Showing papers on "Iodine published in 1979"

Germicidal iodine compositions with enhanced iodine stability

Abstract: New and improved germicidal iodine compositions are provided in which iodine levels, in the presence of organic adjuvants containing at least carbon, hydrogen and oxygen atoms, are maintained for extended periods of time in the presence of iodide, through the addition of iodate and control of pH within the range of pH 5-7.

The goitrogen 3-hydroxy-4(1H)-pyridone, a ruminal metabolite from Leucaena leucocephala: effects in mice and rats.

Abstract: Mice fed a diet containing 1% (w/w) 3-hydroxy-4(1H)-pyridone (DHP) developed goitre even with a diet high in iodine whereas mimosine (0.5% w/w) did not produce goitre even with a low-iodine diet. Thyroid enlargement was apparent (measured morphometrically) by the 7th week and was advanced by the 11th week. Histologically the goitre was hyperplastic in type. No marked histological changes were found in other organs of mice fed DHP or any organs of mice fed mimosine, except for some atrophy of hair follicles. A single intragastric dose of DHP inhibited the uptake of 125I by the thyroid in the rat but an equivalent dose of mimosine did not. Evidence is presented that the inhibition occurs at the iodine binding step, as with methyl thiouracil, rather than at the iodide trapping step, as with thiocyanate. Chronic treatment of mice with DHP, as with 6-methyl thiouracil, increased the avidity of the thyroid in taking up 125I. The major conjugated form of DHP in mammals, DHP-3-O-glucuronide, was almost as effective a goitrogen as the unconjugated compound when given by mouth but considerably less active than the free form in the blood stream. It was concluded that DHP is a potent antithyroid compound of the thiouracil type with low general toxicity, since mammals can tolerate a level of intake sufficient to produce goitre in spite of iodine supplementation.

Potassium Iodide Sensitivity in Four Patients with Hypocomplementemic Vasculitis

Abstract: During metabolism studies of radiolabeled proteins in 126 participants four patients were suspected of being sensitive to potassium iodide (KI) because they repeatedly developed urticaria ...

Mixed-form polyhalide resins for disinfecting water

Abstract: A strongly basic anion-exchange resin loaded with iodine and a less than stoichiometic amount of an iodide salt or bromine and a less than stoichiometric amount of bromide salt is an effective demand bactericide for disinfecting water. The bactericidal resin according to the invention elutes only small amounts of halide ions and is especially suited for killing bacteria in feed water supplies having relatively high salt content.

Speciation of dissolved iodine in estuarine waters

Abstract: IODINE in seawater is present as iodate (IO3−) and as iodide (I−)1–3. Although there is some uncertainty in the true redox potentials of natural waters4, the thermodynamically stable species of iodine in seawater, and in river waters which are well oxygenated, is iodate5–7. We have studied an estuary to determine the distribution of iodine species as a function of salinity, and examined the results for evidence of interconversion of species in the estuary. We report here that iodide is the dominant form in river water and is oxidised to the thermodynamically stable iodate in the sea, not in the estuary.

Iodine Balance in Rainbow Trout (Salmo gairdneri) and Effects of Testosterone Propionate

Abstract: Iodine balance was studied in immature rainbow trout (Salmo gairdneri) held at 12 °C in water of iodine content 1.85 μg/L and fed daily 1% of body weight with food containing 0.48 μg I/g. Iodide fl...

Thiourea and cyanamide as inhibitors of thyroid peroxidase: the role of iodide.

Abstract: Thiourea, methylmercaptoimidazole, propylthiouracil, and thiouracil are all potent inhibitors of thyroid peroxidase (TPO)-catalyzed iodination Unlike the cyclic thioureylenes, thiourea at 5 mM has no effect on guaiacol oxidation If iodide is added to guaiacol assays containing thiourea, enzyme activity is lost The latter observation may be explained as follows In the presence of iodide, the iodinating species [TPOIoxid], oxidizes thiourea to formamidine disulfide This product decomposes to cyanamide at neutral pH We have shown cyanamide to be an inhibitor of the peroxidative and iodinating functions of TPO Studies in rats demonstrate that doses of thiourea which completely inhibit in vivo protein-bound iodine formation have no irreversible effect on TPO, as measured by guaiacol peroxidation after removal of the thyroids The major in vivo action of cyanamide is similar to that of thiourea The data suggest that the primary in vivo and in vitro mode of action of thiourea is the reversible Ioxid-trapping mechanism The anomalous inhibition of guaiacol peroxidation seen in the presence of thiourea plus iodide derives from the formation of formamide disulfide, followed by its nonenzymic decomposition to cyanamide

In Vitro and In Vivo Refractoriness to Thyrotropin Stimulation of Iodine Organification and Thyroid Hormone Secretion

Abstract: A B S T RA C T Earlier studies indicated that initial exposure of thyroid slices to thyrotropin diminished responsiveness of the adenylate cyclase-cyclic AMP system, glucose oxidation, and 32Pi incorporation into phospholipids upon readdition of the hormone. The present studies demonstrate that slices from dog, beef, and human thyroid glands initially incubated with thyrotropin (TSH) were less responsive to subsequent addition of the hormone when organification of iodide was examined. Increasing the amount of TSH did not overcome the refractoriness induced by the initial exposure to the hormone. Furthermore, the stimulatory effects of dibutyryl cyclic AMP and prostagladin E1 were abolished in slices previously incubated with TSH. Development of such refractoriness did not depend upon new protein synthesis and was not abolished by 1 mM prophylthiouracil in the first incubation. Addition of 0.1 ,uM thyroxine or triiodothyronine or 1.5 ,M iodide during all three incubations did not modify the response to TSH, added for the first time in the third incubation. However, 1mM iodide in the buffer during all three incubations inhibited the response toTSH during the third incubation. During the refractory period, effects ofTSH on colloid droplet formation were also diminished. The in vivo effect ofTSH on serum 1- triiodothyronine in rats was significantly reduced when the rats had been injected with TSH 8 h earlier. These studies demonstrate that TSH-induced refractoriness also includes effects on organification of iodine and secretion of thyroid hormone. The results cannot be adequately explained by

Treatment of Disseminated Granuloma Annulare With Potassium Iodide

Abstract: To the Editor.— Yet to be found is a completely safe and effective treatment for disseminated granuloma annulare, an often refractory dermatosis that is marring, if not disabling. Cryotherapy, locally applied steroids, diethylstilbestrol, and, most recently, chlorambucil 1 have met with varying success. The favorable effect in certain granulomatous panniculitises of potassium iodide taken orally in a dosage of 500 to 900 mg/day reported by Schulz and Whiting 2 prompted the following study. Method and Materials.— After obtaining informed consent, four adult patients (patients 1, 2, and 4 were women; patient 3 was a man) with biopsy-verified disseminated granuloma annulare began therapy of either a saturated solution of potassium iodide or a placebo (water) in a randomized, double-blind study, beginning with 3 drops three times a day with meals and increasing to a maximum dose of 1 mL/day, which is equivalent to approximately 900 mg of potassium iodide per day.

Intraperitoneal povidone-iodine in experimental canine and murine peritonitis.

Abstract: 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.

Method of extraction, trapping and storage of radioactive iodine contained in irradiated nuclear fuels

Abstract: After dissolving irradiated nuclear fuel in a nitric acid medium, the vapor produced by this dissolution and consisting of water, nitrogen oxides and iodine is passed into a condenser, then into a column for the absorption of the nitrous vapor in which is formed recombined nitric acid containing iodine and nitrous ions, the iodine contained in the recombined acid being then separated-out. The nitrous ions present in the recombined acid have a favorable influence on the important first stage of that separation.

Method for producing iodine

Abstract: This invention relates to the production of iodine. More particularly, the invention relates to the enzymatic oxidation of iodide to iodine and the recovery of said formed iodine.

Failure of organic iodine enrichment to influence the binding of bovine thyrotropin to rat thyroid tissue

Abstract: In an effort to clarify the mechanism whereby increases in the thyroid content of organic iodine lead to inhibition of the stimulation of thyroid adenylate cyclase produced by TSH, studies have been conducted of the effect of enrichment with iodine on the specific binding of TSH by receptors in thyroid tissue. Enhancement of thyroid organic iodine content was induced acutely by incubating thyroid lobes of intact iodinedeficient rats in media containing iodide, with or without TSH, in vitro or by administering iodide to intact or hypophysectomized iodine-deficient rats in vivo. Specific binding of 125I-labeled bovine TSH (bTSH) and its displacement by unlabeled bTSH was then assessed in fractions prepared from these and control glands using methods which make possible study of the properties of the saturable binding site for bTSH previously demonstrated in rat thyroid tissue. In none of the models employed did prior enhancement of the thyroid organic iodine content appear to influence either the maximum ca...

The Determination of the Formation Constant of Triiodide Ion in Micellar Solution of Dodecyltrimethylammonium Chloride

Abstract: Spectrophotometric measurements were undertaken at 360 nm in order to estimate the formation constant of triiodide ion in micellar solution of dodecyltrimethylammonium chloride. The absorption spectra of the solutions suggested that both iodine molecule and triiodide ion are solubilized in a hydrophilic surface region of the surfactant micelle. The apparent formation constant of triiodide ion, Ka, was found to be much larger in micellar solution than in water. It was also shown that the value of Ka decreases regularly with increasing surfactant concentration. A tentative estimation based on a lamellar micelle model led to the intrinsic formation constant of triiodide ion of 650 mol−1 dm3 or less at 30 °C, which is comparable with that in water. The thermodynamic consideration revealed that the formation reaction of triiodide ion from iodine and iodide ion in micellar solution is accompanied by an anomalous entropy decrease.

A semi-automated method for the determination of iodine in plants.

Abstract: A method for the determination of iodine in plants is described. This method involves destruction of organic matter by alkaline incineration and automated spectrophotometric determination of iodide based on the Sandell and Kolthoff's reaction. The mean recovery of 131I was 93.4% (S.D. = 3.19)). For replicate analyses of different plant material, the coefficient of variation is between 3 and 5%.

Oxidation and isomerization of retinoic acid by iodine and light: A novel preparation of all-trans- and 13-cis-4-oxoretinoic acid

Abstract: A mixture of all-trans-retinoic acid and iodine in heptane was irradiated. Two oxidation products were isolated by high performance liquid chromatography and identified as all-trans- and 13-cis-4-oxoretinoic acid by nuclear magnetic reasonance, ultra violet, Infrared spectroscopy, and mass spectral analysis. Under the same conditions, but without light, a mixture of all-trans- and 13-cis-retinoic acid resulted. The corresponding methyl esters were obtained when methyl all-trans-retinoate was used in place of all-trans-retinoic acid.

Quantitative in vivo measurement of thyroidal iodine content by static x-ray fluorescent technique: some preliminary clinical observations.

Abstract: A static x-ray fluorescent technique utilizing an 241Am source of low activity and a wide view diverging collimator which allows in vivo determination of the concentration and total content of iodine in the thyroid is described. Determinations of normal thyroidal iodine concentration and total iodine content were as follows: 0.40 mg/g and 10.6 mg for 16 men, and 0.67 mg/g and 17.6 mg for 14 women. This fluorescent system has been applied to 70 patients to date. Thyroidal iodine concentrations in patients with Graves' disease were approximately equal to those in healthy suspects, and little change was observed among the concentrations in patients before, during, or after treatment. In most of the patients with chronic or subacute thyroiditis, concentrations levels were lower.