Association between interleukin-6 polymorphism in the −174 G/C region and hearing loss in the elderly with a history of occupational noise exposure

IntroductionThe biological processes involved in noise-induced hearing loss (NIHL) are still unclear. The involvement of inflammation in this condition has been suggested.ObjectiveTo investigate the association between interleukin – 6 (IL-6) polymorphism and susceptibility to NIHL.MethodsThis was a cross-sectional study with a sample of 191 independent elderly individuals aged >60 years of age. Information on exposure to occupational noise was obtained by interviews. Audiological evaluation was performed using pure tone audiometry and genotyped through PCR by restriction fragment length polymorphism – PCR-RFLP. Data were analyzed using the chi-square test and the odds ratio (OR), with the significance level set at 5%.ResultsAmong elderly with hearing loss (78.0%), 18.8% had a history of exposure to occupational noise. There was a statistically significant association between the genotype frequencies of the IL-6 −174 and NIHL. The elderly with the CC genotype were less likely to have hearing loss due to occupational noise exposure when compared to those carrying the GG genotype (OR = 0.0124; 95% CI 0.0023–0.0671; p < 0.001).ConclusionThis study suggests there is an association of polymorphisms in the IL-6 gene at position – G174C with susceptibility to noise-induced hearing loss.     

Interleukin-13 gene polymorphisms at −1055 C/T and +2044 G/A positions in patients with squamous cell carcinoma of head and neck

Squamous cell carcinoma (SCC) is the most common malignancy that involves the upper aerodigestive tract. Interleukin-13 (IL-13) is an immunoregulatory cytokine that has been reported to have some polymorphisms in it gene associated with same disease especially asthma and allergy. The present study aimed to investigate whether the polymorphisms of IL-13 gene (at positions of 1055C/T in the promoter of 1L-13 gene and +2044G/T exon-4) differ in patients with head and neck SCC from healthy controls.MethodsThis study was investigated in patient with head and neck SCC (n = 137) and age- and sex-matched healthy controls (n = 127). Genotyping of IL-13 gene polymorphism was performed using polymerase chain reaction-based restriction fragment length polymorphism method.ResultsNo statistically significant differences were found in the frequencies of genotypes and alleles between patients and control group at both sites (p = 0.16). In addition, no association was observed between investigated genotypes and other potential prognostic factors such as age, sex, primary tumor site, tumor size and smoking.ConclusionThis study suggests that there is no association between IL-13 gene polymorphisms (at position ?1055C/T and +2044GI A) and susceptibility of the patients to SCC of head and neck.     

The correlation of serum levels of leptin,leptin receptor and NO x (NO2 − and NO3 −) in patients with obstructive sleep apnea syndrome

The aim of this study was to investigate the relations between nitric oxide (NO) and leptin levels in a cohort of untreated adult Obstructive sleep apnea syndrome (OSAS) patients. Between June 1, 2012, and January 1, 2013, we evaluated a total of 58 subjects including 36 OSAS patients and 22 healthy controls, both polysomnographically confirmed. Following the completion of polysomnographic evaluation, serum samples were taken at 08:00. Leptin, leptin receptor, NO₂ ^? and NO₃ ^? levels were analyzed by commercial ELISA kits. Data analysis was performed using the Statistical Package for the Social Sciences (SPSS) version 16.0 (SPSS Inc., Chicago, IL, USA). There was no statistically significant difference between the OSAS patients and control groups with relation to the demographic parameters and body mass index (p > 0.05). Significantly higher serum leptin and plasma NO levels were found in OSAS patients compared to the controls (p < 0.001). In this study, higher leptin levels which were positively correlated with NO levels in OSAS group may indicate a possible link with increased incidence of airway pathologies in these patients.