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Teruo Yamada

Publications and source records attributed to Teruo Yamada.

3 recordsLinked to original sources
PubMed2003

Differential, histochemical and immunohistochemical changes in rat hepatocytes after isoflurane or sevoflurane exposure.

Differential, histochemical and immunohistochemical changes were observed in hepatocytes from immediately to 7 days after isoflurane or sevoflurane exposure (at H 0 to on Day 7) to study the process of development and recovery in anesthetic-induced hepatic injury. A total of 570 7-week-old male Sprague-Dawley rats with or without phenobarbital treatment were exposed to isoflurane or sevoflurane in 100%, 21%, or 10% oxygen, or to 10% oxygen alone for 2h. In phenobarbital-treated rats, hepatocytes both with and without anesthetic exposure markedly changed in 10% oxygen at H 0. Glycogen and ribosomal ribonucleic acid (rRNA) disappeared at H 0 and at H 6, respectively, and at H 6, AST levels in the blood rose. From H 6 to Day 1, necrosis developed more markedly and widely in zone 3 hepatocytes exposed to anesthetics in 10% oxygen than in those exposed to oxygen alone. All degenerated tissues had returned to normal levels by day 7. Recovery of the hepatolobular structure may be attributed to rearrangement of remaining hepatocytes in the portal vein area. Both the disappearance of glycogen and rRNA and the increase in blood AST levels after exposure to isoflurane or sevoflurane are considered to be factors contributing to the induction of necrosis around the central vein. The grade of isoflurane-induced hepatic injury was found to be significantly higher than that of sevoflurane.

Anesthetics, Inhalation↗
PubMed2002

Cathepsin-L, a key molecule in the pathogenesis of drug-induced and I-cell disease-mediated gingival overgrowth: a study with cathepsin-L-deficient mice.

Drug-induced gingival overgrowth, the chronic side effect of calcium antagonists, is frequently seen due to the increase in patients with hypertension, although the etiology of the disease is largely unknown. I-cell disease, which accompanies gingival overgrowth, is characterized by a deficiency in UDP-N-acetyl-glucosamine and is classified as one of the lysosomal storage diseases. Here, we hypothesized that a common mechanism may underlie the etiology of gingival overgrowth seen in patients treated with calcium antagonist and in patients with I-cell disease. A calcium antagonist, nifedipine, specifically suppressed cathepsin-L activity and mRNA expression, but not that of cathepsin-B in cultured gingival fibroblasts. The activity of cathepsin-L was suppressed up to 50% at 24 hours after treatment of the cells with the reagent. The selective suppression of cathepsin-L activity appeared not to be dependent on Ca(2+), since treatment of the cells with thapsigargin suppressed both cathepsin-B and -L activity. Mice deficient in the cathepsin-L gene manifested enlarged gingivae. Histological observation of the gingivae demonstrated typical features of acanthosis, a phenotype very similar to that of experimentally induced gingival overgrowth. Since cathepsin-L deficiency was reported to be associated with thickening of the skin, impaired cathepsin-L activity may play a key role in the establishment of skin and gingival abnormalities seen in I-cell disease. In addition, reduced cathepsin-L activity may play an important role in inducing drug-induced gingival overgrowth.

Animals↗