Fernando Gombos

In vitro bone production using stem cells derived from human dental pulp.

To harvest bone for autologous grafting is a daily problem encountered by craniofacial and oral surgeons. Stem cells derived from human dental pulp are able to differentiate in osteoblasts and are a potential source of autologous bone produced in vitro. The authors describe their preliminary results in this new field with its potential application in craniomaxillofacial surgery. Dental pulp was gently extracted from 34 human permanent teeth (all third molars) of patients 19 to 37 years of age. After they were digested, the cells were selected using a cytometer for c-kit, STRO-1, CD34, CD45, and then for CD44 and RUNX-2. This study, made on a considerable number of cases, provided evidence that dental pulp is extremely rich in stem cells, which were c-kit+/CD34+/STRO-1+/CD45−, capable of differentiation toward several stromal-derived differentiated cells and mainly osteoblasts. These findings, supported by the large number of cases, are of great interest for tissue regeneration, tissue-based clinical therapies, and transplantation.

C677T variant form at the MTHFR gene and CL/P: A risk factor for mothers?

Maternal folic acid supplementation in early pregnancy has been suggested to play a role in the prevention of nonsyndromic orofacial cleft, i.e., cleft lip with or without cleft palate (CL/P). Moreover, some authors demonstrated association of the C-->T mutation (C677T), converting an alanine to a valine residue in 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, with other congenital anomalies such as neural tube defects (NTDs). Because of MTHFRs involvement in the metabolism of folate, we investigated 64 CL/P patients and their parents for C677T MTHFR mutation. No linkage disequilibrium was found using the transmission disequilibrium test (TDT). However, a significantly higher mutation frequency was detected in mothers of CL/P patients compared to controls. The odds ratios calculated for mothers having CT or TT genotype, compared to the normal CC genotype, were 2.75 (95% confidence interval 1.30-5.57) and 2.51 (1.00-6.14), respectively. These results support the involvement of the folate pathway in the etiology of CL/P, and indicate an effect of the maternal genotype, rather than influence of the embryos genotype.

Recent developments in orofacial cleft genetics.

Nonsyndromic cleft of the lip and/or palate (CLP or orofacial cleft) derives from an embryopathy with consequent failure of the nasal process and/or palatal shelves fusion. This severe birth defect is one of the most common malformations among live births. Nonsyndromic CLP is composed of two separate entities: cleft lip and palate (CL±P) and cleft palate only (CPO). Both have a genetic background, and environmental factors probably disclose these malformations. In CL±P, several loci have been identified, and, in one case, a specific gene has also been found. In CPO, one gene has been identified, but many more are probably involved. Because of the complexity of the genetics of nonsyndromic CLP as a result of the difference between CL±P and CPO, heterogeneity of each group caused by the number of involved genes, type of inheritance, and interaction with environmental factors, we discuss the more sound results obtained with different approaches: epidemiological studies, animal models, human genetic studies, and in vitro studies.

Guidelines for diagnosis and management of aphthous stomatitis

Aphthous ulcers are the most common oral mucosal lesions in the general population. These often are recurrent and periodic lesions that cause clinically significant morbidity. Many suggestions have been proposed but the etiology of recurrent aphthous stomatitis (RAS) is unknown. Several precipitating factors for aphthous ulcers appear to operate in subjects with genetic predisposition. An autoimmune or hypersensitivity mechanism is widely considered possible. Sometimes aphthous ulcers can be the sign of systemic diseases, so it is essential to establish a correct diagnosis to determine suitable therapy. Before initiating medications for aphthous lesions, clinicians should determine whether well-recognized causes are contributing to the disease and these factors should be corrected. Various treatment modalities are used, but no therapy is definitive. Topical medications, such as antimicrobial mouth-washes and topical corticosteroids (dexamethasone, triamcinolone, fluocinonide, or clobetasol), can achieve the primary goal to reduce pain and to improve healing time but do not improve recurrence or remission rates. Systemic medications can be tried if topical therapy is ineffective.

Oral malignant melanoma: a review of the literature

Primary oral melanoma (POM) is an uncommon malignant tumor that originates from the proliferation of melanocytes. Such tumors can be present at any location in the oral cavity; however, it affects more frequently the hard palate and the maxillary alveolar mucosa. POM is usually asymptomatic in the early stages and it presents normally as a pigmented patch or as a mass with a rapid growth rate. In the advanced stages, it can show ulceration, swelling, bleeding, rapid enlargement and loosening of teeth. Melanoma of the mouth is rare, most commonly occurring in the upper jaw of patients more than 65 years. Because of a frequent delay in diagnosis, the tumors are often diagnosed when they are deeper than the average cutaneous melanoma. The prognosis is extremely poor, especially in advanced stages. Therefore, pigmented lesions of undetermined origin should be routinely subjected to a biopsy examination. In this study, we aimed to present a review on primary malignancy.

Serum from pemphigus vulgaris reduces desmoglein 3 half-life and perturbs its de novo assembly to desmosomal sites in cultured keratinocytes

Defects of cell–cell adhesion underlie disruption of epithelial integrity observed in patients with pemphigus vulgaris (PV), an autoimmune disease characterized by severe mucosal erosions and skin blisters. Pathogenic PV autoantibodies found in patients’ sera target desmoglein 3 (Dsg3), a major component of the desmosome, but how does this phenomenon affect Dsg‐dependent adhesion and lead to acantholysis still remains controversial. Here, we show that PV serum determines a reduction of Dsg3 half‐life in HaCaT keratinocytes, although the total amount of Dsg3 remains unchanged. Immunofluorescence studies suggest that PV IgG exert their effect prevalently by binding non‐desmosomal Dsg3 without causing its massive internalization. Furthermore, PV IgG targeting desmosome‐assembled Dsg3 do not induce depletion of Dsg3 from the adhesion sites. Conversely, incorporation of PV IgG‐Dsg3 complexes into new forming desmosomes appears perturbed. With our study, the basic biochemical changes of Dsg3 in an in vitro model of PV have been defined.

Physical training and metabolic supplementation reduce spontaneous atherosclerotic plaque rupture and prolong survival in hypercholesterolemic mice

Moderate physical exercise (PE) combined with metabolic treatment (MT) (antioxidants and l-arginine) are well known to reduce atherosclerotic lesion formation in hypercholesterolemic mice. However, the long-term beneficial effects on unstable atheroma remain poorly understood. We started early PE training in large groups of 6-week-old hypercholesterolemic mice (by graduated swimming) alone or in combination with nutritional supplementation (1.0% vitamin E added to the chow and 0.05% vitamin C and 6% l-arginine added to the drinking water). Inactive controls did not receive PE. The spontaneous development of atherosclerotic plaque rupture (associated with advanced atherosclerosis) and survival rates were evaluated. Moderate PE elicited an increase in plasma levels of nitric oxide. Early combined treatment with PE and MT in the hypercholesterolemic mice significantly reduced lesions (also detected noninvasively at 10 months) and spontaneous atherosclerotic plaque rupture and prolonged survival more effectively than each intervention alone. Thus, early concerted actions of MT and PE improve the natural history of atherosclerotic lesions and reduce the plaque instability in hypercholesterolemic mice.

Evidence of Key Role of Cdk2 Overexpression in Pemphigus Vulgaris

The pathogenesis of pemphigus vulgaris (PV) is still poorly understood. Autoantibodies present in PV patients can promote detrimental effects by triggering altered transduction of signals, which results in a final acantholysis. To investigate mechanisms involved in PV, cultured keratinocytes were treated with PV serum. PV sera were able to promote the cell cycle progression, inducing the accumulation of cyclin-dependent kinase 2 (Cdk2). Microarray analysis on keratinocytes detected that PV serum induced important changes in genes coding for one and the same proteins with known biological functions involved in PV disease (560 differentially expressed genes were identified). Then, we used two different approaches to investigate the role of Cdk2. First, small interfering RNA depletion of Cdk2 prevented cell-cell detachment induced by PV sera. Second, pharmacological inhibition of Cdk2 activity through roscovitine prevented blister formation and acantholysis in the mouse model of the disease. In vivo PV serum was found to alter multiple different pathways by microarray analysis (1463 differentially expressed genes were identified). Major changes in gene expression induced by roscovitine were studied through comparison of effects of PV serum alone and in association with roscovitine. The most significantly enriched pathways were cell communication, gap junction, focal adhesion, adherens junction, and tight junction. Our data indicate that major Cdk2-dependent multiple gene regulatory events are present in PV. This alteration may influence the evolution of PV and its therapy.

Burning mouth syndrome: the efficacy of lipoic acid on subgroups

Objective  We have examined the effect of alpha‐lipoic acid (ALA, tioctic acid; Tiobec), a free radical scavenger, on the discomfort of burning mouth syndrome (BMS) in patients who had used tranquillizers previously, compared with those who had not.

Pemphigus vulgaris with oral involvement: evaluation of two different systemic corticosteroid therapeutic protocols

Background Pemphigus vulgaris is a potentially life‐threatening disease characterized by cutaneous and mucosal blistering. Systemic corticosteroids remain the mainstay of therapy, transforming an invariably fatal disease into one with a mortality that is now less than 10%. Nevertheless, oral lesions are often recalcitrant and corticosteroid therapy can provoke adverse effects.