微波辅助快速合成卵清蛋白金纳米簇检测苦味酸

本文采用微波加热法快速合成了卵清蛋白金纳米簇荧光探针(OVA-Au NCs)并应用于检测苦味酸(PA)。该探针在350 nm波长激发下,能发射红色荧光,最大发射荧光峰为680 nm,Stokes位移高达330 nm,可有效消除共振散射光的干扰。该合成方法与水热法相比,步骤简单快速,仅用50 s即可完成。由于PA的吸收光谱与OVA-Au NCs的激发光谱有较大范围的重叠,基于内滤效应(IFE) PA可选择性猝灭OVA-Au NCs的荧光,据此建立了检测苦味酸的新方法。在最佳实验条件下,在20~240μmol/L范围内,检测体系的荧光猝灭效率ΔF/F0与PA的浓度具有良好的线性关系,r为0.9985,检测限为6.4μmol/L。该方法简便、快速、准确,易于实现实时监测。

Aryl hydrocarbon receptor nuclear translocator 2 as a prognostic biomarker and immunotherapeutic indicator for clear cell renal cell carcinoma

Background:In many cancer types,aryl hydrocarbon receptor nuclear translocator 2(ARNT2)has been found to be associated with tumor cell proliferation and prognosis.However,the role of ARNT2 in clear cell renal cell carcinoma(ccRCC)has not been completely elucidated.In this study,the potential role of ARNT2 in ccRCC development was characterized.Methods:A pan-cancer dataset(TCGA-TARGET-GTEx)was accessed from UCSC Xena Data Browser.ARNT2 expression in normal and tumor samples was compared.Univariate Cox regression was performed to evaluate the prognostic value of ARNT2.Single sample gene set enrichment analysis(ssGSEA)was used to estimate the enrichment of functional pathways and gene signatures.CIBERSORT and ESTIMATE methods evaluated the immune infiltration.The ARNT2 expression was determined in ccRCC tissue and cell lines using RT-qPCR and Western blot.Results:ARNT2 expression was significantly dysregulated in 23 out of 30 cancer types.Pan-cancer data revealed a strong correlation between ARNT2 expression and immune modulators,immune cell infiltration,and genomic alternations.In ccRCC patients,the low-ARNT2 expression group had higher immune infiltration,CD8 T cells,and programmed cell death ligand 1 expression,as well as higher enrichment score of immunotherapeutic predictors than those in the high-ARNT2 expression group.Low-ARNT2 expression group was more responsive to immunotherapy.Moreover,low ARNT2 expression was observed in ccRCC tissue and cell lines.Conclusions:Dysregulated ARNT2 expression is involved in cancer development and the modulation of the immune microenvironment.ARNT2 can be potentially used as a prognostic indicator and an immunotherapeutic indicator for ccRCC.

In Vitro and In Vivo Evaluation of Antitumor Activity ofLigustrum robustum, A Chinese Herbal Tea

Objective: To examine the effect of the aqueous extract of Ligustrum robustum on tumor growth in vitro and in vivo and explore the possible molecular mechanisms. Methods: In in vitro study, cell viabilities of human cervical carcinoma cells(HeLa), human breast cancer cells(MCF-7), human prostate cancer cells(PC-3),human hepatoma cells(7721) and human colon carcinoma cells(SW480) were evaluated with cell counting kit-8.For L. robustum-treated Hela cells, early or late apoptosis were evaluated by annexin V/PI staining. Mitochondrial membrane potential was measured by staining cells with JC-1. Apoptosis was monitored by nuclear morphology based on chromatin condensation and fragmentation by 4’,6-diamidino-2-phenylinole(DAPI) staining. Caspase-3 and-8 activity levels were measured by a colorimetric assay. In vivo, to evaluate the possible mechanism of L. robustum-mediated antitumor effect, nude mouse xenograft study was also conducted. Results: In in vitro study, L. robustum was found to be toxic to HeLa, MCF-7, PC-3, 7721, SW480, with an half maximal inhibitory concentration value of 2–5 mg/mL(P<0.05). Moreover, externalization of phosphatidylserine, loss of mitochondrial membrane potential, DNA fragmentation and activation of caspase-3 and-8 were detected in L. robustumtreated Hela cells. Using a nude mouse model bearing Hela xenografts, we found that L. robustum reduced tumor volume and tumor weight(P<0.05), but had no effect on body weight and histological damage of important organs. Intraperitoneal injection of L. robustum caused a signi?cant reduction in serum aspartate transaminase and alanine transaminase levels(P<0.05). Furthermore, cleaved caspase-3-positive and terminal nucleotidyl transferase-mediated nick end labeling(TUNEL)-positive cells were observed in L. robustum-treated tumor tissues.Conclusions: L. robustum inhibits tumor cell growth both in vitro and in vivo by inducing apoptosis in a caspasedependent way without apparent hepatic toxicity and histological damage, which may offer partial scienti?c support for the ethnopharmacological claims of L. robustum as a herbal tea for its antitumor activity.

A high-efficiency pretreatment method for elution of pathogenic bacteria in lettuce

Many current studies on rapid detection of pathogenic bacteria in foods have focused on the construction of detection methods,neglecting pretreatment.It is also a key step to efficiently elute pathogenic bacteria from food samples for rapid detection and can even determine the success or failure of an assay.In this study,we used Escherichia coli(E.coli),Salmonella enteritidis(S.enteritidis),and Listeria monocytogenes(L.monocytogenes)as model bacteria to compare the elution efficiency of different eluants;explore the effect of surfactant,ionic strength,protein(or amino acid and peptide),and enzyme on the recovery rate of bacteria in lettuce;and compare the compound effect caused by multiple factors.Finally,we developed an efficient bacterial recovery method and confirmed the superiority of this method to analyze the bacterial diversity of eluants from lettuce.The results showed that the recovery efficiency of E.coli,S.enteritidis,and L.monocytogenes,which were artificially contaminated with approximately 10^(5)CFU/g in lettuces,could reach 94.4%,90.6%,and 93.7%by using 10 mmol/L Tris·HCl(pH 9.5)with 0.1%peptone and 300 U/100 mL of cellulase,and furthermore,the elution efficiency could reach 99.6%,98.6%,and 100%with the aid of a 2-min stomaching.For the lettuce samples with only native bacteria,the recovery rate reached 92.1%for viable aerobic bacteria by this method,which was approximately 10%higher than that of the modified previous method.The bacterial diversity of the eluted solution was analyzed,and the result was significantly improved.Considering these advantages,it is important to improve the elution efficiency to achieve rapid and accurate detection of pathogenic bacteria in lettuces.