Viable human buccal mucosa cells do not yield typical nucleoids: Impacts on the single-cell gel electrophoresis/comet assay

Buccal mucosa (BM) cells have been used in human biomonitoring studies for detecting DNA adducts and chromosomal damage in an epithelial cell population. In the present study, we have investigated if human BM cells are suitable for use in the single-cell gel electrophoresis (SCGE)/Comet assay as an approach for estimating the exposure of epithelial cells to DNA-damaging agents. Our results indicate that only a few cells from BM cell samples yield comets that can be analyzed by current methods, and that the yield of cells with comets is independent of the percentage of viable BM cells in the sample. Data generated after enzymatic enrichment of viable cells and immunomagnetic separation of epithelial cells suggest that most of the BM cells that do form comets are probably leukocytes. Moreover, by reevaluating specific cells after running the Comet assay, we found that viable epithelial BM cells give rise to atypical comets that are not included in the analysis. Comparing DNA migration patterns between small groups of smokers and nonsmokers indicated that long-term smoking had no effect on the subpopulation of cells that yield typical comets. Our results indicate that the SCGE assay, as it is commonly performed, may not be useful for genotoxicity monitoring in human epithelial BM cells.

Cytogenetic damage in circulating lymphocytes and buccal mucosa cells of head-and-neck cancer patients undergoing radiotherapy

This study evaluated cytogenetic damage by measuring the frequency of micronucleated cells (MNC) in peripheral blood and buccal mucosa of head-and-neck cancer patients undergoing radiotherapy.MNC frequencies were assessed in 31 patients before, during, and after radiotherapy, and in 17 C, healthy controls matched for gender, age, and smoking habits. Results showed no statistically significant difference between patients and controls prior to radiotherapy in cytokinesis-blocked lymphocytes or buccal mucosa cells. During treatment, increased MNC frequencies were observed in both cell types. Micronucleated lymphocyte levels remained high in samples collected 30 to 140 days after the end of treatment, while MNC frequency in buccal mucosa decreased to values statistically similar to baseline values. There is controversy over the effects of age, smoking habit, tumor stage, and/or metastasis on MNC frequency. However, increased frequency of micronucleated buccal mucosa cells was seen in patients under 60 years old and in those with tumors >4cm.In conclusion, the data show that radiotherapy has a potent clastogenic effect in Circulating lymphocytes and buccal mucosa cells of head-and-neck cancer patients, and that the baseline MNC frequency in these two tissues is not a sensitive marker for head-and neck neoplasm.

DNA damage in lymphocytes and buccal mucosa cells of children with malignant tumours undergoing chemotherapy

The aim of the present study was to evaluate DNA damage (micronucleus) in cytokinesis-blocked lymphocytes and exfoliated buccal mucosa cells from children with malignant tumours and under chemotherapy. Micronucleated cells (MNCs) were assessed from children before and during chemotherapy. A total of 21 healthy children (controls), matched for gender and age, were used as control. The results pointed out higher frequencies of micronucleated lymphocytes in children with malignant tumour before any therapy when compared to healthy probands. Furthermore an increase of micronucleated lymphocytes during chemotherapy was detected when compared to the data obtained before chemotherapy. No statistically significant increases of MNCs were noticed in buccal mucosa cells at any of the timepoints evaluated. Taken together, these data indicate that the presence of malignant tumours may increase the frequency of DNA damage in circulating lymphocytes, these cells being more sensitive for detecting chromosome aberrations caused by anti-cancer drugs.

Comparative Study Between Porcine Small Intestinal Submucosa and Buccal Mucosa in a Partial Urethra Substitution in Rabbits

Purpose: Several urethral conditions may require tissue substitution. One collagen-base biomaterial that recently emerged as an option is small intestinal submucosa (SIS). The aim of this study was to compare the results of SIS and buccal mucosa for urethral substitution in rabbits.Materials and Methods: Thirty-six North Folk male rabbits were randomized into three groups. In all animals, a 10 x 5 mm urethral segment was excised, and the urethral defect was repaired using a one-layer SIS patch (group I [GI]); four-layer SIS (group II [GII]); or buccal mucosa (group III [GIII]). Urethrography was performed preoperatively and after 12 weeks. After sacrifice, graft retraction was objectively measured using Scion Image (R) computer analysis and by calculation of ellipse area. The grade of fibrosis, inflammatory reaction, vascular/epithelial regeneration, and collagen III/I ratio were analyzed by hematoxylin/eosin and Picrosirius red staining.Results: Urethrography confirmed a wide urethral caliber without any signs of strictures after surgery. Urethral fistulae was diagnosed in 8.3% of cases (1 animal each group). Average graft shrinkage was 55.2% in GI; 44.2% in GII; and 57.2% in GIII (p < 0.05). The intensity of chronic inflammation, fibrosis, epithelium regeneration, and neovascularization was similar in all groups (p > 0.05). Collagen III/I ratio was higher in GII (GI: 119.6; GII: 257.2 and GIII: 115.0); p < 0.01.Conclusions: The four-layer SIS is more advantageous than the one-layer SIS and buccal mucosa for urethral substitution in rabbits.

Osteolipoma of the buccal mucosa

Lipomas are benign mesenchymal neoplasms of soft tissue that can be found in any part of the human body. Conversely, their presence in the oral mucosa is rather uncommon, with approximately 4% of the cases occurring in the oral cavity. In such cases, they are likely to have originated from mature adipose tissue and to be among several described histological variants of lipomas, which are identified according to the predominant type of tissue. There is a rare lipoma, known as an osteolipoma or an ossifying lipoma; however, little has been written this type of lipoma characterized by a classical lipoma with areas of osseous metaplasia. Considering the few cases of oral osteolipomas previously described in the English-related literature and the consequent risk of misdiagnosis and overtreatment, this paper describes an extreme case of an osteolipoma affecting the buccal mucosa of an adult patient. This paper focuses particularly on the pathogenesis of this lesion and the discussion of a correct diagnosis.

Histological study of hamster buccal mucosa following topical application of DMBA and exposition to low power 337 nm laser light

The aim of the present work is to analyze the histological changes on hamster buccal mucosa caused by the topical use of 7,12-dimethylbenzanthracene (DMBA) and exposition to a 220 μJ/pulse nitrogen laser light (@ 337 nm) at an average power of 2,3 mW. Twenty-one hamsters divided into two experimental groups were treated six times with DMBA. One hamster was kept as control. Group I was composed by ten hamsters and was submitted only to DMBA. Group II, also with ten hamsters, received the same treatment as group I and was exposed to the laser radiation. The time duration of each irradiation section was 10 seconds. All the treatment happened in alternated days. The histological analysis took place twice, after the end of the treatment and after sixty days. Both experimental groups presented dilatation of vessels, thickening of the epithelial tissue and the presence of inflammatory infiltrates. The preliminary results indicates that in group II the number of dilated vessels and its new area are much more significant than in group I.

Keratocyst of the buccal mucosa: case report and immunohistochemical comparative study with sporadic intraosseous keratocystic odontogenic tumor

Objectives: Describe a new case of keratocyst of the buccal mucosa and compare its immunohistochemical features with 13 sporadic intraosseous keratocystic odontogenic tumors (KOT). Case Report and Study Design: A male complaining about an enlargement on the left buccal mucosa was referred to the Stomatology Clinic. Clinical examination revealed a solitary nodule posterior to the parotid papilla. An excisional biopsy was performed following clinical diagnosis of epidermoid cyst. Microscopically, the lesion was characterized by a lining of five cell layers, with columnar basal cells and a corrugated parakeratinized surface. Immunohistochemical reactions for PTCH-1, Smo, Shh, mTOR, bcl-2, Ck17, and Ck19 were performed. PTCH-1 was not expressed in the keratocyst of the buccal mucosa, but was observed in suprabasal layers of eight (61.5%) cases of sporadic intraosseous KOT. Shh, mTOR, bcl-2, Ck17, and Ck19 expression was observed in all the cases investigated. Conclusions: The morphology and immunoprofile of this lesion are similar to sporadic intraosseous KOT. © 2013 Elsevier Inc. All rights reserved.

Spindle cell lipoma occurring in the buccal mucosa: an unusual location of this benign lipomatous neoplasm

Spindle cell lipoma is a benign lipomatous neoplasm, which rarely occurs in the oral cavity. The aims of this paper are to report a case of spindle cell lipoma located in buccal mucosa and discuss the main clinical, histological, and immunohistochemical findings of this entity. Thus, we report a 4-year history of an asymptomatic smooth surface nodule in an elderly Caucasian man with clinical hypothesis of fibroma. The histopathological examination showed spindle cells, mature adipose tissue, and many mast cells in a stroma of connective tissue presenting ropey collagen fibers bundles. After immunohistochemical analysis, the final diagnosis was spindle cell lipoma.

Candida albicans Isolation from Buccal Mucosa of Patients with HIV Wearing Removable Dental Prostheses

Purpose: The aim of this study was to evaluate the influence of complete or partial removable dental prostheses (RDPs) on the frequency of Candida albicans isolated from the mouth and the presence of oral candidiasis in human immunodeficiency virus positive (HIV+) patients correlated with CD4 levels. Materials and Methods: One hundred ninety-three HIV+ patients were evaluated; 68 had RDPs and 125 did not. CD4 cell count was obtained after blood sampling and performed on the day of clinical examination. The material was collected from the buccal mucosa for isolation of yeasts with a sterile swab and seeded onto Sabouraud dextrose agar with chloramphenicol. C albicans strains were identified by testing germ tubes and chlamydospore formation and biochemical (zymogram, auxanogram) characteristics. The results were subjected to the Fischer exact test and chi-square tests. Results: C albicans were isolated from 45(66.17%) patients who had RDPs and 48 (38.4%) who did not (P = .0003). The presence of oral candidiasis was observed in 14 patients (7.25%), and 10 of the 14 (71.43%) were RDP users. The absence of candidiasis occurred in 121 (67.59%) nonusers and 58 (32.40%) users of RDPs (P = .0065). The mean CD4 cell count was lower in patients with oral candidiasis regardless of the use of RDPs. Conclusion: The use of RDPs was an important factor in the isolation of C albicans among HIV+ patients, and CD4 level seems to play a role in the presence of oral candidiasis. Int J Prosthodont 2012;25:127-131.

Diffuse swelling of the buccal mucosa and palate as first and only manifestation of an extranodal non-Hodgkin 'double-hit' lymphoma: report of a case

Most of the lymphomas arising in the oral cavity are of B-cell origin. Among these, diffuse large B-cell lymphomas are the most common. Diffuse large B-cell lymphomas may exhibit more than one chromosomal rearrangement and are then referred to as 'double-hit' or 'triple-hit' lymphomas.