Iodine metabolism and thyroid physiology: current concepts

Portable purge and trap-microplasma optical emission spectrometric device for field detection of iodine in water

Iodine is essential for human growth and can enter the body through food, water, and air. Analyzing its presence in the environment is crucial for ensuring healthy human development. However, current large-scale instruments have limitations in the field analysis of iodine. Herein, a miniaturized purge and trap point discharge microplasma optical emission spectrometric (P&T-μPD-OES) device was developed for the field analysis of iodine in water. Volatile iodine molecules were produced from total inorganic iodine (TII) through a basic redox reaction under acidic conditions, then the purge and trap module effectively separated and preconcentrated iodine molecules. The iodine molecules were subsequently atomized and excited by the integrated point discharge microplasma and an iodine atomic emission line at 206.24 nm was monitored by the spectrometer. Under optimal conditions, this proposed method had a detection limit of 16.2 μg L-1 for iodine and a precision better than 4.8%. Besides, the accuracy of the portable device was validated by successful analysis of surface and groundwater samples and a comparison of the mass spectrometry method. This proposed portable, low-power device is expected to support rapid access to iodine levels and distribution in water.

In Vivo Evaluation of the Pharmacokinetic Interaction between Levothyroxine and Amiodarone in Rat Plasma: Evaluation of Importance of Therapeutic Drug Monitoring during Co-Therapy

Amiodarone-induced thyrotoxicosis (AIT) is a common condition in patients who are receiving amiodarone for cardiac arrhythmia. This risk is elevated in iodine-deficient regions. Levothyroxine is the standard treatment for patients with hypothyroidism. This investigation is concerned with the evaluation of the possible pharmacokinetic interaction between amiodarone and levothyroxine upon co-therapy in rats and to investigate the cause of thyrotoxicosis. A selective, sensitive and precise RP-HPLC method was developed for the simultaneous determination of levothyroxine and amiodarone in rat plasma. A stationary phase of C18 Xterra RP column and a mobile phase consisting of acetonitrile: acidified water with 0.1% trifluoracetic acid (pH = 4.8) with gradient elution were used. The experiment was conducted at ambient temperature with flow rate of 1.5 mL/min for the chromatographic separation and quantitation of the investigated drugs. Protein precipitation with methanol was applied for the analysis of the two drugs in rat plasma. The method was linear over concentration range of 5-200 μg/mL for both levothyroxine and amiodarone. The European Medicines Agency guideline was applied for the validation of the developed bioanalytical method. The method was successfully applied to in vivo pharmacokinetic study in which levothyroxine and amiodarone were quantified in plasma of rats after receiving an oral dose of levothyroxine and amiodarone. After the calculation of the pharmacokinetic parameters, a statistical analysis was performed to elucidate the existence of significant difference between test and control groups in rats. The combination of levothyroxine and amiodarone significantly decreased levothyroxine bioavailability in rats, making the therapeutic drug monitoring mandatory in patients receiving levothyroxine and amiodarone. In addition, the increased clearance of levothyroxine upon the co-administration with amiodarone may explain the reported hypothyroidism.

Ultrasound and Sialendoscopy Findings in Radioactive Iodine-Induced Sialadenitis: Comparative Analysis and Possible Impact on Management

BACKGROUND

To assess the correlation/association between ultrasound and sialendoscopy findings in radioactive iodine therapy-induced sialadenitis (RAIS).

METHODS

Patients presenting with RAIS were investigated with ultrasound and sialendoscopy. Four pathologic ultrasound parameters and seven pathologic sialendoscopy parameters were retrospectively assessed. Correlations/associations between ultrasound and sialendoscopy findings and associations between the changes between the first and last ultrasound and sialendoscopy findings were assessed separately for the parotid (PG) and submandibular glands (SMG).

RESULTS

Sixty-seven patients were included. In the first examination, 107 glands were investigated (PGs 88.8%, SMGs 11.21%), and in the last examination, 64 glands were investigated (90.6% PGs, 9.4% SMGs). Highly significant positive associations were observed between the severity or category of ultrasound and sialendoscopy findings for first and last examinations for PGs (both p = 0.0001) and SMGs (p = 0.002; p = 0.037). Duct dilation had a significant negative association with the sialendoscopy findings for PGs in the first and last examinations (both p = 0.0001), but not for SMGs. Comparison of changes in the ultrasound and sialendoscopy findings between the first and last examinations showed a significant positive association for PGs (p = 0.0001) but not for SMGs.

CONCLUSIONS

Ultrasound and sialendoscopy findings for the parenchyma and duct system in RAIS showed significant associations/correlations and can be useful for effective management in RAIS.

Thyroid-Disrupting Effects of Exposure to Fipronil and Its Metabolites from Drinking Water Based on Human Thyroid Follicular Epithelial Nthy-ori 3-1 Cell Lines

Fipronil is a broad-spectrum insecticide used for plants and poultry. Owing to its widespread use, fipronil and its metabolites (fipronil sulfone, fipronil desulfinyl, and fipronil sulfide), termed FPM, can be frequently detected in drinking water and food. Fipronil can affect the thyroid function of animals, but the effects of FPM on the human thyroid remain unclear. We employed human thyroid follicular epithelial Nthy-ori 3-1 cells to examine combined cytotoxic responses, thyroid-related functional proteins including the sodium-iodide symporter (NIS), thyroid peroxidase (TPO), deiodinases I-III (DIO I-III), and the nuclear factor erythroid-derived factor 2-related factor 2 (NRF2) pathway induced by FPM of 1-1000-fold concentrations detected in school drinking water collected from a heavily contaminated area of the Huai River Basin. Thyroid-disrupting effects of FPM were evaluated by examining biomarkers of oxidative stress and thyroid function and tetraiodothyronine (T4) levels secreted by Nthy-ori 3-1 cells after FPM treatment. FPM activated the expression of NRF2, HO-1 (heme oxygenase 1), TPO, DIO I, and DIO II but inhibited NIS expression and increased the T4 level of thyrocytes, indicating that FPM can disrupt the function of human thyrocytes through oxidative pathways. Given the adverse impact of low FPM concentrations on human thyrocytes, supportive evidence from rodent studies, and the critical importance of thyroid hormones on development, the effects of FPM on the neurodevelopment and growth of children warrant priority attention.

Radioiodine therapy in advanced differentiated thyroid cancer: Resistance and overcoming strategy

Thyroid cancer is the most prevalent endocrine tumor and its incidence is fast-growing worldwide in recent years. Differentiated thyroid cancer (DTC) is the most common pathological subtype which is typically curable with surgery and Radioactive iodine (RAI) therapy (approximately 85%). Radioactive iodine is the first-line treatment for patients with metastatic Papillary Thyroid Cancer (PTC). However, 60% of patients with aggressive metastasis DTC developed resistance to RAI treatment and had a poor overall prognosis. The molecular mechanisms of RAI resistance include gene mutation and fusion, failure to transport RAI into the DTC cells, and interference with the tumor microenvironment (TME). However, it is unclear whether the above are the main drivers of the inability of patients with DTC to benefit from iodine therapy. With the development of new biological technologies, strategies that bolster RAI function include TKI-targeted therapy, DTC cell redifferentiation, and improved drug delivery via extracellular vesicles (EVs) have emerged. Despite some promising data and early success, overall survival was not prolonged in the majority of patients, and the disease continued to progress. It is still necessary to understand the genetic landscape and signaling pathways leading to iodine resistance and enhance the effectiveness and safety of the RAI sensitization approach. This review will summarize the mechanisms of RAI resistance, predictive biomarkers of RAI resistance, and the current RAI sensitization strategies.

Thyroidal and Extrathyroidal Requirements for Iodine and Selenium: A Combined Evolutionary and (Patho)Physiological Approach

Iodide is an antioxidant, oxidant and thyroid hormone constituent. Selenoproteins are needed for triiodothyronine synthesis, its deactivation and iodine release. They also protect thyroidal and extrathyroidal tissues from hydrogen peroxide used in the 'peroxidase partner system'. This system produces thyroid hormone and reactive iodine in exocrine glands to kill microbes. Exocrine glands recycle iodine and with high urinary clearance require constant dietary supply, unlike the thyroid. Disbalanced iodine-selenium explains relations between thyroid autoimmune disease (TAD) and cancer of thyroid and exocrine organs, notably stomach, breast, and prostate. Seafood is iodine unconstrained, but selenium constrained. Terrestrial food contains little iodine while selenium ranges from highly deficient to highly toxic. Iodine vs. TAD is U-shaped, but only low selenium relates to TAD. Oxidative stress from low selenium, and infection from disbalanced iodine-selenium, may generate cancer of thyroid and exocrine glands. Traditional Japanese diet resembles our ancient seashore-based diet and relates to aforementioned diseases. Adequate iodine might be in the milligram range but is toxic at low selenium. Optimal selenoprotein-P at 105 µg selenium/day agrees with Japanese intakes. Selenium upper limit may remain at 300-400 µg/day. Seafood combines iodine, selenium and other critical nutrients. It brings us back to the seashore diet that made us what we currently still are.

ESPEN micronutrient guideline

BACKGROUND

Trace elements and vitamins, named together micronutrients (MNs), are essential for human metabolism. Recent research has shown the importance of MNs in common pathologies, with significant deficiencies impacting the outcome.

OBJECTIVE

This guideline aims to provide information for daily clinical nutrition practice regarding assessment of MN status, monitoring, and prescription. It proposes a consensus terminology, since many words are used imprecisely, resulting in confusion. This is particularly true for the words "deficiency", "repletion", "complement", and "supplement".

METHODS

The expert group attempted to apply the 2015 standard operating procedures (SOP) for ESPEN which focuses on disease. However, this approach could not be applied due to the multiple diseases requiring clinical nutrition resulting in one text for each MN, rather than for diseases. An extensive search of the literature was conducted in the databases Medline, PubMed, Cochrane, Google Scholar, and CINAHL. The search focused on physiological data, historical evidence (published before PubMed release in 1996), and observational and/or randomized trials. For each MN, the main functions, optimal analytical methods, impact of inflammation, potential toxicity, and provision during enteral or parenteral nutrition were addressed. The SOP wording was applied for strength of recommendations.

RESULTS

There was a limited number of interventional trials, preventing meta-analysis and leading to a low level of evidence. The recommendations underwent a consensus process, which resulted in a percentage of agreement (%): strong consensus required of >90% of votes. Altogether the guideline proposes sets of recommendations for 26 MNs, resulting in 170 single recommendations. Critical MNs were identified with deficiencies being present in numerous acute and chronic diseases. Monitoring and management strategies are proposed.

CONCLUSION

This guideline should enable addressing suboptimal and deficient status of a bundle of MNs in at-risk diseases. In particular, it offers practical advice on MN provision and monitoring during nutritional support.

Corroles at work: a small macrocycle for great applications

Corrole chemistry has witnessed an impressive boost in studies in the last 20 years, thanks to the possibility of preparing corrole derivatives by simple synthetic procedures. The investigation of a large number of corroles has highlighted some peculiar characteristics of these macrocycles, having features different from those of the parent porphyrins. With this progress in the elucidation of corrole properties, attention has been focused on the potential for the exploitation of corrole derivatives in different important application fields. In some areas, the potential of corroles has been studied in certain detail, for example, the use of corrole metal complexes as electrocatalysts for energy conversion. In some other areas, the field is still in its infancy, such as in the exploitation of corroles in solar cells. Herein, we report an overview of the different applications of corroles, focusing on the studies reported in the last five years.

Low Urinary Iodine Concentration Is Associated with Increased Risk for Elevated Plasma Glucose in Females: An Analysis of NHANES 2011-12

Iodine intake in the US has declined in recent years. Iodine insufficiency increases the risk for inadequate thyroid hormone production and there is growing evidence that sub-clinical hypothyroidism may be disruptive to metabolic health, including insulin resistance (IR). We investigated the association between urinary iodine concentrations (UIC), a measurement of iodine status, and IR in adults. Data from 1286 US adults (≥20 years) in the NHANES 2011-2012 were analyzed. Two subgroups (low = UIC < 100 µg/L and normal = UIC ≥ 100 µg/L) were compared for markers of IR, including fasting plasma glucose (FPG) and insulin, homeostatic model assessment of insulin resistance (HOMA-IR), and glycated hemoglobin (HbA1C). Chi-square test, both linear and logistic regression models were used. In males, there were no significant associations between UIC and markers of IR; however, females with normal UIC had greater risks for elevated HOMA-IR (AOR = 0.56, 95% CI= 0.32-0.99) and HbA1C (AOR = 0.56, 95% CI = 0.34-0.90), while females with low UIC had a greater risk for FPG ≥ 5.6 mmol/L (AOR = 1.73, 95% CI = 1.09-2.72). Results only partially support our hypothesis that UIC is associated with the odds of IR in adults. The finding of an increased risk for elevated FPG, a marker of prediabetes, in female adults with low iodine status requires further investigation.

Radioiodine therapy in patient of differentiated thyroid cancer with end-stage renal disease on maintenance hemodialysis: case report with review of literature

Surgical resection followed by radioactive-iodine (¹³¹I) therapy constitutes a standard treatment for differentiated thyroid cancer (DTC). ¹³¹I is normally excreted through kidneys and treatment of patients with end stage renal disease (ESRD) on hemodialysis requires special attention for dosage of ¹³¹I, timing of dialysis and radiation safety. We present a case of a post-thyroidectomy patient with ESRD on haemodialysis who required radioactive iodine ablation with review of literature.

Clinical Management of End-Stage Renal Disease Patients on Dialysis Receiving Radioactive Iodine Treatment

PURPOSE

Radioactive iodine (RAI) is used to treat thyroid cancer patients with a clear paradigm for most patients. End-stage renal disease (ESRD) patients pose several challenges when undergoing RAI treatment, primarily due to the lack of renal clearance. We retrospectively report our experience with RAI treatment in a cohort of patients with ESRD and provide a set of recommendations on aspects such as the need for adjusted dose activity, balancing scheduling between RAI therapy and dialysis, and radiation safety precautions.

PATIENTS AND METHODS

In this study, we report on 5 patients (6 cases), with ESRD on dialysis, treated with RAI for thyroid cancer. Retention measurements to determine individual biological clearance of RAI from the patient's body before and after dialysis sessions were assessed using external exposure dose rates measured at 1 m.

RESULTS

Delayed biological clearance of RAI, after the first hemodialysis session, resulted in a longer RAI effective half-life as a consequence of longer retention periods, consistent with observations reported in scientific literature. To achieve a much closer radiation exposure compared with a nondialysis patient, one would recommend administering ~20%-30% of the dose activity normally administered to a thyroid cancer patient based on their medical history, histopathology, and uptake with the appropriate dialysis schedule.

CONCLUSIONS

Special precautions should be taken with the administration of RAI in ESRD patients by adjusting the prescribed dose activity, dialysis sessions, and paying special attention to wastes. Pooling data from multiple centers may be useful to build a consensus and substantiated recommendations.

Prediction of Radiation-Induced Hypothyroidism Using Radiomic Data Analysis Does Not Show Superiority over Standard Normal Tissue Complication Models

Simple Summary

Radiation-induced hypothyroidism (RIHT) commonly develops in cancer survivors that receive radiation therapy for cancers in the head and neck region. The state-of-art normal tissue complication probability (NTCP) models perform satisfactorily; however, they do not use the whole spectrum of information that can be obtained from imaging techniques. The radiomic approach offers the ability to efficiently mine features, which are imperceptible to the human eye, but may provide crucial data about the patient’s condition. We gathered CT images and clinical data from 98 patients undergoing radiotherapy for head and neck cancers, 27 of whom later developed RIHT. For them, we created machine-learning models to predict RIHT using automatically extracted radiomic features and appropriate clinical and dosimetric parameters. We also validated the well-established external state-of-art NTCP models on our datasets and observed that our radiomic-based models performed very similarly to them. This shows that automated tools may perform as well as the current standard but can be theoretically applied faster and be implemented into existing imaging software used when planning radiotherapy.

Abstract

State-of-art normal tissue complication probability (NTCP) models do not take into account more complex individual anatomical variations, which can be objectively quantitated and compared in radiomic analysis. The goal of this project was development of radiomic NTCP model for radiation-induced hypothyroidism (RIHT) using imaging biomarkers (radiomics). We gathered CT images and clinical data from 98 patients, who underwent intensity-modulated radiation therapy (IMRT) for head and neck cancers with a planned total dose of 70.0 Gy (33–35 fractions). During the 28-month (median) follow-up 27 patients (28%) developed RIHT. For each patient, we extracted 1316 radiomic features from original and transformed images using manually contoured thyroid masks. Creating models based on clinical, radiomic features or a combination thereof, we considered 3 variants of data preprocessing. Based on their performance metrics (sensitivity, specificity), we picked best models for each variant ((0.8, 0.96), (0.9, 0.93), (0.9, 0.89) variant-wise) and compared them with external NTCP models ((0.82, 0.88), (0.82, 0.88), (0.76, 0.91)). We showed that radiomic-based models did not outperform state-of-art NTCP models (p > 0.05). The potential benefit of radiomic-based approach is that it is dose-independent, and models can be used prior to treatment planning allowing faster selection of susceptible population.

Tissue quantification of radioiodine thyroid uptake in humans by an isotopic imaging technique on slides

BACKGROUND

Thyroid metabolism involves iodine, which allows us to use radioactive iodine for diagnostic and therapy purposes. The efficiency of radioiodine therapy depends on several parameters; the ability of thyroid tissue to uptake radioactive iodine is one of them.

OBJECTIVE

The objective of this work is to quantify the radioactive iodine uptake on thyroid tissue.

METHODS

In this work, we developed a method to quantify the in vivo uptake of iodine-131 on sections of thyroid glands removed by thyroidectomies. We performed an analysis of histological sections of the thyroid tissue by beta imaging. We had the opportunity to quantify the fixed radioactivity and to analyze its distribution in the thyroid gland, thanks to the good spatial resolution available with the type of detector used.

RESULTS

The results gave a high image resolution showing the heterogeneity of iodine-131 fixation by the thyroid tissue. We were able to quantify the tissue radioactivity in mega Becquerel (MBq) per volume unit.

CONCLUSION

This work has shown that the direct quantification of the thyroid tissue uptake is possible using the beta imaging system.

Variable 131I Activity in Renal Stone in a Patient With Thyroid Cancer

ABSTRACT

A 42-year-old woman underwent 131I radiotherapy for thyroid papillary cancer. A focal elevated 131I activity in the right kidney was revealed on the initial whole-body posttherapeutic images, which was located in the region of a renal stone. However, on the follow-up 131I images acquired 6 months later, there was no longer any increased activity in the region of this stone, which had moved into right ureter. Our case indicates that the 131I activity accumulated in the region of urinary stone is due to stagnated radioactive urine rather than due to the stone per se.

Iodine Absorption in Celiac Children: A Longitudinal Pilot Study

Background: non-autoimmune thyroid disorder is a common finding in celiac patients, more frequent than in the general population. An impairment of iodine absorption has been hypothesized, but it has never been investigated so far. We aimed to evaluate the iodine absorption in children and adolescents with newly diagnosed celiac disease. Methods: 36 consecutive celiac patients (age 7.4 years, range 2.4-14.5 years) before starting a gluten-free diet (GFD) were enrolled. We assayed the urinary iodine concentration (UIC) in a 24-h urine sample, at baseline (T0) after 3 (T1) and 12 months (T2) of GFD. Results: UIC at T0 was 64 μg/L (IQR 45-93.25 μg/L) with an iodine deficiency rate of 77.8%. UIC was not different according to histological damage, clinical presentation (typical vs atypical); we found no correlation with the thyroid function tests and auxological parameters. UIC was not statistically different at T1 (76 μg/L) and T2 (89 μg/L) vs T0. UIC at T2 was similar between patients with positive and negative anti-transglutaminase antibodies at T2. No patients presented overt hypothyroidism during the study. Conclusions: We found that iodine absorption in celiac children is impaired compared to the general population; it increases slightly, but not significantly, during the GFD. We should regularly reinforce the need for a proper iodine intake in celiac disease patients to reduce iodine deficiency risk.

Iodine concentration and content measured by dual-source computed tomography are correlated to thyroid hormone levels in euthyroid patients: a cross-sectional study in China

Background

The aim of this study was to investigate the correlation of the dual energy CT measured iodine concentration and total iodine content with blood measured thyroid parameters.

Methods

Forty-three patients with normal thyroid function at our hospital from August 2017 to October 2019 were included in this retrospective study. Dual energy CT was used to scan the neck of thyroid patients. The mean iodine concentration and thyroid tissue volume were measured to calculate the total iodine content of the thyroid. Relevant tests of triiodothyronine (FT3), total triiodothyronine (TT3), total thyroxine (TT4), free thyroxine (FT4), and thyroid hormone (TSH) were conducted. The correlation of the thyroid mean iodine concentration and total iodine content with blood-measured thyroid function was analysed.

Result

The total iodine content in the thyroid was positively correlated with FT3 but negatively correlated with TSH. The mean iodine concentration of the thyroid was positively correlated with both FT3 and TT3.

Conclusion

The thyroid iodine content measured by dual energy CT can be used to determine the human iodine nutritional status and evaluate thyroid function, which will facilitate the diagnosis and treatment of thyroid diseases.

Micronutrients and Breast Cancer Progression: A Systematic Review

Epidemiological studies on micronutrient consumption have reported protective associations in the incidence and/or progression of various cancer types. Supplementation with some of these micronutrients has been analyzed, showing chemoprotection, low toxicity, antiproliferation, and the ability to modify epigenetic signatures in various cancer models. This review investigates the reported effects of micronutrient intake or supplementation in breast cancer progression. A PubMed search was conducted with the keywords "micronutrients breast cancer progression", and the results were analyzed. The selected micronutrients were vitamins (C, D, and E), folic acid, metals (Cu, Fe, Se, and Zn), fatty acids, polyphenols, and iodine. The majority of in vitro models showed antiproliferative, cell-cycle arrest, and antimetastatic effects for almost all the micronutrients analyzed, but these effects do not reflect animal or human studies. Only one clinical trial with vitamin D and one pilot study with molecular iodine showed favorable overall survival and disease-free interval.

Clinical and Sialographic Imaging Features of 131I Radiation-induced Submandibular Gland Sialadenitis

PURPOSE

¹³¹I radiation-induced sialadenitis is the most frequent complication of ¹³¹I treatment for papillary thyroid carcinoma, but little is known about ¹³¹I radiation-induced submandibular gland sialadenitis. The purpose of this study was to compare and contrast the clinical and sialographic imaging features of ¹³¹I radiation-induced submandibular gland sialadenitis to ¹³¹I radiation-induced parotitis.

PATIENTS AND METHODS

This retrospective cross-sectional study included patients with ¹³¹I radiation-induced submandibular gland sialadenitis and parotitis. Clinical records and sialographic image features were evaluated. The predictor variables included age at the time of diagnosis, gender, course of the disease, site of symptoms, and sialographic image grades. The outcome variable was the location of sialadenitis. A student t-test was conducted to analyze the associations between predictor variables and the outcome.

RESULTS

The sample was composed of 4 patients with submandibular gland sialadenitis (100% female), 28 with parotitis (85.7% female), and 1 with submandibular gland sialadenitis and parotitis (P < .05). The occurrence of bilateral glands dysfunction was less often in submandibular glands (SMG: 1/4; PG: 19/28). The age and course of disease were not different between submandibular gland sialadenitis and parotitis (Age, SMG: 46.00 ± 13.59 years; PG: 50.04 ± 10.71 years, P > .05; Course of the disease, SMG: 11.00 ± 16.69 months; PG: 6.96 ± 11.18 months, P > .05). Radiographically, 7 of 16 patients with parotitis were identified as grade 2 and 9 patients as grade 3. In 3 patients with submandibular gland sialadenitis, 1 patient was identified as grade 2 and 2 patients as grade 3. The postoperative pathological results showed that the proliferation of glandular tissue from the hilum of the submandibular gland caused duct stenosis.

CONCLUSION

The results suggest ¹³¹I radiation-induced submandibular gland sialadenitis has a lower incidence compared with parotitis and ¹³¹I radiation-induced submandibular gland sialadenitis might be related to duct stenosis caused by proliferative glandular tissue after ¹³¹I radiation treatment.

Genomic and Non-Genomic Mechanisms of Action of Thyroid Hormones and Their Catabolite 3,5-Diiodo-L-Thyronine in Mammals

Since the realization that the cellular homologs of a gene found in the retrovirus that contributes to erythroblastosis in birds (v-erbA), i.e. the proto-oncogene c-erbA encodes the nuclear receptors for thyroid hormones (THs), most of the interest for THs focalized on their ability to control gene transcription. It was found, indeed, that, by regulating gene expression in many tissues, these hormones could mediate critical events both in development and in adult organisms. Among their effects, much attention was given to their ability to increase energy expenditure, and they were early proposed as anti-obesity drugs. However, their clinical use has been strongly challenged by the concomitant onset of toxic effects, especially on the heart. Notably, it has been clearly demonstrated that, besides their direct action on transcription (genomic effects), THs also have non-genomic effects, mediated by cell membrane and/or mitochondrial binding sites, and sometimes triggered by their endogenous catabolites. Among these latter molecules, 3,5-diiodo-L-thyronine (3,5-T2) has been attracting increasing interest because some of its metabolic effects are similar to those induced by T3, but it seems to be safer. The main target of 3,5-T2 appears to be the mitochondria, and it has been hypothesized that, by acting mainly on mitochondrial function and oxidative stress, 3,5-T2 might prevent and revert tissue damages and hepatic steatosis induced by a hyper-lipid diet, while concomitantly reducing the circulating levels of low density lipoproteins (LDL) and triglycerides. Besides a summary concerning general metabolism of THs, as well as their genomic and non-genomic effects, herein we will discuss resistance to THs and the possible mechanisms of action of 3,5-T2, also in relation to its possible clinical use as a drug.

Interference on Iodine Uptake and Human Thyroid Function by Perchlorate-Contaminated Water and Food

BACKGROUND

Perchlorate-induced natrium-iodide symporter (NIS) interference is a well-recognized thyroid disrupting mechanism. It is unclear, however, whether a chronic low-dose exposure to perchlorate delivered by food and drinks may cause thyroid dysfunction in the long term. Thus, the aim of this review was to overview and summarize literature results in order to clarify this issue.

METHODS

Authors searched PubMed/MEDLINE, Scopus, Web of Science, institutional websites and Google until April 2020 for relevant information about the fundamental mechanism of the thyroid NIS interference induced by orally consumed perchlorate compounds and its clinical consequences.

RESULTS

Food and drinking water should be considered relevant sources of perchlorate. Despite some controversies, cross-sectional studies demonstrated that perchlorate exposure affects thyroid hormone synthesis in infants, adolescents and adults, particularly in the case of underlying thyroid diseases and iodine insufficiency. An exaggerated exposure to perchlorate during pregnancy leads to a worse neurocognitive and behavioral development outcome in infants, regardless of maternal thyroid hormone levels.

DISCUSSION AND CONCLUSION

The effects of a chronic low-dose perchlorate exposure on thyroid homeostasis remain still unclear, leading to concerns especially for highly sensitive patients. Specific studies are needed to clarify this issue, aiming to better define strategies of detection and prevention.

Iodine nutrition in pregnant and breastfeeding women: sufficiency, deficiency, and supplementation

Iodine is a micronutrient used by the thyroid gland to produce thyroid hormones, which manage different aspects of body metabolism. Humans depend on exogenous sources of iodine to maintain the normal concentration of thyroid hormones. Pregnancy alters iodine turnover and is associated with significant changes in thyroid function. Daily iodine requirement during pregnancy increases to 250 μg, compared with 150 μg for nonpregnant women. According to recent guidelines of scientific organizations, to improve maternal thyroid status and to prevent child neurocognitive defects, all pregnant and breastfeeding women should take 150 μg of iodine supplementation, not only in iodine-deficient regions but also in iodine-sufficient areas. However, some recent studies have confirmed that iodine supplementation of mildly iodine-deficient pregnant women has no clear benefits as concerns maternal thyroid function or child neurodevelopment.

Mass Spectrometry-Based Protein Footprinting for Higher-Order Structure Analysis: Fundamentals and Applications

Proteins adopt different higher-order structures (HOS) to enable their unique biological functions. Understanding the complexities of protein higher-order structures and dynamics requires integrated approaches, where mass spectrometry (MS) is now positioned to play a key role. One of those approaches is protein footprinting. Although the initial demonstration of footprinting was for the HOS determination of protein/nucleic acid binding, the concept was later adapted to MS-based protein HOS analysis, through which different covalent labeling approaches "mark" the solvent accessible surface area (SASA) of proteins to reflect protein HOS. Hydrogen-deuterium exchange (HDX), where deuterium in D2O replaces hydrogen of the backbone amides, is the most common example of footprinting. Its advantage is that the footprint reflects SASA and hydrogen bonding, whereas one drawback is the labeling is reversible. Another example of footprinting is slow irreversible labeling of functional groups on amino acid side chains by targeted reagents with high specificity, probing structural changes at selected sites. A third footprinting approach is by reactions with fast, irreversible labeling species that are highly reactive and footprint broadly several amino acid residue side chains on the time scale of submilliseconds. All of these covalent labeling approaches combine to constitute a problem-solving toolbox that enables mass spectrometry as a valuable tool for HOS elucidation. As there has been a growing need for MS-based protein footprinting in both academia and industry owing to its high throughput capability, prompt availability, and high spatial resolution, we present a summary of the history, descriptions, principles, mechanisms, and applications of these covalent labeling approaches. Moreover, their applications are highlighted according to the biological questions they can answer. This review is intended as a tutorial for MS-based protein HOS elucidation and as a reference for investigators seeking a MS-based tool to address structural questions in protein science.

Variability of iodine concentrations in the human placenta

Iodine is an essential trace element, necessary for the production of thyroid hormones, which play a key role in optimal foetal growth and (neuro-) development. To date, iodine deficiency remains a health burden in many countries. We investigated the variability of placental iodine concentrations within and between individuals. We used 20 mother-neonate pairs from the ENVIRONAGE birth cohort, took samples at three standardized locations of the placentas, pooled and digested them, and determined the iodine concentrations using an ICP-MS method as an alternative for the Sandell-Kolthoff method. The variability between and within the three sample regions was calculated using the intra-class correlation coefficient (ICC) from the variance components of mixed models. With the Friedman test, the differences between placental biopsies were assessed. The ICC showed a higher between-placenta (68.6%) than within-placenta (31.4%) variability. Subsequently, we used our optimized method to determine iodine concentrations in 498 mother-neonate pairs, which averaged 26.1 μg/kg. For 96 mothers, the urinary iodine concentrations were also determined, which showed no correlation with the placental iodine storage, as was expected. Future studies are necessary to explore the effects of these placental iodine concentrations in relation to health outcomes of mother and child at birth and later in life.

Thyroid hormone therapy in differentiated thyroid cancer

Surgery-with or without postoperative radioiodine-is the standard of care for most patients with differentiated thyroid carcinoma (DTC). Thyroid hormone replacement therapy is the mainstay of long-term medical management. Patients treated with total thyroidectomy and some who undergo lobectomy alone require thyroid hormone therapy to restore euthyroidism with normal serum thyroid-stimulating hormone (TSH) levels. Because TSH acts as a growth factor for thyroid follicular cells (including those that are neoplastic), it can potentially affect the onset and/or progression of follicular-cell derived thyroid cancer. For this reason, some patients are placed on thyroid hormone therapy at doses that suppress secretion of TSH (suppression therapy). This mini-review looks at the potential benefits and risks of this practice in patients diagnosed with DTC. Aggressive TSH-suppressive therapy is of little or no benefit to the vast majority of patients with DTC. Practice guidelines, therefore, recommend a graded algorithm in which the potential benefits of suppression are weighed against the associated cardiovascular and skeletal risks. Large randomized controlled studies are needed to confirm the presumed oncological benefits of TSH-suppression and its causal role in adverse cardiac, skeletal, and quality of life effects and to assess the efficacy of TSH normalization in reversing or reducing these effects.

Biocompatible Iodine-Starch-Alginate Hydrogel for Tumor Photothermal Therapy

Photothermal therapy (PTT) with the advantages of high efficiency and minimal invasiveness is a promising technique for tumor therapy, but clinical application of PTT agents has been stifled by the great safety concerns. Herein, a deep blue iodine-starch-alginate (ALG) hydrogel is elegantly fabricated based on the classic and simple "iodine-starch test" for in vivo tumor PTT in a facile and mild way. The iodine-starch-ALG hydrogel composed of clinically used agents is fabricated by dispersing blue iodine-starch complex into alginate-Ca²⁺ hydrogel, which guarantees the good chemical stability of iodine-starch complex via separating them from surrounding reductive environment. The iodine-starch-ALG hydrogel possesses favorable biocompatibility derived from the biosafe and degradable components and possesses good photothermal heating ability based on iodine-starch chromophore. The proposed iodine-starch-ALG hydrogel is successfully applied in tumor PTT in vitro and in vivo for the first time. This work lays down a novel way for the development of high-performance and biocompatible biomaterials via teaching old drugs new tricks.

Determination of effective half-life of 131I in patients with differentiated thyroid carcinoma: comparison of cystatin C and creatinine-based estimation of renal function

PURPOSE

Renal function and effective half-life (t_1/2,eff) of I-131 have not been fully elucidated in patients undergoing radioiodine therapy (RAIT) for differentiated thyroid cancer (DTC). Aim of the present analysis was to evaluate the potential of cystatin C-based estimated glomerular filtration rate (eGFR_CysC) in comparison to conventional creatinine (eGFR_Crea) and to verify which methods to determine t_1/2,eff are most accurate to predict t_1/2,eff.

METHODS

Forty-eight patients receiving whole-body I-131-scintigraphy were included. eGFR_CysC was compared to eGFR_Crea with regard to accuracy of t_1/2,eff prediction. Three different methods (i.e. blood-based, gamma camera-based and probe-based) and two protocols with either three (short period,SP; up to 42 h) or four (long period,LP; up to 114 h) time points were compared using the Akaike's information criterion.

RESULTS

The eGFR_CysC measurement is more likely than eGFR_Crea in predicting the t_1/2,eff. High correlation coefficients were found between t_1/2,eff assessed by gamma camera and probe measurements and blood-based determination revealed lower values. Patients with normal eGFR showed higher values of t_1/2,eff of LP compared to SP.

CONCLUSIONS

eGFR_CysC should be included in further study protocols. As camera and probe measurements lead to almost superimposable results, one of the methods is expendable. Blood-based results of t_1/2,eff were lower, presumably due to unspecific iodine retention, whereas the lower correlation with renal function may be caused by individual differences in intestinal iodine resorption. SP-protocols up to 42 h after I-131 administration are sufficient to determine t_1/2,eff. Further studies are necessary for specific recommendations regarding I-131 activity reduction during RAIT in patients with DTC and renal insufficiency.

Effects of repeated potassium iodide administration on genes involved in synthesis and secretion of thyroid hormone in adult male rat

BACKGROUND

A single dose of potassium iodide (KI) is recommended to reduce the risk of thyroid cancer during nuclear accidents. However in case of prolonged radioiodine exposure, more than one dose of KI may be necessary. This work aims to evaluate the potential toxic effect of repeated administration of KI.

METHODS

Adult Wistar rats received an optimal dose of KI 1 mg/kg over a period of 1, 4 or 8 days.

RESULTS

hormonal status (TSH, FT4) of treated rats was unaffected. Contrariwise, a sequential Wolff-Chaikoff effect was observed, resulting in a prompt decrease of NIS and MCT8 mRNA expression (-58% and -26% respectively), followed by a delayed decrease of TPO mRNA expression (-33%) in conjunction with a stimulation of PDS mRNA expression (+62%).

CONCLUSION

we show for the first time that repeated administration of KI at 1 mg/kg/24h doesn't cause modification of thyroid hormones level, but leads to a reversible modification of the expression of genes involved in the synthesis and secretion of thyroid hormones.

Safety profile after prolonged C3 inhibition

The central component of the complement cascade, C3, is involved in various biological functions, including opsonization of foreign bodies, clearance of waste material, activation of immune cells, and triggering of pathways controlling development. Given its broad role in immune responses, particularly in phagocytosis and the clearance of microbes, a deficiency in complement C3 in humans is often associated with multiple bacterial infections. Interestingly, an increased susceptibility to infections appears to occur mainly in the first two years of life and then wanes throughout adulthood. In view of the well-established connection between C3 deficiency and infections, therapeutic inhibition of complement at the level of C3 is often considered with caution or disregarded. We therefore set out to investigate the immune and biochemical profile of non-human primates under prolonged treatment with the C3 inhibitor compstatin (Cp40 analog). Cynomolgus monkeys were dosed subcutaneously with Cp40, resulting in systemic inhibition of C3, for 1 week, 2 weeks, or 3 months. Plasma concentrations of both C3 and Cp40 were measured periodically and complete saturation of plasma C3 was confirmed. No differences in hematological, biochemical, or immunological parameters were identified in the blood or tissues of animals treated with Cp40 when compared to those injected with vehicle alone. Further, skin wounds showed no signs of infection in those treated with Cp40. In fact, Cp40 treatment was associated with a trend toward accelerated wound healing when compared with the control group. In addition, a biodistribution study in a rhesus monkey indicated that the distribution of Cp40 in the body is associated with the presence of C3, concentrating in organs that accumulate blood and produce C3. Overall, our data suggest that systemic C3 inhibition in healthy adult non-human primates is not associated with a weakened immune system or susceptibility to infections.

Correlation of 18F-FDG uptake and thyroid cancer stem cells

BACKGROUND

2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography (¹⁸F-FDG PET) has the potential to detect various types of cancers, including thyroid cancer (TC), at a potentially curable stage. Increased uptake of ¹⁸F-FDG was observed in anaplastic and poorly differentiated thyroid cancer cells, and PET-positive tumors are more likely to be resistant to ¹³¹I treatment. As cancer stem cells (CSCs) possess a dedifferentiated phenotype and are resistant to many anticancer therapies, we hypothesized that the expression of CSC-related markers is correlated with the ability of tumor cells in TC to uptake FDG.

METHODS

The present study cohort included 12 patients with TC, who underwent ¹⁸F-FDG PET/CT imaging before surgery. Quantitative polymerase chain reaction (QPCR) and immunohistochemical (IHC) staining were performed to analyze the expression patterns of gene markers related to embryonic stem (ES) cells and CSCs in TC.

RESULTS

The mRNA expression levels of CSC- (CD133 and CD44) and ES-related genes (Oct4 and Nanog) were higher in TC tissue than in normal thyroid tissue, whereas the mRNA expression levels of thyroid-specific genes (Tg, TSHR, and TTF1) were higher in normal thyroid tissue than in TC tissue. There was a positive and statistically significant correlation between FDG uptake (SUV<inf>max</inf>) of tumor and relative mRNA levels of CD133, CD44, Oct4, and Nanog. The IHC results demonstrated that CD133 and Nanog were expressed in TC tissue but not in normal thyroid tissue, however, CD44 expression was observed in both TC and normal thyroid tissue. Comparisons of the clinicopathological parameters between TC tissues with low and high SUV<inf>max</inf> demonstrated significant differences in protein level of CD133 but not in that of Nanog.

CONCLUSIONS

The pre-therapeutic tumor SUV<inf>max</inf> obtained from ¹⁸F-FDG PET/CT may be a potential predictor for evaluating the proportion of CSC population in individual patients with TC.

The minimum amount of fluids needed to achieve the fastest time to reach permissible level for release in well-differentiated thyroid patients undergoing high-dose I-131 therapy

Radioiodine (131I) therapy is the mainstay of treatment for patients who had undergone total thyroidectomy for well differentiated thyroid carcinoma. Increased fluid intake has always been encouraged to minimize the risk of non-target organ exposure to I-131radiation. This study aimed to determine the minimum amount of fluids needed for patients to have the fastest time to achieve permissible level for release after high dose I-131therapy. Methodology: All the patients who were treated with high dose I-131from 18^th January 2016 till 31^st December 2016 in Hospital Pulau Pinang, Malaysia were recruited. The data from 126 patients on thyroxine hormone withdrawal (THW) group and 18 patients on recombinant human thyroid stimulating hormone (rhTSH) group were analysed. There is no change in patient management in terms of preparation, dose or post therapy whole-body scan. Fluid intake of patients were monitored strictly and whole-body retention of I-131are measured using ionizing chamber meter immediately after ingestion of I-131then at 1 hour, 24 hours, 48 hours, 72 hours and 96 hours. Results: The median time to achieve permissible release limit (50 μSV/hr at 1 meter) was 21.6 hours and 22.1 hours post-ingestion of I-131in the THW and rhTSH group respectively. The minimum amount of fluid needed to reach permissible release limit in the fastest time was 2,103 ml and 2,148ml for the THW and TSH respectively. Conclusion: Clinicians would be able to evidently advise their patient on the amount of fluid to consume and utilize their isolation wards faster to treat more patients.

[18F]Tetrafluoroborate ([18F]TFB) and its analogs for PET imaging of the sodium/iodide symporter

Sodium/iodide symporter (NIS)-mediated iodide uptake in thyroid follicular cells is the basis of clinical utilization of radioiodines. The cloning of the NIS gene enabled applications of NIS as a reporter gene in both preclinical and translational research. Non-invasive NIS imaging with radioactive iodides and iodide analogs has gained much interest in recent years for evaluation of thyroid cancer and NIS reporter expression. Although radioiodines and [^99mTc]pertechnetate ([^99mTc]TcO₄^-) have been utilized in positron emission tomography (PET) and single photon emission computed tomography (SPECT), they may suffer from limitations of availability, undesirable decay properties or imaging sensitivity (SPECT versus PET). Recently, [¹⁸F]tetrafluoroborate ([¹⁸F]TFB or [¹⁸F]BF₄^-) and other fluorine-18 labeled iodide analogs have emerged as a promising iodide analog for PET imaging. These fluorine-18 labeled probes have practical radiosyntheses and biochemical properties that allow them to closely mimic iodide transport by NIS in thyroid, as well as in other NIS-expressing tissues. Unlike radioiodides, they do not undergo organification in thyroid cells, which results in an advantage of relatively lower uptake in normal thyroid tissue. Initial clinical trials of [¹⁸F]TFB have been completed in healthy human subjects and thyroid cancer patients. The excellent imaging properties of [¹⁸F]TFB for evaluation of NIS-expressing tissues indicate its bright future in PET NIS imaging. This review focuses on the recent evolution of [¹⁸F]TFB and other iodide analogs and their potential value in research and clinical practice.

Histological and ultrastructural alterations of rat thyroid gland after short-term treatment with high doses of thyroid hormones

The aim of the present study was to investigate histological alterations of rat thyroid gland after short-term treatment with supraphysiological doses of thyroid hormones. Rats from experimental groups were treated with triiodothyronine (T3) or thyroxine (T4) during five days. In both treated groups, thyrocyte height was reduced and follicular lumens were distended. Progressive involutive changes of the thyroid parenchyma were apparent, including follicular remodeling (fusion) and death of thyrocytes. Morphological changes confirmed by quantitative analysis were more pronounced in the T4-treated group. Our results demonstrate that thyrotoxicosis, whether induced by T3 or T4, leads to different grades of thyroid tissue injury, including some irreversible damages. These changes might be explained at least in part by lack of trophic and cytoprotective effects of the thyroid stimulating hormone. Since the period required for morphophysiological recovery may be unpredictable, findings presented here should be taken into consideration in cases where the thyroid hormones are used as a treatment for thyroid and non-thyroid related conditions.

Field-effect transition sensor for KI detection based on self-assembled calixtube monolayers

A series of novel calixarene-based tubes comprising different numbers of silatrane anchoring groups was synthesized. For the first time, a self-assembled monolayer (SAM) derived from calixtubes was formed on a SiO₂ surface. The formation of the SAM was confirmed by X-ray photoelectron spectroscopy, scanning electron microscopy-energy dispersive X-ray analysis, and contact angle measurements. Modification of the sensitive surface of a conventional ion-selective field effect transistor (ISFET) with the afforded SAM resulted in the production of a KI-sensitive sensor. This sensor selectively determined KI compare to different alkali metal iodides: NaI, RbI, CsI; also investigation of different potassium salts (acetate, iodide, nitrate, chloride, dihydrophosphate, perchlorate) showed the highest response to KI. This sensor was successfully employed to determine the presence of KI in artificial saliva with a limit of detection of ~3 × 10^-8 М. In addition, it was found that the detection limit of the sensor could be increased by combining the sensor with a microfluidic system. Due to the obtained sensor sensitivity and its ability to detect KI in artificial saliva, we could conclude that this sensor shows great potential for application in the determination of KI in different media, such as the human body and in biological liquids, such as saliva or urine.

Active Site Binding Is Not Sufficient for Reductive Deiodination by Iodotyrosine Deiodinase

The minimal requirements for substrate recognition and turnover by iodotyrosine deiodinase were examined to learn the basis for its catalytic specificity. This enzyme is crucial for iodide homeostasis and the generation of thyroid hormone in chordates. 2-Iodophenol binds only very weakly to the human enzyme and is dehalogenated with a k_cat/K_m that is more than 4 orders of magnitude lower than that for iodotyrosine. This discrimination likely protects against a futile cycle of iodinating and deiodinating precursors of thyroid hormone biosynthesis. Surprisingly, a very similar catalytic selectivity was expressed by a bacterial homologue from Haliscomenobacter hydrossis. In this example, discrimination was not based on affinity since 4-cyano-2-iodophenol bound to the bacterial deiodinase with a K_d lower than that of iodotyrosine and yet was not detectably deiodinated. Other phenols including 2-iodophenol were deiodinated but only very inefficiently. Crystal structures of the bacterial enzyme with and without bound iodotyrosine are nearly superimposable and quite similar to the corresponding structures of the human enzyme. Likewise, the bacterial enzyme is activated for single electron transfer after binding to the substrate analogue fluorotyrosine as previously observed with the human enzyme. A cocrystal structure of bacterial deiodinase and 2-iodophenol indicates that this ligand stacks on the active site flavin mononucleotide (FMN) in a orientation analogous to that of bound iodotyrosine. However, 2-iodophenol association is not sufficient to activate the FMN chemistry required for catalysis, and thus the bacterial enzyme appears to share a similar specificity for halotyrosines even though their physiological roles are likely very different from those in humans.

Diagnostic Utility of Acoustic Structure Quantification for Evaluation of Radiation Sialadenitis after Radioactive Iodine Therapy

Acoustic structure quantification (ASQ) software was used to analyze statistical information on acquired echo signals, to determine the ability of ASQ to distinguish normal salivary glands of asymptomatic patients from glands of patients with radiation sialadenitis (RS) after radioactive iodine therapy. The ASQ values of 192 salivary glands were compared by multinomial logistic regression analysis, and receiver operating characteristic curves were constructed. Between-observer agreement was assessed by calculating the intra-class correlation coefficient. The mean ASQ values of patients with chronic RS or asymptomatic patients who had undergone radioactive iodine therapy were greater than those of patients with normal glands (p < 0.001). The ratio was associated with the highest odds ratio in patients with chronic RS compared with normal patients. Diagnostic performance was moderate; the intra-class correlation coefficient between observers was very good. ASQ can objectively differentiate RS-affected tissue from normal salivary tissue and is thus valuable for clinically diagnosing RS after radioactive iodine therapy.

Outcome of Radioiodine Therapy in a West African Population

Hyperthyroidism continues to be a pressing public health concern in West Africa. Its prevalence in Africa has been quoted as 1.2%-9.9%, with Graves' disease as its most common cause. Radioiodine-131 (RAI) therapy of hyperthyroidism recently commenced in two government hospitals in Ghana and Nigeria. This is a retrospective analysis of consecutive patients treated with RAI for primary hyperthyroidism at the National Centre for Radiotherapy and Nuclear Medicine (NCRNM) from 2008-2013, and in the University College Hospital (UCH) from 2006-2013. Cure was defined as euthyroidism or hypothyroidism occurring at 6 months post-RAI. Data were analysed using SPSS version 21 and Epi Info version, categorical data were evaluated with the Chi-square test and Fisher's exact test. 94 patients were studied, aged 20-74 years; 78 were females, and 16 were males. 38 were Ghanaian and 56 Nigerian. The presence of thyroid-associated ophthalmopathy (TAO) made cure less likely (χ(2) P = 0.006, odds ratio = 0.118; 95% confidence interval, 0.027-0.518). Other factors assessed proved to be insignificant. Our findings suggest that hyperthyroid patients with TAO will benefit from a higher RAI dose than their counterparts without TAO.

Thyroid side effects prophylaxis in front of nuclear power plant accidents

The better knowledge of the mechanisms of nuclear incidents and lessons learned from accidents in the recent past to improve the effectiveness of measures taken following a nuclear accident exposure to fallout of radioactive iodine isotopes. Thus, immediate, passive measures, such as containment, and stopping consumption of contaminated products are paramount. The earliest possible administration of stable iodine as potassium iodide (KI) reduces significantly (up to 90% if taken at the same time of the accident) thyroid radioactive contamination. These tablets should be given in priority to children and pregnant women. The side effects are minor. KI is not recommended for persons aged over 60 years, or for adults suffering from cardiovascular disorders.

(131)I treatment in Differentiated Thyroid Cancer and End-Stage Renal Disease

PURPOSE

Radioiodine (RAI) is a cornerstone in the treatment of Differentiated Thyroid Cancer (DTC). In patients on haemodialysis due to End-Stage Renal Disease (ESRD), it must be used cautiously, considering the renal clearance of this radionuclide. Also, the safety of the procedure and subsequent long-term outcome is still not well defined. In 2001, we described a dosimetric method and short-term results in three patients, with a good safety profile. We hypothesize that our method is safe in a long-term scenario without compromising the prognosis of both renal and thyroid disease.

MATERIAL AND METHODS

Descriptive-retrospective study. A systematic search was carried out using our clinical database from 2000 to 2014.

INCLUSION CRITERIA

DTC and radioiodine treatment while on haemodialysis.

EXCLUSION CRITERIA

peritoneal dialysis.

RESULTS

Final sample n=9 patients (n=5 males), age 48 years (median age 51 years males, 67 years female group); n=8 papillary thyroid cancer, n=1 follicular thyroid cancer; n=5 lymph node invasion; n=1 metastatic disease. Median RAI dose administered on haemodialysis 100mCi. 7.5 years after radioiodine treatment on haemodialysis, n=7 deemed free of thyroid disease, n=1 persistent non-localised disease. No complications related to the procedure or other target organs were registered. After 3.25 years, n=4 patients underwent successful renal transplantation; n=4 patients did not meet transplantation criteria due to other conditions unrelated to the thyroid disease or its treatment. One patient died due to ischemic cardiomyopathy (free of thyroid disease).

CONCLUSIONS

Radioiodine treatment during haemodialysis is a long-term, safe procedure without worsening prognosis of either renal or thyroid disease.

Assessment of the Effect of Two Distinct Restricted Iodine Diet Durations on Urinary Iodine Levels (Collected over 24 h or as a Single-Spot Urinary Sample) and Na(+)/I(-) Symporter Expression

INTRODUCTION

A restricted iodine diet (RID) may be recommended for depletion of the whole-body iodine pool in patients with differentiated thyroid cancer referred for radioiodine treatment or a whole-body scan. Evaluation of the iodine pool is possible through urinary iodide (UI) measurements, which can be collected in 24-hour (24U) or spot urinary (sU) samples. However, the minimum period required for an RID to lower the iodine pool, the measurement of iodine in sU samples as a iodine pool marker, and the influence of the iodine pool on Na(+)/I(-) symporter (NIS) expression are debatable in the literature.

OBJECTIVES

To compare the effects of 15- and 30-day RID on UI measurements in 24U and sU samples and the impact of RID on NIS expression.

METHODS

Thyroidectomized patients went on a 15- or 30-day RID and collected 24U and sU samples before and after the RID. Twenty healthy individuals were evaluated for mRNA NIS expression before and after the RID.

RESULTS

Of 306 patients, only 125 properly complied with both the RID and 24U collection. We observed a correlation between sU and 24U UI before the RID (n = 306, ρ = 0.47, p < 0.001), after a 15-day RID (n = 79, ρ = 0.49, p < 0.001), and after a 30-day RID (n = 46, ρ = 0.73, p < 0.001). There was a significant decrease in UI after the RID. The median UI measurement was 275 μg/l at baseline and 99 and 80 μg/l after a 15- and 30-day RID, respectively. There was a significant increase in NIS expression after a 15-day RID.

CONCLUSIONS

A 15-day RID is sufficient to deplete the iodine pool. sU can replace 24U UI as a marker for assessing the iodine pool. NIS expression was increased after a 15-day RID.

(131)I treatment for thyroid cancer and the risk of developing salivary and lacrimal gland dysfunction and a second primary malignancy: a nationwide population-based cohort study

OBJECTIVE

The aim of this study was to determine the prevalence of salivary and lacrimal gland dysfunction and a second primary malignancy in patients from Taiwan with thyroid cancer after radioiodine therapy.

METHODS

This nationwide population-based cohort study was based on data obtained from the Taiwan National Health Insurance Database from 2000 to 2011. A total of 1,834 thyroid cancer patients treated with (131)I therapy and 1,834 controls (thyroid cancer without (131)I therapy) selected by 1:1 matching on a propensity score were enrolled. The cumulative (131)I dose in each patient was calculated. A Cox proportional hazards model was applied to estimate the effect of radiation from the (131)I therapy on the risk of salivary and lacrimal gland impairment as well as second primary malignancies in terms of hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

In patients treated with (131)I therapy and in controls, the incidence rates of salivary gland dysfunction were 6.76 and 1.01 per 10,000 person-years, respectively (HR 6.81, 95% CI 0.74 - 55.3), the incidence rates of keratoconjunctivitis sicca (KCS) were 13.6 and 16.3 per 10,000 person-years, respectively (HR 0.84, 95% CI 0.41 - 1.73), and the incidence rates of second primary malignancy were 76.7 and 62.4 per 10,000 person-years, respectively (HR 1.23, 95% CI 0.88 - 1.72). The risk of salivary secretion impairment significantly increased with increasing administered doses (HR 14.3, 95% CI 1.73 - 119.0). However, there was no increase in the incidence of KCS or secondary cancer in patients treated with higher doses.

CONCLUSION

(131)I therapy insignificantly increased the risk of salivary gland dysfunction and second primary malignancy. In patients with higher cumulative doses, an increase in the incidence of salivary gland dysfunction was observed. By contrast, we did not find an association between (131)I treatment and KCS development.

Thyroid-related neurological disorders and complications in children

BACKGROUND

Thyroid hormones exert critical roles throughout the body and play an important and permissive role in neuroendocrine, neurological, and neuromuscular function.

METHODS

We performed a PubMed search through June 2014 with search terms including "hypothyroidism," "hyperthyroidism," "neurological complications," "neuropathy," "myopathy," "congenital hypothyroidism," and "encephalopathy." Relevant publications reviewed included case series, individual case reports, systematic reviews, retrospective analyses, and randomized controlled trials. The neurological outcomes of congenital hypothyroidism were reviewed, along with the clinical features of associated neuromuscular syndromes of both hypothyroidism and hyperthyroidism, including other autoimmune conditions. Evidence for, and pathophysiological controversies surrounding, Hashimoto encephalopathy was also reviewed.

RESULTS

The establishment of widespread newborn screening programs has been highly successful in attenuating or preventing early and irreversible neurological harm resulting from congenital thyroid hormone deficiency, but some children continue to display neuromuscular, sensory, and cognitive defects in later life. Acquired disorders of thyroid function such as Hashimoto thyroiditis and Graves' disease are associated with a spectrum of central nervous system and/or neuromuscular dysfunction. However, considerable variation in clinical phenotype is described, and much of our knowledge of the role of thyroid disease in childhood neurological disorders is derived from adult case series.

CONCLUSIONS

Early and aggressive normalization of thyroxine levels in newborn infants with congenital hypothyroidism is important in minimizing neurological sequelae, but maternal thyroid hormone sources are also critically important to the early developing brain. A spectrum of neurological disorders has been reported in older children with acquired thyroid disease, but the frequency with which these occur remains poorly defined in the literature, and much must be extrapolated from adult data. A high index of suspicion for acquired thyroid disease is paramount in the investigation of many neurological disorders of youth, as many reported sequelae of hypothyroidism and hyperthyroidism are reversible with appropriate endocrine management.

Incremental amounts of Ascophyllum nodosum meal do not improve animal performance but do increase milk iodine output in early lactation dairy cows fed high-forage diets

The objective of this study was to investigate the effects of incremental amounts of Ascophyllum nodosum meal (ANOD) on milk production, milk composition including fatty acids and I, blood metabolites, and nutrient intake and digestibility in early lactation dairy cows fed high-forage diets. Twelve multiparous Jersey cows averaging (mean±standard deviation) 40±21 d in milk and 464±35 kg of body weight and 4 primiparous Jersey cows averaging 75±37 d in milk and 384±17kg of body weight were randomly assigned to treatment sequences in a replicated 4×4 Latin square design. Each period lasted 21 d with 14 d for diet adaptation and 7 d for data and sample collection. Cows were fed a total mixed ration (64:36 forage-to-concentrate ratio) supplemented (as fed) with 0, 57, 113, or 170 g/d of ANOD. Milk yield as well as concentrations and yields of milk components (fat, protein, lactose, milk urea N) were not affected by increasing dietary amounts of ANOD. Concentration (from 178 to 1,370 µg/L) and yield (from 2.8 to 20.6 mg/d) of milk I increased linearly in cows fed incremental amounts of ANOD as a result of the high concentration of I (820 mg/kg of dry matter) in ANOD. Overall, only minor changes were observed in the proportion of milk fatty acids with ANOD supplementation. Quadratic trends were observed for dry matter intake and total-tract digestibilities of organic matter and neutral detergent fiber, whereas negative linear trends were observed for serum concentration of cortisol and crude protein digestibility with ANOD supplementation. Serum concentrations of triiodothyronine and thyroxine were not affected by ANOD supplementation and averaged 1.1 and 48.4 ng/mL, respectively. However, feeding increasing amounts of ANOD linearly reduced the plasma concentration of nonesterified fatty acids (from 164 to 132 mEq/L). Quadratic effects were found for the total-tract digestibility of ADF and urinary output of purine derivatives, suggesting that ANOD supplementation may stimulate growth of ruminal cellulolytic bacteria in a dose-dependent fashion. In general, feeding incremental amounts of ANOD to early lactation dairy cows dramatically increased milk I concentration and output with no effect on animal performance.

Iodine-deficiency disorders in the Aseer region, south-western Saudi Arabia: 20 years after the national survey and universal salt iodization

OBJECTIVE

To study (i) the current prevalence of iodine-deficiency disorders among schoolchildren in south-western Saudi Arabia after universal salt iodization and (ii) the iodine content of table salts and water.

DESIGN

Cross-sectional study on a stratified proportional allocation sample of children. Thyroid gland enlargement was assessed clinically and by ultrasound scanning. Urine, table salt and water samples were taken to measure iodine content. Settings The Aseer region, south-western Saudi Arabia.

SUBJECTS

Schoolchildren aged 8-10 years.

RESULTS

The study included 3046 schoolchildren. The total goitre rate amounted to 24·0 %. Prevalence of enlarged thyroid by ultrasound was 22·7 %. The median urinary iodine concentration of the study sample amounted to 17·0 µg/l. The iodine content of table salt ranged from 0 to 112 mg/kg; 22·5 % of the table salt samples were below the recommended iodine content (15 mg/kg) set by WHO. The total goitre rate increased significantly from 19·8 % among children using table salt with iodine content ≥15 mg/kg to reach 48·5 % among children using table salt with 0 mg iodine/kg. Analysis of water samples taken from schools showed that the majority of water samples (78·8 %) had an iodine content of 0 µg/l.

CONCLUSIONS

The study documented that 18 years after the national study, and after more than a decade of universal salt iodization in Saudi Arabia, the problem of iodine-deficiency disorders is still endemic in the Aseer region. Efforts should focus on fostering advocacy and communication and ensuring the availability of adequately iodized salt.

A turn-on fluorescence probe for imaging iodide in living cells based on an elimination reaction

Based on a unique elimination reaction prompted by the iodide, a turn-on fluorescent probe (HCy-OMe-Br) without containing heavy metal has been developed for the first time. The probe can monitor iodide with excellent selectivity and sensitivity and was successfully applied to visualize iodide in living cells.