Long-term effects of an early-life exposure of fathead minnows to sediments containing bitumen. Part II: Behaviour, reproduction, and gonad histopathology.

The oil sands area of northern Alberta has river sediments that contain natural bitumen. Eggs and fish in these rivers may be exposed to bitumen-related chemicals early in life. This paper assesses a short embryo-larval fish exposure to oil sands sediment and follows the fish behaviour as they mature in clean water and examines their breeding success as adults (5 months afterwards). The three different oil sands river sediments tested were: a sediment collected outside of the bitumen deposit (tested at 3 g/L, Reference sediment from upstream Steepbank River site), and two sediments collected within the deposit (each tested at low (1 g/L) and high (3 g/L) concentrations). The sediments within the bitumen deposit were from the Ells and Steepbank (Stp) Rivers, and both contained significant total PAHs (>170 ng/g wet weight sediment) and alkylated PAHs (>4480 ng/g). Fish were exposed to these sediments for 21 days (as eggs and larval fish), and then transferred permanently to clean water to mature and breed. There was a significant decrease in the number of egg clutches produced by fish exposed early in life to Stp downstream high sediment (compared to Reference sediment). There was also a decrease in overall cumulative egg production, with fish from Stp downstream high sediment producing just over 1000 eggs in total while fish exposed to Ref sediment produced nearly 6900 eggs. The fish with reduced egg production were also less social than expected as they matured, and they had a lower % of early vitellogenic eggs in their ovaries. Overall, the exposure shows that a single, brief exposure during early life stages to natural bitumen can affect fish in adulthood. Naturally occurring bitumen-derived PAHs can reduce fish reproductive output by complex mechanisms, measurable as lower ovary maturity and changes in social behaviour.

Assessing Receptor Activation in 2D and 3D Cultured Hepatocytes: Responses to a Single Compound and a Complex Mixture.

Responding to global standards and legislative updates in Canada, including Bill S-5 (2023), toxicity testing is shifting towards more ethical, in vitro methods. Traditional two-dimensional (2D) monolayer cell cultures, limited in replicating the complex in vivo environment, have prompted the development of more relevant three-dimensional (3D) spheroidal hepatocyte cultures. This study introduces the first 3D spheroid model for McA-RH7777 cells, assessing xenobiotic receptor activation, cellular signaling, and toxicity against dexamethasone and naphthenic acid (NA)-fraction components; NAFCs. Our findings reveal that 3D McA-RH7777 spheroids demonstrate enhanced sensitivity and more uniform dose-response patterns in gene expression related to xenobiotic metabolism (AhR and PPAR) for both single compounds and complex mixtures. Specifically, 3D cultures showed significant gene expression changes upon dexamethasone exposure and exhibited varying degrees of sensitivity and resistance to the apoptotic effects induced by NAFCs, in comparison to 2D cultures. The optimization of 3D culture conditions enhances the model's physiological relevance and enables the identification of genomic signatures under varied exposures. This study highlights the potential of 3D spheroid cultures in providing a more accurate representation of the liver's microenvironment and advancing our understanding of cellular mechanisms in toxicity testing.

Chemical communication in wood frog (Rana sylvatica) tadpoles is influenced by early-life exposure to naphthenic acid fraction compounds.

Environmental pollutants can disrupt chemical communication between aquatic organisms by interfering with the production, transmission, and/or detection of, as well as responses to, chemical cues. Here, we test the hypothesis that early-life exposure to naphthenic acid fraction compounds (NAFCs) from oil sands tailings disrupts antipredator-associated chemical communication in larval amphibians. Wild adult wood frogs (Rana sylvatica) captured during their natural breeding period were combined (1 female:2 males) in six replicate mesocosms filled with either uncontaminated lakewater or with NAFCs isolated from an active tailings pond in Alberta, Canada, at nominal 5 mg/L concentrations. Egg clutches were incubated and tadpoles maintained in their respective mesocosms for ∼40 days post-hatch. Tadpoles (Gosner stage 25-31) were then transferred individually to trial arenas filled with uncontaminated water and exposed to one of six chemical alarm cue (AC) stimuli solutions following a 3 × 2 × 2 design (3 AC types × 2 stimulus carriers × 2 rearing exposure groups). Relative to control tadpoles, NAFC-exposed tadpoles demonstrated higher baseline activity levels (line crosses and direction changes) when introduced to uncontaminated water. Antipredator responses differed in graded fashion with AC type, with control ACs eliciting the greatest latency to resume activity, water the least, and NAFC-exposed ACs intermediate. Pre- to post-stimulus difference scores were non-significant in control tadpoles, while NAFC-exposed tadpoles demonstrated significantly greater variation. While this suggests that exposure to NAFCs from fertilization through hatching may have interfered with AC production, it is unclear whether the quality or quantity of cues was affected. There was also no clear evidence that NAFC carrier water interfered with ACs or the alarm response in unexposed control tadpoles. These results emphasize the importance of understanding how behavioral and physiological effects of early-life NAFC exposure on critical antipredator responses may persist across life history stages.

Naphthenic acid fraction compounds reduce the reproductive success of wood frogs (Rana sylvatica) by affecting offspring viability.

Understanding the toxicity of organic compounds in oil sands process-affected water (OSPW) is necessary to inform the development of environmental guidelines related to wastewater management in Canada's oil sands region. In the present study, we investigated the effects of naphthenic acid fraction compounds (NAFCs), one of the most toxic components of OSPW, on mating behaviour, fertility, and offspring viability in the wood frog (Rana sylvatica). Wild adult wood frogs were exposed separately from the opposite sex to 0, 5, or 10 mg/L of OSPW-derived NAFCs for 24 h and then combined in outdoor lake water mesocosms containing the same NAFC concentrations (n = 2 males and 1 female per mesocosm, n = 3 mesocosms per treatment). Mating events were recorded for 48 h and egg masses were measured to determine adult fertility. NAFC exposure had no significant effect on mating behaviour (probability of amplexus and oviposition, amplexus and oviposition latency, total duration of amplexus and number of amplectic events) or fertility (fertilization success and clutch size). Tadpoles (50 individuals per mesocosm at hatching, and 15 individuals per mesocosm from 42 d post-hatch) were reared in the same mesocosms under chronic NAFC exposure until metamorphic climax (61-85 d after hatching). Offspring exposed to 10 mg/L NAFCs during development were less likely to survive and complete metamorphosis, grew at a reduced rate, and displayed more frequent morphological abnormalities. These abnormalities included limb anomalies at metamorphosis, described for the first time after NAFC exposure. The results of this study suggest that NAFCs reduce wood frog reproductive success through declines in offspring viability and therefore raise the concern that exposure to NAFCs during reproduction and development may affect the recruitment of native amphibian populations in the oil sands region.

The acute toxicity of bitumen-influenced groundwaters from the oil sands region to aquatic organisms.

The extraction of surface mined bitumen from oil sands deposits in northern Alberta, Canada produces large quantities of liquid tailings waste, termed oil sands process-affected water (OSPW), which are stored in large tailings ponds. OSPW-derived chemicals from several tailings ponds migrating past containment structures and through groundwater systems pose a concern for surface water contamination. The present study investigated the toxicity of groundwater from near-field sites adjacent to a tailings pond with OPSW influence and far-field sites with only natural oil sands bitumen influence. The acute toxicity of unfractionated groundwater and isolated organic fractions was assessed using a suite of aquatic organisms (Pimephales promelas, Oryzias latipes, Daphnia magna, Hyalella azteca, Lampsilis spp., Ceriodaphnia dubia, Hexagenia spp., and Vibrio fischeri). Assessment of unfractionated groundwater demonstrated toxicity towards all invertebrates in at least one far-field sample, with both near-field and far-field samples with bitumen influence toxic towards P. promelas, while no toxicity was observed for O. latipes. When assessing the unfractionated groundwater and isolated organic fractions from near-field and far-field groundwater sites, P. promelas and H. azteca were the most sensitive to organic components, while D. magna and L. cardium were most sensitive to the inorganic components. Groundwater containing appreciable amounts of dissolved organics exhibited similar toxicities to sensitive species regardless of an OSPW or natural bitumen source. The lack of a clear distinction in relative acute toxicities between near-field and far-field samples indicates that the water-soluble chemicals associated with bitumen are acutely toxic to several aquatic organisms. This result, combined with the similarities in chemical profiles between bitumen-influenced groundwater originating from OSPW and/or natural sources, suggests that the industrial bitumen extraction processes corresponding to the tailings pond in this study are not contributing unique toxic substances to groundwater, relative to natural bitumen compounds present in groundwater flow systems.

Naphthenic acid fraction components from oil sands process-affected water from the Athabasca Oil Sands Region impair murine osteoblast differentiation and function.

The extraction of bitumen from surface mining in the Athabasca Oil Sands Region (AOSR) produces large quantities of oil sands process-affected water (OSPW) that needs to be stored in settling basins near extraction sites. Chemical constituents of OSPW are known to impair bone health in some organisms, which can lead to increased fracture risk and lower reproductive fitness. Naphthenic acid fraction components (NAFCs) are thought to be among the most toxic class of compounds in OSPW; however, the effect of NAFCs on osteoblast development is largely unknown. In this study, we demonstrate that NAFCs from OSPW inhibit osteoblast differentiation and deposition of extracellular matrix, which is required for bone formation. Extracellular matrix deposition was inhibited in osteoblasts exposed to 12.5-125 mg/L of NAFC for 21 days. We also show that components within NAFCs inhibit the expression of gene markers of osteoblast differentiation and function, namely, alkaline phosphatase (Alp), osteocalcin, and collagen type 1 alpha 1 (Col1a1). These effects were partially mediated by the induction of glucocorticoid receptor (GR) activity; NAFC induces the expression of the GR activity marker genes Sgk1 (12.5 mg/L) and p85a (125 mg/L) and inhibits GR protein (125 mg/L) and Opg RNA (12.5 mg/L) expression. This study provides evidence that NAFC concentrations of 12.5 mg/L and above can directly act on osteoblasts to inhibit bone formation and suggests that NAFCs contain components that can act as GR agonists, which may have further endocrine disrupting effects on exposed wildlife.

The effects of oil sands process-affected water naphthenic acid fraction components on GDF15 secretion in extravillous trophoblast cells.

Exposure to compounds present in petroleum and wastewaters from oil and gas extraction sites in the Alberta Oil Sands Region can impair reproductive health. It has been established that acid extractable organics found in oil sands process-affected water (OSPW) such as naphthenic acids (NA-fraction components; NAFC) can adversely affect reproductive outcomes. We have shown that NAFC exposure results in a significant upregulation of GDF15 in placental trophoblasts, a cellular stress marker known to be involved in human embryonic development and necessary for the maintenance of pregnancy. However, little is known regarding the mechanism(s) underlying NAFC-induced increases in GDF15 production during early placentation. The goal of this study was to examine the effects of NAFC exposure on the regulation of critical transcription factors of GDF15 in extravillous trophoblast cells. Of these transcription factors, inflammatory mediators including prostaglandins have been reported to inhibit proliferation and migration of trophoblast cells in vitro. Hence, the secondary goal of this study was to determine whether inflammation mediated through prostaglandin production is critical to GDF15 secretion. HTR-8/SVneo cells were exposed to an NAFC for 6 and 24 h to assess the expression of key transcriptional regulators, GDF15 secretion, and prostaglandin (PGE2) output. Treatment with NAFC (125 mg/L only) significantly increased GDF15 expression and secretion in association with upregulation of the transcription factors KLF4, EGR1, ATF3 and TP53. Similarly, PTGS2 (i.e. COX2) expression and PGE2 output were significantly increased at the same concentration. However, co-treatment with a COX2 selective antagonist (SC236) only partially blocked the NAFC-induced increase in PGE2 output and did not block GDF15 expression or secretion. These findings suggest that while NAFC may affect GDF15 production, it is not exclusively a result of prostaglandin-mediated inflammation. This study provides new insights into the mechanisms by which NAFC may adversely affect placental trophoblast cell function in mammals.

Durability of the Clinical Benefit of Droxidopa for Neurogenic Orthostatic Hypotension During 12 Weeks of Open-Label Treatment.

INTRODUCTION: Droxidopa is approved to treat neurogenic orthostatic hypotension (nOH) symptoms in patients with autonomic failure based on short-term clinical trial data. Additional data on the long-term efficacy of droxidopa are needed. We have evaluated the 12-week efficacy and tolerability of droxidopa in patients with nOH in an open-label period of an ongoing phase 4 study . METHODS: Patients received 12 weeks of open-label treatment with an individually optimized droxidopa dose (100-600 mg, 3 times daily) as identified during a preceding titration period. Patient-reported outcomes included the Orthostatic Hypotension Symptom Assessment (OHSA), Orthostatic Hypotension Daily Activity Scale (OHDAS), and clinician- and patient-rated Clinical Global Impression-Severity (CGI-S) scales. Supine blood pressure (BP) and adverse events (AEs) were recorded. RESULTS: Data from 114 patients enrolled into the 12-week open-label period were available for analyses. After 12 weeks of droxidopa treatment, patients reported significant (P < 0.0001) improvements from baseline in OHSA and OHDAS composite and individual item scores and on clinician and patient CGI-S scores. Mean ± SD supine systolic and diastolic BP at week 12 increased by 15.5 ± 22.9 and 7.8 ± 11.7 mmHg from baseline, respectively (P < 0.0001 for both). The most frequently reported AEs were falls (17%), headache (13%), and dizziness (9%); one (0.9%) patient reported an AE of supine hypertension. CONCLUSION: During 12 weeks of open-label treatment, droxidopa was associated with significant improvement from baseline in nOH symptoms and activities of daily living. No clinically important changes in supine hypertension or AEs of concern were observed. These results support the efficacy of droxidopa beyond 2 weeks of treatment. TRIAL REGISTRATION: NCT02586623.

Fathead Minnows Exposed to Organic Compounds from Oil Sands Tailings as Embryos Have Reduced Survival, Impaired Development, and Altered Behaviors That Persist into Larval Stages.

Our study evaluated whether exposure to naphthenic acid fraction compounds (NAFCs) extracted from oil sands process-affected waters (OSPW) has adverse effects on fish embryos that persist into later life. We exposed fathead minnow (Pimephales promelas) embryos to concentrations of NAFCs found in OSPW (2.5-54 mg/L) for 7 days (1 day postfertilization to hatch), then raised surviving larvae in outdoor mesocosms of uncontaminated lake water for 1 month. Embryos exposed to NAFCs were more likely to exhibit malformations (by up to 8-fold) and had slower heart rates (by up to 24%) compared to controls. Fish raised in uncontaminated lake water following exposure to NAFCs as embryos, were 2.5-fold less likely to survive during the larval stage than control fish. These fish also showed up to a 45% decrease in swim activity and a 36% increase in swim burst events during behavioral tests relative to controls. We conclude that exposure to NAFCs during the embryonic stage can have lasting effects on fish survival, physiology, and behavior that persist at least through the larval stage. These findings of delayed mortalities and persistent sublethal effects of embryonic NAFC exposure are relevant to informing the development of regulations on treated OSPW releases from mining operations. Environ Toxicol Chem 2022;41:1319-1332. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Psychometric validation of a patient-reported single-item assessment of 'Good Day Bad Day' in a neurogenic orthostatic hypotension population treated with droxidopa.

BACKGROUND: Symptoms of neurogenic orthostatic hypotension (nOH), including lightheadedness/dizziness, presyncope, syncope, and falls, can lead to impaired functional ability and reduced quality of life. Because the severity and frequency of nOH symptoms fluctuate, it may be difficult for patients to accurately quantify the effect of symptoms on their daily lives using available outcome measures. A new single-item instrument, the 'Good Day Bad Day,' was developed, and its psychometric validity was assessed in patients with nOH. METHODS: Data from a 6-month, prospective, observational cohort study of patients with nOH who were newly initiating droxidopa treatment were used. Patients were asked to quantify the number of good and bad days in the previous 7 days and responded to other validated patient-reported outcomes instruments. The concurrent and discriminant validities and the stability of the Good Day Bad Day instrument were assessed. RESULTS: A total of 153 patients were included in the analysis (mean [SD] age, 62.3 [17] years). Change in the number of good days moderately correlated with improvements in other patient-reported outcomes (rho value range, -0.38 to -0.61). When data were examined categorically (low vs high symptom severity), the mean number of good days was higher in subgroups representing low symptom severity across measures at 1, 3, and 6 months (all P ≤ 0.01). CONCLUSIONS: The Good Day Bad Day instrument provided good discrimination at baseline and over time and may aid in assessment of the effects of nOH symptoms on patients.

Polycyclic aromatic compounds in the Canadian Environment: Aquatic and terrestrial environments.

Polycyclic aromatic compounds (PACs) are ubiquitous across environmental media in Canada, including surface water, soil, sediment and snowpack. Information is presented according to pan-Canadian sources, and key geographical areas including the Great Lakes, the Alberta Oil Sands Region (AOSR) and the Canadian Arctic. Significant PAC releases result from exploitation of fossil fuels containing naturally-derived PACs, with anthropogenic sources related to production, upgrading and transport which also release alkylated PACs. Continued expansion of the oil and gas industry indicates contamination by PACs may increase. Monitoring networks should be expanded, and include petrogenic PACs in their analytical schema, particularly near fuel transportation routes. National-scale roll-ups of emission budgets may not expose important details for localized areas, and on local scales emissions can be substantial without significantly contributing to total Canadian emissions. Burning organic matter produces mainly parent or pyrogenic PACs, with forest fires and coal combustion to produce iron and steel being major sources of pyrogenic PACs in Canada. Another major source is the use of carbon electrodes at aluminum smelters in British Columbia and Quebec. Temporal trends in PAC levels across the Great Lakes basin have remained relatively consistent over the past four decades. Management actions to reduce PAC loadings have been countered by increased urbanization, vehicular emissions and areas of impervious surfaces. Major cities within the Great Lakes watershed act as diffuse sources of PACs, and result in coronas of contamination emanating from urban centres, highlighting the need for non-point source controls to reduce loadings.

A retrospective 'real-world' cohort study of azole therapeutic drug monitoring and evolution of antifungal resistance in cystic fibrosis.

BACKGROUND: Individuals with cystic fibrosis (CF) have an increased susceptibility to fungal infection/allergy, with triazoles often used as first-line therapy. Therapeutic drug monitoring (TDM) is essential due to significant pharmacokinetic variability and the recent emergence of triazole resistance worldwide. OBJECTIVES: In this retrospective study we analysed the 'real-world' TDM of azole therapy in a large CF cohort, risk factors for subtherapeutic dosing, and the emergence of azole resistance. METHODS: All adults with CF on azole therapy in a large single UK centre were included. Clinical demographics, TDM and microbiology were analysed over a 2 year study period (2015-17) with multivariate logistic regression used to identify risk factors for subtherapeutic dosing. RESULTS: 91 adults were treated with azole medication during the study period. A high prevalence of chronic subtherapeutic azole dosing was seen with voriconazole (60.8%) and itraconazole capsule (59.6%) use, representing significant risk factors for subtherapeutic levels. Rapid emergence of azole resistance was additionally seen over the follow-up period with a 21.4% probability of CF patients developing a resistant fungal isolate after 2 years. No significant relationship was found however between subtherapeutic azole dosing and azole resistance emergence. CONCLUSIONS: Our study demonstrates a high prevalence of subtherapeutic azole levels in CF adults with increased risk using itraconazole capsules and voriconazole therapy. We show rapid emergence of azole resistance highlighting the need for effective antifungal stewardship. Further large longitudinal studies are needed to understand the effects of antifungal resistance on outcome in CF and the implications of subtherapeutic dosing on resistance evolution.

Erratum to: A retrospective 'real-world' cohort study of azole therapeutic drug monitoring and evolution of antifungal resistance in cystic fibrosis.

[This corrects the article DOI: 10.1093/jacamr/dlab026.].

Sex-Related Embryotoxicity of Pulp Mill Effluent Extracts in Medaka (Oryzias latipes) Female Leucophore-free FLFII Strain.

The aim of the present study was to evaluate the effects of exposure to Chilean pulp mill effluent extracts on developing postfertilized medaka embryos before and after sex definition relative to sex steroids (testosterone and 17beta-estradiol) and a wood phytoestrogen (beta-sitosterol). Our study included 2 waterborne semichronic exposure experiments, using a 24-h post fertilization (hpf) unknown-sex FLFII (female leucophore free) group and a second 72-hpf FLFII phenotypic sex-identified group (male autofluorescence leucophore) strain of medaka embryos. Chronic exposure of both FLFII strain embryo groups showed similar delay in time to hatch and decreased hatchability. Teratogenic responses such as vertebral malformation (fusion, incomplete formation, and lack of vertebral formation process) and pericardial edema were observed in both experiments, with a high percentage related to FLFII fluorescent leucophore-identified males. In addition, high mortality associated with severe malformations was observed in male and female embryos exposed to testosterone. Our research has demonstrated that exposure to Chilean mill effluent extracts caused severe male medaka embryotoxicity (in postfertilized embryos) before and after sex definition and, irrespective of the experimental group and effluent treatment, suggests partial removal following secondary treatment. Furthermore, differences in the severity and type of teratogenic effects with previous experiments (d-rR medaka strain), are associated with the unique phenotypes of this medaka mutant strain. Environ Toxicol Chem 2021;40:2297-2305. © 2021 SETAC.

Endocrine Disruptor Impacts on Fish From Chile: The Influence of Wastewaters.

Industrial wastewaters and urban discharges contain complex mixtures of chemicals capable of impacting reproductive performance in freshwater fish, called endocrine-disrupting compounds (EDCs). In Chile, the issue was highlighted by our group beginning over 15 years ago, by analyzing the impacts of pulp and paper mill effluents (PPME) in the Biobio, Itata, and Cruces River basins. All of the rivers studied are important freshwater ecosystems located in the Mediterranean region of Central Chile, each with a unique fish biodiversity. Sequentially, we developed a strategy based on laboratory assays, semicontrolled-field experiments (e.g., caging) and wild fish population assessments to explore the issue of reproductive impacts on both introduced and native fish in Chile. The integration of watershed, field, and laboratory studies was effective at understanding the endocrine responses in Chilean freshwater systems. The studies demonstrated that regardless of the type of treatment, pulp mill effluents can contain compounds capable of impacting endocrine systems. Urban wastewater treatment plant effluents (WWTP) were also investigated using the same integrated strategy. Although not directly compared, PPME and WWTP effluent seem to cause similar estrogenic effects in fish after waterborne exposure, with differing intensities. This body of work underscores the urgent need for further studies on the basic biology of Chilean native fish species, and an improved understanding on reproductive development and variability across Chilean ecosystems. The lack of knowledge of the ontogeny of Chilean fish, especially maturation and sexual development, with an emphasis on associated habitats and landscapes, are impediment factors for their conservation and protection against the threat of EDCs. The assessment of effects on native species in the receiving environment is critical for supporting and designing protective regulations and remediation strategies, and for conserving the unique Chilean fish biodiversity.

Characterization of the changes in supine blood pressure with long-term use of droxidopa in patients with neurogenic orthostatic hypotension.

BACKGROUND AND AIMS: Patients with neurogenic orthostatic hypotension (nOH) due to autonomic dysfunction may also experience supine hypertension (defined as supine systolic blood pressure [SBP] ≥140 mmHg). Because pressor agents used to improve nOH symptoms by increasing standing blood pressure (BP) may exacerbate or cause supine hypertension, changes in supine BP with nOH treatments are of interest. METHODS: This post hoc study examined changes in SBP in patients receiving droxidopa (100-600 mg, three times daily) during a 12-month long-term extension study based on whether patients had supine hypertension (ie, supine SBP ≥140 mmHg) at baseline. Shifts from baseline in supine hypertension categorization and mean supine and standing SBP after 6 and 12 months of treatment with droxidopa were determined. RESULTS: At baseline, 64 patients did not have supine hypertension (mean supine SBP, 120 mmHg) and 38 patients had supine hypertension (mean supine SBP, 157 mmHg). A similar percentage of patients shifted from their respective baseline supine hypertension categorization (ie, with or without supine hypertension) to the other category after receiving droxidopa for 6 or 12 months. After 12 months of droxidopa treatment, patients with supine hypertension at baseline had a mean supine SBP decrease of 3 mmHg and a mean standing SBP increase of 9 mmHg. Patients without supine hypertension at baseline had mean supine and standing SBP increases of 12 and 15 mmHg, respectively. CONCLUSIONS: There was no consistent or progressive elevation in supine SBP over time during the 12-month treatment with droxidopa in patients either with or without supine hypertension at baseline. These data suggest that long-term droxidopa treatment for nOH does not adversely affect supine BP.

Non-target profiling of bitumen-influenced waters for the identification of tracers unique to oil sands processed-affected water (OSPW) in the Athabasca watershed of Alberta, Canada.

RATIONALE: The objective of this study was to identify unique chemical tracers of oil sands process-affected water (OSPW) to enable definitive discrimination of tailings pond seepage from natural bitumen-influenced waters from the Canadian Alberta McMurray formation. METHODS: The approach involved comparing unknowns from an unprecedented sample set of OSPW (n = 4) and OSPW-affected groundwaters (n = 15) with natural bitumen-influenced groundwaters (n = 20), using high-performance liquid chromatography/electrospray ionisation high-resolution mass spectrometry (HPLC/ESI-HRMS) operated in both polarities. RESULTS: Four unknown chemical entities were identified as potential tracers of OSPW seepage and subsequently subjected to structural elucidation. One potential tracer, tentatively identified as a thiophene-containing carboxylic acid [C15 H23 O3 S]- , was only detected in OSPW and OSPW-affected samples, thereby showing the greatest diagnostic potential. The remaining three unknowns, postulated to be two thiochroman isomers [C17 H25 O3 S]+ and an ethyl-naphthalene isomer [C16 H21 ]+ , were detected in one and two background groundwaters, respectively. CONCLUSIONS: We advanced the state of knowledge for tracers of tailings seepage beyond heteroatomic classes, to identifying diagnostic substances, with structures postulated. Synthesis of the four proposed structures is recommended to enable structural confirmations. This research will guide and inform the Oil Sands Monitoring Program in its efforts to assess potential influences of oil sands development on the Athabasca River watershed.

Development of a Reduced-Volume Acute Lethality Toxicity Test for Hyalella azteca.

Effects-directed analysis (EDA) is used to identify the principal toxic components within a complex mixture using iterative steps of chemical fractionation guided by bioassay results. Bioassay selection can be limited in EDA because of the volume requirements for many standardized test methods, and therefore, a reduced-volume acute toxicity test that also provides whole-organism responses is beneficial. To address this need, a static, 7-d, water-only, reduced-volume method (50 mL, 10 organisms) was developed for Hyalella azteca that substantially decreases the volume requirements of standard-volume acute test exposures (200-500 mL of test solution, 15-20 organisms) while maintaining water quality and meeting control survival criteria. Standard- and reduced-volume methods were compared by conducting concurrent toxicity tests with 2 inorganic toxicants (KCl and CdCl2 ) and 2 organic mixtures of naphthenic acid fraction components (NAFCs) to evaluate test performance. There was no difference between methods when comparing the median lethal concentrations (LC50s) for KCl and both NAFC mixtures (p > 0.05). The LC50s for CdCl2 were statistically different (p = 0.0002); however, this was not considered biologically meaningful because the difference between LC50s was <2-fold. In conclusion, the reduced-volume H. azteca test method generated results comparable to standard-volume test methods and is suitable for use in situations where limited testing material is available, such as when conducting EDA. Environ Toxicol Chem 2020;39:2221-2227. © Her Majesty the Queen in Right of Canada 2020. Reproduced with the permission of the Minister of Environment and Climate Change Canada.

A Call to Action: The Role of Healthcare Providers in Reducing the Burden Associated with Neurogenic Orthostatic Hypotension.

Neurogenic orthostatic hypotension (nOH) is a sustained fall in blood pressure upon standing that frequently affects patients with neurodegenerative diseases (e.g., Parkinson disease) and manifests with symptoms such as lightheadedness and dizziness upon standing. nOH can severely affect patients by increasing the risk of falls and injuries and by decreasing functionality, independence, and quality of life. However, the condition is often under-recognized because of many factors, including the nonspecific nature of the symptoms, patient comorbidities, and patients' reluctance to discuss their symptoms with their healthcare providers. Increased awareness of the burden of nOH and recognition of potential barriers to efficient diagnosis may lead to improved clinical outcomes and better quality of life for patients. To better understand the manifestations and real-life impact of living with nOH symptoms, perspectives from a patient with nOH and his caregiver (wife) are provided, along with key findings from a published survey of patients and caregivers on the burden of nOH. In addition, insights and advice on a practical approach for diagnosing, educating, and treating patients with nOH are outlined.

This article discusses what neurogenic orthostatic hypotension (nOH) is, its symptoms, and how patients and healthcare providers (HCPs) can work together to manage nOH symptoms. What is nOH? People with neurologic disorders, like Parkinson disease, may also have a separate condition called nOH. nOH occurs when blood pressure drops too much when standing up after sitting or lying down. What are the symptoms of nOH, and how can they affect people's lives? Most often, people with nOH report feeling lightheaded, faint, or dizzy when standing up. Other symptoms of nOH include pain in the shoulders and neck, trouble thinking clearly, tiredness, or blurry vision. The symptoms of nOH can cause falls and injuries. Because of nOH symptoms, people may be unable to do daily activities and may feel worried or anxious. What do patients and HCPs need to know when discussing nOH symptoms? A survey showed that patients may not talk about their nOH symptoms with their HCPs unless symptoms are severe, and that patients can find receiving a diagnosis of nOH challenging. Patients can track nOH symptoms in a daily journal to use in discussions with their HCPs. How can HCPs help patients with nOH? HCPs can ask patients with underlying neurologic disorders about symptoms that occur on standing and confirm a diagnosis of nOH by comparing the patient's blood pressures measured lying down and after standing up. HCPs can provide information about lifestyle changes and medications that are available to manage nOH symptoms.

Mucin expression in gastric- and gastro-oesophageal signet-ring cell cancer: results from a comprehensive literature review and a large cohort study of Caucasian and Asian gastric cancer.

BACKGROUND: The literature on the prognostic relevance of signet-ring cell (SRC) histology in gastric cancer (GC) is controversial which is most likely related to inconsistent SRC classification based on haematoxylin-eosin staining. We hypothesised that mucin stains can consistently identify SRC-GC and predict GC patient outcome. METHODS: We performed a comprehensive literature review on mucin stains in SRC-GC and characterised the mucin expression in 851 Caucasian GC and 410 Asian GC using Alcian Blue (AB)-Periodic Acid-Schiff (PAS), MUC2 (intestinal-type mucin), and MUC5AC (gastric-type mucin). The relationship between mucin expression and histological phenotype [poorly cohesive (PC) including proportion of SRCs, non-poorly cohesive (non-PC), or mucinous (MC)], clinicopathological variables, and patient outcome was analysed. RESULTS: Depending on mucin expression and cut-offs, the positivity rates of SRC-GC reported in the literature varied from 6 to 100%. Patients with MUC2 positive SRC-GC or SRC-GC with (gastro)intestinal phenotype had poorest outcome. In our cohort study, PC with ≥ 10% SRCs expressed more frequently MUC2, MUC5AC, and ABPAS (p < 0.001, p = 0.004 and p < 0.001, respectively). Caucasians with AB positive GC or combined ABPAS-MUC2 positive and MUC5AC negative had poorest outcome (all p = 0.002). This association was not seen in Asian patients. CONCLUSIONS: This is the first study to suggest that mucin stains do not help to differentiate between SRC-GC and non-SRC-GC. However, mucin stains appear to be able to identify GC patients with different outcome. To our surprise, the relationship between outcome and mucin expression seems to differ between Caucasian and Asian GC patients which warrants further investigations.