Dorland’s Illustrated Medical Dictionary

Dorland’s Illustrated Medical Dictionary

SCIENTIFIC EDITION February 1958 possible storage sites for IPG or iodine metabolized from it was discarded. For its size, the thyroid gland is capa...

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February 1958

possible storage sites for IPG or iodine metabolized from it was discarded. For its size, the thyroid gland is capable of storing a large amount of iodide. However, the amounts observed cannot be considered as representing significant storage in comparison t o the total therapeutic dose, and the chromatograms did not detect any IPG. The possibility exists that the acetal portion of IPG could be broken enzymatically t o release iodinated three-carbon residues, which might escape detection as organic iodine by means of chloroform extracts because of higher water solubility. However, this same alteration of solubilities should have resulted in the appearance of separate entities in the paper chromatographic studies, but no reproducible evidence of separate entities was obtained. This was not construed to mean that the acetal ring is not broken in the metabolism of the compound. It merely gave some evidence that, if this does occur, it is probably after the iodine has been removed. The possibility exists of the release of iodine from IPG in elemental form by a metabolic process of general distribution in the body, with consequent rzpid combination with body proteins. This could be sufficiently widespread to be unobservable as a storage in a specific tissue. Also, widespread lowconcentration storage of I P G itself in these tissues, with relatively slow release of iodide, is possible. These two mechanisms seem to be reasonable explanations for the data obtained in the investigation. The investigation of iodine storage in the thyroid gland indicated that, following a single therapeutic dose, the gland was able t o trap more iodine from IPG than from potassium iodide, was able to convert more of the iodide to thyroxin form from the IPG dose, and able to maintain these higher iodine levels over the comparison period studied. The investigatioxs also revealed that the thyroid glands did not trap IPG as such, but trapped iodide released from IPG. The blood iodide levels alone, compared with those of potassium iodide, do not constitute a reason-


able explanation of this picture. The possibility that this effect was the result of the use of a 60%glycerin solution as the vehicle for IPG exists, and further work on this point is indicated. From the prolonged duration of blood levels of IPG following a single dose, it might be presumed that in a course of therapy continuously effective thyroxin-blocking levels of blood iodide would be produced by IPG. Also, it might be considered that these levels would be maintained with IPG at a lower daily dosage than would be necessary with potassium iodide. It might be noted here that McKnight (1, 2) produced successful involution of hyperthyroid glands and rapid cessation of thyrotoxic symptoms in the patients with large (300 mg.), once-daily, intravenous doses of IPG, without untoward symptoms. Comparison of data obtained in this investigation with those of Broking (12). Bonanni (13), and Forbes (14), on the rate of release of iodine from iodized fatty acids and fats indicates that I P G releases iodine more rapidly than these compounds, and seems, therefore, to be intermediate between them and inorganic iodine compounds with respect t o the rate of availability of its iodine.

REFERENCES McKnight R . B. N . Carolina Med. J . 7 590(1946). McKnight: R. B.:Southern Surgery, I;, 810(1947). Slaughter, D., Belogorsky, J. B., and Schwartz, C., Therab. Soc. Meetina. Boston. Auril 13-16. 1950. (4) Slauehter. D.. S. Dakofa J . M i d . and Phorm.. 1. 425( 1948). (5) Information supplied by Henry K. Wampole & C o . , Inc., Phila., Pa. (6) Brochure, “[email protected],”Henry K. Wampole & Co.. Inc., Phila. Pa. (7) Brokn, H. B., and Page, I. H., Circulafion, 10, 714 (1954). (8) Blau, N. F., J . Bio2. Chem., 110,351(1935). (9) Owen. C. A.. and Power. M. A,. ibid.. ZOO. 111 (1953). (10) Gross, J., Lehlond, C. P., Franklin, A. E., and Quastel. J. H., Science 111, 605(1950). ( 1 1 ) Hoffnagle,’ G. F., Sideri, C . N . , and Osol. A., “Paper Chromatography of IlSl-Labeled Iocl,?propylidene Glycerol with Autoradiographic Identification to be published. (12) Broking, E., 2. Exptl. Path. ’Therap:, 8 , 125(1910). (13) Bonanni.. A , . Z e n f r . Biochem. u BzoPhvs.. ~. . IS. 120 (iGi3). (14) Forbes, J. C., THISJOURNAL, 37, 509(1948).

(1) (2) (3) Amer.

Book Notices A Glossary of Mycology. By WALTERH. SNELL and ESTHERA. DICK. Harvard University Press, Cambridge, Mass., 1957. xxxi 171 pp. 17 x 26 cm. Price $5. This dictionary includes among its 7,000 terms some which are not strictly mycological but might be useful to students because they do occur in mycological literature. Definitions referring t o the fungi includes technical, popular, vernacular, and obsolete terms; terms used in medical mycology and antibiotics; folklore, and color terms; and names of the originators of the terms. The type is small, but this is typical of books in this and related fields. It should be a useful reference for


teachers, advanced students, and amateur and professional mycologist s. Dorland’s Illustrated Medical Dictionary. 23rd ed. W. B. Saunders Company, Philadelphia, 1957. xvii 1,598 pp. 17 x 26 cm. Price $12.50. This new edition of Dorland’s is bigger and, if possible, better than ever. Accuracy, authority, and quick usefulness remain the principal objectives of this reference work. It has been reviewed, revised and modernized. It is a s new as the recently coined “ataractic” and “ataraxic,” with their blurred difference; the respective definitions being: “Per-