Cell cycle kinetic activity in the cortical cells of the lentil (Lens culinaris Me-die. cv. Verte du Puy) primary root during germination was examined both temporally and spatially. Immunohistochemical and cytological...Cell cycle kinetic activity in the cortical cells of the lentil (Lens culinaris Me-die. cv. Verte du Puy) primary root during germination was examined both temporally and spatially. Immunohistochemical and cytological evidence indicated that DNA replication and cell division started in the cortical cells of tire lentil primary root after around 13 and 17 h of imbibition, respectively. The first cells in DNA synthesis and the First mitotic figures all appeared in the cortical cells about I mm front the root-cap junction, but these divided cells had synthesized their DNA during the maturity of seed instead of during germination. The kinetic pattern of activity of the first cell cycle showed that these cells were not activated synchronously, but re-entered the cell cycle in turn depending on their places in the root tip, However, the adjacent cells partially synchronously proceeded their cell cycle.展开更多
Searching for more potent and less toxic HMBA related agents. Methods. Human erythroleukemia cell K562, murine erythroleukemia cell (MEL) and its sub line MEL DS19 were used as target cells to select a cell line which...Searching for more potent and less toxic HMBA related agents. Methods. Human erythroleukemia cell K562, murine erythroleukemia cell (MEL) and its sub line MEL DS19 were used as target cells to select a cell line which is the most sensitive to HMBA, then analyzed the activity of inducing differentiati on of two new designed HMBA derivatives: HMBPA [hexamethylenebi (3 pyridin) ami de] and Co HDTA (ethylenediaminetetra acetic acid cobalt) using cell biology, c ytochemical and molecular biology techniques. Results. We found that the MEL DS19 cells were most sensitive to HMBA (benzidine positive, B+～76%). Co HDTA can inhibit the growth of MEL DS19, but induces differentiation just in a small population (B+ 2%～4.5%). Between 0.02～5μmo l/L, HMBPA induces 3%～8% cells committed to differentiation with little inhib ition of cell proliferation. 1μmol/L HMBPA and 2mmol/L HMBA together, can obvio usly increase the percentage of differentiated cell (B+～ 72%), inhibit DNA sy nthesis and accelerate β globin transcription. Conclusion. The new HMBA derivatives may provide potential cancer differentiatio n inducers.展开更多
Intercellular communication of notochord cells during their differentiation was studied by microinjection of a fluorescent dye, Lucifer Yellow. Close correlation existed between the incidences of dye coupling and quan...Intercellular communication of notochord cells during their differentiation was studied by microinjection of a fluorescent dye, Lucifer Yellow. Close correlation existed between the incidences of dye coupling and quantitative evaluation of gap junctions. High incidences of dye coupling and of gap junctions occurred at a stage when notochord cells were active in the change of cell shape and cell arrangement. With the subsidence of cell movements, both dye coupling and gap junctions were reduced to lower levels. It was, therefore, suggested that intercellular communication via gap junctions played an important role in the coordination of notochord cell movements.Gap junctions of altered configuration occurred in notochord cells in late tailbud stage. The comparison of incidences of dye coupling at this stage with those at other stages strongly suggested that the gap junctions of altered configuration functioned just as those of generalized type.展开更多
The studies from 7 or 8 days old mice were used to prepare the spermatogonial stem cells. The isolation and purification of spermatogonial stem cells were done by means of the Percoll discontinual density gradient con...The studies from 7 or 8 days old mice were used to prepare the spermatogonial stem cells. The isolation and purification of spermatogonial stem cells were done by means of the Percoll discontinual density gradient concentration. The cells of the 3rd band were collected and cultured in vitro in DMEM supplemented with 2.5% or 10% fetal bovine serum （FBS）. The results showed that with the feeder layer and 2.5% serum, the spermatogonial stem cells could proliferate, differentiate last more than 4 months.展开更多
文摘Cell cycle kinetic activity in the cortical cells of the lentil (Lens culinaris Me-die. cv. Verte du Puy) primary root during germination was examined both temporally and spatially. Immunohistochemical and cytological evidence indicated that DNA replication and cell division started in the cortical cells of tire lentil primary root after around 13 and 17 h of imbibition, respectively. The first cells in DNA synthesis and the First mitotic figures all appeared in the cortical cells about I mm front the root-cap junction, but these divided cells had synthesized their DNA during the maturity of seed instead of during germination. The kinetic pattern of activity of the first cell cycle showed that these cells were not activated synchronously, but re-entered the cell cycle in turn depending on their places in the root tip, However, the adjacent cells partially synchronously proceeded their cell cycle.
文摘Searching for more potent and less toxic HMBA related agents. Methods. Human erythroleukemia cell K562, murine erythroleukemia cell (MEL) and its sub line MEL DS19 were used as target cells to select a cell line which is the most sensitive to HMBA, then analyzed the activity of inducing differentiati on of two new designed HMBA derivatives: HMBPA [hexamethylenebi (3 pyridin) ami de] and Co HDTA (ethylenediaminetetra acetic acid cobalt) using cell biology, c ytochemical and molecular biology techniques. Results. We found that the MEL DS19 cells were most sensitive to HMBA (benzidine positive, B+～76%). Co HDTA can inhibit the growth of MEL DS19, but induces differentiation just in a small population (B+ 2%～4.5%). Between 0.02～5μmo l/L, HMBPA induces 3%～8% cells committed to differentiation with little inhib ition of cell proliferation. 1μmol/L HMBPA and 2mmol/L HMBA together, can obvio usly increase the percentage of differentiated cell (B+～ 72%), inhibit DNA sy nthesis and accelerate β globin transcription. Conclusion. The new HMBA derivatives may provide potential cancer differentiatio n inducers.
文摘Intercellular communication of notochord cells during their differentiation was studied by microinjection of a fluorescent dye, Lucifer Yellow. Close correlation existed between the incidences of dye coupling and quantitative evaluation of gap junctions. High incidences of dye coupling and of gap junctions occurred at a stage when notochord cells were active in the change of cell shape and cell arrangement. With the subsidence of cell movements, both dye coupling and gap junctions were reduced to lower levels. It was, therefore, suggested that intercellular communication via gap junctions played an important role in the coordination of notochord cell movements.Gap junctions of altered configuration occurred in notochord cells in late tailbud stage. The comparison of incidences of dye coupling at this stage with those at other stages strongly suggested that the gap junctions of altered configuration functioned just as those of generalized type.
文摘The studies from 7 or 8 days old mice were used to prepare the spermatogonial stem cells. The isolation and purification of spermatogonial stem cells were done by means of the Percoll discontinual density gradient concentration. The cells of the 3rd band were collected and cultured in vitro in DMEM supplemented with 2.5% or 10% fetal bovine serum （FBS）. The results showed that with the feeder layer and 2.5% serum, the spermatogonial stem cells could proliferate, differentiate last more than 4 months.
