A panel of steady-state cytokine mRNAs was analyzed in the bronchoalveolar lavage (BAL) cells from asthmatic subjects or patients challenged with ragweed allergen. This was achieved by combining both qualitative and quantitative assays using the reverse transcription-polymerase chain reaction (RT-PCR). Analysis of BAL cells from six mild allergic asthmatic and five nonasthmatic, nonallergic subjects showed no qualitative differences in the profile of cytokine mRNAs (including interleukin [IL]-1 beta, IL-2, IL-5, IL-6, IL-8, and granulocyte/macrophage colony-stimulating factor), except for tumor necrosis factor-alpha, which was detected in three out of six asthmatic BAL samples but in none of the controls. A key cytokine, IL-5, has been implicated in the pathogenesis of allergic inflammation through the recruitment of eosinophils. We found a significant enhancement of steady-state IL-5 transcripts in the BAL cells from allergen-challenged as compared with the saline-challenged control sites of four asthmatic patients; furthermore, the cellular source for IL-5 mRNA was identified in the mononuclear cell fraction, but not in the purified eosinophils, of the allergen-challenged BALs. These results suggest that the significant increase of IL-5 transcripts is primarily from the infiltrating mononuclear cells. Our study also demonstrates the power of qualitative and quantitative PCR analysis in determining the molecular basis of allergic inflammatory diseases.
Abstract. Methimazole concentrations in plasma and in the thyroid glands were measured by means of high-performance liquid chromatography. Pharmacokinetics of methimazole were studied after a single oral dose (175 μmol/m2) in nine children and adolescent who were in the thyrotoxic state. Plasma levels of methimazole showed peak concentrations of 4.4 to 12.6 (median 9.2) μmol/l at 0.5 to 4 h after drug administration. Plasma half-life, area under the curve, and distribution volume ranged from 2.73 to 6.04 h, 32.8 to 77.9 μmol · l−1 · h−1, and 0.516 to 0.913 l/kg, respectively. These pharmacokinetic parameters showed a wide variation among the patients, but were quite reproducible in the same subject. Intrathyroidal concentrations of methimazole were measured in another nine subjects including four adolescents and five adults who underwent thyroidectomy. The drug concentrations in the thyroid glands ranged between 3.5 and 23.8 μmol/kg tissue and were far higher than those in the plasma obtained at the time of surgery. In this series of experiments, the dose of the drug varied from 76 to 319 μmol/m2, time after the last dose to surgery from 5 to 24 h, and the mode of drug administration from a single to three divided doses. Among these variable factors, only the daily dose of methimazole corrected by body surface area showed significant correlation with the intrathyroidal concentration, whereas the time after the last dose of the drug and the mode of drug administration did not. Our results revealed that methimazole was concentrated in the thyroid gland and that the intrathyroidal concentrations were maintained for 16 to 24 h in spite of a short plasma half-life. It is suggested that a single daily dose of methimazole is adequate for the treatment of Graves' disease in children and adolescents.
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