Thyroid storm associated with probable subclinical hypoadrenocorticism in an elderly woman.
(41/166)
A 73-year-old woman was admitted to the hospital for severe persistent vomiting with fever, drowsiness, and weight loss. Elevated serum levels of thyroid hormones and the presence of a consciousness disorder with fever and vomiting led to the diagnosis of thyroid storm. A low normal concentration of serum cortisol, urinary 17-hydroxycorticosteroids and an elevated plasma level of corticotropin suggest that an inadequate adrenal reserve have been involved in the pathogenesis of the thyroid storm in this patient. She responded to the administration of intravenous methimazole and oral supersaturated potassium iodide solution. (+info)
The effects of metal ions on the DNA damage induced by hydrogen peroxide.
(42/166)
The effects of metal ions on DNA damage induced by hydrogen peroxide were investigated using two methods, agarose-gel electrophoretic analysis of supercoiled DNA and sequencing-gel analysis of single end-labeled DNA fragments of defined sequences. Hydrogen peroxide induced DNA damage when iron or copper ion was present. At least two classes of DNA damage were induced, one being direct DNA-strand cleavage, and the other being base modification labile to hot piperidine. The investigation of the damaged sites and the inhibitory effects of radical scavengers revealed that hydroxyl radical was the species which attacked DNA in the reaction of H2O2/Fe(II). On the other hand, two types of DNA damage were induced by H2O2/Cu(II). Type I damage was predominant and inhibited by potassium iodide, but type II was not. The sites of the base-modification induced by type I damage were similar to those by lipid peroxidation products and by ascorbate in the presence of Cu(II), suggesting the involvement of radical species other than free hydroxyl radical in the damaging reactions. (+info)
Innate and drug-induced resistance to acute lung damage caused in rats by alpha-naphthyl thiourea (ANTU) and related compounds.
(43/166)
During the 3rd and 4th weeks of life rats were highly resistant to the toxic effects of alpha-naphthyl thiourea (ANTU) and of thiourea and its derivatives but toxicity developed rapidly during the following 2 weeks. Marked resistance to lung damage by toxic thioureas could be induced in older, mature rats by pretreatment with the toxic agent itself (tachyphylaxis), with other toxic and non-toxic antithyroid drugs or with iodine or iodide--even if the rats were pretreated at an early age before susceptibility to the agent developed. ANTU-tachyphylaxis was dose-dependent. Total thyroidectomy did not affect either lung damage induced by ANTU or the resistance due to tachyphylaxis or to pretreatment with iodide or the antithyroid drugs thiourea, 1-ethyl-1-phenyl thiourea or propyl thiouracil. Neither total nor medullary adrenalectomy affected ANTU toxicity. Marked resistance to ANTU-induced lung damage was induced in rats by pretreatment with either an activator (3-4 benzypyrene) or an inhibitor (SKF 525-A) of drug-metabolizine mixed-function microsomal enzyme systems; the inhibitor, sodium phenobarbitone, had no significant effect on toxicity. The sulphydryl compound, AET, induced marked resistance to ANTU; cysteine was less effective. Neither autonomic blockade with nicotine and atropine nor actinomycin D had significant effects on toxicity to ANTU. The acute pulmonary oedema induced in rats by high pressure oxygen, chemical convulsants, pressor agents and ammonium sulphate differed in many respects from that induced by toxic thioureas; it was typically haemorrhagic in nature, did not result in significant pleural effusion, did not exhibit tachyphylaxis, and was not influenced by pretreatment with iodide or derivatives of thiourea. (+info)
Simultaneous determination of arsenic and antimony species in environmental samples using bis(trifluoroethyl)dithiocarbamate chelation and supercritical fluid chromatography.
(44/166)
Simultaneous separation and quantitation of arsenic(III) and antimony(III) can be achieved by extraction with lithium bis(trifluoroethyl)dithiocarbamate followed by supercritical fluid chromatographic (SFC) analysis. Arsenic(V) and antimony(V) are extracted after reduction with potassium iodide and sodium thiosulfate. Detection limits of 7 pg As and 11 pg Sb are achieved using this extraction method and SFC. Application to natural water and biological sample analysis is discussed. (+info)
PRELIMINARY REPORT OF AN EXPERIMENT IN THE KANGRA VALLEY FOR THE PREVENTION OF HIMALAYAN ENDEMIC GOITRE WITH IODIZED SALT.
(45/166)
This report incorporates the results of an investigation designed to test the effectiveness of potassium iodide and potassium iodate in the control of Himalayan endemic goitre when these compounds are added in small physiological doses to the domestic salt habitually consumed by the people in the endemic belt. In a prospective study lasting five years, a striking reduction in the prevalence of goitre was observed in areas receiving salt fortified with either potassium iodide or potassium iodate. During the same period, goitre prevalence remained unchanged in the control zone, which received plain, unfortified salt. The study has an important bearing on the problem of goitre control in developing countries that use moist, coarsely crystalline salt. (+info)
ESTIMATION OF THE NITRIC OXIDE FORMED FROM HYDROXYLAMINE BY NITROSOMONAS.
(46/166)
1. Nitric oxide that was produced by reducing nitrite with an excess of acidified potassium iodide under nitrogen in Warburg respirometer flasks was rapidly absorbed by a solution of permanganate in sodium hydroxide held in the side arm. A small amount of nitrous oxide (or nitrogen) that was also produced was not absorbed. 2. By using a quantitative method for the recovery of nitrite from samples of the alkaline permanganate, it was found that the sum of the nitrite N formed and the residual nitrous oxide N was equivalent to the nitrite N used to generate the gases. These results showed that alkaline permanganate completely oxidized nitric oxide to nitrite. The method was suitable for determining 0.4-20 mumoles of nitric oxide. 3. The technique was used to determine the nitric oxide content of the nitrogenous gas that was produced anaerobically from hydroxylamine by an extract of the autotrophic nitrifying micro-organism Nitrosomonas in the presence of methylene blue as electron acceptor. (+info)
A functional interaction between chromogranin B and the inositol 1,4,5-trisphosphate receptor/Ca2+ channel.
(47/166)
Chromogranins A and B (CGA and CGB) are high capacity, low affinity calcium (Ca2+) storage proteins found in many cell types most often associated with secretory granules of secretory cells but also with the endoplasmic reticulum (ER) lumen of these cells. Both CGA and CGB associate with inositol 1,4,5-trisphosphate receptor (InsP3R) in a pH-dependent manner. At an intraluminal pH of 5.5, as found in secretory vesicles, both CGA and CGB bind to the InsP3R. When the intraluminal pH is 7.5, as found in the ER, CGA totally dissociates from InsP3R, whereas CGB only partially dissociates. To investigate the functional consequences of the interaction between the InsP3R and CGB monomers or CGA/CGB heteromers, purified mouse InsP3R type I were fused to planar lipid bilayers and activated by 2 microM InsP3. In the presence of luminal CGB monomers or CGA/CGB heteromers the InsP3R/Ca2+ channel open probability and mean open time increased significantly. The channel activity remained elevated when the pH was changed to 7.5, a reflection of CGB binding to the InsP3R even at pH 7.5. These results suggest that CGB may play an important modulatory role in the control of Ca2+ release from the ER. Furthermore, the difference in the ability of CGA and CGB to regulate the InsP3R/Ca2+ channel and the variability of CGA/CGB ratios could influence the pattern of InsP3-mediated Ca2+ release. (+info)
Urinary iodine kinetics after oral loading of potassium iodine.
(48/166)
We studied the kinetics of iodine in various forms, in order to establish appropriate guidelines of iodine prophylaxis for thyroid blockade at nuclear emergency in "iodine rich areas", such as Japan. First, the effect of equivalent dose of potassium iodide (KI) (solution vs. tablet) was evaluated with excretions of urinary iodine (UI) at Nagasaki, Japan, and it was revealed that there was no difference of iodine kinetics between solution and tablet. We also performed the same study at Gomel, Belarus, which was known to be an iodine deficient area, and obtained the same results. Second, the kinetics of iodine included in "iodine rich" food was also evaluated with excretions of UI. Interestingly, the ratio of UI excretion with iodine rich food was significantly lower than that with KI tablets until 6 h after the intake (ANOVA, p = 0.02). These results proved that 1) KI solution as well as its tablet is useful for prophylaxis and 2) prophylaxis by iodine rich food is not effective for rapid blockade of thyroid gland at nuclear emergency. Finally, we emphasized that the approach from social medicine is definitely important to establish an effective iodine prophylaxis. (+info)