Could formaldehyde induce mutagenic and cytotoxic effects in buccal epithelial cells during anatomy classes?

BACKGROUND: Due to increased formaldehyde exposure, carcinogenic to humans, several researches have been studying the potential toxicity and the safe levels for human beings. The aim of this study was to investigate mutagenicity and cytotoxicity in buccal epithelial exfoliated cells (BEC) of students subjected to formaldehyde (FA) during anatomy classes. MATERIAL AND METHODS: BEC were collected periodically from 17 volunteers of undergraduate programs, who had participated in practical anatomy classes, before and after FA exposure. Cells were stained according to Feulgen method and then micronucleus test was applied. A total of 1,500 cells were assessed per individual in this study for the micronucleus frequency and other parameters of cytotoxicity. RESULTS: There was statistically significant increase in number of micronucleated BEC after FA exposure (after 1 month p=.034 and after 3.5 months p=.017). However, FA exposure caused no significant increase in other nuclear alterations closely related to cytotoxicity (p≥.05). CONCLUSIONS: FA induced mutagenicity during anatomy classes. Cell death increased, but it was not statistically significant. Efforts have to be made to improve air quality and reduce exposures during anatomy classes.

Microchimerism in labial salivary glands of hematopoietic stem cell transplanted patients.

OBJECTIVE: Microchimerism has been extensively investigated in autoimmune diseases, which display similarities with graft-vs-host disease. This study was conducted to investigate the presence of microchimerism in minor salivary glands of hematopoietic stem cell transplanted patients, one of the targets of graft-vs-host disease. METHODS: Labial salivary glands biopsy specimens from 11 stem cell transplanted patients were analysed. The samples were grouped in control (five specimens from a female-to-female transplantation) and study group (five glands from male-to-female transplantation). One male transplanted patient was used as a positive control. Fluorescence in situ hybridization with Y-chromosome probe and immunofluorescence with anticytokeratin AE1/AE3 and CD45 were used to identify Y-chromosome positive glandular epithelial cells from allogeneic hematopoietic stem cell transplanted patients. RESULTS: In the study group, all samples were positive to Y-chromosome and cytokeratin AE1/AE3, in agreement with the pattern exhibited by male labial salivary gland. None of the samples from control group were positive to Y-chromosome despite being positive to cytokeratin AE1/AE3. Positivity to CD45 was not relevant. CONCLUSION: Microchimerism in the labial salivary glands of sex-mismatched stem cell transplanted patients is a real phenomenon. Further studies are necessary to elucidate the impact of this phenomenon on the clinical status of stem cell transplanted patients.

Peripheral odontogenic fibroma (WHO type) of the newborn: a case report.

AIM: The present paper reports a case of peripheral odontogenic fibroma (POF) (WHO type) in a newborn. The differential diagnosis and treatment were discussed. BACKGROUND: POF is well described in the literature, but this is the first report in a newborn. PATIENT: A 4-month-old female newborn was referred to our department because of an exophytic, sessile, firm, and well-delimited lesion on the right upper alveolar ridge. The covering mucosa was apparently normal. The lesion measuring 10 x 3 mm was present since birth. The clinical diagnosis of congenital granular cell tumour (congenital epulis) or dental lamina cyst of the newborn was made. A conservative excisional biopsy was performed under local anaesthesia, and the specimen was submitted to histopathological examination. RESULTS: The microscopic examination revealed a pattern of POF (WHO type). Normal primary incisors teeth eruption, and no signs of recurrence were noted on 16 months follow-up. CONCLUSION: Despite the rarity of POF in a newborn, this lesion should be included as a possible diagnosis to focal gingival growth.

Effect of bone marrow transplantation on the immunolocalization of p53, hMSH2, and hMLH1 proteins on oral mucosa.

OBJECTIVE: Considering that hMSH2, hMLH1 and p53 are important in maintaining genomic stability of the oral mucosa epithelium, the purpose of the present study was to investigate the immunolocalization of these proteins in the epithelium of the oral mucosa of patients submitted to bone marrow transplantation (BMT) compared with controls. MATERIALS AND METHODS: Twenty-one samples of lip biopsies from BMT recipients were retrieved. Twenty samples of normal lower labial mucosa associated with mucocele in non-transplanted patients were included as control group. The streptavidin-biotin complex stain was used to detect the human DNA mismatch repair proteins hMSH2, hMLH1 and p53 protein. RESULTS: The main findings demonstrated that the mean number of suprabasal epithelial cells positive for MSH2 was statistically higher than the control group. The immunostaining of hMLH1 and p53 at the basal and suprabasal epithelial layers were statistically higher in the oral labial mucosa of the BMT patients compared with controls. CONCLUSION: The present study shows that oral epithelial cells of BMT patients show increased immunolocalization of the DNA repair related proteins.

Cutaneous horn occurring on the lip of a child.

Cutaneous horn is a relatively uncommon lesion consisting of keratotic material resembling that of an animal horn. This kind of lesion is more common in Caucasians and in older age groups. The primary lesion underlying the horny material may be benign, premalignant or malignant. The treatment of choice is an excisional biopsy with a narrow margin, because of the possibility of malignancy. The material must be submitted for histopathological evaluation. The first reported case of cutaneous horn arising on the vermillion border of the lower lip in a black child is presented.

Oral recurrent human herpes virus infection and bone marrow transplantation survival.

OBJECTIVE: This study was conducted to compare the survival rates of bone marrow transplantation (BMT) patients who were affected with the survival rates of those who were not affected by oral recrudescent human herpes virus-1 infection (HHV-1) after transplantation. STUDY DESIGN: Fifty-two consecutive patients who underwent BMT were included in the study. The time of death after BMT was displayed, by means of the Kaplan-Meier method, for the following parameters: age and gender of the patient, donor gender, primary disease, stem cells, conditioning regimen, platelet number after day 100, acute and chronic graft-versus-host disease, oral recurrent HHV-1 infection post-BMT, oral lichenoid lesions of graft-versus-host disease, graft-versus-host disease at the salivary glands, parenteral nutrition, and oral mucositis. The data were initially analyzed by means of the log-rank test and then included in the Cox proportional hazards model. RESULTS: The multivariate analysis demonstrated a significance of 5% for only the platelet numbers and oral recurrent HHV-1 infection. CONCLUSION: The present study provides evidence that platelet numbers below 100,000 cells/mm(3) after day 100 and oral recurrent HHV-1 infection are independent negative prognostic variables in BMT patients' 24-month survival rates.