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Background: Squamous cell carcinoma of the head and neck (SCCHN) remains a prevalent and devastating disease. Recently, there has been an increase in SCCHN cases that are associated with high-risk human papillomavirus (HPV) infection. The clinical characteristics of HPV-positive and HPV-negative SCCHN are known to be different but their molecular features are only recently beginning to emerge. MicroRNAs (miRNAs, miRs) are small, non-coding RNAs that are likely to play significant roles in cancer initiation and progression where they may act as oncogenes or tumor suppressors. Previous studies in our laboratory showed that miR-363 is overexpressed in HPV-positive compared to HPV-negative SCCHN cell lines, and the HPV type 16-E6 oncoprotein upregulates miR-363 in SCCHN cell lines. However, the functional role of miR-363 in SCCHN in the context of HPV infection remains to be elucidated.Methods: We analyzed miR-363 levels in SCCHN tumors with known HPV-status from The Cancer Genome Atlas (TCGA) and an independent cohort from our institution. Cell migration studies were conducted following the overexpression of miR-363 in HPV-negative cell lines. Bioinformatic tools and a luciferase reporter assay were utilized to confirm that miR-363 targets the 3'-UTR of myosin 1B (MYO1B). MYO1B mRNA and protein expression levels were evaluated following miR-363 overexpression in HPV-negative SCCHN cell lines. Small interfering RNA (siRNA) knockdown of MYO1B was performed to assess the phenotypic implication of reduced MYO1B expression in SCCHN cell lines.Results: MiR-363 was found to be overexpressed in HPV-16-positive compared to the HPV-negative SCCHN tumors. Luciferase reporter assays performed in HPV-negative JHU028 cells confirmed that miR-363 targets one of its two potential binding sites in the 3'UTR of MYO1B. MYO1B mRNA and protein levels were reduced upon miR-363 overexpression in four HPV-negative SCCHN cell lines. Increased miR-363 expression or siRNA knockdown of MYO1B expression reduced Transwell migration of SCCHN cell lines, indicating that the miR-363-induced migration attenuation of SCCHN cells may act through MYO1B downregulation.Conclusions: These findings demonstrate that the overexpression of miR-363 reduces cellular migration in head and neck cancer and reveal the biological relationship between miR-363, myosin 1b, and HPV-positive SCCHN. [ABSTRACT FROM AUTHOR]

Background: Painless gastrointestinal endoscopy under intravenous propofol anesthesia is widely applied in the clinical scenario. Despite the good sedation and elimination of anxiety that propofol provides, low SpO2 may also result. Doxapram is a respiratory stimulant with a short half-life. The primary aim of this study was to investigate the effects of doxapram on alleviating low SpO2 induced by the combination of propofol and fentanyl during painless gastrointestinal endoscopy. Methods: In this prospective study, patients scheduled for painless gastrointestinal endoscopy were randomly assigned to group D or S with 55 patients per group. Initially, both groups received a combination of propofol and fentanyl. Patients in group D received 50 mg doxapram after propofol injection, while patients in group S received an equal volume of saline. Vital signs of the patients, propofol dose, examination duration, and incidences of low SpO2 were recorded. Results: There were no statistical differences in propofol consumption and examination duration between the two groups. Twenty-six patients in group S experienced low SpO2 versus 10 in group D (P = 0.001). Nineteen patients in group S underwent oxygenation with a face mask in contrast to 8 in group D (P = 0.015). Eighteen patients in group S were treated with jaw lifting compared to 5 in group D (P = 0.002). Four patients in group S underwent assisted respiration compared to 2 in group D (without statistical difference). The average oxygen saturation in group S was significantly lower than that in group D at 1, 2 and 3 min after propofol injection (P < 0.001, P = 0.001 and P = 0.020, respectively). There were no statistical differences in oxygen saturation at other time points. There were no statistical differences in MAP and HR (except for the time point of 1 min after the induction) between the two groups. Conclusions: Low dose of doxapram can effectively alleviate low SpO2 in painless gastrointestinal endoscopy with intravenous propofol, without affecting propofol consumption, examination duration, MAP, or HR. Trail registration: The study was approved by the Institutional Ethics Committee of Clinical and New Technology of Wuxi People's Hospital on 20th July, 2018 (KYLLH2018029) and registered in the Chinese Clinical Trial Register on 16th August, 2018 (ChiCTR1800017832). [ABSTRACT FROM AUTHOR]

Background: Pseudorabies virus (PRV) of the family Herpesviridae is the causative agent of Aujeszky's disease. Attenuation of PRV by serial passaging in vitro is a well-established method; however, the dynamic variations occurring on viral genome during this process have not been characterized. Methods: Genome sequencing and comparative genomic analyses of a virulent pseudorabies virus and a series of its plaque-purified strains via serial passaging in vitro were performed, and the properties in vitro and in vivo of which were further characterized. Results: Compared to the parental virus, replication in vitro was enhanced in the highly passaged F50, F91, and F120. In contrast, lethality in mice decreased gradually with passage number. Genome sequencing of F50, F91, and F120 showed deletion of a large fragment containing gE, which is likely related to their attenuation. In addition, single nucleotide variations were identified in many genes of F50, F91, and F120. In-frame and frameshift indels were also detected in specific genes of passaged strains. Particularly frameshift mutations were observed in highly passaged strains, resulting in a truncated but overexpressed pUL46. Conclusion: During attenuation of PRV by serial passaging in Vero cells, dynamic variation patterns including a large deletion, single nucleotide variations, small in-frame indels, and also frameshifts mutations successively emerged, contributing to evolution of the viral population and enabling the gradual attenuation of the virus. These data provide clues to better understand PRV attenuation during passaging. [ABSTRACT FROM AUTHOR]

Background: Oriental melon is one of the most popular crops for its nutritional and flavour quality. Components that determine melon quality, such as sugar, colour, texture, flavour and aroma, among other factors, accumulate in different developmental stages. Thus, correlating the proteomic profiles with the biochemical and physiological changes occurring in the oriental melon is very important for advancing our understanding of oriental melon quality in the ripening processes., Results: iTRAQ-based protein profiling was conducted on 'YuMeiren' oriental melon fruit at different developmental stages. Physiological quality indices, including firmness, rind colour, soluble solids content (SSC), ethylene production, sugar content and volatile compounds were also characterized during four maturity periods of the melon, including 5, 15, 25 and 35 days after anthesis (DAA). A principal component analysis (PCA) revealed that the aroma volatiles at 5 DAA and 15 DAA were similar and separated from that of 35 DAA. More than 5835 proteins were identified and quantified in the two biological repeats and divided into 4 clusters by hierarchical cluster analysis. A functional analysis was performed using Blast2GO software based on the enrichment of a GO analysis for biological process, molecular function and cellular components. The main KEGG pathways, such as glycolysis, α-linolenic acid and starch and sucrose metabolism, were analyzed. The gene family members corresponding to differentially expressed proteins, including lipoxygenase (CmLOX01-18) and alcohol acetyltransferase (CmAAT1-4) involved in the α-linolenic acid metabolic pathway, were verified with real-time qPCR. The results showed that the expression patterns of 64.7% of the genes were consistent with the expression patterns of the corresponding proteins., Conclusions: This study combined the variation of the quality index and differentially expressed proteins of oriental melon at different developmental stages that laid the foundation for the subsequent protein and gene function validation.

Background: Klebsiella pneumoniae is a prominent nosocomial pathogen that accounts for up to 10 % of all hospital-acquired infections. It is a frequent cause of ventilator-associated pneumonia (VAP). The purpose of this study was to investigate the clinical characteristics of K. pneumoniae-associated VAP and the molecular characteristics of K. pneumoniae strains., Methods: We retrospectively reviewed 70 mechanically ventilated patients with K. pneumoniae isolated. All K. pneumoniae strains were examined to determine hypermucoviscosity (HV) phenotype, capsular serotypes, virulence genes, multilocus sequence typing and antimicrobial susceptibility., Results: Hypermucoviscosity was found in 14 of 70 (20 %) isolates of K. pneumoniae. Among the 70 patients, 43 cases (61.4 %) developed VAP. Furthermore, VAP was more frequently induced by HV-positive K. pneumoniae (14/14, 100 %) than by HV-negative strains (29/56, 51.7 %). HV-positive K. pneumoniae-associated VAP patients were more inclined to develop bacteremia and had a higher mortality rate than HV-negative strains VAP patients. Antibiotic resistance was more frequent in HV- negative strains- than in HV- positive strains-infected patients. The prevalence of rmpA and aerobactin genes were 85.7 % and 85.7 % respectively, and serotypes K1 and K2 accounted for 14.3 % and 28.6 % of the hypermucoviscosity strains, respectively. Strains carrying rmpA and aerobactin genes were significantly associated with HV-phenotype, and rmpA and aerobactin coexisted in HV-positive strains. Multilocus sequence typing analysis identified 24 different sequence types from K. pneumoniae VAP samples., Conclusions: HV-phenotype is the major virulence determinant for mechanically ventilated patients. There was a specific sequence typing (ST) distribution between HV-positive and HV-negative strains.

Background: Microbial lipases particularly Pseudomonas lipases are widely used for biotechnological applications. It is a meaningful work to design experiments to obtain high-level active lipase. There is a limiting factor for functional overexpression of the Pseudomonas lipase that a chaperone is necessary for effective folding. As previously reported, several methods had been used to resolve the problem. In this work, the lipase (LipA) and its chaperone (LipB) from a screened strain named AB which belongs to Pseudomonas aeruginosa were overexpressed in E. coli with two dual expression plasmid systems to enhance the production of the active lipase LipA without in vitro refolding process., Results: In this work, we screened a lipase-produced strain named AB through the screening procedure, which was identified as P. aeruginosa on the basis of 16S rDNA. Genomic DNA obtained from the strain was used to isolate the gene lipA (936 bp) and lipase specific foldase gene lipB (1023 bp). One single expression plasmid system E. coli BL21/pET28a-lipAB and two dual expression plasmid systems E. coli BL21/pETDuet-lipA-lipB and E. coli BL21/pACYCDuet-lipA-lipB were successfully constructed. The lipase activities of the three expression systems were compared to choose the optimal expression method. Under the same cultured condition, the activities of the lipases expressed by E. coli BL21/pET28a-lipAB and E. coli BL21/pETDuet-lipA-lipB were 1300 U/L and 3200 U/L, respectively, while the activity of the lipase expressed by E. coli BL21/pACYCDuet-lipA-lipB was up to 8500 U/L. The lipase LipA had an optimal temperature of 30°C and an optimal pH of 9 with a strong pH tolerance. The active LipA could catalyze the reaction between fatty alcohols and fatty acids to generate fatty acid alkyl esters, which meant that LipA was able to catalyze esterification reaction. The most suitable fatty acid and alcohol substrates for esterification were octylic acid and hexanol, respectively., Conclusions: The effect of different plasmid system on the active LipA expression was significantly different. pACYCDuet-lipA-lipB was more suitable for the expression of active LipA than pET28a-lipAB and pETDuet-lipA-lipB. The LipA showed obvious esterification activity and thus had potential biocatalytic applications. The expression method reported here can give reference for the expression of those enzymes that require chaperones.