Kazuki Shinohara

Human-human hybridomas secreting antibodies specific to human lung carcinoma

SummaryHuman Namalwa cells were screened in serum-free medium and in 6-thioguanine, then fused with human lymphocytes from lymph nodes of lung adenocarcinoma cancer patients. Extensive testing using 14 lung cancer cell lines, 11 other cancer cell lines and 4 normal fibroblast lines identified monoclonal antibodies produced by 4 hybridoma clones that reacted specifically with lung adenocarcinoma cells. These monoclonal antibodies also reacted with lung adenocarcinoma tissues and not normal tissues or erythrocytes of any blood type. These hybridoma clones grew and stably secreted the antibodies in serum-free medium as well as in serum-containing medium.

HO-323, a human B-lymphoblastoid cell line useful for making human-human hybridomas.

A 6-thioguanine-resistant human B-lymphoblastoid cell line, HO-323, was isolated for making human-human hybridomas with high efficiency. Fusions with peripheral blood lymphocytes of systemic lupus erythematosus (SLE) patients and lymphocytes isolated from lymph nodes of lung and breast cancer patients yield constantly more than one hybridoma clones per 10(5) HO-323 cells plated. HO323 cells also fused with lymphocytes from normal peripheral blood to give hybridomas in the same efficiency. The HO-323 cells were diploid with 46 chromosomes and non-secretors of immunoglobulins. This parent cells doubled every 15 hr and could proliferate in serum-containing medium, even if they were plated at low cell density of less than 10(3) cells/ml. The cells could grow in serum-free medium as well as in serum-containing medium, and the resultant human-human hybridomas could also grow in the same media.

Formation of mutagens by amino-carbonyl reactions

The formation of mutagens by amino-carbonyl reactions of 20 kinds of amino acid and sugars after heating at 100 degrees C for 10 h was examined by the Ames test. The browned solutions of Gly, Ala, Val, Leu, Ile, Ser, Thr, Gln, Lys X HCl, Arg, Phe, Cys, Met and Pro with Glc caused mutation of Salmonella typhimurium TA100 and/or TA98 with or without S9 mix. The presence of S9 mix increased the mutagenic activity of the browned solutions of Cys and Phe with Glc on TA100 and of those of Gly, Ala, Val, Ile and Cys on TA98, but decreased the activity of other solutions. No revertants of Salmonella were induced by the browned solutions of Trp, Tyr, Asp, Asn, Glu and (Cys)2 with Glc. Among positive browned solutions, Cys, Lys, Arg and Phe had the stronger activity, but their activity was weak compared with that of pyrolysates or chemical mutagens such as Trp-P-1, Trp-P-2 and 4-nitroquinoline-N-oxide. The mutagenic activity of the browned solutions increased with prolongation of heating time and varied with the pH of the reaction mixture. Fru, Gal, Ara, Xyl, Man, Lac and Suc also had the ability to form mutagens in the browning reactions with amino acids.

Algal phycocyanins promote growth of human cells in culture.

SummaryThe growth-promoting substances in a non-dialyzable extract of Synechococcus elongatus var. on RPMI 8226 cells (a human myeloma cell line) were separated by gel filtration and ion exchange chromatography. By gel filtration with Sepharose 4B, the dialyzate was separated into two fractions. One fraction was green-colored (P-1) and the other was blue-colored (P-2). The P-2 fraction had a higher growth-promoting activity than P-1. By ion exchange chromatography, the P-2 fraction was separated into two blue-colored fractions of phycocyanin and allophycocyanin. Both biliproteins promoted the growth of RPMI 8226 cells; however, allophycocyanin was more active than phycocyanin.

Antitumour potentiality of polyhedral protein and its action on deoxyribonucleic acid

Polyedrisches Protein hat die Fähigkeit, das Wachstum von Sarkom-180 zu hemmen. Hitze-denaturierte DNS ist fähig, sich mit diesem Protein zu kombinieren, was von einem Aufbrechen des Proteins begleitet wird. Partiell mit Trypsin hydrolysiertes Protein kann sich auch an einstrangige Nucleinsäure binden, eine Bindung, welche seine Neigung zum Aufbrechen vergrößert. Die Schmelztemperatur von DNS wird durch die Kombination mit dem teilweise zersetzten Protein herabgesetzt. Seine Injektion hindert außerdem die Ekdyse von Larven. Polyhedral protein has the ability to inhibit the growth of sarcoma-180. Heat-denatured DNA is able to combine with the protein; the combination is accompanied by breakage of the former. The protein hydrolyzed partially with trypsin can also bind with single stranded nucleic acid; the binding causes an enhancement of breakability of the latter. The melting temperature of DNA is decreased by combining with the partly decomposed protein. Nuclear DNA in silkworms is split by injecting the protein. The injection further impedes the larval ecdysis.

The Mass Culture of a Thermophilic Spirulina in the Desert

Spirulina is a unique algal crop consumed traditionally by humans in Chad and Mexico, and taken as a health food in Japan. Current investigations, in countries such as the U.S.A. and Israel, aim at the production of Spirulina in the desert. The purpose is to open up the desert as a new base for the production of protein and other organic substances from algae.