Effects of intestinal flora on the pharmacokinetics and pharmacodynamics of aspirin in high-altitude hypoxia.

Since hypobaric hypoxia significantly affects metabolic characteristics of intestinal flora, which plays an important role in the biotransformation of aspirin, high altitudes may influence the pharmacokinetics and therapeutic effects of aspirin in the intestines. In the present study, to test alterations of intestinal microbiota at high altitude comparing to that at low altitude, we analyzed rat feces from plain group and high-altitude group by 16S rRNA analysis. To detect concentrations of aspirin and salicylic acid, we established a reliable liquid chromatography tandem mass spectrometry method to measure aspirin and salicylic acid concentrations in fecal suspensions and plasma. Our study found that the plateau hypoxic environment caused a significant increase in Bacteroides in rat feces, while Corynebacterium, Prevotella, and Coprococcus were declined. In addition, compared with the plain group, the metabolic activity of fecal suspensions from the plateau group on aspirin was significantly reduced. More importantly, these changes in the intestinal microbiota led to increasing absorption of aspirin in the rats after rapidly ascent to the plateau, and a reduction in the pharmacodynamic index TXB2, which would possibly result in bleeding. In conclusion, our research provides new ideas for changes in plateau pharmacokinetics, and then guide the corresponding reduction in aspirin dose for the population quickly entering the plateau.

Endothelial progenitor cells in peripheral blood may serve as a biological marker to predict severe acute pancreatitis.

AIM: To investigate the significance of endothelial progenitor cells (EPCs) in predicting severe acute pancreatitis (SAP). METHODS: We recruited 71 patients with acute pancreatitis (AP) and excluded 11 of them; finally, cases of mild acute pancreatitis (MAP) (n = 30) and SAP (n = 30), and healthy volunteers (n = 20) were internalized to investigate levels of EPCs, C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), fibrinogen (FIB) and white blood cells (WBC) in peripheral blood. RESULTS: The levels of TNF-α, WBC, FIB and CRP were higher both in SAP and MAP cases than in healthy volunteers (P < 0.05, all). Interestingly, the level of EPCs was higher in SAP than MAP (1.63% ± 1.47% vs 6.61% ± 4.28%, P < 0.01), but there was no significant difference between the MAP cases and healthy volunteers (1.63% ± 1.47% vs 0.55% ± 0.54%, P > 0.05). Receiver operating characteristics curve (ROC) showed that EPCs, TNF-α, CRP and FIB were significantly associated with SAP, especially EPCs and CRP were optimal predictive markers of SAP. When the cut-off point for EPCs and CRP were 2.26% and 5.94 mg/dL, the sensitivities were 90.0% and 73.3%, and the specificities were 83.3% and 96.7%. Although, CRP had the highest specificity, and EPCs had the highest sensitivity and highest area under the curve value (0.93). CONCLUSION: Data suggest that EPCs may be a new biological marker in predicting SAP.

Enhancement of Gastric Ulcer Healing and Angiogenesis by Hepatocyte Growth Factor Gene Mediated by Attenuated Salmonella in Rats.

The present study developed an oral hepatocyte growth factor (HGF) gene therapy strategy for gastric ulcers treatment. An attenuated Salmonella typhimurium that stably expressed high HGF (named as TPH) was constructed, and the antiulcerogenic effect of TPH was evaluated in a rat model of gastric ulcers that created by acetic acid subserosal injection. From day 5 after injection, TPH (1 × 109 cfu), vehicle (TP, 1 × 109 cfu), or sodium bicarbonate (model control) was administered orally every alternate day for three times. Then ulcer size was measured at day 21 after ulcer induction. The ulcer area in TPH-treated group was 10.56 ± 3.30 mm², which was smaller when compared with those in the TP-treated and model control groups (43.47 ± 4.18 and 56.25 ± 6.38 mm², respectively). A higher level of reepithelialization was found in TPH-treated group and the crawling length of gastric epithelial cells was significantly longer than in the other two groups (P < 0.05). The microvessel density in the ulcer granulation tissues of the TPH-treated rats was 39.9 vessels/mm², which was greater than in the TP-treated and model control rats, with a significant statistical difference. These results suggest that TPH treatment significantly accelerates the healing of gastric ulcers via stimulating proliferation of gastric epithelial cells and enhancing angiogenesis on gastric ulcer site.