Blood iodine

TRANSPORT OF THYROID HORMONES IN THE BLOOD Iodine circulates as both organic iodine (95%) and inorganic iodide (5%). Most organic iodine is in T (90-95%), while Tj contains approximately 5%. Both T and T are transported in the blood in strong but noncovalent association with plasma proteins. 

Blood iodine levels were elevated at subtoxic doses of iodine, indicating adequate exposure. Iodine toxicity manifested itself as reduced performance. Since iron supplementation prevented it, this toxicity may have resulted from an apparent interference of iodate or iodine, respectively, with iron uptake or utiftzation. NOELs for pigs were observed at 400 parts per million (ppm) calcium iodate added to hog mash calves were more susceptible with a NOEL of only 25 ppm. The toxic signs were attributed either to iron deficiency or to general iodine toxicity. 

Well tolerated systemically Although well tolerated, elevated blood iodine levels have been reported... 

Kurt TL et al Fatal iatrogenic iodine toxicity in a nine-week old infant. J Toxicol Clin Toxicol 1996 34(2) 231-234. [PMID 8618260] (A 9-week-okJ infant with colic was given an enema using so mL of povidone-iodine diluted in 250 mL of a bowel irrigant, resulting in fatal corrosive necrosis of the lower Gl trad and total blood iodine level of 14,600 mcg/dL.)... 

About half of the blood iodine is associated with the red cells the remaining is in the serum. The serum contains 1 pg of inorganic iodides per 100 ml. The inorganic iodide in the general circulation is picked up mainly by two organs— the kidney, which excretes the iodide, and the thyroid, which uses it for thyroid hormone biosynthesis. 

The metabolism of the thyroid gland can be investigated clinically by a number of different techniques such as studies on the concentration of iodine in blood, iodine excretion, thyroidal uptake of radioactive iodine, and determination of iodine in blood. The concentration of total iodine in blood is increased in hyperthyroid individuals. The increase is mainly in protein-bound iodine as it is determined in alcohol or zinc hydroxide precipitates. 

The results summarized in table 3 show that, in normal sheep, for a Lipiodol dose of 10 mg iodine per kg, blood iodine levels increased for 2 to 3 weeks and return to the baseline within 5 months in the case of intramuscular administration, and 1.5 months in the case of oral administration. 

In iodine-deficient pigs (results in table 4), the same dose administered orally caused a very rapid increase in blood iodine levels which were maximum within the days following administration and lasted a little longer than in normal sheep, i.e. 2.5 months. 

Farm animal studies demonstrate that in normal large animals, the oral absorption of lipiodol causes a progressive increase in blood iodine levels. In iodine deficient pigs, a very rapid increase in blood iodine levels, which lasted 2,5 months, was observed. The clinical efficiency of the iodized oils therapy was strongly suggested by various authors who evidenced lamb goiter in Australia and New Zealand and successfully treated it by iodized oils . 

In other applications of CT, orally administered barium sulfate or a water-soluble iodinated CM is used to opacify the GI tract. Xenon, atomic number 54, exhibits similar x-ray absorption properties to those of iodine. It rapidly diffuses across the blood brain barrier after inhalation to saturate different tissues of brain as a function of its lipid solubility. In preliminary investigations (99), xenon gas inhalation prior to brain CT has provided useful information for evaluations of local cerebral blood flow and cerebral tissue abnormalities. Xenon exhibits an anesthetic effect at high concentrations but otherwise is free of physiological effects because of its nonreactive nature. 

The main role of the human thyroid gland is production of thyroid hormones (iodinated amino acids), essential for adequate growth, development, and energy metaboHsm (1 6). Thyroid underfunction is an occurrence that can be treated successfully with thyroid preparations. In addition, the thyroid secretes calcitonin (also known as thyrocalcitonin), a polypeptide that lowers excessively high calcium blood levels. Thyroid hyperfunction, another important clinical entity, can be corrected by treatment with a variety of substances known as antithyroid dmgs. 

The philosophy of public health protection used by the AEC and pursued ever since, is the use of multiple independent barriers, each a significant shield for the public. The last barrier involves the removal of people from the area over which the radioactive plume is expected to pass, interdiction of food supplies and the use of prophylaxis to reduce the iodine dose. Blood... 

Other electrolytes of importance include calcium (especially if the patient is receiving a calcium channel blocker, such as nicardipine) and magnesium, as hypomagnesemia may predispose the patient to seizures, further complicating the ICP management. If the patient received intravenous iodinated contrast as part of their stroke evaluation, then careful monitoring of the blood urea nitrogen (BUN) and creatinine levels is necessary to detect contrast nephropathy. 

Pharmacologic management of infections should cover the gram-positive organisms that most frequently cause access-related infections. Patients who have positive blood cultures should receive treatment tailored to the organism isolated. Preventive measures for access-related infections include mupirocin at the exit site and povidone-iodine ointment. The recommendations of the NKF for treatment of infections associated with hemodialysis are listed in Table 23-9. 

Radioactive iodine uptake (RAIU) Red blood cell (RBC) count (blood) Less than 6% in 2 hours ... 

Puacz et al. (1995) developed a catalytic method, based on the iodine-azide reaction, for the determination of hydrogen sulfide in human whole blood. The method involves the generation of hydrogen sulfide in an evolution-absorption apparatus. In addition, the method allows for the determination of sulfide in blood without interference from other sulfur compounds in blood. A detection limit of 4 g/dm3 and a percent recovery of 98-102% were achieved. Although the accuracy and precision of the catalytic method are comparable to those of the ion-selective electrode method, the catalytic method is simpler, faster, and would be advantageous in serial analysis. 

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