73 research outputs found
Inter-population variations in concentrations, determinants of and correlations between 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE): a cross-sectional study of 3161 men and women from Inuit and European populations
BACKGROUND: The study is part of a collaborative project (Inuendo), aiming to assess the impact of dietary persistent organochlorine pollutants (POPs) on human fertility. The aims with the present study are to analyze inter-population variations in serum concentrations of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE), to assess inter-population variations in biomarker correlations, and to evaluate the relative impact of different determinants for the inter-individual variations in POP-biomarkers. METHOD: In study populations of 3161 adults, comprising Greenlandic Inuits, Swedish fishermen and their wives, and inhabitants from Warsaw, Poland and Kharkiv, Ukraine, serum concentrations of CB-153 and p,p'-DDE, were analysed by gas chromatography-mass spectrometry. RESULTS: The median serum concentrations of CB-153 were for male and female Inuits 200 and 110, for Swedish fishermen 190 and their wives 84, for Kharkiv men and women 44 and 27, and for Warsaw men and women 17 and 11 ng/g lipids, respectively. The median serum concentrations of p,p'-DDE were for Kharkiv men and women 930 and 650, for male and female Inuits 560 and 300, for Warsaw men and women 530 and 380, and for Swedish fishermen 240 and their wives 140 ng/g lipids, respectively. The correlation coefficients between CB-153 and p,p'-DDE varied between 0.19 and 0.92, with the highest correlation among Inuits and the lowest among men from Warsaw. Men had averagely higher serum concentrations of CB-153 and p,p'-DDE, and there were positive associations between age and the POP-biomarkers, whereas the associations with BMI and smoking were inconsistent. Dietary seafood was of importance only in the Inuit and Swedish populations. CONCLUSION: CB-153 concentrations were much higher in Inuits and Swedish fishermen's populations than in the populations from Eastern Europe, whereas the pattern was different for p,p'-DDE showing highest concentrations in the Kharkiv population. The correlations between the POP-biomarkers varied considerably between the populations, underlining that exposure sources differ and that the choice of representative biomarkers of overall POP exposure has to be based on an analysis of the specific exposure situation for each population. Age and gender were consistent determinants of serum POPs; seafood was of importance only in the Inuit and Swedish populations
Environmental occurrence, analysis, and toxicology of toxaphene compounds.
Toxaphene production, in quantities similar to those of polychlorinated biphenyls, has resulted in high toxaphene levels in fish from the Great Lakes and in Arctic marine mammals (up to 10 and 16 microg g-1 lipid). Because of the large variabiliity in total toxaphene data, few reliable conclusions can be drawn about trends or geographic differences in toxaphene concentrations. New developments in mass spectrometric detection using either negative chemical ionization or electron impact modes as well as in multidimensional gas chromatography recently have led researchers to suggest congener-specific approaches. Recently, several nomenclature systems have been developed for toxaphene compounds. Although all systems have specific advantages and limitations, it is suggested that an international body such as the International Union of Pure and Applied Chemistry make an attempt to obtain uniformity in the literature. Toxicologic information on individual chlorobornanes is scarce, but some reports have recently appeared. Neurotoxic effects of toxaphene exposure such as those on behavior and learning have been reported. Technical toxaphene and some individual congeners were found to be weakly estrogenic in in vitro test systems; no evidence for endocrine effects in vivo has been reported. In vitro studies show technical toxaphene and toxaphene congeners to be mutagenic. However, in vivo studies have not shown genotoxicity; therefore, a nongenotoxic mechanism is proposed. Nevertheless, toxaphene is believed to present a potential carcinogenic risk to humans. Until now, only Germany has established a legal tolerance level for toxaphene--0.1 mg kg-1 wet weight for fish
Epidemiological study of traumatic dental injuries in 5- to 6-year-old Brazilian children
Monitoring traumatic dental injury (TDI) in primary teeth through epidemiological cross-sectional surveys provides descriptive information relevant to the development of public policies focused on the prevention of such injuries for the target population. The aim of this study was to assess the prevalence of TDI in 5- to 6-year-old Brazilian children and its association with biological and socioeconomic factors. A total of 684 children aged 5 to 6 years old, from 11 public schools in the city of Barueri (Brazil) were evaluated. Clinical examinations were carried out in the schools, by two trained and calibrated examiners. Gauze and a mouth mirror were used for the examinations. The reported TDIs were classified according to the Andreasen (2007) criteria for primary teeth. The results showed that 52.3% of the children had TDI. Enamel fracture (63.4%) was the most frequently observed sign of TDI, and the most affected teeth were the primary maxillary central incisors (26.9% maxillary right central incisor and 24% maxillary left central incisor). There was no association between the presence of TDI and biological or socioeconomic factors. In conclusion, the prevalence of TDI was high and had no statistically significant association with biological and socioeconomic factors
Degradation of haloaromatic compounds
An ever increasing number of halogenated organic compounds has been produced by industry in the last few decades. These compounds are employed as biocides, for synthetic polymers, as solvents, and as synthetic intermediates. Production figures are often incomplete, and total production has frequently to be extrapolated from estimates for individual countries. Compounds of this type as a rule are highly persistent against biodegradation and belong, as "recalcitrant" chemicals, to the class of so-called xenobiotics. This term is used to characterise chemical substances which have no or limited structural analogy to natural compounds for which degradation pathways have evolved over billions of years. Xenobiotics frequently have some common features. e.g. high octanol/water partitioning coefficients and low water solubility which makes for a high accumulation ratio in the biosphere (bioaccumulation potential). Recalcitrant compounds therefore are found accumulated in mammals, especially in fat tissue, animal milk supplies and also in human milk. Highly sophisticated analytical techniques have been developed for the detection of organochlorines at the trace and ultratrace level
The spread and clinical impact of ST14CC-PBP3 type IIb/A, a clonal group of non-typeable Haemophilus influenzae with chromosomally mediated β-lactam resistance-a prospective observational study
Objectives: Increasing incidences of non-typeable Haemophilus influenzae (NTHi) with β-lactam resistance mediated through mutations in penicillin-binding protein 3 (BLNAR or rPBP3) have been observed in the past decades. Recently, an rPBP3 NTHi sequence type (ST) 14 with PBP3 type IIb/A caused a disease outbreak in a nursing home in Sweden with severe outcomes, indicating increased bacterial virulence. In this prospective observational study, the epidemiology and clinical significance of the corresponding clonal group (ST14CC-PBP3IIb/A) in Skåne, Sweden was investigated. Methods: ST14CC-PBP3IIb/A isolates were identified through partial multilocus sequence typing and ftsI(PBP3 gene)-sequencing of prospectively collected H. influenzae from patients with respiratory tract or invasive infections (n=3262) in 2010-2012. Data on type of infection, hospitalization and outcomes were analysed, and the geographical distribution of isolates from different groups was investigated. Results: Isolates belonging to ST14CC-PBP3IIb/A constituted 26% (n=94/360) of respiratory tract rPBP3 NTHi. From mapping of patient addresses, a dynamic geographical spread was apparent during the study period. Furthermore, patients with infections by ST14CC-PBP3IIb/A isolates had higher hospitalization rates compared with patients infected with other rPBP3 NTHi (14/83 versus 21/255, p 0.025) and to a group of patients infected with susceptible NTHi (14/83 versus 13/191, p 0.010). ST14CC-PBP3IIb/A isolates constituted 25% (n=2/8) of invasive rPBP3 NTHi during the study period. Conclusions: Our investigation suggests that the ST14CC-PBP3IIb/A clonal group is associated with increased clinical virulence, resistance to several antimicrobial agents, and is persistent over time. We conclude that virulence varies between different NTHi, and that NTHi disease may be more dependent on bacterial factors than previously recognized
Influence of 17a-ethynylestradiol on CYP1A, GST and biliary FACs responses in male African sharptooth catfish (Clarias gariepinus) exposed to waterborne Benzo[a]Pyrene
Ecotoxicology, 2006; 15:629–637Dose dependent effects of Benzo[a]pyrene
(BaP) on cytochrome P4501A (CYP1A), glutathione-
S-transferase (GST) and fluorescent aromatic compounds
(FACs) metabolites biomarker responses
were studied in African sharptooth catfish (Clarias
gariepinus) following 24 h of waterborne exposures.
Based on biomass of C. gariepinus in different tanks,
BaP concentrations of 1.60, 3.44, and 18.21 lg/L that
corresponded to 0.5, 1.0, and 5.0 mg/kg body weight
were used. Significant induction of EROD activities
in gill filaments was observed at all doses and the accumulation of FACs metabolites in bile was significantly
different between groups. Accumulation of
FACs metabolites in bile strongly correlated
(r2 = 0.99) with BaP doses. Hepatic EROD activities
were undetectable and no effect on GST activities
was observed. The highest dose of BaP from the dose
dependent study was further studied to assess the
interactive and temporal responses of C. gariepinus
on CYP1A, GST, and FACs metabolites biomarkers
following exposure to either BaP alone, 17a-ethynylestradiol
(EE2) alone or a combination of both
compounds at concentrations of 54.17 lg/L for BaP,
51.38 lg/L for EE2 and 54.44 lg/L for each of both
compounds. Based on biomass in each tank, these
concentrations corresponded to 5 mg/kg body weight.
While a group of six fish was sacrificed on day 0 from
the control tank only, other groups of six fish were
sacrificed after 1, 3, and 6 days of exposure from the
control and exposed groups. Maximum induction of
gill filament and hepatic EROD activities was observed
after 1 day of exposure. Both EROD activities
in gill filaments and liver were significantly induced
by exposure to BaP alone or co-administration with
EE2. Gill filament EROD induction was significantly
inhibited (50%) by co-administration of BaP and EE2
compared to administration of BaP alone. Levels of
FACs in bile for BaP and BaP + EE2 exposed groups
were significantly different from the control at all
doses and time points. A significant induction of GST
activities was observed in fish exposed to BaP and
BaP + EE2 after 3 days. Exposure to EE2 alone
caused significant induction of this enzyme after day
6. This study reports for the first time the significant
antagonistic influence of EE2 on BaP in gills of fish
following waterborne exposures. The results also indicate that chemical mixtures may affect biomarker
responses differently from compounds administered
alone and that the sensitivity of CYP1A to interactive
chemicals is different in gills and liver
Influence of 17a-ethynylestradiol on CYP1A, GST and biliary FACs responses in male African sharptooth catfish (Clarias gariepinus) exposed to waterborne Benzo[a]Pyrene
Ecotoxicology, 2006; 15:629–637Dose dependent effects of Benzo[a]pyrene
(BaP) on cytochrome P4501A (CYP1A), glutathione-
S-transferase (GST) and fluorescent aromatic compounds
(FACs) metabolites biomarker responses
were studied in African sharptooth catfish (Clarias
gariepinus) following 24 h of waterborne exposures.
Based on biomass of C. gariepinus in different tanks,
BaP concentrations of 1.60, 3.44, and 18.21 lg/L that
corresponded to 0.5, 1.0, and 5.0 mg/kg body weight
were used. Significant induction of EROD activities
in gill filaments was observed at all doses and the accumulation of FACs metabolites in bile was significantly
different between groups. Accumulation of
FACs metabolites in bile strongly correlated
(r2 = 0.99) with BaP doses. Hepatic EROD activities
were undetectable and no effect on GST activities
was observed. The highest dose of BaP from the dose
dependent study was further studied to assess the
interactive and temporal responses of C. gariepinus
on CYP1A, GST, and FACs metabolites biomarkers
following exposure to either BaP alone, 17a-ethynylestradiol
(EE2) alone or a combination of both
compounds at concentrations of 54.17 lg/L for BaP,
51.38 lg/L for EE2 and 54.44 lg/L for each of both
compounds. Based on biomass in each tank, these
concentrations corresponded to 5 mg/kg body weight.
While a group of six fish was sacrificed on day 0 from
the control tank only, other groups of six fish were
sacrificed after 1, 3, and 6 days of exposure from the
control and exposed groups. Maximum induction of
gill filament and hepatic EROD activities was observed
after 1 day of exposure. Both EROD activities
in gill filaments and liver were significantly induced
by exposure to BaP alone or co-administration with
EE2. Gill filament EROD induction was significantly
inhibited (50%) by co-administration of BaP and EE2
compared to administration of BaP alone. Levels of
FACs in bile for BaP and BaP + EE2 exposed groups
were significantly different from the control at all
doses and time points. A significant induction of GST
activities was observed in fish exposed to BaP and
BaP + EE2 after 3 days. Exposure to EE2 alone
caused significant induction of this enzyme after day
6. This study reports for the first time the significant
antagonistic influence of EE2 on BaP in gills of fish
following waterborne exposures. The results also indicate that chemical mixtures may affect biomarker
responses differently from compounds administered
alone and that the sensitivity of CYP1A to interactive
chemicals is different in gills and liver
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