Israel Medical Association Journal

Background: Fractures of the humerus in neonates can pose a diagnostic challenge, especially when the fracture occurs in the proximal or distal epiphysis.

Objectives: To review our experience in the diagnosis and treatment of birth-related humeral fractures.

Methods: Between the years 2001 and 2009, seven newborn patients and two patients treated in the neonatal intensive care unit sustained a fracture of the humerus. Four of the fractures occurred in the humeral shaft, three in the proximal epiphysis and two in the distal epiphysis. In all the newborn patients the diagnosis was made on the first day of life using radiography and ultrasonography. The fractures of the shaft and of the distal epiphysis were treated by gentle manipulation and casting, and the fractures of the proximal epiphysis were treated by swaddling.

Results: All of the patients demonstrated fracture union within 2 weeks, and radiographs at the age of 6 months demonstrated complete remodeling of the fracture.

Conclusions: Ultrasonography is a simple, readily available and inexpensive modality for the diagnosis of birth-related fractures of the humerus, especially in the yet unossified epiphyses.

Background: Fractures of the femur in neonates are relatively uncommon. The infants feel pain and discomfort, causing parental distress, and the hospital stay is longer. Treatment of this specific fracture is problematic because of the small size of the baby.

Objectives: To review the results of the treatment of neonatal femoral fractures.

Methods: We retrospectively reviewed all neonatal fractures of the femur during a 12 year period. Thirteen fractures of the femur in 11 babies were treated with improvised Bryant skin traction of both legs. All the patients were re-examined after a mean follow-up period of 5.2 years.

Results: All fractures healed satisfactorily clinically and radiographically, with no residual deformity, no leg length discrepancy and no functional impairment.

Conclusions: Bryant’s traction for 2–3 weeks in hospital is a safe method for the treatment of femoral fractures in neonates, and the outcome is good.
 

The Ink4a-Arf locus, which encodes two distinct tumor suppressor proteins, is inactivated in many cancers. Whereas p16^Ink4a is an inhibitor of cyclin D-dependent kinases, p19^Arf (p14^ARF in humans) antagonizes the E3 ubiquitin protein ligase activity of Mdm2 to activate p53. We now recognize that Arf functions in both p53-dependent and -independent modes to counteract hyper-proliferative signals originating from proto-oncogene activation, but its p53-independent activities remain poorly understood. Arf proteins are highly basic (> 20% arginine content, pI > 12) and predominantly localize within nucleoli in physical association with an abundant acidic protein, nucleophosmin (NPM/B23). When bound to NPM[1], Arf proteins are relatively stable with half-lives of 6–8 hours. Although mouse p19^Arf contains only a single lysine residue and human p14^ARF has none, both proteins are N-terminally ubiquitinated and degraded in proteasomes. Through as yet uncharacterized mechanisms, p19^Arf induces p53-independent sumoylation of a variety of cellular target proteins with which it interacts, including both Mdm2 and NPM. A naturally occurring NPM mutant (NPMc) expressed in myeloid leukemia cells redirects both wild-type NPM and p19^Arf to the cytoplasm, inhibits Arf-induced sumoylation, and attenuates p53 activity. Thus, ubiquitination and sumoylation can each influence Arf tumor suppressor activity.