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Y Hase

Publications and source records attributed to Y Hase.

At least 19 recordsLinked to original sources
PubMed2003

The infrared fundamental intensities and polar tensor of CH3NC.

The molecular force field and polar tensor of methyl isocyanide have been determined from its gas phase vibrational frequencies and infrared intensities. Quantum chemical results from MP2(FC), B3LYP and quadratic configuration interaction calculation including single and double substitutions procedures using a 6-311 + +G(3d,3p) basis set have been used to determine the signs of the dipole moment derivatives with respect to the normal coordinates as well as estimate individual fundamental intensities of the overlapped v1-v5 and v3-v6 band systems. Principal component graphical representations of the A1 and E symmetry polar tensor elements were useful in determining preferred sets of tensor elements. The mean dipole moment derivative (GAPT charge) of the methyl carbon in CH3NC, 0.347 e, is between the corresponding values in CH3CN, 0.110 e, and CH3F, 0.541 e. The mean dipole moment derivatives obtained here indicate the correct 1s methyl carbon ionization energy as 293.35 eV which is 0.98 eV higher than the corresponding ionization energy of the terminal atom.

Carbon↗
PubMed2003

LET dependence of lethality of carbon ion irradiation to single tobacco cells.

PURPOSE: To determine the radiation sensitivity and relationship between linear energy transfer (LET) and relative biological effectiveness (RBE) in single plant cells irradiated with heavy ions. MATERIALS AND METHODS: Single cells were isolated from the tobacco BY-2 cell line and irradiated with carbon ions (78.6-309 keV microm(-1)) and gamma-rays (0.2 keV microm(-1)). Two weeks after irradiation, colonies with 16 cells or more derived from the irradiated cells were counted as survivors. The surviving fraction was fitted using the single-hit, multitarget theory. RESULTS: The doses needed to reduce the surviving fraction of the cells to 0.1 (D10) of gamma-rays and carbon ions were 47.2 and 10.5-12.6 Gy, respectively. The RBE based on the D10 peaked at an LET of 247 keV microm(-1). The inactivation cross-section of carbon ions reached a plateau of 11.3 microm2 at an LET of 247 keV microm(-1). CONCLUSIONS: The radiation sensitivity of single tobacco cells was much lower than that of mammalian cells, although the mean number of base pairs per chromosome in the two cell types was similar. The RBE peak based on the D10 of carbon ions in single tobacco cells occurred at a higher LET than it does in other organisms.

Carbon↗
PubMed2002

Reduction of survival and induction of chromosome aberrations in tobacco irradiated by carbon ions with different linear energy transfers.

PURPOSE: To determine the relationship between linear energy transfer (LET) and the relative biological effectiveness (RBE) for survival reduction and chromosome aberration induction in plants. MATERIALS AND METHODS: Tobacco seeds were exposed to carbon ions having LET ranging from 92 to 260 keV microm(-1). Survival ratc was determined at 7 weeks after sowing. Chromosome aberrations were observed when the root length reached about 0.5 mm (immediately after radicle emergence), 3 and 10 mm. RESULTS: The RBE for both endpoints increased with increasing LET and showed the highest value at 230 keV um(-1). The highest RBE was 65.0 for survival reduction and 52.5 for chromosome aberration induction. The types and yield ratio of chromosome aberrations such as fragments and bridges were not affected by radiation type at 0.5mm root length. As the roots elongated from 0.5 to 10 mm, the frequency of aberrant cells gradually decreased. The number of cells with fragments decreased faster than the number of cells with bridges. The decrement of chromosome aberrations appeared to be slower in roots irradiated by carbon ions than in roots irradiated by gamma-rays. CONCLUSIONS: The results show a close relationship between survival reduction and chromosome aberration induction in plants. The types and yield ratio of initial chromosome aberrations did not differ among gamma-rays and carbon ions with different LET.

Carbon↗
PubMed2001

The infrared fundamental intensities and polar tensor of allene.

The polar tensor of allene was calculated from the infrared fundamental band intensities of C3H4 and C3D4. The ambiguities in the signs of the dipole moment derivatives with respect to their normal coordinates were resolved by comparison of tensor elements with ab initio calculations at the B3LYP, MP2(FC) and CCD(FC) levels with a 6/311 + + G(3d,3p) basis set. The results are similar to those previously obtained by Koga and co-workers except for the choice of an average of two sign combinations for the E symmetry elements. The values of the mean dipole moment derivatives for the sp and sp2 carbon atoms obtained in this work, 0.032 and -0.133 e, respectively, are in good agreement with the CCD(FC)/6-311 + + G(3d,3p), 0.061 and -0.128 e, and MP2(FC)/6-311 + + G(3d,3p), 0.072 and -0.153 e, theoretical results. The mean dipole moment derivatives are shown to be consistent with potential models relating 1s electron ionization energies and atomic charges.

Alkadienes↗
PubMed2001

Molecular characterisation of glutamate dehydrogenase gene defects in Japanese patients with congenital hyperinsulinism/hyperammonaemia.

Congenital hyperinsulinism and hyperammonaemia (CHH) is caused by dysregulation of glutamate dehydrogenase (GDH). We characterised the GDH gene in two Japanese patients with CHH. Patient 1 showed late-onset and mild hypoglycaemic episodes and mild hyperammonaemia, compared with patient 2. In GDH activity of lymphoblasts, patient 1 showed twofold higher basal GDH activity than control subjects and mild insensitivity for GTP inhibition. Patient 2 showed severe insensitivity for GTP inhibition, and similar allosteric stimulation by ADP in the controls. Genetic studies identified heterozygous and de novo L413V and G446D mutations in patients 1 and 2, respectively. COS cell expression study confirmed that both mutations were disease-causing gene. The insensitivity for GTP inhibition in L413V and G446D was emphasised in COS cell expression system as a result of the dosage effect of mutant GDH gene. L413V showed less impairment of GDH than G446D based on biochemical and genetic results, which was consistent with the clinical phenotype. Based on the structure of bovine GDH, G446D was located in GTP binding site of pivot helix and its surroundings, while L413V was located in alpha-helix of antenna-like structure. These different locations of mutations gave different effects on GDH enzyme. The antenna-like structure plays an important role in GDH activity.

Animals↗
PubMed2000

Theoretical study of the force field and vibrational assignments of thioacetamide and its deuterated analogues.

The harmonic force field of thioacetamide has been obtained by Hartree-Fock level ab initio calculations using the 4-31G(d) basis set. The force constants have been scaled to reproduce the infrared fundamental bands of argon matrix isolated CH3CSNH2 and CD3CSNH2. Normal coordinate calculations based on the scaled force field suggested the co-presence of cis-CH3CSNHD and trans-CH3CSNHD in the infrared spectrum measured for CH3CSND2. The prediction of the fundamental bands was made for CD3CSND2, cis-CD3CSNHD and trans-CD3CSNHD.

Deuterium↗
PubMed2000

FRL1 is required for petal and sepal development in Arabidopsis.

A novel flower mutant, frl1 (frill 1) was isolated in Arabidopsis thaliana. The frl1 mutant has serrated petals and sepals but the other floral and vegetative organs appear to be normal. To analyse the role of the FRL1 gene, morphological, cytological and double mutant analyses were carried out. The frl1 flower had broader petals and sepals as compared with the wild-type. The distal region of frl1 petals contained fewer epidermal cells but their size was variable and generally larger than that in the wild-type. However, no significant difference was found in the basal region. Observations of the early petal development revealed that the morphology of the developing frl1 petal was normal until the middle of stage 9, but the frl1 phenotype became apparent in stages later than 10. Furthermore, larger nuclei with varied sizes were observed in the distal region of frl1 petals, but not in this region in wild-type petals. This strongly suggests that abnormal endo-reduplication had occurred. These observations indicate that the frl1 mutation affects the number of cell divisions and the subsequent cell expansion during the late stage of petal lamina formation, and that FRL1 might be maintaining the mitotic state or suppressing the transition to the endo-reduplication cycle. Double mutants with the homeotic mutants apetala3-1 and agamous showed additive phenotypes. Ectopic petals in the third whorl of fr11 ag flowers were serrated, indicating that the FRL1 gene acts in petal and sepal development in an organ-specific manner.

Arabidopsis↗
PubMed1999

Biological effects of ion beams in Nicotiana tabacum L.

The biological effects of ion beams on Nicotiana tabacum L., particularly the induction of chromosome aberrations, were investigated. Dry seeds were exposed to 12C5+, 4He2+ and 1H+ beams with linear energy transfer (LET) ranging from 1 to 111 keV/microm and irradiated with gamma-rays. Ion beams were more effective in reducing germination and survival of the seeds than gamma-rays. The LD50 for 12C5+ beams, 4He2+ beams and gamma-rays were 35, 60 and 500 Gy, respectively. The frequencies of mitotic cells with chromosome aberrations, such as chromosome bridges, acentric fragments and lagging chromosomes in the root tip cells of the exposed seeds, increased linearly with increasing doses. Relative biological effectiveness (RBE) values, based on the doses that induced a survival inhibition of 50% and a 10% frequency of aberrant cells, were 14.3-17.5 for the 12C5+ beams, 7.0-8.3 for the 4He2+ beams and 7.8 for the 1H+ beams. Furthermore, the relative ratios of the chromosome aberration types were significantly different between the ion beam and the gamma-ray regimes: chromosome fragments were more frequent in the former, and chromosome bridges in the latter. Based on these results, we concluded that the repair process of initial le

Cell Division↗
PubMed1999

Molecular characterization of 6-pyruvoyl-tetrahydropterin synthase deficiency in Japanese patients.

We identified three mutations in four Japanese patients with central type 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency. One missense mutation was a C-to-T transition, resulting in the substitution of Pro by Ser at codon 87 (P87S) in exon 5. Another missense mutation was a G-to-A transition, resulting in the substitution of Asp by Asn at codon 96 (D96N) in exon 5. A splicing mutation was found by skipping of exon 4 on PTPS mRNA analysis, and a G-to-A transition at the third base of codon 81 (E81E) and at the terminal base in exon 4 were detected on genomic PTPS DNA analysis. The E81E mutation affected the splice donor site of exon 4 and caused the splicing error. In COS cell expression analysis, the P87S and D96N mutant constructs revealed, respectively, 52% and 10% of wild-type activity. Patients with P87S/P87S (52%/52% in-vitro PTPS activity) exhibited 0.11 and 0 microU/g hemoglobin [Hb] in erythrocyte PTPS activity (wild-type control: 11-29 microU/gHb) erythrocyte PTPS activity, and the patient with P87S/D96N mutations (52%/10%) had 0.97 microU/gHb in PTPS erythrocyte activity. The PTPS erythrocyte activity did not coincide with the in-vitro PTPS activity based on patient genotype.

Amino Acid Metabolism, Inborn Errors↗
PubMed1999

Molecular characterization of galactokinase deficiency in Japanese patients.

Galactokinase (GALK) deficiency is an autosomal recessive disorder, which causes cataract formation in children not maintained on a lactose-free diet. We characterized the human GALK gene by screening a Japanese genomic DNA phage library, and found that several nucleotides in the 5'-untranslated region and introns 1,2, and 5 in our GALK genomic analysis differed from published data. A 20-bp tandem repeat was found in three places in intron 5, which were considered insertion sequences. We identified five novel mutations in seven unrelated Japanese patients with GALK deficiency. There were three missense mutations and two deletions. All three missense mutations (R256W, T344M, and G349S) occurred at CpG dinucleotides, and the T344M and G349S mutations occurred in the conserved region. The three missense mutations led to a drastic reduction in GALK activity when individual mutant cDNAs were expressed in a mammalian cell system. These findings indicated that these missense mutations caused GALK deficiency. The two deletions, of 410delG and 509-510delGT, occurred at the nucleotide repeats GGGGGG and GTGTGT, respectively, and resulted in in-frame nonsense codons at amino acids 163 and 201. These mutations arose by slipped strand mispairing. All five mutations occurred at hot spots in the CpG dinucleotide for missense mutations and in short direct repeats for deletions. These five mutations in Japanese have not yet been identified in Caucasians. We speculate that the origin of GALK mutations in Japanese is different from that in Caucasians.

Adolescent↗
PubMed1998

Molecular characterization of phenylketonuria in Japanese patients.

We characterized phenylalanine hydroxylase (PAH) genotypes of Japanese patients with phenylketonuria (PKU) and hyperphenylalaninemia (HPA). PKU and HPA mutations in 41 Japanese patients were identified by denaturing gradient gel electrophoresis and direct sequencing, followed by restriction fragment length polymorphism analysis to find a large deletion involving exons 5 and 6. Of 82 mutant alleles, 76 (92%) were genotyped showing 21 mutations. The major mutations were R413P (30.5%), R243Q (7.3%), R241 C (7.3%), IVS4nt-1 (7.3%), T2781 (7.3%), E6nt-96A-->g (6.1%), Y356X (4.9%), R111X (3.7%), and 442-706delE5/6 (2.4%). Eight new mutations (L52 S, delS70, S70P, Y77X, IVS3nt-1, A132 V, W187 C, and C265Y) and a polymorphism of IVS10nt-14 were detected. In vitro PAH activities of mutant PAH cDNA constructs were determined by a COS cell expression system. Six mutations, viz., R408Q, L52 S, R241 C, S70P, V388 M, and R243Q, had 55%, 27%, 25%, 20%, 16% and 10% of the in vitro PAH activity of normal constructs, respectively. The mean pretreatment phenylalanine concentration (0.83+/-0.21 mmol/l) of patients carrying the R408Q, R241 C, or L52 S mutation and a null mutation was significantly lower (P<0.0005) than that (1.99+/-0.65 mmol/l) of patients with both alleles carrying mutations associated with a severe genotype. Simple linear regression analysis showed a correlation between pretreatment phenylalanine concentrations and predicted PAH activity in 29 Japanese PKU patients (y=31.9-1.03x, r=0.59, P<0.0001). Genotype determination is useful in the prediction of biochemical and clinical phenotypes in PKU and can be of particular help in managing patients with this disorder.

Animals↗
PubMed1998

[Home mechanical ventilation with nasal intermittent positive pressure ventilation for a boy with congenital central hypoventilation syndrome].

We report a 4-year-old boy with congenital central hypoventilation syndrome (CCHS) successfully treated with home mechanical ventilation with nasal intermittent positive pressure ventilation (NIPPV) during sleep hours. He had had frequent severe apneic attacks from the neonatal period. At 8 months, he was treated with positive pressure ventilation following a tracheostomy. At 4 year and 2 months, NIPPV was attempted because of recurrent respiratory tract infections and cor pulmonale. The tracheostomy was successfully abandoned 6 months later. Adequate ventilation has been maintained for more than 3 years without troubles. NIPPV is an effective and non-invasive treatment of CCHS that it significantly improves the quality of life during daytime.

Child, Preschool↗
PubMed1996

Synthesis and biological activity of conformationally restricted analogs of milnacipran: (1S,2R)-1-phenyl-2-[(S)-1-aminopropyl]-N,N-diethylcyclopropanecarboxami de, an efficient noncompetitive N-methyl-D-aspartic acid receptor antagonist.

We recently demonstrated that (+/-)-(Z)-2-(aminomethyl)-1-phenyl-N,N-diethylcyclopropanecarboxamide [milnacipran, (+/-)-1], an inhibitor of the reuptake of serotonin (5-HT), was a noncompetitive NMDA receptor antagonist. On the basis of the cyclopropane structure of (+/-)-1, conformationally restricted analogs with different stereochemistries, namely 1-phenyl-2-(1-aminoalkyl)-N,N-diethylcyclopropanecarboxamindes (2, 3, ent-2, and ent-3), were designed and synthesized. Among these analogs, 2a, 2b, and 2f, with (1S,2R,1'S)-configuration, were more efficient than milnacipran as NMDA receptor antagonists; these compounds significantly inhibited the binding of [3H]MK-801 at IC50 = 0.35 +/- 0.08, 0.20 +/- 0.024, and 0.16 +/- 0.02 microM, respectively, and blocked the response of voltage-clamped oocytes to NMDA, surpassing the effects of (+/-)-1. Although both the 1'-methyl analog 2a and the 1'-vinyl analog 2f, like (+/-)-1, strongly inhibited 5-HT uptake in vitro, the corresponding 1'-ethyl analog 2b was devoid of the inhibitory effect on 5-HT uptake, while it was about 30 times more potent as an NMDA receptor antagonist than (+/-)-1.

Animals↗
PubMed1996

Partial deletion of the long arm of chromosome 11: ten Japanese children.

The clinical features of partial deletion 11q were correlated with the size of the deleted region. Ten Japanese children with partial deletion of 11q were investigated. They were divided into three groups. Three patients in the first group had interstitial deletions and preserved subband q24.1. Six patients in the second group demonstrated terminal deletion of 11q including subband q24.1, with typical features of 11q- syndrome (Jacobsen syndrome). The third group included only one patient, who had terminal deletion of 11q without characteristics of typical 11q- syndrome. Prominent features of patients in the first group included severe mental and motor developmental delay, seizures, cleft lip and palate, and ophthalmological findings. Patients in the second group showed mild to moderate developmental delays without deterioration. Abnormalities in neuroimages, high intensity in the cerebral white matter in T2-weighted magnetic resonance (MR) images, and recurrent infections were not observed after the age of 7 years. The subject in the third group, with the smallest amount of deleted chromosome, did not show developmental delays, suggesting that some unknown genes related to developmental delays may be located adjacent to subband q24.1. Variation in the deleted parts of 11q resulted in different clinical features in each group.

Abnormalities, Multiple↗
PubMed1995

(+/-)-(Z)-2-(aminomethyl)-1-phenylcyclopropanecarboxamide derivatives as a new prototype of NMDA receptor antagonists.

(+/-)-(Z)-2-(Aminomethyl)-1-phenylcyclopropane-N,N-diethylcarbo xamide (milnacipran, 1), a clinically useful antidepressant, and its derivatives were prepared by an improved method and were evaluated as NMDA receptor antagonists. Of these, milnacipran (1), its N-methyl and N,N-dimethyl derivatives, 7 and 8, respectively, and its homologue 12 at the aminomethyl moiety had binding affinity for the receptor in vitro (IC50: 1, 6.3 +/- 0.3 microM; 7, 13 +/- 2.1 microM; 8, 88 +/- 1.4 microM; 12, 10 +/- 1.2 microM). These also protected mice from NMDA-induced lethality. These compounds would be important as anovel prototype for designing potent NMDA-receptor antagonists because of their characteristic structure, which clearly differentiated them from known competitive and noncompetitive antagonists to the receptor.

Animals↗