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Biomedical subjects

J Yoshinaga

Publications and source records attributed to J Yoshinaga.

At least 19 recordsLinked to original sources
PubMed2006

Dietary intake of toxic and essential trace elements by the children and parents living in Tokyo Metropolitan Area, Japan.

This study estimated the dietary intakes of 25 pairs of Japanese children and their parents to 12 toxic and essential trace elements using 7-day duplicate diet composites. The estimated intakes of lead (children = 5.34 microg day-1, adults = 6.74 microg day-1) and tin (162 and 152 microg day-1) were below tolerable limits, but large difference in aluminium intakes (7.32 and 12.1 mg day-1) among the subjects warranted further investigations. Intakes of cadmium in both children and adults (13.2 and 15.9 microg day-1) were high, but a low uranium (U) intake was observed (0.593 and 0.587 microg day-1). Intakes of copper (567 and 784 microg day-1), manganese (1.56 and 2.72 mg day-1), zinc (4.93 and 6.75 mg day-1), and molybdenum (103 and 131 microg day-1) were close to the recommended values. Concentrations of chromium, nickel and selenium were lower than the detection limits in most cases.

Adult↗
PubMed2001

Analysis of organic esters of plasticizer in indoor air by GC-MS and GC-FPD.

The aim of this study was to assess the performance of a method of analyzing organic esters of plasticizer in indoor air by sampling air in a charcoal tube and extracting the esters in toluene using a gas chromatography-mass spectrometer (GC-MS) and flame photometric detector (FPD). An internal standardization method was used for the GC-MS measurement of phthalate esters, whereas an external calibration method was employed to determine the levels of phosphate esters by FPD. The instrumental detection limit, the instrumental lower limit of determination, and the blank and method detection limits were also determined. Mean recoveries of phthalate esters from the charcoal tube were 97.9-115%. Mean recoveries of phosphate esters were lower but reproducible. Recoveries of the esters from indoor air were generally greater than 80%. For all the compounds, no significant breakthrough was detected up to 100 microg. Thus, indoor organic esters could be accurately determined in the range of 0.6 x 10(-3)-23 microg/m3 by the procedure presented here. Preliminary analysis of the organic esters indicated that exposure to phthalate esters via indoor air inhalation could constitute a significant contribution to total daily intake.

Air Pollution, Indoor↗
PubMed2000

Determination of arsenic compounds by high-performance liquid chromatography-ultrasonic nebulizer-high power nitrogen-microwave-induced plasma mass spectrometry: an accepted coupling.

To establish a sensitive, accurate, and precise determination of arsenic compounds, a high power nitrogen microwave-induced plasma (1.3 kW) mass spectrometer (N2-MIP-MS) has been successfully coupled with an ultrasonic nebulizer (HPLC-USN) that is attached to a high-performance liquid chromatograph. It is examined as an element-specific detector for its applicability to the optimization and determination of seven arsenic compounds [arsenic acid, methylarsonic acid (MA), dimethylarsinic acid (DMA), arsenobetaine (AB), arsenocholine (AC), trimethylarsine oxide (TMAO), and tetramethylarsonium ion (CMI)]. This HPLC-USN-MIP-MS coupling is an encouraging combination as an alternative method for mass spectroscopy for elemental speciation analysis. Interchanging of the MIP-MS fabricated nebulizer (concentric) with an ultrasonic nebulizer, increases 3-6 times the ion signals for the anionic and 6-12 times those for the cationic arsenic compounds as compared to traditional methods. The HPLC-USN-MIP-MS combination used is excellent, amplifying the ion signals about 1.5-2 times for cationic and 1.3-2.8 times for the anionic arsenic compounds as compared to the HPLC-ICPMS coupling. The detection limits for As(V), MA, DMA, AB, TMAO, AC, and TMI (in Milli-Q-water) obtained with the optimized HPLC-USN-N2-MIP-MS system are 0.46, 0.36, 0.73, 0.21, 3.64, 0.39, and 0.32 microg L(-1), respectively, about 13-50 times lower than the HPLC-MIP-MS and about 3-11 times lower than the HPLC-ICPMS. The detection limits of As(V), MA, DMA, AB, TMAO, AC, and TMI, which spike in the urine, are deteriorated by 1.7-4.2 times compared with the detection limits of the seven different As compounds, which are prepared in the Milli-Q-water. The repeatability (RSD for three successive analyses) and reproducibility (RSD for three successive analyses performed on three different days), considering peak area and peak height, achieved for seven different arsenic compounds are 0.5-7 and 0.7-8%, comparable with the HPLC-ICPMS (0.3-8.5%; 4-12%) and HPLC-MIP-MS (0.4-9%; 5-12%) systems. The combined HPLC-USN-N2-MIP-MS has been adequately applied to the determination of AB in NIES Candidate Human Urine CRM. The results agree with the HPLC-ICPMS values. Chloride interference as 40Ar35Cl+ is not found in the urine and with the high chloride matrix (10000 mg L(-1)).

Arsenicals↗
PubMed2000

Human urine certified reference material for arsenic speciation.

BACKGROUND: Chemical speciation analysis is essential for the biological monitoring of inorganic arsenic exposure using urine as indicator medium. There is increasing demand for a certified reference material (CRM) of urine matrix for arsenic speciation. METHODS: Urine (10 L) was collected from non-occupationally exposed Japanese males. We prepared 954 bottles of urine, each containing approximately 10 mL, after filtering and blending the urine stock. The urine in each bottle was freeze-dried. Between-bottle homogeneity was confirmed by measuring the concentrations of selected minor and trace elements in the material and subsequent statistical analysis. Certification was based on a collaborative analysis involving 15 laboratories. RESULTS: Certified values were determined for arsenobetaine (0.069+/-0.012 mg As/L), dimethylarsinic acid (0.036+/-0.009 mg As/L), and total arsenic (0.134+/-0.011 mg/L) as well as for total selenium (0.059+/-0.005 mg/L) and zinc (0.62+/-0.05 mg/L), based on the analytical values from the collaborating laboratories. Reference values are given for copper (0.010 mg/L) and lead (0.0011 mg/L), based on definitive analysis at the National Institute for Environmental Studies (NIES). CONCLUSIONS: The present CRM, NIES CRM No. 18 Human Urine, is the first human urine CRM for arsenic speciation and will be of value for analytical quality assurance of the biological monitoring of arsenic exposure.

Arsenicals↗
PubMed1997

Specimen banking at National Institute for Environmental Studies, Japan.

The National Institute for Environmental Studies (NIES) in Japan has had more than fifteen years practical experience in specimen banking. Stored specimens are used for the assessment of long-term trends of pollutants. The use of new analytical techniques facilitates the finding of the pollutants of the past.

Academies and Institutes↗
PubMed1997

[Multivariate analysis of the problems of long-term levodopa therapy in Parkinson's disease].

We investigated clinical features of adverse reactions to long-term levodopa therapy by the multivariate analysis. Dyskinesia, wearing off effect, on-off effect, mental symptoms, and frozen gait were noted in 29 (11.2%), 78 (30.0%), 17 (6.5%), 45 (17.7%), and 52 (20.0%), respectively, of 260 patients with Parkinson's disease to whom levodopa had been administered for over one year. In the statistical investigation by the multivariate analysis (quantification method type II), the age of initial levodopa therapy, the duration from the onset to the initiation of levodopa therapy, and the duration of levodopa therapy were not closely related to the development of any adverse reaction, while Hoehn & Yahr's stage and the dosage of levodopa had the most significant influence on the development of adverse reactions. Furthermore, concomitant use of amantadine hydrochloride produced an inhibitory effect on the development of dyskinesia. We conclude that early institution of levodopa therapy in Parkinson's disease may not be an important risk factor of adverse reactions.

Adult↗
PubMed1996

Stable carbon and nitrogen isotopic composition of diet and hair of Gidra-speaking Papuans.

The carbon and nitrogen stable isotopic composition of the scalp hair and diet of Gidra-speaking people in four villages in Papua New Guinea is presented. The isotopic composition of hair was measured, while that of the diet was estimated from food consumption survey data and the measured isotopic composition and protein and carbohydrate contents of food items. The average isotopic ratios of the hair samples and of the diet varied among the four study villages, which were selected because of their diverse ecological settings. Comparison was made between hair and calculated dietary isotopic compositions. Two of the four diet-hair enrichment values obtained for 13C (+1.8 and 2.2%) were similar to those previously reported (1.4-2.0%), but the other two values (3.7 and 4.8%) were greater than in earlier reports. 15N enrichment was systematically greater (by 1.0%) than reported values (4.3%) except for one village, where a much greater enrichment (6.9%) was found. The factors potentially relevant to these deviations are discussed. Possible errors in estimating the dietary isotopic composition and minor modifications of dietary habits revealed by food consumption surveys could explain most of the discrepancies. However, the great enrichment of 15N found in one of the villages remains unexplained.

Adult↗
PubMed1996

Isotope ratio analysis of lead in biological materials by inductively coupled plasma mass spectrometry.

Inductively coupled plasma mass spectrometry (ICP-MS) allowed 0.2-0.3% imprecision (1 sigma) in 204Pb/206Pb, 207Pb/206Pb, and 208Pb/206Pb measurements at the 20-100 ppb level, which was precise enough to detect some of the isotopic variations observed in nature. Mass discrimination could be corrected within +/- 0.5% of the true value by periodical analysis of standard reference material of known lead isotopic composition. As a separation method for lead in human bone, which contains enormous amounts of calcium and phosphorus, anion exchange of the Pb-Br complex was found to be effective. Lead isotope ratios in bone, measured by ICP-MS after separation, were consistent with those measured by thermal ionization mass spectrometry. Hair matrix did not have any influence on the accuracy and precision of the analysis; a digested sample could be directly analyzed and this offered rapid sample throughput. Preliminary data on lead isotope ratios in bone and hair from prehistoric and contemporary Japanese are presented.

Archaeology↗
PubMed1996

An application of nitrogen microwave-induced plasma mass spectrometry to isotope dilution analysis of selenium in marine organisms.

Nitrogen microwave-induced plasma mass spectrometry was studied for its applicability to the isotope dilution analysis of selenium in biological samples. Spectroscopic interference by calcium, which is present in high concentrations in biological samples, was investigated. No detectable background spectrum was observed for the major selenium isotopes of 78Se and 80Se. No detectable interferences by sodium, potassium, calcium and phosphorus on the isotope ratio 80Se/78Se were observed up to concentration of 200 mg/ml. The method was applied to the analysis of selenium in biological reference materials of marine organisms. The results showed good agreement between the certified and found values.

Animals↗
PubMed1996

[Inductively coupled plasma atomic emission spectrometry and ICP mass spectrometry].

General analytical procedures for determination of trace elements in clinical samples (serum, urine, milk, organs and bone) by inductively coupled plasma atomic emission spectrometry (ICP-AES) and ICP mass spectrometry (ICP-MS) are described. Minerals and major trace elements can be simultaneously determined only after 10-20 fold dilution, which is preceded by acid digestion in the case of solid sample, by ICP-AES. Elements of lower concentration range can be determined by ICP-MS but there are some analytical limitations. Reference values in these samples from Japanese, determined by ICP-AES, are also presented. Use of ICP-AES and ICP-MS for chemical speciation analysis is referred.

Body Fluids↗
PubMed1996

[A case of atypical progressive supranuclear palsy with degeneration of the fronto-pontine tracts, and without grumose degeneration of the dentate nucleus].

An autopsy case of progressive supranuclear palsy (PSP) with degeneration of the fronto-pontine tracts of the midbrain and pons, and without grumose degeneration of the dentate nucleus is reported. A 72-year-old woman was suffering from dysarthria and gait disturbance. Moderate dementia was noted and gradually worsened. Pyramidal and extrapyramidal signs and cerebellar ataxia were not observed. Eye movements were fully preserved. Brain CT showed cerebellar atrophy. Three years later, she was unable to stand or move, and became mutistic. At the age of 75, she died suddenly. The duration of her illness was approximately 4 years. Clinical diagnosis was LCCA (late cortical cerebellar atrophy). Neuropathological examination revealed gliosis of the deep layers of the cerebral cortex around the precentral gyrus, fronto-pontine tracts degeneration (posterior part of the anterior crus, genu and anterior part of the posterior crus of the internal capsule, cerebral peduncles of the midbrain, pontine base and pyramis of the medulla oblongata). Also, atrophy of the pons and marked degeneration of the superior colliculi and substantia nigra were observed. Neurofibrillary tangles (NFTs) and glial fibrillary tangles (GFTs) were found in the subcortical nuclei. These findings were almost consistent with PSP. However, the following differed from those of previously reported typical PSP cases: firstly, mild gliosis in the reticular formation of the midbrain; secondly, few NFTs in the pontine nuclei and superior colliculi and; thirdly, no grumose degeneration in the dentate nucleus. In addition, clinical symptoms of the present case are not consistent with PSP. Therefore, we concluded this case to be an atypical PSP both clinically and neuropathologically.

Aged↗
PubMed1995

Trace elements in ribs of elderly people and elemental variation in the presence of chronic diseases.

Element concentrations in ribs obtained from elderly Japanese people (17 males and 28 females; mean age, 81.5 years) were determined by atomic absorption spectrometry (AAS), inductively coupled plasma atomic emission spectrometry (ICP-AES), and ICP mass spectrometry (ICP-MS). Nine elements--Na, Mg, P, K, Ca, Fe, Zn, Sr, and Pb--were determinable in most of the subjects by a combination of AAS and ICP-AES. The levels of these elements were generally comparable with those obtained in our previous study on ribs from younger Japanese. By the use of ICP-MS, Sn (median, 0.79 micrograms/g dry bone) and Ba (1.3 micrograms/g) were determinable in all of the subjects analysed (n = 35) and 18 other elements at lower concentration levels were also detected in some of the subjects. An exploratory statistical analysis was carried out to find element(s) of which level(s) in rib vary in the presence of degenerative chronic diseases, using information obtained from pathological autopsy reports and medical histories of the present subjects. It indicated that (i) Pb and Zn, (ii) Ba, and (iii) Sr levels in the ribs varied in the presence of cancer, cerebrovascular damage, and bone problems, respectively. The present results were discussed in relation to the results of the previous epidemiologic and experimental studies.

Aged↗
PubMed1995

Long-term change of anti-acetylcholine receptor antibody in patients with myasthenia gravis after thymectomy.

Anti-acetylcholine receptor antibody (AChR Ab) plays an important role in the pathogenesis of myasthenia gravis (MG). We investigated the change of anti-AChR Ab titer after thymectomy of 10 MG patients including five patients whose age at onset was younger than 16 years. Anti-AChR Ab titer was increased in four of six patients with remission and three of four patients without remission. Change of anti-AChR Ab titer in individual patients showed an increase occurred 1-4 years after thymectomy. It is likely that thymectomy influences immune response and induces autoreactive lymphocytes and autoantibodies.

Adolescent↗
PubMed1994

Analysis of serum elements and the contaminations from devices used for serum preparation by inductively coupled plasma mass spectrometry.

Two different samples of serum were prepared from a blood specimen by using two types of serum-separation tubes. Each serum sample was diluted by 100 times with deionized and sub-boiling distilled water. Thirty-six elements in the serum and exudate, from devices used for the serum preparation, were determined by inductively coupled plasma mass spectrometry (ICP-MS). From the comparison of elemental concentrations in two groups of 11 serum samples, it was found that the exudate from serum-separation tubes, as well as from disposable stainless steel needles, had serious effects on the elemental concentrations in the serum. Means for the concentrations of Li, Co, Ga, Cd, Sn, Sb, Ba, La, and Ce in the two serum groups were statistically different from each other. The concentrations of Cr, Mn, Fe, and Mo in both groups were apparently higher than those reported in the literature, suggesting contamination from the disposable stainless steel needle and spectral interferences due to molecular species produced in the argon plasma.

Disposable Equipment↗
PubMed1993

Trace elements determined along single strands of hair by inductively coupled plasma mass spectrometry.

Flow injection-inductively coupled plasma mass spectrometry has been evaluated for determining the distribution profile of trace elements along a single strand of hair. Hair was cut into several mm long sections from follicle to the distal end. Each section was solubilized in a capped 1.5-mL polypropylene tube with small volume of nitric acid (typically 50 microL) at room temperature. After dilution an aliquot (50 microL) was introduced into the mass spectrometer by flow injection. The limit of determination was typically 5-50 pg with 5-10% precision (CV), depending on the element examined; this corresponds to sub-microgram/g concentrations of these elements in hair segments. Recent exposure and intake history of individuals to thallium or mercury could be reconstructed by this system.

Adult↗
PubMed1992

Arsenic lipids in the digestive gland of the western rock lobster Panulirus cygnus: an investigation by HPLC ICP-MS.

The digestive gland of the western rock lobster, Panulirus cygnus, was shown to contain phosphatidylarsenocholine and a phosphatidyldimethylarsinylriboside by HPLC ICP-MS examination of lipid materials rendered water-soluble by hydrolysis. Water-soluble arsenic material in the digestive gland was chiefly arsenobetaine but the deacylated analogue of the phosphatidyldimethylarsinylriboside and an unidentified compound were also present.

Animals↗