scispace - formally typeset
Search or ask a question

Showing papers on "Iodine published in 1991"


Journal ArticleDOI
TL;DR: The results show that the increased thyroid size in the control group was mainly a result of relative iodine deficiency and that iodoprophylaxis should be warranted even in areas with moderate iodine deficiency to prevent the increase in thyroid size and, probably, to avoid the risk of maternal and fetal hypothyroidism.

134 citations



Journal ArticleDOI
01 Jan 1991
TL;DR: Iodine speciation was determined on water samples collected from the upper 250 m of the Black Sea during 11-14 June 1988 as discussed by the authors, using three separate voltammetric methods.
Abstract: Iodine speciation was determined on water samples collected from the upper 250 m of the Black Sea during 11–14 June 1988. Iodate, iodide and total iodine were determined by three separate voltammetric methods. In most samples, the sum of iodide plus iodate equalled the total iodine. In four samples obtained near the oxic/anoxic nonsulfidic interface, however, the sum of the iodide plus iodate was less than the total iodine (range 17–38% lower). Thus, a third form of iodine is present. Addition of sulfite to the samples did not increase the iodide concentration which would be expected if I 2 or OI − were present. It is suggested that the third form of iodine is organic and probably of high molecular weight (peptide or aromatic?). The differences with the previous results of Wong and Brewer (1977, Geochimica et Cosmochimica Acta , 41 , 151–159) can be attributed to different methods used and to differences in the water column chemistry of the Black Sea over time and perhaps season. In the previous work, O 2 and H 2 S coexisted in the zone between the oxic and sulfidic zones whereas in this work, O 2 and H 2 S were not present in the zone between the oxic and sulfidic zones.

77 citations


Journal ArticleDOI
TL;DR: In this paper, the authors compared the oxidative chemisorption and cathodic stripping reductive desorption of iodine at smooth polycrystalline and well-defined Au(111) single-crystal electrodes.
Abstract: The oxidative chemisorption and cathodic stripping reductive desorption of iodine have been compared at smooth polycrystalline and well-defined Au(111) single-crystal electrodes. Experimental measurements were based upon cyclic voltammetry, thin-layer coulometry, X-ray photoelectron spectroscopy, Auger electron spectroscopy, and low-energy electron diffraction. The results indicate that iodide is oxidatively adsorbed as zerovalent atomic iodine at potentials between −0.4 V and +0.4 V (Ag/AgCl reference); at lower potentials, surface iodine is reductively desorbed as aqueous iodide, while at considerably more positive potentials, it is oxidized to aqueous iodate

76 citations


Journal ArticleDOI
TL;DR: An exisiting iodometric method was modified to correct for interfering phenomena and to provide a more specific measurement of the lipid hydroperoxide content of plasma to indicate that insignificant amounts of hydro peroxide may be in the less polar lipids, but the total amount of lipid hydroPeroxide esterfied in the plasma lipids of apparently healthy humans may be as much as 4.0 +/- 1.7 microM.

73 citations


Journal ArticleDOI
TL;DR: In this article, a series of experiments were performed to investigate the kinetics and mechanism of the leaching reaction between gold and iodide, and a comparison of gold leaching between iodide and cyanide was also presented, in which a rate of about 2.6 × 10−9 mol/cm2 sec for 10−2M Nal and 5 × 10 −3M I2 was obtained.

71 citations


Journal ArticleDOI
TL;DR: In this article, the authors collected and analyzed Chesapeake Bay water samples for the inorganic iodine species: iodide (by cathodic-stripping squarewave voltammetry) and iodate (by differential pulse polarography); and total iodine (by hypochlorite oxidation of the seawater sample to iodate).
Abstract: During the summer of 1987, we collected and analysed Chesapeake Bay water samples for the inorganic iodine species: iodide (by cathodic-stripping squarewave voltammetry) and iodate (by differential pulse polarography); and total iodine (by hypochlorite oxidation of the seawater sample to iodate). The difference between the sum of the inorganic iodine species and the total iodine was significant for about one-third of the samples collected from the Bay. Thus, in these samples, a third (or more) ‘new’ form(s) of iodine was present. These samples were primarily from oxygen-saturated surface waters of high biological activity (primary productivity and bacterial processes). This ‘new’ form can make up as much as 70% of the total iodine. Waters containing low oxygen concentrations showed less of this ‘new’ form of iodine whereas anoxic and sulphidic bottom waters contained only iodide. This ‘new’ form of iodine is organic in nature and probably non-volatile. It may reside in the peptide and humic fractions. Only reduced iodine (iodide and organic iodine) was detected in waters from the northern section of the Bay, whereas only iodide and iodate were detected in the southern section of the Bay. In only two samples were iodide, iodate and the ‘new’ form of iodine found to coexist. Iodide and organic iodine are probably cycled in the surface waters of the northern section of the Bay via a combination of biogeochemical and photochemical processes which produce the reactive intermediates, molecular iodine and hypoiodous acid. These react quickly with reduced inorganic and organic compounds to maintain the reduced forms of iodine in the water column. Only total iodine is conservative throughout the estuary. The inorganic iodine forms can be used as geochemical tracers.

66 citations


Journal ArticleDOI
TL;DR: Iodine is a requisite substrate for the synthesis of the thyroid hormones, the minimum daily requirement being about 50 micrograms, and in addition to its role in reversing iodine deficiency, iodine is used as adjunctive therapy for hyperthyroidism.

61 citations


Journal ArticleDOI
TL;DR: The aim of the study was to evaluate the risk of exposure to an increase in dietary Iodide Intake amongst potentially susceptible population groups in Britain.
Abstract: OBJECTIVE The aim of the study was to evaluate the risk of exposure to an increase in dietary iodide intake amongst potentially susceptible population groups in Britain. DESIGN A randomized controlled trial was performed in healthy women and in women with underlying thyroid abnormalities due to subclinical Hashimoto's thyroiditis (diagnosed on the basis of antithyroid antibodies) or previous iodide deficiency of supplementation with 500 micrograms/day iodide (giving a total intake of approximately 750 micrograms/day) for 28 days versus placebo. PATIENTS Two hundred and twenty-five women aged 25-54, randomly selected from a general practice in Cardiff, were screened for thyroid microsomal antibody. Antibody positive women (n = 20), and antibody negative controls (n = 30) were recruited into the trial comparing iodide and placebo. In addition, groups of patients aged 60-75 randomly selected from the Cardiff practice (n = 29), an iodide sufficient area, and a practice in Dowlais (n = 35), a previously iodide deficient area, were also enrolled into the trial. MEASUREMENTS Changes in free thyroxine and thyrotrophin levels were measured after 14 and 28 days of iodide supplementation. RESULTS All the iodide supplemented groups responded in the same way with a small fall in free thyroxine and rise in thyrotrophin levels (combined fall in free thyroxine 14 days after the start of supplementation -1.22 (95% confidence interval -0.59 to -1.84) pmol/l and at 28 days -0.86 (-0.30 to -1.43) pmol/l and rise in thyrotrophin at 14 days 0.55 (0.19 to 0.92) mU/l and at 28 days 0.59 (0.12 to 1.07) mU/l). In two of the iodide supplemented subjects thyrotrophin levels rose above the laboratory reference range and in a further three subjects initially elevated thyrotrophin values increased further. In contrast, no changes in thyroid function were observed in the placebo treated controls and none developed biochemical hypothyroidism. CONCLUSIONS Dietary iodide intakes of 750 micrograms/day or more may adversely affect thyroid function, especially in individuals with borderline hypothyroidism.

60 citations


Journal ArticleDOI
TL;DR: In this paper, the adsorption and thermal behavior of methyl iodide on Si(100)-(2 × 1) have been studied by kinetic uptake measurements, Auger electron spectroscopy (AES) and temperature-programmed desorption (TPD) Mass Spectroscopy.

58 citations


Journal ArticleDOI
TL;DR: Several oxidants (hypochlorite, iodine, and hydrogen peroxide) were used to evaluate the dissolution of gold in iodide electrolytes at ambient temperatures as discussed by the authors, and the Evans diagrams constructed for the two half cells involved in the dissolution process showed that hydrogen permoxide is not a suitable oxidant for the iodide system.

Journal ArticleDOI
TL;DR: It is concluded that thyroid blood flow responds inversely, and independently from TSH, to changes in iodine intake in euthyroid humans.
Abstract: High intake of iodine inhibits iodide trapping, iodide organification, and hormone release from the human thyroid. We investigated whether iodine intake also affects thyroid blood flow, as was suggested by a recent study in euthyroid rats. With a Color Doppler device we made 14 consecutive Duplex-Doppler registrations of both superior thyroid arteries in 10 euthyroid volunteers during baseline iodine intake (1 week), iodine restriction (2 weeks), return to baseline (1 week), and iodine excess (1 week; 80 mumol sodium iodide/day). Vessel diameters and mean flow velocity were measured on videotape recordings by a "blinded" observer. Baseline iodide excretion was 0.88 +/- 0.38 (+/- SD) mumol/day. Mean flow velocity was 13.9 +/- 4.1 cm/s, and vessel diameter was 1.07 +/- 0.22 mm. Blood flow was 7.7 +/- 3.8 mL/min.superior thyroid artery. During the low iodine diet, excretion dropped to 0.49 +/- 0.16 mumol/day, and blood flow increased to 11.0 +/- 5.0 mL/min (P less than 0.001), remaining elevated (10.3 +/- 4.4 mL/min) during the second baseline diet. During high iodide intake, blood flow averaged 5.8 +/- 3.4 mL/min (P less than 0.001), and the expected decrease in thyroid hormone levels and increase in TSH were seen. We conclude that thyroid blood flow responds inversely, and independently from TSH, to changes in iodine intake in euthyroid humans.

Journal ArticleDOI
TL;DR: A simple preconcentration neutron activation analysis (PNAA) method has been developed for the determination of low levels of iodine in biological and nutritional materials and total diet samples.
Abstract: A simple preconcentration neutron activation analysis (PNAA) method has been developed for the determination of low levels of iodine in biological and nutritional materials. The method involves dissolution of the samples by microwave digestion in the presence of acids in closed Teflon bombs and preconcentration of total iodine, after reduction to iodide with hydrazine sulfate, by coprecipitation with bismuth sulfide. The effects of different factors such as acidity, time for complete precipitation, and concentrations of bismuth, sulfide, and diverse ions on the quantitative recovery of iodide have been studied. The absolute detection limit of the PNAA method is 5 ng of iodine. Precision of measurement, expressed in terms of relative standard deviation, is about 5% at 100 ppb and 10% at 20 ppb levels of iodine. The PNAA method has been applied to several biological reference materials and total diet samples.

Journal ArticleDOI
TL;DR: It is strongly suggested that euthyroid women with a previous episode of PPT have permanent subtle defects in thyroid hormone synthesis and are inordinately prone to develop iodide-induced hypothyroidism, similar to findings previously reported in euthYroid subjects with Hashimoto's thyroiditis.
Abstract: Postpartum thyroiditis (PPT) is common and occurs in 1.7 to 16.7% of pregnant women, depending upon the study population. Most of these women develop transient hypothyroidism and thyroid function usually returns to normal. We have studied 11 euthyroid women with a previous history of PPT to determine the incidence of subtle defects in thyroid function measured by iodide-perchlorate (I-CIO4) discharge tests and TRH tests and to determine whether these women would develop iodide-induced hypothyroidism. Seven (64%) had positive I-CIO4 discharge tests and 5 (46%) had an abnormally high TSH response to TRH. Thyroid antimicrosomal and antithyroid peroxidase were positive in 8 women (73%) with a previous episode of PPT. The administration of pharmacological amounts of iodide (10 drops of saturated solution of potassium iodide daily) for 90 days to these 11 women resulted in elevated basal and TRH stimulated serum TSH concentrations in 8 (72.7%) compared to TSH values during iodide administration to women who had...



Journal ArticleDOI
TL;DR: The results of this study indicate that iodine and iodide affect thyroid hormone status in substantially different ways.
Abstract: In risk assessments the various forms of iodine have been treated as if they were toxicologically equivalent. While iodide (I-) and iodate (IO3-) have been studied, no studies concerned with the subchronic toxicity of iodine (I2) have been conducted in experimental animals. This study examined toxicities associated with iodine. Rats were treated with 0, 1, 3, 10, and 100 mg/l of either iodine or iodide (as Nal) in the drinking water for 100 d. Treatment had no effect on body, brain, or heart weights in either sex, or on testes weights in male rats. Although differences in kidney and liver weights were noted, they did not appear to be treatment related. Thyroid weight in male rats was significantly increased with an increasing concentration of iodide in the water, but not iodine. In contrast, thyroid weight decreased at the highest dose of iodide in female rats. Hematocrit, hemoglobin, and blood urea nitrogen (BUN) values were relatively constant and did not vary with treatment. There were no significant differences in AST, ALT, cholesterol, and triglyceride values. After 10 d on treatment a dose-related trend in increased plasma T4 concentrations was observed in both sexes treated with iodine. Statistically significant increases in the T4/T3 ratio in both sexes was also noted with iodine treatment. This increase was maintained for 100 d of treatment. Iodide did not produce this effect at 10 d. Although there was a significant increase in T4/T3 ratios in female rats after 100 d of treatment with iodide, the magnitude of the changes was smaller than that observed with iodine treatments. The results of this study indicate that iodine and iodide affect thyroid hormone status in substantially different ways.

Journal ArticleDOI
TL;DR: In this paper, the electrochemical quartz crystal microbalance (EQCM) and rotating ring-disk electrode (RRDE) techniques were used to study the adsorption and desorption of iodide-containing species.

Journal ArticleDOI
T. R. Brown1, Roy S. Sundick, A. Dhar, D Sheth, N. Bagchi 
TL;DR: In this paper, the effect of antithyroid drugs that reduce thyroidal iodine or prevent its metabolism was investigated in the obese strain (OS) chicken, a model of spontaneous and severe disease.
Abstract: To assess the importance of the role of thyroidal iodine in the pathogenesis of thyroiditis in the obese strain (OS) chicken, a model of spontaneous and severe disease, we studied the effect of antithyroid drugs that reduce thyroidal iodine or prevent its metabolism. Reduction of thyroidal iodine was achieved with KClO4, an inhibitor of iodine transport and mononitrotyrosine (MNT), a drug that promotes loss of thyroidal iodine as iodotyrosines. A regimen consisting of KClO4 and MNT administration beginning in ovo and continuing after hatching reduced thyroidal infiltration to 2% of control values and decreased thyroglobulin antibody (TgAb) production for as long as 9 wk. Untreated birds had severe disease by 5 wk of age. The suppression of disease was independent of TSH, not mediated by generalized immunosuppression and reversed by excess dietary iodine. Two drugs that inhibit the metabolism of iodine, propylthiouracil (PTU) and aminotriazole, reduced thyroidal infiltration and TgAb levels, although to a lesser extent. When splenocytes from OS chickens with thyroiditis were transferred to Cornell strain (CS) chickens, a related strain that develops late onset mild disease, only the recipients that were iodine supplemented developed thyroiditis. In conclusion, autoimmune thyroiditis in an animal model can be prevented by reducing thyroidal iodine or its metabolism and optimal effects require intervention at the embryonic stage.

Journal ArticleDOI
TL;DR: The inhibitory actions of insulin, IGF-I, and hydrocortisone on cAMP-induced iodide porter activity contrast with their simultaneous and synergistic stimulation of the transcriptional action of cAMP on DNA and thyroglobulin synthesis under these conditions.
Abstract: Insulin enhances the ability of TSH to induce iodide uptake in FRTL-5 rat thyroid cells maintained in 5% serum; however, in cells maintained in 0.2% serum, insulin inhibits the ability of TSH to induce iodide uptake. Since the inhibitory action of insulin is duplicated by 100-fold lower concentrations of insulin-like growth factor-I (IGF-I), inhibition appears to be mediated by the IGF-I receptor. Insulin and IGFI inhibit the action of a cAMP analog to induce iodide uptake in a manner identical to TSH, but do not inhibit basal or TSHincreased cAMP levels; inhibition, thus, results from regulation of cAMP signal action rather than cAMP signal generation. Inhibition is associated with a more than 2-fold decrease in the maximum velocity of iodide influx, a less than 15% change in the rate of iodide efflux, and no change in the Km for iodide influx, i.e. inhibition effectively results from a decrease in the number of iodide porters. The inhibitory action of insulin/IGFI is not additive with hydrocortisone, wh...

Journal ArticleDOI
TL;DR: A greater inhibitory effect was observed in subsequent germination and outgrowth studies when spores were pre-treated with respective biocide than when untreated spores were added to germination media containing biocide at t = 0.
Abstract: Sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) were more active against Bacillus subtilis 8236 spores in both viability and in germination and outgrowth studies than were polyvinylpyrrolidone-iodine (PVP-I) and Lugol's solution. Of the two chlorine compounds studied NaOCl proved to be the more active. The two iodine-containing compounds gave contrasting results with the Lugol's solution demonstrating increased antibacterial activity with increasing available iodine concentration. The antibacterial behaviour of PVP-I, however, reflected the more complex nature of aqueous iodine-surfactant mixtures. Initially, non-complexed iodine concentration (the active species) increased with increasing total available iodine concentration, resulting in increasing antibacterial activity. However, due to changes in the physical properties of the mixture, a maximum concentration of non-complexed iodine was reached so that a further increase in total available iodine resulted in a decrease in non-complexed iodine concentration and consequently a decrease in the antibacterial activity of the solution was observed. A greater inhibitory effect was observed in subsequent germination and outgrowth studies when spores were pre-treated with respective biocide than when untreated spores were added to germination media containing biocide at t = 0. This may reflect a combination of different contact times plus the neutralizing effect of the germination media on such halogen compounds.

Journal ArticleDOI
TL;DR: For evaluation of thyroidal iodine kinetics and thyroid nodules, the authors carried out quantitative in vivo measurement of thyroid iodine concentration by CT and found that the CT attenuation values were obtained from the regions of interest in the CT image that corresponded to the analyzed fragment.
Abstract: For evaluation of thyroidal iodine kinetics and thyroid nodules, we carried out quantitative in vivo measurement of thyroid iodine concentration by CT. Neuron activation analysis of iodine content was conducted on 48 thyroid fragments without calcification operatively obtained from 18 patients who had undergone CT of the thyroid without contrast enhancement. The CT attenuation values were obtained from the regions of interest in the CT image that corresponded to the analyzed fragment. When iodine concentration in the thyroid tissue was greater than 0.02 mg/g, the CT values correlated linearly with the iodine concentrations in thyroid nodules, thyroids with diffuse thyroid disease, and normal thyroids. The relationship is represented by the following formula: iodine concentration (mg/g) = (CT value-65)/104. The relationship between iodine concentration and CT value in diffuse thyroid disease, thyroid nodules, and normal thyroids was not significantly different.

Journal ArticleDOI
TL;DR: Results suggest that cells cultured in this culture system are able to reproduce several steps of thyroidal iodide metabolism although there may be unknown factors which could interfere and reduce the efficiency of thyroglobulin iodination.
Abstract: Thyroid cells cultured as monolayers on the porous bottom of culture chambers have been shown to express some specific functions of thyroid follicles. This system, which allows independent access to apical and basal media, is suitable for the long-term study of polarized processes, as the cells maintain their polarized organization. Iodination of thyroglobulin has been investigated under different culture conditions in the presence or absence of TSH. Apical thyroglobulin accumulation, apical iodide concentration and thyroglobulin iodination have been followed simultaneously. Iodide (0.5 mumol/l) was added to basal medium at various stages: only once for 4-day incubations and at each medium change or daily for longer experiments. TSH increased the amount of thyroglobulin secreted into the apical medium by five- to sixfold, whereas high basal iodide concentrations (greater than 5 mumol/l) inhibited thyroglobulin secretion by TSH-stimulated cells. TSH increased iodide uptake giving an iodide concentration ratio between apical and basal media of about 5. Thyroglobulin iodination was dependent upon TSH. Thyroglobulin was iodinated only in the apical compartment. Secretion and iodination of thyroglobulin were polarized phenomena, but the polarity of iodination was total whereas the polarity of secretion was only partial (10% basal secretion). This functional asymmetry was maintained for up to 29 days. The maximal incorporation of iodine into thyroglobulin obtained was never higher than 3.5 atoms/mol. Apical iodide concentrations from 1 to 15 mumol/l, depending on culture conditions, did not increase this value. These results suggest that cells cultured in this culture system are able to reproduce several steps of thyroidal iodide metabolism although there may be unknown factors which could interfere and reduce the efficiency of thyroglobulin iodination.

Journal ArticleDOI
TL;DR: The data suggest that retinoids inhibit TSH-stimulated iodine metabolism by reducing cAMP accumulation and also by acting on the steps subsequent to cAMP production.
Abstract: Effects of retinoids on DNA synthesis, iodine metabolism, and thyroid peroxidase messenger RNA levels were studied in cultured porcine thyroid cells. Retinol (10(-8)-10(-5) M) alone did not affect DNA synthesis but potentiated that induced by epidermal growth factor or insulin-like growth factor-I without changes in the number or affinity of receptors for the growth factors, suggesting that retinol stimulates postreceptor events responsible for DNA synthesis. Retinol was an inhibitor of TSH-stimulated iodine metabolism. Iodide uptake and release of organified iodine stimulated by TSH or forskolin were inhibited dose dependently by treatment with retinol. The inhibition was detected at 10(-8) M and was approximately 50% at 10(-6) M. The potency of retinoic acid was comparable to that of retinol. The inhibitory effect of retinol was detected after treatments of thyroid cells for 24 h, and the maximal effect occurred after 48 h incubation. The cAMP accumulation in cultures treated with TSH plus retinol was lower than that of control cultures treated with TSH alone. However, iodide uptake stimulated by 8-bromo-cAMP was also inhibited by retinoids. Retinol reduced TSH- or 8-bromo-cAMP-stimulated gene expression of thyroid peroxidase. Thus, the data suggest that retinoids inhibit TSH-stimulated iodine metabolism by reducing cAMP accumulation and also by acting on the steps subsequent to cAMP production.

Journal ArticleDOI
TL;DR: The results suggest that the waterborne route of IHNV transmission can be blocked by adding low iodine concentrations to the water supplies of hatcheries and preventing infection of rainbow trout fry.
Abstract: The fish rhabdovirus infectious hematopoietic necrosis virus (IHNV) was rapidly inactivated by extremely low concentrations of iodine in water. A 99.9% virus reduction was obtained in 7.5 s when virus (105 PFU/ml) and iodine (0.1 mg/liter, final concentration) were combined in distilled-deionized or hatchery water. Iodine efficacy decreased at pHs greater than 7.5 or when proteinaceous material was added to the water. Bovine serum albumin blocked iodine inactivation of the virus more effectively than did equal concentrations of fetal bovine serum or river sediment. Sodium thiosulfate effectively neutralized free iodine. Powder, iodophor, and crystalline iodine solutions inactivated IHNV equally. Iodine rapidly inactivated IHNV isolates representing each of the five electropherotypes. Under the conditions used in this study, inactivation was not affected by temperature, salinity, or water hardness. When Dworshak National Fish Hatchery water was continuously treated to provide a free iodine concentration of 0.14 mg/liter, a 7.5-s exposure to iodine was sufficient to inactivate 99.9% of the IHNV. Iodine added to water that contained IHNV prevented infection of rainbow trout (Oncorhynchus mykiss) fry. These results suggest that the waterborne route of IHNV transmission can be blocked by adding low iodine concentrations to the water supplies of hatcheries.

Book ChapterDOI
01 Jan 1991
TL;DR: Gould et al. as mentioned in this paper performed laboratory experiments to study the effect of potassium iodide addition to chlorinated Missouri River water and noticed a chloroform decrease with simultaneous formation of 3 iodinated trihalomethanes.
Abstract: Iodinated THM’s were identified as early as 1976 in XAD resin extracts of 3 Kansas and Missouri chlorinated drinking waters (1). As a result of these findings, the authors performed laboratory experiments to study the effect of potassium iodide addition to chlorinated Missouri River water and noticed a chloroform decrease with simultaneous formation of 3 iodinated THM’S. Dichloroiodomethane (DCIM) was soon identified in 85 of 111 water supplies during a national organic monitoring survey and was dubbed the “fifth trihalomethane” (2). Thomas subsequently used the procedure of Hine and Ehrenson (3) to synthesize DCIM and study its stability in various organic solvents and tap water samples (4). In a detailed laboratory investigation, Gould compared the incorporation of bromide and iodide into total trihalomethanes (5).

Journal ArticleDOI
TL;DR: The ratios of iodide to thiocyanate in urine excreted by subjects from both goitrous and non-goitrous areas show a strong correlation withGoitre endemia, exemplify goitre as having multicausal factors--lack/deficiency of iodine, familial or genetic tendencies, diet, and pollutants which serve as goitrogens.

Journal ArticleDOI
TL;DR: In this paper, a method is described to determine iodide, iodate, total inorganic iodine, and charcoal-adsorbable iod compounds in seawater, based on adsorption on charcoal of iodine subsequent to pretreatment and detection of iodine by neutron activation of the charcoal.

Journal ArticleDOI
TL;DR: In vivo discharge of accumulated labelled iodide by perchlorate administration revealed defective organification of iodide, which was complete in one cat and partial in the other, suggesting that the loose enzyme anchoring caused decreased availability of peroxidase and as a consequence reduced capacity for organic binding of trapped iodide.
Abstract: Two cats with congenital hypothyroidism are described. In vivo discharge of accumulated labelled iodide by perchlorate administration revealed defective organification of iodide, which was complete in one cat and partial in the other. In the cat with the partial organification defect, thyroid tissue was obtained for biochemical studies. No membrane-bound peroxidase activity could be demonstrated. The activity was found in the 100,000 x g supernatant. It is suggested that the loose enzyme anchoring caused decreased availability of peroxidase and as a consequence reduced capacity for organic binding of trapped iodide.