The impact of environmental factors and contaminants on thyroid function and disease from fetal to adult life: current evidence and future directions

The thyroid gland regulates most of the physiological processes. Environmental factors, including climate change, pollution, nutritional changes, and exposure to chemicals, have been recognized to impact thyroid function and health. Thyroid disorders and cancer have increased in the last decade, the latter increasing by 1.1% annually, suggesting that environmental contaminants must play a role. This narrative review explores current knowledge on the relationships among environmental factors and thyroid gland anatomy and function, reporting recent data, mechanisms, and gaps through which environmental factors act. Global warming changes thyroid function, and living in both iodine-poor areas and volcanic regions can represent a threat to thyroid function and can favor cancers because of low iodine intake and exposure to heavy metals and radon. Areas with high nitrate and nitrite concentrations in water and soil also negatively affect thyroid function. Air pollution, particularly particulate matter in outdoor air, can worsen thyroid function and can be carcinogenic. Environmental exposure to endocrine-disrupting chemicals can alter thyroid function in many ways, as some chemicals can mimic and/or disrupt thyroid hormone synthesis, release, and action on target tissues, such as bisphenols, phthalates, perchlorate, and per- and poly-fluoroalkyl substances. When discussing diet and nutrition, there is recent evidence of microbiome-associated changes, and an elevated consumption of animal fat would be associated with an increased production of thyroid autoantibodies. There is some evidence of negative effects of microplastics. Finally, infectious diseases can significantly affect thyroid function; recently, lessons have been learned from the SARS-CoV-2 pandemic. Understanding how environmental factors and contaminants influence thyroid function is crucial for developing preventive strategies and policies to guarantee appropriate development and healthy metabolism in the new generations and for preventing thyroid disease and cancer in adults and the elderly. However, there are many gaps in understanding that warrant further research

In vitro evaluation of controlled-release 14% doxycycline gel for decontamination of machined and sandblasted acid-etched implants

Background: Peri-implant infections are associated with the establishment and maturation of a bacterial biofilm characterized by a predominance of Gram-negative fusiform anaerobic species. The decontamination of implant surfaces is then crucial for a successful peri-implant therapy. Methods: Twenty-one smooth and 21 rough implants, divided into four groups according to surface and treatment modality, were contaminated with Streptococcus sanguinis and then placed in an incubator with the atmosphere of 5% CO2 at 37◦C for 24 hours to allow the bacteria to grow. After 24 hours, the test groups were treated with controlled release 14% doxycycline gel injecting the gel circumferentially over the surface of the implant for 3 minutes, while the control groups were irrigated with sterile saline for 1 minute. The implants were then vortexed into triptych soy broth to allow the bacteria to detach from the surface, diluted 1:100 and plated. Colony forming units (CFU) were counted 48 hours after incubation. Results: The use of a 14% doxycycline gel minimized CFU counts compared to control groups, with the difference being statistically significant (P < 0.05). The reduction of CFUs in the smooth test group is more marked than in the rough test group, but the difference doesn't reach statistically significance (P = 0.215). Conclusions: The use of 14% doxycycline gel in implant surface decontamination was efficacious in this in-vitro study. Adjunctive use of locally delivered 14% doxycycline gel might be a viable option in the management of peri-implantitis and peri-implant mucositis considering its efficacy in reducing bacterial colonization

Local antibiotic/antimicrobial therapy in the periodontal treatment. A review of the literature

OBJECTIVES. This review is intended to present a narrative report of the latest scientific papers published in the literature, concerning the use of local antibiotics and antimicrobial agents in addition to causal periodontal therapy in order to provide an update on the latest scientific evidence about the benefits, limitations and clinical results obtained by the use of such substances. MATERIALS AND METHODS. A narrative review of the literature has been conducted, using PubMed, Medline and Google Scholar including articles published in peer-reviewed journals between January 2009 and December 2014. The following keywords were used: "local delivery antimicrobials", "local delivery antibiotics", "local delivery AND periodontitis", "local antibiotics AND periodontitis", "local antimicrobials AND periodontitis" RESULTS. From this review we can infer that the use of local antibiotics or antimicrobial agents delivers significant benefits in periodontal therapy. Although it cannot replace the mechanical therapy, it is a useful aid, avoiding many of the side effects that systemic antibiotic therapy may involve. CONCLUSIONS. The local antibiotic and antimicrobial therapy is effective in the treatment of periodontal disease when used in addition to the mechanical therapy. In the opinion of the authors, the use of such agents should be preferred in cases of localized acute lesions or individual sites that do not respond to the causal therapy, always following a thorough scaling and root planing of the areas affected by the pathological process. However, to date, it is not possible to establish guidelines on the use of these agents given the heterogeneity of the protocols used in the various studies and the lack of consensus accepted by the scientific community

Thermodynamic effects of 3 different diode lasers on an implant-bone interface: An ex-vivo study with review of the literature

The aim of this study is to assess the increase of temperature following laser irradiation with 810 nm, 980 nm, and 1064 nm diode laser wavelengths, of an implant under conditions that more closely replicate those of the human body. A 4314 mm machined surface implant was placed in a porcine rib to replicate the conductivity of heat given by the bone. A peri-implant vertical defect was made that was 2 mm wide and 2 mm deep to simulate bone resorption. Two thermocouples were positioned crestally and apically on the implant surface. The tip of the laser was kept 3 mm away from the surface and continuously moved in an up-and-down and side-to-side fashion, inside the defect for 60 seconds. Initial temperatures and the time needed to reach an increase of 10°C were recorded. The experiment was repeated at room temperature and in a 37°C water bath with the following settings: 0.6 W, 0.8 W, 1 W continuous and repeated in pulsed. A critical increase of temperature of more than 10°C is reached with all lasers at 0.8 W and 1 W in continuous mode at room temperature. Only the 1064 nm diode laser reached the critical increase at 0.8 W in pulsed mode. No critical increase of temperature was registered with other settings and when the bone block was placed in a 37°C water bath. The results of this study suggest that use of these diode lasers does not cause a harmful increase in temperature when used under conditions similar to those of the human body

Carbonate Accretion Processes, Conservation and Enjoyment of the "Mannute Caves" Geoheritage site (Salento, Southern Italy)

The Mannute Caves (Salento, Italy) are a karst system that can only be reached using vertical rope techniques for caving and, hence, are not suitable for tourist visits because of their inaccessibility. New texture, geochemistry and age data of a peculiar type of carbonate accretion known as ‘bulky stalactites’ are presented here. Based on previous topographic surveys and observations on calcareous tufas, new geological data enables us to infer the palaeo-environmental history of the Mannute Piccola Cave. The present location of the bulky stalactites, close to the entrance of the cave, is in disagreement with an accretion process which requires sciophilous conditions. Based on U-Th dating, the growth of the bulky stalactites can be shown to have occurred in the Holocene and ended abruptly when the entrance of the cave was enlarged, probably due to a rockslide. The growing demand for geotourism in Salento suggests that management guidelines are required for coastal cave attractions, along with strategies to protect and evaluate the Mannute Piccola Cave as a potential geosite. Improved geological knowledge of the cave should be seen as a preliminary stage for geoheritage promotion through information communication technology (ICT) strategies, with the aim being to integrate the site within regional networks for cultural heritage enjoyment

Current evidence on the impact of the COVID-19 pandemic on paediatric endocrine conditions

Severe acute respiratory coronavirus 2 (SARS-CoV-2) interacts with the host cells through its spike protein by binding to the membrane enzyme angiotensin-converting enzyme 2 (ACE2) and it can have a direct effect on endocrine function as ACE2 is expressed in many glands and organs with endocrine function. Furthermore, several endocrine conditions have features that might increase the risk of SARS-CoV-2 infection and the severity and course of the infection, as obesity for the underlying chronic increased inflammatory status and metabolic derangement, and for the possible changes in thyroid function. Vitamin D has immunomodulatory effects, and its deficiency has negative effects. Adrenal insufficiency and excess glucocorticoids affect immune conditions also besides metabolism. This review aims to analyze the rationale for the fear of direct effects of SARS-Cov-2 on endocrinological disorders, to study the influence of pre-existing endocrine disorders on the course of the infection, and the actual data in childhood. Currently, data concerning endocrine function during the pandemic are scarce in childhood and for many aspects definite conclusions cannot be drawn, however, data on properly managed patients with adrenal insufficiency at present are re-assuring. Too little attention has been paid to thyroid function and further studies may be helpful. The available data support a need for adequate vitamin D supplementation, caution in obese patients, monitoring of thyroid function in hospitalized patients, and confirm the need for an awareness campaign for the increased frequency of precocious puberty, rapidly progressive puberty and precocious menarche. The changes in lifestyle, the increased incidence of overweight and the change in the timing of puberty lead also to hypothesize that there might be an increase in ovarian dysfunction, as for example polycystic ovarian disease, and metabolic derangements in the next years, and in the future we might be facing fertility problems. This prompts to be cautious and maintain further surveillance