A new pathogen transmission mechanism in the ocean: the case of sea otter exposure to the land-parasite Toxoplasma gondii.

Toxoplasma gondii is a land-derived parasite that infects humans and marine mammals. Infections are a significant cause of mortality for endangered southern sea otters (Enhydra lutris nereis), but the transmission mechanism is poorly understood. Otter exposure to T. gondii has been linked to the consumption of marine turban snails in kelp (Macrocystis pyrifera) forests. It is unknown how turban snails acquire oocysts, as snails scrape food particles attached to surfaces, whereas T. gondii oocysts enter kelp beds as suspended particles via runoff. We hypothesized that waterborne T. gondii oocysts attach to kelp surfaces when encountering exopolymer substances (EPS) forming the sticky matrix of biofilms on kelp, and thus become available to snails. Results of a dietary composition analysis of field-collected snails and of kelp biofilm indicate that snails graze the dense kelp-biofilm assemblage composed of pennate diatoms and bacteria inserted within the EPS gel-like matrix. To test whether oocysts attach to kelp blades via EPS, we designed a laboratory experiment simulating the kelp forest canopy in tanks spiked with T. gondii surrogate microspheres and controlled for EPS and transparent exopolymer particles (TEP - the particulate form of EPS). On average, 19% and 31% of surrogates were detected attached to kelp surfaces covered with EPS in unfiltered and filtered seawater treatments, respectively. The presence of TEP in the seawater did not increase surrogate attachment. These findings support a novel transport mechanism of T. gondii oocysts: as oocysts enter the kelp forest canopy, a portion adheres to the sticky kelp biofilms. Snails grazing this biofilm encounter oocysts as 'bycatch' and thereby deliver the parasite to sea otters that prey upon snails. This novel mechanism can have health implications beyond T. gondii and otters, as a similar route of pathogen transmission may be implicated with other waterborne pathogens to marine wildlife and humans consuming biofilm-feeding invertebrates

Minipellets: A new and abundant size class of marine fecal pellets

Minipellets, fecal pellets from 3 to 50 μm in diameter, were found on detritus collected by a particle interceptor trap array in the upper 2000 m of the eastern tropical Pacific. The fluxes of minipellets reached 5 × 106 m−2 day−1, and exceeded fluxes of larger (\u3e50 μm diameter) fecal pellets by 3 orders of magnitude. Carbon flux of minipellets was 11–49% that of larger pellets; however, carbon flux of ultrastructurally intact cells (microalgae and bacteria) in minipellets was equal to that of intact cells in the larger pellets. Minipellets also occurred in water samples from similar depths, where they numbered up to 105 m−3, and were usually not associated with particles. Minipellets appear ubiquitous; we have found them in all our samples of particulates from other cruises from surface waters to bathypelagic depths. Minipellet morphologies ranged from Type A, which contained intact, picoplankton-sized cells (cyanobacteria, nitrifying bacteria, morphologically non-descript, Gram-negative bacteria, Chiarella-like cells) in an amorphous matrix surrounded by a boundary, to Type D minipellets, which were identical to previously described olive-green cells. Minipellets are probably wastes of protozoans and small invertebrates that consume marine snow and larger fecal pellets throughout the water column, thereby maintaining the high numbers of minipellets from the surface to 2000 m. We found several sources of minipellets: two groups of sarcodine protozoans (phaeodarian and spumellarian radiolarians) and small hydromedusae. The minipellet producers reprocess a major portion of surface-derived detritus, and represent important biological intermediates that transform particulate matter settling through the ocean

An Integrated Model for STEM Teacher Preparation: The Value of a Teaching Cooperative Educational Experience

The purpose of this article is to evaluate an intensive, integrated model for teacher preparation, specifically, a preservice STEM teacher education model which incorporates science or mathematics content with pedagogical content knowledge in an early, intensive classroom immersion program based entirely in a local school. STEM preservice teachers participated in a cooperative teaching experience which placed them at the school site for their university course work and field placements, thus ensuring a more seamless connection between theory and practice. The findings from this comparative study of the STEM preservice students in the teaching co-op and STEM preservice teachers in a traditional preparation model indicate that the STEM preservice teachers in the teaching cooperative model were more confident about their teaching skills, more comfortable with their content knowledge, and prepared to work effectively with high-needs students

Aquatic polymers can drive pathogen transmission in coastal ecosystems.

Gelatinous polymers including extracellular polymeric substances (EPSs) are fundamental to biophysical processes in aquatic habitats, including mediating aggregation processes and functioning as the matrix of biofilms. Yet insight into the impact of these sticky molecules on the environmental transmission of pathogens in the ocean is limited. We used the zoonotic parasite Toxoplasma gondii as a model to evaluate polymer-mediated mechanisms that promote transmission of terrestrially derived pathogens to marine fauna and humans. We show that transparent exopolymer particles, a particulate form of EPS, enhance T. gondii association with marine aggregates, material consumed by organisms otherwise unable to access micrometre-sized particles. Adhesion to EPS biofilms on macroalgae also captures T. gondii from the water, enabling uptake of pathogens by invertebrates that feed on kelp surfaces. We demonstrate the acquisition, concentration and retention of T. gondii by kelp-grazing snails, which can transmit T. gondii to threatened California sea otters. Results highlight novel mechanisms whereby aquatic polymers facilitate incorporation of pathogens into food webs via association with particle aggregates and biofilms. Identifying the critical role of invisible polymers in transmission of pathogens in the ocean represents a fundamental advance in understanding and mitigating the health impacts of coastal habitat pollution with contaminated runoff

Engagement of patients with scleroderma to revise an internet self-management program

Systemic sclerosis (SSc) or scleroderma is a rare connective tissue disease. Many people do not have access to education programs. A self-management program was developed several years ago based on the literature and input from people with SSc. However, new therapies and treatment options have been developed since the program was developed. The purpose of this qualitative study was to identify and remedy gaps in an internet SSc self-management program to improve the quality of critical information relevant to effective management of the disease. Six focus groups with 30 participants with SSc were conducted: 2 telephone groups and 4 face-to-face groups. Prior to the focus group meetings, participants reviewed the existing website. A semi-structured interview guide elicited participants’ responses. Gaps were expressed in affect and positive affirmation; disease and symptom management; self-advocacy; information for caregivers, families, coworkers and strangers; tracking systems; information about local support groups; pictures and information on underrepresented groups; and general format. Discussants were positive regarding the audio voice over, exercise module, current content, health logs and checklists. People with SSc identified additional content to improve the internet self-management program. Many of the suggestions were incorporated into the existing program as modifications and additions to existing modules, patient testimonials, worksheets, resources sheets, and/or links to additional websites. People with rare, chronic conditions such as SSc need education and reliable sources of information and self-management skills. Experience Framework This article is associated with the Innovation & Technology lens of The Beryl Institute Experience Framework. (http://bit.ly/ExperienceFramework) Access other PXJ articles related to this lens. Access other resources related to this len

Role of low Km cyclic AMP phosphodiesterase inhibition in tracheal relaxation and bronchodilation in the guinea pig.

ABSTRAC

Randomized Controlled Trial to Evaluate an Internet‐Based Self‐Management Program in Systemic Sclerosis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148240/1/acr23595.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148240/2/acr23595_am.pd

Functional disruption of α4 integrin mobilizes bone marrow–derived endothelial progenitors and augments ischemic neovascularization

The cell surface receptor α4 integrin plays a critical role in the homing, engraftment, and maintenance of hematopoietic progenitor cells (HPCs) in the bone marrow (BM). Down-regulation or functional blockade of α4 integrin or its ligand vascular cell adhesion molecule-1 mobilizes long-term HPCs. We investigated the role of α4 integrin in the mobilization and homing of BM endothelial progenitor cells (EPCs). EPCs with endothelial colony-forming activity in the BM are exclusively α4 integrin–expressing cells. In vivo, a single dose of anti–α4 integrin antibody resulted in increased circulating EPC counts for 3 d. In hindlimb ischemia and myocardial infarction, systemically administered anti–α4 integrin antibody increased recruitment and incorporation of BM EPCs in newly formed vasculature and improved functional blood flow recovery and tissue preservation. Interestingly, BM EPCs that had been preblocked with anti–α4 integrin ex vivo or collected from α4 integrin–deficient mice incorporated as well as control cells into the neovasculature in ischemic sites, suggesting that α4 integrin may be dispensable or play a redundant role in EPC homing to ischemic tissue. These data indicate that functional disruption of α4 integrin may represent a potential angiogenic therapy for ischemic disease by increasing the available circulating supply of EPCs

The state of hypertension care in 44 low-income and middle-income countries:a cross-sectional study of nationally representative individual-level data from 1·1 million adults

Evidence from nationally representative studies in low-income and middle-income countries (LMICs) on where in the hypertension care continuum patients are lost to care is sparse. This information, however, is essential for effective targeting of interventions by health services and monitoring progress in improving hypertension care. We aimed to determine the cascade of hypertension care in 44 LMICs-and its variation between countries and population groups-by dividing the progression in the care process, from need of care to successful treatment, into discrete stages and measuring the losses at each stage. In this cross-sectional study, we pooled individual-level population-based data from 44 LMICs. We first searched for nationally representative datasets from the WHO Stepwise Approach to Surveillance (STEPS) from 2005 or later. If a STEPS dataset was not available for a LMIC (or we could not gain access to it), we conducted a systematic search for survey datasets; the inclusion criteria in these searches were that the survey was done in 2005 or later, was nationally representative for at least three 10-year age groups older than 15 years, included measured blood pressure data, and contained data on at least two hypertension care cascade steps. Hypertension was defined as a systolic blood pressure of at least 140 mm Hg, diastolic blood pressure of at least 90 mm Hg, or reported use of medication for hypertension. Among those with hypertension, we calculated the proportion of individuals who had ever had their blood pressure measured; had been diagnosed with hypertension; had been treated for hypertension; and had achieved control of their hypertension. We weighted countries proportionally to their population size when determining this hypertension care cascade at the global and regional level. We disaggregated the hypertension care cascade by age, sex, education, household wealth quintile, body-mass index, smoking status, country, and region. We used linear regression to predict, separately for each cascade step, a country's performance based on gross domestic product (GDP) per capita, allowing us to identify countries whose performance fell outside of the 95% prediction interval. Our pooled dataset included 1 100 507 participants, of whom 192 441 (17·5%) had hypertension. Among those with hypertension, 73·6% of participants (95% CI 72·9-74·3) had ever had their blood pressure measured, 39·2% of participants (38·2-40·3) had been diagnosed with hypertension, 29·9% of participants (28·6-31·3) received treatment, and 10·3% of participants (9·6-11·0) achieved control of their hypertension. Countries in Latin America and the Caribbean generally achieved the best performance relative to their predicted performance based on GDP per capita, whereas countries in sub-Saharan Africa performed worst. Bangladesh, Brazil, Costa Rica, Ecuador, Kyrgyzstan, and Peru performed significantly better on all care cascade steps than predicted based on GDP per capita. Being a woman, older, more educated, wealthier, and not being a current smoker were all positively associated with attaining each of the four steps of the care cascade. Our study provides important evidence for the design and targeting of health policies and service interventions for hypertension in LMICs. We show at what steps and for whom there are gaps in the hypertension care process in each of the 44 countries in our study. We also identified countries in each world region that perform better than expected from their economic development, which can direct policy makers to important policy lessons. Given the high disease burden caused by hypertension in LMICs, nationally representative hypertension care cascades, as constructed in this study, are an important measure of progress towards achieving universal health coverage. Harvard McLennan Family Fund, Alexander von Humboldt Foundation