ATP-induced cardioprotection against myocardial ischemia/reperfusion injury is mediated through the RISK pathway.

The aim of the present study was to examine the post-infarct acute effect of adenosine-5'-triphosphate (ATP) on myocardial infarction (MI) size as well as its precise molecular mechanism. Sixty New Zealand white male rabbits were exposed to 40 min of ischemia followed by 180 min of reperfusion. The rabbits were intravenously administered 3 mg/kg of ATP (ATP group) or saline (control group) immediately after reperfusion and maintained throughout the first 30 min. The wortmannin+ATP, PD-98059+ATP, and 5-hydroxydecanoic acid (5-HD) sodium salt+ATP groups were separately injected with wortmannin (0.6 mg/kg), PD-98059 (0.3 mg/kg), and 5-HD (5 mg/kg) 5 min prior to ATP administration. MI size was calculated as the percentage of the risk area in the left ventricle. Myocardial apoptosis was determined using a TUNEL assay. Western blot analysis was performed to examine the levels of protein kinase B (Akt)/p-Akt and extracellular signal-regulated kinase (ERK)/p-ERK in the ischemic myocardium, 180 min after reperfusion. The infarct size was significantly smaller in the ATP group than in the control group (p<0.05). The infarct size-reducing effect of ATP was completely blocked by wortmannin, PD-98059 and 5-HD. Compared with the control group, cardiomyocyte apoptosis was significantly reduced in the ATP group, while this did not occur in the wortmannin+ATP, PD-98059+ATP and 5-HD+ATP groups. Western blot analysis revealed a higher myocardial expression of p-Akt and p-ERK 180 min following reperfusion in the ATP versus the control group. In conclusion, cardioprotection by postischemic ATP administration is mediated through activation of the reperfusion injury salvage kinase (RISK) pathway and opening of the mitochondrial ATP-dependent potassium channels.

Evaluation of Cranial and Cervical Arteries and Brain Tissue in Transient Ischemic Attack Patients with Magnetic Resonance Angiography and Diffusion-Weighted Imaging.

BACKGROUND: Magnetic resonance angiography (MRA) and diffusion-weighted imaging (DWI) have been widely used in the prediction of ischemic stroke; however, the differences of the 2 methods in detection the artery lesion differences between transient ischemic attack (TIA) and infarction patients have been long neglected. We performed the present study to investigate the differences between vessel characteristics detected by MRA and DWI in acute stroke and TIA patients. MATERIAL AND METHODS: We classified 110 subjects into 2 groups and all the patients underwent both MRA and DWI. The degree of stenosis of cranial and cervical arteries, the distribution of the stenosis, the development and changes of the vessels, and the DWI scanning results of the brain tissue were all analyzed. RESULTS: We detected a significant difference in the number and the degree of stenosis of cranial and cervical arteries among the 3 groups (P=0.006). Compared with health controls, patients with TIA and cerebral infraction had much more severe stenosis and occlusive arteries (P<0.05). However, no significant difference was detected between TIA and cerebral infraction patients (P=0.148). Moreover, a higher rate of unilateral vertebral artery dysplasia was found in the vertebrobasilar TIA patients. Higher lesion signals were also observed by DWI in TIA patients of internal carotid artery system (4/8, 50%). CONCLUSIONS: Vessel characteristics were not significantly different between TIA and infarction patients. Unilateral vertebral artery hypoplasia was a predisposing factor for vertebrobasilar TIA and ischemic focus in DWI detection was always caused by severe artery lesions.

[Current situation on the China infectious disease automated-alert and response system in Guangdong Province, China].

OBJECTIVE: To analyze the current situation on China Infectious Disease Automated-alert and Response System (CIDARS) in Guangdong province, China. METHODS: Early-warning signals and response time were analyzed by using three approaches of CIDARS. Positive rates of early-warning signals and error early-warning rates prior and after the adjustment,were compared. RESULTS: Totally, 114 585 early-warning signals appeared, with an average response time of 1.35 hours from April 21, 2008 to December 31, 2012. There were 12,394 early-warning signals in terms of fixed threshold method with a positive rate of 7.96%. 85 727 early-warning signals appeared under the mobile percentile method with a positive rate of 0.85%. There were 16,464 early-warning signals by using accumulation and control chart methods,with a positive rate of 1.82%. Results showed there was a positive correlation between the number of reported cases and the number of early-warning signals (r = 0.924, P < 0.01). The overall positive rate in Guangdong province increased from 1.48% to 2.14%, after the adjustment done by the Chinese Center for Disease Control and Prevention in 2010. The error early-warning rates regarding eight infectious diseases including hepatitis A, bacillary or amebic dysentery, both typhoid and paratyphoid fevers had reduced. CONCLUSION: The early-warning signal response appeared timely in CIDARS with good operation. However, despite the improvement on the efficacy of CIDARS, some functions and parameters of the systems still need to be adjusted.