Understanding the role of B cells during Leishmania amazonensis infection

Leishmaniasis is a vector-borne zoonotic disease caused by obligate intracellular protozoan parasites of the genus Leishmania. Infection of C3HeB/FeJ and C57BL/6 mice with Leishmania major stimulates a healing cell-mediated immune response, while Leishmania amazonensis infection leads to chronic disease. Here we show C3HeB/FeJ mice co-infected with both species of Leishmania heal, while co-infected C57BL/6 mice do not. Using an in vitro killing assay we determined B cells from infected C57BL/6 mice are ineffective in promoting parasite killing compared to B cells from infected C3HeB/FeJ mice. Furthermore, infected C57BL/6 mice produce less antigen-specific antibodies as compared to infected C3HeB/FeJ mice. The mechanism behind the inability of C57Bl/6 mice to heal L. amazonensis is not known. Here we describe for the first time a difference in the draining lymph node germinal center B cell response between co-infected C3H and B6 mice. There are more germinal center B cells, more antibody isotype-switched germinal center B cells, more memory B cells and more antigen-specific antibody-producing cells in co-infected C3H mice compared to B6 mice as early as 2 weeks post-infection. We also show that IL-21 production in both mouse strains is similar at 2 weeks, suggesting the difference in these mouse strains is due to intrinsic B cell differences, rather than a difference in IL-21 production within germinal centers. Mice infected with L. amazonensis have a non-polarized T helper cell response and non-healing, chronic lesions. In vitro, a productive response to this pathogen has been recapitulated through macrophage production of both nitric oxide and superoxide. We show FcγR and cytochrome b558 are necessary for superoxide production during an established infection. We demonstrate NADPH oxidase assembly of gp91phox and p67phox occurs by day 1 during the in vitro infection and is localized directly adjacent to the parasite. However, measurable superoxide production was only detectable at day 5 in vitro, indicating that assembly of these subunits was not sufficient to trigger superoxide production. Using wortmannin inhibition of PI3K, we show inhibition of superoxide production at day 5 and indicating that PI3K is critical for superoxide production at this late stage of infection. These data establish that the FcγR-NADPH oxidase activation pathway is required to kill intracellular L. amazonensis. We propose that this novel pathway requires L. major antigen-specific B cell production of antibodies which bind stimulatory Fcγ receptors to produce superoxide through PI3K-mediated activation of assembled NADPH oxidase complexes that are associated with intracellular amastigote parasites. Understanding the role of this pathway in controlling non-healing cutaneous leishmaniasis caused by L. amazonensis may be critical in determining specific immunomodulation to successfully treat this disease

Metallothionein’s role in PCB126 induced hepatotoxicity and hepatic micronutrient disruption

AbstractPolychlorinated biphenyls (PCBs), industrial chemicals and persistent environmental pollutants, are found in rural and urban settings. Rodent studies have shown that exposure to PCB126, a dioxin-like PCB, causes a significant disruption of hepatic micronutrient homeostasis and an increase in metallothionein (MT), an antioxidant protein and metal carrier. A MT knockout mouse strain was used to assess metallothionein’s role in micronutrient disruption and overall hepatotoxicity. Twenty four 129S male mice (12 wild type (WT) and 12 MT knockout (MTKO)) were placed on a purified diet (AIN-93G) for 3 weeks to achieve hepatic metal equilibrium. Mice were then given a single IP injection of either vehicle or 150μmol/kg PCB126 in vehicle. The animals were sacrificed 2 weeks later and organs processed for analysis. Liver histology, hepatic lipids, gene expression, micronutrient and ROS status were investigated. Liver weights, liver lipids, ROS, and hepatocyte vacuolation were increased with PCB126 exposure along with AhR responsive genes. The MTKO animals had more severe histological changes in the liver and elevated liver lipids than their wild type counterparts. Hepatic and renal metals levels (Cu, Zn, Se and Mn) were mostly reduced by PCB126 treatment. Renal micronutrients were more affected by PCB126 treatment in the MTKO animals. This research suggests that MT may not be the sole/primary cause of the metal disruption caused by PCB126 exposure in mice, but may provide protection against overall hepatotoxicity

Disseminated \u3ci\u3eLeishmania infantum\u3c/i\u3e infection in two sibling foxhounds due to possible vertical transmission

Two sibling foxhounds born to a Leishmania seropositive bitch were presented after testing seropositive for Leishmania. Leishmania infantum infection was detected via histopathology, culture, and quantitative polymerase chain reaction (q-PCR). This is the first report of natural infection with Leishmania infantum with the possibility for vertical transmission in North America. Infection disséminée à Leishmania infantum chez deux chiots Fox hound d’une même portée reliée possiblement à une transmission verticale. Deux chiots Fox hound d’une même portée nés d’une mère séropositive à Leishmania ont été présentés après un contrôle sérologique positif. Une infection à Leishmania infantum a été détectée par histopathologie, culture et amplification en chaîne par polymérase quantitative (ACP-q). Il s’agit du premier rapport d’infection naturelle par Leishmania infantum possiblement relié à une transmission verticale en Amérique du Nord

The epigenetic clock is correlated with physical and cognitive fitness in the Lothian Birth Cohort 1936

Background: The DNA methylation-based 'epigenetic clock' correlates strongly with chronological age, but it is currently unclear what drives individual differences. We examine cross-sectional and longitudinal associations between the epigenetic clock and four mortality-linked markers of physical and mental fitness: lung function, walking speed, grip strength and cognitive ability. Methods: DNA methylation-based age acceleration (residuals of the epigenetic clock estimate regressed on chronological age) were estimated in the Lothian Birth Cohort 1936 at ages 70 (n=920), 73 (n=299) and 76 (n=273) years. General cognitive ability, walking speed, lung function and grip strength were measured concurrently. Cross-sectional correlations between age acceleration and the fitness variables were calculated. Longitudinal change in the epigenetic clock estimates and the fitness variables were assessed via linear mixed models and latent growth curves. Epigenetic age acceleration at age 70 was used as a predictor of longitudinal change in fitness. Epigenome-wide association studies (EWASs) were conducted on the four fitness measures. Results: Cross-sectional correlations were significant between greater age acceleration and poorer performance on the lung function, cognition and grip strength measures (r range: -0.07 to -0.05, P range: 9.7 x 10 to 0.024). All of the fitness variables declined over time but age acceleration did not correlate with subsequent change over 6 years. There were no EWAS hits for the fitness traits. Conclusions: Markers of physical and mental fitness are associated with the epigenetic clock (lower abilities associated with age acceleration). However, age acceleration does not associate with decline in these measures, at least over a relatively short follow-up

Observational Study Design in Veterinary Pathology, Part 1: Study Design

Observational studies are the basis for much of our knowledge of veterinary pathology and are highly relevant to the daily practice of pathology. However, recommendations for conducting pathology-based observational studies are not readily available. In part 1 of this series, we offer advice on planning and conducting an observational study with examples from the veterinary pathology literature. Investigators should recognize the importance of creativity, insight, and innovation in devising studies that solve problems and fill important gaps in knowledge. Studies should focus on specific and testable hypotheses, questions, or objectives. The methodology is developed to support these goals. We consider the merits and limitations of different types of analytic and descriptive studies, as well as of prospective vs retrospective enrollment. Investigators should define clear inclusion and exclusion criteria and select adequate numbers of study subjects, including careful selection of the most appropriate controls. Studies of causality must consider the temporal relationships between variables and the advantages of measuring incident cases rather than prevalent cases. Investigators must consider unique aspects of studies based on archived laboratory case material and take particular care to consider and mitigate the potential for selection bias and information bias. We close by discussing approaches to adding value and impact to observational studies. Part 2 of the series focuses on methodology and validation of methods

Retaining biodiversity in intensive farmland: epiphyte removal in oil palm plantations does not affect yield.

The expansion of agriculture into tropical forest frontiers is one of the primary drivers of the global extinction crisis, resulting in calls to intensify tropical agriculture to reduce demand for more forest land and thus spare land for nature. Intensification is likely to reduce habitat complexity, with profound consequences for biodiversity within agricultural landscapes. Understanding which features of habitat complexity are essential for maintaining biodiversity and associated ecosystem services within agricultural landscapes without compromising productivity is therefore key to limiting the environmental damage associated with producing food intensively. Here, we focus on oil palm, a rapidly expanding crop in the tropics and subject to frequent calls for increased intensification. One promoted strategy is to remove epiphytes that cover the trunks of oil palms, and we ask whether this treatment affects either biodiversity or yield. We experimentally tested this by removing epiphytes from four-hectare plots and seeing if the biodiversity and production of fruit bunches 2 months and 16 months later differed from equivalent control plots where epiphytes were left uncut. We found a species-rich and taxonomically diverse epiphyte community of 58 species from 31 families. Epiphyte removal did not affect the production of fresh fruit bunches, or the species richness and community composition of birds and ants, although the impact on other components of biodiversity remains unknown. We conclude that as they do not adversely affect palm oil production, the diverse epiphyte flora should be left uncut. Our results underscore the importance of experimentally determining the effects of habitat complexity on yield before introducing intensive methods with no discernible benefits.We would like to thank our local collaborator Chey Vun Khen for support and advice; Mike Bernadus and Markus Gubilil for help identifying angiosperms and ferns respectively; Anthony Karolus, Imogen Ogilvie, Ahmad Amat, Deddier Deddy, Sam Fabian, Sophus Zu Ermgassen, Gabriella Prescott, and several oil palm harvesters for research assistance; Hereward Corley, Bernard Tinker, Tom Fayle, Rhys Green, Andrea Manica, Andreas Knoell, Christopher Stewart, for advice; Claudia Gray, Michael Senior, Tara Thean, David Williams, Edgar Turner, and two anonymous reviewers for comments on the manuscript; the managers of the oil palm estates we worked at, Danumpalm Sdn. Bhd., Wilmar Int. Ltd., Sabah Softwoods Bhd., Economic Planning Unit of Malaysia, Sabah Biodiversity Centre, Yayasan Sabah, SEARRP, DVMC, and Glen Reynolds for permissions and logistical help. This work was done as part of SEARRP project RS309, with permission from the Sabah Biodiversity Centre (reference HJM/MBS.1000-2/2(60)). GWP was supported by a NERC studentship and by a CASE partner (ProForest).This is the final published version. It first appeared from Wiley via http://onlinelibrary.wiley.com/doi/10.1002/ece3.1462/full

A preliminary analysis of interleukin-1 ligands as potential predictive biomarkers of response to cetuximab

The epidermal growth factor receptor (EGFR) monoclonal IgG1 antibody cetuximab is approved for first-line treatment of recurrent and metastatic (R/M) HNSCC as a part of the standard of care EXTREME regimen (platinum/5-fluorouracil/cetuximab). This regimen has relatively high response and disease control rates but is generally not curative and many patients will experience recurrent disease and/or metastasis. Therefore, there is a great need to identify predictive biomarkers for recurrence and disease progression in cetuximab-treated HNSCC patients to facilitate patient management and allow for treatment modification. The goal of this work is to assess the potential of activating interleukin-1 (IL-1) ligands (IL-1 alpha [IL-1α], IL-1 beta [IL-1β]) as predictive biomarkers of survival outcomes in HNSCC patients treated with cetuximab-based chemotherapy.2016 AACR-Bayer Innovation and Discovery Grant [16-80-44-SIMO]; National Institutes of Health (NIH) [R01DE024550, F99CA223062, R01 CA177669, P30 CA006973, P50 DE019032, T32 AI007511]; University of Iowa Department of Pathology Research Grant; University of Iowa Head and Neck Cancer Symposium Seed Grant; Johns Hopkins University Catalyst AwardOpen access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Development and validation of a questionnaire to measure moral distress in community pharmacists

The Author(s) 2016. . This article is published with open access at Springerlink.com This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Jayne L. Astbury, and Cathal T. Gallagher, 'Development and validation of a questionnaire to measure moral distress in community pharmacists', International Journal of Clinical Pharmacy (2017) Vol 39(1): 156-164, first published online on 22 December 2016, the version of record is available on line via doi: 10.1007/s11096-016-0413-3 Funding for this work was provided by Pharmacy Research UK (PRUK).Background Pharmacists work within a highly-regulated occupational sphere, and are bound by strict legal frameworks and codes of professional conduct. This regulatory environment creates the potential for moral distress to occur due to the limitations it places on acting in congruence with moral judgements. Very little research regarding this phenomenon has been undertaken in pharmacy: thus, prominent research gaps have arisen for the development of a robust tool to measure and quantify moral distress experienced in the profession. Objective The aim of this study was to develop an instrument to measure moral distress in community pharmacists. Setting Community pharmacies in the United Kingdom. Method This study adopted a three-phase exploratory sequential mixed-method design. Three semi-structured focus groups were then conducted to allow pharmacists to identify and explore scenarios that cause moral distress. Each of the identified scenarios were developed into a statement, which was paired with twin seven-point Likert scales to measure the frequency and intensity of the distress, respectively. Content validity, reliability, and construct validity were all tested, and the questionnaire was refined. Main outcome measure The successful development of the valid instrument for use in the United Kingdom. Results This research has led to the development of a valid and reliable instrument to measure moral distress in community pharmacists in the UK. The questionnaire has already been distributed to a large sample of community pharmacists. Conclusion Results from this distribution will be used to inform the formulation of coping strategies for dealing with moral distress.Peer reviewedFinal Published versio

When decision support systems fail: insights for strategic information systems from Formula

Decision support systems (DSS) are sophisticated tools that increasingly take advantage of big data and are used to design and implement individual - and organization - level strategic decisions . Yet, when organizations excessively rely on their potential the outcome may be decision - making failure, particularly when such tools are applied under high pressure and turbulent conditions. Partial understanding and unidimensional interpretation can prevent learning from failure. Building on a practice perspective, we study an iconic case of strategic failure in Formula 1 racing. Our approach, which integrates the decision maker as well as the organizational and material context , identifies three interrelated sources of strategic failure that are worth investigation for decision - makers using DSS and big data: (1) t he situated nature and affordances of decision - making ; (2) t he distributed nature of cognition in decision - making; and (3) the performativity of the DSS. We outline specific research questions and their implications for firm performance and competitive advantage. Finally, we advance an agenda that can help close timely gaps in strategic IS research