Cell Structure and Function

Dislocation of Sialic Acid on Erythrocytes Membrane by nesthetics and its Blocking by SH-reagents, Colchicine r Cytochalasin B

Chikako Sato, Kiyohide Kojima, Kimiko Nishizawa, Kazuya Sato

1978 Volume 3 Issue 3 Pages 145-151
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.145

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The cell electrophoretic mobility of rat erythrocytes decreased by treatment with thiopental or droperidol (intravenous anesthetics) at clinical concentrations. The amount of sialic acid, the main determinant of electrophoretic mobility, was not changed by the anesthetics. By using phosphate buffers of different ionic strengths, which determines the effective thickness of the ionic layer for electrophoretic mobility, translocation of sialic acid from the most peripheral zone to a deeper zone was suggested. When mobility recovered by washing out of the drugs followed by subsequent incubation, sialic acid was restored to the peripheral zone. The decrease in mobility was inhibited by sulfhydryl-blocking agents and disulfide-bridging agent. Cytochalasin B and colchicine completely blocked the mobility reduction when used single, but not when used simultaneously. These results suggest conformational changes of membrane sialoprotein by anesthetics involving sulfhydryls and cytochalasin B-and colchicine-sensitive proteins.

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The Cell Cycle in the Fission Yeast, Schizosaccharomyces pombe.II. Recovery Mode of the Period of a Cycle Extended by Pulse Treatment with Hydroxyurea.

Miyata Hisao, Miyata Machiko, Ito Michio

1978 Volume 3 Issue 3 Pages 153-159
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.153

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Extension of the cell cycle by inhibition of DNA synthesis with 8 mM hydroxyurea in fission yeast, Schizosaccharomyces pombe, shortened the duration of successive cycles. The presence of the inhibitor did not interfere with elongation of the yeast cell, but did cause a delay in septation, depending on the exposure period of cells to the inhibitor. A short delay e.g. within 1/3 of the normal cycle time, was fully recovered during the next cell cycle. When the period was more than about 1/3 of normal, the delay was not recovered in the next cycle which was shortened by about 1/3 the normal time. The succeeding cycle(s) was also shortened to compensate for the delay. The initial delay was equivalent to the total of shortened periods during successive cycles. The perturbed cycle thus finally returned to the normal length.

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On Correlation between Gland Stiffness and Cell Coupling in Salivary Gland of Chironomus plumosus Larva

Kazuo Suzuki, Manas Sangworasil, Shoji Higashino

1978 Volume 3 Issue 3 Pages 161-172
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.161

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A correlation between gland stiffness and electrical cell coupling in the salivary gland of Chironomus plumosus was studied by electrophysiological and mechanical measurements. Local anaesthetics, such as alcohols, procaine and chlorpromazine increased gland stiffness. On the other hand, agents influencing cell membrane components, such as glycoletherdiaminetetraacetic acid (EGTA), lipase, trypsin, butylic acid and tetraethylammonium (TEA) decreased gland stiffness. These agents all produced intercellular uncoupling at high concentrations. Alkaline and low medium temperature led to increased gland stiffness and junctional uncoupling. Acid and high medium temperature induced decreased gland stiffness and junctional uncoupling. It was found that gland stiffness had an optimum range (11-27 dyne/cm) for maintenance of cell coupling.

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Coupled Increases in Nuclear and Nucleolar Sizes with the Cell Phase Transition in the Cell Cycle of Physarum polycephalum

Shinji Matsumoto, Hiromi Funakoshi

1978 Volume 3 Issue 3 Pages 173-179
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.173

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The dependence of nuclear growth on cell stages in the mitotic cycle was investigated in plasmodia of Physarum polycephalum. Nuclei were photographed and the areas of nuclei and nucleoli were measured. Parallel changes in the increase curves of the nuclear and nucleolar areas were observed.Both sizes increased considerably after the S to G2 and the G2 to M phase transitions. Curves for increases in both sizes were also obtained from shortened mitotic cycles after UV-irradiation during incubation with or without nutrients. These curves were similar to those of corresponding controls. Increases in nuclear and nucleolar size seem to be highly coordinated with the progress of the cell stage rather than with increases in synthetic cellular activities. Furthermore, the protein and RNA contents were determined for nucleoli isolated during the cell cycle. The ratio of RNA to protein increased with the progress of age in the cell cycle.

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Extraction of Contractile Protein from Myxoamoebae of Physarum polycephalum

Machiko Taniguchi, Kimiko Yamazaki, Jiro Ohta

1978 Volume 3 Issue 3 Pages 181-190
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.181

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Contractile protein (myosin B) was isolated from myxoamoebae (haploid vegetative phase) of Physarum polycephalum. Myxoamoeba myosin B showed properties similar to those of natural actomyosin (myosin B) from muscle. Myxoamoeba myosin B appeared similar to myosin B of smooth muscle and non-muscle cells than to that of skeletal muscle, on the basis of quantitative characteristics and presence of only two light chains.
Myosin B isolated from myxoamoebae had almost the same properties asmyosin B from plasmodia (diploid vegetative phase of Physarum). On SDS-gel electrophoresis, identical to actin and myosin subunits of myxoamoeba werethose of the plasmodium. The apparent particle length of myxoamoeba myosin B was 0.62 to 0.55 μm, which was shorter than that of natural muscle actomyosin. Short length particles were also observed in plasmodium preparations. Some differences in ATPase activity were observed between myxoamoeba and plasmodium.

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Rearrangement of Tonofilament-like Intermediate Filaments in the Spreading Proc ss of JTC-12 Cells as Studied by Microscopy, Electron

Masayoshi Kaiho, Atsushige Sato

1978 Volume 3 Issue 3 Pages 191-198
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.191

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A_BSTRACT. Tonofilament-like intermediate filaments measuring 60-90 Å in diameter were observed in the cytoplasm of the epithelial cell JTC-12, a cell line derived from the kidney of a healthy monkey. In flattened cells, the filaments were in compact bundles which traversed the cytoplasm in parallel to the substratum, and the bundles branched and interconnected at places. In suspended spherical cells after trypsinization, free filaments or short strands of bundles were scattered throughout the cytoplasm in random orientation. In the spreading process, the arrangement of the filaments was restored to order. The growth of bundles occurred by addition of free filaments and by fusion of thinner and shorter bundles. In view of its reorganization and developmental pattern, the 60-90 Å filament system was suggested as playing a role in maintaining the flattened cell Shape.

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Ion Exchange Dish as a Tool for Cell Separation Based on Cell Surface Charge

Shoshi Inooka

1978 Volume 3 Issue 3 Pages 199-207
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.199

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Methods of animal cell separation were studied based on cell surface charge. An ion exchange dish was devised by the author by coupling DEAE-or CM-Sephadex beads with polyacrylamide gel. Binding was shown of various animal cells to DEAE-Sephadex beads in the devised dish. The dissociation of bound mouse spleen lymphocytes was then examined using various reagents. More than 60 % of adsorbed cells were dissociated by addition of a mixed solution of sodium citrate and Tween 80 with no detectable decrease in cell viability. The actual recovery of bound cells was also tested, and the stepflow method for elution was useful with solution containing sodium citrate, Tween 80, polybrene and EDTA at various concentrations of NaCl. The possibility of cell separation based on differences in cell surface charges was demonstrated in some cells.

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Studies on the Cell Division of Heliozoans II. Active Role of Axopodia on Division Process and Transformation of Remnants of Cytoplasmic Connecting Bridge to New Axopodia

Toshinobu Suzaki, Voshinobu Shigenaka, Yumi Takeda

1978 Volume 3 Issue 3 Pages 209-218
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.209

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The cell division of Echinosphaerium nucleofilum, strain MA, was carefully observed under differential interference optics and a polarizing microscope, by using a microchamber for side-viewing. The results were as follows : (i) organisms undergoing cell division always exhibited intensive adhesion to the glass substratum with remarkably shortened, supporting axopodia; (ii) motive force generated during cell division was considered to be derived mainly from retraction of supporting and leading axopodia located at both ends of the just-dividing organism; (iii) poly-L-lysine-coated substratum enhanced cell adhesion considerably but did not appear to result in cell division ; and (iv) remnants of cytoplasmic connecting bridges were often observed transformed to new axopodia, in which the filamentous structures showed positive birefringence.

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Effects of Cholesterol and Cholesterol Esters on Cell Function I. Incorporation of Free Cholesterol and Cholesterol Oleate into the Cell Membrane and its Effects on Membrane Fluidity, Membrane Fragility and DNA Synthesis

Mitsuko Naito

1978 Volume 3 Issue 3 Pages 219-226
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.219

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The incorporation of cholesterol oleate and free cholesterol into the cells was observed by incubating them with the ¹⁴C-labeled compounds in vitro. Free cholesterol and cholesterol oleate were incorporated into the cytoplasmic membrane of Ehrlich ascites tumor cells (EATC) and human red blood cells (RBC). The oleate ester was taken up by cells faster than was free cholesterold. The resistance to osmotic hemolysis of RBC incubated with cholesterol oleate for 20 minutes increased but cells incubated with free cholesterol for the same period showed no increase in osmotic resistance. Cholesterol oleate strikingly suppressed FITC-Con A cap formation of EATC but free cholesterol had much less effect. Both free cholesterol and cholesterol oleate suppressed DNA synthesis or 3H-thymidine uptake of EATC, though the oleate ester had a much stronger effect than free cholesterol.

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Effects of Cholesterol and Cholesterol Esters on Cell FunctionII. The Effects of Various Cholesterol Esters on the Cell Membrane and Related Functions

Naito Mitsuko

1978 Volume 3 Issue 3 Pages 227-235
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.227

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Effects of different cholesterol-fatty acid esters and free cholesterol were observed in vitro on membrane-related functions in human red blood cells (RBC) and Ehrlich ascites tumor cells (EATC). The esters used were acetate, oleate, linoleate, linolenate, palmitate and stearate. All these cholesterol esters were superior to free cholesterol in suppression of osmotic red cell fragility and of EATC cap formation and its DNA synthesis or 3H-thymidine incorporation. Of these esters cholesterol linoleate, linolenate and palmitateweremoreeffective.Inlong term incubation, however, free cholesterol showed nearly the same biological activity as cholesterol esters. The possible mechanism controlling the outstanding effects of cholesterol ester on cell functions was discussed.

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Enhancement of Chondrogenesis of Cultured Quail Limb Bud Mesenchymal Cells by Cellophane Films

Etsuya Matsutani, Yukiaki Kuroda

1978 Volume 3 Issue 3 Pages 237-248
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.237

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Cultures of mesenchymal cells dissociated from the hind limb buds of 3.5 day quail embryos (stages 22-23) were used to study the effect of the cellular microenvironment on chondrogenesis. The degree of chondrogenesis in cultures was estimated by two methods : the number of cartilage nodules (characteristic structures formed by chondrocytes) was counted under a phasecontrast microscope, and the amount of toluidine blue absorbed into the extracellular matrix of chondrocytes was measured by spectrophotometry. Aculture technique with cellophane films was devised to establish a suitable microenvironment for culture. When mesenchymal cells were cultured by thistechnique, chondrogenesis was much greater than in usual cultures without cellophane films. Examinations of differences between cultures with and without films indicated that cellophane films promoted differentiation of mesenchymal cells, by the accumulation of some effective factor(s) in culture medium.

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Sister Chromatid Exchanges and Chromosome Aberrations Induced by Chemical Agents in L5178Y Cells

Akira Sono, Kazuhiko Matsumoto, Kazuo Hayano, Kengo Sakaguchi

1978 Volume 3 Issue 3 Pages 249-254
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.249

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Bredinin, a new cytotoxic antibiotic, induced chromosome aberrations and sister chromatid exchanges in L5178Y cells. The respective maximum sensitivity occurred about the late S and middle S phases of the cell cycle. Bredinin enhanced sister chromatid exchanges when added to ethylmethanesulfonate, but caffeine had little effect. The sister chromatid exchanges induced by bredinin are discussed in relation to formation of chromosome aberrations.

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Different Utilization of Deoxycytidine as DNA-Thymine in Lymphoid Tissues of the Mouse

Kiyohiro Hamatani, Minoru Amano

1978 Volume 3 Issue 3 Pages 255-257
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.255

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Small pieces of tissues were cut and homogenized in an appropriate volume of 2 M NaCl. Pure, highly polymerized DNA was extracted after RNase and protease treatment from the homogenate of lymphoid tissues of mouse. The extracted DNA contained no detectable RNA, and the yields ranged from 30 % to 70 % of DNA in the starting material. Using pure DNA extracted by this method, the rate of [G-3H]deoxycytidine incorporation into cytosine and thymine of DNA in thymus was different from that in mesenteric lymph nodes in mouse after administration of [G-31-1]deoxycytidine. Thus, the utilization of deoxycytidine as DNA-thymine was differed between the thymus and mesenteric lymph nodes in the mouse.

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Measurement of Intracellular Free Calcium Concentration of the Starfish Egg by Means of the Microiniection of Aequorin

Yukihisa Hamaguchi, Issei Mabuchi

1978 Volume 3 Issue 3 Pages 259-263
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.259

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Intracellular free calcium concentration was measured in the starfish egg by the luminescence intensity of aequorin microinjected into the cell. In oocyte with a germinal vesicle, the free calcium concentration was about 1.7 p, M in Asterias amurensis and 0.25 p, M or less in Asterina pectinifera. The free calcium concentration was lower in oocyte after disappearance of the germinal vesicle than in oocyte with a germinal vesicle. The starfish egg may have a mechanism for maintaining intracellular free calcium concentration below about 1.7 p, M.

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Spitzenkorper' in the Invasive Pseudohyphae of Candida albicans

K.C. Rajasingham, R.A. Cawson

1978 Volume 3 Issue 3 Pages 265-267
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.265

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Ultrastructural investigation of the invasive phase of Candida albicans has brought to light densely staining, apical bodies or 'SpitzenkOrper' which are most likely to be concerned with the apical extension of the fungus.

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Effect of Growth Conditions on Ribosome Profile in Mouse Ascites Tumor Cells

Masazumi Sameshima, Mitsuo Izawa

1978 Volume 3 Issue 3 Pages 269-273
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.269

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In mouse ascites tumor cells, one subcomponent of native small ribosomal subunits having a buoyant density at 1.46 g/cm3 was capable of binding to poly U. A small amount of polysomes and the simultaneous incorporation into polysomes of both newly formed small and large subunits were observed in tumor cell grown in peritoneal cavity in vivo. Cells incubated in defined medium in vitro, showed a large proportion of polysomes and the earlier appearance of small subunits rather than large ones in polysome fraction. A decrease of 1.46 g/cm3 particle was also characteristic of cells grown in vitro. The correlation of the amount of particles with polysome and ribosomal subunit profile is discussed in different growth conditions.

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Fusion of Dissociated Embryonic Cells in the Teleost, Oryzias latipes III. Nuclear Fusion during Interphase in the Fused Cells

Setsuro Mizukami

1978 Volume 3 Issue 3 Pages 275-277
Published: 1978
Released on J-STAGE: April 18, 2008

DOIhttps://doi.org/10.1247/csf.3.275

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Blastomeres were mechanically dissociated in normal saline solution from blastula stage eggs of the medaka, Oryzias latipes. When isolated embryonic cells were brought into physical contact within 30 seconds of dissociation, cell fusion could be induced in more than half of the paired cells. In these fused cells, the two nuclei coalesced during interphase. This direct nuclear fusion was highly reproducible and was observed in 29 of 50 fused cells. Following cell division, the mononucleated cell divided either into four daughter cells with one nucleus each or into two cells each with two nuclei.

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