During the 2010 Deepwater Horizon (DWH), oil spill an estimated 800 million L oil and 7.9 million L dispersant entered the environment. The potential adverse effects of the oil-dispersant mixture are ...poorly understood. The aim of this study was to investigate the impacts of this mixture on early development of sheepshead minnow (Cyprinodon variegatus), a small-bodied estuarine fish commonly found in the area affected by the DWH spill. Embryos were exposed to a chemically enhanced water accommodated fraction (CEWAF; 10:1 mixture of Macondo oil; Corexit 9500) for 48 hr, after which organisms were maintained in uncontaminated water for an additional 8 days. Impacts were assessed on embryonic (heart rate, development of eye pigmentation, embryonic movement measured) and larval (time to hatch, larval survival, standard length, and cyp1a gene expression) development. No significant alterations were found in survival, time to hatch or cyp1a at the end of the experiment. However, CEWAF induced significant decreases in heart rate of embryos, delayed development of eye pigmentation, reduced embryonic movement, and diminished standard length. These results indicate potential sublethal adverse consequences attributed to CEWAF exposure during early development, even in the absence of maintained cyp1a induction or survival rate, potentially affecting the fitness of organisms later in life.
•Fundulus heteroclitus were exposed to non-aromatizable 5α-dihydrotestosterone.•Exposures occurred under low (2 ppt) and high (16 ppt) salinity.•Egg production in the high salinity group ...significantly declined at all DHT levels.•Egg production in the low salinity group was depressed independent of DHT exposure.•Environmental variables can affect reproductive effects of endocrine disruptors.
Endocrine disrupting substances (EDSs) have the potential to disturb sensitive hormone pathways, particularly those involved in development and reproduction. Both fresh and estuarine water bodies receive inputs of EDSs from a variety of sources, including sewage effluent, industrial effluent and agricultural runoff. Based on current literature, freshwater species appear to respond to lower levels of EDSs than estuarine or marine species. Therefore, effects elicited by EDSs in freshwater teleosts may not be an accurate representation of how EDSs affect teleosts in estuarine and marine environments. To address this potential difference, a short-term reproductive bioassay was conducted under conditions of low and high salinity using mummichog (Fundulus heteroclitus), a euryhaline species that is native to the east coast of North America. The goals of this study were to determine the response of mummichog when exposed to an androgenic EDS and whether salinity affected the response. A model androgen, 5α-dihydrotestosterone (DHT), was selected for this experiment. Impacts on reproduction were evaluated at multiple biological levels, including physiological (sex steroid levels), organismal (gonad size and gonad morphology), and functional (egg production) endpoints. Under conditions of high salinity, egg production was significantly reduced at all exposure concentrations. Under conditions of low salinity, there were no significant differences based on DHT treatment; however, egg production in all treatment groups including the control were significantly reduced relative to the high salinity control group. Other reproductive endpoints, such as sex steroid production, showed stronger correlation to fecundity in females than males. This study demonstrates that mummichog fecundity is sensitive to androgenic endocrine disruption while also underscoring the importance of how changes in salinity, an environmental variable, can impact reproduction.
Threatened loggerhead sea turtles (Caretta caretta) face numerous environmental challenges, including exposure to anthropogenic chemicals such as polychlorinated biphenyls (PCBs). Despite being ...banned by the USA in the 1970s, PCBs persist in the environment and produce immunotoxic effects in a wide range of marine vertebrate species. This is of particular concern, as the modulation of the immune system may enhance the susceptibility to a variety of pathogens. Blood samples were collected from 19 immature, captive-reared loggerhead sea turtles. Functional immune assays phagocytosis and natural killer (NK) cell activity were used to quantify the direct effects of PCB congeners 105, 138, and 169 on innate immune functions upon in vitro exposure of sea turtle cells to increasing concentrations (control (0), 0.5, 1, 2.5, 5, 10, 15, or 20 ppm) of each PCB. PCB 105 significantly elevated eosinophil phagocytosis at 10 and 15 ppm and PCB 138 at 15 ppm compared to unexposed (0 ppm). The effects of PCB 169 on phagocytosis were not evaluated. PCB 138 and 105 significantly decreased NK cell activity at 15 and 20 ppm, compared to unexposed (0 ppm) controls. PCB 169 did not markedly modulate NK activity. This constitutes the first study to investigate the in vitro effects of these three PCBs on sea turtle innate immune functions. These results add to our understanding of PCB-induced immunotoxicity in sea turtles and may provide a framework for establishing the relationships between chemical levels and turtle immunity.
Sea turtles face numerous environmental challenges, such as exposure to chemical pollution and biotoxins, which may contribute to immune system impairment, resulting in increased disease ...susceptibility. Therefore, a more thorough assessment of the host's immune response and its susceptibility is needed for these threatened and endangered animals. In this study, the innate and acquired immune functions of sixty-five clinically healthy, immature, captive loggerhead sea turtles (Caretta caretta) were assayed using non-lethal blood sample collection. Functional immune assays were developed and/or optimized for this species, including mitogen-induced lymphocyte proliferation, natural killer (NK) cell activity, phagocytosis, and respiratory burst. Peripheral blood mononuclear cells (PBMC) and phagocytes were isolated by density gradient centrifugation on Ficoll–Paque and discontinuous Percoll gradients, respectively. The T lymphocyte mitogens ConA significantly induced lymphocyte proliferation at 1 and 2μg/mL while PHA significantly induced lymphocyte proliferation at 5 and 10μg/mL. The B lymphocyte mitogen LPS significantly induced proliferation at 1μg/mL. Monocytes demonstrated higher phagocytic activity than eosinophils. In addition, monocytes exhibited respiratory burst. Natural killer cell activity was higher against YAC-1 than K-562 target cells. These optimized assays may help to evaluate the integrity of loggerhead sea turtle's immune system upon exposure to environmental contaminants, as well as part of a comprehensive health assessment and monitoring program.
Context
The National Institute of Excellence in Health and Social Services (INESSS), which functions as the Québec health technology assessment (HTA) agency, tested a new way to engage patients along ...with health‐care professionals in the co‐construction of recommendations regarding implantable cardioverter‐defibrillator replacement.
Objective
The objective of this article was to describe the process of co‐construction of recommendations and to propose methods of building best practices for patient involvement (PI) in HTA.
Design
Throughout the process, documents were collected and participant observations were made. Individual interviews were conducted with patients, health‐care professionals and the INESSS scientific team, from January to March 2018.
Results
Three committees were established: an expert patient committee to reflect on patient experience literature; an expert health professional committee to reflect on medical literature; and a co‐construction committee through which both patients and health‐care professionals contributed to develop the recommendations. The expert patients validated and contextualized a literature review produced by the scientific team. This allowed the scientists to consider aspects related to the patient experience and to integrate the feedback from patients into HTA recommendations. The most important factor contributing to a positive PI experience was the structured methodology for selecting patient participants, and a key factor that inhibited the process was a lack of training in PI on the part of the scientific team.
Conclusions
This experience demonstrates that it is possible to co‐construct recommendations, even for technically complex HTA subjects, through a more democratic process than usual which led to more patient‐focused guidance.
A small isolated population of beluga whales (Delphinapterus leucas) that are highly contaminated by pollutants, mostly of industrial origin, resides in the St. Lawrence estuary, Québec, Canada. ...Overhunting in the first half of the century was the probable cause for this population to dwindle from several thousand animals to the current estimate of 500. The failure of the population to recover might be due to contamination by organochlorine compounds, which are known to lead to reproductive failure and immunosuppression in domestic and laboratory animals and seals. Functional and morphological changes have been demonstrated in thyroid gland and adrenal cortex in many species exposed to organochlorinated compounds, including seals. Morphological lesions, although different, were also found in belugas. Functional evaluation of thyroid and adrenal glands of contaminated (St. Lawrence) versus much less contaminated (Arctic) belugas is currently under way. Necropsy of St. Lawrence belugas showed numerous severe and disseminated infections with rather mildly pathogenic bacteria, which suggests immunosuppression. Organochlorine compounds and other contaminants found in beluga whales cause immunosuppression in a variety of animal species including seals. Thirty-seven percent of all the tumors reported in cetaceans were observed in St. Lawrence beluga whales. This could be explained by two different mechanisms: high exposure to environmental carcinogens and suppression of immunosurveillance against tumors. Overall, St. Lawrence belugas might well represent the risk associated with long-term exposure to pollutants present in their environment and might be a good model to predict health problems that could emerge in highly exposed human populations over time.
The effects of in vitro exposure of beluga whale splenocytes and thymocytes to different concentrations of mercury chloride (HgCl2), cadmium chloride (CdCl2), and lead chloride (PbCl2) were ...evaluated. The cells were cultured for 66 h with either concanavalin A (Con‐A), phytohemagglutinin‐P, or without mitogen, after which percentage of cell death and proliferation were evaluated. Increased percentage of cell death was observed in Con‐A‐stimulated thymocytes cultured with HgCl2, while the viability of splenocytes was not affected by exposure to metals. Decreased splenocyte and thymocyte proliferation was observed with the highest concentration of HgCl2 and CdCl2 (10−5 M), while lower concentrations of these metals (10−6 and 10−7 M) as well as all the different concentrations of PbCl2 (10−4, 10−5, and 10−6 M) did not significantly influence cell proliferation. Concentrations of metals that were found to affect the proliferation of beluga lymphocytes are similar to those found in the liver of beluga whales from wild populations.
A quantitative assay was developed to evaluate mitogen-induced lymphoblastic transformation in beluga whales (
Delphinapterus leucas) using peripheral blood mononuclear cells, splenocytes and ...thymocytes. Optimal concentrations of four different mitogens (Con-A, PHA, LPS and PWM) were determined with the use of standard curves. Addition of human recombinant IL-2 (rhIL-2) after 48 h in culture with the different mitogens suggests that Con-A, PHA and PWM, but not LPS, stimulate T cells in belugas, as they do in other animal species. The addition of 2-mercaptoethanol did not enhance significantly the proliferation of cells stimulated by Con-A, PHA and LPS, while it did with the cells stimulated by PWM and those cultured without mitogen. The proliferative response of cells was suppressed when the culture medium was supplemented by beluga serum instead of fetal calf serum. This assay will be useful to assess the status of the immune functions in different populations of beluga whales as well for further in vitro immunotoxicological experiments.
Flow cytometric assays using peripheral blood were developed to study phagocytosis and respiratory burst, the two major functions of neutrophils and among the most important non-specific defense ...mechanisms, in beluga whales. The use of flow cytometry avoids the problems associated with the isolation and purification of different cell types, and allows the measurement of a large number of cells (10 000) in a very short period of time. The methods described will be used to compare these functions in blood samples from highly contaminated beluga whales from the St. Lawrence and from relatively clean arctic beluga whales.
A hermaphrodite beluga whale (Delphinapterus leucas) was found in the St. Lawrence Estuary, Quebec, Canada. This animal had two testicles, two separate ovaries, and the complete ducts of each sex; ...cervix, vagina and vulva were absent. Mature spermatozoa were found in the lumen of seminiferous tubules in the testicles, and numerous involuted corpora lutea were recognized in the ovaries. This represents the first case of true hermaphroditism in a cetacean, and is the fourth hermaphrodite mammal with two testicles and two separate ovaries.
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