Proliferative verrucous and homogeneous Leukoplakias exhibit differential methylation patterns.

OBJECTIVE: Proliferative verrucous leukoplakia (PVL) is considered a clinically distinct entity from other oral leucoplakias (OLs) due to its clinical presentation and evolution. However, molecular differences between them remain unclear. We aimed to determine whether there are methylation differences between PVL and other forms of OLs. MATERIALS AND METHODS: Oral biopsies from 12 patients with PVL, eight patients with homogeneous leucoplakia (HL), and 10 healthy individuals were obtained for a genome-wide DNA methylation analysis via the Infinium EPIC Platform. RESULTS: A total of 1815 differentially methylated CpGs were found between PVL and HL, with a prominent state of hypermethylation in HL patients. CpGs covered 813 genes with distinct roles, including cell adhesion, extracellular matrix organization, and cell and synaptic signaling. 43% of these genes had been previously described in cancer and associated with prognosis. We developed a multinomial logistic regression model able to differentiate HL, PVL, and control samples. The model had a cross-validated estimate of 73% and included differentially methylated cancer-related genes between the pathological conditions and the healthy donors, including ADNP, BRCA2, CDK13, GNB1, NIN, NUMB, PIK3C2B, PTK2, SHISA4, THSD7B, WWP1, and ZNF292. It also included CpGs covering differentially methylated genes in HL (MEN1 and TNRC6B) and PVL (ACOXL, ADH1B, CAMTA1, CBFA2T3, CPXM2, LRFN2, SORCS2, and SPN). CONCLUSIONS: PVL and HL present differential methylation patterns that could be linked to their differential clinical behavior. Our findings show the potential of methylation markers and suggest novel diagnostic biomarkers.

Quantitative proteomics in medication-related osteonecrosis of the jaw: A proof-of-concept study.

OBJECTIVE: Medication-related osteonecrosis of the jaw (MRONJ) is a paradoxical effect associated with bone-modifying agents (BMAs) and other drugs. Currently, no valuable diagnostic or prognosis biomarkers exist. The goal of this research was to study MRONJ-related salivary proteome. MATERIALS AND METHODS: This case-control aimed to study salivary proteome in MRONJ versus control groups (i) formed from BMAs consumers and (ii) healthy individuals to unravel biomarkers. Thirty-eight samples of unstimulated whole saliva (18 MRONJ patients, 10 BMA consumers, and 10 healthy controls) were collected. Proteomic analysis by SWATH-MS coupled with bioinformatics analysis was executed. RESULTS: A total of 586 proteins were identified, 175 proteins showed significant differences among MRONJ versus controls. SWATH-MS revealed differentially expressed proteins among three groups, which have never been isolated. These proteins had distinct roles including cell envelope organization, positive regulation of vesicle fusion, positive regulation of receptor binding, or regulation of low-density lipoprotein particle clearance. Integrative analysis prioritized 3 proteins (MMP9, AACT, and HBD). Under receiver-operating characteristic analysis, this panel discriminated MRONJ with a sensitivity of 90% and a specificity of 78.9%. CONCLUSION: These findings may inform a novel biomarker panel for MRONJ prediction or diagnosis. Nonetheless, further research is needed to validate this panel.

Effect of clinical and histologic features on time to malignancy in 224 cases of oral leukoplakia treated by surgery.

OBJECTIVES: Our main purpose and research question were to analyze and quantify whether there were significant differences in the time to develop cancer among patients with oral leukoplakia (OL), comparing the more susceptible cases to those with the least susceptibility to malignancy. MATERIALS AND METHODS: We followed 224 cases of OL after surgical or CO2 laser treatment for a mean time of 6.4 years. A Bayesian mixture cure model based on the Weibull distribution was used to model the relationship between our variables and cancer risk. In this model type, the population is considered a mixture of individuals who are susceptible or non-susceptible to developing cancer. The statistical model estimates the probability of cure (incidence model) and then infers the time to malignancy. The model was adjusted using the R-package INLA using default priors. RESULTS: Histology type (moderate or severe dysplasia) and tongue location showed hazard ratios (HR) of 3.19 (95% CI [1.05-8.59]) and 4.78 (95% CI [1.6-16.61]), respectively. Both variables increased the risk of malignant transformation, thus identifying a susceptible subpopulation with reduced time required to develop cancer, as with non-homogeneous leukoplakias. The median time for cancer development was 4 years and 5 months, with a minimum of 9 months after the diagnosis of OL and a maximum of 15 years and 2 months. CONCLUSIONS: Susceptible patients with non-homogeneous leukoplakia, dysplasia, or leukoplakia in the tongue develop cancer earlier than those with homogeneous OL and those without dysplasia. CLINICAL RELEVANCE: The novel contribution of this research is that, until now, the time it took for oral leukoplakias to develop cancer based on whether they were homogeneous or non-homogeneous, and if they have or not epithelial dysplasia, had not been comparatively described and quantified. As a final result, the time to malignant transformation in non-homogeneous and dysplastic leukoplakias is significantly shorter.

Recurrences following treatment of proliferative verrucous leukoplakia: A systematic review and meta-analysis.

BACKGROUND: A systematic review and meta-analysis were made of the incidence of recurrences in patients with proliferative verrucous leukoplakia (PVL) subjected to different types of treatment. METHODS: The study was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines. A literature search was made in the Medline (PubMed), EMBASE, and Web of Science databases, together with a manual search, covering the period from 1985 to January 2020, with no language restrictions. Studies were included if they described treatments applied to at least 10 patients with the corresponding outcomes. Methodological quality was evaluated using Jadad scale and Newcastle-Ottawa tool. Global incidence was calculated by random effects meta-analysis using the Comprehensive Meta-analysis version 3.0 software. Publication bias was assessed using funnel plots and the Duval and Tweedie trim and fill method. RESULTS: Of the 922 identified articles, 12 were found to meet the inclusion criteria. Most of them presented moderate or low risk of bias. A total of 397 patients were analyzed. The mean age was 62.34 years and 248 were women (62.5%). The mean follow-up was 79.3 months. The most frequent treatment was surgical removal with a cold scalpel or laser (339 patients). A total of 232 subjects presented lesion recurrence. The combination of proportions global effect meta-analysis yielded a recurrence rate of 67.2% (95% CI: 48.3-81.8), with the absence of publication bias. CONCLUSIONS: There is not enough scientific evidence to conclude that any treatment strategy is able to reduce the recurrence in PVL.

Immune expression profile identification in a group of proliferative verrucous leukoplakia patients: a pre-cancer niche for oral squamous cell carcinoma development.

OBJECTIVES: To explore the pathophysiology of proliferative verrucous leukoplakia, a rare oral disorder that exhibits high rates of recurrence and malignant transformation, through a RNAseq case-control study. MATERIAL AND METHODS: We obtained oral biopsies from 10 patients with verrucous leukoplakia lesions and from the mucosa of 5 healthy individuals for sequencing using RNAseq technology. Using bioinformatic methods, we investigated gene expression and enrichment differences between patients both with and without the disorder. We applied network biology methods to investigate functional relations among those genes that were differentially deregulated. RESULTS: We detected 140 differentially expressed genes with distinct roles in immune surveillance, tissue and organ morphogenesis, development, and organization. Of these 140 genes, 111 have been previously described as cancer expression biomarkers, being oral squamous cell carcinoma the most represented type of cancer among them. Of these 140 genes, 26 were prioritized for further investigation as biomarkers using larger sample sizes. CONCLUSIONS: The gene expression patterns of healthy and unhealthy patients differed in 140 genes whose deregulation has a functional impact on normal functioning of the immune system. This immune expression profile provides a plausible hypothesis to explain the transformation to oral squamous cell carcinoma observed in 6 of the 10 assayed cases. CLINICAL RELEVANCE: By determining the molecular bases of the proliferative verrucous leukoplakia disorder and identifying early biomarkers of malignancy, this can allow us to develop new treatment strategies.

Second primary tumors in proliferative verrucous leukoplakia: a series of 33 cases.

OBJECTIVES: To describe the number of second primary malignancies in a series of 33 patients with proliferative verrucous leukoplakia (PVL), detailing the mean time between primary malignancies and their clinical characteristics. MATERIALS AND METHODS: Two groups of patients were included in this study: group 1 comprised 33 PVL patients who had developed ≥ 2 oral squamous cell carcinoma (OSCC) and group 2 comprised 48 PVL patients without malignant degeneration. We compared the groups with regard to age, gender, oral location, and number of oral sites affected. For patients in group 1, we determined the locations, clinical forms, and TNM stages of oral cancers. We also recorded the intervals of time between instances of oral cancer for all patients. RESULTS: The groups did not differ significantly in age; however, group 1 included more women (p < 0.05). The follow-up period and number of oral PVL locations were greater in group 1 (p < 0.01). Moreover, in group 1, as the number of OSCCs increased, the intervals between them became shorter. The gingiva was the most common site. The mean number of cancers in group 1 was 3.15; five second primary tumors were diagnosed in one patient. CONCLUSIONS: Multiple cancers in PVL patients were more frequently located on the gingiva in the form of erythroleukoplastic areas. In addition, the interval between new cancers decreased over time. CLINICAL RELEVANCE: This is the series with the highest number of cases described with second primary tumors in PVL.

Oral manifestations of rheumatoid arthritis. A cross-sectional study of 73 patients.

OBJECTIVE: A study is made of the main oral manifestations of patients with rheumatoid arthritis (RA), particularly salivary flow, and of its possible association to periodontal disease. MATERIAL AND METHODS: A prospective comparative study was made of 146 patients (73 with RA and 73 controls), recording pocket depth, clinical attachment loss, bleeding index, plaque index, and the DMFT index to assess periodontal and dental alterations. Sialometric measurements were also made to determine resting, stimulated, and parotid salivary flow. RESULTS: The patients with RA had greater periodontal pocket depths (with moderate depths in most cases), as well as greater attachment loss and more bacterial plaque. The resting whole saliva and stimulated parotid saliva rates were also clearly decreased in the RA group compared with the controls. CONCLUSIONS: Patients with RA are more likely to present periodontal disease, poorer oral hygiene manifesting as an increased accumulation of bacterial plaque, and decreased salivary flow rates. CLINICAL RELEVANCE: Vulnerability to periodontitis is confirmed in one of the largest samples ever studied of patients with rheumatoid arthritis (RA). Also, there is evidence of hyposialia (decrease in salivary rate) in RA patients without Sjögren's syndrome.

Salivary and serum interleukin-6 levels in proliferative verrucous leukoplakia.

BACKGROUND: Cytokines and chemokines have been analysed in patients with oral squamous cell carcinoma and potentially malignant disorders. We selected interleukin-6 (IL-6) because it is a multifunctional interleukin reported to be altered in potentially malignant oral disorders and in malignant lesions. To date, this has not been evaluated or tested in proliferative verrucous leukoplakia (PVL), however. OBJECTIVES: This study aimed to analyse the differences in serum and saliva IL-6 levels among patients with PVL, oral squamous cell carcinoma (OSCC) and healthy controls and to examine the relationship between salivary IL-6 levels and the extent of the verrucous area. METHODS: Using an enzyme-linked immunosorbent assay, we determined the serum and saliva IL-6 levels in three groups: 20 patients with PVL, 20 with OSCC and 20 healthy controls. RESULTS: There were significant (p < 0.01) differences in the serum and saliva IL-6 levels among the three groups and among the three grades of extent of the verrucous areas (p = 0.01). In the OSCC group, there was a significant difference in the saliva IL-6 levels between patients with and without lymph node metastasis at diagnosis (p = 0.02). CONCLUSIONS: We found that patients with OSCC had the highest salivary and serum IL-6 levels, while PVL had lower values than OSCC, but higher than the controls, and these altered levels were associated with the extent of the verrucous areas. CLINICAL RELEVANCE: Salivary and plasma IL-6 are altered in patients with PVL, with more extensive verrucous areas being associated to the highest IL-6 levels. This could be a significant tool for monitoring patients with PVL, their progression to more advances stages and their recurrences.

Prevalence of salivary Epstein-Barr virus in potentially malignant oral disorders and oral squamous cell carcinoma.

BACKGROUND: To analyze the presence of salivary Epstein-Barr virus (EBV) DNA in oral squamous cell carcinoma and potentially malignant oral disorders. MATERIAL AND METHODS: Three groups were studied: Group 1 (12 oral squamous cell carcinomas (OSCC)), Group 2 (12 potentially malignant oral disorders (PMD)) and Group 3 (47 healthy controls). EBV DNA salivary analysis was performed by PCR. RESULTS: The highest percentage of positive salivary EBV DNA corresponded to the OSCC group (58.3%), followed by the PMD group (41.7%) and the controls (40.4%). The differences between groups were not statistically significant, however (p>0.05). CONCLUSIONS: Salivary EBV DNA was more prevalent in OSCC than in PMD or the controls.

Extra-nodal B-cell non-Hodgkin's lymphomas of the head and neck: a study of 68 cases.

OBJECTIVES: The objectives of this study are to describe the distinctive characteristics of extra-nodal B-cell non-Hodgkin's lymphomas (BNHLs) located in the head and neck in a series of patients, to discuss patient survival, and to compare the oral versus the non-oral locations of the extra-nodal BNHLs of the head and neck. MATERIAL AND METHODS: We studied 68 patients with BNHL of the head and neck. We analyzed the clinical and survival characteristics. Additionally, we performed Kaplan-Meier and Cox regression analyses to determine the influence of the different factors on survival. RESULTS: This study included 68 non-nodal lymphomas; 30 lymphomas (31.9%) were located intraorally, with the gingiva as the most frequent location. The oral lymphomas in stages 1 and 2 showed a prevalence of 60% (18/30). The Kaplan-Meier analysis showed that the stage of disease and the oral versus non-oral extranodal lymphomas were significant prognostic factors (p<0.05). However, the multivariate Cox analysis indicated that only complete remission and oral versus non-oral location were significant prognostic factors (p<0.01). CONCLUSIONS: The gingiva was the most common location of the intraoral lymphomas. Complete remission and non-oral location were the only significant survival factors in the multivariate Cox regression analysis.

Palatal positioned implants in severely atrophic maxillae versus conventional implants to support fixed full-arch prostheses: Controlled retrospective study with 5 years of follow-up.

BACKGROUND: To evaluate soft tissue conditions and bone loss around palatal positioned implants supporting fixed full-arch prostheses to rehabilitate edentulous maxillae with horizontal atrophy and compare them with conventional well-centered implants placed in non-atrophic maxillae after a minimum follow-up of 5 years. MATERIAL AND METHODS: A clinical retrospective study was performed of patients that were rehabilitated with full-arch fixed implant-supported maxillary prostheses and had a minimum follow-up of 5 years after implant loading. Patients were divided into 2 groups: patients with class IV maxilla according to Cawood and Howell and treated with palatal positioned implants (test) and with class III maxilla and treated with implants well-centered in the alveolar ridge and completely surrounded by bone (control). The following variables were assessd: age, sex, frequency of toothbrushing, smoking, type of prosthesis, type of implant, implant success, amount of buccal keratinized mucosa, buccal retraction, probing depth, plaque index, modified bleeding index, presence of mucositis or peri-implantitis and peri-implant bone loss. Statistical analysis was performed applying Chi2 Test and Student's t-test using alpha set at 0.05. RESULTS: A total of 57 patients were included: 32 patients with 161 palatal positioned implants (test) and 25 patients with 132 well centered implants (control). No statistically significant differences were found regarding age, sex and smoking, but test group patients reported a significantly higher frequency of daily toothbrushing. Implant success rates were 96.9% for test group implants and 96.0% for control group implants. Peri-implant mucosa retraction was significantly higher in the control group than in the test group (p=0,017). No significant differences were observed either for all the other assessed clinical parameters or for peri-implant bone loss. CONCLUSIONS: Despite its limitations the outcomes of the present study suggest that palatal positioned implants may be a good treatment alternative for patients with severe horizontal maxillary alveolar bone atrophy. Palatal positioned implants presented similar success rates, soft tissue conditions and peri-implant bone loss than well-centered implants placed completely surrounded by bone in non-atrophic ridges.

Does HIV infection have an impact upon dental implant osseointegration? A systematic review.

OBJECTIVE: A systematic review is made to determine whether human immunodeficiency virus (HIV) infection has an impact upon dental implant osseointegration. STUDY DESIGN: A PubMed (MEDLINE) literature search was made of articles published up until 14 April 2014. The systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). The quality of the studies included in the review was assessed using the Methodological Index for Nonrandomized Studies (MINORS) and levels of evidence (based on the University of Oxford's Center for Evidence Based Medicine criteria). RESULTS: The combinations of search terms resulted in a list of 132 titles. Nine studies finally met the inclusion criteria and were selected for inclusion in the systematic review. A total of 173 dental implants were placed in 80 patients (135 implants in 56 HIV-positive subjects and 38 implants in 24 HIV-negative patients), and a single loss of dental implant osseointegration was recorded in an HIV-positive patient. CONCLUSIONS: Our results suggest that dental implant placement in HIV-positive patients does not increase the dental implant failure rate. Prophylactic antibiotic treatment, the administration of highly active antiretroviral therapy, and control of the CD4+ T lymphocyte counts appear to be the main influencing factors in this respect. Given the few studies included in our systematic review, further prospective studies involving larger sample sizes and longer durations of follow-up are required in order to confirm the results obtained.

Oxidative stress in bisphosphonate-related osteonecrosis of the jaws.

OBJECTIVES: To analyze whether oxidative stress (OS) changes are present in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ) versus controls. MATERIALS AND METHODS: Oxidative stress was analyzed in serum and unstimulated saliva of three groups: Group 1 consisted of 24 patients who had been treated with intravenous bisphosphonates (ivBPs) and developed BRONJ, group 2 consisted of 20 patients who had received ivBPs and did not develop BRONJ, and group 3 comprised 17 control subjects. Reduced glutathione (GSH), malondialdehyde (MDA), oxidized glutathione (GSSG), and 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxo-dG) levels, as well as the GSSG/GSH ratio, were measured. RESULTS: Mean serum and saliva levels of MDA, GSSG, and 8-oxo-dG and the GSSG/GSH ratio were significantly higher in patients with BRONJ than in controls. We found no significant difference in OS according to BRONJ stage, sex, or location in the jaws. Logistic regression analysis revealed that the GSSG/GSH ratio was a significant factor predicting the development of BRONJ (P = 0.01). CONCLUSIONS: Oxidative stress was detected in patients with BRONJ, and the GSSG/GSH ratio was the most significant OS variable found; it was a significant factor predicting the development of BRONJ.

Oxidative stress and recurrent aphthous stomatitis.

OBJECTIVES: This study analyzed the oxidative stress status in patients with recurrent aphthous stomatitis (RAS) in the presence and absence of active ulceration. MATERIAL AND METHODS: Oxidative stress was analyzed in peripheral mononuclear cells of 28 RAS patients with active ulceration and 29 controls. A further blood sample was collected from nine subjects randomly selected from the 28 RAS cases, during the period in which the patients did not have active oral ulceration. The reduced glutathione (GSH), malondialdehyde (MDA), and oxidized glutathione (GSSG) levels were measured in these samples. RESULTS: The mean MDA and GSSG levels were significantly higher in patients with active RAS than in the controls, while GSH was lower in the RAS group (p < 0.01). There was a nonsignificant tendency toward higher MDA and GSSG levels in patients with major RAS compared with minor RAS. On comparing the serum findings in the nine RAS patients in the presence and absence of lesions, the presence of ulceration was associated with even higher MDA and GSSG levels and lower GSH concentrations (p < 0.05) CONCLUSIONS: Oxidative stress was detected in our RAS patients.

Impression of multiple implants using photogrammetry: description of technique and case presentation.

AIM: To describe a technique for registering the positions of multiple dental implants using a system based on photogrammetry. A case is presented in which a prosthetic treatment was performed using this technique. STUDY DESIGN: Three Euroteknika® dental implants were placed to rehabilitate a 55-year-old male patient with right posterior maxillary edentulism. Three months later, the positions of the implants were registered using a photogrammetry-based stereo-camera (PICcamera®). After processing patient and implant data, special abutments (PICabutment®) were screwed onto each implant. The PICcamera® was then used to capture images of the implant positions, automatically taking 150 images in less than 60 seconds. From this information a file was obtained describing the relative positions - angles and distances - of each implant in vector form. Information regarding the soft tissues was obtained from an alginate impression that was cast in plaster and scanned. A Cr-Co structure was obtained using CAD/CAM, and its passive fit was verified in the patient's mouth using the Sheffield test and the screw resistance test. RESULTS AND CONCLUSIONS: Twelve months after loading, peri-implant tissues were healthy and no marginal bone loss was observed. The clinical application of this new system using photogrammetry to record the position of multiple dental implants facilitated the rehabilitation of a patient with posterior maxillary edentulism by means of a prosthesis with optimal fit. The prosthetic process was accurate, fast, simple to apply and comfortable for the patient.

Single-blind randomized clinical trial to evaluate clinical and radiological outcomes after one year of immediate versus delayed implant placement supporting full-arch prostheses.

PURPOSE: To evaluate and compare peri-implant health, marginal bone loss and success of immediate and delayed implant placement for rehabilitation with full-arch fixed prostheses. MATERIAL AND METHODS: The present study was a prospective, randomized, single-blind, clinical preliminary trial. Patients were randomized into two treatment groups. In Group A implants were placed immediately post-extraction and in Group B six months after extraction. The following control time-points were established: one week, six months and twelve months after loading. Measurements were taken of peri-implant crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of mucositis. Implant success rates were evaluated for the two groups. The study sample included fifteen patients (nine women and six men) with a mean average age of 63.7 years. One hundred and forty-four implants were placed: 76 placed in healed sites and 68 placed immediately. RESULTS: At the moment of prosthetic loading, keratinized mucosa width and probing depth were higher in immediate implants than delayed implants, with statistically significant differences. However, after six and twelve months, differences between groups had disappeared. Bone loss was 0.54 ± 0.39 mm for immediate implants and 0.66 ± 0.25 mm for delayed implants (p=0.201). No implants failed in either group. CONCLUSIONS: The present study with a short follow-up and a small sample yielded no statistically significant differences in implant success and peri-implant marginal bone loss between immediate and delayed implants with fixed full-arch prostheses. Peri-implant health showed no statistically significant differences for any of the studied parameters (crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of mucositis) at the twelve-month follow-up.

Bisphosphonates-related osteonecrosis of the jaws: a preliminary study of salivary interleukins.

OBJECTIVE: The aim of this preliminary study was analyze the possible alterations in some salivary interleukins, usually associated with the inflammatory processes. MATERIAL AND METHODS: The study comprised three groups: group 1, with 26 cases with bisphosphonates-related osteonecrosis of the jaws (BRONJ). Group 2, with 29 patients who had received iBF but without BRONJ. Group 3, with 26 control patients not treated with BF and without oral lesions. We collected unstimulated whole saliva in all groups. A semiquantitative study was performed based on a cytokine array panel. We used the proteome profiler array for the study. We analyzed: Interleukin 1 alpha (IL-1α), interleukin-1 receptor antagonist (IL-1RA), and interleukin 1 beta (IL-1ß). RESULTS: We found higher salivary values for all the cytokines studied in group 1 than in group 2 and 3. IL-1ß showed the major differences compared with control group. (P < 0.05) CONCLUSIONS: This preliminary study confirms that there are alterations in these interleukins in patients with BRONJ. These results give support to further additional salivary studies on these biomarkers by quantitative measures.

Oxidative Stress and DNA Damage in Human Gastric Carcinoma: 8-Oxo-7'8-dihydro-2'-deoxyguanosine (8-oxo-dG) as a Possible Tumor Marker.

We characterized the oxidative stress (OS) status by the levels of reduced/oxidized glutathione (GSH/GSSG), malondialdehyde (MDA) and the mutagenic base 8-oxo-7'8-dihydro-2'-deoxyguanosine (8-oxo-dG) in human gastric carcinoma (HGC) samples and compared the results with normal tissue from the same patients. We also analyzed 8-oxo-dG in peripheral mononuclear cells (PMNC) and urine from healthy control subjects and in affected patients in the basal state and one, three, six, nine and twelve months after tumor resection. The levels of DNA repair enzyme mRNA expression (hOGG1, RAD51, MUYTH and MTH1) were determined in tumor specimens and compared with normal mucosa. Tumor specimens exhibited increased levels of MDA and 8-oxo-dG compared with normal gastric tissue. GSH levels were also increased, while GSSG levels remained stable. DNA repair enzyme mRNA expression was induced in the tumor tissues. Levels of 8-oxo-dG were significantly elevated in both urine and PMNC of gastric cancer patients compared with healthy controls. After gastrectomy, the levels of the damaged base in urine and PMNC decreased progressively to values close to those found in the healthy population. The high levels of 8-oxo-dG in urine may be related to the increased induction of DNA repair activity in tumor tissue, and the changes observed after tumor resection support its potential use as a tumor marker.

Epidermal growth factor receptor copy number in potentially malignant oral disorders and oral squamous cell carcinoma: a short communication and preliminary study.

INTRODUCTION: This preliminary study compared the epidermal growth factor receptor (EGFR) copy number in patients with potentially malignant oral disorders (PMODs) and oral squamous cell carcinoma (OSCC). MATERIAL AND METHODS: Group 1 comprised 20 patients with oral leukoplakia and group 2 comprised 19 cases of OSCC. We estimated the EGFR copy number in both groups using real-time reverse-transcription polymerase chain reaction assays. We used laser microdissection (LMD) for EGFR amplification, and overexpression was performed. RESULTS: The EGFR copy number was higher in group 2 (9.1 ± 6.2) than in group 1 (3.8 ± 1.5). The greatest copy number was found in the non-homogeneous leukoplakias, but the difference in homogeneous cases was not significant (Mann-Whitney test, P>0.05). In group 2, the EGFR copy number was higher in advanced stages than in early stages, but again lacked statistical significance. CONCLUSIONS: The EGFR copy number may be a useful biomolecular marker to differentiate PMODs from OSCC. The EGFR was higher in non-homogeneous leukoplakias and in the advanced stages of OSCC.

Cytological changes in the oral mucosa after use of a mouth rinse with alcohol. A prospective double blind control study.

AIM: The aim of this preliminary study was to detect cytological changes in the oral mucosa after using a mouth wash with alcohol. MATERIAL AND METHODS: A prospective double-blind, controlled study was performed, for 6 months. Group 1 consisted of 30 subjects who used a mouth rinse with 26.9% of alcohol [Listerine] and Group 2 consisted of 30 subjects who used a mouth rinse with the same ingredients but with no alcohol. We obtained three cytological samples from the oral mucosa. The presence of cytological atypia, binucleation and karyorrhesis, and type of cells were studied. We also used a fluorescent in situ hybridization technique (FISH) in 15 samples in each group, for the micronucleus. RESULTS: We found no clinical mucosal alteration after using the mouth wash at the end of the study in either group. We observed no cytological differences between the groups at the end of the study (p>0.05). Regarding the study of the micronucleus by FISH, we observed no significant difference between the groups (p>0.05). CONCLUSIONS: Our results showed no cytological alteration in patients using a mouth rinse with alcohol, but these findings should be considered preliminary results, to be confirmed in a greater sample of patients.