All issues
Volume 13 (1988)
- Issue 6 Pages 459-
- Issue 5 Pages 359-
- Issue 4 Pages 271-
- Issue 3 Pages 193-
- Issue 2 Pages 105-
- Issue 1 Pages 1-
Volume 13, Issue 4
Displaying 1-7 of 7 articles from this issue
- |<
- <
- 1
- >
- >|
-
Hiroto Kuga, Akira Matsuno1988 Volume 13 Issue 4 Pages 271-279
Published: 1988
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe brachiopoda, Lingula unguis, has a pair of anterior adduc-tors located in the center of the shell. Each muscle consists of an opaque and a translucent portion which is constructed of smooth and obliquely-striated muscle respectively.
According to our ultrastructural observations, the opaque portion seems to have two types of cells. They differ only in the diameters of their thick myofilaments. The fine structure of their cell organelles resembles each other. We measured the diameters of the thick myofilaments in each type of cell to distinguish between the two cell types. About 500 measurements of myofila-ment diameters were made for each type of cell and statistically analyzed. For one type of cell, the distribution of diameters of the thick myofilaments fit a normal distribution curve with a peak at 37-60 nm. The distribution of diameters of the thick myofilaments for the other type fit a curve in which two normal distribution curves having peaks at 37-60 and 75-97 nm respectively partially overlapped. According to these results, we suggest that the opaque portion contains two types of cells, each having a different distribution of thick myofilament sizes.View full abstractDownload PDF (1100K) -
Takemi Yatohgo, Masako Izumi, Heihachiro Kashiwagi, Masao Hayashi1988 Volume 13 Issue 4 Pages 281-292
Published: 1988
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe glycoprotein vitronectin (also called S-protein, serum spreading factor, or epibolin) promotes spreading of a variety of cultured cells, inhibits the cytotoxicity of membrane attack complex C5b-9, and modulates thrombin-antithrombin III activity. We developed a strikingly simple method to purify vitronectin from human plasma by heparin affinity chromatography. Serum was obtained from plasma by adding calcium and then centrifuging. The heparin-binding activitiy of vitronectin in human serum was activated with 8 M urea. The activated vitronectin specifically bound to heparin-Sepharose in 8 M urea and was eluted with 0.5 M NaCl containing 8M urea. This procedure resulted in an approximately 250-fold purification of vitronectin with a 15-30% recovery; 3-6 mg of pure vitronectin were obtained from 100 ml human plasma within 2 days. The purified vitronectin preparations promoted spreading of BHK fibroblastic cells on substrates with a half-maximal activity at only 0.1 //g/ml. This new method is very simple, rapid, inexpensive, and flexible. It could probably be readily scaled up for commercial applications.View full abstractDownload PDF (1272K) -
Yasuko Watanabe, Masami Taniguchi, Nobuko Fukamachi, Bonro Kobayashi1988 Volume 13 Issue 4 Pages 293-300
Published: 1988
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSBovine brain gangliosides were applied to primary cultures of murine bone marrow cells to examine the role of gangliosides in development of megakaryocytes. Megakaryocytes in the cultures were detected by staining for a cytoplasmic enzyme, acetylcholinesterase, and divided into two types, 1) immature megakaryocytes which were stained less intensely, and 2) mature ones which were stained intensely. A medium containing total ganglioside fraction from bovine brain increased the number of both immature and mature megakaryocytes in the presence of pokeweed mitogen-stimulated murine spleen cell conditioned medium. Between the two cell types, the number of the mature cells was more significantly increased than the immature cells. The ganglioside GDla could substitute for the total ganglioside mixture. The results suggested that bovine brain gangliosides potentiated both megakaryocytic proliferation and maturation in vitro.View full abstractDownload PDF (811K) -
Fernando Costa e Silva Filho, Wanderley de Souza1988 Volume 13 Issue 4 Pages 301-310
Published: 1988
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe Madin-Darby canine kidney epithelial cell line (MDCK) was used as a model for trichomonad-host cell interaction. Two laboratory strains of the human parasite Trichomonas vaginalis and the cattle's parasite Tritrichomonas foetus or their supernatants from axenic cultures were allowed to interact with confluent epithelial cultures. The interaction process studied by transmission and scanning electron microscopy revealed that both parasites adhere to monolayers through flagella, cell body and particularly for T. foetus, through the posterior projection of the axostyle. A close contact region between the trichomonad's surface and MDCK cells was observed. A study of the involvement of trichomonad surface component in the interaction process indicated that cytochalasin B treated-parasites adhere much less to epithelial monolayers than untreated parasites. Colchicine treatment did not affect such adhesion. Treatment of the parasites with trypsin reduced the adhesion of trichomonads to monolayers but did not interfere with the cytopathic effect. In contrast, treatment of the parasites with neuraminidase did not interfere with their adhesion to epithelial cells and the monolayer destruction was further increased.View full abstractDownload PDF (1193K) -
Tamotsu Yoshimori, Yasutsugu Shimonishi, Tsuyoshi Uchida1988 Volume 13 Issue 4 Pages 311-324
Published: 1988
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSHybridomas secreting monoclonal antibodies to transferrin receptor (TFR) were isolated. One of these antibodies, U-1, recognized the cytoplasmic domain of TFR and the others, N-2 and W-3, recognized its cell surface domains. Only antibody W-3 competed with transferrin (TF) for binding to TFR. Antibody U-1 bound to purified TFR but not to 35S-or 125I-TFR in cell extracts. 125I-Antibody U-1 bound to TFR alone in cell extracts when TFR was bound to antibody N-2-Sepharose 4B, but even in the presense of cell extracts it did not bind to TFR bound to antibody W-3-Sepharose 4B. Antibody W-3 co-precipitated TFR and a protein of about 30 kDa from cell extracts, and also reacted with the 30 kDa protein in cell extracts in the absence of TFR. Based on these results, the existence of two different states of the cytoplasmic domain of TFR is discussed.View full abstractDownload PDF (1571K) -
Katsuyuki Imai1988 Volume 13 Issue 4 Pages 325-332
Published: 1988
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSβ-Glucosidase was purified from lysosomal membranes isolated from rat liver. Binding and uptake of the purified β-glucosidase were mediated via an apparently single binding site on rat peritoneal macrophages. The number of sites and the Kd were 4.20 x 104/cell and 1.00 x 10-7 M, respec-tively. Neither of the processes was inhibited by ligands for mannose/fucose receptors, mannose 6-phosphate receptors, or scavenger receptors, or by other glycoproteins and sugar compounds. A portion of the β-glucosidase taken up into the macrophages was degraded rapidly. These results suggested that liver lysosomal β-glucosidase was endocytosed via a receptor not previously described.View full abstractDownload PDF (686K) -
S.S. Han, A.P. Gupta1988 Volume 13 Issue 4 Pages 333-343
Published: 1988
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe German cockroach, Blattella germanica (L.) (Dic-tyoptera: Blattellidae) has two major immunocytes (blood cells) (granulocytes (GRs) and plasmatocytes). The GRs participate both in encapsulation and phagocytosis of nonself tissue. Structurally, the GRs are flattened and discoid, and contain, among other organelles, microtubules that are arranged in the form of a bundle in their peripheral region in the plane of flattening. If one implants a foreign tissue in the cockroach's abdomen, the GRs become activated and begin to encapsulate the implant by flattening and wrapping around it. The activated GRs show considerable increase in the number of both the microtubules and the nuclear pores of the nuclear envelope. Such structural changes in an activated arthropod immunocyte and their functional significance in its immune reaction against a foreign tissue have not been previously reported. We believe that the large number of microtubules is necessary not only to maintain the flattened nature of the GRs, but also to ensure the formation of an effective capsule against the deforming and shearing forces of the foreign tissue. And to keep up with the rapid assembly of new microtubules during encapsulation, the nucleus apparently triggers the synthesis of tubulin via ribosomes, its nuclear pores serving as channels for molecular transport to and from the nucleus. A structural and functional analogy between GRs and human platelet has also been suggested.View full abstractDownload PDF (1587K)
- |<
- <
- 1
- >
- >|