Showing papers on "Iodine published in 1998"
TL;DR: Hydrogen peroxide and various substances known to interfere with oxidative metabolism were shown to either inhibit or enhance the uptake of iodide, confirming that apoplastic oxidations play a key role in iodide uptake in Laminaria.
Abstract: Sporophytes of Laminaria digitata (L.) Lamour. were assayed for their content of accumulated iodine, which ranged from 0.4% of dry weight in adult plants up to 4.7% for young plantlets. Sporophyte tissue from Laminaria saccharina (L.) Lamour. and L. digitata took up iodide according to Michaelis-Menten kinetics. Hydrogen peroxide and various substances known to interfere with oxidative metabolism were shown to either inhibit or enhance the uptake of iodide, confirming that apoplastic oxidations play a key role in iodide uptake in Laminaria. Consistently, iodide uptake was triggered in L. saccharina protoplasts by incubation in the presence of hydrogen peroxide. Similarly, the uptake of iodide was enhanced in L. digitata gametophytes by addition of haloperoxidase, suggesting that this enzyme catalyses the oxidation of iodide by hydrogen peroxide and plays a key role in iodine uptake. Oxidative stress resulted in a marked efflux of the intracellular iodine. In both influx and efflux experiments, a marked proportion (10–30%) of the tracer was not accounted for, indicating volatilisation of iodine. The mechanism and possible functions of the accumulation of iodine by kelps are discussed.
232 citations
TL;DR: In this article, the development and application of a simple alkaline extraction method employing tetramethylammonium hydroxide (TMAH) and ICP-MS for the determination of iodine are described.
Abstract: The development and application of a simple alkaline extraction method employing tetramethylammonium hydroxide (TMAH) and ICP-MS for the determination of iodine are described. Iodine, as naturally contained in Milk Powder, Egg Powder, Cod Muscle, Pig Kidney and Hay Powder, was extracted quantitatively at elevated temperatures (90 °C). A complete extraction of iodine from algae powder was achieved only if the particle size of the sample was below 300 µm. The applicability of the method was demonstrated by a round-robin test on two dietetic child nutrition food samples enriched artificially with iodine. All the iodine present in the samples was extracted completely by TMAH. The results were confirmed by decomposition of the samples. Consequently, the procedure was accepted as a German reference method for the determination of iodine in dietetic foodstuffs. The limit of determination, based on nine standard deviations of the blank, was 30 ng g–1 (dry sample, 100 mg sample mass). Advice is given on preventing sources of error and contamination.
184 citations
TL;DR: Although nearly comparable results were obtained with both treatment regimens regarding thyroid size, partly reversible iodine-induced thyroid dysfunction and autoimmunity were observed among patients with endemic goitre.
Abstract: Objective: Iodine is essential for normal thyroid function and the majority of individuals tolerate a wide range of dietary levels. However, a subset of individuals, on exposure to iodine, develop thyroid dysfunction. In this double-blind trial, we evaluated the efficacy and tolerability of low-dose iodine compared with those of levo-thyroxine (T4) in patients with endemic goitre. Methods: Sixty-two patients were assigned randomly to groups to receive iodine (0.5 mg/day) or T4 (0.125 mg/day) for 6 months. Subsequently, both groups were subject to placebo for another 6 months. Thyroid sonography, determination of thyroid-related hormones and antibodies, and urinary excretion of iodine were carried out at baseline and at 1, 6 and 12 months. Results: At 6 months, markedly increased urinary values of iodine were found in patients receiving iodine (36 mg/24 h at baseline, 415 mg/24 h at 6 months) compared with those receiving T4 (47 mg/ 24 h at baseline, 165 mg/24 h at 6 months; P < 0.0001 compared with iodine group). T4 administration engendered a greater (P < 0.01) decrease in thyroid volume (from 32 ml to 17 ml, P < 0.0001) than did intake of iodine (33 ml to 21 ml, P < 0.005). High microsomal and thyroglobulin autoantibody titres were present in six of 31 patients (19%) receiving iodine, and iodine-induced hypo- and hyperthyroidism developed in four and two of them, respectively. Fine-needle biopsy revealed marked lymphocyte infiltration in all six. After withdrawal of iodine, thyroid dysfunction remitted spontaneously and antibody titres and lymphocyte infiltration decreased markedly. Follow-up of these six patients for an additional 3 years showed normalisation of antibody titres in four of them. Conclusion: Although nearly comparable results were obtained with both treatment regimens regarding thyroid size, partly reversible iodine-induced thyroid dysfunction and autoimmunity were observed among patients with endemic goitre.
130 citations
TL;DR: It is indicated that iodine can be highly unstable and in order to ensure the effectiveness of local salt-iodization programmes countries should determine iodine losses from local iodized salt under local conditions of production climate packaging and storage.
Abstract: The purpose of this study was to assess the effect of humidity and packaging materials on the stability of iodine in typical salt samples from countries with tropical and subtropical climates under controlled climatic conditions. Initially we examined eight samples. In the second phase we expanded the study to salts from 18 sources and attempted to correlate the observed stability with salt impurities naturally present in these samples. High humidity resulted in rapid loss of iodine from salt iodized with potassium iodate ranging from 30% to 98% of the original iodine content. Solid low-density polyethylene packaging protected the iodine to a great extent. High losses were observed from woven high-density polyethylene bags which are often the packaging material of choice in tropical countries. Impurities that provided moisture at the salt surface had the most deleterious effect. Although clear correlations were not obtained the presence of reducing agents hygroscopic compounds of magnesium and so forth seemed to have the most adverse effects on the stability of iodine. Surprisingly carbonates had little effect on stability over the range present in the samples. Packaging salt in low-density polyethylene bags which provided a good moisture barrier significantly reduced iodine losses and in most cases the iodine content remained relatively stable for six months to a year. The findings from this study indicate that iodine can be highly unstable and in order to ensure the effectiveness of local salt-iodization programmes countries should determine iodine losses from local iodized salt under local conditions of production climate packaging and storage. (authors)
127 citations
TL;DR: The factors that modulate human NIS mRNA expression and iodide uptake in primary thyroid follicular cell (TFC) cultures are analysed and NIS RNA tissue distribution was investigated.
Abstract: OBJECTIVE
Iodide uptake by the thyroid gland is mediated by the sodium iodide symporter (NIS). In the present report, we have analysed the factors that modulate human NIS mRNA expression and iodide uptake in primary thyroid follicular cell (TFC) cultures. In addition, NIS mRNA tissue distribution was investigated.
METHODS
Primary thyroid follicular cell cultures were treated with human recombinant TSH with or without cytokines for 72 h. Subsequently, NIS gene expression and iodide uptake were analysed using reverse transcription–polymerase chain reaction (RT–PCR) and 125I uptake, respectively. Human tissue samples were investigated for NIS gene expression using both RT–PCR and Northern blotting.
RESULTS
Human TSH increased both NIS gene expression and iodide uptake in TFC cultures in a dose-dependent manner. Using concentrations of 0.1 U/l of hTSH, a minor increase in NIS gene expression was detected without a detectable increase in iodide uptake. IL-1α,TNFα and IFNγ at concentrations of 105 U/l all inhibited TSH-induced NIS gene expression and iodide uptake. In these experiments, there was a good correlation between NIS mRNA expression and iodide uptake. Using RT–PCR higher levels of NIS mRNA were detected in Graves' disease (GD) compared to multi-nodular goitre tissue samples. Stomach and salivary gland tissue also expressed NIS mRNA, whereas low levels were found in the mammary gland and extraocular muscle tissue. No expression was detected in the ovary, oesophagus, colon, extraocular fat or skin. In contrast, Northern blot analysis failed to detect NIS in stomach, salivary gland, intestinal fat or non-toxic multi-nodular goitre tissue samples, although this was present in GD thyroid tissue.
CONCLUSION
TSH upregulates sodium iodide symporter gene expression and iodide uptake in primary thyroid follicular cell cultures, and this induction is modulated by cytokines. Variable levels of sodium iodide symporter mRNA are present in different tissue samples, with high expression evident in Graves' disease thyroid tissue.
93 citations
TL;DR: The study data indicated that the iodine intake and excretion of Koreans depends mostly on the amount of seaweed consumption like sea tangle and sea mustard, and the current iodine intakeand excretion by Koreans seems to be higher than in other countries.
Abstract: Korea is a region abundant in foods containing iodine such as seaweed and fish. An adequate amount of iodine consumption is extremely important as both a deficiency and excess of iodine can result in health problems. This study was undertaken to assess the iodine nutritional status of normal Korean adults who consume seaweed and fish, and to determine the relationship between the dietary iodine intake and the urinary excretion of iodine. The dietary assessment of iodine using a food frequency questionnaire and a urinary iodine excretion examination were carried out in 278 healthy adults. The iodide selective electrode (ISE) method was used to determine urinary iodine excretion. The average usual iodine intake of Korean adults was 479 micrograms per day (ranging from 61 micrograms to 4086 micrograms). There was no significant difference in sex or age. The major food sources of dietary iodine included seaweed (66%), milk and dairy products (11%), and fish (9%). The contribution of seaweed to the total iodine intake tended to increase with age while the contribution of milk decreased. The average urinary excretion of iodine was 674 micrograms/g creatinine and there was no significant difference in sex or age. The dietary iodine intake was positively correlated with the urinary excretion of iodine (gamma = 0.60, p < 0.01). The study data indicated that the iodine intake and excretion of Koreans depends mostly on the amount of seaweed consumption like sea tangle and sea mustard. As well, the current iodine intake and urinary iodine excretion by Koreans seems to be higher than in other countries.
92 citations
TL;DR: The ICP-IDMS method is faster, more precise, widely independent of matrix effects, and, therefore, relatively accurate, which makes this method especially attractive for use as a routine method.
Abstract: Two different sample treatment methods are used in connection with inductively coupled plasma isotope dilution mass spectrometry for accurate and precise determinations of iodine traces in food samples. 129I-enriched iodate is applied as a spike compound for the isotope dilution step. Extraction of iodine by tetramethylammonium hydroxide (TMAH) solution at high temperatures in a closed vessel is one of the sample treatment methods. The other one is a complete decomposition of the sample with a mixture of perchloric acid and nitric acid using microwave assistance. By analyzing different certified reference materials (three milk powders with different iodine levels, BCR CRM 63, 150, and 151; bovine liver BCR CRM 185), the accuracy of ICP−IDMS with both sample treatment methods could be demonstrated. The relative standard deviation was typically in the range of 0.6−2.8% for iodine concentrations between 0.1 μg g-1 and 5 μg g-1. The detection limit was 8 ng g-1 using sample weights of 0.8 g. In a round robin ...
83 citations
TL;DR: A CHO cell line stably expressing the hNIS is established and it is shown that antibodies in GD sera can inhibit iodide uptake in these cells, emphasizing the role of NIS as a novel autoantigen in thyroid immunity.
Abstract: The transport of iodide into the thyroid, catalyzed by the Na+/I− symporter (NIS), is the initial and rate-limiting step in the formation of thyroid hormones. To study the basic characteristics of the human (h) NIS, we have established a Chinese hamster ovary cell line stably expressing the hNIS (CHO-NIS9). In agreement with previous work on the rat NIS, iodide uptake in these cells was initiated within 2 min of the addition of 131I, reaching a plateau after 30 min. Both perchlorate and thiocyanate inhibited iodide uptake in a dose-dependent manner, with inhibition evident at concentrations of 0.01 and 0.1 μmol/L, respectively, and reaching complete inhibition at 20 μmol/L and 500 μmol/L, respectively. Ouabain, which blocks the activity of the Na+/K+ adenosine triphosphatase, also inhibited iodide uptake in a dose-dependent manner, starting at concentrations of 100 μmol/L and reaching maximum inhibition at 1600 μmol/L, indicating that iodide uptake in these cells is sodium dependent. CHO-NIS9 cells were f...
67 citations
TL;DR: The use of the tertiary amine matrix solution permits the simultaneous determination of iodine and other trace metals of biological and toxicological importance, including Mn, Co, Ni, Cu, Zn, Rb, Cd, and Pb.
Abstract: A mineralization and determination method for total iodine in nutritional and biological samples is described. Combustion of the sample in an oxygen stream is followed by collection of the combustion products in a 5% water-soluble tertiary amine solution. Iodine is determined by inductively coupled plasma mass spectrometry. The accuracy and precision of the quantitative iodine analysis using standard addition is better than +/- 10%. A semi-quantitative analysis of four standard reference materials is evaluated. Owing to the presence of low-level iodine contaminant in the blank solution, the determination limit of the method is +/- 10 micrograms kg-1. Good agreement with certified iodine values is obtained for six reference materials. The use of the tertiary amine matrix solution permits the simultaneous determination of iodine and other trace metals of biological and toxicological importance, including Mn, Co, Ni, Cu, Zn, Rb, Cd, and Pb.
63 citations
TL;DR: It is suggested that blocking agents may help reduce normal organ radiation doses in endoradiotherapeutic procedures with 211At-labeled radiopharmaceuticals.
56 citations
TL;DR: It is concluded that oral potassium iodide is effective for the prophylaxis of iodine deficiency if given as a dose of 30 mg I monthly or 8 mg biweekly.
TL;DR: The results are consistent with a critical role for selenium in both the normal function of cattle thyroid and key enzymes to compensate for the effects of iodine deficiency.
TL;DR: In this article, the vapour pressure of saturated aqueous solutions of NH 4 I, KI, KNO 3, SrCl 2, Li 2 SO 4, Na 2 S 2 O 3, Mg(NO 3 ) 2, and UO 2 (NO 3 ), were determined in the temperature range (278 to 323) K using an electronic hygrometer with an electrolyte sensor.
TL;DR: Small amounts of supplementary iodine (250 microg) cause slight but significant changes in thyroid hormone function in predisposed individuals.
Abstract: Objective: Several studies have suggested that iodine may influence thyroid hormone status, and perhaps antibody production, in patients with autoimmune thyroid disease. To date, studies have been carried out using large amounts of iodine. Therefore, we evaluated the effect of small doses of iodine on thyroid function and thyroid antibody levels in euthyroid patients with Hashimoto’s thyroiditis who were living in an area of mild dietary iodine deficiency. Methods: Forty patients who tested positive for anti-thyroid (TPO) antibodies or with a moderate to severe hypoechogenic pattern on ultrasound received 250 mg potassium iodide daily for 4 months (range 2‐13 months). An additional 43 patients positive for TPO antibodies or with hypoechogenicity on ultrasound served as a control group. All patients were TBII negative. Results: Seven patients in the iodine-treated group developed subclinical hypothyroidism and one patient became hypothyroid. Three of the seven who were subclinically hypothyroid became euthyroid again when iodine treatment was stopped. One patient developed hyperthyroidism with a concomitant increase in TBII titre to 17 U/l, but after iodine withdrawal this patient became euthyroid again. Only one patient in the control group developed subclinical hypothyroidism during the same time period. All nine patients who developed thyroid dysfunction had reduced echogenicity on ultrasound. Four of the eight patients who developed subclinical hypothyroidism had TSH concentrations greater than 3 mU/l. In 32 patients in the iodine-treated group and 42 in the control group, no significant changes in thyroid function, antibody titres or thyroid volume were observed. Conclusions: Small amounts of supplementary iodine (250 mg) cause slight but significant changes in thyroid hormone function in predisposed individuals.
TL;DR: The results obtained from the analyses of free and total SO(2) in 30 wine samples showed good agreement between the proposed method and the rapid assay method recommended by the UE and OIV.
Abstract: This paper describes the development and application of a flow injection analysis system manifold comprising a gas diffusion unit and a potentiometric detector to the determination of free and total SO2 in white and red wines. A homogeneous crystalline iodide double-membrane tubular electrode was used as detector. SO2 determination based on the Ripper method was carried out by dosing the iodide formed in the oxidation of SO2 with iodine, followed by the separation of the formed compound through a diffusion Teflon membrane. The results obtained from the analyses of free and total SO2 in 30 wine samples showed good agreement between the proposed method and the rapid assay method recommended by the UE and OIV. The relative error deviations of the results obtained by both methods were <6%. This procedure is suitable for samples with ∼3.2−180 mg L-1 SO2, performing determinations of 75−100 samples h-1. Keywords: SO2; flow injection analysis; wines; tubular electrode; increased sensitivity
Journal Article•
TL;DR: In a study carried out in residential school children where such variables did not exist, DFS was found to have significant impact on haemoglobin status in anaemic children and improved their urinary iodine excretion and is presented as a feasible and effective strategy to control the double deficiency of iron and iodine in the authors' community.
Abstract: As a novel approach to tackle the problems of iron deficiency anaemia and iodine deficiency disorders (IDDs), which often coexist, the National Institute of Nutrition has developed iron and iodine fortified common salt (double fortified salt-DFS) as a public health measure. This salt has undergone a battery of laboratory and field tests to evaluate its feasibility for use in a national programme. The DFS is designed to provide 1 mg of iron and 15 micrograms of iodine per gram of common salt. This was made possible by the inclusion of a polyphosphate stabilizer, sodium hexametaphosphate (SHMP) at 1 per cent level. The stability of iron and iodine was found to be good up to 6 months. However, the stability of iodine depended upon the quality of the salt used for fortification. The biological effects of long-term consumption of DFS were evaluated in experimental rats and in field trials. Both iron and iodine from the salt were found to be biologically available in regenerating haemoglobin and in increasing excretion of iodine in urine. When this salt was tested in tribal villages endemic for goitre and iron deficiency anaemia, the bioresponse was good with regard to the iodine status but was not uniform in all segments with regard to iron, probably due to confounding variables. In a study carried out in residential school children where such variables did not exist, DFS was found to have significant impact on haemoglobin status in anaemic children and improved their urinary iodine excretion. The consumption of DFS for 2 yr did not have any adverse effects in school children as well as in the tribal population. Parameters related to calcium homeostasis were not altered in children receiving DFS. Histopathological examination of tissues and radiological examination of bone did not reveal any abnormality in DFS fed rats. Similarly serum and urinary parameters related to calcium and phosphorus were not altered in DFS fed rats. Therefore, DFS is presented as a feasible and effective strategy to control the double deficiency of iron and iodine in our community.
TL;DR: The trifluoromethylation of these diiodides using FSO2CF2CO2Me/CuI/DMF proceeded in excellent yields in a stereospecific and highly regioselective manner.
Abstract: Reaction of terminal alkynes with iodine in the presence of CuI (5%) in acetonitrile under reflux for several hours gave the trans-1,2-diiodoalkenes in high yields. The trifluoromethylation of thes...
TL;DR: In this article, carbon paste electrodes (CPEs) of various compositions were studied to elucidate the stripping voltammetric behavior of iodide, and the results were compared to those obtained by reference methods.
Abstract: Carbon paste electrodes (CPEs) of various compositions were studied to elucidate the stripping voltammetric behavior of iodide. At an accumulation potential of +0.7 V (vs. Ag/AgCl), the CPE containing tricresyl phosphate as a pasting liquid was able to preconcetrate iodide effectively via ion-pairing reaction followed by oxidation to iodine and its extraction onto pasting liquid. In a supporting electrolyte containing 0.5 M NaCl and 0.1 M HCl, the reduction signal was proportional to iodide concentration from 5 × 10−6 to 5 × 10−7 mol/L with a detection limit of approximately 2.5 × 10−7 mol/L (accumulation for 5 min). Other halides and pseudohalides did not interfere with the determination, except for a high concentration excess of thiocyanate and bromide (100:1). The method was tested on model solutions and was applied to determine total iodine in samples of table salts and mineral water. The results were compared to those obtained by reference methods.
TL;DR: It is concluded that patients with less iodine uptake in postoperative thyroid scans can receive lower activities of 131I, allowing a significant proportion of patients to be treated on an outpatient basis while maintaining a high ablation rate.
TL;DR: In this article, the iodine values of marine oils were directly calculated from fatty acid profiles by using reacting ratios (calculation factors) between I2 (iodine) and either the fatty acids bound to a triglyceride or the free fatty acids.
Abstract: The iodine values of marine oils were directly calculated from fatty acid profiles by using reacting ratios (calculation factors) between I2 (iodine) and either the fatty acids bound to a triglyceride or the free fatty acids. A total of 20 factors were incorporated from C14:1 to C24:1, placed into an Excel® spreadsheet, and used to calculate the iodine values. The calculated values were then compared to the oil’s iodine value obtained by the traditional titration method. The results indicate that this method can be used to obtain the iodine value of marine oils directly from the oil’s fatty acid composition, thus giving two results from one analysis.
TL;DR: A semiquantitative rapid test, based on the iodide-catalyzed oxidation of 3,3',5,5'-tetramethylbenzidine by peracetic acid/H2O2, to yield colored products, which is suited to epidemiological surveys of iodine deficiency, especially in developing countries.
Abstract: Assessment of iodine deficiency and monitoring of iodine supplementation programs demand rapid, simple, and cost-effective methods for the determination of urinary iodide concentrations. We propose a semiquantitative rapid test, based on the iodide-catalyzed oxidation of 3,3′,5,5′-tetramethylbenzidine by peracetic acid/H2O2, to yield colored products. The color of the chemical reaction is compared with color categories of a pictogram corresponding to three ranges: 300μ g/L ( 2.36 μmol/L) of iodide concentrations. The test is very easy to perform and does not require any instrumentation or apparatus. Sample preparation is simple and consists of the removal of interfering substances by disposable columns, 65 × 10.5 mm, packed with purified activated charcoal. For comparison with a reference method for measuring urinary iodide, by high-performance liquid chromatography, we determined the iodide concentrations of 370 random (untimed) urine samples from consecutive pat...
Journal Article•
TL;DR: Iodine and fluorine do have mutually interacting effects on both goiter and fluorosis in the experimental mice and both iodine deficiency and excess induced goiter as well as other functional and histopathological changes in the mouse thyroid.
Abstract: Objective. To elucidate the participation of the independent and combined long term effect of various concentrations of iodine and fluorine on the pathogenesis of goiter and fluorosis in mice. Methods. Nine drinking water supplies with different iodine and fluorine content were prepared by combination of potassium iodate and sodium fluoride solutions in bidistilled water. The concentrations of iodide were: 1. iodine deficiency (ID): 0.0; 2. iodine normal (IN): 20.0; 3. iodine excess (IE) 2500.0 µg/l; and these of fluoride were: 1. fluoride deficiency (FD) 0.0; 2. fluoride normal 0.6; 3. fluoride excess (FE), 30.0 mg/l. A total of 288 Kunmim mice was divided into 9 groups consisting of 32 animals each and each group, in addition to basal diet, received one of following iodide/fluoride mixtures: ID+FD, ID+FN, ID+FE, IN+FD, IN+FN, IN+FE, IE+FD, IE+FN, IE+FE. By such manner, one half of the animals of each group was treated for 100 days and the other half for 150 days. Results. It was found that ID only and IE only could both induce the goiter. FE induced dental fluorosis and increased fluorine content in the bone. In addition, fluorine also affected the thyroid changes induced by ID or IE. After 100 days of treatment, fluorine showed some stimulatory effect on the thyroid in ID conditions and inhibitory effect in IE conditions. After 150 days, however, the effects of fluorine on the thyroid reversed as compared with that of 100 days. On the other hand, difference of iodide intake could also increase the toxic effects of FE on the incisors and bones. The rate and degree of the incisor fluorosis, the fluorine contents in the bone were significantly higher in the ID+FE group than those in the IN+FE and IE+FE groups. Conclusions. Both iodine deficiency and excess induced goiter as well as other functional and histopathological changes in the mouse thyroid. Excessive fluorine caused fluorosis of incisors and limb bones. In addition, iodine and fluorine do have mutually interacting effects on both goiter and fluorosis in the experimental mice.
TL;DR: Iodine concentration in eggs increased significantly depending on iodine intake after a 2 week period and this new strategy is thought to accompany salt iodization programs, not to replace them.
Abstract: Iodine deficiency still exists in many countries worldwide, to a certain degree this is also true for Germany. Food of animal origin can be a good source for iodine depending on the feed. To investigate the possible use of laying hen feed enriched with iodine, we conducted a feeding experiment with 40 laying hens receiving feed with different amounts of iodine either as KIO3 or in the form of seaweed. Iodine concentration in eggs increased significantly depending on iodine intake after a 2 week period. Seaweed could also be used as an iodine source by the hens. A subsequent consumption study with 24 volunteers showed that eggs enriched with iodine can increase human's iodine excretion and therefore improve human's iodine supply. This new strategy is thought to accompany salt iodization programs, not to replace them.
TL;DR: The influence of TSH in the variation of the concentration of iodine, selenium and zinc in normal and altered human thyroid tissues was significant and reflected a functional variability in thyroid follicles.
TL;DR: This human experiment failed to confirm the differential effect of I2 on maintenance of serum T4 concentrations relative to the effect ofI- that was observed in prior experiments in rats, but there should be some concern over the potential impacts of chronic consumption of iodine in drinking water.
Abstract: The present experiment in humans failed to confirm the differential effect of I(sub 2) on maintenance of serum T(sub 4) concentrations relative to the effects of I(-) that was observed in prior experiments in rats. The reaction of I(sub 2) with metabolites of thyroid hormones in the intestine that appears responsible for this effect in rats probably also exists at some level in humans. The present results suggest that the concentrations of such metabolites in the human intestinal tract are too small to significantly affect circulating concentration of T(sub 4). However, based on the elevations in TSH, there should be some concern over the potential impacts of chronic consumption of iodine in drinking water.
TL;DR: In this article, the resonance Rayleigh scattering (RRS) spectra of selenium(IV)/iodide/basic triphenylmethane dye systems have been studied.
Abstract: The resonance Rayleigh scattering (RRS) spectra of selenium(IV)/iodide/basic triphenylmethane dye systems have been studied. Intense RRS appears when selenium(IV) reacts with iodide and a basic triphenylmethane dye, such as Crystal Violet (CV), Ethyl Violet (EV), Brilliant Green (BG), Malachite Green (MG) and Iodine Green (IG), to form an ion-association complex. The characteristics of the RRS spectra of the ion-association complexes and the suitable conditions for the reactions were investigated. The intensity of RRS is directly proportional to the concentration of selenium(IV) in the range 0 - 0.30 μg/25 ml for the CV and EV systems, and 0 - 0.40 μg/25 ml for other systems. The RRS methods have very high sensitivities for an indirect determination of selenium(IV); the detection limits are between 0.094 ng/ml and 0.86 ng/ml for different dye systems. A new way to determine trace amounts of selenium based on the RRS spectra of the ion-association complex has been developed.
TL;DR: Iodides, especially CH 3 I, were used as modifiers in the oxidative dehydrogenation of methanol to formaldehyde over electrolytic silver catalyst, and the yield of formaldehyde was as high as 93% at 98% conversion of CH 3 OH for the I-modified catalyst, while it was only 85% at 94% conversion without I-modification.
Abstract: Iodides, especially CH 3 I, were used as modifiers in the oxidative dehydrogenation of methanol to formaldehyde over electrolytic silver catalyst. The yield of formaldehyde was as high as 93% at 98% conversion of CH 3 OH for the I-modified catalyst, while it was only 85% at 94% conversion without I-modification. The optimum reaction conditions were determined and the interaction between the silver surface and the iodide additive was investigated by means of XPS and SEM. The chemisorbed iodine atoms on the silver surface caused a decrease of the surface concentration of atomic oxygen species and prevented the complete oxidation of CH 3 OH to CO 2 .
Patent•
30 Nov 1998
TL;DR: In this article, the authors proposed non-staining topical iodine disinfecting compositions having the ability to inactivate pathogens associated with skin infections or diseases based upon the presence of molecular iodine in a concentration above at least 15 ppm.
Abstract: Non-staining topical iodine disinfecting compositions having the ability to inactivate pathogens associated with skin infections or diseases. based upon the presence of molecular iodine in a concentration above at least 15 ppm. Any other iodine species selected from the group consisting of complexed iodine and triiodide may be present with the total of such other iodine species limited to a concentration of less than about 700 ppm so that any visible stain resulting from the application of this composition on the skin will dissipate without leaving any visible skin coloration.
TL;DR: The results show that there was no significant difference between the number of colonies cultured for the 1-minute scrub compared with the 5-minute Scrub with povidone-iodine for either the1-hour or the 2-hour study, and the total number of bacterial colonies was less than after the standard 5-hour scrub.
Abstract: The purpose of this study was to determine if a 1-minute scrub with povidone-iodine followed by alcohol foam is as effective as a 5-minute scrub with povidone-iodine in reducing skin bacterial counts. A 1-minute scrub with povidone-iodine followed by alcohol foam and a 5-minute scrub with povidone-iodine was done. In the first study, cultures were obtained after 1 hour, and in the second study, cultures were obtained after 2 hours. Cultures were obtained by imprinting the first, second, and third fingers on nutrient agar plates. Bacterial counts were then obtained at 24 and 48 hours. The study involved two groups of 12 participants and a total of 37 patients over a period of 5 months. The results show that there was no significant difference between the number of colonies cultured for the 1-minute scrub compared with the 5-minute scrub for either the 1-hour or the 2-hour study. In fact, the total number of bacterial colonies was less after the 1-minute scrub with alcohol foam than after the standard 5-minute scrub in both the 1-hour group (10 vs. 18) and the 2-hour group (18 vs. 44).
Patent•
13 Mar 1998
TL;DR: Stable aqueous glycerin iodide concentrates are provided in this paper which are adapted for dilution in water to yield germicidal iodide use solutions and are stable for a period of at least about 3 months at room temperature and are dilutable at a ratio of 1 part concentrate with from about 2-80 parts water.
Abstract: Stable aqueous glycerin iodine concentrates are provided which are adapted for dilution in water to yield germicidal iodine use solutions. The concentrates include from about 30-87 % by weight glycerin, from about 0.15-15 % by weight iodine, from about 0.15-15 % by weight iodide ion, and one or more additives such as compatible wetting agents, hydrotropes, thickening agents, additional emollients and buffering systems. The concentrates are stable for a period of at least about 3 months at room temperature and are dilutable at a ratio of 1 part concentrate with from about 2-80 parts water. The concentrates can be formulated to give very low free iodine values as concentrates, but provide dramatically increased free iodine values as diluted use solutions.