Domoic acid in Canadian Pacific waters, from 2016 to 2021, and relationships with physical and chemical conditions.

Domoic acid, a phycotoxin produced by species of the marine diatom Pseudo-nitzschia, can cause deleterious impacts to marine food webs and human health. Domoic acid and Pseudo-nitzschia spp. were surveyed from 2016 to 2021 in the Pacific waters of Canada to assess their occurrences, concentrations, and relationships with physical and chemical conditions. Domoic acid was common, occurring in measurable concentrations in 73 % of the 454 samples. It occurred in all regions (west coast of Vancouver Island, Salish Sea, Queen Charlotte Sound / Hecate Strait, deep oceanic NE Pacific), in all years and all seasons. Median concentrations were highest along the west coast of Vancouver Island, and lowest in the oceanic waters of the NE Pacific. Winter had the lowest concentrations; no significant differences occurred between spring, summer, and autumn. High domoic acid concentrations equal to or above 100 ng/L were not common, occurring in about 5 % of samples, but in all seasons and all years except 2019. All six Pseudo-nitzschia taxa identified had similar median concentrations, but different frequencies of occurrence. P. cf. australis appeared to be the major contributor to high concentrations of domoic acid. Physico-chemical conditions were described by ten variables: temperature, salinity, density difference between 30 m and the surface (a proxy for vertical stability), chlorophyll a, nitrate, phosphate, silicate, and the ratios nitrate:phosphate, nitrate:silicate, and silicate:phosphate. Statistical analyses, using general linear models, of their relationships with the absence/presence of Pseudo-nitzschia spp. found silicate (negative) to be the most influential variable common in both the west coast of Vancouver Island and Salish Sea regions. Temperature and chlorophyll a were the most influential variables which determined the log10 abundance of Pseudo-nitzschia spp. in both regions. Analyses of the absence/presence of particulate domoic acid per Pseudo-nitzschia cell (excluding P. americana) found chlorophyll a to be the most influential variable common in both regions, whereas no common influential variable determined the log10 concentration of particulate domoic acid per Pseudo-nitzschia cell (excluding P. americana). These results were generally similar to those of other studies from this area, although this study extends these findings to all seasons and all regions of Canada's Pacific waters. The results provide important background information against which major outbreaks and unusual events can be compared. A domoic acid surveillance program during synoptic oceanographic surveys can help to understand where and when it reaches high concentrations at sea and the potential impacts to the marine ecosystem.

Simultaneous determination of steroid hormones and pharmaceuticals in killer whale (Orcinus orca) faecal samples by liquid chromatography tandem mass spectrometry.

We describe a non-invasive method for profiling selected hormones, pharmaceuticals and personal care products (PPCPs) in killer whales (Orcinus orca) based on analysis of faecal samples by liquid chromatography tandem mass spectrometry (LC-MS/MS). The method targets 21 compounds of interest including glucocorticoids, mineralocorticoids, androgens, estrogens, progestogens, selective serotonin uptake inhibitors and an antibacterial/antifungal agent. This method is suitable for routine simultaneous determination of target compounds in killer whale faecal samples as well as validation of immunoassays for the detection and measurement of steroid hormones in faeces. The optimized method involves extraction of freeze-dried faecal material with reagent alcohol and water followed by isolation of the analytes using solid phase extraction with hydrophilic-lipophilic balance cartridges and liquid-liquid extraction with methyl tertiary-butyl ether. Reconstituted extracts were analysed by LC-MS/MS using an electrospray ionization interface. Method limit of quantification ranged from 0.06 to 45.2 ng/g in freeze-dried faecal samples. Except for sertraline, triclosan and estradiol (which was not recovered at the lowest spiked concentration), average intra- and inter-day precisions were within 10%, and average recoveries were between 89.3% and 129.3%, for faecal samples spiked with 5.3, 26.7 or 133 ng/g of each analyte. The method was applied successfully to the analysis of hormones and PPCPs in whale faeces during which 17α-hydroxyprogesterone, a common intermediate in steroid biosynthesis that cross-reacts with precursors and sulphated conjugates in immunoassays, was identified and quantified in all samples.

Dissolved Algal Toxins along the Southern Coast of British Columbia Canada.

Harmful algal blooms (HABs) in coastal British Columbia (BC), Canada, negatively impact the salmon aquaculture industry. One disease of interest to salmon aquaculture is Net Pen Liver Disease (NPLD), which induces severe liver damage and is believed to be caused by the exposure to microcystins (MCs). To address the lack of information about algal toxins in BC marine environments and the risk they pose, this study investigated the presence of MCs and other toxins at aquaculture sites. Sampling was carried out using discrete water samples and Solid Phase Adsorption Toxin Tracking (SPATT) samplers from 2017-2019. All 283 SPATT samples and all 81 water samples tested positive for MCs. Testing for okadaic acid (OA) and domoic acid (DA) occurred in 66 and 43 samples, respectively, and all samples were positive for the toxin tested. Testing for dinophysistoxin-1 (DTX-1) (20 samples), pectenotoxin-2 (PTX-2) (20 samples), and yessotoxin (YTX) (17 samples) revealed that all samples were positive for the tested toxins. This study revealed the presence of multiple co-occurring toxins in BC's coastal waters and the levels detected in this study were below the regulatory limits for health and recreational use. This study expands our limited knowledge of algal toxins in coastal BC and shows that further studies are needed to understand the risks they pose to marine fisheries and ecosystems.

Acute Toxicity of 6PPD-Quinone to Early Life Stage Juvenile Chinook (Oncorhynchus tshawytscha) and Coho (Oncorhynchus kisutch) Salmon.

The breakdown product of the rubber tire antioxidant N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone (6PPD)-6-PPD-quinone has been strongly implicated in toxic injury and death in coho salmon (Oncorhynchus kisutch) in urban waterways. Whereas recent studies have reported a wide range of sensitivity to 6PPD-quinone in several fish species, little is known about the risks to Chinook salmon (Oncorhynchus tshawytscha), the primary prey of endangered Southern Resident killer whales (Orcinus orca) and the subject of much concern. Chinook face numerous conservation threats in Canada and the United States, with many populations assessed as either endangered or threatened. We evaluated the acute toxicity of 6PPD-quinone to newly feeding (~3 weeks post swim-up) juvenile Chinook and coho. Juvenile Chinook and coho were exposed for 24 h under static conditions to five concentrations of 6PPD-quinone. Juvenile coho were 3 orders of magnitude more sensitive to 6PPD-quinone compared with juvenile Chinook, with 24-h median lethal concentration (LC50) estimates of 41.0 and more than 67 307 ng/L, respectively. The coho LC50 was 2.3-fold lower than what was previously reported for 1+-year-old coho (95 ng/L), highlighting the value of evaluating age-related differences in sensitivity to this toxic tire-related chemical. Both fish species exhibited typical 6PPD-quinone symptomology (gasping, increased ventilation, loss of equilibrium, erratic swimming), with fish that were symptomatic generally exhibiting mortality. The LC50 values derived from our study for coho are below concentrations that have been measured in salmon-bearing waterways, suggesting the potential for population-level consequences in urban waters. The higher relative LC50 values for Chinook compared with coho merits further investigation, including for the potential for population-relevant sublethal effects. Environ Toxicol Chem 2023;42:815-822. © 2023 His Majesty the King in Right of Canada and The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Fisheries and Oceans Canada.

Optimizing pre-Descemet endothelial keratoplasty technique.

Pre-Descemet endothelial keratoplasty (PDEK) is an alternative technique to Descemet membrane endothelial keratoplasty (DMEK). The preparation of PDEK tissue by pneumatic dissection is simple and reproducible. The PDEK clamp helps to consistently obtain a type 1 big bubble. The mean size of type 1 big bubble is 7.255 ± 0.535 × 6.745 ± 0.668 mm. The volume of air required to obtain type 1 big bubble is 0.14 to 0.37 mL. Dissection of PDEK tissue can be achieved by trephination or manual excision. Insertion of tissue into the recipient eye can be by injection or pulling. Unfolding techniques used for PDEK are similar to those used in DMEK. Unlike DMEK, PDEK tissue is easier to handle and unscroll and allows use of younger donors. It could help surgeons converting to endothelial keratoplasty, with significant advantages in preparation, handling, and unscrolling in the eye.

Clinical and in vivo confocal microscopic features of neuropathic corneal pain.

AIMS: To describe clinical and in vivo confocal microscopy (IVCM) features of neuropathic corneal pain (NCP) without clinically visible signs. METHODS: Prospective, observational study of 27 eyes of 14 patients who had continuous severe ocular pain for one or more years, with minimal or no ocular surface signs and were non-responsive to topical lubricants, steroids and/or ciclosporin. All patients were evaluated using Ocular Surface Disease Index, Oxford grading scale, Schirmer test 1, Cochet Bonnet esthesiometry and response to topical anaesthesia. Central and paracentral regions of the cornea of patients and seven healthy controls were studied by IVCM. Corneal epithelial thickness and sub-basal nerve density were measured in patients and controls. RESULTS: Four patients responded to topical anaesthesia (responsive group (RG)), indicating peripheral NCP while 10 patients did not show any improvement (non-responsive group (NRG)), indicating central NCP. Schirmer-1 test was within normal limits in the RG but significantly greater in the NRG (p<0.001). None of the other clinical parameters nor corneal epithelial thickness were statistically significantly different. The sub-basal nerve density was significantly reduced (p<0.008) in patients compared with controls. Stroma of all patients demonstrated activated keratocytes and spindle, lateral and stump microneuromas. There was a statistically significant greater number of microneuromas (p<0.0001) and activated keratocytes in RG compared with NRG. CONCLUSION: NCP without visible clinical signs does not represent typical dry eye disease. Distinct signs demonstrated on IVCM suggest that peripheral NCP, which responds to topical anaesthesia, and central NCP, which does not, are separate entities.

Management of primary pterygium with intra-lesional injection of 5 flurouracil and bevacizumab (Avastin).

BACKGROUND: To assess the efficacy of combined 5FU and Avastin injections in the treatment of primary pterygium METHODS: Sixteen eyes with primary pterygium received intralesional 5 fluorouracil and Avastin (2.5-5 mg) injections every 2 weeks for a maximum of five injections. Fourteen eyes of 14 patients received five injections, one eye received three injections and one eye received two injections. All eyes were followed at monthly intervals for 3 months after last injection. Tissue was obtained by surgical excision of primary pterygium from four eyes who received injections and three eyes with primary pterygium who did not receive injections (control) and subjected to immunohistological examination for beta fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), von-Willebrand factor (vWF), lymphatic vessel endothelial hyaluronan receptor (LYVE-1) and collagen-I. RESULTS: Pterygium progression was arrested in all patients. Sixty-two percent of patients had improvement of redness while 89% had reduced thickness of the lesion. VEGF, bFGF, EGF, vWF, LYVE-1 and collagen-I were all reduced in the injected samples. CONCLUSIONS: The injection of 5 fluorouracil and Avastin act synergistically to arrest progression and induce atrophy in primary pterygium. This is related to the effect of agents on fibroblasts, collagen, and vascular tissues. Such medical intervention is a safe and viable option in the management of primary pterygium though excision of residual tissue is still required in some cases. Longer follow up is needed to ascertain whether this will reduce the recurrence rate following excision.

Development of a gastroschisis core outcome set.

OBJECTIVE: Outcome reporting heterogeneity impedes identification of gold standard treatments for children born with gastroschisis. Use of core outcome sets (COSs) in research reduces outcome reporting heterogeneity and ensures that studies are relevant to patients. The aim of this study was to develop a gastroschisis COS. DESIGN AND SETTING: Systematic reviews and stakeholder nomination were used to identify candidate outcomes that were subsequently prioritised by key stakeholders in a three-phase online Delphi process and face-to-face consensus meeting using a 9-point Likert scale. In phases two and three of the Delphi process, participants were shown graphical and numerical representations of their own, and all panels scores for each outcome respectively and asked to review their previous score in light of this information. Outcomes were carried forward to the consensus meeting if prioritised by two or three stakeholder panels in the third phase of the Delphi process. The COS was formed from outcomes where ≥70% of consensus meeting participants scored the outcome 7-9 and <15% of participants scored it 1-3. RESULTS: 71 participants (84%) completed all phases of the Delphi process, during which 87 outcomes were assessed. Eight outcomes, mortality, sepsis, growth, number of operations, severe gastrointestinal complication, time on parenteral nutrition, liver disease and quality of life for the child, met criteria for inclusion in the COS. CONCLUSIONS: Eight outcomes have been included in the gastroschisis COS as a result of their importance to key stakeholders. Implementing use of the COS will increase the potential for identification of gold standard treatments for the management of children born with gastroschisis.

Elastin Content and Distribution in Endothelial Keratoplasty Tissue Determines Direction of Scrolling.

PURPOSE: Descemet membrane endothelial keratoplasty (DMEK) and pre-Descemet endothelial keratoplasty (PDEK) tissues always scroll with the endothelial cells (EC) outside. We designed a study to understand the reason for this behavior. DESIGN: Experimental study. METHODS: Elastin content in Descemet membrane (DM), pre-Descemet layer (PDL), central and peripheral stroma, sclera, and trabecular meshwork were measured by the Fastin elastin assay kit. Distribution of elastin in DM, PDL, and anterior lens capsule (ALC) were examined by immunohistology. The effect of recombinant elastase enzyme and the effect of complete removal of EC and epithelial cells on the scrolling of DM and ALC, respectively, were studied. RESULTS: PDL showed the highest elastin content among the different tissues studied. Elastin localized as a distinct anterior band in the DM and was uniformly distributed in the PDL demarcating the latter from corneal stroma. Enzymatic treatment of DM with elastase reversed scrolling and corresponded with degradation or disappearance of elastin. Removal of EC did not affect the direction of scrolling. ALC behaved in the same manner with regard to distribution of elastin, scrolling, and removal of epithelial cells. CONCLUSIONS: This pattern of elastin distribution in DM explains why DMEK and PDEK tissues always scroll with the EC outside. This behavior is not influenced by the EC. High elastin content and uniform distribution in the PDL suggest a structural difference from the posterior stroma.

Deep anterior lamellar keratoplasty: dissection plane with viscoelastic and air can be different.

AIMS: To investigate and define the nature of big bubbles (BB) formed by injection of viscoelastic in deep anterior lamellar keratoplasty. METHODS: Intrastromal injections of 0.1 and 0.3 mL of sodium hyaluronate 1.2% and 0.6% were made into sclera-corneal discs (n = 32) at superficial (anterior-third), midstromal (middle-third) and deep (posterior-third) levels to simulate deep anterior lamellar keratoplasty. Postinjection optical coherence tomograms (OCT) were obtained with the needle in situ. The samples were sectioned and examined histologically. Twelve control samples were injected with air. RESULTS: With superficial injections (n=8) only intrastromal accumulation of viscoelastic was noted. With midstromal injections (n=10) intrastromal accumulation of viscoelastic (n=6) and intrastromal big bubbles (IBB) (n=4) with substantial and variable stromal tissue in the walls were noted. No type 1, type 2 or mixed BB were noted. With deep injections (n=14), type 1 BB (n=4), IBB (n=4) and mixed BB (n=6) were obtained.There was no difference in the results with the two different concentrations of viscoelastic used. With air injection (n=12), 10 type 1 and 1 type 2 BB and 1 mixed BB were obtained. No IBB was noted. CONCLUSIONS: BB obtained by injection of viscoelastic and air can be different. The former tends to occur at the site of injection, especially with midstromal injections, takes the form of tissue separation by stretch and tearing and does not cleave in a consistent plane like air. Surgeons should be aware of IBB created by viscodissection and not confuse it for a type1 BB. Intraoperative OCT should help identify IBB.

Cataract surgery with intraocular lens implantation in 3 brothers with megalocornea: Long-term follow-up.

Cataract surgery in patients with megalocornea is challenging because of the large capsular bag in which a conventional intraocular lens (IOL) does not fit and the atrophic nature of the iris. We report the procedures and outcomes of cataract surgery in 6 eyes of 3 brothers with megalocornea. In 2 eyes, a posterior chamber IOL (PC IOL) was inserted and sutured to the iris with 10-0 nylon sutures. In the other 4 eyes, an iris-clip anterior chamber IOL (AC IOL) was inserted. In all cases, the postoperative corrected distance visual acuity (CDVA) was 6/6. In the PC IOL group, 1 IOL dislocated and was replaced with an iris-clip AC IOL. In the AC IOL group, 1 IOL subluxated and was reenclavated. In both eyes with dislocation, the CDVA improved to 6/6.

Outcome reporting in randomized controlled trials and systematic reviews of gastroschisis treatment: a systematic review.

BACKGROUND: Core outcome sets (COS) facilitate clinical research by providing an agreed set of outcomes to be measured when evaluating treatment efficacy. Gastroschisis is increasing in frequency and evidence-based treatments are lacking. We aimed to identify initial candidate outcomes for a gastroschisis COS from existing literature. METHODS: Using a sensitive search strategy we identified randomized controlled trials (RCTs) and systematic reviews (SRs) of treatment interventions for gastroschisis. Outcomes were extracted and assigned to the core areas, 'Pathophysiological Manifestations', 'Life Impact', 'Resource Use', 'Adverse Events' and 'Mortality'. RESULTS: A total of 50 outcomes were identified. RCTs reported 6-9 outcomes each; SRs reported 9-25. The most frequently reported outcomes were 'Length of hospital stay' (reported in 8 studies), 'Duration of ventilation' and 'Time to full enteral feeds' (7 studies). Outcomes identified could be assigned to all five core areas. CONCLUSIONS: There is wide heterogeneity in outcomes reported in studies evaluating treatment interventions for gastroschisis. It is unclear which outcomes are of highest importance across stakeholder groups. Developing a COS to standardize outcome measurement and reporting for gastroschisis is warranted.

The extramucosal interrupted end-to-end intestinal anastomosis in infants and children; a single surgeon 21year experience.

BACKGROUND/PURPOSE: To report outcomes of a standardised technique for intestinal anastomosis in infants and children. METHODS: Data were prospectively collected on all paediatric intestinal anastomosis by a single surgeon over a 21year period. Anastomoses were constructed using an end-to-end extramucosal technique with interrupted polypropylene sutures. Demographic and clinical data were recorded. RESULTS: Six-hundred and thirteen anastomoses were constructed in 550 patients. Median age at time of anastomosis was 6months (range 1day-226months). The most common reason for anastomosis was stoma closure (n=271, 49%). For those patients that required multiple anastomoses the most common pathology was acute NEC (n=22/41, 54%). One-hundred and one (18.4%) patients passed stool within 24hours of surgery, 175 (31.8%) between 24-48 hours and 95 (17.3%) between 48-72 hours. Anastomotic complications occurred in 7 patients (1.3%) including anastomotic leakage (n=5, 0.9%) and anastomotic stricture (n=2, 0.4%). The majority of anastomotic leakages (80%) followed resection of acute NEC. CONCLUSIONS: The interrupted extramucosal anastomosis is safe and effective. The return of bowel function is rapid and the complication rate acceptable. We recommend this technique be used for all intestinal anastomoses in children and infants.

Educational survey of regional general practitioner's management of paediatric patients with undescended testis.

INTRODUCTION: Recent recommendations have lowered the ideal age of surgery for undescended testis (UDT) to 3-6 months of age. However, many publications demonstrate that age at surgery is still above the recommended age of 1 year as originally suggested in 1996. AIM: Through a web-based educational survey, we aimed to combine questions regarding General Practioner's (GPs) management of these patients with educational slides with advice to update them with current recommendations. METHODS: The regional GPs were invited by email and letter to undertake the web-based questionnaire devised using SurveyMonkey(®). Educational slides were shown after each questionnaire slide. Feedback was immediate and a one-page summary was emailed to the GP on completion. A pre- and post-educational intervention audit was undertaken to ascertain the change in age of referral for patients <5 years of age. RESULTS: 144 (36%) of 401 GPs undertook this survey. 84% were happy assessing infants (<1year) with UDT. 16% were unhappy discussing management with parents for palpable UDT. 52% were happy discussing malignant risk with parents. 80% thought that ultrasonography was routinely used. Optimal referral time was thought to be 6-12 months (42%) and time of surgery was 1-2 years (50%). 72% would refer a patient with palpable UDT after 6 months of age. Only 41% were happy to assess testicular size at puberty. 98% found this format of an educational survey was helpful. The average age of referral for patients <5 years improved significantly after educational intervention from 2.8 years in 2010 to 1.25 years in 2013 (p < 0.01). DISCUSSION: With an interactive survey, we were able assess and also educate the regional GPs with regard to management of paediatric patients with UDT. There is a varied range of knowledge and practice demonstrated which we hoped to standardise and thereby increase efficiency and decrease the age of referral. A large majority would refer patients with UDT after 6 months of age that would make the target of surgery <6 months unachievable unless they are aware of current recommendations. This study is limited by a 36% response rate but that is comparable to other surveys. Also, referrals come from other sources that were not included. The causal effect of the educational survey is hypothesised. CONCLUSION: This educational survey has confirmed the varied management by GPs. The referral age was demonstrated to be reduced after this intervention and this process was widely accepted by GPs that undertook the educational survey.

A novel method for the rapid determination of polyethoxylated tallow amine surfactants in water and sediment using large volume injection with high performance liquid chromatography and tandem mass spectrometry.

Polyethoxylated tallow amine (POEA) surfactants have been used in many glyphosate-based herbicide formulations for agricultural, industrial and residential weed control. The potential for release of these compounds into the environment is of increasing concern due to their toxicity towards aquatic organisms. Current methods for analysis of POEA surfactants require significant time and effort to achieve limits of quantification that are often higher than the concentrations at which biological effects have been observed (as low as 2 ng mL(-1)). We have developed a rapid and robust method for quantifying the POEA surfactant mixture MON 0818 at biologically relevant concentrations in fresh water, sea water and lake sediment using reversed phase high-performance liquid chromatography and electrospray ionization-tandem mass spectrometry. Water samples preserved by 1:1 v/v dilution with methanol are analyzed directly following centrifugation. Sediment samples undergo accelerated solvent extraction in aqueous methanol prior to analysis. Large volume (100 µL) sample injection and multiple reaction monitoring of a subset of the most abundant POEA homologs provide limits of quantification of 0.5 and 2.9 ng mL(-1) for MON 0818 in fresh water and sea water, respectively, and 2.5 ng g(-1) for total MON 0818 in lake sediment. Average recoveries of 93 and 75% were achieved for samples of water and sediment, respectively spiked with known amounts of MON 0818. Precision and accuracy for the analysis of water and sediment samples were within 10 and 16%, respectively based upon replicate analyses of calibration standards and representative samples. Results demonstrate the utility of the method for quantifying undegraded MON 0818 in water and sediment, although a more comprehensive method may be needed to identify and determine other POEA mixtures and degradation profiles that might occur in the environment.

Enrichment and Analysis of Intact Phosphoproteins in Arabidopsis Seedlings.

Protein phosphorylation regulates diverse cellular functions and plays a key role in the early development of plants. To complement and expand upon previous investigations of protein phosphorylation in Arabidopsis seedlings we used an alternative approach that combines protein extraction under non-denaturing conditions with immobilized metal-ion affinity chromatography (IMAC) enrichment of intact phosphoproteins in Rubisco-depleted extracts, followed by identification using two-dimensional gel electrophoresis (2-DE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). In-gel trypsin digestion and analysis of selected gel spots identified 144 phosphorylated peptides and residues, of which only 18 phosphopeptides and 8 phosphosites were found in the PhosPhAt 4.0 and P3DB Arabidopsis thaliana phosphorylation site databases. More than half of the 82 identified phosphoproteins were involved in carbohydrate metabolism, photosynthesis/respiration or oxidative stress response mechanisms. Enrichment of intact phosphoproteins prior to 2-DE and LC-MS/MS appears to enhance detection of phosphorylated threonine and tyrosine residues compared with methods that utilize peptide-level enrichment, suggesting that the two approaches are somewhat complementary in terms of phosphorylation site coverage. Comparing results for young seedlings with those obtained previously for mature Arabidopsis leaves identified five proteins that are differentially phosphorylated in these tissues, demonstrating the potential of this technique for investigating the dynamics of protein phosphorylation during plant development.