Ectodermal-Neural Cortex 1 Isoforms Have Contrasting Effects on MC3T3-E1 Osteoblast Mineralization and Gene Expression.

The importance of Wnt pathway signaling in development of bone has been well established. Here we investigated the role of a known Wnt target, ENC1 (ectodermal-neural cortex 1; NRP/B), in osteoblast differentiation. Enc1 expression was detected in mouse osteoblasts, chondrocytes, and osteocytes by in situ hybridization, and osteoblastic expression was verified in differentiating primary cultures and MC3T3-E1 pre-osteoblast cells, with 57 kDa and 67 kDa ENC1 protein isoforms detected throughout differentiation.

Clinical, Molecular, and Genetic Characteristics of PAPA Syndrome: A Review.

PAPA syndrome (Pyogenic Arthritis, Pyoderma gangrenosum, and Acne) is an autosomal dominant, hereditary auto-inflammatory disease arising from mutations in the PSTPIP1/CD2BP1 gene on chromosome 15q. These mutations produce a hyper-phosphorylated PSTPIP1 protein and alter its participation in activation of the "inflammasome" involved in interleukin-1 (IL-1β) production. Overproduction of IL-1β is a clear molecular feature of PAPA syndrome.

Transient disturbance in physeal morphology is associated with long-term effects of nitrogen-containing bisphosphonates in growing rabbits.

Unlabelled: Bisphosphonates have clinical benefit in children with severe osteogenesis imperfecta or osteoporosis and potential benefit in children with Perthes disease or undergoing distraction osteogenesis. However, there is concern about the effects of bisphosphonates on the physis and bone length. In 44 growing rabbits, zoledronic acid caused a transient disruption of physeal morphology, retention of cartilaginous matrix in trabeculae and cortical bone of the metaphysis, and a minor decrement in tibial bone length at maturity.

Transient retention of endochondral cartilaginous matrix with bisphosphonate treatment in a long-term rabbit model of distraction osteogenesis.

Unlabelled: Bisphosphonates induce major increases in strength of callus in distraction osteogenesis in the short term. Poor understanding of the underlying mechanism, however, raises concerns about long-term consequences. In this long-term study in 32 rabbits, zoledronic acid transiently increased trabeculae by delayed temporal progression of endochondral bone remodeling but did not prevent radiographic completion of bone repair.

Low-intensity ultrasound stimulation in distraction osteogenesis in rabbits.

Low-intensity pulsed ultrasound has been shown to accelerate fracture healing. This experiment investigated its possible role in distraction. Thirty-four New Zealand White rabbits had distraction osteogenesis, followed by low-intensity pulsed ultrasound therapy.

Zoledronic acid treatment results in retention of femoral head structure after traumatic osteonecrosis in young Wistar rats.

Unlabelled: Osteonecrosis (ON) of the femoral head in childhood can lead to loss of femoral head architecture and subsequent deformity. When femoral head ON was surgically induced in 24 rats, zoledronic acid treatment and prophylaxis improved sphericity and maintenance of architecture at 6 weeks. This preliminary experiment supports the use of bisphosphonates in childhood ON.

Zoledronic acid prevents osteopenia and increases bone strength in a rabbit model of distraction osteogenesis.

Unlabelled: Prolonged healing times and stress-shielding osteopenia remain problematic in distraction osteogenesis. In this study of 30 rabbits, zoledronic acid increased regenerate volume, mineralization, and tibial strength and prevented osteopenia over a 6-week period. Translation to the clinical setting, if safe, could improve outcomes in distraction osteogenesis in children.