Research progress of endoplasmic reticulum stress in methamphetamine induced neurotoxicity / 中国药理学通报

At present, METH has surpassed the traditional illegal psychoactive substances and become the most widely abused illegal psychostimulant in China.Endoplasmic reticulum ( ER) plays an important role in regulating the normal physiological functions of various cells by virtue of its strong membrane strnc- ture and a large number of enzymes on the membrane.Endoplasmic reticulum stress ( ERS) is a series of adaptive responses made by cells when ER homeostasis is destroyed.When ERS occurs, it will drive the activation of unfolded protein response (I PR ) , which aims to protect cells from stress, reduce biosyn- thetic load and help to rebuild cell homeostasis.Persistent ERS will further aggravate the pressure of ER and induce cell death by using UPR signaling pathway.'Hie neurotoxicity induced by METH is closely related to ERS.This paper elaborates on ERS and UPR signaling pathway, and summarizes the relationship between ERS.apoptosis and autophagy, so as to provide new ideas and potential therapeutic targets for the basic research and prevention of METH induced neurotoxicity mechanism.

Impact of catheter-tissue contact force on lesion size during right ventricular outflow tract ablation in a swine model.

BACKGROUND: The catheter-tissue contact force (CF) is one of the significant determinants of lesion size and thus has a considerable impact on the effectiveness of ablation procedures. This study aimed to evaluate the impact of CF on the lesion size during right ventricular outflow tract (RVOT) ablation in a swine model. METHODS: Twelve Guangxi Bama miniature male pigs weighing 40 to 50 kg were studied. After general anesthesia, a ThermoCool SmartTouch contact-sensing ablation catheter was introduced to the RVOT via the femoral vein under the guidance of the CARTO 3 system. The local ventricular voltage amplitude and impedance were measured using different CF levels. We randomly divided the animals into the following four groups according to the different CF levels: group A (3-9 g); group B (10-19 g); group C (20-29 g); and group D (30-39 g). Radiofrequency ablations were performed at three points in the free wall and septum of the RVOT in power control mode at 30 W for 30 s while maintaining the saline irrigation rate at 17 mL/min. At the end of the procedures, the maximum depth, surface diameter, and lesion volume were measured and recorded. A linear regression analysis was performed to determine the relationship between continuous variables. RESULTS: A total of 72 ablation lesions were created in the RVOT of the 12 Bama pigs. The maximum depth, surface diameter, and volume of the lesions measured were well correlated with the CF (free wall: ß = 0.105, ß = 0.162, ß = 3.355, respectively, P < 0.001; septum: ß = 0.093, ß = 0.150, ß = 3.712, respectively, P < 0.001). The regional ventricular bipolar voltage amplitude, unipolar voltage amplitude, and impedance were weakly positively associated with the CF (ß = 0.065, ß = 0.125, and ß = 1.054, respectively, P < 0.001). There was a significant difference in the incidence of steam pops among groups A, B, C, and D (free wall: F = 7.3, P = 0.032; septum: F = 10.5, P = 0.009); and steam pops occurred only when the CF exceeded 20 g. Trans-mural lesions were observed when the CF exceeded 10 g in the free wall, while the lesions in the septum were non-trans-mural even though the CF reached 30 g. CONCLUSIONS: CF seems to be a leading predictive factor for the size of formed lesions in RVOT ablation. Maintaining the CF value between 3 and 10 g may be reasonable and effective for creating the necessary lesion size and reducing the risk of complications, such as steam pops and perforations.