Comprehensive identification strategy for rapid profiling of chemical constituents using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry with Rhubarb as an example.

In this study, the collision induced dissociation tandem mass spectrometry (CID-MS/MS) fragmentation pathway of chemical components in rhubarb was wholly explored using 34 standards by UHPLC-QTOF-MS/MS in negative ion mode. In consequently, the diagnostic product ions for speedy screening and categorization of chemical components in rhubarb were ascertained based on their MS/MS splitting decomposition patterns and intensity analysis. According to these findings, a fresh two-step data mining strategy had set up. The initial key step involves the use of characteristic product ions and neutral loss to screen for different types of substituents and basic skeletons of compounds. The subsequent key step is to screen and classify different types of compounds based on their characteristic product ions. This method can be utilized for rapid research, classification, and identification of compounds in rhubarb. A total of 356 compounds were rapidly identified or tentatively characterized in three rhubarb species extracts, including 150 acylglucoside, 125 anthraquinone, 65 flavanols and 15 other compounds. This study manifests that the analytical strategy is feasible for the analysis of complex natural products in rhubarb.

[The effect of acute urinary retention on serum prostate specific antigen concentration].

OBJECTIVES: To study the effect of acute urinary retention on the serum prostate-specific antigen (PSA) concentration. METHODS: Blood samples from 34 benign prostatic hyperplasia (BPH) patients with acute urinary retention were drawn immediately before suprapubic cystomy and 48 hours after relief of urinary retention. Serum PSA concentrations were measured with radioimmunoassay. RESULTS: The mean serum PSA levels of BPH patients with acute urinary retention was (24.6 +/- 16.1) micrograms/L (range from 2.6 micrograms/L to 45.8 micrograms/L). Forty-eight hours after relief of urinary retention, the mean serum PSA levels declined to (9.4 +/- 6.3) micrograms/L (range from 1.7 micrograms/L to 16.6 micrograms/L). The difference was significant (P < 0.01). CONCLUSIONS: Acute urinary retention could dramatically increase the serum PSA value of patients with BPH. After relief of the urinary retention, the patients had a great than 50% decreased of PSA values.