Diagnostic value of VEGF in peri-implantitis and its correlation with titanium particles: A controlled clinical study.

OBJECTIVES: VEGF is prototypic marker of neovascularization, repeatedly proposed as intrinsic characteristic of peri-implantitis. This study aimed to assess pattern of VEGF in peri-implantitis, its correlation with titanium particles (TPs) and capacity as respective biomarker. MATERIAL AND METHODS: Pathological specificity of VEGF was assessed in peri-implant granulations using immunohistochemistry, periodontal granulations represented Ti-free positive controls. VEGF was correlated to TPs, identified using scanning electron microscopy coupled with dispersive x-ray spectrometry. Diagnostic accuracy, sensitivity and specificity of VEGF were estimated in PICF specimens from peri-implantitis, peri-implant mucositis (PIM) and healthy peri-implant tissues (HI) using machine learning algorithms. RESULTS: Peri-implantitis exhibited rich neovascular network with expressed density in contact zones toward neutrophil infiltrates without specific pattern variations around TPs, identified in all peri-implantitis specimens (mean particle size 8.9 ± 24.8 µm2; Ti-mass (%) 0.380 ± 0.163). VEGF was significantly more expressed in peri-implantitis (47,065 ± 24.2) compared to periodontitis (31,14 ± 9.15), and positively correlated with its soluble concentrations in PICF (p = 0.01). VEGF was positively correlated to all clinical endpoints and significantly increased in peri-implantitis compared to both PIM and HI, but despite high specificity (96%), its overall diagnostic capacity was average. Two patient clusters were identified in peri-implantitis, one with 8-fold higher VEGF values compared to HI, and second with lower values comparable to PIM. SIGNIFICANCE: VEGF accurately reflects neovascularization in peri-implantitis that was expressed in contact zones toward implant surface without specific histopathological patter variation around TPs. VEGF answered requests for biomarker of peri-implantitis but further research is necessary to decrypt its exact underlying cause.

Red Light and 5% Aminolaevulinic Acid (5%) Inhibit Proliferation and Migration of Dysplastic Oral Keratinocytes via ROS Production: An In Vitro Study.

Undiagnosed and untreated oral precancerous lesions often progress into malignancies. Photodynamic therapy (PDT) might be a minimally invasive alternative to conventional treatments. 5-aminolevulinic acid (5-ALA) is one of the most commonly used photosensitizers in PDT, and it is effective on many cancer types. However, its hydrophilic characteristic limits cell membrane crossing. In the present study, the effect of a newly formulated gel containing 5% 5-ALA in combination with red light (ALAD-PDT) on a premalignant oral mucosa cell line was investigated. The dysplastic oral keratinocyte (DOK) cells were incubated with ALAD at different concentrations (0.1, 0.5, 1, and 2 mM) at two different times, 45 min or 4 h, and then irradiated for 7 min with a 630 nm LED (25 J/cm2). MTT assay, flow cytometry, wound healing assay, and quantitative PCR (qPCR) were performed. ALAD-PDT exerted inhibitory effects on the proliferation and migration of DOK cells by inducing ROS and necrosis. mRNA analysis showed modulation of apoptosis-related genes' expression (TP53, Bcl-2, survivin, caspase-3, and caspase-9). Furthermore, there was no difference between the shorter and longer incubation times. In conclusion, the inhibitory effect of the ALAD-PDT protocol observed in this study suggests that ALAD-PDT could be a promising novel treatment for oral precancerous lesions.

Antimicrobial and Osteogenic Effects of Collagen Membrane Decorated with Chitosan-Nano-Hydroxyapatite.

Collagen membranes are routinely used in oral surgery for bone regeneration. Despite their numerous advantages, such as stimulating bone growth, bacterial contamination still remains one of the disadvantages of membrane use. Thus, we assessed the biocompatibility and osteogenic and antibacterial properties of a collagen membrane (OsteoBiol) modified with chitosan (CHI) and hydroxyapatite nanoparticles (HApNPs). Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR FT-IR), X-ray powder diffraction (XRD), and field emission scanning electron microscopy (FE-SEM) were performed for membrane characterization. Biocompatibility was assessed on dental pulp stem cells (DPSCs) by an MTT assay, while the osteogenic effect was assessed by an ALP activity assay and qPCR analysis of osteogenic markers (BMP4, ALP, RUNX2, and OCN). Antimicrobial properties were investigated by counting colony-forming units (CFUs) of Streptococcus mitis, Porphyromonas gingivalis, and Fusobaterium nucleatum on membranes and in the surrounding medium. Membranes showed no cytotoxicity. ALP activity was higher and ALP, BMP4, and OCN genes were up-regulated in DPSCs on modified membranes compared to unmodified membranes. The CFUs were reduced on modified membranes and in the medium. Modified membranes showed great biocompatibility and a high osteoinductive effect. Additionally, they showed antimicrobial and antibiofilm effects against periopathogens. It can be concluded that the incorporation of CHI and hydroxyapatite nanoparticles in collagen membranes may be advantageous to promote osteogenesis and reduce bacterial adhesion.

Biofilm Formation on the Surfaces of CAD/CAM Dental Polymers.

Dental polymers are now available as monolithic materials which can be readily used in computer-aided design and computer-aided manufacturing (CAD/CAM) systems. Despite possessing numerous advantages over conventionally produced polymers, the polymers produced by either of these systems fail to exhibit immunity to surface microbial adhesion when introduced into the oral environment, leading to the development of oral diseases. The aim of this study was to analyze the biofilm formation of six microorganisms from the oral cavity and its correlation to the surface characteristics of CAD/CAM dental polymers. A total of ninety specimens were divided into three groups: resin-based composite, polymethyl methacrylate, and polyether ether ketone. The experimental procedure included surface roughness and water contact angle measurements, colony forming unit counting, and scanning electron microscopy analysis of biofilm formed on the surface of the tested materials. The data were analyzed using the Kruskal-Wallis test, with a Dunn's post hoc analysis, and one way analysis of variance, with a Tukey's post hoc test; the correlation between the measurements was tested using Spearman's correlation coefficient, and descriptive statistics were used to present the data. Despite using the same manufacturing procedure, as well as the identical manufacturer's finishing and polishing protocols, CAD/CAM dental polymers revealed significant differences in surface roughness and water contact angle, and the increased values of both parameters led to an increase in biofilm formation on the surface of the materials. The CAD/CAM resin-based composite showed the lowest number of adhered microorganisms compared to CAD/CAM polymethyl methacrylate and CAD/CAM polyether ether ketone.

Microbial adhesion and viability on novel CAD/CAM framework materials for implant-supported hybrid prostheses.

The aim of the study was to investigate the adhesion and viability of Streptococcus oralis and Candida albicans under in vitro conditions on CAD/CAM framework materials for implant-supported hybrid prostheses. Twenty-nine specimens were prepared from each of three different materials: ZR (zirconia), PEEK (polyether ether ketone) and CoCr4 (CoCr4 alloy). The experimental part included surface roughness (SR) and contact angle of water (CAW) measurements, followed by colony forming unit (CFU), cell viability assay and scanning electron microscopy (SEM) analyses of Strep. oralis and C. albicans biofilms on the materials' surfaces. Kruskal-Wallis and one-way analysis of variance (ANOVA) tests were used for differences between materials, and the correlation between measurements was estimated using Spearman's correlation coefficient. PEEK specimens revealed higher SR, CAW and CFU mean values, than ZR and CoCr4 specimens. Strong positive correlation was found between SR and CFU and between CAW and CFU for both microbial species. Cell viability assay revealed similar values for both species across materials. Higher numbers of Strep. oralis and C. albicans on PEEK specimens confirm the impact of the higher surface roughness and contact angle values on the microbial adhesion and describes PEEK as less desirable than ZR and CoCr4 from microbiological aspect.

Unraveling the Antibiofilm Activity of a New Nanogold Resin for Dentures and Epithesis.

Dentures and epitheses are mostly made from poly(methyl methacrylate) (PMMA), which does not show antimicrobial properties. They present reservoirs of microorganisms grown in biofilms. The aim of this study is to prepare a PMMA enriched with gold nanoparticles (AuNPs)-PMMA/AuNPs and the examination of its physical, mechanical and antimicrobial properties. The AuNPS were synthetized from HAuCl4 using the ultrasonic spray pyrolysis method with lyophilization. The PMMA/AuNP samples were compared to PMMA samples. Density was measured by pycnometer. Microhardness was evaluated using the Vickers hardness test. Monomicrobial biofilm formation (Streptococcus mitis, Candida albicans, Staphylococcus aureus and Escherichia coli) was measured by colony-forming units (CFUs) and MTT test and visualized by SEM. AuNP release was measured indirectly (the CFUs of the medium around the sample). The density and microhardness of the PMMA/AuNPs were similar to those of the PMMA. CFU and MTT values for the biofilms formed on the PMMA for each of the tested species were higher than those of the biofilms formed on the PMMA/AuNPs. The CFUs of the medium around the sample were similar for both materials. PMMA/AuNPs showed a significant reduction in the monomicrobial biofilms of all tested species. AuNPs are not released from PMMA/AuNPs. Density, indirect measurement of residual monomer and dentures weight were similar between PMMA and PMMA/AuNPs. Microhardness, as a measure of the wear resistance, was also similar between tested discs.

Antifungal Susceptibility of Candida albicans Isolated from Tongue and Subgingival Biofilm of Periodontitis Patients.

The subgingival biofilm, as the most complex microbial community, has been proven to be reservoir of Candida spp. The main concept of this study was to investigate if there is a difference between the sensitivity of Candida albicans (C. albicans) isolated from tongue and subgingival areas of periodontitis patients to antifungal agents. The aim of the study was to determine: (1) the distribution of different Candida species in the tongue and subgingival samples of periodontitis patients; (2) the susceptibility of Candida albicans strains from tongue and subgingival biofilm to the effects of commonly used antifungal agents: fluconazole, amphotericin B and itraconazole; (3) the correlation between the susceptibility of Candida albicans and clinical periodontal parameters. Tongue and subgingival biofilm samples of periodontitis subjects (N = 163) were examined. Susceptibility was tested when the same Candida species was isolated from both sites (17 subjects). Candida spp. were isolated in 23.3% of tongue and 21.5% of the subgingival samples. All isolates were susceptible to amphotericin B, while 64.71% of tongue and 52.94% of subgingival isolates were susceptible to fluconazole. A low frequency of itraconazole susceptibility was observed for tongue (17.64%) and subgingival isolates (11.76%). The correlations between full-mouth plaque score and Minimal Inhibitory Concentration (MIC) for tongue isolates were strongly positive for all antimycotics. Positive correlation was also observed between moderate periodontal destruction and MICs for tongue and subgingival isolates. The susceptibility of C. albicans to antifungals correlate with oral hygiene and moderate periodontal destruction. There is no difference in antifungal susceptibility between tongue and subgingival isolates.

Biocompatibility and antibiofilm activity of graphene-oxide functionalized titanium discs and collagen membranes.

The aims of the study were: 1) to evaluate the effect on biofilm formation of barrier membranes and titanium surfaces coated with graphene-oxide (GO); 2) to analyze the connection between the superficial topography of the tested materials and the amount of bacterial accumulation on them and 3) to analyze the biocompatibility of GO functionalized discs using the zebrafish model. METHODS: Single species bacterial biofilms (Streptococcus oralis, Veilonella parvula, Fusobacterium nucleatum, Porphyomonas gingivalis) were grown on GO-free membranes, membranes coated with 2 and 10 µg/ml of GO, GO-free and GO-coated titanium discs. The biofilms were analyzed by determining the CFU count and by Scanning Electron Microscopy (SEM) and the materials' topography by Atomic Force Microscopy (AFM). Zebrafish model was used to determine the materials' toxicity and inflammatory effects. RESULTS: AFM showed similar roughness of control and GO-coated materials. CFU counts on GO-coated discs were significantly lower than on control discs for all species. CFU counts of S. oralis, V. parvula and P. gingivalis were lower on biofilms grown on both types of GO-coated membranes than on GO-free membrane. SEM analysis showed different formation of single species biofilm of S. oralis on control and GO-coated materials. GO-functionalized titanium discs do not induce toxic or inflammatory effects. SIGNIFICANCE: Titanium implant surfaces functionalized with GO have shown to be biocompatible and less susceptible to biofilm formation. These results encourage further in vivo investigation of the tested materials on infection prevention, specifically in prevention and reduction of peri-implant mucositis and periimplantitis incidence.

Study on the immunopathological effect of titanium particles in peri-implantitis granulation tissue: A case-control study.

OBJECTIVES: To identify titanium particles (TPs) in biopsy specimens harvested from peri-implantitis lesions and secondarily to study the histopathological characteristics in peri-implantitis compared to periodontitis, in order to evaluate whether the presence of TPs could alter respective inflammatory patterns. MATERIAL AND METHODS: Biopsies containing granulation tissue were harvested during routine surgical treatment in 39 peri-implantitis cases and 35 periodontitis controls. Serial sections were obtained using titanium-free microtome blades. The first and last sections of the peri-implantitis specimens were used for identification of TPs by scanning electron microscopy coupled with dispersive X-ray spectrometry. Intermediate sections and periodontitis specimens were processed for descriptive histological study using haematoxylin-eosin staining and for immunohistochemical analysis using CD68, IL-6, Nf-kB and VEGF markers. RESULTS: TPs were identified in all peri-implantitis specimens as free metal bodies interspersed within granulation tissue. However, presence of macrophages or multinucleated giant cells engulfing the TPs were not identified in any specimen. Peri-implantitis granulations were characterized by a chronic inflammatory infiltrate rich in neutrophils. About half of peri-implantitis patients exhibited a subacute infiltrate characterized with lymphocytes interweaved with neutrophils and eosinophils. When compared to periodontitis, peri-implantitis tissues showed higher proportions of macrophages and a more intense neovascularization, based on significantly higher expression of CD68 and VEGF respectively. CONCLUSION: TPs were identified in all peri-implantitis specimens, but without evidencing any foreign body reaction suggestive for direct pathological effects of TPs. The peri-implantitis granulation tissue was characterized by intense neovascularization and presence of a chronic inflammatory infiltrate dominated by plasma cells, neutrophils and macrophages.

Periodontal Pathogens and Preterm Birth: Current Knowledge and Further Interventions.

Preterm labor is defined as a birth before 37 weeks of gestation and occurs in 5-20% of pregnancies. Preterm labor, as multifactorial entity associated with a high risk of neonatal morbidity and mortality, is influenced by maternal, fetal and environmental factors. Microbiological studies suggest that infectious pathogens may account for 25-40% of preterm birth. Infections of different sites, like genital, urinary tract infections, and pneumonia, are linked to the preterm labor. The most recent epidemiological studies consistently report that maternal periodontal disease is associated with preterm delivery, as well as the association between the presence of pathogenic oral bacteria in the placenta and adverse pregnancy outcomes. On the other hand, some previously published papers found periodontal bacteria in placentas of term pregnancies. In spite of a huge research done on the topic, both experimental and clinical, there are many controversial opinions about the role of periodontal infections in preterm birth. Thus, this comprehensive review addresses this very important topic and evaluates novel strategies of preventive and therapeutic approaches.

Cymbopogon citratus essential oil: an active principle of nanoemulsion against Enterococcus faecalis root canal biofilm.

Aim: The objective was to formulate and characterize the nanoemulsion based on Cymbopogon citratus oil, intended for use in infected teeth root canal therapy. The investigation of the antioxidant and antibiofilm potential toward Enterococcus faecalis was aimed as well. Materials & methods: Characterization of oil (by GC/MS analysis) and nanoemulsion (by dynamic light scattering instrument), and determination of antibacterial (by microdilution assay), antibiofilm (by crystal violet assay) and antioxidant properties (by 2,2-diphenyl-1-picryl-hydrazyl-hydrate and thiobarbituric acid assay methods) were provided. Antibiofilm efficacy of irrigation procedure including nanoemulsion was screened on extracted teeth (by CFU-counting assay). Results: Notable antibacterial and antibiofilm activity, both against forming and preformed biofilms of oil, was observed. Irrigation involved nanoemulsion showed remarkable antibiofilm potential. Both substances induced some antioxidant activity. Conclusion: Results encourage further research with the aim of application of the nanoemulsion in dental practice.

Subgingival areas as potential reservoirs of different Candida spp in type 2 diabetes patients and healthy subjects.

OBJECTIVES: The aim of this cross-sectional observational study was to compare the prevalence of different oral Candida spp. in patients with Type 2 Diabetes and chronic periodontitis in two oral sites: dorsal surface of the tongue and subgingival area. In order to determine subgingival areas as potential reservoirs of yeasts, this study aimed to find differences in the yeasts' detection between the dorsum of the tongue, as the oral site most commonly inhabited with microorganisms, and subgingival samples. Additionally, potential predictors for the yeasts prevalence were determined. MATERIAL AND METHODS: Subjects (N = 146) were divided into four groups: group A- healthy individuals without periodontitis, group B- healthy individuals with chronic periodontitis, group C- Type 2 Diabetes patients with good glycoregulation and Chronic periodontitis and group D- Type 2 Diabetes patients with poor glycoregulation and Chronic periodontitis. Samples were obtained from the tongue by swabbing. Subgingival plaque samples were taken by paper points and periodontal curette. Isolation and identification of different Candida spp. was done using ChromAgar medium. In addition, germ-tube production and carbohydrate assimilation tests were performed. RESULTS: The prevalence of Candida spp. was higher in diabetics with poor glycoregulation. The most frequently isolated species was Candida albicans followed by Candida glabrata and Candida tropicalis. In 15.6% of cases, Candida spp. was present in the subgingival area while absent on the tongue. Multivariate regression model showed that HbA1c was Candida spp. predictor for both locations. CONCLUSIONS: Our results confirmed that there are Candida spp. carriers among subjects with clinically healthy oral mucosa. Also, this study identified subgingival areas as potential reservoirs of these pathogenic species. Glycoregulation has been recognized as a positive predictor factor of Candida spp.

Laboratory-Based Investigation of Denture Sonication Method in Patients with Candida-Associated Denture Stomatitis.

PURPOSE: Denture stomatitis (DS) is a disease characterized by inflammation and erythema of the oral mucosa areas covered by the denture. Multifactorial etiological factors contribute to DS, but it seems that Candida plays the key role. The aim of the study was to evaluate the denture sonication method to: (i) increase the possibility of diagnosing patients with Candida-associated DS; (ii) detect and identify the mixed Candida spp., and (iii) determine the Candida colony forming units (CFU) and its possible relationship with DS severity, based on Newton's classification. MATERIALS AND METHODS: The cross-sectional study conducted at the Clinic for Dental Prosthetics, Belgrade (Serbia) from June 2013 to December 2014 enrolled edentulous patients with dentures (n = 250). Patients without DS (n = 20) were the control group (CG). The patients' data were collected, and patients with DS (study group/SG) were selected and divided into SG Candida+ and SG Candida-. Based on severity of DS, the SG patients were classified in 3 groups (Newton's classification). Four sampling methods were applied to detect patients with Candida-associated DS: mucosa swab, denture swab, oral rinse, and denture sonication method. The sensitivity and specificity of denture sonication method were shown using the receiver operating characteristic (ROC) curve and the area under the curve (AUC). RESULTS: In 97 (38.8%), out of 250 clinically examined patients, DS was diagnosed. In 82 (84.5%), out of 97 mycologically examined patients, Candida-associated DS was detected when denture sonication method was applied. Additionally, using the denture sonication method we observed: (i) the largest number of Candida positive patients compared to other sampling methods (p < 0.0001); (ii) the highest number of Candida CFU/ml (105 ), and (iii) the possibility to detect mixed Candida cultures. The largest number of patients with Candida-associated DS showed type II (60%) DS, followed by type I (21%), and type III (19%) DS. CONCLUSION: The denture sonication method is easy, accurate, and sensitive, and increases the possibility of diagnosing patients with Candida-associated DS. Additionally, yeast quantification, mixed Candida spp., and non-albicans Candida were detectable when cultivation on Candida CHROMagar was performed. It was not possible using conventional methods, such as swab or oral rinse.

The severity of denture stomatitis as related to risk factors and different Candida spp.

OBJECTIVES: 1) To select patients with Candida-related denture stomatitis (DS) and to study possible risk factors associated with DS, 2) to evaluate the severity of DS according to Newton's classification, and 3) to investigate the association between the presence of non-albicans Candida spp. (NAC) or mixed Candida spp. and the severity of DS. STUDY DESIGN: Eighty-two patients with Candida-positive DS have undergone 1) filling in the interview questionnaire, 2) clinical examination, and 3) microbiologic examination. RESULTS: A total of 113 Candida spp. isolates were obtained from Candida-positive DS patients: C. albicans (as a single species) in 47/82 (57%) patients (study group A [SG_A]) and NAC/mixed Candida spp. in 35/82 (43%) patients (SG_B). Univariate logistic regression analysis showed that older age, longer age of the mandibular denture, and ex-smoker status were associated with SG_A. A multivariate model revealed no significant predictor of DS severity. Patients from SG_A were 3 times as likely to have DS type I, while patients from SG_B were 4.9 times as likely to have DS type III. CONCLUSIONS: Our results show the association between type III of DS (by Newton's classification) and the presence of NAC or mixed Candida spp. in denture wearers.

Osteoblastic differentiating potential of dental pulp stem cells in vitro cultured on a chemically modified microrough titanium surface.

Titanium surface modification is critical for dental implant success. Our aim was to determine surfaces influence on dental pulp stem cells (DPSCs) viability and differentiation. Implants were divided into sandblasted/acid-etched (control) and sandblasted/acid-etched coated with calcium and magnesium ions (CaMg), supplied as composite (test). Proliferation was evaluated by MTT, differentiation checking osteoblastic gene expression, PGE2 secretion and matrix formation, inflammation by Interleukin 6 (IL-6) detection. MTT and IL-6 do not modify on test. A PGE2 increase on test is recorded. BMP2 is higher on test at early experimental points, Osterix and RUNX2 augment later. Alizarin-red S reveals higher matrix production on test. These results suggest that test surface is more osteoinductive, representing a start point for in vivo studies aiming at the construction of more biocompatible dental implants, whose integration and clinical performance are improved and some undesired effects, such as implant stability loss and further surgical procedures, are reduced.

The presence of periopathogenic bacteria in subgingival and atherosclerotic plaques - An age related comparative analysis.

INTRODUCTION: There is a known connection between periodontitis and atherosclerosis and the presence of periopathogens in blood vessels. However, changes of the oral microflora related to the aging process and its possible effects on atherosclerosis, have yet to be analyzed. The aim of this study was to assess temporal changes in the frequency of periodontal bacteria in the subgingival plaque and in atherosclerotic blood vessels of patients with atherosclerosis. METHODOLOGY: The study included 100 patients with atherosclerosis and periodontitis, divided into two groups, below and over 60 years of age. Clinical examinations were performedand subgingival plaque specimens were collected as well as biopsy specimens from the following arteries: coronary (34), carotid (29), abdominal (10), femoral (10), mammary (13) and iliac (4). Subgingival and artery specimens were subjected to PCR detection of 5 major periodontal pathogens: Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Aggregatibacter actinomycetemcomitans (Aa), Tannerella forsythensis (Tf) and Treponema denticola (Td). RESULTS: Tf was the most and Td the least frequent bacteria in both age groups and in both types of samples. The frequencies of bacteria in subgingival versus atherosclerotic samples were: Tf (76%:53%), Pi (71%:31%), Pg (60%:38%), Aa (39%:14%) and Td (21%:6%). Only Aa and Pi showed a significant difference of prevalence between younger and older patients. The most colonized artery was a. coronaria, followed by a. carotis, a. abdominalis, a. mammaria, and a. femoralis. CONCLUSIONS: Patient's age and the distance of a given blood vessel from the oral cavity influenced microbiological findings in the atherotic plaque.

P14 methylation: an epigenetic signature of salivary gland mucoepidermoid carcinoma in the Serbian population.

OBJECTIVE: To investigate the prevalence of p16INK4 a, p14ARF, tumor protein p53 (TP53), and human telomerase reverse transcriptase (hTERT) promoter hypermethylation in mucoepidermoid carcinomas (MECs) and search for a possible association between methylation status and clinicopathological parameters. STUDY DESIGN: DNA extracted from 35 formalin-fixed and paraffin-embedded MEC samples and 10 normal salivary gland (NSG) tissue samples was analyzed for the presence of promoter hypermethylation using methylation-specific polymerase chain reaction testing. RESULTS: The percentages of gene hypermethylation in MECs versus NSGs were the following: p14: 100% versus 20% (P<.001); p16: 60% versus 20% (P = .035); hTERT: 54.3% versus 20% (P = .078); and TP53: 31.4% versus 30% (P = .981). Multiple sites were found to be methylated in 86% of MECs compared with 10% in NSGs (P< .001). TP53 and hTERT were more often methylated in lower clinical stages (P = .033 and P = .005, respectively). CONCLUSIONS: Hypermethylation of p14 appears to be an important event in the development of mucoepidermoid carcinoma. High frequency of gene hypermethylation and high incidence of methylation at multiple sites point to the importance of epigenetic phenomena in the pathogenesis of MECs, although with modest impact on clinical parameters.

Immunohistochemical study of cyclin A and p16 expression in patients with renal cell carcinoma.

PURPOSE: Renal cell carcinoma (RCC) is the most common malignant kidney tumor in adults. Dysregulation of the cell cycle can lead to cancer development. In this study, the mitosis-associated cyclin A and p16, a negative controller, were investigated as potential key points in the RCC development. METHODS: This retrospective study included 74 patients with RCC. The expression of cyclin A and p16 and their correlation to histopathological parameters (TNM stage, histological subtype, nuclear grade, tumor size), gender, age, and clinical outcome were studied and analyzed. RESULTS: The highest median value for cyclin A (40%; range 0-70)) and for p16 (57.5%); range 35-80) were found in the papillary histological subtype. Survival analysis showed that in the group of patients that had died before September 2015, the median value for cyclin A was 20% (range 0-60), which was significantly higher than 5% (range 0-70), found in the group of patients that survived (p=0.019). CONCLUSIONS: In relation to the histological subtype, the papillary type of RCC was associated with a significantly higher expression of cyclin A and p16 compared to other subtypes of RCC. High expression of cyclin A indicated worse prognosis, therefore cyclin A could be considered to be a significant prognostic marker.

Graphene oxide improves the biocompatibility of collagen membranes in an in vitro model of human primary gingival fibroblasts.

Commercial collagen membranes are used in oral surgical procedures as scaffolds for bone deposition in guided bone regeneration. Here, we have enriched them with graphene oxide (GO) via a simple non-covalent functionalization, exploiting the capacity of oxygenated carbon functional moieties of GO to interact through hydrogen bonding with collagen. In the present paper, the GO-coated membranes have been characterized in terms of stability, nano-roughness, biocompatibility and induction of inflammatory response in human primary gingival fibroblast cells. The obtained coated membranes are demonstrated not to leak GO in the bulk solution, and to change some features of the membrane, such as stiffness and adhesion between the membrane and the atomic force microscopy (AFM) tip. Moreover, the presence of GO increases the roughness and the total surface exposed to the cells, as demonstrated by AFM analyses. The obtained material is biocompatible, and does not induce inflammation in the tested cells.

Polymorphisms of survivin -31 G/C gene are associated with risk of urothelial carcinoma in Serbian population.

PURPOSE: Survivin is thought to play an important role in carcinogenesis and is found to be associated with poor clinical outcome in various malignancies. Gene -31 G/C polymorphism has been identified as a risk factor for the development of several types of tumors. The purpose of this study was to investigate the association between survivin gene promoter -31C/G polymorphism and urothelial carcinoma (UC) risk in Serbian population and to compare the different expressions of survivin in UC of different disease stages, histological grades and tumor location in the upper or lower urinary tract. METHODS: DNA from 94 patients with primary UC and from 82 healthy subjects was subjected to PCR restriction fragment length polymorphism analysis (PCR-RFLP) to identify individual genotypes. UC samples were subjected to immunohistochemical analysis to assess survivin expression in these lesions. RESULTS: It was observed that the frequency of G/G genotype was greater in patients with UC (58.7%) than in controls (32%). Compared with study subjects carrying the C/G or C/C genotypes, significantly increased UC risk was found for individuals carrying the G/G genotype. Those carrying the G/G genotype had a significantly increased UC risk compared with those with C/G or C/C genotypes. Patients with UC carrying the G/G genotype had a greater prevalence of muscle-invading (stage T2-T4), high-grade (G2) tumor and immunohistochemicaly overexpressed survivin compared with those carrying the C/G or C/C genotypes. CONCLUSIONS: G/G genotype of the -31C/G polymorphism might be a risk factor for UC development.