Objective To investigate etiology of the 18 -45 years young ischemic stroke and risk factors .Methods We retro-spectively analyzed clinical data of 106 cases patients with ischemic stroke ,carotid ultrasound ,MRA ,CTA ,DSA results analyzed e-tiology ,type .compared patients and the same period youth for the medical check with risk factors .Results The proportion of LAA、SOE in low ages had significant differences with high age(P<0 .05) .The proportion of LAA was 29 .2% and the proportion of SUE was 25 .4% ,On hypertension ,hyperlipidemia ,drinking ,smoking ,obesity ,diabetes ,heart disease ,high homocystine ,young stroke group had significant differences with young control group (P<0 .05) .Conclusion Youth main cause of ischemic stroke is large artery atherosclerotic stroke and unknown cause of stroke .The main youth ischemic stroke risk factors are smoking ,hyperten-sion ,hyperlipidemia ,diabetes ,drinking ,heart disease .

ObjectiveTo evaluate the changes in the expression of purinergic P2X4 receptor (P2X4R) in spinal cord dorsal horn and dorsal root ganglion in a rat model of acute morphine tolerance or inflammatory pain.MethodsThirty male SD rats were randomly divided into 3 groups:normal saline group (group NS,n =5);acute morphine tolerance group (group M,n =5) and inflammatory pain group (group F,n =20).Inflammatory pain was induced by subcutaneous injection of 4％ formalin 50 μl into the plantar surface of left hindpaw in group F.The animals received intrathecal morphine 10 μg ( 10 μl) once every 2 h for 6 times (T1-6) in group M,while the equal volume of normal saline was given instead in group NS.The rats were then sacrificed 2 h after the last time administration.Paw withdrawal latency (PWL) to a thermal nociceptive stimulus was measured at T1-6 in groups M and NS,or on day 4,7,10 and 14 after establishing the model of inflammatory pain in group F,The rats were sacrificed after measurement of PWL and spinal cord dorsal horn and dorsal root ganglion were removed to detect the expression of P2X4 R by immuno-histochemisty.ResultsCompared with the baseline value,PWL was significantly decreased on day 4-14 after intlammatory pain in group F,and PWL was significantly increased at T1-5,while no significant change was found at T6 in group M ( P ＞ 0.05).Compared with group NS,the expression of P2X4 R was up-regulated in group M,and the expression of P2X4 R was up-regulated on day 4 after inflammatory pain,peaked on day 7 after inflammatory pain,and then was down-regulated gradually on day 10 and 14 after inflammatory pain in group F ( P ＜ 0.01).ConclusionThe expression of purinergic P2Y4 R is up-regulated in spinal cord dorsal horn and dorsal root ganglion in rats with acute morphine tolerance or inflammatory pain,and the change may be related to the development of acute morphine tolerance or inflammatory pain.