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At least 19 recordsLinked to original sources
PubMed1982

Inhibition of purified rabbit muscle phosphorylase a and phosphorylase b by polychlorinated biphenyls, polychlorinated biphenylols and polybrominated biphenyls.

Polychlorinated biphenyls, polychlorinated biphenylols and polybrominated biphenyls inhibited both rabbit muscle phosphorylase a and phosphorylase b (1,4-alpha-D-glucan:orthophosphate alpha-d-glucosyltransferase, EC 2.4.1.1). The degree of inhibition was dependent upon the relative hydrophobicity of the compounds and steric hinderance. 2,4,5,2',4',5'-Hexabromobiphenyl and Firemaster BP-6 were the most effective inhibitors (Ki, 15 . 10(-6) M). Phosphorylase b was inhibited by compounds of all three groups. 2,4,5,2',4',5'-Hexachlorobiphenyl and 2,4,5,2',4',5'-hexabromobiphenyl did not significantly inhibit phosphorylase a. All of the compounds inhibited phosphorylase a less than phosphorylase b, except 2',3',4',5,5'-pentachloro-2-biphenylol, which was equally effective on each enzyme. Kinetic analysis showed the inhibition was non-competitive and mixed. The results indicate that the compounds bind to hydrophobic site(s) on phosphorylase, access to which is limited by phosphorylation of serine 24.

Animals↗
PubMed2001

Suitability of several carbon sorbents for the fractionation of various sub-groups of toxic polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans.

Feasibility of several sorbents, Amoco PX-21, Carbosphere, Carbopack B and C and 2-(1-pyrenyl) ethyldimethylsilylated silica gel (PYE), for the fractionation of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and furans was investigated. Selection was based on their suitability for quantitative isolation of the target compounds with special attention for the most toxic mono- and non-ortho-CBs to prevent coelution with other congeners during the final determination by gas chromatography. Cost-effectiveness in terms of solvent and time consumption as well as feasibility for routine analysis and automation were considered additional merits of the methods compared. Final evaluation of the procedures providing the best results was done by comparison of the results obtained from the analysis of real-life samples. The results showed that, among the sorbents tested, Carbopack B and PYE were the most suitable for routine analysis. In particular, these sorbents allowed a more reliable determination of the toxic congeners and, consequently, of the toxic equivalents of 2,3,7,8-tetrachlorodibenzo-p-dioxin content in environmental samples.

Benzofurans↗
PubMed2001

Polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans as endocrine disrupters--what we have learned from Yusho disease.

Polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans (PCDFs) are persistent environmental pollutants. In some areas wildlife reproduction has been affected by these compounds, which are recognized as endocrine disrupters. In 1968 in northern Kyushu in Japan about 2000 people were poisoned by PCBs and PCDFs (pyrolysis products of PCBs) which contaminated rice oil. Their condition was named "Yusho" disease. A similar poisoning by PCBs in Taiwan was named "Yu-Cheng" disease. The major symptoms of Yusho disease were dermal and ocular lesions, but some of the symptoms, such as irregular menstrual cycles and altered immune responses, were notable with respect to the endocrine disrupting activities of PCBs and related compounds. Several important observations relevant to the mechanisms of Yusho have been made from animal studies. For example, a coplanar PCB congener was shown to cause atrophy of the thymus and PCB administration was thought to alter androgen metabolism. The most tragic aspect of Yusho and Yu-Cheng diseases was the exposure of children to PCBs. In the case of Yu-Cheng, children exposed to PCBs in utero and lactationally were reported to have poor cognitive development. Intellectual impairment was also observed in children born to women who had eaten fish contaminated with PCBs in the United States. From animal studies, alterations in thyroid hormone status, modulation of protein kinase C, and changes in dopamine levels, etc. were proposed as the possible mechanisms for the adverse effects of PCBs on brain development. Whereas coplanar PCB and related congeners, e.g., 2,3,7,8-tetrachlorodibenzo-p-dioxin, induce gene expression via a ligand-dependent transactivating factor, the arylhydrocarbon receptor, alternative pathways for gene expression, e.g., c-Src and cross talk with the MAP kinase pathway, are also reviewed with respect to understanding the toxic mechanisms of these compounds. Finally, the "precautionary principle" is discussed for prevention of the health hazards caused by exposure to endocrine disrupters.

Animals↗
PubMed1997

Organochlorine pesticides, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans in human adipose tissue from western Kyungnam, Korea.

Hexachlorocyclohexanes (HCHs), dichlorodiphenyl trichloroethane and its metabolites (DDTs), hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs) were determined in human adipose tissue samples collected from western Kyungnam, Korea. The residue levels of organochlorine compounds were in the order of DDTs followed by PCBs > HCHs > HCB > PCDDs/DFs. The mean concentrations of 2,3,7,8-TeCDD in male and female tissues were 2.8 and 1.7 pg.g-1 on lipid weight basis, respectively. No significant difference was found in the residue levels of PCDDs/DFs between sexes. In contrast, PCBs and DDTs showed a significant difference between sexes. Unlike the age trend observed for HCHs, PCBs and DDTs, PCDDs/DFs revealed a constant or rather decreasing pattern with increasing age. This is the first report on PCDDs/DFs contamination in human adipose tissue from Korea. Organochlorine concentrations in human adipose tissues from western Kyungnam were generally much lower than those of other countries.

Adipose Tissue↗
PubMed1997

[Effect of green tea (matcha) on gastrointestinal tract absorption of polychlorinated biphenyls, polychlorinated dibenzofurans and polychlorinated dibenzo-p-dioxins in rats].

This paper presents the liver distribution and fecal excretion of polychlorinated biphenyls (PCB), polychlorinated dibenzofurans (PCDF) congeners and polychlorinated dibenzo-p-dioxins (PCDD) congeners, in male rats fed with powdered green tea (matcha). The rats were given a treatment diet containing 10% matcha for the first five days. Then, the animals were administered 4 g of 10% matcha diet containing 0.5 ml of the casual rice-bran oil of Yusho that had occurred in the Southwest part of Japan in 1968 and kept on the same diet for another five days. The fecal excretion of PCB, PCDF and PCDD in the group fed with 10% matcha were 4.4, 2.4-9.1 and 2.5-4.7 times higher (p < 0.01), respectively, than that in the control group. The liver distribution of PCB, PCDF and PCDD in the same groups were 79%, 20-75% and 26-67% of the control group, respectively. These findings suggest that administration of matcha is useful as a treatment of Yusho patients exposed to PCB, PCDF and PCDD.

Animals↗
PubMed2006

Evidence for the transfer of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans from soil into biota.

The concentrations of six indicator and co-planar polychlorinated biphenyls (PCBs), 17 polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans (PCDD/Fs) were determined in soil and associated biota samples collected from a polluted and wasted farmland in southern China. The sum of six indicator PCBs (Nos 28, 52, 101, 138, 153 and 180) concentrations in biota samples were proportional to the total amount of PCBs that transferred from soil to the corresponding biota samples, and the sum six indicator PCB congeners in samples were about 20% of the total PCBs, respectively. The ratios of the sum six indicator PCBs and the total PCBs in samples collected in the same area were approximately equal. The sums of six indicator PCBs were proportional to the total PCBs that transferred from soil to plant, while the co-planar PCBs were not. Analysis of individual PCB and PCDD/F congener signatures in soil revealed the original pollutant source after transportation and biodegradation for 14 years using principal component analysis (PCA). The pattern of PCBs in soils and plants could reflect the original pollution source after transportation and biodegradation for 14 years, while the pattern of PCBs in the terrestrial animals could not reflect the primary source. The consumption foods in this region such as foraging chicken eggs, foraging duck eggs, and loach (Misgurnus anguillicaudatus) were highly contaminated, the total toxicity equivalent (TEQ) was up to 784 pg WHO-TEQ/g on basis lipid in foraging chicken eggs.

Animals↗
PubMed1994

Probabilistic health risk assessment for exposures to estuary sediments and biota contaminated with polychlorinated biphenyls, polychlorinated terphenyls and other toxic substances.

A Latin Hypercube probabilistic risk assessment methodology was employed in the assessment of health risks associated with exposures to contaminated sediment and biota in an estuary in the Tidewater region of Virginia. The primary contaminants were polychlorinated biphenyls (PCBs), polychlorinated terphenyls (PCTs), polynuclear aromatic hydrocarbons (PAHs), and metals released into the estuary from a storm sewer system. The exposure pathways associated with the highest contaminant intake and risks were dermal contact with contaminated sediment and ingestion of contaminated aquatic and terrestrial biota from the contaminated area. As expected, all of the output probability distributions of risk were highly skewed, and the ratios of the expected value (mean) to median risk estimates ranged from 1.4 to 14.8 for the various exposed populations. The 99th percentile risk estimates were as much as two orders of magnitude above the mean risk estimates. For the sediment exposure pathways, the stability of the median risk estimates was found to be much greater than the stability of the expected value risk estimates. The interrun variability in the median risk estimate was found to be +/- 1.9% at 3000 iterations. The interrun stability of the mean risk estimates was found to be approximately equal to that of the 95th percentile estimates at any number of iterations. The variation in neither contaminant concentrations nor any other single input variable contributed disproportionately to the overall simulation variance. The inclusion or exclusion of spatial correlations among contaminant concentrations in the simulation model did not significantly effect either the magnitude or the variance of the simulation risk estimates for sediment exposures.

Adult↗
PubMed2006

Polybrominated biphenyls, polychlorinated biphenyls, body weight, and incidence of adult-onset diabetes mellitus.

BACKGROUND: Prior studies have reported an increased risk of diabetes related to polychlorinated biphenyl (PCB) exposure. No study has yet investigated whether polybrominated biphenyls (PBBs), which are similar in chemical structure, increase the incidence of diabetes. METHODS: The Michigan PBB cohort was established in 1976 and surveyed again in 1991-1993 and in 2001. PBB and PCB serum levels were measured from blood collected at enrollment. To determine the incidence of adult-onset diabetes, we analyzed cohort members without diabetes at enrollment, ages 20 years and older, with known PBB and PCB levels, who participated in at least 1 follow-up survey (n = 1384). Using Poisson regression, we determined the incidence density ratio (IDR) of diabetes for different serum levels of PBB and PCB, controlling for age, body mass index, smoking, and alcohol consumption at enrollment. RESULTS: Analyzing 25 years of follow-up data, we did not find that higher PBB serum levels were a risk factor for the incidence of diabetes mellitus. However, in women, but not in men, higher PCB serum levels were associated with increased incidence of diabetes (IDR = 2.33; 95% confidence interval = 1.25-4.34 in the highest PCB group compared with the lowest). In both men and women, overweight and obesity increased the diabetes incidence. CONCLUSIONS: We found no association between PBB serum levels and diabetes incidence. In women, there was a positive linear association of diabetes incidence with PCB serum levels at enrollment. This finding is in agreement with 2 prior studies indicating a higher relative risk of diabetes in PCB-exposed women.

Adult↗
PubMed2000

Validation of an analytical procedure for polychlorinated biphenyls, coplanar polychlorinated biphenyls and polycyclic aromatic hydrocarbons in environmental samples.

This work describes an efficient analytical procedure for the analysis of PCBs (polychlorinated biphenyls), coplanar PCBs and PAHs (polycyclic aromatic hydrocarbons) from the same sample. The method includes a solvent extraction followed by a combined purification-separation step on an alumina-silica column. Coplanar PCBs are isolated from the first fraction (PCBs) by a further high-performance liquid chromatography (HPLC) fractionation on a PYE [2-(1-pyrenyl)ethyldimethylsilylated silica gel] column. PCBs are identified and quantified by gas chromatography (GC) with electron-capture detection whereas GC with flame ionization detection or mass spectrometry are used for PAH determinations. This method allows the measurement of these contaminants in biota and sediment at trace levels as low as 1 pg g(-1) for coplanar PCBs with a precision better than 20%.

Chromatography, Gas↗
PubMed1995

Effect of polychlorinated biphenyls and polychlorinated dibenzofurans on leukocyte in peripheral blood and bronchoalveolar lavage fluid.

In order to investigate immunological abnormalities induced by polychlorinated biphenyls and polychlorinated dibenzofurans, we have performed bronchoalveolar lavage in the rats given polychlorinated biphenyls and polychlorinated dibenzofurans. We have administrated 5.0 mg of polychlorinated biphenyls or 0.5 mg of polychlorinated dibenzofurans to Sprague-Dawley rats intraperitoneally. Four weeks after the administration, mild necrosis of bronchiolar Clara cells and mild edema associated with chronic inflammatory infiltration in the alveoli were seen in both groups. In the peripheral blood, percentage of T-lymphocyte, helper T-cell and suppressor T-cell decreased significantly both in polychlorinated biphenyls and polychlorinated dibenzofurans given rats. On the other hand, in the bronchoalveolar lavage fluid, percentage of T-cell increased only in polychlorinated dibenzofurans given rats and percentage of suppressor T-cell increased in both groups. O2- release by alveolar macrophage increased significantly both when stimulated with wheat germ lectin and with phorbol myristate acetate. These results indicate that immunological alternation may be different between peripheral blood and respiratory system as one of the target organs of these chemicals. Further examination is needed for the analysis of immunological abnormalities in the target organs of polychlorinated biphenyls and polychlorinated dibenzofurans poisoning.

Animals↗
PubMed1991

Glioblastoma multiforme occurring in a patient following exposure to polychlorinated biphenyls.

Polychlorinated biphenyls have been shown to be carcinogens in animal studies. Because of lipid solubility and lack of biodegradation, they are known to deposit preferentially in fat and nervous tissue. In this report, we describe a 31-year-old male with prolonged polychlorinated biphenyls exposure who developed glioblastoma multiforme. Fat biopsy documented the presence of markedly elevated PCB levels. A co-worker also developed a malignant astrocytoma. The nature of PCBs and their role in human carcinogenesis are discussed. The possibility of an etiologic link between PCBs and brain tumors should be further investigated.

Adult↗
PubMed1994

Nucleotide sequence and functional analysis of the meta-cleavage pathway involved in biphenyl and polychlorinated biphenyl degradation in Pseudomonas sp. strain KKS102.

Pseudomonas sp. strain KKS102 is able to degrade biphenyl and polychlorinated biphenyls via the meta-cleavage pathway. We sequenced the upstream region of the bphA1A2A3BCD (open reading frame 1 [ORF1]) A4 and found four ORFs in this region. As the deduced amino acid sequences of the first, second, and third ORFs are homologous to the meta-cleavage enzymes from Pseudomonas sp. strain CF600 (V. Shingler, J. Powlowski, and U. Marklund, J. Bacteriol. 174:711-724, 1992), these ORFs have been named bphE, bphG, and bphF, respectively. The fourth ORF (ORF4) showed homology with ORF3 from Pseudomonas pseudoalcaligenes KF707 (K. Taira, J. Hirose, S. Hayashida, and K. Furukawa, J. Biol. Chem. 267:4844-4853, 1992), whose function is unknown. The functions of meta-cleavage enzymes (BphE, BphG, and BphF) were analyzed by using crude extracts of Escherichia coli which expressed the encoding genes. The results showed that bphE, bphG, and bphF encode 2-hydroxypenta-2,4-dienoate hydratase, acetaldehyde dehydrogenase (acylating), and 4-hydroxy-2-oxovalerate aldolase, respectively. The biphenyl and polychlorinated biphenyl degradation pathway of KKS102 is encoded by 12 genes in the order bphEGF (ORF4)A1A2A3BCD (ORF1)A4. The functions of ORF1 and ORF4 are unknown. The features of this bph gene cluster are discussed.

Aldehyde Oxidoreductases↗
PubMedDate not supplied

Middle-ear disease in children exposed prenatally to polychlorinated biphenyls and polychlorinated dibenzofurans.

During 1978 and 1979, an episode of poisoning from ingestion of rice oil contaminated with polychlorinated biphenyls and polychlorinated dibenzofurans occurred in central Taiwan. We followed-up children who had been born between June 1978 and March 1985, as well as matched unexposed children. The mothers of exposed children had consumed contaminated oils before the children were born. In 1993, otolaryngologists examined the middle ear of each child with a pneumatic otoscope, and they measured the middle-ear pressure by tympanometry with a Rion RS20 impedance audiometer. The exposed children had a significantly higher prevalence of middle-ear diseases than their matched controls. The exposed children who had ear diseases had higher serum levels of 2,3,4,7,8-pentachloro- and 1,2,3,4,7,8-hexachloro-dibenzofurans than the children who did not have similar diseases. Therefore, in this study, children exposed to polychlorinated biphenyls and polychlorinated dibenzofurans had a higher incidence of middle-ear diseases than their controls.

Benzofurans↗
PubMed1989

Polychlorinated biphenyls.

Polychlorinated biphenyls (PCBs) and their contaminants have definite ocular and dermatologic side effects, often directly related to the serum level of these compounds. These are usually the first symptoms and signs to appear. Other side effects are far more variable, and the carcinogenic role of PCBs and their contaminants remains controversial.

Animals↗
PubMed2003

Molecular hologram derived quantitative structure-property relationships to predict physico-chemical properties of polychlorinated biphenyls.

Polychlorinated biphenyls (PCBs) congeners with various degrees of chlorination and substitution patterns are among the most widespread and persistent man-made organic pollutants. They are toxic, lipophilic and tend to be bioaccumulated. The knowledge of the physico-chemical properties is very useful to explain the environmental behavior of PCBs and to perform an exposure assessment. In this paper, we have used a new molecular representation, the molecular hologram, to generate quantitative structure-property relationship models to predict the physico-chemical properties of biphenyl and all of its chlorinated congeners. The investigated properties include 1-octanol/water partition coefficient (logK(ow)), aqueous solubility (-logS(w)), aqueous activity coefficient (-logY(w)), Total molecular surface area, Henry's law constant (logH). The results show that this new quantitative structure-activity relationship approach presents highly predictive models for important physico-chemical properties of PCBs.

Chemical Phenomena↗