Bone Morphogenetic Protein 7 Expression in Alveolar Bone Addition With Autologous Blood, Lyophilized Bone and Atelocollagen.

BACKGROUND/AIM: The biomaterials used in guided bone regeneration have undergone significant diversification in recent years. This study aimed to evaluate alveolar bone addition and bone morphogenetic protein 7 (BMP7) expression using an improved autologous and xenogeneic biomaterial. MATERIALS AND METHODS: Chronic marginal periodontitis was induced in sheep; the intervention group received bone addition as periodontal therapy, using a composite system with lyophilized bovine bone enriched with atelocollagen type 1, platelet-rich plasma and advanced platelet-rich fibrin (A-PRF). Six weeks after the intervention, the dentoalveolar structures were evaluated using hematoxylin-eosin and immunohistochemical staining, to evaluate bone addition and BMP7 expression. RESULTS: The untreated sheep showed inflammation, periodontal ligament destruction, remnants of calculus and bacterial plaque as well as foreign bodies in the desmodontal space, without sings of repair. In the treated sheep, fibroblasts/fibrosis, cartilage and/or new bone, cellular cementum and desmodontium, along with remnants of biomaterial with various degrees of cellularity were observed. In the untreated group, the presence of BMP7 was found in osteoblasts and osteocytes while in the treated group, it was mainly found in the biomaterial remnants, while immunohistochemical staining was less intense in the newly formed osteo-periodontal tissues. Quantitative analysis using the Mann-Whitney U-test showed highly statistically significant differences between the two groups, demonstrating the efficiency of this composite system. CONCLUSION: The current composite system meets all the necessary conditions for promising guided alveolar bone regeneration.

Different patterns of p16INK4a immunohistochemical expression and their biological implications in laryngeal squamous cell carcinoma.

INTRODUCTION: p16INK4a immunohistochemistry (IHC) is widely used to facilitate the diagnosis of human papillomavirus (HPV)-associated neoplasia, when ≥70% of cells show strong nuclear and cytoplasmic positivity. In this study, we aim to compare partial expression patterns that do not fulfill the above criteria and seek biological implications in laryngeal squamous cell carcinoma (LSCC). MATERIALS AND METHODS: p16INK4a IHC staining was conducted on representative sections of archived tissue from 88 LSCCs. Immunoreactivity was described based on four parameters: intracellular localization of immunostaining, intensity of immunostaining, distribution pattern and percentage of positive cells. RESULTS: Six patterns of p16INK4a immunoexpression were observed and defined as: strong diffuse (strong immunostaining, expression in cytoplasm and nucleus in >70% of tumor cells), weak diffuse (moderate or weak immunostaining, expression in cytoplasm in >70% of tumor cells), marginal (strong cytoplasmic immunostaining, limited to the periphery of tumor islets), strong scattered (strong immunostaining, expression in cytoplasm and nucleus in <50% of tumor cells), weak scattered (moderate or weak immunostaining, expression in cytoplasm in <50% of tumor cells), negative (no expression). The pN stage of the patients was associated with p16INK4a immunoexpression patterns, the marginal pattern was only found in the pN0-Nx stages, while the weak diffuse pattern was more frequently observed in pN2-N3 stages. CONCLUSIONS: Partial immunostaining with architecturally distinct p16INK4a immunoexpression patterns may prove significant in stratifying characteristic clinicopathological subgroups among LSCC. Our observations may support the hypothesis that p16INK4a has different roles in different subcellular locations, with tumorigenic molecular pathways unrelated to HPV infection.

Could oral cytomorphometry be of value in distinguishing diabetes mellitus?

The present study refers to a quantitative, morphometric analysis of exfoliative cytology smears collected from diabetes mellitus (DM) patients, in order to distinguish subtle changes in cellular and nuclear parameters. The study was carried out on 30 adult subjects: a control group of 10 healthy subjects and a study group of 20 diabetic subjects (type 1 and type 2 DM). Another factor that was taken into consideration was the abundance of the microbial flora. The oral smears were stained using Hematoxylin and Eosin and several parameters were measured (nuclear diameter, perimeter and area, cell large diameter and area), and calculated: nuclear/cytoplasmic ratio and nuclear roundness factor. We found out that the cells collected from DM patients had higher values of the nuclear parameters (the nuclei were larger) and lower cell dimensions. The nuclear to cytoplasmic ratio was increased in these patients, but the nuclear roundness factor was closer to one in the study group. Also, an increased number of bacteria, often seen in DM patients, decreased the nuclear parameters. Our findings complete recently descriptive cytology studies with the morphological measurements in case of bacterial abundance and sustain the possible value as screening method for morphometry.