Search tips
Search criteria

Results 1-4 (4)

Clipboard (0)
more »
Year of Publication
Document Types
author:("Liu, changing")
1.  A multi-omic analysis of an Enterococcus faecium mutant reveals specific genetic mutations and dramatic changes in mRNA and protein expression 
BMC Microbiology  2013;13:304.
For a long time, Enterococcus faecium was considered a harmless commensal of the mammalian gastrointestinal (GI) tract and was used as a probiotic in fermented foods. In recent decades, E. faecium has been recognised as an opportunistic pathogen that causes diseases such as neonatal meningitis, urinary tract infections, bacteremia, bacterial endocarditis and diverticulitis. E. faecium could be taken into space with astronauts and exposed to the space environment. Thus, it is necessary to observe the phenotypic and molecular changes of E. faecium after spaceflight.
An E. faecium mutant with biochemical features that are different from those of the wild-type strain was obtained from subculture after flight on the SHENZHOU-8 spacecraft. To understand the underlying mechanism causing these changes, the whole genomes of both the mutant and the WT strains were sequenced using Illumina technology. The genomic comparison revealed that dprA, a recombination-mediator gene, and arpU, a gene associated with cell wall growth, were mutated. Comparative transcriptomic and proteomic analyses showed that differentially expressed genes or proteins were involved with replication, recombination, repair, cell wall biogenesis, glycometabolism, lipid metabolism, amino acid metabolism, predicted general function and energy production/conversion.
This study analysed the comprehensive genomic, transcriptomic and proteomic changes of an E. faecium mutant from subcultures that were loaded on the SHENZHOU-8 spacecraft. The implications of these gene mutations and expression changes and their underlying mechanisms should be investigated in the future. We hope that the current exploration of multiple “-omics” analyses of this E. faecium mutant will provide clues for future studies on this opportunistic pathogen.
PMCID: PMC3879163  PMID: 24373636
E. faecium; Genome; Transcriptome; Proteome; Multi-omics
2.  Assessment of the green florescence protein labeling method for tracking implanted mesenchymal stem cells 
Cytotechnology  2012;64(4):391-401.
Although green fluorescent protein (GFP) labeling is widely accepted as a tracking method, much remains uncertain regarding the retention of injected GFP-labeled cells implanted in ischemic organs. In this study, we evaluate the effectiveness of GFP for identifying and tracking implanted bone marrow- mesenchymal stem cells (BM-MSCs) and the effect of GFP on the paracrine actions of these cells. MSCs isolated from rat femur marrow were transduced with a recombinant adenovirus carrying GFP. After transplantation of the GFP-labeled BM-MSCs into the infarct zone of rat hearts, the survival, distribution, and migration of the labeled cells were analyzed at 3, 7, 14, and 28 days. To evaluate the effect of GFP on the paracrine actions of BM-MSCs, Western blot analysis was performed to detect the expression of vascular endothelial growth factor (VEGF), b fibroblast growth factor (b FGF), tissue inhibitor of metalloproteinase-1 (TIMP-1) and matrix metalloproteinases-2 (MMP-2). GFP was successfully expressed by BM-MSCs in vitro. At 14 days after cell transplantation the GFP-positive cells could not be detected via confocal microscopy. By using a GFP antibody, distinct GFP-positive cells could be seen and quantitative analysis showed that the expression volume of GFP was 6.42 ± 0.92 mm3 after 3 days, 1.24 ± 0.76 mm3 after 7 days, 0.33 ± 0.03 mm3 after 14 days, and 0.09 ± 0.05 mm3 after 28 days. GFP labeling did not adversely affect the paracrine actions of BM-MSCs. GFP labeling could be used to track MSC distribution and their fate for at least 28 days after delivery to rat hearts with myocardial infarction, and this stem cell tracking strategy did not adversely affect the paracrine actions of BM-MSCs.
PMCID: PMC3397108  PMID: 22373822
Cell tracking; Green fluorescent protein; Mesenchymal stem cells; paracrine; Myocardial infarction
3.  Diagnostic value of urine sCD163 levels for sepsis and relevant acute kidney injury: a prospective study 
BMC Nephrology  2012;13:123.
Sepsis is a common syndrome in critically ill patients and easily leads to the occurrence of acute kidney injury (AKI), with high mortality rates. This study aimed to investigate the diagnostic value of urine soluble CD163 (sCD163) for identification of sepsis, severity of sepsis, and for secondary AKI, and to assess the patients’ prognosis.
We enrolled 20 cases with systemic inflammatory response syndrome (SIRS), 40 cases with sepsis (further divided into 17 sepsis cases and 23 severe sepsis cases) admitted to the intensive care unit (ICU), and 20 control cases. Results for urine sCD163 were recorded on the day of admission to the ICU, and AKI occurrence was noted.
On the day of ICU admission, the sepsis group exhibited higher levels of urine sCD163 (74.8 ng/ml; range: 47.9-148.3 ng/ml) compared with those in the SIRS group (31.9 ng/ml; 16.8-48.0, P < 0.001). The area under the curve (AUC) was 0.83 (95% confidence interval [CI]: 0.72-0.94, P < 0.001) the sensitivity was 0.83, and the specificity was 0.75 (based on a cut-off point of 43.0 ng/ml). Moreover, the severe sepsis group appeared to have a higher level of sCD163 compared with that in the sepsis group (76.2; 47.2-167.5 ng/ml vs. 74.2; 46.2-131.6 ng/ml), but this was not significant. For 15 patients with AKI, urine sCD163 levels at AKI diagnosis were significantly higher than those of the remaining 35 sepsis patients upon ICU admission (121.0; 74.6-299.1 ng/ml vs. 61.8; 42.8-128.3 ng/ml, P = 0.049). The AUC for urine sCD163 was 0.688 (95% CI: 0.51-0.87, P = 0.049). Sepsis patients with a poor prognosis showed a higher urine sCD163 level at ICU admission (98.6; 50.3-275.6 ng/ml vs. 68.0; 44.8-114.5 ng/ml), but this was not significant. Patients with AKI with a poor prognosis had higher sCD163 levels than those in patients with a better prognosis (205.9; 38.6-766.0 ng/ml vs. 80.9; 74.9-141.0 ng/ml), but this was not significant.
This study shows, for the first time, the potential value of urine sCD163 levels for identifying sepsis and diagnosing AKI, as well as for assessment of patients’ prognosis.
Trial Registration
PMCID: PMC3506529  PMID: 23013330
Urine; Soluble CD163 (sCD163); Sepsis; Systemic inflammatory response syndrome (SIRS); Prognosis; Acute kidney injury (AKI)
4.  Value of soluble TREM-1, procalcitonin, and C-reactive protein serum levels as biomarkers for detecting bacteremia among sepsis patients with new fever in intensive care units: a prospective cohort study 
BMC Infectious Diseases  2012;12:157.
The purpose of this study was to explore the diagnostic value of soluble triggering receptor expressed on myeloid cells 1 (sTREM-1), procalcitonin (PCT), and C-reactive protein (CRP) serum levels for differentiating sepsis from SIRS, identifying new fever caused by bacteremia, and assessing prognosis when new fever occurred.
We enrolled 144 intensive care unit (ICU) patients: 60 with systemic inflammatory response syndrome (SIRS) and 84 with sepsis complicated by new fever at more than 48 h after ICU admission. Serum sTREM-1, PCT, and CRP levels were measured on the day of admission and at the occurrence of new fever (>38.3°C) during hospitalization. Based on the blood culture results, the patients were divided into a blood culture-positive bacteremia group (33 patients) and blood culture-negative group (51 patients). Based on 28-day survival, all patients, both blood culture-positive and -negative, were further divided into survivor and nonsurvivor groups.
On ICU day 1, the sepsis group had higher serum sTREM-1, PCT, and CRP levels compared with the SIRS group (P <0.05). The areas under the curve (AUC) for these indicators were 0.868 (95% CI, 0.798–0.938), 0.729 (95% CI, 0.637–0.821), and 0.679 (95% CI, 0.578–0.771), respectively. With 108.9 pg/ml as the cut-off point for serum sTREM-1, sensitivity was 0.83 and specificity was 0.81. There was no statistically significant difference in serum sTREM-1 or PCT levels between the blood culture-positive and -negative bacteremia groups with ICU-acquired new fever. However, the nonsurvivors in the blood culture-positive bacteremia group had higher levels of serum sTREM-1 and PCT (P <0.05), with a prognostic AUC for serum sTREM-1 of 0.868 (95% CI, 0.740–0.997).
Serum sTREM-1, PCT, and CRP levels each have a role in the early diagnosis of sepsis. Serum sTREM-1, with the highest sensitivity and specificity of all indicators studied, is especially notable. sTREM-1, PCT, and CRP levels are of no use in determining new fever caused by bacteremia in ICU patients, but sTREM-1 levels reflect the prognosis of bacteremia.
Trial registration identifier NCT01410578
PMCID: PMC3426475  PMID: 22809118
Soluble triggering receptor expressed on myeloid cells 1 (sTREM-1); Fever; Sepsis; Bacteremia; Diagnosis; Prognosis

Results 1-4 (4)