Treatment of Vancouver B1 periprosthetic femoral fractures using Intrauma Iron Lady® locking plate: A retrospective study on 32 patients

Introduction: Periprosthetic femoral fractures (PFF) actually represent a serious public health problem. They are reported to occur in 0,1-4.5% of all patients undergoing total hip replacement (THR). PFF are commonly distinguished using the Vancouver classification. This study principal aim is to evaluate results obtained using the Intrauma Iron Lady® Conical Coupling locking plate for the treatment of Vancouver type B1 periprosthetic femoral fractures. Materials and Methods: We enrolled 32 patients affected by Vancouver B1 PFF and treated with the same device. Metal cerclages were additionally used in 12 (38%) patients. A clinical and radiographical post-operative follow-up was then planned at 1, 3 and 6 months after surgery; than the follow-up was annually fixed. Results: Mean age at the moment of trauma was 76,7 years. All involved femoral stem were uncemented and the they were all radiographically and intraoperativelly judged to be stable. Mean post-operative follow-up period was 5,8 years. 29 patients (91%) presented healed fracture at 6 months follow-up. 9% patients developed a superficial surgical site infection. Discussion and Conclusions: Literature highlights that Vancouver B1 PFF should be treated with open reduction and internal fixation (ORIF) using polyaxial locking plates. However, no single technique has gained universal acceptance to be superior that the other. The current reported healing rate ranges from 40 to 100%. Using the Intrauma Iron Lady® Conical Coupling locking plate, we obtained a healing rate of 91%; this data is consistent with recent literature. Moreover, the role of cerclages in addition to femoral plating is actually controversial because they potentially damage the soft callus vascularization. Our results showed no difference in term of healing rate between patients with and without cerclages, according with some of most recent articles. A prospective study with a higher number of patients should be carried out in order to better evaluate the role of cerclages on healing rate but also the complications frequency after PFF surgical treatment

Identification of non-canonical Wnt receptors required for Wnt-3a-induced early differentiation of human neural stem cells

Wnt proteins preferentially activate either β-catenin-dependent or β-cateninindependent signals, but the activity of a particular Wnt also depends on cellular context and receptor availability. We previously reported that Wnt-3a induces neural differentiation of human embryonic stem cell-derived neural stem cells (NSCs) in a β-catenin-independent manner by activating a signal involving JNK and the AP-1 family member ATF-2. Here, we report the results of a gene silencing approach to identify the Wnt receptors that mediate this response to Wnt-3a. Silencing of ROR2 increased neuronal differentiation, as measured by expression of the genes DCX, NEUROD1 and NGN1, suggesting ROR2 signals normally prevent differentiation. Silencing of the other Wnt receptors singly did not affect Wnt-3ainduced neuronal differentiation. However, pair-wise silencing of ROR1 and FZD4 or FZD5 and of LRP6 and FZD4 or FZD5 inhibited neuronal differentiation, as detected by reductions in the expression of neuronal genes and immunocytochemical detection of DCX and NEUROD1 and DCX. Ectopic expression of these receptors in HEK 293 cells increased ATF2-dependent transcription. In addition, ROR1 co-immunoprecipitated with FZD4 and LRP6 in transfected HEK 293 cells and colocalized with FZD4 and with LRP6 at the cell surface of transfected L cells. Wnt-3a did not appear to affect these interactions but did alter the interactions between LRP6 and FZD4/5. Together, these observations highlight roles for ROR1, LRP6, FZD4 and FZD5 in neural stem cell differentiation and provide support for a model in which dynamic interactions among these receptors mediate Wnt-3a activation of ATF2 signaling

Characterization of a surface-active protein extracted from a marine strain of penicillium chrysogenum

Marine microorganisms represent a reservoir of new promising secondary metabolites. Surface-active proteins with good emulsification activity can be isolated from fungal species that inhabit the marine environment and can be promising candidates for different biotechnological applications. In this study a novel surface-active protein, named Sap-Pc, was purified from a marine strain of Penicillium chrysogenum. The effect of salt concentration and temperature on protein production was analyzed, and a purification method was set up. The purified protein, identified as Pc13g06930, was annotated as a hypothetical protein. It was able to form emulsions, which were stable for at least one month, with an emulsification index comparable to that of other known surface-active proteins. The surface tension reduction was analyzed as function of protein concentration and a critical micellar concentration of 2 M was determined. At neutral or alkaline pH, secondary structure changes were monitored over time, concurrently with the appearance of protein precipitation. Formation of amyloid-like fibrils of SAP-Pc was demonstrated by spectroscopic and microscopic analyses. Moreover, the effect of protein concentration, a parameter affecting kinetics of fibril formation, was investigated and an on-pathway involvement of micellar aggregates during the fibril formation process was suggested