Are gastric mucosal macrophages responsible for gastric injury in acute pancreatitis?

AIM:To investigate the protective effect of clodronatecontaining liposomes against severe acute pancreatitis(SAP)-triggered acute gastric mucosal injury(AGMI) in rats.METHODS:Clodronate- and phosphate-buffered saline(PBS)-containing liposomes were prepared by reverse-phase evaporation.The SAP rat model was established by injecting sodium taurocholate into the pancreatic subcapsular space.Sprague-Dawley rats were randomly divided into three groups:control(C),SAP plus PBS-containing liposome(P) and SAP plus clodronate-containing liposome(T).Serum tumor necrosis factor(TNF)-α levels were estimated by ELISA.Pathological changes in the gastric mucosa and pancreas were observed by hematoxylin and eosin(HE) staining.Apoptotic cells were detected by terminal deoxynucleotidyl transferase d UTP nick end labeling staining.The numbers of macrophages in the gastric mucosa were analyzed by CD68 immunohistochemical staining.RESULTS:The liposomes had a mean diameter of 150 ± 30 nm.The TNF-α levels were significantly higher in the P group than that in the C group(2 h,145.13 ± 11.50 vs 23.2 ± 2.03; 6 h,245.06 ± 12.11 vs 30.28 ± 6.07,P < 0.05),and they were significantly lower in the T group than that in the P group(2 h,93.24 ± 23.11 vs 145.13 ± 11.50; 6 h,135.18 ± 13.10 vs 245.06 ± 12.11,P < 0.05).The pathological scores of the pancreas were lower in the T group than in the P group(2 h,1.88 ± 0.83 vs 4.13 ± 0.83; 6 h,2.87 ± 0.64 vs 6.25 ± 0.88,P < 0.01).The pathological scores of the gastric mucosa were also lower in the T group than in the P group(2 h,1.12 ± 0.64 vs 2 ± 0.75; 6 h,1.58 ± 0.53 vs 3 ± 1.31,P < 0.05).In addition,increased CD68 levels were observed in the gastric mucosa of the P group compared with the C group.Clodronate-containing liposomes decreased the CD68 levels in the mucosa of the T group.The apoptotic indexes of the gastric mucosa were higher in the T group than in the P group(2 h,15.7 ± 0.92 vs 11.5 ± 1.64; 6 h,21.12 ± 1.06 vs 12.6 ± 2.44,P < 0.01).CONCLUSION:Gastric macrophages contribute to the pathogenesis of gastric injury in SAP.Clodronatecontaining liposomes have protective effects against AGMI in rats with SAP.

Effect of Chinese national holidays and weekends versus weekday admission on clinical outcomes in patients with STEMI undergoing primary PCI

Background Data regarding the influence of weekends and Chinese national holiday＇s admission on the outcomes of patients with ST-elevated myocardial infarction （STEMI） is lacking. This study sought to investigate the effect of Chinese national holidays and weekend admission on outcomes in patients with STEMI undergoing primary percutaneous coronary intervention （PPCI）. Methods Patients pre- senting with STEMI within 12 h of symptom onset who underwent PPCI were retrospectively enrolled. The primary outcome of in-hospital mortality and major adverse cardiovascular events in patients presenting Chinese national holiday＇s and weekends versus weekdays was evaluated. Results A total of 441 STEMI patients were enrolled in this study. Of these, 129 （29.3%） patients were admitted during Chinese national holidays and weekends and 312 （70.7%） during weekdays. Patients admitted during holidays and weekends were more likely to present with Killip class Ⅲ-Ⅳ. Patients admitted during holidays and weekends experienced a significantly longer door-to-baUoon time, symptom onset-to-door time as well as symptom onset-to-balloon time. The in-hospital mortality between patients presenting holidays and weekends versus weekdays was comparable. However, patients admitted during holidays and weekends have a signitieantly higher rate of in-hospital major adverse cardiovascular events. Multivariate analysis demonstrated that holidays and weekends admission was independ- ently associated with adverse outcomes. Conclusions In China, STEMI patients undergoing PPCI during national holidays and weekends have worse in-hospital outcomes compared to those admitted during weekdays. These findings suggest that continuous efforts should be undertaken to enhance the Chinese healthcare system and to ensure that comparable outcomes are achieved for all STEMI patients regardless of time of presentation.