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OBJECTIVE: To evaluate in vitro the sealing capability at the prosthetic connection interface of 2 conometric systems. MATERIALS AND METHODS: Two conometric systems with the same design and different material were used, for a total of 24 samples. Each sample was assembled by a tapered abutment and respective coping. In group A, the copings were made of gold, whereas in group B they were made of PEEK. Three µL of mix bacterial suspension (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Fusobacterium nucleatum species) was inoculated into the abutment screw hole, and the coping was inserted on the abutment. Samples were immersed into culture tubes and incubated for 24, 48, and 72 hours into anaerobic conditions. Visual evaluation of turbidity was performed at each time point. Qualitative-quantitative assessment using real-time polymerase chain reaction was performed at 72 hours. Any difference between the groups was checked by means of Fisher exact test. RESULTS: Microbial leakage occurred in both groups, and there was no statistically significant difference between groups. Microbial concentration resulted in a presence inferior to 1 × 10 copies/µL in all positive assemblies. CONCLUSIONS: Because of the low bacterial count, it can be concluded that a minimal bacterial infiltration may be allowed by conometric interfaces for prosthetic connection.
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Dente Suporte , Implantes Dentários/microbiologia , Infiltração Dentária/microbiologia , Aggregatibacter actinomycetemcomitans , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Fusobacterium nucleatum , Humanos , Técnicas In Vitro , Porphyromonas gingivalisRESUMO
AIM: The aim of this retrospective multicenter study was to verify the efficacy of Nd:YAG laser in the treatment of periodontal pockets infected by Epstein-Barr Virus (EBV) and Herpes Simplex Virus 1 (HSV1). METHODS: Subgingival plaque samples of 291 Italian periodontal patients were analyzed by Real Time PCR to evaluate the frequency of both viruses before and after Nd:YAG laser-assisted periodontal treatment. RESULTS: Before treatment, EBV and HSV1 were observed in 29.9% and in 3.8% of periodontal patients respectively, while co-infection with both viruses was detected in 1.7% of cases. Periodontal Nd:YAG laser treatment ("Periodontal Biological Laser-Assisted Therapy", PERIOBLAST) produced statistical significant benefits, especially in EBV periodontal infection: 78.2% of EBV positive patients became EBV-negative following treatment. CONCLUSIONS: Results of this preliminary study highlight that EBV is found in periodontal pockets more frequently than HSV1, supporting the theory of the potential role of EBV in the onset and progression of periodontal disease. Moreover, our data showed that Nd:YAG laser-assisted periodontal treatment (Perioblast) is also effective in case of viral infection, validating evidences that it represents a successful alternative approach to traditional periodontal protocols.
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Placa Dentária/radioterapia , Gengiva/efeitos da radiação , Herpesvirus Humano 1/efeitos da radiação , Herpesvirus Humano 4/efeitos da radiação , Lasers de Estado Sólido/uso terapêutico , Terapia com Luz de Baixa Intensidade , Bolsa Periodontal/radioterapia , Placa Dentária/virologia , Gengiva/virologia , Herpesvirus Humano 1/isolamento & purificação , Herpesvirus Humano 4/isolamento & purificação , Humanos , Itália/epidemiologia , Terapia com Luz de Baixa Intensidade/métodos , Bolsa Periodontal/epidemiologia , Bolsa Periodontal/virologia , Periodontia/instrumentação , Periodontia/métodos , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
OBJECTIVE: The potential role of VDR gene variations in modulating periodontal susceptibility have been a subject of scientific investigations. The aim of this paper is to perform a literature review of the potential correlation between Vitamin D Receptor (VDR) gene polymorphisms and periodontal disease. MATERIALS AND METHODS: A PubMed literature search was made using "vitamin d receptor polymorphisms periodontal disease" as keys words. Only clinical studies in "Humans" as species and "English" as language were considered. Titles and abstracts of all identified records were examined to determine if the candidate articles contained sufficient information on the association of the VDR polymorphisms and the risk of development periodontal disease. CONCLUSIONS: Vitamin D may affect the risk of developing periodontal disease via an effect on bone mineral density or via immunomodulatory effects. There are scientific evidences about the correlation between some VDR polymorphisms, periodontitis and bone metabolism. The use of new simple and economics diagnostic techniques of genetic screening, allows to the dental specialists to identify periodontal patients with possible decreased bone mineral density. The complete acquisition of awareness by dentists of the strong relationship between skeletal bone density with periodontal health and osteointegrated implant success, could open a new therapeutic approach for periodontists with an important role in the early detection of osteoporosis and a better patient compliance of the periodontal therapy.
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PURPOSE: In this study the temporal texture differentiation associated with the bone formation properties, around loaded oral implants after Platelet Rich Plasma (PRP) employment, was investigated in Panoramic Radiographs. MATERIALS AND METHODS: Thirty eligible patients are randomly assigned to two groups. The test group received PRP application around new implants, while in the control group no PRP treatment was made. The bone-to-implant contact region was analyzed in a clinical sample of 60 Digitized Panoramic Radiographs, 30 corresponding to immediate implant loading (Class-I) and 30 after an 8 month follow-up period (Class-II). This region was sampled by 1146 circular Regions-of-Interest (ROIs), resulting from a specifically designed segmentation scheme based on Markov-Random-Fields (MRF). From each ROI, 41 textural features were extracted, then reduced to a subset of 4 features due to redundancy and employed as input to Receiver-Operating-Characteristic (ROC) analysis, to assess the textural differentiation between two classes. RESULTS: The selected subset, achieved Area-Under-Curve (AUC) values ranging from 0.77-0.81 in the PRP group, indicating the significant temporal textural differentiation has been made. In the control group, the AUC values ranged from 0.56-0.68 demonstrating lesser osseo integration activity. CONCLUSION: This study provides evidences that PRP application may favor bone formation around loaded dental implants that could modify the dental treatment planning.
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OBJECTIVE: The aim of this study was to determine the impact of the polymorphisms at position -607 (C/A) and -137 (G/C) in the promoter of the IL-18 gene and their haplotypes, on the individual susceptibility of developing Aggressive (AgP) and/or Chronic (CP) periodontitis. MATERIALS AND METHODS: A total of 213 unrelated Italian subjects with periodontitis (AgP=109 and CP=104) and 100 periodontal-health subjects were studied. IL-18 gene promoter polymorphisms were analyzed by TaqMan® SNP Genotyping Assays. Genotype and allele frequencies were analyzed using the chi-square test and multiple logistic regression analysis. RESULTS: χ(2) of comparisons between diseased patients and healthy controls indicated a significant differentiation between the control and AP and CP groups (χ(2)=26.359, P<0.02). Interestingly, genotypes AACG, AACC and AACG have a moderate association with AgP and CP. For alleles, multiple logistic regression analysis showed that the polymorphism CG at position -137 is moderately associated with AgP (ExpB=2.880), while the polymorphism AA at position -607 is moderately associated with CP (ExpB=2.076). Finally, a moderate association of CA at position -607 (ExpB=2.099) with the healthy status compared to aggressive periodontitis was found. CONCLUSIONS: Results obtained indicated the presence of some potential moderate protective and moderate susceptible alleles and genotypes to both aggressive and chronic periodontitis, demonstrating that IL-18 -607 C/A and -137 G/C gene promoter polymorphisms are not suitable diagnostic features for AgP and CP.
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The aim of this study was to investigate subgingival bacterial composition of untreated Italian subjects with aggressive and chronic periodontitis. The total bacterial load, pathogenic bacteria belonging to "red" and "orange" complexes and Aggregatibacter actinomycetemcomitans were determined by Real-Time PCR in 1216 patients. Data were analysed by looking for relationships between bacteriological parameters, age and periodontal probing depth. The obtained results showed a significant higher number of red complex bacteria in older rather than in younger patients. The total number of bacteria and the presence of A. actinomycetemcomitans did not clearly associate with an age group.
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Infecções por Actinobacillus/complicações , Aggregatibacter actinomycetemcomitans/isolamento & purificação , Bolsa Periodontal/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Periodontite Crônica/microbiologia , Inquéritos de Saúde Bucal , Placa Dentária/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice Periodontal , Reação em Cadeia da Polimerase em Tempo Real , Fatores de RiscoRESUMO
Cyclooxygenase (COX)-2 and 5-lipoxygenase (5-LOX) are key enzymes involved in arachidonic acid metabolism. Their products, prostaglandins and leukotrienes, are involved in colorectal tumor development. We aimed at evaluating whether combined blocking of the COX-2 and 5-LOX pathways might have additive antitumor effects in colorectal cancer. The expression/activity of COX-2 and 5-LOX were assessed in 24 human colorectal cancer specimens. The effects of the COX-2 inhibitor celecoxib and the 5-LOX inhibitor MK886 on prostaglandin E(2) and cysteinyl leukotriene production, tumor cell proliferation, cell apoptosis, and Bcl-2/Bax expression were evaluated in the Caco-2 and HT29 colon cancer cells. We also investigated the effect of the enzymatic inhibition on mitochondrial membrane depolarization, one of the most important mechanisms involved in ceramide-induced apoptosis. Up-regulation of the COX-2 and 5-LOX pathways was found in the tumor tissue in comparison with normal colon mucosa. Inhibition of either COX-2 or 5-LOX alone resulted in activation of the other pathway in colon cancer cells. Combined treatment with 10 micromol/L celecoxib and MK886 could prevent this activation and had additive effects on inhibiting tumor cell proliferation, inducing cell apoptosis, decreasing Bcl-2 expression, increasing Bax expression, and determining mitochondrial depolarization in comparison with treatment with either inhibitor alone. The administration of the ceramide synthase inhibitor fumonisin B1 could prevent some of these antineoplastic effects. In conclusion, our study showed that inhibition of 5-LOX by MK886 could augment the antitumor activity of celecoxib in human colorectal cancer.
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Antineoplásicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Inibidores de Ciclo-Oxigenase/farmacologia , Indóis/farmacologia , Inibidores de Lipoxigenase , Pirazóis/farmacologia , Sulfonamidas/farmacologia , Idoso , Animais , Antineoplásicos/uso terapêutico , Araquidonato 5-Lipoxigenase/metabolismo , Células CACO-2 , Celecoxib , Linhagem Celular , Proliferação de Células , Neoplasias do Colo/metabolismo , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase/uso terapêutico , Dinoprostona/metabolismo , Feminino , Células HT29 , Humanos , Indóis/uso terapêutico , Masculino , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Pirazóis/uso terapêutico , Receptores de Leucotrienos/metabolismo , Sulfonamidas/uso terapêutico , Proteína X Associada a bcl-2/metabolismoRESUMO
PURPOSE: Activity of histidine decarboxylase, the key enzyme in the synthesis of histamine, has been shown to be increased in several types of human tumors. We attempted to establish whether the possible involvement of histidine decarboxylase and histamine in colorectal carcinogenesis might be mediated by the activation of the cyclooxygenase-2 (COX-2) pathway. EXPERIMENTAL DESIGN: Expression/activity of histidine decarboxylase, histamine content, and prostaglandin E2 (PGE2) production were analyzed in 33 colorectal cancer samples and in the HT29, Caco-2, and HCT116 colon cancer cell lines. The effects of histamine, celecoxib, and H1, H2, and H4 receptor antagonists on COX-2 expression/activity, cell proliferation, and vascular endothelial growth factor (VEGF) production were assessed in the three colon cancer lines that showed different constitutive COX-2 expression. RESULTS: We showed the up-regulation of histidine decarboxylase protein expression and activity in the tumor specimens when compared with normal colonic mucosa. Histidine decarboxylase activity and histamine content were also significantly higher in metastatic tumors than in nonmetastatic ones. These variables significantly correlated with tumor PGE(2) production. The administration of histamine increased COX-2 expression/activity, cell proliferation, and VEGF production in the COX-2-positive HT29 and Caco-2 cells. Treatment with either H2/H4 receptor antagonists or celecoxib prevented these effects. Histamine had no effect on both the COX-2 pathway and VEGF production in the COX-2-negative HCT116 cells. CONCLUSIONS: Our data showed that histamine exerts both a proproliferative and a proangiogenic effect via H2/H4 receptor activation. These effects are likely to be mediated by increasing COX-2-related PGE2 production in COX-2-expressing colon cancer cells.
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Neoplasias Colorretais/metabolismo , Ciclo-Oxigenase 2/fisiologia , Regulação Neoplásica da Expressão Gênica , Histamina/metabolismo , Fator A de Crescimento do Endotélio Vascular/biossíntese , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Células CACO-2 , Celecoxib , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Colo/metabolismo , Neoplasias Colorretais/enzimologia , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase/farmacologia , Dinoprostona/metabolismo , Feminino , Células HL-60 , Histidina Descarboxilase/metabolismo , Humanos , Mucosa Intestinal/patologia , Masculino , Pessoa de Meia-Idade , Pirazóis/farmacologia , Receptores Acoplados a Proteínas G/metabolismo , Receptores Histamínicos/metabolismo , Receptores Histamínicos H2/metabolismo , Receptores Histamínicos H4 , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sulfonamidas/farmacologia , Fatores de Tempo , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Satellite cells are quiescent cells that can be induced to proliferate by a variety of stimuli such as injury and exercise, providing in this way a source of new myoblasts that repopulate the damaged muscle. It is well known that, as senescence progresses, the muscle regenerative potential progressively diminishes, but the molecular mechanisms underlying this process are not yet completely defined. Many growth factors, including Platelet Derived Growth Factor (PDGF-BB)*, have been associated to satellite cells activation, acting as potent mitogenic agents for these cells. The aim of this study is to explore if the diminished response of senescent myoblasts to growth stimuli could be due to the inability to receive and transduce hormonal signals. Herein, we demonstrate that that although PDGF-r expression is down-regulated during senescence, the receptor is fully able to be phosphorylated and to transmit the signal. Although senescent myoblasts display increased level of phosphotyrosine phosphatases (PTPs), neither the PDGF receptor (PDGF-r) phosphorylation level nor the citosolic signal transduction machinery is affected. Indeed, we demonstrated that senescent human myoblasts are able to initiate a proper mitogenic signalling cascade, since the activation of mitogen-activated protein kinases (MAPK) and phosphatydil inositole 3 kinase (PI-3K) pathways is similar in young and senescent cells. Our data underline that, despite a conserved capability to activate PDGF-r after agonist stimulation and a functional signal transduction machinery, the mitogenic signal initiated by growth factors in senescent cells does not lead to cell division, being unable to overcome the cell cycle block, likely caused by the accumulation of the inhibitor p21WAF1.
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Senescência Celular , Mitógenos/farmacologia , Mioblastos Esqueléticos/citologia , Transdução de Sinais , Becaplermina , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Senescência Celular/fisiologia , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Lactente , Mitógenos/metabolismo , Músculos/fisiologia , Mioblastos Esqueléticos/efeitos dos fármacos , Mioblastos Esqueléticos/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Proteínas Proto-Oncogênicas c-sis , Transdução de Sinais/efeitos dos fármacosRESUMO
AIM: Periodontal diseases entail a variety of conditions affecting the periodontium. The pathogenesis results from a complex interaction of genetic and environmental factors. Although there are evidences to confirm a role of genetic determinants, the outcome of the available studies is controversial and the largest part of the research has been carried out in Asian populations. METHODS: We investigated two polymorphisms in the genes encoding Interelukin-1ß (IL-1ß +3953 C>T; rs1143634) and vitamin D receptor (VDR Taq1; rs731236) in 42 Caucasian patients with chronic periodontal disease and 39 Caucasian subjects, matched for age and gender. RESULTS: The IL-1ß C allele was present in 100% of cases and 92% of controls (p=0.07), the T allele was present in 19% of cases and in 44% controls (p=0.017). The prevalence of the VDR Taq1 tt genotype was lower in patients as compared with controls (i.e., 10 versus 59%; p<0.01), whereas the tT and TT genotypes were disproportionally higher in patients than in cases (i.e., 62 versus 33% for tT and 29% versus 8% for TT; p<0.01). The t allele was present in 71% of cases and 92% of controls (p=0.016), whereas the T allele was present in 90% of patients with periodontal disease and in 41% controls (p<0.01). CONCLUSION: The results of this case control study at-test that the T allele of VDR Taq1 is strongly associated with periodontal disease, whereas the t allele of the IL-1ß +3953 confers a slightly protection against the risk of periodontitis.
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BACKGROUND: Poly(ADP-Ribose) polymerase (PARP) activity has been demonstrated fundamental in many cellular processes, including DNA repair, cell proliferation and differentiation. In particular, PARP activity has been recently found to affect proliferation, migration, and tube formation of human umbilical vein endothelial cells. In recent times, PARP inhibitors have entered in clinical trials to potentiate cancer treatments by preventing DNA repair, but little is known about the effects performed by different drug concentrations on neoangiogenesis, an essential step in tumor growth. METHODS: Human umbilical vein endothelial cells were treated with 3 aminobenzamide (3ABA), a PARP inhibitor, and tested for several different cellular parameters. RESULTS: Here we present in vitro evidence that a low concentration of 3ABA (50 µM), stimulates angiogenesis by decreasing fibrinolytic activity, carried out by urokinase-type plasminogen activator (uPA), and by enhancing matrix metalloprotease-2 (MMP-2) gelatinolytic activity, in fibroblast growth factor-2-stimulated endothelial cells. These unbalanced pathways modify in vitro angiogenic steps, inhibiting chemoinvasion and stimulating tubulogenic activity. CONCLUSIONS: Our results suggest that the proangiogenic effect of low concentrations of 3ABA alerts on the efficacy of PARP inhibitors to potentiate anticancer therapy. Moreover, they indicate that endothelial chemoinvasion and tubulogenesis depend on distinct proteolytic pathways.
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Nitric oxide (NO) is a diatomic free radical molecule that has been implicated in tumour angiogenesis and progression of head and neck squamous cell carcinoma (HNSCC). However, the mechanism underlying the effect of NO on tumour spread remains largely unknown. Tumour lymphangiogenesis has recently received considerable attention and there is increasing evidence that it is relevant for metastasis to lymph nodes in HNSCC. Here, we study the correlation between inducible NOS synthase (iNOS) activity and lymphangiogenesis in a series of 60 HNSCCs and the possible involvement of the lymphangiogenic factor vascular endothelial growth factor (VEGF)-C. HNSCC presenting with lymph node metastasis had a significantly higher lymphatic vessel density in both the tumour mass and the peritumour area (p = 0.006 and p = 0.001, respectively). Similarly, tumours with lymph node metastasis showed greater lymphatic vessel area than tumours with no lymph node involvement (p = 0.001 for intratumour lymphatics and p < 0.001 for peritumour lymphatics). iNOS activity measured in specimens from the tumour periphery correlated strongly with both lymphatic vessel density and lymphatic vessel area (p = 0.01, rs = 0.45 and p < 0.001, rs = 0.725, respectively). Conversely, these correlations were not observed in specimens from the tumour core. In addition, VEGF-C mRNA expression was significantly elevated in tumours with high iNOS activity (p = 0.008, rs = 0.563), and VEGF-C expression correlated positively with the presence of lymph node metastases (p = 0.03). In vitro, in the A431 human squamous carcinoma cell line, exogenous and endogenous stimulation of the iNOS pathway led to up-regulation of VEGF-C, which was blocked by the NOS inhibitor L-NNA. Taken together, our results indicate that iNOS activity may promote lymphangiogenesis and spread to lymph nodes in HNSCC, with the possible involvement of VEGF-C.
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Carcinoma de Células Escamosas/enzimologia , Neoplasias de Cabeça e Pescoço/enzimologia , Linfangiogênese , Óxido Nítrico Sintase Tipo II/metabolismo , Fator C de Crescimento do Endotélio Vascular/metabolismo , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Lipopolissacarídeos/farmacologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase Tipo II/análise , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Nitroarginina/farmacologia , Penicilamina/análogos & derivados , Penicilamina/farmacologia , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator C de Crescimento do Endotélio Vascular/análise , Fator C de Crescimento do Endotélio Vascular/genéticaRESUMO
We investigated the role of low molecular weight (LMW) and high molecular weight (HMW) isoforms of basic fibroblast growth factor 2 (FGF-2) in the expression of transformation-related phenotypic alterations, drug sensitivity modulation, and gene amplification potential. For this purpose, we used NIH 3T3 and A31 cells transfected with different cDNA FGF-2 constructs allowing expression of the different proteins. Both cell lines showed marked phenotypic alterations when expressing the LMW FGF-2 or the four HMW FGF-2 isoforms: they acquired a transformed morphology, grew at higher saturation densities in 10% serum, and exhibited anchorage-independent growth and increased invasive potential. However, HMW FGF-2-expressing cells also grew in 1% serum and their invasive potential was lower than in cells expressing all FGF-2 forms or LMW FGF-2 alone. We have grown the different cell lines under a selective pressure of N-(phosphonacetyl)-l-aspartate (PALA), a drug which specifically inhibits the aspartate transcarbamylase activity of the multifunctional carbamyl-P-synthetase/aspartate transcarbamylase/dihydro-orotase genes (CAD) enzyme (and thus inhibits de novo pyrimidine biosynthesis) and selects for cells with amplified copies of the CAD gene. Our results demonstrate that aberrant expression of the LMW FGF-2 and/or HMW FGF-2 isoforms differently modulates drug resistance and gene amplification properties in the NIH 3T3 and A31 cell lines by differential amplification of the CAD gene. Coexpression of all isoforms appears to be necessary to obtain cumulative effects and nuclear-targeted HMW FGF-2 has a pivotal role in such a cooperation.