1.Pathogenic Bacteria in Hospital:Distribution and Drug Resistance of 1 213 Strains
Qing-Xia XU ; Xiao-Xian LV ; Xiao-Xiang CHEN ;
Chinese Journal of Nosocomiology 1994;0(01):-
OBJECTIVE To determine the distribution of bacterial flora in hospital infection and to provide laboratory(evidence) for controlling hospital infection and selecting rationally antibiotics in clinic practice.METHODS All(isolates) were identified by routine procedure.MRSA and ESBLs-producing rate of Escherichia coli and Klebsiella pneumoniae were(examined.) RESULTS Among all these clinical infectious specimens,there were 202 strains of Gram negative bacilli,(accounting) for 40.9%(202/495);166 strains of fungi,accounting for 33.5%;621 strains of Gram positive cocci,for 20.6%(102/495).Candida albicans,E.coli,Pseudomonas aerugionosa,C.tropicalis and C.glabrata took the first five bacteria in infection.Analysis of drug resistant bacteria suggested that the isolated rate of ESBLs-producing strains in Staphylococcus aureus be 47.6%,be CNS in MRCNS 78.1% and MRSA in SA be 42.3%.CONCLUSIONS Multidrug resistance and fungus infection are the main risk factors in our hospital.We must improve means of treatment on clinical work and use antibiotic rationally to reduce the infection rate.
2.In-Vitro Culture and Plant Regeneration of Morinda officinalis How
Hong HE ; Sheng'E XIAO ; Jianchun XIAN ; Honghua XU ;
Journal of Guangzhou University of Traditional Chinese Medicine 2000;0(04):-
The sterile stem tips, nodular and non-nodular stem of Morinda officinalis How were cultured in vitro. The results showed that the most suitable procedure for sterilization of explants was soaking into 0.1% HgCl 2 solution for 10 to 15 minutes after pretreating with 70% ethanol for 30 seconds. MT culture medium with BA was effective to induce direct shooting of stem tips and nodular stem, the shooting rate of nodular stem being 97.5% . The optimal BA concentration was 1 mg?L -1 , the shooting rate would decrease when the concentration of BA increased. As for the induction of rooting, MT culture medium adding with 0.2 to 0.5 mg?L -1 NAA was optimal, the rooting rate being over 80.0% .
3.Development of a cell culture system based on recombinant hepatitis C virus expressing enhanced green fluorescent protein
Hongtao XU ; Li XIAO ; Jianchun XIAN ; Yabao CHEN
Chinese Journal of Microbiology and Immunology 2012;(12):1034-1038
Objective To develop a time saving and sensitive cell culture system based on hepatitis C virus chimera expressing enhanced green fluorescent protein(EGFP) and to facilitate the study on HCV pathogenesis and screening of anti-HCV drugs.Methods Enhanced green fluorescent protein reporter gene and a mutation V2440L that can yield higher virus titers were introduced into the C-terminus of non-structural protein 5A (NS5A) of the JFH1 viral genome by using recombinant PCR.The viral RNA was transfected into Huh7.5 cells.Viral RNA in supernatant of HCV RNA-transfected cells was determined after transfection by RT-PCR.HCV replication and infection were determined by immunofluorescence assay.IFN-α was used to evaluate the feasibility of this system for anti-HCV drugs screening.Results The viral RNA replicated efficiently in transfected cells.These cells can produce HCV-EGFP reporter virus.Viral RNA levels in supernatant were 3.06× 105 copies/ml and 7.96×106 copies/ml at 72 h and 9 d after transfection,respectively.The virus titer reached to 104 FFU/ml 9 d after transfection.The expression of EGFP was inhibited by IFN-α in a dose dependent manner in Huh7.5 cells infected by HCV-EGFP reporter virus.Conclusion The recombinant HCV JFH1-EGFP reporter gene system is a time saving,cost effective and sensitive method for studying viral replication cycles and screening of anti-HCV drugs.
4.Development of a cell culture system with consistently expression of whole hepatitis C virus gene and Renilla luciferase and its application
Hongtao XU ; Li XIAO ; Jianchun XIAN ; Yabao CHEN
Chinese Journal of Infectious Diseases 2011;29(10):589-592
ObjectiveTo develop a cell culture system with consistent expression of whole hepatitis C virus (HCV) gene and Renilla luciferase gene and to facilitate the study on HCV pathogenesis and the screening of new antiviral drugs.MethodsRenilla luciferase (RLuc) reporter gene and a mutation that could yield higher virus gene expression were introduced into the C-terminus of non-structural protein 5A (NS5A) of the JFH1 viral genome by using recombinant PCR.The viral RNA was transfected into Huh7.5 cells.Naǐve Huh7.5 cells were infected by the supernatant from the viral RNA transfected cells.HCV replication and infection were determined by virus titration,Renilla luciferase assay,immunofluorescence assay and western blotting.IFN-α was used to evaluate the feasibility of this system for anti-HCV new drug screening.ResultsThe viral RNA replicated efficiently in transfected cells.These cells could produce high titer of HCV-Rluc reporter virus and the virus titer reached to 1.5 × 104 FFU/ml at day 15 of posttransfection.The activity of Renilla luciferase was inhibited by IFN-α in a dose dependent manner in Huh7.5 cells infected by HCV-Rluc reporter virus.ConclusionThe recombinant HCV-JFH1-Rluc reporter gene system is sensitive and efficient.It can be a useful tool for high throughput screening of anti-HCV drugs.
6.Inhibition of proliferation of retinal microvascular endothelial cells by pericytes through down-regulating KDR/Flk-1 in a co-culture system
Ying-Li, WANG ; Yan-Nian, HUI ; Bin, GUO ; Xiao-Guang, ZHANG ; Xu, HOU ; Ji-Xian, MA
International Eye Science 2006;6(2):255-263
· AIM :To investigate the role of pericytes in growth of retinal microvascular endothelial cells with a co-culture system in order to understand some mechanism of angiogenesis in hypoxia induced retinal neovascular disorders.(RMECs) were isolated by a modified protocol using CD31 coated Dynabeads, and identified by immunocytochemical staining with anti-Factor Ⅷ and CD31 antibodies. Rat retinal pericytes were isolated and characterized by immunofluorescent staining with PDGFR-β; and desmin antibodies. Pericytes and RMECs were cultured in a contact co-culture system both under normoxia and hypoxia by Millicell chamber. RMECs proliferation was evaluated by MTT and cell cycle assay with flow cytometry. RT-PCR was used to detect the alteration of KDR/Flk-1 mRNA level in RMECs under normoxia or hypoxia in the co-culture system.harvested with the modified isolating method. The two cell types were identified by positive Factor Ⅷ, CD31 and PDGFR-β, desmin cytochemical staining respectively.RMECs proliferated significantly under hypoxia from 3 to 9d with a maximal rate on day 6 (24.9%, P < 0.01) by MTT. In the co-culture system, the proliferation of RMECs was inhibited by pericytes. After 6d exposure to hypoxia,the fraction of S-phase RMECs number was greatly increased by 43.9% (P < 0.01). In the co-culture system,RMECs proliferation was inhibited by pericytes through decreasing the fraction of S-phase cell number both under normoxia (3.6%, P<0.05) and under hypoxia (15.1%,P<0.01). KDR/Flk-1 mRNA level in single cultured RMECs was shown to increase approximately 1.3-fold when exposed to hypoxia. Compared with single cultured RMECs, co-culture with pericytes could decrease KDR/Flk-1 mRNA by 45.1% (P<0.05) and 27.7% (P < 0.05) under normoxia and hypoxia condition respectively.pericytes could inhibit proliferation of RMECs under both normoxia and hypoxia. The inhibition effects of pericytes maybe, at least in part, due to downregulation of KDR/Flk-1 of RMECs. These findings confirm that pericytes could be a potential inhibitor in the pathogenesis of retinal neovascularization.
7.Purification of recombinant human IE—2 by McAb affinity chromatography
Xiao-Li WANG ; Ben XU ; Lan ZHENG ; Ying-Hua XIE ; Xian-Tao KONG ;
Chinese Journal of Immunology 1985;0(01):-
For purifying recombinant human IL—2 (rhIL—2),the columns of immunoabsorptionwere prepared with 4 anti—IL—2 McAb (9B12,9F5,9B2 and 8H7) purified by caprylic acid.Although 4 McAbs differ as regards their antigen—antibody binding characteristics,all they canserve as effective immnoabsorbents,provided optimum condition was adopted.The recoveryrate of 9B12,9F5,8H7 and 9B2 columns were 49.2%,37.5%,31.5% and 18.8% respec-tively.The purity of rhIL—2 obtained was more than 95% and biological activity remainedhigher.
8.The effect of Connexin43 downregulation on biological functions of HUVEC.
Cai-zhen ZHANG ; Xiao-feng MU ; Xian-xiang XU ; Fei QIU ; Jun-sheng LIN ; Yong DIAO
Acta Pharmaceutica Sinica 2015;50(3):298-304
Connexin43 has been shown to play a pivotal role in wound healing process. Wound repair is enhanced by acute downregulation of connexin43, by increasing proliferation and migration of keratinocyte and fibroblast. Angiogenesis is also a central feature of wound repair, but little is known about the effects of connexin43 modulation on functions of endothelial cells. We used connexin43 specific small interference RNA (siRNA) to reduce the expression of connexin43 in human umbilical vein endothelial cell (HUVEC), and investigated the effects of connexin43 downregulation on intercellular communication, viability, proliferation, migration and angiogenic activity of HUVEC. Treatment of siRNA markedly reduced the expression of connexin43 by -80% in HUVEC (P < 0.05), and decreased the intercellular communication by -65% (P < 0.05). The viability, proliferation, migration and angiogenic activity of HUVEC decreased significantly (P < 0.05), compared with that of the normal cells. The results suggest that temporally downregulation of connexin43 expression at early stage of wound to inhibit the abnormal angiogenesis characterized with leaky and inflamed blood vessels, maybe a prerequisite for coordinated normal healing process.
Cell Movement
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Cell Proliferation
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Cell Survival
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Connexin 43
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metabolism
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Down-Regulation
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Human Umbilical Vein Endothelial Cells
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cytology
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Humans
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Neovascularization, Physiologic
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Umbilical Veins
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cytology
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Wound Healing
10.Clinical investigation of mild cognitive impairment in patients with Parkinson's disease
Haibing XIAO ; Lili JIANG ; Xu CAO ; Xifeng WANG ; Xian QIAO ; Shenggang SUN
Chinese Journal of Neurology 2008;41(8):520-523
Objective To describe the prevalence and neuropsychological character of mild cognitive impairment (MCI) associated with Parkinson' s disease(PD-MCI). Methods One hundred and three PD patients and a control group of 32 healthy old subjects were chosen. Psychometric assessment included the Mini Mental State Examination, the Dementia Rating Scale and a series of neuropsychol ogicaltests. The Hamilton Rating Scale of Depression was used to assess depression in PD patients. Results (1)Twenty-one (20.4%) PD patients was diagnosed with dementia, 45 (43.7%) had a MCI and only 37(35.9%) had no cognitive impairment; (2) Subjects with PD-MCI were older, had a later onset of the PD,and displayed more severe motor symptoms compared with those without cognitive impairment; (3) The prevalence and neuropsychological profile of PD-MCI were thought to correlate with the dominating side and subtype of Parkinsonian symptoms, for patients with left-sided dominant symptoms had a significantly higher chance of suffering MCI than those with right-sided dominant symptoms, the ratio being 74.2% vs 42.2%,χ<'2 =7. 589,P <0.05; The tremor-dominant group took less time than the mixed group for Stroop word test measurement ((80.8±39.9) s vs (94.4±30.0) s,t=3.332,P<0.01). Conclusion Identification of MCI is of important clinical significance, which helps to treat patients differently and thus predict the prognosis.