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Mesenchymal stem cells (MSCs) are of great interest for the regeneration of tissues and organs. Bone marrow is the first sources of MSCs, but in the recent years there has been interest in other tissues for the isolation of these pluripotent cells. In this study, we investigated the features of MSCs isolated from different oral regions in order to evaluate their potential application in the regeneration of damaged maxillofacial tissues. Sampling from human periodontal ligament, dental pulp, maxillary periosteum as well as bone marrow were collected in order to obtain different stem cell populations. Cells were morphologically and immunophenotipically characterized. Their proliferation potential and their ability to differentiate in osteoblasts were also assessed. All tested cell population showed a similar fibroblast-like morphology and superimposable immunophenotype. Slight differences were observed in proliferation and differentiation potential. Cells isolated from human periodontal ligament, dental pulp, maxillary periosteum had the characteristics of stem cells. Considering their peculiar feature they may alternatively represent interesting cell sources in stem cell-based bone/periodontal tissue regeneration approaches.

Oral malignant melanoma (OMM) is an aggressive tumour, and shows deep tissue invasion at initial presentation. The prognosis is worse than that for cutaneous melanoma (CM), and the overall 5-year survival rate is 10-25%. A study of the molecular mechanisms involved in the development of OMM is necessary to identify new prognostic markers. In this study, we evaluated the possible role of nicotinamide N-methyltransferase (NNMT) in OMM. We carried out immunohistochemical analyses to evaluate the expression of NNMT in 15 OMM and 15 CM, measuring the percentage of positive cells and the value of NNMT expression intensity. Furthermore, we explored the relationship between NNMT levels and the prognostic parameters of patients with OMM. NNMT was significantly more expressed in CM compared with OMM, whereas higher staining intensity for NNMT was observed in OMM cases (P

The aim of the present study was to investigate if aging is associated with platelet membrane modifications possibly related with cellular activation and hyperaggregability and if platelets from centenarians show different properties which might play a role in successful aging and longevity. Platelet plasma membranes were obtained from 60 healthy subjects, divided into four groups according to the age range: (1) 21-39 years; (2) 40-59 years; (3) 60-79 years; (4) centenarians (>/=100 years). Both centenarians and control subjects were submitted to the following inclusion criteria: liver, kidney, and thyroid function tests within the normal range; absence of history of diabetes, hypertension or coronary heart disease; no signs of edema or dehydration; no drug or vitamin supplement in the 4 weeks before the study; absence of Alzheimer's disease or secondary dementia. The following determinations were performed: lipid peroxide levels (Lp) evaluated by the measurement of thiobarbituric acid (TBA) reactivity, fluidity studied by the fluorescence anisotropy of the probe 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH), Na(+)/K(+)-ATPase activity measured by the method of Kitao and Hattori, and sialic acid (SA) content evaluated by the periodate-thiobarbituric acid method. Centenarians showed: (i) Lp concentrations lower than elderly subjects; (ii) increased Na(+)/K(+)-ATPase activity compared with adult and elderly subjects; (iii) higher TMA-DPH anisotropy than elderly subjects; (iv) SA content similar to the young and adult groups.The present work found deep platelet membrane modifications in centenarians compared with elderly subjects. These changes are likely associated with a decreased platelet activation and therefore might exert a protective role against cardiovascular accidents, as platelet activation is a key event in the initiation and progression of arteriosclerosis.