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Volume 12 (1987)
- Issue 6 Pages 509-
- Issue 5 Pages 407-
- Issue 4 Pages 317-
- Issue 3 Pages 225-
- Issue 2 Pages 141-
- Issue 1 Pages 1-
Volume 12, Issue 4
Displaying 1-10 of 10 articles from this issue
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Fumio Matsuzaki, Fumiko Harada, Yo-ichi Nabeshima, Yoshiaki Fujii-Kuri ...1987 Volume 12 Issue 4 Pages 317-325
Published: 1987
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThree β-tubulin isoforms, mβIb, MβIa and mβll, were detected by isoelectric focusing gel electrophoresis (IEF) in extracts of cultured cells of a mouse T cell lymphoma, L5178Y. To investigate the origin(s) of the isoforms, we have isolated cDNA clones encoding β-tubulin from a cDNA library prepared from poly (A)+ RNA of L5178Y cells. Seventeen cDNA clones carrying the entire coding sequences of β-tubulin were isolated and classified into two distinct isotypes, represented by two clones designated pMT27 and pMT49, according to the results of restriction mapping. On the basis of the nucleotide sequences of the two cDNAs, pMT27 and pMT49 were identified as mouse β-tubulin isotypes 3 and 5, respectively. By using in vitro translation products of hybrid-selected mRNAs and of the SP6 in vitro trans-cripts of the cDNAs, polypeptides encoded by the two cDNA clones were analyzed by IEF. We found that pMT27 and pMT 49 encode MβIb and MβIa, respectively. In addition, mβll was detected in translation products of mRNA specifically hybridized to pMT49, but not in those of the in vitro transcript of pMT49 DNA. These results suggest that mβll is the translation product of mRNA whose 3'-untranslated region is highly homologous to that of pMT49.View full abstractDownload PDF (4493K) -
Chu-tse Wu, Yu-zhi Wang, Fu-lu Liu, Kazuko Tsuneoka, Mikio Shikita1987 Volume 12 Issue 4 Pages 327-337
Published: 1987
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSTwo different types of colony-stimulating factors (CSF) were used to support the clonal growth of myeloid progenitor cells (CFUC) in semi-solid agar or viscous methylcellulose cultures of mouse bone marrow cells. The cultures stimulated for 5 days with RSP-2•P3 cell CSF (CSFRSP) contained mainly granulocyte colonies, whereas the cultures stimulated for 10 days with human urine CSF (CSFhu) contained mainly monocyte/macro-phage colonies. Four lines of study were carried out : 1) a kinetic study using combinations of the two types of CSFS in the same culture; 2) a study of transferring CFUC from the initial 3-day cultures to recipient cultures con-taining the same or different types of CSF; 3) an examination of the morpholo-gy over time of colonies that were confined by glass capillaries plunged in agar; and 4) electron microscopic observations on disintegrating granulocytes. The results of all these lines of study suggest that about one third of the CFUC can be stimulated both by CSFRSP and CSFhu while the other two thirds react specifically either with CSFRSP or with CSFhu. The present study also suggests that granulocytes in the culture stop proliferation and disintegrate while macrophages are still growing there. Thus, mixed-type colonies con-taining both macrophages and granulocytes later become macrophage colonies.View full abstractDownload PDF (4769K) -
Bernadette Bouchon, Masao Iwamori, Hiroshi Masago, Yoshitaka Nagai1987 Volume 12 Issue 4 Pages 339-344
Published: 1987
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSCholera toxin binding sites in frozen sections of rat thymus were studied by indirect immunofluorescence and were found to be localized selectively in the medulla of thymic lobules. By flow cytometric analysis, two populations of thymocytes differing in size and reactivity towards cholera toxin were detected; the small thymocytes comprising 15 % of the total thymo-cytes were found to express the receptor. The two kinds of cells isolated were not however, distinctly different in morphology. But ganglioside GM1, the cholera toxin binding site in the small thymocytes, when quantified by TLC-immunostaining, was contained at a higher concentration than in the large thymocytes. These results indicate that GM1 should be a useful marker for analysis of thymocyte differentiation, and that cholera toxin-mediated thymocyte proliferation might only occur in the small medullary thymocytes.View full abstractDownload PDF (3931K) -
Hiroshi Komada, Hiroshi Nakabayashi, Hiroshi Nakano, Hideki Takanari, ...1987 Volume 12 Issue 4 Pages 345-355
Published: 1987
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe uptake of free calcium ion (Ca2+) in PHA-or A23187-stimulated lymphocytes was measured using 45CaC12 and 3H-water. Augmen-tation of Ca2+ uptake by both mitogens was observed, but the enhanced uptake occured transiently, sometime within 30 min of the stimulation. The total amount of calcium in quiescent lymphocytes as determined by atomic absorption spectroscopy was about 2.9 x 10-15 g/cell. When stimulated with PHA, more calcium gradually accmulated in the cells. The maximum amount of accmulation occured at around 40 h, and was about 2-fold higher than that of control cells. In A23187-stimulated cells, the calcium content increased within 1 h by about 4-fold, reached a maximum at about 6 h (6-fold) and thereafter, surplus calcium was pumped out. The cytosolic free calcium ion concentration (the [Ca2+]i) within single cells was measured using quin 2 or fura-2. The [Ca2+]i was about 1×10-7 M, and a transient increase in the [Ca2+]i was observed around the 40th h, and the maximum expression of the IL-2 receptor was observed at about this time. Therefore the results may indicate that the IL-2-mediated lymphocyte transformation is dependent on the rise in the [Ca2+]i.View full abstractDownload PDF (1014K) -
Masazumi Yamamoto, Eiji Okimasu, Sigeo Terada, Kozo Utsumi1987 Volume 12 Issue 4 Pages 357-367
Published: 1987
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe stimulative effects of myristate on the superoxide gene-ation and depolarization of membrane potential of polymorphonuclear leukocytes (PMN) are particularly strong, yet myristate does not affect the intracellular free Ca2+ level ([Ca2+]i) in the presence of 1 μM free calcium in calcium-EGTA buffer. The half maximum concentration of myristate was 10μM. Myristate inhibited the transitory changes in [Ca2+]i induced by formylmethionyl-leucyl-phenylalanine (FMLP), but stimulated further the FMLP-induced superoxide generation; these effects are similar to those of phorbol myristate acetate (PMA). The myristate-induced superoxide gener-ation was partially inhibited by H-7, a specific inhibitor of protein kinase C. Myristate stimulated the activity of Ca2+-and phospholipid-dependent protein kinase (protein kinase C) in a concentration-dependent manner in the presence of 10-6 M Ca2+. The Ka was 100 μM. These results suggested that there is no relation between the superoxide generation and the [Ca2+]i change in PMNs and that the effects of myristate are similar to those of PMA against PMN.View full abstractDownload PDF (1057K) -
Shogo Nakamura, Hiroyoshi Takino, Manabu K. Kojima1987 Volume 12 Issue 4 Pages 369-374
Published: 1987
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSWe have found that Li+ causes the flagella of Chlamydomonas reinhardtii to elongate. After incubation with 50 mM Li+ for 3-4 hr, flagellar length increased to about 1.4 times the original length. However, the addition of 50 mM Li+ after flagellar amputation caused the regeneration of only half-length flagella, similar to those regenerated in the presence of 20 μg/ml cycloheximide. When regenerated flagella grown in the presence of either Li+ or cycloheximide were re-amputated, they did not regrow. These results suggest that (1) Li+ removes a suppressor(s) in the regulatory mechanism which normally controls flagellar length, (2) flagellar length may exceed a length-dependent "maximum" value (Tamm, S. L., 1967, J. Exp. Zool., 164, 163-186), and (3) Li+ inhibits the protein synthesis required for the complete regeneration of flagella. Thus, normal flagella elongate to 1.4 times their original length in the presence of 50 mM Li+ by using flagellar precursors from a preexisting cytoplasmic pool.View full abstractDownload PDF (522K) -
Koichi Nobori, Eiji Okimasu, Eisuke F. Sato, Kozo Utsumi1987 Volume 12 Issue 4 Pages 375-385
Published: 1987
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSMany cytoplasmic proteins, including Ca2+-and phospholipid-dependent protein kinase (protein kinase C) of polymorphonuclear leukocytes (PMNs) associate in Ca2+-dependent manner with phospholipid liposomes containing cardiolipin (CL), as in the case of phosphatidylserine (PS)-con-taining liposomes. A crude protein kinase C fraction was purified by association of the enzyme with CL-containing liposomes (flotation method). The partially purified protein kinase C from rat brain or guinea pig PMN was activated by the CL-containing liposomes in the presence of dioleoylglyc-erol (DG) and Ca2+. This activation was analogous to that of PS. The half maximum activity was obtained with 20 μM CL in the presence of 1μM Ca2+ and 5μM DG. Many of the cytoplasmic proteins which associate with CL-containing liposomes were preferentially phosphorylated by membrane-associated protein kinase C in the presence of DG and Ca2+. These results suggest that the association of cytoplasmic protein kinase C with the membrane has an important role in regulation of protein kinase C activity in relation to the association of other cytoplasmic proteins to the membrane.View full abstractDownload PDF (5673K) -
Maria de Nazareth Leal de Meirelles, Tania C. de Araujo Jorge, Wanderl ...1987 Volume 12 Issue 4 Pages 387-393
Published: 1987
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSParasite-containing endocytic vacuoles are formed during the process of in vitro interiorization of the trypomastigote forms of Trypanosoma cruzi by primary culture of mouse fibroblasts, heart and skeletal muscle cells. Fusion of these vacuoles with host cell lysosomes takes place. The process of T. cruzi-muscle cell interaction was analysed by ultrastructural cytochemistry. Two lysosomal enzymes, acid phosphatase and aryl sulphatase and the fusion of peroxidase-labeled secondary lysosomes with the parasito-phorus vacuoles were studied. These finding indicate that the basic mechanism of interaction of T. cruzi with the so called non phagocytic cells is similar to that whichoccurs with phagocytic cells.View full abstractDownload PDF (6120K) -
Motoyuki Sugai, Taira Enomoto, Yoichiro Miyake, Hidekazu Suginaka1987 Volume 12 Issue 4 Pages 395-399
Published: 1987
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe effect of extracellular products from Staphylococcus aureuson the differentiation of mouse epidermal cells was studied using an in vitro cell culture system. The extracellular products from a clinical strain of S. aureus isolated from human skin lesions reversibly inhibited the Ca++-induced terminal differentiation of epidermal cells, as determined by their morphology and the extent of cornified envelope formation. This suggests that a similar modification of cell differentiation is involved in the pathogenesis of S. aureus-induced skin disease.View full abstractDownload PDF (2091K) -
Masahiro Sato, Takashi Muramatsu1987 Volume 12 Issue 4 Pages 401-406
Published: 1987
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSBlastomeres isolated from 16-cell mouse embryos consist of larger cells and smaller cells. In the intact embryo, the larger cells tend to differentiate to the trophectoderm, while the smaller cells give rise to the inner cell mass. The mode of phenotypic alteration of isolated blastomeres from early 16-cell embryos was examined by culturing them as single cells in vitro. The smaller blastomeres showed an increased tendency to be engulfed, as revealed by aggregation experiments during a 15 h culture period just prior to division into the 32-cell stage, while the larger cells remained showing high engulfing activity during this period. The present result demonstrates that the smaller blastomere continues to adopt a selected differentiation program for a certain period, even after its environment is changed.View full abstractDownload PDF (2535K)
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