99 research outputs found

    Expression of both N- and C-terminal GFP tagged huCD36 and their discrepancy in OxLDL and pRBC binding on CHO cells

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    CD36, an 88 kDa membrane glycoprotein, is found in several cell types and it has been characterized to have two hydrophobic domains at their N- and C-termini which are essential for protein folding and targeting. In this study, we first tagged the green fluorescent protein (GFP) to both the N- and C-termini of huCD36 and investigated their cellular expression and influences on lipoprotein and plasmodium falciparium parasitized erythrocytes (pRBC) binding. Our work revealed that huCD36 proteins are expressed normally irrespective of the GFP tag presence at either the N- or C-termini. However, the two recombinant proteins showed discrepancy in uptake and surface-binding of OxLDL but they did not affect pRBC binding. These results suggested that the interaction between oxLDL and CD36 could be blocked using recombinant proteins and this may be useful in potential control of the trafficking of modified lipoproteins into monocytes leading to atherogenesis

    Lipoprotein binding preference of CD36 is altered by filipin treatment

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    The class B scavenger receptor CD36 binds multiple ligands, including oxidized and native lipoprotein species. CD36 and the related receptor SR-B1 have been localized to caveolae, domains that participate in cell signaling, transcytosis, and regulation of cellular cholesterol homeostasis. Previous work has indicated that the ligand preference of CD36 may depend on the cell type in which it is expressed. To determine if the presence or absence of caveolae is the determining factor for lipoprotein preference, we treated CHO-CD36 and C32 cells with filipin. Filipin treatment rapidly increased the binding capacity of CD36 for the native lipoproteins HDL and LDL, but did not affect the binding capacity of CD36 for oxidized LDL. Filipin treatment affected the distribution of caveolin and CD36 suggesting that the presence caveolae may modulate the ligand preference of CD36. However, its molecular mechanism how CD36 and caveolin interaction in regulating lipoprotein transport remains to be further studied

    The Economic Contribution of Snowmobiling in Maine

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    Snowmobiling has been a popular winter pastime in Maine for decades. During the 2018-2019 snowmobiling season, nearly 60,000 snowmobiles were registered in Maine by resident snowmobilers, and over 25,000 snowmobiles were registered by non-residents. Since the 1998 report An Economic Evaluation of Snowmobiling in Maine, overall registrations have increased, and registrations among non-residents have more than doubled. There has been no comprehensive evaluation of snowmobiling in Maine since the 1998 report completed by the University of Maine in collaboration with the Maine Snowmobile Association and State of Maine Snowmobile Program. In order to update the information on snowmobiling related expenditures, the sociodemographic characteristics of snowmobilers in Maine, and the opinions of Maine snowmobilers on snowmobiling tourism infrastructure and issues related to snowmobiling in Maine today, a new study was commissioned by the State of Maine Snowmobile Program and the Maine Department of Agriculture, Conservation and Forestry through the University of Maine’s School of Forest Resources. The results are contained in this report. The results conclude that snowmobiling generated 459millionindirectspendingacrossmanysectorsduringthe2018−2019season.Accountingforindirectandinducedeconomicactivity,thecontributionofsnowmobilingtoMaine’seconomywasover459 million in direct spending across many sectors during the 2018-2019 season. Accounting for indirect and induced economic activity, the contribution of snowmobiling to Maine’s economy was over 606 million. Snowmobiling generates a significant amount of spending during the winter in Maine, especially in the rural areas which benefit from snowmobiling activity. Snowmobile related spending also directly supports 2,279 jobs in the state of Maine and indirect and induced effects of the spending support an additional 1,060 jobs. Trip-related spending accounts for approximately 209.5millionorabout46209.5 million or about 46% of the total direct spending for the 2018-2019 season. Trip-related expenditures include but are not limited to, gas/oil for a snowmobile, gas/oil for a tow vehicle, restaurant purchase, souvenirs, clothing purchased during the trip, and overnight accommodations. The greatest amount of direct spending in a single category was snowmobile purchases, which generated approximately 132 million in direct spendin

    Rocaglates as dual-targeting agents for experimental cerebral malaria

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    Cerebral malaria (CM) is a severe and rapidly progressing complication of infection by Plasmodium parasites that is associated with high rates of mortality and morbidity. Treatment options are currently few, and intervention with artemisinin (Art) has limited efficacy, a problem that is compounded by the emergence of resistance to Art in Plasmodium parasites. Rocaglates are a class of natural products derived from plants of the Aglaia genus that have been shown to interfere with eukaryotic initiation factor 4A (eIF4A), ultimately blocking initiation of protein synthesis. Here, we show that the rocaglate CR-1-31B perturbs association of Plasmodium falciparum eIF4A (PfeIF4A) with RNA. CR-1-31B shows potent prophylactic and therapeutic antiplasmodial activity in vivo in mouse models of infection with Plasmodium berghei (CM) and Plasmodium chabaudi (blood-stage malaria), and can also block replication of different clinical isolates of P. falciparum in human erythrocytes infected ex vivo, including drug-resistant P. falciparum isolates. In vivo, a single dosing of CR-1-31B in P. berghei-infected animals is sufficient to provide protection against lethality. CR-1-31B is shown to dampen expression of the early proinflammatory response in myeloid cells in vitro and dampens the inflammatory response in vivo in P. berghei-infected mice. The dual activity of CR-1-31B as an antiplasmodial and as an inhibitor of the inflammatory response in myeloid cells should prove extremely valuable for therapeutic intervention in human cases of CM.We thank Susan Gauthier, Genevieve Perreault, and Patrick Senechal for technical assistance. This work was supported by a research grant (to P.G.) from the Canadian Institutes of Health Research (CIHR) (Foundation Grant). J.P. and P.G. are supported by a James McGill Professorship salary award. D.L. is supported by fellowships from the Fonds de recherche sante Quebec, the CIHR Neuroinflammation training program. J.P. is supported by CIHR Research Grant FDN-148366. M.S. is supported by a CIHR Foundation grant. J.A.P. is supported by NIH Grant R35 GM118173. Work at the Boston University Center for Molecular Discovery is supported by Grant R24 GM111625. K.C.K. was supported by a CIHR Foundation Grant and the Canada Research Chair program. (Canadian Institutes of Health Research (CIHR); James McGill Professorship salary award; Fonds de recherche sante Quebec; CIHR Neuroinflammation training program; FDN-148366 - CIHR Research Grant; CIHR Foundation grant; R35 GM118173 - NIH; Canada Research Chair program; R24 GM111625

    Optimization and inhibition of the adherent ability of Plasmodium falciparum-infected erythrocytes

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    The vast majority of the 1-2 million malaria associated deaths that occur each year are due to anemia and cerebral malaria (the attachment of erythrocytes containing mature forms of Plasmodium falciparum to the endothelial cells that line the vascular beds of the brain). A "model" system"for the study of cerebral malaria employs amelanotic melanoma cells as the "target"cells in an vitro cytoadherence assay. Using this model system we determined that the optimum pH for adherence is 6.6 to 6.8, that high concentrations of Ca²* (50mM) result in increased levels of binding, and that the type of buffer used influences adherence (Bis Tris > MOPS > HEPES > PIPES). We also observed that the ability of infected erythrocytes to cytoadhere varied from (erythrocyte) donor to donor. We have produced murine monoclonal antibodies against P. falciparum-infected red cells which recognized modified forms of human band 3; these inhibit the adherence of infected erythrocytes to melanoma cells in a doso responsive fashion. Antimalarials (chloroquine, quinacrine, mefloquine, artemisinin), on the other hand, affected adherence in an indirect fashion i.e. since cytoadherence is due, in part to the presence of knobs on the surface of the infected erythrocyte, and knob formation is dependent on intracellular parasite growth, when plasmodial development is inhibited so is knob production, and consequently adherence is ablated

    A Molecular Surveillance System for Global Patterns of Drug Resistance in Imported Malaria

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    Analysis of imported malaria in travelers may represent a novel surveillance system for drug-resistant malaria. We analyzed consecutive falciparum malaria isolates from Canadian travelers from 1994 to 2000, for polymorphisms in pfcrt, dhfr, and dhps linked to chloroquine and pyrimethamine/sulfadoxine resistance. Forty percent of isolates possessed the K76 pfcrt allele, suggesting that many imported falciparum infections are still responsive to chloroquine. Travelers who had recently taken chloroquine had a significantly increased risk of harboring isolates with pfcrt resistance alleles (odds ratio = 4.47; p=0.03). The presence of two or more mutations in dhfr or dhps was found in 64.8% (95% confidence interval [CI] 54.6 to 73.9) and in 30.4% (95% CI 21.7 to 40.3) of isolates, respectively, and increased significantly over the course of the study. These molecular markers indicate that pyrimethamine/sulfadoxine resistance is increasing and is now too high to rely on this drug as a routine therapeutic agent to treat malaria in travelers

    Metataxonomic and Metagenomic Approaches vs. Culture-Based Techniques for Clinical Pathology.

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    Diagnoses that are both timely and accurate are critically important for patients with life-threatening or drug resistant infections. Technological improvements in High-Throughput Sequencing (HTS) have led to its use in pathogen detection and its application in clinical diagnoses of infectious diseases. The present study compares two HTS methods, 16S rRNA marker gene sequencing (metataxonomics) and whole metagenomic shotgun sequencing (metagenomics), in their respective abilities to match the same diagnosis as traditional culture methods (culture inference) for patients with ventilator associated pneumonia (VAP). The metagenomic analysis was able to produce the same diagnosis as culture methods at the species-level for five of the six samples, while the metataxonomic analysis was only able to produce results with the same species-level identification as culture for two of the six samples. These results indicate that metagenomic analyses have the accuracy needed for a clinical diagnostic tool, but full integration in diagnostic protocols is contingent on technological improvements to decrease turnaround time and lower costs

    Implementable Strategies and Exploratory Considerations to Reduce Costs Associated with Anti-TNF Therapy in Inflammatory Bowel Disease:

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    A health care system is needed where care is based on the best available evidence and is delivered reliably, efficiently, and less expensively (best care at lower cost). In gastroenterology, anti-tumor necrosis factor (anti-TNF) agents represent the most effective medical therapeutic option for patients with moderate-to-severe inflammatory bowel disease (IBD), but are very expensive and account for nearly a quarter of the cost of IBD care, representing a major area of present and future impact in direct health care costs. The ImproveCareNow Network, consisting of over 55 pediatric IBD centers, seeks ways to improve the value of care in IBD – curtailing unnecessary costs and promoting better health outcomes through systematic and incremental quality improvement initiatives. This report summarizes the key evidence to facilitate the cost-effective use of anti-TNF agents for patients with IBD. Our review outlines the scientific rationale for initiating cost-reducing measures in anti-TNF use and focuses on three implementable strategies and four exploratory considerations through practical clinical guidelines, as supported by existing evidence. Implementable strategies can be readily integrated into today’s daily practice, while exploratory considerations can guide research to support future implementation
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