scispace - formally typeset
Search or ask a question

Showing papers on "Iodine published in 1996"


Journal ArticleDOI
TL;DR: Iodine supplementation during pregnancy in an area of moderate iodine deficiency results in a lower size of neonatal thyroid volume and that this supplementation was not accompanied by an increase in the frequency of TPO-ab.
Abstract: During pregnancy complex changes of maternal thyroid function occur and they are influenced by the maternal iodine supply. It has been demonstrated that with decreasing iodine supply maternal goiter and hypothyroxinemia as well as fetal and neonatal hypothyroidism become more prevalent. Therefore iodine supplementation during pregnancy is now strongly recommended also in areas of moderate iodine deficiency. To monitor the success of iodine supplementation and its theoretical risk of increasing the frequency of thyroid autoantibodies, we have investigated the thyroid volume, thyroid function, urinary iodine excretion and antibodies to thyroid peroxidase at 10-12 weeks of gestation and postpartum in 38 mothers receiving 300 micrograms potassium iodide/day and in 70 mothers without iodine supplementation. In all of their newborns thyroid volume was determined by ultrasound. The thyrotropin (TSH) levels and antibodies to thyroid peroxidase (TPO-ab) in the neonates were measured in dried blood spots on filter paper from their newborn screening. Urinary iodine excretion was increased significantly after iodine supplementation in mothers (p < 0.001) and their newborns (< 0.05). No hypo- or hyperthyroidism was observed in the mothers or newborns. Interestingly, no difference of maternal thyroid volumes was observed between the two groups after pregnancy, but the volumes of the thyroid glands in newborns of mothers who received iodine were significantly (p < 0.004) lower (0.7 +/- 0.4 ml) than in the control group (1.5 +/- 1.1 ml). There was no change in the frequency of TPO-ab in either group after pregnancy. In four mothers transplacental passage of these antibodies was documented by positive measurement in the blood sample of the newborn. This study documents that iodine supplementation during pregnancy in an area of moderate iodine deficiency results in a lower size of neonatal thyroid volume and that this supplementation was not accompanied by an increase in the frequency of TPO-ab.

123 citations


Journal ArticleDOI
TL;DR: The results of analyses of samples from the Bermuda Atlantic Time Series (BATS) and Hawaii Ocean Time-series (HOT) for dissolved iodine speciation are presented in this paper.
Abstract: The results of analyses of samples from the Bermuda Atlantic Time Series (BATS) and Hawaii Ocean Time-series (HOT) for dissolved iodine speciation are presented. At both sites iodate is reduced to iodide in surface waters by biological processes, but the iodide concentrations in the upper 100 m at the HOT site are approximately twice those at the BATS site. Using published estimates of surface water residence times and primary productivity at each station we use the differences between the two sites to derive an estimate of the in situ rate of iodide oxidation and the relationship between iodate reduction and primary production using a simple mass balance model. The model results suggest that on an annual basis iodide oxidation is relatively fast (half-life about 70 days) and that biological iodate reduction to iodide is about 100 times faster than iodide incorporation into particulate organic carbon.

97 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated whether the speciation of the nitrate-nitrite and iodate-iodide redox couples is influenced by light and organic matter in both deionised and sea waters.

91 citations


Journal ArticleDOI
TL;DR: In this paper, it is suggested that iodine from oceanic sources migrates in a series of ‘steps' across landmasses by deposition followed by revolatilization, and that high pH soils and organic-rich soils then act as a migration barrier for iodine.
Abstract: Abstract Seawater is the most important reservoir for terrestrial iodine (mean concentration 58 µgl−1 I); this is a major influence on iodine distribution in the secondary environment. Volatilization of iodine from the oceans, possibly as elemental iodine or as an organically-bound species, is the main source of the element in the environment. The distribution of iodine in the secondary environment is, therefore, largely controlled by proximity to the oceans, with rainwater and surface run-off relatively enriched in iodine in near-coastal regions. Soil iodine content is also strongly influenced with coastal soils being much enriched and central continental soils being depleted. Topography has a marked influence with soils in rain shadow areas being relatively depleted in iodine. While iodine input is a major controlling influence on its geographical distribution in soils, the soil’s ability to retain iodine is also an important factor. Organic matter together with iron and aluminium oxides and clays are the important sinks of soil iodine. An additional factor in the distribution of iodine in the secondary environment, and its subsequent availability to the biosphere, relates to its speciation in soils. In acid oxidizing conditions iodine is likely to be present as the I− ion and as such liable to be volatilized as I2. In near-neutral or alkaline conditions iodine is likely to be present as the IO3− ion which is not volatilized. Soils in limestone areas, with pH values of 7 and above, have thus been found to be much enriched in iodine compared to acidic soils in neighbouring areas. It is suggested that iodine from oceanic sources migrates in a series of ‘steps’ across landmasses by deposition followed by revolatilization. High pH soils and organic-rich soils then act as a migration barrier for iodine. In addition, it is suggested that volatilized iodine is bioavailable and any geochemical barrier to such volatilization deprives the biosphere of a major source. In this context it is interesting to note that several goitre endemias occurred in areas with limestone bedrock.

85 citations


Journal ArticleDOI
TL;DR: In this article, a technique for the determination of iod, iodide and iodade in aqueous solution is proposed, which consists of the derivatization of iodine in the presence of 2,6-dimethylphenol and a single-step extraction of the derivative with diethyl ether.

70 citations


Journal ArticleDOI
TL;DR: Investigation of the correlation between fasting or random casual urine samples and 24 hour urines for iodine and selenium excretion in New Zealand residents indicated that fasting urine samples, but not casual urines, may give a reasonable estimate of urinary output of iodine and Selenium on a population basis, but that 24 hours urines are necessary for diagnosis of iodine deficiency in an individual and for research purposes.

61 citations


Journal ArticleDOI
TL;DR: In the comparison of tissue iodine content in growth‐suppressive tumors with that in nonsuppressive tumors, the former showed a much higher iodine content, which suggests that direct uptake of inorganic iodine by breast tumors led to the suppression of tumor growth.
Abstract: Concerning the suppressive effect of inorganic iodine on the growth of 7,12-dimethyl-benz(a)anthracene (DMBA)-induced breast tumor in female Sprague-Dawley (SD) rats, we previously reported that although iodine itself had a suppressive effect on the tumor growth, its effect was not as strong as that of MPA (medroxy-progesterone acetate). However, the combined medication of iodine at a low concentration + MPA showed a stronger effect than MPA alone. The purpose of the present study is to elucidate this mechanism of action by determining the uptake of the administered iodine into breast tumor tissue. Breast tumors were induced with DMBA in female SD rats, and these animals were treated with MPA + inorganic iodine at various concentrations for 4 weeks to determine tumor growth and tumor iodine content. In the comparison of tissue iodine content in growth-suppressive tumors with that in nonsuppressive tumors, the former showed a much higher iodine content. This suggests that direct uptake of inorganic iodine by breast tumors led to the suppression of tumor growth.

59 citations


Journal ArticleDOI
01 May 1996
TL;DR: In this article, the vertical profiles of iodide, iodate and total free iodine were determined monthly for one year (from July 1993 to June 1994) at the DYFAMED permanent station located in the northwestern Mediterranean Sea.
Abstract: Vertical profiles of iodide, iodate and total free iodine were determined monthly for one year (from July 1993 to June 1994) at the DYFAMED permanent station located in the northwestern Mediterranean Sea. Dissolved iodate and iodide were directly determined by differential pulse polarography and cathodic stripping square wave voltammetry, respectively. Iodate is the predominant species, ranging from 390 nM in surface waters to 485 nM in deep waters. Iodide is present in significant concentrations up to 80 nM in surface waters and from undetectable levels to several nanomolar (

50 citations


Journal ArticleDOI
Feng Xu1
TL;DR: A fungal laccase (Myceliophthom thermophila) has been shown to function as an iodide oxidase, suggesting that the property could be a common feature for copper-containing oxidases.
Abstract: A fungal laccase (Myceliophthom thermophila) has been shown to function as an iodide oxidase. Unlike other halides which interact with the type 2 copper site and are inhibitors for the laccase, iodide interacts with the type 1 copper site and serves as a substrate capable of donating an electron to the laccase. Under anaerobic conditions, the interaction between the laccase and iodide results in the reduction of the laccase type 1 copper and the concomitant oxidation of iodide to form iodide. In aerated solutions, the laccase catalyzes the oxidation of iodide to iodine and the concomitant reduction of dioxygen to water. The reaction exhibits typical Michaelis kinetics with aK m of 0.16 ± 0.02M and ak cat of 2.7 ± 0.2 turnovers per min at the optimal pH (3.4). The catalysis can be enhanced by 2,2′-azino-bis-(3-ethylbenz-thiazoline-6-sulfonic acid), which shuttles electrons rapidly between iodide and the laccase. Bilirubin oxidase also demonstrates significant iodide oxidase activity, suggesting that the property could be a common feature for copper-containing oxidases. Possible industrial and medicinal applications for a laccase-based iodine production system are discussed.

49 citations


Journal ArticleDOI
TL;DR: In this article, a series of volcanic-ash soils was compared with reaction onto noncrystalline materials that constitute much of the inorganic fraction of these soils, and it was shown that these high surface area materials account for iodide retention by providing sites for anion exchange.

47 citations



Journal ArticleDOI
01 Feb 1996-Tellus B
TL;DR: The results of measurements of sea-to-air fluxes of methyl iodide and air-tosea wet depositional fluxes over the southern North Sea are reported in this article.
Abstract: The results of measurements of sea-to-air fluxes of methyl iodide and air-to-sea wet depositional fluxes of iodide and iodate over the southern North Sea are reported. The estimated average annual flux of methyl iodide out of the southern North Sea is 8 × 10 5 moles yr −1 while the iodine deposition flux, based on average rainwater concentrations, is 6 × 10 5 moles yr −1 . Both emission fluxes of methyl iodide and deposition fluxes of total iodine show a modest seasonality with minimum fluxes in winter. The average concentration of iodine in the rainwater samples ( n = 40) over a one year period was 6.8 + 7.5 nm for total iodine, 3.1 + 2.7 nm for iodate and 3.7 + 6.6 nm for iodide. There is no evidence of seasonality in the iodide/iodate ratio in rainwater over the year. DOI: 10.1034/j.1600-0889.1996.00010.x

Journal ArticleDOI
TL;DR: In this article, the hydrogen evolution and oxidation of iodide on photoirradiated Pt-loaded TiO2 powder were studied in the deaerated solutions containing iodide ions.
Abstract: Hydrogen evolution and oxidation of iodide on photoirradiated Pt-loaded TiO2 powder were studied in the deaerated solutions containing iodide ions. These photocatalytic reactions have been considered to be difficult because the reaction is endothermic and reversible. However, we found that under some experimental conditions the reactions proceeded until the concentration of I3− ions reached a limiting level. The initial rate of the reactions and the limiting concentration of I3− ions in solution were enhanced as the pH of the solution decreased. In order to elucidate the pH dependence, the anodic current due to the oxidation of iodide ions on TiO2 film electrodes and the adsorptivity of iodide ions on TiO2 powder were measured. The results showed that the enhanced reactivity at low pH is due to the increased adsorptivity of iodide ions on TiO2. It was also found that the electric contact between platinum and TiO2 is important to make the reactions go forward.

Journal ArticleDOI
TL;DR: In this paper, specific concentration profiles of iodate, iodide and organo-iodine in the water column of the Rogoznica Lake, where both oxic and anoxic conditions occur, were observed.

Journal ArticleDOI
TL;DR: It was shown that the total iodine content, concentration and weight did not depend on age and sex, and the typical mean thyroid parameters were found for healthy people of non-endemically goitrous regions where iodated food is not eaten.
Abstract: The iodine thyroid content of 57 relatively healthy men and women 14–60 years old was studied using instrumental neutron activation analysis. Two methods were used: analysis of whole glands and the analysis of lyophilized samples weighing 50 mg each. Very good agreement between results was obtained. It was shown that the total iodine content, concentration and weight did not depend on age and sex. The typical mean thyroid parameters were found for healthy people of non-endemically goitrous regions where iodated food is not eaten. Average thyroid weight was 14.2g, iodine concentration was 350 μg/g of wet weight and thus total iodine content was 5 mg.

Journal ArticleDOI
TL;DR: A method for the determination of free iodide in human serum was developed in this paper, where iodide from pooled serum samples was separated from the organic manner by SEC, and the iodide fraction subsequently was freezed and analyzed by ion chromatography for quantification.
Abstract: A method for the determination of free iodide in human serum was developed. For this purpose iodide from pooled serum samples was separated from the organic manner by SEC. The iodide fraction subsequently was freezedried and analyzed by ion chromatography for quantification. Investigations for recovery and precision were carried out and were found to show sufficient results. For quality assurance ICP-MS was taken additionally as an total I-detector [1], using native and iodide-spiked serum samples. The iodide results of ICP-MS as well as those of IC were well corresponding. Iodine containing SEC-fractions from iodide-spiked samples showed no increased I-values except that in the iodide fractions, proving that there was no iodide conversion into other I-species (and vice versa) during the whole procedure. Free iodide from two serum pools of different healthy persons was determined as 2.25 and 2.43 μg I−/L, respectively. The values are related to total iodine levels determined by ICP-MS. For comparative reasons a table of individual iodine and iodide values is presented.

Journal ArticleDOI
TL;DR: Gold can be dissolved on heating in iodine-iodide-acetonitrile solvent systems, where the ratio I2/I− is > 0.5, as [AuI2] as mentioned in this paper.

Journal ArticleDOI
TL;DR: An increase in iodine intake in the Danish population is needed and the best way to achieve this is to iodize all salt, to avoid side effects of a sudden large increase in thyroiditis.
Abstract: A working group was established to evaluate the need for iodine enrichment in Denmark. Judged from studies of urinary iodine excretion and one dietary survey the intake of iodine in Denmark is low compared with recommended intakes. The occurrence of non-toxic goitre is relatively high; between 9 and 13 % in elderly women. Furthermore, a high occurrence of toxic goitre has been seen in the western part of Denmark. On the other hand, an increased or a high intake of iodine may lead to hyperthyroidism and thyroiditis. The working group concluded that an increase in iodine intake in the Danish population is needed and the best way to achieve this is to iodize all salt. To avoid side effects of a sudden large increase in iodine intake the initial amount of iodine in salt will only be 2 ppm.

Journal ArticleDOI
TL;DR: Results show that thyroid 2-IHDA is derived from plasmenylethanolamine via an attack of reactive iodine on the vinyl ether group, and reduction into the biologically inactive 1-IHDO is thus a major metabolic pathway of 2- IHDA in dog thyrocytes.

Journal ArticleDOI
TL;DR: In this article, the adsorption process of iodide on a highly ordered Au(111) electrode has been investigated using an electrochemical quartz crystal microbalance, and the surface concentration of ion and the change of surface excess of water on the Au(1) surface have been determined quantitatively.

Journal ArticleDOI
TL;DR: In this paper, a combination of theory and experiment is used to separate the changes in the absorption due to the temperature dependence of dimer formation from the narrowing of the absorption band that results from rotational and vibrational cooling of isolated methyl iodide molecules.
Abstract: Due to the implication of iodine chemistry in stratospheric ozone depletion, an accurate atmospheric lifetime of methyl iodide has recently become of interest. To calculate this lifetime, a reliable temperature-dependent UV photodissociation cross section, in the region that overlaps with available solar light, is vital. Unfortunately, measurement of this cross section is complicated by the fact that, at typical laboratory pressures, methyl iodide readily forms dimers whose ultraviolet absorption differs from that of the monomer and that dimer formation is also temperature-dependent. We use a combination of theory and experiment to separate the changes in the absorption due to the temperature dependence of dimer formation from the narrowing of the absorption band that results from rotational and vibrational cooling of isolated methyl iodide molecules. Calculation of the predicted absorption cross section shows that the valence band absorption spectrum narrows only slightly upon cooling from 25 to −73 °C (...

Journal ArticleDOI
TL;DR: The findings from these studies suggest that PRL may stimulate both the accumulation of free iodide in milk and iodide incorporation into milk proteins, and the effect of PRL likely causes the elevated concentration of iodide that occurs in the milk of a number of species.
Abstract: Rillema, J. A. and T. X. Yu. Prolactin stimulation of iodide uptake into mouse mammary gland explants. Am. J. Physiol. 271 (Endocrinol. Metab. 34): E879-E882, 1996. These studies show that prolactin (PRL) stimulates iodide accumulation in cultured mouse mammary tissues. This effect of PRL likely causes the elevated concentration of iodide that occurs in the milk of a number of species. In time course studies, an initial effect of PRL occurred after 4 h, whereas a maximum two- to threefold increase was observed after 24 h. In dose-response studies, 1 ng/ml PRL elicited a significant response, whereas PRL concentrations >5 ng/ml stimulated maximum responses. Other lactogenic hormones, including human growth hormone (GH) and human placental lactogens, also stimulated iodide uptake, whereas nonlacto-genic substances, including bovine GH, bovine serum albumin, and thyroid-stimulating hormone, were without effect. PRL had no effect on iodide uptake into fat cells. In further studies it was shown that PRL stimulates iodide incorporation into macromolecules in a 10% trichloroacetic acidprecipitable tissue fraction as well as in a pH 4.6 isoelectric precipitate. The findings from these studies suggest that PRL may stimulate both the accumulation of free iodide in milk and iodide incorporation into milk proteins.

Journal ArticleDOI
TL;DR: In this article, total dissolved iodide (I - ) and iodine (I 2 ) are determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) using iodine vapor generation.
Abstract: Total dissolved iodide (I - ) and iodine (I 2 ) are determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) using iodine vapor generation. I - is determined directly after filtration. It is oxidized in situ to I 2 with potassium nitrite in sulfuric acid in a simplified continuous-flow manifold. A standard nebulizer separates I 2 , which is quantitated by ICP-AES at 206.16 nm. The instrument detection limit for I - is 0.04 μg/mL. Recoveries from seawater, saltwater, and freshwater standard reference materials ranged from 86.5 to 118.6%, averaging 98.2%. I 2 is analyzed by ICP-AES without the iodine vapor generation reagents. For samples containing both I 2 and I - , total iodine is determined with oxidizing reagents, I 2 alone is determined without oxidizing reagents, and I - is calculated from the difference. The analysis is specific for the 2 species (I - and I 2 ). Stability of I 2 in environmental samples was briefly investigated. This method demonstrates good accuracy and precision for samples of environmental interest and is especially well suited to small samples. It requires no additional apparatus for iodine generation or sample introduction.

Journal ArticleDOI
01 Jun 1996-Talanta
TL;DR: A simple head-space (HS) flow injection (FI) system with chemiluminescence (CL) detection for the determination of iodide as iodine in urine is presented, and the iodide levels found for 100 subjects were lower than the WHO's optimal level.

Journal Article
TL;DR: In rats treated with iodolactones, methimazole induced goiter formation could be prevented and in human and porcine thyroid cells in vitro, delta-iodolactone inhibited epidermal growth factor (EGF) induced proliferation in 50-fold lower concentrations than iodide itself.
Abstract: Different iodolipids have been identified within the last decades in thyroid cells exposed to iodine in vitro as well as in vivo. Iodolipids have been supposed to be involved in thyroid autoregulation, but no specific compounds could be found. A new approach was stimulated by the finding that rat thyroid lobes were able to iodinate arachidonic acid and docosahexaenoic acids in vitro. Meanwhile 6-iodo-5 hydroxy-eicosatrienoic acid (delta-iodolactone) has been identified in human thyroid tissue, but only after treating the patients with high doses of iodine before thyroidectomy, whereas in untreated endemic goiter this delta-iodolactone could not be found. In rats treated with iodolactones, methimazole induced goiter formation could be prevented. In human and porcine thyroid cells in vitro, delta-iodolactone inhibited epidermal growth factor (EGF) induced proliferation in 50-fold lower concentrations than iodide itself. Furthermore it could be demonstrated that only the IP3-, but not the cAMP generation in porcine thyroid cells could be inhibited by this compound. Also a structure specifity for delta-iodolactones for the biological activity could be shown. We will summarize and discuss these important new findings on the role of iodolactones on thyroid growth.

Journal ArticleDOI
TL;DR: In this article, the influence of iodine fertilisation on the iodine concentration of cress (Lepidium sativum) was determined by a pot experiment in which different amounts of iodine were added.
Abstract: Germany is reported to be an iodine deficient region of the world. Therefore investigations of the iodine concentration in plants and soils are of particular importance. The low concentration of iodine (μg and ng levels) in plant and soil samples, can be determined by photometry based on the SANDELL‐KOLTHOFF‐Reaction, the reduction of Ce(IV) by As(III) catalysed by iodine. The reaction, essentially depending on time and temperature, can also be affected by the ions, such as: Cl% NO2 ‐, SCN‐, Fe2+, BrO3 ‐, MnO4 ‐, Ag+, CN‐, Hg+ and metals like Os. Using the alkaline dry ashing method by adding KOH and ZnSO4, the digestion with the calorimetric bomb and the SCHONIGER digestion arc gives reliable results for iodine determination for use in conjunction with photometric analytical techniques. For this investigation, the influence of iodine fertilisation on the iodine concentration of cress (Lepidium sativum) was determined by a pot experiment in which different amounts of iodine were added. The iodine...

Journal ArticleDOI
TL;DR: The changes in surface energy of a gold electrode in deaerated 1.0 mol dm -3 NaClO 4 solutions with and without iodide ions were sensitively detected by using a piezoelectric technique as mentioned in this paper.
Abstract: The changes in surface energy of a gold electrode in deaerated 1.0 mol dm -3 NaClO 4 solutions with and without iodide ions were sensitively detected by using a piezoelectric technique. The potential of electrocapillary maximum or potential of zero charge (pzc) of gold electrode was evaluated from the piezoelectric signal curve. The addition of iodide ions shifted significantly pzc to the negative direction, indicating the strong contact adsorption of iodide ions. It was found from the iodide concentration dependence of pzc that the Esin-Markov relation held at pzc. The piezoelectric signals at the high potentials far from pzc suggested the possibility of structural change or phase change of iodine adlayer with sign reversal of total surface charge density.

Journal ArticleDOI
TL;DR: In this paper, the authors derived the limiting molar conductivities of tetrabutylammonium iodide, sodium tetraphenylboride, and sodium iodide reference electrolyte for the determination of the limiting ionic conductivity.
Abstract: The conductance behavior of potassium iodide, potassium perchlorate, silver perchlorate, silver picrate, sodium iodide, sodium tetraphenylboride, and tetrabutylammonium iodide has been studied in 20, 40, 60, and 80 mass % ethylene carbonate + water mixtures at 25 °C. The conductance data are treated on the basis of the Fuoss equation, and the limiting molar conductivity (Λo), association constant (KA), and cosphere diameter (R) are derived from the treatment. From the algebraic sum of the limiting molar conductivities of tetrabutylammonium iodide, sodium tetraphenylboride, and sodium iodide, the value of limiting molar conductivity of tetrabutylammonium tetraphenylboride reference electrolyte is calculated for the determination of the limiting ionic conductivity (λo) of the systems studied.

Patent
19 Jul 1996
TL;DR: In this paper, the use of an enzymatically generated iodine microbiocide for the inactivation of pathogenic organisms that are contaminants in sensitive biological materials is discussed. But the present invention relates generally to an enzyme-generated iodine bacteria and not specifically to the use such a bacteria for inactivation.
Abstract: The present invention relates generally to an enzymatically generated iodine microbiocide and more specifically to the use of such a microbiocide for the inactivation of pathogenic organisms that are contaminants in sensitive biological materials. The biocidal agent from the enzymatic reaction is free molecular iodine generated so as to (1) establish a minimum level above 10 ppm of free molecular iodine and (2) to establish defined ratios of free molecular iodine to other iodine species such that free molecular iodine comprises at least 10% of the total iodine species present on a molar basis.

Patent
27 Sep 1996
TL;DR: In this paper, the authors present a flow control system for a full-scale laser operation with the use of a mixture of liquid and gaseous mixture of iodine in diluent gas.
Abstract: This invention provides a means of achieving the close control of iodine flow rate, temperature of the resulting combined gaseous mixture of iodine in diluent gas, as well as the rapid start and stop response time needed for full-scale laser operation. It comprises an iodine charge stored as a solid and is heated to converted the iodine to a liquid, a means to heat the iodine under pressure to extend the liquid temperature range of iodine, an atomizer for complete vaporization of the iodine, a helium iodine mixer to provide heat for iodine vaporization purporting iodine to helium proportion mass ratio and provides for complete mixing and a flow control system which controls the low iodine flow rates accurately.