Extraction and measurement of urinary tetranor-PGDM in disposable diapers.

Urinary tetranor-PGDM is a useful diagnostic biomarker for food allergy which often affects infants. We attempted to extract and measure urinary tetranor-PGDM absorbed in polymer of diapers. We applied CaCl2 to the collected polymer, determined the adequate time length of shaking the polymer to release urine, and measured tetranor-PGDM in the extracted urine. This procedure provided high linearity and recovery rate in tetranor-PGDM measurement. We also found that urinary tetranor-PGDM was stable for 24 h at 4°C in diapers. This method can be useful to monitor the food allergic condition of non-toilet trained children.

A fast one-step extraction and UPLC-MS/MS analysis for E2/D 2 series prostaglandins and isoprostanes.

Prostaglandins (PG) and isoprostanes (iso-PG) may be derived through cyclooxygenase or free radical pathways and are important signaling molecules that are also robust biomarkers of oxidative stress. Their quantification is important for understanding many biological processes where PG, iso-PG, or oxidative stress are involved. One of the common methods for PG and iso-PG quantifications is LC-MS/MS that allows a highly selective, sensitive, simultaneous analysis for prostanoids without derivatization. However, the currently used LC-MS/MS methods require a multi-step extraction and a long (within an hour) LC separation to achieve simultaneous separation and analysis of the major iso-PG. The developed and validated for brain tissue analysis one-step extraction protocol and UPLC-MS/MS method significantly increases the recovery of the PG extraction up to 95 %, and allows for a much faster (within 4 min) major iso-PGE2 and -PGD2 separation with 5 times narrower chromatographic peaks as compared to previously used methods. In addition, it decreases the time and cost of analysis due to the one-step extraction approach performed in disposable centrifuge tubes. All together, this significantly increases the sensitivity, and the time and cost efficiency of the PG and iso-PG analysis.

[Preparation and properties of prostaglandin D2 labelled with tritium with high molar radioactivity]. / Poluchenie i svoistva mechennogo tritiem prostaglandina D2 s vysokoi moliarnoi radioaktivnost'iu.

Kinetic parameters of enzymatic and non-enzymatic transformations of [3H]prostaglandin H2 (PGH2) were determined; the maximum yield of [3H]PGD2 being obtained at the keobs/koobs ratio equal to 10. The two-stage enzymatic synthesis of [3H]PGD2 with high molar radioactivity (3.15 TBq/mmol) from [3H]arachidonic acid carried out. Its identity in properties to the natural PGD2 was shown in experiments on the inhibition of ADP-induced aggregation of thrombocytes and on enzymatic oxidation with 15-hydroxyprostaglandin dehydrogenase.