A new validated HPLC method for the determination of levodopa: Application to study the impact of ketogenic diet on the pharmacokinetics of levodopa in Parkinson's participants.

A simple, accurate, and reproducible HPLC-UV method has been developed and validated for the quantification of levodopa (l-Dopa) in human plasma. The method involves a simple protein precipitation procedure to extract both l-Dopa and methyldopa, the internal standard. The chromatographic analysis was achieved on a Shimadzu LC 20A HPLC system equipped with a Zorbax Eclipse XDB C18 column and an isocratic mobile phase consisting of 20 mm KH2 PO4 (pH 2.5) and methanol (95:5, v/v) run at a flow rate of 1 mL/min. The UV detection wavelength was set at 230 nm. The method exhibited good linearity (R2 > 0.999) over the assayed concentration range (0.1-10 µg/mL) and demonstrated good intra- and inter-day precision and accuracy (relative standard deviations and the deviation from predicted values were <15%). This method was also successfully applied for studying the potential effect of ketogenic diet on the pharmacokinetics of l-Dopa in Parkinson's participants. Our data analysis indicates that ketogenic diet does not significantly affect the pharmacokinetics of l-Dopa.

Impact of Nurses Taking Daily Work Breaks in a Hospital Garden on Burnout.

BACKGROUND: Nurses working in hospital environments are at risk for burnout. Exposure to nature has psychological benefits, but the effect of hospital gardens on nurse burnout is less understood. OBJECTIVE: To compare the effect on nurse burnout of taking daily work breaks in a hospital-integrated garden with the effect of indoor-only breaks. METHODS: A prospective crossover trial was conducted of nurses assigned to either 6 weeks of a work break in an outdoor hospital garden or 6 weeks of indoor-only breaks. After a 1-week washout period, break assignments were switched for a subsequent 6 weeks. The Maslach Burnout Inventory was administered at the beginning and end of each 6-week period, and a Present Functioning Visual Analogue Scale was completed at the start and end of each break to capture immediate psychological symptoms. Change scores were analyzed by using generalized estimating equations. RESULTS: For 29 nurses, for garden compared with indoor breaks, significant improvement was apparent in scores on the Maslach Burnout Inventory subscales for emotional exhaustion (4.5 vs -0.2; P < .001) and depersonalization (1.8 vs 0.0; P = .02) but not for personal accomplishment (-0.6 vs -0.0; P = .55). Compared with indoor breaks, total symptom scores on the Present Functioning Visual Analog Scale improved significantly when nurses took a break in the garden (garden vs indoor breaks, 4.0 vs 2.4; P = .04). CONCLUSIONS: Taking daily work breaks in an outdoor garden may be beneficial in mitigating burnout for nurses working in hospital environments.