The current study was undertaken to evaluate the possibility of producing a human pro-insulin transgenic cow by means of somatic cell nuclear transfer （SCNT）. A double selection system, Neomycin resistance （Neo^r）...The current study was undertaken to evaluate the possibility of producing a human pro-insulin transgenic cow by means of somatic cell nuclear transfer （SCNT）. A double selection system, Neomycin resistance （Neo^r） gene and enhanced green fluorescent protein （EGFP） gene linked through an inner ribosomal entry site （IRES） sequence directed by a Cytomegalovirus （CMV） promoter, was used for enrichment and selection of the transgenic cells and preimplantation embryos. Transgenes were introduced into bovine fetal fibroblast cells （BFF） cultured in vitro through electroporation （900 V/cm, 5 ms）. Transgenic bovine fibroblast cells （TBF） were enriched through addition of G418 in culture medium （800 μg/mL）. Before being used as a nuclear donor, the TBF cells were either cultured in normal conditions （10% FBS） or treated with serum starvation （0.5% FBS for 2-4 days） followed by 10 hours recovery for G1 phase synchronization. Transgenic cloned embryos were produced through GFP-expressing cell selection and SCNT. The results were the percentage of blastocyst development following SCNT was lower using TBF than BFF cells （23.2% VS 35.2%, P 〈 0.05）. No difference in the percentage of cloned blastocysts between the two groups of transgenic nuclear donor of normal and starvation cultures were observed （23.2% VS 18.9%, P 〉 0.05）. Two to four GFP-expressing blastocysts were transferred into the uterus of each synchronised recipient. One pregnancy from of seven recipients （21 embryos） was confirmed by rectum palpation 60 days after embryo transfer and one recipient has given birth to a calf at term. PCR and DNA sequencing analysis confirmed that the calf was produced using human proinsulin transgenic animal.展开更多
Calf spleen extract(CSE) has been clinically used as an adjuvant agent in malignant tumor therapy.It can improve the physical status of patients.However,its mechanism of action remains relatively unclear.In this study...Calf spleen extract(CSE) has been clinically used as an adjuvant agent in malignant tumor therapy.It can improve the physical status of patients.However,its mechanism of action remains relatively unclear.In this study,we investigated the effect of CSE on leucopenia in mice and on promyelocytic leukemia cells(HL60).CSE in 10 mL/kg(2.5 mg bioactive polypeptides and 190μg ribose/mL) significantly increased leukocyte numbers in leucopenia mice.The effect on neutrophil numbers,among all leukocytes,was the most evident.CSE stimulated the proliferation of bone marrow cells in vitro and decreased the GM-CSF level in serum.In addition,CSE significantly reduced the viability of HL60 cells,decreased the production of lactate and adenosine triphosphate(ATP) of these cells.CSE induced the apoptosis and S-phase arrest in HL60 cells.In conclusion,CSE can enhance leukocyte numbers,which may be attributed to its direct stimulatory effect on bone marrow cells.CSE is an inhibitor of promyelocytic leukemia cell viability,which may be attributed to the induction of the apoptosis,the arrest of cell cycle and the inhibition of the glycolysis of cells.展开更多
文摘The current study was undertaken to evaluate the possibility of producing a human pro-insulin transgenic cow by means of somatic cell nuclear transfer （SCNT）. A double selection system, Neomycin resistance （Neo^r） gene and enhanced green fluorescent protein （EGFP） gene linked through an inner ribosomal entry site （IRES） sequence directed by a Cytomegalovirus （CMV） promoter, was used for enrichment and selection of the transgenic cells and preimplantation embryos. Transgenes were introduced into bovine fetal fibroblast cells （BFF） cultured in vitro through electroporation （900 V/cm, 5 ms）. Transgenic bovine fibroblast cells （TBF） were enriched through addition of G418 in culture medium （800 μg/mL）. Before being used as a nuclear donor, the TBF cells were either cultured in normal conditions （10% FBS） or treated with serum starvation （0.5% FBS for 2-4 days） followed by 10 hours recovery for G1 phase synchronization. Transgenic cloned embryos were produced through GFP-expressing cell selection and SCNT. The results were the percentage of blastocyst development following SCNT was lower using TBF than BFF cells （23.2% VS 35.2%, P 〈 0.05）. No difference in the percentage of cloned blastocysts between the two groups of transgenic nuclear donor of normal and starvation cultures were observed （23.2% VS 18.9%, P 〉 0.05）. Two to four GFP-expressing blastocysts were transferred into the uterus of each synchronised recipient. One pregnancy from of seven recipients （21 embryos） was confirmed by rectum palpation 60 days after embryo transfer and one recipient has given birth to a calf at term. PCR and DNA sequencing analysis confirmed that the calf was produced using human proinsulin transgenic animal.
文摘Calf spleen extract(CSE) has been clinically used as an adjuvant agent in malignant tumor therapy.It can improve the physical status of patients.However,its mechanism of action remains relatively unclear.In this study,we investigated the effect of CSE on leucopenia in mice and on promyelocytic leukemia cells(HL60).CSE in 10 mL/kg(2.5 mg bioactive polypeptides and 190μg ribose/mL) significantly increased leukocyte numbers in leucopenia mice.The effect on neutrophil numbers,among all leukocytes,was the most evident.CSE stimulated the proliferation of bone marrow cells in vitro and decreased the GM-CSF level in serum.In addition,CSE significantly reduced the viability of HL60 cells,decreased the production of lactate and adenosine triphosphate(ATP) of these cells.CSE induced the apoptosis and S-phase arrest in HL60 cells.In conclusion,CSE can enhance leukocyte numbers,which may be attributed to its direct stimulatory effect on bone marrow cells.CSE is an inhibitor of promyelocytic leukemia cell viability,which may be attributed to the induction of the apoptosis,the arrest of cell cycle and the inhibition of the glycolysis of cells.
