Association of Murine Double Minute 2 polymorphisms with gastric cancer: A systematic review with meta-analysis.

Gastric cancer (GC) is the 5th most common type of cancer, with the 3rd highest mortality rate worldwide in both sexes. Murine double minute 2 (MDM2) protein is the major negative regulator of p53, and genetic polymorphisms in this gene have shown to be associated with several types of cancer. In the present study, a literature search was performed using PubMed and Scopus with the following key word combinations 'gastric cancer AND polymorphism AND MDM2'. Studies were carefully revised according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify eligible studies that matched the inclusion criteria. Statistical analysis was performed to assess the association between the different genetic polymorphisms and GC risk, by calculating the odds ratios (OR) and the confidence intervals (CI), with a 5% level of significance. A total of 11 manuscripts studied MDM2 polymorphisms in GC: rs937283 (n=1), rs3730485 (n=1) and rs2279744 (n=9). Both the rs937283 and rs3730485 reports showed an association with GC; however, there was only one study on each of these polymorphisms in the literature. A meta-analysis was performed for the rs2279744 polymorphism, of which studies showed a positive association between the G allele and risk of GC, either in the dominant model (OR=1.46; 95% CI 1.21-1.75; P<0.001) or recessive model (OR 1.65; 95% CI 1.45-1.87; P<0.001). In conclusion, genetic polymorphisms in MDM2 seemed to be associated with an increased risk of GC development, nevertheless, the number of studies were relatively low and the studied populations were primarily Chinese. The present meta-analysis emphasizes the need for additional studies in other populations to corroborate the association of these polymorphisms with GC.

Optimization and Clinical Evaluation of a Multi-Target Loop-Mediated Isothermal Amplification Assay for the Detection of SARS-CoV-2 in Nasopharyngeal Samples.

SARS-CoV-2 is the coronavirus responsible for COVID-19, which has spread worldwide, affecting more than 200 countries, infecting over 140 million people in one year. The gold standard to identify infected people is RT-qPCR, which is highly sensitive, but needs specialized equipment and trained personnel. The demand for these reagents has caused shortages in certain countries. Isothermal nucleic acid techniques, such as loop-mediated isothermal amplification (LAMP) have emerged as an alternative or as a complement to RT-qPCR. In this study, we developed and evaluated a multi-target RT-LAMP for the detection of SARS-CoV-2. The method was evaluated against an RT-qPCR in 152 clinical nasopharyngeal swab samples. The results obtained indicated that both assays presented a "good concordance" (Cohen's k of 0.69), the RT-LAMP was highly specific (99%) but had lower sensitivity compared to the gold standard (63.3%). The calculated low sensitivity was associated with samples with very low viral load (RT-qPCR Cq values higher than 35) which may be associated with non-infectious individuals. If an internal Cq threshold below 35 was set, the sensitivity and Cohen's k increased to 90.9% and 0.92, respectively. The interpretation of the Cohen's k for this was "very good concordance". The RT-LAMP is an attractive approach for frequent individual testing in decentralized setups.

Hepatitis E virus in hematopoietic stem cell transplant recipients: A systematic review.

BACKGROUND: In developed countries, Hepatitis E virus (HEV) infections, especially by HEV-3, are frequently associated with asymptomatic infection or self-limiting acute hepatitis, although it has been described as a cause of chronic infection, especially in immunocompromised hots. Hematopoietic stem cell transplant (HSCT) recipients have been recognized as an important risk group for HEV infection due to their prolonged immunosuppression state. OBJECTIVES: We aimed to perform a systematic review of published data to evaluate HEV infection prevalence among HSCT recipients. STUDY DESIGN: Literature search was performed concerning published manuscripts regarding 'hepatitis E virus AND stem cell transplantation' following the Preferred Reporting of Systematic Reviews and MetaAnalyses (PRISMA) guidelines. Statistical analysis was performed using the MetaXL software to estimate the overall prevalence of HEV infection according to the different diagnostic approaches (HEV RNA and anti-HEV IgM and/or IgG detection). RESULTS: A total of 7 manuscripts were included for data analysis, with 6 studies performed in Europe and 1 study in China. Regarding HEV RNA detection, the overall HEV infection prevalence was 1.50% (95% CI: 0.70-2.60). The overall anti-HEV IgM seroprevalence was 2.00% (95% CI: 0.30-4.50), and anti-HEV IgG was 11.4% (95% CI: 1.80-26.3). CONCLUSIONS: This systematic review reveals that the overall prevalence of HEV infection in HSCT patients differ according to the diagnostic, thus emphasizing the need of more studies to increase the data regarding prevalence and incidence in HSCT recipients.