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Acetaldehyde dehydrogenase 2 (ALDH2) is an enzyme involved in redox homeostasis as well as the detoxification process in alcohol metabolism. Nearly 8% of the world’s population have an inactivating mutation in the ALDH2 gene. However, the expression patterns and specific functions of ALDH2 in skeletal muscles are still unclear. Herein, we report that ALDH2 is expressed in skeletal muscle and is localized to the mitochondrial fraction. Oxidative muscles had a higher amount of ALDH2 protein than glycolytic muscles. We next comprehensively investigated whether ALDH2 knockout in mice induces mitochondrial adaptations in gastrocnemius muscle (for example, content, enzymatic activity, respiratory function, supercomplex formation, and functional networking). We found that ALDH2 deficiency resulted in partial mitochondrial dysfunction in gastrocnemius muscle because it increased mitochondrial reactive oxygen species (ROS) emission (2′,7′-dichlorofluorescein and MitoSOX oxidation rate during respiration) and the frequency of regional mitochondrial depolarization. Moreover, we determined whether ALDH2 deficiency and the related mitochondrial dysfunction trigger mitochondrial stress and quality control responses in gastrocnemius muscle (for example, mitophagy markers, dynamics, and the unfolded protein response). We found that ALDH2 deficiency upregulated the mitochondrial serine protease Omi/HtrA2 (a marker of the activation of a branch of the mitochondrial unfolded protein response). In summary, ALDH2 deficiency leads to greater mitochondrial ROS production, but homeostasis can be maintained via an appropriate stress response.

The bending strength, stiffness, and torsional strength of novel one-third or semi-tubular bioabsorbable plates, when fixed on a PEEK rod, were comparable with those for titanium plates for 1.5 or 2.0-mm screws. There were no significant differences in clinical results between these two types of plates in a small group of patients after short-term follow-up.

Currently, volar locking plates are commonly used to treat distal radius fractures (DRF) because of their stable biomechanical construct and because they cause less soft tissue disturbance and allow early mobilisation of the wrist. Complications such as rupture of tendons have been reported to occur with use of volar locking plates. We describe six cases of rupture of extensor pollicis longus (EPL) tendons after the use of volar locking plates. EPL tendon injuries occurred in 2.1% (6/286) of cases after DRF surgery. The causes of EPL rupture after DRF surgery were protrusion of the head tip and insufficient reduction of the dorsal roof fragment of the distal radius. These were considered iatrogenic problems. The cause of EPL rupture was unknown in three cases. We should be extremely careful when determining optimum screw length and reducing displaced dorsal roof fragments to prevent damaging the EPL tendons.