1.Effect of HI_(47) (CD_(20)) monoclonal antibody on human B Iymphocyte activation and proliferation
Chinese Journal of Immunology 1985;0(01):-
We have previously reported that a CD_(20) monoclonal antibody (HI_(47)) had obvious inhibition to ~3H-TdR incorporation of tonsil B cells in SAC drived system. This paper describes that McAb HI_(47) also markedly inhibited ~3H-UdR uptake and enlargement of B lymphocytes induced by SAC. However, it had no effect on B cell activation in PMA and anti-immunoglobul in antibody drived systems and the proliferation of established T, B and myeloid cell lines. The non-specific inhibition of HI_(47) Fc fragment had been ruled out by the experiments with irrelative MoAbs, which Ig subclass was same as HI_(47) (IgG_3),and with HI_(47) F (ab')2 fragment. Exposure of tonsil B cell to either SAC or PMA resulted in an increase in expression of HI_(47) antigen. McAb HI_(47), neverthless, induced reduction of HI_(47) antigen expressed on B cells stimulated by SAC. but not by PMA. In conclusion, antigen HI_(47) (CD_(20)) only involved in the SAC-activation pathway. The modulation of HI47 antigen by McAb HI47 may be one of the mechanisms of the depressed SAC activation.
2.Analysis of distribution and drug resistance of bacteria in 1 -6 months infants with lower respiratory infection
Guixia XU ; Qingwei MA ; Xifeng ZHANG ; Yancheng YANG ; Xueyi LYU
Chinese Journal of Primary Medicine and Pharmacy 2015;(11):1696-1699,1700
Objective To investigate the distribution and drug resistance of bacteria in 1 -6 months infants with lower respiratory infection(LRI).Methods Induced sputum was extracted from 326 infants with LRI who were 1 -6 months.Antibiotic susceptibility tests were performed after bacteria had been identified.Results 61 cases were detected pathogenic bacteria and the detection rate of bacteria was 18.71%.5 cases were detected two kinds of bacte-ria.66 bacterial strains were isolated among which gram -positive bacteria(33 strains)accounted for 50.00% and gram -negative bacteria(33 strains)accounted for 50.00%.Staphylococcus aureus was the most common gram -pos-itive bacteria and Streptococcus pneumoniae was the second.13 strains were methicillin -resistant Staphylococcus au-reus(MRSA).Hemophilus influenzae was the most common gram -negative bacteria,followed by Klebsiella pneumo-nia and Escherichia coli among which ESBL positive Klebsiella pneumonia were 5 cases and ESBL positive Escherich-ia coli were 4 cases.The common gram -positive bacteria had higher rate of penicillin resistance.MRSA had higher rate of penicillin,oxacillin,erythomycin and clindamycin resistance.Resistant strains to vancomycin and rina thiazole amine were not found.The common gram -negative bacteria had higher rate of ampicillin,ampicillin/shu tan,cefazo-lin and ceftriaxone resistance and had lower rate of cefepime,ceftazidime,piperacillin/he azole temple and imipenem resistance.Conclusion The common pathogenic bacteria in 1 -6 months infants with lower respiratory infection were Staphylococcus aureus,Hemophilus influenzae,Streptococcus pneumoniae,Klebsiella pneumonia and Escherichia coli. We should pay attention to the common antibiotic resistance.MRSA and ESBL positive bacteria were the common mul-tiple drug resistant bacterias.Reasonable selection of antibiotics should be based on susceptibility results earlier.
3.The Injury of Metronidazole on Morphology of Giardia lamblia in Vitro
Xifeng TIAN ; Ru WEI ; Zhihong YANG ; Siqi LU
Chinese Journal of Parasitology and Parasitic Diseases 1997;0(05):-
Trophozoites of Giardia lamblia were axenically cultivated with modified TYI-S-33 medium contained 500 ?g/ml metronidazole(12h LC50).The morphology of drug-treated trophozoites was observed with light and electron micro-scopes at 2,4,8,12 h respectively.The light microscopy revealed that the trophozoites treated with MTZ showed swollen,detached from the wall of the culture tube,and were with vacuoles in the cytoplasm.Movement of the flagella become slowly or stopped.Electronic microscopy showed that the trophozoites were swollen and deformed;lots of vacuoles were seen in the cytoplasm;the contents of cytoplasm were depleted and the nuclei deformed.This study indicated that MTZ has injured the morphology of G.lamblia.
4.Human umbilical cord blood mesenchymal stem cells differentiated into neuron-like cells in vitro
Hong XU ; Xifeng MA ; Lirong RUAN ; Bo YANG ; Yin DU
Basic & Clinical Medicine 2006;0(03):-
Objective The mononuclear cells(MNCs) were cultivated and expanded into mesenchymal stem cells(MSCs) from human umbilical cord blood,and the purpose of this study was to explore the biological characteristics and induced differentiation ability in vitro.Methods Human umbilical cord blood samples were obtained and the mononuclear cells were isolated from it,then inoculated the MNCs into 25-mm culture flasks containing DMEM/F12 medium.The morphology was observed under microscope.Nissl body staining was used,The passage 2,4,7 of the expanded MSCs were induced to differentiate to neuron-like cells.The expressions of nestin and neuron-specific enolase (NSE) on the treated cells were detected by immunocytochemical method.Results Nissl body staining was positive;Nestin expression was found in(51.2?3.2)% of the second,(34.6?2.7)% of the fifth,(11.3?3.3)% of the seventh passage of MSCs;NSE expression was found in(11.4?2.3)% of the second,(21.78?3.1)% of the fifth,(40.7?3.4)% of the seventh passage of MSCs.Conclusion Cord bloodMSCs possess some features of neural stem cells,and have the capacity to differentiate into neuron-like cells under proper conditions.
5.Effect of down-regulation of TRPC6 on the puromycin aminonucleoside-induced apoptosis of mouse podocytes.
Xifeng, SUN ; Zhan, FANG ; Zhonghua, ZHU ; Xiao, YANG ; Fangfang, HE ; Chun, ZHANG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2009;29(4):417-22
Eukaryotic expression vectors carrying the small hairpin RNA (shRNA) for TRPC6 mRNA were constructed, and the effects of knocking-down TRPC6 on puromycin aminonucleoside (PAN)-induced apoptosis of mouse podocytes were observed. Two eukaryotic expression vectors containing small hairpin structure targeting TRPC6 named pGCsi-TRPC6A and pGCsi-TRPC6B were designed and synthesized. The plasmids were transfected into conditionally immortalized murine podocyte cell line by liposome. The changes in the TRPC6 mRNA and protein expression were observed by RT-PCR and Western blot after 48 h. Cultured podocytes were divided into four groups: control group, PAN treatment group, PAN treatment+shRNA transfection group, and PAN treatment+ negative control group. The expression of Bax and Bcl-2 mRNA and proteins was detected by RT-PCR and Western-blot respectively. The apoptotic rate of podocytes was measured by flow cytometry. The results showed that the expression of TRPC6 mRNA and protein was decreased in the podocytes when transfected with pGCsi-TRPC6A, and pGCsi-TRPC6B. The expression of Bax was increased, and that of Bcl-2 was decreased at protein and mRNA levels in the podocytes after treated with PAN for 48 h. These changes was attenuated by knocking-down TRPC6. Knocking-down TRPC6 could effectively decrease the PAN-induced apoptosis of podocytes. It was concluded that TRPC6 may play an important role in the PAN-induced apoptosis of podocytes. Knocking-down TRPC6 gene could effectively prevent the podocytes from apoptosis induced by PAN.
6.Application of spiral computed tomography in clinical dental implantation
Xifeng WU ; Liming YANG ; Ai JIANG ; Shuping CHEN ; Ziyun XIANG ; Yongbo GAO
Chinese Journal of Primary Medicine and Pharmacy 2011;18(9):1180-1181,后插3
Objective To evaluate the value of spiral CT and panoramic radiographs in preoperative assessment the jaw condition of patients for dental implantation.Methods 80 patients required dental implant restoration,these patients were Manned by CT and panoramic radiographs in preoperative,then selected suitable patients for dental implant restoration,reconstructed the jaw based on spiral CT data and guided the dental implant design and implanration.Results The spiral CT examination could be more accurate selection criteria for the patients needed dental implant restoration and more accurately showed the situation of edentulous ridge bone.Conclusion The reconstructed of three-dimensional imaging of spiral CT could precisely show the bone situation in the jaw needed dental implant and the important anatomic structures,could effectively assist denture design and the direction and depth of dental implants.was more superiority than panoramic radiographs.
7.Cloning and bioinformatics analysis of Giardia lamblia C2 strain SENP gene and prokaryotic expression of SENP catalytic domain
Shaodong LI ; Yingbin ZHOU ; Xiaoli LIU ; Han ZHU ; Sijin LI ; Xifeng TIAN ; Yang WANG
Chinese Journal of Zoonoses 2015;(3):203-207
SUMOylation is a post‐translational modification involved in various cellular processes .SUMO‐specific protease (SENP) regulates SUMOylation by removing SUMO from conjugated substrates (deSUMOylation) and promoting maturation of SUMO precursor .In order to express Giardia lambia (C2 strain) SENP catalytic domain in E .coli ,the full‐length open reading frame of SENP was amplified by PCR from Giardia lamblia genome DNA .The PCR product about 1 620 bp was cloned into cloning vector pGM‐T .Sequencing result showed the sequence of SENP in C2 strain was identical with that in Gi‐ardia WB strain .Bioinformatics analysis showed that SENP protein possessed a 372 aa discontinuous ULP catalytic domain at C‐terminal .The catalytic domain of SENP was cloned into prokaryotic expression vector pET‐28a(+ ) .The recombinant vector pET‐28a(+ )‐SENPc was transformed into E .coli Rosetta(DE3) ,then the recombinant SENPc protein was expressed by IPTG induction .SDS‐PAGE and Western blot using anti‐His Tag antibody showed that the expression product of SENPc was a fusion protein with a molecular weight of 43 kD .The successful prokaryotic expression and bioinformatics analysis of Giardia lamblia SENP protein provide basis for further functional study of SENP .
8.Effects of overexpression of TRPC6 on angiotensin Ⅱ-induced apoptosis of mouse podocytes
Xifeng SUN ; Chun ZHANG ; Xiuyan SHI ; Zhan FANG ; Zhonghua ZHU ; Xiao YANG ; Huajun JIANG
Chinese Journal of Nephrology 2008;24(11):797-803
Objective To study the effect of overexpression of TRPC6 on Ang Ⅱ-induced apoptosis of mouse podocytes in vitro and to explore the possible mechanisms. Methods Mouse TRPC6 cDNA eukaryotie expression vector pEGFP-NI-mTRPC6 was transfected to conditionally immortalized routine podocyte cell line by liposome. The fluorescent microscopy was used to examine the expression of EGFP after 24 hours. The change of TRPC6 protein expression was observed by Western-blot. Podocytes were treated by different concentrations of Ang Ⅱ. The podocyte intracellular calcium concentration was measured with laser-scanning con_focal microscope. The expression of Bax and Bcl-2 mRNA was assessed by RT-PCR and the expression of Bax and Bcl-2 protein was measured by Western-blot. The apoptotic ratio of podocytes was monitored by flow cytometry and Hoechst staining. Results About 35% of the cells expressed EGFP. An up-regulation of protein expression of TRPC6 was detected in podocytes when transfected with pEGFP-N1-mTRPC6 (P<0.01). The overexpression of TRPC6 promoted the Ang Ⅱ-induced influx of extracellular calcium and elevated the expression of Bax but decreased the expression of Bcl-2 (P<0.01, P<0.05). The apoptotic ratio of podocyte was (2.50±0.72)% when treated by low-dose Ang Ⅱ (10-10 mol/L), and it was increased to (4.33±0.45)% when transfected with pEGFP-N1-mTRPC6 (P <0.05 ). Transfection with pEGFP-NI-mTRPC6 increased apoptosis rate from (15.46± 1.40)% to (18.33±0.87)%(P<0.01) by high-dose Ang Ⅱ (10-6 mol/L). Conclusion TRPC6 plays an important role in the Ang Ⅱ-induced apoptosis of podocytes by promoting the influx of extraeellular calcium, which leads to the apoptosis cascade initiation.
9.Effects of dihydroartemisinin on the expression level of Alpha-7 .3 giardin mRNA in C2 Giardia lamblia
Yuan YU ; Yang CHEN ; Shuang GE ; Yang WANG ; Weiwei LI ; Lina ZHAO ; Aqian LIU ; Zhigiang LIN ; Xue GAO ; Xifeng TIAN
Chinese Journal of Zoonoses 2014;(7):669-672
Effects of dihydroartemisinin (DHA) on the expression level of Alpha-7 .3 giardin mRNA in C2 Giardia lam-blia was investigated in this study to explore the damage to skeleton protein of C 2 Giardia lamblia .Giardia lamblia was culti-vated respectively for 2 ,4 ,8 ,and 12 hours with modified TYI-S-33 medium containing 100 μg/mL and 200 μg/mL DHA , while the control group performed in the same experimental conditions without DHA .The expressive quantity of Alpha-7 .3 gi-ardin mRNA was determined by using real-time reverse transcription PCR ,and then we found that the expressive quantities of Alpha-7 .3 giardin mRNA with DHA were significantly lower than those in the control group .It’s suggested that dihydroarte-misinin has obvious inhibitory effect on the expression level of Alpha-7 .3 giardin mRNA in C2 Giardia lamblia .The actions of dihydroartemisinin on skeleton protein of C2 Giardia lamblia are effective .
10.Stress distribution in natural maxillary central incisor and implant: a three-dimensional finite element analysis
Linzi WAN ; Lei SUN ; Xifeng WU ; Zhenyan LIN ; Liangwei XU ; Zhenzhe LIU ; Duoling XU ; Yang LI ; Yanmin ZHOU ; Yongbo GAO
Chinese Journal of Tissue Engineering Research 2015;19(16):2545-2550
BACKGROUND:Biomechanical compatibility is the necessary condition to ensure the stable osseointegration with implants that then can function over a long period; therefore, it is especialy important to get knowledge about distribution of stress and strain between the maxilary central incisor and its surrounding bone tissue. OBJECTIVE: Based on five different anatomical types of natural teeth, to study the regularity of stress distribution between the maxilary central incisor root and implant.METHODS: According to the five different anatomical types of natural maxilary central incisors, UGNX and ANSYS were used to set up three-dimensional finite element models (B1, B2, M1, M2, P1) for the implant and surrounding structures, which were under 100 N static load at angles of 0o, 30o, 45o, 60o, 90o with the long axis of teeth. Then, the stress distribution between the five kinds of maxilary central incisor roots and implants was analyzed. RESULTS AND CONCLUSION:Among the five different anatomical types, the equivalent stress for both the natural central incisor and implant were increased with the increasing of angles, and the implant had a higher raising trend. The equivalent stress for the natural tooth concentrated upon B1 for the maximum value and M1 for the minimum value; while the equivalent stress for the implant focused on the maximum value at M1 and the minimum value at M2. There was a gap of 2%-31% between the equivalent stresses for the natural tooth roots and a gap of 4%-21% for the implants. The stress distribution range for the implant was just smaler than that for the natural tooth roots. It implies that the bit force of implant and natural tooth is in positive proportion to the bite angles, and the bite force that implant can burden is smaler than that the central incisor can.