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Biomedical subjects

K Ueda

Publications and source records attributed to K Ueda.

At least 1,117 records · Page 62Linked to original sources

[The multidrug-resistance gene MDR1].

MDR1 gene encodes a membrane glycoprotein (P-glycoprotein) that acts as a energy-dependent pump to transport antitumor drugs out of the cells. P-glycoprotein, 1280 amino acids long, consists of two homologous parts of approximately equal length. The protein has binding sites for ATP, antitumor drugs and calcium channel blockers. MDR1 gene is expressed tissue-specific in human normal adrenal, kidney, liver and colon. The normal function and transcriptional regulation of this gene are also discussed.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Characterization and clinical study on the acellular pertussis vaccine produced by a combination of column purified pertussis toxin and filamentous hemagglutinin.

Bordetella Pertussis Tohama phase I was cultured in a 300-liter fermentor using a medium containing 0.1% heptakis (2,5-0-dimethyl) beta-cyclodextrin (MeCD). Pertussis toxin (PT) and filamentous hamagglutinin (FHA) were purified using affinity and ion exchange gel column chromatographies. Endotoxin contents of these antigens (10 micrograms PN/ml) were less than 10 ngLPS/ml. PT and FHA were independently treated with formalin in the presence of amino acid and were mixed at a protein concentration ratio of 1:4, the same ratio of our commercialized acellular pertussis vaccine. PDT vaccine containing 2 micrograms PN of PT and 8 micrograms PN of FHA per milliliter was prepared. This PDT vaccine satisfied all the items of the Japanese Minimum Requirements including potency and toxicity tests. Even after this vaccine was incubated for 4 weeks at 37 degrees C, no deaths of the inoculated mice were observed after challenge with 4 mg of histamine on the 4th and 12th day of the inoculation. Compared with the conventional vaccine, this new vaccine caused less swelling in the mouse footpad test. A field trial of our two vaccines, one manufactured by the conventional method (lot No. 21A) and the other produced by the new method (lot No. KC8702), revealed that children receiving KC8702 showed almost the same anti-PT and anti-FHA antibody levels as those given 21A. Those who received KC8702 suffered from less local side effects such as redness, swelling or induration than those given 21A. Our new method for the production of acellular pertussis vaccine permits us the economical manufacturing of the vaccine with uniform quality in a closed system.

Animals↗

DNA damage caused by ascorbate in the presence of Cu2+ induces mutations.

The DNA damage induced by ascorbate in the presence of Cu2+ was analyzed by sequencing, and the mutagenic consequences of damages to plasmid pUC18 lacZ' were assayed in a forward repairing system in E. coli JM109 in vivo. Ascorbate induced two classes of DNA damage in the presence of Cu2+, one being non-base-specific direct strand cleavage, and the other being sequence-specific base modification labile to alkali treatment. Radicals generated from ascorbate hydroperoxide were involved in DNA damaging reactions. Ascorbate and Cu2+ caused mutations in pUC18 lacZ' gene. The mutation frequency by this method was about 10(-4) at 18% survivors when measured as a loss of alpha-complementation. All the mutations found were single-base substitutions that occurred in the structural part of the lacZ' gene. They were predominantly G:C----A:T transitions.

Ascorbic Acid↗