Cystathionine Levels in Patients With Huntington Disease.

BACKGROUND: Recently a profound depletion of cystathionine γ-lyase (CSE), the principal enzyme involved in the generation of cysteine from cystathionine, was shown in Huntington disease (HD) patients and several transgenic HD mouse models. We therefore hypothesized that blood and urine cystathionine levels may be increased in HD patients and that this increase might correlate with disease progression. METHODS: We measured concentrations of cystathionine as well as 22 other amino acids in fasting plasma and 24-h urine samples of nine early-stage HD patients and nine age, sex, and body mass index matched controls. RESULTS: There were no significant differences in the plasma or urine concentrations of cystathionine or any other amino acid between HD patients and controls. CONCLUSION: We found no evidence for changes in plasma or urine concentrations of cystathionine in early-stage HD patients. Therefore, cystathionine levels are unlikely to be useful as a state biomarker in HD.

Gas chromatographic determination of the pesticide dodemorph for assessment of occupational exposure.

As part of a health hazard survey of occupational exposure to pesticides in greenhouse growing of ornamentals, analytical methods are developed and validated for measurement of exposure of workers to the fungicide dodemorph. A gas chromatographic method is developed using on-column injection and nitrogen-phosphorus detection for quantification. Methods for the determination of (potential) dermal exposure by the analysis of foliar dislodgeable residues and cotton gloves are validated with respect to background, analytical recovery, stability, limit of detection, and between-day coefficients of variation. Analytical recovery from 'foliar dislodgeable residue solutions' and cotton gloves is more than 95%. Dodemorph in 'foliar dislodgeable residue solutions' and on cotton gloves is stable for at least five and six months, respectively, when stored in the refrigerator. Between-day coefficients of variation are 6% for both matrices. The limit of detection is 3 micrograms per leaf sample and 150 micrograms per pair of gloves. Institute of Occupational Medicine (IOM) samplers, designed for the collection of a defined inspirable fraction of aerosols, are tested for sampling air-borne dodemorph. IOM samplers equipped with glass-fiber or cellulose filters appear unsuitable for reliable sampling of the fungicide because of breakthrough or breakdown during sampling.