Comparative proteomic analysis of wild-type and a SlETR-3 (Nr) mutant reveals an ethylene-induced physiological regulatory network in fresh-cut tomatoes.

Ethylene plays a crucial role in regulating fruit ripening, quality, and defense response. However, the mechanism(s) responsible for wound-induced ethylene regulation of fruit physiology at a network level is unclear. We used mass spectrometry (MS) to identify differences in the physiological response between fresh-cut fruits of wild-type (WT) tomato and an ethylene receptor mutant (SlETR-3) (also referred to as Nr) during storage. We found that Nr mutants exhibited better appearance and quality, as well as higher ethylene levels during the first 3 d of storage at 4 °C. Thirty-seven (0 h), eighty-two (12 h) and twelve (24 h) differentially abundant proteins were identified between the fresh-cut slices of the two genotypes during storage at the designated timepoints. In particular, antioxidant enzymes, such as ascorbate peroxidase, glutathione S-transferase, and peroxiredoxin were highly expressed in WT fruit, which was associated with higher H2O2 production, and high levels of transcription of cell-wall degrading enzymes. Leucine aminopeptidase, a marker enzyme for response to wounding exhibited higher levels in the Nr mutant, which is consistent with its higher production of ethylene. Collectively, our results provide a deeper insight into the ethylene-induced physiological regulatory network that is activated in fresh-cut tomatoes.

Integrative Physiological and Transcriptome Analysis Reveals the Mechanism for the Repair of Sub-Lethally Injured Escherichia coli O157:H7 Induced by High Hydrostatic Pressure.

The application of high hydrostatic pressure (HHP) technology in the food industry has generated potential safety hazards due to sub-lethally injured (SI) pathogenic bacteria in food products. To address these problems, this study explored the repair mechanisms of HHP-induced SI Escherichia coli O157:H7. First, the repair state of SI E. coli O157:H7 (400 MPa for 5 min) was identified, which was cultured for 2 h (37 °C) in a tryptose soya broth culture medium. We found that the intracellular protein content, adenosine triphosphate (ATP) content, and enzyme activities (superoxide dismutase, catalase, and ATPase) increased, and the morphology was repaired. The transcriptome was analyzed to investigate the molecular mechanisms of SI repair. Using cluster analysis, we identified 437 genes enriched in profile 1 (first down-regulated and then tending to be stable) and 731 genes in profile 2 (up-regulated after an initial down-regulation). KEGG analysis revealed that genes involved in cell membrane biosynthesis, oxidative phosphorylation, ribosome, and aminoacyl-tRNA biosynthesis pathways were enriched in profile 2, whereas cell-wall biosynthesis was enriched in profile 1. These findings provide insights into the repair process of SI E. coli O157:H7 induced by HHP.

Herceptin functionalized microfluidic polydimethylsiloxane devices for the capture of human epidermal growth factor receptor 2 positive circulating breast cancer cells.

Building on recent breakthroughs in the field of microfluidic-based capture of rare cancer cells circulating in the blood, the present article reports on the use of Herceptin functionalized PDMS devices designed to efficiently capture from blood cancer cells, overexpressing the tyrosine kinase human epidermal growth factor receptor (HER2). The identification of patients overexpressing HER2 is critical as it typically associates with an aggressive disease course in breast cancer and poor prognosis. Importantly, HER2 positive patients have been found to significantly benefit from Herceptin (Trastuzumab), a humanized monoclonal antibody (MAb) against HER2. Disposable PDMS devices prepared using standard soft lithography were functionalized by the plasma polymerization of an epoxy-containing monomer. The epoxy-rich thin film (AGEpp) thus created could be conjugated with Herceptin either directly or through a polyethylene glycol interlayer. The properties and reactivity toward the monoclonal antibody conjugation of these coatings were determined using x-ray photoelectron spectroscopy; direct conjugation provided a good compromise in reactivity and resistance to biologically nonspecific fouling and was selected. Using the breast cancer cell line SK-BR-3 as a model for cells overexpressing HER2, the immunocapture efficacy of the Herceptin functionalized PDMS was demonstrated in model studies. Validation studies confirmed the ability of the device to efficiently capture (∼80% capture yield) HER2 positive cells from full blood.

In vitro susceptibility testing of Aspergillus spp. against voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin.

BACKGROUND: During recent years, the incidence of serious infections caused by opportunistic fungi has increased dramatically due to alterations of the immune status of patients with hematological diseases, malignant tumors, transplantations and so forth. Unfortunately, the wide use of triazole antifungal agents to treat these infections has lead to the emergence of Aspergillus spp. resistant to triazoles. The present study was to assess the in vitro activities of five antifungal agents (voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin) against different kinds of Aspergillus spp. that are commonly encountered in the clinical setting. METHODS: The agar-based Etest MIC method was employed. One hundred and seven strains of Aspergillus spp. (5 species) were collected and prepared according to Etest Technique Manuel. Etest MICs were determined with RPMI agar containing 2% glucose and were read after incubation for 48 hours at 35°C. MIC(50), MIC(90) and MIC range were acquired by Whonet 5.4 software. RESULTS: The MIC(90) of caspofungin against A. fumigatus, A. flavus and A. nidulans was 0.094 µg/ml whereas the MIC(90) against A. niger was 0.19 µg/ml. For these four species, the MIC(90) of caspofungin was the lowest among the five antifungal agents. For A. terrus, the MIC(90) of posaconazole was the lowest. For A. fumigatus and A. flavus, the MIC(90) in order of increasing was caspofungin, posaconazole, voriconazole, itraconazole, and amphotericin B. The MIC of amphotericin B against A. terrus was higher than 32 µg/ml in all 7 strains tested. CONCLUSIONS: The in vitro antifungal susceptibility test shows the new drug caspofungin, which is a kind of echinocandins, has good activity against the five species of Aspergillus spp. and all the triazoles tested have better in vitro activity than traditional amphotericin B.