High-Throughput, Quantitative Screening of Quorum-Sensing Inhibitors Based on a Bacterial Biosensor.

Quorum sensing (QS) is a cell-cell communication mechanism by which bacteria synchronize social behaviors such as biofilm formation and virulence factor secretion by producing and sensing small molecular signals. Quorum quenching (QQ) by degrading signals or blocking signal transmissions has become a promising strategy for disrupting QS and preventing bacterial infection and biofilm formation. However, studies of high-throughput screening and identification approaches for quorum-sensing inhibitors (QSIs) are still inadequate. In this work, we developed a sensitive, high-throughput approach for screening QSIs based on the bacterial biosensor strain Agrobacterium tumefaciens N5 (pBA7P), which contains a traG gene promoter induced by QS signals fused with a promoterless ß-lactamase gene reporter. Using this approach, we identified 31 QQ bacteria from ∼2000 soil bacterial isolates, some belonging to the genera Bosea, Cupriavidus, and Flavobacterium that have not been reported previously as QQ bacteria. We also identified four QS inhibitory compounds and one QS signal analogue from ∼5000 small-molecule compounds, which profoundly affected the expression of QS-regulated genes and phenotypes of the pathogenic bacteria. This high-throughput screening system is effective and sensitive for screening of both QQ microbes and small molecules, enabling the discovery of a wide variety of biocompatible compounds.

Military-related posttraumatic stress disorder and mindfulness meditation: A systematic review and meta-analysis.

PURPOSE: Posttraumatic stress disorder (PTSD) is a significant global mental health concern, especially in the military. This study aims to estimate the efficacy of mindfulness meditation in the treatment of military-related PTSD, by synthesizing evidences from randomized controlled trials. METHODS: Five electronic databases (Pubmed, EBSCO Medline, Embase, PsychINFO and Cochrane Library) were searched for randomized controlled trials focusing on the treatment effect of mindfulness meditation on military-related PTSD. The selection of eligible studies was based on identical inclusion and exclusion criteria. Information about study characteristics, participant characteristics, intervention details, PTSD outcomes, as well as potential adverse effects was extracted from the included studies. Risk of bias of all the included studies was critically assessed using the Cochrane Collaboration's tool. R Statistical software was performed for data analysis. RESULTS: A total of 1902 records were initially identified and screened. After duplicates removal and title & abstract review, finally, 19 articles in English language with 1326 participants were included through strict inclusion and exclusion criteria. The results revealed that mindfulness meditation had a significantly larger effect on alleviating military-related PTSD symptoms compared with control conditions, such as treatment as usual, present-centered group therapy and PTSD health education (standardized mean difference (SMD) = -0.33; 95% CI [-0.45, -0.21]; p < 0.0001). Mindfulness interventions with different control conditions (active or non-active control, SMD = -0.33, 95% CI [-0.46, -0.19]; SMD = -0.49, 95% CI [-0.88, -0.10], respectively), formats of delivery (group-based or individual-based, SMD = -0.30, 95% CI [-0.42, -0.17], SMD = -0.49, 95% CI [-0.90, -0.08], respectively) and intervention durations (short-term or standard duration, SMD = -0.27, 95% CI [-0.46, -0.08], SMD = -0.40, 95% CI [-0.58, -0.21], respectively) were equally effective in improving military-related PTSD symptoms. CONCLUSION: Findings from this meta-analysis consolidate the efficacy and feasibility of mindfulness meditation in the treatment of military-related PTSD. Further evidence with higher quality and more rigorous design is needed in the future.

Efficacy and Safety of Transarterial Chemoembolization for the Treatment of Unresectable Hepatocellular Carcinoma Associated with Bile Duct Tumor Thrombus: A Real-World Retrospective Cohort Study.

BACKGROUND: The occurrence of hepatocellular carcinoma (HCC) with bile duct tumor thrombus (BDTT) is rare. The aim of the study was to evaluate the effectiveness and safety of transarterial chemoembolization (TACE) for patients with unresectable HCC with BDTT. METHODS: This retrospective study was conducted on newly diagnosed HCC and BDTT patients who were initially treated with TACE or conservative management (CM) from 2009 to 2018. Survival outcomes of patients treated with TACE were compared with those of patients given CM. Multivariate analyses were performed to identify independent prognostic factors related to survival. RESULTS: Out of 100 patients included in this study, 40 patients underwent TACE, while the remaining 60 received CM. The median survival time of the TACE group was 8.0 months longer than that of the CM group (13.0 versus 5.0 months, P < 0.001). The 6-, 12-, 18-, 24-month overall survival (OS) rates were 90.0%, 52.5%, 22.5%, and 12.5%, respectively, for the TACE group compared with 26.7%, 8.3%, 5.0%, and 3.3%, respectively, for the CM group. Multivariate analyses showed that treatment allocation (hazard ratio [HR], 0.421; 95% confidence interval [CI], 0.243-0.730; P = 0.002), Child-Pugh status (HR, 2.529; 95% CI, 1.300-4.920; P = 0.006) and total bilirubin level (HR, 1.007; 95% CI, 1.004-1.009; P < 0.001) on first admission were independent predictors of OS. There was no procedure-related mortality within one month after TACE treatment. CONCLUSION: TACE is a safe and effective treatment method that may improve the OS of patients with unresectable HCC with BDTT.

Removal of gaseous pollutants by using 3DOM-based catalysts: A review.

Catalytic oxidation is a promising technique to control the emission of gaseous pollutants. Three-dimensionally ordered macroporous (3DOM)-based catalysts have aroused widespread attention because of their high porosity, large surface area and pore volume, superb ability of mass transfer. Therefore, they have been widely used in gaseous pollutants control field, such as soot and methane catalytic combustion, VOCs catalytic oxidation, photocatalytic CO2 reduction and so on. In this review, the recent studies about the preparation and applications of 3DOM catalysts are summarized. At the same time, the advantages and mechanism of the 3DOM catalysts used in gaseous pollutants control are introduced in depth. Finally, the perspective and future direction of 3DOM-based catalysts for gaseous pollutants control are proposed.

Enhancement of the activity of Cu/TiO2 catalyst by Eu modification for selective catalytic reduction of NOx with NH3.

The Cu/TiO2 catalysts with the addition of Eu were developed by the sol-gel way for the selective catalytic reduction (SCR) of NOx by NH3. Activity tests revealed that CuEu/TiO2-0.15 catalyst showed the optimal de-NOx performance in a wide temperature range (150-300 °C), along with an admirable SO2 tolerance. According to characterization analysis, the relationship between the NH3-SCR performance and physicochemical characters of samples was explored. The adjunction of Eu on Cu/TiO2 catalyst can contribute to the formation of a large amount of Cu2+, adsorbed oxygen, and acid sites on the catalyst surface. Moreover, the Eu addition on Cu/TiO2 is favorable to the generation of activated NOx and NH3 substances adsorbed on the catalyst surface, which would conduce to the NH3-SCR process by Langmuir-Hinshelwood (L-H) mechanism effectively.

[Establishment of A Myelodysplastic Syndrome Transformed to Leukemia Cell Line Stably Expressing Green Fluorescent Protein].

OBJECTIVE: To establish a myelodysplastic syndrome transformed to leukemia cell line stably expressing green fluorescent protein (GFP), and to evaluate its biological characteristics and applications. METHODS: SKM-1 cells were transfected by lentiviral particles with vector of GFP. The GFP positive single cell clone was isolated by limiting dilution and continued being cultured. The cells were injected into mice subcutaneously and were screened in vivo. Then SKM-1/GFP cells were obtained after tumour plaque was separated and cultivated. The cell morphology was observed by fluorescence microscopy. The GFP expression was further detected by flow cytometry. The cell proliferation was analysed by CCK-8 assay. SKM-1/GFP cells were inoculated to subcutaneous tissue of the immunodeficiency mice. The growth and invasion of the tumour were observed after tumour formation. RESULTS: No differences in cell morphology and growth characteristics were observed between SKM-1 cells and SKM-1/GFP cells. The rate of GFP expression was 100%. No differences in cell proliferation were observed between SKM-1 cells and SKM-1/GFP cells. The tumour mass was observed after 14 days of subcutaneous vaccination in NOD/SCID mice. Spontaneous fluorescence from plaque was observed by living fluorescence microscopy at 30th day after vaccination. Homogenous GFP positive cells were observed by fluorescence microscopy in the frozen section of tumour mass. The invasion of SKM-1/GFP cells was also detected in heart, liver, stomach and kidney of mice. CONCLUSION: A myelody-splastic syndrome transformed to leukemia cell line stably expressing green fluorescent protein has been established successfully, which can track tumor cell sensitively and can be applied to the research of minimal residual leukemia. The establishment of SKM-1/GFP cells may serve as a powerful means for studing myelodysplastic syndrome transformation.

[Occupational and residential exposure to electric and magnetic field and its relationship on acute myeloid leukemia in adults - A Meta-analysis].

OBJECTIVE: Studies had suggested that risk of leukemia might be associated with occupational or residential exposures to electromagnetic fields and varied at distance to and level of the exposure or type of occupations. Through pooled analyses, etiologic insight on the associations between exposure and disease might be explained. METHODS: We carried out a Meta-analysis based on primary data (1980 - 2010) from 9 studies related to the electric and magnetic fields exposure and acute myeloid leukemia in adults to assess whether the combined results, adjusted for potential confounding, would indicate an association between them. RESULTS: In this study the overall estimated OR value was 1.24 (95%CI: 1.11 - 1.37). The odds ratios for exposure categories of 0.1 - 0.2 µT, ≥ 0.2 µT, compared with < 0.1 µT, were 1.17 (95%CI: 0.98 - 1.39) and 1.51 (95%CI: 1.15 - 1.98), respectively. CONCLUSION: Through employing the alternate cut points, stratification by level of exposure or distance and the relation on different ways of exposure, there appeared consistent evidence of increased risk between acute myeloid leukemia in adults and the extremely low frequency-electromagnetic to field exposure.

[Functional study of mdr1 and GSTpi expression reversed by hairpin siRNA in K562/A02 cell line].

OBJECTIVE: To investigate the effect of hairpin small interference RNA (shRNA) on mdr1 and GSTpi protein expression in multidrug resistance human leukemia cell line K562/A02. METHOD: The shRNAs were synthesized targeting the coding region sequences of mdr1 (79 - 99 nt) and GSTpi (308 - 327 nt) respectively, and cloned to plasmid pSilencer2.1-U6 neo. The cloned products pSilence mdr1 and pSilence GSTpi were transfected into K562/A02 cells. Western blot and immunofluorescence analysis were used to detect the effectiveness and the specificity of the gene silence. 50% inhibition concentration (IC(50)) of doxorubicin (ADM) on K562/A02 cells was determined by MTT method. RESULT: pSilence mdr1 and pSilence GSTpi reduced the expression of P-gp and GSTpi protein from 0.75 +/- 0.02 and 0.54 +/- 0.02 to 0.48 +/- 0.05 and 0.39 +/- 0.02 (P < 0.01) respectively, with no effect on alpha-tubulin expression in comparison with the mock treatment. Transfection of pSilence lamin A/C into K562/A02 decreased lamin A/C expression but had no effect on the expression of P-gp and GSTpi. Immunofluorescence assay also showed that shRNAs significantly reduced the P-gp and GSTpi positive cells from (71.25 +/- 9.65)% and (81.25 +/- 6.49)% to (35.25 +/- 5.97)% and (41.25 +/- 4.43)% (P < 0.01), respectively, compared with the mock treatment. The resistance indexes after transfection were decreased to 8 (pSilence mdr1) and 10 (pSilence GSTpi) respectively from 23 (mock transfection) (P < 0.01). CONCLUSION: The shRNA could effectively and specifically reverse the multidrug resistance on K562/A02 cell line.

[Reversal of multidrug resistance of K562/A02 cell line by mdr1 and GSTpi gene silence].

OBJECTIVE: To investigate the effect of short hairpin RNA (shRNA) on mdr1 and GSTpi expression of human multidrug resistant leukemia cell line K562/A02. METHODS: shRNAs were synthesized according to the sequence targeting mdr1 and GSTpi coding region of 79-99nt and 308 approximately 327nt, and cloned into pSilencer 2.1-U6 neo vector. The cloned products, pSilence-mdr1 and pSilence-GSTpi, were transfected into K562/A02 cell line. Expression of mdr1 and GSTpi mRNA was assayed by real time PCR. 50% inhibition concentration (IC(50)) of doxorubicin (ADM) for K562/A02 cell line was determined by MTT method. RESULTS: After transfected with pSilence mdr1, the expression of mdr1 mRNA in K562/A02 cells was reduced by 71.5%, from (2.80 +/- 1.65) x 10(8) copy/microg RNA to (3.90 +/- 2.37) x 10(7) copy/microg RNA(P < 0.01). While the expression of GSTpi mRNA in pSilence-GSTpi transfected K562/A02 cells reduced by 39.8%, from (2.30 +/- 1.14) x 10(5) copy/microg RNA to (5.40 +/- 2.45) x 10(4) copy/microg RNA (P < 0.01). The resistance indexes after transfection were decreased to 8 and 10 respectively as compared to 23 of the mock transfection (P < 0.01). CONCLUSION: The shRNA could effectively reverse the multidrug resistance of K562/A02 cell line.