Microbial communities contribute to the elimination of As, Fe, Mn, and NH4+ from groundwater in household sand filters.

Household sand filters (SFs) are widely applied to remove iron (Fe), manganese (Mn), arsenic (As), and ammonium (NH4+) from groundwater in the Red River delta, Vietnam. Processes in the filters probably include a combination of biotic and abiotic reactions. However, there is limited information on the microbial communities treating varied groundwater compositions and on whether biological oxidation of Fe(II), Mn(II), As(III), and NH4+ contributes to the overall performance of SFs. We therefore analyzed the removal efficiencies, as well as the microbial communities and their potential activities, of SFs fed by groundwater with varying compositions from low (3.3 µg L-1) to high (600 µg L-1) As concentrations. The results revealed that Fe(II)-, Mn(II)-, NH4+-, and NO2--oxidizing microorganisms were prevalent and contributed to the performance of SFs. Additionally, groundwater composition was responsible for the differences among the present microbial communities. We found i) microaerophilic Fe(II) oxidation by Sideroxydans in all SFs, with the highest abundance in SFs fed by low-As and high-Fe groundwater, ii) Hyphomicropbiaceae as the main Mn(II)-oxidizers in all SFs, iii) As sequestration on formed Fe and Mn (oxyhydr)oxide minerals, iv) nitrification by ammonium-oxidizing archaea (AOA) followed by nitrite-oxidizing bacteria (NOB), and v) unexpectedly, the presence of a substantial amount of methane monooxygenase genes (pmoA), suggesting microbial methane oxidation taking place in SFs. Overall, our study revealed diverse microbial communities in SFs used for purifying arsenic-contaminated groundwater, and our data indicate an important contribution of microbial activities to the key functional processes in SFs.

A Five-miRNA Panel Identified From a Multicentric Case-control Study Serves as a Novel Diagnostic Tool for Ethnically Diverse Non-small-cell Lung Cancer Patients.

Circulating microRNAs (miRNAs) are promising biomarkers for cancer detection. However, multiethnic and multicentric studies of non-small-cell lung cancer (NSCLC) are lacking. We recruited 221 NSCLC patients, 161 controls and 56 benign nodules from both China and America. Initial miRNA screening was performed using the TaqMan Low Density Array followed by confirming individually by RT-qPCR in Chinese cohorts. Finally, we performed a blind trial from an American cohort to validate our findings. RT-qPCR confirmed that miR-483-5p, miR-193a-3p, miR-25, miR-214 and miR-7 were significantly elevated in patients compared to controls. The areas under the curve (AUCs) of the ROC curve of this five-serum miRNA panel were 0.976 (95% CI, 0.939-1.0; P < 0.0001) and 0.823 (95% CI, 0.75-0.896; P < 0.0001) for the two confirmation sets, respectively. In the blind trial, the panel correctly classified 95% NSCLC cases and 84% controls from the American cohort. Most importantly, the panel was capable of distinguishing NSCLC from benign nodules with an AUC of 0.979 (95% CI, 0.959-1.0) in the American cohort and allowed correct prediction of 86% and 95% stage I-II tumors in the Chinese and American cohorts, respectively. This serum miRNA panel holds the potential for diagnosing ethnically diverse NSCLC patients.

Comparison of mass spectrometry and clinical assay measurements of circulating fragments of B-type natriuretic peptide in patients with chronic heart failure.

BACKGROUND: Multiple B-type natriuretic peptide (BNP) fragments circulate in patients with heart failure (HF) but the types and relative quantities, particularly in relation to bioactive BNP 1-32, remain poorly defined. The purpose of the study was to relate clinically available BNP values with quantitative information on the concentration of pre-secretion and post-processed fragments of BNP detected by mass spectrometry. METHODS AND RESULTS: Seventy Class I-IV patients were prospectively enrolled with blood drawn into tubes containing a preservative to protect against BNP degradation. Samples were analyzed by quantitative mass spectrometry (MS) immunoassay for intact BNP 1-32 and its fragments. Clinical BNP 1-2 was measured by standard clinical laboratory methods. ProBNP 1-108, corin, and clinically measured BNP levels were elevated, but MS BNP 1-32 levels were low and differed from clinical BNP (P=0.01). Intact MS BNP 1-32 correlated modestly with clinical BNP (r=0.46, P<0.001). MS BNP fragments 3-32, 4-32, and 5-32 demonstrated the best associations with clinical BNP; fragment 5-32 with a correlation coefficient of r=0.81 (P<0.001). CONCLUSIONS: ProBNP 1-108 is measured by clinical BNP assays and contributes to the cumulative results of the BNP assay. However, the observation that clinically measured BNP correlates best with MS degradation fragments and relatively poorly with MS BNP 1-32 suggests that a significant component of circulating clinical BNP is composed of such fragments that are known to demonstrate little biological activity. There appear to be multiple pathways involved in the dysregulation of proBNP in HF, and both the processing of proBNP and the downstream degradation to BNP 1-32 appear to be critical.