1,074 research outputs found

    SIGN-R1 Contributes to Protection against Lethal Pneumococcal Infection in Mice

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    Rapid clearance of pathogens is essential for successful control of pyogenic bacterial infection. Previous experiments have shown that antibody to specific intracellular adhesion molecule-grabbing nonintegrin (SIGN)-R1 inhibits uptake of capsular polysaccharide by marginal zone macrophages, suggesting a role for SIGN-R1 in this process. We now demonstrate that mice lacking SIGN-R1 (a mouse homologue of human dendritic cell–SIGN receptor) are significantly more susceptible to Streptococcus pneumoniae infection and fail to clear S. pneumoniae from the circulation. Marginal zone and peritoneal macrophages show impaired bacterial recognition associated with an inability to bind T-independent type 2 antigens such as dextran. Our work represents the first evidence for a protective in vivo role for a SIGN family molecule

    Morphological Enumeration of Resting Spores in Sporosori of the Plant Pathogen Spongospora subterranean

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    Plasmodiophorid sporosori (aggregations of resting spores) reach their most complex form in Spongospora subterranea f. sp. subterranea, the biotrophic plant pathogen which causes the economically important disease powdery scab of potato (Solanum tuberosum). Resting spores are the perennation life cycle stage of plasmodiophorids, allowing them to survive for long periods and infect subsequent host generations. Light microscopy was used to measure resting spores and sporosori of Sp. subterranea, and enumerate resting spores in individual sporosori. Mean resting spore diameters differed for two sporosorus collections, being 4.0 μm (from New Zealand) and 4.3 μm (from Switzerland). Counts of resting spores in 4 μm thick serial sections of sporosori from one collection gave a mean of 667 (range 155 to 1,526) resting spores per sporosorus. Number of resting spores per sporosorus was closely related to sporosorus volume, and could be accurately estimated using the formula; number of resting spores = 0.0081 × sporosorus volume (assuming sporosori to be spheroids). Using this formula, mean numbers of resting spores in sporosori from 37 Sp. subterranea collections from field-grown potato tubers from 13 countries were determined to range from 199 to 713. Differences in numbers of resting spores between the collections were statistically significant (P < 0.05), and independent of country or host cultivar of origin, indicating that enumeration should be carried out for individual sporosorus collections to accurately quantify inoculum. Morphology, using scanning electron microscopy, also showed that between 2 and 51% (average 20%) of resting spores released zoospores after exposure to roots of host plants. The formula for resting spore enumeration validated in this study can be used to standardise Sp. subterranea resting spore inoculum for plant pathology studies, and possibly to assist determination of soil inoculum potential for disease risk evaluations

    Identification of an interleukin (IL)-25–dependent cell population that provides IL-4, IL-5, and IL-13 at the onset of helminth expulsion

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    Type 2 immunity, which involves coordinated regulation of innate and adaptive immune responses, can protect against helminth parasite infection, but may lead to allergy and asthma after inappropriate activation. We demonstrate that il25−/− mice display inefficient Nippostrongylus brasiliensis expulsion and delayed cytokine production by T helper 2 cells. We further establish a key role for interleukin (IL)-25 in regulating a novel population of IL-4–, IL-5–, IL-13–producing non–B/non–T (NBNT), c-kit+, FcɛR1− cells during helminth infection. A deficit in this population in il25−/− mice correlates with inefficient N. brasiliensis expulsion. In contrast, administration of recombinant IL-25 in vivo induces the appearance of NBNT, c-kit+, FcɛR1− cells and leads to rapid worm expulsion that is T and B cell independent, but type 2 cytokine dependent. We demonstrate that these IL-25–regulated cells appear rapidly in the draining lymph nodes, implicating them as a source of type 2 cytokines during initiation of worm expulsion

    The Value of In Vivo Reflectance Confocal Microscopy as an Assessment Tool in Chemotherapy-Induced Peripheral Neuropathy:A Pilot Study

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    Chemotherapy-induced peripheral neuropathy (CIPN) is a common dose-limiting toxicity with significant sequelae. There is a lack of standardized objective and reliable assessment tools in CIPN. In vivo reflectance confocal microscopy (RCM) imaging offers a non-invasive method to identify peripheral neuropathy markers, namely Meissner's corpuscles. This article reports on the feasibility and value of RCM in CIPN.Background There is a lack of standardized objective and reliable assessment tools for chemotherapy-induced peripheral neuropathy (CIPN). In vivo reflectance confocal microscopy (RCM) imaging offers a non-invasive method to identify peripheral neuropathy markers, namely Meissner's corpuscles (MC). This study investigated the feasibility and value of RCM in CIPN. Patients and Methods Reflectance confocal microscopy was performed on the fingertip to evaluate MC density in 45 healthy controls and 9 patients with cancer (prior, during, and post-chemotherapy). Quantification was completed by 2 reviewers (one blinded), with maximum MC count/3 x 3 mm image reported. Quantitative Sensory Testing (QST; thermal and mechanical detection thresholds), Grooved pegboard test, and patient-reported outcomes measures (PROMS) were conducted for comparison. Results In controls (25 females, 20 males; 24-81 years), females exhibited greater mean MC density compared with males (49.9 +/- 7.1 vs 30.9 +/- 4.2 MC/3 x 3 mm; P = .03). Differences existed across age by decade (P < .0001). Meissner's corpuscle density was correlated with mechanical detection (rho = -0.51), warm detection (rho = -0.47), cold pain (rho = 0.49) thresholds (P < .01); and completion time on the Grooved pegboard test in both hands (P <= .02). At baseline, patients had reduced MC density vs age and gender-matched controls (P = .03). Longitudinal assessment of MC density revealed significant relationships with QST and PROMS. Inter-rater reliability of MC count showed an intraclass correlation of 0.96 (P < .0001). Conclusions The findings support the clinical utility of RCM in CIPN as it provides meaningful markers of sensory nerve dysfunction. Novel, prospective assessment demonstrated the ability to detect subclinical deficits in patients at risk of CIPN and potential to monitor neuropathy progression

    Adapting without retreating : responses to shoreline change on an inlet-associated coastal beach

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    Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Coastal Management 45 (2017): 360-383, doi:10.1080/08920753.2017.1345607.Coastal barrier systems around the world are experiencing higher rates of flooding and shoreline erosion. Property owners on barriers have made significant financial investments in physical protections that shield their nearby properties from these hazards, constituting a type of adaptation to shoreline change. Factors that contribute to adaptation on Plum Island, a developed beach and dune system on the North Shore of Massachusetts, are investigated here. Plum Island experiences patterns of shoreline change that may be representative of many inlet-associated beaches, encompassing an equivocal and dynamically shifting mix of erosion and accretion. In the face of episodic floods and fleeting erosive events, and driven by a combination of strong northeast storms and cycles of erosion and accretion, the value of the average Plum Island residence increases by 34% for properties on the oceanfront where protection comprises a publicly constructed soft structure. Even in the face of state policies that ostensibly discourage physical protection as a means of adaptation, coastal communities face significant political and financial pressures to maintain existing protective structures or to allow contiguous groups of property owners to build new ones through collective action. These factors mitigate against adapting to shoreline change by retreating from the coast, thereby potentially increasing the adverse effects of coastal hazards.Support for this study was provided by NSF Grant Nos. OCE 1325430 and AGS 1518503 and NOAA Cooperative Agreement No. NA14OAR4170074

    Associations between subspecialty fellowship interest and knowledge of internal medicine: A hypothesis-generating study of internal medicine residents

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    <p>Abstract</p> <p>Background</p> <p>Little is known about whether and how medical knowledge relates to interest in subspecialty fellowship training. The purpose of this study was to examine the relationships between residents' interest in subspecialty fellowship training and their knowledge of internal medicine (IM).</p> <p>Methods</p> <p>A questionnaire was emailed to 48 categorical postgraduate-year (PGY) two and three residents at a New York university-affiliated IM residency program in 2007 using the Survey Monkey online survey instrument. Overall and content area-specific percentile scores from the IM in-training examination (IM-ITE) for the same year was used to determine objective knowledge.</p> <p>Results</p> <p>Forty-five of 48 residents (response rate was 93.8%) completed the survey. Twenty-two (49%) were PG2 residents and 23(51%) were PGY3 residents. Sixty percent of respondents were male. Six (13%) residents were graduates of U.S. medical schools. Eight (18%) reported formal clinical training prior to starting internal medicine residency in the U.S. Of this latter group, 6 (75%) had training in IM and 6 (75) % reported a training length of 3 years or less. Thirty-seven of 45 (82%) residents had a subspecialty fellowship interest. Residents with a fellowship interest had a greater mean overall objective knowledge percentile score (56.44 vs. 31.67; p = 0.04) as well as greater mean percentile scores in all content areas of IM. The adjusted mean difference was statistically significant (p < 0.02) across three content areas.</p> <p>Conclusions</p> <p>More than half of surveyed residents indicated interest in pursuing a subspecialty fellowship. Fellowship interest appears positively associated with general medical knowledge in this study population. Further work is needed to explore motivation and study patterns among internal medicine residents.</p

    Toll-like Receptor 3 L412F Polymorphism Promotes a Persistent Clinical Phenotype in Pulmonary Sarcoidosis

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    Background: Sarcoidosis is a multisystemic disorder of unknown etiology, characterised by the presence of non-caseating granulomas in target organs. In ninety percent of cases, there is thoracic involvement. Fifty to seventy percent of pulmonary sarcoidosis patients will experience acute, self-limiting disease. For the subgroup of patients who develop persistent disease, no targeted therapy is currently available. Aim: To investigate the potential of the single nucleotide polymorphism (SNP), Toll-like receptor 3 Leu412Phe (TLR3 L412F; rs3775291), as a causative factor in the development of, and in disease persistence in pulmonary sarcoidosis. To investigate the functionality of TLR3 L412F in vitro in primary human lung fibroblasts from pulmonary sarcoidosis patients. Methods: Cohorts of Irish sarcoidosis patients (n=228), healthy Irish controls (n = 263) and a secondary cohort of American sarcoidosis patients (n=123) were genotyped for TLR3 L412F. Additionally, the effect of TLR3 L412F in primary lung fibroblasts from pulmonary sarcoidosis patients was quantitated following TLR3 activation in the context of cytokine and type I interferon production, TLR3 expression, and apoptotic- and fibroproliferative-responses. Results: We report a significant association between TLR3 L412F and persistent clinical disease in two cohorts of Irish and American Caucasians with pulmonary sarcoidosis. Furthermore, activation of TLR3 in primary lung fibroblasts from 412F-homozygous pulmonary sarcoidosis patients resulted in reduced IFN-â and TLR3 expression, reduced apoptosis- and dysregulated fibroproliferative-responses compared with TLR3 wild-type patients. Conclusions: This study identifies defective TLR3 function as a previously unidentified factor in persistent clinical disease in pulmonary sarcoidosis and reveals TLR3 L412F as a candidate biomarker
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