Stable Iodide Research Articles

Risk perception of the pre-distribution of stable iodine to guardians of children living around the Genkai Nuclear Power Plant, Saga Prefecture, Japan.

Iodine thyroid blocking (ITB) is effective for preventing childhood thyroid cancer when radioactive iodine is released into the environment during a nuclear power plant accident. Japan employs the pre-distribution of stable iodine (PDSI) to residents living near nuclear power plants; however, the number of residents who have actually received stable iodine to date remains limited. The aim of this study was to evaluate the profile of guardians of children living around the Genkai Nuclear Power Plant (GNPP) in Japan. We distributed self-administered questionnaires regarding perception of risks associated with administration of stable iodide to approximated 400 guardians of children aged 0–6 in 10 kindergartens located in four municipalities. We obtained responses from 286 guardians, and after excluding invalid responses, 247 were included in the analysis. Logistic regression analysis revealed that living within 5 km of the GNPP (odds ratio [OR] = 4.48, 95% confidence interval [CI]: 2.43–8.24), awareness of preferential implementation of ITB to children (OR = 3.33, 95%CI: 1.78–6.22), and awareness of the prophylaxis booklet published by the local government (OR = 2.53, 95%CI: 1.37–4.68) were independently associated with PDSI for children. The main reasons for not receiving PDSI were “anxiety about the side effects of stable iodine” (40.2%), “distrust of the effectiveness of SI” (23.5%), “complicated procedures for receiving stable iodine” (15.7%) and “missed the date for receiving stable iodine” (8.8%). In the case of ITB implementation during a nuclear emergency, it is necessary to clarify the risk perceptions of guardians and adapt risk communication accordingly.

Shallow Iodine Defects Accelerate the Degradation of α-Phase Formamidinium Perovskite

Summary Shallow defects are mostly benign in covalent semiconductors, such as silicon, given that they do not constitute non-radiative recombination sites. In contrast, the existence of shallow defects in ionic perovskite crystals might have significant repercussions on the long-term stability of perovskite solar cells (PSCs) because of the metastability of the ubiquitous formamidinium lead triiodide (FAPbI3) perovskite and the migration of charged point defects. Here, we show that shallow iodine interstitial defects ( I i ) can be generated unintentionally during commonly used post-fabrication treatments, which can lower the cubic-to-hexagonal transformation barrier of FAPbI3-based perovskites to accelerate its phase degradation. We demonstrate that concurrently avoiding the generation of I i and the more effective passivation of iodine vacancies ( V I ) can improve the thermodynamic stability of the films and operational stability of the PSCs. Our most stable PSC retained 92.1 % of its initial performance after nearly 1,000 h of continuous illumination operational stability testing.

A systems biology approach to propose a new mechanism of regulation of repetitive prophylaxis of stable iodide on sodium/iodide symporter (NIS)

Our group showed that repetitive dose of potassium iodide (KI) for eight days offers an efficient protection for exposure to repeated radioactive emissions without adverse effects on adult rats. However, differential expression of genes implicated in Wolff-Chaikoff effect was observed. To understand the Wolff-Chaikoff regulation and its molecular constituents during repetitive administration of KI, a biochemical reaction network was constructed as a “geographical” map of the thyrocyte depicting iodide and thyroid hormone synthesis. Path analysis of the network has been performed to investigate the presence of a regulatory circuit of the node iodide to the node “nis transcription”. NIS is responsible for the uptake of KI and plays an important role in the Wolff-Chaikoff effect. The map is a source for the most updated information about iodide and thyroid hormone metabolism. Based on this map, we propose a hypothesis that shows a putative mechanism behind NIS regulation and KI uptake.

Pharmacological study of stable potassium iodide (KI) repeated prophylaxis in adult rats

Pharmacological study of stable potassium iodide (KI) repeated prophylaxis in adult rats

A putative mechanism of the Sodium/Iodide Symporter regulation during repetitive administration of stable Iodide described by a Systems Biology approach

A single dose of potassium iodide (KI) against a prolonged exposure to repeated radioactivity might not be effective enough to protect the thyroid. Our group have shown that a repetitive dose of KI for eight days offers efficient protection without adverse effects in male rats [1].

Stable iodide doping induced by photonic curing for carbon nanotube transparent conductive films

Doping has become crucial for achieving stable and high-performance conductive transparent carbon nanotube (CNT) films. In this study, we systematically investigate the doping effects of a few materials including alkali metal iodides, nonmetal iodide, and metals. We demonstrate that photonic curing can enhance the doping effects, and correspondingly improve the conductivity of CNT films, and that such iodides have better doping effects than metals. In particular, doping with a nonmetal compound (NH4I) shows the largest potential to improve the conductivity of CNT films. Typically, doping with metal iodides reduces the sheet resistance (RS) of CNT films with 70–80% optical transmittances at λ = 550 nm from 600–2400 to 250–440 Ω/square, whereas doping with NH4I reduces RS to 57 and 84 Ω/square at 74 and 84% optical transmittances, respectively. Interestingly, such a doped CNT film exhibits only a slight increase in sheet resistance under an extreme environment of high temperature (85 °C) and high relative humidity (85%) for 350 h. The results suggest that photonic-curing-induced iodide doping is a promising approach to producing high-performance conductive transparent CNT films.

On the possibility of preparing stable silver iodide nanosols in the presence of chitosan used as a polymer stabilizer

The effect of preparation conditions for positively and negatively charged silver iodide sols on the particle size and number concentration has been determined. It has been found that the preparation of a mixture of precursors with a concentration of 0.01 mol/L at a KI to AgNO3 volume ratio of 10: 7 or 7: 10 leads to the formation of a large number of small particles (on the order of 50–60 nm) corresponding to the range of true colloidal systems with a maximum interfacial area. The presence of a polymer stabilizer–chitosan–leads to a significant improvement of the stability of the sol particles, which makes it possible to use the resulting polymer-colloidal dispersions containing nanoparticles of silver iodide sols to design hybrid materials for biomedical applications.

Influence of iodine supply on the radiation-induced DNA-fragmentation

The protective effect of stable iodide against radiation on thyroid cells was investigated. One physiological effect of stable iodine is well-rooted: stable iodine leads to a reduced thyroid uptake of radioactive iodine. This work wants to focus on an intrinsic effect of stable iodine by which DNA-damage in cells is prevented.To investigate this intrinsic effect thyroid cells (FRTL-5) were externally irradiated by use of a linear accelerator (LINAC) applying energy doses of 0.01 Gy–400 Gy and by incubation with various activity concentrations of 131I (0.1–50 MBq/ml for 24 h). We added stable iodine (NaI) to the cells prior to external irradiation and investigated the effect of the concentration of stable iodine (1, 5, 15 μg/ml). In order to clarify whether thyroid cells have a distinctive and iodine-dependent reaction to ionizing radiation, keratinocytes (HaCaT) without NIS were exposed in the same way. As indicators for the cellular reaction, the extent of DNA fragmentation was determined (Roche, Mannheim, Germany).Both cell types showed distinct ability for apoptosis as proven with camptothecin. The addition of “cold” iodine from 1 to 15 μg/ml without irradiation (“negative control”) did not change the response in both cell types. Plausibly, the radio-sensitivity of both cell types did increase markedly with increasing radiation dose but the radiation effect is diminished if iodine is added to the thyroid cells beforehand. The DNA-damage in thyroid cells after addition of cold iodine is reduced by a factor of 2–3. The skin cells did not show an significant change of radio-sensitivity depending on the presence of cold iodine. Elementary iodine possibly acts as a radical scavenger and thus markedly reduces the secondary radiation damage caused by the formation of cytotoxic radicals. This intrinsic radioprotective effect of iodine is seen only in cells with NIS.

Acyl iodides in organic synthesis: XIII. Reaction of acyl iodides with nitrogen-containing heteroaromatic compounds

Reactions of acetyl iodide with pyridine at room temperature and with quinoline both at 20–25°C and on cooling to −50°C involve dehydrohalogenation of acetyl iodide with formation of ketene and pyridinium or quinolinium iodides. The reaction of acetyl iodide with pyridine at −5 to −50°C led to the formation of N-acetylpyridinium iodide. Benzoyl iodide reacted with both pyridine and quinoline at both −50°C and at 20–25°C to form stable N-benzoylpyridinium and N-benzoylquinolinium iodides. The reaction of pyrrole with acetyl iodide under analogous conditions was accompanied by polymerization.

Evaluation of Potassium Iodide (KI) and Ammonium Perchlorate (NH4ClO4) to Ameliorate 131I- Exposure in the Rat

Nuclear reactor accidents and the threat of nuclear terrorism have heightened the concern for adverse health risks associated with radiation poisoning. Potassium iodide (KI) is the only pharmaceutical intervention that is currently approved by the Food and Drug Administration for treating 131I- exposure, a common radioactive fission product. Though effective, KI administration needs to occur prior to or as soon as possible (within a few hours) after radioactive exposure to maximize the radioprotective benefits of KI. During the Chernobyl nuclear reactor accident, KI was not administered soon enough after radiation poisoning occurred to thousands of people. The delay in administration of KI resulted in an increased incidence of childhood thyroid cancer. Perchlorate (ClO4 -) was suggested as another pharmaceutical radioprotectant for 131I- poisoning because of its ability to block thyroidal uptake of iodide and discharge free iodide from the thyroid gland. The objective of this study was to compare the ability of KI and ammonium perchlorate to reduce thyroid gland exposure to radioactive iodide (131I-). Rats were dosed with 131I- tracer and 0.5 and 3 h later dosed orally with 30 mg/kg of either ammonium perchlorate or KI. Compared to controls, both anion treatments reduced thyroid gland exposure to 131I- equally, with a reduction ranging from 65 to 77%. Ammonium perchlorate was more effective than stable iodide for whole-body radioprotectant effectiveness. KI-treated animals excreted only 30% of the 131I- in urine after 15 h, compared to 47% in ammonium perchlorate-treated rats. Taken together, data suggest that KI and ammonium perchlorate are both able to reduce thyroid gland exposure to 131I- up to 3 h after exposure to 131I-. Ammonium perchlorate may offer an advantage over KI because of its ability to clear 131I- from the body.

Aspects of Intramolecularly Coordinated Organochalcogen Derivatives

Recent progress in the area of intramolecularly coordinated organochalcogens, in particular, organoselenium derivatives, is reviewed. Intramolecular coordination facilitates isolation of (a) stable organoselenenyl iodides, (b) chiral diselenides, (c) organotriselenides, d) cleavage of Te─C bond, e) metal-free synthesis of chalcogenaaza macrocycles, and f) isolation of cyclic selenenate esters. The synthesis of organoselenium compounds incorporating two ortho-coordinating groups is also discussed.

Negative ion mode matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometric analysis of oligosaccharides using halide adducts and 9‐aminoacridine matrix

9-Aminoacridine was established as a matrix for the detection of neutral oligosaccharides in negative ion mode matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry. Sodium iodide proved to be a useful additive inducing formation of stable iodide adducts of the analytes, in particular for oligosaccharides with a degree of polymerisation (DP) of three and higher. Lower oligomers (DP <3) and monosaccharides show more stable adducts with chloride ions. After optimisation of the sample preparation procedure, limits of quantitation were determined for alpha-cyclodextrin and cellopentaose at 7 and 13 pmol, respectively, with a linear detector response over two concentration orders. The iodide additive could be successfully employed on MALDI-TOF mass spectrometers with vacuum and atmospheric pressure ion sources. The value of the new method to solve biological problems has been demonstrated by the analysis of a mixture of beta-glucane elicitors isolated from the cell walls of Phytophthora sojae.

Hydrogen detachment of the hexahydrated hydroiodic acid upon attaching an excess electron

A hydroiodic acid molecule is dissociated by more than four water molecules. Here, the effect of an excess electron on the hexahydated hydroiodic acid where the dissociated structure [H3O+(H2O)5I−] is much more stable than the undissociated one [(H2O)6HI], is investigated. Upon binding an excess electron (e−), the cluster releases a hydrogen radical and forms the stable hexahydrated iodide [(H2O)6I−] when the initial kinetic energy is above ∼200 K, due to the small transition barrier (∼0.5 eV). The system with the hydrogen radical released, [(H2O)6I− + H·], is much more stable than the systems with an excess electron, [(H3O)+{e−(H2O)5}I−] or [e−(H2O)2(H3O)+(H2O)3I−].

Barriers in the quest for quality drug information: salutary lessons from TGA‐approved sources for thyroid‐related medications

Product information (PI) for thyroid-related medications endorsed by the Therapeutic Goods Administration, as reproduced in the commonly used compilation publications June 2006 MIMS (Monthly index of medical specialties) annual, MIMS Online and the Australian prescription products guide 2006, was evaluated to see whether it reflects contemporary therapeutic practice. Compared with current medical literature, these PI-based sources provide inadequate, inaccurate or outdated therapeutic directives. Examples include: Incorrect advice that thyroxine therapy should always begin at very low dosage. Failure to recommend increased thyroxine dosage early in pregnancy (thus placing the offspring of women being treated for hypothyroidism at risk of impaired fetal brain development). Incorrect and potentially unsafe advice to treat thyrotoxicosis with stable iodide in late pregnancy. Failure to advise serial adjustment of antithyroid drug dosage until after a patient becomes euthyroid (this can result in iatrogenic thyroid dysfunction). Outdated advice that antithyroid drugs are not compatible with breastfeeding. Recent initiatives to upgrade consumer medicine information (CMI) appear to accept PI-based sources as a reliable benchmark for CMI. That inference is not warranted for thyroid-related medications. Accountability for the updating of clinical information in PI needs to be defined, and the process for updating PI may need to be modified. Quality drug information, both PI and CMI, depends on fluent, evidence-based collaboration between suppliers, regulators, prescribers, specialist clinicians and consumers.

CALCIUM IODATE???ANOTHER EFFECTIVE BLOCKER OF RADIOIODINE UPTAKE BY THE THYROID GLAND

KI and KIO3 are the commonly used prophylactic drugs for the protection of thyroid glands against radioiodine. In this study, we have demonstrated the use of another iodine containing salt, calcium iodate [Ca(IO3)2], as an effective blocker of radioiodine uptake by the thyroid gland in rats. Ca(IO3)2 is permitted by the FDA as a food additive and is "generally regarded as safe" (GRAS, CFR No.1206). We have also compared the efficacy of Ca(IO3)2 with KIO3 in blocking thyroidal uptake of radioiodine, which could be important considering the better shelf life of Ca(IO3)2. Laboratory rats were administered 131I and stable iodide in the form of KIO3 or Ca(IO3)2 was given orally, 2 h after the administration of 131I. All the animals were monitored for whole body retention (WBR) of 131I, at 24 h and further for 14 d. The results of the present study provide us with evidence that Ca(IO3)2 can serve as another promising radioiodine blocker, and is as equipotent as KI/KIO3 in protecting the thyroid gland. We have not found any studies that examined the property of Ca(IO3)2 in blocking radioiodine uptake by the thyroid gland and the present study is an attempt in this direction.

Comparison betweenin situand laboratory diffusion studies of HTO and halides in Opalinus Clay from the Mont Terri

SummaryA long-term single-borehole diffusion experiment (DI) using tritiated water (HTO) and stable iodide (127I-) was carried out In the Opalinus Clay of the Mont Terri Underground Rock Laboratory (URL). Diffusion coefficientsDLand accessible porosity for HTO,36Cl-and125I-were also measured on centimetric Opalinus clay samples using the through diffusion technique. The evolution of tritium and iodide concentration in the injection system over time andin situprofiles were interpreted with a 3-D numerical simulation. A detailed analysis of the results pointed out the effect of a disturbed zone around the borehole with higher diffusion coefficients. The best estimate values for HTO and iodide in the undisturbed rock areDL= 5×10-11m2/s andDL= 1.5×10-11m2/s respectively. For the laboratory tests,DLvalues for HTO are in the range of 5×10-11m2/s to 8.5×10-11m2/s. For125I-and36Cl-the measured values areDL=νmber1.4×10-11andDL=1.6×10-11m2/s respectively.All HTO results obtained with a through diffusion technique are within the same range as those obtained in thein situtests. TheDLvalues obtained in diffusion cells with125I-and36Cl-and the value drawn from the interpretation of stable127I-concentration profiles from thein situtests are very close. In fact, some significant uncertainties could be identified (i.e.a likely chemical retention of iodide on argillites, effect of the disturbed zone).

Recombinant Human Thyroid-Stimulating Hormone

The major functions of pituitary thyroid-stimulating hormone (TSH) are to maintain the biosynthesis and secretion of the thyroid hormones L-thyroxine (T4) and L-3,5,3'triidothyronine (T3). The TSH core contains two apoproteins, the alpha and beta subunits. The alpha subunit is identical to that of pituitary follitropin, pituitary lutropin and placental chorionic gonadotropin, whereas the beta subunit is unique. TSH is a glycoprotein; the glycoprotein components of the alpha and beta subunits account for more than 10% of their mass and are essential for normal thyrotropic action and intravascular kinetics. The hypothalamic tripeptide, TSH-releasing hormone (TRH) is required for optimum TSH biosynthesis, particularly as far as addition of the glycoprotein components is concerned. TRH deficiency is associated with secretion of TSH molecules that are appropriately measured in most assays but have reduced bioactivity. In previous years the TSH used in clinical practice was obtained and purified from bovine pituitaries. Bovine TSH was used to test thyroid function and to augment the uptake of radioiodine in patients with thyroid cancer. Bovine TSH has been largely abandoned as a clinical agent because of adverse immune reactions. A recombinant human TSH (rhTSH; Thyrogen), has been approved by the US FDA for diagnostic use in patients with thyroid cancer. The alpha and beta subunits of Thyrogen are identical to those of human pituitary TSH. Thyrogen has a specific activity of approximately 4 IU/mg and is a potent stimulator of T4, T3 and thyroglobulin (Tg) secretion in healthy volunteers. It also increases thyroid iodide uptake in patients with thyroid cancer or multinodular goitre and in volunteers, even those exposed to large amounts of stable iodide. Thyroid cancer patients who have been treated by thyroidectomy and radioiodine ablation but are at risk of harbouring residual thyroid cancer are candidates for Thyrogen administration to prepare them for whole body iodide scans and serum Tg measurements. In thyroidectomised thyroid cancer patients who are unable to secrete pituitary TSH upon thyroid hormone withdrawal, Thyrogen is the only acceptable method to prepare them for these procedures. Thyrogen has been used on a compassionate basis to prepare patients for radioiodine ablation. rhTSH, in addition to being useful in the management of patients with thyroid cancer, is potentially useful to test thyroid reserve and to aid in thyroid-related nuclear medicine procedures. In the future, TSH analogues that have superagonist or antagonist properties may become available as therapeutic agents.

Can stable iodide influence radioactive iodide transport in breast tissue?

Can stable iodide influence radioactive iodide transport in breast tissue?

Thyroidal uptake and radiation dose after repetitive I‐131‐MIBG treatments: Influence of potassium iodide for thyroid blocking

In I-131-MIBG therapy, I-131-iodide can be released from the I-131-MIBG molecule. Hypothyroidism might result from the undesirable irradiation of the thyroid gland. To prevent this, stable iodide such as potassium iodide (KI) is given to oversaturate the thyroid before I-131-MIBG is administered. In the present study, the incidence of hypothyroidism (elevated TSH) was correlated with the thyroidal uptake of I-131 and dose (MIRD dosimetry) after 35 individual treatments in ten patients. Iodine-131-MIBG therapy was performed using a modified dosage of 1.9-11.1 GBq (50-300 mCi) IV. Premedication with KI was done as recommended with a dose of 100 mg KI orally from 2 days before until 4 weeks after I-131-MIBG. The absorbed thyroidal dose amounted to a very variable range of 0.2 (patient # 1) up to 30.0 (patient 3) Gy with 7.1 +/- 7.9 Gy per treatment and 24.1+/- 19.2 Gy per patient (mean+/- SD), despite the same and compliantly taken KI premedication protocol. Up to now, 4/10 or 40% of patients have developed hypothyroidism after a mean follow-up period of 11 months and a mean total administered dose of 18.7 GBq (505 mCi). A trend towards higher thyroidal doses was seen in the hypothyroid patients. This study observes a general high inter- and intra-individual variability in radio-iodide uptake in the thyroid after I-131-MIBG therapy despite KI premedication, as well as possible occurrence of hypothyroidism. A dose-response relationship needs confirmation on a larger cohort of patients to reach statistical value. An alternative thyroid cytoprotection strategy for possible long-term survivors may be considered.

Similarities and differences between free 211At and 125I− transport in porcine thyroid epithelial cells cultured in bicameral chambers

The transport and accumulation of free 211At and 125I− were investigated in thyrocytes cultured as monolayers in bicameral chambers under the influence of thyroid-stimulating hormone, stable iodide, ouabain and perchlorate. The results indicate that there are similarities and differences in the transport mechanisms of free 211At and 125I−. These results will be valuable in the development of radiation protection when handling and using 211At-labeled radiopharmaceuticals, and for the potential use of free 211At in radiation therapy of poorly differentiated thyroid cancer.