Iodine concentration in different human brain parts

Iodine is one of the most important essential elements as demonstrated by the fact that its deficiency can cause goitre. Nevertheless, quantitative data on its concentration in biological materials, especially in the human brain, are scarce. There is therefore a demand for accurate and reliable information on iodine in these types of samples. The purpose of the present work was to determine the concentration of total iodine in some control human brain parts by rapid radiochemical neutron activation analysis. Our second goal was to determine I distribution between lipid fraction and in brain tissue without lipid by applying two types of solvent extraction methods. The results were checked by the analysis of biological standard reference materials with certified or literature values for iodine and good agreement was found.     

Iodine and creatinine testing in urine dried on filter paper

Iodine deficiency is a world-wide health problem. A simple, convenient, and inexpensive method to monitor urine iodine levels would have enormous benefit in determining an individual's recent iodine intake or in identifying populations at risk for iodine deficiency or excess. Current methods used to monitor iodine levels require collection of a large volume of urine and its transport to a testing laboratory, both of which are inconvenient and impractical in parts of the world lacking refrigerated storage and transportation. To circumvent these limitations we developed and validated methods to collect and measure iodine and creatinine in urine dried on filter paper strips. We tested liquid urine and liquid-extracted dried urine for iodine and creatinine in a 96-well format using Sandell–Kolthoff and Jaffe reactions, respectively. Our modified dried urine iodine and creatinine assays correlated well with established liquid urine methods (iodine: R² = 0.9483; creatinine: R² = 0.9782). Results demonstrate that the dried urine iodine and creatinine assays are ideal for testing the iodine status of individuals and for wide scale application in iodine screening programs.     

甲状腺肿机制在会成蛋白质时Zn/Ca失调抑制I~-向I~0转化的研究

虽然碘缺乏假说一直被认为是导致甲状腺肿的病因,但实质并不清楚。本文根据中外文献资料、多学科交叉理论,结合江苏省苏南西部地区地甲病与环境地质条件关系综合研究,论述了碘元素在自然环境中分布差异取决于是否有适宜微生物生长繁殖的环境,碘元素靠生物吸收聚积,碘流失理论无法解释。人体甲状腺缺碘,并非环境缺碘,甲状腺肿机制在合成蛋白质时Zn／Ca失调．摄入体内Ca含量高,合成Ca蛋白质高,阻碍Zn元素合成Zn蛋白质,Zn蛋白质合成的醉不足,摄入的无机碘（I-）不能被酶活化为分子砍（Io）合成甲状腺素,而经细胞外──肾系统排出体外,导致恩者尿中高I-、Ca2+,而甲状腺内缺碘的反常病理生化特征。     

2007年重庆市璧山县和云阳县抽样地区环境碘含量调查分析

为了解重庆市抽样地区自然环境中的碘含量,为碘盐的合理摄入和防治碘相关疾病提供依据,采用多级整群随机抽样法,选择重庆市渝东地区云阳县和渝西地区璧山县为调查点,在两县经济状况中等的乡镇各抽取3所乡镇小学的8～10岁儿童各30名作为调查对象,以直接滴定法(GB/T13025.7-1999)检测了其家庭食用盐碘含量;采用随机抽样方法抽取两县居民饮用水样和土壤样,以GB5750-85中砷铈催化分光光度法测定了水碘含量,反向放大比色法测定了土壤碘含量。结果表明,检测两县居民食盐样本556份,璧山县与云阳县食盐碘均数分别为30.41和35.78mg/kg;抽取两县居民饮用水样87份,两县水碘中位数分别为6.50和2.78μg/L;水碘含量10μg/L的水样分别占73.33%和100%;抽取两县浅表层土壤样品88份,两县土壤碘中位数分别为8.20和7.56mg/kg。提示两抽样县均属于碘缺乏地区,需要通过食盐加碘防治碘缺乏病。可根据各地区具体情况,考虑适当调整食盐含碘量。     

科学补碘:消除碘缺乏病的成败关键

碘对甲状腺功能具有双向作用,在消除碘缺乏病的同时,切不可忽略全民食盐加碘后高碘甲状腺病的防治。分别从水碘和尿碘两个方面论述了碘与甲状腺病之间的双向关系,并根据流行病学调查数据和全国碘缺乏病监测数据确定了盐碘与尿碘之间的数学关系,计算了食盐碘含量的最适宜范围,提出了下调食盐碘含量、设计区域化碘盐和补碘个性化的科学补碘新策略。     

3671例少儿头发微量元素检测结果的分析

为掌握广州市某大型国有企业属下的幼儿园、小学、中学生微量元素状况,给微量元素缺乏病的临床诊断提供科学依据,对该企业的5所幼儿园、2所小学、1所中学的3 671例儿童进行了头发中元素钙、锌、铁、铜、锰、碘、铅的含量检测。结果表明,缺钙181人次,占4.9%;缺铁177人次,占4.8%;缺锌769人次,占20.9%;缺铜551人次,占15.0%;缺碘2 056人次,占56.0%;缺锰129人次,占3.5%;高铅2 668人次,占72.7%。提示幼儿园、小学生存在微量元素缺乏比例大,中学生除了碘、锰外大多数微量元素都不缺乏,无论是幼儿、小学生或中学生有害元素铅都偏高,是保健的重点。     

Iodine determination in biological materials Options for sample preparation and final determination

This paper describes the development of various new acid sample decomposition methods, as well as an extraction (leaching) method and compares them with the “Sch?niger Combustion” technique. The methods have been developed as sample preparation techniques for iodine determination in biological materials, especially in solid samples. ICP-MS (inductively coupled plasma mass spectrometry) and a catalytic technique are employed and discussed for the final determination of iodine concentrations. Accuracy and reliability of the different analytical methods are shown in the examples of different CRMs (certified reference materials) available for iodine. The results of an interlaboratory comparison are specifically presented for the extraction (leaching) method. Received: 11 May 1998 / Revised: 14 June 1998 / Accepted: 16 June 1998     

Determination of iodine in seafood by inductively coupled plasma/mass spectrometry.

A method was developed for determination of total iodine content in different standard reference materials (SRMs) and seafood products by inductively coupled plasma/mass spectrometry (ICP/MS). If iodine is present as iodide and nitric acid is used in the wet digestion system, the observed signal is not stable when iodine is measured by ICP/MS at m/z 127. To stabilize the iodine signal, 3% ammonia solution (1 + 1, v/v) was added to the digest. The limit of quantitation of the method, defined as 6 times the standard deviation in the blank solution (n = 20) was estimated to be 15 mg/kg (using 0.2 g dry mass and a dilution factor of 50). The precision, expressed as repeatability of the iodine concentration, varied between 3.2 and 12% in SRMs, with concentrations of 4.70-0.17 mg/kg dry matter. The described method was compared with a method using tetramethylammonium hydroxide extraction. Both methods showed good precision and trueness by analyses of SRMs. The 2 methods were used to determine iodine in seafood from the Barents Sea, the Norwegian Sea, and the North Sea. The results showed great variation between different fish species as well as between individuals within a species. The lowest values of iodine were recorded in muscle of ling (Molva molva) with a mean of 0.07 mg/kg fresh weight and a variation between 0.03 and 0.11 mg/kg fresh weight. The highest values were found in cod (Gadus morhua) from the Barents Sea, with a mean of 2.5 mg/kg and a variation between 0.7 and 12.7 mg/kg fresh weight.     

Determination of iodine in human brain by epithermal and radiochemical neutron activation analysis

Despite the role of iodine for proper development of the brain and the functions of the element, the accurate data on its concentration in brain tissue are largely lacking, the main reason being analytical difficulties associated with determination of the element especially at low levels. In this work, samples from human brain regions from Hungarian patients were analyzed using epithermal and radiochemical neutron activation analysis (ENAA and RNAA, respectively). The RNAA procedure is based on alkaline-oxidative fusion followed by extraction of elemental iodine in chloroform. The results were checked by the analysis of biological standard reference materials, namely bovine liver, bone meal and diet, and by comparison with previous results obtained by a different RNAA procedure.     

重庆地区食盐加碘含量下调的可行性研究

为探讨重庆市食盐加碘含量下调的可行性,分析比较了重庆市碘盐和碘缺乏病监测结果(儿童甲状腺肿大率、智商、尿碘、家庭食用碘盐)。结果表明,碘盐含量稳定,全民食盐加碘防治碘缺乏病的措施成功,但尿碘水平高于适宜水平,甲肿率居高不下,可能存在补碘过量,引起高碘性甲状腺肿大。为有效控制甲肿率和尿碘水平,建议下调食盐加碘含量。     

重庆地区特需人群碘营养水平及影响因素分析

为了解重庆地区孕妇、婴儿及其母亲碘营养现状,给该地区实施科学补碘提供科学依据,采用砷铈催化分光光度法测定了当地水碘和孕妇、婴儿及其母亲的尿碘,电化学发光法检查了孕妇甲状腺功能.结果表明,水碘为5.99 μg/L,孕妇、乳母、婴儿尿碘中位数为203.80 μg/L、218.3 μg/L、288.4 μg/L,FT3、FT4为(3.94±0.59) pmol/L、(12.44±2.30) pmol/L;逐步回归分析表明,碘营养与文化程度、食用优质蛋白及富硒食品呈正相关,母亲缺碘是小孩缺碘的危险因素之一.提示特需人群的碘营养水平适宜,文化程度、食用优质蛋白及富硒食品为主要影响因素,婴儿尿碘与母亲相关.     

Instrumental Neutron Activation Analysis of Iodine Levels in Fourteen Seaweed Species from the Coastal Belt of Ghana

Fourteen seaweed species were sampled from October 1997 to May 1999 along the rocky shores of Ghana, which is being washed by the Gulf of Guinea (part of the Atlantic Ocean). Instrumental neutron activation analysis (INAA) was used to measure the iodine levels in the species, with the basic aim of selecting seaweed species that are rich in iodine and hence can be used as supplement in the diet of humans. This is to help solve the problems associated with iodine deficiency disorders (IDD). The levels of iodine found in the seaweed species ranged between 55 to 804 ppm. The precision, expressed in terms of relative standard deviation, and accuracy of measurements are within ±5–10%. The results show high variability in and between species and among sampling sites. The high values of iodine concentrations in the macroalgae suggest that these marine organisms can be used as supplement in the diet of humans.     

Iodine monochloride in anhydrous acetic acid as an oxidizing agent

A systematic study of the redox reactions of iodine monochloride with various inorganic ions in glacial acetic acid medium is described. Sodium sulphite, mercury(I) perchlorate, antimony trichloride, arsenic trichloride and iron(II) perchlorate were examined. Potentiometric and amperometric methods were used to follow the reduction of iodine monochloride, which yields different products according to the type of reductant.     

Iodine trichloride in glacial acetic acid as an oxidizing titrant

A systematic study of the redox reactions of iodine trichloride with various inorganic ions in glacial acetic acid medium is described. Sodium sulphite, arsenic trichloride, antimony trichloride, iron(II) perchlorate and mecury(I) perchlorate were examined. Potentiometric and amperometric methods were used to follow the reduction of iodine trichloride, which yields different products according to the type of reductant.     

Iodine determination in water samples from endemic goitrous areas using MAA

A rapid and simple method for the determination of iodine from water has been described which is based on preconcentration of iodine with 0.1M solution of 4-(5-nonylpyridine) in benzene or carbon tetrachloride from 1–2M HNO₃ followed by neutron irradiation and gamma-ray activity measurements. A clinical survey of endemic goitrous area has also been made to find a possible correlation between the endemic goiter and iodine deficiency in water.     

Epithermal instrumental neutron activation analysis of biological reference materials for iodine

Epithermal instrumental neutron activation analysis (EINAA) methods have been optimized and applied to several biological reference materials and selected food items for the determination of iodine. The method involves irradiation of the samples for different periods in epi-cadmium and/or epi-boron flux of the Dalhousie University SLOWPOKE-2 reactor and direct counting without any pre-treatment on a 25-cm³ hyperpure Ge detector. The 443 keV photopeak of ¹²⁸I is used for assaying the iodine content. Precision of measurements, expressed as the relative standard deviation, is 10–15% at 200–500 ppb and 3–12% at 500–6000 ppb levels of iodine. Accuracy of iodine measurements is within 5%. The detection limits for iodine in several biological materials with cadmium and boron, either alone or a combination of the two, as thermal neutron shields have been found to vary between 0.1 and 0.4 mg · kg^–1 for different periods of irradiation, decay and counting. The results suggest that the EINAA methods can be successfully applied to biological materials for routine analysis of iodine at levels higher than 200 ppb.     

Minerals in Pregnancy and Their Impact on Child Growth and Development

During pregnancy, women undergo metabolic and physiological changes, and their needs are higher, to maintain growth and development of the fetus. If the nutritional status of the expectant mother is not satisfactory, some maternal and neonatal complications can occur. In the second and third trimester of pregnancy, there is a reserve of nutrients in the fetus that can be utilized after birth; thereby, children present an accelerated growth in the first years of life, which is a proven response to the available nutrition pattern. However, if such a pattern is insufficient, there will be deficits during development, including brain function. Therefore, despite many recent published works about gestational nutrition, uncertainties still remain on the mechanisms of absorption, distribution, and excretion of micronutrients. Further elucidation is needed to better understand the impacts caused either by deficiency or excess of some micronutrients. Thus, to illustrate the contributions of minerals during prenatal development and in children, iodine, selenium, iron, zinc, calcium, and magnesium were selected. Our study sought to review the consequences related to gestational deficiency of the referred minerals and their impact on growth and development in children born from mothers with such deficiencies     

Microsatellite instability and its correlation with clinicopathological features in a series of thyroid tumors prevalent in iodine deficient areas

Thyroid tumors display diverse spectrum of histopathological groups with geographic variation in its prevalence. Influence of iodine deficiency (a major causative factor) in its etiology, prevalence, or aggressiveness is debatable which reflects the existence of various genetic events in pathogenesis. The present study was undertaken to study the role of Microsatellite instability (MSI) or LOH (loss of heterozygosity), an indicator of defective mismatch repair system as a genetic change and to explore it as a prognostic marker in thyroid tumors. Tumor tissues from total thyroidectomy surgical specimens and blood (matched control) of 36 patients from iodine deficient areas (10 benign; 26 malignant) were obtained after their consent. Urinary iodine analysis was done by alkali ash method for which 10 ml of urine was collected from 18 patients before surgery. Genomic DNA, isolated from tumor tissue and blood was amplified by polymerase chain reaction (PCR) using mono and dinucleotide markers - BAT-26, BAT-40, TGF(RII, IGFIIR, hMSH3, BAX, D2S123, D9S283, D9S851 and D18S58. PCR products were analysed on 8% denaturing polyacrylamide gel followed by autoradiography. Of total, 66.6% of tumors [70% (7/10) benign and 65.4% malignant cases (17/26)] showed MSI/LOH. Strong association of MSI/LOH with low iodine (P = 0.01) and with AMES risk groups i.e. age (P = 0.02), tumor size (P = 0.04) and metastases (P = 0.002) in thyroid tumors was observed. This may help in predicting the biological behaviour and strengthening the hypothesis that iodine deficiency has influence on MSI in thyroid tumors. Our results further substantiate the risk group classification and help in deciding the treatment modality in particular patient.     

缺碘区居民膳食结构及营养素摄入量对尿碘水平的影响

通过抽样调查,了解重庆市环境缺碘地区居民的饮食习惯,分析了膳食因素对人群尿碘水平的影响,为制订地方性碘缺乏病综合防治措施提供依据.采用24 h膳食回顾法,对重庆市两县居民的膳食摄人情况进行现况调查,比较各营养素摄入量.结果表明,两地膳食结构属于东方膳食模式,璧山县各营养素摄入量高于云阳县.结论:蛋白质、能量、维生素等缺...     

FTIR spectroscopy study of the interaction between fibre of polyamide 6 and iodine

The IR spectra of several samples of polyamide 6 fibres treated with solutions of different concentrations of iodine and potassium iodide were studied. The IR spectra of their respective iodine desorptions, obtained by means of treatment with sodium thiosulphate, were also studied. The spectral changes observed are related to variations in the polymorphic crystalline α and γ forms of the polyamide, which demonstrate the formation of a complex between the tri-iodide ion and the polymer during the iodine sorption process and a structural change during desorption.