| 1. |
- Fukuzawa, Hironobu, et al.
(författare)
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Real-time observation of X-ray-induced intramolecular and interatomic electronic decay in CH2I2
- 2019
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- The increasing availability of X-ray free-electron lasers (XFELs) has catalyzed the development of single-object structural determination and of structural dynamics tracking in real-time. Disentangling the molecular-level reactions triggered by the interaction with an XFEL pulse is a fundamental step towards developing such applications. Here we report real-time observations of XFEL-induced electronic decay via short-lived transient electronic states in the diiodomethane molecule, using a femtosecond near-infrared probe laser. We determine the lifetimes of the transient states populated during the XFEL-induced Auger cascades and find that multiply charged iodine ions are issued from short-lived (∼20 fs) transient states, whereas the singly charged ones originate from significantly longer-lived states (∼100 fs). We identify the mechanisms behind these different time scales: contrary to the short-lived transient states which relax by molecular Auger decay, the long-lived ones decay by an interatomic Coulombic decay between two iodine atoms, during the molecular fragmentation. © 2019, The Author(s).
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| 2. |
- Nakajima, Yoko, et al.
(författare)
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Altered Pre-mRNA Splicing Caused by a Novel Intronic Mutation c.1443+5G>A in the Dihydropyrimidinase (DPYS) Gene.
- 2016
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Dihydropyrimidinase (DHP) deficiency is an autosomal recessive disease caused by mutations in the DPYS gene. Patients present with highly elevated levels of dihydrouracil and dihydrothymine in their urine, blood and cerebrospinal fluid. The analysis of the effect of mutations in DPYS on pre-mRNA splicing is hampered by the fact that DHP is primarily expressed in liver and kidney cells. The minigene approach can detect mRNA splicing aberrations using cells that do not express the endogenous mRNA. We have used a minigene-based approach to analyze the effects of a presumptive pre-mRNA splicing mutation in two newly identified Chinese pediatric patients with DHP deficiency. Mutation analysis of DPYS showed that both patients were compound heterozygous for a novel intronic mutation c.1443+5G>A in intron 8 and a previously described missense mutation c.1001A>G (p.Q334R) in exon 6. Wild-type and the mutated minigene constructs, containing exons 7, 8 and 9 of DPYS, yielded different splicing products after expression in HEK293 cells. The c.1443+5G>A mutation resulted in altered pre-mRNA splicing of the DPYS minigene construct with full skipping of exon 8. Analysis of the DHP crystal structure showed that the deletion of exon 8 severely affects folding, stability and homooligomerization of the enzyme as well as disruption of the catalytic site. Thus, the analysis suggests that the c.1443+5G>A mutation results in aberrant splicing of the pre-mRNA encoding DHP, underlying the DHP deficiency in two unrelated Chinese patients.
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| 3. |
- Nakajima, Yoko, et al.
(författare)
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Clinical, biochemical and molecular analysis of 13 Japanese patients with beta-ureidopropionase deficiency demonstrates high prevalence of the c.977G > A (p.R326Q) mutation
- 2014
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Ingår i: Journal of Inherited Metabolic Disease. - : Wiley. - 0141-8955 .- 1573-2665. ; 37:5, s. 801-812
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Tidskriftsartikel (refereegranskat)abstract
- beta-ureidopropionase (beta UP) deficiency is an autosomal recessive disease characterized by N-carbamyl-beta-amino aciduria. To date, only 16 genetically confirmed patients with beta UP deficiency have been reported. Here, we report on the clinical, biochemical and molecular findings of 13 Japanese beta UP deficient patients. In this group of patients, three novel missense mutations (p.G31S, p.E271K, and p.I286T) and a recently described mutation (p.R326Q) were identified. The p.R326Q mutation was detected in all 13 patients with eight patients being homozygous for this mutation. Screening for the p.R326Q mutation in 110 Japanese individuals showed an allele frequency of 0.9 %. Transient expression of mutant beta UP enzymes in HEK293 cells showed that the p.E271K and p.R326Q mutations cause profound decreases in activity (a parts per thousand currency sign 1.3 %). Conversely, beta UP enzymes containing the p.G31S and p.I286T mutations possess residual activities of 50 and 70 %, respectively, suggesting we cannot exclude the presence of additional mutations in the non-coding region of the UPB1 gene. Analysis of a human beta UP homology model revealed that the effects of the mutations (p.G31S, p.E271K, and p.R326Q) on enzyme activity are most likely linked to improper oligomer assembly. Highly variable phenotypes ranging from neurological involvement (including convulsions and autism) to asymptomatic, were observed in diagnosed patients. High prevalence of p.R326Q in the normal Japanese population indicates that beta UP deficiency is not as rare as generally considered and screening for beta UP deficiency should be included in diagnosis of patients with unexplained neurological abnormalities.
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| 4. |
- Nakajima, Yoko, et al.
(författare)
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Dihydropyrimidinase deficiency in four East Asian patients due to novel and rare DPYS mutations affecting protein structural integrity and catalytic activity
- 2017
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Ingår i: Molecular Genetics and Metabolism. - : Elsevier BV. - 1096-7192 .- 1096-7206. ; 122:4, s. 216-222
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Tidskriftsartikel (refereegranskat)abstract
- Dihydropyrimidinase (DHP) is the second enzyme of the pyrimidine degradation pathway and catalyzes the ring opening of 5,6-dihydrouracil and 5,6-dihydrothymine. To date, only 31 genetically confirmed patients with a DHP deficiency have been reported and the clinical, biochemical and genetic spectrum of DHP deficient patients is, therefore, still largely unknown. Here, we show that 4 newly identified DHP deficient patients presented with strongly elevated levels of 5,6-dihydrouracil and 5,6-dihydrothymine in urine and a highly variable clinical presentation, ranging from asymptomatic to infantile spasm and reduced white matter and brain atrophy. Analysis of the DHP gene (DPYS) showed the presence of 8 variants including 4 novel/rare missense variants and one novel deletion. Functional analysis of recombinantly expressed DHP mutants carrying the p.M250I, p.H295R, p.Q334R, p.T418I and the p.R490H variant showed residual DHP activities of 2.0%, 9.8%, 9.7%, 64% and 0.3%, respectively. The crystal structure of human DHP indicated that all point mutations were likely to cause rearrangements of loops shaping the active site, primarily affecting substrate binding and stability of the enzyme. The observation that the identified mutations were more prevalent in East Asians and the Japanese population indicates that DHP deficiency may be more common than anticipated in these ethnic groups.
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| 5. |
- Robertson, Betty H, et al.
(författare)
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Genetic relatedness of hepatitis A virus strains recovered from different geographical regions
- 1992
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Ingår i: Journal of General Virology. - : Microbiology Society. - 1465-2099 .- 0022-1317. ; 73, s. 1365-1377
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Tidskriftsartikel (refereegranskat)abstract
- A pairwise comparison of the nucleic acid sequence of 168 bases from 152 wild-type or unique cell culture-adapted strains of hepatitis A virus (HAV) revealed that HAV strains can be differentiated genetically into seven unique genotypes (I to VII). In general, the nucleotide sequence of viruses in different genotypes differs at 15 to 25% of positions within this segment of the genome. Viruses from four of the genotypes (I, II, III and VII) were recovered from cases of hepatitis A in humans, whereas viruses from the other three genotypes (IV, V and VI) were isolated only from simian species developing a hepatitis A-like illness during captivity. Among non-epidemiologically related human HAV strains, 81 were characterized as genotype I, and 19 as genotype III. Within each of these major genotypes, there were two distinct groups (subgenotypes), which differed in sequence at approximately 7.5% of base positions. Each genotype and subgenotype has a characteristic amino acid sequence in this region of the polyprotein, with the most divergent genotypes differing at 10 of 56 residues. Strains recovered from some geographical regions belonged to a common (endemic) genotype, whereas strains from other regions belonged to several, probably imported, genotypes. Thus, HAV strains recovered in North America were for the most part closely related at the nucleotide sequence level, whereas in other regions, such as Japan and Western Europe, HAV strains were derived from multiple genotypes or sub-genotypes. These data indicate that patterns of endemic transmission can be differentiated from situations in which infections are imported due to travel.
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| 6. |
- van Kuilenburg, André B P, et al.
(författare)
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ß-ureidopropionase deficiency : phenotype, genotype and protein structural consequences in 16 patients
- 2012
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Ingår i: Biochimica et Biophysica Acta. - : Elsevier BV. - 0006-3002 .- 1878-2434. ; 1822:7, s. 1096-108
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Tidskriftsartikel (refereegranskat)abstract
- ß-ureidopropionase is the third enzyme of the pyrimidine degradation pathway and catalyzes the conversion of N-carbamyl-ß-alanine and N-carbamyl-ß-aminoisobutyric acid to ß-alanine and ß-aminoisobutyric acid, ammonia and CO(2). To date, only five genetically confirmed patients with a complete ß-ureidopropionase deficiency have been reported. Here, we report on the clinical, biochemical and molecular findings of 11 newly identified ß-ureidopropionase deficient patients as well as the analysis of the mutations in a three-dimensional framework. Patients presented mainly with neurological abnormalities (intellectual disabilities, seizures, abnormal tonus regulation, microcephaly, and malformations on neuro-imaging) and markedly elevated levels of N-carbamyl-ß-alanine and N-carbamyl-ß-aminoisobutyric acid in urine and plasma. Analysis of UPB1, encoding ß-ureidopropionase, showed 6 novel missense mutations and one novel splice-site mutation. Heterologous expression of the 6 mutant enzymes in Escherichia coli showed that all mutations yielded mutant ß-ureidopropionase proteins with significantly decreased activity. Analysis of a homology model of human ß-ureidopropionase generated using the crystal structure of the enzyme from Drosophila melanogaster indicated that the point mutations p.G235R, p.R236W and p.S264R lead to amino acid exchanges in the active site and therefore affect substrate binding and catalysis. The mutations L13S, R326Q and T359M resulted most likely in folding defects and oligomer assembly impairment. Two mutations were identified in several unrelated ß-ureidopropionase patients, indicating that ß-ureidopropionase deficiency may be more common than anticipated.
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| 7. |
- Wilunda, Calistus, et al.
(författare)
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Sleep duration and risk of cancer incidence and mortality : A pooled analysis of six population-based cohorts in Japan
- 2022
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 151:7, s. 1068-1080
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Tidskriftsartikel (refereegranskat)abstract
- Sleep duration is emerging as an important modifiable risk factor for morbidity and mortality. We assessed the association between sleep duration and cancer incidence and mortality among Japanese adults using data from six population-based cohorts with 271 694 participants. During a total follow-up period of about 5.9 million person-years, we identified 40 751 incident cancer cases and 18 323 cancer deaths. We computed study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression models and pooled the estimates using random-effects meta-analysis. Sleep duration of ≥10 hours (vs 7 hours) was associated with increased risk of cancer incidence among women (HR 1.19, 95% CI 1.02-1.38), but not men, and increased risk of cancer mortality among men (HR 1.18, 95% CI 1.00-1.39) and women (HR 1.44, 95% CI 1.20-1.73). Sleep duration of ≤5 hours (vs 7 hours) was not associated with cancer incidence and mortality. However, among postmenopausal women, sleep durations of both ≤5 and ≥10 hours (vs 7 hours) were associated with an increased risk of cancer mortality. Among Japanese adults, sleep duration of ≥10 hours is associated with increased risk of cancer incidence and mortality among women and cancer mortality among men.
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