Impacts and challenges for Japanese nuclear operators as a result of legislative change to extend the legal lifetime of nuclear power plants in Japan.

The purpose of nuclear regulation is not to impede the sound development of industry's competitiveness. Therefore, the regulations must be coherent, transparent and most of all, logical. On May 31st, 2023, a bill including rules to change the legal lifetime of nuclear power plants was approved and endorsed at the 211th ordinary session of the National Diet in Japan. An important characteristic of this legislative change is that it does not simply grant additional operating years to the original lifetime; rather, it considers the length of time that the plant was under shutdown status due to reasons not attributable to the plant owners and excludes this period from the countdown of the predetermined lifetime, thus extending the original legal lifetime. Three major problems could be listed in the procedures for changing the rules and in the new rules themselves. Firstly, the period during which this matter was discussed was too short to discuss issues raised by the change in detail. Secondly, the definitions of the period to be excluded from the predetermined lifetime are neither scientifically logical nor clear and would likely cause a great deal of confusion for both licensees and regulators when the new rule comes into effect. Thirdly, under this rule, the legal lifetime of a plant which performance is worse would be longer than that of the one with better operating performance. In particular, the second and the third problems deviate greatly from the purpose of nuclear regulation, which is not to impede the sound development of industry's competitiveness. The author strongly urges all parties involved to reconsider their decisions even after the bill has got an official approval at the National Diet.

Characterization of causative allergens for wheat-dependent exercise-induced anaphylaxis sensitized with hydrolyzed wheat proteins in facial soap.

BACKGROUND: In Japan, hydrolyzed wheat proteins (HWP) have been reported to cause wheat-dependent exercise-induced anaphylaxis (WDEIA) by transcutaneous sensitization using HWP-containing soap. Patients develop allergic reactions not only with soap use, but also with exercise after the intake of wheat protein (WP). ω5-Gliadin and HMW-glutenin were identified as major allergens in conventional WP-WDEIA patients. However, the allergens in HWP-WDEIA have yet to be elucidated. METHODS: Sera were obtained from 22 patients with HWP-sensitized WDEIA. The allergenic activities of HWP and six recombinant wheat gluten proteins, including α/ß-, γ-, ω1,2- and ω5-gliadin and low- and high molecular weight (HMW)-glutenins, were characterized by immunoblot analysis and histamine releasing test. IgE-binding epitopes were identified using arrays of overlapping peptides synthesized on SPOTs membrane. RESULTS: Immunoblot analysis showed that IgE antibodies (Abs) from HWP-WDEIA bound to α/ß-, γ- and ω1,2-gliadin. Recombinant γ-gliadin induced significant histamine release from basophils in eight of 11 patients with HWP-WDEIA. An IgE-binding epitope "QPQQPFPQ" was identified within the primary sequence of γ-gliadin, and the deamidated peptide containing the "PEEPFP" sequence bound with IgE Abs more strongly compared to the native epitope-peptide. The epitope-peptide inhibited IgE-binding to HWP, indicating that the specific IgE to HWP cross-reacts with γ-gliadin. CONCLUSIONS: HWP-WDEIA patients could be sensitized to HWP containing a PEEPFP sequence, and WDEIA symptoms after WP ingestion could partly be induced by γ-gliadin. These findings could be useful to help develop tools for diagnosis and desensitization therapy for HWP-WDEIA.

New KIT mutations in patients with piebaldism.

BACKGROUND: Piebaldism is an autosomal dominantly inherited disorder characterized by congenital leukoderma, typically on the forehead, abdomen, and knees. The leukoderma is usually stable throughout life. KIT mutations have been demonstrated in about 75% of patients with piebaldism. OBJECTIVES: To identify KIT mutations of the family with piebaldism and examine genotype-phenotype correlations in this disorder. METHODS: PCR-direct-sequencing technique using genomic DNA from peripheral leukocytes. RESULTS: We have studied 10 individuals within six piebaldism families and able to identify six novel mutations in the KIT gene in patients with piebaldism. These include four frameshift mutations: 142delG, 1768-1769delAG, 2139delC, 2246-2249delAAAG, and two missense mutations: M541L, Y870C. CONCLUSIONS: These six new mutations are associated with phenotypes that are well in accordance with our knowledge of genotype-phenotype correlations in KIT.

Formation of 1-octen-3-ol from Aspergillus flavus conidia is accelerated after disruption of cells independently of Ppo oxygenases, and is not a main cause of inhibition of germination.

Eight-carbon (C8) volatiles, such as 1-octen-3-ol, are ubiquitous among fungi. They are the volatiles critical for aroma and flavor of fungi, and assumed to be signals controlling germination of several fungi. In this study, we found that intact Aspergillus flavus conidia scarcely synthesized C8 volatiles but repeated freeze-thaw treatment that made the cell membrane permeable promoted (R)-1-octen-3-ol formation. Loss or down regulation of any one of five fatty acid oxygenases (PpoA, PpoB, PpoC, PpoD or lipoxygenase) hypothesized contribute to 1-octen-3-ol formation had little impact on production of this volatile. This suggested that none of the oxygenases were directly involved in the formation of 1-octen-3-ol or that compensatory pathways exist in the fungus. Germination of the conidia was markedly inhibited at high density (1.0 × 10(9)spores mL(-1)). It has been postulated that 1-octen-3-ol is an autoinhibitor suppressing conidia germination at high density. 1-Octen-3-ol at concentration of no less than 10 mM was needed to suppress the germination while the concentration of 1-octen-3-ol in the suspension at 1.0 × 10(9) mL(-1) was under the detection limit (<1 µM). Thus, 1-octen-3-ol was not the principal component responsible for inhibition of germination. Instead, it was evident that the other heat-labile factor(s) suppressed conidial germination.

Purification, characterization and amino acid sequence of a novel enzyme, D-threo-3-hydroxyaspartate dehydratase, from Delftia sp. HT23.

D-threo-3-hydroxyaspartate dehydratase (D-THA DH) was purified from the cell-free extract of the soil-isolated bacterium Delftia sp. HT23. The enzyme exhibited dehydratase activity towards D-threo-3-hydroxyaspartate, l-threo-3-hydroxyaspartate, l-erythro-3-hydroxyaspartate and d-serine. Absorption of the purified enzyme at 412 nm suggests that it contains pyridoxal 5'-phosphate (PLP) as a cofactor. The NH(2)-terminal and internal amino acid sequences showed significant similarity to hypothetical alanine racemase of genome-sequenced Delftia acidovorans SPH-1; however, the purified enzyme showed no alanine racemase activity. Using the sequence information of D. acidovorans SPH-1, the gene encoding d-THA DH was cloned. The deduced amino acid sequence, which belongs to the alanine racemase family, shows significant (26-36%) similarity to d-serine dehydratase of both Saccharomyces cerevisiae and chicken. In order to obtain purified d-THA DH efficiently, the gene was expressed in Escherichia coli. The recombinant enzyme was highly activated by divalent cations, such as Mn(2+), Co(2+) and Ni(2+). Site-directed mutagenesis experiment revealed that lysine 43 is an important residue involved in PLP binding and catalysis. This is the first reported enzyme that acts on d-THA. In addition, this enzyme is the first example of a prokaryotic dehydratase belonging to the fold-type III PLP-dependent enzyme family.

Gene cloning and expression of pyridoxal 5'-phosphate-dependent L-threo-3-hydroxyaspartate dehydratase from Pseudomonas sp. T62, and characterization of the recombinant enzyme.

L-threo-3-Hydroxyaspartate dehydratase (L-THA DH, EC 4.3.1.16), which catalyses the cleavage of L-threo-3-hydroxyaspartate (L-THA) to oxalacetate and ammonia, has been purified from the soil bacterium Pseudomonas sp. T62. In this report, the gene encoding L-THA DH was cloned and expressed in Escherichia coli, and the gene product was purified and characterized in detail. A 957-bp nucleotide fragment was confirmed to be the gene encoding L-THA DH, based on the agreement of internal amino acid sequences. The deduced amino acid sequence, which belongs to the serine/threonine dehydratase family, shows similarity to YKL218c from Saccharomyces cerevisiae (64%), serine racemase from Schizosaccharomyces pombe (64%) and Mus musculus (36%), and biodegradative threonine dehydratase from E. coli (38%). Site-directed mutagenesis experiments revealed that lysine at position 53 is an important residue for enzymatic activity. This enzyme exhibited dehydratase activity specific only to L-THA [K(m) = 0.54 mM, V(max) = 39.0 micromol min(-1) (mg protein)(-1)], but not to other 3-hydroxyaspartate isomers, and exhibited no detectable serine/aspartate racemase activity. This is the first report of an amino acid sequence of the bacterial enzyme that acts on L-THA.

Effects of arginine treatment on nutrition, growth and urea cycle function in seven Japanese boys with late-onset ornithine transcarbamylase deficiency.

BACKGROUND: The aim of this study was to investigate the effects of arginine on nutrition, growth and urea cycle function in boys with late-onset ornithine transcarbamylase deficiency (OTCD). Seven Japanese boys with late-onset OTCD enrolled in this study resumed arginine treatment after the cessation of this therapy for a few years. Clinical presentations such as vomiting and unconsciousness, plasma amino acids and urinary orotate excretion were followed chronologically to evaluate urea cycle function and protein synthesis with and without this therapy. In addition to height and body weight, blood levels of proteins, lipids, growth hormone (GH), insulin-like growth factor-I (IGF-I) and IGF-binding protein -3 (IGFBP-3) were monitored. RESULTS: The frequency of hyperammonemic attacks and urinary orotate excretion decreased significantly following the resumption of arginine treatment. Despite showing no marked change in body weight, height increased gradually. Extremely low plasma arginine increased to normal levels, while plasma glutamine and alanine levels decreased considerably. Except for a slight increase in high-density lipoprotein cholesterol level, blood levels of markers for nutrition did not change. In contrast, low serum IGF-I and IGFBP-3 levels increased to age-matched control levels, and normal urinary GH secretion became greater than the level observed in the controls. CONCLUSION: Arginine treatment is able to reduces attacks of hyperammonemia in boys with late-onset OTCD and to increase their growth.

Relationship between oxidative stress and antioxidant systems in the liver of patients with Wilson disease: hepatic manifestation in Wilson disease as a consequence of augmented oxidative stress.

The role of oxidative stress in the pathogenesis of liver disease in Wilson disease (WD), a genetic disorder characterized by excess hepatic deposition of copper that generates free radicals, remains unclear. This study investigates oxidative stress on the liver and hepatic antioxidant responses in WD using liver specimens from affected patients showing mild liver damage (group I, n = 3), moderate or greater liver damage (group II, n = 5), and fulminant hepatic failure (group III, n = 5) and from asymptomatic carriers (n = 2). Decreased ratios of reduced glutathione (GSH) to oxidized glutathione (GSSG) and increased thiobarbituric acid reactive substance (TBARS), a lipid peroxidation product, were found in every affected patient, especially in group II and III patients. Activities and protein expressions of Mn-dependent superoxide dismutase (Mn-SOD), CuZn-dependent superoxide dismutase (CuZn-SOD), and catalase were decreased in all patients, especially in group III patients. Glutathione peroxidase (GPx) activity was decreased only in group III patients. Asymptomatic carriers without any clinical manifestations showed normal TBARS level and GSH/GSSG ratio with increases in both GSH and GSSG levels. Their CuZn-SOD, Mn-SOD, and catalase activities were increased. These results suggest that excessive copper-derived oxidants contribute to development and progression of liver disease in WD.