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Volume 1 (1975 - 1976･･･
- Issue 4 Pages 299-
- Issue 3 Pages 205-
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- Issue 1 Pages 1-
Volume 1, Issue 1
Displaying 1-15 of 15 articles from this issue
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James C.W. Chen, Kamiya Noburo1975 Volume 1 Issue 1 Pages 1-9
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSCytoplasmic streaming in the internodal cell of Nitella ceased quickly following the application of the SH-group modifying reagent Nethylmaleimide (NEM). Centrifugation and NEM application were combined in a single cell mounted in a double-chambered vessel. This arrangement made possible the separate treatment of the streaming endoplasm and stationary cortex with NEM. Streaming occurred normally when the endoplasm was kept intact while the cortex was treated with the reagent. In the reciprocal case, in which endoplasm was treated while cortex was untreated, no streaming occur-red. The results obtained suggest that myosin molecules are not intermingled with actin filaments localized on the cortex but reside in the endoplasm, since it is known that NEM inhibits actomyosin-type ATPase conspicuously while it has little effect on F-actin. It was tentatively concluded that the cytoplasmic streaming in Nitella results from the sliding of the endoplasmic myosin mole-cules alongside the stationary F-actin filaments lying on the cortex.View full abstractDownload PDF (985K) -
Kenzo Ohtsuka, Yuji Tonomura1975 Volume 1 Issue 1 Pages 11-21
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSHeart cells singly dissociated from mouse embryos were cul-tured at high (4 × 105 cells per plate) or low (0.5 × 105 cells per plate) density. After cultivation for one day, the percentages of beating cells were 51 % and 75 %, respectively, and the average beating rates were 39 beats/min (b/m) and 70 b/m, respectively. The average beating rate of single heart cells cultured at low density in the medium consisting of 3 parts of conditioned medium and 1 part of fresh medium was 72-85 b/m, while the value in the fresh medium was 40-57 b/m. Lung, kidney, skeletal muscle and L cells from mice, FL cells, chick embryonic cells and reptilian iguana heart cells were effective at high density in increasing both the percentage of beating cells and the average beating rate of mouse myocardial cells cultured at low density.View full abstractDownload PDF (3671K) -
I. Appearance of Hybrid Clones at High Frequency in a Short Period and Its Relation to Cell Fusion in Dictyostelium discoideumYoshio Fukui, Yasuko Miyake1975 Volume 1 Issue 1 Pages 23-31
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSParasexual hybrids of Dictyostelium discoideum were obtained at a high frequency of 10-2 to 10-3 when stationary phase cells in the primary culture were allowed to multiply secondarily before inoculating onto selective plates. This selection following secondary multiplication demonstrated that hybridization occurred even under standard culture conditions during primary culture. Progenies of the hybrid clones retained genetic markers originating from both parents in a recombined manner. Culturing cells with labelled and non-labelled nuclei together revealed that a certain portion of multinucleated cells appearing in the primary culture resulted from cell fusion. The fused cells gradually increased in number during the stationary phase of primary culture, and the frequency of their appearance was comparable to that of the genetic hybrids that arose in the secondary culture.View full abstractDownload PDF (998K) -
Miyako Saiki, Yukio Hiramoto1975 Volume 1 Issue 1 Pages 33-41
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSMixtures of calcium and EGTA [ethyleneglycol bis (β-amino- ethylether)-N, N'-tetraacetate] solution containing stabilized concentrations ofionized calcium (calcium buffers) were injected into ciliate Paramecium caudatum. Ciliary reversal was induced when the ionized calcium concentra- tion in the buffer was above a certain level. The threshold Ca2+ concentration for inducing ciliary reversal varied (10-6-10-8 M) by the pH of the buffer and by the medium surrounding the organism. From theoretical considerations and the experimental results, it was concluded that the threshold difference in Ca2+ concentration was due to insufficient pH-buffering action of the injected liquid and to differences in pH values in the protoplasm of the organism in different media. This conclusion is consistent with the result of the Triton-extracted model in which the threshold concentration of calcium ions for inducing ciliary reversal was 10-6 M. Injection of potassium citrate solution into the organism induced ciliary reversal. The implications of the latter result are discussed.View full abstractDownload PDF (887K) -
Kouichi Asami, Akiko Fujiwara, Ross L. Shoger, Ikuo Yasumasu1975 Volume 1 Issue 1 Pages 43-50
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSABSTRAKT. Phosphofructokinase from eggs of the sea urchin Hemicentrotus pulcherrimus was inhibited with ATP at concentrations above 0.2 mM. AMP, ADP, adenosine 3'5'-cyclic phosphate (cyclic AMP) and orthophosphate relieved the enzyme from the ATP-inhibited state. Cyclic AMP was the most effective compound among these agents. Phosphofructokinase activity was measured in the presence of these positive and negative effectors. Concentrations of the effectors were chosen to match the intracellular concentrations of sea urchin eggs at selected post-fertilization periods. The results suggested that changes in phosphofructokinase activity after fertilization were due to changes in the concentrations of these effectors, especially cyclic AMP.View full abstractDownload PDF (748K) -
Masanobu Miyahara, Kozo Utsumi1975 Volume 1 Issue 1 Pages 51-59
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe investigation was performed to examine the correlation between int amitochondrial potassium content and oxidative phosphorylation. The results indcated a parallel relationship among them. Endogenous potassium content was controlled by treating mitochondria with relatively small amounts of lead and magnesium. The lead-induced potassium release was accompanied by mitochondrial swelling and H+flux changes. Potassium depletion was also found in aged mitochondria together with decreased respiratory control and oxidative phosphorylation, but these parameters recovered after the addition of potassium ions. These results are discussed in relation to the role of potassium ions in mitochondrial functions.View full abstractDownload PDF (726K) -
Hiroto Naora1975 Volume 1 Issue 1 Pages 61-70
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSA crude enzyme preparation from "uninfected" rat livers can catalyze the synthesis of RNA when rat liver mRNA or nuclear RNA is added to the system. The newly synthesized RNA contains sequences comple-mentary to those of the RNA template and, after phenol extraction, is found to be partially hydrogen-bonded to the added poly (A)-containing RNA. The possibility of message amplification in normal cells is discussed.View full abstractDownload PDF (944K) -
Ken Higashi, Noriko Hanasaki, Koichi Shikichi, Minoru Kohno, Yuichi Ta ...1975 Volume 1 Issue 1 Pages 71-79
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSChromatin from isolated Ehrlich ascites tumor cell nucleoli was fractionated on a sucrose gradient to examine the distribution of ribosomal genes. The isolated nucleoli were treated with polyvinylsulphate, and then the ribonucleoprotein particles were extracted with 20 mM dithiothreitol in buffer solution. The chromatin was then solubilized by sonication in 10 mM Tris-HCl buffer (pH 8.0). Centrifugation of solubilized chromatin fraction on a sucrose gradient gave two peaks of chromatin containing approximately equal amounts of DNA, regardless of whether the sonication period was 20 sec or 40 sec. Peak I (which sedimented slower) had less RNA than peak II. Ribonucleoprotein particles appeared to merely cosediment with peak II because the profiles of DNA component differed from RNA. Therefore, the presence of ribonucleoprotein particles was probably not the primary cause of the rapid sedimentation of peak II. Examination of the distribution of ribosomal genes in the fractionated nucleolar chromatin by hybridization of DNA with 32P-labeled ribosomal RNA showed that peak I contained three times more ribosomal genes than peak II. Fractionation of DNA in the chromatin fractionsby CsCl equilibrium density gradient centrifugation showed that the profiles of DNA complimentary to ribosomal RNA in the two fractions were essentially similar, but that peak I contained more ribosomal genes than peak II.View full abstractDownload PDF (975K) -
M. Amano, B. Osogoe1975 Volume 1 Issue 1 Pages 81-92
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSLabeling patterns with generally labeled tritiated deoxy- cytidine ([G-3H]dCyd) in lymphoid tissues were quite different from those labeled with tritiated thymidine ([methyl-3H]dThd). Thymic cortex and ger-minal centers of lymph node, spleen and Peyer's patch were labeled intensely with 3HdCyd but only a few lymphocytes in medulla of thymus and medullary cords of lymph node labeled with 3HdThd. The incorporation of 3HdThd into DNA was reduced significantly in the thymic cortex and germinal center of lymphoid tissues by the simultaneous administration of nonradioactive dCyd. On the other hand, the autoradiographic intensity in the labeled lymphocytes in medullary cord of lymph node did not change by administrating nonradioactive dCyd. These results support the proposition that the metabolic activities of pyrimidine utilization for DNA synthesis differ within lymphocyte populations with respect to the specific sites of origin and development within the lymphoid tissues.View full abstractDownload PDF (17094K) -
Kazuhiko R. Utsumi, Tatsuya Tanaka1975 Volume 1 Issue 1 Pages 93-99
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSAn attempt was made to reveal the chromosomal structure of Raji cells by light microscopy after treatment with several kinds of hypotonic saline solutions. Among various concentrations of sodium citrate, 0.4 % solution was found suitable for analysis of chromatid spiral structures. Similareffects of uncoiling on chromatids were obtained by solutions of 0.81 % potassium citrate, 0.3 % potassium acetate, 0.74 % guanidine chloride and 0.78% Veronal buffer, and 1/6 isotonic solution of sodium chloride (0.15 %) and potassium chloride (0.18 %). The mode of uncoiling, however, was somewhat different from solution to solution probably reflecting the action of electrolytes on cellular permeability.View full abstractDownload PDF (2851K) -
I. Disappearance of Hemadsorption Activity and Movement of Viral AntigensIgnez Koseki, Yumiko Maeda, Yoshio Okada1975 Volume 1 Issue 1 Pages 101-109
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe fate of HVJ envelopes fused with Ehrlich ascites tumor cells was examined. On culture at 37°, the hemadsorption (HA) activity of the cells, which depended on the fused envelopes, disappeared within 4 hrs without liberation of the viral hemagglutinins into the medium. The viral antigens detectable on whole surface of fused cells also disappeared on culture. During this period a specific projection developed on the fused cells. Development of this projection was maximal after 4 hrs, when viral antigens had accumulated on it like a "cap". On further incubation, the fused cells became HA-positive again for 6 hrs and viral antigens reappeared on the whole of the cell surfaces. These were due to new growth of viral glycoproteins in the cells.
Both disappearance of HA and cap formation of viral antigens were dependent on temperature and pH. They occurred in cultures in Eagle's minimum essential medium with or without serum. In cultures in a buffered salt solution, decrease in the HA-activity was about 80 % of that in cultures in MEM, but the accumulation of viral antigens was very low. Sodium azide inhibited HA-disappearance and the cap formation. Monosaccharides had most effect and inhibited all these changes completely.View full abstractDownload PDF (6810K) -
Y. Kuroda1975 Volume 1 Issue 1 Pages 111-118
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe effect of intercellular materials on aggregation of dis-sociated embryonic quail liver cells was examined in rotation-mediated cellcultures in th presence and absence of the medium (dissociation medium) in which cells were dispersed. Transfer of cells to a fresh medium after removal of the dissociation medium resulted in the formation of smaller aggregates than incubation in the dissociation medium, but on addition of the dissociation medium to the fresh medium, the aggregate size was restored. Dissociation medium was not effective in enhancing cell aggregation in the presence of cycloheximide. The cell aggregate size depended on the length of trypsin treatment, with prolonged treatment resulting in smaller aggregates. This decrease in aggregate size with prolonged trypsin treatment was more marked in the presence of cycloheximide.View full abstractDownload PDF (2993K) -
Satimaru Seno, Akisuke Tanaka, Masako Urata, Koichi Hirata, Hisashi Na ...1975 Volume 1 Issue 1 Pages 119-127
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe purpose of the study was to examine whether the uptake of substances by Kupffer cells and capillary endothelial cells was related to the electrostatic charges of the substance. Morphologic observations were made on rat liver after introducing iron colloid particles of positive or negative charge with or without preliminary perfusion by Hanks' solution for removing blood. Iron colloid particles introduced into the portal vein without preliminary perfusion of Hanks' solution were taken up by Kupffer cells but not by capil-lary endothelial cells irrespective of the electrostatic charge, as revealed by Prussian blue reaction and by electron microscopy. In liver irrigated with Hanks' solution, the positive charged iron colloid particles were taken up by capillary endothelial cells, as well as by Kupffer cells. The negatively charged colloidal particles were taken up selectively by Kupffer cells but not by capillary endothelial cells. The mechanisms for the selective uptake of foreign sub-stances by reticuloendothelial cells and the pinocytic uptake of some sub-stances by capillary endothelial cells are discussed in relation to the electrostatic charge of the substances to which the cells show affinity.View full abstractDownload PDF (12112K) -
Yoshio Okada, Yasuhiro Hosaka, Kazufumi Shimizu, Katsuaki Matsui1975 Volume 1 Issue 1 Pages 129-132
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSAn envelope fraction free of nucleocapsids was reassembled from HVJ (hemag-glutinating virus of Japan, Sendai virus) virions solubilized with Nonidet P40 (4) or alkali-emasol (16). The procedure proved to be useful in place of ultraviolet-inactivated HVJ virions for fusion of cells in the formation of somatic hybrid cells.View full abstractDownload PDF (419K) -
Kozo Utsumi, Masanobu Miyahara, Masayasu Inoue, Masaharu Mori, Katsumi ...1975 Volume 1 Issue 1 Pages 133-136
Published: 1975
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (347K)
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