50 research outputs found

    Effects of 17α-Ethinylestradiol (EE\u3csub\u3e2\u3c/sub\u3e) on Reproductive Endocrine Status in Mummichog (\u3cem\u3eFundulus Heteroclitus\u3c/em\u3e) Under Differing Salinity and Temperature Conditions

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    Waterborne exposure to 17α-ethinylestradiol (EE2), a synthetic estrogen, has previously been shown to decrease reproductive endocrine status in the estuarine killifish or mummichog (Fundulus heteroclitus macrolepidotus; northern subspecies). To evaluate if variations in salinity or temperature holding conditions modify the effects of EE2 on gonad size, plasma reproductive steroid levels, and gonadal steroidogenesis, mummichog were exposed in vivo for 14 days to 0, 50 and 250 ng/L EE2 in 0, 16 and 32 ppt salinity at 18°C and to 0 and 250 ng/L EE2 at 10, 18 and 26°C at 16 ppt salinity. Effects due to salinity were limited; however, 250 ng/L EE2 decreased plasma 17β-estradiol (E2) levels and in vitro gonadal E2 production and plasma 11-ketotestosterone (11-KT) across all salinities. Higher temperatures triggered gonadal growth in both sexes as well as increased plasma E2 and gonadal E2 production in females, while 11-KT production was decreased in males. EE2 counteracted the effect of temperature as determined by depressed gonadal growth in males. In both exposures, the effects of EE2 on testosterone (T) production were variable. The use of steroidogenic precursors (25-OH cholesterol, and/or pregnenolone and/or testosterone) in the in vitro gonadal incubations indicated decreased E2 production in females and 11-KT production in males were predominately due to suppression of the terminal conversion step between T and E2 or 11-KT. Ovarian cyp19a gene expression was not affected by 250 ng/L EE2 compared to controls at 16 ppt and 18oC (the only treatment combinations tested). The lack of effects of salinity could be protective for a species spawning in such a variable environment. Gonadal growth at higher temperatures confirms previous work on northern mummichog while EE2 effects on gonadal growth could be due to temperature-related increases in EE2 uptake and/or increased susceptibility during gonadal maturation. In conclusion, the present work demonstrated that environmental conditions impact effects of EE2, including terminal steroid production in the gonads. These results should be considered in designing standardized estuarine fish reproductive bioassays and in understanding the potential effects of reproductive contaminants in estuarine environments

    The Influence of Water Quality Characteristics on Vanadium Toxicity to Model Aquatic Organisms

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    Vanadium (V) is a contaminant of emerging concern for the Alberta oil sands region that could present a risk for aquatic organisms. Petroleum coke (PC) has been experimentally used to treat oil sands process-affected water (OSPW) to reduce organic toxicants. However, PC contains up to 1,000 mg of V per kg of PC, and during OSPW treatment V leaches from coke reaching levels of up to 7 mg/L in “treated” OSPW, a concentration that is toxic to aquatic organisms. Little information is available on how common water quality variables affect the toxicity of V to aquatic organisms. Furthermore, there is no clear understanding of the mechanism(s) of toxicity of V in aquatic organisms. Vanadium is a transition metal with several oxidation states, and could potentially elicit its toxicity through either ion imbalance or oxidative stress. Therefore, the objectives of this research were to (i) investigate the influence of key water chemistry variables representative of the Alberta oil sands region on V toxicity to freshwater organisms, and (ii) determine if ion imbalance and oxidative stress are part of its mechanism of toxicity. To describe how water chemistry influences V toxicity to two representative freshwater organisms, Daphnia pulex and Oncorhynchus mykiss, descriptive relationships were developed between those parameters that differ the most between OSPW and the Athabasca River. Results indicate that an increase in pH increases V acute toxicity to both species, whereas increasing alkalinity and sulphate ameliorate V toxicity to both species. Sodium only causes amelioration of V toxicity to daphnids above 325 mg/L. The mechanistic studies with Daphnia magna and O. mykiss suggest that concentrations of V close to their respective median lethal concentration (LC50) cause sodium imbalance in both species, as well as calcium imbalance in rainbow trout, and oxidative stress in O. mykiss. In conclusion, the influence of pH, alkalinity and sulphate on V toxicity should be considered when creating new acute water quality guidelines or local benchmarks for V. The mechanism of V toxicity to aquatic organisms includes ion imbalance and oxidative stress, but further mechanistic research will be needed to increase knowledge on the ecological risks of V contamination, which will enable the formulation of possible mitigation strategies

    Proteinase 3 contributes to endothelial dysfunction in an experimental model of sepsis

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    In sepsis-induced inflammation, polymorphonuclear neutrophils (PMNs) contribute to vascular dysfunction. The serine proteases proteinase 3 (PR3) and human leukocyte elastase (HLE) are abundant in PMNs and are released upon degranulation. While HLE’s role in inflammation-induced endothelial dysfunction is well studied, PR3’s role is largely uninvestigated. We hypothesized that PR3, similarly to HLE, contributes to vascular barrier dysfunction in sepsis. Plasma PR3 and HLE concentrations and their leukocyte mRNA levels were measured by ELISA and qPCR, respectively, in sepsis patients and controls. Exogenous PR3 or HLE was applied to human umbilical vein endothelial cells (HUVECs) and HUVEC dysfunction was assessed by FITC-dextran permeability and electrical resistance. Both PR3 and HLE protein and mRNA levels were significantly increased in sepsis patients (P \u3c 0.0001 and P \u3c 0.05, respectively). Additionally, each enzyme independently increased HUVEC monolayer FITC-dextran permeability (P \u3c 0.01), and decreased electrical resistance in a time- and dose-dependent manner (P \u3c 0.001), an effect that could be ameliorated by novel treatment with carbon monoxide-releasing molecule 3 (CORM-3). The serine protease PR3, in addition to HLE, lead to vascular dysfunction and increased endothelial permeability, a hallmark pathological consequence of sepsis-induced inflammation. CORMs may offer a new strategy to reduce serine protease-induced vascular dysfunction

    Implantation failure in female Kiss1-/- mice is independent of their hypogonadic state and can be partially rescued by leukemia inhibitory factor.

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    The hypothalamic kisspeptin signaling system is a major positive regulator of the reproductive neuroendocrine axis, and loss of Kiss1 in the mouse results in infertility, a condition generally attributed to its hypogonadotropic hypogonadism. We demonstrate that in Kiss1(-/-) female mice, acute replacement of gonadotropins and estradiol restores ovulation, mating, and fertilization; however, these mice are still unable to achieve pregnancy because embryos fail to implant. Progesterone treatment did not overcome this defect. Kiss1(+/-) embryos transferred to a wild-type female mouse can successfully implant, demonstrating the defect is due to maternal factors. Kisspeptin and its receptor are expressed in the mouse uterus, and we suggest that it is the absence of uterine kisspeptin signaling that underlies the implantation failure. This absence, however, does not prevent the closure of the uterine implantation chamber, proper alignment of the embryo, and the ability of the uterus to undergo decidualization. Instead, the loss of Kiss1 expression specifically disrupts embryo attachment to the uterus. We observed that on the day of implantation, leukemia inhibitory factor (Lif), a cytokine that is absolutely required for implantation in mice, is weakly expressed in Kiss1(-/-) uterine glands and that the administration of exogenous Lif to hormone-primed Kiss1(-/-) female mice is sufficient to partially rescue implantation. Taken together, our study reveals that uterine kisspeptin signaling regulates glandular Lif levels, thereby identifying a novel and critical role for kisspeptin in regulating embryo implantation in the mouse. This study provides compelling reasons to explore this role in other species, particularly livestock and humans

    Inflammation Profiling of Critically Ill Coronavirus Disease 2019 Patients.

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    Objectives: Coronavirus disease 2019 is caused by severe acute respiratory syndrome-coronavirus-2 infection to which there is no community immunity. Patients admitted to ICUs have high mortality, with only supportive therapies available. Our aim was to profile plasma inflammatory analytes to help understand the host response to coronavirus disease 2019. Design: Daily blood inflammation profiling with immunoassays. Setting: Tertiary care ICU and academic laboratory. Subjects: All patients admitted to the ICU suspected of being infected with severe acute respiratory syndrome-coronavirus-2, using standardized hospital screening methodologies, had daily blood samples collected until either testing was confirmed negative on ICU day 3 (coronavirus disease 2019 negative), or until ICU day 7 if the patient was positive (coronavirus disease 2019 positive). Interventions: None. Measurements and Main Results: Age- and sex-matched healthy controls and ICU patients that were either coronavirus disease 2019 positive or coronavirus disease 2019 negative were enrolled. Cohorts were well-balanced with the exception that coronavirus disease 2019 positive patients were more likely than coronavirus disease 2019 negative patients to suffer bilateral pneumonia. Mortality rate for coronavirus disease 2019 positive ICU patients was 40%. We measured 57 inflammatory analytes and then analyzed with both conventional statistics and machine learning. Twenty inflammatory analytes were different between coronavirus disease 2019 positive patients and healthy controls ( Conclusions: While many inflammatory analytes were elevated in coronavirus disease 2019 positive ICU patients, relative to healthy controls, the top six analytes distinguishing coronavirus disease 2019 positive ICU patients from coronavirus disease 2019 negative ICU patients were tumor necrosis factor, granzyme B, heat shock protein 70, interleukin-18, interferon-gamma-inducible protein 10, and elastase 2

    Metal size distribution in rainfall and snowmelt-induced runoff from three urban catchments

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    The size distribution of metals transported by urban runoff has implications for treatment type and design, predicting their mobility and evaluating their potential impact on receiving waters. There is an urgent need to better understand the distribution of metals between fractions, particularly those in the sub-dissolved fractions. As a contribution to addressing this need, this study characterises the size distribution of Cd, Cr, Cu, Ni, V and Zn using conventional and novel techniques. Data is presented as event mean concentrations (EMC) of a total of 18 rainfall and snowmelt events at three urban sites. For all studied metals in all events and at all sites, the contribution of the truly dissolved fraction made a greater contribution to the total concentrations than the colloidal fraction. Truly dissolved Cd and Zn concentrations contributed (on average) 26% and 28% respectively, of the total EMCs with truly dissolved Cu and Ni contributing (on average) 18%. In contrast, only 1% (V) and 3% (Cr) were identified in the truly dissolved fraction. The greatest contribution of truly dissolved Cd, Cu and Zn concentrations (relative to total oncentrations) were reported during rainfall events. However, no seasonal differences were identified and differences between the sites regarding the EMCs distribution by fractions were not at a statistically significant level (p N 0.05) for any metal or event. The loads of truly dissolved and colloidal metals did not follow the patterns of particulate metal loads indicating particulates are not the main source of subdissolved metals. The data suggests that ultrafiltration as a treatment technique would not efficiently mitigate the risks posed by metals to receiving water cologie
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