For providing some experimental basis in establishing malignant phenotypic reversed indexes of gastric carcinoma cells, human gastric adenocar-cinoma cell line MGc80-3 was induced by dBcAMP in vitro to appraise the ef...For providing some experimental basis in establishing malignant phenotypic reversed indexes of gastric carcinoma cells, human gastric adenocar-cinoma cell line MGc80-3 was induced by dBcAMP in vitro to appraise the effect of gastric carcinoma cell differentiation by chemical inducers.Under light microscope, MGc80-3 cells, after treated with 1 mM dBcAMP, tended to be flat and disperse, and their volume gradually enlarged, with their uncleus relatively smaller and their shape rather regular. Morphological changes, like norma differentiated epithelial cells, were observed. The cells attached firmly, grew slowly, their growth curve showed inhibitory rate amounted to 52.87%, and cellular division exponent displayed their peak value 1.5 times less than that of MGc80-3 cells. It was clear that dBcAMP could effectively inhibit the multiplication activity of MGc80-3 cells. After dBcAMP treatment, remarkable changes of cell surface charges was indicated by cell electrophoresis, the ratio dropped to 3.043 from 3.988, and their re-tardant ratio reached up to 31.2%. cAMP content in cells after this treatment, detected by cAMP and cGMP radioimmunoassay, was enhanced by 2.42 times, and cAMP/cGMP ratio, by 1.73 times. Thus, cAMP level within MGc80-3 cells was raised obviously by dBcAMP. Heterotransplantation experiments showed that tuntorigenic rate of MGc80-5 cells (transplanted subcutaneously to BALB/c mice) amounted to 100%, and that of the cells after this treatment was only 5.6%. Their tumorigenic ability was extremely reduced.These results confirmed that dBcAMP was able to change malignant phenotypic characteristics of MGc80-3 cells and produce a reversed alteration: Thus, it has a remarkable inductive effect in differentiating gastric carcinoma cells. All these characteristics were also considered as the reference indexes in appraising reversed effect for the homologous cancer cells.展开更多
There was no detectable expression of c-fos,but a little c-myc,high c-fms and mederate high IGF-ⅡmRNA in the untreated human hepatocarcinoma cell SMMC- 7721.After treatment with 10 μmol/L retinoic acid or 0.5 mmol/L...There was no detectable expression of c-fos,but a little c-myc,high c-fms and mederate high IGF-ⅡmRNA in the untreated human hepatocarcinoma cell SMMC- 7721.After treatment with 10 μmol/L retinoic acid or 0.5 mmol/L dibutyryl cyclic-3',5'adenosine monophosphate(db-cAMP),the c-fos was transiently expressed within 20- 60mins.If the treatment of RA or db-cAMP prolonged to 1-5 days, the transcriptions of c- myc were increased,reaching the highest level on the 2nd and 4th day.Simultaneously the transcriptions of c- fms and IGF- Ⅱwere gradually decreased.On the 5th day of the treatment,c-fms and IGF-ⅡmRNA were decreased to 32% and 14%respectively of the control (untreated cell) value by RA,and 35% and 22%respectively by db-cAMP.The biological significance of the above mentioned results was discussed.展开更多
Eight lines of temperature-responsive leaf colormutants induced by applying 300 Gy Gamma-ray irradiation to Thermo-sensitive genic malesterile line 2177s,were obtained through con-tinuous selection in seven generation...Eight lines of temperature-responsive leaf colormutants induced by applying 300 Gy Gamma-ray irradiation to Thermo-sensitive genic malesterile line 2177s,were obtained through con-tinuous selection in seven generations..Theleaves of these lines started to become greenafter the fourth leaf extension,and except展开更多
For the first time, the fertility of rice genic male sterile line was partially restored with the application of chemical regulators at Hainan Rice Breeding Nursery on Mar 1993. A single panicle of the rice plant coul...For the first time, the fertility of rice genic male sterile line was partially restored with the application of chemical regulators at Hainan Rice Breeding Nursery on Mar 1993. A single panicle of the rice plant could bear as many as 27 grains. The chemical agent that could modulate the growth of the rice plants of genic male sterile line was developed by Prof ZHOU Guangqia and his colleagues at the Biology Institute, Hunan Teachers University, China.展开更多
A new type of worm gearing, rolling cone enveloping worm gearing possessing high virtues of transmission, is presented. With theoretical deduction, numerical calculations and parameter analyses, the effect of prime pa...A new type of worm gearing, rolling cone enveloping worm gearing possessing high virtues of transmission, is presented. With theoretical deduction, numerical calculations and parameter analyses, the effect of prime parameters to the character of instantaneous contact line are obtained. The ranges of the main parameters are selected reasonably. It provides the theoretical basis for the structure design and application of this new type of worm gearing.展开更多
文摘For providing some experimental basis in establishing malignant phenotypic reversed indexes of gastric carcinoma cells, human gastric adenocar-cinoma cell line MGc80-3 was induced by dBcAMP in vitro to appraise the effect of gastric carcinoma cell differentiation by chemical inducers.Under light microscope, MGc80-3 cells, after treated with 1 mM dBcAMP, tended to be flat and disperse, and their volume gradually enlarged, with their uncleus relatively smaller and their shape rather regular. Morphological changes, like norma differentiated epithelial cells, were observed. The cells attached firmly, grew slowly, their growth curve showed inhibitory rate amounted to 52.87%, and cellular division exponent displayed their peak value 1.5 times less than that of MGc80-3 cells. It was clear that dBcAMP could effectively inhibit the multiplication activity of MGc80-3 cells. After dBcAMP treatment, remarkable changes of cell surface charges was indicated by cell electrophoresis, the ratio dropped to 3.043 from 3.988, and their re-tardant ratio reached up to 31.2%. cAMP content in cells after this treatment, detected by cAMP and cGMP radioimmunoassay, was enhanced by 2.42 times, and cAMP/cGMP ratio, by 1.73 times. Thus, cAMP level within MGc80-3 cells was raised obviously by dBcAMP. Heterotransplantation experiments showed that tuntorigenic rate of MGc80-5 cells (transplanted subcutaneously to BALB/c mice) amounted to 100%, and that of the cells after this treatment was only 5.6%. Their tumorigenic ability was extremely reduced.These results confirmed that dBcAMP was able to change malignant phenotypic characteristics of MGc80-3 cells and produce a reversed alteration: Thus, it has a remarkable inductive effect in differentiating gastric carcinoma cells. All these characteristics were also considered as the reference indexes in appraising reversed effect for the homologous cancer cells.
文摘There was no detectable expression of c-fos,but a little c-myc,high c-fms and mederate high IGF-ⅡmRNA in the untreated human hepatocarcinoma cell SMMC- 7721.After treatment with 10 μmol/L retinoic acid or 0.5 mmol/L dibutyryl cyclic-3',5'adenosine monophosphate(db-cAMP),the c-fos was transiently expressed within 20- 60mins.If the treatment of RA or db-cAMP prolonged to 1-5 days, the transcriptions of c- myc were increased,reaching the highest level on the 2nd and 4th day.Simultaneously the transcriptions of c- fms and IGF- Ⅱwere gradually decreased.On the 5th day of the treatment,c-fms and IGF-ⅡmRNA were decreased to 32% and 14%respectively of the control (untreated cell) value by RA,and 35% and 22%respectively by db-cAMP.The biological significance of the above mentioned results was discussed.
文摘Eight lines of temperature-responsive leaf colormutants induced by applying 300 Gy Gamma-ray irradiation to Thermo-sensitive genic malesterile line 2177s,were obtained through con-tinuous selection in seven generations..Theleaves of these lines started to become greenafter the fourth leaf extension,and except
文摘For the first time, the fertility of rice genic male sterile line was partially restored with the application of chemical regulators at Hainan Rice Breeding Nursery on Mar 1993. A single panicle of the rice plant could bear as many as 27 grains. The chemical agent that could modulate the growth of the rice plants of genic male sterile line was developed by Prof ZHOU Guangqia and his colleagues at the Biology Institute, Hunan Teachers University, China.
文摘A new type of worm gearing, rolling cone enveloping worm gearing possessing high virtues of transmission, is presented. With theoretical deduction, numerical calculations and parameter analyses, the effect of prime parameters to the character of instantaneous contact line are obtained. The ranges of the main parameters are selected reasonably. It provides the theoretical basis for the structure design and application of this new type of worm gearing.
