1.Factors influencing Intracranial aneurysm rupture
Yongtao ZHENG ; Yingjun LIU ; Bing LENG
International Journal of Cerebrovascular Diseases 2014;22(6):464-469
Increasing detection of unruptured intracranial aneurysms,catastrophic outcomes from subarachnoid hemorrhage,and risks and cost of treatment necessitate defining objective predictive parameters of aneurysm rupture risk.However,long-term follow-up have shown the risk of intracranial aneurysm rupture is associated with its morphologic characteristics,hemodynamic factors and patient's own situation.
2.Construction of Tre enzyme eukaryotic expression vector and identification of its function in loxLTR sequence-specific recognition
Qingquan LIU ; Zhuoran YU ; Yongtao SUN
Journal of Medical Postgraduates 2014;(12):1254-1257
Objective Clearing HIV provirus is the key to cure AIDS .The study was to construct the Tre enzyme eukaryotic expression vector and identify its function in specific recognition of loxLTR sequence in HIV provirus . Methods Tre gene was in-serted into eukaryotic expression vector pcDNA 3.1 gene recombination manipulation by genetic recombination techniques including gene synthesis , PCR, restriction enzyme digestion and ligation .EGFPpA-LoxLTR sequence was inserted into pmCherry-N1 vector and was tested by restriction enzyme digestion , PCR and sequencing .Constructed vectors were electroporated into HeLa cells , then using fluorescence microscopy to observe fluorescence intensity changes . Results PCR, restriction enzyme digestion , electrophoresis and sequencing confirmed that Tre enzyme eukaryotic expression vector had been constructed successfully , and it could specifically recog-nize and cut loxLTR sequence after being transfected into Hela cells . Conclusion Constructed Tre enzyme eukaryotic expression vector can be expressed in Hela cells and specifically recognize loxLTR sequence , which has prepared the experimental ground for fur-ther studies of clearing HIV provirus .
3.Lipoxin A4 protects diabetic rats against focal cerebral ischemia-reperfusion by downregulating tumor necrosis factor-α and nuclear factor-κB
Chengling LIU ; Yongtao HU ; Jiangquan HAN
International Journal of Cerebrovascular Diseases 2014;22(11):853-857
Objective To investigate the protective effect of lipoxin A4 on diabetic rats with focal cerebral ischemia-reperfusion and its mechanisms.Methods Thirty-six adult male Sprague-Dawley rats were randomly divided into a sham operation group,a cerebral ischemia-reperfusion group,and a lipoxin A4 group (n=12 in each group).Diabetes was induced by repeated intraperitoneal injection of low-dose streptozotocin.A model of middle cerebral artery occlusion and reperfusion was induced by the intraluminal suture method.Five minutes after cerebral ischemia,lipoxin A4 0.03 nmol/5 μ1 was injected via intracerebroventricular in the lipoxin A4 group.The other groups were injected equal volume of saline.Two hours after ischemia,the suture was pulled out and reperfusion was achieved.Neurological deficit scores were performed at 24 hours.Then the rats were decapitated and their brains were taken out.2,3,5-triphenyl tetrazolium chloride (TTC) staining was used to detect infarct size.Western blotting was used to detect the expression of cortical tumor necrosis factor-α (TNF-α) and nuclear factor-κB (NF-κB).Results The neurological deficit score showed that no neurological deficit was observed in the sham operation group (score 0).The neurological deficit score in the lipoxin A4 group was significantly lower than that in the cerebral ischemia-reperfusion group (2.20 ± 1.03 vs.3.20 ± 1.03; P <0.05).TTC staining showed that no infarct was observed in the sham operation group.The infarct size in the lipoxin A4 group was significantly lower than that in the cerebral ischemia-reperfusion group (27.52% ± 5.71% vs.55.45% ± 9.29% ; P <0.05).Western blotting showed that the expression levels of TNF-α in the sham operation,cerebral ischemiareperfusion,and lipoxin A4 groups were 0.64 ± 0.16,1.85 ± 0.52,and 1.40 ± 0.34,respectively.There were significant differences among the 3 groups (F =18.868,P <0.001).The expression level of TNF-α in the lipoxin A4 group was significantly lower than that in the cerebral ischemia-reperfusion group (P <0.05).The expression levels of NF-κB in the sham operation,cerebral ischemia-reperfusion and lipoxin A4 groups were 0.79 ±0.24,2.09 ± 0.47,and 1.27 ± 0.35,respectively.There were significant differences among the 3 groups (F =16.736,P < 0.001).The expression level of NF-κB in the lipoxin A4 group was significantly lower than that in the cerebral ischemia-reperfusion group (P <0.05).Conclusions Lipoxin A4 has certain protective effect on focal cerebral ischemia-reperfusion injury in diabetic rats,its mechanism may be associated with the inhibition of the expression of TNF-α and NF-κB.
4.Diabetes mellitus aggravates cerebral ischemia-reperfusion injury in rats by inflammatory response
Chengling LIU ; Jiangquan HAN ; Yongtao HU
International Journal of Cerebrovascular Diseases 2015;(5):349-353
Objective To investigate the roles of tumor necrosisfactor-α(TNF-α) and nuclear factor-κB (NF-κB) in cerebral ischemia-reperfusion injury in rats w ith diabetes mel itus. Methods Thirty-six healthy male Sprague-Daw ley rats w ere divided into a euglycemic sham operation group, a euglycemic isc hemia-reperfusion group, and a diabetes ischemia-reperfusion group (n=12 in each group) according to a random number table. A diabetes model w as induced by intraperitoneal injection of streptozotocin, and then a focal cerebral ischemia-reperfusion model w as induced by the suture method. The neurological deficit score was performed at 24 h after reperfusion. 2,3,5 triphenyl tetrazolium staining was used to measure the cerebral infarction area. Western blotting w as used to detect the expression levels of NF-κB and TNF-αon the ischemic sides. Results The neurological function scores w ere 0.00 ±0.00, 2.50 ±1.08, and 3.20 ± 1.03, respectively in the euglycemic sham operation, euglycemic cerebral ischemia-reperfusion and diabetes cerebral ischemia-reperfusion groups, and there w ere significant differences (F=38.015, P<0.001). The neurological deficit scores of the diabetes cerebral ischemia-reperfusion group w ere significantly aggravated compared with the euglycemic cerebral ischemia-reperfusion group (P<0.05). The infarct areas of the euglycemic sham operation, euglycemic cerebral ischemia-reperfusion and diabetes cerebral ischemia-reperfusion groups w ere 0.00% ±0.00%, 33.09% ±5.17%, and 55.45% ±9.29%, respectively, and there w ere significant differences among the groups (F=206.614, P<0.001), in w hich the infarct area in the diabetes cerebral ischemia-reperfusion group w as enlarged significantly compared w ith the euglycemic cerebral ischemia-reperfusion group ( P< 0.05 ). At 24 h after reperfusion, there w ere no significant differences in the expression levels of the cortical NF-κB (F=29.993, P<0.001) and TNF-α(F=28.722, P<0.001) on the ischemic sides in each group, in w hich the expression levels of NF-κB and TNF-αin the diabetes cerebral ischemia-reperfusion group w ere increased significantly compared w ith the euglycemic cerebral ischemia-reperfusion group (al P<0.05). Conclusions Diabetes may aggravate cerebral ischemia reperfusion injury. The upregulated expression of TNF-αand NF-κB may be one of the mechanisms of diabetes aggravating cerebral ischemia-reperfusion injury.
5.Protective roles of lipoxin A4 in cerebral ischemia-reperfusion
Chengling LIU ; Jiangquan HAN ; Yongtao HU
International Journal of Cerebrovascular Diseases 2014;22(1):67-71
Lipoxin A4 is an arachidonic acid metabolite,it is an important endogenous anti-inflammatory mediators in the body,which is known as an inflammatory braking signal. Inflammatory response is an important factor for causing cerebral ischemia-reperfusion injury.Lipoxin A4 can exert neuroprotective effects by inhibiting inflammatory response.In addition,lipoxin A4 can also reduce blood-brain barrier permeability,reduce cerebral edema,and promote recovery of neurological function.This article reviews the neuroprotective roles and mechanisms of lipoxin A4 in cerebral ischemia-reperfusion.
6.Influences of Stress on Attentional Bias of Elite Athletes
Yunzhou LIU ; Yongtao YANG ; Zhongqiu ZHANG
Chinese Journal of Sports Medicine 2017;36(7):618-621
Objective To demonstrate the influence of stress on attentional bias in athletes,in order to make guidance for athletes' attention training and control.Method Using dot-probe paradigm,we analyzed the attention behavior of 25 athletes either under stress or not when viewing different pictures of emotional face.The reaction time and the score of the attention bias were recorded and compared.Result The reaction time to negative face pictures under stress was significantly shorter than that to the positive and neutral ones.The value of the attention bias to negative pictures was significantly bigger than O.Conclusion Stress tends to induce attention bias of athletes to negative information.
7.Influence of Decoction Time on The Total Count of The Total Free Anthraquinone in Radix et Rhizoma Rhei
Yongtao LIU ; Hong ZHANG ; Zhou HANG
Journal of Zhejiang Chinese Medical University 2006;0(05):-
[Objective]To determine the relation between the total count of the five free anthraquinone(A loe-emodin,Rhein,Emodin,Chrysophanol,Physcion) in Radix et Rhizoma Rhei and the decoction time.[Method]HPLC was used with the chromatographic conditions as follows:mobile phase:methanol-0.1% phosphonic acid solution = 85 :15,detection wave length:254nm,flow rate:1.0 ml/min,column temperature:room temperature.The count of the five free anthraquinone in the decoction taken in every 2 minutes after the solution boiled was determined.[Results]During the 22 minutes after the solution was boiled,the total count took on a ascending tendency,afterwards,it took on a descending tendency.[Conclusion]The biggest number of the total count was obtained 20min after the solution was boiled.
8.Construction and expression of eukaryotic expression vector harboring human neutrophil peptide 1
Juan LIU ; Yongtao SUN ; Guangyu LI
Medical Journal of Chinese People's Liberation Army 2001;0(10):-
Objective To explore the possibility of human neutrophil peptide 1 (HNP1) gene engineering, we construct the eukaryotic expression vector carrying HNP1 gene. Methods With RNA extracted from human neutrophil cell as template, cDNA encoding mature HNP1 was amplified by RT-PCR, and then it was inserted into vector pMD18-T. After restriction endonuclease digestion and DNA sequencing confirmation the gene was subcloned into eukaryotic expression plasmid pcDNA3.1/V5-His-TOPO to construct a recombinant expression plasmid pcDNA3.1/V5-His-TOPO/HNP1, then the recombinant plasmid was transfected into COS-7 cells by lipofectamine, and the expressed product was identified by biotin-avidin enzyme-linked immunosorbent assay ( BA-ELISA). Results The sequence of HNP1 completely matched those published in GenBank, thus eukaryotic expression vector pcDNA3.1/V5-His-TOPO/HNP1 was constructed correctly. The ELISA results showed that the eukaryotic expression plasmid pcDNA3.1/V5-His-TOPO/HNP1 could temporarily express HNP1 in COS-7 cells. Conclusion The successful construction and expression of pcDNA3.1/V5-His-TOPO/HNP1 pave the way for the stable expression HNP1 in mammalian engineering cells.
9.Construction, expression, putification and bioactivity analysis of a two functional domains containing small molecule CR1 derivative
Yongtao YANG ; Li HE ; Gaoke LIU ; Bing TAN ; Zhengqing WANG
Chinese Journal of Microbiology and Immunology 2008;28(11):1044-1049
Objective To construct and express a small complement receptor type 1 (CR1) deriv-ative which contained two functional domains. Methods Total RNA was isolated from the peripheral blood mononuclear cell. The functional fragment Ⅰ of CR1 was amplified using the RT-PCR. The functional frag-ment Ⅱ was amplified with the plasmid of pET-32a-CR1-SCR15-18 as template which had been already con-structed in our laboratory. Then the chimeric gene that contained the two fragments was constructed with spli-cing overlap extention PCR. The chimeric gene was then inserted into the plasmid of pET-32a (+) and transformed into E. coli Rosetta(DE3). The inserted gene was verified by enzyme digestion and DNA se-quencing. After induced by IPTG, the expressed protein was analyzed by SDS-PAGE and Western blot. Then the fusion protein was purified by Ni-NTA affinity column and renatured through dialysis. The comple-ment inhibition activity was determined by CH50 method. Results The chimeric gene was successfully cloned into pET-32a(+). The result of SDS-PAGE and Western blot confirmed the expressed protein and showed that the molecule mass(Mr) of the expressed protein was 63×103. The purity of the recombinant protein was up to 92% after Ni-NTA column affinity chromatography. The bioactivity assay showed the fusion protein had a concentration-dependent complement inhibition activity within the concentration range of 0-200 μg/ml. Conclusion The two functional domains contained small CR1 derivative was successfully construc-ted and expressed in E. coli Rosetta. The fusion protein had a relative high bioactivity, providing a basis for further function experiment in vivo.
10.Protective effect of sCR1-SCR15-18 on cerebral ischemia/reperfusion injury in rat via inhibition of complement
Li HE ; Yongtao YANG ; Guangjin GUO ; Gaoke LIU ; Zhengqing WANG
Chinese Journal of Pathophysiology 2009;25(12):2436-2440
AIM: To explore the effect of complement on the cerebral ischemia/reperfusion injury in rat and the protection by sCR1-SCR15-18. METHODS: 75 male SD rats were randomly divided into three groups: sham operation group (SO, n=15), middle cerebral artery occlusion and reperfusion (MCAO) without treatment group (I/R, n=30); MCAO treated with sCR1-SCR15-18 group (sCR1-SCR15-18, n=30). After the MCAO for 2 h, then reperfusion for 24 h, the scores of neural behavioral functional deficits were determined. Infarction area was measured by TTC staining. Activity of MPO in cerebral cortex was detected. C3b deposition and pathological change were observed by immunohistochemial staining and HE staining, respectively. RESULTS: After reperfusion for 24 h, the neurological deficits score, infarction area and activity of MPO in sCR1-SCR15-18 group were decreased compared to I/R group. In sCR1-SCR15-18 group, C3b deposition in ischemic area was decreased and pathological injury was improved compared to I/R group. CONCLUSION: Complement plays a role in cerebral ischemia-reperfusion injury and sCR1-SCR15-18 exerts a protective effect by inhibiting the excessive activation of complement.