Karen Cherubini

Oral lichen planus: Focus on etiopathogenesis

Lichen planus is a chronic mucocutaneous inflammatory disease, which frequently affects the oral mucosa of white females over 40 years old. Its aetiology remains uncertain and the pathogenesis is still the object of much speculation. The present paper presents the most well known antigens, and describes the action of different cells and proteins associated with the development of that disease, as well as the possible agents involved with its malignant transformation. Different external agents, especially virus, and internal agents, like stress, and the heat shock protein antigen expression, associated or not, can alter the basal keratinocytes of the oral mucosa making them susceptible to apoptosis by CD8(+) cytotoxic T cell as well as activate matrix metalloproteinase and mast cell degranulation, which produce a great range of inflammatory mediators and cytokines determining the clinical onset of the disease. Regarding carcinogenesis, since it is a complex process and presents multifactorial origin, it is believed that there may be a synergism between intrinsic, such as inflammation mediators, and extrinsic agents (tobacco, alcohol, viral infections) for the OLP malignant transformation to occur. However, further studies are needed to better understand the origin, pathogenesis and process of malignant transformation of OLP.

The role of epigenetic transcription repression and DNA methyltransferases in cancer

Epigenetic alterations such as DNA methylation have been implicated in the development and progression of various cancers. DNA methylation consists of the reversible addition of a methyl group to the carbon 5 position of cytosine in CpG dinucleotides and is considered essential for normal embryonic development. However, global genomic hypomethylation and aberrant hypermethylation of regulatory regions of tumor suppressor genes have been associated with chromosomal instability and transcription repression, respectively, providing neoplastic cells with a selective advantage. DNA methyltransferases are the enzymes responsible for the addition of methyl groups to CpG dinucleotides, which, together with histone modifiers, initiate the events necessary for transcription repression to occur. It has been demonstrated that increased expression of DNA methyltransferases may contribute to tumor progression through methylation‐mediated gene inactivation in various human cancers. Given their importance, this article reviews the main epigenetic mechanisms for regulating transcription and its implications in cancer development. Cancer 2011.

Salivary hypofunction: An update on aetiology, diagnosis and therapeutics

Saliva is of paramount importance for the maintenance of oral and general homeostasis. Salivary hypofunction predispose patients to disorders such as dysgeusia, pain and burning mouth, caries and other oral infectious diseases, dysphagia and dysphonia. The aim of this study was to provide an update on the aetiology, diagnostic methods and therapeutic strategies for the management of hyposalivation and xerostomia. The present paper describes subjective and objective methods for the diagnosis of salivary dysfunctions; moreover a number of drugs, and systemic disorders associated with decreased salivary flow rate are listed. We also focused on the underlying mechanisms to radiotherapy-induced salivary damage. Therapeutics for hyposalivation and xerostomia were discussed and classified as preventive, symptomatic, topical and systemic stimulants, disease-modifying agents, and regenerative. New therapeutic modalities have been studied and involve stem cells transplantation, with special attention to regeneration of damage caused by ionizing radiation to the salivary glands. More studies in this area are needed to provide new perspectives in the treatment of patients with salivary dysfunctions.

Association between bisphosphonates and jaw osteonecrosis: a study in Wistar rats

This work aimed at determining whether bisphosphonate therapy produces a sufficient condition for jaw osteonecrosis after tooth extraction.

Salivary cortisol and dehydroepiandrosterone (DHEA) levels, psychological factors in patients with oral lichen planus.

OBJECTIVE The aim of this study was to determine the salivary levels of dehydroepiandrosterone (DHEA) and cortisol and scores of depression, anxiety and stress in patients with oral lichen planus (OLP). STUDY DESIGN Thirty-one patients with a diagnosis of OLP were selected; they were matched by sex and age with 31 control patients. Symptoms of depression, anxiety and stress were investigated by the instruments Beck Depression Inventory, Beck Anxiety Inventory and Lipps Inventory of Stress Symptoms for Adults, respectively. Saliva was collected in the morning and at night for the determination of DHEA and cortisol levels by radioimmunoassay. RESULTS There was no significant difference between the groups with respect to depression (P=0.832), anxiety (P=0.061) or stress (P=0.611), or with respect to morning and night salivary levels of DHEA (P=0.888, P=0.297) and cortisol (P=0.443, P=0.983). CONCLUSIONS The results suggest an association of OLP with anxiety. However, DHEA and cortisol levels did not differ between groups, which does not support any neuroendocrine aetiology for OLP.

Oral erythroplakia and speckled leukoplakia: retrospective analysis of 13 cases

UNLABELLED Erythroplakia and speckled leukoplakia are oral precancerous lesions that have a high potential for malignant transformation. AIM A retrospective analysis was conducted to investigate the clinicopathologic features of 13 cases of oral erythroplakia and speckled leukoplakia in patients who were seen at a center specialized in stomatology and Histopathological diagnosis of oral diseases. MATERIALS AND METHODS All cases diagnosed with erythroplakia and speckled leukoplakia between 1978 and 2006 were retrieved from the service archives. RESULTS The lesions exhibited a predilection for males with a female-to-male ratio of 1:3.3. Mean age was 57 years old and soft palate was the site affected in 77% of the cases. Pain symptoms were reported by 61.5% of the patients and association with risk factors such as smoking and excessive alcohol intake was seen in 100% and in 46% of the cases, respectively. The lesions showed epithelial dysplasia, where more than 50% were diagnosed as in situ or invasive carcinoma. CONCLUSIONS Despite low prevalence, oral homogeneous erythroplakia and speckled leukoplakia show Histopathological alterations vary from epithelial dysplasia to invasive carcinoma. These lesions must be included among those oral lesions with the highest potential for malignant tranformation.

Important aspects regarding the role of microorganisms in bisphosphonate-related osteonecrosis of the jaws

Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is an important side effect of bisphosphonates, whose etiopathogenesis has not been completely elucidated. Theories pointing to bone turnover and angiogenesis inhibition, as well as effects on epithelial cells of oral mucosa and the role of microorganisms have been reported. Nevertheless, the true contribution of each one of these factors to BRONJ is unknown. We present here a literature review focusing on important aspects regarding the role of microorganisms in BRONJ development. Knowledge about specific microbiota and its role in the etiopathogenesis of this disease can help the optimisation of preventive and therapeutic interventions in patients with or at-risk for BRONJ.

Salivary dehydroepiandrosterone (DHEA) levels in patients with the complaint of burning mouth: a case-control study

OBJECTIVE This study was conducted to evaluate salivary dehydroepiandrosterone (DHEA) levels, salivary flow rate (SFR), depression, and hopelessness in patients with the complaint of burning mouth (BM). STUDY DESIGN Thirty female patients with BM and 30 age-matched control women without any complaint of burning mouth were enrolled. After anamnesis and oral examination, the salivary flow rate was determined. Depression and hopelessness were evaluated by the application of inventories. Two saliva samples were collected for DHEA analysis. RESULTS Dysgeusia (P = .045) and xerostomia (P = .003) were significantly higher in the BM group. The BM patients showed significantly lower salivary flow rate, both under stimulation (P = .001) and at rest (P < .001). Significant differences between the groups were not found in the depression (P = .416) or hopelessness (P = .597) scores. The BM group revealed significantly lower salivary DHEA levels in the morning samples (P = .003). CONCLUSION Patients with BM exhibit decreased morning salivary DHEA as well as dysgeusia and hyposalivation more frequently than control subjects. Additional investigations are needed to clarify this association.

Important aspects of oral paracoccidioidomycosis–a literature review

Paracoccidioidomycosis is a deep mycosis endemic to Latin America, with considerable morbidity and mortality. It is caused by the dimorphic fungus Paracoccidioides brasiliensis, which affects, among other organs in the human body, the oral cavity. Fungus virulence and immunocompetence of the host determine the establishment of infection or active disease, whose severity and clinical behaviour depend mostly on the cellular immune response of the host. Often, oral lesions constitute the first sign and site of confirmation of diagnosis, which in most cases is delayed. The success of the treatment depends on early and correct diagnosis, as well as on the patient’s adherence to the drug therapy.

Identification of Candida spp. by phenotypic tests and PCR

The correct identification of Candida species is of great importance, as it presents prognostic and therapeutical significance, allowing an early and appropriate antifungical therapy. The purpose of this study was to identify isolates of Candida spp. from oral mucosa of 38 patients with oral candidosis evaluated in 2004 by phenotypic methods and PCR, discriminating C. albicans from the other Candida species. The tests used for phenotypic analysis were germ-tube and chlamydoconidia production, culture in CHROMAgar™ Candida, carbohydrate assimilation test, growth at 45ºC and culture in Tween 80 agar. Genotypic confirmation was performed by PCR. Phenotypic tests showed that 63.2% strains formed germ-tubes, 73.7% produced chlamydoconidia, and 63.2% showed green colonies in chromogenic medium, presumptively indicating C. albicans or C. dubliniensis. The carbohydrate assimilation test confirmed these results. A total of 21% strains were identified as C. krusei and 13.2% were indicative of C. tropicalis. Of these later strains, three produced chlamydoconidia. The association of other phenotypic tests with culture in Tween 80 agar identified 95.8% of strains as C. albicans and 4.2% as C. dubliniensis. All 24 strains indicative of C. albicans and C. dubliniensis were confirmed by PCR as C. albicans.