Miyoshi myopathy associated with spine rigidity and multiple contractures: a case report.

BACKGROUND: Dysferlinopathy is a phenotypically heterogeneous group of hereditary diseases caused by mutations in the DYSF gene. Early contractures are considered rare, and rigid spine syndrome in dysferlinopathy has been previously reported only once. CASE PRESENTATION: We describe a 23-year-old patient with Miyoshi myopathy with a rigid spine and multiple contractures, a rare phenotypic variant. The disease first manifested when the patient was 13 years old, with fatigue of the gastrocnemius muscles and the development of pronounced contractures of the Achilles tendons, flexors of the fingers, and extensors of the toes, followed by the involvement of large joints and the spine. Magnetic resonance imaging revealed signs of connective tissue and fatty replacement of the posterior muscles of the thighs and lower legs. Edema was noted in the anterior and medial muscle groups of the thighs, lower legs, and the multifidus muscle of the back. Whole genome sequencing revealed previously described mutations in the DYSF gene in exon 39 (c.4282 C > T) and intron 51 (c.5785-824 C > T). An immunohistochemical analysis and Western blot showed the complete absence of dysferlin protein expression in the muscle fibers. CONCLUSIONS: This case expands the range of clinical and phenotypic correlations of dysferlinopathy and complements the diagnostic search for spine rigidity.

The effect of temperature and oxygen partial pressure on the concentration of iron and manganese ions in La1/3Sr2/3Fe1-xMnxO3-δ.

The oxygen content was measured in cubic perovskite-type La1/3Sr2/3Fe1-xMnxO3-δ (x = 0.1, 0.17, 0.25, and 1/3) in the range of oxygen partial pressure from 10-22 to 0.5 atm at 750-950 °C with a step of 50 °C by coulometric titration. Gradual removal of oxygen from the oxides during the measurements was carried out until the stability limit was achieved and the reductive decomposition began. An increase in manganese content was shown to lead to a decrease in the stability of La1/3Sr2/3Fe1-xMnxO3-δ under reducing conditions. The obtained data on oxygen content were used for defect chemistry modeling in the oxides. The enthalpy of the Fe3+ to Fe4+ and Mn3+ to Mn4+ oxidation reactions (ΔHox0) was determined to be -103.2 ± 0.3 and -250 ± 2 kJ mol-1, respectively, for the x = 0.1 composition, and increased slightly with increasing manganese content. The large difference in ΔHox0 determines a strong distinction between the behavior of iron and manganese in perovskite-type oxides. An increase in manganese content in La1/3Sr2/3Fe1-xMnxO3-δ was found to lead to a decrease in the concentration of Fe4+ ions, but did not affect the concentration of Fe2+ ions. The impact of La/Sr ratio was evaluated by comparison of the obtained data with that for La0.5Sr0.5Fe1-xMnxO3-δ, and found to be different for iron and manganese. An increase in lanthanum fraction causes a decrease in the concentration of Fe2+ ions and an increase in the concentration of Mn2+ under reducing conditions.