Characterization of a sensitive biosensor based on an unmodified DNA and gold nanoparticle composite and its application in diquat determination

AbstractDNA usually adsorbs gold nanoparticles by virtue of mercapto or amino groups at one end of a DNA molecule. However, in this paper, we report a sensitive biosensor constructed using unmodified DNA molecules with consecutive adenines (CA DNA) and gold nanoparticles (GNPs). The CA DNA–GNP composite was fabricated on gold electrodes and characterized by using of scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and the electrochemical method. Using an electrochemical quartz crystal microbalance (EQCM), the mechanism by which the CA DNA and GNPs combined was also studied. The modified electrode exhibited an ultrasensitive response to diquat. Differential pulse voltammetry (DPV) was used to study the linear relationships between concentrations and reduction peak currents, ranging from 1.0×10−9M to 1.2×10−6M. The detection limit of it is 2.0×10−10M. The feasibility of the proposed assay for use in human urine and grain was investigated, and the satisfactory results were obtained

Strong Association Between Two Polymorphisms on 15q25.1 and Lung Cancer Risk: A Meta-Analysis

Background: The association between polymorphisms on 15q25.1 and lung cancer has been widely evaluated; however, the studies have yielded contradictory results. We sought to investigate this inconsistency by performing a comprehensive meta-analysis on two polymorphisms (CHRNA3 gene: rs1051730 and AGPHD1 gene: rs8034191) on 15q25.1. Methods: Data were extracted from 15 and 14 studies on polymorphisms rs1051730 and rs8034191 involving 12301/14000 and 14075/12873 lung cancer cases/controls, respectively. The random-effects model was applied, addressing heterogeneity and publication bias. Results: The two polymorphisms followed Hardy-Weinberg equilibrium for all studies (P\u3e0.05). For rs1051730-G/A, carriers of A allele had a 36% increased risk for lung cancer (95% confidence interval [CI]: 1.27–1.46; P\u3c0.0005), without heterogeneity (P = 0.258) or publication bias (PEgger = 0.462). For rs8034191-T/C, the allelic contrast indicated that C allele conferred a 23% increased risk for lung cancer (95% CI: 1.08–1.4; P = 0.002), with significant heterogeneity (P\u3c0.0005), without publication bias (PEgger = 0.682). Subgroup analyses suggested that the between-study heterogeneity was derived from ethnicity, study design, matched information, and lung cancer subtypes. For example, the association of polymorphisms rs1051730 and rs8034191 with lung cancer was heterogeneous between Caucasians (OR = 1.32 and 1.22; 95% CI: 1.25–1.44 and 1.05–1.42; PP = 0.237 and 0.934, respectively) under the allelic model, and this association was relatively strengthened under the dominant model. There was no observable publication bias for both polymorphisms. Conclusions: Our findings demonstrated that CHRNA3 gene rs1051730-A allele and AGPHD1 gene rs8034191-T allele might be risk-conferring factors for the development of lung cancer in Caucasians, but not in East-Asians

Increasing Nonsteroidal Anti-inflammatory Drugs and Reducing Opioids or Paracetamol in the Management of Acute Renal Colic: Based on Three-Stage Study Design of Network Meta-Analysis of Randomized Controlled Trials

Background: Currently, although non-steroidal anti-inflammatory drugs (NSAIDs) were recommended for acute renal colic in the 2018 European Association of Urology guidelines, there are no specific NSAIDs and no specific routes of administration in this guideline. The clinical practice of advocating intravenous opioids as the initial analgesia is still common out of the fear of adverse events from NSAIDs.Objectives: To comprehensively assess the efficacy and safety of NSAIDs, opioids, paracetamol, and combination therapy for acute renal colic.Methods: Ovid MEDLINE, Ovid EMbase, the Cochrane Library, Clinical Trials Registry Platform for Clinicaltrials.gov, and WHO International Clinical Trials Registry Platform were searched through February 2, 2018. Two reviewers selected all randomized controlled trails (RCTs) regarding NSAIDs, opioids, paracetamol, combination therapy, and placebo were identified for analysis. We designed a three-stage strategy based on classification and pharmacological mechanisms in the first stage, routes of administration in the second stage, and specific drug branches with different routes in the third stage using network meta-analysis. The pain variance at 30 min was seen as the primary outcome.Results: 65 RCTs with 8633 participants were involved. Comparing different classification and pharmacological mechanisms, combination therapy with more adverse events was more efficient than NSAIDs for the primary outcomes. Opioids gave rise to more nonspecific adverse events and vomiting events. NSAIDs were superior to opioids, paracetamol, and combination therapy after a full consideration of all outcomes. Comparing different routes of administration, NSAIDs with IV or IM route ranked first from efficacy and safety perspective. Comparing different specific drug branches with different routes, ibuprofen via IV route, ketorolac via IV route and diclofenac via IM route were superior for the management of acute renal colic. The results from diclofenac using IM route were more than those from ibuprofen used with IV route and ketorolac with IV route.Conclusions: In patients with adequate renal function, diclofenac via the IM route is recommended for patients without risks of cardiovascular events. Ibuprofen and ketorolac with IV route potentially superior to diclofenac via IM route remain to be investigated. Combination therapy is an alternative choice for uncontrolled pain after the use of NSAIDs

Anti-tumor effect of polysaccharides isolated from Taraxacum mongolicum Hand-Mazz on MCF-7 human breast cancer cells

Purpose: To optimize the extraction conditions for the ultrasound-assisted extraction of polysaccharides from T. mongolicum (PTM) and investigate their anti-tumor effect on human breast cancer MCF-7 cells.Methods: To optimize the extraction conditions of PTM, response surface methodology (RSM) was performed. The effects of extraction temperature, liquid-solid ratio and extraction time on the yield of PTM were investigated using a Box-Behnken design (BBD). The in vitro anti-tumor effect of PTM on MCF-7 cells was investigated by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay, while the mechanism of PTM-induced apoptosis was assessed by evaluating the expressions of p53, Bax and Bcl-2 proteins using western blot analysis. Furthermore, the in vivo anti-tumor effect of PTM on MCF-7 cells was studied in mice.Results: The optimal conditions for the extraction of PTM were as follows: extraction temperature, 58.2°C; liquid-solid ratio, 15 mL/g; and extraction time, 44.12 min. Under these optimal conditions, the yield of PTM was 4.84 ± 0.13 %. PTM showed significant anti-tumor effect on MCF-7 cells in vitro. The expressions of pro-apoptotic proteins, p53 and Bax, were significantly upregulated (p < 0.05), while the expression of anti-apoptotic protein, Bcl-2, was significantly down-regulated (p < 0.05) after treatment with PTM. PTM also showed significant inhibitory effect (p < 0.05) on MCF-7 cells in vivo in a dosedependent manner.Conclusion: RSM is effective in optimizing the extraction conditions of PTM by ultrasonic extraction. PTM possesses significant anti-tumor effect on MCF-7 human breast cancer cells, both in vitro and in vivo.Keywords: Polysaccharides, Taraxacum mongolicum, Human breast cancer, MCF-7 cells, Apoptosis, Box–Behnken design, Response surface methodolog

A single nucleotide mutation in the dual-oxidase 2 (DUOX2) gene causes some of the panda's unique metabolic phenotypes

This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB13030100 and XDB29020000), the Creative Research Group Project of National Natural Science Foundation of China (31821001), the Key Project of the Chinese Academy of Sciences (QYZDB-SSW-SMC047), the National Key Research and Development Program of China (2018YFC2000500), the Chinese Academy of Sciences President's International Fellowship Initiative Postdoctoral Fellowship (to A.M.R.) and the President's International Fellowship Initiative Professorial and Wolfson Merit Award (to J.R.S.).Peer reviewedPublisher PD

Evaluation of Real-Time PCR Coupled With Multiplex Probe Melting Curve Analysis for Pathogen Detection in Patients With Suspected Bloodstream Infections.

Background: This study aimed to evaluate real-time polymerase chain reaction coupled with multiplex probe melting curve analysis (PCR-MCA) for pathogen detection in patients with suspected bloodstream infections (BSIs). Methods: A PCR-MCA assay was developed for simultaneous identification of 28 kinds of the most common pathogens and two resistance genes within a few hours. The diagnostic performance of the PCR-MCA assay was determined and compared to the results of blood culture. Results: A total of 2,844 consecutive new episodes of suspected BSIs in 2,763 patients were included in this study. There were 269 episodes of pathogens identified by blood culture. For all the pathogens tested, the PCR-MCA assay exhibited a sensitivity of 88.8% (239/269), specificity of 100% (2,575/2,575), and agreement of 98.9% (2,814/2,844). For the pathogens on the PCR-MCA list, the PCR-MCA results had a sensitivity of 99.2% (239/241), specificity of 100% (2,575/2,575), and agreement of 99.9% (2,814/2,816) compared with the results of blood culture. For seven samples with multiple pathogens identified simultaneously during one blood culture investigation, the PCR-MCA assay verified the results of the blood culture, with an agreement rate of 100% for each. Conclusion: The PCR-MCA assay could discover 88.8% of the pathogens in clinical practice, showing excellent diagnostic performance vs. that of blood culture for pathogen detection in patients with suspected BSIs, and would contribute to rapid diagnosis and correct antibiotic administration

Effects of sea-buckthorn leaves on performance and serum metabolic profiles in Altay lambs

In this study, the effects of sea-buckthorn (Hippophae rhamnoides L.) leaves (SL) on the biochemical parameters and metabolomic profiling in Altay lamb (Ovis aries) were observed. Sixty six-month-old male Altay lambs (body weight 28.0 ± 3.5 kg) were randomly assigned to four groups (n=15). The experimental groups were named as CON, 2.5%, 5.0% and 7.5%. The group CON, contained animals fed with a basal diet. Animals of the other groups were fed a treatment diet consisting of 2.5% (Group 2.5%), 5.0% (Group 5.0%) and 7.5% (Group 7.5%) SL. The experimental period lasted 56 days. The results showed that the average daily gain (ADG) and average daily feed intake (ADFI) increased with the increase in the levels of dietary SL. Dietary SL showed a direct relationship with total protein (TP), albumin, globulin and total cholesterol (TC) content of the experimental animals. However, an indirect relationship was observed between dietary SL and the concentration of urea nitrogen (UN). The concentrations of glucose, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) showed quadratic change. Additional changes occurred in the endogenous metabolites involving multiple pathways. The pathways were tricarboxylic acid (TCA) cycle, the metabolism of protein and amino acid and the metabolism of fatty acid and steroid. The changes in metabolites primarily revealed an increase in amino acids and carbohydrates and a decrease in lipid metabolites. These findings provide a comprehensive insight into the effects of the metabolic aspects of sea-buckthorn leaves on Altay lambs. In addition, the present research results provide a better understanding to the development and utilization of sea-buckthorn as a healthy additive for small ruminant production.Keywords: Hippophae rhamnoides L., lamb, metabolomics, growth performance, serum parameter

Construction of a cDNA library and preliminary analysis of the expressed sequence tags of the earthworm Eisenia fetida (Savigny, 1826)

Earthworms are useful indicator organisms of soil health and Eisenia fetida have been extensively used as test organisms in ecotoxicological studies. In order to gain insight into the gene expression profiles associated with physiological functions of earthworms, a full‑length enriched cDNA library of the Eisenia fetida genome was successfully constructed using Switching Mechanism at 5\u27End of RNA Template technology. Construction of a cDNA library and analysis of Expressed Sequence Tags (ESTs) are efficient approaches for collecting genomic information and identifying genes important for a given biological process. Furthermore, analysis of the expression abundance of ESTs was performed with the aim of providing genetic and transcriptomic information on the development and regenerative process of earthworms. Phrep and Crossmatch were used to process EST data and a total of 1,140 high‑quality EST sequences were determined by sequencing random cDNA clones from the library. Clustering analysis of sequences revealed a total of 593 unique sequences including 225 contiguous and 368 singleton sequences. Basic Local Alignment Search Tool analysis against the Kyoto Encyclopedia of Genes and Genomes database resulted in 593 significant hits (P‑value \u3c1x10‑8), of which 168 were annotated through Gene Ontology analysis. The STRING database was used to determine relationships among the 168 ESTs, identifying associated genes involved in protein‑protein interactions and gene expression regulation. Based on nucleic acid and protein sequence homology, the mutual relationships between 287 genes could be obtained, which identified a portion of the ESTs as known genes. The present study reports on the construction of a high‑quality cDNA library representative of adult earthworms, on a preliminary analysis of ESTs and on a putative functional analysis of ESTs. The present study is expected to enhance our understanding of the molecular basis underlying the biological development of earthworms