Iodine Dose Research Articles

Efficacy of a single fixed 131I dose of Radioactive iodine for the treatment of hyperthyroidism

A total of 135 patients were treated for hyperthyroidism with 131I 15 mCi radioiodine ablation. The therapeutic target was achieving hypothyroidism. Between January 2014 and December 2018, clinical records were reviewed and the data was collected and reviewed for 135 patients with hyperthyroidism that were referred to the Nuclear Medicine Department at Salmaniya Medical Center, for Radioactive Iodine (RAI) thyroid gland ablation procedure for definitive treatment of hyperthyroidism. About 39.7% of our patients achieved response between 4-6 months out of which 35.7% of the patients showed response in the first 3 months. 21.4% of the patients took between 7-12 months to show response and only 3.2% responded after 12 months. The most significant response was hypothyroidism comprising of 94.4%. It is also worth mentioning that 4.0% of patients achieved euthyroidism and did not require any followup medication. Using a fixed dose of RAI of 15mCi for treating various types of Hyperthyroidism, successful treatment with a single dose of RAI can be achieved in 92.7% of the patients, with first therapy failure rate in 7.3%, with few patients requiring additional doses of RAI.

Efficacy of a single fixed 131I dose of radioactive iodine for the treatment of hyperthyroidism

A total of 135 patients were treated for hyperthyroidism with 131I 15 mCi radioiodine ablation. The therapeutic target was achieving hypothyroidism. Between January 2014 and December 2018, clinical records were reviewed and date was collected and reviewed for 135 patients with hyperthyroidism that were referred to the Nuclear Medicine Department at Salmaniya Medical Center, for radioactive iodine (RAI) thyroid gland ablation procedure for definitive treatment of hyperthyroidism. About 39.7% of our patients achieved response between 4-6 months out of which 35.7% of the patients showed response in the first 3 months. 21.4% of the patients took between 7-12 months to show response and only 3.2% responded after 12 months. The most significant response was hypothyroidism comprising of 94.4%. It is also worth mentioning that 4.0% of patients achieved euthyroidism and did not require any follow-up medication. Using fixed dose of RAI of 15mCi for treating various type of Hyperthyroidism, successful treatment with a single dose of RAI can be achieved in 92.7% of the patients, with first therapy failure rate in 7.3%, with few patients requiring additional doses of RAI.

False Positive Radioiodine Post-Ablation Scan in Scalp Region in a Woman who Used Hair Coloring Revealed by SPECT/CT

Radioiodine ablation with iodine-131 is a standard therapeutic procedure for patients diagnosed with differentiated thyroid carcinoma (DTC). We present a contamination artifact on whole-body scan (WBS), after radioiodine ablation due to papillary thyroid carcinoma. The hybrid imaging resolved the question of metastasis versus contamination. In the case of 35-year-old female patient we used a General Electric hybrid gamma camera with a high-energy-general-purpose collimator for performing WBS, and single photon emission computed tomography combined with low dose computed tomography (SPECT/CT) for the detection of any residual thyroid tissue or meta-static disease and at the same time ablation and treatment of any confirmed metastasis. A thyroid scan showed activity in the remnant thyroid tissue of the right lobe, but also laterally in the calvaria (left temporal region). The patient's neck ultra-sound and thyroglobulin level were not in favor of metastasis. A false positive finding due to hair coloring was concluded with SPECT/CT hybrid imaging. SPECT/CT scan can contribute to establishing a final diagnosis in patients being evaluated for atypical locations of radioactive iodine accumulation after ablative doses of radioactive iodine, distinguishing between metastases from DTC and false positive accumulations or artifacts.

Clinical, Pathological, and Molecular Profiling of Radioactive Iodine Refractory Differentiated Thyroid Cancer.

Background: Six to 20% of thyroid cancer (TC) patients develop distant metastases, and one-third become radioiodine refractory (RAIR). Available targeted therapies increase progression-free survival but are associated with toxicities. This study aims to characterize clinical, pathological, and molecular profiles of patients with RAIR TC. Methods: Data of TC patients seen during 2013-2017 at two tertiary care centers were retrospectively analyzed. Patients were considered RAIR according to American Thyroid Association guidelines. The control cohort was sex matched and age matched and had either regression or stable disease (by Response Evaluation Criteria in Solid Tumors) on follow-up at least three years after initial therapy. Molecular profiles on a subset of RAIR patients were reviewed. Results: Compared with 22 matched controls, 54 RAIR patients had an average age of 57 years (standard deviation [SD] = 13), 56% were male (41% in the control group); the average tumor size was 4 cm (SD = 2.5); tumors were multifocal in 54%, with involved surgical margins in 42%, focal invasion in 79%, and extrathyroidal extension (ETE) in 61%. Sixty-six percent had distant metastases at initial presentation with metastases to the lungs in 85%, bone in 56%, both sites in 43%, brain in 9%, and liver in 4%. There were no statistically significant differences between RAIR and controls in tumor size, focal invasion, ETE, and histology. The RAIR group received a higher cumulative radioactive iodine (RAI) dose and number of therapies compared with the controls (518 mCi vs. 302 mCi, p = 0.002 and 2.2 vs. 1.3 treatments, p = 0.001). Overall, patients >46 years had 4.5 times higher odds ratio (OR) of being RAIR; white race/ethnicity was associated with a reduced OR of RAIR disease (OR 0.33, p = 0.079). Molecular profiling data in the RAIR subgroup indicated that 50% of patients harbored mutations in the RAS/RAF pathway (11/22). Among 19 patients with a more extensive molecular panel, median tumor mutational burden was 5 megabase (range 3-16) and 26% (5/19) exhibited strong PD-L1 positivity. Conclusion: Among patients with metastatic differentiated thyroid carcinomas, patients with RAIR have similar histopathological and clinical characteristics as patients with RAI avid cancer. The risk of having RAIR TC is increased at age ≥46 and reduced in Caucasians.

Contrast Material Injection Protocol With the Dose Determined According to Lean Body Weight at Hepatic Dynamic Computed Tomography: Comparison Among Patients With Different Body Mass Indices.

The objective of this study was to compare enhancement of the aorta and liver on hepatic dynamic computed tomography scans acquired with contrast material doses based on the lean body weight (LBW) or the total body weight (TBW). We randomly divided 529 patients (279 men, 250 women; median age, 66 years) scheduled for hepatic dynamic computed tomography into 2 groups. The LBW patients (n = 278) were injected with 679 mg iodine/kg (men) or 762 mg iodine/kg (women). The TBW group (n = 251) was injected with 600 mg iodine/kg TBW. Each group was subdivided into the 3 classes based on the body mass index (BMI; low, normal, high). Aortic enhancement during the hepatic arterial phase and hepatic enhancement during the portal venous phase was compared. The aortic and hepatic equivalence margins were 100 and 20 Hounsfield units, respectively. Comparison of the median iodine dose in patients with a normal or high BMI showed that it was significantly lower under the LBW protocol than the TBW protocol (558.2 and 507.0 mg iodine/kg, P < 0.001, respectively). However, in patients with a low BMI, the LBW protocol delivered a significantly higher dose than the TBW protocol (620.7 vs 600.0 mg iodine/kg, P < 0.001). The 95% confidence interval for the difference in aortic and hepatic enhancement between the 2 protocols was within the range of the predetermined equivalence margins in all BMI subgroups. Contrast enhancement was equivalent under both protocols. The LBW protocol can avoid iodine overdosing, especially in patients with a high BMI.

Dosing Iodinated Contrast Media According to Lean Versus Total Body Weight at Abdominal CT: A Stratified Randomized Controlled Trial

To compare the magnitude and interpatient variability in normalized mean hepatic enhancement (MHE) indices when dosing contrast media (CM) according to total body weight (TBW) and lean body weight (LBW). This ethics-approved stratified randomized controlled study allocated 280 outpatients for abdominal Computed Tomography (CT) between February-November 2018 to TBW- or LBW-dosing using computer-generated tables. CTs were acquired in portal venous phase after fixed 35-second injection of Iohexol 350. Patients with missing precontrast image, incorrect dose, or chronic kidney, liver or heart disease were excluded. The number of included patients and CM doses were: TBW arm, 51 women and 60 men, 1.22 mL/kg; LBW arm, 59 women, 1.66 mL/kg LBW, and 59 men, 1.52 mL/kg LBW. Liver attenuations were obtained from regions of interest. Values and standard deviations in MHE indices normalized to iodine dose (MHE/I) and iodine dose per kg TBW (aMHE = MHE/[I/TBW]) were compared (unpaired t tests and F-tests). Cohorts were similar in age, sex, TBW, and LBW. TBW groups received more CM than LBW groups: men, 106.5 ± 20 versus 98.4 ± 11 mL, p = 0.007; women, 93.7 ± 20 versus 77.5 ± 11 mL, p < 0.0001. TBW and LBW groups showed no significant difference in MHE/I (women, 1.75 ± 0.5 versus 1.86 ± 0.6 HU/g, p = 0.31; men, 1.53 ± 0.4 versus 1.52 ± 0.4 HU/g, p = 0.90) or aMHE (women, 0.03 ± 0.01 versus 0.03 ± 0.01 HU/g/kg, p = 0.25; men, 0.02 ± 0.01 versus 0.02 ± 0.01 HU/g/kg, p = 0.52). Variances in MHE/I and aMHE were not significantly different for all groups (p > 0.05). TBW- and LBW-based CM dosing yield a similar magnitude and interpatient variability in normalized MHE indices at routine abdominal CT.

Development of New Biokinetic-Dosimetric Models for the Simulation of Iodine Blockade in the Case of Radioiodine Exposure in Man.

In the case of nuclear incidents, radioiodine may be liberated. After incorporation it accumulates in the thyroid and by internal irradiation enhances the risk of cancer occurrence. By administering a large dose of non-radioactive iodine the uptake of radioiodine into the gland can be inhibited ("iodine blockade"). Biokinetic models using first order kinetics are not suited to simulate iodine blockade, as the uptake into the gland is mediated by a saturable active transport. Therefore, we integrated an uptake mechanism described by a Michaelis-Menten kinetic into a simple ICRP biokinetic model. We moreover added a total uptake blocking mechanism representing the Wolff-Chaikoff effect becoming active when the gland is saturated with iodine. The validity of the model was ascertained by comparison with IMBA software. The competition of radioiodine and stable iodine at the membrane carrier site was modeled according to the rate law for monomolecular reactions for competing substrates. Our simulations show that competition for the uptake at the membrane carrier site accounts for about 60% and the saturation of the gland with iodine for over 35% of the total protective efficacy that exceeds 95%. Following acute radioiodine exposure, it is preferable to administer a single large dose of stable iodine. In the case of continuous radioiodine exposure, a single dose of stable iodine is less effective than after an acute exposure and splitting the total available dose and shortening the dosage intervals enhance efficacy. Model-based simulations may be a useful tool to develop antidote dosage schemes for uncommon emergencies.

Reducing Iodine Dose Based on Lean Body Weight

Reducing Iodine Dose Based on Lean Body Weight

Individualized Delay for Abdominal Computed Tomography Angiography Bolus-Tracking Based on Sequential Monitoring: Increased Aortic Contrast Permits Decreased Injection Rate and Lower Iodine Dose

The aim of this study was to determine if computed tomography (CT) angiography using an individualized transition delay (CTA-ID) would facilitate reductions in injection rate and iodine dose. The CTA-ID was performed in 20 patients with routine injection rate and iodine dose; 20 patients with injection rate lowered by 1 mL/s; and 40 patients with injection rate lowered by 1 mL/s with 29% less iodine. Routine CTAs in the same or size-matched patients served as controls. Diagnostic image quality and intra-arterial CT numbers were assessed. The median transition delay between aortic threshold and CTA-ID image acquisition was significantly longer than with conventional bolus tracking (mean increase, 13.3 seconds; P < 0.0001), with image quality being the same or better. Intra-arterial CT numbers were 200 Hounsfield units or greater for 80 of 80 CTA-ID, but not for 6 of 49 (12%) internal control or for 11 of 80 (14%) size-matched control patients. The CTA-ID bolus-tracking software alters transition delays to permit diagnostic CTA examinations despite slower injection rate and less iodine.

Reply to "Minimizing IV Iodine Doses for Contrast-Enhanced CT".

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Schiff base as a novel kind of catalyst for reversible complexation‐mediated radical polymerization of methyl methacrylate

ABSTRACTTwo kinds of Schiff base, N,N′‐dibenzylidene‐1,2‐diaminoethane (NDBE) and N,N′‐disalicylidene‐1,2‐diaminoethane, have been found as efficient organic catalyst for reversible complexation‐mediated radical polymerization (RCMP) of methyl methacrylate (MMA) for the first time. The polymerization results show obvious features of “living”/controlled radical polymerization. Well‐defined and low‐polydispersity polymers (Mw/Mn = 1.20–1.40) are obtained in RCMP of MMA catalyzed by Schiff base at mild temperature (65–80°C). Moreover, Schiff base also exhibits a particularly high reactivity for RCMP of MMA with in situ formed alkyl iodide initiator. The polymer molecular weight and its polydispersity (Mw/Mn is around 1.20) are well controlled even with high monomer conversion. Notably, when the dosage of azo initiator is same as the dosage of iodine, the polymerization could also be realized in the presence of NDBE. The living feature of synthesized polymer is confirmed through the chain extension experiment. In short, Schiff base is a kind of high‐efficient catalyst for RCMP and reverse RCMP of MMA, which can be one of the most powerful and robust techniques for polymer synthesis. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1653–1663

Efficient peroxodisulfate activation by iodine vacancy rich bismuth oxyiodide: A vacancy induced mechanism

Defect engineering is a promising strategy to improve the efficiency of persulfate based advanced oxidation processes. Different from previous reports on oxygen vacancy containing catalysts, an iodine vacancy rich material is found highly active in persulfate activation and organic degradation. The Bi7O9I3 with abundant iodine vacancies is synthesized by solvothermal method, and exhibits superior catalytic performance for peroxydisulfate (PDS) activation, with 90% phenol degradation in 60 min. Furthermore, the catalytic activity of Bi7O9I3 can be enhanced by increasing iodine vacancies through calcination below the phase transition temperature or reduction of the iodine dosage in the source materials. The electron paramagnetic resonance spectra, electrochemical measurements, and quenching tests suggest that PDS activation by the iodine vacancy rich Bi7O9I3 is a non-radical pathway. Moreover, the presence of iodine vacancies can not only increase the carrier density to boost the electron transfer capacity of the catalysts, but also lower the Bi valence to enable its role in donating electrons to PDS and receiving electrons from organic substrates. This study provides a new iodine vacancy engineered strategy for PDS activation and non-radical oxidation, and brings insights for defects induced active sites both in materials and vacancy types.

Transoral endoscopic thyroidectomy for thyroid carcinoma: outcomes and surgical completeness in 150 single-surgeon cases.

Transoral endoscopic thyroid surgery vestibular approach (TOETVA) is a promising technique involving no skin incision. Since its first use in 60 patients in 2015, TOETVA has been adopted by several hospitals worldwide. However, reports of TOETVA for thyroid cancer are scarce. Between August 2016 and March 2019, 150 and 125 thyroid cancer patients underwent TOETVA and open thyroidectomy (OT), respectively, by a single endocrine surgeon. Comparative analyses were performed on clinical and pathological findings, complications, and surgical completeness in total thyroidectomy cases, as indicated by the serum thyroglobulin (Tg) level. Data were collected prospectively and analyzed retrospectively. Mean age was younger in the TOETVA than in the OT group (43.06 ± 10.90 vs. 51.02 ± 12.42). The percentage of females was 96.7% in the TOETVA group. Total thyroidectomy was higher in the OT group (26.7% vs. 65.0%). Operation time (min) was longer in the TOETVA group for lobectomy (102.12 ± 32.59 vs. 76.38 ± 21.24) and total thyroidectomy (132.65 ± 34.79 vs. 90.71 ± 25.09). The largest tumor diameter was 0.91 (± 1.00) in the TOETVA group and 1.19 (± 1.07) in the OT group. The harvested lymph node number was not significantly different between the two groups for lobectomy (3.19 ± 2.89 vs. 3.49 ± 2.41, p = 0.319) and total thyroidectomy (4.98 ± 3.12 vs. 5.70 ± 4.35, p = 0.714). The thyroid-stimulating hormone stimulated Tg level before administration of the first dose of radioactive iodine was also not different (3.38 ± 10.87 vs. 3.44 ± 11.51, p = 0.595). Percentage of stimulated Tg below 1.0ng/ml was 80.0% in the TOETVA group. TOETVA is feasible in selected thyroid cancer patients, not only because it is cosmetically advantageous but also because it is oncologically safe. A large prospective cohort study including recurrence surveillance is needed to consolidate the feasibility of TOETVA.

Does the dose of iodine-131 influence the incidence of Graves' ophthalmopathy?

Radioactive iodine-131 (RAI) is an established treatment for patients with Graves' hyperthyroidism. RAI is reported to be associated with a 20-30% incidence of development or exacerbation of Graves' ophthalmopathy (GO). This study compares the progression of GO in patients who had evidence or no evidence of GO before RAI therapy. Forty-eight patients were studied. One group had no evidence whereas the other group had evidence of GO before RAI treatment. All underwent RAI therapy. Group A (27 patients, 18 women, nine men, age: 19-68 with a mean of 49 years) had pre-existing exophthalmos. Group B consisted of 21 patients (13 women, eight men, age: 30-63 with a mean of 43 years) developed exophthalmos after treatment. All patients underwent RAI therapy and followed by ophthalmologists. The average administered dose in group A was 24.3 mCi (range: 10-36.2 mCi) compared with group B: 25.4 mCi (range: 13-35.9 mCi), P=0.60. Ten (37%) of the 27 patients in group A experienced worsening of symptoms post-treatment. There was no significant difference between the administered dose of RAI in patients with worsening symptoms, 25.1 mCi versus patients with stable symptoms, 24.5 mCi (P=0.82). However, group A developed GO symptoms earlier than group B (4.5 vs. 9.5 months), P=0.02. RAI is known to exacerbate ophthalmopathy. Our study showed it was not dose-dependent. Patients without a previous history of GO were observed to have a significantly delayed period for the development of symptoms.

Iodine Dose of Administered Contrast Media Affects the Level of Radiation-Induced DNA Damage During Cardiac CT Scans.

OBJECTIVE. The purpose of this study is to investigate the contributing effect of contrast media (CM) iodine dose on radiation-induced DNA damage in blood lymphocytes during a cardiac CT scan. MATERIALS AND METHODS. The minipigs were exposed 12 times in total to a fixed cardiac CT scan protocol. An unenhanced and two CM injection protocols were considered, the latter with 50% saline diluted (160 mg I/mL) and standard iodixanol. Blood samples were collected before and after CT, and radiation-induced DNA double-strand breaks were assessed using γ-H2AX (H2A histone family member X) immunofluorescent staining of the blood lymphocytes. Significant differences in foci numbers were investigated with an independent sample t test. In addition, a numeric dosimetry model was applied that simulates the cardiac CT scan, with the heart represented by a blood volume containing a mixture of six iodine concentrations (0, 10, 20, 30, 40, and 50 mg I/mL). RESULTS. Compared with the unenhanced (0 mg I/mL) protocol, the number of γ-H2AX foci per cell increased significantly (p < 0.038), by 56.1% for the reduced iodine dose (160 mg I/mL) and by 141.1% for the standard iodine dose (320 mg I/mL) protocols. These in vivo results are confirmed by the dosimetry simulation model, in which 78.8% and 133.7% increases in locally absorbed blood dose in the left ventricle were observed for the reduced and standard iodine dose protocols, respectively. CONCLUSION. Administration of CM during a cardiac CT examination significantly increases radiation-induced DNA damage in blood lymphocytes. Moreover, a lower CM iodine dose results in a reduced level of DNA damage, at constant radiation exposure.

The prophylactic granola development with increased iodine content

The article is dedicated to development of dry breakfasts meals technology with a high nutritional value in order to prevent iodine deficit and its unfavorable affects in Ukrainian nation. The research purpose is a scientific justification and development a new recipe composition and technology of a new prophylactic dish – granola with increased iodine content. The implementation became possible due to successful combination, in terms of nutrient content optimization in the new dish recipe from natural raw material with high nutritional value, as candied feijoa, honey, oat flakes, sesame seeds, flax, pumpkin, sunflower and chia. The article substantiates the feasibility of producing and introducing innovative dry-breakfast production technologies, including granola, using iodine-containing plant components, namely candied feijoa, since this will solve an important problem of the iodine deficiency and other important essential nutrients in diets, as well as increase of efficiency their digestibility, which will improve the population health. Feijoa fruits contain almost a daily dose of iodine (70–100 μg/100 g) and a complex of biologically active substances. The potassium iodide is a very unstable compound, it destroys as a result of temperature rise, which leads to significant iodine los. Owing to this, in order to maximize the useful properties of Feijoa fruits in the production of candied fruits, we used a savvy technology of infrared drying at relatively low temperatures (T = 55–60 °C) in AVERNO drier. To form a clearer and more complete picture of the candied feijoa influence on the change of the new dish properties, there were developed recipient granola formulations, containing this fruit component in the amount of 22% to the mass of the finished dish, as well as without it. The study’s results have shown that the candied feijoa adding improves the organoleptic characteristics of the granola. It was established that,due to the addition of candiedfaijoa,the granola’s titrated acidity increases by more than 2.6 times. Thehumidity of granola samples with candied feijoa is increased by 6.8% and is within the recommended limits for a dry fruit breakfast. It has been proved that the candied feijoa granola addition in the formulation allows the product to be substantially enriched with iodine. Thus, iodine content in candied feijoagranola is 26 μg/100 g. Based on the comparative analysis of the organoleptic, physicochemical and microbiological parameters, the optimum ratio of the recipe components was substantiated and the technology of prophylactic granola with high iodine content was developed.

SUN-574 Exogenous Iodine Supplementation-Induced Thyroid Storm in a Patient with Multinodular Goiter

Introduction: Iodine is an essential micronutrient for thyroid hormone synthesis. Its primary source is fortified foods. Supraphysiologic doses of iodine are often found in iodine supplements that are advertised to support thyroid metabolism and reduce goiter size. Normally, excess iodine temporarily inhibits production of thyroid hormone (Wolff-Chaikoff effect), causing goiter and hypothyroidism. In patients with a pre-existing nodular goiter, the auto-regulation of iodine entry into thyroid cells and thyroid hormone synthesis are ineffective. Exposure to high doses of iodine in such cases can precipitate hyperthyroidism (Jod-Basedow phenomenon). Clinical Case: A 50 year-old lady with morbid obesity, chronic lymphedema, longstanding hypothyroidism, and a large retrosternal goiter presented with severe sepsis from cellulitis and tachycardia-induced cardiomyopathy (ejection fraction 30%) from a new-onset atrial flutter with rapid ventricular rate requiring cardioversion. Free (f)T4 was 4.81 ng/dL (0.93-1.7), fT3 6.0 pg/mL (2.0-4.4) and TSH 0.006 mcu/mL (0.27-4.2). Two years ago, she was seen by endocrinology, at which time TSH was 1.58 mcu/mL on desiccated thyroid 30 mg qd. Due to substernal goiter, surgery was recommended then but declined by the patient. Later, she increased desiccated thyroid to 60mg qd and started OTC iodine supplements at 30,000 mcg qd (20,000% RDA) of her own volition, hoping to decrease the size of the goiter. The patient was subsequently lost to follow-up. On this admission, hospital course was complicated by disseminated intravascular coagulation, acute kidney injury needing renal replacement therapy (RRT), encephalopathy, and mechanical ventilation. CT and US demonstrated stable heterogeneous, multinodular goiter (12.5 x 9.3 cm with mediastinal extension), without prominent vascularity. Treatment with PTU, beta-blockers, hydrocortisone, and cholestyramine was initiated on day 1. Serum iodine was markedly elevated at 2,160 ng/ml (40-92) and improved to 221 ng/ml after six days of RRT. Despite PTU 300mg q6h for > 3 weeks, fT4 remained elevated. Eventually fT3 and fT4 normalized to 2.1pg/mL and 1.30ng/dL, respectively, with continued improvement in iodine level. TSH remained undetectable. Severe medical comorbidities precluded surgical resection of the goiter. Conclusion: Dessicated thyroid hormone, markedly supraphysiologic iodine intake, and thyroid autonomy characteristic of MNG contributed to life-threatening thyrotoxicosis in this patient. Extremely high iodine content in the blood and thyroid undoubtedly impeded therapeutic response to PTU, and RRT helped to lower systemic iodine load. This case demonstrates the importance of careful history taking to identify unusual sources of iodine in patients, and patient education regarding possible dangers associated with unregulated OTC and dietary supplements.

SAT-561 Protective Effect of Moderated Dose of Iodine in Pancreatic Alterations during Hypothyroidism

Pancreatitis and insulitis are known causes of type 2 diabetes mellitus, and recently it has been shown that hypothyroidism can exacerbate these alterations. Molecular iodine (I2) exerts antioxidant, anti-inflammatory, and anti-dyslipidemia effects in diverse tissues. The objective of this study was to evaluate the effect of the oral supplement of this halogen in the induction of prediabetic status in a model of pharmacological hypothyroidism. Adult virgin rabbits of the Chinchilla breed were divided into control (n = 6) and hypothyroid (methimazole, MMI n = 6, 10 mg/kg in drinking water) groups, supplemented with moderate (MMI + I2 0.2 mg/kg; n= 6) and high dose of I2 (MMI + I2 2 mg/kg, n= 6). The results showed that hypothyroidism (1 month) was accompanied by circulating elevations of total cholesterol, HDL, LDL (enzymatic methods) and sCD163 (Western blot). It also promoted pancreatitis (H & E, Masson's trichrome, and PAS stains, as well as western blot for CD163) and insulitis (PAS and Masson's trichrome stains). In the pancreas, hypothyroidism increased the beta-amyloid around vessels (Congo red stain); triglycerides (Folch method), lipoperoxidation (levels of malondialdehyde MDA, enzymatic method) and expression of insulin and GLUT4. A low cholesterol synthesis (Folch method and western blot for CYP51A1) and a decrease in the expression of PPARγ (immunohistochemistry and western blot) were also observed. High doses of I2 supplement (2 mg/kg) aggravated pancreatic damage, promoting even islet amyloidosis and fibrosis. In contrast, the moderate dose of I2 (0.2 mg / kg) was able to prevent alterations in circulating lipids and in the pancreatic tissue. This prevention was accompanied by a significant decrease in the lipoperoxidation and a great expression of PPARγ. These results describe for first time the anti-inflammatory and anti-dyslipidemia effect of the moderate dose of I2 in the pancreas and suggest the possible participation of PPARγ receptors. More studies are needed to analyze the therapeutic effect of iodine in chronic pancreatic diseases associated with inflammation. This work was partially supported by grants CONACyT 257549 and PAPIIT-UNAM 201516.

Personalized administration of contrast medium with high delivery rate in low tube voltage coronary computed tomography angiography.

High delivery rate is an important factor in optimizing contrast medium administration in coronary computed tomography angiography (CCTA). A personalized contrast volume calculation algorithm incorporating high iodine delivery rate (IDR) can reduce total iodine dose (TID) and produce optimal vessel contrast enhancement (VCE) in low tube voltage CCTA. In this study, we developed and validated an algorithm for calculating the volume of contrast medium delivered at a high rate for patients undergoing retrospectively ECG-gated CCTA with low tube voltage protocol. The algorithm for an IDR of 2.22 gI·s-1 was developed based on the relationship between VCE and contrast volume in 141 patients; test bolus parameters and characteristics in 75 patients; and, tube voltage in a phantom study. The algorithm was retrospectively tested in 45 patients who underwent retrospectively ECG-gated CCTA with a 100 kVp protocol. Image quality, TID and radiation dose exposure were compared with those produced using the 120 kVp and routine contrast protocols. Age, sex, body surface area (BSA) and peak contrast enhancement (PCE) were significant predictors for VCE (P<0.05). A strong linear correlation was observed between VCE and contrast volume (r=0.97, P<0.05). The 100-to-120 kVp contrast enhancement conversion factor (Ec) was calculated at 0.81. Optimal VCE (250 to 450 HU) and diagnostic image quality were obtained with significant reductions in TID (32.1%) and radiation dose (38.5%) when using 100 kVp and personalized contrast volume calculation algorithm compared with 120 kVp and routine contrast protocols (P<0.05). The proposed algorithm could significantly reduce TID and radiation exposure while maintaining optimal VCE and image quality in CCTA with 100 kVp protocol.

Impact of repeated dose of stable iodine in an in utero rat model using a metabolomic approach

The Fukushima nuclear power plant blast resulted in the release of 131Iodine for several weeks. This unexpected issue challenged the iodin doctrine [1], in which the counter-measure is to provide a unique iodine tablet to saturate thyroid during the radioactive contamination not expected to last more than several hours. A new doctrine must be implemented to take into account such case of extended exposure based on repeated iodine administration with adapted dosage. But repeated administration of iodine can block the thyroid [2] and few scientific evidences regarding repeated iodine administration (and its potential undesirable effect) are at our disposal [3]. Moreover, unborn and young children are at high risk during a nuclear incident: it is currently recognized that one of the risks of exposure to radioactive iodine is the development of thyroid cancer, especially when exposure occurred during childhood [4]. Their protection is a main priority. Our goal was to evaluate the potential undesirable effects of such repeated iodine administration in the offspring using an untargeted metabolomic approach on a rat reproductive model.