Expression of PROX-1 in oral Kaposi's sarcoma spindle cells.

BACKGROUND: The histogenesis of neoplastic spindle cells of Kaposi's sarcoma is still uncertain, but some studies consider it a lymphatic vessel differentiation. Prox-1 is a nuclear transcription factor that plays a major role during embryonic lymphangiogenesis, and it has been considered a specific and sensitive lymphatic endothelial cell marker. The aim of this study was to determine the expression of Prox-1 in oral Kaposi's sarcoma comparing the results with oral benign vascular tumors including capillary hemangiomas and pyogenic granulomas. METHODS: Expression of Prox-1 and HHV-8 was evaluated by immunohistochemistry in 30 oral Kaposi's sarcoma, 5 oral capillary hemangiomas, and 10 oral pyogenic granulomas. The labeling index was expressed as the percentage of positive cells for each case studied. Statistical comparison was performed using the Wilcoxon-Mann-Whitney rank sum test. RESULTS: Twenty-eight (93.3%) and 30 oral Kaposi's sarcoma cases were positive for Prox-1 and HHV-8, respectively, while all oral benign vascular tumors were negative for these markers. The number of Prox-1 and HHV-8 oral Kaposi's sarcoma-positive cells increased significantly from patch/plaque to nodular histological stages. CONCLUSION: The expression of Prox-1 in the neoplastic spindle cells supports the view of a lymphatic differentiation in oral Kaposi's sarcoma. Prox-1 may also be involved in the pathogenesis of oral Kaposi's sarcoma as the number of positive spindle cells increased progressively from patch to nodular stages and could be eventually useful as an additional diagnostic tool for differential diagnosis between oral Kaposi's sarcoma and benign oral vascular lesions.

Myxoid calcified hamartoma and natal teeth: a case report.

We report the case of a 4-month-old Caucasian male baby who presented an uncommon mass in the anterior mandibular ridge. The patient was born with two natal mandibular incisors, which exfoliated some weeks after birth, followed by a growth of nodular lesion in the same region. Based on the clinical and histopathological features, the diagnosis was of myxoid calcified hamartoma. Immunohistochemical and scanning electron microscopic analysis of the lesion were performed. Hamartomas in the mandibular ridges associated with natal teeth are rare, but they must be considered in the differential diagnosis of common lesions, such as congenital granular cell epulis.

Combining discovery and targeted proteomics reveals a prognostic signature in oral cancer.

Different regions of oral squamous cell carcinoma (OSCC) have particular histopathological and molecular characteristics limiting the standard tumor-node-metastasis prognosis classification. Therefore, defining biological signatures that allow assessing the prognostic outcomes for OSCC patients would be of great clinical significance. Using histopathology-guided discovery proteomics, we analyze neoplastic islands and stroma from the invasive tumor front (ITF) and inner tumor to identify differentially expressed proteins. Potential signature proteins are prioritized and further investigated by immunohistochemistry (IHC) and targeted proteomics. IHC indicates low expression of cystatin-B in neoplastic islands from the ITF as an independent marker for local recurrence. Targeted proteomics analysis of the prioritized proteins in saliva, combined with machine-learning methods, highlights a peptide-based signature as the most powerful predictor to distinguish patients with and without lymph node metastasis. In summary, we identify a robust signature, which may enhance prognostic decisions in OSCC and better guide treatment to reduce tumor recurrence or lymph node metastasis.

Hereditary gingival fibromatosis: a systematic review.

Generalized gingival enlargement can be caused by a variety of etiological factors. It can be inherited (hereditary gingival fibromatosis [HGF]); associated with other diseases characterizing a syndrome; or induced as a side effect of systemic drugs, such as phenytoin, cyclosporin, or nifedipine. HGF, previously known as elephantiasis gingivae, hereditary gingival hyperplasia, and hypertrophic gingiva, is a genetic disorder characterized by a progressive enlargement of the gingiva. This review will focus on diagnosis, treatment, and control of HGF. The pattern of inheritance, the histopathologic characteristics, and the known biologic and genetic features associated with HGF are also emphasized.

[Comparison between gingival and periodontal ligament fibroblasts from the same subject]. / Comparação entre fibroblastos gengivais e do ligamento periodontal de um mesmo indivíduo.

The objective of this study was to compare fibroblasts from the periodontal ligament (PLF) and gingival fibroblasts (GF) as to morphology, proliferation rate and protein synthesis. PLF and GF were explanted from tissues of the same patient. To characterize and compare the morphology of cells, PLF and GF were plated and analyzed under phase-contrast and optical microscopies. Proliferation rates were determined by means of automated counts carried out in days 1, 4, 7, 15 and 21, and also by means of the bromodeoxyuridine labelling index (BrdU). Total protein content was analyzed by means of electrophoresis in 10% polyacrylamide gel and zimography containing gelatin as substrate. PLF were bigger and more elongated than GF in subconfluence and confluence conditions. The proliferative rate of PLF was higher than that of GF at 1, 4, and 7 days (p < 0.05). At 15 and 21 days, there was no statistically significant difference as to the number of cells. PLF presented a significantly greater proliferative potential, in relation to GF (p < 0.05). The synthesis of protein in a period of 24 hours was similar for both PLF and GF. Our results demonstrated that PLF and GF are different as to morphology and proliferative capacity, however, they do not differ as to protein synthesis.

Smad7 blocks transforming growth factor-ß1-induced gingival fibroblast-myofibroblast transition via inhibitory regulation of Smad2 and connective tissue growth factor.

BACKGROUND: Transforming growth factor-ß1 (TGF-ß1), its downstream signaling mediators (Smad proteins), and specific targets, including connective tissue growth factor (CTGF), play important roles in tissue remodeling and fibrosis via myofibroblast activation. We investigated the effect of overexpression of Smad7, a TGF-ß1 signaling inhibitor, on transition of gingival fibroblast to myofibroblast. Moreover, we analyzed the participation of CTGF on TGF-ß1-mediated myofibroblast transformation. METHODS: To study the inhibitory effect of Smad7 on TGF-ß1/CTGF-mediating gingival fibroblast transition into myofibroblasts, we stably overexpressed Smad7 in normal gingival fibroblasts and in myofibroblasts from hereditary gingival fibromatosis (HGF). Myofibroblasts were characterized by the expression of the specific marker isoform α of the smooth muscle actin (α-SMA) by Western blot, flow cytometry, and immunofluorescence. Enzyme-linked immunosorbent assay for type I collagen was performed to measure myofibroblast activity. CTGF's role on myofibroblast transformation was examined by enzyme-linked immunosorbent assay and small interference RNA. RESULTS: TGF-ß1 induced the expression of α-SMA and CTGF, and small interference RNA-mediating CTGF silencing prevented fibroblast-myofibroblast switch induced by TGF-ß1. In Smad7-overexpressing fibroblasts, ablation of TGF-ß1-induced Smad2 phosphorylation marked decreased α-SMA, CTGF, and type I collagen expression. Similarly, HGF transfectants overexpressing Smad7 demonstrated low levels of α-SMA and phospho-Smad2 and significant reduction on CTGF and type I collagen production. CONCLUSIONS: CTGF is critical for TGF-ß1-induced gingival fibroblast-myofibroblast transition, and Smad7 overexpression is effective in the blockage of myofibroblast transformation and activation, suggesting that treatments targeting myofibroblasts by Smad7 overexpression may be clinically effective in gingival fibrotic diseases, such as HGF.

Cyclosporin A-induced gingival overgrowth is not associated with myofibroblast transdifferentiation.

Cyclosporin A (CyA) induces gingival overgrowth via its stimulatory effects on expression of transforming growth factor-beta1 (TGF-beta1) and collagen. It is not known whether CyA has a direct effect on gingival fibroblasts or induces its effect indirectly via stimulation of myofibroblast transdifferentiation. The present study was undertaken to examine the in vivo and in vitro effect of CyA on myofibroblast transdifferentiation. Rats were treated for 60 days with a daily subcutaneous injection of CyA, and the gingival overgrowth tissue was analyzed by immunohistochemistry. In vitro, fibroblasts from normal gingiva (NG) were cultured in the presence of different concentrations of CyA, and subjected to semi-quantitative reverse transcriptase-polymerase chain reaction and western blot. Although CyA treatment stimulated TGF-beta1 expression by NG fibroblasts, it lacked to induce expression and production of isoform alpha of smooth muscle actin (alpha-SMA), the specific myofibroblast marker. The expression levels of connective tissue growth factor (CTGF), which has been considered a key molecule to promote the transdifferentiation of myofibroblasts via TGF-beta1 activation, were unaffected by CyA. Our results demonstrate that CyA-induced gingival overgrowth is not associated with activation of myofibroblast transdifferentiation, since CyA is not capable to increase CTGF expression.

Goldenhar syndrome: clinical features with orofacial emphasis.

OBJECTIVES: Goldenhar syndrome (GS) is a relatively common developmental disorder characterized by craniofacial anomalies in association with vertebral, cardiac, renal, and central nervous system defects. This paper describes GS features with special emphasis on oral characteristics. MATERIAL AND METHODS: The clinical features of 6 patients with GS aged 3 months to 12 years are described, and a brief review of the literature about this genetic disorder is presented. RESULTS: All patients demonstrated the classical triad of GS, including mandibular hypoplasia resulting in facial asymmetry, ear and/or eye malformation, and vertebral anomalies. In addition, renal and gastrointestinal abnormalities were observed in 2 patients. Regarding the oral involvement, 2 patients presented cleft lip and palate, and 1 patient had temporomandibular joint malformation. Malocclusion was found in all patients. CONCLUSION: Our orofacial findings correlate with the reported cases in the literature, and point out that after diagnosis GS patients need to be examined for systemic abnormalities.

Opposite effects of TGF-beta1 and IFN-gamma on transdifferentiation of myofibroblast in human gingival cell cultures.

BACKGROUND/AIM: Previously, we have shown that myofibroblasts, the main cell type associated with interstitial fibrosis, may be implicated with the gingival overgrowth observed in hereditary gingival fibromatosis (HGF) patients. The goal of this study was to determine whether transforming growth factor-beta1 (TGF-beta1) stimulates myofibroblast generation in gingival fibroblast cultures. Moreover, we analysed how interferon-gamma (IFN-gamma) interferes in this process. MATERIAL AND METHODS: Fibroblast cultures from normal gingiva and myofibroblast cells from HGF were included in this study. To determine the effects of TGF-beta1 and IFN-gamma stimulation in these cells, the expression of the specific myofibroblast marker smooth muscle isoform of alpha-actin (alpha-SMA) was examined by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot and immunofluorescence. Enzyme-linked immunosorbent assay (ELISA) for type I collagen was performed to measure the myofibroblast activity. RESULTS: Our results demonstrated that TGF-beta1 promotes a dose- and time-dependent increase in the expression of alpha-SMA, whereas IFN-gamma blocks it and markedly prevents the fibroblast-myofibroblast switch induced by TGF-beta1 on normal gingiva cultures. IFN-gamma altered HGF myofibroblasts metabolism with a decrease of both alpha-SMA and type I collagen expression. Additionally, IFN-gamma treatment stimulated SMAD7 expression and inhibited connective tissue growth factor, which has been considered a key molecule to promote the transdifferentiation of myofibroblasts via TGF-beta1 activation. CONCLUSIONS: These findings demonstrate that TGF-beta1 induces gingival fibroblast-myofibroblast transdifferentiation, whereas IFN-gamma blocks this process. More importantly, this study suggests that IFN-gamma may be clinically effective in attenuating excessive accumulation of extracellular matrix produced by myofibroblasts in HGF.

Heterogeneous presence of myofibroblasts in hereditary gingival fibromatosis.

BACKGROUND/AIM: Hereditary gingival fibromatosis (HGF) fibroblasts are characterized by an increased production of collagen and transforming growth factor-beta1 (TGF-beta1), resulting in a fibrotic enlargement of the gingiva of affected patients. A common feature of interstitial fibrosis is the occurrence of myofibroblasts, which are regarded as the predominant cells in matrix synthesis. The goal of this article is to describe the presence of myofibroblasts in HGF in order to elucidate the mechanisms underlying HGF gingival overgrowth. MATERIALS AND METHODS: Fibroblast cell lines and gingival samples from patients of two distinct families affected by HGF and from normal gingiva (NG) were included in this study. To characterize the presence of myofibroblasts, the expression of specific myofibroblast marker smooth muscle isoform of alpha-actin (alpha-SMA) was examined by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot, immunofluorescence, and flow cytometric analysis. Immunohistochemistry against the alpha-SMA antigen was performed in the gingival tissue samples. RESULTS: Our results demonstrated a significant increase in the expression of the myofibroblast marker alpha-SMA in cells from one HGF family (designed as HGF Family 2), which are also characterized by an elevated expression of type I collagen, TGF-beta1 and connective tissue growth factor (CTGF). Additionally, alpha-SMA-positive cells were broadly detected in the gingival tissue samples from HGF Family 2 patients. In contrast, alpha-SMA expression by HGF Family 1 cells was quite similar to NG cells and no myofibroblasts were detected immunohistochemically, despite the higher levels of TGF-beta1 and type I collagen in HGF Family 1 fibroblasts than in NG cells. The expression of CTGF, which has been considered a key molecule to promote the transdifferentiation of myofibroblasts via TGF-beta1 activation, by HGF Family 1 cultures was significantly lower compared with HGF Family 2 and similar to NG control cells. CONCLUSIONS: Our results suggest that the presence of myofibroblasts in HGF could be dependent on CTFG expression levels, and different biological mechanisms may account for the gingival overgrowth observed in HGF patients. This could be an underlying reason for the high variable clinical expressivity of disease.

Cyclosporin A-induced gingival overgrowth is not associated with myofibroblast transdifferentiation

Cyclosporin A (CyA) induces gingival overgrowth via its stimulatory effects on expression of transforming growth factor-beta1 (TGF-â1) and collagen. It is not known whether CyA has a direct effect on gingival fibroblasts or induces its effect indirectly via stimulation of myofibroblast transdifferentiation. The present study was undertaken to examine the in vivo and in vitro effect of CyA on myofibroblast transdifferentiation. Rats were treated for 60 days with a daily subcutaneous injection of CyA, and the gingival overgrowth tissue was analyzed by immunohistochemistry. In vitro, fibroblasts from normal gingiva (NG) were cultured in the presence of different concentrations of CyA, and subjected to semi-quantitative reverse transcriptase-polymerase chain reaction and western blot. Although CyA treatment stimulated TGF-â1 expression by NG fibroblasts, it lacked to induce expression and production of isoform á of smooth muscle actin (á-SMA), the specific myofibroblast marker. The expression levels of connective tissue growth factor (CTGF), which has been considered a key molecule to promote the transdifferentiation of myofibroblasts via TGF-â1 activation, were unaffected by CyA. Our results demonstrate that CyA-induced gingival overgrowth is not associated with activation of myofibroblast transdifferentiation, since CyA is not capable to increase CTGF expression.

Goldenhar syndrome: clinical features with orofacial emphasis

OBJECTIVES: Goldenhar syndrome (GS) is a relatively common developmental disorder characterized by craniofacial anomalies in association with vertebral, cardiac, renal, and central nervous system defects. This paper describes GS features with special emphasis on oral characteristics. MATERIAL AND METHODS: The clinical features of 6 patients with GS aged 3 months to 12 years are described, and a brief review of the literature about this genetic disorder is presented. RESULTS: All patients demonstrated the classical triad of GS, including mandibular hypoplasia resulting in facial asymmetry, ear and/or eye malformation, and vertebral anomalies. In addition, renal and gastrointestinal abnormalities were observed in 2 patients. Regarding the oral involvement, 2 patients presented cleft lip and palate, and 1 patient had temporomandibular joint malformation. Malocclusion was found in all patients. CONCLUSION: Our orofacial findings correlate with the reported cases in the literature, and point out that after diagnosis GS patients need to be examined for systemic abnormalities.

Comparaçäo microscópica e proliferativa de fibroblastos gengivais de pacientes com gengiva normal e com fibromatose gengival hereditária / Microscopic and proliferative comparison of gingival fibroblasts from patients with normal gingiva and with hereditary gingival fibromatosis

Fibromatose gengival hereditária (FGH) é uma condiçäo bucal rara clinicamente manifestada por um aumento gengival generalizado e fibrótico, podendo apresentar-se de forma isolada ou associada a outras alteraçöes, como parte de síndromes. Os mecanismos biológicos envolvidos na FGH säo desconhecidos, e os resultados de estudos de cultura celulares säo controversos. Para elucidar as características fenotípicas dos fibroblastos de FGH, nós isolamos quatro linhagens celulares de fibroblastos de FGH de indivíduos de uma mesma família e comparamos as características morfológicas e proliferativas com fibroblastos provenientes de pacientes com gengiva clinicamente normal (GN). Fibroblastos de GN e FGH em condiçöes de subconfluência celular apresentaram típicas características morfológicas, como formato fusiforme, núcleo central e longos prolongamentos citoplasmáticos, mas em condiçöes de saturaçäo da densidade celular, os fibroblastos de FGH apresentaram dimensöes menores que as células controle. A relaçäo núcleo/citoplasma foi sempre menor para todas as linhagens celulares de fibroblastos de FGH, sugerindo que a reduçäo celular, é proveniente de uma reduçäo ou compactaçäo citoplasmática e näo nuclear. A capacidade proliferativa de fibroblastos de FGH foi maior que a de fibroblastos de GN. Estes resultados sugerem que diferenças morfológicas e proliferativas dos fibroblastos de FGH podem estar associadas aos eventos biológicos envolvidos na etiopatogenia do aumento gengival observado em pacientes com FGH

Comparaçäo entre fibroblastos gengivais e do ligamento periodontal de um mesmo indivíduo / Comparison between gingival and periodontal ligament fibroblast of the same subject

O objetivo deste estudo foi comparar as características morfológicas, o potencial proliferativo e a produçäo protéica de fibroblastos do ligamento periodontal (FLP) e de fibroblastos gengivais (FG). Os fibroblastos foram cultivados pela técnica do explante a partir de fragmentos da gengiva e do ligamento periodontal de um mesmo indivíduo. As células foram isoladas e plaqueadas para análise por microscopia de contraste de fase e microscopia óptica. O índice de proliferaçäo celular foi determinado por contagem automática de células e pelo ensaio de incorporaçäo de bromodioxiuridina (BrdU). A produçäo de proteína total foi verificada por eletroforese em gel de poliacrilamida e o perfil enzimático por análise zimográfica. Os FLP säo maiores e mais alongados que os FG em condiçöes de subconfluência e confluência celular. Os FLP demonstraram um potencial proliferativo significantemente maior que os FG. Os perfis protéico e enzimático foram similares entre os FLP e FG. Os resultados demonstram que os FLP e FG säo diferentes na morfologia e na capacidade proliferativa, porém säo semelhantes na produçäo protéica

Oral changes associated with biliary atresia and liver transplantation / Alterações bucais associadas com a atresia biliar e transplante de fígado

A child is reported with green hypoplastic teeth in both dentitions, resulting from hyperbilirubinemia biliary atresia. Following liver transplantation, labial hirsutism, gingival hyperplasia and herpes labial, were seen as a consenquence of cyclosporin therapy and iatrogenic immunosuppression. The oral manifestations and management in biliary atresia and after liver transplantation are reviewed

Rabdomiossarcoma manifestando-se na boca / Rhabdomyosarcoma affecting the mouth

Rabdomiossarcoma é um tumor mesenquimal maligno de músculo esquelético que raramente afeta a cavidade oral. Microscopicamente apresenta vários padröes com células variando de fusiformes a arredondadas com núcleo excêntrico. A análise imuno-histoquímica mostra positividade para vimentina, desmina e actina muscular específica. Neste artigo, nós apresentamos um caso clínico de rabdomiossarcoma com um seguimento de sete anos

Uso de imunossupressor em lesöes inflamatórias da polpa e periápice: lesöes pulpares e periapicais em ratos normais e tratados com ciclosporina A / The use of an imunological supressor in pulpal and periapical lesions in conventional rats and treated with cyclosporin A

As polpas coronárias dos primeiros molares inferiores de 20 ratos tratados com ciclosporina A (CyA) foram expostas e deixadas abertas ao meio bucal por período de 7, 14, 21 e 28 dias. Em todos os períodos estudados, as alteraçöes pulpares e periapicais das raízes mesiais foram semelhantes nos dois grupos, sugerindo que a imunossupressäo provocada pela CyA näo modificou a evoluçäo das lesöes

Fumo e doença periodontal: uma revisão / Smoking and periodontal disease: a revision

A influência do hábito de fumar no desenvolvimento da doença periodontal é assunto controvertido. Diversos estudos têm relacionado o fumo com os seguintes aspectos: quantidade de placa, inflamação gengival, porcentagem de microorganismos aeróbicos e anaeróbicos, índice de placa, índice gengival, mobilidade dental, profundidade de sondagem e outros. Revendo estes aspectos podemos situar o fumo como fator predisponente ou interferente na patogenia periodontal

Periodontite associada ao virus da AIDS: uma revisão / Periodontitis associated to the AIDS virus: a review

As manifestaçõe bucais da AIDS como leucoplasia pilosa e candidíase, entre outras, frequentemente antecedem as manifestações sistêmicas, fato que confere ao exame clínico bucal realizado pelo cirurgião-dentista, papel decisivo na detecção e manejo destes pacientes. Paciente com HIV+, ARC e com AIDS podem apresentar uma periodontite de rápida progressão e destruição óssea, algumas vezes exibindo superposição de aspectos clínicos da GUNA, denominada periodontite associada ao vírus da AIDS ou P.A.V.A. O periodontista deve conhecer todas as manifestações bucais da AIDS, lembrando-se que, nem sempre estas estão presentes, e conhecer os testes para detecção do anti-HIV a fim de solicitá-los quando julgar necessário

Periodontite e lesões pulpares - interação através de canais: acessórios nas regiões de bifurcação em molares de ratos / Periodontitis and pulpar lesions - interaction through accessory canals on the function area of rat's molars

Os canais acessórios são frequentemente observados no assoalho da câmara pulpar, nas áreas de bifurcação de raízes dos primeiros molares inferiores de ratos. Alterações pulpares associadas com a presença desses canais acessórios foram estudadas após a indução de uma periodontite experimental nestes dentes. Os molares do grupo controle apresentaram polpas normais, independentemente da presença dos canais acessórios. Os molares do grupo experimental mostraram variados graus de alterações pulpares associados com os canais acessórios