Characterizing the marine mammal exposome by iceberg modeling, linking chemical analysis and in vitro bioassays.

The present study complements work on mixture effects measured with in vitro bioassays of passive equilibrium sampling extracts using the silicone polydimethylsiloxane (PDMS) in organs from marine mammals with chemical profiling. Blubber, liver, kidney and brain tissues of harbor porpoise (Phocoena phocoena), harbor seal (Phoca vitulina), ringed seal (Phoca hispida) and orca (Orcinus orca) from the North and Baltic Seas were investigated. We analyzed 117 chemicals including legacy and emerging contaminants using gas chromatography-high resolution mass spectrometry and quantified 70 of those chemicals in at least one sample. No systematic differences between the organs were found. Only for single compounds a clear distribution pattern was observed. For example, 4,4'-dichlorodiphenyltrichloroethane, enzacamene and etofenprox were mainly detected in blubber, whereas tonalide and the hexachlorocyclohexanes were more often found in liver. Furthermore, we compared the chemical profiling with the bioanalytical results using an iceberg mixture model, evaluating how much of the biological effect could be explained by the analyzed chemicals. The mixture effect predicted from the quantified chemical concentrations explained 0.014-83% of the aryl hydrocarbon receptor activating effect (AhR-CALUX), but less than 0.13% for the activation of the oxidative stress response (AREc32) and peroxisome-proliferator activated receptor (PPARγ). The quantified chemicals also explained between 0.044-45% of the cytotoxic effect measured with the AhR-CALUX. The largest fraction of the observed effect was explained for the orca, which was the individuum with the highest chemical burden. This study underlines that chemical analysis and bioassays are complementary to comprehensively characterize the mixture exposome of marine mammals.

Measuring health professionals' beliefs about skin-to-skin care during a cesarean.

Women and their newborns are at risk of delayed or withheld skin-to-skin care (SSC) during a caesarean, which is about one-third of births, worldwide. To date, no instrument exists to assess health professionals' (HPs) beliefs, and potential barriers and strategies for implementing SSC during a cesarean. The study aims were to (1) develop an instrument, Health Professionals' Beliefs about Skin-to-Skin Care During a Cesarean (SSCB ), (2) establish its validity and reliability and (3) describe HPs' beliefs about SSC during a caesarean. Quantitative and qualitative analyses were used to test the SSCB and describe HPs' beliefs. SSCB analysis yielded a content validity of 0.83 and reliability of α = 0.9. We grouped all practice roles as either nurses or physicians. The mean rank score for nurses (n = 120, M = 90) was significantly higher (p = 0.001) than physicians (n = 46, M = 79). Despite this difference, scores for both roles reflected support for SSC. Participants identified hospital readiness to implement SSC and maintaining maternal and newborn safety as major issues. SSCB is a valid, reliable instrument to measure HPs' beliefs about SSC during a caesarean birth. HPs can use the SSCB during quality improvement initiatives to improve access to immediate SSC for women who have a caesarean birth. Improved access can enhance breastfeeding outcomes and promote optimal maternal and child health.

On the half-life of thiocyanate in the plasma of the marine fish Amphiprion ocellaris: implications for cyanide detection.

The illegal practice of using cyanide (CN) as a stunning agent to collect fish for both the marine aquarium and live fish food trades has been used throughout the Indo-Pacific for over 50 years. CN fishing is destructive to all life forms within the coral reef ecosystems where it is used and is certainly one of many anthropogenic activities that have led to 95% of the reefs in the Indo-Pacific being labeled at risk for degradation and loss. A field-deployable test for detecting fish caught using CN would assist in combating the use of this destructive practice, however, no reliable and robust test exists. Further, there is little toxicokinetic data available on marine fish to support the development of such a test, yet such data is critical to establishing the concentration range and time scale over which such a test would be viable. This study presents the first direct measurement of the half-life of the metabolite thiocyanate (SCN) after pulsed exposure to CN in a marine fish. SCN was measured in the plasma of Amphiprion ocellaris after exposure to 50 ppm CN for three exposure times (20, 45, and 60 s) using HPLC-UV and a C30 column pre-treated with polyethylene glycol. Plasma SCN levels observed are dose-dependent, reflecting a longer time for conversion of CN to SCN as the dose of CN increases. SCN plasma levels reached a maximum concentration (1.2-2.3 ppm) 12-20 h after exposure to CN. The half-life for the elimination of SCN was 1.01 ± 0.26 days for 45 s exposure and 0.44 ± 0.15 days for 20 s exposure. Fish were also directly exposed to SCN (100 ppm for 11 days) and the observed half-life for SCN elimination was 0.35 ± 0.07 days. Plasma SCN levels did not return to control levels, even after 41 days when exposed to CN but did return to control levels after 48 days when exposed to SCN. The similar half-lives observed for CN and SCN exposure suggests that SCN exposure can be used as a proxy for measuring the rate of SCN elimination following CN exposure. In order for plasma SCN to be used as a marker for CN exposure, these results must be extended to other species and endogenous levels of SCN in wild caught fish must be established.