Showing papers on "Iodine published in 1969"

Antifungal Effects of Peroxidase Systems

Abstract: In the presence of hydrogen peroxide and either potassium iodide, sodium chloride, or potassium bromide, purified human myeloperoxidase was rapidly lethal to several species of Candida. Its candidacidal activity was inhibited by cyanide, fluoride, and azide, and by heat inactivation of the enzyme. A hydrogen peroxidegenerating system consisting of d-amino acid oxidase, flavine-adenine dinucleotide, and d-alanine could replace hydrogen peroxide in the candidacidal system. Horseradish peroxidase and human eosinophil granules also exerted candidacidal activity in the presence of iodide and hydrogen peroxide; however, unlike myeloperoxidase or neutrophil granules, these peroxidase sources were inactive when chloride replaced iodide. Cells of Saccharomyces, Geotrichum, and Rhodotorula species, and spores of Aspergillus fumigatus and A. niger were also killed by the combination of myeloperoxidase, iodide, and hydrogen peroxide. Peroxidases, functionally linked to hydrogen peroxide-generating systems, could provide phagocytic cells with the ability to kill many fungal species.

Induction of myxedema by iodide in patients euthyroid after radioiodin or surgical treatment of diffuse toxic goiter.

Abstract: In all 10 patients with diffuse toxic goiter of Graves disease rendered euthyroid by radioiodine six months to six years earlier, myxedema (as evidenced by typical signs and symptoms, rises in serum TSH and cholesterol concentrations and decrease in serum thyroxine into the hypothyroid range) developed after small, pharmacologic doses of iodide. Of seven similar patients who had been treated surgically, frank hypothyroidism developed in two, one remained entirely unchanged, and the remaining four displayed slight abnormalities in serum thyroxine or TSH concentrations without overt hypothyroidism. The thyroid gland in Graves disease appears to be inherently susceptible to the induction of iodide myxedema, and such susceptibility may be enhanced or its demonstration facilitated by radioiodine treatment.

Changing normal values for thyroidal radioiodine uptake.

Abstract: Determinations of 24-hour thyroidal radioiodine uptake were made on 63 euthyroid subjects in 1959 and by the same method on 53 euthyroid subjects in 1967–68. The uptake was 28.6 ± 6.5 per cent in 1959 and 15.4 ± 6.8 per cent in 1967–68 (mean ± S.D.). The low values currently seen reflected a large intake of iodine in the subjects, who displayed elevated urinary iodine excretions and plasma inorganic iodide concentrations, and depressed thyroidal iodide clearances. Food analyses revealed the diet to be very rich in iodine, and bread to be a major contributor of this substance to the diet. Further investigation showed that the process used for the commercial manufacture of bread was changed in the interval between the two studies and that the present method includes large quantities of iodine. About half the commercial white pan bread in the United States is now made by this process.

Thyroid Iodine Content and Turnover in Euthyroid Subjects: Validity of Estimation of Thyroid Iodine Accumulation from Short-Term Clearance Studies

Abstract: Measurements of thyroidal (k1) and renal (k2) radioiodine clearances, urinary iodine excretion (qe) and fractional thyroidal radioiodine release rate (αk) were conducted in 18 euthyroid young adult subjects in presumed iodine equilibrium, enabling the thyroid iodine accumulation (A) to be calculated. Thyroid iodide content (TI) was also calculated as: Mean thyroid iodine content assessed in this way (14.9 mg) was in good agreement with thyroid iodine content measured chemically (15 mg) in 8 young adult victims of accidents. These data suggest validity of A estimated in this way.

Lead Intoxication and the Thyroid

Abstract: Thyroid function has been studied in 24 patients judged to have saturnism on the basis of their urinary excretion of lead following an infusion of edetate calcium disodium. Following administration of sodium iodide I 131 the mean 24 hour 131 I uptake for 23 was 10.0% ± 3.7% SD. A single patient had an uptake of 26.1%. All but three patients responded normally to stimulation with thyroid stimulating hormone. Of two patients studied, one had a decreased secretion of thyroxine by the thyroid. Other measures of thyroid function were normal in the group. The findings are consistent with injury of the iodine concentrating mechanism of the thyroid.

Formation of iodoprotein during the peripheral metabolism of 3,5,3'-triiodo-L-thyronine-125I in the euthyroid man and rat.

Abstract: 3,5,3'-Triiodo-L-thyronine-(125)I (T3-(125)I) metabolism was studied in nine euthyroid human subjects on blocking doses of nonradioactive iodide. After the intravenous injection of T3-(125)I, the fractional disappearance rate of plasma radioactivity progressively disappearance rate of plasma radioactivity progressively decreased with time. Analysis of individual plasma samples by dialysis, electrophoretic, and extraction techniques revealed three radioactive components: T3-(125)I, iodide-(125)I, and an unidentified material which was nonextractable in acid butanol (NE(125)I). Ne(125)I rose to maximal levels 24-36 hr after injection of T3-(125)I and then decreased with a fractional rate which approached, after 12-14 days, approximately 0.05 day(-1) (t(1/2) = 14 days). The plasma T3-(125)I concentration, obtained by subtraction of iodide-(125)I and NE(125)I from the plasma total (125)I, declined at a constant fractional rate with time with a t(1/2) of 1.5 days. Qualitatively similar results were obtained in rats. After 72 hr, 57% of the plasma and 40% of the liver radioactivity was NE(125)I. Chromatographic purification of the T3-(125)I before injection did not alter these results. The extrathyroidal origin of NE(125)I was further demonstrated by similar results in thyroidectomized rats maintained on thyroxine. NE(125)I from human sera separated from the other radioiodinated substances by ion-exchange chromatography was quantitatively precipitated by trichloracetic acid, not dialyzable, insoluble in CHCl(3):CH(2)OH, and migrated with albumin during starch-gel electrophoresis. Based on these properties, NE(125)I was tentatively identified as iodoalbumin. Observations in rats equilibrated with (125)I, as well as nonradioactive iodine determinations in human sera before and after acid butanol extraction, indicate that 10-20% of the serum organic iodine is in the form of iodoprotein. Our studies suggest that this moiety may be derived at least in part from the peripheral metabolism of the thyroid hormones.

The subcellular distribution of 32P-labelled phospholipids, 32P-labelled ribonucleic acid and 125I-labelled iodoprotein in pig thyroid slices. Effect in vitro of thyrotrophic hormone and dibutyryl-3′,5′-(cyclic)-adenosine monophosphate

Abstract: 1. The incorporation in vitro of [32P]phosphate into phospholipids and RNA and of [125I]iodide into protein-bound iodine by pig thyroid slices incubated for up to 6hr. was studied. The subcellular distribution of the labelled products formed after incubation with radioactive precursor in the nuclear, mitochondrial, smooth-microsomal, rough-microsomal and cell-sap fractions was also studied. 2. Pig thyroid slices actively took up [32P]phosphate from the medium during 6hr. of incubation; the rate of incorporation of 32P into phospholipids was two to five times that into RNA. 3. The uptake of [125I]iodide by the slices from the medium was rapid for 4hr. of incubation, 6–10% of the label being incorporated into iodoprotein. 4. Much of the 32P-labelled phospholipid accumulated in mitochondria and microsomes, whereas the nuclear fraction contained most of the 32P-labelled RNA. After 2hr. of incubation most of the 32P-labelled cytoplasmic RNA accumulated in the rough-microsomal fraction. The major site of localization of proteinbound 125I was the smooth-microsomal fraction, and gradually increasing amounts appeared in the soluble cytoplasm fraction, suggesting a vectorial discharge of [125I]iodoprotein (presumably thyroglobulin) from smooth vesicles into the colloid. 5. The addition of 0·1–0·4 unit of thyrotrophic hormone/ml. of incubation medium markedly enhanced the accumulation of 32P-labelled phospholipids in the microsomal fractions and to a much smaller extent that of 32P-labelled RNA without any increase in the total uptake of the label. Almost simultaneously the hormone increased the uptake of [125I]iodide by the slices and enhanced the accumulation of protein-bound 125I in the smooth-microsomal fraction. 6. As a function of time of incubation, thyrotrophic hormone had a biphasic effect on [125I]iodide uptake and protein-bound 125I formation, the stimulatory effect being reversed after 4hr. of incubation. 7. 6-N-2′-O-Dibutyryl-3′,5′-(cyclic)-AMP, but not 3′,5′-(cyclic)-AMP or 5′-AMP, mimicked the action of thyrotrophic hormone on iodine uptake as well as on iodination of protein. On the other hand, the mimicry by 6-N-2′-O-dibutyryl-3′,5′-(cyclic)-AMP of the stimulatory effect of thyrotrophic hormone on the formation of labelled thyroid phospholipids and RNA was only an apparent one resulting from an enhanced uptake of [32P]phosphate. 8. It is concluded that thyrotrophic hormone causes a co-ordinated increase in the formation or accumulation of phospholipids, RNA and iodoprotein associated with the endoplasmic reticulum, and that 6-N-2′-O-dibutyryl-3′,5′-(cyclic)-AMP mimics the more rapid effects of thyrotrophic hormone on transport and metabolic functions of thyroid cells, but does not influence their slower biosynthetic responses to the hormone.

Thyroxine metabolism and thyroid function in the cold-adapted rat.

Abstract: Thyroid function and thyroxine (T4) metabolism were assessed in rats maintained at 4 or 22 C for at least 3 months. In the coldadapted rat, thyroidal uptake of iodine was increased up to 3-fold. Since total glandular iodine was unchanged, thyroid secretion rate was presumed to be similarly increased. The metabolism of T4 was studied in rats (KC104-treated to prevent 131I uptake by the thyroid) iso topically equilibrated with 131I-T4 of known specific activity. Cold-adapted rats excreted less iodide in urine than did controls, when receiving twice the dose of T4, and not significantly more than controls when given 4 times the dose, although the latter dose raised the serum T4 level above normal. The apparent reduction in the rate of deiodination was not due to changes in the intrinsic deiodinating activity of tissues, or to changes in the T4-binding activity of serum. Total and free T4 levels were not altered. The total turnover of T4 was increased due to a marked increase in the clearance from plasma thro...

Iodine Balance Studies in Nongoitrous Children and in Adolescents on Low Iodine Intake

Abstract: Iodine balance studies have been performed on short-term periods of time in 26 nongoitrous children and adolescents on a relatively low iodine intake (32±1.94 μg/day). Although these studies correspond to 141 patient days, the results of these balances appear to be systematically negative, with a mean value of −23.8±2.64 μg I/day. In 7 fasting subjects of this group, the mean thyroid clearance was 24.6 ml/min and the plasma inorganic iodine 0.108 μg/100 ml; the absolute iodine uptake averaged 31.1 μg I/day.

System for total iodine retention

Abstract: A method of absorbing and retaining air-borne inorganic iodine and organic iodine species by passing a gaseous stream containing these iodines through a filter bed of synthetic zeolite in a metal ion-exchanged form, which metal is reactive with iodine

Light Induced Changes in the Conductivity of Thin Lipid Membranes in the Presence of Iodine and Iodide Ion

Abstract: SINCE the announcement by Mueller et al.1 of a technique for forming thin (<100 A) lipid membranes separating two aqueous phases, there has been a growing interest in the permeability of these films to ions, neutral solutes and water. In the absence of any modifying agents, the membranes have resistances of approximately 108 Ω cm2 in 0.1 M salt solutions1. In the presence of both iodine and iodide ions, the membrane resistance falls to values of 104 Ω cm2 or lower2,3. In this state the membrane behaves as an ideal iodide ion electrode. The current carriers in the membrane appear to be polyiodides (for example, I5−), which, because of their large size and delocalized charge, have sufficient solubility in the low dielectric constant, hydrophobic interior of the membrane to enter this phase. We have now found that in this state the membrane responds to brief pulses of light in the near ultraviolet with a fast (rise time < 40 µs) decrease in conductance (1 per cent) followed by a recovery of the conductance to its original value with a time course measured in milliseconds.

Osmium tetroxide-zinc iodide reactive sites in the photoreceptor cells of the retina of the rat.

Abstract: The osmium tetroxide-zinc iodide fixative of Champy-Maillet has been used to study the rat's retina at the electron microscope level. Electron opaque deposits were observed all along the photoreceptor cells and concentrated in the outer segments of rods and cones and in the nerve endings. In the outer segments that deposits are located in the inter and intra disk spaces as well as between the disk and outer membranes. In the outer plexiform layer reactive sites include synaptic vesicles and mitochondria; other minor reactive sites are described in the inner segment and inner plexiform layer. Electron opaque deposits were not seen if potassium iodide substitutes zinc iodide in the fixative. However, if osmium tetroxide-potassium iodide fixed retinae are immersed in osmium tetroxide-zinc iodide the characteristic electron-dense material is evidenced at those same sites. The effect of other several fixatives were studied with a similar “double” fixation procedure. Our finding points to the histochemical demonstration of an unidentified component (s) of the retina which shows a striking specificity of localization and which is made evident when zinc iodide is used in the Champy-Maillet mixture.

The Demand for Iodine and Bromine of three Marine Brown Algae grown in Bacteria‐free Cultures

Abstract: Three marine brown algae have been cultivated with different additions of iodine and bromine in bacteria-free cultures. Ectocarpus jasciculatus appeared to have an absolute demand for iodine and was inhibited by a concentration of 64 μmol of KJ per 1. Lithosiphon pusillus had the best growth in the highest concentration tested (64 μmol/1) but there was always some growth in the series without iodine. Additions could be made either as inorganic iodine or as organically bound iodine. Additions of KJ to a culture medium consisting of vitamin-free Asp 6 F with B12 (1 μg/1) and kinetin (20 μmol/1) remarkably increased the growth of the zoospores of Pylaiella litoralis. Lithosiphon pusilius proved to be indifferent to bromide additions in media containing KJ. In media lacking KJ addition of 1 μmol of KBr per 1 is stimulating but higher concentrations of KBr are inhibiting. The inhibiting effect is overcome by iodide addition.

Studies on the syntheses of heterocyclic compounds. Part CCCII. Alternative total syntheses of (±)-nandinine, (±)-canadine, and berberine iodide

Abstract: Mannich reaction of 1-(2-bromo-5-hydroxy-4-methoxybenzyl)-1,2,3,4-tetrahydro-6,7-methylenedioxyisoquinoline (IX) gave 12-bromonandinine (II) which was debrominated to afford (±)-nandinine (I). Methylation of (±)-nandinine with diazomethane gave (±)-canadine (III), dehydrogenation of which with iodine afforded berberine iodide (XI).

Pulses in Iodide Concentration during the Periodic Decomposition of Hydrogen Peroxide

Abstract: WE have discovered marked pulses in the concentration of iodide ions, [I−], during the periodic decomposition of hydrogen peroxide in the acidic reaction system comprising iodine, iodate and intermediate compounds1–3. In one experiment, two sections of which are shown in Fig. 1, seventy-two pulses were recorded in the potential of an electrode selective for iodide ion (Model 94–53, Orion Research Inc., Cambridge, Mass.). Pulses in the rate of oxygen evolution, (dO2/dt), were simultaneously recorded as the electrical output of a mass flowmeter (model LF–20; Matheson and Co., East Rutherford, N.J.).

A comparison between the gastric and salivary concentration of iodide, pertechnetate, and bromide in man

Abstract: The concentration of iodide (I−) and pertechnetate (TcO4−) and bromide (Br−) has been measured simultaneously in gastric juice and parotid saliva The combined gastric and salivary clearance for iodide and pertechnetate is more than twice the clearance of these ions by the thyroid gland The concentration of the ions was in the order I−>TcO4−>Br− in both gastric juice and saliva Differences exist between the secretion of iodide, pertechnetate, and bromide Bromide, in contrast to iodide and pertechnetate, was found to be more concentrated in gastric juice than in saliva The ratio of the iodide to pertechnetate clearance was greater in gastric juice than in saliva

Mechanism of antifungal action of potassium iodide on sporotrichosis.

Abstract: From past experience, it has been known that potassium iodide is a highly effective agent in the treatment of sporotrichosis, failing only in widely disseminated cases. However, no experimental or theoretical evidence has been presented to substantiate this knowledge, as potassium iodide has practically no fungistatic effect i)i vitro on Sporofrichum schenckii, the causative agent of this disease.

Effects of epinephrine and of alteration in glandular blood flow upon thyroid function: studies using thyroid vein cannulation in dogs.

Abstract: The effects of systemically infused epinephrine were studied by the thyroid vein cannulation technique in dogs whose thyroid iodine stores had been prelabeled with 131I. Epinephrine resulted in great reduction of thyroid blood flow and simultaneous comparable increase in thyroid veno-arterial plasma concentration difference (V-A) for PB131I; as a consequence, the thyroid secretion rate of hormonal iodine was relatively unchanged from control values, and in no case was secretion rate increased during infusion. The V-A for radioiodide derived from intraglandular deiodination also increased under these conditions, but,as in the case of hormonal iodine, release rate per min did not increase. Reduction of thyroid blood flow ininduced by controlled hemorrhage produced changes similar to epinephrine, i.e., increased V-A for both PB131I and mI-iodide generated in the gland, without great change in their release rate per min. Studies of glandular clearance of circulating iodide (125I) under these conditions reveal...