Yasuo Yajima

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A soluble enzyme fraction from Phanerochaete chrysosporium catalyzed the oxidative decarboxylation of vanillic acid to methoxy-p-hydroquinone. The enzyme, partially purified by ammonium sulfate precipitation, required NADPH and molecular oxygen for activity. NADH was not effective. Optimal activity was displayed between pH 7.5–8.5. Neither EDTA, KCN, NaN3,(More)
The presence of the enzyme aldose reductase is increasingly being linked to diabetic complications. The distribution of this enzyme in human cornea, lens, retina, and optic nerve has been studied using specific antibodies against purified human placental aldose reductase raised in both rabbit and goat. The antisera from both animals gave equal, specific(More)
Collagenolytic enzyme activities presumed to play an important role in ovulation were investigated in the human follicular apex, base, and granulosa cell layer throughout the ovarian cycle. Those analyzed were human ovarian collagenase, 2,4-dinitrophenyl-Pro-Gln-Gly-Ile-Ala-Gly-Gln-D-Arg-OH peptidase, N-carbobenzoxy-Gly-Pro-Gly-Gly-Pro-Ala peptidase, and(More)
The apical wall was studied ultrastructurally in 16 human follicles at various stages of development. In the theca externa and tunica albuginea at the apex of growing follicles, fibroblasts with little cytoplasm and abundant collagen fibres were observed. In the mature follicles, the fibroblastic cytoplasm was well developed, rich in lysosome-like granules(More)
Participation of collagenolytic activities in the ovulatory process had been recently studied in the experimental animals, though their existence in the human ovary remains obscure. In the previous report, we demonstrated the collagenolytic activity by using synthetic substrates N-carbobenzoxy-Gly-Pro-Gly-Gly-Pro-Ala and the cathepsin B1 activity in human(More)
In order to clarify the nature and possible roles of lysosome-like granules observed electronmicroscopically in the granulosa cells of human preovulatory follicles, lysosomal activities in human preovulatory granulosa cells were investigated ultrastructurally by staining a marker enzyme acid phosphatase with modified Gomori technique. In the granulosa cells(More)
To elucidate the mechanisms of follicular rupture at ovulation in human, activities of collagenolytic enzymes were measured in the human follicles at various stages of development by using two kinds of synthetic substrates, alpha-N-benzoyl-DL-arginine-2-naphthylamide HCl and N-carbobenzoxy-glycyl-prolyl-glycyl-glycyl-prolyl-alanine. The result clarified(More)
To elucidate the mechanism of follicular rupture at ovulation in human, ultrastructural changes of stromal tissue of the follicular apex during follicular growth and ovulation were studied by focusing on the collagen and fibroblasts in the stroma. Sixteen ovaries were obtained from women at their thirties who underwent the abdominal hysterectomy for(More)
To examine the possible roles of collagenolytic enzymes in the follicular wall at ovulation, we measured in rabbit ovaries collagenolytic enzymes by using synthetic substrates, DNP-Pro-Gln-Gly-Ile-Ala-Gly-Gln-D-Arg OH supposed to be specific for vertebrate collagenase. Our results clearly demonstrated that DNP-peptidase activity existed, with its optimal(More)
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