RESUMO
Objective To evaluate whether Vitamin B supplementation could prevent ischemic stroke recurrence.Methods Randomized controlled trials (RCTs) observing Vitamin B supplementation in patients with stroke was performed in databases including ScienceDirect, PubMed/Medline, China National Knowledge Infrastructure, Chinese Biomedical Data-Base, Wanfang Database, and VIP Chinese Science and Technology Journal Database to find related studies in English or Chinese published before August 2016. The patients in control group received a placebo or basic therapy without Vitamin B, and those in experimental group was treated with Vitamin B alone or Vitamin B on the basis of conventional treatment. The data were collected by two researchers independently and the quality of studies was assessed by the modified Jadad Scale. The Meta-analysis was performed using Stata 12.0, funnel plot was drawn, and Egger and Begg regressions were used to evaluate the publication bias, and sensitivity was also analyzed. Results Seven RCTs studies were enrolled to analyze with a total number of 9846 stroke patients, 4755 patients in control group, and 5091 in experimental group, respectively. ① Vitamin B supplementation for prevention of recurrent stroke: heterogeneity test results showed a heterogeneity in literatures enrolled (I2 = 62.9%,P = 0.009), and a random effect model was used for Meta-analysis. It was shown that the incidence of recurrent stroke in the experimental group was significantly lower than that in the control group [pooled relative risk(RR) = 0.64, 95% confidence interval (95%CI) = 0.47-0.87], which indicated that the supplementation of Vitamin B could prevent the recurrence of stroke. Cumulative Meta-analysis showed that Vitamin B supplementation exhibited positive effects in the prevention stroke recurrence from 2012. The 95%CI tended to be stable while demonstrating good change trend as sample growing. The publication bias evaluation results showed that the funnel plot was not symmetrical by visual inspection, further quantitative analysis showed thatP value from Egger regression was 0.008, while that from Begg regression was 0.035, bothP 0.05, which indicating that there was no evidence of publication bias in the study included.Conclusions Vitamin B supplementation was associated with a lower risk of recurrent stroke in stroke patients and could significantly improve the quality of secondary prevention of stroke. Furthermore, supplementation of Vitamin B could reduce plasma Hcy levels in stroke patients which might contribute to its effect in preventing stroke recurrence.
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AIM To study pathogenesis of Alzheimers disease and screen ?- secretase and ?- secretase inhibiting drug, PS-1(M 146L)and APP 751 gene double stably transfected CHO cell lines have been established. METHODS A? cDNA encoding human PS-1 was obtained by polymerase chain reaction from a human placental library. Mutant PS-1 (M 146L) cDNA was also generated by polymerase chain reaction from wild type PS-1 cDNA. Wild type and mutant PS1 were subcloned into CMV-based mammalian expression vectors PCI-neo,then recombined plasmid were co-transfected into APP expressing CHO cells at 1∶10 ratio using LipofectAmine. Stable expressing cell lines were screened and selected by using selection media. RESULTS Several CHO cell lines stably transfected with wide type or mutant PS-1 (M 146L) as well as APP 751 genes were established. Overexpression of PS-1 in CHO cell accumulated full length 45 kDa PS-1 protein. A? released to conditioned media were not changed in wild type PS-1 transfected APP expression CHO cells. A? 1～42 level in conditioned media of M 146L mutant PS-1 stably transfected of APP expression CHO cells were elevated about 1.6 fold. CONCLUSION Expression of M 146L mutant PS-1 in stably transfected APP expression CHO cells increased a secretion of A? 1～42. The PS-1 and APP double stably transfected CHO cell lines we generated can be used for either ?-or ?-secretase inhibitor study and related drug screening.