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- Bauer, Michael, et al.
(författare)
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Association between solar insolation and a history of suicide attempts in bipolar I disorder.
- 2019
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Ingår i: Journal of psychiatric research. - : Elsevier BV. - 1879-1379 .- 0022-3956. ; 113, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- In many international studies, rates of completed suicide and suicide attempts have a seasonal pattern that peaks in spring or summer. This exploratory study investigated the association between solar insolation and a history of suicide attempt in patients with bipolar I disorder. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area on Earth. Data were collected previously from 5536 patients with bipolar I disorder at 50 collection sites in 32 countries at a wide range of latitudes in both hemispheres. Suicide related data were available for 3365 patients from 310 onset locations in 51 countries. 1047 (31.1%) had a history of suicide attempt. There was a significant inverse association between a history of suicide attempt and the ratio of mean winter solar insolation/mean summer solar insolation. This ratio is smallest near the poles where the winter insolation is very small compared to the summer insolation. This ratio is largest near the equator where there is relatively little variation in the insolation over the year. Other variables in the model that were positively associated with suicide attempt were being female, a history of alcohol or substance abuse, and being in a younger birth cohort. Living in a country with a state-sponsored religion decreased the association. (All estimated coefficients p<0.01). In summary, living in locations with large changes in solar insolation between winter and summer may be associated with increased suicide attempts in patients with bipolar disorder. Further investigation of the impacts of solar insolation on the course of bipolar disorder is needed.
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| 2. |
- Hollert, Henner, et al.
(författare)
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A new sediment contact assay to assess particle-bound pollutants using zebrafish (Danio rerio) embryos
- 2003
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Ingår i: Journal of Soils and Sediments. - : Springer Science and Business Media LLC. - 1439-0108 .- 1614-7480. ; 3:3, s. 197-207
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Tidskriftsartikel (refereegranskat)abstract
- Goal, Scope and Background. Based on a bioassay battery coveringonly primary producers and consumers as well as degraders, the potential ecological hazard of sediments to vertebrates cannot be estimated comprehensively. Therefore, there is an urgent need to develop and standardize integrated vertebrate-based test systems for sediment investigation strategies. Whereas vertebrate-based in vitro systems have frequently been used for the investigation of aqueous samples, there is a significant lack of whole sediment assays. Thus, the purpose of the present study was: (1)to develop a rapid and reliable, but comprehensive method to investigate native sediments and particulate matters without preceding extraction procedures; (2) to compare the hazard potential of solid phase sediments to the effects of corresponding pore waters and organic extracts in order to characterize the bioavailability of the particle-bound pollutants; and (3) to relatively evaluate the embryotoxic effects of sediments from the catchment areas of the rivers Rhine, Neckar and Danube.Methods (or Main Features). To investigate the toxicity of sediment samples on vertebrates, the standard embryo toxicity test with the zebrafish (Danio rerio; Hamilton-Buchanan 1922) according to DIN 38415-6 was modified with respect to exposure scheme and toxicological endpoints. Sediments from the catchment area of the Neckar River were assessed using pore waters, acetonic extracts and native sediments in order to get inside into the potential bioavailability of particle-bound pollutants. A comprehensive test protocol for the investigation of native sediments in the embryo toxicity test with the zebrafish is presented.Results and Discussion. The fish embryo assay with Danio rerio can be carried out with both aqueous and organic sediment extracts as well as native (whole, solid phase) sediment samples. Elongation of exposure time from 48 to up to 196 h significantly increased the mortality. Using the fish egg assay with native sediments, a broad range of embryotoxic effects could be elucidated, including clear-cut dose-response curves for the embryotoxic effects of contaminated sediments; in contrast, absence ofembryotoxic effects could be demonstrated even for the highest test concentrations of unpolluted sediments. With native sediments, embryotoxicity was clearly higher than with corresponding pore waters, thus corroborating the view that – at least for fish eggs – the bioavailability of particle-bound lipophilic substances in native sediments is higher than generally assumed. The relative ranking of sediment toxicity was identical using both native sediments and sediment extracts, EC20 values of the latter, however, being eight time lower higher than with the native sediments. A comparison of the embryo toxic effects of samples from the Neckar area with locations along the Rhine and Danube rivers elucidated a broad range of results, thus indicating different levels of contamination.Conclusions. A modified protocol of the zebrafish embryo test allows the assessment of sediment toxicity in both aqueous extracts and native sediments. The isolated investigation of pore waters may result in a clear-cut underestimation of the bioavailability of lipophilic particle-bound substances (as determined by native sediments).Recommendations and Perspectives. The zebrafish embryo test with native (whole, solid phase) sediments appears very promising for the evaluation of the bioavailable fraction of lipophilicparticle-bound substances and can therefore be recommended for the evaluation of vertebrate toxicity in tiered sediment test strategies and dredging directives such as the HABAB-WSV. Whereas acetone extracts may be tested as a rough estimation of embryotoxicity, native sediment samples will provide a more comprehensive and realistic insight into the bioavailable hazard potential
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