miR-486 is essential for muscle function and suppresses a dystrophic transcriptome.

miR-486 is a muscle-enriched microRNA, or "myomiR," that has reduced expression correlated with Duchenne muscular dystrophy (DMD). To determine the function of miR-486 in normal and dystrophin-deficient muscles and elucidate miR-486 target transcripts in skeletal muscle, we characterized mir-486 knockout mice (mir-486 KO). mir-486 KO mice developed disrupted myofiber architecture, decreased myofiber size, decreased locomotor activity, increased cardiac fibrosis, and metabolic defects were exacerbated in mir-486 KO:mdx 5cv (DKO) mice. To identify direct in vivo miR-486 muscle target transcripts, we integrated RNA sequencing and chimeric miRNA eCLIP sequencing to identify key transcripts and pathways that contribute towards mir-486 KO and dystrophic disease pathologies. These targets included known and novel muscle metabolic and dystrophic structural remodeling factors of muscle and skeletal muscle contractile transcript targets. Together, our studies identify miR-486 as essential for normal muscle function, a driver of pathological remodeling in dystrophin-deficient muscle, a useful biomarker for dystrophic disease progression, and highlight the use of multiple omic platforms to identify in vivo microRNA target transcripts.

Extraskeletal Osteochondroma of the Great Toe in a Teenager.

Osteochondromas are common, benign surface tumors of bone, composed of the cartilage-capped bone confluent with the medullary canal of the metaphyseal bone. Extraskeletal osteochondromas have the same gross appearance and histologic characteristics as a typical osteochondroma but do not have any boney attachment to the surrounding osseous structures. They are rare and most frequently reported in the middle-age and older adults. We present the first case of an extraskeletal osteochondroma of the foot reported in a teenager. Our patient was a 17-year-old male complaining of a slow-growing mass along the medial border of the great toe that he first noted at the age of 14 years. The increasing size of the mass and frequency of complaints with shoe wear prompted medical attention. Imaging studies showed an ossified 1-cm boney mass with trabecular detail, located on the medial aspect of the great toe at the level of the interphalangeal joint, without any connection to the surrounding structures. An excisional biopsy revealed a well-circumscribed, easily removable mass, which proved to be an extraskeletal osteochondroma both clinically and histologically.

Avascular Necrosis of Trochlea After Supracondylar Humerus Fractures in Children.

Avascular necrosis (AVN) is a rare but important complication after supracondylar humerus fractures. Posttraumatic humerus deformity was first reported in 1948 and sporadically thereafter. AVN deformity has been classified as type A (AVN of the lateral ossification center) and type B (AVN of the entire medial crista and a metaphyseal portion). In this article, we present 5 cases of AVN after supracondylar humerus fracture, discuss the importance of late clinical findings, and postulate a mechanism of AVN in nondisplaced fractures. Five cases of AVN after supracondylar humerus fracture were reviewed from the Children's of Alabama database. Four of the 5 patients were female. Four patients sustained a Gartland type III fracture, and 1 patient sustained a nondisplaced Gartland type I fracture. Age at time of injury ranged from 5 years to 10 years. All patients had an asymptomatic clinical period after treatment and re-presented 6 months to 7 years later with elbow pain or loss of motion. All patients were treated symptomatically. AVN of the trochlea has a late clinical presentation. The cause of this complication is interruption of the trochlea blood supply. In displaced fractures, the medial and/or lateral vessels are injured, leading to type A or type B deformity. In nondisplaced fractures, the lateral vessels are interrupted by tamponade because of encased fracture hematoma; this presents as a type A deformity. Both type A and type B deformities can be clinically significant. AVN of the trochlea should be considered in patients with late presentation of pain or loss of motion after treatment of supracondylar humerus fractures.

The Use of Chewing Gum Postoperatively in Pediatric Scoliosis Patients Facilitates an Earlier Return to Normal Bowel Function.

PURPOSE: In surgical correction of scoliosis in pediatric patients, gastrointestinal complications including postoperative ileus can result in extended hospital stays, poorer pain management, slower progression with physical therapy, and overall decreased patient satisfaction. In patients undergoing gastrointestinal, gynecological, and urological surgery, gum chewing has been shown to reduce time to flatus and passage of feces. The authors hypothesized that chewing gum could also speed return to normal bowel function in pediatric patients undergoing surgical correction of scoliosis. METHODS: The researchers obtained institutional review board approval for a prospective, randomized, controlled trial. Eligible patients included all adolescent idiopathic scoliosis patients undergoing posterior spinal fusion. Exclusion criteria included previous gastrointestinal surgery or preexisting gastrointestinal disease. Patients were randomized by coin flip. The treatment group chewed sugar-free bubble gum 5 times a day for 20 to 30 minutes beginning on postoperative day 1; the control group did not chew gum. Patients were asked a series of questions regarding subjective gastrointestinal symptoms each day. Time to flatus and first passage of feces were recorded as indicators of return to normal bowel function. Normality of data was assessed using normal probability plots. RESULTS: A total of 83 patients completed the study (69 females and 14 males; mean age, 14.4 years). Of the 42 patients in the chewing gum group, 8 elected to stop chewing gum regularly before discharge for to a variety of reasons. Patients who chewed gum experienced first bowel movement on average 145.9 hours after surgery, 30.9 hours before those who did not chew gum (p = .04). Gum-chewing patients first experienced flatus an average of 55.2 hours after surgery, compared with 62.3 hours for controls. This trend did not reach statistical significance (p = .12). No difference was noted in duration of hospital stay, medications administered as required, or subjective symptoms. CONCLUSION: Chewing gum after posterior spinal fusion for scoliosis is safe and may speed return of normal bowel function. Chewing gum after surgical correction of scoliosis facilitates an earlier return to normal bowel function, which may improve patient satisfaction in the early postoperative period.