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Determination of Essential & Toxic Elements in Biological Samples of Human Subjects Having Thyroid Disorders by Different Analytical Techniques

Ghulam , Abbas (2010) Determination of Essential & Toxic Elements in Biological Samples of Human Subjects Having Thyroid Disorders by Different Analytical Techniques. PhD thesis, University of Sindh, Jamshoro.

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Abstract

Direct association of trace and toxic elements in relation to human disease has been observed in many research studies.The health of human being depends largely on a normal supply of essential trace elements in tissues and changes to its concentrations may lead to different physiological disorders including thyroid disorders.Thyroid disorders including: Grave’s disease, Hashimotoe’s disease, lymphocytic thyroiditis, toxic multinodular goiter, thyroid cancer, pituitary disease, infection, tumors, cretinism, congenital anomalies, neurological dysfunction, impaired reproduction, still birth and spontaneous abortion. In many developing countries, human populations are at high risk of goiter, related to iodine, iron (Fe), zinc (Zn) and selenium (Se) deficiencies, whilst excess level of Copper (Cu) and Cadmium (Cd) can have adverse effects on thyroid metabolism.The iodine, Fe, Zn, Se, and Cu are critically importance in the proper functioning of the thyroid hormones such as: thyroid stimulating hormone (TSH), free triiodothyronine (FT3) and thyroxine (FT4). These hormones are involved in many different ways in human metabolism and are essential for normal growth, mental and physical development. The intracellular localization of Cu/Zn and Mn-superoxide dismutase (SOD), which catalyze the dismutation of superoxide radicals (O2-) to O2 and H2O2, was studied in the thyroid tissue of various thyroid disorders by an immunohistochemical technique.Nutrient deficiencies, including Fe, Zn, Se and vitamin A and severe protein malnutrition also contribute to an inability to use iodine well and to the development of various types of thyroid disorders. The Cd appears to be the largest single contributor to autoimmune thyroid disease.It is a very powerful and toxic metal which seems to be placed at the very center of the thyroid story.On other hand, Cd has been found to inhibit FT4 synthesis and/or its release and to depress type I iodothyronine 59-monodeiodinase (59D-I) activity, resulting in a decreased serum FT3 level. In present study, the concentration of iodine, Fe, Zn, Se, Cu and Cd in biologica samples (serum and urine) of different thyroid disease patients (age ranged 15-50 yrs) with healthy subjects of both genders from different areas of Sindh. Both controlled and study group patients were of same socio-economic status, localities and dietary habits. The mothers have hypothyroid thyroid and their neonates were also scrutinized for understudy essential trace and toxic metals in present study.The biological samples (serum and urine) were oxidized by 65% nitric acid, 30% hydrogen peroxide (2:1) ratio in microwave oven for 2-5 minutes, to reduce the conventional wet acid digestion period 2-3 hours. The all digested samples were analyzed for iodine by iodide-ion selective electrode (iodide-ISE), Zn and Fe concentrations using flame atomic absorption spectrometer, while Se and Cu by Electrothermal atomic absorption spectrometer. The results showed the significantly lower concentrations of iodine, Fe, Zn and Se, while high level of Cu and Cd obtained in the serum and urine samples of hypothyroid patients as compared to the control healthy subjects of both genders. The mean values of iodine, Fe and Se in serum and urine samples of thyroid mothers and their infants were significantly lower as compared to the referent mothers-infants pairs (p< 0.01).Deficiencies of iodine, Fe, Zn and Se may play an important role in the etiology of thyroid disease in the subjects of present study as compared to the normal subjects.

Item Type:Thesis (PhD)
Uncontrolled Keywords:Determination, Essential, Toxic Elements, Biological Samples, Human Subjects, Thyroid Disorders, Different, Analytical, Techniques
Subjects:Physical Sciences (f) > Chemistry(f2) > Analytical chemistry(f2.2)
ID Code:7434
Deposited By:Mr. Javed Memon
Deposited On:12 Jul 2012 08:57
Last Modified:12 Jul 2012 08:57

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