Showing papers on "Iodine published in 2010"
TL;DR: Unreduced silver-containing zeolites may offer a more secure route for radioactive iodine capture, with the potential to more effectively trap the iodine for long-term storage.
Abstract: The effective capture and storage of radiological iodine (129I) remains a strong concern for safe nuclear waste storage and safe nuclear energy. Silver-containing mordenite (MOR) is a longstanding benchmark for iodine capture; however, the molecular level understanding of this process needed to develop more effective iodine getters has remained elusive. Here we probe the structure and distribution of iodine sorbed by silver-containing MOR using differential pair distribution function analysis. While iodine is distributed between γ-AgI nanoparticles on the zeolite surface and subnanometer α-AgI clusters within the pores for reduced silver MOR, in the case of unreduced silver-exchanged MOR, iodine is exclusively confined to the pores as subnanometer α-AgI. Consequently, unreduced silver-containing zeolites may offer a more secure route for radioactive iodine capture, with the potential to more effectively trap the iodine for long-term storage.
474 citations
TL;DR: It is confirmed that Swiss school children and pregnant women remain iodine sufficient and then to assess iodine status in infancy and the relative contribution of breast milk and IFM/CF to their iodine intakes.
Abstract: Background: If children and pregnant women in the population are iodine sufficient, it is generally assumed infants are also sufficient. But weaning infants may be at risk of iodine deficiency because iodized salt contributes little dietary iodine during this period. To fill this gap, iodine fortification of infant formula milk (IFM) and complementary foods (CF) is likely important. Objectives: The objective of the study was to first confirm that Swiss school children and pregnant women remain iodine sufficient and then to assess iodine status in infancy and the relative contribution of breast milk and IFM/CF to their iodine intakes. Methods: We measured urinary iodine concentrations (UIC) in national cross-sectional samples of: 1) pregnant women (n = 648); 2) school children (n = 916); 3) infants at three time points: at 3–4 d after birth and at 6 and 12 months (n = 875); and 4) breast-feeding mothers (n = 507). We measured breast milk iodine concentrations in the mothers, assessed iodine sources in infa...
128 citations
TL;DR: Low-level perchlorate exposure is ubiquitous but did not affect thyroid function in this cohort of iodine-deficient pregnant women.
Abstract: Context: Thyroid hormone, requiring adequate maternal iodine intake, is critical for fetal neurodevelopment. Perchlorate decreases thyroidal iodine uptake by competitively inhibiting the sodium/iodide symporter. It is unclear whether environmental perchlorate exposure adversely affects thyroid function in pregnant women. Thiocyanate, derived from foods and cigarette smoke, is a less potent competitive sodium/iodide symporter inhibitor than perchlorate.
Objective: Our objective was to determine whether environmental perchlorate and/or thiocyanate exposure is associated with alterations in thyroid function in pregnancy.
Design and Setting: We conducted a cross-sectional study at health centers in Cardiff, Wales, and Turin, Italy.
Patients: During 2002–2006, 22,000 women at less than 16 wk gestation were enrolled in the Controlled Antenatal Thyroid Screening Study. Subsets of 261 hypothyroid/hypothyroxinemic and 526 euthyroid women from Turin and 374 hypothyroid/hypothyroxinemic and 480 euthyroid women from Cardiff were selected based on availability of stored urine samples and thyroid function data.
Main Outcome Measures: Urinary iodine, thiocyanate, and perchlorate and serum TSH, free T4 (FT4), and thyroperoxidase antibody were measured.
Results: Urinary iodine was low: median 98 μg/liter in Cardiff and 52 μg/liter in Turin. Urine perchlorate was detectable in all women. The median (range) urinary perchlorate concentration was 5 μg/liter (0.04–168 μg/liter) in Turin and 2 μg/liter (0.02–368 μg/liter) in Cardiff. There were no associations between urine perchlorate concentrations and serum TSH or FT4 in the individual euthyroid or hypothyroid/hypothyroxinemic cohorts. In multivariable linear analyses, log perchlorate was not a predictor of serum FT4 or TSH.
Conclusions: Low-level perchlorate exposure is ubiquitous but did not affect thyroid function in this cohort of iodine-deficient pregnant women.
109 citations
TL;DR: The synthesis of 3H-indoles was achieved via the iodine-mediated intramolecular cyclization of enamine derivatives bearing multifunctional groups in good to high yields under transition metal-free reaction conditions.
Abstract: The synthesis of 3H-indoles was achieved via the iodine-mediated intramolecular cyclization of enamines. A wide variety of 3H-indole derivatives bearing multifunctional groups were obtained in good to high yields under transition metal-free reaction conditions.
92 citations
TL;DR: Biofortification of lettuce with iodine is easily applicable in a hydroponic growing system, both with I(-) and IO(3)(-) and was more effective than IO( 3)(-).
Abstract: BACKGROUND: Iodine is an essential trace element for humans. Two billion individuals have insufficient iodine intake. Biofortification of vegetables with iodine offers an excellent opportunity to increase iodine intake by humans. The main aim was to study the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce, grown in water culture. RESULTS: In both a winter and summer trial, dose rates of 0, 13, 39, 65, and 90 or 129 µg iodine L-1, applied as iodate (IO3-) or iodide (I-), did not affect plant biomass, produce quality or water uptake. Increases in iodine concentration significantly enhanced iodine content in the plant. Iodine contents in plant tissue were up to five times higher with I- than with IO3-. Iodine was mainly distributed to the outer leaves. The highest iodide dose rates in both trials resulted in 653 and 764 µg iodine kg-1 total leaf fresh weight. CONCLUSION: Biofortification of lettuce with iodine is easily applicable in a hydroponic growing system, both with I- and IO3-. I- was more effective than IO3-. Fifty grams of iodine-biofortified lettuce would provide, respectively, 22% and 25% of the recommended daily allowance of iodine for adolescents and adults
81 citations
TL;DR: Randomised controlled intervention trials in iodine- and iron-deficient populations have shown that providing iron along with iodine results in greater improvements in thyroid function and volume than providing iodine alone, while little evidence is available on interactions between iodine and zinc metabolism.
77 citations
TL;DR: A sensitive and rapid method was developed which enables determination of isotopic ratios of speciated iodine and was successfully applied to water samples from the contaminated Savannah River Site, South Carolina, and more pristine Galveston Bay, Texas.
Abstract: In aquatic environments, iodine mainly exists as iodide, iodate, and organic iodine. The high mobility of iodine in aquatic systems has led to 129I contamination problems at sites where nuclear fuel has been reprocessed, such as the F-area of Savannah River Site. In order to assess the distribution of 129I and stable 127I in environmental systems, a sensitive and rapid method was developed which enables determination of isotopic ratios of speciated iodine. Iodide concentrations were quantified using gas chromatography−mass spectrometry (GC−MS) after derivatization to 4-iodo-N,N-dimethylaniline. Iodate concentrations were quantified by measuring the difference of iodide concentrations in the solution before and after reduction by Na2S2O5. Total iodine, including inorganic and organic iodine, was determined after conversion to iodate by combustion at 900 °C. Organo-iodine was calculated as the difference between the total iodine and total inorganic iodine (iodide and iodate). The detection limits of iodide-...
73 citations
TL;DR: An unexpected mechanism of halogen bonding that cannot be rationalized within the accepted sigma-hole model was found in the co-crystal of N-methylpyrazine iodide with molecular iodine via the topological analysis of the electron density distribution derived from the high-resolution X-ray diffraction data.
68 citations
TL;DR: The proposed biokinetic model for systemic iodine for use in dose assessments for internally deposited radioiodine predicts higher absorbed doses to the thyroid per unit uptake to blood for very short-lived iodine isotopes, and substantially higher estimates of absorbed dose to stomach wall, salivary gland and kidneys for most iodine isotope.
Abstract: This paper summarizes the biokinetic database for iodine in the human body and proposes a biokinetic model for systemic iodine for use in dose assessments for internally deposited radioiodine. The model consolidates and extends existing physiological systems models describing three subsystems of the iodine cycle in the body: circulating inorganic iodide, thyroidal iodine (trapping and organic binding of iodide and synthesis, storage and secretion of thyroid hormones), and extrathyroidal organic iodine. Thyroidal uptake of inorganic iodide is described as a function of stable iodine intake (Y, µg day−1) and thyroidal secretion of hormonal iodine (S, µg day−1). Baseline parameter values are developed for reference adults with typical iodine intake. Compared with the current systemic biokinetic model of the International Commission on Radiological Protection (ICRP) for occupational intake of radioiodine, the proposed model predicts higher absorbed doses to the thyroid per unit uptake to blood for ve...
66 citations
TL;DR: The growth of silver iodide nanoparticles on silk fiber was achieved by sequential dipping in an alternating bath of potassium iodide and silver nitrate under ultrasound irradiation and parameters such as effect of pH, concentration and numerous sequential dipped in growth of the nanocrystal have been studied.
64 citations
TL;DR: A carrier free method using coprecipitation of AgI with AgCl for preparing micrograms of iodine target, associated with combustion using a tube furnace for separating iodine from solid samples and anion exchange chromatography for preconcentrating iodine from a large volume of water is presented.
Abstract: Separation of carrier free iodine from low iodine level samples and accurate measurement of ultralow level (129)I in micrograms of iodine target are essential but a bottleneck in geological dating of terrestrial system and tracer research using naturally produced (129)I. In this work, we present a carrier free method using coprecipitation of AgI with AgCl for preparing micrograms of iodine target, associated with combustion using a tube furnace for separating iodine from solid samples and anion exchange chromatography for preconcentrating iodine from a large volume of water. An accelerator mass spectrometry was used to measure ultralow level (129)I in micrograms of iodine target. The recovery of iodine in the entire separation procedure is higher than 80% and 65% for solid and water samples, respectively. One microgram iodine in the target (AgI-AgCl) can produce a stable (127)I signal for AMS measurement of (129)I/(127)I, and a detection limit of this method for (129)I is calculated to be 10(5) atoms. This will allow us to accurately determine (129)I in prenuclear geological samples of low iodine concentration with (129)I/(127)I of 10(-12), such as loess, soil, coral, rock, sediment, and groundwater. Some samples with low iodine content have been successfully analyzed, and the lowest value of the (129)I/(127)I ratio of 2 × 10(-11) was observed in 23.5 and 63.5 m loess samples collected in the Loess Plateau, China. The developed method sheds light on a wide application in earth science.
TL;DR: In this article, the ubiquitous presence of iodide at 1 −5 ǫ kg −1 level in the Callovian-Oxfordian (COx) clayy formation was confirmed at a value in the range of ∼20 −40 m −1, i.e. higher than the expected range of radio-iodine concentration in the far field of the storage.
TL;DR: A proposed model in eight steps explains the new experimental results and gives a semi-quantitative explanation of the oxygen effect and allows simulations of the Bray-Liebhafsky oscillations at 25 degrees C.
Abstract: The kinetics of the iodine oxidation by hydrogen peroxide is a complicated function of the concentrations of iodine, hydrogen peroxide, perchloric acid and iodate. A proposed model in eight steps explains the new experimental results. It explains also the effect of the concentrations at the steady state of the hydrogen peroxide decomposition catalyzed by iodine and iodate. Without iodate added initially, the iodine oxidation by hydrogen peroxide is preceded by an induction period that depends on the oxygen concentration. A simple extension of the proposed model gives a semi-quantitative explanation of the oxygen effect and allows simulations of the Bray-Liebhafsky oscillations at 25 °C.
TL;DR: In all species, except for the mixotrophic dinoflagellate Scrippsiella trochoidea, iodide production commenced in the stationary growth phase and peaked in the senescent phase of the algae, indicating that iodine production is connected to cell senescence, which suggests that iodate reduction results from increased cell permeability.
Abstract: Previous studies have suggested that phytoplankton play an important role in the biogeochemical cycling of iodine, due to the appearance of iodide in the euphotic zone. Changes in the speciation of iodine over the course of the growth cycle were examined in culture media for a variety of phytoplankton taxa (diatoms, dinoflagellates and prymnesiophytes). All species tested showed the apparent ability to reduce iodate to iodide, though production rates varied considerably between species (0.01 to 0.26 nmol l–1 µg–1 chl a d–1), with Eucampia antarctica the least and Pseudo-nitzschia turgiduloides the most efficient iodide producers. Production was found to be species specific and was not related to biomass (indicated by e.g. cell size, cell volume, or chl a content). In all species, except for the mixotrophic dinoflagellate Scrippsiella trochoidea, iodide production commenced in the stationary growth phase and peaked in the senescent phase of the algae, indicating that iodide production is connected to cell senescence. This suggests that iodate reduction results from increased cell permeability, which we hypothesize is due to subsequent reactions of iodate with reduced sulphur species exuded from the cell. A shift from senescence back to the exponential growth phase resulted in a decline in iodide and indicated that phytoplankton-mediated oxidation of iodide to iodate was likely to be occurring. Iodide production could not be observed in healthy cells kept in the dark for short periods. Bacterial processes appeared to play only a minor role in the reduction of iodate to iodide.
TL;DR: A general and versatile one-pot three-component procedure for the selective synthesis of mono substituted quinazolin-4(3H)-ones and 2,3-dihydroquinazolin -4(1H-ones was described.
TL;DR: It is inferred that reactive anionic phenolates inhibit I(2)(g) and IO(g) emissions by competing with I(-)(aq) for O(3)(g), with aqueous iodide at the air/water interface.
Abstract: The fast reaction of gaseous ozone, O_3(g), with aqueous iodide, I−(aq), was found to be affected by environmentally relevant cosolutes in experiments using cavity ring-down spectroscopy (CRDS) and electrospray ionization mass spectrometry (ESIMS) for the detection of gaseous and interfacial products, respectively. Iodine, I_2(g), and iodine monoxide radical, IO(g), product yields were suppressed in the presence of a few millimolar phenol (pK_a = 10.0), p-methoxyphenol (10.2), or p-cresol (10.3) at pH ≥ 3 but unaffected by salicylic acid (pK_(a2) = 13.6), tert-butanol, n-butanol, or malonic acid. We infer that reactive anionic phenolates inhibit I_2(g) and IO(g) emissions by competing with I−(aq) for O_3(g) at the air/water interface. ESIMS product analysis supports this mechanism. Atmospheric implications are discussed
TL;DR: In this article, the technique of iodide estimation in brine by ion chromatography with amperometric detection was applied to iodate estimation in salt and the method involved reduction of iodate to iodide with excess sodium bisulphite followed by estimation of the iodide.
TL;DR: The aim of this study was to evaluate iodine status and to examine the main sources of iodine in pregnant women from an apparently iodine‐sufficient area.
Abstract: Objective An adequate iodine intake during pregnancy is essential for normal development of the foetus. The World Health Organization (WHO) recommends that the median urinary iodine concentration (UIC) in a population of pregnant women should range between 150 and 249 microg/l. The aim of this study was to evaluate iodine status and to examine the main sources of iodine in pregnant women from an apparently iodine-sufficient area. Methods Six hundred pregnant women in the third trimester completed a food frequency questionnaire, and iodine was measured in urine samples. Urinary iodine concentrations were described in the whole population and in subgroups according to their frequency of intake of milk, fish, eggs, bread and iodized salt, as iodine supplements. Results The median UIC was 104 microg/l (n = 600), however, the median was higher among women who had a high milk intake (117 microg/l), used iodized salt (117 microg/l) or who were supplemented with iodine (141 microg/l). Women receiving iodine supplementation who also consumed more than one cup of milk per day had median UIC higher than 150 microg/l. In multivariate models, women with moderate and high milk intake had lower risk of having UIC below 150 microg/l [OR (95% CI): 0.42 (0.22-0.82) and 0.29 (0.15-0.55) respectively], after adjustment for potential confounders. Conclusions On the basis of WHO criteria, the iodine status of pregnant women was inadequate in this area. Milk was the most important dietary source of iodine, and iodine supplementation was also an important source of iodine, although not enough to reach the current recommendations.
TL;DR: The results suggest a seasonal cycle in which iodide concentrations increase and iodate concentrations decrease during the summer, though the magnitude of these changes appears to be subject to considerable interannual variability as mentioned in this paper.
TL;DR: The assessment of exposure showed that adults in 63% of the households, including 90% with pregnant women, were at risk of insufficient iodine intake, and a monitoring and evaluation system needs to be established to ensure adequate supply of iodine along the distribution chain.
Abstract: Iodine is essential for good function of the thyroid, and its deficiency is of public-health importance in Ethiopia. Iodization of salt is an effective and sustainable strategy to prevent and control iodine deficiency in large populations. The effectiveness of salt-iodization programmes depends on the conservation of iodine concentration in salt at various stages of the supply-chain. The overall objective of the study was to assess the loss of iodine in salt from production to consumption and to estimate the proportion of adults, especially pregnant women, at risk of dietary iodine insufficiency. A cross-sectional study was conducted during February-April 2007 in northern Ethiopia. Iodine concentrations of salt samples from producers (n=41), retailers (n=7), and consumers (n=32) were determined using iodiometric titration. A risk assessment was conducted for dietary iodine insufficiency among adults, including pregnant women, using a semi-probabilistic approach. The concentration of iodine in the sampled salts decreased by 57% from the production site to the consumers. The assessment of exposure showed that adults in 63% (n=20) of the households, including 90% (n=29) with pregnant women, were at risk of insufficient iodine intake. A monitoring and evaluation system needs to be established to ensure adequate supply of iodine along the distribution chain. Special attention is needed for the retailers and consumers. At these levels, dissemination of information regarding proper storage and handling of iodized salt is necessary to address the reported loss of iodine from salt.
TL;DR: Two experiments were undertaken on lactating cows to determine the milk concentrations of iodine and selenium, carry over (CO) in milk, the fraction in curdle portion and how milk yield affects the milk iodine and Selenium concentrations and CO, highlighting the possibility of fortification with iodine in milk and seenium in cheese through animal feeding.
Abstract: Iodine and selenium are essential trace elements involved in the regulation of thyroid metabolism and antioxidant status. Two experiments were undertaken on lactating cows to determine the milk concentrations of iodine and selenium, carry over (CO) in milk, the fraction in curdle portion and how milk yield affects the milk iodine and selenium concentrations and CO. Sources of elements were potassium iodide and sodium selenite. In Experiment 1, 12 cows were randomly allotted to three diet groups in a completely randomized design: control group (CTR) - total mixed ration (TMR) containing 1.71 and 0.08 mg/kg dry matter (DM); Group 1 (T1) - TMR plus 23.8 and 2.2 mg; Group 2 (T2) - TMR plus 45.5 and 4.3 mg, respectively, for iodine and selenium. In Experiment 2, 30 cows were allotted to three groups according to milk yield: high (H), average (A) and low (L). Within each group, cows were randomly assigned two levels of iodine and selenium: Level 1: TMR containing 1.55 and 0.15 mg/kg DM; Level 2: TMR plus 47.2 mg and 8.0 mg, respectively, iodine and selenium. In both experiments, individual milk samples were collected and analyzed for iodine and selenium contents. In Experiment 1, Grana Padano cheese was obtained at lab scale and the iodine and selenium fractions in the curd were measured. In Experiment 1, the iodine intake increased (P < 0.001) the concentration and total excretion in milk. The CO increased (P < 0.05) from 16 (CTR) to 27 (T1) and 26% (T2); the sampling time was significant (P < 0.05) with no interaction with treatments. Concentration of selenium in milk was increased (P < 0.05) by treatment and CO decreased (P < 0.01) from 26 (CTR) to 12 (T1) and 9% (T2). The iodine showed a mild enrichment factor in the curdle (about 1.7-fold), whereas selenium enriched five- to sevenfold. In Experiment 2, the level of iodine supplementation affected (P < 0.05) the concentration and total excretion in milk. No effects on milk iodine concentration were related to milk yield or milk yield × treatment interaction; however, the iodine excretion in milk was major (P < 0.05) in higher yielding groups. The iodine CO was affected (P < 0.05) by the milk yield in supplemented groups. The selenium milk concentration and excretion were affected (P < 0.01) by the milk yield, whereas the CO was affected (P < 0.05) by the milk yield and selenium supplementation. Results highlight the possibility of fortification with iodine in milk and selenium in cheese through animal feeding.
TL;DR: In this article, a novel vapor-generation technique is described for iodine determination in aqueous solutions, which is achieved by in situ produced highly reactive chemical species in the discharge, thereby eliminating the need for externally supplied sources of any redox reagents.
Abstract: A novel vapor-generation technique is described for iodine determination in aqueous solutions. The iodide and iodate in the solution are converted to volatile iodine vapor through solution cathode glow discharge induced advanced redox processes. It is achieved by in situ produced highly reactive chemical species in the discharge, thereby eliminating the need for externally supplied sources of any redox reagents. Iodine vapor is readily generated from a background electrolyte containing 0.01 mol L−1 HNO3. The generated iodine vapor is then transported to inductively coupled plasma for determination by optical emission spectrometry. The influences of the background electrolyte, pH, discharge voltage, carrier gas flow rate and ICP power were examined. The detection limits of plasma induced vapor generation for KI and KIO3 were 0.30 and 0.43 μg L−1, respectively. The repeatability, expressed as the relative standard deviation (n = 11) of a 0.05 mg L−1 standard, was 1.2% for KI and 1.9% for KIO3. Compared with conventional vapor generation technology, it offers several advantages. First, it eliminates the need for redox regents, and thus minimizes a source of contamination as well as hazards. Second, it is applicable to both iodide and iodate determination. In addition to iodide, iodate could also be directly converted to volatile iodine vapor without prior reduction. The method is sensitive and simple in operation, and requires no auxiliary reagents, served as a useful alternative to conventional vapor generation for trace iodine determination.
TL;DR: Mild iodine deficiency has recurred in Tehranians and the results emphasize the need for continuous monitoring in all regions, even in a country with iodine sufficiency.
Abstract: Background: Production of iodized salt in Iran for household consumption began in 1990. Previous studies have reported sustainable elimination of iodine deficiency disorders in Iran. The aim of this study was to evaluate the iodine nutritional status in Tehran in 2009. Methods: In this cross-sectional study, 383 Tehranian households were enrolled through randomized cluster sampling and a total of 639 adult subjects (242 men and 397 women), aged 19 and over, participated. A 24-hour urine sample was collected for measurement of urinary iodine, sodium, and creatinine concentrations using the digestion method, flame photometry, and autoanalyzer assay, respectively. Salt intake was estimated and iodine content of household salt was measured by titration. Results: Median (interquartile range) iodine content of household salt and urinary iodine concentration (UIC) in Tehran were 21.2 (3.2–31.7) parts per million and 70.0 (34.0–131.2) μg/L, respectively. There was no statistically significant difference in 24-hou...
TL;DR: It was observed that the deficiencies of Fe, I, and thyroid hormone in goitrous patients could be influenced by efficiency of Cu.
Abstract: In many developing countries, men and women are at high risk of goiter and iron deficiency. The aim of the recent study is to assess the interaction of (Cu), with iron (Fe), iodine/iodide (I), and thyroid hormones in goitrous patients. Sixty goitrous male (GMPs) and 72 female patients (GFPs) were evaluated for the Cu, Fe, I, and thyroid hormones status in biological samples (serum and urine), and compared to non-goitrous subjects of both genders (M = 106, F = 120). The biological samples were analyzed for Cu and Fe concentration using atomic absorption spectrometer, while I was measured by the potentiometric method, prior to microwave-assisted acid digestion (MD). Quality control for the method was established with certified samples. Significantly higher mean values of Cu in serum, and urine samples of GMPs and GFPs, while lower value of Fe and I were observed as compared to control subjects (p < 0.015), respectively. The mean values of free triiodothyronine (FT3) and free thyroxin (FT4) were found to be lower in goitrous patients of both genders than in the age-matched healthy controls (p < 0.006 and 0.002), respectively, in contrast high mean values of thyroid-stimulating hormone (TSH) were detected in patients (p < 0.009), as compared to non-goitrous subjects. It was observed that the deficiencies of Fe, I, and thyroid hormone in goitrous patients could be influenced by efficiency of Cu.
TL;DR: The incidence of Anaplastic thyroid carcinoma decreased after higher iodination of salt, and the patients with ATC during the period of higher iodinations of salt were older than those from the period with lower iodinated salt.
Abstract: Background: Anaplastic thyroid carcinoma (ATC) may arise de novo or from a preexistent differentiated carcinoma. It is well known that higher iodine intake in the diet causes higher frequency of papillary thyroid carcinoma, but decreases the frequency of follicular thyroid carcinoma. However, it is not known how the change in iodine intake influences the frequency of ATC. The aim of our study was to compare the incidence of ATC during the periods when the intake of potassium iodide in salt was 10 and 25 mg/kg. Methods: A total of 205 patients with ATC (140 women, 65 men; median, 69 years) were treated in the Republic of Slovenia between 1972 and 2008. In Slovenia, a country with a population of 2 million people, the salt was iodinated with 10 mg of potassium iodide/kg from 1972 to 1997. From 1998 to 2008 the degree of iodination of salt was increased to 25 mg of potassium iodide/kg. The frequency of ATC during the two periods and the characteristics of the patients during these periods were compared. Resu...
TL;DR: A simple, precise and accurate automatic method for the determination of total iodine in milk products by indirect atomic absorption spectrometry is proposed, which avoids interferences from anions present in the samples.
TL;DR: δ-iodolactone seems to be the main iodocompound which can inhibit growth and induce apoptosis in B-CPAP cells as well as in MCF 7 breast cancer cells.
Abstract: As we previously demonstrated, the inhibitory effect of iodine on thyroid cell growth is mediated by iodolactones, especially 6-iodo-5-hydroxy-eicosatrienoic acid (δ-iodolactone). In this communication we compare the effect of iodide, molecular iodine and δ-iodolactone on growth inhibition and apoptosis on three human thyroid carcinoma cell lines (B-CPAP cells, FTC-133 cells and 8505C cells) as well as on human breast cancer cells (MCF 7). Thyroid carcinoma cells were cultured in Dulbecco’s modified Eagle’s medium (DMEM) and MCF 7 cells in Rowswell Park Memorial Institute (RPMI) culture medium, both containing 10% (v/v) Fetal Calf Serum (FCS), until they were confluent. Around 2000 cells were then distributed in 12-well plates and grown for 48 h in either DMEM (thyroid cancer cells) or in RPMI medium (MCF 7 cells) both containing 5% FCS. Thereafter, different concentrations of iodide, iodine or δ-iodolactone were added for 24 h. Growth rate was estimated by cell counting in a Coulter Counter adapted for epithelial cells. Apoptosis was determined by a mitochondrial potential assay.
The growth rate of B-CPAP cells was unaffected by iodide, but was reduced by high concentreations of molecular iodine (100 and 500 µM). However, δ-iodolactone significantly reduced cell proliferation already with low concentrations (5 µM and 10 µM) and further in a dose-dependent manner up to 82%. FTC-133 and 8505C cells were unaffected by iodide, iodine or δ-iodolactone. In contrast, in MCF 7 cells, molecular iodine (100 µM) inhibited growth from 100% to 83% but δ-iodolactone (1, 5 and 10 µM) dose-dependently decreased growth rate from 100% to 82% and 62%, respectively. The inhibition of growth was through apoptosis, and not necrosis, as the amount of apoptotic cells corresponded to the growth inhibition. δ-?odolactone seems to be the main iodocompound which can inhibit growth and induce apoptosis in B-CPAP cells as well as in MCF 7 breast cancer cells.
TL;DR: The kinetics of uptake of ozone to deliquesced potassium iodide aerosol particles has been investigated in an aerosol flow tube and indicates that uptake was driven by fast bulk accommodation and reaction in the bulk for all conditions investigated.
Abstract: The kinetics of uptake of ozone to deliquesced potassium iodide (KI) aerosol particles has been investigated in an aerosol flow tube at 72−75% relative humidity, room temperature, and atmospheric pressure. The observed loss of ozone was further analyzed in terms of a numeric model to explicitly track the iodide concentration in the particles. This allowed retrieving a value αb = 0.6 ± 0.50.4 for the bulk accommodation coefficient (αb). The second order rate constant in the bulk phase agreed with available literature (kb = (1.0 ± 0.3) × 109 M−1 s−1) even for the high ionic strength conditions of the present experiments. As long as iodide remained in excess, the average uptake coefficient was γ = (1.10 ± 0.20) × 10−2. Different experiments were performed where the iodide to chloride ratio, the ozone concentration, and the surface to volume ratio of particles were varied. In combination, the results obtained indicate that uptake was driven by fast bulk accommodation and reaction in the bulk for all condition...
TL;DR: To study the fast kinetic decolourisation of textile dyes by ozone a continuous quench-flow system was used and the effect of dye and ozone concentrations was researched and the kinetic equations thus established.