Publications by authors named "Kechen Xu"

11 Publications

  • Page 1 of 1

Correction to: Vogesella perlucida-induced bacteremia in an advanced-age patient: first case report.

BMC Infect Dis 2020 Sep 29;20(1):709. Epub 2020 Sep 29.

Clinical Laboratory Center, Wuyi First People's Hospital, Wuyi, Jinhua, Zhejiang, 321200, China.

An amendment to this paper has been published and can be accessed via the original article.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12879-020-05442-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7523318PMC
September 2020

Vogesella perlucida-induced bacteremia in an advanced-age patient: first case report.

BMC Infect Dis 2020 Sep 18;20(1):687. Epub 2020 Sep 18.

Clinical Laboratory Center, Wuyi First People's Hospital, Wuyi, Jinhua, 321200, Zhejiang, China.

Background: Vogesella species are common aquatic, Gram-negative rod-shaped bacteria, originally described in 1997. Vogesella perlucida was first isolated from spring water in 2008. Furthermore, bacterial pathogenicity of Vogesella perlucida has never been reported. Here, we report the first case of rare Vogesella perlucida-induced bacteremia in an advanced-age patient with many basic diseases and history of dexamethasone abuse.

Case Presentation: A 71-year-old female was admitted with inflamed upper and lower limbs, rubefaction, pain and fever (about 40 °C). She had been injured in a fall at a vegetable market and then touched river snails with her injury hands. A few days later, soft tissue infection of the patient developed and worsened. Non-pigmented colonies were isolated from blood cultures of the patient. Initially, Vogesella perlucida was wrongly identified as Sphingomonas paucimobilis by Vitek-2 system with GN card. Besides, we failed to obtain an acceptable identification by the MALDI-TOF analysis. Finally, the isolated strain was identified as Vogesella perlucida by 16S rRNA gene sequences. In addition, the patient recovered well after a continuous treatment of levofloxacin for 12 days.

Conclusion: Traditional microbiological testing system may be inadequate in the diagnosis of rare pathogenic bacteria. Applications of molecular diagnostics techniques have great advantages in clinical microbiology laboratory. By using 16S rRNA gene sequence analysis, we report the the first case of rare Vogesella perlucida-induced bacteremia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12879-020-05420-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7501676PMC
September 2020

Role of identified noncoding RNA in erectile dysfunction.

Andrologia 2020 Aug 22;52(7):e13596. Epub 2020 May 22.

Hangzhou Xixi Hospital affiliated to Zhejiang Chinese Medical University, Hangzhou, China.

Erectile dysfunction (ED) is a common male sexual dysfunction and is closely related to many risk factors such as age, chronic diseases and mental disorder. Phosphodiesterase type 5 inhibitor (PDE5i) is recommended as the first-line medicine in therapy, but up to 35% of patients fail to this treatment. Unfortunately, the pathogenesis of ED is still poorly understood. Hence, it has reached the state that researchers should seek for new candidate biomarkers or therapeutic targets. Recent studies have reported that noncoding RNAs (ncRNAs) such as microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) are involved in the pathogenesis process of ED, even in stem cell therapy. In this review, we aim to summarise the mechanisms and functions of identified ncRNAs that are associated with ED.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/and.13596DOI Listing
August 2020

Fate of dissolved organic nitrogen during the Anammox process using ultra-high resolution mass spectrometry.

Environ Int 2019 10 31;131:105042. Epub 2019 Jul 31.

National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China.

Anaerobic ammonium oxidation (Anammox) is a cost-effective process for treating highly nitrogenous wastewater. However, the fate of organic nitrogen during Anammox treatment is still unclear, which limits its practical application. In this work, the changes in the quality of dissolved organic nitrogen (DON) in coal liquefaction wastewater (CLW) during Anammox were studied in relation to its chemical composition, which was determined by Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). The molecular-level characterization of extracellular polymeric substances (EPS) in the Anammox sludge is also reported for the first time in this paper. The relative contribution of N-containing compounds to the total dissolved organic matter (DOM) determined by summating the normalized intensities exceeded 30%, highlighting the complexity of the nitrogenous compounds in the influent. Additionally, Anammox appeared to be better suited to removing DON compounds with fewer carbonyl or carboxyl groups, more aromatic structures, and higher oxidative properties. Lignin-like substances were verified as the predominant component of N-containing compounds in Anammox EPS, followed by protein and substances with condensed aromatic structures. DON compounds with higher degrees of saturation, lower molecular weight, and higher lignin-like properties were more prone to absorption by Anammox EPS. A series of microbe-mediated pathways were demonstrated to be responsible for DON biodegradation, which revealed the organic and inorganic nitrogen removal mechanisms in the Anammox reactor. The obtained results provide great support to the ongoing efforts to optimize the Anammox process.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envint.2019.105042DOI Listing
October 2019

Gender effect of hyperuricemia on the development of nonalcoholic fatty liver disease (NAFLD): A clinical analysis and mechanistic study.

Biomed Pharmacother 2019 Sep 25;117:109158. Epub 2019 Jun 25.

Hangzhou Xixi Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, 310023, Zhejiang, China. Electronic address:

Background And Aims: Hyperuricemia is a risk factor for nonalcoholic fatty liver disease (NAFLD), however, the effect of gender on the hyperuricemia-related NAFLD development remains unclear. Here, we evaluated the clinical characteristics of NAFLD patients with hyperuricemia, and experimentally recapitulated this condition in male rats in order to gain insights on the possible impact of gender on the development of NAFLD in patients with hyperuricemia.

Methods: The clinical characteristics of 238 NAFLD patients, together with the impacts of hyperuricemia on the major parameters related to the development of NALFD were analysed. In animal studies, NAFLD with hyperuricemia was induced in male SD rats using high-yeast high-fat diet containing potassium oxonate. The impact of uric acids on liver pathology, and the expression patterns of key molecules involved in the development of NAFLD, including silent information regulator 1 (SIRT1), nuclear factor kappa B subunit p65 (NF-κB p65), fork-head box class O-3a (FOXO3a), androgen receptor (AR), and xanthine oxidase (XO) were analysed.

Results: Male NAFLD patients with hyperuricemia displayed more frequent and extensive liver injury than those in female patients. In male rats, hyperuricemia was associated with increased levels of insulin, alanine aminotransferase (ALT) and triglyceride (TG). At the molecular level, hyperuricemia was associated with decreased expression of SIRT1 and its phosphorylation, phosphorylation of FOXO3a, increased expression of AR and XO, and deacetylation of NF-κB P65.

Conclusions: Hyperuricemia is a compounding factor for NAFLD, particularly in males. The severer hepatic injury observed in male NAFLD patients may be attributed to the suppression of SIRT1 signalling induced by hyperuricemia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biopha.2019.109158DOI Listing
September 2019

Role of identified RNA N6-methyladenosine methylation in liver.

Anal Biochem 2019 08 7;578:45-50. Epub 2019 May 7.

The Fourth Clinical Medicine School of Zhejiang Chinese Medical University, Hangzhou, 310053, Zhejiang, China. Electronic address:

N6-Methyladenosine (mA) is the most abundant and important internal modification site of RNA methylation in viruses and eukaryotic. mA RNA methylation plays key roles in the regulation of post-transcriptional gene expression, including messenger RNA (mRNA), microRNA (miRNA) and long noncoding RNA (lncRNA). And mA methylation regulates the various aspects of RNA metabolism, including structure, maturation, stability, splicing, export, translation and decay. Liver is a vital metabolic and digestive organ in the pathophysiological processes. Recent studies suggested that mA RNA modification highly regulates hepatic function and development of liver diseases. Here, we aim to summarize the biological and clinical significance of mA modification in hepatic growth and hepatic disease including viral hepatitis, non-alcoholic fatty liver disease (NAFLD), and liver cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ab.2019.05.005DOI Listing
August 2019

Roles of Identified Long Noncoding RNA in Diabetic Nephropathy.

J Diabetes Res 2019 12;2019:5383010. Epub 2019 Feb 12.

The First Clinical Medical College, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075 Sichuan, China.

Diabetes mellitus is the leading chronic disease in the world, and diabetic nephropathy (DN) as one of its complications could increase the mortality. The development of DN is associated to abnormal hemodynamic factors like cytokine networks and the intervention of metabolic risk factors like blood pressure, blood glucose, and blood lipid. However, the pathogenesis of DN is still poorly understood. Although glucose-lowering drugs and insulins have significant effects on blood glucose, the fluctuation of blood glucose or other risk factors could continuously damage the kidney. Recent studies reported that the progression of DN is closely related to the expression of long noncoding RNA (lncRNA), which is important for the early diagnosis and targeted intervention of DN. In this review, we briefly summarize the published studies on the functions and potential mechanism of reported lncRNA in the regulation of DN.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2019/5383010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6390257PMC
July 2019

Treating hyperuricemia related non-alcoholic fatty liver disease in rats with resveratrol.

Biomed Pharmacother 2019 Feb 14;110:844-849. Epub 2018 Dec 14.

The Hangzhou Xixi Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou 310023, Zhejiang, China. Electronic address:

Background Hyperuricemia is a recognised risk factor for the development of nonalcoholic fatty liver disease (NAFLD). This study aims to investigate the therapeutic effect of resveratrol (RES) on the treatment of hyperuricemia-related NAFLD in rats and the underlying mechanisms. Methods NAFLD with hyperuricemia was induced in rats using high-yeast high-fat diet containing potassium oxonate. The impact of RES on liver pathology, and the expression of silent information regulator 1 (SIRT1), fork-head box class O-3a (FOXO3a), and nuclear factor kappa B subunit p65 (NF-κB p65) was analysed. Results RES significantly improved liver histology and reversed serum biochemical abnormalities. At the molecular level, RES improved insulin resistance (IR), inhibited hepatic steatosis, reduced oxidative stress and liver inflammation, and these effects were likely mediated through SIRT1-mediated FOXO3a phosphorylation and NF-κB P65 deacetylation. Conclusions Resveratrol is a promising agent for the treatment of hyperuricemia-related NAFLD through activating SIRT1 pathways.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biopha.2018.12.039DOI Listing
February 2019

In-depth molecular characterization and biodegradability of water-extractable organic nitrogen in Erhai Lake sediment.

Environ Sci Pollut Res Int 2018 Jul 8;25(20):19779-19789. Epub 2018 May 8.

Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100022, China.

Dissolved organic nitrogen (DON) constitutes a significant fraction of the total dissolved nitrogen content of most aquatic systems and is thus a major nitrogen source for bacteria and phytoplankton. The present work applied Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to a compound-level analysis of the depth-dependent molecular composition of water-extractable organic nitrogen (WEON) in lake sediment. The study focused on Erhai Lake, China. It was found that a large portion (from 16.33 ± 7.87 to 39.54 ± 5.77%) of the WEON in the lake sediment was reactive under cultivation by algal or bacteria. The WEON in the mid-region of Erhai sediment particularly exhibited a lower bioavailability, having been less affected by the basin environment. The FT-ICR MS results revealed the presence of thousands of compounds in the Erhai Lake sediment samples collected at different depths, with the N-containing compounds accounting for 28.3-34.4% of all the compounds. The WEON molecular weight was also observed to increase with increasing sediment depth. A van Krevelen diagram showed that the lignin-type components were dominant (~ 56.2%) in the sediment WEON, contributing to its stabilization and reducing the risk of sediment nutrient release. The FT-ICR MS results further revealed 204 overlapping formulas of WEON for each core sediment sample, attributable to the presence of refractory components. It was observed that 78.4% of the formulas were within the lignin-like region, suggesting unique allochthonous DON sources. The aliphatic component proportion of all the unique formulas was also found to increase with increasing sediment depth. This indicates that, with the development and evolution of the Erhai Basin, the more labile WEON components were transformed into more stable lignin-like substrates, with a positive effect on the Lake Erhai ecosystem. Graphical abstract ᅟ.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11356-018-2122-zDOI Listing
July 2018

Using combined multiple techniques to characterize refractory organics during anammox process with mature coal chemical wastewater as influent.

Environ Sci Pollut Res Int 2018 Apr 16;25(12):12107-12118. Epub 2018 Feb 16.

National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing, 100124, China.

This study combined spectroscopy techniques to assess the composition of refractory organics and highlighted the potential application of excitation-emission matrix (EEM) fluorescence spectroscopy within future monitoring of coal chemical wastewater treatment by the anammox process. The results showed that the anammox process could effectively degrade refractory organic substances, with fulvic-like, UV-humic acid, and Vis-humic acid component removal efficiencies of 43.61, 53.93, and 100%, respectively. In this study, EEM fluorescence spectroscopy was proven to be an effective method of assessing the removal of dissolved organic nitrogen during anammox treatment of mature coal chemical wastewater. Furthermore, remarkable accumulation (9.3-16.2%) of Ca. Kuenenia occurred in the anammox granules that underwent long-term cultivation in mature coal chemical wastewater, which provided the high nitrogen removal rate. The abundance of Anaerolineaceae and Bacteroides was vital in refractory organic degradation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11356-018-1441-4DOI Listing
April 2018

Composition characterization and transformation mechanism of refractory dissolved organic matter from an ANAMMOX reactor fed with mature landfill leachate.

Bioresour Technol 2018 Feb 6;250:413-421. Epub 2017 Nov 6.

National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China. Electronic address:

This study applied combined spectroscopy techniques to assess rDOM compositional characteristic and investigated its transformation mechanisms during the treatment of mature landfill leachate by ANAMMOX process. A novel rDOM metabolism mechanism was proposed in this study for the first time. A stable, high nitrogen removal rate of 5.95 kg N/m/day and a rDOM conversion efficiency of 51% were achieved in ANAMMOX reactor (AR). In additionally, the initial rDOM removal was closely related to sludge adsorption, with the adsorption force mainly originating from electrostatic interaction and hydrophobicity. As the operating time increased, the removal mechanism of rDOM in the AR changed from adsorption to adsorption-biodegradation and finally stabilized. Furthermore, Anaerolineaceae, associated with the hydrophobic reaction, were the primary degraders for the rDOM and Candidatus Kuenenia dominated the nitrogen consumption. rDOM removal efficiency was suggested to be increased by a moderate enhancement of Anaerolineaceae content in the AR.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biortech.2017.11.007DOI Listing
February 2018
-->