Showing papers on "Iodine published in 1983"

Methyl halides in and over the eastern Pacific (40°N–32°S)

Abstract: Methyl chloride, methyl bromide, and methyl iodide measurements in and over the eastern Pacific (40 /sup 0/N and 32 /sup 0/S latitude) show mean air concentrations of 633 parts per trillion (ppt), 23 ppt, and 2 ppt, and mean surface seawater concentrations of 11.5 ng/l, 1.2 ng/l, and 1.6 ng/l respectively. Long-term ambient measurements at a marine Pacific site (39 /sup 0/N) show an essentially unchanging background, with some indication of high concentrations of methyl bromide and methyl iodide during summertime. The oceanic data indicate a mean surface supersaturation of 275%, 250%, and 340%, respectively, for these three methyl halides. Depth profiles show that methyl halides are most abundant in the top mixed layer of the ocean. Oceanic concentrations of methyl chloride and methyl bromide are significantly correlated (linear regression coefficient of 0.85), suggesting a common source. No relationship between oceanic methyl iodide concentrations and the other two halides could be found. Coexistence of high concentrations of methyl iodide with relatively low concentrations of methyl chloride and vice versa provided no direct support for the hypothesis that chloride ion reactions with methyl iodide may be the dominant oceanic source of methyl chloride. For the eastern Pacific, mean ocean to airmore » fluxes (in units of 10/sup -7/ g cm/sup -2/ yr/sup -1/) of 13,1, and 1 are determined for methyl chloride, methyl bromine, and methyl iodide, respectively. When extrapolated to global waters, they provide an adequate source to explain the atmospheric reservoir of these organic halides. Total organic bromine and iodine measurements would suggest that methyl bromide and methyl iodide contribute predominately to the tropospheric bromine and iodine organic reservoir.« less

Radiation dose enhancement in tumors with iodine

Abstract: The loading of tissue with iodine can result in the enhancement of the radiation dose absorbed from low-energy x-ray or gamma ray sources. We have explored the potential of this phenomenon for radiation therapy. We have demonstrated the effect of iodine concentration and radiation quality on this dose enhancement in lymphocytes, we have calculated the effect of such enhancement on depth dose distributions in the brain, we have estimated the iodine content in two human brain tumors during computerized tomography (CT) scans, we have studied the dispersion of the iodine contrast media after direct injection into rabbit tumors, and we have demonstrated that the combination of x-ray and contrast media injection is far more effective than either agent alone in causing the regression of mouse tumors. These results suggest that there may be a therapeutic advantage from loading tumors with iodine and treating them with low-energy photons.

Low iodine diet in I-131 ablation of thyroid remnants.

Abstract: A low-iodine diet was developed for use in decreasing iodine intake and excretion in patients undergoing evaluation with radioactive I-131 for ablation of thyroid remnants as treatment for thyroid cancer. It has been demonstrated to effectively lower iodine excretion to less than 25% of basal values. Preliminary calculations suggest that such iodine depletion may be potentially useful in increasing the radiation dose per mCi of administered activity in I-131 ablative therapy.

Congenital Goiter with Defective Iodide Transport

Abstract: THE TWENTY-TWO known cases of congenital goiter, with or without cretinism, that are due to defective iodide concentrating ability have been compared. The defect may be total or partial, sometimes becomes clinically manifest long after the neonatal period, shows male predominance, and frequently occurs without evidence of consanguinity or partial defects in the parents. The degree of clinical or laboratory hypothyroidism may vary but radioiodide uptake is low or absent. The diagnosis is based on the failure to concentrate iodide in salivary or gastric secretions on the one hand, and the attainment of the euthyroid state by iodide replacement alone. Limited evidence suggests that the defect is due to the absence or malfunction of the iodide carrier. The ion exchange basis of thyroidal anion selectivity dictates certain properties for the hypothetical iodide carrier which are dicussed. Introduction The concept that iodide transport is an independent step in the biosynthesis of the thyroid hormones was first...

Potassium iodide in erythema nodosum and other erythematous dermatoses

Abstract: Potassium iodide therapy has a history of more than 150 years. It has been tried in many diseases in the past. However, with the development of modern medications indications for potassium iodide therapy are very limited. It is well known that potassium iodide is the drug of choice for sporotrichosis. Subacute nodular migratory panniculitis and erythema nodosum have also been treated successfully with this drug.

Use of adjunctive potassium iodide after radioactive iodine (131I) treatment of Graves' hyperthyroidism.

Abstract: One hundred and nineteen patients with Graves' hyperthyroidism who were treated with 131I alone or 131I followed by potassium iodide (131I + KI) were studied retrospectively. Patients in both groups who required only a single dose of 131I for successful treatment of hyperthyroidism had similar age, gland size, 24-h radioactive iodine uptake, pretreatment serum T4 concentrations, and radioactive iodine treatment dose. Seven weeks after 131I, mean serum T4 concentrations were 12.3 +/- 6.1 micrograms/dl (mean +/- SD) in patients who received 131I alone and 8.0 +/- 3.9 micrograms/dl in patients who received 131I + KI (p less than 0.001). Sixty percent of the patients who received 131I + KI and remained euthyroid 1 yr after 131I treatment developed documented transient hypothyroidism while receiving KI (serum T4, 1.4 +/- 0.9 micrograms/dl). Patients with transient hypothyroidism receiving KI had larger estimated thyroid gland weights when hypothyroid than patients whose hypothyroidism was permanent (32 +/- 6 vs. 16 +/- 11 g; P less than 0.001). The overall incidence of hypothyroidism 1 yr after treatment with 131I was 58% in each of the two groups. Sixteen percent of each group were not successfully treated by a single dose of 131I and required further therapy. Adjunctive KI effectively treated thyrotoxicosis more rapidly than 131I alone without adversely affecting outcome at 1 yr; however, patients taking KI more often develop transient hypothyroidism.

Evidence that Organic Iodine Attenuates the Adenosine 3″,5″-Monophosphate Response to Thyrotropin Stimulation in Thyroid Tissue by an Action at or near the Adenylate Cyclase Catalytic Unit*

Abstract: Studies were conducted to define more clearly the site in the thyroid adenylate cyclase complex at which iodine exerts its inhibitory effect on activation of this enzyme by TSH. Iodine- and TSH-induced desensitization were additive. Dissociation was observed between the rates of recovery from TSH-and iodine-induced desensitization. Cycloheximide (10–4 M)prevented recovery from the inhibitory effect of iodine on thyroid adenylate cyclase activation. Preincubation of freshlyisolated dog thyroid follicles in 10–4 M iodide decreased the subsequent cAMP response to cholera toxin (0.5 μg/ml)stimulation. This effect of iodide was prevented by 3 mM methimazole. Thyroid adenylate cyclase regulatory protein (Ns) activity was assessed by the ability of detergent extracts of thyroid plasma membranes to reconstitute adenylate cyclase responsiveness to isoproterenol in N-deficient S49 eye– plasma membranes. Thyroid Ns activities were similar in control and iodide-pretreated thyroid cells. The inhibitory effect of iodin...

New myocardial imaging agents: stabilization of radioiodine as a terminal vinyl iodide moiety on tellurium fatty acids

Abstract: To determine the myocardial uptake and retention properties of radioiodinated tellurium fatty acids, we prepared two new tellurium fatty acids in which iodine-/sup 125/ has been chemically stabilized by attachment as a trans-vinyl iodide (I-CH . CH-R-Te-R'-COOH) and evaluated them in rats. Fabrication of 18-iodo-13-tellura-17-octadecenoic acid was accomplished by coupling 1,5-diiodo-1-pentene with sodium 12-(methoxycarbonyl)-n-dodecan-1-yl telluride. The (5-/sup 125/I)-1,5-diiodo-1-pentene was prepared by an organoborane technique involving /sup 125/I+ treatment of 5-iodo-1-penten-1-ylboronic acid (I(CH/sub 2/)/sub 3/CH . CHB(OH)/sub 2/). The absolute heart uptake of this agent was moderate (1.47-2.52% dose/g after 60 min), but the heart/blood ratios were low (approximately 2.6:1). Only marginal in vivo deiodination occurred, since the thyroid uptake was low (15-18% dose/g after 60 min). The effect of tellurium in position 13 was unexpected. To determine if the low heart specificity and low heart/blood ratios were dependent upon the position of the tellurium, we prepared an analogue with the same chain length, 18-(/sup 125/I)iodo-7-tellura-17-octadecenoic acid, in the same manner by reaction of (11-/sup 125/I)-1,11-diiodo-1-undecene with sodium 6-(methoxycarbonyl)-n-hexan-1-yl telluride. This agent showed pronounced heart uptake (2.47-3.94% dose/g after 60 min) and prolonged retention (1.76-3.14% dose/g after 4 h) in rats. Furthermore, the heart/blood ratios remained high for several hours (13:1more » after 60 min; 9:1 after 4 h). Iodine-123 labeled 18-iodo-7-tellura-17-octadecenoic acid is an attractive new compound for evaluation as a myocardial imaging agent.« less

Influence of chemical forms on iodine uptake by plant.

Abstract: Uptake of iodide and iodate by komatsuna, Brassica Rapa var. pervidis, was studied using culture solution containing radioiodine as a tracer. After 24 hours'' exposure, accumulation of iodide in the plant was several times higher than that of iodate. The concentrations of both iodide and iodate in roots were much higher than those in shoots. It was estimated that high accumulation of iodide in roots was due to the adsorption of the element on the root surface. The plant of the earlier growth stage absorbed iodide selectively from the solution. On the contrary that of the older growth stage, more than 40 days after seeding, showed less absorption of the element. Influence of stable iodine content on the uptake of radioiodine was also examined. The transfer rate of radioactive iodide to roots decreased remarkably with increasing amount of stable iodide in the culture solution, whereas that to shoots remained relatively constant indicating that the element content in shoots increased almost proportionally with the increasing concentration of stable iodine in the solution. A significant amount of iodate in the culture solution was transformed to iodide in the presence of plant. The dominant chemical form of iodine in the plant was thought to be iodide.

The Determination of Iodine in Milk and Milk Chocolate by Anion HPLC

Abstract: An HPLC method is described for the extraction and analysis of iodine as iodide in milk, cocoa beans and milk chocolate. Prior to analysis samples are finely ground if necessary and combusted in a modified Shoeninger flask. The liberated halide is absorbed in a basic reducing medium which is concentrated and brought to volume with distilled water prior. HPLC analysis used an 8 mm 5μ C18 cartridge in a RCM-100 with detection of the iodide ion at 226 nm. The mobile phase consisted of an ion-pairing agent, buffer and acetonitrile. The method is accurate and precise showing reasonable agreement with a National Bureau of Standards spray dried milk sample.

Nylon composition for use in rotational molding

Abstract: A rotational moldable polyamide composition, a method of preparing the composition, and a method of rotational molding. The composition contains from about 0.001 percent to about 0.5 percent by weight of a copper compound, preferably cuprous iodide. Preferably, the composition contains from about 0.001 percent to about 0.3 percent by weight of potassium iodide.

Germicidal solutions effective for solid surface disinfection

Abstract: A germicidal solution effective for disinfection of solid surfaces to destroy or to inactivate bacteria, microorganisms, protozoa, molds and viruses and the like contaminating said surfaces which comprises a polyvinylpyrrolide-aqueous solution of elemental iodine, a water-soluble iodide, and potassium bromide, said solution containing a sufficiently high concentration of elemental iodine to effect said destruction or inactivation.

Reduction of Organic Sulfonic Acids, Sodium Sulfonates, and Sulfonic Esters to the Corresponding Disulfides with Polyphosphoric Acid Derivatives, Potassium Iodide and Tetrabutylammonium Iodide System

Abstract: Organic sulfonic acids, sodium sulfonates, and alkyl sulfonates were readily reduced to the corresponding disulfides in moderate yields upon treatment with a mixture of a polyphosphoric acid derivative and iodide. In these reactions, formation of mixed anhydrides each having a P–O–S linkage is the key step, and subsequent attack of iodide on the sulfur atom gives the corresponding sulfonyl iodides which are reduced further exothermally to the disulfides with hydrogen iodide. Actually, p-toluenesulfonyl chloride was isolated in the reaction of p-toluenesulfonic acid and polyphosphoric acid derivatives with chloride ion. The competitive reduction of various aromatic sulfonic acids reveals that an aromatic sulfonic acid bearing an electron-donating para-substituent is more readily reduced to the disulfide than that which has an electron-withdrawing para-substituent.

Reaction of fluorine atoms with alkyl iodides: a possible observation of the Walden inversion in the gas phase

Abstract: Evidence is presented to show that The Walden Inversion does take place in these gaseous reactions. CO/sub 2/ laser radiation of a mixture of SF/sub 6/ and alkyl iodides at equal pressures dissociated the SF/sup 6/ to F and SF/sup 5/. One ..mu..s later, the alkyl iodides were dissociated by a pulse from a dye laser. The experiment was repeated at 5 Hz. The resulting fluorescence intensities at 304.7 nm and 306.7 nm for I/sup */ atoms and excited I atoms are shown for methyl, ethyl, isopropyl, and tert-butyl iodide. From the relative intensities produced, conclusions can be drawn that a tertiary iodide does not produce any iodine atoms, while a primary iodide produces many more. Tests were performed to show that the iodine atoms were not photodissociated from the alkyl iodide cy the CO/sub 2/ laser or by 2-photon dissociation by the dye laser of the radical products of competing reactions. In the absence of SF/sub 6/, CO/sub 2/ laser pulses did not produce additional I atoms. 1 figure.

Total diet study: determination of iodine intake by neutron activation analysis.

Abstract: The daily intakes of iodine by adults, infants, and toddlers (approximately 400 μg. per day) exceeded the RDAs. Moreover, these diets did not include discretionary iodized salt.

Copper texturing process

Abstract: The invention is a room-temperature dry process for texturing copper on polyester, to improve adhesion of coatings to the copper surface through mechanical as well as chemical bonding. An iodine plasma is produced by backfilling an evacuated chamber with iodine and applying an RF potential. The iodine plasma includes both positive and negative iodine ions. Unprotected surface areas of the copper form a copper iodide; when the copper iodide is removed, the remaining surface is highly textured. The associated polyester is not damaged. The copper iodide is conveniently removed by a 10% hydrochloric acid solution which has no damaging effects on the associated polyester or on the metallic copper, or on associated polyester in a plastic laminated with copper.

Determination of selenium, arsenic, iodine and bromine in fish, plant and mammalian oils by cyclic instrumental neutron activation analysis

Abstract: The concentrations of arsenic, selenium, iodine and bromine in a series of fish, plant and mammalian oils have been determined by cyclic instrumental neutron activation analysis (CINAA). Crude fish oils contain between 0.047 and 0.151 μg Se g−1, 2.36–14.5 μg As g−1, 2.36–9.63 μg Br g−1 and 0.97–4.76 μgI g−1. Seal oil contains the same four elements, but at levels below the lower end of the fish oil ranges. Iodine, bromine and arsenic were not detected in rape-seed or soybean oils and the concentration of selenium varied from < 0.010 to 0.042 μg g−1. The levels of selenium, iodine and bromine are reduced markedly by hydrogenation of the menhaden oils. The CINAA method yielded results which were in agreement with pub-lished values obtained by other methods. The technique was rapid, requiring minimal sample manipulation, and was essentially free from interferences.