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Biomedical subjects

K Tsukamoto

Publications and source records attributed to K Tsukamoto.

At least 289 records · Page 16Linked to original sources

Comparison of the biological properties of purified natural and recombinant human interleukin-2.

We compared the biological properties of the purified recombinant human IL-2 derived from E. coli with those of purified natural IL-2. Both had almost the same specific in vitro activities on a weight basis to support long-term proliferation of IL-2 dependent human peripheral blood lymphocytes, a mouse killer T cell line, and a mouse natural killer cell line; induce killer cells in normal mouse spleen cells; and induce antibody forming cells in nude mouse spleen cells. No differences in these biological activities were found between two forms of natural IL-2 that were separable by reverse phase high performance liquid chromatography.

Animals↗

Purification and partial sequence analysis of human interleukin-2 derived from peripheral blood leukocytes.

Human peripheral blood leukocyte-derived interleukin-2 (IL-2) was resolved by DEAE-cellulose column chromatography into three peaks of activity, IL-2A, B, and C, with isoelectric points of 7.2, 6.6, and 7.9, respectively. IL-2 A, B, and C were further purified by reverse phase high performance liquid chromatography and resolved into two apparently homogeneous peaks each with identical molecular weight: A-1 and A-2 (Mr17000); B-1 and B-2 (Mr17500); and C-1 and C-2 (Mr14400). The amino acid compositions and partial NH2-terminal amino acid sequences of these molecular species were consistent with those predicted from IL-2 cDNA sequences derived from Jurkat and peripheral blood leukocytes.

Amino Acid Sequence↗

Production of plasminogen activators by human T-cell leukaemia virus-transformed human T cell lines.

Six human T cell lines HAMA, KUN, KAN, TCL-Haz, TCL-Ter, and TCL-Mor, which were transformed by a retrovirus, human T-cell leukaemia virus (HTLV), constitutively produced plasminogen activators (PAs) in culture supernatants. The amount of PAs produced varied among the cell lines. The PAs were distinguished by immunochemical analysis between two types: urokinase (UK)-type and non-UK-type. KUN, TCL-Ter, and HAMA mainly produced UK-type PA, whereas the other cell lines produced both types. Thus, HTLV-transformed T cell lines differ in the quality and quantity of the PAs they produce. The PAs in the culture supernatants of each cell line were separated into several mol. w forms on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The results indicate that the same cell line produces PAs of different mol. wt. PA production by these cell lines was affected by treatment with phorbol miristate acetate, concanavalin A, and phytohaemagglutinin; the effects were substantially different in each cell line. The data described here indicate that HTLV-transformed T cell lines constitutively produce PAs which are very heterogeneous in both quality and quantity.

Cell Line↗

Establishment of hybridomas secreting monoclonal antibodies against C epsilon 2 and C epsilon 4 domains of human IgE.

Three kinds of hybridomas secreting monoclonal antibodies (MAbs) against the epsilon chain of human IgE were constructed by somatic cell hybridization between mouse myeloma P3U1 cells and spleen cells from BALB/c mice immunized with human IgE purified from the culture supernatant of U-266 cells. These MAbs were used effectively for the purification and determination of human IgE. The recognition site in the IgE molecule of each antibody was examined by using various epsilon chain fragment peptides produced in Escherichia coli. From these experiments, it was suggested that one recognized C epsilon 2 and the second C epsilon 4. The third did not recognize the C epsilon 1-C epsilon 4 domains of the recombinant epsilon chain from E. coli, although it bound to the epsilon chain of natural human IgE.

Animals↗

A study on erythrocyte membrane plasmalogen in myotonic dystrophy.

Phospholipid classes that included plasmalogens of erythrocyte membranes in seven myotonic dystrophy (MyD) patients and seven normal controls were analyzed by HPLC. No significant difference in phospholipid classes was found between patients with MyD and normal controls, but there was a visible difference in peak profiles of compounds of the phosphatidylethanolamine class. In the study of plasmalogens, we used two preparation methods: exposure to HCl and deacylation with mild alkaline. The area ratio of the plasmalogen form to the diacyl form in the phosphatidylethanolamine class of MyD erythrocyte membranes was significantly lower than that of normal controls. Fatty acid analyses showed that fatty acids of both phosphatidylethanolamine subclasses have less unsaturation in MyD.

Adolescent↗

Habitat segregation and biochemical activities of marine members of the family vibrionaceae.

A comparative study of marine members of the family Vibrionaceae with the technique of numerical taxonomy revealed habitat segregation as well as a cosmopolitan nature of species distribution among the vibrios in different marine environments. The bacterial strains analyzed were isolated from seawater, sediments, phyto- and zooplankton, and fish in the Indian Ocean, the South and East China Sea, and West Pacific Ocean, and coastal areas of Japan. A total of 155 morphological, physiological, and biochemical tests were carried out for each of 405 strains examined. The results showed that most of the large taxonomical clusters which emerged from the computation corresponded to ecological groups which have particular niches. For instance, each group of seawater vibrios inhabited a particular water layer of limited depth range, in spite of the fact that strains of the group were isolated from sampling locations spread over a wide area from the Indian Ocean to Japanese coast. Various vibrio groups showed remarkable differences in their physiological and biochemical activities, and the activities of each group seemed to correspond with its ecological niche. The strains which inhabited surface-water layers grew fast and actively utilized many high-molecular-weight organic compounds and carbohydrates that are derived from fresh, easily degradable organic matter present in the surface waters, whereas the middle- and deep-water vibrios did not decompose most of the high-molecular-weight organic compounds except chitin but, rather, utilized some carbohydrates and organic acids which seemed to be derived from refractory particulate organic matter present in the deeper waters.

Journal Article↗

Leser-Trélat sign associated with Sézary syndrome.

The Leser-Trélat sign is a rare but well known cutaneous indicator of internal malignancy, most commonly adenocarcinoma of the stomach. There have been only a few cases associated with lymphoproliferative malignancies. Sézary syndrome is a chronic leukemia/lymphoma characterized by generalized erythroderma and circulating Sézary cells. We describe a rare case of the Leser-Trélat sign associated with the Sézary syndrome. The skin sign was alleviated through combination chemotherapy.

Aged↗

Two distinct class II molecules encoded by the genes within HLA-DR subregion of HLA-Dw2 and Dw12 can act as stimulating and restriction molecules.

By using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), we investigated the difference in the HLA class II molecule between HLA-Dw2 and Dw12, both of which are typed as HLA-DR2 serologically. The anti-HLA-DR framework monoclonal antibody (MoAb) HU-4 precipitated an alpha-chain and two beta-chains of human class II molecules from both Dw2 and Dw12 homozygous B lymphoblastoid cell lines. It was demonstrated clearly that an alpha-chain (alpha 1) and one of the beta-chains (beta 1) showed no difference in mobility in the 2D-PAGE between Dw2 and Dw12, but that another beta chain (beta 2) of Dw2 was distinct from that of Dw12 in the 2D-PAGE profile. Thus, MoAb HU-4 precipitated alpha 1 beta 1 and alpha 1 beta 2 molecules from Dw2 and Dw12, and the alpha 1 beta 1 molecule appears to be an HLA-DR2 molecule. The alpha 1 beta 2 molecule, on the other hand, is a class II molecule distinct from those precipitated with anti-DR2, anti-DQw1 (DC1, MB1, MT1), or anti-FA MoAbs. MoAb HU-4 completely inhibited the mixed lymphocyte culture reaction (MLR) between Dw2 and Dw12, but anti-DR2 MoAb HU-30, which reacts only with the alpha 1 beta 1 molecule, did not show an inhibitory effect on the MLR between Dw2 and Dw12. The alpha 1 beta 2 molecule is therefore the molecule which elicits MLR between Dw2 and Dw12. An IL 2-dependent T cell line established from an HLA-Dw12/D blank heterozygous high responder to the streptococcal cell wall antigen (SCW) clearly distinguished the Dw2 specificity from Dw12 specificity expressed on the antigen-presenting cell (APC). Moreover, MoAb HU-4 markedly inhibited the cooperation between the T cell line and APC to respond to SCW. These observations indicate that the alpha 1 beta 2 molecule is recognized as a restriction molecule by the T cell line at the antigen presentation of SCW through APC MoAb HU-30 on the other hand partially inhibited the MLR between Dw2 or Dw12 homozygous cell as a stimulator cell and non DR2 cell as a responder cell. It markedly inhibited the proliferative response of the Dw12/D- heterozygous T cell line to SCW, presented by Dw2+ but Dw12- allogeneic APC, and the peripheral response of Dw2 or Dw12 homozygous peripheral blood lymphocytes to SCW. Thus, two distinct class II molecules encoded by the genes within the HLA-DR subregion of HLA-Dw2 and Dw12 can act as stimulating molecules in the MLR and as restriction molecules in the antigen presentation by APC.

Antibodies, Monoclonal↗