Combining stable isotope, multielement and untargeted metabolomics with chemometrics to discriminate the geographical origins of ginger (Zingiber officinale Roscoe).

Ginger (Zingiber officinale Roscoe) is a high-value food and herb worldwide. The quality of ginger is often related to its production regions. In this study, stable isotopes, multiple elements, and metabolites were investigated together to realize ginger origin traceability.

Magnetic covalent organic framework as a solid-phase extraction absorbent for sensitive determination of trace organophosphorus pesticides in fatty milk.

A simple and efficient magnetic solid-phase extraction (MSPE) method was established with magnetic covalent organic framework (COF) as adsorbent to enrich organophosphorus pesticides from fatty milk samples, followed by the sensitive determination via LC-MS/MS. The key parameters influencing the MSPE efficiency were comprehensively investigated to afford an optimized procedure. All the target analytes could be captured directly by magnetic COF from milk without protein precipitation, making the pretreatment rapid and convenient.

Geographical origin of Chinese wolfberry (goji) determined by carbon isotope analysis of specific volatile compounds.

Chinese wolfberry or goji berry (Lycium barbarum) is an important traditional Chinese medicine. Its price and function has a close correlation with its geographical provenance. Illegal mislabeling motivated by commercial gains brings serious food safety problems and damages consumer confidence.

Hnf4α is a key gene that can generate columnar metaplasia in oesophageal epithelium.

Barrett's metaplasia is the only known morphological precursor to oesophageal adenocarcinoma and is characterized by replacement of stratified squamous epithelium by columnar epithelium. The cell of origin is uncertain and the molecular mechanisms responsible for the change in cellular phenotype are poorly understood. We therefore explored the role of two transcription factors, Cdx2 and HNF4α in the conversion using primary organ cultures.

Potent tetravalent replicon vaccines against botulinum neurotoxins using DNA-based Semliki Forest virus replicon vectors.

Human botulism is commonly associated with botulinum neurotoxin (BoNT) serotypes A, B, E and F. This suggests that the greatest need is for a tetravalent vaccine that provides protection against all four of these serotypes. In current study, we investigated the feasibility of generating several tetravalent vaccines that protected mice against the four serotypes.

Three types of human CpG motifs differentially modulate and augment immunogenicity of nonviral and viral replicon DNA vaccines as built-in adjuvants.

NakedDNA vaccines given by intramuscular injection are efficient in mouse models, but they require improvement for human use. As the immunogenicity of DNA vaccines depends, to a large extent, on the presence of CpG motifs as built-in adjuvants, we addressed this issue by inserting three types of human CpG motifs (A-type, B-type, and C-type) into the backbone of nonviral DNA and viral DNA replicon vectors with distinct immunostimulatory activities on human PBMCs. The adjuvant effects of CpG modifications in DNA vaccines expressing three types of antigens (β-Gal, AHc, or PA4) were then characterized in mice and found to significantly enhance antigen-specific humoral and cell-mediated immune responses.

Developmental stalling and organ-autonomous regulation of morphogenesis.

Timing of organ development during embryogenesis is coordinated such that at birth, organ and fetal size and maturity are appropriately proportioned. The extent to which local developmental timers are integrated with each other and with the signaling interactions that regulate morphogenesis to achieve this end is not understood. Using the absolute requirement for a signaling pathway activity (bone morphogenetic protein, BMP) during a critical stage of tooth development, we show that suboptimal levels of BMP signaling do not lead to abnormal morphogenesis, as suggested by mutants affecting BMP signaling, but to a 24-h stalling of the intrinsic developmental clock of the tooth.

Binding activity and immunogenic characterization of recombinant C-terminal quarter and half of the heavy chain of botulinum neurotoxin serotype A.

In the present study, we explored and compared the binding activity and immunogenic characterization of the most effective part corresponding to C-terminal quarter of heavy chain of botulinum neurotoxin serotype A (AHc-C) with C-terminal half of heavy chain of botulinum neurotoxin serotype A (AHc). Firstly, the fully soluble AHc-C protein successfully expressed in Escherichia coli by co-expression with thioredoxin (Trx) was shown to bind with ganglioside as the AHc, indicating that the recombinant AHc-C protein retains a functionally active conformation. Furthermore, a solid-phase assay showed that the anti-AHc-C sera effectively inhibited the binding of AHc or AHc-C to the ganglioside GT1b, the first step in BoNT/A intoxication of neurons, as good as the anti-AHc sera.

Co-expression of tetanus toxin fragment C in Escherichia coli with thioredoxin and its evaluation as an effective subunit vaccine candidate.

The receptor-binding domain of tetanus toxin (THc), which mediates the binding of the toxin to the nerve cells, is a candidate subunit vaccine against tetanus. In this study one synthetic gene encoding the THc was constructed and highly expressed in Escherichia coli by co-expression with thioredoxin (Trx). The purified THc-vaccinated mice were completely protected against an active toxin challenge in mouse models of disease and the potency of two doses of THc was comparable to that of three doses of toxoid vaccine.

Enhancement of the immunogenicity of DNA replicon vaccine of Clostridium botulinum neurotoxin serotype A by GM-CSF gene adjuvant.

Granulocyte-macrophage clony-stimulating factor (GM-CSF) is an attractive adjuvant for a DNA vaccine on account of its ability to recruit antigen-presenting cells to the site of antigen synthesis as well as stimulate the maturation of dendritic cells.This study evaluated the utility of GM-CSF as a plasmid DNA replicon vaccine adjuvants for botulinum neurotoxin serotype A (BoNT/A) in mouse model. In balb/c mice that received the plasmid DNA replicon vaccines derived from Semliki Forest virus (SFV) carrying the Hc gene of BoNT/A (AHc), both antibody and lymphoproliferative response specific to AHc were induced, the immunogenicity was enhanced by co-delivery or coexpress of the GM-CSF gene.

Distinct immune responses of recombinant plasmid DNA replicon vaccines expressing two types of antigens with or without signal sequences.

Here, DNA replicon vaccines encoding the Hc domain of botulinum neurotoxin serotype A (AHc) or the receptor binding domain of anthrax protective antigen (PA4) with or without signal sequences were evaluated in mice. Strong antibody and protective responses were elicited only from AHc DNA vaccines with an Ig κ signal sequence or tissue plasminogen activator signal sequence. Meanwhile, there were no differences in total antibody responses or isotypes, lymphocyte proliferative responses, cytokine profiles and protective immune responses with the PA4 DNA vaccines with or without a signal sequence.

Enhanced potency of individual and bivalent DNA replicon vaccines or conventional DNA vaccines by formulation with aluminum phosphate.

DNA vaccines against botulinum neurotoxin (BoNTs) induce protective humoral immune responses in mouse model, but when compared with conventional vaccines such as toxoid and protein vaccines, DNA vaccines often induce lower antibody level and protective efficacy and are still necessary to increase their potency. In this study we evaluated the potency of aluminum phosphate as an adjuvant of DNA vaccines to enhance antibody responses and protective efficacy against botulinum neurotoxin serotypes A and B in Balb/c mice. The administration of these individual and bivalent plasmid DNA replicon vaccines against botulinum neurotoxin serotypes A and B in the presence of aluminum phosphate improved both antibody responses and protective efficacy.

Development and evaluation of candidate vaccine and antitoxin against botulinum neurotoxin serotype F.

To produce a vaccine suitable for human use, a recombinant non His-tagged isoform of the Hc domain of botulinum neurotoxin serotype F (rFHc) was expressed in Escherichia coli and purified by sequential chromatography. The rFHc was evaluated as a subunit vaccine candidate in mouse model of botulism. A dose-response was observed in both antibody titer and protective efficacy with increasing dosage of rFHc and number of vaccinations.

Development and preclinical evaluation of a new F(ab')₂ antitoxin against botulinum neurotoxin serotype A.

Concern about the malicious applications of botulinum neurotoxin has highlighted the need for a new generation of safe and highly potent antitoxins. In this study, we developed and evaluated the preclinical pharmacology and safety of a new F(ab')₂ antitoxin against botulinum neurotoxin serotype A (BoNT/A). As an alternative to formalin-inactivated toxoid, the recombinant Hc domain of botulinum neurotoxin serotype A (rAHc) was used to immunize horses, and the IgGs from the hyperimmune sera were digested to obtain F(ab')₂ antitoxin.

Generation of stable cell lines by site-specific integration of transgenes into engineered Chinese hamster ovary strains using an FLP-FRT system.

Random integration linking genomic amplification is widely used to generate desired cell lines for stable and high-level expressing recombinant proteins. But this technique is laborious, and the expression level is unpredictable due to position effects. After reading many reports on gene amplification, we hypothesized that there should be several loci in the genome of Chinese hamster ovary (CHO) cells that allow not only high-level, but also stable gene expression.

Barrett's metaplasia: molecular mechanisms and nutritional influences.

Barrett's metaplasia is discussed in the context of a general theory for the formation of metaplasias based on developmental biology. The phenotype of a particular tissue type becomes established during embryonic development by the expression of a specific set of transcription factors. If this combination becomes altered, then the tissue type can be altered.

Isolation, culture, and characterisation of mouse embryonic oesophagus and intestine.

The gastrointestinal tract of vertebrates is lined by epithelium that develops from the endodermal germ layer. The oesophagus and intestine form part of the gastrointestinal tract and studying the normal development of both tissues is difficult due to lack of suitable in vitro model systems. One of the criteria for a reliable culture model includes the ability to carry out real-time observations in vitro.

[Construction of mammalian cell lines continuously expressing JEV structural proteins].

Based on the infectious clone of JEV vaccine strain SA14-14-2, prM-E genes and C-prM-E genes were cloned into pCDNA3.1 vector. The recombinant plasmid pCJE-ME was transfected into BHK-21 cells, the expressed proteins were toxic to the cell growth and accelerated the cell death.

Neutralizing antibodies of botulinum neurotoxin serotype A screened from a fully synthetic human antibody phage display library.

The botulinum neurotoxins (BoNTs) produced by Clostridium botulinum are the most poisonous protein substances known. The neutralizing antibodies against botulinum neurotoxin can effectively prevent and cure the toxicosis. Using purified Hc fragments of botulinum neurotoxin serotype A (BoNT/A-Hc) as antigen, 2 specific neutralizing antibodies mapping different epitopes were selected from a fully synthetic human antibody library.

Improved immunogenicity and protective efficacy of a replicon DNA vaccine encoding the Hc domain of botulinum neurotoxin serotype A by electric pulses and protein boosting.

Vaccination by intramuscular injection of naked DNA is very efficient in mouse model, but immunogenicity of DNA vaccines needs to be improved in human use. Thus, we wanted to determine whether suitable electric pulses-mediated DNA delivery technology and DNA prime-protein boost regimen could improve the immunogenicity and protective efficacy of the replicon DNA vaccine pSCARSHc in mouse model. In this study, the immunogenicity and protective efficacy of the replicon DNA vaccine pSCARSHc following electric pulses were dramatically improved in Balb/c mice.

The recombinant Hc subunit of Clostridium botulinum neurotoxin serotype A is an effective botulism vaccine candidate.

Vaccination with recombinant His-tagged isoforms of the Clostridium botulinum Hc domain of neurotoxin serotype A (rAHc) have effectively protected against challenge with active botulinum neurotoxin serotype A. To establish a formulation suitable for human use, rAHc was expressed in Escherichia coli without a His-tag and purified by sequential chromatography on ion-exchange and hydrophobic-interaction resins. Purified rAHc was used to vaccinate mice and survival was evaluated following challenge with active toxin.

Protection with a recombinant Hc of Clostridium Botulinum neurotoxin serotype A from Escherichia coli as an effective subunit vaccine.

A recombinant Hc of Clostridium botulinum neurotoxin serotype A (AHc) was successfully expressed in Escherichia coli for use as an antigen, and the purified AHc was used to vaccinate mice and evaluate their survival against challenge with active botulinum neurotoxin serotype A. The mice, given twice or third subcutaneous vaccinations with a dosage of 1 microg AHc mixed with Freund adjuvant, were completely protected against an intraperitoneal administration of 1,000,000 50% lethal doses (LD(50)) of neurotoxin serotype A. Following the administration of AHc using alhydrogel adjuvant via the intramuscular route, a strong protective immune response was also elicited in the vaccinated mice.

Evaluation of a recombinant Hc of Clostridium botulinum neurotoxin serotype F as an effective subunit vaccine.

A new gene encoding the Hc domain of Clostridium botulinum neurotoxin serotype F (FHc) was designed and completely synthesized with oligonucleotides. A soluble recombinant Hc of C. botulinum neurotoxin serotype F was highly expressed in Escherichia coli with this synthetic FHc gene.

High-level expression of the Hcc domain of Clostridium botulinum neurotoxin serotype A in Escherichia coli and its immunogenicity as an antigen.

A completely synthetic gene encoding the He domain of Clostridium botulinum neurotoxin serotype A (AHc, 1287 bp, 429 aa, -50 kD) was constructed with oligonucleotides. After expressed in Escherichia coli, soluble product AHc was gained and verified by SDS-PAGE and Western blot analysis. The expressive level of recombinant AHc in E.

Enhanced immune responses using plasmid DNA replicon vaccine encoding the Hc domain of Clostridium botulinum neurotoxin serotype A.

In current study, the immunogenicity of a plasmid DNA replicon vaccine (pSCARSHc) encoding the Hc domain of Clostridium botulinum neurotoxin serotype A (AHc) was investigated and compared with a conventional plasmid DNA vaccine (pcDNASHc) encoding the same antigen. In vitro, pSCARSHc incorporating Semliki Forest virus (SFV) replicon could express AHc protein and induce apoptosis of transfected cells. Comparison with the conventional plasmid DNA vaccine (pcDNASHc) yielded several interesting results.