Fabrizio Bambini

Nevoid basal cell carcinoma syndrome. Clinical findings in 37 Italian affected individuals

Nevoid basal cell carcinoma syndrome (NBCCS) is a hereditary condition transmitted as an autosomal dominant trait with complete penetrance and variable expressivity. The syndrome is characterised by numerous basal cell carcinomas (BCCs), odontogenic keratocysts of the jaws, palmar and/or plantar pits, skeletal abnormalities and intracranial calcifications.In this paper, the clinical features of 37 Italian patients are reviewed. Jaw cysts and calcification of falx cerebri were the most frequently observed anomalies, followed by BCCs and palmar/plantar pits. Similar to the case of African–Americans, the relatively low frequency of BCCs in the Italian population is probably due to protective skin pigmentation. A future search based on mutation screening might establish a possible genotype–phenotype correlation in Italian patients.

Raloxifene covalently bonded to titanium implants by interfacing with (3-aminopropyl)-triethoxysilane affects osteoblast-like cell gene expression

Since Raloxifene, a drug used in osteoporosis therapy, inhibits the osteoclast functions but not osteoblast functions, it could improve the recovery during implant surgery. This preliminary report describes a simple method to link, through a covalent bond, Raloxifene to titanium by interfacing with (3-aminopropyl)-Triethoxysilane as assessed by the IR-FT and SEM. To evaluate the biological response of osteoblast-like cells to this implant, we compared expression gene profiling of cell cultures on Raloxifene conjugated implant and normal implant by DNA microarray. By using DNA microarrays containing 19,200 genes, we identified differently expressed genes in osteoblast-like cell line (MG-63). Surface Raloxifene conjugated implants have been shown to have a relevant importance in modifying cell response. This result could be an interesting starting point for the use of an immediate functional loading of implants.

Nuclear Survivin as a Prognostic Factor in Squamous-Cell Carcinoma of the Oral Cavity.

Oral squamous-cell carcinoma (OSCC) and most human tumors are characterized by an imbalance of regulatory mechanisms controlling cell processes such as apoptosis. Survivin, a member of the inhibitor of apoptosis family, is overexpressed in most solid and hematological malignancies and correlates with a reduced overall survival rate. Thus, the aim of this study was to find a correlation between nuclear Survivin expression and clinicopathologic data and the prognosis in OSCC patients. A total of 152 OSCC samples were investigated by immunohistochemistry for nuclear Survivin expression. Then, Survivin was scored semiquantitatively using an immunoreactivity score (IRS), calculated by multiplying the percentage of positive cells with the staining intensity. Using a digital image analysis software, OSCC patients were stratified into 4 groups. Results showed that patients with a lower IRS score displayed better survival rates than patients with a higher IRS score, reaching statistical significance. As the expression of Survivin at the nuclear level seems to suggest a poor prognosis in OSCC patients, the evaluation of nuclear Survivin IRS may be a useful tool to identify patients with more aggressive and disseminated disease, influencing follow-up and therapeutic protocols.

Potential bone to implant contact area of short versus standard implants: An in vitro micro-computed tomography analysis

Aim:To compare the available potential bone-implant contact (PBIC) area of standard and short dental implants by micro–computed tomography (&mgr;CT) assessment. Methods:Three short implants with different diameters (4.5 × 6 mm, 4.1 × 7 mm, and 4.1 × 6 mm) and 2 standard implants (3.5 × 10 mm and 3.3 × 9 mm) with diverse design and surface features were scanned with &mgr;CT. Cross-sectional images were obtained. Image data were manually processed to find the plane that corresponds to the most coronal contact point between the crestal bone and implant. The available PBIC was calculated for each sample. Later on, the cross-sectional slices were processed by a 3-dimensional (3D) software, and 3D images of each sample were used for descriptive analysis and display the microtopography and macrotopography. Results:The wide-diameter short implant (4.5 × 6 mm) showed the higher PBIC (210.89 mm2) value followed by the standard (178.07 mm2 and 185.37 mm2) and short implants (130.70 mm2 and 110.70 mm2). Conclusions:Wide-diameter short implants show a surface area comparable with standard implants. Micro-CT analysis is a promising technique to evaluate surface area in dental implants with different macrodesign, microdesign, and surface features.

Novel hydroxyapatite biomaterial covalently linked to raloxifene

Since raloxifene, a drug used in osteoporosis therapy, inhibits osteoclast, but not osteoblast functions, it has been suggested to improve recovery during implant surgery. The present paper describes an effective method to link raloxifene, through a covalent bond, to a nano-Hydroxyapatite-based biomaterial by interfacing with (3-aminopropyl)-Triethoxysilane as assessed by Infra Red-Fourier Transformed (IR-FT) spectroscopy and Scanning Electron Microscope (SEM). To evaluate the safety of this modified new material, the vitality of osteoblast-like cells cultured with the new biomaterial was then investigated. Raloxifene-conjugated HA-biomaterial has been shown to be a safe material easy to obtain which could be an interesting starting point for the use of a new functional biomaterial suitable in bone regeneration procedures.

MG63 AND MC3T3-E1 OSTEOBLASTIC CELL LINES RESPONSE TO RALOXIFENE

Bone resorption in edentulous regions often results in inadequate ridge for implant osseointegration. In order to overcome this problem, the use of osteoconductive biomaterials has been proposed as a carrier for different types of pharmacological molecules. Since raloxifene, a drug used in osteoporosis therapy, inhibits the osteoclast, but not osteoblast functions, it has been suggested to improve recovery during implant surgery. The present work evaluated in vitro the effect of raloxifene on two different cell populations: the human osteoblast-like cells (MG63) and osteoblasts derived from rat calvaria (MC3T3-E1). The morpho-functional investigations carried out showed a different behavior of the two cell lines. Raloxifene showed a stimulatory effect towards MG63 cell proliferation with a significant increase in cell viability after 7 days of culture. On the contrary, MC3T3-E1 cells showed a significant reduction in cell viability, when compared with the same cells at 72 h, or with the control cell population. The predominantly proliferative effect of raloxifene on MG63 cells is partly confirmed by the reduction of alkaline phosphatase activity, an early marker of osteoblast differentiation. The different effect of raloxifene on osteoblastic population in relationship to the type and age of the cell is an issue that needs further investigation.

Pre-clinical evaluation of a new coral-based bone scaffold

Coral is used worldwide for bone reconstruction. The favorable characteristics that make this material desirable for implantation are (i) osteoinduction, (ii) and osteoconduction. These proprieties have been demonstrated by in vivo studies with animal models and clinical trials over a twenty-year period. Also poly(2-hydroxyethylmethacrylate) [poly(HEMA)] is a widely used biomaterial. By using coral and poly(HEMA), a scaffold for bone reconstruction application has been recently synthesized. Cytological, histological and genetic analyses were performed to characterize this new alloplastic material. Four samples were analyzed: (a) white coral (WC), (b) red coral (RC), (c) WC plus polymer (WCP) and (d) RC plus polymer (RCP). Quantification of mitochondrial dehydrogenase activity by MTT assay was performed as indirect detector of cytotoxicity. In vivo effects were revealed by implanting corals and coral-based polymers in rabbit tibia. Samples were collected after 4 weeks and subjected to histological analysis. To evaluate the genetic response of cells to corals and coral-derived polymers an osteoblast-like cell line (i.e. MG63) was cultured in wells containing (a) medium, (b) medium plus corals and (c) medium plus two types of scaffolds (RCP or WCP). RNAs extracted from cells were retro-transcribed and hybridized on DNA 19.2K microarrays. No cytotoxicity was detected in corals and coral-based biopolymers. No inflammation or adverse effect was revealed by histological examination. By microarray analysis 154 clones were differentially expressed between RC and WC (81 up and 73 down regulated) whereas only 15 clones were repressed by the polymer. Histological evaluation not only confirmed that coral is a biocompatible material, but also that the polymer has no adverse effect. Microarray results were in agreement with cytological and histological analyses and provided further data regarding the genetic effects of RC, WC and the new polymer.