1.Treatment effect of partial liquid ventilation on pulmonary edema after seawater drowning in rabbits
Xinhong ZHANG ; Yunyou DUAN ; Huijun HU ; Huasong FENG ; Life LAI
Academic Journal of Second Military Medical University 2001;0(09):-
Objective:To observe the effect of partial liquid ventilation (PLV) on gas exchange,pulmonary compliance and blood dynamics in the pulmonary edema rabbits after seawater drowning(PE-SWD). Methods:Totally 42 healthy male New Zealand rabbits were randomly allocated into 3 groups (n=14);each group was treated with various methods after PE-SWD model was established:PE group with no treatment,CMV group with conventional mechanical ventilation and positive end-expiratory pressure(PEEP),PLV group with CMV,PEEP and FDC.After being treated for 3 h,blood gases,pulmonary mechanics,hemodynamics,pulmonary histopathology and survival time were observed.Results:In PLV group,PaO 2 increased obviously and reached (262.84?64.33) mmHg (1 mmHg=0.133 kPa), airway pressure decreased by 23.4%,pulmonary static compliance increased by 31.3% and TNF-? decreased by 24.9%.HR and MAP showed no significant changes after treatment compared with PE group.Conclusion: Pulmonary gas exchange and compliance are improved significantly during PLV in the PE-SWD rabbits without obvious influence on hemodynamic status, although the survival time of PLV group is less than that of CMV group.
2.L-Theanine-Treated Adipose-Derived Mesenchymal Stem Cells Alleviate the Cytotoxicity Induced by N-Nitrosodiethylamine in Liver
Yun-Ju LAI ; Yi-Ting SUNG ; Yi-An LAI ; Li-Nian CHEN ; Tung-Sheng CHEN ; Chiang-Ting CHIEN
Tissue Engineering and Regenerative Medicine 2022;19(6):1207-1221
BACKGROUND:
Liver inflammation is the main cause of severe liver diseases, including liver fibrosis, steatohepatitis, cirrhosis and hepatocellular carcinoma. Cell therapy topics are receiving increasingly more attention. The therapeutic applications of mesenchymal stem cells (MSC) have become one of the most discussed issues. While other stem cells have therapeutic effects, they have only one or two clinical applications. MSCs are responsible for repairing a variety of tissue injuries. Moreover, MSCs could be derived from several sources, including adipose tissue. MSCs are usually more abundant and easier to obtain compared to other stem cells.
METHODS:
To prove the concept that MSCs have homing ability to the injured tissue and assist in tissue repair, we examined the effects of intravenous injected adipose-derived mesenchymal stem cells (ADSCs) in a N-nitrosodiethylamine (DEN)-induced liver injury rat model.
RESULTS:
The significant repairing ability of ADSCs was observed. The levels of fibrosis, apoptosis, and tumorigenesis in the DEN-injured liver tissues all decreased after ADSC treatment. Furthermore, to enhance the therapeutic effects of ADSCs, we pretreated them with L-theanine, which promotes the hepatocyte growth factor secretion of ADSC, and therefore improved the healing effects on injured liver tissue.
CONCLUSION
ADSCs, especially L-theanine-pretreated ADSCs, have anti-inflammation, anti-apoptosis, and anti-tumorigenesis effects on the N-nitrosodiethylamine-induced liver injury rat model.
3.Synchronization analysis of ECoG and EHG from eplieptiform discharges rats.
Yansu LIU ; Yang XIA ; Hongyi WU ; Yongxiu LAI ; Dezhong YAO
Journal of Biomedical Engineering 2007;24(3):496-499
The mechanisms leading to the occurrence of seizures in humans are still poorly understood. It is widely accepted, however, that the process of seizure generation is closely associated with an abnormal synchronization of neurons. In order to investigate this process, we have studied synchronization between different regions of the brain from intracranial EEG recordings of Pilocarpine-induced epileptic rat by Synchronization likelihood (SL). It was found that during the state of transition from non-epileptiform discharges to continuous-epileptiform discharges, synchronization between left-ECoG and left-EHG was significantly strengthened, and similar change had taken place between right-ECoG and right-EHGd; left-ECoG; and right-ECoG and left-EHG and right-EHG (P < 0.05). During the state of transition from continuous-epileptiform discharges to period-epileptiform discharges, the synchronization was significantly weakened between left-ECoG and left-EHG, and similar change was noted between left-EHG and right-EHG (P < 0.01). The results showed that SL might be used to assess the dynamics of synchronization and it might be helpful to understanding the mechanisms involving the origin of epileptiform discharge.
Animals
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Cerebral Cortex
;
physiopathology
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Electroencephalography
;
methods
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Epilepsy
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chemically induced
;
physiopathology
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Hippocampus
;
physiopathology
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Male
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Pilocarpine
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Rats
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Rats, Sprague-Dawley
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Signal Processing, Computer-Assisted
4.Cloning and function analysis of L-lactate dehydrogenase gene from Lactobacillus sp. MD-1.
Jian LI ; Yun TANG ; Feng-Lai LIANG ; Xin-Ping ZHANG ; Ru-Lin LIU
Chinese Journal of Biotechnology 2004;20(5):725-729
It was constructed that a genomic DNA library from Lactobacillus sp. MD-1 yielding D, L-lactic acid. The gene encoding L-lactate dehydrogenase (L-LDH) was cloned from the genomic library of strain MD-1 by complementation in E. coli FMJ144 which was lactate dehydrogenase and pyruvate-formate lyase double defective mutant. The nucleotide sequence of the ldhL gene predicted a protein of 316 amino acid starting with ATG. The putative molecular weight of the L-LDH amino acid sequence was 33.84kD. A putative typical promoter (-35 and -10 boxes) had been observed in the 5' noncoding region. An rho-independent transcriptional terminator has been observed in the 3' noncoding region. Three highly conserved regions (Gly13 approximately Asp50, Asp73 approximately Ileul00 and Asn123 approximately Arg154) with several conserved residues had been identified. Gly13 approximately Asp50 was NADH-binding site domain. Asp73 approximately Ileu100 and Asn123 approximately Arg154 were reported to be the active site domains. The ldhL and the L-LDH of Lactobacillus sp. MD-1 showed the low identity and similarity with other Lactobacilli, and the highest percentage were 61.9% and 68.9% respectively. All the above indicated this gene is a novel ldhL.
Amino Acid Sequence
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Base Sequence
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Cloning, Molecular
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L-Lactate Dehydrogenase
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chemistry
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genetics
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physiology
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Lactobacillus
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genetics
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Molecular Sequence Data
5.Use of Ssp dnaB mini-intein as a fusion partner for preparation of recombinant human brain natriuretic peptide.
Lie DI ; Hong-Wei ZHANG ; Lang-Lai XU
Chinese Journal of Biotechnology 2006;22(2):180-203 passim
Human brain natriuretic peptide (hBNP) was used clinically for the treatment of acute decompensated congestive heart failure. In this paper, hBNP was expressed as a fusion protein with a histidine tag and Ssp dnaB mini-intein which was capable of self-cleavage. After affinity chromatography with Ni-Sepharose and renaturation, the fusion protein was enriched with CM-cellulose. Ssp dnaB mini-intein mediated peptide-bond hydrolysis was triggered by shifting the pH and temperature in the CM-cellulose column, which let to the release of hBNP from the fusion protein and the separation of hBNP from His-DnaB. The hBNP sample was further purified by C4 reverse phase HPLC, and 2.8mg of the peptide with homogeneity of 97% was obtained from one liter of culture medium. The biological activity was assayed in vitro, which indicated that hBNP had a potent vasodilatory effect on rabbit aortic strips with an EC50 of 1.94 x 10(-6) mg/mL.
Animals
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DnaB Helicases
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biosynthesis
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genetics
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Escherichia coli
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genetics
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metabolism
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Genetic Vectors
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Inteins
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genetics
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Natriuretic Peptide, Brain
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biosynthesis
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genetics
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Protein Engineering
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methods
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Protein Splicing
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Rabbits
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Recombinant Fusion Proteins
;
biosynthesis
;
genetics
;
pharmacology
6.cGAS/STING signaling pathways induces the secretion of type Ⅰ interferon in porcine alveolar macrophages infected with porcine circovirus type 2.
Hongbo CHEN ; Feng LI ; Wenyan LAI ; Yuhao FANG ; Mingyong JIANG ; Dianning DUAN ; Xiaoyan YANG
Chinese Journal of Biotechnology 2021;37(9):3201-3210
In order to study the signal pathway secreting type Ⅰ interferon in porcine alveolar macrophages (PAMs) infected with porcine circovirus type 2 (PCV2), the protein and the mRNA expression levels of cGAS/STING pathways were analyzed by ELISA, Western blotting and quantitative reverse transcriptase PCR in PAMs infected with PCV2. In addition, the roles of cGAS, STING, TBK1 and NF-κB/P65 in the generation of type I interferon (IFN-I) from PAMs were analyzed by using the cGAS and STING specific siRNA, inhibitors BX795 and BAY 11-7082. The results showed that the expression levels of IFN-I increased significantly at 48 h after infection with PCV2 (P<0.05), the mRNA expression levels of cGAS increased significantly at 48 h and 72 h after infection (P<0.01), the mRNA expression levels of STING increased significantly at 72 h after infection (P<0.01), and the mRNA expression levels of TBK1 and IRF3 increased at 48 h after infection (P<0.01). The protein expression levels of STING, TBK1 and IRF3 in PAMs infected with PCV2 were increased, the content of NF-κB/p65 was decreased, and the nuclear entry of NF-κB/p65 and IRF3 was promoted. After knocking down cGAS or STING expression by siRNA, the expression level of IFN-I was significantly decreased after PCV2 infection for 48 h (P<0.01). BX795 and BAY 11-7082 inhibitors were used to inhibit the expression of IRF3 and NF-κB, the concentration of IFN-I in BX795-treated group was significantly reduced than that of the PCV2 group (P<0.01), while no significant difference was observed between the BAY 11-7028 group and the PCV2 group. The results showed that PAMs infected with PCV2 induced IFN-I secretion through the cGAS/STING/TBK1/IRF3 signaling pathway.
Animals
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Cells, Cultured
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Circovirus
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Interferon Type I/genetics*
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Macrophages, Alveolar/virology*
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Membrane Proteins/metabolism*
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Nucleotidyltransferases/metabolism*
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Signal Transduction
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Swine
7.gTME for construction of recombinant yeast co-fermenting xylose and glucose.
Hongmei LIU ; Lin XU ; Ming YAN ; Cangang LAI ; Pingkai OUYANG
Chinese Journal of Biotechnology 2008;24(6):1010-1015
Global transcription machinery engineering (gTME) was employed to engineer xylose metabolism. Mutation of the transcription factor gene Sptl5 was introduced by error-prone PCR, followed by screening on media using xylose as the sole carbon source. One recombinant strain growing well on such media was chosen for further research. This strain showed modest growth rates in the media containing 50 g/L xylose or glucose at the condition of 30 degrees C, 200 r/min, 96 h, 94.0% and 98.9% of xylose and glucose were consumed, with the ethanol yield were 32.4% and 31.6%, respectively. The control strain had the ethanol yield of 44.3% under the glucose concentration of 50 g/L. When the carbon source was 50 g/L glucose/xylose (1:1), the utilization ratio of xylose and glucose was 91.7% and 85.9%, with the ethanol yield was 26%. Xylose was eventually exhausted. Concentration of the by-product xylitol was very low.
DNA-Directed RNA Polymerases
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genetics
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metabolism
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Ethanol
;
metabolism
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Fermentation
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Genetic Engineering
;
methods
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Glucose
;
metabolism
;
Saccharomyces cerevisiae
;
genetics
;
metabolism
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Transcription Factors
;
genetics
;
metabolism
;
Transformation, Genetic
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Xylose
;
metabolism
8.Construction of a Pichia pastoris recombinant strain capable of over-expressing phytase and endoglucanase.
Zhenfang WU ; Zizhong TANG ; Hui CHEN ; Xueyi HAN ; Xin LAI ; Qi WU
Chinese Journal of Biotechnology 2010;26(5):616-622
Both phytase and endoglucanase are additives in feed for mono-gastric animal known for their effects. Recombinant vector pPICZalpha-EG was constructed and transformed to GS115-phyA, a Pichia pastoris strain that had integrated with phytase gene, generating GS115-phyA-EG. Both phytase and endoglucanase activities in the supernatant were determined after methanol induction of GS115-phyA-EG. Phytase and endoglucanase activity reached 39.4% and 56.2% activity compared to GS115-phyA and GS115-EG, respectively. Properties of the mixed enzyme suggest that the optimal temperature and pH value be 55 degrees C and 5.5 respectively. Both phytase and endoglucanase showed greater than 80% activity across temperature ranges 45 degrees C to 55 degrees C and pH ranges 4.5 to 5.5. Expressing more than one enzyme in one system could save time and money during induced expression, and the mixed enzyme might apply for treating forge before feeding with poultry.
6-Phytase
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biosynthesis
;
genetics
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Cellulase
;
biosynthesis
;
genetics
;
Genetic Vectors
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Pichia
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enzymology
;
genetics
;
Recombinant Proteins
;
biosynthesis
;
genetics
9.Screening serum response special antibodies of U251 cell line from surface display phage antibody library.
Min YU ; De-Yong TAN ; Wei QIAN ; Jian-Hua LAI ; Gui-Lin SUN
Chinese Journal of Biotechnology 2004;20(3):356-360
U251 cell is a sensitive cell line to serum, which stops at G0 phase of cell cycle in no-serum medium, and recovers growth when the serum is added into no-serum medium. The cell can express corresponding proteins in different phase of cell cycle. Therefore it is very signification for the study of cell cycle regulation mechanism that explores these proteins. In this paper, the mouse antibody phage display library was added into the bottle in which the serum starvation U251 cells had been cultured, and the special antibody phages were absorbed. Then the absorbed antibody phages were amplified by adding E. coli TG1 and helper phage M13K07. Amplified antibody phages were added into bottle in which the serum cultured cell after serum starvation (follow named as serum recovered cells) were incubated, so that the cell absorbed the no-special antibody phages for the serum starvation cell and the special antibody phages were in supernatant. The remaining no-special antibody phages in the supernatant were discarded by repeating above program 3-4 times. The pure special antibody phages were gotten, and amplified by adding the host cell E. coli TG1 and helper phage M13K07. Then the host bacterium infected special antibody phage was spread on the plate medium with ampicillin, and the monoclonal antibody phages were gotten. Using same as above program, the monoclonal antibody phages absorbed specially for serum recovered U251 cells were obtained when the serum recovered cells instead of serum starvation cells and serum starvation cells instead of serum recovered cells. In this study, ninety-six positive monoclonal antibody phages that absorbed specially the serum starvation cells and eighty-two positive monoclonal antibody phages that absorbed specially the serum recovered cells were obtained. By using cell immunochemistry assay, two special signification antibodies were obtained. one (No.11) was the strong response in serum starvation cells, the other (No.2) was the strong response in serum recovered cells. The antibody No.2 had the distinctive response to the serum recovered cells in different incubation time (15min, 30min, 1h, 2h, 4h, 8h, 12h and 48h) after serum starvation. The results showed that No.2 antibody would be useful to research the factors of cell cycle regulation and apply to tumor diagnosis.
Antibodies, Neoplasm
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genetics
;
immunology
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isolation & purification
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Bacteriophages
;
genetics
;
Brain Neoplasms
;
immunology
;
pathology
;
Cell Line, Tumor
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Escherichia coli
;
genetics
;
metabolism
;
Glioma
;
immunology
;
pathology
;
Humans
;
Peptide Library
10.Culture of hairy roots of Panax japonicus and ginsenoside re synthesis.
Lai ZHANG ; Xianqiang ZHANG ; Zhengwei LUO ; Min SUN
China Journal of Chinese Materia Medica 2010;35(18):2383-2387
OBJECTIVETo establish the induction method and culture system of hairy roots of Panax japonicus, and determine ginsenoside Re contents.
METHODHairy roots of P. japonicus was obtained through infecting pre-incubated terrestrial stem with the Agrobacterium tumefaciens strain C58C1; its enlarging culture was carried out on the 1/2MS medium, and growing characteristics were measured. The transformation of T-DNA was examined by PCR and ginsenoside Re content was determined by HPLC.
RESULTA. tumefaciens strain C58C1 could make terrestrial stem of P. japonicus bring about hairy roots, the max inductivity was 90% when infecting for 25 min. The PCR examination result showed that rolB genes could be inserted into the hair roots of P. japonicus. All hairy roots dould synthesize ginsenoside Re, among them, the max content was PJ8 with 60. 26 mg x g(-1).
CONCLUSIONIt was reported for the first time that the induction method and culture system of hairy roots of P. japonicus were established successfully, which provided a foundation for producing high content ginsenoside Re through culturing the hairy roots of P. japonicus.
Agrobacterium tumefaciens ; genetics ; physiology ; Cells, Cultured ; Culture Techniques ; methods ; Ginsenosides ; biosynthesis ; Panax ; genetics ; growth & development ; metabolism ; microbiology ; Plant Roots ; genetics ; growth & development ; metabolism ; microbiology