Serum Total Iodine Research Articles

Salivary iodine concentration in pregnant women and its association with iodine status and thyroid function.

There have been no reports on the application of salivary iodine concentration (SIC) in evaluating iodine nutrition in pregnant women. This study aimed to clarify the relationship between SIC and indicators of iodine nutritional status and thyroid function during pregnancy, to investigate whether salivary iodine can be applied to the evaluation of iodine nutritional status in pregnant women, and to provide a reference basis for establishing a normal range of salivary iodine values during pregnancy. Pregnant women were enrolled in the Department of Obstetrics, the people's hospital of Yuncheng Country, Shandong Province, from July 2021 to December 2022, using random cluster sampling. Saliva, urine, and blood samples were collected from pregnant women to assess iodine nutritional status, and venous blood was collected to determine thyroid function. A total of 609 pregnant women were included in this study. The median spot urinary iodine concentration (SUIC) was 261μg/L. The median SIC was 297μg/L. SIC was positively correlated with SUIC (r = 0.46, P < 0.0001), 24-h UIC (r = 0.30, P < 0.0001), 24-h urinary iodine excretion (24-h UIE) (r = 0.41, P < 0.0001), and estimated iodine intake (EII) (r = 0.52, P < 0.0001). After adjusting for confounders, there was a weak correlation between SIC and serum total iodine and serum non-protein-bound iodine (P = 0.02, P = 0.04, respectively). Pregnant women with a SIC < 176μg/L had a higher risk of insufficient iodine status (OR = 2.07, 95% CI 1.35-3.19) and thyroid dysfunction (OR = 2.71, 95% CI 1.18-6.21) compared to those with higher SIC. Those having SIC > 529μg/L were more likely to have excessive iodine status (OR = 2.82, 95% CI 1.81-4.38) and thyroid dysfunction (OR = 3.04, 95% CI 1.36-6.78) than those with lower SIC values. SIC is associated with urinary iodine concentration and thyroid function in pregnant women. SIC < 176μg/L was associated with an increased risk for iodine deficiency and hypothyroxinemia, while SIC > 529μg/L was related to excess and thyrotoxicosis. SIC can be used as a reference indicator for evaluating the iodine nutrition status of pregnant women, but it needs further investigation and verification. NCT04492657(Aug 9, 2022).

Evaluation of dermal toxicity and toxicokinetics of povidone‑iodine in Göttingen minipigs

BackgroundPovidone‑iodine (PVP-I) is an effective and commonly used broad-spectrum antiseptic; limited information exists around its long-term safety and impact on endocrine disruption. We assessed the dermal toxicity and toxicokinetics following a once-daily application of 7.5% (w/v) and 10% (w/v) PVP-I in Göttingen Minipigs® for up to 39 weeks. MethodsAn in vivo study was conducted in male (n = 27) and female (n = 27) minipigs. Animals were randomized into untreated control, 7.5% and 10% PVP-I, and matching vehicle treatment groups. Animals were assessed for general in-life measurements, including skin irritation and organ weights. Serum samples were analyzed for PVP, total iodine, triiodothyronine [T3], thyroxine [T4], thyroid stimulating hormone [TSH], and toxicokinetic parameters. ResultsNeither 7.5% nor 10% PVP-I affected general in-life measurements. Increased mean thyroid gland absolute weights were noted with 7.5% and 10% PVP-I. Serum levels of PVP, T3, T4, and TSH in the 7.5% and 10% PVP-I treatment group animals were similar to those in vehicle treatment group animals. Mean total serum iodine concentration was 52- and 13-fold higher with 7.5% and 10% PVP-I, respectively, vs respective vehicle treatments. There was no dose-dependent increase in mean maximum serum concentration and area under the curve from 0 to 24 h for PVP, T3, T4, and TSH, nor accumulation of PVP, T3, T4, or TSH in the study. ConclusionOnce-daily dermal application of 7.5% and 10% PVP-I for up to 39 weeks was safe and well tolerated in Göttingen Minipigs® and was not associated with skin irritation, thyroid dysfunction, or endocrine disruption. As the anatomy and physiology of the minipig skin closely resembles that of human skin, the findings of this study suggest that 7.5% and 10% PVP-I may be translated into antimicrobial benefits for humans without the risk of endocrine disruption.

Effect of different iodide intake during pregnancy and lactation on thyroid and cardiovascular function in maternal and offspring rats

ObjectiveWe aimed to investigate the impact of different iodide intake during pregnancy and lactation on iodine concentration in urine and serum, fatty acid metabolism, thyroid and cardiovascular function in maternal and offspring rats. MethodsPregnant rats were randomly assigned to four groups: normal adult iodide intake (NAI, 7.5 μg/d), normal pregnant iodide intake (NPI, 12.5 μg/d), 5 times (5 HI, 62.5 μg/d) and 10 times higher-than-normal pregnant iodide intake (10 HI, 125 μg/d). The maternal rats were continuously administered potassium iodide until postnatal day 16 (PN16). Thyroid function was measured by enzyme-linked immunosorbent assay (ELISA). The iodine concentration in urine and serum were detected by inductively coupled plasma mass spectrometry (ICP-MS). The messenger ribonucleic acid (mRNA) expressions of Krüppel-like factor 9 (KLF9) and thioredoxin reductase 2 (Txnrd2) were measured using quantitative real-time polymerase chain reaction (RT-qPCR). Characteristic distribution of KLF9 expression and its interaction with TRβ was assessed by immunohistochemical and immunofluorescence staining. Serum fatty acids were analyzed by Liquid Chromatography-Mass Spectrometry (LC-MS). Cardiac function and blood pressure were measured by echocardiography and a non-invasive tail-cuff system. ResultsHigh iodide intake (5 HI and 10 HI) during pregnancy and lactation results in increased urinary iodine concentration (UIC), serum total iodine concentration (STIC) and serum non-protein-bound iodine concentration (SNBIC) in both maternal and offspring rats, along with significantly increased FT3 and its target gene expression of KLF9. In maternal rats of both 5 HI and 10 HI groups, systolic blood pressure (SBP) was significantly higher, the increased SBP was significantly correlated with the increased UIC (r = 0.968, p = 0.002; r = 0.844, p = 0.035), KLF9 (r = 0.935, p = 0.006; r = 0.954, p = 0.003) and the decreased Txnrd2 (r = −0.909, p = 0.012; r = −0.912, p = 0.011). In maternal rats of 10 HI group, cardiac hyperfunction with increased LVEF, LVFS and decreased LVESD were observed. The increased LVEF and decreased LVESD were significantly correlated with UIC, STIC and SNBIC (r = 0.976, p = 0.001; r = 0.945, p = 0.005; r = 0.953, p = 0.003; r = −0.917, p = 0.01; r = −0.859, p = 0.028; r = −0.847, p = 0.033), LVEF, LVFS and LVESD were significant correlated with KLF9 (r = 0.950, p = 0.004; r = 0.963, p = 0.002; r = −0.990, p = 0.0002) and Txnrd2 expression (r = −0.979, p = 0.001; r = −0.915, p = 0.01; r = 0.933, p = 0.007), and the decreased LVESD was correlated with decreased epoxyeicosatrienoic acid (EET) metabolites: 5,6-EET, 8,9-DHET and 11,12-DHET (r = 0.999, p = 0.034; r = 1.000, p = 0.017; r = 1.000, p = 0.017). While in offspring rats, no significant change in SBP and cardiac function was found. STIC and SNBIC were much lower than those in maternal rats, and eicosapentaenoic acid (EPA) metabolites (9-HEPE, 15-HEPE and 14,15 DiHETE) were significantly increased. ConclusionIn addition to thyroid hormones, STIC, SNBIC, KLF9, Txnrd2, EET and EPA metabolites might be promising biomarkers in high iodide intake-induced thyroid and cardiovascular function.

The Relationship Between Iodine Excess and Thyroid Function During Pregnancy and Infantile Neurodevelopment at 18–24 Months

BackgroundThyroid disease is a prevalent condition during pregnancy, and excessive iodine intake can lead to changes in thyroid function. However, research on the relationship between maternal iodine excess, thyroid hormones during pregnancy, and infantile neurodevelopment is limited. ObjectivesThis study aimed to explore the relationship between maternal iodine excess and thyroid hormones during pregnancy and infantile neurodevelopment. The objective was to provide evidence to support and enhance the prevention of neurodevelopmental retardation in infants. MethodsFrom 2016 to 2018, a prospective study was conducted from pregnancy to 18–24 mo postpartum. Maternal urinary iodine concentration (UIC), thyroid-stimulating hormone (TSH), total serum iodine (TSI), and nonprotein-bound serum iodine during pregnancy were determined. The Gesell Development Scale was used to assess neurodevelopment of infants aged 18–24 mo. The iodine status of pregnant females was divided into following 4 groups on the basis of the distribution of maternal UIC: <100 μg/L (moderate deficiency), 100–149 μg/L (mild deficiency), 150–249 μg/L (sufficiency), and >250 μg/L (above requirement). ResultsOur study included 469 mother-infant pairs. Compared with the maternal UIC of 150–249 μg/L during pregnancy, risk of adaptive developmental delay was increased in infants with maternal UIC ≥250 μg/L (OR: 2.38; 95% CI: 1.06, 5.35). Pregnant females with TSI >90th quantiles were more likely to have offspring with language developmental delay than those with lower TSI in 10th–90th quantiles (OR: 3.06; 95% CI: 1.09, 8.58). Risk of fine motor developmental delay was increased in infants with maternal TSH ≥2.5 mIU/L during pregnancy (OR: 4.32; 95% CI: 1.43, 13.0). ConclusionsMaternal iodine nutritional status above requirement (UIC ≥250 μg/L or TSI >90th quantiles) during pregnancy negatively affects infantile neurodevelopment. Maternal TSH ≥2.5 mIU/L during pregnancy was an independent risk factor for infantile neurodevelopment. This trial was registered at clinicaltrials.gov as NCT03710148.

Mechanisms of Sodium/Iodide Symporter-Mediated Mammary Gland Iodine Compensation during Lactation.

This research aimed to investigate the compensation mechanism of iodine deficiency and excess in the mammary gland during lactation. Female rats were divided into the low iodine group (LI), the normal iodine group (NI), the 10-fold high iodine group (10HI) and the 50-fold high iodine group (50HI). We measured the iodine levels in the urine, blood, milk, and mammary gland. The protein expression of sodium/iodide symporter (NIS), DPAGT1, and valosin-containing protein (VCP) in the mammary gland was also studied. The 24-hour urinary iodine concentration, serum total iodine concentration, serum non-protein-bound iodine concentration, breast milk iodine concentration, and mammary gland iodine content in the 50HI group were significantly higher than those in the NI group (p < 0.05). Compared with the NI group, NIS expression in the 50HI group significantly decreased (p < 0.05). DAPGT1 expression was significantly higher in the LI group than in the NI group (p < 0.05). The expression level of VCP was significantly increased in the 10HI and 50HI groups. In conclusion, milk iodine concentration is positively correlated with iodine intake, and the lactating mammary gland regulates the glycosylation and degradation of NIS by regulating DPAGT1 and VCP, thus regulating milk iodine level. However, the mammary gland has a limited role in compensating for iodine deficiency and excess.

Exploration of the optimal range of urinary iodine concentration in Chinese pregnant women in mildly iodine-deficient and -sufficient areas.

There is some uncertainty about the optimal ranges for urinary iodine concentration (UIC) during pregnancy. This study aimed to explore associations between maternal UIC and thyroid function in iodine sufficient and mildly iodine deficient areas. It was a cross-sectional study in which 1461 healthy pregnant women were enrolled to collect their blood and urine samples during their routine antenatal care in Tianjin and Wuqiang, China. Wuqiang was a mildly iodine-deficient region, while Tianjin was iodine sufficient. UIC, free triiodothyronine (FT3), free thyroid hormone (FT4), thyroid stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), serum iodine concentration (SIC) including total serum iodine concentration (tSIC) and non-protein bound serum iodine concentration (nbSIC) were assessed during the routine antenatal care visits. The median UIC in pregnant women was 174 (113, 249) μg/L in Tianjin and 111 (63, 167) μg/L in Wuqiang, respectively. Compared with Tianjin, UIC, FT3 and TSH were lower, and FT4, tSIC, nbSIC, rates of TPOAb and TgAb positivity and the thyroid dysfunction rate (TDR) were higher in Wuqiang (P < 0.001). FT3, FT4, tSIC and nbSIC increased during pregnancy in Tianjin with increasing UIC, while only FT3 and nbSIC increased in Wuqiang (P < 0.05). In Tianjin, the TDR increased with UIC and peaked at UIC ≥ 500μg/L (P = 0.002), while in Wuqiang, the TDR showed a weak "U-shaped" relationship with UIC and the rate was lowest with UIC 100-149μg/L. In iodine-deficient areas, there was a lower TDR in pregnant women with UIC 100-149μg/L. We suspected that the optimal UIC criteria recommended by WHO may be a little high for pregnant women in mild-to-moderate iodine-deficient countries.

Establishment and application of high performance liquid chromatography-inductively coupled plasma mass spectrometry method for the determination of iodine species in serum

To establish a method for the determination of iodine species in human serum by inductively coupled plasma mass spectrometry(ICP-MS). Total iodine was determined by ICP-MS in helium mode after dilution of serum with tetramethylammonium hydroxide solution. The serum was added to methanol solution to precipitate the protein, and the supernatant was separated by liquid chromatography(LC) followed by ICP-MS for the determination of inorganic iodine. The limit of detection(LOD) of serum I~- by ICP-MS was 0.17 μg/L, the limit of quantification(LOQ) was 0.57 μg/L, and the linear correlation coefficient R~2=0.9998; the LOD of serum IO_3~- was 0.16 μg/L, the LOQ was 0.55 μg/L, and the linear correlation coefficient R~2=0.9998.The I~- recoveries were 96.2%-104.5% for the total serum iodine assay and 93.7%-98.6% for the inorganic iodine assay. Analysis of the iodine species of the actual serum samples showed that the I~- content was 2.6-12.2 μg/L, the organic iodine content was 45.3-66.0 μg/L, and the serum samples were essentially free of IO_3~-. A convenient, efficient and accurate method for the determination of serum iodine species was established using high performance liquid chromatography tandem with inductively coupled plasma mass spectrometry.

Identification of Novel Environmental Substances Relevant to Pediatric Graves' Disease.

Graves’ disease (GD) is the most common cause of hyperthyroidism, yet a relatively rare disease in the pediatric population. GD is a complex disorder influenced by both genetic and environmental factors. In this study, we aimed to find new environmental factors influencing the pathogenesis of GD. We investigated serum substances in 30 newly diagnosed GD children and 30 age- and gender-matched healthy controls. We measured total iodine by inductively coupled plasma-mass spectrometry (ICP-MS), analyzed perfluorinated compounds via ultra-high-performance liquid chromatography coupled with multiple reaction monitoring mass spectrometry (UHPLC-MRM-MS), and explored other environmental substances using ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UHPLC–QTOF/MS) analysis. Twenty-nine single-nucleotide polymorphisms (SNPs) in eight genes related to GD were analyzed by SNaPshot. The serum total iodine was significantly higher in GD group, but its association with GD onset was weak, only with Exp(B) value near 1. The perfluorinated compound levels were not different between the two groups. More importantly, we found 16 environmental substances significantly different between GD and control groups, among which ponasterone A is a risk factor (p = 0.007 and Exp(B) = 14.14), while confertifoline is a protective factor against GD onset (p = 0.002 and Exp(B) = 0.001). We also identified 10 substances correlated significantly with thyroid indices in GD patients, among which seven associated with levels of the thyroid autoantibody TPOAb. No known SNPs were found predisposing GD. In this study, we explored a broad variety of environmental substances and identified novel factors that are potentially involved in the pediatric GD pathogenesis.

Cross-sectional analysis of trace element status in thyroid disease

BackgroundThe synthesis of thyroid hormone depends on a set of trace elements, most importantly selenium and iodine. The dietary supply with certain micronutrients is limited in many areas of the world, including central Europe and large parts of Asia and Africa. Moreover, both thyroid disease risk and therapy effects are modulated by trace element supply and status. ObjectiveAssessment of trace element status in thyroid patients in a European metropolis. Material and MethodsAdult patients visiting a medical praxis in Berlin, Germany, were enrolled into a cross-sectional analysis, and serum samples were obtained from thyroid patients (n = 323) with different conditions including goitre, hypothyroidism, malignancy or autoimmune thyroid disease. Trace elements (iodine, selenium, copper and zinc) were assessed by ICP-MS/MS or total reflection X-ray analysis, along with two protein biomarkers of selenium status (selenoprotein P, glutathione peroxidase), and compared to the clinical phenotype. ResultsThe patients displayed relatively low serum zinc and selenium concentrations as compared to a set (n = 200) of healthy subjects (zinc; 1025+/-233 vs. 1068+/−230 μg/L, p < 0.01, selenium; 76.9+/18.8 vs. 85.1+/−17.4 μg/L, p < 0.0001). A high fraction of patients (37.5%) was classified as selenium-deficient (serum selenium concentrations <70 μg/L), in particular the patients with thyroid malignancy (59%). Serum copper was not different between the groups, and total serum iodine concentrations were unrelated to thyroid disease. Explorative statistical analyses yielded no significant interactions between the trace elements and disease parameters, except for free thyroxine inversely correlating to the copper/selenium ratio. ConclusionsIn adult thyroid patients, there is no relation of circulating copper, iodine, selenium or zinc concentrations to thyroid hormone. However, a large fraction of German thyroid patients displays a considerable selenium deficit, known to constitute a disease risk potentially impairing convalescence and aggravating autoimmune disease processes. It appears advisable to testing thyroid patients for selenium deficiency, and once diagnosed, an increased supply via dietary counselling or active supplementation should be considered.

Serum total iodine concentrations in pasture-fed pregnant ewes and newborn lambs challenged by iodine supplementation and goitrogenic kale.

Iodine deficiency can impair the reproductive performance of livestock and affect perinatal mortality of offspring, yet diagnosis of deficiency is complicated and guidelines for I supplementation are imprecise. We challenged pasture-grazing pregnant ewes with a long-acting I supplement and a goitrogenic forage, then monitored their I status during gestation and lactation and in their lambs from birth to weaning. Approximately 46 d into gestation, 376 ewes were assigned to 6 groups comprising 3 supplementation levels × 2 diet regimens. On d 0 the groups received an intramuscular injection of iodized oil providing 0, 300, or 400 mg of I. They grazed until d 23, then half of each supplementation group were fed brassica kale until d 85, then all groups returned to pasture for lambing (parturition approximately d 99) and remained there until weaning (d 192). Serum total I concentration (STIC) was measured repeatedly in 8 'monitor' ewes per group and in their lambs and in milk sampled postpartum. Severity of goiter was determined as the thyroid-weight:birth-weight (TW:BW) ratio in 82 newborn dead lambs. Mean ± SE STIC for all ewes was initially 42 ± 2 (range 24 to 105) µg/L. Diet did not affect I concentrations in ewe serum or milk. Responses to iodized oil were proportional to dose level; STIC increased to approximately 150 and 240 µg/L for the 300- and 400-mg I groups and remained greater than 0-mg I groups for 161 d (P < 0.05). Milk contained 26, 271, and 425 µg I/L for the 0-, 300-, and 400-mg I groups, respectively. Mean STIC of lambs from supplemented ewes did not differ by diet; concentrations for the 300- and 400-mg I groups were 237 and 287 µg I/L at birth, and by weaning all groups were similar (62 ± 3 µg/L). Lamb STIC measured at birth correlated with exposure to I in utero (R(2) = 0.59), which was estimated from the area under the curve (AUC) of ewe STIC measured during the last 99 d of gestation. Thyroid enlargement in lambs affecting the TW:BW ratio was a sensitive indicator of maternal nutrition, being greater with kale feeding (1.27 vs. 0.51 g/kg) and lesser with I supplementation (0.35 vs. 1.44 g/kg). Results support the use of STIC as a biochemical criterion. It was sensitive to the effects of I supplementation with responses in ewes and lambs proportional to dose level and it reflected the relationship between ewe and lamb I metabolism. However STIC did not discriminate between groups of ewes fed pasture vs. goitrogenic forage during pregnancy.

Analysis of factors affecting the prognosis of patients with Graves' disease treated with antithyroid drugs

A total of 96 patients with Graves'disease(GD)were followed for one and half years to observe the effect of antithyroid drugs(ATD)treatment.Serum TRAb,total iodine concentration and CD80 mRNA expression of peripheral blood monouclear ceils were measured.Logistics regression analysis was conducted with the combination of above parameters.Those GD patients with high level of TRAb,positive family history of GD, increased expression of CD80 and early age of onset were more inclined to relapse after ATD treatment. Key words: TSH receptor antibody; Serum total iodine; CD80; Graves'disease; Prognosis

Toxic effects of povidone–iodine on synovial cell and articular cartilage

The objective of this study was to investigate the toxic effects of povidone-iodine (PVI). A series of MTT assay of cultured synovial cells stimulated by PVI have been made. Test for assay of membrane-toxic effect of PVI and lactate dehydrogenase (LDH) has also been carried out. After making intraarticular injection into rats' hind knee joints with 0.1 ml of PVI every day for 1 week, we have extracted the knee joints and blood from rats in four divided groups on the 0, 1st, 3rd, and 7th day. Our microscopic analysis was performed that cartilage and synovium membrane were stained with hematoxylin, toluidine blue, and safranin O. Iodine, glutamic oxaloacetic transminase, creatine phosphokinase (CPK), and LDH in rat sera have been measured. We were able to confirm cytotoxicity in the synovial cells placed in PVI concentration of more than 6.25 x 10(-2)%. In comparison with the positive control, LDH, in this case, was released at the concentration level of 33.3%. Independent of period of stimulation, LDH was released the most in the PVI concentration of 6.25 x 10(-2). The histopathological analysis of articular cartilage has indicated clear morphological alterations in rats' synovium; especially, toluidine blue staining and safranin O staining were seen in the metachromasia of articular cartilage. However, no fissures or erosive changes in the articular cartilage, which were usually observable in the case of osteoarthritis, were observed. In the synovium inflammatory cells, which were mainly plasma cells and lymphoid cells, no neutrophils were infiltrated. The degree of infiltration has increased steadily day by day. Fibrin deposition has been observed even in the synovium of 1-day stimulation. On the 7th day, a serum total iodine concentration has been 544 microg/dl, 4,440 IU/ml for CPK concentration, and 2,049 IU/ml for LDH concentration, while the control concentrations have been 7.1 microg/dl, 491 IU/ml, and 700 IU/ml, respectively. Our experiment has disclosed that PVI preparation is strongly cytotoxic to synovial cell and articular cartilage.

ヨードホルム中毒を生じた頚部ガス壊そ症例

A case of iodoform toxicity is presented in a patient after the treatment of neck gas gangrene. Although iodoform has been widely used for the treatment of wounds, there are few case reports about its side effects, such as headache, consciousness disturbance, delirium and tachycardia. We describe a 56-year-old blind male who under-went hemodialysis for chronic renal failure, with neck gas gangrene. Nonclostridial gas gangrene of the deep neck was improved by surgical drainage and wide debridment of necrotic tissue in combination with conservative treatment. Four kinds of anaerobic gram-positive bacteria including Peptostreptococcus micros were detected in pus. After surgical treatment, we used iodoformgauze (0.22g/day) in the open wounds of the neck. Two days after the iodoform application, he became confused, then delirius. Total serum iodine concentration was high (7440μg/dl; normal range, 4.0 to 9.0μg/dl). To our knowledge, this value of iodine concentration is the highest of the previous patients reported as having iodoform poisoning. We stopped iodoform use and performed direct hemoperfusion, which was considered effective to reduce total serum iodine. The patient became conscious, and was discharged 46 days after hospitalization.

Effects of chronic iodine excess in a cohort of long-term American workers in West Africa.

A cross-sectional survey of 102 Peace Corps volunteers in Niger, West Africa, in 1998 had previously demonstrated a high rate of thyroid dysfunction and goiter attributable to excess iodine from their water filters. The Peace Corps volunteers were followed-up a mean of 30 wk after they ceased using iodine-based water filtration systems. Goiter was present in 44% of subjects during excess iodine ingestion and in 30% after removal of excess iodine. Mean serum iodine decreased from 293 micro g/liter during excess iodine ingestion to 84 micro g/liter after cessation of excess iodine. Mean total serum T(4) values increased from 100.4 to 113.3 nmol/liter (7.8 to 8.8 micro g/dl). Mean serum free T(4) increased from 32.2 to 34.7 pmol/liter (2.5 to 2.7 ng/dl). Mean serum TSH decreased from 4.9 to 1.8 mU/liter. Mean serum thyroid peroxidase antibody levels decreased from 33,000 to 22,000 IU/liter (33 to 22 IU/ml). We found that during prolonged excess iodine exposure there were marked increases in serum total iodine concentrations, and the prevalence of goiter, elevated serum TSH values, and elevated serum thyroid peroxidase antibody values increased. The prevalence of all abnormalities decreased after removal of excess iodine from the drinking water system.

ヨードホルムガーゼ｀ＴＭ´の創充填により意識障害を呈した脊椎硬膜外膿ようの１例

Iodoformgauze topical applications are often used to wound infections. We report a postoperative epidural abscess with delirium due to iodoformgauze topical application in an open wound. We had inserted an epidural catheter in 79-year-old man with an epidural abscess. After proper drainage, iodoformgauze was used to cover for the abscess. He suffered consciousness disturbance for 12 days postoperatively. Suspecting iodoform toxicity, we checked protein binding iodine (PBI) and total serum iodine. PBI was 14.5μg/dl and total serum iodine 152μg/dl. We stopped iodoformgauze use, and the man's consciousness cleared, indicating the importance of watching for side effects such as consciousness disturbance when using iodoformgauze.

Wakame seaweed suppresses the proliferation of 7,12-dimethylbenz(a)-anthracene-induced mammary tumors in rats.

We examined the anti‐tumor proliferation effects of wakame seaweed on 7,12‐dimethylbenz(a)‐anthracene (DMBA)‐induced rat mammary tumor. DMBA was administered to 8‐week‐old female Sprague‐Dawley rats, and rats which developed mammary tumors were assigned randomly to three groups. Commercial rat feed was used in a control group (group I‐A), and two feed mixtures were prepared, which contained commercial rat feed blended with wakame at 1.0% (group I‐B) and 5.0% (group I‐C) by weight. The respective feeds were given to each group for 8 weeks, and changes in mammary tumor size were compared. At the end of the experiment, mammary tumors and thyroid glands were resected to compare their weights. Serum total iodine and thyroxin (T4) levels were measured. Immunohistochemical studies for bromodeoxyuridine (BrdU) labeling, transforming growth factor (TGF)‐β, and apoptosis were carried out in the resected tumor. Significant suppression of tumor growth was observed in groups I‐B and I‐C compared with I‐A. In groups I‐B and I‐C, the weights of resected mammary tumors were significantly lower and serum total iodine concentration was significantly higher than in I‐A. BrdU indices were significantly lower in groups I‐B and I‐C, compared with I‐A. TGF‐β and apoptotic index were inversely related to BrdU. These results suggest that iodine is transported from the serum into mammary tissues and induces apoptosis through the expression of TGF‐β. In conclusion, wakame suppressed the proliferation of DMBA‐induced mammary tumors.

Evidence of thyroid volume increase in normal subjects receiving excess iodide.

A prospective study was conducted on 10 normal male volunteers to investigate the effect of the administration of excess iodide on thyroid volume. After 1 week of dietary iodide restriction, all subjects were given daily oral doses (27 mg daily total iodine dose) of licorice lecithin-bound iodine tablets for 4 weeks. Thyroid function studies, total serum iodine concentration, and urinary iodine excretion were monitored. Thyroid volume was measured by high resolution echoscanner before treatment, on the day of the last treatment, and 1 month after the treatment. There was a significant rise in serum TSH levels, with a small decline in serum free T4 concentration during iodide administration; the values remained within the normal range except for two subjects. Serum thyroglobulin levels were increased in parallel with serum TSH levels, which became higher than normal after 1 week of treatment. The volume of the thyroid gland became significantly enlarged after 28 days of iodide intake. When iodide was discontinued, thyroid volume and function returned to baseline levels within 1 month for all subjects. This is the first documentated objective evidence that the compensatory rise in serum TSH in response to iodide administration elicits reversible thyroid hypertrophy in normal subjects.

Iodide‐induced hypothyroidism in patients after thyroid resection

The purpose of this investigation was to determine whether an intrinsic defect in thyroid hormone production is required for the development of iodide-induced hypothyroidism or does it also develop in TSH-stimulated normal thyroid tissue. To answer this question, we studied the response to iodine administration (180 mg iodide daily for 3-4 months) in eight euthyroid patients who had had partial thyroidectomies 2 months to 10 years previously for benign thyroid nodules, and in three euthyroid control subjects. In all 11 euthyroid patients, basal serum TSH concentrations increased during iodide administration. In six of the eight patients who had previous thyroid operations and in two of the three control patients, basal serum TSH concentrations increased into the abnormal range (greater than 6 U ml-1). Increased serum TSH concentrations were noted as early as 1 week after potassium iodide had been started and the increased levels persisted during the period of iodide administration. Although basal values for serum TSH concentration were initially within the normal range, those patients with highest basal serum TSH values developed the greatest increase in TSH in response to potassium iodine. Among the eight patients treated by partial thyroidectomy, serum T4 concentrations decreased in five, serum T3 concentration decreased in three and all five developed mild symptoms of hypothyroidism while receiving iodide. Serum T4 concentrations also decreased slightly in two of the three control patients. Serum total iodine levels increased from 7.0 +/- 0.5 to 315.7 +/- 108.6 g dl-1 (mean-+/- standard error) during potassium iodide administration, but there was no correlation between the level of serum iodide concentration achieved and inhibition of thyroid function.(ABSTRACT TRUNCATED AT 250 WORDS)

Cythion-induced histophysiological changes in thyroid and thyrotrophs of the teleost fish, Channa punctatus (Bloch)

The chronic effects of continuous exposure for 6 months, from January to June, to safe (2.0 ppm) and sublethal (4.0 ppm) concentrations of a commonly used organophosphorus pesticide, cythion, on the histophysiology of the thyroid and thyrotrophs in Channa punctatus are described in this investigation. The pharyngeal thyroid of fish of both treated groups exhibited hypertrophy and hyperplasia of the follicular epithelium and reduction of colloid content. Apart from this, in the fish exposed to 4.0 ppm, some of the follicles were exhausted and transformed into degenerated cystic masses. The presence of free blood cells at these sites suggests rupture of blood vessels and possible phagocytosis. These histopathological changes could be correlated with a significant and dose-dependent reduction of thyroidal radioiodine uptake and conversion ratio (serum protein-bound iodine:total serum iodine) values. After cythion exposure, the thyrotrophs in the pituitary were activated. These results suggest that the thyroid dysfunction caused by cythion may be responsible for the stimulation of the thyrotrophs which in turn stimulated the thyroid follicles through the pituitary-thyroid axis in this species.

Effect of mouth rinsing with two polyvinylpyrrolidone-iodine mixtures on iodine absorption and thyroid function.

A prospective study was conducted to investigate the effect of long term therapy with two iodine-containing mouth rinses on thyroid function. Two groups of subjects were treated daily for 6 months with either a 5% polyvinylpyrrolidone (PVPI)-1.5% H2O2 mixture (Perimed) or a 5% PVPI-water mixture. Thyroid function studies, serum iodine concentrations, and urinary iodine excretion were measured before treatment, at 6-week intervals during the 6-month treatment period, and 3 weeks after the last treatment. There was evidence of significant iodine absorption (elevated serum total iodine and inorganic iodide concentrations and urinary iodine excretion) from daily use of both Perimed and the PVPI-water mixture. Serum T3 and T4 concentrations and the free T4 index did not change. There was a small significant rise in serum TSH concentrations during mouth rinse therapy, but all values remained within the normal range. This small increase in serum TSH is a normal adaptive response to the antithyroid effect of increased iodine intake and accounts for the maintenance of normal serum T4 and T3 concentrations. While daily use of these iodine-containing mouth rinses does result in significant iodine absorption, there is no evidence for the development of thyroid dysfunction during a 6-month course of therapy.