巻号一覧
10 巻 (1985)
- 4 号 p. 315-
- 3 号 p. 195-
- 2 号 p. 95-
- 1 号 p. 1-
10 巻, 1 号
選択された号の論文の10件中1～10を表示しています
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Toshikazu Nakamura, Akira Ichihara1985 年 10 巻 1 号 p. 1-16
発行日: 1985年
公開日: 2008/04/18
ジャーナル フリーSince methods to disperse and culture hepatocytes were devel-oped 15 years ago, numerous investigations have shown that primary cultures of mature hepatocytes retain most liver functions and respond as well to various hormones as those in vivo. Thus they are the most suitable system in vitro for studies on the liver. Moreover, recently it was found that differentiated hepatocytes in culture can grow under certain conditions and that this growth is regulated not only by several hormones, such as insulin, epidermal growth factor and serum growth factor, but also by a cell membrane factor and proteins in the environmental matrix through cell contact. This article describes the biochemical characterization of regulatory factors for hepatocyte growth and functions and their reciprocal expression. The mechanisms of liver regeneration, differentiation and carcinogenesis and the importance of the tissue architecture for these events are discussed mainly on the basis of our findings.抄録全体を表示PDF形式でダウンロード (1584K) -
Ichiro Kimura, Takayuki Hasegawa, Eijiro Ozawa1985 年 10 巻 1 号 p. 17-27
発行日: 1985年
公開日: 2008/04/18
ジャーナル フリーEvidence has been accumulating that transferrin (Tf), an iron-binding glycoprotein, is a unique ligand in that it is recycled intact. We ex-amined the properties of chicken Tf molecules recycled in a myogenic chicken cell culture. No difference in the isoelectric focusing pattern before and after recycling, nor any marked change in the total Tf concentration in the culture medium was found during culture. And, although recycled Tf had no myotrophic activity in vitro, it regained its original activity when reloaded with iron. These results are evidence of the molecular intactness of recycled Tf.抄録全体を表示PDF形式でダウンロード (5271K) -
Yasuaki Yoshimoto, Yukio Hiramoto1985 年 10 巻 1 号 p. 29-36
発行日: 1985年
公開日: 2008/04/18
ジャーナル フリーA cell model, in which cleavage could be induced, was obtained from fertilized sea urchin eggs by putting eggs that were in the first cleavage into a solution containing 3 × 10-5 g/ml saponin and suitable amounts of ATP and Ca2+. The cell membrane became freely permeable to ATP and Ca2+ within 1 minute. The respective optimal concentrations of ATP and Ca2+ that advanced the cleavage furrow in this model were 2 mM and 10-8 M. With the optimal ATP and Ca2+ concentrations, the cleavage furrow of the model advanced at a rate that differed little from that in living eggs. The cleavage furrow soon receded, however, when the concentration of ATP was decreased to less than 1 mM or increased to more than 3 mM, as well as when the concentration of Ca2+ was increased to more than 10-7 M.抄録全体を表示PDF形式でダウンロード (688K) -
Tsunetaka Ohta, Tsuyoshi Takasuka, Sadahiko Ishibashi, Toshinori Idei1985 年 10 巻 1 号 p. 37-46
発行日: 1985年
公開日: 2008/04/18
ジャーナル フリーWhen the growth of serum-arrested GC-7 cells, a clone from African green monkey kidney, was induced by the addition of 10 % calf serum, they began to enter S phase after 15-16 h. When stimulated cells were cultured in the presence of 0.6 μg/ml of cytochalasin D, the entrance into S phase was inhibited. Treatment of cells with cytochalasin D during the period earlier than 8 h or later than 11 h after the serum stimulation showed no or little inhibitory effect on the entrance of cells into S phase. Inhibition of the entrance into S phase was observed only when stimulated cells were treated with cytochalasin D during the periods including 9-10 h after stimulation. A rapid increase in protein synthesis occurred 9-12 h after the serum stimulation and was inhibited in the presence of cytochalasin D. These and other results suggested that in the course of the prereplicative process from Go through S phase only the stage around 9-10 h after the start of the cell cycle was sensitive to cytochalasin D and that the block of the cycle was correlated with the inhibition of protein synthesis at this stage.抄録全体を表示PDF形式でダウンロード (908K) -
Clonal Growth and Mesenchymal Differentiation of PCC3/A/1 Teratocarcinoma Cells in Serum-Free MediumTadao Atsumi, Takehiko Noguchi, Yoji Ikawa1985 年 10 巻 1 号 p. 47-54
発行日: 1985年
公開日: 2008/04/18
ジャーナル フリーClonal culture of PCC3/A/1 teratocarcinoma stem cells in serum-free medium has been achieved with feeder layers. Under this culture condition, stem cells effectively differentiated into various types of somatic cells, in particular chondrocytes and adipocytes. Myotubes and neuron-like cells also appeared, but infrequently. Embryonic endoderm cells were rarely observed. There appeared to be two stages in the differentiation process; In the early stage, only fibroblastic cells were found with the undifferentiated stem cells. In the later stage, chondrocytes and adipocytes predominated. Chondro-adipocyte differentiation occurred only after fibroblastic cell differentiation, an indication that fibroblastic cells may have an important function in chondro-adipocyte differentiation. Thus, the serum-free culture of PCC3/A/1 cells provides a suitable system with which to study the cell lineages and regulatory mechanisms of chondro-adipocyte differentiation.抄録全体を表示PDF形式でダウンロード (818K) -
Fumio Sawada1985 年 10 巻 1 号 p. 55-62
発行日: 1985年
公開日: 2008/04/18
ジャーナル フリーThe RNA polymerase activities of the soluble enzymes from the nuclear and cytoplasmic fractions from synchronous macroplasmodia of Physarum polycephalum were measured. Activity in the nuclear fraction pre-pared from cells in the G2 phase was several times higher than that at metaphase, and activity in the cytoplasmic fraction was much higher at metaphase than in the G2 phase. The amount of activity was nearly constnat during the late G2 phase and early prophase, then rose abruptly just before metaphase, becoming tenfold higher at metaphase then decreasing rapidly during anaphase-telophase. The cytoplasmic activity at metaphase was attrib-uted almost exclusively to the type II (or B) enzyme as shown by a-amanitin inhibition and chromatographic analysis of the enzyme. Results indicate that at metaphase RNA polymerase II molecules are loosely associated with con-densed chromosomes or that they move from the mitotic nuclei into the cytoplasm.抄録全体を表示PDF形式でダウンロード (767K) -
Tatsuomi Matsuoka, Yoshinobu Shigenaka, Yutaka Naitoh1985 年 10 巻 1 号 p. 63-70
発行日: 1985年
公開日: 2008/04/18
ジャーナル フリーIn the large heliozoan Echinosphaerium, contractile tubules (formerly called X-bodies) are located between the axopodial membrane and the axonemal microtubules. When axopodial contraction occurs, the tubules have been thought to be transformed from a tubular to a granular form, as seen in ultra-thin sections. Our detailed morphological observations of the contractile tubules, however, have revealed that this so-called granulation of the contractile tubules is mediated by self-twisting and supercoiling during contraction. We also examined the localization of calcium during axopodial contraction using a potassium pyroantimonate assay. Ca-Sb deposits were detected on contractile tubules only during the twisting and coiling of this organelle. Our results indicate that axopodial contraction is enforced by the twisting and coiling of contractile tubules, which action probably is mediated by Ca2+ ions.抄録全体を表示PDF形式でダウンロード (9993K) -
Kimiko Nishizawa, Kiyohide Kojima, Chikako Sato1985 年 10 巻 1 号 p. 71-78
発行日: 1985年
公開日: 2008/04/18
ジャーナル フリーRounded mitotic cells showed 30 % enhanced electrophoretic mobility (EPM) when compared to spindle-formed interphase cells. This in-crease in EPM that was not present in interphase cells that had been rounded chemically by EDTA is considered to reflect a structural change in the cell membrane during mitosis. X-ray irradiation induced a dose-dependent EPM decrease in both interphase and mitotic cells during a 4-hour period. During the next 20 h of incubation, EPM recovery took place in cells irradiated with 250R, but not in cells exposed to 1000R. EPM was enhanced during mitosis in cells irradiated with low doses, but was absent in cells irradiated with 1000R. The ratio of colony-forming cells and of electrophoretically recovered mitotic cells after 24 h of exposure showed a good statistical correlation. These results indicate that unrepaired membrane damage contributes to mitotic cell death after irradiation.抄録全体を表示PDF形式でダウンロード (840K) -
Hidetaro Yasumitsu, Fumio Hanaoka, Hideyo Yasuda, Yasufumi Murakami, T ...1985 年 10 巻 1 号 p. 79-88
発行日: 1985年
公開日: 2008/04/18
ジャーナル フリーA temperature-sensitive mutant, designated tsFT101, was isolated from a mousemammarycarcinomacellline, FM3A, andgivenan initial characterization. In this cell line, cytokinesis was blocked at a nonpermissive temperature (39°C), but DNA synthesis and nuclear division proceeded normally for at least 24 h at 39°C as detected respectively by autoradiography and cytofluorometric analysis. As a result, multinucleate cells accumulated at 39°C (more than 95 % in 36 h). When the culture was returned to a permissive temperature (33°C) after 24 h of arrest at 39°C, cytokinesis was resumed and there was a rapid decrease in the number of multinucleate cells. At 39°C, tsFT101 cells had less F-actin than cells at 33°C, indicative of the existence of an abnormality in actin polymerization in this mutant.抄録全体を表示PDF形式でダウンロード (3369K) -
Tetsuro Ishii, Takeshi Todoroki, Akira Takada, Yoshiki Sugita1985 年 10 巻 1 号 p. 89-93
発行日: 1985年
公開日: 2008/04/18
ジャーナル フリーMouse lymphoma L1210 cells (NCI line) that have low ability to take up cystine became deficient in cellular cysteine and glutathione in normal culture media. The cells entered the resting state during culture when they were seeded at high cell densities. They remained viable and were mostly present in the G1 or GO phase. In the growth-arrested state, the cellular glutathione content was one order of magnitude lower than in the exponentially growing phase in the presence of 2-mercaptoethanol. In the arrested state, DNA synthesis was almost inhibited, and RNA and protein synthesis decreased markedly. Transfer of the cells to medium containing 2-mercaptoethanol, which improves the utilization of cystine by these cells, produced the rapid recovery of RNA and protein synthesis. DNA synthesis slowly increased, reaching a maximum after a lag period.抄録全体を表示PDF形式でダウンロード (518K)
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