Epigenetic modifications such as DNA methylation, histone post-translational modifications, non-coding RNA are reversible, heritable alterations which are induced by environmental stimuli. Major risk factors of diabetes and diabetic complications including hyperglycemia, oxidative stress and advanced glycation end products, can lead to abnormal epigenetic modifications in retinal vascular endothelial cells and retinal pigment epithelium cells. Epigenetic mechanisms are involved in the pathogenesis of macular edema and neovascularization of diabetic retinopathy (DR), as well as diabetic metabolic memory. The heritable nature of epigenetic marks also playsakey role in familial diabetes mellitus. Further elucidation of epigenetic mechanisms in DR can open the way for the discovery of novel therapeutic targets to prevent DR progression.
To perform a meta-analysis of single nucleotide polymorphism needs to calculate gene frequency. This paper employs allele model as an example to introduce how to calculate gene frequency and display the process of a meta-analysis of single nucleotide polymorphism data using Review Manager 5.3 software.
The resistance of non-small cell lung cancer (NSCLC) to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) has been brought into focus. COX-2 signal pathway was found to be closely related to EGFR signal pathway by recent researches, and there has been a growing interest to focus the researches on whether COX-2 pathway inhibition improves the efficacy of EGFR-TKIs in treating advanced NSCLC. In this review, we will illustrate recent advances of combined inhibition of EGFR and COX-2 signal pathways in NSCLC therapy.
Objective To systematically evaluate impact of perioperative use of clopidogrel on coronary bypass grafting (CABG) patients for anti-platelet treatment, in order to provide evidence for the rational drug use of such patients in the perioperative period. Methods PubMed, EMbase, HighWire, CENTRAL and its affiliated clinical trial registered data center, CBM and CNKI were electronically searched from 2003 to November, 2012. Randomized controlled trials (RCTs) and non-randomized clinical trials on perioperative use of clopidogrel of CABG patients were collected. References of included studies were also retrieved. Two reviewers independently screened studies according to exclusion and inclusion criteria, extracted data, and assessed the methodological quality. Then, meta-analysis was performed using RevMan 5.0 software. Results 18 studies (including 10 RCTs and 8 non-randomized clinical trials) involving 14 592 patients were included. The results of meta-analysis showed that: a) Among 10 included RCTs, preoperative use of clopidogrel for anti-platelet treatment reduced the incidence of myocardial infarction obviously, compared with the blank control group (RR=0.63, 95%CI 0.48 to 0.83, P=0.000 9), but there is no significant difference between the two groups in blood loss amount within 24 hours after operation (MD=130, 95%CI –6.21 to 266.22, P=0.06), the number of reoperation patients because of bleeding (RR=1.42, 95%CI 0.92 to 2.20, P=0.12), and risk of postoperative short-term death (RR=1.19, 95%CI 0.89 to 1.58, P=0.24); b) Among 8 non-randomized clinical trials, there was no significant difference between the two groups in reducing the incidence of myocardial infarction (RR=0.83, 95%CI 0.30 to 2.26, P=0.71), but preoperative use of clopidogrel for anti-platelet treatment significantly increased blood loss amount within 24 hours after operation (MD=82.42, 95%CI 35.18 to 129.66, P=0.000 6), the number of reoperation patients because of bleeding (RR=1.71, 95%CI 1.07 to 2.75, P=0.03), and risk of postoperative short-term death (RR=1.89, 95%CI 1.15 to 3.12, P=0.01). Conclusion Current evidence shows that, perioperative use of clopidogrel can reduce the incidence of myocardial infarction, but doctors should consider cautiously the increased risk of bleeding, re-operation and postoperative short-term death. There is contradiction between the results of RCTs and those of non-randomized clinical trials, which may result from the argument intensity, quantity and sample size bias of the included studies. The above conclusion should be proved by large-scale high-quality RCT results in future.
Objective To systematically review the effectiveness and safety of flexible ureteroscope lithtripsy (fURL) and percutaneous nephrolithotomy (PCNL) in treating renal calculus. Methods Such databases as MEDLINE, EMbase, The Cochrane Library, CNKI, CBM, VIP, and WanFang Data from January, 1990 to August, 2012 were searched to comprehensively collect the clinical trials that compared fURL and PCNL in treating renal calculus. Two reviewers independently screened studies according to exclusion and inclusion criteria, extracted data, and assessed the methodological quality. Then, meta-analysis was performed using RevMan 5.1 software. Results Eight non-randomized controlled trials involving 536 patients were included. The results of meta-analysis showed that, PCNL was better than fURL in stone clearance (OR=0.26, 95%CI 0.15 to 0.46), but fURL was better than PCNL in postoperative pyrexia (OR=0.1, 95%CI 0.42 to 3.35), the incidence of blood transfusion (OR=0.17, 95%CI 0.03 to 1.00), and the duration of hospitalization (P=0.45, I2=0%). Conclusion Current evidence has proved that PCNL is better than fURL in decreasing stone clearance, fURL is better than PCNL in complication, the duration of hospitalization, and medical costs.
Objective To systematically review the methodological quality of guidelines concerning infertility, so as to provide references for clinical practice. Methods Guidelines concerning infertility were electronically retrieved (from inception to Feb. 2013) in PubMed, EMbase, CBM, WanFang Data, CNKI, GIN guideline database guideline development websites (including NGC, NICE, SIGN, NZGG, SOGC, etc.), and medical associtation websites (including IFFS, FIGO, ESHRE, NFOG, RCOG, ASRM, ACOG, etc.). We also searched Chinese guideline websites including the website of the National Health and Family Planning Commission of People’s Republic of China, CGC (China Guideline Clearinghouse), and CPGN (Clinical Practice Guideline Net). Two reviews independently screened literature according to the inclusion and exclusion criteria, and assessed the quality of guideline development and reporting using the Appraisal of Guidelines for Research and Evaluation (AGREE II). Results a) A total of 16 guidelines concerning infertility were included, with development time ranging from 1998 to 2012. Among 16 guidelines, 10 guidelines were made by the USA, 3 by Britan, 1 by the Europe, and 1 by America and Europe. b) The scores of guidelines according to the domains of AGREE II decreased from “Clarity of presentations, scope and purpose”, “Participants”, “Applicability”, “Rigour of development”, and “Editorial independence”. 16 guidelines were generally low in quality. The levels of recommendations were Level A (5 guidelines), Level B (8 guidelines), and Level C (3 guidelines). c) Four evidence-based guidelines scored the top three in the domain of “Rigour of development”. d) The recommendations of different guidelines were fairly the same. e) No guidelines on infertility have been developed in China. Conclusion a) The guidelines on infertility should be improved in “Rigour of development” and “Applicability” in future. Conficts of interest should be addressed. b) Guidelines are recommended to be developed on the basis of the methods of evidence-based medicine, and best evidence is recommended. c) National organizations such as ASRM should be established in China, so as to develop biomedicine and TCM guidelines based on evidence and regulate the treatment. d) For the general assessment of guidelines, AGREE II should offer threshold criteria of suggestion.
Objective To systematically review the effectiveness and safety of Zhibitai vs. atorvastatin in the treatment of hyperlipidemia. Methods Randomized controlled trials (RCTs) about Zhibitai vs. atorvastatin for hyperlipidemia were electronically retrieved in databases of PubMed, CENTRAL (Issue 7, 2010), CBM,CNKI, VIP and WanFang Data from inception to July, 2012. Two reviewers independently screened literature, extracted data, and assessed methodological quality. Then, meta-analysis was conducted using RevMan 5.2 software. Results A total of 4 RCTs involving 519 cases were included. The results of meta-analysis showed, Zhibitai was superior to atorvastatin in reducing TG levels after 8-week treatment (MD= −0.12, 95%CI −0.23 to −0.01, P=0.03) and increasing HDL-C levels after 8-week treatment (MD= −0.16, 95%CI −0.22 to −0.11, P=0.000 01). But there was no significant difference in decreasing TC levels and LDL-C levels after 4-week treatment and 8-week treatment as well as decreasing TG levels after 4-week treatment between the two groups. No obvious adverse reaction occurred in the two groups, but atorvastatin may impair liver function. Conclusion Current evidence with weak strength shows that, Zhibitai is superior to atorvastatin in reducing TG levels, and increasing HDL-C levels after 8 weeks. However, they are alike in other blood-fat index and safety. Due to the limited quantity and quality of the included studies, more high quality RCTs are needed to verify the above conclusion.
Objective To evaluate the effectiveness of TCu380AIUD comparing with other common IUDs. Methods CBMDISC (1979 to 2005), Wanfang (1994 to 2005), CNKI (1974 to 2005), CMCC (1979 to 2005), CMAC (1994 to 2005), EMbase (1974 to 2004), MEDLINE (1974 to 2005), WHO/RHL (2004 to 2005), The Cochrane Library (Issue 4, 2004), SCI (1985 to 2005), POPLINE (1966 to 2003) and 9 relevant journals were searched for randomized controlled trials (RCTs) comparing TCu380AIUD with other common IUDs. The quality of included trials was critically appraised. RevMan4.2.7 software was used for statistical analysis. Results Fifteen published studies involving 20 417 participants were included. The results of meta-analyses were expressed with OR (cumulative expulsion rate, cumulative pregnancy rate, cumulative rate of removing for medical reasons) and 95% CI. Compared with TCu380A, TCu220C resulted in lower cumulative expulsion rate at 0.5 and 1 year of follow-up [OR 0.36 (0.18 to 0.70); 0.44 (0.31 to 0.62), respectively], higher cumulative pregnancy rate at ten years of follow-up [1.22 (1.04 to 1.43)], lower cumulative rate of removing for medical reasons at 0.5 year of follow-up [0.59 (0.36 to 0.97)]; MLCu375 resulted in higher cumulative expulsion rate at 1 year of follow-up [2.17 (1.29 to 3.67)], higher cumulative pregnancy rate at 1 and 2 years of follow-up [1.72 (1.18 to 2.50); 1.28 (1.02 to 1.60)]; UCD300 resulted in lower cumulative expulsion rate at five years of follow-up [0.38 (0.27 to 0.56)]; Medicated Gamma 380IUD resulted in lower cumulative rate of removing for medical reasons at 1 year of follow-up [0.31 (0.14 to 0.70)]. Conclusions Compared with TCu380A which is considered as a standard of IUDs, the performance of TCu220C is inferior in contraception, but TCu220C is also a good IUD in performance; The overall clinical performance of MLCu375IUD was as good as that of TCu380A; UCD300 is of the characteristic of lower cumulative expulsion rate; Medicated Gamma 380IUD can decrease side effects effectively. However, larger multi-center randomized comparative trials with longer follow-up periods are needed to confirm the conclusion
Objective To evaluate the effectiveness and safety of different injection sites for collagenase chemonucleolysis for lumbar intervertebral disc protrusion (LIDP). Methods We searched for randomized controlled trials (RCTs) and quasi-RCTs in the following electronic databases: Pubmed (1966 to May 2006), EMBASE(1966 to May 2006), The Cochrane library (Issue 2, 2006), CRD(Center for Reviews and Dissemination),York University, CBM (1978 to May 2006 ), CNKI(1994-2006)and VIP(1989-2006). Quality assessment and data extraction were conducted by two reviewers independently. Disagreement was resolved through discussion. Results Eight studies involving a total of 1035 participants met the inclusion criteria. Meta-analysis was not carried out because of apparent heterogeneity. Four studies made comparisons among intradisc, extradisc, and combined intra- and extra-disc injection. One study (62 participants) showed that intradisc injection was superior to extradisc injection (RR 3.71, 95% CI 1.19 to 11.58, Plt;0.05). Another study (240 participants) showed that intradisc injection was superior to combined intra- and extra-disc injection after 3 months and 6 months of follow-up (RR 0.88, 95% CI 0.80 to 0.98, Plt;0.05). The other two studies showed no significant difference among intradisc, extradisc, and combined intra- and extra-disc injection. Four studies (436 participants in total) showed that amongst three extradisc injections, both anterior epidural space injection and lateral epidural space injection were superior to posterior epidural space injection (Plt;0.05). Although one study indicated that anterior epidural space injection was superior to lateral epidural space injection (RR 1.24, 95% CI 1.03 to 1.51, Plt;0.05), no statistical significance was found between anterior epidural space injection and lateral epidural space injection in two other studies (Pgt;0.05). Conclusions There is insufficient evidence to identify which injection site for collagenase is the most effective for lumbar intervertebral disc protrusion. The included studies showed that both anterior and lateral epidural space injection were superior to posterior epidural space injection. However, these studies are too small and poor quality, and have different diagnostic criteria, follow-up time points, outcome measures and efficacy parameters. Thus, more high quality and large-scale RCTs are needed.
Objective To evaluate the prognostic value of the level of serum neurone specific enolase (NSE) in patients with small cell lung cancer (SCLC). Methods We searched MEDLINE, EMbase, CBMdisc, and The Cochrane Central Register of Controlled Trials (1950 to December 2007). Studies meeting the eligibility criteria were retrieved and their bibliographies were checked for other relevant publications. The quality of included studies was evaluated by 2 reviewers independently. Meta-analyses were performed for the results of homogeneous studies using STATA 7.0 software. Results Nine studies involving 2 021 SCLC patients were included. About 66.0% of patients had high serum levels of NSE, according to the cut-off value defined by the authors. The hazard ratio (HR) of high levels of NSE for overall survival (OS) was 1.27 times of that of low levels of NSE for OS in SCLC patients (95% CI 1.19 to 1.35, P=0.281). Conclusion Patients with high levels of NSE appear to have a poorer OS compared with those with low levels of NSE, thus the level of NSE has a prognostic value in SCLC patients. Due to the potential publication bias, selection bias, and measurement bias among these studies, the conclusion should be interpreted carefully. More high-quality homogeneous studies are required to accurately evaluate the prognostic value of NSE.