[Objective] This study aimed to construct Myostatin （MSTN） gene targeting vector of mouse. [Method] Total RNA was extracted from hindlimb muscle tissues of mouse to synthesize cDNA as the template to clone the codin...[Objective] This study aimed to construct Myostatin （MSTN） gene targeting vector of mouse. [Method] Total RNA was extracted from hindlimb muscle tissues of mouse to synthesize cDNA as the template to clone the coding region of MSTN. The CDS of MSTN gene including 3 kb 5’ homologous arm and 1.4 kb 3’ homologous arm were inserted into vector pBluescript_SK ＋ to construct the targeting vector pLoxP-5N3T-M. The neo and HSV-tk gene were cloned into vector pBluescript_SK＋ as positive and negative selective gene. [Result] Restriction enzyme digestion and sequencing results showed that mouse MSTN gene was cloned into the targeting vector pLoxP-5N3T-M. [Conclusion] The mouse MSTN gene targeting vector pLoxP5N3T-M was successfully constructed.展开更多
AIM: To evaluate the in vitro anti-HBV activity of recombinant human IFN-γ, alone and in combination with lamivudine. METHODS: A recombinant baculovirus-HBV/HepG2 culture system was developed which could support prod...AIM: To evaluate the in vitro anti-HBV activity of recombinant human IFN-γ, alone and in combination with lamivudine. METHODS: A recombinant baculovirus-HBV/HepG2 culture system was developed which could support productive HBV infection in vitro. Expression of HBsAg and HBeAg in infected HepG2 culture medium was detected by commercial enzyme immunoassays. HBV DNA replication intermediates were detected in infected cells by Southern hybridization and viral DNA load was determined by dot hybridization. RESULTS: IFN-γat 0.1 to 5μg/L efficiently down regulated HBsAg expression in transduced HepG2 cells. At 5μg/L, IFN-γalso suppressed HBV DNA replication in these cells. While treatment with a combination of lamivudine and IFN-γshowed no additive effect, sequential treatment first with lamivudine and then IFN-γwas found to be promising. In this culture system the best HBV suppression was observed with a pulse of 2μmol/L lamivudine for two days, followed by 1μg/L IFN-γfor another four days. Compared to treatment with lamivudine alone, the sequential use of 0.2μmol/L lamivudine for two days, followed by 5μg/L IFN-γfor six days showed a 72% reduction in HBV cccDNA pool. CONCLUSION: This in vitro study warrants further evaluation of a combination of IFN-γand lamivudine, especially in IFN-αnon-responder chronic hepatitis B patients. A reduced duration of lamivudine treatment would also restrict the emergence of drug-resistant HBV mutants.展开更多
Objective： To prepare microencapsulated cells releasing human tissue inhibitor ofmetalloproteinase-2 （TIMP-2）, and investigate their biological characteristics in vitro. Methods： Chinese hamster ovary （CHO） cell...Objective： To prepare microencapsulated cells releasing human tissue inhibitor ofmetalloproteinase-2 （TIMP-2）, and investigate their biological characteristics in vitro. Methods： Chinese hamster ovary （CHO） cells were stably transfected with a human TIMP-2 expression vector, encapsulated in barium alginate microcapsules and cultured in vitro. Morphological appearance of the microcapsules was observed under a light microscope. Cell viability was assessed using MTT （3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide） assay. Enzyme linked immunosorbent assay （ELISA） and reverse zymography were used to confirm the release of biologically active TIMP-2 from the microcapsules. Cryopreservation study of the microencapsulated cells was carried out using dimethyl sulfoxide （DMSO） as preservative agent. Results： The microcapsules appeared like a sphere with diameter of 300-600 ~tm. The surface of the capsule wall was clearly smooth. The microencapsulated cells survived well and kept proliferating over the 6 weeks observed. No significant difference in TIMP-2 secretion was found between encapsulated and unencapsulated cells. Reverse zymography confirmed the bioactivity of MMP （matrix metalloproteinase） inhibition of TIMP-2. The cryopreservation process did not damage the microcapsule morphology nor the viability of the cells inside. Conclusion： Microencapsulated engineered CHO cells survive at least 6 weeks after preparation in vitro, and secrete bioactive TIMP-2 freely from the microcapsules.展开更多
The soluble HLA-G1 (sHLA-G1) isoform was found to be secreted by trophoblast cells at the matemo-fetal interface, which suggests that it may act as an immunomodulator during pregnancy. In this paper, we reported that ...The soluble HLA-G1 (sHLA-G1) isoform was found to be secreted by trophoblast cells at the matemo-fetal interface, which suggests that it may act as an immunomodulator during pregnancy. In this paper, we reported that GST-sHLA-G1α chain could bind to its receptor ILT-2 on NK92 cells and then the latter recruited Src homology 2 domaincontaining tyrosine phosphatase-1 (SHP-1), which consequently dephosphorylated some important protein tyrosine kinases and blocked the activation of downstream molecules such as MEK and ERK so that the cytotoxicity of natural killer (NK) cells was inhibited. These results indicated that GST-sHLA-G1α chain might be exploited in new immunotherapy strategies aiming at inducing immunotolerance during allograft, xenograft and autoimmune situations. In addition, we found that modification of O-linked β-N-acetylglucosamine (O-GlcNAc) was involved in NK cells' activating and inhibitory signals. This may provide a novel molecular target for inducing immunotolerance but needs further study.展开更多
Objective To evaluate the bioequivalence between recombinant human growth hormone （rhGH） for reconstitution, and two dosages of liquid formulation of rhGH [ （151U） 5mg or （301U） lOmg per 3ml ]. Methods The study...Objective To evaluate the bioequivalence between recombinant human growth hormone （rhGH） for reconstitution, and two dosages of liquid formulation of rhGH [ （151U） 5mg or （301U） lOmg per 3ml ]. Methods The study drugs were tested in a randomized, single-blind and three-period crossover studies in 24 healthy male subjects. The three drugs were administered by subcutaneous injection at a dose of O. 21U/kg body weight. A continuous somatostatin infusion was given in order to suppress the secretion of endogenous GH. The ve- nous blood samples were drawn at different time points to test the serum concentration of GH. The pharmacokinetic parameters were analyzed by statistical methods. Results 90% confidence intervals （CI） of AUC0-24h among three products were all within 80% - 125% interval （ 103. 4% - 116. 5%, 105. 7% - 119. 6% and 91.9% - 103. 7%, respectively）, and the Cls of C,~ among three products were all within 70% - 143% interval （91.9% - 114. 0%, 103. 7% -127. 2% and 81.6% -97. 4%, respectively）. There was no statisitical difference of tmax among all the three products. Conclusion These data demonstrate that there is bioequivalence between rhGH for reconstitution and two liquid formulations of rhGH.展开更多
基金Supported by Project from Science and Technology Department of Guizhou Province ([2009]2173)~~
文摘[Objective] This study aimed to construct Myostatin （MSTN） gene targeting vector of mouse. [Method] Total RNA was extracted from hindlimb muscle tissues of mouse to synthesize cDNA as the template to clone the coding region of MSTN. The CDS of MSTN gene including 3 kb 5’ homologous arm and 1.4 kb 3’ homologous arm were inserted into vector pBluescript_SK ＋ to construct the targeting vector pLoxP-5N3T-M. The neo and HSV-tk gene were cloned into vector pBluescript_SK＋ as positive and negative selective gene. [Result] Restriction enzyme digestion and sequencing results showed that mouse MSTN gene was cloned into the targeting vector pLoxP-5N3T-M. [Conclusion] The mouse MSTN gene targeting vector pLoxP5N3T-M was successfully constructed.
基金Supported by a grant from the Dabur Research Foundation, India and a Senior Research Fellowship of the CSIR, Gov. of India (to MKP)
文摘AIM: To evaluate the in vitro anti-HBV activity of recombinant human IFN-γ, alone and in combination with lamivudine. METHODS: A recombinant baculovirus-HBV/HepG2 culture system was developed which could support productive HBV infection in vitro. Expression of HBsAg and HBeAg in infected HepG2 culture medium was detected by commercial enzyme immunoassays. HBV DNA replication intermediates were detected in infected cells by Southern hybridization and viral DNA load was determined by dot hybridization. RESULTS: IFN-γat 0.1 to 5μg/L efficiently down regulated HBsAg expression in transduced HepG2 cells. At 5μg/L, IFN-γalso suppressed HBV DNA replication in these cells. While treatment with a combination of lamivudine and IFN-γshowed no additive effect, sequential treatment first with lamivudine and then IFN-γwas found to be promising. In this culture system the best HBV suppression was observed with a pulse of 2μmol/L lamivudine for two days, followed by 1μg/L IFN-γfor another four days. Compared to treatment with lamivudine alone, the sequential use of 0.2μmol/L lamivudine for two days, followed by 5μg/L IFN-γfor six days showed a 72% reduction in HBV cccDNA pool. CONCLUSION: This in vitro study warrants further evaluation of a combination of IFN-γand lamivudine, especially in IFN-αnon-responder chronic hepatitis B patients. A reduced duration of lamivudine treatment would also restrict the emergence of drug-resistant HBV mutants.
文摘Objective： To prepare microencapsulated cells releasing human tissue inhibitor ofmetalloproteinase-2 （TIMP-2）, and investigate their biological characteristics in vitro. Methods： Chinese hamster ovary （CHO） cells were stably transfected with a human TIMP-2 expression vector, encapsulated in barium alginate microcapsules and cultured in vitro. Morphological appearance of the microcapsules was observed under a light microscope. Cell viability was assessed using MTT （3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide） assay. Enzyme linked immunosorbent assay （ELISA） and reverse zymography were used to confirm the release of biologically active TIMP-2 from the microcapsules. Cryopreservation study of the microencapsulated cells was carried out using dimethyl sulfoxide （DMSO） as preservative agent. Results： The microcapsules appeared like a sphere with diameter of 300-600 ~tm. The surface of the capsule wall was clearly smooth. The microencapsulated cells survived well and kept proliferating over the 6 weeks observed. No significant difference in TIMP-2 secretion was found between encapsulated and unencapsulated cells. Reverse zymography confirmed the bioactivity of MMP （matrix metalloproteinase） inhibition of TIMP-2. The cryopreservation process did not damage the microcapsule morphology nor the viability of the cells inside. Conclusion： Microencapsulated engineered CHO cells survive at least 6 weeks after preparation in vitro, and secrete bioactive TIMP-2 freely from the microcapsules.
文摘The soluble HLA-G1 (sHLA-G1) isoform was found to be secreted by trophoblast cells at the matemo-fetal interface, which suggests that it may act as an immunomodulator during pregnancy. In this paper, we reported that GST-sHLA-G1α chain could bind to its receptor ILT-2 on NK92 cells and then the latter recruited Src homology 2 domaincontaining tyrosine phosphatase-1 (SHP-1), which consequently dephosphorylated some important protein tyrosine kinases and blocked the activation of downstream molecules such as MEK and ERK so that the cytotoxicity of natural killer (NK) cells was inhibited. These results indicated that GST-sHLA-G1α chain might be exploited in new immunotherapy strategies aiming at inducing immunotolerance during allograft, xenograft and autoimmune situations. In addition, we found that modification of O-linked β-N-acetylglucosamine (O-GlcNAc) was involved in NK cells' activating and inhibitory signals. This may provide a novel molecular target for inducing immunotolerance but needs further study.
文摘Objective To evaluate the bioequivalence between recombinant human growth hormone （rhGH） for reconstitution, and two dosages of liquid formulation of rhGH [ （151U） 5mg or （301U） lOmg per 3ml ]. Methods The study drugs were tested in a randomized, single-blind and three-period crossover studies in 24 healthy male subjects. The three drugs were administered by subcutaneous injection at a dose of O. 21U/kg body weight. A continuous somatostatin infusion was given in order to suppress the secretion of endogenous GH. The ve- nous blood samples were drawn at different time points to test the serum concentration of GH. The pharmacokinetic parameters were analyzed by statistical methods. Results 90% confidence intervals （CI） of AUC0-24h among three products were all within 80% - 125% interval （ 103. 4% - 116. 5%, 105. 7% - 119. 6% and 91.9% - 103. 7%, respectively）, and the Cls of C,~ among three products were all within 70% - 143% interval （91.9% - 114. 0%, 103. 7% -127. 2% and 81.6% -97. 4%, respectively）. There was no statisitical difference of tmax among all the three products. Conclusion These data demonstrate that there is bioequivalence between rhGH for reconstitution and two liquid formulations of rhGH.
