The association between ambient air pollution and colorectal cancer: a Mendelian randomization study.

Mounting epidemiology studies have reported the potential associations between ambient air pollution exposure and colorectal cancer (CRC). However, the genetic association between ambient air pollution and CRC remains unclear. Using the Genome-wide association study (GWAS) data from UK biobank, we explored the genetic association of CRC (5,657 cases and 372,016 controls) with four ambient air pollutants (PM2.5, PM10, NO2, NOx; n = 423,796 to 456,380) under the framework of Mendelian randomization (MR). Our results revealed a significant association between long-term NO2 exposure (per 10 µg/m3) and increased CRC risk, with an odds ratio (OR) of 1.02 (95% confidence interval [CI]: 1.00-1.03), while no statistical association was found between CRC risk and the other air pollutants. Sensitivity analysis confirmed the robustness of the results. It is imperative to consider the impact of air pollution, particularly NO2, in mitigating the risk of CRC.

Immune checkpoint inhibitors for patients with microsatellite instability-high colorectal cancer: protocol of a pooled analysis of clinical trials.

Introduction: Colorectal cancer (CRC) is the third most common cause of cancer and the second leading cause of cancer-related deaths worldwide. Microsatellite instability-high (MSI-H) is a distinct molecular subtype of CRC that occurs in approximately 15% of all cases. Recently, immune checkpoint inhibitors (ICIs) have emerged as a promising therapeutic approach for patients with MSI-H colorectal cancer, exhibiting higher response rates than standard chemotherapies. To assess the effectiveness and safety of ICIs for the treatment of patients with MSI-H CRC, we propose a comprehensive pooled analysis of clinical trial data. Methods and analysis: A systematic search of multiple electronic databases, including PubMed, EMBASE, Cochrane Library, and Clinicaltrials.gov, will be conducted from their inception until September, 2023 to identify eligible randomized controlled trials (RCTs) and non-randomized studies. Inclusion criteria comprise studies of adult patients with histologically confirmed MSI-H CRC treated with immune checkpoint inhibitors, with a comparison to a control group receiving conventional therapies. Outcomes of interest will be overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and incidence of treatment-related adverse events (AEs). The Cochrane Risk of Bias tool and the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool will be employed to evaluate the methodological quality of included studies. A random-effects model using the DerSimonian and Laird method will be applied for pooling the effect estimates, calculating hazard ratios (HRs) or risk ratios (RRs) with their corresponding 95% confidence intervals (CIs). Heterogeneity will be assessed using I² statistics, and subgroup analysis and meta-regression will be performed to explore potential effect modifiers in case of substantial heterogeneity. Publication bias will be evaluated with funnel plots and Egger's test. Sensitivity analysis will be conducted to assess the robustness of the results. Discussion: This meta-analysis will synthesize available evidence from clinical trials on immune checkpoint inhibitors in treating MSI-H colorectal cancer. The findings will offer valuable information about the effectiveness and safety of ICIs in this patient population, contributing to the refinement of clinical guidelines and enhancing the decision-making process for healthcare providers, policy-makers, and patients. The comprehensive analysis of subgroups and sensitivity allows for an in-depth understanding of potential effect modification, providing essential directions for future research. Ethics and dissemination: This study will involve the use of published data; hence, ethical approval is not required. The results of the study will be disseminated through publications in peer-reviewed journals and presentations at relevant conferences. The findings will potentially impact clinical decision-making and contribute to the development of evidence-based treatment recommendations for patients with MSI-H colorectal cancer. Clinical trial registration: Open Science Framework identifier, 10.17605/OSF.IO/ZHJ85.

[Molecular Genetic Analysis of One Sudden Unexplained Death in the Young by Whole Exome Sequencing].

OBJECTIVE: To find the mutation of disease-causing genes of sudden unexplained death syndrome (SUDS) in the young by whole exome sequencing in one case. METHODS: One SUDS case was found no obvious fatal pathological changes after conventional autopsy and pathological examination. The whole exome sequencing was performed with the Ion Torrent PGM™ System with hg19 as reference sequence for sequencing data. The functions of mutations were analyzed by PhyloP, PolyPhen2 and SIFT. A three-step bioinformatics filtering procedure was carried out to identify possible significative single nucleotide variation (SNV), which was missense mutation with allele frequency < 1% of myocardial cell. RESULTS: Four rare suspicious pathogenic SNV were identified. Combined with the analysis of conventional autopsy and pathological examination, the mutation MYOM2 (8_2054058_G/A) was assessed as high-risk deleterious mutation by PolyPhen2 and SIFT, respectively. CONCLUSION: Based on the second generation sequencing technology, analysis of whole exome sequencing can be a new method for the death cause investigation of SUDS. The gene MYOM2 is a new candidate SUDS pathogenic gene for mechanism research.

[Estimation of postmortem interval by detecting thickness of cornea using ultrasonic method].

OBJECTIVE: To explore the postmortem changes of cornea thickness measured by ultrasonic pachymetry. METHODS: Eleven rabbits were randomly divided into two groups: one group with intact corneal epithelium and another group without intact corneal epithelium. In the later group, the corneal epithelium of the rabbit was scraped using mechanical elimination method. The corneal thickness was monitored continuously by ultrasonic pachymetry at several postmortem interval points in rabbits of the two groups. The changes of corneal thickness and postmortem interval were explored by relative regression analysis. RESULTS: The thickness of the cornea showed a strong non-linear correlation with the postmortem interval in the group with intact corneal epithelium. The group with intact corneal epithelium showed the correlation coefficient 0.922 and the group without intact corneal epithelium showed the correlation coefficient 0.822, respectively. CONCLUSION: The corneal thickness measured by ultrasonic pachymetry shows a potential value for estimating early postmortem interval. The intact corneal epithelium is a crucial factor for the measurement of cornea thickness by ultrasonic pachymetry.