RESUMO
In this retrospective cross-sectional study clinical and muscle imaging data of patients with Miyoshi distal myopathy phenotype (MMD1 and MMD3) and limb girdle muscular dystrophy 2L (LGMD2L) were described. MMD1 and MMD3 are genetically heterogenous diseases based on DYSF and ANO5 gene defects. MMD3 and LGMD2L are clinically different diseases caused by an ANO5 gene defect. All groups showed predominant fatty degeneration of the gluteus minimus muscle and of the posterior segments of the thigh and calf muscles with sparing of the gracilis muscle. Muscle atrophy, hypertrophy and asymmetric muscle involvement on muscle imaging did not differ between groups. The pattern of fatty degeneration of muscles and of muscle weakness shows only minor differences between MMD1 (n=6) and MMD3 (n=8) patients with more frequently fatty degeneration of the rectus femoris, anterior tibial, and extensor digitorum muscles and more frequently muscle weakness in the anterior tibial, peroneal and calf muscle in MMD1. In the ANO5 related phenotypes the lateral head of the gastrocnemius muscle was less frequently involved in LGMD2L (n=13) and no differences in the incidence of muscle weakness was found. Therefore, MMD3 and LGMD2L should be considered as part of one spectrum of ANO5 related muscle disease.
Assuntos
Canais de Cloreto/genética , Miopatias Distais/genética , Miopatias Distais/patologia , Proteínas de Membrana/genética , Proteínas Musculares/genética , Atrofia Muscular/genética , Atrofia Muscular/patologia , Distrofia Muscular do Cíngulo dos Membros/genética , Distrofia Muscular do Cíngulo dos Membros/patologia , Adolescente , Adulto , Anoctaminas , Criança , Estudos Transversais , Disferlina , Feminino , Humanos , Hipertrofia/genética , Hipertrofia/patologia , Perna (Membro)/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Debilidade Muscular/genética , Debilidade Muscular/fisiopatologia , Músculo Esquelético/patologia , Fenótipo , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Adulto JovemRESUMO
Simulations are useful to study the heart's ability to generate flow and the interaction between contractility and loading conditions. The left ventricular pressure-volume (PV) relation has been shown to be nonlinear, but it is unknown whether a linear model is accurate enough for simulations. Six models were fitted to the PV-data measured in five sheep and the estimated parameters were used to simulate PV-loops. Simulated and measured PV-loops were compared with the Akaike information criterion (AIC) and the Hamming distance, a measure for geometric shape similarity. The compared models were: a time-varying elastance model with fixed volume intercept (LinFix); a time-varying elastance model with varying volume intercept (LinFree); a Langewouter's pressure-dependent elasticity model (Langew); a sigmoidal model (Sigm); a time-varying elastance model with a systolic flow-dependent resistance (Shroff) and a model with a linear systolic and an exponential diastolic relation (Burkh). Overall, the best model is LinFree (lowest AIC), closely followed by Langew. The remaining models rank: Sigm, Shroff, LinFix and Burkh. If only the shape of the PV-loops is important, all models perform nearly identically (Hamming distance between 20 and 23%). For realistic simulation of the instantaneous PV-relation a linear model suffices.
