Excess Iodine Research Articles

Serum thyroglobulin as a biomarker of iodine excess and thyroid disease occurrence in adults

BackgroundThyroglobulin (Tg) is considered a sensitive indicator of iodine deficiency. However, the usefulness of Tg as a biomarker of excess iodine is uncertain. The present study aimed to determine the influence of different iodine intake on serum Tg levels, evaluate the influence of thyroid diseases on the distribution of Tg, and identify the factors that may affect Tg levels. MethodsA cross-sectional survey with a total of 1208 adults was conducted in different water iodine areas in China. Urinary iodine concentration (UIC), water iodine concentration (WIC), serum Tg, thyroid-stimulating hormone (TSH), and thyroid antibodies were measured. The thyroid volumes and nodules were measured by B-scan ultrasound. ResultsBased on the WIC data, subjects were divided into three groups. Based on the median urinary iodine concentration (MUIC) data, the iodine levels were adequate, more than adequate, and excess for the WIC < 10 μg/L group, 10 μg/L ≤ WIC ≤ 100 μg/L g, and WIC > 100 μg/L groups, respectively. The median Tg was significantly higher in the excess iodine group than in the adequate iodine group and the more than adequate iodine group (14.6 μg/L vs.12.7 μg/L, P = 0.042; 14.6 μg/L vs.12.5 μg/L, P = 0.004). Multiple linear regression analysis showed that excess iodine intake, goitre, thyroid nodules, and hypothyroidism were significantly related to higher serum Tg levels. ConclusionSerum Tg level can be a promising biomarker of excessive iodine intake, but other factors, especially the presence of thyroid disease, should be considered when using this parameter.

Adverse Effects on the Thyroid of Chinese Pregnant Women Exposed to Long-Term Iodine Excess: Optimal and Safe Tolerable Upper Intake Levels of Iodine

Ensuring optimal iodine nutrition in pregnant women is a global public health concern. However, there is no direct data on safe tolerable upper intake levels (ULs) for pregnant women. A cross-sectional study was performed to determine the ULs of pregnant women. A total of 744 pregnant women were enrolled in this study. The median (IQR) urinary iodine concentration (UIC) in pregnant women was 150.2 (87.6, 268.0) μg/L, and the urinary iodine excretion (UIE) over 24 h was 204.2 (116.0, 387.0) μg/day. Compared with those with a UIE figure of between 150-250 μg/day, the reference group, the prevalence of thyroid dysfunction was 5.7 times higher (95%CI: 1.7, 19.2) in pregnant women with a UIE figure of between 450-550 μg/day, and 3.9 times higher (95%CI: 1.5, 10.3) in pregnant women with a UIE figure of ≥550 μg/day. Compared with an estimated iodine intake (EII) of between 100-200 μg/day, the reference group, the prevalence of thyroid dysfunction was 4.3 times higher (95%CI: 1.3, 14.4) in pregnant women with a UIE figure of between 500-600 μg/day, and 3.6 times higher (95%CI: 1.5, 8.9) in pregnant women with UIE of ≥600 μg/day. In general, our cross-sectional study found that excessive iodine intake during pregnancy appears to directly increase the risk of thyroid dysfunction. Avoiding chronic iodine intakes of 500 μg/day or higher or having a UIE figure of ≥450 μg/day is recommended for pregnant women in China.

Excessive Iodine Enabled Ultrathin Inorganic Perovskite Growth at the Liquid-Air Interface.

The liquid-air interface offers a platform for the in-plane growth of free-standing materials. However, it is rarely used for inorganic perovskites and ultrathin non-layered perovskites. Herein the liquid-air interfacial synthesis of inorganic perovskite nanosheets (Cs3 Bi2 I9 , Cs3 Sb2 I9 ) is achieved simply by drop-casting the precursor solution with only the addition of iodine. The products are inaccessible without iodine addition. The thickness and lateral size of these nanosheets can be adjusted through the iodine concentration. The high volatility of the iodine spontaneously drives precursors that normally stay in the liquid to the liquid-air interface. The iodine also repairs in situ iodine vacancies during perovskite growth, giving enhanced optical and optoelectronic properties. The liquid-air interfacial growth of ultrathin perovskites provides multi-degree-of-freedom for constructing perovskite-based heterostructures and devices at atomic scale.

Excessive Iodine Enabled Ultrathin Inorganic Perovskite Growth at the Liquid‐Air Interface

AbstractThe liquid‐air interface offers a platform for the in‐plane growth of free‐standing materials. However, it is rarely used for inorganic perovskites and ultrathin non‐layered perovskites. Herein the liquid‐air interfacial synthesis of inorganic perovskite nanosheets (Cs3Bi2I9, Cs3Sb2I9) is achieved simply by drop‐casting the precursor solution with only the addition of iodine. The products are inaccessible without iodine addition. The thickness and lateral size of these nanosheets can be adjusted through the iodine concentration. The high volatility of the iodine spontaneously drives precursors that normally stay in the liquid to the liquid‐air interface. The iodine also repairs in situ iodine vacancies during perovskite growth, giving enhanced optical and optoelectronic properties. The liquid‐air interfacial growth of ultrathin perovskites provides multi‐degree‐of‐freedom for constructing perovskite‐based heterostructures and devices at atomic scale.

Relationship between iodine knowledge and dietary iodine intake in pregnant and lactating women: a cross-sectional study.

This study assessed the iodine knowledge of pregnant and lactating women and the relationship to dietary iodine intake and iodine status. The factors influencing iodine intake were analysed. Basic information and iodine knowledge were collected via a questionnaire. A FFQ assessed dietary iodine intake. The urinary iodine concentration (UIC) was measured using the arsenic-cerium catalytic spectrophotometric determination of iodine in urine (WS/T 107 -2016). A cross-sectional study involving pregnant and lactating women in Xinjiang, China was conducted. A total of 1181 pregnant women and 504 lactating women were enrolled in the study. The median UIC for pregnant and lactating women was 179·27 and 192·81 µg/l, respectively, and the dietary iodine intake was 407·16 and 356·89 µg/d, respectively. Of the pregnant and lactating women, 73·4 % and 82·5 % had medium iodine knowledge, respectively. In pregnant women, iodine knowledge and dietary iodine intake were positively correlated. High iodine knowledge and iodine education were shown to be protective factors for excessive iodine intake in pregnant women. This study demonstrated that the iodine nutritional status of women in Xinjiang was appropriate, and iodine knowledge was at a medium level, but there was confusion about iodine nutrition. Public education is needed to improve iodine knowledge and active iodine supplementation awareness among these populations of women.

Excessive iodine status among school‐aged children in the State of Qatar: Results of the National Iodine Deficiency Disorder Survey

AbstractBackgroundIodine deficiency poses a significant public health challenge worldwide, particularly in preschool children and pregnant women. Assessing the iodine intake at a population level is essential, as both deficient and excessive iodine status can have adverse health consequences. The main objective of this survey is to understand the iodine deficiency status in schoolchildren aged 6–12 years in the State of Qatar.MethodsA cross‐sectional survey was conducted from March to June 2014 among school‐aged children using a two‐stage cluster sampling technique. Anthropometric, biochemical, clinical, and dietary parameters for seafood were collected. Spot urine samples were collected from 967 participants, and a repeat random subsample urine was collected from 288 participants. Overall median urinary iodine concentration (UIC) was calculated. Iodine content in household salt samples was estimated by qualitative and quantitative methods. Mann–Whitney U test was used for comparison.ResultsThe median UIC was 333.2 μg/L (IQR = 228.6). UIC prevalence rates between 300–999 and &gt;1000 μg/L were 56.7% and 2.8%, respectively. The goiter prevalence was 0.4%. A significant difference was noted in overall median UIC levels between boys and girls (p = 0.003). Adequate iodized salt consumption was reported by 74.9% of households, and weekly seafood consumption was reported by one third of the respondents.ConclusionThe results indicate an excess intake of iodine among the studied population in the State of Qatar, and national efforts are needed to bring iodine intake and concentration levels within the cutoff value for the concerned survey population's age group. In addition, a surveillance system needs to be set up for continuous monitoring of iodine content and salt intake at the population level in the State of Qatar.

Excessive iodine induces thyroid follicular epithelial cells apoptosis by activating HIF-1α-mediated hypoxia pathway in Hashimoto thyroiditis

BackgroundHashimoto thyroiditis (HT) is considered the most common autoimmune thyroid disease. A growing body of evidence suggests that HT incidence correlates with excessive iodine intake. We should probe the effects of excessive iodine intake in HT development and its possible mechanism.Methods and resultsThe study recruited 20 patients: 10 with HT and 10 with nodular goiter. We detected the expression of an apoptosis-related protein caspase-3 by immunohistochemistry. In vitro study, we explored the proliferation and apoptosis status in thyroid follicular cells (TFCs) stimulated with different iodine concentrations by MTT and flow cytometry. Then we performed RNA sequence analysis of Nthy-ori3-1 cells treated for 48 h with KI to probe the underlying mechanism. Finally, we used RT-PCR and siRNA interference to verify the results. We identified apoptosis in thyroid tissue obtained from HT patients coincides with the increase of caspase-3 levels. In vitro study, iodine suppressed proliferation of TFCs and promoted TFCs apoptosis in a dose-dependent manner with regulating caspase-3 activation. HIF-1α-NDRG1 mediated hypoxia pathway activation promoted the transmission of essential apoptosis signals in TFCs.ConclusionOur study confirmed that excessive iodine adsorption activates the HIF-1α-mediated hypoxia pathway to promote apoptosis of TFCs, which may be an important risk factor contributing to HT development.

Relationship of iodine excess with thyroid function in 6-year-old children living in an iodine-replete area.

Adequate iodine intake is essential for growing children, as both deficient and excessive iodine status can result in thyroid dysfunction. We investigated the iodine status and its association with thyroid function in 6-year-old children from South Korea. A total of 439 children aged 6 (231 boys and 208 girls) were investigated from the Environment and Development of Children cohort study. The thyroid function test included free thyroxine (FT4), total triiodothyronine (T3), and thyroid-stimulating hormone (TSH). Urine iodine status was evaluated using urine iodine concentration (UIC) in morning spot urine and categorized into iodine deficient (< 100 μg/L), adequate (100-199 μg/L), more than adequate (200-299 μg/L), mild excessive (300-999 μg/L), and severe excessive (≥ 1000 μg/L) groups. The estimated 24-hour urinary iodine excretion (24h-UIE) was also calculated. The median TSH level was 2.3 μIU/mL, with subclinical hypothyroidism detected in 4.3% of patients without sex differences. The median UIC was 606.2 μg/L, with higher levels in boys (684 μg/L vs. 545 μg/L, p = 0.021) than girls. Iodine status was categorized as deficient (n = 19, 4.3%), adequate (n = 42, 9.6%), more than adequate (n = 54, 12.3%), mild excessive (n = 170, 38.7%), or severe excessive (n = 154, 35.1%). After adjusting for age, sex, birth weight, gestational age, body mass index z-score, and family history, both the mild and severe excess groups showed lower FT4 (β = - 0.04, p = 0.032 for mild excess; β = - 0.04, p = 0.042 for severe excess) and T3 levels (β = - 8.12, p = 0.009 for mild excess; β = - 9.08, p = 0.004 for severe excess) compared to the adequate group. Log-transformed estimated 24h-UIE showed a positive association with log-transformed TSH levels (β = 0.04, p = 0.046). Excess iodine was prevalent (73.8%) in 6-year-old Korean children. Excess iodine was associated with a decrease in FT4 or T3 levels and an increase in TSH levels. The longitudinal effects of iodine excess on later thyroid function and health outcomes require further investigation.

IL-9-Producing Th9 Cells Participate in the Occurrence and Development of Iodine-Induced Autoimmune Thyroiditis.

Iodine excess may cause and aggravate autoimmune thyroiditis (AIT), which is regarded as a typical kind of autoimmune disease mainly mediated by CD4+ T cells. Thus far, it is unclear whether T helper (Th) 9 cells, a novel subpopulation of CD4+ T cells, play a potential role in AIT. Therefore, in the present study, changes in Th9 cells were detected in murine models of AIT induced by excess iodine intake to explore the possible immune mechanism. Female C57BL/6 mice were divided into 7 groups (n = 8) and were supplied with water containing 0.005% sodium iodide for 0, 2, 4, 6, 8, 10, and 12weeks. With the extension of the high-iodine intake duration, the incidence of thyroiditis and the spleen index were significantly increased, and serum thyroglobulin antibody (TgAb) titers and interleukin 9 (IL-9, major cytokine from Th9 cells) concentrations were also increased. Additionally, it was revealed that the percentages of Th9 cells in spleen mononuclear cells (SMCs) and thyroid tissues were both markedly elevated and accompanied by increased mRNA and protein expression of IL-9 and key transcription factors of Th9 cells (PU.1 and IRF-4). Significantly, dynamic changes in Th9 cells were found, with a peak at 8weeks after high iodine intake, the time point when thyroiditis was the most serious. Importantly, Th9 cells were detected in the areas of infiltrating lymphocytes in thyroid sections. In conclusion, the continuously increasing proportions of Th9 cells may play an important role in the occurrence and development of AIT induced by high iodine intake.

Survey on the prevalence and related factors of thyroid disorders in different iodine intake regions in China in 2015-2017

Objective: To observe the prevalence and related factors of thyroid diseases in different iodine intake areas from 2015 to 2017 after the implementation of national salt iodization policy in China for 20 years. Methods: A cross-sectional survey. Multi-stage stratified cluster random sampling was used to randomly select subjects meeting the inclusion criteria from 31 provinces, municipalities and autonomous regions in China from January 2015 to December 2017, and stratified by age and sex. The survey included questionnaire, physical examination and thyroid ultrasonography. At the same time, the concentrations of serum thyrotropin, thyroxine, thyroid peroxidase antibody (TPOAb), thyroid globulin antibody (TgAb) and urinary iodine were measured.To determine whether the patient has a certain thyroid disease according to the above results. Different iodine nutrition areas were defined according to urinary iodine concentration, and the influence of iodine nutrition status in different iodine intake areas on thyroid diseases was analyzed. Results: A total of 78 470 adults were included, including 39 893 in the area of moderate iodine, 28 779 in the area of adequate iodine, and 9 798 in the area of excessive iodine.In the above three regions, the prevalence of subclinical hyperthyroidism (hyperthyroidism) was 0.45% (95%CI: 0.39%-0.52%), 0.50%(95%CI: 0.35%-0.70%)and 0.27%(95%CI: 0.20%-0.35%), respectively, with statistical significance(χ²=6.92, P=0.003). The prevalence of subclinical hypothyroidism (hypothyroidism) was 11.36% (95%CI: 10.73%-12.02%), 13.57%(95%CI: 11.70%-15.69%) and 16.18%(95%CI: 12.41%-20.82%), respectively, with statistical significance(χ²=5.08, P=0.009). The prevalence rates of Graves' disease, TPOAb, goiter and thyroid nodule among the three regions were statistically significant (all P<0.05). There were no significant differences in the prevalence of clinical hyperthyroidism and clinical hypothyroidism and the positive rate of TgAb among the three regions (all P>0.05). Multivariate logistic regression model analysis showed that excess iodine was a risk factor for subclinical hypothyroidism (OR=1.24, 95%CI: 1.06-1.44), and a protective factor for thyroid nodules (OR=0.73, 95%CI: 0.57-0.94). Iodine overdose was a risk factor for subclinical hypothyroidism (OR=1.47, 95%CI: 1.08-2.01), while it was a protective factor for subclinical hyperthyroidism (OR=0.56, 95%CI: 0.41-0.77), and TPOAb positive (OR=0.93, 95%CI: 0.87-0.99), goiter (OR=0.33, 95%CI: 0.17-0.66) and thyroid nodule (OR=0.77, 95%CI: 0.61-0.97). Conclusions: There are significant differences in the prevalence of subclinical hyperthyroidism, subclinical hypothyroidism, positive TPOAb, thyroid nodule and goiter in different iodine intake regions. Different iodine intake levels have an effect on the incidence of thyroid diseases.

Recognise of iodine effect on thyroid diseases and metabolism

Iodine is an essential trace element for human and an antioxidant. It not only participates in the synthesis of thyroid hormone, but also plays a role in metabolic diseases. Previous studies mainly focused on the effect of iodine on thyroid diseases, but ignored the effect on metabolism. After the implementation of the universal salt iodization (USI) of China, the possible consequences of excessive iodine were emphasized while the harm of iodine deficiency was forgetten. The paper re-examines the effects of iodine nutrition on thyroid diseases and metabolism. Iodine deficiency can lead to an increased risk of iodine deficiency disorders and thyroid diseases, and increase prevalence of metabolic syndrome and its components. Moderate iodine excess is beneficial to metabolism, but it can increase the risk of hyperthyroidism and subclinical hypothyroidism. The average urinary iodine concentration in 100-299 μg/L is the appropriate iodine nutrition state. According to the present iodized content of salt in China, iodized salt is an economical and effective way to ensure adequate iodine nutrition.

Optimizing Growth: The Case for Iodine.

Iodine is an essential micronutrient and component of thyroid hormone. An adequate dietary iodine intake is critical to maintain and promote normal growth and development, especially during vulnerable life stages such as pregnancy and early infancy. The role of iodine in cognitive development is supported by numerous interventional and observational studies, and when iodine intake is too low, somatic growth is also impaired. This can be clearly seen in cases of untreated congenital hypothyroidism related to severe iodine deficiency, which is characterized, in part, by a short stature. Nevertheless, the impact of a less severe iodine deficiency on growth, whether in utero or postnatal, is unclear. Robust studies examining the relationship between iodine and growth are rarely feasible, including the aspect of examining the effect of a single micronutrient on a process that is reliant on multiple nutrients for optimal success. Conversely, excessive iodine intake can affect thyroid function and the secretion of optimal thyroid hormone levels; however, whether this affects growth has not been examined. This narrative review outlines the mechanisms by which iodine contributes to the growth process from conception onwards, supported by evidence from human studies. It emphasizes the need for adequate iodine public health policies and their robust monitoring and surveillance, to ensure coverage for all population groups, particularly those at life stages vulnerable for growth. Finally, it summarizes the other micronutrients important to consider alongside iodine when seeking to assess the impact of iodine on somatic growth.

The Effect of Long-Term Inorganic Iodine on Intrathyroidal Iodothyronine Content and Gene Expression in Mice with Graves' Hyperthyroidism.

Background: The main molecular mechanism underlying acute suppression of iodine organification in normal thyroids after an excessive iodine load, that is, the Wolff-Chaikoff effect, is assumed to be suppression of iodine oxidation and iodothyronine synthesis. However, the mechanism underlying chronic antithyroid action of inorganic iodine in Graves' disease is not fully understood. Using a mouse model of Graves' hyperthyroidism, we examined changes in iodothyronine content and gene expression profiles in the thyroid glands after inorganic iodine loading. Materials and Methods: Graves' hyperthyroidism was induced and maintained in BALB/c mice by repeated immunizations of recombinant adenovirus expressing the human thyrotropin (TSH) receptor A-subunit. Hyperthyroid mice were left untreated (GD-C; n = 8) or treated with inorganic iodine for 12 weeks (GD-NaI; n = 8). We used unimmunized BALB/c mice as a control group (n = 10). In each mouse, serum thyroxine (T4) levels were measured with enzyme-linked immunosorbent assay (ELISA) at 4-week intervals. The intrathyroidal iodothyronine content and gene expression levels were, respectively, evaluated by mass spectrometry and RNA sequencing (RNA-seq) at the end of the experimental period. Results: Serum T4 levels in the GD-C group remained higher than in the control group, whereas those in the GD-NaI group declined to normal levels during the experimental period. Intrathyroidal triiodothyronine (T3), reverse T3 (rT3), and T4 contents in the GD-C group were higher than the control group, and rT3 and T4 were further increased in the GD-NaI group. The observed alterations in iodothyronine levels in the thyroid and sera may be explained by altered expression levels of genes for iodothyronine biosynthetic molecules, their transporter, and deiodinases. Conclusion: In this mouse model of hyperthyroidism, higher intrathyroidal accumulation of T4 and reduced gene expression data of iodothyronine transporters in the GD-NaI group suggest that chronic antithyroid action of iodine in Graves' disease involves suppression of hormone secretion.

Association of Excess Dietary Iodine Intake with Papillary Thyroid Carcinoma

Background: Papillary thyroid carcinoma (PTC) is the most common type of differentiated thyroid carcinoma and accounts for 70–80% of all thyroid carcinomas. After the global iodine fortification of salt and food, the incidence of PTC has been increasing throughout the world in recent years. Aims: To determine the relationship between excessive dietary iodine intake and PTC. Patients and methods: This cross-sectional study was carried out at the National Institute of Nuclear Medicine &amp; Allied Sciences (NINMAS), Dhaka, from March 2020 to June 2021. A total of 111 patients were included in this study, of whom 53 were pre-operative papillary thyroid carcinoma patients and the rest, 58, were age- and sex-matched healthy individuals. Their urinary iodine concentrations were measured in the laboratory of the Bangladesh Reference Institute for Chemical Measurements (BRICM). Urinary iodine concentration is a good marker of dietary iodine intake. Statistical analysis of the results was obtained using Windows-based computer software devised with Statistical Packages for Social Sciences (SPSS) version 23.0. Results: The mean urinary iodine concentration was 223.54±55.78 microgram/liter in the PTC group and 154.29±61.83 microgram/liter in the healthy group. A remarkable number of participants in both the PTC group 42 out of 53 (79.3%) and the healthy group 18 out of 58 (31.0%) had biochemical evidence of excess iodine intake. Excess iodine intake significantly (p&lt;0.05) increased with 8.48 times odds (95% CI 3.30-22.33) in PTC patients. Conclusion: This study revealed that a significant number of participants in the PTC group had evidence of excess iodine intake compared to that of the healthy group, which suggests that excess dietary iodine intake may be related to the occurrence of PTC. Bangladesh J. Nuclear Med. 26(1): 25-30, 2023

Association between iodine intake and metabolic syndrome in euthyroid adult in an iodine-replete area: a nationwide population-based study.

Metabolic syndrome (MetS) is considered very important because of the increased risk for cardiovascular diseases. Identifying modifiable factors may help prevent MetS. We aimed to investigate the relationship between iodine intake as a dietary factor and MetS in euthyroid adult in an iodine-replete area. A total of 4,277 adult aged ≥19 years from the Korea National Health and Nutrition Examination Survey VI (2013-2015) with urinary iodine concentration (UIC) results and normal thyroid function were included. Participants were grouped according to their iodine nutrition status based on the WHO recommendations and modifications: insufficient (<100 μg/L), adequate (100-299 μg/L), and excessive (≥300 μg/L) iodine intake. We estimated the odds ratios (ORs) for MetS according to the UIC groups using logistic regression models. Of the study participants, 27.2% men and 23.9% women had MetS. Men with excessive iodine intake had a significantly lower risk of elevated triglycerides [OR 0.733, 95% confidence interval (CI) 0.603-0.890, p = 0.010], as compared to those with adequate iodine intake. Women with insufficient iodine intake had a significantly greater risk of elevated blood glucose (OR 1.519, 95% CI 1.011-2.282, p = 0.044), as compared to those with adequate iodine intake. In women, insufficient iodine intake was a significant risk factor for MetS compared to adequate iodine intake, even after adjusting for confounding variables including age, smoking, alcohol consumption, walking activity, serum thyroid-stimulating hormone, free thyroxine, and anti-thyroid peroxidase antibody (OR 1.544, 95% CI 1.031-2.311, p = 0.035). There was no association between iodine intake and risk of MetS in men. In conclusion, insufficient iodine intake was associated with an increased risk of MetS only in euthyroid adult women. Our data support that sex differences may influence the relationship between iodine intake as a dietary pattern and MetS.

Knowns and unknowns about congenital hypothyroidism: 2022 update

Several excellent guidelines and expert opinions on congenital hypothyroidism (CH) are currently available. Nonetheless, these guidelines do not address several issues related to CH in detail. In this review, the authors chose the following seven clinical issues that they felt were especially deserving of closer scrutiny in the hope that drawing attention to them through discussion would help pediatric endocrinologists and promote further interest in the treatment of CH. 1. How high should the levothyroxine (L-T4) dose be for initial treatment of severe and permanent CH? 2. What is the optimal method for monitoring treatment of severe CH? 3. At what level does maternal iodine intake during pregnancy affect fetal and neonatal thyroid function? 4. Does serum thyroglobulin differ between patients with a dual oxidase 2 (DUOX2) variants and those with excess iodine? 5. Who qualifies for a genetic diagnosis? 6. What is the best index for distinguishing transient and permanent CH? 7. Is there any cancer risk associated with CH? The authors discussed these topics and jointly edited the manuscript to improve the understanding of CH and related issues.

Синтез и исследование свойств 5-R-2-пропаргилсульфанилбензимидазолов

Synthesis of new medicinal substances and biologically active compounds, in particular, heterocyclic ones, is an integral part of modern pharmacology development. This is one of the reasons for steady synthetic and biological interest in the chemistry of imidazoles and benzimi-dazoles. Synthesis of 2-propargylsulfanylbenzimidazole (2a) (yielding 85 %) and 5-methyl-2-propargylsulfanylbenzimidazole (2b) (yielding 56 %) has been carried out for the first time by alkylation of benzimidazole-2-thiol (1a) and 5-methylbenzimidazole-2-thiol (1b), respectively, with propargyl bromide in the KOH–DMF system. The structure of the synthesized compounds 2a,b has been studied by the ¹Н and ¹³С NMR spectroscopy, as well as GC–MS. It has been found that propargyl sulfides 2а,b undergo acetylene-allene rearrangement and subsequent chemical transformations during chromatography under the GC–MS analysis conditions due to the high temperature in the injector (&gt; 200 °C). The literature data on the synthesis of halogen- and selenium derivatives of [1,3]thiazinobenzimidazole based on 2-propargylsulfanylbenzimidazoles exist. We synthesized tricyclic fused [1,3]thiazolo[3,2-a]benzimidazolium systems by heterocyclization of compounds 2a,b under conditions of acetylene-allene rearrangement (heating in the KOH–DMSO or MeONa–MeOH system). According to the 1H NMR data, the reactions of propargyl sulfides 2a,b with a twofold excess of iodine in chloroform proceeded to give 3-iodomethyleno-2,3-dihydro-9H-[1,3]thiazolo[2,3-b]benzimidazolium iodide (11) and 3-iodomethyleno-6-methyl-2,3-dihydro-9Н-[1,3]thiazolo[2,3-b]benzimidazolium polyiodide (10b), respectively. When the solvent was changed to a more polar one and the iodination of compound 2а in glacial acetic acid at the same ratio of starting reagents (1:2) was carried out, isomerization of the heterocyclization product having an exocyclic double bond into a heterocyclization product having an endocyclic double bond in the thiazolium ring was observed. As a result, an individual 3-iodomethyl-9H-[1,3]thiazolo[2,3-b]benzimidazolium polyiodide (12) was isolated, and its structure was studied by 1H NMR spectroscopy.

Urinary iodine excretion after using povidone iodine or chlorhexidine gluconate for topical disinfectant in patients undergoing thyroidectomy due to thyroid carcinoma: When to do radio active iodine therapy?

Povidone Iodine (PI) is the most frequent antiseptic used as a topical disinfectant in surgery. It has been reported high transcutaneous iodine absorption due to topical PI usage, but there is a lack of data in periods of excess iodine depletion. This is a cross-sectional study designed to assess serial urinary iodine concentration (UIC) after topical administration of PI to evaluate the transcutaneous iodine absorption and the proper iodine depletion time for safe administration of Radio Active Iodine (RAI) therapy as ablative or adjuvant therapy. Thirty-seven patients with papillary thyroid carcinoma undergoing total thyroidectomy were assigned to the PI group (n = 20) or chlorhexidine gluconate (CHG) group (n = 17). In the PI group, the UIC levels rose to a maximum of 2 times in the 4th week after administration and returned to pre-operative levels in the 8th week after. In the CHG group, there was a decrease in UIC levels due to a low iodine diet (LID) with a significant P-value of 0.001, <0.001, and 0.001 in the 2nd, 4th, and 8th weeks follow up respectively compared to the PI group. The urinary excretion of excess iodine lasts about 8 weeks after total thyroidectomy until iodine levels turn back to pre-operative values. If the thyroidectomy was prepared with PI, RAI is better to be performed 6-8 weeks after surgery rather than the standard prescription of 4 weeks.

Impact of iodine intake on the pathogenesis of autoimmune thyroid disease in children and adults.

Thyroid hormone (TH) regulates the body&apos;s metabolism and iodine, a vital trace mineral, is vital for TH synthesis. As a TH biosynthesis catalyst, iodine has a substantial role in our health. When there is a modest iodine deficit, the thyroid gland grows autonomously, resulting in thyrotoxicosis. Those who consume excessive iodine risk developing hypothyroidism and thyroid autoimmunity. A transient hyperthyroid condition may rapidly increase iodine consumption. Iodine deficiency is common across the globe, and provision of supplementary iodine, in forms such as iodized salt or vegetable oil, has many benefits. Vegetarians, for instance, may not consume adequate amounts of iodine in some countries with high iodine content. Reduced dietary iodine intakes may be a consequence of efforts to reduce salt intakes to prevent hypertension. In addition, iodine consumption is decreasing in many countries, even among those where endemic goiter has previously been eradicated, leading to the re-emergence of iodine-deficiency-related disorders such as goiter. This review will discuss how iodine can contribute to the development of thyroid disease.

Synthesis, Structure and Reactivity of Organoindium 1,2‐Benzenedithiolates and 2‐Amidobenzenethiolates

AbstractOrganoindium compounds of redox active 1,2‐benzenedithiolate and 2‐amidobenzenethiolate ligands were synthesized and tested for reactivity against mild oxidants. The reaction of Me3In and (NCN)InMe2 [NCN=2,6‐bis(dimethylaminomethy)phenyl] with 3,4‐toluenedithiol (H2tdt) at room temperature afforded [MeIn(tdt)(py)]2 (1) and (NCN)In(tdt) (2), respectively. A similar reaction of Me3In with 2‐aminobenzenethiol (H2abt) in toluene under reflux afforded [MeIn(abt)(py)]2 (3). The reaction of (NCN)InCl2 with one equivalent of Li2(abt) or two equivalents of Li(Habt) afforded the compounds [(NCN)In(abt)]⋅LiCl(thf)2 (4⋅LiCl(thf)2) and (NCN)In(Habt)2 (5), respectively. The X‐ray crystal structures of 1 and 3 are similar and show dimeric structures via μ‐S‐(tdt) and μ‐N‐(abt) ligands, respectively. Compounds 2 and 4 possess similar monomeric structures and tridentate NCN pincer ligands. DFT computational studies have been used to rationalize the observed solid‐state structures and discern the potential reactivity of compounds 1–4 against oxidants. The reaction of 1 and 2 with excess iodine resulted in loss of the 3,4‐toluenedithiolate ligand and the formation of the oligomeric disulfide [tdt]n, while 3 and 4 showed no reactivity under similar conditions. This contrasts the reactivity of previously reported organoindium o‐amidophenolate complexes which undergo oxidative addition of iodine to afford ligand‐centered radical species.