Thyroid storm is a life-threatening condition of the hyperthyroid state. 26 It most commonly occurs in patients with Graves' disease but may also occur in those with multinodular goiter or toxic adenoma. 27 It is treated by correcting the hyperthyroidism and treating the precipitating events. 26 Correction of the hyperthyroid state involves using drugs such as propylthiouracil or methimazole (Tapazole), beta blockers or corticosteroids, which decrease the peripheral effects of thyroid hormone and the conversion of thyroxine (T 4 ) to the more potent triiodothyronine (T 3 ). 22 , 26 Dexamethasone can be used for that purpose, at a dosage of 2 mg intravenously every six hours, and can eventually can be switched to an oral dosage of 2 mg every six hours. 28
The dioxinlike and estrogenic relative potencies (REPs) of 16 priority polycyclic aromatic hydrocarbons (PAHs), seven methylated PAHs, and two hydroxylated PAHs were examined using three in vitro cell bioassays. An in vitro ethoxyresorufin- O -deethylase assay with PLHC-1 fish hepatoma cells and in vitro luciferase assay with H4IIE-luc recombinant rat hepatoma cells were used to evaluate dioxinlike potency. An in vitro luciferase assay with MVLN, recombinant human breast carcinoma cells, was used to evaluate estrogenic potency. Seven of the 16 priority PAHs tested induced significant dioxinlike responses. Excluding outliers with large ranges of uncertainty, the dioxinlike REPs for the PAHs ranged from 10 −6 to 10 −3 . This is similar to the REPs reported for other xenobiotics of concern including polychlorinated naphthalenes (PCNs) and some polychlorinated biphenyls (PCBs). In general, REP estimates generated in this study were similar to those reported previously. However, a comparison of the estimates of total 2,3,7,8-tetrachlorodibenzo- p -dioxin equivalents derived using assay-specific REPs with REPs reported in other studies indicated that the use of nonspecific REPs could lead to significant error in mass-balance (potency-balance) analyses. A 10-h acid treatment completely destroyed the dioxinlike activity of a PAH mixture. Among the compounds tested, only benzo[ a ]anthracene and dibenz[ a,h ]anthracene induced significant responses in the MVLN bioassay. Relative estrogenic potencies were estimated to be approximately 10 −7 . Overall, this research contributes to the growing consensus regarding the dioxinlike potency of priority PAHs and PAH derivatives and provides some additional evidence about potentially estrogenic PAHs. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 128–137, 2002; Published online in Wiley InterScience (). DOI /
AB - Three experiments were conducted to determine the biological potencies of eight lysine analogues in diets of young turkeys. Diets containing increasing levels of added L-lysine or a lysine analogue were fed to 9-day-old male poults for periods of 12 or 14 days. Multiple regression analyses of body weight gains on levels of supplemental L-lysine or analogue were computed. Relative potencies of the lysine analogues were calculated using the slope-ratio technique. Relative potencies of 6-N-N-dimethylamino-2-hydroxyhexan-N,N-dimethylamide, 6-N-acetylamino-2-hydroxyhexanamide, 6-N-propionylamino-2-hydroxyhexanamide. 6-N-butyrylamino-2-hydroxyhexanamide, 6-N-methylamino-2-hydroxyhexan-N-methylamide and alpha-keto-epsilon-acetylamino-caproic acid were not significantly different from 0%. Mono-hydroxymethyl-L-lysine-calcium and bis-hydroxymethyl-L-lysine-calcium had relative potencies of 62 +/- 6 and 52 +/- 7%, respectively, on a molar basis.