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Showing papers on "Iodine published in 2002"


Journal Article
TL;DR: It is proposed that NIS may serve as an alternative imaging reporter gene in addition to the HSVtk and dopaminergic receptor genes to enable these cells to concentrate iodide from plasma and in so doing offer the possibility of radioiodine therapy.
Abstract: Thyroid iodide uptake is basic to the clinical applications of radioiodine. Iodide uptake occurs across the membrane of the thyroid follicular cells through an active transporter process mediated by the sodium iodide symporter (NIS). The recent cloning of the NIS gene enabled the better characterization of the molecular mechanisms underlying iodide transport, thus opening the way to the clarification and expansion of its role in nuclear medicine. In papillary and follicular carcinoma, NIS immunostaining was positive in only a few tumor cells, and no NIS protein expression was detected in anaplastic carcinomas. Decreased NIS expression levels account for the reduced iodide uptake in thyroid carcinomas. Thus, by targeting NIS expression in cancer cells, we could enable these cells to concentrate iodide from plasma and in so doing offer the possibility of radioiodine therapy. Several investigators have shown that gene transfer of NIS into a variety of cell types confers increased radioiodine uptake by up to several hundredfold that of controls in nonthyroid cancers as well as in thyroid cancer. In addition, my group proposes that NIS may serve as an alternative imaging reporter gene in addition to the HSVtk and dopaminergic receptor genes. The NIS has the potential to expand the role of nuclear medicine in the future, just as it has served as the base for the development of nuclear medicine in the past.

318 citations


Journal ArticleDOI
TL;DR: Two silver-impregnated activated carbons and their virgin granular activated carbon precursors were investigated for their ability to remove and sequester iodide from aqueous solutions in a series of batch sorption and leaching experiments, and silver content, total iodide concentration, and pH were the factors controlling the removal mechanisms.
Abstract: Two silver-impregnated activated carbons (SIACs) (0.05 and 1.05 wt % silver) and their virgin (i.e., unimpregnated) granular activated carbon (GAC) precursors were investigated for their ability to remove and sequester iodide from aqueous solutions in a series of batch sorption and leaching experiments. Silver content, total iodide concentration, and pH were the factors controlling the removal mechanisms of iodide. Iodide uptake increased with decreasing pH for both SIACs and their virgin GACs. The 0.05% SIAC behaved similarly to its virgin GAC in all experimental conditions because of its low silver content. At pH values of 7 and 8 there was a marked increased in iodide removal for the 1.05% SIAC over that of its virgin GAC, while their performances were similar at a pH of 5. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analyses prior to reaction with iodide showed the presence of metallic silver agglomerates on the 1.05% SIAC surface. After the reaction, elemental mapping with EDX showed the formation of silver iodide agglomerates. Oxidation of metallic silver was observed in the presence of oxygen, and the carbon surface appears to catalyze this reaction. When the molar ratio of silver to iodide was greater than 1 (i.e., M(Ag,SIAC) > M(I,TOTAL)), precipitation of silver iodide was the dominant removal mechanism. However, unreacted silver leached into solution with decreasing pH while iodide leaching did not occur. When M(Ag,SIAC) < M(I,TOTAL), silver iodide precipitation occurred until all available silver had reacted, and additional iodide was removed from solution by pH-dependent adsorption to the GAC. Under this condition, silver leaching did not occur while iodide leaching increased with increasing pH.

164 citations


Journal ArticleDOI
TL;DR: Functional analysis of the protein expressed in mammalian cells indicates that it catalyzes a passive iodide transport and was designated hAIT for human Apical Iodide Transporter, suggesting that this new identified protein mediates iodine transport from the thyrocyte into the colloid lumen through the apical membrane.
Abstract: Iodide transport by thyrocytes is a two step process involving transporters located either in the basal or in the apical membranes of the cell. The sodium iodide symporter (NIS) is localized in the basolateral membrane facing the bloodstream and mediates iodide accumulation into thyrocytes. Pendrin has been proposed as an apical transporter. In order to identify new iodide transporters, we developed a PCR cloning strategy based on NIS sequence homologies. From a human kidney cDNA library, we characterized a gene, located on chromosome 12q23, that encodes a 610 amino acid protein sharing 46% identity (70% similarity) with the human NIS. Functional analysis of the protein expressed in mammalian cells indicates that it catalyzes a passive iodide transport. The protein product was immunohistochemically localized at the apical pole of the thyroid cells facing the colloid lumen. These results suggest that this new identified protein mediates iodide transport from the thyrocyte into the colloid lumen through the apical membrane. It was designated hAIT for human Apical Iodide Transporter.

163 citations


Journal ArticleDOI
TL;DR: Pendrin is an iodide-specific transporter in mammalian cells and is responsible for iodide efflux in the thyroid, according to studies using rat thyroid FRTL-5 cells.
Abstract: The Pendred syndrome gene encodes a 780-amino acid putative transmembrane protein (pendrin) that is expressed in the apical membrane of thyroid follicular cells. Although pendrin was shown to transport iodide and chloride using Xenopus laevis oocytes and Sf9 insect cells, there is no report using mammalian cells to study its role in thyroid function. We show here, using COS-7 cells and Chinese hamster ovary cells transfected with expression vectors encoding sodium iodide symporter or human Pendred syndrome gene cDNA and by comparison with studies using rat thyroid FRTL-5 cells, that pendrin is an iodide-specific transporter in mammalian cells and is responsible for iodide efflux in the thyroid.

148 citations


Journal Article
TL;DR: Physicians responsible for treating patients treated with 131I should have an understanding of the clinical pathophysiology and natural history of the disease processes, should be familiar with alternate forms of therapy, and should be able to collaborate closely with other physicians involved in the management of the patient’s condition.
Abstract: The purpose of this guideline is to assist nuclear medicine practitioners in evaluating patients for therapy with 131I (sodium iodide) for benign or malignant conditions of the thyroid gland, performing this treatment, understanding and evaluating the sequelae of therapy, and reporting the results

119 citations


Journal ArticleDOI
TL;DR: Some of the limitations and controversies related to urinary iodine determinations, and recent findings with emphasis on measurements of urinary iodine concentrations in children and during pregnancy are discussed.

113 citations


Journal ArticleDOI
TL;DR: The present data indicate that in marginally iodine-deficient areas, the administration of iodide is recommended in pregnancy and lactation and a dose of 200 microg iodide/day appeared to be more effective without inducing side effects and without enhancing the frequency of post-partum thyroiditis.
Abstract: Objective: A prospective randomized trial was performed to assess the usefulness of iodine supplementation in the prevention of goiter in pregnant women living in marginally iodine-deficient areas. Design: Eighty-six pregnant women were recruited and randomized in two groups and treated daily for up to six months after delivery with 200mg iodide (group A) or 50mg iodide (group B). Sixty-seven women (32 in group A and 35 in group B) completed the study. Methods: Thyroid volume (TV), thyroid functional parameters and urinary iodine concentration were determined in all subjects at booking, at the 18th ‐ 26th, and the 29th ‐ 33rd week of gestation, and at the 3rd and 6th month after delivery. Results: A slight but not significant increase in TV during gestation was observed only in group B. After delivery a progressive decrease in TV was documented in both groups, the final TV being significantly reduced with respect to the initial volume in group A. No significant changes in serum free thyroid hormones and TSH concentrations were found during gestation in either group. Postpartum thyroiditis was observed in 5 women (2 in group A, 3 in group B). No side effects were seen. Conclusion: The present data indicate that in marginally iodine-deficient areas, the administration of iodide is recommended in pregnancy and lactation. In the conditions of the present trial a dose of 50mg iodide/day is a safe and effective measure in preventing an increase in TV during pregnancy but a dose of 200mg iodide/day appeared to be more effective without inducing side effects and without enhancing the frequency of post-partum thyroiditis.

111 citations


Journal ArticleDOI
TL;DR: In spite of low iodine concentrations found in milk of mothers consuming low-iodine natural foods, long lasting or even life-lasting benefits to the breast-fed infant are demonstrable.

111 citations


Journal ArticleDOI
TL;DR: The frequency of urinary iodine concentrations <50 micro g/l in populations with median urinary iodine Concentrations >/=100 microg/l has been overestimated and the threshold of 100 micro G/l does not need to be increased.
Abstract: OBJECTIVE: Urinary iodine concentration is the prime indicator of nutritional iodine status and is used to evaluate population-based iodine supplementation. In 1994, WHO, UNICEF and ICCIDD recommended median urinary iodine concentrations for populations of 100- 200 micro g/l, assuming the 100 micro g/l threshold would limit concentrations 100 micro g/l. The total population was 55 892, including 35 661 (64%) schoolchildren. Median urinary iodine concentrations were 111-540 (median 201) micro g/l for all populations, 100-199 micro g/l in 23 (48%) populations and >/=200 micro g/l in 25 (52%). The frequencies of values 200 micro g/l, respectively. The frequency reached 20% only in two places where iodine had been supplemented for /=100 micro g/l has been overestimated. The threshold of 100 micro g/l does not need to be increased. In populations, median urinary iodine concentrations of 100-200 micro g/l indicate adequate iodine intake and optimal iodine nutrition.

103 citations


Journal ArticleDOI
TL;DR: Serum thyroglobulin concentration appears to be a good marker of iodine status, and even in a geographic area where mild iodine deficiency is common, a significant relation between iodine intake and thyroid volume was found.

95 citations


Journal ArticleDOI
TL;DR: A new, rapid methodology for trace analysis using solid-phase extraction is described, which is adaptable to a wide range of analytes and has been used for monitoring ppm levels of iodine and iodide in spacecraft water.
Abstract: A new, rapid methodology for trace analysis using solid-phase extraction is described The two-step methodology is based on the concentration of an analyte onto a membrane disk and on the determination by diffuse reflectance spectroscopy of the amount of analyte extracted on the disk surface This method, which is adaptable to a wide range of analytes, has been used for monitoring ppm levels of iodine and iodide in spacecraft water Iodine is used as a biocide in spacecraft water For these determinations, a water sample is passed through a membrane disk by means of a 10-mL syringe that is attached to a disk holder assembly The disk, which is a polystyrene-divinylbenzene composite, is impregnated with poly(vinylpyrrolidone) (PVP), which exhaustively concentrates iodine as a yellow iodine-PVP complex The amount of concentrated iodine is then determined in only 2 s by using a hand-held diffuse reflectance spectrometer by comparing the result with a calibration curve based on the Kubelka-Munk function The same general procedure can be used to determine iodide levels after its facile and exhaustive oxidation to iodine by peroxymonosulfate (ie, Oxone reagent) For samples containing both analytes, a two-step procedure can be used in which the iodide concentration is calculated from the difference in iodine levels before and after treatment of the sample with peroxymonosulfate With this methodology, iodine and iodide levels in the 01-50 ppm range can be determined with a total workup time of approximately 60 s with a RSD of approximately 6%

Journal ArticleDOI
TL;DR: The reduction of iodate to iodide by phytoplankton may be a general phenomenon in the marine environment and the rates might vary with growth phase and the patterns of these variations might be species-specific.
Abstract: Six species of phytoplankton, representing 6 major phylogenetic groups (2 oceanic species: a cyanobacteria, Synechococcus sp., and a coccolithophorid, Emiliania huxleyi; and 4 coastal species: a prasinophyte, Tetraselmis sp., the green algae Dunaliella tertiolecta, the diatom Skele- tonema costatum and a dinoflagellate Amphidinium carterae) were tested for their ability to reduce iodate to iodide in batch cultures. They all did so to varying degrees. Thus, the reduction of iodate to iodide by phytoplankton may be a general phenomenon in the marine environment. At ambient con- centrations of iodate, the rates of depletion of iodate and appearance of iodide varied between 0.8 and 0.02, and between 0.3 and 0.02 nmol µg chlorophyll a -1 d -1 , respectively. E. huxleyi was the least efficient while A. carterae was the most efficient in the depletion of iodate. However, in the formation of iodide, while E. huxleyi was also the least efficient, Synechococcus sp. were the most efficient. The rates of appearance of iodide were noticeably slower than the corresponding rates of depletion of iodate, suggesting that part of the iodate might have been converted to forms of iodine other than iodide in these cases. The slight mismatch in the rank order of the rates of depletion of iodate and appearance of iodide between the phytoplankton species was traced to this variable and incomplete conversion of iodate to iodide. These rates were increased by up to over an order of magnitude upon enriching the culture medium with 5 and 10 µM of iodate. The depletion of iodate and appearance of iodide occurred in all growth phases. However, the rates might vary with growth phase and the patterns of these variations might be species-specific. Phytoplankton growth was not impeded even under unnaturally high concentrations of iodate implying that there is little interaction between iodine processing and the metabolic activity of cell growth.

Journal ArticleDOI
TL;DR: In this paper, the synergistic effect of iodide ions on the corrosion inhibition of mild steel in 0.5 M sulfuric acid (H2SO4) in the presence of 3,5-bis(4-methylthiophenyl)-4H-1,2,4-triazole (4-MTHT) was investigated using weight loss measurements and different electrochemical techniques.
Abstract: The synergistic effect of iodide ions on the corrosion inhibition of mild steel in 0.5 M sulfuric acid (H2SO4) in the presence of 3,5-bis(4-methylthiophenyl)-4H-1,2,4-triazole (4-MTHT) was investigated using weight loss measurements and different electrochemical techniques such as potentiostatic polarization curves and electrochemical impedance spectroscopy (EIS). The inhibition efficiency (E, %) increased with 4-MTHT concentration, but the desorption potential (Ed) remained unchanged with increasing 4-MTHT concentration. The addition of potassium iodide (KI) enhanced E considerably and increased the value of Ed. A synergistic effect was observed between KI and 4-MTHT with an optimum mass ratio of [4-MTHT]/[KI] = 4 × 10−2. The synergism parameters (SΘ) calculated from surface coverage were found to be more than unity. This result clearly showed the synergistic influence of iodide ions on the corrosion inhibition of mild steel in 0.5 M H2SO4 by 4-MTHT. The adsorption of this inhibitor alone and in combination with iodide ions followed Langmuir's adsorption isotherm.

Journal ArticleDOI
TL;DR: In this paper, two separate regimes of iodine chemistry are highlighted: (1) the well-oxygenated surface layer (WOSL) where iodide concentrations were in the range of 158-558 nM, and (2) the oxygen minimum zone (OMZ) where total iodine concentrations [primarily as iodide and in excess to the oceanic iodine/salinity ratio of ∼13] varied from ∼200 to 950 nM.
Abstract: Dissolved iodine species and total iodine concentrations were measured in the Arabian Sea during the Spring Intermonsoon of 1995. Two separate regimes of iodine chemistry are highlighted in this study: (1) the well-oxygenated surface layer (WOSL) where iodide concentrations were in the range of 158–558 nM, and (2) the oxygen minimum zone (OMZ) where total iodine concentrations [primarily as iodide and in excess to the oceanic iodine/salinity ratio of ∼13] varied from ∼200 to 950 nM. Iodine data in the WOSL of the Arabian Sea are contrasted with data from the Bermuda Atlantic Time-series Station (BATS), the Hawaii Ocean Time-series Station ALOHA (HOT), VERTEX in the Pacific and the Black Sea. Total iodine concentrations in excess of 400 nM were observed in eastern portions of the OMZ. The eastern portion of the basin has a permanent denitrification zone as well as high concentrations of dissolved Mn2+ (d-Mn2+) and iodide. While there is precedent for high values of iodide and total iodine in several other isolated basins, this is the first report of such values in open-ocean waters. Potential sources of excess total iodine to the OMZ include advection along isopycnals, from hydrothermal vents or margin sediments; atmospheric deposition; and remineralization of sinking particulate organic iodine (POI) associated with elevated productivity in surface waters. We estimate that only 3.6% of the excess total iodine can result from remineralization of sinking POI from the WOSL to the OMZ. Advection from margin sediments off of India is the most plausible source of iodine to the OMZ and contributes ∼96% of the total excess iodine to the OMZ. I− is maintained as the dominant form of iodine via in situ reduction of iodate by bacteria.

Journal Article
TL;DR: Stunning of iodide transport is detected after (131)I irradiation of cultured thyroid cells, and the degree of inhibition of transport is dependent on the absorbed dose.
Abstract: The existence of thyroid stunning (i.e., inhibited thyroidal iodide uptake after administration of diagnostic amounts of 131I) is controversial and is currently a subject of debate. To our knowledge, the stunning phenomenon has not been investigated previously in vitro. Methods: Growth-arrested porcine thyroid cells that formed a tight and polarized monolayer in a bicameral chamber were irradiated with 3–80 Gy 131I present in the surrounding culture medium for 48 h. The iodide transport capacity after irradiation was evaluated 3 d later by measuring the transepithelial (basal to apical) flux of trace amounts of 125I. Results: The basal-to-apical 125I transport decreased with increasing absorbed dose acquired from 131I; a nearly 50% reduction was observed already at 3 Gy. Stable iodide at the same molarity as 131I (10−8 mol/L) had no effect on the 125I transport. Cell number and epithelial integrity were not affected by irradiation. Conclusion: Stunning of iodide transport is detected after 131I irradiation of cultured thyroid cells. The degree of inhibition of transport is dependent on the absorbed dose.

Journal ArticleDOI
TL;DR: It was shown that the supplementation of algae into feed could increase daily body weight gain by 10% and it was suggested that the carry-over of iodine through feeding pigs with an algae-supplemented feed could be beneficial to both the control of IDD and the improvement of pig production.
Abstract: Meat products with a higher iodine content can be produced through feeding animals with a diet supplemented with inorganic iodine salts or with algae containing high iodine. This may help to improve daily iodine intake and to control iodine deficiency disorders (IDD) in man. In the present study a total of 40 crossbred pigs (Deutsche Landrasse x Pietrain) with an average body weight of 17 kg were allotted to either a control group, to two groups receiving potassium iodide (KI) at different concentrations (5 or 8 mg iodine per kg of feed) or to two groups receiving the algae Laminaria digitata containing the same amount of iodine. After pigs were fed with iodine-supplemented diets for 3 months, it was found that compared to the control group the iodine content increased by up to 45% in fresh muscle, by 213% in adipose tissue, by 124% in the heart, by 207% in the liver and by 127% in the kidneys. There was a significant (p 0.05). It is suggested that the carry-over of iodine through feeding pigs with an algae-supplemented feed could be beneficial to both the control of IDD and the improvement of pig production.

Journal ArticleDOI
01 Oct 2002-Thyroid
TL;DR: The introduction of salt iodination led to an improvement in iodine supply with a marked reduction of goiter prevalence in people who were born after 1963, but also to an increase in hyperthyroidism and autoimmune thyroid diseases as well as changes in histologic types of thyroid cancer.
Abstract: Until 1963 Austria was an extremely iodine-deficient area with low iodine intake and high goiter prevalence. Therefore, for the first time in 1963, salt iodination with 10 mg of potassium iodide per kilogram of salt was introduced by federal law. Twenty years after this salt iodination, however, investigations in schoolchildren demonstrated iodine deficiency grade I to II according to the World Health Organization (WHO) (urinary iodine excretion, 42-75 microg/g Crea) and goiter prevalence of far more than 10%. In 1990, salt iodination was increased to 20 mg of potassium iodide per kilogram of salt. In 1994, further investigations in schoolchildren demonstrated an increase of urinary iodine excretion (121 microg/g Crea) and a reduction of goiter prevalence below 5%, with the exception of pupils ages 14-19 (12%). In the year 2000, 10 years after the increase of salt iodination in Austria, 430 nonselected adult inhabitants of three communities in Carinthia (a county of Austria) were investigated for iodine excretion, goiter prevalence, and prevalence of thyroid autoantibodies. This study demonstrated that although iodine supply is sufficient now in Austria (males, 163.7 microg of Crea; females, 183.3 microg of iodine per gram of Crea), goiter prevalence is still high in the elderly, who lived for a longer period of iodine deficiency (34.3% in women and 21.3% in men), whereas goiter prevalence in younger people up to age 40 years is below 5%. It could also be shown that the percentage of thyroid autoantibodies is now as high as in other countries with sufficient iodine supply (3.19% in males, 5.17% in females). In addition to the changes of urinary iodine excretion and goiter prevalence because of salt iodination, changes of incidence in hyperthyroidism and histologic types of thyroid cancer are discussed in this paper. In conclusion, the introduction of salt iodination led to an improvement in iodine supply with a marked reduction of goiter prevalence in people who were born after 1963, but also to an increase in hyperthyroidism and autoimmune thyroid diseases as well as changes in histologic types of thyroid cancer.

Journal ArticleDOI
TL;DR: Addition of encapsulated Fe to iodized salt improves the efficacy of iodine in goitrous children with a high prevalence of anemia.
Abstract: Objective: In many developing countries, children are at high risk for both goiter and anemia. Iron (Fe) deficiency adversely effects thyroid metabolism and reduces efficacy of iodine prophylaxis in areas of endemic goiter. The study aim was to determine if co-fortification of iodized salt with Fe would improve efficacy of the iodine in goitrous children with a high prevalence of anemia. Design and methods: In a 9-month, randomized, double-blind trial, 6 ‐ 15 year-old children ðn ¼ 377Þ were given iodized salt (25mg iodine/g salt) or dual-fortified salt with iodine (25mg iodine/g salt) and Fe (1 mg Fe/g salt, as ferrous sulfate microencapsulated with partially hydrogenated vegetable oil). Results: In the dual-fortified salt group, hemoglobin and Fe status improved significantly compared with the iodized salt group ðP , 0:05Þ: At 40 weeks, the mean decrease in thyroid volume measured by ultrasound in the dual-fortified salt group (2 38%) was twice that of the iodized salt group (2 18%) ðP , 0:01Þ: Compared with the iodized salt group, serum thyroxine was significantly increased ðP , 0:05Þ and the prevalence of hypothyroidism and goiter decreased ðP , 0:01Þ in the dual-fortified salt group. Conclusion: Addition of encapsulated Fe to iodized salt improves the efficacy of iodine in goitrous children with a high prevalence of anemia.

Journal ArticleDOI
01 Oct 2002-Thyroid
TL;DR: It can be speculated that a low-iodine content of mother's milk because of inhibition of NIS in the mammary gland may be one factor of importance for development of myxedematous cretinism.
Abstract: Transport of iodine in the mammary gland into breast milk plays a central role in various fields of prevention of thyroid diseases. First, a sufficient content of iodine in the mother's milk is necessary for normal brain development in the breastfed child. This is attained by expression during lactation in the mammary gland of the sodium iodide symporter (NIS), also responsible for iodine transport in the thyroid. Milk iodine content varies with the iodine intake of the mother, and urinary iodine excretion in groups of mothers seems to be a valuable indicator of the iodine status of their breastfed children. Second, iodine in dairy products provides a considerable part of iodine intake in many populations. Thiocyanate from rapeseed feeding of cows decreases milk iodine content, probably by competitive inhibition of NIS in the mammary gland. Alterations in feeding of dairy cows may alter the iodine content of consumer milk, and this may influence the risk of thyroid diseases in the population. Thiocyanate inhibition of iodine transport into milk may also be operative in humans with a high thiocyanate intake. This could further impair iodine status in breastfed children in low-iodine intake areas of the world. It can be speculated that a low-iodine content of mother's milk because of inhibition of NIS in the mammary gland may be one factor of importance for development of myxedematous cretinism.

Journal ArticleDOI
TL;DR: During prolonged excess iodine exposure there were marked increases in serum total iodine concentrations, and the prevalence of goiter, elevated serum TSH values, and elevated serum thyroid peroxidase antibody values increased, and The prevalence of all abnormalities decreased after removal of excess iodine from the drinking water system.
Abstract: A cross-sectional survey of 102 Peace Corps volunteers in Niger, West Africa, in 1998 had previously demonstrated a high rate of thyroid dysfunction and goiter attributable to excess iodine from their water filters. The Peace Corps volunteers were followed-up a mean of 30 wk after they ceased using iodine-based water filtration systems. Goiter was present in 44% of subjects during excess iodine ingestion and in 30% after removal of excess iodine. Mean serum iodine decreased from 293 μg/liter during excess iodine ingestion to 84 μg/liter after cessation of excess iodine. Mean total serum T4 values increased from 100.4 to 113.3 nmol/liter (7.8 to 8.8 μg/dl). Mean serum free T4 increased from 32.2 to 34.7 pmol/liter (2.5 to 2.7 ng/dl). Mean serum TSH decreased from 4.9 to 1.8 mU/liter. Mean serum thyroid peroxidase antibody levels decreased from 33,000 to 22,000 IU/liter (33 to 22 IU/ml). We found that during prolonged excess iodine exposure there were marked increases in serum total iodine concentrations, a...

01 Jan 2002
TL;DR: Iodine is an essential requirement for thyroid hormone (TH) synthesis in many developing countries, and its eradication is currently addressed by the International Council for Control of Iodine Deficiency Disorders (ICCIDD), United Nations International Children's Education Fund (UNICEF), and World Health Organization (WHO).
Abstract: Iodine is an essential requirement for thyroid hormone (TH) synthesis. The recommended daily iodine intake is variable, depending on the age of the subject; it is 40 µg/d during the neonatal period and 150 µg/d in the adult. The iodine requirement increases to approx 200 µg/d during pregnancy. Severe iodine deficiency, leading to various degrees of cretinism, is the major cause of mental and physical retardation in many developing countries, and its eradication is currently addressed by the International Council for Control of Iodine Deficiency Disorders (ICCIDD), United Nations International Children’s Education Fund (UNICEF), and World Health Organization (WHO). Mild to moderate iodine deficiency, ranging from 40–80 µg iodine daily, also is prevalent, including in many areas of continental Western Europe. In the United States, the average iodine intake in the 1988–1994 population was approx 150 µg/d, a decrease of more than 50% relative to 1971–1974 (1). A low iodine intake (<50 µg/d) was found in 11.7% of the population. Although the findings are not indicative of iodine deficiency in the overall population of the United States, the observed downward trend in iodine intake requires further close monitoring of iodine intake.

Journal ArticleDOI
TL;DR: Investigation of the effects of packaging materials and environmental conditions on the stability of salt double-fortified with iron and iodine indicates that with careful control of processing, packaging, and storage conditions, a double-Fortified salt could be stabilized for the six-month period required for distribution and consumption.
Abstract: Deficiencies in small quantities of micronutrients, especially iodine and iron, severely affect more than a third of the world's population, resulting in serious public health consequences, especially for women and young children. Salt is an ideal carrier of micronutrients. The double fortification of salt with both iodine and iron is an attractive approach to the reduction of both anemia and iodine-deficiency disorders. Because iodine is unstable under the storage conditions found during the manufacturing, distribution, and sale of salt in most developing countries, the effects of packaging materials and environmental conditions on the stability of salt double-fortified with iron and iodine were investigated. Salt was double-fortified with potassium iodide or potassium iodate and with ferrous sulfate or ferrous fumarate. The effects of stabilizers on the stability of iodine and iron were followed by storing the salt under three conditions that represent the extremes of normal distribution and sale for salt in developing countries: room temperature (25 degrees C) with 50%-70% relative humidity, 40 degrees C with 60% relative humidity, and 40 degrees C with 100% relative humidity. The effects of stabilizers, such as sodium hexametaphosphate (SHMP), calcium carbonate, calcium silicate, and dextrose were investigated. None of the combinations of iron and iodine compounds was stable at elevated temperatures. Essentially all of the iodine was lost over a period of six months. SHMP effectively slowed down the iodine loss, whereas magnesium chloride, a typical hygroscopic impurity, greatly accelerated this process. Calcium carbonate did not have a sparing effect on iodine, despite contrary indications in the literature. Ferrous sulfate-fortified salts generally turned yellow and developed an unpleasant rusty flavor. Salt fortified with ferrous fumarate and potassium, iodide was reasonably stable and maintained its organoleptic properties, making it more likely to be acceptable to consumers. We confirmed that application of the iodine compounds as solutions resulted in a more even distribution of the iodine throughout the sample. The effect of the packaging materials was overshadowed by the other variables. None of the packaging materials was clearly better than any other. This may have been due to the fact that the polymer bags were not heat sealed, and thus some moisture penetration was possible. The results indicate that with careful control of processing, packaging, and storage conditions, a double-fortified salt could be stabilized for the six-month period required for distribution and consumption. Unfortunately, the processing and storage required are difficult to attain under typical conditions in developing countries.

Journal ArticleDOI
TL;DR: It is hypothesized that iodine in drinking water in general suggests coexisting humic substances of marine origin, and changing pH and ionic strength and preincubation with iodide indicated that iodine was bound in Humic substances.
Abstract: OBJECTIVE The iodine intake level is important for the occurrence of thyroid disorders in a population. We have previously found that iodine in drinking water is related to iodine excretion but whether iodine is present as iodide or bound in other molecules remains unknown. DESIGN We measured iodine in drinking water from 22 locations in Denmark. Six locations were selected by iodine content for further tap water analysis (Skagen 140 micro g/l, Samsoe 56 micro g/l, Nykoebing S. 50 micro g/l, Nakskov 40 micro g/l, Ringsted 38 micro g/l, Copenhagen 19 micro g/l). METHODS HPLC size exclusion before (Skagen) and after (all sites) freeze drying and measurement of absorbance (280 nm) and iodine in fractions, and fluorescence spectroscopy of bulk organic matter in Skagen drinking water. RESULTS Iodine content was unaltered after 3 Years (P=0.2). All samples contained organic molecules with characteristics similar to humic substances. Most iodine eluted with humic substances (Skagen 99%, Ringsted 98%, Nykoebing S. 90%, Copenhagen 90%, Samsoe 75%, Nakskov 40%). Changing pH and ionic strength and preincubation with iodide indicated that iodine was bound in humic substances. Humic substances may affect thyroid function but differ with geology. Geological and geochemical data agree with tap water humic substances having been released from marine deposits. Iodine is abundant in the marine environment and marine deposits are particularly rich in iodine. Correlation analysis (r=0.85, P=0.03) conform to iodine in drinking water, suggesting marine humic substances at the source rock. CONCLUSION Iodine in Danish drinking water varied considerably. In drinking water with a high iodine content, the iodine mainly eluted with humic substances derived from marine source rock. We hypothesize that iodine in drinking water in general suggests coexisting humic substances of marine origin.

Journal ArticleDOI
TL;DR: The most stable combination, containing 50 mg iodine and 1000 mg iron per kg salt, retained more than 75% of the added iodine for a year at 40°C, 100% RH as mentioned in this paper.

Journal Article
TL;DR: The industrial feasibility of naturally iodized salt using seaweed as source of iodine using Gracilaria verrucosa and Laminaria hyperborea selected due to their high level in iodine as a mineral or an organic form and low levels of heavy metals is investigated.
Abstract: The major procedure used to correct iodine deficiency is the universal salt iodization by addition of iodide or iodate to salt with an iodine content varying from 7 to 100 mg/kg of salt depending on the country legislation. As an important fraction of consumers in the world prefers natural products over artificial ones, we investigated the industrial feasibility of naturally iodized salt using seaweed as source of iodine. We report the results of the iodine bioavailability in healthy subjects from two seaweeds: Laminaria hyperborea and Gracilaria verrucosa selected due to their high level in iodine as a mineral or an organic form and low levels of heavy metals. As a control we studied in a normal man the bioavailability of pure mineral iodine such as potassium iodide which was excellent i.e. 96.4% and of pure organic iodine such as monoiodotyrosine which was a little lower i.e. 80.0%. Iodine bioavailability from these two seaweeds was studied in nine normal subjects from Marseille (France) which is an iodine sufficient area based on a median urinary iodine level of 137 microg/day and innine normal subjects from Brussels (Belgium) who present a mild iodine deficiency with a value of 73 microg/day. The iodine bioavailability of Gracilaria verrucosa is better than for Laminaria hyperborea (101% versus 90% in Marseille, t=0.812, NS; 85% versus 61.5% in Brussels, t = 2.486, p = 0.024, S*). The urinary excretion of iodine is lower in Brussels than in Marseille for the same seaweed because part of the iodine is stored in the thyroid (101% versus 85% for Gracilaria verrucosa, t = 1.010, NS; 90% versus 61.5% for Laminaria hyperborea, t = 3.879, p= 0.001, S***).

Journal ArticleDOI
TL;DR: Subclinical hyperthyroidism is more prevalent in the iodine deficient area than in the severe iodine excessive area, and in the area with mild iodine deficiency, the introduction of universal salt iodization may not be accompanied by an increased incidence of hyper thyroidroidism.
Abstract: Objective: To investigate the effect of different levels of iodine intake on the prevalence of hyperthyroidism and the impact of universal salt iodization on the incidence of hyperthyroidism. Design: A comparative cross-sectional and longitudinal survey was conducted in three areas with borderline iodine deficiency, mild iodine excess (previously mild iodine deficiency) and severe iodine excess. Universal salt iodization had been introduced 3 years previously except in the area with borderline iodine deficiency. Methods: In total 16 287 inhabitants from three areas answered a questionnaire concerning the history of thyroid disease. Among them 3761 unselected subjects received further investigations including thyroid function, thyroid autoantibodies, thyroid ultrasonography and urinary iodine excretion. Results: Among areas with median urinary iodine excretion of 103mg/l, 375mg/l and 615mg/lOP , 0:05U; the prevalence of hyperthyroidism did not differ significantly (1.6%, 2% and 1.2%). The prevalence of subclinical hyperthyroidism was higher in areas with borderline iodine deficiency and mild iodine excess than in the area with severe excess iodine intake (3.7%, 3.9% and 1.1%, P , 0:001). The prevalence of Graves’ disease and its proportion in hyperthyroidism did not differ among areas. The incidence of hyperthyroidism did not significantly increase after the introduction of universal salt iodization. Conclusion: Different iodine intakes under a certain range do not affect the prevalence and type of hyperthyroidism. Subclinical hyperthyroidism is more prevalent in the iodine deficient area than in the severe iodine excessive area. In the area with mild iodine deficiency, the introduction of universal salt iodization may not be accompanied by an increased incidence of hyperthyroidism.

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TL;DR: The increased proliferation rate induced under the experimental conditions described in this study is apparently not sufficient to cause thyroid carcinomas, but the presence of a mutagen-like radiation is required.
Abstract: It is believed that a combination of environmental factors with mutagens induces carcinomas derived from thyroid follicular cells. In this study we tried to ascertain whether a single short-term exposure to external radiation is sufficient to induce thyroid carcinomas in rats under long-term high or low dietary iodine intake. Rats were tested over a period of 110 wk under high (∼10-fold of normal), normal, and low (∼0.1-fold of normal) daily iodine intake. Forty-day-old animals were subjected to single external radiation of 4 Gy or sham radiation. Thyroid function was tested weekly, and thyroid morphology was determined after 15, 35, 55, and 110 wk. Iodine deficiency, but not high iodine intake, led to a decrease in T3 and T4 plasma levels, but to an increase in TSH, which became significant after 9 and 11 wk of treatment, respectively. Both high and low iodine treatment significantly increased the proliferation rate and induced thyroid adenomas, but no malignancies after 55 and 110 wk. Radiation with 4 G...

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TL;DR: The seeds, oil and oil-cake of the pumpkin (Cucurbita pepo L.) with thin-husked seeds, grown in Slovenia, were analysed for iodine and selenium contents using radiochemical neutron activation analysis as discussed by the authors.
Abstract: The seeds, oil and oil-cake of the pumpkin (Cucurbita pepo L.) with thin-husked seeds, grown in Slovenia, were analysed for iodine and selenium contents using radiochemical neutron activation analysis. Selenium determination was based on destruction by fusion of the irradiated sample with Mg(NO3)2 as added carrier and HNO3; iodine determination was based on combustion of the sample in a closed oxygen atmosphere with an ashing aid and carrier, followed by double extraction of I2 with CCl4, after the use of classical selective redox reactions involving NaNO2 and Na2SO3 in an acid medium. Pumpkin seeds were found to contain 0.023–0.037 mg kg–1 of selenium, and the oil-cake 0.034–0.047 mg kg–1 of selenium. However, in the oil the selenium content was below the detection limit (0.001 mg kg–1). Pumpkin seeds contained 0.005–0.013 mg kg–1 of iodine, and the contents in oil and oil-cake were 0.002–0.003 and 0.007–0.032 mg kg–1 of iodine, respectively. Pumpkin oil may thus contain some iodine, but seems to be a poor source of selenium. In iodine and selenium deficient areas pumpkin seed and oil-cake may be a moderate source of these dietary trace elements.

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TL;DR: The mutation was the direct cause of the iodide transport defect in these patients and the mutant NIS protein was synthesized, but not properly expressed, on the cell surface, but was mostly accumulated in the cytoplasm, suggesting impaired targeting to the plasma membrane.
Abstract: Previously, we reported two Spanish siblings with congenital hypothyroidism due to total failure of iodide transport. These were the only cases reported to date who received long-term iodide treatment over 10 yr. We examined the sodium/iodide symporter (NIS) gene of these patients. A large deletion was observed by long and accurate PCR using primers derived from introns 2 and 7 of the NIS gene. PCR-direct sequencing revealed a deletion of 6192 bases spanning from exon 3 to intron 7 and an inverted insertion of a 431-base fragment spanning from exon 5 to intron 5 of the NIS gene. The patients were homozygous for the mutation, and their mother was heterozygous. In the mutant, deletion of exons 3–7 was suggested by analysis using programs to predict exon/intron organization, resulting in an in-frame 182-amino acid deletion from Met142 in the fourth transmembrane domain to Gln323 in the fourth exoplasmic loop. The mutant showed no iodide uptake activity when transfected into COS-7 cells, confirming that the m...

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TL;DR: In this paper, the stabilization of iodine in salt has been determined by using isotope dilution analysis, and the parameters of heating, heating with oxidizing agent, incubation by time were determined.
Abstract: lodization of consumed salts is mandatory in many countries fighting against to iodine deficiency. In salts iodine stability is affected by storage conditions. In this study, stabilization of iodine in salt has been determined by using Isotope Dilution Analysis. Heating, heating with oxidizing agent, incubation by time were the parameters which have been determined. Iodine loss was 41.16% by heating at 200 degrees C up to 24 hours. When the iodized salt heated with oxidized agent iodine loss rose up to 58.46% in 24 hours. Iodine loss mechanism seems similar in both cases. However iodine loss is greater in the presence of H202. After the salt was stored at room temperature with a relative humidity of 30%-45% and in sealed paper bags for three years, 58.5% of iodine content lost in approximately 3.5 years.