Search

Nucleic acid amplification tests (NAATs) have become an attractive approach for pathogen detection, and obtaining high-quality nucleic acid extracts from biological samples plays a critical role in ensuring accurate NAATs. In this work, we established an elution-free magnetic bead (MB)-based method by introducing polyethylene-polypropylene glycol (PEPPG) F68 in lysis buffer and using NaOH solution instead of alcohols as the washing buffer for rapid nucleic acid extraction from multiple types of biological samples, including nasopharyngeal swabs, serum, milk, and pork, which bypassed the nucleic acid elution step and allowed the nucleic acid/MB composite to be directly used as the template for amplification reactions. The entire extraction process was able to be completed in approximately 7 min. Even though the nucleic acid/MB composite could not be used for quantitative real-time PCR (qPCR) assays, this elution-free MB-based method significantly improved the sensitivity of the loop-mediated isothermal amplification (LAMP) assay. The sensitivity of the quantitative real-time LAMP (qLAMP) assays combined with this elution-free MB-based method showed an improvement of one to three orders of magnitude compared with qLAMP or qPCR assays combined with the traditional MB-based method. In addition to manual operation, like the traditional MB-based method, this universal, rapid, and facile nucleic acid extraction method also has potential for integration into automated robotic processing, making it particularly suitable for the establishment of an analysis platform for ultrafast and sensitive pathogen detection in various biological samples both in centralized laboratories and at remote sites. [ABSTRACT FROM AUTHOR]

To enrich an effective Chinese cabbage waste-anaerobic digesting microorganism community, a mixture of cellulolytic microbial community, anaerobic straw-digesting sludge, and cow dung was loaded in a continuous stirred tank reactor, and the Chinese cabbage wastes were fed as carbon and nitrogenous sources. The methane conversion efficiency reached 235.6 mL/g VS after 37 days of operation. The average biogas producing yield was 452.6 mL/g VS with 10.1 g/(L day) of organic loading rate between day 213 and day 231. This microorganism community could effectively degrade Chinese cabbage waste and filter paper, and the weight losses were 72.6 ± 1.1% and 91.4 ± 2.4% in 7 days, respectively. This microorganism community was further analyzed by high-throughput sequencing of the 16S rRNA gene and shown to have abundant bacterial diversity, but poor archaeal diversity. Longilinea, Candidatus Cloacamonas, and Caldisericum were the top three classes of abundant bacterial community, and the proportional abundances were 7.0%, 5.5%, 3.6%, respectively. Methanothrix and Methanolinea dominated the methanogenic archaeal community and occupied 90.8% proportion of total archaeal abundance. [ABSTRACT FROM AUTHOR]

The microRNA miR-133a is dysregulated in many types of cancer, but the underlying mechanism remains largely unknown. In this study, we showed that the expression level of miR-133a was reduced in ovarian cancer tissues compared with normal ovaries. Ectopic expression of miR-133a significantly inhibited ovarian cancer cell proliferation and colony formation, and induced G1-phase cell cycle arrest, whereas decreased miR-133a expression dramatically enhanced cell proliferation and colony formation. Importantly, miR-133a overexpression suppressed in vivo tumor growth in nude mice models. Through in silico search, we found that the 3′-untranslated region (UTR) of insulin-like growth factor 1 receptor (IGF1R) contains an evolutionarily conserved miR-133a binding site. miR-133a overexpression repressed IGF1R-3′UTR reporter activity, and reduced the mRNA and protein levels of endogenous IGF1R. Rescue experiments showed that ectopic expression of IGF1R significantly promoted the proliferation of ovarian cancer cells stably overexpressing miR-133a. Taken together, these findings indicate that miR-133a is an important regulator in ovarian cancer, and that its suppressive effects are mediated by targeting IGF1R. [ABSTRACT FROM AUTHOR]

CD4 count is the standard method for determining eligibility for highly active antiretroviral therapy (HAART) and monitoring HIV/AIDS disease progression, but it is not widely available in resource-limited settings. This study examined the correlation between total lymphocyte count (TLC) and CD4 count of HIV-infected patients before and after HAART, and assessed the thresholds of TLC for making decisions about the initiation and for monitoring HAART. A retrospective study was performed, and 665 HIV-infected patients with TLC and CD4 count from four counties (Shangcai, Queshan, Shenqiu and Weishi) were included in the study. Pearson correlation and receiver operating characteristic (ROC) were used. TLC and CD4 count after HAART was significantly increased as compared with pre-HAART ( P<0.01). An overall positive correlation was noted between TLC and CD4 count (pre-HAART, r=0.73, P=0.0001; follow-up HAART, r=0.56, P=0.0001). The ROC curve between TLC and CD4 count showed that TLC ≤ 1200 cells/mm could predict CD4 < 200 cells/mm with a sensitivity of 71.12%, specificity of 66.35% at pre-HAART. After 12-month HAART, the optimum prediction for CD4 count < 200 cells/mm3 was a TLC ≤ 1300 cells/mm, with a sensitivity of 63.27%, and a specificity of 74.84%. Further finding indicated that TLC change was positively correlated to CD4 change ( r=0.77, P=0.0001) at the time point of 12-month treatment, and the best prediction point of TLC change for CD4 increasing was 135 cells/mm. TLC and its change can be used as a surrogate marker for CD4 count and its change of HIV-infected individuals for making decisions about the initiation and for monitoring HAART in resource-limited settings. [ABSTRACT FROM AUTHOR]