Investigation of thyroid nodules in the female population in Cyprus and in Romania

The Qualitative and Quantitative Structure of Oral Microbiocenosis in Rats with Periodontitis in a Setting of Hyper- and Hypothyroidism

Background and aims. Oral microbial flora is a highly sensitive indicator system producing qualitative and quantitative responses to changes in various individual organs and systems. The aim of study was to perform a comparative analysis of qualitative and quantitative structure of oral microbiocenosis in rats with comorbidity-free periodontitis and in animals with periodontitis in a setting of hyper- and hypothyroidism.

Material and methods. Experimental studies were conducted on 48 mature male white rats. Samples for microbiological tests were taken from dental surfaces (on the border between hard tissue and gums in the interdental spaces). The isolated pure cultures were identified by their morphological, tinctorial, cultural and biochemical properties and the signs of pathogenecity.

Results. We found that the oral dysbiosis occurring in a setting of periodontitis in rats is chiefly characterized by increased quantity of coccal forms and by increased candidal inoculation; these organisms cumulatively inhibit the growth of normal microbial flora, such as Lactobacilli, bacteroids and Bifidobacteria. Thyroid dysfunction exacerbates changes in the qualitative and quantitative structure of oral microbiocenosis.

Conclusions. The periodontitis in a setting of thyroid dysfunction increases both the species variety and the quantitative counts of oral microbial flora, with predominance of such microbial organisms as Staph. aureus, E. coli, E. faecalis, Candida albicans and P. aeruginosa.

Human Exposures to Bisphenol A, Bisphenol F and Chlorinated Bisphenol A Derivatives and Thyroid Function

Although the increasing prevalence of thyroid nodular disease (TND) has been partially attributed to the more frequent usage of improved diagnostics, environmental factors, such as exposures to thyroid-disrupting chemicals may contribute to TND and altered thyroid function. We investigated the association between exposures to bisphenol A (BPA), its chlorinated derivatives (ClxBPA), and bisphenol F (BPF) with TND and thyroid measures in adult women. A case-control study in Cyprus and Romania (n = 212) was conducted, where cases were those with thyroid nodules (diameter >3mm), and controls without nodules. Serum TSH and free thyroxine and urinary levels of BPA, BPF and ClxBPA were measured using immunoassays and tandem mass spectrometry, respectively. The association between exposures to BPA compounds and TND, adjusting for age, BMI, thyroid hormones and urinary iodine was assessed using logistic regression. Linear regression was used to explore associations between urinary BPA, BPF and ClxBPA and serum thyroid hormones. With the exception of a chlorinated BPA compound (30%), the rest of bisphenols were quantified in 100% of urine samples. A positive and significant (p<0.05) association was observed between urinary BPA and serum TSH that remained after adjusting for urinary creatinine, age, BMI, study site and disease status; there was no significant association between BPF or ClxBPA with TSH. None of the BPA compounds were associated with higher odds of TND. Our study found associations of urinary BPA with TSH but not with BPF or ClxBPA. A larger study would be justified.