeded PEF and CPF (P < 0.001). For normal subjects, PEF and CPF were not significantly different. For patients with neuromuscular disease/restrictive pulmonary syndrome, the CPF significantly exceeded PEF (P < 0.05). No normal subjects but 14 patients had DF lower than CPF. Thirteen of these 14 had the ability to air stack (maximum insufflation capacity greater than vital capacity), indicating greater compromise of mouth and lip than of glottic muscles. For 14 of 88 patients, maximum insufflation capacity values did not exceed vital capacity, mostly because of inability to close the glottis (inability to air stack). Nonetheless, for 11 of these 14 patients, the DF were within a standard deviation of the whole patient group; thus, bulbar-innervated muscle dysfunction was not uniform. CPF and PEF correlated with vitalcapacity ( r = 0.85 and 0.86, respectively), and with maximum insufflation capacity ( r = 0.76 and 0.72, respectively).
Conclusions: Measurements of CPF, PEF, and DF are useful for assessing bulbar-innervated, inspiratory, and expiratory muscle function. Care must be taken to not confuse them.
19 - Association of duchenne muscular dystrophy with autism spectrum disorder
11 - (IN PRESS: Muscle Cell Biology and Cell Motility. 290:C616-C625,2006) Green tea extract and its major polyphenol (–)-epigallocatechin gallate improve muscle function in a mouse model for Duchenne muscular dystrophy
Duchenne muscular dystrophy is a frequent muscular disorder caused by mutations in the gene encoding dystrophin, a cytoskeletal protein that contributes to the stabilization of muscle fiber membrane during muscle activity. Affected individuals show progressive muscle wasting that generally causes death by age 30. In this study, the dystrophic mdx5Cv mouse model was used to investigate the effects of green tea extract, its major component (–)-epigallocatechin gallate, and pentoxifylline on dystrophic muscle quality and function. Three-week-old mdx5Cv mice were fed for either 1 or 5 wk a control chow or a chow containing the test substances. Histological examination showed a delay in necrosis of the extensor digitorum longus muscle in treated mice. Mechanical properties of triceps suræ muscles were recorded while the mice were under deep anesthesia. Phasic and tetanic tensions of treated mice were increased, reaching values close to those of normal mice. The phasic-to-tetanic tension ratio was corrected. Finally, muscles from treated mice exhibited 30–50% more residual force in a fatigue assay. These results demonstrate that diet supplementation of dystrophic mdx5Cv mice with green tea extract or (–)-epigallocatechin gallate protected muscle against the first massive wave of necrosis and stimulated muscle adaptation toward a stronger and more resistant phenotype.
10 - (IN PRESS: Experimental Neurology,2006) Nuclear factor kappa-B blockade reduces skeletal muscle degeneration and enhances muscle function in Mdx mice
Sonia Messina, Alessandra Bitto, M'hammed Aguennouz, Letteria Minutoli, Maria C. Monici, Domenica Altavilla, Francesco Squadrito, Giuseppe Vita - Italy
Abstract
Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disease due to a mutation in the dystrophin gene and the consequential protein deficiency in muscle. How the lack of the sarcolemmal protein dystrophin gives rise to the final disease status is still not clear. Several evidences suggest a role of nuclear factor kappa-B (NF-κB), a pleiotropic transcription factor, in muscle degeneration and regeneration in DMD patients and mdx mice. We investigated the effects of NF-κB blocking by pyrrolidine dithiocarbamate (PDTC), a well-known NF-κB inhibitor, on dystrophic process in mdx mice. Five-week-old mdx and wild-type mice received three times a week for 5 weeks either PDTC (50 mg/kg) or its vehicle. PDTC treatment: (i) increased forelimb strength (+20%; P < 0.05) and strength normalized to weight (+24%; P < 0.05) and a decreased fatigue percentage (−61%; P < 0.05) in mdx mice, (ii) blunted the augmented NF-κB nuclear binding activity and the enhanced TNF-α expression in dystrophic muscles (P < 0.01), (iii) at a quantitative morphological evaluation of extensor digitorum longus (EDL) and biceps muscles, increased area with normal fibers (P < 0.05, in EDL), reduced muscle necrosis (P < 0.05 in biceps; P < 0.01 in EDL), and enhanced muscle regeneration (P < 0.01, in biceps). Our data support the hypothesis that NF-κB contributes to the perpetuation of the dystrophic damage and show that its blockade produces beneficial effects on functional, biochemical, and morphological parameters
7 - BCL-2 overexpression prevents calcium overload and subsequent apoptosis in dystrophic myotubes
7 - Enhancement of plasmid-mediated gene therapy for muscular dystrophy by directed plasmid integration