Leticia Bagan

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.

Malignant transformation of proliferative verrucous leukoplakia to oral squamous cell carcinoma: A series of 55 cases

In this study, we compared clinical differences between patients with proliferative verrucous leukoplakia (PVL) who did and did not develop oral cancer. This was a retrospective study of 55 PVL cases. All patients were followed for at least 1year, with a mean follow-up of 7.53 (SD=4.18) years. The mean age of the patients was 61.69 (SD=11.76) years. There were 36 (65.5%) females and 19 (34.5%) males. Group 1 included the 28 PVL patients who did not develop oral squamous cell carcinoma (OSCC) during the period. Group 2 included the 27 PVL patients who developed at least one OSCC during the period. The latter group was subdivided into patients with PVL who developed one (Subgroup 2a; n=16) or more than one (Subgroup 2b; n=11) OSCC during follow-up. There was no statistical difference in age or oral location of the PVL between Groups 1 and 2. Females had a greater tendency to develop cancer than males (58.3% vs. 31.6%). In Group 2, only six (22.2%) were smokers. There was no difference between Subgroups 2a and b in terms of age, gender, and oral location of the PVL. Subgroup 2b included fewer smokers, had higher gingival involvement rate, and lower frequency of PVL on the tongue. The PVL patients who develop oral cancers were more commonly female and non-smokers. Those patients who developed more than one OSCC were most likely to develop lesions of the gingiva.

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-1β). RESULTS We found higher salivary values for all the cytokines studied in group 1 than in group 2 and 3. IL-1β 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.

Soft tissue cell adhesion to titanium abutments after different cleaning procedures: Preliminary results of a randomized clinical trial

Objectives: A randomized controlled trial was performed to assess soft tissue cell adhesion to implant titanium abutments subjected to different cleaning procedures and test if plasma cleaning can enhance cell adhesion at an early healing time. Study Design: Eighteen patients with osseointegrated and submerged implants were included. Before re-opening, 18 abutments were divided in 3 groups corresponding to different clinical conditions with different cleaning processes: no treatment (G1), laboratory customization and cleaning by steam (G2), cleaning by plasma of Argon (G3). Abutments were removed after 1 week and scanning electron microscopy was used to analyze cell adhesion to the abutment surface quantitatively (percentage of area occupied by cells) and qualitatively (aspect of adhered cells and presence of contaminants). Results: Mean percentages of area occupied by cells were 17.6 ± 22.7%, 16.5 ± 12.9% and 46.3 ± 27.9% for G1, G2 and G3 respectively. Differences were statistically significant between G1 and G3 (p=0.030), close to significance between G2 and G3 (p=0.056), and non-significant between G1 and G2 (p=0.530). The proportion of samples presenting adhered cells was homogeneous among the 3 groups (p-valor = 1.000). In all cases cells presented a flattened aspect; in 2 cases cells were less efficiently adhered and in 1 case cells presented filipodia. Three cases showed contamination with cocobacteria. Conclusions: Within the limits of the present study, plasma of Argon may enhance cell adhesion to titanium abutments, even at the early stage of soft tissue healing. Further studies with greater samples are necessary to confirm these findings. Key words:Connective tissue, dental abutments, randomized controlled trial, clinical research, glow discharged abutment, plasma cleaning.

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

ObjectiveA 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 methodsA 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.ResultsThe 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.ConclusionsPatients 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 relevanceVulnerability 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.

A Classification Proposal for Peri-Implant Mucositis and Peri-Implantitis:A Critical Update

Definitions of peri-implant mucositis and peri-implantitis vary in the literature, and no clear criteria have been established for the diagnosis and treatment of such disorders. This study proposes a classification for peri-implant mucositis and peri-implantitis based on the severity of the disease, using a combination of peri-implant clinical and radiological parameters to classify severity into several stages (Stage 0A and 0B = peri-implant mucositis, and Stage I to IV = periimplantitis). Following a review of the literature on the subject and justification of the proposed peri-implant disease classification, the latter aims to facilitate professional communication and data collection for research and community health studies.

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-Hodgkins 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.

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.

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

Background A systematic review is made to determine whether human immunodeficiency virus (HIV) infection has an impact upon dental implant osseointegration. Material and Methods 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. Key words: Dental implants, implant failure, HIV positive, systematic review, AIDS, HAART.

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. Key words:Immediate implants, delayed implants, peri-implant health, success rate.