Vascular endothelial growth factor(VEGF)is a major angiogenic factor that regulates multiple endothelial cell functions. After cerebral ischemia, VEGF not only promotes vascular endothelial proliferation and migration. involving in angiogenesis and increasing vascular permeability, but also plays important roles in both neuroprotection and neurogenesis. This article reviews the roles of VEGF in ischemic cerebral injury.

Studies have shown that erythropoietin (EPO) may have neuroprotective effect on cerebral ischemia, and exogenous EPO may also exert neuroprotective effect on cerebral ischemic injury through blood-brain barrier. Its mechanisms may include the upregulation of the expressions of apoptosis inhibiting genes bcl-2 and bcl-xl, the expression of key proteases during the process of inhibiting apoptosis, inhibiting nitric oxide oversynthesis, protecting against glutamate-induced excitotoxicity, etc.

Hypoxia inducible factor 1 (HIF-1), a nuclear protein with transcription activity, can make the body produce adaptive response to hypoxia/ischemia by binding to target gene, transcription and post-transcriptional control. Ischemic tolerance refers to the adaptive response to transient ischemia and reperfusion, which can improve tissue tolerance during the following damage caused by more severe ischemic events. The recent studies have found that the expression of HIF-1 has an important significance in ischemic tolerance. HIF-1 may be a key factor of the oxygen signal transduction pathway in the development of cerebral ischemic tolerance.

Objective To investigate the clinical significances of thyroid function changes in patients with post-stroke depression(PSD). Methods Sixty two cases with acute cerebral infarction (CI) were stratified into two groups by Zung self-rating depression scale, single cerebral infarct patients group (CI group) and PSD group. Serum levels of FT3, FT4 and TSH of the patients were detected on 2 days,7days,14 days and 21days after admission. Results ①On each time point after admission, FT3 levels in PSD group were lower than those in CI group. FT3 levels in the two groups on the 7 days were higher than those on 2 days(2.04±0.53 vs 1.28±0.19, 1.43±0.91 vs 1.07±0.37, P <0.05).On the 14 and 21 days, levels of FT3 in the PSD group were continuously increased.②On the 2 days and 7 days after admission, FT4 levels in PSD group were higher than those in CI group. FT4 levels in the two groups on the 14 days were lower than those on 7 days(1.52±0.18 vs 2.09±0.26, 1.57±0.31 vs 2.28±0.38, P <0.05). ③On the 2 days after admission,the TSH level in the PSD group were lower than that in CI group(2.02±0.36 vs 2.27±0.49,P <0.05). Conclusion The results indicated that the hypothalamic-pituitary-thyroid axis plays important role in the pathogenesis of PSD.

The incidence of cerebral watershed infarction is higher.At present,the correlation studies of cerebral watershed infarction and cerebral vascular stenosis are mostly limited to the guilty vascular lesions,and the atherosclerotic disease is a chronic systemic inflammatory response.It often exists multiple vascular stenosis.This article elaborates cerebral watershed infarction from the aspects of carotid artery complicated with other parts of the arterial stenosis,middle cerebral artery complicated with other parts of the artery stenosis and collateral circulation in order to improve the awareness of the correlation between watershed cerebral infarction and multiple cerebral artery stenosis.

Objective To study the association of V249I and T280M polymorphisms of fractalkine receptor CX3CR1 with carotid artery stenosis (CAS). Methods 318 patients with CAS diagnosed using color Doppler ultrasound criteria were studied and compared with 292 subjects without CAS. V249I and T280M polymorphic genotypes of CX3CR1 were determined by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) and sequencing analysis. Results The genotypes of MM and TM were associated with reduced risk of CAS,the frequency of genotype MM + TM in the two groups being 22. 6% and 31.2% respectively ( OR = 0. 646, 95% CI 0. 451-0. 928, P = 0. 017), the frequency of M allele was significantly lower in patients with CAS than in those without CAS ( 13.8% and 19. 2% respectively, OR = 0. 677, 95%CI 0.499--0. 918,P=0. 010). No differences were observed in the Ⅱ, Ⅵ, or VV genotype, the frequency of genotype Ⅱ + Ⅵ in the two groups being 39. 0% and 43.8% respectively ( OR = 1. 012, 95% CI 0. 731-1. 403 ,P = 0. 940), the frequency of Ⅰ allele was significantly lower in patients with CAS than in those without CAS (28. 6% and 32. 7% respectively, OR = 0. 842, 95% CI 0. 660-1. 076, P = 0. 034). The genotypes of Ⅱ and Ⅵ in patients with stable plaques were more frequent than in vulnerable plaques( OR = 0. 610, 95% CI 0. 387-0. 962, P = 0. 033 ). Multiple Logistic regression analysis revealed that the genotypes of MM and TM were an independent risk factor for CAS ( OR = 1. 847,95% CI 1. 091- 3. 127 ,P = 0. 022). Conclusion The genotypes of MM and TM are independent risk factors for carotid artery stenosis, and the genotypes of Ⅱ and Ⅵ are associated with the stability of carotid artery plaques.

Objective To investigate the effects of ischemic preconditioning (IP) on blood-brain barrier permeability and matrix metalloproteinase-9 expression after cerebral ischemia reperfusion in rats.Methods A total of 154 Wistar rats were randomly divided into sham operation (n = 14),non-ischemic preconditioning (NIP,n = 70),and IP (n = 70) group.The latter two groups were redivided into 5 subgroups (n = 14 in each subgroup).A middle cerebral artery occlusion model was induced by intraluminal suture method.After 10 minutes IP,re-ischemia for 2 hours and reperfusion for 22 hours were performed at day 1,3,7,14,and 21,respectively.The infarct volume was detected using 2,3,5-triphenyltetrazolium chloride (TTC)staining.The BBB permeability were evaluated by measuring the content of the extravascular exudation of Evan's blue (EB).The degree of cerebral edema was evaluated using the wet-dry weight method.MMP-9 protein and mRNA expression were detected by immunohistochemical staining and in situ hybridization.Results Compared to the corresponding subgroups in the NIP group,the neurological deficit scores,infarct volume,EB content,and brain water content were decreased significantly,and MMP-9 protein and mRNA expression were down-regulated significantly in the day 1,3,and 7 subgroups in the IP group (P ＜ 0.05 or P ＜ 0.01 ).The infarct volume and MMP-9 mRNA expression of the day 1,3,7 subgroups in the IP group were more significantly reduced or down-regulated than those of the day 14 and21 subgroups in the IP group.The EB content,brain water content,and MMP-9 protein expression of the day 3 and 7 subgroups were more significantly lower than those in other subgroups.Among them,they were decreased most significantly in the day 3 subgroup (P ＜ 0.05).Conclusions The changes of IP-induced BBB permeability and the down-regulated MMP-9 expression may play important roles in cerebral ischemic tolerance.

The mild cognitive impairment and vascular cognitive impairment no dementia are the early stages for Alzheimer's disease and vascular dementia proposed in recent years.They both not only have some differences,but also have many crosses and contacts in concepts,diagnostic criteria,epidemiology,pathology,neuropsychology,and biological markers,etc.This article reviews the recent progresses and problems facing in recent years.

Objective To research the expression and correlation between erythropoietin(EPO)mRNA and hypoxia inducible factor-1?(HIF-1?)mRNA in rats with brain ischemic tolerance induced by ischemic preconditioning.Methods Models of cerebral ischemic preconditioning and ischemic-reperfusion(preconditioning group)were made by twice suture method,after the short ischemic preconditioning 1 d,3 d,7 d,14 d and 21 d respectively,the models were underwent ischemic-reperfusion again.The infarct volume was measured by tetrazolium chloride(TTC)staining,the expressions of HIF-1? mRNA and EPO mRNA in the different time(1～21 d)of ischemic-reperfusion were detected by reverse transcriptase polymerase chain reaction(RT-PCR)and compared with non-preconditioning group.Results The infarct volume in the 1 d,3 d and 7 d subgroups of preconditioning group were significantly smaller compared with non-preconditioning group(all P

Patients with asymptomatic carotid stenosis (ACS) are the potentially high-risk population of stroke.Screening for high-risk patients with ACS and giving them appropriate interventions may have great significance for the prevention of the occurrence of stroke.This article reviews the advances in research of ACS screening in recent years.