Lithogenic and anthropogenic impacts on soil surface magnetic susceptibility in an arid region of Central Iran

In this study, natural and anthropogenic factors affecting the spatial distribution of topsoil mass magnetic susceptibility (χlf) were investigated in an arid region in Isfahan province, central Iran. A total of 100 surface (0–5 cm) soil samples were collected, and the χlf value of the soil samples was measured. High values of χlf in the east and northeast parts of the area indicated the occurrence of hilly igneous rocks and pediment geomorphic surface, enriched by ferrimagnetic minerals. In order to investigate the effects of human activities, multivariate geostatistics was applied to the results on the concentrations of eight heavy metals in surface soil samples. The results indicated that the spatial variability of second factor extracted by factor analysis, with high contribution of Zn, Pb and Cu, was well in agreement with the distribution of urban and industrial sites. This implied that magnetic particles accompanying the heavy metal emissions have increased χlf in the topsoil of the west of the area studied. Multiple linear regression analysis of χlf with studied factors revealed that the developed model explained about 64% of total variability in χlf in the studied area; and geology was identified as the most important controlling factor.     

Mitochondrial DNA Copy Number Variations and Serum Pepsinogen Levels for Risk Assessment in Gastric Cancer

Background:Variations in mtDNA-CN of PBLs, as a potential biomarker for GC screening has currently been subject to controversy. Herein, we have assessed its efficiency in GC screening, in parallel and in combination with sPG I/II ratio, as an established indicator of gastric atrophy. Methods:The study population included GC (n = 53) and non-GC (n = 207) dyspeptic patients. The non-GC group was histologically categorized into CG (n = 104) and NM (n = 103) subgroups. The MtDNA-CN of PBLs was measured by quantitative real-time PCR. The sPG I and II levels and anti-H. pylori serum IgG were measured by ELISA. Results:The mtDNA-CN was found significantly higher in GC vs. non-GC (OR = 3.0; 95% CI = 1.4, 6.4) subjects. Conversely, GC patients had significantly lower sPG I/II ratio than the non-GC (OR = 3.2; CI = 1.4, 7.2) subjects. The combination of these two biomarkers yielded a dramatic amplification of the odds of GC risk in double-positive (high mtDNA-CN-low sPGI/II) subjects, in reference to double-negatives (low mtDNA-CN-high sPGI/II), when assessed against non-GC (OR = 27.1; CI = 5.0, 147.3), CG (OR = 13.1; CI = 2.4, 72.6), or NM (OR = 49.5; CI = 7.9, 311.6) groups. Conclusion:The combination of these two biomarkers, namely mtDNA-CN in PBLs and serum PG I/II ratio, drastically enhanced the efficiency of GC risk assessment, which calls for further validations. Key Words: Biomarkers, DNA copy number variation, Mitochondrial DNA, Stomach neoplasms