8 results on '"Masataka Nagao"'
Search Results
2. Dental radiographic information of term newborn babies within the first month: Analyzing five radiographic cases along with physical attributes in Japan
- Author
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Hiroko Oka, Yuria Asao, Naoki Nakao, Chieko Mitsuhata, Yoriaki Matsumoto, Ryota Nomura, Naoya Kakimoto, Masataka Nagao, and Katsuyuki Kozai
- Subjects
Issues, ethics and legal aspects ,Pathology and Forensic Medicine - Abstract
Although dental radiography is a valuable tool for age estimation in forensic anthropology and odontology, very limited radiological data are available regarding tooth development in healthy newborn babies during the first month of life.This study aimed to describe the radiological findings of tooth development in babies aged 0 days to 1 month.We analyzed the postmortem findings of five newborn babies with no known natural cause of death who had undergone autopsy, computed tomography (CT), and dental radiography. We estimated the gestational age for the babies aged 0 days and analyzed the condition of mandibular symphysis, existence of tooth germs, and presence or absence of calcification of the first permanent molars of all the babies.The calcified form of 20 deciduous teeth, tooth germs of the permanent upper and lower first molars, and non-calcified mandibular symphysis were observed in each case. However, calcification of the first permanent molar was observed in only two 1-month-old babies.The dental radiographic findings and anthropometric measurements of non-skeletonized, non-mummified term babies confirmed calcification of all the deciduous teeth and the first permanent molar at the age of 0 days and 1 month, respectively.
- Published
- 2023
3. A method for determining valproic acid in human whole blood and urine via gas chromatography-mass spectrometry and small-scale inter-laboratory trial
- Author
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Akira Namera, Kyoko Uekusa, Takeshi Saito, Kanji Yoshimoto, Naoki Ishiuchi, Kazuhiro Murata, and Masataka Nagao
- Subjects
Methyl Ethers ,Issues, ethics and legal aspects ,Valproic Acid ,Humans ,Gas Chromatography-Mass Spectrometry ,Pathology and Forensic Medicine - Abstract
A simple and cost-effective method for analyzing valproic acid (VPA) in biological samples was developed. VPA was extracted in methyl tertiary-butyl ether (MTBE) and derivatized using trimethylsilyldiazomethane. The MTBE extract was analyzed by gas chromatography-mass spectrometry (GC-MS). The extraction recovery in human whole blood and urine was over 90 %, with good linearity in the range of 1.0 to 250 µg/mL of VPA. The RSD for 2.0, 20, and 200 μg/mL VPA in whole blood ranged from 0.9 to 4.7 % for intra-day and 1.5 to 5.9 % for inter-day. The RSD for 2.0, 20, and 200 μg/mL VPA in urine ranged from 1.9 to 2.6 % for intra-day and 1.2 to 2.9 % for inter-day. As a preliminary cross-validation study, a cross-check was conducted using blinded concentration samples. The results demonstrated that the assay data of the two laboratories were comparable.
- Published
- 2022
4. Association of SNPs in genes encoding zinc transporters on blood zinc levels in humans
- Author
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Toshihiro Yasuda, Kaori Kimura-Kataoka, Yoshikazu Takinami, Junko Fujihara, Masataka Nagao, and Haruo Takeshita
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Adult ,Male ,0301 basic medicine ,medicine.medical_specialty ,chemistry.chemical_element ,Single-nucleotide polymorphism ,Zinc ,Biology ,Polymerase Chain Reaction ,Polymorphism, Single Nucleotide ,Pathology and Forensic Medicine ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Japan ,Internal medicine ,Genotype ,medicine ,Genetic predisposition ,Humans ,Genetic Predisposition to Disease ,030216 legal & forensic medicine ,Allele ,Gene ,Aged ,Aged, 80 and over ,Middle Aged ,medicine.disease ,Issues, ethics and legal aspects ,030104 developmental biology ,Endocrinology ,chemistry ,Zinc deficiency ,Female ,Restriction fragment length polymorphism ,Carrier Proteins - Abstract
Zinc homeostasis in cells depends on zinc transporters, which are divided into 2 families: ZnT (SLC30A) and ZIP (SLC39A). In this study, we examined the effect of 20 single nucleotide polymorphisms (SNPs) in 10 genes encoding zinc transporters on blood zinc concentration in Japanese subjects ( n = 102). Blood zinc levels were determined by microwave plasma-atomic emission spectrometry, and SNPs were analyzed by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Among the 20 SNPs examined, 3 SNPs (SLC30A3 rs11126936, SLC39A8 rs233804, and SLC39A14 rs4872479) were significantly associated with blood zinc concentration. Individuals with genotype TT and TG in rs11126936 showed significantly higher blood zinc concentrations than those with GG. As for rs233804, individuals harboring the A allele had significantly higher blood zinc concentrations than those without this allele. Furthermore, the genotype TT and TG in rs4872479 had significantly higher blood zinc concentrations than those with GG. Among these three SNPs, combination of SLC30A3 rs11126936 and SLC39A8 rs233804 may strongly affect blood zinc levels. This study is the first comprehensive investigation of the effect of SNPs in genes encoding zinc transporters on blood zinc concentration. Adverse effects of zinc deficiency are reported and above 3 SNPs may be related to genetic susceptibility to zinc deficiency.
- Published
- 2018
5. Neural dysfunctions following experimental permanent occlusions of bilateral common carotid arteries cause an increase of rat voluntary alcohol drinking behavior
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Kazuhiro Murata, Yusuke Urashige, Yoshikazu Hiraga, Kanji Yoshimoto, Ayaka Mori, Kaori Murakami, Naotaka Yoshikawa, Akira Namera, Masataka Nagao, Kazuhisa Hatakenaka, and Koji Maeda
- Subjects
Serotonin ,medicine.medical_specialty ,Microdialysis ,Alcohol Drinking ,Lateral hypothalamus ,Carotid Artery, Common ,Dopamine ,Neural degeneration ,Nucleus accumbens ,Serotonergic ,Nucleus Accumbens ,Pathology and Forensic Medicine ,Brain ischemia ,Central Nervous System Diseases ,Internal medicine ,medicine ,Animals ,Carotid Stenosis ,business.industry ,Dopaminergic ,medicine.disease ,Rats ,Issues, ethics and legal aspects ,Endocrinology ,business ,medicine.drug - Abstract
We have previously reported that ischemic animal models treated with a respiratory inhibitor, rotenon, show an increased voluntary alcohol intake. Although it is clear that ischemic brain, as a result of reduced-blood flow, shows pathological events and/or neuro-degenerations apparently, little is known of causal relationship between the mechanism of neural dysfunction and voluntary alcohol consumption. Authors have investigated effects of permanent two-vessel occlusion (p2VO) on rat voluntary alcohol drinking behavior. In first experiment the p2VO-treated rats showed an increase of voluntary alcohol drinking behavior, as compared with sham controls. Using brain microdialysis technique, increases of only nucleus accumbens (ACC) dopamine (DA) releases were suppressed in the p2VO-treated rats significantly, following the high K+ (40 mM) perfusion through the microdialysis probe membrane. Alcohol (200 mM) perfusion-induced DA and serotonin (5-HT) releases in the ACC of the p2VO-treated rats were suppressed significantly in the second experiment, as compared with the sham-treated rats. In third experiment p2VO-treated rats showed significant decreases of the contents of DA, not 5-HT, in the ACC, caudate-putamen (C/P), ventral tegmental area-substantia nigra (VT/SN) and lateral hypothalamus (LH). Dopaminergic neurons in the ACC showed more functional vulnerability against the p2VO treatments, as compared with the serotonergic neurons. An increase of alcohol intake in the p2VO-treated rats means the compensation for the neural degeneration of the dopaminergic system in the ACC consisted brain rewarding system. It was likely suggested that neural disturbance of higher functions involved with incomplete global brain ischemia leads the risk of an abnormal alcohol drinking in human.
- Published
- 2021
6. Detection of abused drugs in human blood by using the on-site drug-screening device Oratect® III
- Author
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Masataka Nagao, Yukie Uchida, Yousuke Arima, Hirokazu Toubou, Aiko Torikoshi, Akira Namera, and Fumio Moriya
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Drug ,Illicit Drugs ,business.industry ,media_common.quotation_subject ,Codeine ,Forensic toxicology ,Forensic Medicine ,Pharmacology ,Dihydrocodeine ,Mass Spectrometry ,Estazolam ,Pathology and Forensic Medicine ,Substance Abuse Detection ,Issues, ethics and legal aspects ,medicine ,Morphine ,Humans ,business ,Prazepam ,Chromatography, Liquid ,medicine.drug ,media_common ,Whole blood - Abstract
A simple and precise drug screening method was developed for the detection of abused drugs in whole blood by using the Oratect® III device that is usually employed for the detection of drugs in saliva. Whole blood was acidified with phosphoric acid, following which the hemolyzed solution was filtered through the ultrafiltration column Vivaspin 2 Hydrosart®. The filtrate was then tested for the presence of drugs using Oratect III. The detection limit of the device for methamphetamine, amphetamine, morphine, codeine, dihydrocodeine, diazepam, alprazolam, estazolam, and prazepam in whole blood was 125, 125, 50, 50, 50, 25, 60, 15, and 75ng/mL, respectively. The concentration range detected was between therapeutic and toxic drug levels; therefore, the proposed method can be applied for detecting the presence of abused drugs in blood. Our method is a novel, optimized technique for use in forensic laboratories to screen whole blood for drugs of abuse.
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- 2014
7. Molecular analysis of mitochondrial hypervariable region 1 in 394 Japanese individuals
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Yoshihiro Yamada, Masataka Nagao, Hiroshi Ohira, Yoshitaka Maeno, and Hideaki Kato
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mtDNA control region ,Genetics ,Genetic diversity ,Mitochondrial DNA ,education.field_of_study ,Transition (genetics) ,Haplotype ,Population ,Genetic Variation ,Biology ,Complementarity Determining Regions ,DNA, Mitochondrial ,Polymerase Chain Reaction ,Pathology and Forensic Medicine ,Hypervariable region ,Issues, ethics and legal aspects ,Asian People ,Haplotypes ,Japan ,Humans ,education ,Sequence Analysis ,Sequence (medicine) - Abstract
Mitochondrial DNA (mtDNA) is a powerful tool for forensic casework when the resource is highly putrefied or very limited. It is important that mtDNA sequence databases continue to be generated and published, to extend mtDNA typing capability to additional populations and to increase the size of existing databases. The aim of this study was to analyze hypervariable region 1 (HV1) of mtDNA and establish a new database of mtDNA in Japanese population. Three hundred and ninety-four unrelated Japanese individuals were investigated. They were classified into 193 haplotypes based on HV1 sequence. Nucleotide substitutions were clustered in several positions and were 79% at 16,223, 50% at 16,362, and 29% at 16,189. Transition accounts for 81% of all the mutations and especially transition from cytosine to thymine (33%) was the most frequent substitution. 16,223–16,362 was observed in 34 individuals, following 16,129–16,223–16,362 in 29 individuals, and haplotype 16,223–16,278–16,362 in 14 individuals. Genetic diversity and random match probability in this population were estimated to 0.987% and 1.95%, respectively. In conclusion, HV1 of mitochondria sequence has a high discrimination power, but in addition to HV1, analysis of other region such as HV2 and HV3 are required in certain cases.
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- 2009
8. Preliminary screening method for the determination of inorganic arsenic in urine
- Author
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Masataka Nagao, Li Hua, Akira Namera, Akira Fujiwara, Manami Nishida, and Mikio Yashiki
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Male ,Arsenic poisoning ,chemistry.chemical_element ,Urine ,Mass Spectrometry ,Arsenic ,Pathology and Forensic Medicine ,Forensic Toxicology ,chemistry.chemical_compound ,Spectrophotometry ,Arsenic Poisoning ,medicine ,Humans ,Arsenic trioxide ,Coloring Agents ,Colorimetry ,Chromatography, High Pressure Liquid ,Molybdenum ,Ammonium molybdate ,Chromatography ,medicine.diagnostic_test ,Chemistry ,Extraction (chemistry) ,Middle Aged ,medicine.disease ,Trace Elements ,Issues, ethics and legal aspects ,Copper - Abstract
A simple and rapid method was developed for the routine determination and classification of inorganic arsenic based on its clinical and forensic properties. Inorganic arsenic was isolated from urine by using copper granules, which was then made to react with ammonium molybdate in order to detect its presence with the naked eye. Based on studies of extraction and reaction conditions, e.g., reaction temperature and time, a colorimetric screening method was established. The reaction mixture was measured by a spectrophotometer, and there was linearity from 0.05 to 2.0microg/ml and the correlation coefficients of the calibration curves were greater than 0.99. The coefficients of intra-day variation at 0.2 and 2.0microg/ml of inorganic arsenic in urine were 9.6 and 4.2%, respectively (n=5). The minimum detectable level in urine is 0.03microg/ml, and it is possible to detect the lowest level of poisoning according to the published reports. The proposed method was applied to a poisoning case wherein the patient ingested NEOARSEN BLACK with alcohol, which contained 45% of arsenic trioxide. This method produced positive results in all the urine samples tested, and this method is useful for the screening of inorganic arsenic based on its clinical properties because it enables the detection of inorganic arsenic in urine without expensive equipment.
- Published
- 2009
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