Bias in meta-analysis

Association of MTHFR gene polymorphisms with pancreatic cancer: meta-analysis of 17 case-control studies

BACKGROUND

Pancreatic cancer (PC) is a seriously malignant tumor with a low 5-year survival rate. The relationship between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and PC has been reported by several studies. However, the results were controversial. Thus, we conducted a meta-analysis to summarize available data on MTHFR gene and PC.

METHODS

We searched PubMed, Embase, Web of Science, Wanfang, CNKI databases prior to July 2019. Data were analyzed by RevMan 5.3 and STATA 12.0 software. Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the strength of the association. Subgroup analysis, sensitivity analysis and assessment of publication bias were performed in this study.

RESULTS

Ten articles with 17 reports (10 for C677T, 7 for A1298C) were eligible for inclusion in the meta-analysis (1864 cases and 3165 controls for C677T, and 1488 cases and 1946 controls for A1298C). Our meta-analysis detected that C677T was associated with PC for three genetic models (allele model: OR = 1.24, 95% CI: 1.00-1.53, P = 0.047; recessive model: OR = 1.39, 95% CI: 1.04-1.86, P = 0.027; homozygous model: OR = 1.60, 95% CI: 1.04-2.45, P = 0.034). In the stratified analyses according to ethnicity, source of controls and genotyping method, significant association was observed in genotyping method subgroup. For the A1298C polymorphism, no significant association was observed either in overall analysis or in subgroup analysis under all genetic models.

CONCLUSIONS

MTHFR gene C677T rather than A1298C polymorphism may be associated with PC. Larger sample size studies should be performed to find the association between MTHFR gene and PC.

NINJ2 Gene Polymorphisms and Susceptibility to Ischemic Stroke: An Updated Meta-Analysis

BACKGROUND

Ischemic stroke (IS) is a significant disease which threatens human health condition. Genome-wide association studies (GWAS) have demonstrated that two intergenic single- nucleotide polymorphisms (SNPs) rs11833579 and rs12425791 G>A on chromosome 12p13 are associated with IS susceptibility. However, later studies came to contradictory outcomes. Thus, we carried out a meta-analysis to identify the association between nerve injury-induced protein 2 (NINJ2) gene polymorphisms (rs11833579 and rs12425791) and the risk of IS.

METHODS

PubMed, Embase, Web of Science, CBM, Wanfang, VIP, and CNKI databases were searched until March 2019. Data was analyzed by RevMan 5.3 and STATA 12.0 software. The pooled odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the strength of the association.

RESULTS

Eighteen qualified articles were selected in total. For rs12425791 and rs11833579, a total of 14055 cases with 13148 controls and 10635 cases with 10462 controls, respectively, were identified for the present study. Our meta-analysis found that rs12425791 was associated with IS for three genetic models (allele model: OR=1.04, 95% CI: 1.00-1.08, P=0.04; dominant model: OR=1.06, 95% CI: 1.01-1.12, P=0.01 and heterozygous model: OR=1.07, 95% CI: 1.01-1.12, P=0.02). Whereas rs11833579 polymorphism was not associated with IS among different genetic models.

CONCLUSION

NINJ2 gene rs12425791 confers a susceptible factor for IS, while there is no association between NINJ2 gene rs11833579 and IS. Larger sample size studies should be performed to find the association between NINJ2 gene and IS.

Where does homeopathy fit in pharmacy practice?

Homeopathy has been the cause of much debate in the scientific literature with respect to the plausibility and efficacy of homeopathic preparations and practice. Nonetheless, many consumers, pharmacists, physicians, and other health care providers continue to use or practice homeopathic medicine and advocate its safety and efficacy. As drug experts, pharmacists are expected to be able to counsel their patients on how to safely and effectively use medications, which technically includes homeopathic products. Yet many pharmacists feel that the homeopathic system of medicine is based on unscientific theories that lack supporting evidence. Since consumers continue to use homeopathic products, it is necessary for pharmacists to have a basic knowledge of homeopathy and to be able to counsel patients about its general use, the current state of the evidence and its use in conjunction with other medications.

Immunology and homeopathy. 4. Clinical studies-part 2

The clinical studies on the effectiveness of homeopathy in respiratory allergy (18 randomized trials and 9 observational studies) are described. The literature of common immunologic disorders including also upper respiratory tract infections (URTI) and otorhinolaryngology (reported in part 1), is evaluated and discussed. Most of initial evidence-based research was addressed to the question of whether homeopathic high dilutions are placebos or possess specific effects, but this question has been often equivocal and is still a matter of debate. The evidence demonstrates that in some conditions homeopathy shows significant promise, e.g. Galphimia glauca (low dilutions/potencies) in allergic oculorhinitis, classical individualized homeopathy in otitis and possibly in asthma and allergic complaints, and a few low-potency homeopathic complexes in sinusitis and rhinoconjunctivitis. A general weakness of evidence derives from lack of independent confirmation of reported trials and from presence of conflicting results, as in case of homeopathic immunotherapy and of classical homeopathy for URTI. The suitable methods to evaluate homeopathy effectiveness, without altering the setting of cure, are also analyzed.

Immunology and homeopathy. 4. Clinical studies-part 1

The evidence-based research of the effectiveness of homeopathic medicines in common immunologic disorders is reviewed. In part 1, we introduce methodological issues of clinical research in homeopathy, and criteria utilized to evaluate the literature. Then 24 studies (12 randomized and 12 non-randomized) on common upper respiratory tract infections and otorhinolaryngologic complaints are described. In part 2, the focus will be on allergic diseases and the effectiveness of homeopathy will be globally evaluated and discussed using the criteria of evidence-based medicine.