Objective To investigate the phenotype and the immunoregulatory function of CD8αα+TCRαβ+regulatory T cells in peripheral blood samples from mice.Methods The distribution profile and the phenotype of CD8αα+TCRαβ+regulatory T cells in C57BL/6 mice were detected by flow cytometry.The cytokines released by CD8αα+TCRαβ+regulatory T cells upon the stimulation with anti-CD3 antibody were analyzed by cytometric bead array.The in vitro immunosuppressive activity of CD8αα+TCRαβ+regulatory T cells on activated CD4+T cells was analyzed by using flow cytometry and carboxyfluorescein succinimidyl ester ( CFSE ) .An adoptive cell transfer assay was set up to evaluate the immunoprotective effects of CD8αα+TCRαβ+ regulatory T cells in a mouse model of experimental autoimmune encephalomyelitis ( EAE) .Results CD8αα+TCRαβ+regulatory T cells were detected in liver, spleen and peripheral blood samples collected from na?ve C57BL/6 mice.Compared with CD8αβ+TCRαβ+regulatory T cells, CD8αα+TCRαβ+regulatory T cells showed a memory-activated phenotype of CD25+CD122high CD44high CD62Llow CD69high NK1.1+DX5+.CD8αα+TCRαβ+regulatory T cells could produce IL-2 after 24 hours stimulation with anti-CD3 antibody, followed by producing IFN-γ, TNF-α, IL-4, IL-17A and traces of IL-6 and IL-10. In vitro, CD8αα+TCRαβ+regulatory T cells specifically suppressed the proliferation of activated CD4+T cells ( P<0.01 ).Moreover, they could delay the onset of EAE in mice and reduce clinical score (P<0.01).Conclusion CD8αα+TCRαβ+regulatory T cells were a unique population with immunoregula-tory function, which could be used as a potential therapeutic target in the treatment of autoimmune disease.

Objective To evaluate the correlation between cerebral blood flow perfusion and memory impairment in patients with severe stenosis of vertebral basilar artery (VBA).Methods 62 cases of patients with VBA stenosis diagnosed by digital subtraction angiography(DSA) in Beijing Tiantan Hospital from September 2016 to March 2017 were enrolled.Mental State Examination (MMSE),Clinical Memory Scale (CMS) test and CT perfusion(CTP) was performed.All patients were divided into memory normal group(n=24,including 1 excellent case,6 above normal cases,and 14 normal cases) and memory impairment group(n =38,including 18 below normal cases,12 periphery cases,8 impaired cases) according to CMS.The ratios of side-to-side period were compared between bilateral mesial temporal lobe and anterior circulation area.The relative time to peak (rTTP),relative mean transit time(rMTY),relative cerebral blood flow(rCBF) and relative cerebral blood volume (rCBV) were calculate.Results The incidence of CTP decompensation in the medial temporal lobe was higher than that in the patients with memory impairment(P＜0.05).The difference of rTTP and rMTT value between the two groups in the bilateral medial temporal lobes was statistically significant (rTFP:(1.131 ±0.037),(1.437±0.139),t=10.520,P＜ 0.05);rMTT:(1.081 ±0.059),(1.281 ±0.174),t=5.423,P＜0.05).Conclusion The patients with VBA severe stenosis are more likely to get memory impairment due to cerebral hypoperfusion.

Objective To analyze the correlation between smoking and occurrence of intracranial artery stenosis.Methods From June 2015 to May 2016,a total of 10 711 inpatients with transient ischemic attack (TIA) or ischemic stroke from 20 basel hospitals of nationwide were enrolled using a cross-sectional study,76 patients with unknown smoking and smoking cessation years were excluded.Finally,a total of 10 635 patients were enrolled.Transcranial color coded sonography and/or transcranial Doppler were used evaluate the intracranial artery stenosis lesions.The basic risk factors for cerebrovascular disease (age,sex,smoking and smoking years,whether smoking cessation and years,hypertension,diabetes,hyperlipidemia,atrial fibrillation,and family history of stroke) were recorded.According to the different smoking years,the smoking years were divided into five groups:non-smoking,smoking time ≤10-year,11 to 20-year,21 to 30-year,and >30-year groups for trend chi square test.According to the different smoking cessation years in the smokers,the smoking cessation years were divided into four groups:non-cessation,cessation time 1 to 10-year,11 to 20-year,and >20-year groups for trend chi square test.The effects of different smoking years and different smoking cessation years on the occurrence of intracranial arterial stenosis were analyzed.Results The incidence of intracranial artery stenosis in the smokers (40.4%[1 433/3 547]) was significantly higher than that in the non-smoking patients (29.4%[2 085/7 088]).There was significant difference (χ2=128.850,P<0.01),and the incidence of cerebral infarction in the smokers (91.6%[3 250/3 547]) was significantly higher than the non-smokers (85.0%[6 027/7 088]).There was significant difference (χ2=92.328,P<0.01).Smoking was an independent risk factor for intracranial artery stenosis (OR,1.603;95%CI 1.456-1.765;P<0.01).With the increase of smoking years,the detection rate of intracranial arterial stenosis increased gradually (trend χ2=115.437,P<0.01).Whether giving up smoking had no significant effect on the incidence of intracranial artery stenosis in patients with ≥20 years of smoking (trend χ2=1.043,P=0.307).Conclusions Smoking is an independent risk factor for affecting intracranial artery stenosis;the risk of disease increases with the number of smoking years.Long-term smokers (≥20 years) cannot reduce the effect on intracranial artery stenosis,even if they give up smoking.

Objective To investigate the effect of serum lipid level on carotid artery stenosis in patients with ischemic cerebrovascular disease.Methods Using a multi-center cross-sectional study,10 711 consecutive inpatients with transient ischemic attack (TIA) or ischemic stroke diagnosed clearly in 20 stroke screening and prevention project base hospitals from June 2015 to May 2016 were enrolled.According to the results of carotid ultrasonography,1 560 patients with extracranial carotid artery stenosis rate≥50% screened were enrolled in the study.They were divided into a severe stenosis group (70%-99%) and a mild-moderate stenosis group (<70%).The distribution of total cholesterol (TC),triacylglycerol (TG),low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels in both groups of carotid stenosis patients were analyzed,and the quantitative classification was based on the normal range of serum lipids.The distributions of serum lipid levels in different grades in patients of both groups were compared with the non-parameter test.Results The incidence of dyslipidemia in the severe stenosis group was higher than that in the mild and moderate stenosis group.There was no significant difference between the two groups (54.4%[319/586]vs.48.3%[470/974],P<0.05).Dyslipidemia was an independent risk factor for severe carotid artery stenosis (OR,1.27,95% CI 1.24-1.30,P<0.01).The TC and LDL-C levels in patients of the severe stenosis group were significantly higher than those in the mild-moderate stenosis group (TC:3.98[3.31,4.82]mmol/L vs.3.91[3.31,4.53]mmol/L,LDL-C:2.48[1.86,3.14]vs.2.30[1.79,2.80];all P<0.01).With the increase of TC and LDL-C levels,there was significant differences between the severe stenosis group and the mild-moderate stenosis group (all P<0.05),and the proportions of TC >5.80 mmol/L (7.3%[43/586]vs.0.4%[4/974]) and LDL-C>3.12 mmol/L (26.3%[154/586]vs.10.0%[97/974]) in patients of the severe stenosis group were higher than those in the mild-moderate stenosis group (26.3%[154/586]vs.10.0%[97/974]).Conclusion The high LDL-C and TC levels may increase the incidence of severe carotid artery stenosis or occlusion.

Objective To investigate the differences of distribution characteristics and risk factors of large artery lesions in patients with ischemic cerebrovascular disease in different age groups in order to provide the basis for the prevention and treatment of stroke in different age groups.Methods From June 2015 to May 2016,a total of 10 711 consecutive inpatients with transient ischemic attack (TIA) and ischemic stroke from 20 centers nationwide were enrolled.Each 10 years was used as an age group from 40 years.All the patients were divided into 5 age groups.The differences of the different risk factors for cerebrovascular disease among the 5 groups were compared.All patients were separated by gender.The chi square test was used to compare the incidences of large artery stenosis of the intracranial and external and anterior and posterior circulation,and the number of vascular lesions in the same sex in different age groups.Results (1) The risk factors of elderly patients were mainly hypertension,diabetes mellitus,and atrial fibrillation (χ2=61.938,χ2=13.349,and χ2=55.940;all P<0.01).The smoking history,family history of cerebrovascular disease,and obesity were more frequent among the young and middle-aged people (χ2=131.505,χ2=7.298,and χ2=100.911,all P<0.01).(2) The linear trend chi square test results showed that the proportion of multivessel diseases in female and male extracranial arterial lesions increased gradually with the increase of age.(χ2=54.799,χ2=161.370,all P<0.01).The proportion of multivessel diseases in the intracranial artery in female decreased gradually (χ2=5.328,P=0.021),and that in male did not have obvious trend of change (χ2=0.289,P=0.591).(3) The linear trend chi square test results showed that the incidence of simple intracranial arterial stenosis in female and male intracranial arterial stenosis decreased gradually with the increase of age (χ2=20.090,χ2=42.351,all P<0.01),and the incidence of simple extracranial arterial stenosis increased gradually (χ2=40.311,χ2=90.698,all P<0.01).The incidence of both intracranial and extracranial artery stenoses increased gradually (χ2=12.077,χ2=45.887,all P<0.01).The incidence of simple posterior circulation vascular stenosis increased gradually in female (χ2=16.434,P<0.01),but that did not have obvious trend of change in male (χ2=1.701,P=0.192).The incidence of stenosis of both anterior and posterior arteries in female and male increased gradually (χ2=4.587,P=0.032;χ2=35.156,P<0.01).Conclusions The distribution of atherosclerotic lesions in ischemic cerebrovascular disease of the different age groups was different.No matter female or male patients,the majority of the young and middle-aged patients were intracranial artery lesions,and the elderly patients were mainly extracranial artery lesions.The majority of elderly women had posterior circulation artery lesions.Understanding the characteristics in patients with intracranial arterial lesion in different age groups will help to develop individualized stroke prevention and treatment strategies for the population of different age groups.

Objective To investigate the distribution characteristics and risk factors of intracranial and extracranial aterial lesions in Chinese patients with ischemic stroke . Methods In this multi‐center study ,2 310 continuously inpatients with ischemic stroke diagnosed in 20 stroke screening and prevention project base hospitals from June 2015 to M ay 2016 were enrolled . Carotid ultrasonography and transcranial color‐coded sonography or transcranial Doppler were performed in all patients to confirm the presence of cerebral artery stenosis or occlusion . According to the distribution of lesions ,the subjects were divided into 2 groups :the simple intracranial artery stenosis group and the simple extracranial artery stenosis group . T he difference of risk factors between the two groups was compared . Results Of the 2 310 patients with ischemic stroke ,1 516 ( 65 .6% ) had simple intracranial artery stenosis and 794 ( 34 .4% ) had simple extracranial artery stenosis . T he incidence of anterior circulation artery stenosis was higher in the group of intracranial artery stenosis than that in the extracranial artery stenosis group ( 68 .1% vs 48 .7% , P ＜0 .001) . Posterior circulation artery stenosis and combined anterior with posterior circulation artery stenosis were more common in patients with extracranial artery stenosis group than those in intracranial artery stenosis group ( 36 .4% vs 22 .1% ,14 .9% vs 9 .8% ;all P ＜0 .001) . Univariate analysis of risk factors for stroke showed that patients with intracranial arterial stenosis had a higher prevelence of hypertension , diabetes ,obesity ,and family history of stroke ,and their systolic blood pressure ,diastolic blood pressure , body mass index ( BM I) ,fasting blood‐glucose ,glycosylated hemoglobin ,triacylglycerol ,total cholesterol , and low‐density lipoprotein cholesterol were significantly higher than those in the extracranial arterial stenosis group ( all P ＜ 0 .05 ) . T he proportion of elderly ( ≥ 65 years old ) ,male and smokers in the extracranial arterial stenosis group was significantly higher than that in the intracranial arterial stenosis group ( all P ＜0 .05) . Multivariate logistic regression analysis showed that elderly ( ≥65 years old) ,male , and smoking history were independent risk factors for extracranial arterial stenosis ( OR＝ 2 .012 ,1 .637 , 1 .325 ,respectively ;all P ＜0 .05) . While hypertension ,diabetes ,less physical activity ,and high BM I levels were independent risk factors for simple intracranial arterial disease ( OR ＝ 1 .301 ,1 .252 ,1 .248 ,1 .030 , respectively ;all P ＜0 .05) . Conclusions There are significant differences in the distribution characteristics and risk factors of intracranial and extracranial aterial lesions in patients with ischemic stroke in China .