47 research outputs found

    Differences between panoramic and Cone Beam-CT in the surgical evaluation of lower third molars

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    The aim of this study was to evaluate the ability to identify the contiguity between the root of the mandibular third molar and the mandibular canal (MC) in panoramic radiographs compared with Cone Beam-CT. Panoramic radiographs of 326 third molars and CBCT radiographs of 86 cases indicated for surgery and considered at risk were evaluated. The following signs were assessed in panoramic radiographs as risk factors: radiolucent band, loss of MC border, change in MC direction, MC narrowing, root narrowing, root deviation, bifid apex, superimposition, and contact between the root third molar and the MC. Radiographic signs associated with absence of MC cortical bone are: radiolucent band, loss of MC border, change in MC direction, and superimposition. The number of risk factors was significantly increased with an increasing depth of inclusion. CBCT revealed a significant association between the absence of MC cortical bone and a lingual or interradicular position of the MC. In cases in which panoramic radiographs do not exclude contiguity between the MC and tooth, careful assessment the signs and risks on CBCT radiographs is indicated for proper identification of the relationships between anatomic structures

    Autologous Periosteum-Derived Micrografts and PLGA/HA Enhance the Bone Formation in Sinus Lift Augmentation

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    Sinus lift augmentation is a procedure required for the placement of a dental implant, whose success can be limited by the quantity or quality of available bone. To this purpose, the first aim of the current study was to evaluate the ability of autologous periosteum-derived micrografts and Poly(lactic-co-glycolic acid) (PLGA) supplemented with hydroxyl apatite (HA) to induce bone augmentation in the sinus lift procedure. Secondly, we compared the micrograft's behavior with respect to biomaterial alone, including Bio-Oss® and PLGA/HA, commercially named Alos. Sinus lift procedure was performed on 24 patients who required dental implants and who, according to the study design and procedure performed, were divided into three groups: group A (Alos + periosteum-derived micrografts); group B (Alos alone); and group C (Bio-Oss® alone). Briefly, in group A, a small piece of periosteum was collected from each patient and mechanically disaggregated by Rigenera® protocol using the Rigeneracons medical device. This protocol allowed for the obtainment of autologous micrografts, which in turn were used to soak the Alos scaffold. At 6 months after the sinus lift procedure and before the installation of dental implants, histological and radiographic evaluations in all three groups were performed. In group A, where sinus lift augmentation was performed using periosteum-derived micrografts and Alos, the bone regeneration was much faster than in the control groups where it was performed with Alos or Bio-Oss® alone (groups B and C, respectively). In addition, the radiographic evaluation in the patients of group A showed a radio-opacity after 4 months, while after 6 months, the prosthetic rehabilitation was improved and was maintained after 2 years post-surgery. In summary, we report on the efficacy of periosteum-derived micrografts and Alos to augment sinus lift in patients requiring dental implants. This efficacy is supported by an increased percentage of vital mineralized tisssue in the group treated with both periosteum-derived micrografts and Alos, with respect to the control group of Alos or Bio-Oss® alone, as confirmed by histological analysis and radiographic evaluations at 6 months from treatment

    Sperm protein 17 is expressed in human nervous system tumours

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    BACKGROUND: Human sperm protein 17 (Sp17) is a highly conserved protein that was originally isolated from a rabbit epididymal sperm membrane and testis membrane pellet. It has recently been included in the cancer/testis (CT) antigen family, and shown to be expressed in multiple myeloma and ovarian cancer. We investigated its immunolocalisation in specimens of nervous system (NS) malignancies, in order to establish its usefulness as a target for tumour-vaccine strategies. METHODS: The expression of Sp17 was assessed by means of a standardised immunohistochemical procedure [(mAb/antigen) MF1/Sp17] in formalin-fixed and paraffin embedded surgical specimens of NS malignancies, including 28 neuroectodermal primary tumours (6 astrocytomas, 16 glioblastoma multiforme, 5 oligodendrogliomas, and 1 ependymoma), 25 meningeal tumours, and five peripheral nerve sheath tumours (4 schwannomas, and 1 neurofibroma),. RESULTS: A number of neuroectodermal (21%) and meningeal tumours (4%) were found heterogeneously immunopositive for Sp17. None of the peripheral nerve sheath tumours was immunopositive for Sp17. The expression pattern was heterogeneous in all of the positive samples, and did not correlate with the degree of malignancy. CONCLUSION: The frequency of expression and non-uniform cell distribution of Sp17 suggest that it cannot be used as a unique immunotherapeutic target in NS cancer. However, our results do show the immunolocalisation of Sp17 in a proportion of NS tumour cells, but not in their non-pathological counterparts. The emerging complex function of Sp17 makes further studies necessary to clarify the link between it and immunopositive cells

    Ex vivo release of eicosanoids after aneurysmal subarachnoid hemorrhage: a preliminary experience in humans

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    Authors addressed the question whether the byosynthesis and the release of specific eicosanoids may occur in human brain cortex, and if the qualitative pattern of arachidonic acid metabolism is similar to that observed in experimental SAH. Human brain samples from 18 patients operated on for anterior communicating artery aneurysm (5 unruptured aneurysms considered as control cases, 7 patients operated on between Days 1 and 4 after SAH and 6 patients operated on between Days 10 and 14) were studied for the ex vivo release of 4 selected eicosanoids (Prostaglandin D2, E2, 6-keto-PGF1a and Leukotriene C4). Levels of arachidonate metabolites were determined by radioimmunoassay technique. PGD2 release is significantly lower in cases operated on delayed phase if compared to both control cases (p less than 0.05) and patients operated on in the acute phase, while there is no significant difference between the release of PGD2 in control cases and patients operated on in the acute phase. Release of 6-keto-PGF1a is significantly higher in patients operated on in a delayed phase (p less than 0.03 vs patients operated on in the acute phase and p less than 0.05 versus control cases). The release of LTC4 is significantly enhanced (p less than 0.05) in cases operated on in the acute phase if compared with unruptured aneurysms. The release of PGE2 is significantly enhanced in patients operated on in the acute phase (p less than 0.05) if compared to patients with unruptured aneurys

    A Mechanics-Based Model for 3-D Steering of Programmable Bevel-Tip Needles

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    Antioxidant enzymatic activities after experimental subarachnoid hemorrhage in rats

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    Lipid peroxidation has been hypotesized as one of possible factors involved in the pathogenesis of neuronal damage and delayed vasospasm after subarachnoid hemorrhage. In the brain there are anti-oxidant enzymatic systems which act as scavengers of superoxides and free radicals. In the present study the pattern of enzymatic anti-oxidant activities (Cu-Zn and Mn superoxide dismutase, and glutathione peroxidase) was investigated in an experimental model of subarachnoid hemorrhage in the rat in order to verify whether the hemorrhagic insult may be responsible for an impairment of such anti-oxidant systems. Enzymatic activities were assayed in three different rat brain areas (cerebral cortex, hippocampus and brain stem) of sham-operated and at 30 min, 1, 6 and 48 h after subarachnoid hemorrhage induction. After the hemorrhage induction the Cu-Zn superoxide dismutase activity in cerebral cortex was significantly reduced at all the set times (p < .05), while Mn-superoxide dismutase activity was significantly decreased since 1 h (p < .05) until 48 h (p < .05). Glutathione peroxidase activity was significantly reduced only in the late phase (48 h) of subarachnoid hemorrhage (p < .01). In the hippocampus, all enzymatic activities were significantly reduced in the late phase. In the brain stem Cu-Zn superoxide dismutase was significantly impaired at 1 and 6 h (p < .05) after subarachnoid hemorrhage induction, while in the late phase (48 h) reached the control value. The mitochondrial Mn-superoxide dismutase was significantly reduced since 1 h (p < .05) until 48 h (p < .02) after subarachnoid hemorrhage.(ABSTRACT TRUNCATED AT 250 WORDS
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