Thyroid functional disturbances

We have no data on the thyroid function parameters except in cases suspected for thyroid function disturbances. We have no neonatal thyroid screening yet. 

Potassium Iodide. When potassium iodide [7681-11-0] is adrninistered orally for several (6—8) weeks, a therapeutic effect may be obtained ia the subcutaneous form of sporotrichosis. Amphotericin B is used iatravenously to treat systemic sporotrichosis. The KI dosage is usually a saturated solution ia water (1 g/mL). The usual oral dose is 30 mg/kg/d. Children should receive five droplets, three times a day (after meals) the dose may be iacreased to 15—20 droplets. Side effects iaclude digestive disorders, swelling of the saUvary glands, and lacrimation. Thyroid function tests may be disturbed. 

Disruption of thyroid functions in vertebrates has been suggested to constitute a potential threat to many vital functions. For example, there is a possibility that disruption to the thyroid hormone levels during embryogenesis could result in disturbed behaviour patterns in the adult form, possibly interfering with migration in certain species and sonar functions in cetaceans. In anurans, thyroid hormones are essential for initiating metamorphosis. ... 

The function of the target molecule may be critical or mncritical. Thus, if the target molecule is an enzyme, this could be involved in a crucial metabolic pathway, such as mitochondrial oxidative phosphorylation. In this case, an adverse interaction with the ultimate toxicant is likely to lead to cell dysfunction and possibly death (e.g., as with cyanide or salicylate). Chemicals such as methimazole and resorcinol, which are activated to free radical intermediates by thyroperoxidase, cause destruction of the enzyme. This then disturbs thyroid hormone synthesis and thyroid function with pathological consequences such as thyroid tumors. 

Therapeutic uses. Because of their narrow therapeutic margin, antiarrhythmics are only employed when rhythm disturbances are of such severity as to impair the pumping action of the heart, or when there is a threat of other complications. Combinations of different antiarrhythmics are not recommended (e.g., quinidine plus verapamil). Some agents, such as amiodarone, are reserved for special cases. This iodine-containing substance has unusual properties its elimination half-life is 50-70 days depending on its electrical charge, it is bound to apolar and polar lipids, stored in tissues (corneal opacification, pulmonary fibrosis) and it interferes with thyroid function. 

In a study by Lancranjan et al. (1972), 109 workers exposed to carbon disulfide for 7-31 years were examined for thyroid function. A group of 40 workers served as controls. The exposure concentrations varied from 19 to 29 ppm and from 72 to 96 ppm. The study authors concluded that carbon disulfide did not induce thyroid alterations or disorders of lipid metabolism. In another study, the effect of long-term exposure to carbon disulfide (10-36 years) was studied in 15 exposed and 16 age-matched controls (Wagar et al. 1981). The exposure levels ranged from 10 to 51 ppm. No disturbance was noted in either thyroid function or serum prolactin values. Serum cortisol was also unchanged. 

Consequently, the observed disturbance of the development of the young nursed by the dams drinking water with the highest bromide concentration could be the result of an impairment of the youngs thyroid function. 

Ethyl alcohol is found in alcoholic beverages and is a known teratogenic material, which is the reason doctors tell pregnant women not to drink alcohol. When a mother drinks, the unborn child drinks as well. Ethyl alcohol causes growth failure and impaired brain development. Unborn children exposed to alcohol may suffer the effects of Eetal Alcohol Syndrome when they are bom. Symptoms of Fetal Alcohol Syndrome include sleep disturbance, jitteriness, a higher incidence of impaired vision and hearing, lack of motor coordination, balance problems, abnormal thyroid function, and a decrease in immune system effectiveness. Additional teratogens include heavy metals, methyl mercury, mercury salts, lead, thallium, selenium, penicillin, tetracyclines, excess Vitamin A, and carbon dioxide. 

Disturbances in thyroid function are associated with abnormal TBP capacities and a brief review of these is relevant, as the findings have a bearing on the free T4 concept. Untreated thyrotoxicosis is associated with decreases in both TBPA (Bll, C2, II, 14, V3) and TBG (Bll, G2, II) and myxedema with decreases in TBPA (V3) and increases in TBG (II). The increase in TBG in myxedema would outweigh the decreases in TBPA, and therefore the overall effect is a decrease in serum T4-binding in thyrotoxicosis and an increase in myxedema. These findings favor the theory that the important serum T4 fraction is that attached to TBP rather than the free fraction, as the increased binding capacity in myxedema would help to offset the effects of declining T4... 

These three antibodies acting against different thyroid constituents are associated with destructive inflammatory lesions of the thyroid. This results in disturbed thyroid function which may present as either hypo or hyperthyroidism. 

Goiter and hypothyroidism due to iodine deficiency are major world health problem. Intake of excess iodine, either in food, water or drugs, may also result in disturbances of thyroid function and goiterl>2 Clinical data as well as animal experiences have shown a sharp rise in the incidence of autoimmune thyroiditis when iodine consumption was increased.2>3,4 Administration of iodine or or iodine containing drugs increases the incidence of thyroid autoantibodies in humans without illness as well as in populations with endemic goiter. Hokkaido is located in the northernmost part of Japan. Separated from the main island by the sea, Hokkaido covers an area of 83,511Km2, and its population of 5.3 million is considerably lower than that of the rest of Japan. 

Biologic Effect of the Thyroid Hormone. The thyroid gland regulates the entire metabolism of the adult organism. Disturbances of the thyroid function are reflected in the basal metabolic rate (metabolism while resting, cf. Chapt. XXII-1). In hyperthyroidism (thyrotoxicosis) the rate is elevated during hypofunction (clinical manifestation myxedema), it is lowered. This phenomenon is used frequently in judging thyroid function. Administration of thyroxine raises the basal... 

The functional form of thyroxine (T3) is generated by the deiodination of T4, and PCBs can influence the tissue levels of this form by disturbing metabolism, as well as by reducing the binding of T4. PCBs have been shown to inhibit the sulfation of thyroid hormones and the deiodination of T4 to T3. They can also induce the glucuronyl transferase that conjugates T4 (Brouwer et al. 1998). 

Strong disturbance rof P-Ca, Na-H-CI equilibrium, Decreased protein synthesis, significant changes in protein blood fractions. Disturbance of thyroid goiter and kidney functions. Excessive content of Si Ca in milk and meat... 

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