Repair of segmental mandibular bone defects in sheep using bone marrow stromal cells and autologous serum scaffold: a pilot study.

AIM: The aim of this study was to evaluate effective bone regeneration using an autologous serum scaffold (alone or seeded with autologous bone marrow-mesenchymal stem cells, BM-MSCs), when implanted in a 30 mm length segmental mandibular defect in sheep. MATERIALS AND METHODS: The bone defect was filled either with serum scaffold alone (control group; n = 5) or combined with BM-MSCs (experimental group; n = 10). Bone regeneration was determined at 12 (T12; 2 control sheep and 4 experimental sheep) and 32 weeks (T32; 3 control and 6 experimental sheep), as measured by computed and microcomputed tomography and histological examination. RESULTS: Two sheep of the Experimental group died after surgery. While complete bone union in the control group was only observed at T32, it was observed both at T12 (1/4 sheep) and T32 (3/4 sheep) in the experimental group. When properties/characteristics of new bone where compared, a better bone quality, similar to native bone, was observed in the scaffold combined with BM-MSCs. CONCLUSIONS: Based on these results, we conclude that the serum scaffold can promote efficient repair of large bone defects, but the combination with BM-MSCs accelerates this process, increasing significantly the amount and quality of bone formed.

Sinus mucosal thickening in bisphosphonate-related osteonecrosis of the jaws: a case-control study.

Osteonecrosis of the jaws is a clinically significant complication of bisphosphonate (BP) medications. Otherwise, the effects of BPs on oral soft tissue or cells remain unknown. The main objective of the present study was to determine whether the presence of sinus mucosal thickening was significantly related to BP-related osteonecrosis of the jaw (BRONJ). A case-control study was conducted on 32 patients who underwent treatment of BRONJ with conventional radiological investigations (panoramic radiographs) and computed tomography. The results indicated that patients with BRONJ had a 5.57-fold greater probability of presenting sinus mucosal thickening than controls. Although the existence of this thickening was more common in patients with advanced-stage disease or low levels of C-telopeptide-cross-linked type I collagen, no significant difference was observed between cases and controls. While considering the limitations inherent in the design and number of cases analyzed in our study, patients with osteonecrosis of the jaw were found to have a 5.57-fold greater probability of presenting sinus mucosal thickening (>3 mm) than healthy subjects.

Bisphosphonate-related osteonecrosis associated with dental implants: a microcomputed tomography study.

PURPOSE: The aims of this study were to quantify bone mineral density (BMD) and trabecular architecture of sequestra in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ) associated with dental implants and to assess if there are differences between trabecular bone in "implant loading-triggered" and "implant surgery-triggered" BRONJ. MATERIALS AND METHODS: Bone sequestra of 2 patients diagnosed with BRONJ associated with dental implants were scanned using high-resolution microcomputed tomography (microCT). Images were obtained at a voltage of 50 kV and 800 µA, and the specimens were scanned at 180 degrees with a single rotation step of 0.3, 1-mm aluminum filter, and a pixel size of 12 µm. The morphometric parameters examined were: BMD, ratio of bone volume/tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), connectivity density (Conn.D, mm), degree of anisotropy, and the structural model index. RESULTS: BMD and BV/TV were higher in bone sequestration than in healthy bone. Tb.Sp was lower and Tb.N and Tb.Th were higher in the BRONJ group. Conn.D and Tb.N values were significantly high in implant surgery-triggered sequestrum but substantially low in sequestra caused by loading as compared with those of the control sample. CONCLUSIONS: MicroCT is useful for assessing bone sequestration of BRONJ associated to dental implants. The necrotic bone is similar to that described in conventional BRONJ.

Proof of concept for the use of trained sniffer dogs to detect osteosarcoma.

Sarcomas are mesenchymal cancers which often show an aggressive behavior and patient survival largely depends on an early detection. In last years, much attention has been given to the fact that cancer patients release specific odorous volatile organic compounds (VOCs) that can be efficiently detected by properly trained sniffer dogs. Here, we have evaluated for the first time the ability of sniffer dogs (n = 2) to detect osteosarcoma cell cultures and patient samples. One of the two dogs was successfully trained to discriminate osteosarcoma patient-derived primary cells from mesenchymal stem/stromal cells (MSCs) obtained from healthy individuals. After the training phase, the dog was able to detect osteosarcoma specific odor cues in a different panel of 6 osteosarcoma cell lines with sensitivity and specificity rates between 95 and 100%. Moreover, the same VOCs were also detected by the sniffer dog in saliva samples from osteosarcoma patients (n = 2) and discriminated from samples from healthy individuals with a similar efficacy. Altogether, these results indicate that there are common odor profiles shared by cultures of osteosarcoma cells and body fluid samples from patients and provide a first proof of concept about the potential of canine odor detection as a non-invasive screening method to detect osteosarcomas.

Pathological mandibular fracture after simple molar extraction in a patient with osteogenesis imperfecta treated with alendronate.

Osteogenesis imperfecta (OI), is a heterogeneous group of inherited disorders of connective tissue characterized by bone fragility. Patients with this disease frequently suffer fractures, over 80% of the extremities due to the more intensive mechanical load. Fractures of the facial bones occur very infrequently. Several studies have proved that bisphosphonate therapy may be effective in reducing fracture risk in OI patients. We report here an unusual case of pathological mandibular fracture following simple molar extraction in an adult patient with OI type I and oral alendronic acid treatment. Extraction was atraumatical and without bone removal. Fracture was treated by internal fixation by plate osteosynthesis and additional mandibulomaxillary fixation (MMF). Bone healing after fracture treatment was completely normal and no clinical signs of osteoneocrosis were observed. To the best of our knowledge, this is an unusual complication even in this type of patients. Particular care is necessary is these patients during oral surgery, even when they have been treated and controlled.

New Chondrosarcoma Cell Lines with Preserved Stem Cell Properties to Study the Genomic Drift During In Vitro/In Vivo Growth.

For the cancer genomics era, there is a need for clinically annotated close-to-patient cell lines suitable to investigate altered pathways and serve as high-throughput drug-screening platforms. This is particularly important for drug-resistant tumors like chondrosarcoma which has few models available. Here we established and characterized new cell lines derived from two secondary (CDS06 and CDS11) and one dedifferentiated (CDS-17) chondrosarcomas as well as another line derived from a CDS-17-generated xenograft (T-CDS17). These lines displayed cancer stem cell-related and invasive features and were able to initiate subcutaneous and/or orthotopic animal models. Different mutations in Isocitrate Dehydrogenase-1 (IDH1), Isocitrate Dehydrogenase-2 (IDH2), and Tumor Supressor P53 (TP53) and deletion of Cyclin Dependent Kinase Inhibitor 2A (CDKN2A) were detected both in cell lines and tumor samples. In addition, other mutations in TP53 and the amplification of Mouse Double Minute 2 homolog (MDM2) arose during cell culture in CDS17 cells. Whole exome sequencing analysis of CDS17, T-CDS17, and matched patient samples confirmed that cell lines kept the most relevant mutations of the tumor, uncovered new mutations and revealed structural variants that emerged during in vitro/in vivo growth. Altogether, this work expanded the panel of clinically and genetically-annotated chondrosarcoma lines amenable for in vivo studies and cancer stem cell (CSC) characterization. Moreover, it provided clues of the genetic drift of chondrosarcoma cells during the adaptation to grow conditions.

Transvenous coil embolisation for the treatment of single congenital portosystemic shunts in six dogs.

This article describes the treatment of single congenital portosystemic shunts (CPSs) (intrahepatic and extrahepatic) using an interventional radiology technique involving embolisation of anomalous vessels with percutaneous coils. Briefly, a multipurpose catheter was introduced into the caudal vena cava and then into the portosystemic shunt. An autoexpandable stent was placed in the caudal vena cava, next to the shunt, in order to avoid coil migrations, and a cobra-like vascular catheter was used to pass through the stent and to place the coils in the shunt. This technique was used for treatment of CPS in six dogs. The results indicate that percutaneous embolisation of a CPS using coils, a less invasive technique than the traditional surgical technique, may result in complete closure of the anomalous vessel without development of portal hypertension.

Hepatic Nrf2 expression is altered by quercetin supplementation in X-irradiated rats.

Whole-body irradiation has been associated with liver function alterations. Ionizing radiation exposure increases oxidative stress and antioxidants can activate transcription of antioxidant target genes. In the present study, modifications of the liver antioxidant system were evaluated at 7 and 30 days following sub-lethal whole-body X-irradiation in male Wistar rats, which were intragastrically supplemented with quercetin or control solvent for 4 days prior to and 6 days following irradiation. Animal groups were as follows: CS, control, solvent-supplemented; CQ, control, quercetin-supplemented; RS, irradiated, solvent-supplemented; and RQ, irradiated, quercetin-supplemented. After 7 days, liver tissue from RS animals demonstrated marked hydropic panlobular degeneration with Mallory bodies in ballooning hepatocytes. These changes were mostly reversed in RQ rats. Lipid peroxidation in addition to copper/zinc superoxide dismutase (Cu/Zn-SOD), nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and Kelch-like ECH-associated protein 1 (Keap1) protein expression levels were all increased by X-irradiation, but significantly decreased by quercetin supplementation. Catalase (CAT) and NAD(P)H: quinone oxidoreductase 1 (NQO1) expression levels remained high in irradiated rats regardless of quercetin supplementation. After 30 days, the liver from RS animals had small portal infiltrates and diffuse cytoplasmic vacuolization, with reduced lipid peroxidation and reduced expression levels of CAT, NQO1, Nrf2 and Keap1, but consistently elevated Cu/Zn-SOD expression. RQ animals indicated reduced expression levels of Nrf2 and Keap1 30 days after irradiation. The present study demonstrated a quercetin-induced reduction of the oxidative stress-associated increase in Nrf2 expression that may be useful for preventing cancer cell survival in response to ionizing radiation exposure.

Thymic carcinoid tumours.

Carcinoid tumours of the thymus are rare. The case of a 57-year-old asymptomatic man with a carcinoid tumour of the thymus, who showed a widened mediastinum by chest x-ray, is presented. Fine needle aspiration suggested the diagnosis, which was confirmed by biopsy.

Repair of rat mandibular bone defects by alveolar osteoblasts in a novel plasma-derived albumin scaffold.

Repair of bone deficiencies in the craniofacial skeleton remains a difficult clinical problem. The aim of this study was to evaluate a novel albumin scaffold seeded with human alveolar osteoblasts and implanted into experimental mandibular defects. An experimental solid protein scaffold was prepared with human plasmatic albumin crossed with a glutaraldehyde-type agent. Microstructure of scaffold and mechanical properties were examined using scanning electron microscopy and a stress-controlled rheometer. Bilateral critical mandibular defects were created in eight immunodeficient rats. Defects of the right side of the mandibles received the cell-scaffold construct in all animals. All left mandibular defects were left untreated as blank controls. Sections of the defects were collected at 5, 8, and 11 weeks postsurgery and processed for histological and immunohistochemical observation, computed tomography examination, and computed tomography digital analysis. Histologically, bone formation was observed in both groups at 5 weeks postsurgery, and the engineered bone became more mature after 8 and 11 weeks, which was similar to normal bone. The origin of bone-forming cells within the defects and the localization of implanted human osteoblasts were confirmed by human vimentin expression. No bone formation could be observed at any control defect. Bone density after 8 weeks was significantly higher than that of the 5-week group (p = 0.02), and significant differences were also observed between 8 and 11 weeks (p < 0.01). The results indicate the clinical feasibility of albumin scaffold loaded with human alveolar cells and that it can be used as a good alternative for bone regeneration.