Metabarcoding to investigate changes in soil microbial communities within forensic burial contexts

The estimation of the time elapsed since death (post-mortem interval, or PMI) is one of the key themes that forensic scientists have to address frequently. However, the estimation of PMI still suffers from poor accuracy and biases especially when decomposition stages are prolonged, so further improvements in methods for PMI estimation are desirable. Soil microbial communities associated with decomposing bodies have been shown to be good candidates for the estimation of the PMI of exposed bodies. Nevertheless, further research is required to better understand the bacterial succession associated with decomposition of buried carcasses in order to test its reliability and applicability for the estimation of PMI and to better understand the dynamics involved with decomposition within this particular scenario. Therefore we explored the succession of soil microbial communities associated with four decomposing pig carcasses (from one to six months PMI) using a metabarcoding approach. The sequencing of the bacterial 16S rRNA variable region 4 (V4) revealed trends linking particular microbial taxa with specific PMIs, and notably an increase in Proteobacteria, Firmicutes and Bacteroidetes at specific PMIs as well as a decrease in Acidobacteria. Our results, in accordance with previous studies conducted on exposed bodies of different mammalian species (including humans), also showed a general reduction of the taxonomic richness from two months PMI onwards, as well as an incomplete re-establishment of the starting soil microbial conditions after six months PMI. We also found specific mammal-derived taxa, such as Bacteroides spp., being still present in the soil after six months PMI. As such, this study serves as a baseline for additional research to allow the characterisation of biomarkers associated with specific PMIs. Due to the similarity between the results presented here and those reported in other types of decomposition studies we believe that the metabarcoding approach has considerable potential in the estimation of the PMI, particularly to clarify cases involving heavily skeletonised bodies or for the investigation of clandestine graves in which the carcass has been moved from its original place of deposition.     

A Ca2+ chelator ameliorates chromium (VI)-induced hepatocyte L-02 injury via down-regulation of voltage-Dependent anion channel 1 (VDAC1) expression

Hexavalent chromium could result in cell malfunctions. Intracellular Ca²⁺ ([Ca²⁺]_i) content and VDAC1 expression are both important features related to cell survial. This study aimed to explore the mechanism of cell injury induced by Cr(VI) and tentatively offer clues to repairing this cell damage using [Ca²⁺]_i and VDAC1. L-02 hepatocytes were treated with Cr(VI)/BAPTA, and the levels of [Ca²⁺]_i and cell injury associated with Cr(VI) were determined in addition to the effect of BAPTA. The expression of VDAC1 in Cr(VI)-induced cells was evaluated. The results showed a dose-dependent elevation of the level of VDAC1 and the mRNA level of the VDAC1 biogenesis-related gene Sam50. BAPTA could ameliorate less severe damage induced by 4 μM Cr(VI) via reducing VDAC1 and Sam50. Additionally, cell injury caused by less than 4 μM Cr(VI) could be ameliorated by VDAC1 knockdown. Taken together, the findings of this study suggest that inhibition of intracellular Ca^2± overload could protect cells from damage and that VDAC1 plays a considerable role in Cr(VI)-induced liver injury.     

Understanding Restaurant Healthfulness in Food Deserts

ObjectiveTo determine differences in restaurant environments between neighborhood and restaurant type to understand better a food desert's eating environments.MethodsThe Nutrition Environment Measures Survey for restaurants was used to assess restaurant healthfulness. Kruskal-Wallis compared healthy index scores, and Pearson chi-square compared individual items.ResultsHealthy index scores were consistently low across neighborhoods (total mean = 4.6 out of 23). Fast-food restaurants (mean = 5.7) were more healthful than sit-down restaurants (mean = 3.1). Individual comparisons showed more healthy eating facilitators (eg, nutrition information at point-of-purchase, P = 0.004) in food deserts and more available healthful items (eg, whole grain bread, P < 0.001) in the neighborhoods with high incomes.Conclusions and ImplicationsFindings indicate equities in restaurant environments across all neighborhoods but inequities across restaurant types, thus conclude the importance of restaurant type in understanding restaurant healthfulness. Policymakers can use these findings to develop healthy eating strategies in varying neighborhoods.     

Autophagy mediates neutrophil responses to bacterial infection

Neutrophils constitute the first line of cellular defense against pathogens and autophagy is a fundamental cellular homeostasis pathway that operates with the intracellular degradation/recycling system. Induction of the autophagic process in neutrophils, in response to invading pathogens, constitutes a crucial mechanism in innate immunity. Exploration of autophagy has greatly progressed and diverse strategies have been reported for studying this molecular process in different biological systems; especially in infectious and inflammatory diseases. Furthermore, the role of autophagy in neutrophils, during pathogenic infection, continues to be of interest, due to the role of the cell in immunity function, its recruitment to the site of infection and its implication in inflammatory diseases. This review focuses on the known role of autophagy in neutrophils defence against pathogenic infections. A more detailed discussion will concern the recent findings highlighting the role of autophagy in inflammation and cell death in infected neutrophils.