Distributions of serum thyroid-stimulating hormone in 2020 thyroid disease-free adults from areas with different iodine levels: a cross-sectional survey in China

PURPOSE

The aim of the present study was to describe the distributions of serum thyroid- stimulating hormone (TSH) levels in thyroid disease-free adults from areas with different iodine levels in China. Meanwhile, we aimed to evaluate the influence of age and gender on the distribution of TSH, assess the relationship between concentrations of TSH and free thyroxine (FT₄), and analyze the factors that may affect TSH levels.

METHODS

2020 adults were included from April 2016 to June 2019. Urinary iodine concentration, serum iodine concentration, serum TSH, FT₄, free triiodothyronine, thyroid peroxidase antibodies and thyroglobulin antibodies were measured, and thyroid ultrasonography was performed.

RESULTS

The median of TSH in iodine-fortification areas (IFA), iodine-adequate areas (IAA), iodine-excessive areas (IEA) were 2.32, 2.11 and 2.34 mIU/L, respectively. Serum TSH concentrations were significantly higher in IFA and IEA than that in IAA (p = 0.005 and < 0.0001). The TSH values of most adults were distributed within the range of 1.01-3.00 mIU/L with the same trend in three groups. In our study, TSH levels did not change with age, and the TSH level of females was higher than that of males (p < 0.0001). There was a negative correlation between FT₄ and TSH in IAA (r = - 0.160, p < 0.0001) and IEA (r = - 0.177, p < 0.0001), but there was no correlation between FT₄ and TSH in IFA (r = - 0.046, p = 0.370). BMI, smoking status, education levels, and marital status were associated with TSH.

CONCLUSION

Our study provides a basis for establishing the reference intervals of TSH in different iodine level areas.

Feasibility of microwave-induced combustion combined with inductively coupled plasma mass spectrometry for bromine and iodine determination in human nail

RATIONALE

Bromine and iodine have important physiological functions; however, in inadequate concentration, they can also cause several physiological problems. Their mobility assessment in human organisms through biological sampling may help clarify some doubts related to metabolic routes, which are still not well elucidated. In this context, a suitable analytical method for this purpose should be developed.

METHODS

An analytical method for determining ultratrace levels of bromine and iodine in human nail samples was developed. Inductively coupled plasma mass spectrometry (ICP-MS) using a conventional nebulization system was immediately chosen as the determination tool because of its powerful sensitivity and selectivity. Sample preparation methods including microwave-induced combustion (MIC), microwave-assisted extraction, and microwave-assisted digestion were evaluated. The compatibility of the final solutions with ICP-MS analysis was considered while the method was developed.

RESULTS

MIC was chosen as the most suitable method for the sample preparation for determining the levels of bromine and iodine in human nail samples using ICP-MS. Unlike other sample preparation methods, this one fully eliminated interferences related to the carbon content and memory effects. Sample masses up to 100 mg were efficiently digested, and the analytes were quantitatively absorbed using only 50 mmol L^-1 NH₄ OH solution. Recoveries ranged from 93% to 102%, and the relative standard deviation was < 8%.

CONCLUSIONS

The proposed analytical method presents important characteristics for routine analysis. It allows ultratrace determination even when low sample masses are used because of the low blank values, reduced volume of reagents, and powerful detectability using ICP-MS.

Surface modification of polypropylene membrane for the removal of iodine using polydopamine chemistry

The development of stable and effective iodine removal systems would be highly desirable in addressing environmental issues relevant to water contamination. In the present research, a novel iodine adsorbent was synthesized by self-polymerization of dopamine (PDA) onto inert polypropylene (PP) membrane. This PP/PDA membrane was thoroughly characterized and its susrface propeties was analyzed by various analytical techniques indcluding field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH), contact angle, and surface free energy measurement. The PP/PDA membranes were subsequently used for batchwise removal of iodine at different temperatures (25-70 °C), pH (2-7), and surface areas (1-10 cm²) to understand the underlying adsorption phenomena and to estimate the membrane capacity for iodine uptake. The increase in temperature and pH both led to higher adsorption of iodine. The present approach showed a removal efficiency of over 75% for iodine using 10 cm² PP/PDA membrane (18.87 m² g^-1) within 2 h at moderate temperatures (∼50 °C) and pH > 4, about 15 fold compared to the PP control membrane. The adsorption kinetics and isotherms were well fitted to the pseudo-second-order kinetic and Langmuir isotherm models (R² > 0.99). This adsorbent can be recycled and reused at least six times with stable iodine adsorption. These findings were attributed to the homogenous monolayer adsorption of the iodide on the surface due to the presence of catechol and amine groups in the PP/PDA membrane. This study proposes an efficient adsorbent for iodine removal.

Multifunctional conjugated microporous polymers with pyridine unit for efficient iodine sequestration, exceptional tetracycline sensing and removal

In this work, two multifunctional conjugated microporous polymers (CMP-LS7-8) were obtained via the Pd-catalyzed Suzuki coupling reactions of 2,4,6-tris(4-bromophenyl)pyridine with two aromatic borates. The Brunauer-Emmett-Teller (BET) surface areas of CMP-LS7-8 were calculated to be 507 and 2028 m² g^-1. CMP-LS7-8 exhibit excellent volatile iodine adsorption about 2.77 and 5.29 g g^-1, respectively, and outstanding reversible adsorption. High adsorption capacity should be attributed to an integrated effect by excellent porous characteristics, effective sorption sites, and expanded π-conjugated network. In addition, this platform integrated two functions of sensing and adsorption of tetracycline (TC) into one material. The excellent luminescence of CMP-LS7-8 can be effectively quenched by TC, which demonstrates they can be acted as new sensitive and selective fluorescence probes toward TC. Simultaneously, CMP-LS7-8 also display high adsorption ability of TC. The adsorption kinetics of TC suggested that the process of adsorption followed a pseudo-second-order model, and the adsorption behaviour of these polymers fitted with the Langmuir model. These results suggest that CMP-LS7-8 posess high volatile iodine capture and exceptional TC detection and removal performance, which can be promising candidates for environmental remediation.

Pyrrolidone-based polymers capable of reversible iodine capture for reuse in antibacterial applications

Numerous emerging and re-emerging advanced materials have been successful in capturing iodine pollutants that pose an unprecedented global challenge to public health. However, little attention has been paid to the reutilization of the captured iodine. Herein, we report on a pyrrolidone-based polymer capable of reversible iodine capture for reutilization in antibacterial applications. The pyrrolidone-based polymer poly(N-vinyl-2-pyrrolidone-co-vinyl acetate), denoted as P(VAc-NVP), was synthesized facilely via a one-step radical copolymerization strategy, and the synthesis was regulated by step-by-step optimization, specifically by tuning the feed ratio of NVP to VAc. The as-synthesized P(VAc-NVP) copolymer functioned as an adsorbent for iodine in various solutions, including water/ethanol, cyclohexane, and petroleum ether, in addition to having the special capability of releasing iodine in the presence of starch or bacteria. This opens up a new horizon for its functional practical use as a flexible adsorbent to capture iodine for safe disposal. Interestingly, the P(VAc-NVP) copolymer, after adsorbing iodine, showed antibacterial ability against pathogenic bacteria, including Staphylococcus aureus and Escherichia coli, when a series of simulated and practical antibacterial assays were conducted. It is believed that this proposed strategy based on the synergism of iodine capture and antibacterial use should have great potential for environmental remediation and public healthcare.

Measuring the density of iodine depositions: Detecting an invisible residual tumor after conventional transarterial chemoembolization

Purpose

The purpose of this study is to evaluate the use of density measurements in the diagnosis of an underlying residual tumor beyond iodine depositions after Lipiodol-based conventional transarterial chemoembolization (cTACE).

Method and materials

Thirty follow-up CT scans of 20 patients 6–12 weeks after Lipiodol-based cTACE, receiving a digital subtraction angiography at the same time, were analyzed. Reference for the detection of a residual tumor was the angiography, and a visible contrast enhancement was categorized as a residual tumor (n = 16 with residual tumor; n = 14 without residual tumor). The density of the iodine depositions was measured in all containing slices in non-contrast-, arterial- and portal venous-phase CT scans, with a slice thickness of 5.00 mm. The mean density of the iodine deposition during the portal venous phase was subtracted from the mean density of the arterial phase to calculate the density changes (a positive enhancement score represents washout in the portal venous phase). In addition, a quotient relating to the non-contrast measurement was evaluated.

Results

Patients with a residual tumor displayed significantly higher enhancement scores in favor of density reduction between the arterial and portal venous phases, compared to patients without a residual tumor (1.41 ± 3.59, n = 14 vs. -13.97 ± 2.88, n = 16; p-value < 0.01). Furthermore, 87.75% of patients with an enhancement score higher than -1.00 (n = 9) had a residual tumor, whereas 100.00% of patients with an enhancement score lower than -20.00 (n = 6) were shown to be tumor-free. The enhancement score quotient resulted in similar findings.

Conclusion

After cTACE in patients with hepatocellular carcinoma (HCC), the presence of a viable tumor correlated with enhancement scores based on the density measurements of iodine depositions in different phases of the CT scan. Low enhancement scores were associated with completely treated tumors and can aid the decision process to avoid possibly unnecessary angiographies.

Pyridinium ionic liquid-based liquid-solid extraction of inorganic and organic iodine from Laminaria

A simple, green and effective extraction method, namely, pyridinium ionic liquid- (IL) based liquid-solid extraction (LSE), was first designed to extract the main inorganic and organic iodine compounds (I-, monoiodo-tyrosine (MIT) and diiodo-tyrosine (DIT)). The optimal extraction conditions were as follows: ultrasonic intensity 100W, IL ([EPy]Br) concentration 200mM, extraction time 30min, liquid/solid ratio 10mL/g, and pH value 6.5. The morphologies of Laminaria were studied by scanning electron microscopy and transmission electron microscopy. The recovery values of I-, MIT and DIT from Laminaria were in the range of 88% to 94%, and limits of detection were in the range of 59.40 to 283.6ng/g. The proposed method was applied to the extraction and determination of iodine compounds in three Laminaria. The results showed that IL-based LSE could be a promising method for rapid extraction of bioactive iodine from complex food matrices.

Silver oxide nanocrystals anchored on titanate nanotubes and nanofibers: promising candidates for entrapment of radioactive iodine anions

Iodine radioisotopes are released into the environment by the nuclear industry and medical research institutions using radioactive materials. The (129)I(-) anion is one of the more mobile radioactive species due to a long half-life, and it is a great challenge to design long-term management solutions for such radioactive waste. In this study, a new adsorbent structure with the potential to efficiently remove radioactive iodine anions (I(-)) from water is devised: silver oxide (Ag2O) nanocrystals firmly anchored on the surface of titanate nanotubes and nanofibers via coherent interfaces between Ag2O and titanate phases. I(-) anions in fluids can easily access the Ag2O nanocrystals and be efficiently trapped by forming AgI precipitate that firmly attaches to the adsorbent. Due to their one-dimensional morphology, the new adsorbents can be readily dispersed in liquids and easily separated after purification; and the adsorption beds loaded with the adsorbents can permit high flux. This significantly enhances the adsorption efficiency and reduces the separation costs. The proposed structure reveals a new direction in developing efficient adsorbents for the removal of radioactive anions from wastewater.

Removal of radioactive iodine from water using Ag2O grafted titanate nanolamina as efficient adsorbent

Emergency treatment of radioactive material leakage and safety disposal of nuclear waste is a constant concern all along with the development of radioactive materials applications. To provide a solution, titanate with large surface area (143 m(2)g(-1)) and a lamina morphology (the thickness of the lamina is in range of tens of nanometers) was prepared from inorganic titanium compounds by hydrothermal reactions at 433 K. Ag(2)O nanocrystals (5-30 nm) were deposited onto the titanate lamina. The surface of the titanate lamina has crystallographic similarity to that of Ag(2)O nanocrystals. Hence, the deposited Ag(2)O nanocrystals and titanate substrate join together at these surfaces, forming a well-matched phase coherent interface between them. Such coherence between the two phases reduces the overall energy by minimizing surface energy and anchors the Ag(2)O nanocrystals firmly on the external surface of the titanate structure. The composite thus obtained was applied as efficient adsorbent to remove radioactive iodine from water (one gram adsorbent can capture up to 3.4 mmol of I(-) anions). The composite adsorbent can be recovered easily for safe disposal. The structure changes of the titanate lamina and the composite adsorbent were monitored by various techniques. The isotherm and kinetics of iodine adsorption, competitive adsorption and column adsorption using the adsorbent were studied to assess its iodine removal abilities. The adsorbent exhibited a capacity as high as 3.4 mmol of iodine per gram of adsorbent in 1h. Therefore, Ag(2)O deposited titanate lamina is an effective adsorbent for removing radioactive iodine from water.

Surface properties and adsorption characteristics to methylene blue and iodine of adsorbents from sludge

Adsorbent materials created from wastewater sludge have unique surface characteristics and could be effective in adsorption applications. In this research, the sludge-adsorbents were generated by pyrolyzing mixtures of sewage sludge and H(2)SO(4). Scanning electron microscope (SEM), thermal analysis, X-ray diffraction (XRD) and X-ray photoelectron spectroscope (XPS) were used to analyze the properties of sludge-adsorbent. XPS results show that the adsorbent surface functional groups with high contents of oxygen-containing groups serve as active sites for the adsorption and affect the surface characteristics; the adsorption mechanism of methylene blue (MB) is mainly Brönsted acid-base reaction between the adsorbent surface and MB; and iodine atoms are bonded to the surface of the adsorbent mainly by dispersive interactions rather than by electrostatic interactions. The results also show that H(2)SO(4) level, pyrolysis temperature and sulfuric acid/sludge weight ratio actually affected the adsorption characteristics. Using the conditions (H(2)SO(4) level of 1-18 M, pyrolysis temperature of 650°C, and weight ratio of 0.8), the adsorption capacities for MB and iodine were 74.7-62.3 mg g(-1) and 169.5-209.3 mg g(-1), respectively.

Methylene blue and iodine adsorption onto an activated desert plant

Although frequently less toxic than many colorless effluents, colored effluents are generally considered by the public as an indicator of pollution. The present investigation aimed at identifying the effectiveness of a local desert plant characteristic of Southwest Algeria and known as Salsolavermiculata, which was pyrolyzed and treated chemically with a 50% zinc chloride solution, to remove methylene blue and iodine. The natural plant adsorption capacities were respectively 23mg/g and 272mg/g for methylene blue and iodine. Corresponding results for the pyrolyzed plant uptakes were 53mg/g and 951mg/g, while those for the pyrolyzed plant, chemically treated and activated at 650 degrees C, were 130mg/g and 1178mg/g, respectively. In comparison, the standard Merck activated carbon capacities were 200mg/g for methylene blue and 950mg/g for iodine. Consequently, this low-cost local plant may also prove useful for the removal of large organic molecules as well as potential inorganic contaminants.

A field survey of iodine supplementation of primary school children and their parents in a rural village in the endemic area of iodine deficiency disorder, northeastern Thailand

Iodine deficiency disorder (IDD) is an important health problem in Thailand. Due to the geographical limitation of marine salt distribution, the Northern and Northeastern regions of Thailand are endemic areas of this disorder. In this study, a cross-sectional survey on the domestic use of iodine-enriched salt by the people in a rural village, Non Sam Ran, Borabue district, Mahasarakarm province in the northeastern region of Thailand was conducted. A salt survey was undertaken in the village, involving the specific health knowledge of both primary school students and their parents, and including a home visit with kitchen salt sampling. As a result of this survey, despite the smallness of the sample, concern is raised regarding the application of public health information about IDD due to a taste preference for non-iodised salt, and the quality control of the manufacture of iodine-fortified salt.

Release of bioactive active iodine in kelp

The release process and influencing factors of bioactive iodine of kelp are systemically studied by leaching experiment. The results showed that the bioactive iodine of kelp can be released rapidly and the principal form of iodine in lixivium is I-. There is a dynamic process between the release and absorption of iodine. With the increase of leaching water, the gross amounts of released iodine rise. There also exists a transforming process among I-, IO3- and organic iodine in lixivium.

Effects of speciation on partitioning of iodine in aqueous biphasic systems and onto ABEC® resins

Polyethylene glycol (PEG)-aqueous biphasic systems (ABS) and PEG-grafted aqueous biphasic extraction chromatographic (ABEC) resins have been shown to remove inorganic species from environmental and nuclear wastes. The partitioning behavior of several iodide species (iodide, iodine, triiodide, iodate, and 4-iodo-2,6-dimethylphenol (I-DMP)) have been studied for PEG (MW 2000)-salt systems and ABEC resins. Iodide partitioning to PEG-rich phases or onto ABEC resins can be enhanced by derivatization with 2,6-dimethylphenol to form 4-iodo-2,6-dimethylphenol or by addition of I(2) to form triiodide. Conversely, iodide partitioning to the PEG-rich phase or onto ABEC resins is reduced by oxidation of iodide to IO(3)(-). Partitioning studies of iodide, iodate, and iodine in a PEG-ABS are compared to results using ABEC resins.

Bank filtration: a suitable process for the removal of iodinated X-ray contrast media?

After bank filtration, effluent influenced surface waters are often used as raw drinking water. It is known that high concentrations of iodinated X-ray contrast media are detectable in such surface waters and thus, more knowledge about the behaviour of the contrast media during bank filtration is necessary and the subject of investigations in this study. The adsorbable organic iodine (AOI), four widely used iodinated X-ray contrast media and four possible transformation products were quantified in an influenced lake, five groundwater wells and a drinking water well. Under anoxic conditions the AOI as well as the concentration of the contrast media are decreased by bank filtration, whereby the AOI is decreased by 64% and the contrast media concentration can be reduced up to 95%, depending on the compound. In the raw drinking water the following average concentrations were determined: lopromid < 20 ng/L, Diatrizote 166 ng/L, lopamidol 166 ng/L and lohexol 34 ng/L. Instationary conditions during the sampling period indicate that, at least under anoxic conditions, a large part of the contrast media and transformation products, which are still iodinated, may be associated to colloids and/or humic material.

[Bromo- and iodo-containing alkaloids from marine microorganisms and sponges]

The taxonomic distribution, structure, and biological activity of halogenated alkaloids isolated from marine microorganisms and sponges are reviewed. The structures of nearly 140 natural bromo- and iodo-containing alkaloids are shown.

Application of quantitative salt iodine analysis compared with the standard method

Laboratory investigation of 50 iodated salt samples (from producers, households, markets etc) were studied at the Research Nuclear Medicine Building, Siriraj Hospital. Two methods for the determination of iodine in salt are herein described. The standard method as recommended by The Programme Against Micronutrient Malnutrition (PAMM) / The Micronutrient Initiative (MI)/ The International Council for Control of Iodine Deficiency Disorders (ICCIDD) was the iodometric titration method. The starch-KI salt iodine quantitative method was developed in our laboratory for validation purposes. This method is high in precision, accuracy, sensitivity as well as specificity. The coefficient of variation (%CV) for intra and inter assay was below 10. Iodine contents as low as 10 ppm, could be detected. The proposed starch-KI method offered some advantages: e.g. not complicated, easier to learn and easier to perform competently, could be applied for spot qualitative test and readily performed outside the laboratory. The results obtained by the starch-KI method correlated well with the standard method (y = 0.98x - 3.22, r = 0.99).

Mapping the subcellular distribution of biomolecules at the ultrastructural level by ion microscopy

Analytical ion microscopy, a method proposed and developed in 1960 by Casting and Slodzian at the Orsay University (France), makes it possible to obtain easily and rapidly analytical images representing the distribution in a tissue section of elements or isotopes (beginning from the three isotopes of hydrogen until to transuranic elements), even when these elements or isotopes are at a trace concentration of 1 ppm or less. This method has been applied to study the subcellular distribution of different varieties of biomolecules. The subcellular location of these molecules can be easily determined when the molecules contain in their structures a specific atom such as fluorine, iodine, bromine or platinum, what is the case of many pharmaceutical drugs. In this situation, the distribution of these specific atoms can be considered as representative of the distribution of the corresponding molecule. In other cases, the molecules must be labelled with an isotope which may be either radioactive or stable. Recent developments in ion microscopy allow the obtention of their chemical images at ultra structural level. In this paper we present the results obtained with the prototype of a new Scanning Ion Microscope used for the study of the intracellular distribution of different varieties of molecules: glucocorticoids, estrogens, pharmaceutical drugs and pyrimidine analogues.

Rapid radiochemical neutron activation analysis for iodine in urine by different separation techniques

In the present work on radiochemical neutron activation analysis for the determination of iodine in urine samples, the performance of three different radiochemical separation techniques, namely, direct extraction, use of an iodinated ion-exchange resin column and Schöniger combustion, were intercompared and validated. The practical advantages of the iodinated-resin technique make it most suitable for the rapid routine determination of iodine in urine. It was further verified by participation in an international intercomparison run of urine analysis, and used in a pilot study on iodine determination in the urine of 171 Slovenian schoolchildren, where it gave results in good agreement with the catalytic method.

3'-Monoiodothyronine degradation in rat liver homogenate: enzyme characteristics and documentation of deiodination by high-pressure liquid chromatography

Characteristics of 3'-monoiodothyronine (3'-T1) degradation were examined in vitro in rat tissue homogenates. In rat liver homogenates, 3'-T1 degradation was optimal at pH 7.4, and was dependent upon time, temperature, and tissue concentration. The Michaeli's constant (Km) = 0.84 mumol/L. 3'-T1 degradation was enhanced by dithiothreitol and inhibited by propylthiouracil, sodium ipodate, ANS, and sodium azide but not by methimazole. Animals that fasted for three days had significant reductions in both hepatic T4 to T3 conversion (199 +/- 12 v 116 +/- 12 pg T3 generated/mg protein; P less than 0.001) and 3'-T1 degradation (588 +/- 31 v 148 +/- 53 pg 3'-T1 degraded/mg protein; P less than 0.001). To document that 3'-T1 degradation was occurring by deiodination, both liver and kidney homogenates were incubated with 125I-3'-T1 (approximately 3 microCi; 13.1 nmol/L). The reaction products were separated on a reverse-phase high pressure liquid chromatography (HPLC) column. In both tissues an iodide peak was generated, and no other radiolabeled peaks appeared except for 125I-3'-T1. These data suggest that 3'-T1 is metabolized by phenolic-ring monodeiodination and is enzymic in nature.

Amino acid sequence of the unique 3,5,3'-triiodothyronine-containing sequence from porcine thyroglobulin

A unique T3-containing peptide was isolated by chemical and enzyme treatments from pTgb of different iodine contents and microsequenced: Leu-Ala-Ser-Lys-Ser-T3. This site can also form T4 to a small extent. It contains all the T3 of the protein and presents a special susceptibility to proteolysis thus suggesting a likely mechanism to explain that the thyroid secretes T3 preferentially to T4 in vivo.

Iodopeptides from human thyroglobulin

Human thyroglubulin labelled in vivo by 125I was purified from eight different thyroid glands including normal thyroid tissue, thyrotoxic goitre and euthyroid multinodular goitre. The purified protein was cleaved with cyanogen bromide (CNBr) and the resulting peptides were separated by column chromatography and ion exchange chromatography. Reproducible elution profiles of both protein and iodine were obtained. However, the distribution of iodine depended on the iodine content of the intact thyroglobulin. Small CNBr peptides seemed to be preferentially iodinated, but with a limited capacity. With higher degrees of iodination, larger peptides became richer in iodine. This suggests sequential iodination of the thyroglobulin molecule. The mixture of small peptides was digested by trypsin. Two iodopeptides were identified in this material by peptide mapping and they had identical migration in thyroglobulins of different origin. One of them was purified by ion exchange chromatography and high voltage electrophoresis. Analogous amino acid composition was obtained for the iodopeptide purified from two different thyroglobulins. The data indicates that thyroglobulin iodination occurs in specific portions of the polypeptide chain and probably in a sequential manner.

[Isolation of iodine-protein components from sea algae]

The isolation of iodorganic compounds from the Black Sea red alga Phyllophora nervosa and its by-products obtained from industrial treatment was investigated. The algal biomass was pressed to remove alkali, subjected to 5-10 min treatment with 11-12% sodium hydrate, and drying at 125-130 degrees C and washed to yield 95% iodine and over 80% proteins. Iodine was found to be bound with protein of Phyllophora. Properties of the isolated iodine-peptide fractions were studied.