The stable inhibition of miR-214 in the aged osteoporotic rats induced by OVX could be achieved by periodic administration of AntagomiR-214 at a dosage of 4 mg/kg and at an interval of 7 days, which will provide a potential bone anabolic strategy for treatment of osteoprosis. MiR-214 has a crucial role in suppressing bone formation and miR-214 inhibition in osteogenic cells may be a potential anabolic strategy for ameliorating osteoporosis (Wang X, et al. 2013). An aged ovariectomised rat has been regarded as a golden model to test bone anabolic agents for reversing established osteoporosis in aged postmenopausal women (Li X, et al. 2009). However, there is still lack of evidence to demonstrate bone anabolic potential of therapeutic inhibition of miR-214 within osteogenic cells in the golden model. So, it should be necessary to establish RNAi-based administration protocol toward stable inhibition of miR-214 at a low level in the golden model. A targeted delivery system specifically facilitating Antagomir-214 approaching osteogenic cells, Summary Statement
Introduction
The objective of this study was to evaluate the rotation and
translation of each joint in the hindfoot and compare the load response
in healthy feet with that in stage II posterior tibial tendon dysfunction
(PTTD) flatfoot by analysing the reconstructive three-dimensional
(3D) computed tomography (CT) image data during simulated weight-bearing. CT scans of 15 healthy feet and 15 feet with stage II PTTD flatfoot
were taken first in a non-weight-bearing condition, followed by
a simulated full-body weight-bearing condition. The images of the
hindfoot bones were reconstructed into 3D models. The ‘twice registration’
method in three planes was used to calculate the position of the
talus relative to the calcaneus in the talocalcaneal joint, the
navicular relative to the talus in talonavicular joint, and the cuboid
relative to the calcaneus in the calcaneocuboid joint.Objective
Methods
Mesenchymal stromal cells (MSCs) are an attractive choice for regenerative medicine. We previously showed that MSCs enhance wound healing in animals after radiotherapy. The effect of MSCs on tumor growth is not well understood. The potential use of MSCs to enhance wound healing after radiotherapy (RT) and resection of soft tissue sarcoma (STS) is dependent on a satisfactory safety profile to ensure that tumor proliferation does not occur and recurrence is not increased. Primary cell lines (human myxofibrosarcoma and undifferentiated sarcoma) derived from sarcoma bearing patients and a commercialized human fibrosarcoma cell line (HT1080) were used. Cell line proliferation assay after co-culture with MSCs was done using flow cytometry (CFSE) and bioluminescence emission (BLI) (using eGFP/Fluc transduced cell lines). Five xenograft models were developed with NOD/SCID gc-null mice (n=164) harbouring primary tissue lines obtained from patients biopsies (myxofibrosarcoma and three pleomorphic undifferentiated sarcoma [PUS A, B and C]) and a a fibrosarcoma cell line previously transduced with eGFP/Fluc. Tumors were passaged to three mouse generations before a tissue line was established and the model was then used. For the fibrosarcoma model, eGFP/Fluc HT1080 were injected under the dorsal skin. When tumors reached 1cm in diameter, they received localized RT and 48hr later were resected. MSCs (n=82) or medium alone (n=82) was injected subcutaneously adjacent to the wound after tumor resection. Histological and in vivo BLI analysis were performed 3 and 12 weeks after surgery.Purpose
Method
Follow-up radiographs are usually used as the
reference standard for the diagnosis of suspected scaphoid fractures. However,
these are prone to errors in interpretation. We performed a meta-analysis
of 30 clinical studies on the diagnosis of suspected scaphoid fractures,
in which agreement data between any of follow-up radiographs, bone scintigraphy,
magnetic resonance (MR) imaging, or CT could be obtained, and combined
this with latent class analysis to infer the accuracy of these tests
on the diagnosis of suspected scaphoid fractures in the absence
of an established standard. The estimated sensitivity and specificity
were respectively 91.1% and 99.8% for follow-up radiographs, 97.8%
and 93.5% for bone scintigraphy, 97.7% and 99.8% for MRI, and 85.2%
and 99.5% for CT. The results were generally robust in multiple
sensitivity analyses. There was large between-study heterogeneity
for the sensitivity of follow-up radiographs and CT, and imprecision
about their sensitivity estimates. If we acknowledge the lack of a reference standard for diagnosing
suspected scaphoid fractures, MRI is the most accurate test; follow-up
radiographs and CT may be less sensitive, and bone scintigraphy
less specific.
Enhanced angiogenesis and osteogenesis may provide new strategies for the treatment of osteonecrosis. Synergistic effects of vascular endothelial growth factor (VEGF) and bone morphogenetic protein - 6 (BMP-6) on Introduction
Methods
Osteonecrosis of the femoral head is a devastating disease in young patients and remains a challenge for clinicians and researchers alike. To increase understanding of the disease and produce effective treatments that preserve a patient's native hip, an animal model that mimics the disease process in humans, including collapse of the femoral head, is essential. Our goal was to create such a bipedal model by surgically inducing osteonecrosis in the femoral heads of chickens. A lateral approach to the proximal femur was used to access the hip, dislocate the femoral head, and sever the periosteal network of blood vessels. At 4, 8, 12, and 20 weeks after surgery, both the left (experimental) and right (control) femoral heads were harvested from 6 chickens for micro-CT and histological analysis.Introduction
Methods
Corticosteroids are prescribed for the treatment of many medical conditions and their adverse effects on bone, including steroid-associated osteoporosis and osteonecrosis, are well documented. Core decompression is performed to treat osteonecrosis, but the results are variable. As steroids may affect bone turnover, this study was designed to investigate bone healing within a bone tunnel after core decompression in an experimental model of steroid-associated osteonecrosis. A total of five 28-week-old New Zealand rabbits were used to establish a model of steroid-induced osteonecrosis and another five rabbits served as controls. Two weeks after the induction of osteonecrosis, core decompression was performed by creating a bone tunnel 3 mm in diameter in both distal femora of each rabbit in both the experimental osteonecrosis and control groups. An In the osteonecrosis group all measurements of bone healing and maturation were lower compared with the control group. Impaired osteogenesis and remodelling within the bone tunnel was demonstrated in the steroid-induced osteonecrosis, accompanied by inferior mechanical properties of the bone. We have confirmed impaired bone healing in a model of bone defects in rabbits with pulsed administration of corticosteroids. This finding may be important in the development of strategies for treatment to improve the prognosis of fracture healing or the repair of bone defects in patients receiving steroid treatment.
We reviewed the outcome of a retrospective case series of eight patients with atlantoaxial instability who had been treated by percutaneous anterior transarticular screw fixation and grafting under image-intensifier guidance between December 2005 and June 2008. The mean follow-up was 19 months (8 to 27). All eight patients had a solid C1–2 fusion. There were no breakages or displacement of screws. All the patients with pre-operative neck pain had immediate relief from their symptoms or considerable improvement. There were no major complications. Our preliminary clinical results suggest that percutaneous anterior transarticulation screw fixation is technically feasible, safe, useful and minimally invasive when using the appropriate instruments allied to intra-operative image intensification, and by selecting the correct puncture point, angle and depth of insertion.
Patients must be warned of potential reduction of forearm rotation.
We examined the pathogenesis of Schmorl’s nodes, correlating the histological findings from 12 lumbar vertebrae with the corresponding conventional radiographs, tomographs, MR images and CT scans. The last revealed round, often multiple cystic lesions with indistinct sclerotic margins beneath the cartilaginous endplate. The appearances are similar to the typical CT changes of osteonecrosis. Histological examination of
Introduction: No appropriate animal model for studying adolescent idiopathic scoliosis (AIS) exists and this hampers research. In recent years, we have been examining a model in which scoliosis consistently develops in young chickens following pinealectomy and which has been shown to have many characteristics similar to those seen in AIS. Not all of the pinealectomised chickens develop scoliosis following the pinealectomy and so we have the opportunity to examine differences between the two groups. The obvious candidate for study of the mechanism underlying this phenomenon is melatonin which is the principal product of the pineal gland. In this study we have measured the serum melatonin levels of pinealectomised chickens that have developed scoliosis and compared these with similar measurements taken from chickens that have developed scoliosis. Methods and results: Newly-hatched chickens were obtained from a local hatchery and kept in a single pen with standard heating and lighting. A 12:12 light dark cycle was introduced immediately and the two-thirds of the chickens were pinealectomised three days later. The remainder acted as controls. At weekly intervals following surgery, the chickens were radiographed in a supine position while anaesthetised and the presence of scoliosis was determined from the radiographs. Three weeks after surgery the chickens were euthanised and blood samples were collected and analysed using radioimmunological techniques to determine levels of serum melatonin. The samples were collected in the presence of red light in the middle of the dark cycle when melatonin levels have been shown to be at their highest. Approximately 55% of the pinealectomised chickens developed scoliosis within the three weeks following surgery whereas none of the control chickens developed scoliosis. The results showed that the serum melatonin levels of pinealectomised chickens were significantly lower than the normal controls and were in fact all close to zero. However, there was no significant difference in serum melatonin levels between those chickens that developed scoliosis and those that did not. Conclusion: The results of this study have shown that pinealectomy significantly reduces serum melatonin levels close to zero in all chickens. The results also show that there is no significant difference in serum melatonin levels between those pinealectomised chickens that develop scoliosis and those that do not. Unless there is a subtle threshold level that is unable to be detected using our methodology or that melatonin levels in the days immediately after surgery are of critical importance, these results suggest that other causes for this phenomenon need to be examined. An understanding of the underlying cause would be of great importance and might represent a significant breakthrough in the study of AIS.