Detection of choline and phosphatidic acid (PA) catalyzed by phospholipase D (PLD) using MALDI-QIT-TOF/MS with 9-aminoacridine matrix.

Phospholipase D (PLD) catalyzes the hydrolysis of phosphatidylcholine (PC), the most abundant phospholipids of plasma membrane, resulting in the production of choline and phosphatidic acid (PA). Choline is a precursor of the neurotransmitter acetylcholine, whereas PA functions as an intracellular lipid mediator of diverse biological functions. For assessing PLD activity in vitro, PLD-derived choline has been often analyzed with radioactive or non-radioactive methods. In this study, we have developed a new method for detecting choline and PA with MALDI-QIT-TOF/MS by using 9-aminoacridine as a matrix. The standard calibration curves showed that choline and PA could be detected with linearity over the range from 0.05 and 1 pmol, respectively. Importantly, this method enables the concomitant detection of choline and PA as a reaction product of PC hydrolysis by PLD2 proteins. Thus, our simple and direct method would be useful to characterize the enzymatic properties of PLD, thereby providing insight into mechanisms of PLD activation.

Potentially inappropriate medication discontinued or changed based on pharmacists' recommendations in older end-stage cancer patients receiving palliative care: a cross-sectional study.

BACKGROUND: Avoiding potentially inappropriate medications (PIMs) can reduce adverse events in older cancer patients receiving palliative care. However, studies have not examined the extent to which pharmacists' recommendations reduce the prescription of PIMs. Therefore, we designed a cross-sectional study to determine the extent to which their recommendations play a role in reducing the prescription of PIMs for older cancer patients receiving palliative care. METHODS: Patients brought their medications with them upon admission to the hospital. These medications were examined by pharmacists and deemed inappropriate based on the Screening Tool of Older People's Prescriptions version 2 (STOPP2). In this study, these 220 patients were surveyed, and the percentage of medications that were discontinued or changed based on pharmacists' recommendations was compared with previously published results of similar studies on older non-cancer inpatients, using univariate analysis. RESULTS: A total of 218 PIMs were detected in 1261 medications administered to 220 patients. Of these, 61 medications were discontinued or changed based on the recommendation of pharmacists (rate of discontinuation/change of medications: 28.0%). The univariate analysis results showed that this rate of discontinuation or change of medications was significantly lower than that of a previous report intended for non-cancer patients (40.6%). The rate of discontinuation/change of medications for benzodiazepines was extremely low, but for other drugs it was almost the same as in the previous report. CONCLUSIONS: In the case of older end-stage cancer patients receiving palliative care, compared with older patients hospitalized for other diseases, it was more difficult, on pharmacists' recommendations, to discontinue or change PIMs detected by STOPP2. The low significance of discontinuing or changing benzodiazepines in subjects was a major reason it was difficult to reduce the prescription and, eventually, administer PIMs based on pharmacists' recommendations.