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BACKGROUND Increased lipogenesis and lipid droplet accumulation are observed in diverse tumors, and these processes are associated with poor prognosis in several tumors, representing potential therapeutic targets. The presence of lipid droplets in odontogenic tissues and/or tumors is unknown. METHODS Immunohistochemistry for perilipin 1 and adipophilin was performed in 12 human tooth germs (TG), 27 conventional ameloblastoma (AM), and 8 ameloblastic carcinoma (AC) samples. Cytoplasmic staining was analyzed using an immunoreactive score (IRS), and the results were compared for the TG, AM, and AC samples by Kruskal-Wallis test followed by Dunn's post-test and confirmed by Mann-Whitney U test. RESULTS Perilipin 1 was negative in 91.7% of the TG samples, positive in 48.2% of the AM samples, and positive in 87.5% of the AC samples. Adipophilin was positive in 100% of the TG samples, 92.6% of the AM samples, and 100% of the AC samples. The perilipin 1 and adipophilin IRS revealed statistically significant differences between the TG, AM, and AC samples (p = .007 and p = .018, respectively). The perilipin 1 levels among the TG and AC samples were statically significant (**p = .0085), as well as the adipophilin levels when TG and AM samples were compared (**p

Background The caveolin-1 protein (structural component of membrane caveolae) plays important roles in several biological functions, such as endocytosis, cell adhesion, and cell signaling. However, this protein has been associated with mechanisms of tumorigenesis in several neoplasms. The expression patterns and roles of caveolin-1 in the oral epithelium and in embryonic and odontogenic tumor tissues are still unclear. Material and Methods The expression of caveolin-1 was evaluated in samples of the normal gingival epithelium (n=7), human tooth germ (TG) (n=12), ameloblastoma (AM) (n=83), and ameloblastic carcinoma (AC) (n=9) by immunohistochemistry. Additionally, AM samples were analyzed by qRT-PCR and Western blot. Results Most TG (91.7%), AM (73.5%) and AC (100%) samples showed diverse patterns of immunohistochemical positivity for caveolin-1, while only one gingival sample was positive. The transcript levels of cav-1 were significantly upregulated by 14.9-fold in AM tissue (P = 0.0014) compared to those in normal gingival epithelial tissue, as shown by qRT-PCR. Presence of caveolin-1 protein was confirmed by Western blot analysis. The caveolin-1 immunoexpression patterns throughout the stages of TG show its importance during odontogenesis. Conclusions The overexpression of caveolin-1 in AM and AC compared to its expression in normal gingival epithelium (adult tissue) suggests a possible role of caveolin-1 in protumoral events, but due to the similar immunoexpression observed in AM and AC, caveolin-1 may not necessarily participate in the malignant transformation process. However, future studies are needed to clarify and confirm these hypotheses. Key words:Ameloblastoma, ameloblastic carcinoma, caveolin-1, immunohistochemistry, real-time polymerase chain reaction.

Background and objective Hansen disease, or leprosy, is caused by Mycobacterium leprae or Mycobacterium lepromatosis. Because these bacteria enter the body via the upper airways, they generate clinical manifestations in the nasal mucous membranes and the mouth. We aimed to describe the characteristics of oral lesions in patients with Hansen disease. Material and methods Cross-sectional observational study of 100 patients diagnosed with Hansen disease. We examined the oral cavity and recorded clinical findings on a disease reporting form for each patient. We also included the histopathologic findings for lesions that required a biopsy. Samples suggestive of Hansen disease were processed with hematoxylin-eosin, Ziehl–Neelsen, and Fite–Faraco staining. Variables were analyzed, as appropriate, with the χ2 test, the Mann-Whitney U test, or the Spearman correlation coefficient. Results Sixty-seven men and 33 women were included. The mean (SD) age was 48.1 (16.4) years. Thirty-four patients had oral lesions. Lesions related to Hansen disease were found in 9 patients. The locations were the hard palate and upper lip. Oral lesions were significantly more frequent in patients with lepromatous leprosy, borderline lepromatous leprosy (P = .029), and erythema nodosum leprosum (P = .031). Conclusions The frequency of oral lesions is low in Hansen disease. Such lesions present as lepromas and leprous plaques on the hard palate and upper lip.

Introduction Lupus erythematosus (LE) is an autoimmune disease often treated with antimalarial drugs. The prolonged use of chloroquine and hydroxychloroquine can cause hyperpigmentation in the skin, oral mucosa and retinal pigment epithelium, which in turn can trigger toxicity in this epithelium, which in some cases causes vision loss. The objective of the present work was to establish the association between the presence of oral pigmented macules by antimalarial and secondary retinal toxicity. Methods A total of 105 patients diagnosed with LE being treated with chloroquine/hydroxychloroquine were evaluated. All patients were ophthalmologically evaluated for retinopathy screening. When the patient showed oral hyperpigmented maculae, an incisional biopsy was performed with the corresponding histopathological study with informed consent. The variables were compared using the chi-square test for quantitative variables and the non-parametric Mann–Whitney U-test for categorical variables. The confidence level was established at 95%, and p-values of ≤0.005 were considered statistically significant. Results Only 9.5% of the patients showed oral brown spots. Histopathologically, 100% of the oral macules showed characteristics of oral pigmentation by drug and 100% ophthalmological parameters of normality. Two patients presented with a diagnosis of pre-retinopathy, but none showed oral lesions. Conclusion Hyperpigmented macules in the buccal mucosa in lupus patients receiving antimalarial treatment are not frequent and do not represent a predictive finding of toxicity of the drug.

Objective: To evaluate interleukin-1ß (IL-1ß) and interleukin-8 (IL-8) epithelial expressions in potentially malignant disorders of the oral mucosa as malignant predictive markers.Study design: About 55 tissues embedded in paraffin, comprising 15 oral lichen planus (OLP) lesions, 15 leukoplakias, 15 oral squamous cell carcinomas (OSCC), and 10 samples of normal oral mucosa were included in the study. IL-1ß and 8 expressions were assessed by immunohistochemistry using antibodies antihuman IL-1ß human (sc-7884, Santa Cruz® H-153) and antihuman IL-8 (ab7747, abcam®). The number of positive cells was compared using Student's t-test. Any p-value < 0.05 was considered statistically significant.Results: Nuclear and cytoplasmatic keratinocyte staining were positive for both cytokines in all study groups. However, a statistically significant decrease was observed within all cases compared to normal mucosa, both staining for IL-1β and 8. Moreover, IL-8 showed significant differences between OLP and leukoplakia, and when compared to OSCC.Conclusions: Oral epithelial expression of IL-1β and 8 seems to decrease when the malignant transformation of the oral mucosa increases.

OBJECTIVE: To report the clinicopathologic features of acquired oral syphilis cases in South American countries. MATERIALS AND METHODS: Clinical data were retrospectively collected from the records of 18 oral diagnostic services in Argentina, Brazil, Chile, Colombia, Venezuela, Uruguay, and Peru. Serologies of nontreponemal and treponemal tests were used for diagnosis. RESULTS: The series comprised 339 cases of acquired oral syphilis. Secondary syphilis ranked as the most common stage (86.7%). Lesions were more frequent among males (58.0%) and young adults with a mean age of 33.3 years. Individuals aged 20-29 years were most affected (35.3%). The most commonly involved sites were the tongue (31.6%), lip/labial commissure (25.1%), and hard/soft palate (20.4%). Clinically, acquired oral syphilis usually presented as mucous patches (28.4%), papules (25.7%), and ulcers (18.1%). Skin manifestations occurred in 67.7% of individuals, while lymphadenopathy and fever were observed in 61.3% and 11.6% of all subjects, respectively. Most patients were treated with the benzathine penicillin G antibiotic. CONCLUSION: This report validates the spread of acquired oral syphilis infection among young adults in South America. Our directives include accessible diagnostic tools for proper disease screening, surveillance, and counselling of affected individuals, especially in low- and middle-income countries

Objective This study aimed to assess the frequency of KRAS mutation and its association with the presence of the MAPK/ERK signaling pathway proteins in adenomatoid odontogenic tumors. Study design Paraffin-embedded tissue samples from nine cases of adenomatoid odontogenic tumor were used. Genomic DNA was extracted from each sample; in one case, genetic mutations in 50 cancer-associated genes were examined by next-generation sequencing. Hotspot mutations in the RAS family were analyzed by Luminex assay using the remaining eight cases. Subsequently, immunohistochemistry for KRAS, CRAF, BRAF, EGFR, ERK, MEK, and BRAFV600E was performed. Results A KRAS G12D missense mutation was detected in the DNA sequence of the tumor cells, but it was not detected in the stromal tissue. KRAS G12V and KRAS G12R mutations were detected in two and four cases, respectively. For immunohistochemistry, all the cases were EGFR, KRAS, BRAF, CRAF positive, one case was ERK negative,and one case was MEK and ERK negative, all the other remaining cases were MEK and ERK positive. Conclusion KRAS mutation at codon 12 and the presence of MAPK/ERK pathway proteins were detected suggesting their association with tumorigenesis of adenomatoid odontogenic tumors.

Many predisposing factors to caries are present in autism, however, it is unlikely that autistic patients exhibit higher caries indexes than the rest of the population. Objective: To evaluate salivary factors related to caries in autistic patients. Study design: 34 autistics and 34 controls aged between 4–13 years old were included. Decayed, missing, and filled teeth (DMFT) index and oral hygiene simplified index (IHO-S) were assessed, as well as, pH, total proteins, phosphate, calcium and IgA in saliva. All data were analyzed by chi2 and Student t tests for independent samples. P values

BACKGROUND: The aim of this study was to characterize oral lesions in patients with systemic and cutaneous lupus erythematosus (LE) in a Venezuelan group. METHODS: Ninety patients with LE were studied. Oral biopsies were taken from patients who showed oral mucosal involvement. Tissue samples were investigated with histology and direct immunofluorescence techniques for the presence of immunoglobulins G, M, A and complement factor C3. RESULTS: In 90 patients with LE, 10 patients showed oral lesions related to the disease. Sixteen lesions were investigated. Oral ulcerations accompanied by white irradiating striae occurred in five patients, erythema was observed in five patients and a white homogeneous plaque in one patient. Fifteen lesions demonstrated vacuolar basal degeneration and 12 thickening of the basement membrane histologically. Direct immunofluorescence was negative in three samples. CONCLUSIONS: These findings corroborated that ulcers are not the only manifestation of LE in the oral mucosa. Clinical and histological examinations are significant as immunoproteins are not always found on the oral sample. J Oral Pathol Med (2007) 36: 524–7

Background: Current evidence suggests that immunological mechanisms are involved in oral lichen planus (OLP) pathogenesis. The events implicate activated epithelia that comprise antigen-presenting Langerhans cells, immunocompetent keratinocytes and subepithelial inflammatory infiltrate. Also, the presence of a high density of leucocyte cells may occur for the expression of a variety of adhesion molecules. The aim of this study was to analyse the immunoexpression of some adhesion molecules as well as lymphocytic markers in order to determine the disease pathogenesis in a Venezuelan population. Methods: The 18 OLP and 10 normal oral mucosa biopsies were immunostained for CD4, CD8, CD1a, LFA-1, VCAM-1 and ICAM-1. Results: The results showed an increased number of CD4+, CD8+, CD1a+ cells in OLP. Serial sections showed CD4+ and CD8+ cells also expressed LFA-1. The expression of ICAM-1 and VCAM-1 were significantly higher in OLP. Conclusions: The immunological reaction begins with Langerhans cells activation, which presents an antigen to CD4+ lymphocytes. Those cells through ICAM-1 and LFA-1 promote epithelial destruction. Afterwards, cytokine production, ICAM-1 and VCAM-1 expression can activate CD8+ lymphocytes leading to the chronic form of the disease.

Squamous cell carcinoma is a rare consequence of lupus erythematosus and it is generally associated with skin lesions rather than with oral mucosa. This paper reports a patient diagnosed with systemic lupus erythematosus who developed a squamous cell carcinoma on the palate as an outcome of a persistent ulcer, a frequent lesion in patients with this disease and, in fact, clinical criterion for its diagnosis. A 38-year-old female patient diagnosed with systemic lupus erythematosus 12 years previously, who attended the dental school for routine dental control. The patient was being treated with prednisone 10 mg per day and cyclophosphamide 750 mg per month until 10 months prior to her diagnostic biopsy. She had, however, been previously treated with chloroquine. Oral lesions started 6 months before consultation as symptomatic multiple ulcers on the palate. After topical treatment with steroids for 1 month, the lesions regressed except for the central lesion, from which an incisional biopsy was taken and a well differentiated squamous cell carcinoma was diagnosed. The oncological phase consisted of partial palatectomy. To date, 3 years after surgery, the patient is free from malignant lesions. Lupus erythematosus is considered a potentially malignant disorder, although the cause for neoplasic transformation in these patients is still not clear, but cyclophosphamide consumption may be implicated; the case emphasizes the importance of periodical oral evaluation of such patients. Repeated biopsies should be performed if there is failure to respond to conventional therapy.

CD40 is a transmembrane glycoprotein belonging to the tumour necrosis factor receptor superfamily, which has a role in a number of biological functions, including the regulation of cell growth and division, and cell mediated immunity. Although originally described on leucocytes, principally B lymphocytes, there is now abundant evidence for the cellular diversity of CD40. The aim of this article is to review the available data on CD40 in oral epithelium, principally that lining the oral mucosa, but also that of the salivary glands.