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Hip fractures are common in older and frail adults, and the risk of adverse outcomes and mortality is significantly increased in patients affected by osteosarcopenia. Identifying particularly vulnerable subjects is a critical step to act aimed at promoting postoperative recovery and reducing the risk of adverse events. However, the diagnostic criteria that are currently used to establish the severity of osteosarcopenia are not easily applicable in patients with hip fractures and impaired mobility. In this review, the new knowledge on the pathophysiology of osteosarcopenia that provides several cues for studying biomarkers potentially useful in clinical practice is summarized. Although significant progress has been obtained in understanding the biological mechanisms leading to the involution of the bone- muscle unit, further studies are needed to identify clinically relevant biomarkers and their diagnostic accuracy in establishing the severity of the osteosarcopenia, predicting adverse outcomes, and guiding physicians in choosing appropriate therapeutic interventions.

Current methods for the replacement of skeletal tissue involve the use of autografts, allografts and, recently, synthetic substitutes, which provide a proper amount of material to repair large bone defects. Engineered bone seems a promising approach, but a number of variables have to be set prior to anyclinical application. In this study, four different poly caprolactone-based polymers (PCL) were prepared and tested in vitro using osteoblast-like Saos- 2 cells. Differences among three-dimensional polymers include porosity, addition of hydroxyapatite (HA) particles, and treatment with simulated bodyfluid. Biochemical parameters to assess cell/material interactions include viability, growth, alkaline phosphatase release, and mineralization of osteoblastic cells seeded onto three-dimensional samples, while their morphologywas observed using light microscopyand SEM. Preliminaryresults show that the polymers, though degrading in the medium, have a positive interaction with cells, as they support cell growth and functions. In the short-term culture (3–7 days) of Saos-2 on polymers, little differences were found among PCL samples, with the presence of HA moderatelyimproving the number of cells onto the surfaces. In the long term (3–4 weeks), it was found that the HA-added polymers obtained the best colonization by cells, and more mineral formation was observed after coating with SBF. It can be concluded that PCL is a promising material for three-dimensional scaffold for bone formation, and the presence of bone-like components improves osteoblast activity.

Several issues concerning the biocompatibility) testing of medical devices as stated in European directive 90/385 and 93/42 are discussed. The authors describe the fundamental characteristics that biomaterials should have to be employed in the human body, the assays useful for testing different aspects of biocompatibility and the harmonized regulations already available or under development. The testing protocol applied by the a. in their Lab covering many issues of biocompatibility is presented: a body of experience was gained over the years and it has been revised under the new regulatory items. In conclusion, the biocompatibility of devices must be assessed following the European harmonized standards, the available. Where proper standards are still lacking, feasible testing methods, even if not officially adopted yet, have to be used.

The authors have examined the alterations in the coagulation pathway of plasma filtered through a polyester filter coated by a hydrophilic polymer. The activation of the coagulation pathway was evaluated by measuring prothrombin time, activated partial thromboplastin time, coagulation factors and fibrinopeptide A. The results obtained demonstrate that the examined filter does not induce significative activation of the coagulation pathway.

We have studied the effect of gamma radiation on differentiation in neuroblastoma cell lines AF8 and SJ-N-KP. Growth inhibition and morphological and biochemical differentiation have been examined following radiation exposure to 1-10 Gy. Gamma radiation induced marked growth inhibition and morphological differentiation in a dose-and time-dependent manner in both cell lines, and induced biochemical differentiation in AF8 cells.

B-cell acute lymphoblastic leukemia (B-ALL) presents FAB L3 morphology and surface Ig, CD19, CD20, CD24. This pattern may show some morphological and immunological heterogeneity. Seventeen pediatric cases of B-ALL at onset, treated in twelve AIEOP Centers (Italian Association for Pediatric Hematology and Oncology), are presented.Clinical and hematological features were characterized by low WBC counts at presentation, high M/F ratio, older age and association with extramedullary involvement. The overall survival curve at 78 months is 40%. All patients showed blasts positive for surface Ig (sIg), DR, CD19, and CD24. Ten/17 cases presented the classical features of B-ALL: FAB L3 morphology, sIg+ restricted to light chains, CD20+, cytoplasm mu (c mu)-, CD10-, TdT-. The remainder showed some differences in this pattern, such as non-L3 morphology (3 cases), absence of CD20 (3 cases), CD10+ (4 cases), TdT+ (3 cases), c mu+ (1 case), lack of surface light chains (1 case). This rare ALL subset seems to be characterized by a high phenotype heterogeneity, indicating various degrees of differentiation.

BACKGROUND: The contribution of angiogenesis to renal carcinoma bone metastases is virtually unknown. MATERIALS AND METHODS: The effect of a cell line from a renal carcinoma bone metastasis (CRBM) was compared in vitro with the primitive renal adenocarcinoma line ACHN, by evaluating the influence on the ability of bone endothelial cells to activate osteoclasts. RESULTS: The ACHN-conditioned medium produced a significant expression of macrophage-colony-stimulating factor mRNA. The conditioned medium from ACHN, CRBM, or from endothelial cells previously stimulated with the neoplastic cell-conditioned media, had no direct effect on osteoclast differentiation from blood precursors (PBMC), such as CRBM and ACHN co-cultured with PBMC. However, PBMC co-cultured with endothelial cells previously stimulated with the CRBM-conditioned medium showed significantly higher levels of tartrate-resistant acid phosphatase. CONCLUSION: It is possible that the bone metastatic line CRBM releases factors that induce endothelial cells to favor osteoclast differentiation.

BACKGROUND: Fibroblast growth factor-2 (FGF-2) has a role in the angiogenesis induced by renal carcinoma. MATERIALS AND METHODS: Blockage of FGF-2 by an antisense oligonucleotide (ASO) or by a mouse neutralizing anti-human FGF-2 monoclonal antibody (anti-FGF-2-mAb) was evaluated on a cell line isolated from a renal carcinoma bone metastasis (CRBM-1990), on Caki-1 and ACHN cells. Cocultures of endothelial cells and ASO- or mAb-treated carcinoma lines were investigated. RESULTS: Anti-FGF-2-mAb treatment induced a 33% reduction of FGF-2 released by ACHN, a 31% reduction of FGF-2 released by Caki-1, and a 70% reduction of FGF-2 released by CRBM-1990. ASO treatment did not inhibit endothelial cell proliferation. In contrast, anti-FGF-2-mAb significantly decreased endothelial cells proliferation induced by ACHN and CRBM-1990. The inhibition of endothelial cell growth was reverted by recombinant FGF-2. CONCLUSION: Modulation of FGF-2 production by renal cell carcinoma with a blocking mAb produced a significant inhibition of endothelial cell growth.

In this study, we explored if urinary lithogenic risk parameters could have some application for monitoring bone health status. We recruited 20 women with postmenopausal osteopenia and a negative medical history for nephrolithiasis. Markers of lithogenic risk were evaluated on 24-h urine and fastingmorning urine. Serum levels of bone turnover markers (BTM) were measured in fasting-blood samples. We found that cross-linked telopeptide of type I collagen (CTX) was significantly correlated with 24-h calcium excretion. N-terminal propeptide of type I procollagen (PINP) correlated with 24-h excretion of potassium, calcium and citrate. CTX had considerably increased in patients with pH less than 5.5. Low citrate levels (less than 3.3 mmol/24 h) were associated with lower levels of CTX and PINP. Our findings suggest that a low-grade acidosis and some lithogenic risk factors are detectable in a proportion of patients with postmenopausal osteopenia. Further studies are necessary to confirm that this evaluation could be clinically relevant.

Authors evaluated the correlation between immune system and metal ions release in blood of 17 subjects with Cr/Co/Ni joint prostheses. For the purpose Chromium (Cr), Cobalt (Co) and Nickel (Ni) serum levels were measured and, at the same time some immunological parameters (Leukocytes, Lymphocytes and Lymphocytes T, B and Natural Killer cells sub-populations) were evaluated. The results showed a significant decrease of Leukocytes, Lymphocytes and of T Lymphocytes sub-populations. At the same time it was demonstrated a significant increase of Chromium, Cobalt and Nickel levels in patients with joint prostheses as compared to control population (23 patients). In conclusion, ions release from metallic surface of the prostheses is correlated with a depression of immune system. This correlation could depend on a toxic action on immune system caused by the products released by the implant. It could also depend on a lymphocytes compartimentalization in periprosthetic tissues as a consequence of a cell-mediated hypersensitivity reaction towards implants corrosion products.

The employment in clinical practice and prosthetic surgery of a number of medical devices implies a great responsibility to the operators so as to make the knowledge of existing regulations mandatory. The authors illustrate the problems concerning the free circulation of medical devices within the European market. They describe the new strategy of EEC which led to the definition of the directives which apply to all medical devices and of the harmonized standards for inspecting their biological effects. The appointment of certification bodies and the accreditation of Testing Laboratories are described. Finally, particular attention is given to product certification, which is compulsory for the pre-market approval of medical devices.

On the basis of a vast experience deriving from the histological study of explants of hip joint prostheses, the authors emphasize the role of histomorphometric testing in allowing for a quantitative evaluation of periprosthetic cellular reaction, of the bone structure, and of the wear phenomena of the implant, in order to gain a better understanding of the pathogenetic mechanisms responsible for the phenomenon of loosening. In agreement with what has been reported by other authors, they describe what they were able to observe by image analysis, microradiography, x-ray diffraction, and microdurimetry in various types of explanted prostheses. In particular, they describe data on the features of the wear particles, the periprosthetic cellular component, the thickness of the interfacial membrane and of the joint neocapsule, the volume of bone-ingrowth, the contact surface, and the structure of the bone-implant interface. Based on the changes observed using histomorphometry, a pathogenetic hypothesis was formulated according to which physical phenomena closely related to the type of implant used, such as wear and metal ion release, and non-physiological stress exerted on the bone, cause a series of cellular chain reactions. Within this context, macrophages, lymphocytes, osteoblasts and osteoclasts are in a continuous state of activation and, both directly and by means of the production of cytokines and other substances, they are responsible for bone resorption and thus loss of continuity between the bone and the implant, resulting in prosthetic loosening.

The Authors evaluated some immunological parameters in women carrying silicone gel-filled breast implants for over one year. Peripheral blood samples from 22 patients were examined in order to assess both the antigenic pattern of lymphocyte subpopulations by cytofluorimetric analysis, and the cell proliferation of PHA-stimulated lymphocytes by the uptake of tritiated thymidine. These tests were performed at the time of the sample withdrawal and after in vitro reexposure to silicone extract for 48-72h. Changes in lymphocyte subpopulations and functional response were observed when patients were divided into groups according to the type of surgery, i.e. breast augmentation or reconstruction, or to the degree of periprosthetic capsular contracture. These results suggest the possibility of an interaction between silicone and the immune system, which cannot be disregarded for the explanation of the silicone related complications.

Arterial embolization, aimed at the mechanical occlusion of tumor-feeding vessels, represents a satisfactory palliative therapy for bone metastases. In this study, we evaluated if the circulating levels of three factors related to the metastatic process change in response to embolization. Seven patients who underwent embolization of a single skeletal metastasis from carcinomas were analyzed prospectively. Circulating levels of Vascular Endothelial Growth Factor A (VEGF-A), Fibroblast Growth Factor 2 (FGF-2), and Tartrate-Resistant Acid Phosphatase-5b Isoform (TRACP5b) were evaluated before and after embolization at 1, 3, and 6 months. According to morphological and clinical evaluations, all the embolizations were successful. VEGF-A and TRACP5b did not show significant changes after the treatment. On the contrary, FGF-2 signifi- cantly decreased 1 month after the treatment. FGF-2 appears as a promising candidate for monitoring the efficacy of emboli- zation in patients with osteolytic metastases.

Background Safety and feasibility of a regenerative strategy based on the use of culture-expanded mesenchymal stromal cells (MSCs) have been investigated in phase 2 trials for the treatment of nonunion and osteonecrosis of the femoral head (ONFH). As part of the clinical study, we aimed to evaluate if bone turnover markers (BTMs) could be useful for predicting the regenerative ability of the cell therapy product. Materials and Methods The bone defects of 39 patients (nonunion: n = 26; ONFH: n = 13) were treated with bone marrow–derived MSCs, expanded using a clinical-grade protocol and combined with biphasic calcium phosphate before implantation. Bone formation markers, bone-resorption markers and osteoclast regulatory proteins were measured before treatment (baseline) and after 12 and 24 weeks from surgery. At the same time-points, clinical and radiological controls were performed to evaluate the bone-healing progression. Results We found that C-Propeptide of Type I Procollagen (CICP) and C-terminal telopeptide of type-I collagen (CTX) varied significantly, not only over time, but also according to clinical results. In patients with a good outcome, CICP increased and CTX decreased, and this trend was observed in both nonunion and ONFH. Moreover, collagen biomarkers were able to discriminate healed patients from non-responsive patients with a good diagnostic accuracy. Discussion CICP and CTX could be valuable biomarkers for monitoring and predicting the regenerative ability of cell products used to stimulate the repair of refractory bone diseases. To be translated in a clinical setting, these results are under validation in a currently ongoing phase 3 clinical trial.

Sarcomas are frequent tumors in children and young adults that, despite a relative chemo-sensitivity, show high relapse rates with up to 80% of metastatic patients dying in 5 years from diagnosis. The real ontogeny of sarcomas is still debated and evidences suggest they may derive from precursors identified within mesenchymal stromal/stem cells (MSC) fractions. Recent studies on sarcoma microenvironment additionally indicated that MSC could take active part in generation of a supportive stroma. Based on this knowledge, we conceived to use modified MSC to deliver tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) targeting different sarcoma histotypes. Gene modified MSC expressing TRAIL were cocultured with different osteosarcoma, rhabdomyosarcoma, and Ewing's Sarcoma (ES) cell lines assessing viability and caspase-8 activation. An in vivo model focused on ES was then implemented considering the impact of MSC-TRAIL on tumor size, apoptosis, and angiogenesis. MSC expressing TRAIL induced significantly high apoptosis in all tested lines. Sarcoma death was specifically associated with caspase-8 activation starting from 8 hours of coculture with MSC-TRAIL. When injected into pre-established ES xenotransplants, MSC-TRAIL persisted within its stroma, causing significant tumor apoptosis versus control groups. Additional histological and in vitro studies reveal that MSC-TRAIL could also exert potent antiangiogenic functions. Our results suggest that MSC as TRAIL vehicles could open novel therapeutic opportunities for sarcoma by multiple mechanisms.

Ethnopharmacological relevance Four Indian plants, traditionally used in Ayurvedic medicine: Asparagus racemosus Willd., Emblica officinalis Gaertn., Hemidesmus indicus R. Br., and Rubia cordifolia L. were selected on the basis of their ethnobotanical use and of scientific evidence that suggests a potential efficacy in the treatment of bone-loss diseases. The antiresorptive properties of the four plants have been investigated. The aim was to provide adequate evidence for the exploitation of natural compounds as alternative therapeutics for the treatment of diseases caused by increased osteoclast activity. Materials and methods Decoctions were prepared from dried plant material according to the traditional procedure and standardization by HPLC was performed using marker compounds for each species. Total polyphenols, flavonoids and radical scavenging activity of the decoctions were also determined. The bioactivity of the plant decoctions was evaluated in subsequent phases. (1) A cytotoxicity screening was performed on the mouse monocytic RAW 264.7 cell line to define the concentrations that could be utilized in the following step. (2) The antiresorptive properties of plant decoctions were compared with that of a “gold standard” drug (alendronate) by measuring osteoclastogenesis inhibition and osteoclast apoptosis. (3) The toxic effect on bone forming cells was excluded by evaluating the impact on the proliferation of osteogenic precursors (mesenchymal stem cells, MSC). Results All the decoctions inhibited osteoclastogenesis similarly to alendronate at the highest doses, but Hemidesmus indicus and Rubia cordifolia were also effective at lower concentrations. Apoptosis increased significantly when cells were exposed to the highest concentration of Emblica officinalis, Hemidesmus indicus, and Rubia cordifolia. All concentrations of Emblica officinalis tested inhibited the proliferation of osteogenic precursors, while only the highest doses of Asparagus racemosus and Rubia cordifolia were toxic. On the contrary, Hemidesmus indicus did not affect osteogenic precursor growth at any concentration tested. Conclusion Among the medicinal plants included in the study, Hemidesmus indicus showed the greatest antiosteoclastic activity without toxic effect on osteogenic precursors. Therefore, Hemidesmus indicus exhibits the properties of an antiresorptive drug and represents the ideal candidate for further clinical investigations.

The aim of the study was to obtain the highest number of multipotent adipose-derived mesenchymal stem cells (ADMSCs) by using culture conditions which favour cell expansion without loss of mesenchymal stem cells (MSC)-like properties. Based on the assumption that stem cells reside in niches characterized by hypoxic condition, we investigated if the low oxygen tension may improve the proliferation and stemness of ADMSCs. Intact adipose tissue was resected from eight subjects, and the stromal vascular fraction was obtained by using type II collagenase. The heterogeneity of cellular lineages was confirmed by immunophenotypic analysis that showed the presence of leukocytes (CD45+), endothelial cells (CD34+), and pericytes (CD140+). The immunophenotype of confluent ADMSCs was similar to that of bone marrow-derived MSCs, except for the expression of CD34, which was variable (donor-dependent) and inversely correlated to the CD36 expression. ADMSCs showed a high clonal efficiency (94.5 ± 1 %) and were able to generate osteoblastic, chondrocytic and adipocytic lineages. ADMSCs were cultured under normoxic (21 % O2) and hypoxic (1 % O2) conditions, and we found that hypoxia significantly favoured ADMSC proliferation and preserved the expression of stemness genes, i.e. Nanog and Sox2. Since hypoxia reflects the microenvironment in which ADMSCs must proliferate and differentiate, the culture in hypoxic condition allows to better understand the biology of these cells and their regenerative potential. Low oxygen concentrations promote cell proliferation and stemness, thus enriching the pool of cells potentially able to differentiate into multi-lineages, and extending the possibility of a long-term expansion.

BACKGROUND: The addition of progressive tension sutures to the abdominoplasty technique is advocated to reduce the risk of several complications. High superior tension abdominoplasty is another technique aimed at reducing tension at the prepubic suture line and improving cosmesis of the umbilical area. METHODS: A cohort of massive weight loss patients undergoing abdominoplasty, treated with the progressive tension suture technique in association with the high superior tension technique (group A), was followed up and compared to a cohort of patients who underwent high superior tension abdominoplasty (group B). Several variables including rate of complications and patient satisfaction were explored to determine any possible benefit deriving from the combination of progressive tension suture and high superior tension techniques in the abdominoplasty. RESULTS: A total of 90 patients were included in the study, of whom 34 were in group A and 56 were in group B. No statistically significant difference was found between the two groups in terms of duration of the procedure, hospitalization time, rate of complications, drained volume, and patient or physician satisfaction. CONCLUSION: No beneficial effect appears to derive from the progressive tension suture technique in massive weight loss patients undergoing abdominoplasty, provided that the high superior tension technique is performed as an adjunct to the traditional method.

Osteogenesis is the result of a complex sequence of events that involve the differentiation of mesenchymal stem cells (MSC) into osteoblasts. MSCs are multipotent adult stem cells that can give rise to different cell types of the mesenchymal germ layer. The differentiation fate of MSCs depends on the microenvironmental signals received by these cells and is tightly regulated by multiple pathways that lead to the activation of specific transcription factors. Among the transcription factors involved in osteogenic differentiation Osterix (Sp7) plays a key role and has been shown to be fundamental for bone homeostasis. However, the molecular events governing the expression of this transcription factor are not fully understood. In this study we set out to investigate the changes in the microRNA (miRNA) expression that occur during the osteogenic differentiation of bone marrow-derived MSCs. To this purpose, we analyzed the miRNA expression profile of MSCs deriving from 3 donors during the differentiation and mineralization processes by microarray. 29 miRNAs were significantly and consistently modulated during the osteogenic differentiation and 5 during the mineralization process. Interestingly, most of the differentially expressed miRNAs have been reported to be implicated in stemness maintenance, differentiation and/or oncogenesis. Subsequently, we focused our attention on the regulation of Osterix by miRNAs and demonstrated that one of the miRNAs differentially modulated during osteogenic differentiation, miR-31, controls Osterix expression through association to the 3' untranslated region of this transcription factor. By analyzing miR-31 and Osterix expression levels we found an inverse miRNA-target expression trend during osteogenic differentiation and in osteosarcoma cell lines. Moreover, the inhibition of the microRNA activity led to an increase in the endogenous expression of Osterix. Our results define a miRNA signature characterizing the osteogenic differentiation of MSCs and provide evidence for the involvement of miR-31 in the regulation of the bone-specific transcription factor Osterix.

BACKGROUND AND AIMS: Congenital pseudarthrosis of the tibia (CPT) is a rare orthopedic disease presenting spontaneous fractures that do not heal. The treatment of CPT is characterized by repeated surgical procedures that often fail, with the inevitable outcome of severe disability and amputation. We tested the hypothesis that CPT may benefit from regenerative strategies based on mesenchymal stromal cells (MSC) combined with platelet-rich fibrin (PRF) as a source of growth factors. The aim of the study was to verify whether laboratory testing to assess the osteogenic properties of MSC and the osteo-inductive activity of PRF correlated with the clinical outcome.METHODS: Ten patients affected by refractory CPT were treated by using MSC derived from the iliac crest (IC-MSC), PRF and lyophilized bone. In six patients, CPT was associated with type 1 neurofibromatosis (NF1). Biochemical, functional and molecular assays were performed to assess the intrinsic osteogenic potential of IC-MSC (cells cultured with fetal calf serum) and the osteo-inductive properties of PRF (cells cultured with autologous serum).RESULTS: Bone consolidation was obtained in three patients who had CPT and NF1. In these patients, the IC-MSC exposed to autologous serum were able to form mineral nodules in vitro, while the mineralizing ability was totally abrogated in patients with a poor clinical outcome.CONCLUSIONS: Cell therapy may be a useful tool for the treatment of refractory CPT because it increases the opportunity to achieve effective bone tissue regeneration. Our data suggest that the presence of pro-osteogenic growth factors is an essential requirement for bone healing.

Purpose For bone regeneration therapy using stem cells, well-defined ex vivo protocols to expand mesenchymal stromal cells (MSC), as well as assays to show their potential differentiation into the osteogenic lineage, are needed. Aim of this study was to analyze the role of the biochemical osteogenic inducers, i.e. ascorbic acid, dexamethasone, and β-glycerophosphate, employed in the current protocols for osteogenic differentiation of MSC in vitro, to address the requirements for reliable differentiation systems. Methods MSC were isolated from the bone marrow of donors (46–73 years of age) undergoing total hip replacement, and expanded in vitro. At confluence, MSC were cultured under four different conditions: α-MEM plus serum (basal medium or C1), basal medium plus ascorbate (C2), basal medium plus ascorbate and dexamethasone (C3), or basal medium plus ascorbate, dexamethasone and β-glycerophosphate (C4). Morphology, proliferation, mineralization, alkaline phosphatase, collagen and expression of bone-related genes of MSC under the different media were analyzed at fixed time points. Results MSC proliferation and the number of colony forming units were increased by ascorbic acid, whereas dexamethasone enhanced the proportion of ALP-positive CFU and was critical for mineral deposition. Runx-2 and type I collagen gene expression decreased along with additive-induced MSC differentiation, i.e. from C1 to C4, while ALP and osteocalcin were differently regulated. Conclusion Our findings support the role of different inducers on the sequential stages of MSC expansion and osteogenic differentiation in vitro, suggesting the addition of DEX following proliferation to ensure mineralization, as an index of in vivo osteogenic potency of human mesenchymal cells.

The insulin-like growth factors 2 (IGF2) is a peptide hormone that binds to the insulin-like growth factor 1 receptor (IGF1R) and is abundantly stored in bone. IGF1R is deeply involved in the pathogenesis of many cancers that growth within bone and is also involved in osteoclast biology. Among different cell lines representative of osteolytic tumors, we found a very high expression of IGF2 in SH-SY5Y cells derived from neuroblastoma (NB). We previously showed that NB cells induce an osteolytic process through the Osteoprotegerin/RANKL/RANK and the canonical Wnt pathway system. Here, we hypothesized that NB promotes osteoclastogenesis also via IGF2. First, we demonstrated the presence of IGF1R on the osteoclast basolateral membrane, and we observed a cyclic IGF1R activation along with the differentiation process, also when induced by SH-SY5Y. Moreover, we found that IGF2 mRNA expression in SH-SY5Y cells was further increased when co-cultured with mesenchymal stromal cells, suggesting that IGF2 is important for NB interaction with the bone microenvironment. Finally, the treatment of SH-SY5Y cells with an anti-IGF2 siRNA or the addition of anti-IGF1R molecules impaired NB-induced osteoclastogenesis, even though the chemoattraction of monocytes by NB cells was unaffected. Our findings suggest that in IGF2-producing osteolytic tumors IGF1R is a good candidate for targeted therapies in combination with conventional drugs.

The study was designed to establish the biological basis for the use of autologous bone-marrow stromal cells (MSC) in order to improve the curing opportunities of congenital pseudarthrosis of the tibia (CPT). The investigation was planned by taking into account that the pathophysiology of bone healing mainly depends on the osteogenic potential of the resident cells, although several factors play a crucial role in restoring the normal bone structure. Bone marrow samples were collected from the lesion site (P) and the iliac crest (IC) of 7 patients affected by CPT and type 1 neurofibromatosis (NF1+) and 6 patients affected by CPT without NF1 (NF1-). Four patients without CPT served as control group. Biochemical, functional and molecular assays showed that the ability to generate bone-forming cells was higher in IC-MSC than in P-MSC, but lower in CPT patients than in control group. We evaluated whether host factors, such as autologous serum and the microenvironment surrounding the pseudarthrosis lesion, could impair the osteogenic differentiation of IC-MSC. Autologous serum was less effective than FBS in promoting the IC-MSC differentiation, but the damage was more evident in NF1- than in NF1+ patients. Additionally, the supernatant of osteoblast cultures obtained from bone fragments close to the lesion site favoured the differentiation of IC-MSC in NF1- patients. In summary, our results suggest that MSC transplantation could be a promising strategy for the therapy of CPT. Further studies are warranted to confirm the clinical effectiveness in comparison to standard surgical treatment.

Materials used for total knee arthroplasty (TKA), may elicit an immune response whose role in the outcome of the arthroplasty is still unclear. The aim of this study was to evaluate the frequency of sensitization in patients who had undergone TKA, and the clinical impact of this event on the outcome of the implant. Ninety-four subjects were recruited, including 20 patients who had not yet undergone arthroplasty, 27 individuals who had a well-functioning TKA, and 47 patients with loosening of TKA components. Sensitization was detected by using patch testing including haptens representative of cobalt-based alloys (CoCrMo), titanium-based alloys (TiAlV), and bone cements. The frequency of positive skin reactions to metals increased significantly after TKA, either stable or loosened (No Implant 20%; Stable TKA 48.1%, p = 0.05; Loosened TKA 59.6%, p = 0.001, respectively). We found a higher frequency of positive patch testing to vanadium in patients who had a Stable TKA with at least one TiAlV component (39.1%, p = 0.01). The medical history for metal allergy seems to be a risk factor, because the TKA failure was fourfold more likely in patients who had symptoms of metal hypersensitivity before TKA. The prognostic value was supported by survival analysis, because in these individuals the outcome of the implant was negatively influenced (the logrank test Chi square 5.1, p = 0.02). This study confirms that in patients with a TKA the frequency of positive patch testing is higher than in the normal population, although no predictive value is attributable to the sensitization because patch testing was not able to discriminate between stable and loose implants. On the contrary, the presence of symptoms of metal allergy before implantation should be taken into account as a potential risk factor for TKA failure.