The molecular biological expression of SDF-1 and VEGF in rat diabetic retinopathy and the intervention effect of AMD3100

AIM: To measure the expression of stromal cell derived factor-1(SDF-1)and vascular endothelial growth factor(VEGF)in retina of diabetic rats model at the different stage and explore the inhibitory effect of AMD3100 on the expression of SDF-1 and VEGF mRNA by RT-PCR and Western-Blot test.<p>METHODS: RT-PCR and Western-Blot tests were carried out. In RT-PCR test, 60 adult SD rats were divided into normal group, antagonist group, and diabetes group. After diabetic rat model was induced using streptozotocin and antagonist group and diabetic group were injected intravitreously and postocularly with AMD3100 and PBS respectively. All rats were killed and the retina was extracted. after 1,3,5 months and the HE stain of paraffin sections was used and the expression of SDF-1 and VEGF mRNA were measured with RT-PCR. In Western-Blot test, 18 rats were divided into normal group, diabetes group and four antagonist groups which were using different concentration of AMD3100, and killed after 3 months.<p>RESULTS: SDF-1 and VEGF mRNA were expressed in normal group, antagonist group and diabetes group. At the same age group(1, 3 and 5 months)and among the normal group, antagonist group and diabetes group, the difference of expression of SDF-1 and VEGF mRNA were significant. The expressions in diabetic group were always highest and antagonist group lower than diabetic group. The expression of SDF-1 and VEGF mRNA was increased significantly with the extension of disease. The HE Stain of paraffin sections showed DM group had more cell nucleus which protruded internal limited membranes than normal control group and antagonist group. The Western-Blot test showed in 4 antagonist groups the SDF -1 and VEGF protein expression levels gradually decreased with the increases of SDF-1 antagonist AMD3100 concentration, the difference was significant. When intravitreous injected concentration of AMD3100 increased over 10μg/μL, the expression of SDF-1 and VEGF protein did not change, the difference was not statistically significant<p>CONCLUSION: With the progression of diabetic retinopathy, the expression of VEGF and SDF-1 mRNA in the retinal tissue of diabetic rats increased. The antagonist AMD3100 could reduce the expression of SDF-l, VEGF and inhibit the development of new blood vessels. In a certain concentration range, this inhibitory effect of AMD3100 was dose-dependent

Scalable Distributed Communication Architectures to Support Advanced Metering Infrastructure in Smart Grid

In this paper, we investigate the scalability of three communication architectures for advanced metering infrastructure (AMI) in smart grid. AMI in smart grid is a typical cyber-physical system (CPS) example, in which large amount of data from hundreds of thousands of smart meters are collected and processed through an AMI communication infrastructure. Scalability is one of the most important issues for the AMI deployment in smart grid. In this study, we introduce a new performance metric, accumulated bandwidth distance product (ABDP), to represent the total communication resource usages. For each distributed communication architecture, we formulate an optimization problem and obtain the solutions for minimizing the total cost of the system that considers both the ABDP and the deployment cost of the meter data management system (MDMS). The simulation results indicate the significant benefits of the distributed communication architectures over the traditional centralized one. More importantly, we analyze the scalability of the total cost of the communication system (including MDMS) with regard to the traffic load on the smart meters for both the centralized and the distributed communication architectures. Through the closed form expressions obtained in our analysis, we demonstrate that the total cost for the centralized architecture scales linearly as O(λN), with N being the number of smart meters, and λ being the average traffic rate on a smart meter. In contrast, the total cost for the fully distributed communication architecture is O(λ⅔N⅔), which is significantly lower

Methological quality of systematic reviews and meta-analyses on acupuncture for stroke: a review of review

Objective: To assess the methodological quality of systematic reviews and meta-analyses regarding acupuncture intervention for stroke and the primary studies within them. Methods: Two researchers searched PubMed, Cumulative index to Nursing and Allied Health Literature, Embase, ISI Web of Knowledge, Cochrane, Allied and Complementary Medicine, Ovid Medline, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Wanfang and Traditional Chinese Medical Database to identify systematic reviews and meta-analyses about acupuncture for stroke published from the inception to December 2016. Review characteristics and the criteria for assessing the primary studies within reviews were extracted. The methodological quality of the reviews was assessed using adapted Oxman and Guyatt Scale. The methodological quality of primary studies was also assessed. Results: Thirty-two eligible reviews were identified, 15 in English and 17 in Chinese. The English reviews were scored higher than the Chinese reviews (P=0.025), especially in criteria for avoiding bias and the scope of search. All reviews used the quality criteria to evaluate the methodological quality of primary studies, but some criteria were not comprehensive. The primary studies, in particular the Chinese reviews, had problems with randomization, allocation concealment, blinding, dropouts and withdrawals, intent-to-treat analysis and adverse events. Conclusions: Important methodological flaws were found in Chinese systematic reviews and primary studies. It was necessary to improve the methodological quality and reporting quality of both the systematic reviews published in China and primary studies on acupuncture for stroke