OBJECTIVEDual detection of Salmonella and Shigella using modified molecular beacons and real-time PCR was developed. The established method was applied to rapid diagnosis of Salmonella and Shigella' food poisoning, and for routine monitoring programs.

METHODSTwo sets of primers were designed based on the core sequence of invA gene and ssaR gene published on GenBank to detect Salmonella, and ipaH gene were selected to detect Shigella. Three corresponding modified molecular beacons labeled with different fluorophors were designed. The molecular beacons and primer sets were tested against numerous strains from 55 different bacterial species. Then the two assays were combined to establish the dual real-time PCR assay, and were applied to the food poisoning diagnosis and surveillance.

RESULTSFor the modified molecular beacons-based dual real-time PCR assay, the sensitivity achieved was 69-93 fg/microl, 32-64 CFU/ml or 1-2 CFU/PCR reaction. There was no cross-reaction with other bacteria served as control. The dual real-time PCR assay was used to detect 134 Salmonella strains and 67 Shigella strains but no false signals were observed. 1100 food poisoning samples were tested with 569 Salmonella and 42 were Shigella identified by real time PCR. Among the positive samples, 551 were detected Salmonella and 41 were Shigella by traditional culture method. The overall test could be finished within 2 hours to one day starting from sample preparation.

CONCLUSIONThe modified molecular beacons-based dual real-time PCR assay was rapid, sensitive, and specific. It could be applied to the rapid diagnosis of Salmonella and Shigella' food poisoning.

DNA Primers ; Dysentery, Bacillary ; diagnosis ; Genes, Bacterial ; Humans ; Polymerase Chain Reaction ; methods ; Salmonella ; genetics ; Salmonella Food Poisoning ; diagnosis ; Sensitivity and Specificity ; Shigella ; genetics

BACKGROUNDAccumulating evidence demonstrates that the microenvironment of the host has an important effect on the chemoresistance of tumors. We also found that the formation of intrinsic multidrug resistance is related to environmental factors that are common with tumor growth of hepatocellular carcinoma. The aim of this study was to explore the molecular mechanisms by which multidrug resistance of hepatocellular carcinoma is induced by the microenvironment. In particular, the regulation of nuclear transcription factor (hypoxia-inducible factor-1α, HIF-1α) activation in the process of multidrug resistance formation was investigated.

METHODSHepG2 cells were exposed to different microenvironmental conditions respectively, such as hypoxia, stimulation of glucose deprivation and transfection of plasmid PcDNA3/HBx. In the HepG2 cells, the expression of the related MDR proteins, HIF-1α protein expression and localization, activity of extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) were detected. Specific inhibitor U0126 was used to block ERK/MAPK signal pathway, the alteration of HIF-1α and the related MDR proteins were investigated. Multivariate analysis of variance (MANOVA) repeated measures and one-way analysis of variance (ANOVA) followed by Tukey test or t-test were used to determine differences over time and effects of the treatments.

RESULTSThe above three microenvironment factors increase the expression of the related MDR proteins (including P-gp, LRP, and MRP1) and induce MDR of HepG2 cells. HIF-1α was induced at the protein and mRNA levels and the nuclear translocation was also increased. The activity of ERK/MAPK was also increased in HepG2 cells. But when ERK/MAPK pathway was inhibited, the mRNA and protein expression of MDR1, MRP1, and LRP was to some extent decreased. Inhibition of ERK/MAPK significantly reduced activated HIF-1α protein and the nuclear translocation of HIF-1α, whereas HIF-1α mRNA levels were not affected.

CONCLUSIONSThe microenvironmental factors could induce MDR of HepG2 cells by the activity of HIF-1α. The activity of HIF-1α is regulated by the ERK/MAPK pathway at the phosphorylation level. As an important nuclear transcription factor, HIF-1α controls the transcription of MDR-related genes and the synthesis of their corresponding proteins by ERK/MAPK signal pathway in HepG2 cells.

Drug Resistance, Neoplasm ; Hep G2 Cells ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; physiology ; MAP Kinase Signaling System ; Tumor Microenvironment

AIM To explore analgesic mechanism of Yaobitong Capsules (Notoginseng Radix et Rhizoma,Chuanxiong Rhizoma,Corydalis Rhizoma,etc.) on lumbar intervertebral discs.METHODS An array of data mining,molecular docking and network analysis were employed to investigate the active compounds and key target protein.RESULTS Among the forty-six active hits identified by virtual screening,most compounds displayed good oral bioavailability and might confer an optimal CNS exposure.And eleven molecules (coptisine,diligustilide,corypalmine,chuanxiongterpene,etc.) were further confirmed to alleviate lumbar intervertebral discs through their targeting at nineteen proteins (such as p38,CGRP,MMPs,TNFα) to inhibit the inflammatory response and the infiltration of microvasculature,to reduce the nociceptors sensitivity,and to modulate the balance of Collagen and proteoglycans in catabolic and anabolic responses.CONCLUSION Yaobitong Capsules' clear molecular working mechanism and the key active compounds are revealed by this network-assisted investigation highlight the subsequent experiments on targets and active compounds.

【Objective】A full exome sequencing of an early-onset family Alzheimer′s disease (EOFAD) was conduct? ed to identify the mutational sites which may cause diseases. The result of the current study may provide suggestion to genetic counseling and prenatal diagnosis.【Methods】Whole exome sequencing was performed on the family members and software PolyPhen-2 as well as SIFT was employed for hazard prediction (Prediction on functional effects of the missense mutation).【Results】The heterozygous mutation c.758A>G (p.Tyr253Cys) in exon 9 of TTC3 gene had been identified in proband whose mother had been proved with heterozygous mutation c.758A>G. According to the family separation and related bioinformatics analysis, the mutant gene was a possible pathogenic mutation. 【Conclusion】 A new mutation was found of c.758A>G in TTC3 gene within a Chinese EOFAD family and a new mutation to the spectrum of genetic mutation in EOFAD was expanded. The finding provides a significant groundwork for future exploration on the mechanisms underlying EOFAD.