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At least 19 recordsLinked to original sources
PubMed1978

Polybrominated biphenyl toxicosis in rats fed an iodine-deficient, iodine-adequate, or iodine-excess diet.

Young male Sprague-Dawley rats were fed 0, 1, 10, or 100 ppm of polybrominated biphenyls (PBB) in iodine-deficient, iodine-adequate (0.2 ppm), or iodine-excess (1000 ppm) diets. Six rats in each of the 12 groups were killed at 30 days and the remaining six in each group at 60 days. Growth rates were similar in all rats fed diets containing 0, 1, or 10 ppm PBB but were slower from 30 to 60 days in rats given 100 ppm PBB. Results of routine hematologic examinations and urinalyses were essentially normal. Although liver weights were substantially increased by PBB, the smallest increases were in rats fed an iodine-deficient diet. Thyroid weights were increased by iodine deficiency and by 10 and 100 ppm PBB. Electropherograms of serum proteins, serum lipoproteins, and LDH isozymes at 60 days from rats given PBB indicated hepatic alterations, but changes were least dramatic in rats fed an iodine-deficient diet plus PBB and most severe in rats fed iodine-excess diets plus PBB. Hepatic lesions were basically similar to those previously described except that bile duct proliferation was seen at 60 days only in rats fed an iodine-deficient diet and 100 ppm PBB. Histologic changes in thyroid glands were associated with iodine deficiency and with PBB. The iodine-excess diet plus 100 ppm PBB induced squamous metaplasia of respiratory bronchiolar epithelium. These results indicate interrelationships between PBB and iodine which may affect the toxicosis caused by PBB.

Animal Feed↗
PubMed1979

The iodine content of amniotic fluid and placental transfer of iodinated drugs.

Determinations of total iodine content, levels of thyroxine (T4) and triiodothyronine (T3), and protein concentrations were made on amniotic fluid. A total of 218 samples obtained at various stages of pregnancy, from both normal and pathological pregnancies, were studied. Normal values for the iodine and hormone concentrations are presented. Several amniotic fluid samples showed greatly elevated iodine levels, thought to be the result of maternal iodine intake. This study demonstrated that such elevated levels can be produced by urography with an iodinated medium, by thyroid extract therapy, and by vaginal therapy with an iodinated agent. Levels of T4 and T3 in amniotic fluid decreased slightly from the second to the third trimester and were unrelated to the total iodine levels. Despite reports in the literature of fetal hypothyroidism produced by amniography with a fat-soluble medium, no thyroid defect was observed in this series in the presence of elevated amniotic fluid iodine levels or when a water-soluble iodinated medium was used for amniography.

Amniotic Fluid↗
PubMed1976

Iodination of DNA. Studies of the reaction and iodination of papovavirus DNA.

Iodination of DNA by the reaction originally described by S. L. Commerford ((1971), Biochemistry 10, 1993) is extremely sensitive to the secondary structure of the DNA. Cytidines in denatured simian virus 40 (SV40) DNA react at a slightly slower rate than free cytidine monophosphate; hydrogen-bonded cytidines in SV40 form I DNA are iodinated considerably more slowly; elimination of the negative supercoils in form I DNA by conversion to form II or form III reduces reactivity even further. The residual reactivity of form II or form III duplex DNA is not due to preferential iodination of unpaired cytidines near phosphodiester bond breaks; rather iodination occurs throughout the molecule. Cytidine monophosphate has been used as a model for DNA, to enable spectral measurements of its reaction with iodine and T1C13. At temperatures above 42 degrees C and at pH 5.0, formation of 5-iodocytidine is limited by the rate of formation of an intermediate, probably 5-iodo-6-hydroxydihydrocytidine. At lower temperatures, the conversion of intermediate to product is rate limiting, but can be accelerated by lowering the pH. By appropriate adjustment of pH, or temperature, the formation of intermediate or its conversion to product can be accelerated. Iodination destabilizes the DNA duplex. Iodocytosines in SV40 DNA are preferentially removed by S1 nuclease. Heavily iodinated DNA does not reassociate normally, but DNA with only 5-10% of its cytosines iodinated appears to reassociate with normal kinetics, if duplex formation is measured by hydroxylapatite chromatography. Conditions are described to permit preparation of DNA, which reassociates normally, having a specific activity of 10(8) cpm/mug.

Binding Sites↗
PubMed1978

Radiation effects of iodine-125 and iodine-131 on the overactive rat thyroid.

The effects of graded doses of iodine-125 and iodine-131 on rat thyroid glands under prolonged stimulation with oral thyrotropin-releasing hormone were assessed by histological and autoradiographic studies. No evidence for a difference in effect between iodine-125 and iodine-131 was found. The reason for this is suggested.

Animals↗
PubMed1976

[Salivary gland scintigraphy after radio-iodine therapy. Functional scintigraphy of the salivary gland after high dose radio-iodine therapy (author's transl)].

Following high dose radio-iodine therapy, some radiation damage to the salivary glands is to be expected since iodine is taken up by these glands. The great individual variation in the uptake makes it impossible to predict the severity of the damage. T max and maximal excretion capacity after stimulation were therefore estimated by a camera functional scintigram with digital read out in patients following radioiodine therapy (0.1-3.2 Ci); the excretion index was used as an indirect measure of salivary flow. After a dose up to 0.3 Ci there is a change of T max and maximal excretion capacity in 30% of patients; after a dose of 0.5 to 1 Ci it is found in 60 and 80% and after very high doses of 1.1 to 3.2 Ci an abnormal Tmax was found in two-thirds of all patients and reduced or absent excretion capacity in all nine patients in this group. The excretion index also depended significantly on the cumulative dose. All patients who had received very high doses showed marked hyposialia or asialia. The early results of interim examinations suggest, similar to radio-iodine induced hypothyroidism, a cumulative risk of reduced function. In view of the long survival period of patients with differentiated thyroid carcinomas attention should be drawn to this side effect.

Dose-Response Relationship, Drug↗
PubMed1979

[Thyroid incorporation of radioactive iodine in neotenic tritons (Triturus helveticus Raz.). In vivo studies by high resolution radioautography. Comparison of iodine incorporation in adults and larvae].

In vivo kinetics of radioiodine incorporation have been established for 70 newts, collected from Triturus helveticus Raz. populations where spontaneous neoteny occurs. Fifty of these newts which appeared to present four degrees of neoteny (more or less metamorphosed), have been studied. Main results obtained were: 1) The intensity of the iodine incorporation varies according to the degree of neoteny. The higher is this one, the lower is the intensity. 2) In general, iodine uptake rates are more or less similar to these of adults, but more often the evolution of the 125I uptake approaches a plateau-curve. From thyroid radioautographies on some animals (17 neotenic and 2 adult newts) for which in vivo iodine kinetics have been examined and on 9 normal larvae in premetamorphosis or in metamorphosis, we have noticed in those neotenic thyroids, a very small number of silver grains on apical vesicles and colloidal lumina when the degree of neoteny is the highest. This number of marked apical vesicles and colloid is more important in the neotenics which have lost some larval characters. Silver grains on colloid droplets indicating thyroid hormone excretion are inexistent in the most larval neotenics, more numerous in most metamorphosed neotenics. But they always are less numerous than in metamorphosing larvae. For a few animals, the fixation curve is very high, probably because of a stimulation of thyroid function, induced by the test and not because of a goitrous tendancy, as radioautographic observation of their thyroid shows. Thyroid function and its relation with the origin of this total and accidental neoteny are discussed.

Aging↗
PubMed1979

Structure of polyvinylpyrrolidone-iodine (povidone-iodine).

Hydrogen triiodide adducts were prepared from N,N-dimethylacetamide, N-alkylpyrrolidone derivatives, and polyvinylpyrrolidone, and their structures were investigated by IR spectra and X-ray structure analyses and compared with the structure of povidone-iodine USP. The results suggest that the iodine in povidone-iodine USP is complexed by the polymer such that a proton is fixed via a short hydrogen bond between two carbonyl groups of two pyrrolidone rings and that a triiodide anion is bound ionically to this cation.

Chemical Phenomena↗
PubMed1975

Iodine absorption in burn patients treated topically with povidone-iodine.

Providone-iodine is used as a topical antimicrobial in burn patients. Although absorption of iodine has been thought to be negligible, several patients have recently been noted with substantial elevations of serum free iodide. Unexplained abnormalities occurred in several of these patients, renal failure, metabolic acidosis, and elevation of serum glutamic oxaloacetic transaminase. It is conceivable that the large iodide loads noted were at least in part responsible for these abnormalities.

Acid-Base Equilibrium↗
PubMed1979

Intraperitoneal povidone-iodine in experimental canine and murine peritonitis.

In dogs with appendicitis-peritonitis, intraperitoneal povidone-iodine caused death more rapidly than the instillation of saline solution. The bacterial content of canine peritoneal fluid increased with time. Although fewer bacteria were found in fluid from povidone-iodine-treated dogs, the differences were not statistically significant. Qualitative chemical analysis of peritoneal fluid revealed iodide, but not free iodine, 15 to 30 minutes after instillation of povidone-iodine. Iodine was present in the peritoneum at 2 hours but not at 3 or 6 hours. The antibacterial effect of povidone-iodine was demonstrated in mice challenged intraperitoneally with lethal doses of Escherichia coli. Povidone-iodine diminished mortality when injected immediately (p less than 0.005) but not when given 1 to 3 hours later. Immediate injection of povidone-iodine into mice lowered the number of E. coli by 3 logs. Injection of povidone-iodine 3 hours after bacterial challenge lowered the number of E. coli by only 1/3 log. This lesser bactericidal effect in mice is attributed to greater dispersal and sequestration of bacteria throughout the peritoneal cavity with time and with inactivation of povidone-iodine by reduction to iodide in vivo. In dogs with appendicitis-peritonitis, the more rapid death after treatment with povidone-iodine was not associated with differences in peritoneal microflora but with peritoneal absorption of excessive amounts of iodide.

Animals↗
PubMed2026

Excess iodine induces lipid metabolic disorders by the gut microbiota SCFAs/H2S-p-AMPKα/PPARγ/SREBP-1c pathway in female rats.

With the development of living standards, the problem of excess iodine has long been overlooked. This study aimed to investigate the detrimental effects of long-term excess iodine exposure on lipid metabolism in female Sprague-Dawley rats from the gut-liver axis perspective, and to elucidate the underlying molecular mechanisms by which the gut microbiota and its metabolites mediate iodine-induced lipid metabolic disorders. The results indicated that abnormal iodine nutrition has a negative effect on the health of rats. Specifically, excess iodine not only causes thyroid disorders but also leads to liver lipid metabolism disorders, including elevated serum and hepatic total cholesterol/triglyceride levels and lipid accumulation in the liver. Further investigation revealed that excess iodine causes liver lipid metabolism disorders by altering the gut microbiota, which resulted in an increase in the relative abundance of Desulfovibrio and Lachnospiraceae NK4A136_group, and a decrease in the relative abundance of Akkermansia and Blautia in excess iodine groups. A decrease in the relative abundance of Blautia and an increase in Lachnospiraceae NK4A136_group were strongly correlated with reductions in short-chain fatty acids (acetic, propionic, and valeric acids), whereas an increase in Desulfovibrio was strongly correlated with an increase in H2S. Additionally, acetic acid was negatively correlated with H2S in serum and liver. Excess iodine reduced hepatic p-AMPKα expression while upregulating key regulators of lipid metabolism, including SREBP-1c, PPARγ and ACC1. These changes may represent one of the key mechanisms by which excess iodine induces lipid metabolism disorders through the microbiota-metabolite axis. Overall, these findings suggest that excess iodine influences lipid metabolism through the gut-liver axis. The results of this study provide scientific references and guidance for the appropriate intake of iodine and offer novel insights for early nutritional interventions targeting lipid metabolism disorders.

Journal Article↗
PubMed1979

[The thyroid gland of the newborn infant and postnatal iodine overload].

Severe iodine-induced hypothyroidism was recently diagnosed in several neonates raising the responsibility of the iodine antiseptic agents routinely used in these patients. Postnatal iodine overload due to cutaneous application of these agents (povidone iodine and fluorescinated alcoholic-iodine solution) was studied in 5 patients. Thyroid function studies were performed in iodine-overload neonates and in control neonates with comparable gestional age. Results indicated strong evidence of cutaneous absorption of iodine from the antiseptic agents used, leading to hypothyroidism in 12 of them. The frequency and the severity of thyroid dysfunction was closely related to the degree of prematurity. Full recovery was observed in all cases after withdrawal of the iodine-containing agents. It is therefore recommended to avoid any postnatal use of iodine preparations in neonates, mainly in preterm infants, and to use iodine antiseptic agents with great caution, when necessary during the neonatal period.

Anti-Infective Agents, Local↗
PubMed1975

[Clinical application of iodine 123 with special consideration of radionuclide purity, measuring accuracy and radiation dose(author's dose)].

Iodine 123 is a nearly "ideal" radionuclide for thyroid imaging. The production of Iodine 123 requires cyclotrons or accelerators. The production of multicurie amounts of Iodine 123 has been suggested through the use of high-energy accelerators (less than 60 MeV). Most of the methods for the production of Iodine 123 using a compact cyclotron result in contamination with f.e. Iodine 124 which reduces the spatial resolution af imagining procedures and increases the radiation dose to the patient. The radiation dose has been calculated for three methods of production. The various contamination with Iodine 124, Iodine 125, and Iodine 126 result in comparable radiation dose of Iodine 131, provided that the time between production and application is more than four half-live-times of Iodine 123.

Child↗
PubMed1975

The relative roles of iodination and iodothyronine content on thyroglobulin stability.

We have independently varied the degree of iodination and of iodothyronine formation over a wide range by acutely administering various doses of perchlorate and/or methimazole to severely iodine-deficient rats 30 min before giving 131-I- with graded quantities (1-100 mug of 127-I-). Thyroids were removed 4 h later and the soluble protein analyzed for labelled iodoamino acid composition and with sucrose density gradient ultracentrifugation. Since the total thyroid iodine content before administering 127I- was less than 1 mug, calculation of the degree of iodination and iodothyronine content of the labelled Tgb could be made from the known specificity of the injected labelled iodide. Newly organified iodine ranged from smaller than 0.1 to 1.4 mug/thyroid and labelled iodothyronines from smaller than 5 to 962 pmoles/thyroid. Both the degree of iodination and iodothyronine content varied directly with Tgb stability in the absence of inhibitors. But when Tgb iodination was kept constant, Tgb stability at pH 10.1 varied directly with iodothyronine content. When iodothyronine content was kept constant, Tgb stability was independent of the degree of iodination. Correlation of stability with iodothyronine content was highly significant (r=0.79, Psmaller than 0.001) but not of stability with iodine content (r=0.49, P larger than 0.05). We conclude that the primary determinant of Tgb stability in mild alkali is the iodothyronine content and not the degree of iodination of the protein. The increased Tgb stability may be induced by coupling between iodotyrosil residues of different 12 S subunits rather than between residues of the same 12 S subunit.

Animals↗
PubMed1979

[Clinical result of thyroid scintigraphy and iodine estimations using a fluorescent technique (author's transl)].

The new technique of quantitative fluorescent scintigraphy was used for determining the regional distribution and concentration of stable intrathyroid iodine (127 I) in 96 patients. Average iodine concentration in normal people (20 individuals) without thyroid enlargement living in the Bavarian iodine-deficiency area was 0.38 +/- 0.07 mg/g. In 32 patients with simple goitres it was significantly lower at 0.17 +/- 0.06 mg/g. With this technique it was possible to separate two types of hyperthyroidism amongst 21 patients: those with low iodine concentration in the thyroid (0.15 +/- 0.08 mg/g) and those with high iodine concentration (0.42 +/- 0.12 mg/g) after iodine administration. The iodine concentration in decompensated autonomous adenomas in twelve patients was usually low (0.12 +/- 0.12 mg/g). On the other hand iodine concentration was high in the paranodular tissues and could be demonstrated on the fluorescent scintigram. The quality of the scintigram using this technique for concentrations below 0.1 mg/g is inadequate. In this situation good imates can be obtained by radionucleid scintgrams. The situation is reversed by previous administration of iodine.

Diagnosis, Differential↗