Recent domoic acid closures of shellfish harvest areas in Washington State inland waterways

Several species of the toxigenic diatom Pseudo-nitzschia, together with low concentrations of domoic acid (DA) in shellfish have been observed in Puget Sound, Washington State, since 1991. However, for the first time in September 2003, high-density blooms of Pseudo-nitzschia forced the closure of recreational, commercial, and tribal subsistence shellfish harvesting in Puget Sound. Here we report on the environmental conditions associated with shellfish closures in two inland waterways of Washington State during the Fall 2005. In Sequim Bay, shellfish harvest losses occurred on September 12 following the measurement of elevated macronutrient levels on September 2, and a bloom of P. pseudodelicatissima (up to 13 million cells/L) on September 9. Ambient NH₄ concentrations >12 μM (measured on September 2) were likely due to anthropogenic sources, ostensibly from sewage inputs to Sequim Bay. The closure of a Penn Cove commercial shellfish farm on October 16 was caused by a bloom of P. australis that followed a period of sustained precipitation, elevated Skagit River flow, and persistent southeasterly winds. The relative importance of a number of environmental factors, including temperature, stratification caused by rivers, and nutrient inputs, whether natural or anthropogenic, must be carefully studied in order to better understand the recent appearance of massive blooms of toxigenic Pseudo-nitzschia in the inland waterways of Washington State.     

First Nations status and emergency department triage scores in Alberta: a retrospective cohort study

Background:Previous studies have found that race is associated with emergency department triage scores, raising concerns about potential health care inequity. As part of a project on quality of care for First Nations people in Alberta, we sought to understand the relation between First Nations status and triage scores.Methods:We conducted a population-based retrospective cohort study of health administrative data from April 2012 to March 2017 to evaluate acuity of triage scores, categorized as a binary outcome of higher or lower acuity score. We developed multivariable multilevel logistic mixed-effects regression models using the levels of emergency department visit, patient (for patients with multiple visits) and facility. We further evaluated the triage of visits related to 5 disease categories and 5 specific diagnoses to better compare triage outcomes of First Nations and non–First Nations patients.Results:First Nations status was associated with lower odds of receiving higher acuity triage scores (odds ratio [OR] 0.93, 95% confidence interval [CI] 0.92–0.94) compared with non–First Nations patients in adjusted models. First Nations patients had lower odds of acute triage for all 5 disease categories and for 3 of 5 diagnoses, including long bone fractures (OR 0.82, 95% CI 0.76–0.88), acute upper respiratory infection (OR 0.90, 95% CI 0.84–0.98) and anxiety disorder (OR 0.67, 95% CI 0.60–0.74).Interpretation:First Nations status was associated with lower odds of higher acuity triage scores across a number of conditions and diagnoses. This may reflect systemic racism, stereotyping and potentially other factors that affected triage assessments.

Health outcomes are markedly worse for First Nations than non–First Nations people. Although this is largely because of inequities in the social determinants of health,^1–4 inequities in the provision of health care also exist.^5,6 Emergency departments serve as a point of accessible health care. Status First Nations patients make up 4.8% of unique patients and 9.4% of emergency visits in Alberta,⁷ and Canadian studies describe First Nations patients’ experiences with racism when seeking emergency care.^8,9Evaluating triage contributes empirically to understanding the health care of First Nations patients insofar as triage is a quantifiable, intermediate process by which systemic racism¹⁰ may influence patient outcomes. The Canadian Triage Acuity Scale¹¹ is a 5-level scale used to classify the severity of patient symptoms. Triage nurses use a brief assessment, medical history, and presenting signs and symptoms to assign each patient a triage score that determines the priority in which the patient should be seen by a provider. Therefore, accurate triage is important for patient health outcomes.¹² In practice, triage is a social interaction where local practice, biases, stereotypes and communication barriers come into play. Studies have found that women receive less acute triage scores than men,^13,14 and that racial minority^13,15–17 and Indigenous^18–20 patients receive less acute triage scores than white or non-Indigenous patients. Indeed, Indigenous patients in Canada have described a perception “of social triaging in the [emergency department], whereby decisions about who is seen first seemed to them [to be] based less on triaged clinical priorities but on the social positioning of the patient.”²¹ Differential triage scores for minority populations raise health equity concerns.As part of a larger mixed-methods project evaluating the quality of emergency care for First Nations people in Alberta, we sought to evaluate quantitative differences in emergency visit characteristics and outcomes of First Nations and non–First Nations people in Alberta. Specifically, we aimed to estimate the relation between First Nations status and acuity of triage, and to evaluate whether predictors of acuity differ by First Nations status.     

Focus: The Science of Stress: Mesenchymal Stem/Stromal Cells and Their Role in Oxidative Stress Associated with Preeclampsia

Preeclampsia (PE) is a serious medically important disorder of human pregnancy, which features de novo pregnancy-induced hypertension and proteinuria. The severe form of PE can progress to eclampsia, a convulsive, life-threatening condition. When placental growth and perfusion are abnormal, the placenta experiences oxidative stress and subsequently secretes abnormal amounts of certain pro-angiogenic factors (eg, PlGF) as well as anti-angiogenic factors (eg, sFlt-1) that enter the maternal circulation. The net effect is damage to the maternal vascular endothelium, which subsequently manifests as the clinical features of PE. Other than delivery of the fetus and placenta, curative treatments for PE have not yet been forthcoming, which reflects the complexity of the clinical syndrome. A major source of reactive oxygen species that contributes to the widespread maternal vascular endothelium damage is the PE-affected decidua. The role of decidua-derived mesenchymal stem/stromal cells (MSC) in normotensive and pathological placenta development is poorly understood. The ability to respond to an environment of oxidative damage is a “universal property” of MSC but the biological mechanisms that MSC employ in response to oxidative stress are compromised in PE. In this review, we discuss how MSC respond to oxidative stress in normotensive and pathological conditions. We also consider the possibility of manipulating the oxidative stress response of abnormal MSC as a therapeutic strategy to treat preeclampsia.     

Lack of evidence for an immunosuppressive role for MUC1

The in vitro anti-proliferative properties of various supernatants from MUC1-expressing cell lines and of purified preparations of MUC1 were evaluated. We have observed that supernatants from the MUC1- and MUC3-positive cell line T47D, but not from the MUC1- and MUC4-positive cell line MCF7, were able to inhibit proliferation of cells from various haematopoietic cell lines. Although the activity of T47D supernatants could be abrogated by immunodepletion of MUC1, immunopurified MUC1 from T47D was unable to inhibit cell proliferation. Significantly, supernatants from mouse 3T3 cells transfected with a secreted form of MUC1 or from BHK-21 cells infected with a recombinant vaccinia virus coding for the secreted form of MUC1, as well as preparations of purified MUC1 from bile or urine, were likewise unable to inhibit T cell proliferation. Surprisingly, a crude mixture of bile mucins had a suppressive effect on T cell growth. Our results suggest that other molecules, such as amino sugars or other mucins, which can associate with MUC1, are likely to be responsible for the observed anti-proliferative effects of T47D cells. Received: 20 August 1998 / Accepted: 3 December 1998     

Knockout of the alanine racemase gene in Lactobacillus plantarum results in septation defects and cell wall perforation

A stable mutant of Lactobacillus plantarum deficient in alanine racemase (Alr) was constructed by two successive homologous recombination steps. When the mutant was supplemented with D-alanine, growth and viability were unaffected. Surprisingly, deprivation of d-alanine during exponential growth did not result in a rapid and extensive lysis as observed in Alr-deficient strains of Escherichia coli or Bacillus subtilis. Rather, the starved mutant cells underwent a growth arrest and were gradually affected in viability with a decrease in colony forming units over 99% in less than 24 h. Additionally, fluorescent techniques demonstrated a loss of cell envelope integrity in the starved cells. Prolonged d-alanine starvation resulted in cells with an aberrant morphology. Scanning and transmission electron microscopy analyses revealed an increase in cell length, deficiencies in septum formation, thinning of the cell envelope and perforation of the cell wall in the septum region. We discuss the involvement of peptidoglycan hydrolases in these phenotypic defects in the context of the crucial role played by D-alanine in peptidoglycan biosynthesis and teichoic acids substitution.