[Histological detection of dried tiny thyroid tissue in health foods].

Two patients were diagnosed as having hyperthyroidism, and both had taken the same health food. We compared three kinds of histological methods to detect thyroid gland in this health food. The first method used cytology; the second applied the cell-block method; and the last is a modification of the cell particle (CPCB) method proposed by Ushijima. It is the third method that achieved superior results, and this enabled the morphological detection of thyroid gland. Certain kinds of health foods contain dried thyroid as a "slimming supplement", and intake of these products may damage health. Histological techniques are effective for detecting the existence of dried thyroid gland. A health food is very different from clinical specimen; therefore, we have to devise appropriate skills for examining it. Such examinations will be important in the future, because it is expected that the risks of damaging health by consuming certain kinds of health food will increase.

Differential pulse polarographic determination of iodine in thyroid tablets: collaborative study.

A differential pulse polarographic (DPP) method for the determination of iodine in thyroid and thyroid preparations was collaboratively studied by 8 laboratories. The overall concentration of iodine in commercial thyroid tablets containing 1/4, 1,2, and 5 gr. of declared thyroid was 0.196%. The overall repeatability and reproducibility standard deviations were 0.0043 and 0.0067, respectively, and the corresponding coefficients of variation were 2.18 and 3.41%, respectively. The results obtained by the DPP method agreed with those obtained by the U.S. Pharmacopeia XX method at the various concentrations of declared thyroid studied. The DPP method has been adopted official first action.

Quantitative semiautomated colorimetric determination of thyroid (iodine) in thyroid tablets.

A faster, simpler, more sensitive, and semiautomated method was developed for the analysis of thyroid in individual thyroid tablets and composite samples. The sample is combusted in a Schoniger flask in an oxygen atmosphere, and the liberated iodine is trapped in a dilute sodium hydroxide solution. The solution is acidified with sulfuric acid (1:1), and the iodine is determined colorimetrically using a suitable spectrophotometer equipped with an automated analyzer. The proposed methodology was applied to tablets containing 32.4--324 mg of thyroid. Recoveries ranged from 90.0 to 125.0% of the amount of iodine added as potassium iodide. The proposed method is sensitive to 2.5 ng of iodine/ml.

Differential pulse polarographic analysis of thyroid hormone: determination of iodine, thyroxine, and liothyronine.

A differential pulse polarographic method for the analysis of thyroid and thyroid tablets for total iodine, thyroxine, and liothyronine is described. The procedure for iodine, which is also applicable to individual tablet assay, consists of ashing the sample, coverting iodide to iodate, and analyzing by differential pulse polarography. The procedure for thyroxine and liothyronine involves hydrolysis of the sample with barium hydroxide and isolation and separation of the iodoamino acids using ion exchangers, followed by differential pulse polarographic determination in a supporting electrolyte composed of 0.5 N Na2CO3 in 20% 2-propanol containing 1% tetrabutylammonium bromide. The differential pulse polarographic results for iodine agree with values obtained using the USP XIX procedure, and the quantities of thyroxine and liothyronine found agree with literature values.

Triiodothyronine and thyroxine content of desiccated thyroid tablets.

Triiodothyronine (T3) and thyroxine (T4) were measured by radioimmunoassay in Pronase hydrolysates of four lots each of 1- and 2-grain tablets of desiccated thyroid (Thyroid, Armour) and thyroglobulin (Proloid, Warner-Chilcott). The methodology used was verified by studies of tablets containing known quantities of T4 and T3. One grain of desiccated thyroid contained 12 +/- 1 and 64 +/- 3 microgram (mean +/- SD) of T3 and T4 per tablet, respectively (T4/T3 molar ratio, 4.3). A 1-grain tablet of thyroglobulin contained 16 +/- 2 and 55 +/- 5 microgram of T3 and T4, respectively with a T4/T3 ratio of 2.9. Two-grain tablets generally contained twice the quantity of T3 and T4 in the 1-grain preparations. The variation in T3 and T4 content between the four lots of each tablet strength for each product was 10% or less. These estimates of T3 and T4 content are 1.5- to 2-fold greater than those previously published. This difference probably results from the more sophisticated methodology now available which does not require chromatographic separation of T3 and T4 or iodometry. Using calculations based on published estimates of T4 and T3 absorption and of the T3/T4 potency ratio, it would appear that the T3 content of desiccated thyroid and thyroglobulin provide approximately 39% and 51%, respectively, of the thyromimetic activity of these two medications.