Padronização de parâmetros eletrocardiográficos de cães da raça Golden Retriever clinicamente sadios / Standardization of electrocardiographic parameters in healthy Golden Retrievers dogs

A distrofia muscular de Duchenne (DMD) em humanos é uma alteração neuromuscular hereditária, de caráter recessivo, ligada ao cromossomo X e causada pela ausência ou disfunção da distrofina. Clinicamente, caracteriza-se por grave alteração na musculatura esquelética, resultando em morte precoce do indivíduo acometido. Em cães da raça Golden Retriever, a mutação que leva à distrofia muscular ocorre espontaneamente e a extensa homologia entre a patogênese da DMD e da distrofia muscular do Golden Retriever permite qualificar o cão como o principal substituto de humanos nos testes clínicos de novas terapias. O miocárdio deficiente em distrofina é mais vulnerável à sobrecarga de pressão e os pacientes com DMD podem desenvolver cardiomiopatia dilatada, hipertensão arterial e o eletrocardiograma pode se apresentar distintamente anormal. No presente estudo, foram avaliados exames eletrocardiográficos de 38 cães da raça Golden Retriever clinicamente sadios (20 animais de até 12 meses de idade e 18 animais entre 12 e 36 meses de idade), com a finalidade de se obter parâmetros para a padronização do eletrocardiograma nessa referida raça, o que futuramente poderá servir de referência na identificação de cães portadores ou afetados pela distrofia muscular. Os valores eletrocardiográficos obtidos encontraram-se dentro dos valores de normalidade e referência para as diferentes raças de cães; e as variáveis peso e idade alteraram significativamente a freqüência cardíaca e a amplitude do complexo QRS.

The Duchenne's muscular dystrophy (DMD) in humans is a X-linked neuromuscular disease, of recessive character, caused either by the absence or dysfunction of the dystrophin. Clinically, it is characterized by severe alteration in the skeletal musculature, resulting in precocious death. In Golden Retriever dogs, the mutation that takes to the muscular dystrophy happens spontaneously and the extensive homology among the pathogenesis of DMD and of Golden Retriever muscular dystrophy allows to qualify the dog as the main substitute of humans in the clinical tests of new therapies. The deficient myocardium in distrofin is more vulnerable to the pressure overload and the patients with DMD can develop dilated cardiomyopathy, arterial hypertension and the electrocardiogram can come distinctly abnormal. In the present study, 38 healthy Golden Retriever dogs were evaluated by electrocardiographic exam with the purpose to obtain parameters for the standardization of the electrocardiogram in the referred breed, what hereafter can serve as reference in the identification of bearer or affected dogs. Electrocardiographic values obtained were within normal values and reference for the various breeds of dogs, and the variables weight and age significantly altered heart rate and amplitude of the QRS complex.

Quantitative Assessment of the T2 Relaxation Time of the Gluteus Muscles in Children with Duchenne Muscular Dystrophy: a Comparative Study Before and After Steroid Treatment

OBJECTIVE: To determine the feasibility of using T2 mapping as a quantitative method to longitudinally follow the disease activity in children with Duchenne muscular dystrophy (DMD) who are treated with steroids. MATERIALS AND METHODS: Eleven boys with DMD (age range: 5-14 years) underwent evaluation with the clinical functional score (CFS), and conventional pelvic MRI and T2 mapping before and during steroid therapy. The gluteus muscle inflammation and fatty infiltration were evaluated on conventional MRI. The histograms and mean T2 relaxation times were obtained from the T2 maps. The CFS, the conventional MRI findings and the T2 values were compared before and during steroid therapy. RESULTS: None of the patients showed interval change of their CFSs. On conventional MRI, none of the images showed muscle inflammation. During steroid treatment, two boys showed increased fatty infiltration on conventional MRI, and both had an increase of the mean T2 relaxation time (p < 0.05). The remaining nine boys had no increase in fatty infiltration. Of these, three showed an increased mean T2 relaxation time (p < 0.05), two showed no change and four showed a decreased mean T2 relaxation time (p < 0.05). CONCLUSION: T2 mapping is a feasible technique to evaluate the longitudinal muscle changes in those children who receive steroid therapy for DMD. The differences of the mean T2 relaxation time may reflect alterations in disease activity, and even when the conventional MRI and CFS remain stable.

Duchenne muscular dystrophy in northeastern Thai children: a retrospective study

Background: Duchenne muscular dystrophy (DMD) is the most common hereditary neuromuscular disease. No curative treatment for DMD is known. Prednisone therapy is the first medical treatment that alters the course of DMD. Several studies about the doses and administrations of prednisone or prednisolone had been reported. Objectives: To review clinical features, laboratory findings, and the result of treatment of DMD. Methods: DMD patients who came to Srinagarind Hospital, Thailand from January, 1995 to January, 2007 were retrospectively analyzed. Results: Sixty-two patients fulfilled the study criteria. All patients were male (100 %). Mean age at onset was 4.9 years. Family history was found in 10 families (16 %). The most common symptoms were weakness, standing difficulty, and gait abnormality (100, 97, and 93 % respectively). The most common clinical signs were calf hypertrophy, weakness, and Gower sign (100, 100, and 94 % respectively). Serum creatine kinase (CK) was raised in all of the patients with mean serum CK 13,026 IU/L. Fifty patients received prednisolone. Twelve received only supportive treatments. The overall outcomes of prednisolone treatment were better, same, and worse in 37, 51, and 12 % respectively. Mean age at wheel chair was 10.8 years. Three patients with associate diseases; adult respiratory distress syndrome (ARDS), Sturge Weber syndrome, and autism were presented. To the best of our knowledge, this is the first report about DMD concomitant with ARDS and DMD with Sturge-Weber syndrome. DMD with autism, a very rare occurrence, is presented. Conclusion: Clinical features, laboratory findings, and the outcomes of treatments of 62 DMD patients were presented. Prednisolone treatment had some beneficial effects and had significant side effects. Starting with a low dose, and then increasing to high dose in the no response patient is recommended.

Detection of dystrophin gene deletions and pattern of deletion distribution in Vietnamese Duchenne Muscular Dystrophy (DMD) patients

Background/Introduction: DMD is an X\u2013link recessive genetic disease, caused by the dystrophin gene mutation and gene deletion is the most common.\r\n', u'Objectives: Determine the ratio of deletion mutation of dystrophin gene and research the deletion distribution in Vietnamese DMD patients. \r\n', u'Subjects and methods: There are two groups of research Subjects. One group includes two men who have no familial history of DMD. The other includes 62 male patients gathered during 2003 \u2013 2006. The study used multiplex PCR with 19 primer pairs in order to amplify 18 exon and region muscular promoter (Pm) of dystrophin gene for those 62 DMD male patients. Exon deletions are detected by electrophoresis of PCR products.\r\n', u'Results/Outcomes: We found dystrophin gene deletions in 32 cases amongst 62 DMD patients (51.6%). The deletion proportions of DMD patients with clear and unclear familial history are 52.9% and 51.1% respectively. Deletion distribution were clustered in the two \u201chot-spots\u201d regions: region from exon 44 \u2013 52 (89,3%); region the end 5\u2019 (from exon 3-19 and Pm) more rarely (10.7%).\r\n', u'Conclusion: The proportion of dystropin gene deletion in the 62 DMD patients is 51.6%; with familial history of DMD is 52.9%, and without familial history of DMD is 51.1%. \r\n', u'

Efficacy of Duplex-nested PCR and Fluorescent PCR in the Preimplantation Genetic Diagnosis for Duchenne Muscular Dystrophy / 대한불임학회지

OBJECTIVE: Preimplantation genetic diagnosis (PGD) is reserved for couples with a risk of transmitting a serious and incurable disease, and hence avoids the undesirable therapeutic abortion. In this study, we evaluated the efficacy of PGD for Duchenne muscular dystrophy (DMD) cases by the fluorescent PCR with polymorphic linked markers and the conventional duplex-nested PCR methods. METHODS: Biopsy of one or two blastomeres was done from the embryos fertilized by ICSI on the third day after fertilization. We performed two cases of PGD-DMD by the duplex-nested PCR for the causative mutation loci and the SRY gene on Y chromosome. The triplex fluorescent PCR for the mutation loci, the SRY gene and the polymorphic microsatellite marker on X chromosome was applied for two cases of PGD-DMD. RESULTS: By the duplex-nested PCR, successful diagnosis rate was 95.5% (21/22), but we could not discriminate the female embryos whether normal or carrier in this X-linked recessive disease. However, the triplex fluorescent PCR method showed 100% (27/27) of successful diagnosis rate, and all female embryos (n=17) were distinguished normal (n=10) from carrier (n=7) embryos. Unaffected and normal embryos were transferred into mother's uterus after diagnosis. A healthy normal male was achieved after PGD with the duplex-nested PCR method and a twin, a male and a female, were delivered with triplex fluorescent PCR method. The normality of dystrophin gene was confirmed by amniocentesis and postnatal genetic analysis in all offsprings. CONCLUSION: The fluorescent PCR with polymorphic marker might be useful in improving the specificity and reliability of PGD for single gene disorders.

A clinical study on Duchenne muscular dystrophy

No abstract available.