6,200 research outputs found

    Experimental manipulation of immune-mediated disease and its fitness costs for rodent malaria parasites

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    <p>Abstract</p> <p>Background</p> <p>Explaining parasite virulence (harm to the host) represents a major challenge for evolutionary and biomedical scientists alike. Most theoretical models of virulence evolution assume that virulence arises as a direct consequence of host exploitation, the process whereby parasites convert host resources into transmission opportunities. However, infection-induced disease can be immune-mediated (immunopathology). Little is known about how immunopathology affects parasite fitness, or how it will affect the evolution of parasite virulence. Here we studied the effects of immunopathology on infection-induced host mortality rate and lifetime transmission potential – key components of parasite fitness – using the rodent malaria model, <it>Plasmodium chabaudi chabaudi</it>.</p> <p>Results</p> <p>Neutralizing interleukin [IL]-10, an important regulator of inflammation, allowed us to experimentally increase the proportion of virulence due to immunopathology for eight parasite clones. <it>In vivo </it>blockade of the IL-10 receptor (IL-10R) with a neutralizing antibody resulted in a shorter time to death that was independent of parasite density and was particularly marked for normally avirulent clones. This suggests that IL-10 induction may provide a pathway to avirulence for <it>P. c. chabaudi</it>. Despite the increased investment in transmission-stage parasites observed for some clones in response to IL-10R blockade, experimental enhancement of immunopathology incurred a uniform fitness cost to all parasite clones by reducing lifetime transmission potential.</p> <p>Conclusion</p> <p>This is the first experimental study to demonstrate that infection-induced immunopathology and parasite genetic variability may together have the potential to shape virulence evolution. In accord with recent theory, the data show that some forms of immunopathology may select for parasites that make hosts less sick.</p

    Characteristics of ambulatory anticoagulant adverse drug events: a descriptive study

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    <p>Abstract</p> <p>Background</p> <p>Despite the high frequency with which adverse drug events (ADEs) occur in outpatient settings, detailed information regarding these events remains limited. Anticoagulant drugs are associated with increased safety concerns and are commonly involved in outpatient ADEs. We therefore sought to evaluate ambulatory anticoagulation ADEs and the patient population in which they occurred within the Duke University Health System (Durham, NC, USA).</p> <p>Methods</p> <p>A retrospective chart review of ambulatory warfarin-related ADEs was conducted. An automated trigger surveillance system identified eligible events in ambulatory patients admitted with an International Normalized Ratio (INR) >3 and administration of vitamin K. Event and patient characteristics were evaluated, and quality/process improvement strategies for ambulatory anticoagulation management are described.</p> <p>Results</p> <p>A total of 169 events in 167 patients were identified from December 1, 2006-June 30, 2008 and included in the study. A median supratherapeutic INR of 6.1 was noted, and roughly half of all events (52.1%) were associated with a bleed. Nearly 74% of events resulted in a need for fresh frozen plasma; 64.8% of bleeds were classified as major. A total of 59.2% of events were at least partially responsible for hospital admission. Median patient age was 68 y (range 36-95 y) with 24.9% initiating therapy within 3 months prior to the event. Of events with a prior documented patient visit (n = 157), 73.2% were seen at a Duke clinic or hospital within the previous month. Almost 80% of these patients had anticoagulation therapy addressed, but only 60.0% had a follow-up plan documented in the electronic note.</p> <p>Conclusions</p> <p>Ambulatory warfarin-related ADEs have significant patient and healthcare utilization consequences in the form of bleeding events and associated hospital admissions. Recommendations for improvement in anticoagulation management include use of information technology to assist monitoring and follow-up documentation, avoid drug interactions, and engage patients in their care.</p

    The Effect of Enriched Environment on the Outcome of Traumatic Brain Injury; A Behavioral, Proteomics, and Histological Study

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    De novo hippocampal neurogenesis contributes to functional recovery following traumatic brain injury (TBI). Enriched environment (EEN) can improve the outcome of TBI by positively affecting neurogenesis. Blast induced traumatic brain injury (bTBI) characterized by memory impairment and increased anxiety levels, is a leading cause of chronic disability among soldiers. Using a rodent model of bTBI we asked: (a) whether long-term exposure to EEN after injury can ameliorate behavioral abnormalities and (b) what the effects of EEN are at the molecular and cellular levels and on de novo neurogenesis. We found that housing injured animals in EEN resulted in significantly improved spatial memory while animals in normal housing (NH) showed persistent memory impairment. VEGF and Tau protein but not Interleukin-6 (IL-6) levels were normalized in the dorsal hippocampus (DHC) of EEN rats while all three markers remained elevated in NH rats. Interestingly, after peaking at 6 weeks post-injury, anxiety returned to normal levels at 2 months independent of housing conditions. Housing animals in EEN had no significant effect on VEGF and Tau protein levels in the ventral hippocampus (VHC) and the amygdala (AD). We also found that EEN reduced IL-6 and IFNγ levels in the VHC; these markers remained elevated following NH. We observed an increase in GFAP and DCX immunoreactivities in the VHC of NH animals at 2 months post-injury. Conversely, injured animals housed in EEN showed no increase in GFAP or DCX immunoreactivity in their VHC. In summary, long-term exposure of injured animals to EEN appears to play a positive role in the restoration of memory functions but not on anxiety, which returned to normal levels after a significant period of time. Cellular and molecular changes in response to EEN appear to be a part of neurogenesis-independent as well as dependent recovery processes triggered by bTBI

    Implementing a Registry Federation for Materials Science Data Discovery

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    As a result of a number of national initiatives, we are seeing rapid growth in the data important to materials science that are available over the web. Consequently, it is becoming increasingly difficult for researchers to learn what data are available and how to access them. To address this problem, the Research Data Alliance (RDA) Working Group for International Materials Science Registries (IMRR) was established to bring together materials science and information technology experts to develop an international federation of registries that can be used for global discovery of data resources for materials science. A resource registry collects high-level metadata descriptions of resources such as data repositories, archives, websites, and services that are useful for data-driven research. By making the collection searchable, it aids scientists in industry, universities, and government laboratories to discover data relevant to their research and work interests. We present the results of our successful piloting of a registry federation for materials science data discovery. In particular, we out a blueprint for creating such a federation that is capable of amassing a global view of all available materials science data, and we enumerate the requirements for the standards that make the registries interoperable within the federation. These standards include a protocol for exchanging resource descriptions and a standard metadata schema for encoding those descriptions. We summarize how we leveraged an existing standard (OAI-PMH) for metadata exchange. Finally, we review the registry software developed to realize the federation and describe the user experience

    Improved results of induction chemoradiation before surgical intervention for selected patients with stage IIIA-N2 non–small cell lung cancer

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    ObjectiveOptimal management of stage IIIA-N2 non–small cell lung cancer remains controversial. The surgical arm of the North American Intergroup 0139 trial was adopted as the standard treatment for patients with resectable N2 disease at the University Health Network. Results after 7 years of experience are reported.MethodsThis is a retrospective study of consecutive patients with biopsy-proved T1-3 N2 M0 lung cancer who underwent induction chemoradiation before surgical intervention from January 1997 through August 2004. Induction chemotherapy consisted of cisplatin, 50 mg/m2, on days 1 and 8; etoposide, 50 mg/m2, on days 1 to 5, weeks 1 and 5; and concurrent daily external beam radiotherapy to 45 Gy. Lung resection was performed within 6 weeks of completion of chemoradiation, followed by 2 further cycles of consolidation chemotherapy.ResultsBetween January 1997 and August 2004, 40 patients were treated according to this protocol (25% T1, 62.5% T2, 7.5% T3, and 5% T4). Overall and disease-free median survivals were 40 and 37.1 months, respectively, whereas overall and disease-free 3-year survivals were 51.7% and 52.3%, respectively. R0 resection was achieved in 92.5%. The overall operative mortality rate was 7.5% (0% for lobectomy and 27% for pneumonectomy). Notably, all mortalities occurred within the first 2 years of our experience with this regimen.ConclusionChemoradiation before pulmonary resection in carefully selected patients with surgically resectable stage IIIA (N2) non–small cell lung cancer can lead to improved overall and disease-free survival

    The challenges of detecting and attributing ocean acidification impacts on marine ecosystems

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Doo, S. S., Kealoha, A., Andersson, A., Cohen, A. L., Hicks, T. L., Johnson, Z., I., Long, M. H., McElhany, P., Mollica, N., Shamberger, K. E. F., Silbiger, N. J., Takeshita, Y., & Busch, D. S. The challenges of detecting and attributing ocean acidification impacts on marine ecosystems. ICES Journal of Marine Science, 77(7-8), (2020): 2411-2422, https://doi.org/10.1093/icesjms/fsaa094.A substantial body of research now exists demonstrating sensitivities of marine organisms to ocean acidification (OA) in laboratory settings. However, corresponding in situ observations of marine species or ecosystem changes that can be unequivocally attributed to anthropogenic OA are limited. Challenges remain in detecting and attributing OA effects in nature, in part because multiple environmental changes are co-occurring with OA, all of which have the potential to influence marine ecosystem responses. Furthermore, the change in ocean pH since the industrial revolution is small relative to the natural variability within many systems, making it difficult to detect, and in some cases, has yet to cross physiological thresholds. The small number of studies that clearly document OA impacts in nature cannot be interpreted as a lack of larger-scale attributable impacts at the present time or in the future but highlights the need for innovative research approaches and analyses. We summarize the general findings in four relatively well-studied marine groups (seagrasses, pteropods, oysters, and coral reefs) and integrate overarching themes to highlight the challenges involved in detecting and attributing the effects of OA in natural environments. We then discuss four potential strategies to better evaluate and attribute OA impacts on species and ecosystems. First, we highlight the need for work quantifying the anthropogenic input of CO2 in coastal and open-ocean waters to understand how this increase in CO2 interacts with other physical and chemical factors to drive organismal conditions. Second, understanding OA-induced changes in population-level demography, potentially increased sensitivities in certain life stages, and how these effects scale to ecosystem-level processes (e.g. community metabolism) will improve our ability to attribute impacts to OA among co-varying parameters. Third, there is a great need to understand the potential modulation of OA impacts through the interplay of ecology and evolution (eco–evo dynamics). Lastly, further research efforts designed to detect, quantify, and project the effects of OA on marine organisms and ecosystems utilizing a comparative approach with long-term data sets will also provide critical information for informing the management of marine ecosystems.SSD was funded by NSF OCE (grant # 1415268). DSB and PM were supported by the NOAA Ocean Acidification Program and Northwest Fisheries Science Center, MHL was supported by NSF OCE (grant # 1633951), ZIJ was supported by NSF OCE (grant # 1416665) and DOE EERE (grant #DE-EE008518), NJS was supported by NSF OCE (grant # 1924281), ALC was supported by NSF OCE (grant # 1737311), and AA was supported by NSF OCE (grant # 1416518). KEFS, AK, and TLH were supported by Texas A&M University. This is CSUN Marine Biology contribution (# 306)
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