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Koichi Haraguchi

Publications and source records attributed to Koichi Haraguchi.

24 records · Page 2Linked to original sources
PubMed2003

Distribution of methyl sulfone metabolites of polychlorinated biphenyls and p,p'-DDE in human tissues.

We determined methylsulfonyl metabolites of chlorinated biphenyls (MeSO2-CBs) and 1,1-bis(4-chlorophenyl)-2,2-dichloroethene (p,p'-DDE) in human adipose, liver, brain, and lung tissues obtained from 11 Belgian individuals (9-62 years of age). The total concentration of MeSO2-CBs (lipid weight basis) decreased in the following order: liver (mean, 9.30 ng/g; range, 1.68-27.03 ng/g lipid) > lung [mean, 2.72 ng/g; range, not detected (ND) to 11.54 ng/g lipid] > adipose tissue (mean, 1.57 ng/g; range, 0.33-4.33 ng/g lipid) > brain (mean, 0.24 ng/g; range, ND-0.56 ng/g lipid). The profiles of MeSO2-CBs and MeSO2-DDE in each tissue were similar for all 11 subjects. In adipose, brain, and lung tissues, 4'-MeSO2-CB87, 4'-MeSO2-CB101, and 3-MeSO2-CB149 (except brain) occurred at higher concentrations than did other MeSO2-CBs. However, 3'-MeSO2-CB132 was by far the most abundant congener in liver, contributing on average to approximately 60% of the sum of MeSO2-CBs. The concentrations of 3-MeSO2-DDE in different tissues were at the same or lower levels than the total concentrations of MeSO2-CBs. This study suggests that the distribution patterns of MeSO2-CBs and MeSO2-DDE in humans differ between liver and other tissues. Moreover, these profiles differ from those found in other mammals, such as polar bears, porpoises, and otters.

Adipose Tissue↗
PubMed2003

[Peculiar remaining of some PCB congeners in the patients with Yusho for more than 30 years].

Concentrations of polychlorinated biphenyl (PCB) congeners, hexachlorobenzene (HCB) and dichloro dichlorophenyl ethylen (DDE) in the blood of Yusho patients (n = 28) were statistically compared with those in the blood of Fukuoka residents (n = 151). The PCB concentrations in the blood of Yusho patients were higher than those of Fukuoka controls and concentration ratios of Yusho/Control were various depending on PCB congeners, being 1.6 on 2,3',4,4',5-pentaCB (# 118), 17.5 on 2,3,3',4,4',5-hexaCB (# 156) and 5.4 on total PCBs. Correlation coefficients between age and concentrations of 7 PCB congeners, HCB and DDE in the blood of Fukuoka residents were significantly positive each other (p < 0.001), while in Yusho patients, the correlation coefficients were positive but various depending on the congeners. However, correlation coefficient between PCB # 118 and PCB # 156 in the Yusho patients was remarkably low, indicating their peculiar accumulative properties in Yusho patients. The concentration of PCB # 118 had been markedly decreased after the ingestion of PCBs and would be metabolized to hydroxylated PCB, which might cause estrogen disturbance in the Yusho patients.

Adult↗
PubMed2003

[Metabolism of 2,3,3',4,4'-pentachlorobiphenyl in hamsters].

The in vivo metabolism of 2,3,3',4,4'-pentachlorobiphenyl (CB105) was studied in hamsters and the effect of cytochrome P450 inducers, phenobarbital (PB) and 3-methylcholanthrene (MC) on its metabolism was compared to rats. After administration of CB105 intraperitoneally at a dose of 3 mg/body, four metabolites, named M-1, M-2, M-3 and M-4, were detected in 5 days-feces of all groups and the formation ratio of the metabolites M-1-M-4 was 1:39:84:0.2 in untreated hamsters and 1:19:6.7:0.7 in untreated rats. On the basis of the mass spectra of four synthetic authentic compounds and the retention times on DB-1 and MPS50 columns, M-1, M-2, M-3 and M-4 were identified as 4'-hydroxy-2,3,3',4,5'-PenCB, 5'-hydroxy-CB105, 5-hydroxy-CB105 and 4-hydroxy-2,3,3',4',5-PenCB, respectively. The pretreatment of PB and MC resulted in about 2-fold fecal excretion of four metabolites in hamsters and in about 3-fold in rats. Of four metabolites, only M-4 were detected in the serum at 5 days after CB105 administration and the concentration was 0.39 microgram/ml of hamster serum and 0.28 microgram/ml of rat serum. In hamsters, the concentration of M-4 was increased to 1.8-fold of untreated animals by PB treatment and 2.6-fold by MC treatment. On the other hand, the treatment of rats with PB and MC did not show such an increase of serum M-4. These results suggested that the hamster oxidized 2,3,4-trichloro-substituted benzene ring predominantly rather than 3',4'-dichloro-substituted benzene ring differently from the rat and that M-4 formed in hamster liver distributed to the blood and retained there to a considerable extent in comparison with that formed in rat liver.

Animals↗
PubMed2002

Mercury and selenium concentrations in the internal organs of toothed whales and dolphins marketed for human consumption in Japan.

Small cetaceans (toothed whales odontoceti and dolphins delphinidae) have been traditionally hunted along the coast of Japan and fresh red meat and blubber, as well as boiled internal organs such as liver, kidney, lung and small intestine, are still being sold for human consumption. We surveyed mercury contamination in boiled liver, kidney and lung products marketed in Japan between 1999-2001. The average +/- S.D. of total mercury (T-Hg) was 370 +/- 525 (range: 7.60 approximately 1980, n = 26) microg/g in liver, 40.5 +/- 48.5 (7.30-95.1, n = 15) microg/g in kidney and 42.8 +/- 43.8 (2.10-79.6, n = 23) microg/g in lung. A high correlation was observed between T-Hg and selenium (Se) concentrations in these organs, supporting the formation of a Hg-Se complex. The formation of a Hg-Se complex probably contribute to the detoxification of Hg for cetaceans and allows a very large accumulation of Hg in livers. The provisional permitted level of T-Hg in marine foods set by the Japanese Ministry of Health and Welfare is 0.4 microg/ g, and the provisional permitted weekly intake (PTWI) set by WHO is 5 microg/kg bw/week. The maximal T-Hg detected in boiled liver (1,980 microg/g) exceeds the permitted level by approximately 5,000 times and the consumption of only 0.15 g of liver exceeds the PTWI of 60 kg of body weight of the consumer, suggesting the possibility of an acute intoxication by T-Hg even after a single consumption of the product.

Animals↗
PubMed2002

Optimized separation and determination of methyl sulfone metabolites of polychlorinated biphenyls (PCBs) and p,p'-DDE in biota samples.

An optimised method is described for the determination of 27 methyl sulfone polychlorobiphenyls (PCBs) and DDE in biota samples. Initially, the samples were extracted by hot Soxhlet and the methyl sulfones were separated by liquid/liquid extraction with concentrated sulfuric acid and back-extracted with hexane. The parameters of the back-extraction were studied and it was found that for a quantitative extraction of the methyl sulfones from the concentrated acid layer, a 50% dilution with cold water should be done. The hexane layer containing the methyl sulfones was further cleaned-up on basic silica (33% KOH) and Florisil. After concentration, the extract was analysed by gas chromatography-mass spectrometry (GC-MS) with electron capture negative ionisation (ECNI) in selected ion monitoring mode (SIM). It was shown that, for methyl sulfones, the ion formation was dependent on the chlorine substitution, position of the MeSO2-group and the ion source temperature. If the ion source temperature was higher than 200 degrees C, [M-CH3]- was the predominant ion for most methyl sulfones. Therefore, for increased sensitivity, quantitation of most congeners was done using [M-CH3]- ions instead of the molecular ion as used in previously reported methods. The method was validated for the determination of 26 tri- to hepta- 3- and 4-substituted MeSO2-PCBs and 3-MeSO2-DDE in animal and human tissues. Good sensitivity and selectivity of the method were obtained. Limits of detection (LODs) ranged from 0.06 to 0.10 ng g(-1) lipid weight. Average recoveries of individual congeners from vegetable oil spiked with individual standards (3.33 ng g(-1)) ranged from 73 to 112% with a mean value of 89%. The coefficients of variation ranged from 5.2 to 12.2%, which is within the acceptable range for environmental analyses.

Adipose Tissue↗