RESUMO
OBJECTIVES: To analyze the relationship between p53 gene mutations, tobacco smoke, and alcohol consumption in patients with laryngeal squamous cell carcinoma. DESIGN: We analyzed p53 gene mutations in exons 5 through 8 by polymerase chain reaction-single-strand conformation polymorphism analysis in a cohort of 84 patients with laryngeal squamous cell carcinoma. SETTING: University hospital. RESULTS: p53 gene mutations were detected in 24 (28.6%) cases (95% confidence interval, 19.3%-39.5%), and the GC to TA transversion (33%) was the most common type of mutation (95% confidence interval, 15.6%-55.3%). Most mutations mapped to the p53 DNA-binding domain, which is necessary for the physiological activity of p53 as a tumor suppressor. A statistically significant association was found between p53 mutations and exposure to tobacco smoke (P=.001), which was the only variable significantly associated with p53 mutations in a multivariate model. The association with alcohol consumption was only at a borderline level of significance (P=.065). CONCLUSION: Our data document that a smoking habit is the only independent variable associated with an increased risk of p53 mutations in the laryngeal mucosa.
Assuntos
Consumo de Bebidas Alcoólicas/genética , Carcinoma de Células Escamosas/genética , Genes p53/genética , Neoplasias Laríngeas/genética , Mutação de Sentido Incorreto , Fumar/genética , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita SimplesRESUMO
In order to evaluate cochlear function in Type 1 diabetes mellitus, this study analyses otoacoustic emissions (OAEs) on normal hearing subjects with diabetes and on controls. Patients with Type 1 diabetes (n=60), with a mean age of 31+/-6.23 years, mean disease duration of 17.5+/-8.9 years, and mean HbA1c of 8.1+/-1.8%, of whom 43% had signs of retinopathy and 28% had clinical signs of neuropathy, were studied. All patients underwent an OAE analysis and brainstem-evoked potentials. Fifty-eight normal volunteers were used as controls for the OAE analysis. Seventeen patients (28.3%) had no OAEs in at least one ear and 10% in both ears. The mean intensity of the response was lower in diabetic subjects [7.1+/-4.4 vs. 10.9+/-9.3 dB SPL (sound pressure level)] than in controls. The cochlear impairment was over 5 dB for the 1-kHz frequency, which is the critical level for speech understanding. These findings suggest that cochleopathy can be detected in a relatively high proportion of subjects with Type 1 diabetes in spite of a normal audiometric hearing threshold.
