32 results on '"Maseda C"'
Search Results
2. Chiral and nonchiral determination of ketoprofen in pharmaceuticals by capillary zone electrophoresis
- Author
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Blanco, M, Coello, J, Iturriaga, H, Maspoch, S, and Pérez-Maseda, C
- Published
- 1998
- Full Text
- View/download PDF
3. Separation of profen enantiomers by capillary electrophoresis using cyclodextrins as chiral selectors
- Author
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Blanco, M, Coello, J, Iturriaga, H, Maspoch, S, and Pérez-Maseda, C
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- 1998
- Full Text
- View/download PDF
4. Liquid chromatography-tandem mass spectrometry method for the determination of thiosulfate in human blood and urine as an indicator of hydrogen sulfide poisoning.
- Author
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Maseda C, Hayakawa A, Okuda K, Asari M, Tanaka H, Yamada H, Jin S, Horioka K, Matoba K, Shiono H, Matsubara K, and Shimizu K
- Subjects
- Forensic Toxicology, Humans, Qualitative Research, Chromatography, Liquid methods, Hydrogen Sulfide poisoning, Tandem Mass Spectrometry methods, Thiosulfates blood, Thiosulfates urine
- Abstract
Being a stable metabolite of hydrogen sulfide, thiosulfate has been utilized as an index for hydrogen sulfide poisoning (HSP). Thiosulfate analysis is mainly performed using gas chromatography/mass spectrometry (GC-MS) due to its high sensitivity and specificity. The GC-MS analysis requires two-step derivatizations of thiosulfate, and the derivative is not stable in solution as it has a disulfide moiety. To resolve this stability issue, we developed a novel analytical method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for monitoring the pentafluorobenzyl derivative of thiosulfate (the first reaction product of the GC-MS method) in this study. The established method exhibited high reproducibility despite being a more simplified and rapid procedure compare to the GC-MS method. Phenyl 4-hydroxybenzoate was used as an internal standard because 1,3,5-tribromobenzene which had been used in the GC-MS method was not suitable compound for LC-MS/MS with Electrospray ionization (ESI) negative detection. The linear regression of the peak area ratios versus concentrations was fitted over the concentration ranges of 0.5-250μM and 0.25-250μM in blood and urine, respectively. The validation results satisfied the acceptance criteria for intra- and inter-day accuracy and precision. Blood and urine samples from 12 suspected HSP cases were tested using this method. The thiosulfate concentration detected in the sample coincided well with that determined at the scene of each HSP accident., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
5. Postmortem diffusion of n-butane and i-butane used for anticontagious plugging spray.
- Author
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Okuda K, Maseda C, Asari M, Isozaki S, Kiya H, Yajima D, Shiono H, and Shimizu K
- Subjects
- Accidental Falls, Animals, Autopsy, Cause of Death, Dementia diagnosis, Gas Chromatography-Mass Spectrometry, Humans, Male, Middle Aged, Postmortem Changes, Rats, Butanes blood, Forensic Toxicology methods
- Abstract
Blood and tissue samples from a forensic autopsy of a man in his late 60s, who developed dementia and died of multiple head traumas due to a fall from a moving vehicle, contained certain amounts of n-butane and i-butane. The concentration of n-butane was in the range of 0.48-70.5 μL/g, which would be considered as toxic or lethal levels. We had to distinguish whether the cause of his unexplained behavior was due to his pre-existing condition (dementia), or from a confused state induced by butane abuse. No traces of butane use were found at the scene. Police investigation revealed that a propellant used in an anticontagious plugging spray had been administered to him during a postmortem treatment in the emergency hospital. In order to prove the postmortem butane diffusion had resulted from the spray administration and to estimate the diffused concentration, experimental simulation was conducted by using rats. As a result of postmortem treatment with the spray, n-butane at concentrations of 0.54-15.5 μL/mL or g were found in the rat blood and tissues. In this case, we provided further evidence that the postmortem butane diffusion, caused by using the anticontagious plugging spray containing butane gas as a propellant administered to a cadaver during a postmortem procedure prior to forensic autopsy, should be distinguished from cases of actual butane poisoning., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2016
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6. A Case of Sudden Infant Death Due to Incomplete Kawasaki Disease.
- Author
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Yajima D, Shimizu K, Oka K, Asari M, Maseda C, Okuda K, Shiono H, Ohtani S, and Ogawa K
- Subjects
- Autopsy, Humans, Infant, Male, Death, Sudden, Cardiac, Mucocutaneous Lymph Node Syndrome, Myocardial Infarction, Sudden Infant Death
- Abstract
Although Kawasaki disease (KD) is a self-limiting disease, it may cause sudden cardiac death. Diagnosis of KD is principally based on clinical signs; however, some infant cases do not meet the criteria. Such cases are identified as incomplete KD. The sudden death risk in incomplete KD cases is similar to conventional KD. In our 5-month-old case, he had been admitted to a hospital for a fever and suppuration at the site of Bacille de Calmette et Guerin (BCG) vaccination. However, after discharge from the hospital, his C-reactive protein (CRP) levels declined, he got indisposed and died suddenly. A medico-legal autopsy revealed myocarditis, coronaritis, platelet-aggregated emboli in coronary arteries, and myocardial degeneration, suggesting that the fatal myocardial infarction was due to thrombus emboli in the coronary arteries. Forensic pathologists therefore should pay attention to the cardiac pathology originated from incomplete KD as a potential cause in cases of sudden infant death., (© 2015 American Academy of Forensic Sciences.)
- Published
- 2016
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7. An objective approach using three indexes for determining fatal hypothermia due to cold exposure; statistical analysis of oxyhemoglobin saturation data.
- Author
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Yajima D, Asari M, Okuda K, Maseda C, Yamada H, Ichimaru C, Matsubara K, Shiono H, Iwase H, Makino Y, and Shimizu K
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- Adolescent, Adult, Aged, Aged, 80 and over, Cold Temperature adverse effects, Data Interpretation, Statistical, Female, Humans, Hypothermia etiology, Male, Middle Aged, Statistics as Topic, Young Adult, Autopsy methods, Hypothermia mortality, Oxyhemoglobins analysis
- Abstract
Analysis of oxyhemoglobin (O2-Hb) saturation levels in the left and right heart blood is useful in the assessment of exposure to cold surroundings before death. We quantified conventional subjective visual evaluation of O2-Hb saturation levels and developed useful diagnostic criteria for fatal hypothermia: O2-Hb saturation in the left heart blood (L-O2Hb) was ⩾36%, the O2-Hb saturation gap between the left and right heart blood (L-R gap) was ⩾13%, and the O2-Hb saturation ratio of the left to right heart blood (L/R ratio) was ⩾1.8. When we used L-O2Hb of ⩾36% as a basic criterion and applied a further criterion of an L-R gap of ⩾13% or an L/R ratio of ⩾1.8, these criteria registered a sensitivity level of ⩾86% and specificity level of ⩾93% for the diagnosis of fatal hypothermia. This method can be useful for determining fatal hypothermia in connection with conventional autopsy findings, as well as histological and biochemical markers., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2015
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8. Rapid genotyping of 25 autosomal STRs in a Japanese population using fluorescent universal primers containing locked nucleic acids.
- Author
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Asari M, Okuda K, Yajima D, Maseda C, Hoshina C, Omura T, Shiono H, Matsubara K, and Shimizu K
- Subjects
- Asian People genetics, DNA Fingerprinting methods, Heterozygote, Humans, Japan, DNA Primers chemistry, Fluorescent Dyes chemistry, Genotyping Techniques methods, Microsatellite Repeats, Oligonucleotides genetics, Polymerase Chain Reaction methods
- Abstract
Amplification of fluorescently labeled products is one of the most popular methods for genotyping genetic variations. Two-step amplification using fluorescent universal primers simultaneously produces multiple targeted fragments labeled with fluorescent dyes, and this strategy is applicable to large-scale, cost-effective genotyping. In this study, we developed a fast PCR-based, multiple short tandem repeat (STR) genotyping method using fluorescent universal primers containing locked nucleic acids (LNAs). Four amplification reactions, each assaying six or seven markers and using 0.5-1.0 ng of genomic DNA, produced obvious Fam-labeled peaks in all 26 loci tested (25 autosomal STRs and amelogenin). The overall amplification time was 37 min. Moreover, fluorescent signals for the 25 STRs obtained from LNA-containing primers were 1.5-9.0 fold higher compared to those from non-LNA primers. Using genomic DNA from 120 Japanese individuals, 16 out of the 25 STRs had observed heterozygosity greater than 0.7. Some of these 25 STRs also had high discriminatory power, similar to that of the 13 core STRs in the Combined DNA Index System dataset. The probability of incorrectly assigning a match based on the accumulated matching probability for these 25 STRs is 1.2 × 10(-22), and their combined use can provide robust information for Japanese forensics., (Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)
- Published
- 2015
- Full Text
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9. Brain stem hemorrhage due to cerebral amyloid angiopathy: the autopsy of a patient with Alzheimer's disease at a young age.
- Author
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Ohtani S, Shimizu K, Asari M, Maseda C, Oka K, Yamada H, Hoshina C, Doi H, Yajima D, Shiono H, and Ogawa K
- Subjects
- Cerebellum pathology, Humans, Hypertension diagnosis, Intracranial Hemorrhages etiology, Male, Middle Aged, Necrosis, Neurofibrillary Tangles pathology, Plaque, Amyloid pathology, Pons pathology, Alzheimer Disease pathology, Cerebral Amyloid Angiopathy pathology, Intracranial Hemorrhages pathology
- Abstract
We report findings from an autopsy of a male in his 40s who died of a brain stem hemorrhage associated with cerebral amyloid angiopathy (CAA), senile plaques (SPs) and neurofibrillary tangles (NFTs), which are histopathological changes associated with Alzheimer's disease (AD). Our immunohistochemical study demonstrated amyloid β (Aβ) deposition in the small cerebral arteries and SPs. Although hypertension (178/132 mmHg) was detected, the subject was not treated accordingly. CAA coupled with hypertension might have caused the intracerebral hemorrhage (ICH)., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2014
- Full Text
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10. Genotyping of 38 insertion/deletion polymorphisms for human identification using universal fluorescent PCR.
- Author
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Oka K, Asari M, Omura T, Yoshida M, Maseda C, Yajima D, Matsubara K, Shiono H, Matsuda M, and Shimizu K
- Subjects
- Amelogenin genetics, DNA Primers, Fluorescent Dyes, Gene Frequency, Genetic Variation, Genotype, Humans, Japan, Sensitivity and Specificity, Forensic Anthropology methods, Genome, Human, Genotyping Techniques economics, INDEL Mutation, Multiplex Polymerase Chain Reaction, Polymorphism, Genetic
- Abstract
Short insertion/deletion (Indel) polymorphisms of approximately 2-6 bp are useful as biallelic markers for forensic analysis, and the application of Indel genotyping as a supplementary tool would improve human identification accuracy. We examined the allele frequencies of 37 autosomal Indels in the Japanese population and developed a novel dual-color genotyping method for human identification on the basis of universal fluorescent PCR, including the sex-typing amelogenin locus. Target genomic fragment sizes for 38 Indels were 49-143 bp. We analyzed these Indels in 100 Japanese individuals using the M13(-47) sequence as a universal primer. For dual-color genotyping, we designed a novel universal primer with high amplification efficiency and specificity. Using FAM-labeled M13(-47) and HEX-labeled modified M13(-47) primers, fluorescent signals at all loci were clearly distinguished in two independent multiplex PCRs. Average minor allele frequency was 0.39, and accumulated matching probability was 2.12 × 10(-15). Complete profiles were successfully amplified with as little as 0.25 ng of DNA. This method provides robust, sensitive, and cost-effective genotyping for human identification., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2014
- Full Text
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11. Sodium tauroursodeoxycholate prevents paraquat-induced cell death by suppressing endoplasmic reticulum stress responses in human lung epithelial A549 cells.
- Author
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Omura T, Asari M, Yamamoto J, Oka K, Hoshina C, Maseda C, Awaya T, Tasaki Y, Shiono H, Yonezawa A, Masuda S, Matsubara K, and Shimizu K
- Subjects
- Caspase 3 biosynthesis, Cell Line, DNA-Binding Proteins metabolism, Enzyme Activation drug effects, Eukaryotic Initiation Factor-2 metabolism, Herbicides toxicity, Humans, Mitochondrial Proton-Translocating ATPases metabolism, Paraquat toxicity, Regulatory Factor X Transcription Factors, Respiratory Mucosa cytology, Respiratory Mucosa enzymology, Transcription Factors metabolism, Unfolded Protein Response drug effects, Apoptosis drug effects, Endoplasmic Reticulum Stress drug effects, Herbicides antagonists & inhibitors, Lung cytology, Paraquat antagonists & inhibitors, Respiratory Mucosa drug effects, Taurochenodeoxycholic Acid pharmacology
- Abstract
Paraquat is a commonly used herbicide; however, it is highly toxic to humans and animals. Exposure to paraquat causes severe lung damage, leading to pulmonary fibrosis. However, it has not been well clarified as how paraquat causes cellular damage, and there is no established standard therapy for paraquat poisoning. Meanwhile, endoplasmic reticulum stress (ERS) is reported to be one of the causative factors in many diseases, although mammalian cells have a defense mechanism against ERS-induced apoptosis (unfolded protein response). Here, we demonstrated that paraquat changed the expression levels of unfolded protein response-related molecules, resulting in ERS-related cell death in human lung epithelial A549 cells. Moreover, treatment with sodium tauroursodeoxycholate (TUDCA), a chemical chaperone, crucially rescued cells from death caused by exposure to paraquat. These results indicate that paraquat toxicity may be associated with ERS-related molecules/events. Through chemical chaperone activity, treatment with TUDCA reduced paraquat-induced ERS and mildly suppressed cell death. Our findings also suggest that TUDCA treatment represses the onset of pulmonary fibrosis caused by paraquat, and therefore chemical chaperones may have novel therapeutic potential for the treatment of paraquat poisoning., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
- Full Text
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12. Universal fluorescent labeling of amplification products using locked nucleic acids.
- Author
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Asari M, Oka K, Omura T, Maseda C, Tasaki Y, Shiono H, Matsubara K, Matsuda M, and Shimizu K
- Subjects
- Base Composition, Cell Line, Computer Simulation, DNA analysis, DNA genetics, DNA Primers genetics, Female, Gene Frequency, Humans, Microsatellite Repeats, Plasmids genetics, DNA Primers chemistry, Fluorescent Dyes chemistry, Genotyping Techniques methods, Multiplex Polymerase Chain Reaction methods, Oligonucleotides chemistry
- Abstract
Amplification/hybridization-based genetic analyses using primers containing locked nucleic acids (LNAs) present many benefits. Here, we developed a novel design for universal fluorescent PCR using LNAs. Universal fluorescent PCR generates intermediate nonlabeled fragments and final fluorescent fragments in a two-step amplification process that uses locus-specific primers with universal tails and universal fluorescent primers. In this study, a few standard nucleotides were replaced with LNAs only in the fluorescent universal primers. The sequence of the fluorescent universal primer significantly affected the amplification efficiency. For primers with three LNAs, the fluorescent primers with stable M13(-47) sequences provided the most efficient signal (approximately tenfold higher than the primers with M13(-21) sequences at lower Tm values). Moreover, AT-rich LNA substitutions in the fluorescent primers produced much lower amplification efficiencies than GC-rich substitutions. GC-rich LNAs produced greater differences in Tm values among primers, and resulted in the preferential production of fluorescently labeled amplicons. The specificity and sensitivity of LNA-containing fluorescent primers were assessed by genotyping eight STRs in Japanese individuals, and full STR profiles could be generated using as little as 0.25 ng of genomic DNA. The method permitted clear discrimination of alleles and represents sensitive STR genotyping at a reduced cost., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2013
- Full Text
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13. Estimation of the duration after methamphetamine injection using a pharmacokinetic model in suspects who caused fatal traffic accidents.
- Author
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Matsubara K, Asari M, Suno M, Awaya T, Sugawara M, Omura T, Yamamoto J, Maseda C, Tasaki Y, Shiono H, and Shimizu K
- Subjects
- Central Nervous System Stimulants administration & dosage, Cytochrome P-450 CYP2D6 genetics, Forensic Toxicology, Genotype, Humans, Injections, Male, Methamphetamine administration & dosage, Models, Biological, Polymerase Chain Reaction, Accidents, Traffic, Central Nervous System Stimulants blood, Central Nervous System Stimulants pharmacokinetics, Methamphetamine blood, Methamphetamine pharmacokinetics
- Abstract
When the population parameters of drug pharmacokinetics in the human body system are known, the time-course of a certain drug in an individual can generally be estimated by pharmacokinetics. In the present two cases where methamphetamine abusers were suspected to have inflicted mortalities in traffic accidents, the time-elapse or duration immediately after methamphetamine injection to the time when the accidents occurred became points of contention. In each case, we estimated the time-course of blood methamphetamine after the self-administration in the suspects using a 2-compartment pharmacokinetic model with known pharmacokinetic parameters from the literatures. If the injected amount can be determined to a certain extent, it is easy to calculate the average time-elapse after injection by referring to reference values. However, there is considerable individual variability in the elimination rate based on genetic polymorphism and a considerably large error range in the estimated time-elapse results. To minimize estimation errors in such cases, we also analyzed genotype of CYP2D6, which influenced methamphetamine metabolism. Estimation based on two time-point blood samples would usefully benefit legal authorities in passing ruling sentences in cases involving similar personalities and circumstances as those involved in the present study., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2012
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14. Multiplex PCR-based Alu insertion polymorphisms genotyping for identifying individuals of Japanese ethnicity.
- Author
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Asari M, Omura T, Oka K, Maseda C, Tasaki Y, Shiono H, Matsubara K, Matsuda M, and Shimizu K
- Subjects
- Alleles, DNA Primers genetics, Electrophoresis, Capillary methods, Gene Frequency, Genetic Loci, Genetic Markers, Genotype, Humans, Japan, Sequence Analysis, DNA, Alu Elements genetics, Asian People genetics, Multiplex Polymerase Chain Reaction methods, Mutagenesis, Insertional methods, Polymorphism, Genetic
- Abstract
Discrimination of Alu insertions is a useful tool for geographic ancestry analysis, and is usually performed by Alu element amplification and agarose gel electrophoresis. Here, we have developed a new fluorescence-based method for multiple Alu genotyping in forensic identification. Allele frequencies were determined in 70 Japanese individuals, and we selected 30 polymorphic Alu insertions. Three primers were designed for each Alu locus to discriminate alleles using the 3-6 bp differences in amplicon sizes. Furthermore, we classified the amplification primers for the 30 loci into three different sets, and PCR using each set of primers provided 10 loci fragments ranging from 50 to 137 bp. Based on population data, the probability of incorrectly assigning a match was 3.7×10(-13). Three independent amplifications and subsequent capillary electrophoresis enabled the sensitive genotyping of small amounts of DNA, indicating that this method is suitable for identifying individuals of Japanese ethnicity., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2012
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15. HRD1 levels increased by zonisamide prevented cell death and caspase-3 activation caused by endoplasmic reticulum stress in SH-SY5Y cells.
- Author
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Omura T, Asari M, Yamamoto J, Kamiyama N, Oka K, Hoshina C, Maseda C, Awaya T, Tasaki Y, Shiono H, Shimizu K, and Matsubara K
- Subjects
- Anticonvulsants pharmacology, Caspase Inhibitors pharmacology, Cell Death drug effects, Cell Death genetics, Cell Line, Tumor, Endoplasmic Reticulum Stress genetics, Humans, Neuroblastoma enzymology, Neuroblastoma pathology, Ubiquitin-Protein Ligases biosynthesis, Zonisamide, Caspase 3 metabolism, Endoplasmic Reticulum Stress drug effects, Isoxazoles pharmacology, Ubiquitin-Protein Ligases genetics
- Abstract
Zonisamide, which is commonly prescribed at high doses (200-400 mg/day) for the treatment of partial seizures, has recently been used at a low dose (25 mg/day) for improving parkinsonian syndrome. However, the molecular mechanisms that underlie the antiparkinsonian effects of zonisamide have not been clarified. Here we show that low micromolar concentrations of zonisamide prevented cleavage of caspase-3 and cell death in human dopaminergic SH-SY5Y neuroblastoma cells that were subjected to endoplasmic reticulum stress induced by tunicamycin or 6-hydroxydopamine. Hypodense zonisamide increased the expression levels of SEL1L, which is known to stabilize the ubiquitin ligase HRD1. Indeed, upregulation of HRD1 protein was observed. Thus, the results of this study strongly suggest that low concentrations of zonisamide inhibit neuronal cell death by increasing HRD1 protein levels in patients with Parkinson's disease. Consequently, in addition to the treatment of Parkinson's disease, the therapeutic potential of zonisamide should be considered for the treatment of several neurodegenerative disorders with pathophysiological mechanisms involving endoplasmic reticulum stress.
- Published
- 2012
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16. Enhanced discrimination of single nucleotide polymorphisms using 3' nucleotide differences in ligase detection reaction probes.
- Author
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Asari M, Omura T, Maseda C, Shiono H, Tasaki Y, Matsubara K, and Shimizu K
- Subjects
- Base Sequence, Biological Assay, Humans, Molecular Sequence Data, Sequence Deletion, DNA Probes metabolism, Ligase Chain Reaction methods, Nucleotides genetics, Polymorphism, Single Nucleotide genetics
- Abstract
The ligase detection reaction (LDR) is a highly specific genotyping method for single nucleotide variations. Although LDR typically discriminates single nucleotide polymorphism (SNP) alleles at the 3' end of so-called LDR discriminating probes, we designed probes in which the position of nucleotide differences for discrimination was shifted to the second and third nucleotides from the 3' end. Using the 3'-modified probes, we targeted SNPs of the human ABO group and investigated the specificity and efficiency of ligation by a universal LDR assay. We demonstrated that one or two nucleotide shifts of differences in discriminating probes improve the allele balance in detecting both base substitutions and short deletions. In regard to short deletions, moreover, the shifts of nucleotide differences in discriminating probes form the perfect-machted or multiple-mismatched structures (the bulge structures) in the discriminating probe-target DNA duplex and may contribute to enhance ligation efficiency., (Copyright © 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2010
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17. A new method for human ABO genotyping using a universal reporter primer system.
- Author
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Asari M, Omura T, Maseda C, Matsubara K, Shiono H, and Shimizu K
- Subjects
- DNA Degradation, Necrotic, Electrophoresis, Genotype, Humans, Japan, Polymerase Chain Reaction, Sequence Analysis, DNA, ABO Blood-Group System genetics, DNA Primers, Forensic Genetics methods, Polymorphism, Single Nucleotide
- Abstract
We developed a new method for forensic ABO genotyping based on a universal reporter primer (URP) system. This allows for the simultaneous detection of six single nucleotide polymorphism (SNP) sites in the ABO gene (nucleotide positions 261, 297, 526, 703, 796, and 803). This URP system provides obvious peaks, ranging from 82 to 151 bp in length. ABO genotypes were classified and successfully genotyped by our method, including minor alleles that may cause a discrepancy between the genetic data and serological phenotypes. Full profiles were identified using as little as 0.1 ng (0.05 ng ⁄ reaction) of standard K562 and 9947A DNA. Moreover, the success rate of genotyping from a URP system was much higher than that from a conventional primer extension method in degraded DNA. This method enables simple and rapid detection of multiple SNP sites on human ABO genes and is highly specific and sensitive when using limited and degraded DNA.
- Published
- 2010
- Full Text
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18. Determination of enantiomeric purity of a novel COX-2 anti-inflammatory drug by capillary electrophoresis using single and dual cyclodextrin systems.
- Author
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Pérez-Maseda C, Calvet C, Cuberes R, and Frigola J
- Subjects
- Anti-Inflammatory Agents isolation & purification, Chemistry, Pharmaceutical methods, Cyclodextrins, Methanol, Stereoisomerism, Temperature, Cyclooxygenase Inhibitors isolation & purification, Electrophoresis, Capillary methods, Pyrazoles isolation & purification, Sulfonamides isolation & purification
- Abstract
E-6087 is the most advanced compound among the cyclooxygenase-2 (COX-2) inhibitor drugs developed in our company. Its activity is mainly associated with the S(-)-enantiomer (E-6232), whereas the R(-)-enantiomer (E-6231) becomes an impurity whose content should be determined. Five main impurities and degradation products of E-6232 have been found (E-6144, E-6024, E-6072, E-6397 and E-6132), and some of them co-elute with the distomer when using a chiral high-performance liquid chromatography (HPLC) method. Consequently, we have optimized the separation of all the impurities from the two enantiomers of E-6087 by capillary electrophoresis (CE), in order to use the method for the enantiomeric purity determination of E-6232. The effect of the methanol (MeOH) content in the background electrolyte (BGE), the sulfobutyl ether-beta-cyclodextrin (SBE-beta-CD) and heptakis-(2,6-di-O-methyl)-beta-cyclodextrin (DM-beta-CD) concentration, and the capillary temperature have been studied. Separation of all compounds could be achieved in different systems, either in a single CD-system (with SBE-beta-CD) or in a dual CD-system (with DM-beta-CD as a neutral CD). By using the dual CD system a limit of detection (LOD) and a limit of quantitation (LOQ) of 0.03% and 0.1% of distomer, respectively, were achieved*.
- Published
- 2003
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19. Enantioseparation of novel COX-2 anti-inflammatory drugs by capillary electrophoresis using single and dual cyclodextrin systems.
- Author
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Calvet C, Cuberes R, Pérez-Maseda C, and Frigola J
- Subjects
- Chromatography, Micellar Electrokinetic Capillary, Cyclodextrins, Cyclooxygenase 2, Cyclooxygenase 2 Inhibitors, Cyclooxygenase Inhibitors analysis, Ethers, Methanol, Prostaglandin-Endoperoxide Synthases, Pyrazoles, Stereoisomerism, Sulfonamides, Cyclooxygenase Inhibitors isolation & purification, Electrophoresis, Capillary methods, Isoenzymes antagonists & inhibitors, beta-Cyclodextrins
- Abstract
A capillary electrophoresis method was developed for the enantioseparation of three novel cyclooxygenase-2 (COX-2) inhibitor drugs (E-6259, E-6036 and E-6087) with anti-inflammatory and analgesic activities using sulfobutyl ether-beta-cyclodextrin (SBE-beta-CD) as a chiral selector. The use of 50 mM sodium tetraborate at pH 9.2 with 30% v/v methanol, containing 7.1 mM SBE-beta-CD, as a background electrolyte (BGE) allowed the complete enantioseparation of the three neutral racemic mixtures (resolution = 2.4, 3.0 and 8.7, respectively) and their corresponding metabolites (oxidation products) in a single run. Migration times were shortened with some loss of enantioresolution by adding 1.75 mM dimethyl-beta-cyclodextrin (DM-beta-CD) to the previous BGE (dual CD system). The reversal of the migration order of E-6259 enantiomers in the dual CD system was also studied. Furthermore, the addition of DM-beta-CD to the BGE introduced a new chemoselectivity in the system that allowed E-6259 to be separated from the structurally similar compound E-6036.
- Published
- 2002
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20. Stereoselective analyses of selegiline metabolites: possible urinary markers for selegiline therapy.
- Author
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Hasegawa M, Matsubara K, Fukushima S, Maseda C, Uezono T, and Kimura K
- Subjects
- Adult, Amphetamine urine, Amphetamines urine, Biomarkers, Chromatography, Gas, Diagnosis, Differential, Female, Humans, Male, Methamphetamine urine, Middle Aged, Monoamine Oxidase Inhibitors therapeutic use, Stereoisomerism, Substance Abuse Detection, Substance-Related Disorders diagnosis, Substance-Related Disorders urine, Monoamine Oxidase Inhibitors metabolism, Selegiline metabolism, Selegiline therapeutic use
- Abstract
The stereoselective analysis of selegiline metabolites in human urine and plasma by gas chromatography using the chiral column with the non-chiral reagent was investigated for the differentiation of selegiline therapy from the methamphetamine (MA) abuse. This method gave clear separations of MA and amphetamine (AM) isomers without any artifactual optical-opposite peaks due to the reagent. After the administration of selegiline tablets, desmethylselegiline (DMS), MA and AM were observed as (-)-isomers in the urine and plasma. Within the first 48 h after dosing, approximately 40% of selegiline administered was excreted in urine as these three metabolites. The parent drug, selegiline, was not detected in any urine or plasma samples. On the other hand, MA and AM were observed only as (+)-isomers in the urine of MA abusers. For the distinction of selegiline users from street MA abusers in urinalysis, (-)-DMS, a specific metabolite of selegiline, was not a suitable marker. (-)-DMS rapidly disappeared from urine and was excreted only 1% of the given dose. By the moment analysis with the trapezoidal integration, the mean residence times of (-)-DMS in plasma and urine were 2.7 and 3.8 h, respectively, which were 5-20 times shorter than those of (-)-MA or (-)-AM. The values of AM/MA in the urine increased from 0.24 to 0.67 (r = 0.857) along with time after the selegiline administration. This ratio was not a sufficient marker to differentiate selegiline users from MA abusers, although the values of AM/MA in 74% of MA abusers were less than 0.24. The present GC technique improved the chiral analyses of MA and AM. This chiral analysis is the most useful technique to avoid the misinterpretation in the discrimination between clinical selegiline therapy and illicit MA use.
- Published
- 1999
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21. A fatal disaster case based on exposure to hydrogen sulfide--an estimation of the hydrogen sulfide concentration at the scene.
- Author
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Kimura K, Hasegawa M, Matsubara K, Maseda C, Kagawa M, Takahashi S, and Tanabe K
- Subjects
- Adult, Brain Chemistry, Disasters, Fatal Outcome, Gas Chromatography-Mass Spectrometry, Humans, Hydrogen Sulfide analysis, Kidney chemistry, Liver chemistry, Lung chemistry, Male, Middle Aged, Hydrogen Sulfide poisoning, Occupational Exposure
- Abstract
Four adult men fell into an artificial lake which was being used to raise flatfish, after a water pipe had been connected to a tube allowing seawater to flow into the lake. Forensic autopsies were carried out on three of the four men, who died soon after the incident. From autopsy findings, the cause of death was diagnosed to be suffocation after aspirating seawater in the three victims. To clarify why the men fell into the lake, a chemical analysis for hydrogen sulfide was carried out using the extractive alkylation technique combined with gas chromatography/mass spectrometry. The sulfide was detected as its derivative, bis(pentafluorobenzyl)sulfide, in body tissues taken from all the victims, and the concentration of hydrogen sulfide gas at the scene was estimated as having been nearly fatal.
- Published
- 1994
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22. Rapid and sensitive quantitation of cyanide in blood and its application to fire victims.
- Author
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Shiono H, Maseda C, Akane A, and Matsubara K
- Subjects
- Blood Specimen Collection, Carboxyhemoglobin analysis, Cerebral Ventricles, Chromatography, Gas, Cyanides analysis, Humans, Predictive Value of Tests, Reproducibility of Results, Fires, Hydrogen Cyanide blood
- Abstract
We developed a head-space method for the determination of blood cyanide by gas chromatography with electron-capture detection. In this technique, a reaction precolumn packed with chloramine-T was used for the conversion of hydrogen cyanide into cyanogen chloride. Since the reaction precolumn eliminated the necessity of trapping hydrogen cyanide from biological samples, blood cyanide could be analyzed quickly by acidification only. Using this method, blood cyanide levels of fire victims were determined at autopsy. The serum values of cyanide ranged from 0.11 micrograms/ml to 18.12 micrograms/ml. However, a significantly higher cyanide content was detected in the left ventricular blood than in the right. This indicates that death was caused by the fire and suggests that the collecting point of the blood sample is an important factor in the determination of inhaled cyanide. There was a positive correlation between blood cyanide and carboxyhemoglobin contents.
- Published
- 1991
- Full Text
- View/download PDF
23. "First pass phenomenon" of inhaled gas in the fire victims.
- Author
-
Matsubara K, Akane A, Maseda C, and Shiono H
- Subjects
- Carbon Monoxide Poisoning blood, Carboxyhemoglobin analysis, Cyanides blood, Forensic Medicine methods, Gasoline analysis, Humans, Kerosene analysis, Burns blood, Fires, Gases blood
- Abstract
We investigated the differences in the levels of carboxyhemoglobin (COHb), cyanide (HCN) and petroleum fuels (gasoline and kerosene) between left and right ventricular bloods from fire victims. COHb was slightly, and HCN and petroleum fuels were markedly higher levels in the left than those in the right. These effects were so called 'first pass phenomena' due to the circulation, diffusion and metabolization before the deaths of fire victims.
- Published
- 1990
- Full Text
- View/download PDF
24. Chromophoric labeling of cannabinoids with 4-dimethylaminoazobenzene-4'-sulfonyl chloride.
- Author
-
Maseda C, Fukui Y, Kimura K, and Matsubara K
- Subjects
- Chromatography, High Pressure Liquid, Chromatography, Thin Layer, Humans, Cannabinoids analysis, Indicators and Reagents, p-Dimethylaminoazobenzene analogs & derivatives
- Abstract
A simple and sensitive assay for the cannabinoids is presented using a dabsylation procedure. Dabsyl derivatives of delta 9-tetrahydrocannabinol (delta 9-THC) and cannabinol (CBN) were prepared by reacting with 4-dimethylaminoazobenzene-4'-sulfonyl chloride (dabsyl chloride) in acetone in the presence of sodium carbonate-sodium bicarbonate buffer (pH 10). Crystalline dabsylcannabinoids gave intense absorption in the visible region. With these derivatives, analysis by thin-layer chromatography (TLC) and high performance liquid chromatography (HPLC) were tested. These techniques gave good separation and nanogram detection of dabsyl-THC and -CBN by using n-hexane-ethyl acetate-diethylamine (20:5:1) for TLC and MeOH--H2O (95:5) at 450 nm for HPLC.
- Published
- 1983
25. Gas chromatographic determination for forensic purposes of petroleum fuel inhaled just before fatal burning.
- Author
-
Matsubara K, Akane A, Takahashi S, Shiono H, Fukui Y, Kagawa M, and Maseda C
- Subjects
- Aged, Aged, 80 and over, Carboxyhemoglobin analysis, Chromatography, Gas, Female, Forensic Medicine, Gasoline analysis, Humans, Male, Middle Aged, Burns blood, Petroleum analysis
- Abstract
The determination of petroleum fuel in the blood of burned bodies was carried out by three different gas chromatographic procedures. Seven components of gasoline (isopentane, n-pentane, 2-methylpentane, benzene, 2-methylhexane, 3-methylhexane and toluene) and five of kerosene (xylene, C9H20, mesitylene, pseudocumene and C11H24) were chosen as indicators with a coefficient of variation of 5-24%. The methods were applied to four autopsy cases with a relatively low carboxyhaemoglobin (HbCO) content. When gasoline exposure had occurred, the blood concentrations determined were almost identical whatever the components selected. Great variations in the components determined were found after kerosene exposure, and hydrocarbons greater than or equal to C14 were hardly inhaled by the victims. A higher content of fuel in the left than in the right ventricular blood observed in the autopsy cases suggests fuel inhalation just before death. The same phenomenon was also observed in the content of blood HbCO. Determinations of petroleum fuel and HbCO in both the right and left ventricular blood would be useful for the forensic diagnosis on burned bodies with a low HbCO content.
- Published
- 1988
- Full Text
- View/download PDF
26. Quantitation of cocaine, benzoylecgonine and ecgonine methyl ester by GC-CI-SIM after Extrelut extraction.
- Author
-
Matsubara K, Maseda C, and Fukui Y
- Subjects
- Animals, Biotransformation, Dogs, Resins, Plant, Cocaine analogs & derivatives, Cocaine metabolism, Diatomaceous Earth, Forensic Medicine, Gas Chromatography-Mass Spectrometry methods
- Abstract
A method of gas chromatography-chemical ionization selected ion monitoring (GC-CI-SIM) is described for the determination of cocaine, benzoylecgonine and ecgonine methyl ester in biological materials using an Extrelut extraction technique. Recoveries of cocaine, benzoylecgonine and ecgonine methyl ester by this technique were 95, 81 and 97%, respectively. The method uses cocaine-d5, benzoylecgonine-d5 and lidocaine as internal standards, and isobutane as reagent gas for chemical ionization. Sensitivity of the method proved to be 1 ng/ml for cocaine and benzoylecgonine, and 10 ng/ml for ecgonine methyl ester when used in a 10-ml urine sample. With animal experiments, ecgonine methyl ester as well as benzoylecgonine was confirmed as a major metabolite of cocaine.
- Published
- 1984
- Full Text
- View/download PDF
27. Increased plasma free fatty acid and triglyceride levels after single administration of toluene in rabbits.
- Author
-
Takahashi S, Tanabe K, Maseda C, Shiono H, and Fukui Y
- Subjects
- Animals, Blood Glucose analysis, Cholesterol blood, Male, Phospholipids blood, Rabbits, Toluene blood, Fatty Acids, Nonesterified blood, Toluene toxicity, Triglycerides blood
- Abstract
Changes of plasma lipids (triglyceride, TG: total cholesterol, Cho; and phospholipids, PL), free fatty acid (FFA), and blood glucose (BG) were studied in male rabbits after toluene administration (0.5 g/kg per os). Hypertriglyceridemia was observed at and after 2 h. Plasma FFA and BG were elevated temporarily during the early stage and lowered gradually thereafter. Initially, plasma Cho and PL were virtually unchanged, but the Cho level increased slowly after 6 h. The hypertriglyceridemia observed may have some adverse effects on heart function.
- Published
- 1988
- Full Text
- View/download PDF
28. Detection of delta 9-THC in saliva by capillary GC/ECD after marihuana smoking.
- Author
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Maseda C, Hama K, Fukui Y, Matsubara K, Takahashi S, and Akane A
- Subjects
- Adult, Chromatography, Gas methods, Humans, Male, Marijuana Abuse metabolism, Dronabinol analysis, Marijuana Abuse diagnosis, Saliva analysis
- Abstract
A method is described for the determination of delta 9-tetrahydrocannabinol (delta 9-THC) in the saliva by the use of a combination of moving-precolumn injector and glass capillary gas chromatograph with electron capture detector (GC/ECD). There were no interfering peaks due to impurities around the peak of pentafluoropropyl derivative of delta 9-THC (delta 9-THC-PFP). This GC/ECD method was linear over the range of 5-200 ng/ml of delta 9-THC-PFP. The lower detection limit was approximately 1 ng/ml. delta 9-THC content in the saliva after experimental marihuana smoking was measured by this method. It was demonstrated that for at least 4 h after smoking the level of delta 9-THC was sufficient for detection.
- Published
- 1986
- Full Text
- View/download PDF
29. Improved gas chromatography with electron-capture detection using a reaction pre-column for the determination of blood cyanide: a higher content in the left ventricle of fire victims.
- Author
-
Maseda C, Matsubara K, and Shiono H
- Subjects
- Autopsy, Carboxyhemoglobin analysis, Chromatography, Gas, Humans, Burns blood, Cyanides blood, Heart Ventricles analysis
- Abstract
We developed a head-space method for the determination of blood cyanide by gas chromatography with electron-capture detection. In this technique, a reaction pre-column, packed with chloramine-T, was used for the conversion of hydrogen cyanide into cyanogen chloride. Since the reaction pre-column eliminated the necessity for trapping hydrogen cyanide from the biological samples, blood cyanide was quickly analysed by acidification only. The reaction pre-column was durable for at least several months. The calibration curve gave good linearity when dichloromethane was used as the internal standard, and the lower detection limit taken from this plot was ca. 0.05 micrograms/ml. The relative standard deviation of spiked blood samples was in the range 0.6-3.9%. We determined blood cyanide levels at autopsy in victims who had died from fire using this method. A significantly higher cyanide content was detected in the left ventricular blood than in the right. There was a positive correlation between blood cyanide and carboxylhaemoglobin contents. This simple and sensitive technique could be very useful for the determination of cyanide in various samples.
- Published
- 1989
- Full Text
- View/download PDF
30. Derivative spectrophotometric studies on cytotoxic effects of carbon monoxide.
- Author
-
Fukui Y, Akane A, Takahashi S, Matsubara K, and Maseda C
- Subjects
- Animals, Carbon Monoxide blood, Carboxyhemoglobin biosynthesis, Electron Transport Complex IV metabolism, Hypoxia metabolism, Male, Oxygen Consumption drug effects, Rats, Rats, Inbred Strains, Spectrophotometry, Carbon Monoxide toxicity, Electron Transport Complex IV analysis, Hypoxia chemically induced
- Abstract
Characteristics of cytochrome oxidase prepared from hearts of Sprague-Dawley male rats were studied with the use of the fourth derivative spectrophotometry in respect to the cytotoxic effects of carbon monoxide (CO). CO-exposed rats tended to show lower specific activities of cytochrome oxidase than control and recovered rats. Moreover, there was a significant difference in the fourth derivative spectral features of the enzyme: CO-exposed groups indicated peaks at 412 nm in the spectra while controls at 408 nm. This spectral difference seemed to reflect specific effect of CO on cytochrome oxidase, though such trace remained for not more than a day after death.
- Published
- 1987
- Full Text
- View/download PDF
31. Salsolinol in the urine of nonalcoholic individuals after long-term moderate drinking.
- Author
-
Matsubara K, Akane A, Maseda C, Takahashi S, and Fukui Y
- Subjects
- Acetaldehyde urine, Adult, Age Factors, Aged, Catecholamines urine, Chromatography, High Pressure Liquid, Dopamine urine, Female, Humans, Male, Middle Aged, Sex Factors, Time Factors, Alcohol Drinking, Isoquinolines urine
- Abstract
Urine samples were collected before breakfast from 94 normal volunteers (41 males and 53 females) aged 25-70 years. Salsolinol (SA) was analyzed by gas chromatography-mass spectrometry (GC/MS), and dopamine, norepinephrine and epinephrine were determined using high performance liquid chromatography (HPLC). SA levels were significantly higher in the urine of male moderate drinkers (MDs) than in male seldom or non drinkers (SNDs). In females, however, a significant difference of urinary SA levels was not observed between MDs and SNDs. There was a sex difference of urinary SA levels among SND subjects, i.e., females showed a higher SA than males. Urinary catecholamines were not significantly altered by long-term moderate alcohol drinking in either sex. There was no correlation between urinary levels of dopamine and SA. These results indicate that urinary SA can be increased by long-term drinking even in normal, not alcoholic subjects.
- Published
- 1985
32. Letter: Studies on quinolizine derivatives. XI. Synthesis of azacycl(3,3,3)azine derivatives.
- Author
-
Awaya H, Maseda C, Natsuki R, Matsuda Y, and Kobayashi G
- Subjects
- Aza Compounds analysis, Quinolizines analysis, Spectrophotometry, Infrared, Spectrophotometry, Ultraviolet, Aza Compounds chemical synthesis, Quinolizines chemical synthesis
- Published
- 1974
- Full Text
- View/download PDF
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