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H Noji

Publications and source records attributed to H Noji.

40 records · Page 3Linked to original sources

Molecular switch of F0F1-ATP synthase, G-protein, and other ATP-driven enzymes.

Exchange-out of amide tritium from labeled gamma-subunit of alpha 3 beta 3 gamma complex of F0F1-ATP synthase was not accelerated by ATP, suggesting that hemagglutinin-type transition of coiled-coil structure did not occur in gamma-subunit. Local topology of nucleotide binding site and "switch II" region of G-protein alpha resemble those of F1-beta subunit and other proteins which catalyze ATP-triggered reactions. Probably, binding of nucleotide to F0F1-ATP synthase induces conformational change of the switch II-like region with transforming beta subunit structure from "open" to "close" for and this transformation results in loss of hydrogen bonds with gamma subunit, thus enabling the gamma subunit to move.

Adenosine Triphosphate↗

In vivo effects of various therapies on complement-sensitive erythrocytes in paroxysmal nocturnal hemoglobinuria.

The percentage of complement-sensitive erythrocytes varies among patients with paroxysmal nocturnal hemoglobinuria (PNH) and is related to disease severity. We examined the changes of complement-sensitive erythrocytes following administration of androgens, prednisolone, dextran, and iron to 12 PNH patients using the complement lysis sensitivity test or flow cytometric analysis of decay accelerating factor and CD59/membrane attack complex-inhibitory factor expression for 11 years. Five untreated PNH patients were also studied as a control group. The complement-sensitive erythrocyte count remained almost constant in the control group, while it increased in four out of five patients receiving androgens. In addition, it decreased in two out of three patients receiving prednisolone, increased in both patients treated with dextran, and increased slightly in two of the three patients receiving iron therapy. Episodes of hemoglobinuria increased in three of the nine patients showing an increase of complement-sensitive erythrocytes, and decreased in four patients receiving prednisolone or dextran. A good response to treatment was clinically observed in four patients receiving androgens, in one patient treated with prednisolone, and in one patient receiving dextran according to the scoring system. These findings suggest that PNH remains stable when the number of complement-sensitive erythrocytes remains fairly constant, and that the PNH III erythrocyte count is especially related to the frequency of hemoglobinuria. Thus, it seems to be important to determine the long-term effect of drug therapy on complement-sensitive erythrocytes to select the most appropriate treatment.

Adolescent↗

[Negative Ham's test and sugar water test on admission in paroxysmal nocturnal hemoglobinuria].

A 55-year-old man was admitted to our department because of shortness of breath and pancytopenia on March 27, 1992. On admission, palpebral conjuctiva were anemic. Laboratory findings showed pancytopenia, a reticulocyte count of 44,835/microliters, hemosiderinuria, LDH of 710 IU/l, haptoglobin of 6 mg/dl, NAP score of 301, red cell acetylcholinesterase of 1.5 U, negative Ham's test and negative sugar water test. Bone marrow was hypoplastic (2.4 x 10(4)/microliters). The erythrocytes of this patient showed complement-sensitive cells by the complement lysis sensitivity test, and a negative population consisting of double negative erythrocytes by flow cytometric two-color analysis using monoclonal antibodies to CD55 and CD59. A diagnosis of PNH with hypoplastic bone marrow was thus made. Therefore, flow cytometric two-color analysis appears to be superior to the standard tests currently used.

Antibodies, Monoclonal↗