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991.
Parameters of immunological competence in subjects with high consumption of fish contaminated with persistent organochlorine compounds 总被引:7,自引:0,他引:7
B. -G. Svensson T. Hallberg A. Nilsson A. Schütz L. Hagmar 《International archives of occupational and environmental health》1994,65(6):351-358
Summary Consumption of fatty fish species, like salmon and herring, from the Baltic Sea is an important source of human exposure to persistent organochlorine compounds, e.g. polychlorinated dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs). Many of these compounds show immunotoxic and hepatotoxic effects in animals. We have now studied immunological competence, including lymphocyte subsets, in 23 males with a high consumption of fish from the Baltic Sea and in a control group of 20 males with virtually no fish consumption. The high consumers had lower proportions and numbers of natural killer (NK) cells, identified by the CD 56 marker, in peripheral blood than the non-consumers. Weekly intake of fatty fish correlated negatively with proportions of NK cells (r
s = –0.32, P = 0.04). There were also, in a sub-sample of 11 subjects, significant negative correlations between numbers of NK cells and blood levels of a toxic non-ortho-PCB congener (IUPAC 126; r
s = –0.68, P = 0.02) and a mono-ortho congener (IUPAC 118; r
s = –.76, P = 0.01). A similar correlation, in 12 subjects, was seen for p,p-DDT (r
s = –0.76, P = 0.01). The corresponding negative correlation, in 13 subjects, with blood levels of PCDD/Fs was not significant (r
s = –0.57, P = 0.07). No significant association was seen between organic mercury in erythrocytes and NK cells. Fish consumption was not associated with levels of any other lymphocyte subset. Neither were there any correlations with plasma immunoglobulins or liver enzyme activities. Our study indicates that accumulation of persistent organochlorine compounds in high consumers of fatty fish may adversely affect NK cell levels. 相似文献
992.
Summary In a shock-free procedure, goldfish were trained to acquire a preference for quinine or acetic acid for which they have an innate repulsion. Recipients of brain extracts taken from trained donors showed a positive reaction to the previously dislike taste quality. The change in reaction was observed between the second and the seventh day after injection. It was not exhibited by recipients of brain extracts prepared from untrained donors.Supported by Deutsche Forschungsgemeinschaft (Sonderforschungsbereich 33). 相似文献
993.
F. Tatò C. Keller Prof. Dr. G. Wolfram 《Journal of molecular medicine (Berlin, Germany)》1993,71(4):314-318
Summary The effects of two moderate doses of long-chain n-3 fatty acids (3.0 and 4.5 g EPA + DHA per day for 4 weeks each) on serum lipids and lipoproteins of patients with familial combined hyperlipidemia (FCH) were studied in a double-blind, placebo-controlled clinical trial. In nine patients with FCH n-3 fatty acids led to a statistically significant, dose-dependent fall in very low density lipoprotein (VLDL) triglycerides (3 g/day: –42%, 4.5 g/day: –55%) VLDL cholesterol (3 g/day: –41%, 4.5 g/day: –47%), and VLDL apolipoprotein (apo) B-100 (3 g/day: –40%, 4.5 g/day: –56%). No overall change in low-density lipoprotein (LDL) cholesterol was found, as confirmed statistically. However, when analyzing the data of single patients LDL cholesterol and LDL apo B did not change in five patients but increased dose dependently (from pretreatment 4.80±0.93 mmol/l to 5.70+0.93 mmol/l LDL cholesterol after 4.5 g/day) in four. LDL and VLDL composition as indicated by cholesterol/apo B-100 and triglyceride/apo B-100 ratios did not change significantly. High-density lipoprotein (HDL) cholesterol was unchanged; the HDL cholesterol/apo A-I+apo A-II ratio increased by 19% (P<0.05) during fish oil treatment. We conclude that in FCH moderate doses of long-chain n-3 fatty acids are highly effective in lowering pathological VLDL triglycerides, VLDL cholesterol, and VLDL apo B. LDL cholesterol must, however, be monitored during treatment as it may rise substantially in some although not in all patients with this disease.Abbreviations EPA
eicosapentaenoic acid
- DHA
docosahexaenoic acid
- FCH
familial combined hyperlipidemia
- VLDL
very low density lipoprotein
- LDL
low-density lipoprotein
- HDL
high-density lipoprotein
- apo
apolipoprotein
Dedicated to Prof. Dr. N. Zöllner on the occasion of his 70th birthday 相似文献
994.
H. Vanegas B. Williams J. A. Freeman 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1979,34(2):335-349
Summary The marginal fibers (mf) constitute a major fiber component of the teleostean optic tectum, and this report deals with the physiological properties of these fibers and their postsynaptic elements. The mf are unmyelinated axons which originate at the torus longitudinalis and run lateralwards, parallel to one another, along the tectum's most superficial layer (stratum marginale). Here they synapse upon the dendritic arborizations of the pyramidal (p) neurons. These arborizations originate from a single apical dendritic shaft which, near the soma, receives retinofugal axon terminals. The p-neurons also have a basal dendritic shaft and a descending axon, both of which branch out horizontally at the stratum griseum centrale (SGC). The mf were stimulated through surface microelectrodes, and field potentials were recorded on-beam throughout the tectal thickness by means of micropipettes. The mf action potential (M-spike) may show two negative subpeaks which propagate at 0.20 and 0.16 m/s. Its refractory period is followed by a period of increased amplitude and decreased latency. The M-spike is followed by a series of slow waves, namely: (a) The S-wave, which probably represents the monosynaptic depolarization of the p-neuron's apical arbor; (b) The N-wave which possibly represents an active current sink at the point where these dendritic arborizations merge into the apical dendritic shaft; (c) The D-wave, recorded at the SGC, which possibly represents the activation of the p-neuron's axon and terminals (and perhaps also basal dendritic shaft and branches); and (d) the L-wave, which might represent a late depolarization of the p-neuron's apical arborizations.Morphologically and electrophysiologically, there are several similarities between the tectal mf/p-neuron system and the cerebellar parallel fiber/Purkinje cell system. 相似文献
995.
996.
Michael G. Jonz 《Acta histochemica》2018,120(7):623-629
Respiratory chemoreceptors in vertebrates are specialized cells that detect chemical changes in the environment or arterial blood supply and initiate autonomic responses, such as hyperventilation or changes in heart rate, to improve O2 uptake and delivery to tissues. These chemoreceptors are sensitive to changes in O2, CO2 and/or H+. In fish and mammals, respiratory chemoreceptors may be additionally sensitive to ammonia, hypoglycemia, and numerous other stimuli. Thus, chemoreceptors that affect respiration respond to different types of stimuli (or modalities) and are considered to be "polymodal". This review discusses the polymodal nature of respiratory chemoreceptors in vertebrates with a particular emphasis on chemoreceptors of the carotid body and pulmonary epithelium in mammals, and on neuroepithelial cells in water- and air-breathing fish. A major goal will be to examine the evidence for putative polymodal chemoreceptors in fish within the context of studies on mammalian models, for which polymodal chemoreceptors are well described, in order to improve our understanding of the evolution of polymodal chemoreceptors in vertebrates, and to aid in future studies that aim to identify putative receptors in air- and water-breathing fish. 相似文献
997.
The European Plant Protection Products Regulation 1107/2009 requires that registrants establish whether pesticide metabolites pose a risk to the environment. Fish acute toxicity assessments may be carried out to this end. Considering the total number of pesticide (re-) registrations, the number of metabolites can be considerable, and therefore this testing could use many vertebrates. EFSA's recent “Guidance on tiered risk assessment for plant protection products for aquatic organisms in edge-of-field surface waters” outlines opportunities to apply non-testing methods, such as Quantitative Structure Activity Relationship (QSAR) models. However, a scientific evidence base is necessary to support the use of QSARs in predicting acute fish toxicity of pesticide metabolites. Widespread application and subsequent regulatory acceptance of such an approach would reduce the numbers of animals used.The work presented here intends to provide this evidence base, by means of retrospective data analysis. Experimental fish LC50 values for 150 metabolites were extracted from the Pesticide Properties Database (http://sitem.herts.ac.uk/aeru/ppdb/en/atoz.htm). QSAR calculations were performed to predict fish acute toxicity values for these metabolites using the US EPA's ECOSAR software. The most conservative predicted LC50 values generated by ECOSAR were compared with experimental LC50 values.There was a significant correlation between predicted and experimental fish LC50 values (Spearman rs = 0.6304, p < 0.0001). For 62% of metabolites assessed, the QSAR predicted values are equal to or lower than their respective experimental values. Refined analysis, taking into account data quality and experimental variation considerations increases the proportion of sufficiently predictive estimates to 91%. For eight of the nine outliers, there are plausible explanation(s) for the disparity between measured and predicted LC50 values.Following detailed consideration of the robustness of this non-testing approach, it can be concluded there is a strong data driven rationale for the applicability of QSAR models in the metabolite assessment scheme recommended by EFSA. As such there is value in further refining this approach, to improve the method and enable its future incorporation into regulatory guidance and practice. 相似文献
998.
Ming Liu Molly McCann Elizabeth Lewis-Michl Syni-An Hwang 《International journal of hygiene and environmental health》2018,221(5):792-799
Background
Refugees from Burma who consume fish caught from local waterbodies have increased risk of exposure to environmental contaminants. We used respondent driven sampling (RDS) to sample this hard-to-reach population for the first Biomonitoring of Great Lakes Populations program. In the current study, we examined the interview data and assessed the effectiveness of RDS to sample the unique population.Methods
In 2013, we used RDS to sample 205 Burmese refugees and immigrants residing in Buffalo, New York who consumed fish caught from Great Lakes waters. RDS-adjusted population estimates of sociodemographic characteristics, residential history, fish consumption related behaviors, and awareness of fish advisories were obtained. We also examined sample homophily and equilibrium to assess how well the RDS assumptions were met in the study.Results
Our sample was diverse with respect to sex, age, years residing in Buffalo, years lived in a refugee camp, education, employment, and fish consumption behaviors, and each of these variables reached equilibrium by the end of recruitment. Burmese refugees in Buffalo consumed Great Lakes fish throughout the year; a majority of them consumed the fish more than two times per week during summer, and about one third ate local fish more than once per week in winter. An estimated 60% of Burmese refugees in Buffalo had heard about local fish advisories.Conclusions
RDS has the potential to be an effective methodology for sampling refugees and immigrants in conducting biomonitoring and environmental exposure assessment. Due to high fish consumption and limited awareness and knowledge of fish advisories, some refugee and immigrant populations are more susceptible to environmental contaminants. Increased awareness on local fish advisories is needed among these populations. 相似文献999.