Three glutathione peroxidase homologs (YKL026C, YBR244W, and YIR037W/HYR1) were found in the Saccharomyces Genome Database. We named them GPX1, GPX2, and GPX3, respectively, and we investigated the function of each gene product. The gpx3⌬ mutant was hypersensitive to peroxides, whereas null mutants of the GPX1 and GPX2 did not show any obvious phenotypes. Glutathione peroxidase activity decreased approximately 57 and 93% in the gpx3⌬ and gpx1⌬/gpx2⌬/ gpx3⌬ mutants, respectively, compared with that of wild type. Expression of the GPX3 gene was not induced by any stresses tested, whereas that of the GPX1 gene was induced by glucose starvation. The GPX2 gene expression was induced by oxidative stress, which was dependent upon the Yap1p. The TSA1 (thiol-specific antioxidant) gene encodes thioredoxin peroxidase that can reduce peroxides by using thioredoxin as a reducing power. Disruption of the TSA1 gene enhanced the basal expression level of the Yap1p target genes such as GSH1, GLR1, and GPX2 and that resulted in increases of total glutathione level and activities of glutathione reductase and glutathione peroxidase. However, expression of the TSA1 gene did not increase in the gpx1⌬/gpx2⌬/gpx3⌬ mutant. Therefore, de novo synthesis and recycling of glutathione were increased in the tsa1⌬ mutant to maintain the catalytic cycle of glutathione peroxidase reaction efficiently as a backup system for thioredoxin peroxidase.All aerobic organisms use molecular oxygen for respiration or oxidation of nutrients to acquire the energy efficiently. Molecular oxygen is reduced to H 2 O through acceptance of four electrons. During the reduction of molecular oxygen, several reactive oxygen species are formed, i.e. acceptance of one, two, and three electrons to form, respectively, superoxide anion radical (O 2 . ), hydrogen peroxide (H 2 O 2 ), and hydroxyl radical (HO ⅐ ). These reactive oxygen species attack almost all cell components, DNA, protein, and lipid membrane, and they sometimes cause lethal damage to the cells. Among the reactive oxygen species, HO ⅐ as well as perhydroxyl radical (HOO ⅐ ) can extract bis-allylic hydrogen atom of unsaturated fatty acid (LH) to form lipid alkyl radical (L ⅐ ) (1). The L ⅐ is oxidized by molecular oxygen to generate a lipid peroxy radical (LOO ⅐ ), and the LOO ⅐ thus formed reacts with LH to give lipid hydroperoxide (LOOH) and L ⅐ . A radical chain reaction is then propagated. LOOH also belongs to the reactive oxygen species, and the occurrence of the LOOHs in biological membranes may be one of the major oxidative damages to the cells. (2). ␤-Carotene and tocopherol function as radical scavengers. Glutathione is also a major antioxidant in aerobic cells. However, it has been widely believed that microorganisms do not have peroxidases whose electron donor is glutathione. Microorganisms are believed to use cytochrome c as an electron donor for the peroxidase reaction (cytochrome c peroxidase). GPx has been thought to be evolutionarily acquired by mammals. However, we have demonstrated that ...

able because the patients is a poor surgical risk, TAE has To assess intrahepatic metastasis (IM) and multicenbeen considered the treatment of choice. However, the value tric occurrence (MO) after initial treatment of small heof TAE is limited if the small HCCs have intracapsular or patocellular carcinomas (HCC) ß 2 cm in diameter, we extracapsular invasion. performed clinical and pathological studies in 112 pa-PEIT has been shown to be highly effective in patients with tients who underwent percutaneous ethanol injection HCCs ß3 cm in diameter. with HCC were admitted to Ogaki Municipal Hospital, and 163 of the 750 were found to have an HCC ß2 cm in diameter. One hundred and twelve of these patients who had undergone PEIT or hepatic Hepatocellular carcinoma (HCC) is one of the most maligresection were selected for this retrospective study. All cases were nant neoplasms in Japan. Because of recent progress in the diagnosed histologically. Fifteen patients were diagnosed by specific development of new diagnostic modalities, the incidence of imaging diagnosis (histological confirmation was made by analysis detection of small HCCs has increased.1-4 Therapeutic ap-of specimens obtained at surgery) and 97 patients were diagnosed proaches to HCC also have progressed markedly in recent by percutaneous liver tissue core biopsy with ultrasound guidance. years through the development of hepatic resection, trans-The PEIT was performed according to previously published methcatheter arterial embolization, and percutaneous ethanol in-ods 24 in 82 patients who had not undergone surgery because of imjection therapy (PEIT). [5][6][7] The surgical resectability rate of paired liver function or who had requested this type of therapy.Briefly, after administration of a local anesthetic, the needle was HCC, however, has remained low, this is, because most pa- A 25 ). In this series, radical hepatectomy represented the removal of Received December 29, 1995; accepted September 25, 1996. all tumors from the liver. and/or helical with contrast medium were performed every 3 months.

able because the patients is a poor surgical risk, TAE has To assess intrahepatic metastasis (IM) and multicenbeen considered the treatment of choice. However, the value tric occurrence (MO) after initial treatment of small heof TAE is limited if the small HCCs have intracapsular or patocellular carcinomas (HCC) ß 2 cm in diameter, we extracapsular invasion. performed clinical and pathological studies in 112 pa-PEIT has been shown to be highly effective in patients with tients who underwent percutaneous ethanol injection HCCs ß3 cm in diameter. with HCC were admitted to Ogaki Municipal Hospital, and 163 of the 750 were found to have an HCC ß2 cm in diameter. One hundred and twelve of these patients who had undergone PEIT or hepatic Hepatocellular carcinoma (HCC) is one of the most maligresection were selected for this retrospective study. All cases were nant neoplasms in Japan. Because of recent progress in the diagnosed histologically. Fifteen patients were diagnosed by specific development of new diagnostic modalities, the incidence of imaging diagnosis (histological confirmation was made by analysis detection of small HCCs has increased.1-4 Therapeutic ap-of specimens obtained at surgery) and 97 patients were diagnosed proaches to HCC also have progressed markedly in recent by percutaneous liver tissue core biopsy with ultrasound guidance. years through the development of hepatic resection, trans-The PEIT was performed according to previously published methcatheter arterial embolization, and percutaneous ethanol in-ods 24 in 82 patients who had not undergone surgery because of imjection therapy (PEIT). [5][6][7] The surgical resectability rate of paired liver function or who had requested this type of therapy.Briefly, after administration of a local anesthetic, the needle was HCC, however, has remained low, this is, because most pa- A 25 ). In this series, radical hepatectomy represented the removal of Received December 29, 1995; accepted September 25, 1996. all tumors from the liver. and/or helical with contrast medium were performed every 3 months.

The human serine/threonine kinase Aurora-B is structurally related to the protein kinase Ipl1p from S cerevisiae and aurora from Drosophila melanogaster, which are key regulators of mitosis. The present study shows that human Aurora-B is activated by okadaic acid and forms complexes with the protein serine/threonine phosphatase type 1 (PP1) or PP2A, but not with PP5. These data identi®ed Aurora-B associated protein phosphatases as negative regulators of kinase activation. We then used a series of substrates based on a histone H3 phosphorylation site (residues 5 ± 15) to determine the substrate speci®city of human Aurora-B. We found that this enzyme is an arginine-directed kinase that can phosphorylate histone H3 at serines 10 and 28 in vitro, suggesting that human Aurora-B is a mitotic histone H3 kinase.

Yap1 is a transcription factor that responds to oxidative stress in Saccharomyces cerevisiae. The activity of Yap1 is regulated at the level of its intracellular localization, and a cysteine-rich domain at the C terminus of Yap1 is involved in this regulation. We investigated the effects of redox-regulatory proteins, thioredoxin and glutaredoxin, on the regulation of Yap1, using the deficient mutants of these thiol-disulfide oxidoreductases. In the thioredoxin-deficient mutant (trx1⌬/trx2⌬), Yap1 was constitutively concentrated in the nucleus and the level of expression of the Yap1 target genes was high under normal conditions, while this was not the case for the glutaredoxin-deficient mutant (grx1⌬/grx2⌬). No distinct difference was observed in the levels of Yap1 protein between the wild type and trx1⌬/trx2⌬. The constitutive activation of Yap1 in trx⌬/trx2⌬ was observed under aerobic conditions but not under anaerobic conditions. These findings suggest that thioredoxin has negative effects on this regulation via the redox states. We also show the synthetic lethality between yap1⌬ and trx1⌬/trx2⌬ mutation, but the yap1⌬/grx1⌬/grx2⌬ triple mutant was viable, suggesting a difference of the functions between thioredoxin and glutaredoxin and a genetic interaction between Yap1 and thioredoxin in vivo.

Glutathione is synthesized in two sequential reactions catalyzed by ␥-glutamylcysteine synthetase (GSH1 gene product) and glutathione synthetase (GSH2 gene product). The expression of GSH1 in Saccharomyces cerevisiae has been known to be up-regulated by Yap1p, a critical transcription factor for the oxidative stress response in yeast. The present study demonstrates that GSH2 expression is also regulated by Yap1p under oxidative stress-induced conditions. In addition to oxidative stress, expression of GSH1 and GSH2 was induced by heat shock stress in a Yap1p-dependent manner with subsequent increases in intracellular glutathione content. Oxygen respiration rate increased when cells were exposed to higher temperatures, and as a result, intracellular oxidation levels were increased. The heat shock-induced expression of GSH1 and GSH2 did not occur under anaerobic conditions. Furthermore, even under aerobic conditions, the heat shock response of these genes was not observed when cells were pretreated with KCN to block oxygen respiration. We speculate that heat shock stress enhances oxygen respiration, which in turn results in an increase in the generation of reactive oxygen species in mitochondria. This signal may be mediated by Yap1p, resulting in the elevation of intracellular glutathione levels.Stress-inducible proteins are synthesized by all organisms, and important functional insights of this group of proteins have been obtained from studies with the heat shock protein (HSP). 1A sudden increase in the temperature at which cells are growing induces the synthesis of a set of HSPs. When the temperature of Escherichia coli cells is increased from 30 to 42°C, the intracellular concentration of sigma factor 32 increases 15-20-fold. The sigma factor is one of the components of E. coli RNA polymerase, and substitution of a vegitative sigma factor ( 70 ) by 32 modifies the RNA polymerase to specifically recognize the promoter of HSP genes. In higher eukaryotes, a heat shock transcription factor is trimerized, phosphorylated, and translocated into the nucleus by heat shock stress and binds to the heat shock element (HSE) on the promoter of HSP genes to activate transcription (for a review, see Ref.

A 35-year-old woman with a 6-month history of ulcerative colitis and treatment with oral mesalazine (5-aminosalicylic acid) developed dry cough, low-grade fever and bilaterally wandering pulmonary infiltrates. Improvement in clinical symptoms and radiological abnormalities occured spontaneously after discontinuation of mesalazine. The transbronchial lung biopsy demonstrated the organizing stage of eosinophilic pneumonia. Drug lymphocyte stimulation test was positive for mesalazine and negative for sulfasalazine and sulfapyridine. The present case indicates that although mesalazine-induced eosinophilic pneumonia is an extremely rare entity, its possibility should be fully considered in patients developing unexplained respiratory symptoms while on mesalazine therapy.

There is not yet an effective standard therapy for severe advanced hepatocellular carcinoma (HCC). We attempted continuous local arterial infusion chemotherapy using 5-fluorouracil (5-FU) and cisplatin (CDDP) with an implanted reservoir for these patients, and evaluated its efficacy. Twenty-one HCC patients received continuous arterial infusion of 5-FU and CDDP for 1 week, followed by a 1-week no-infusion period; this regimen was repeated 1-32 times, and patients were observed for 36-549 days. The 1-year survival rate was 61.1 %, and alpha fetoprotein levels decreased in 13 patients. All could continue as outpatients for 94.0% of the entire course of therapy. Because CDDP amplifies the effect of 5-FU as a biochemical modulator, and because continuous infusion strengthens the effect of 5-FU and reduces the side effects of CDDP, we consider this therapy to be effective for patients with severe advanced HCC, prolonging survival and improving the quality of life.