856 research outputs found

    A luciferase based viability assay for ATP detection in 384-well format for high throughput whole cell screening of Trypanosoma brucei brucei bloodstream form strain 427

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    <p>Abstract</p> <p>Background</p> <p>Human African Trypanosomiasis (HAT) is caused by two trypanosome species, <it>Trypanosoma brucei rhodesiense </it>and <it>Trypanosoma brucei gambiense</it>. Current drugs available for the treatment of HAT have significant issues related to toxicity, administration regimes with limited effectiveness across species and disease stages, thus there is a considerable need to find alternative drugs. A well recognised approach to identify new drug candidates is high throughput screening (HTS) of large compound library collections.</p> <p>Results</p> <p>We describe here the development of a luciferase based viability assay in 384-well plate format suitable for HTS of <it>T.b.brucei</it>. The parameters that were explored to determine the final HTS assay conditions are described in detail and include DMSO tolerability, Z', diluents and cell inoculum density. Reference compound activities were determined for diminazene, staurosporine and pentamidine and compared to previously published IC<sub>50 </sub>data obtained. The assay has a comparable sensitivity to reference drugs and is more cost effective than the 96-well format currently reported for <it>T.b.brucei</it>.</p> <p>Conclusion</p> <p>Due to the reproducibility and sensitivity of this assay it is recommended for potential HTS application. As it is commercially available this assay can also be utilised in many laboratories for both large and small scale screening.</p

    Beyond Consultation: A New Model for Librarian's Office Hours

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    Given the many changes in our students and their study and research practices, libraries are finding it necessary to seek new ways to reach these students. The Undergraduate Library at the University of Illinois at Urbana-Champaign created a new model to do so. Librarian's Office Hours are a hybrid of reference and instructional services that fulfill the dual purposes of meeting the needs of term paper research counseling and library workshops. This article discusses the strategies involved in the creation and implementation of this service and examines suggestions for the future of such a service.Ope

    Tripanocidno i citotoksično djelovanje etanolskoga iscrpka lišća Psidium guajava određivano bojanjem alamarskim plavilom

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    Ethanolic extracts prepared from the leaves of Psidium guajava were evaluated for anti-trypanosoma and cytotoxicity activity in the bloodstream species of Trypanosoma brucei brucei (BS427) and HEK293 in 384-well Alamar Blue assays respectively. Cytotoxicity activity in HEK293 cells was subsequently used to estimate the selectivity index of the extracts. The activities of the plant extracts were determined to evaluate if further chemical and biological profi ling may be warranted for potential development in early drug discovery for African Sleeping Sickness. Two trypanocides, pentamidine and diminazene, were employed as reference drugs, while puromycin was also included as control for general cell growth inhibition. The results show that the extracts inhibited growth of T. b. brucei with an IC50 of 6.3 μg/mL and 48.9 μg/mL for 80% and 20% ethanolic preparations respectively, with corresponding activity of less than 50% against HEK293 at the highest screening dose of 238.10 μg/mL. The estimated selectivity index of the extracts compares favourably with pentamidine and diminazene. Meanwhile the reference compounds were found to have activities in agreement with published sensitivities at the doses screened. The lack of cytotoxicity at the doses screened and direct activity against T. b. brucei whole cells, make these extracts suitable candidates for further chemical elucidation and biological profiling.Istraženo je tripanocidno djelovanje etanolskog iscrpka lišća Psidium guajava na vrstu Trypanosoma brucei brucei (BS427) i njegova citotoksičnost na stanice HEK293 bojanjem alamarskim plavilom u 384 jažice. Citotoksični učinak na stanice HEK293 rabljen je za procjenu indeksa selektivnosti. Učinkovitost biljnih iscrpaka određivana je da bi se procijenila svrhovitost budućih kemijskih i bioloških istraživanja potencijalnoga lijeka za afričku bolest spavanja. U istraživanju su rabljena dva tripanocida, pentamidin i diminazen, te puromicin kao sredstvo koje usporava rast stanica. Rezultati su pokazali da 80% etanolskih pripravaka s IC50 od 6,3 μg/mL koči rast i razvoj tripanosoma, a samo 20% onih s IC50 od 48,9 μg/mL, s odgovarajućom aktivnosti manjom od 50% na stanice HEK293 u najvećoj dozi od 238,10 μg/mL. Indeks selektivnosti iscrpaka bio je sukladan s aktivnošću pentamidina i diminazena. Aktivnost istraživanih sastojaka bila je sukladna s razinom prije objavljene osjetljivosti. Izostanak citotoksičnosti na razini rabljenih koncentracija i izravna djelotvornost na stanice T. b. brucei daju osnovu za daljnja kemijska i biološka istraživanja predmetnih pripravaka

    Burden of respiratory viral infection in persons with human immunodeficiency virus

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    This study was conducted to determine the prevalence of respiratory viral infections (RVI) in persons living with HIV (PLH) admitted with a respiratory complaint using real-time reverse transcription polymerase chain reaction and primer-independent next-generation sequencing (NGS). Of 82 subjects, respiratory viruses were the most common pathogen identified in 27 (33%), followed by fungus and bacteria in 8 (10%) and 4 (5%) subjects, respectively. Among subjects with RVI, 11 (41%) required ICU admission and 16 (59%) required mechanical ventilation. The proportion of respiratory viruses identified, and the associated complicated hospital course highlights the significant role that RVIs play in the lung health of PLH

    Associations Between Echocardiographic Arterial Compliance and Incident Cardiovascular Disease in Blacks: The ARIC Study

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    Systemic arterial compliance is sometimes derived by echocardiographic stroke volume to pulse pressure ratios. Few studies have assessed echocardiographic arterial compliance in blacks or its associations with explicit, rather than composite, cardiovascular disease (CVD) outcomes

    Decreased function of survival motor neuron protein impairs endocytic pathways

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    This document is the Accepted Manuscript version. The final, definitive version is available online at https://doi.org/10.1073/pnas.1600015113.Spinal muscular atrophy (SMA) is caused by depletion of the ubiquitously expressed survival motor neuron (SMN) protein, with 1 in 40 Caucasians being heterozygous for a disease allele. SMN is critical for the assembly of numerous ribonucleoprotein complexes, yet it is still unclear how reduced SMN levels affect motor neuron function. Here, we examined the impact of SMN depletion in Caenorhabditis elegans and found that decreased function of the SMN ortholog SMN-1 perturbed endocytic pathways at motor neuron synapses and in other tissues. Diminished SMN-1 levels caused defects in C. elegans neuromuscular function, and smn-1 genetic interactions were consistent with an endocytic defect. Changes were observed in synaptic endocytic proteins when SMN-1 levels decreased. At the ultrastructural level, defects were observed in endosomal compartments, including significantly fewer docked synaptic vesicles. Finally, endocytosis-dependent infection by JC polyomavirus (JCPyV) was reduced in human cells with decreased SMN levels. Collectively, these results demonstrate for the first time, to our knowledge, that SMN depletion causes defects in endosomal trafficking that impair synaptic function, even in the absence of motor neuron cell death.Peer reviewedFinal Accepted Versio

    Outcomes of Patients With Anemia and Acute Decompensated Heart Failure With Preserved Versus Reduced Ejection Fraction (from the ARIC Study Community Surveillance)

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    Anemia is associated with poor prognosis in patients hospitalized with acute decompensated heart failure (ADHF). Whether the impact of anemia differs by heart failure with preserved (HFpEF) or reduced (HFrEF) ejection fraction is uncertain. We examined hospital surveillance data captured by the Atherosclerosis Risk in Communities Study from January 1, 2005 – December 31, 2010. Diagnoses of ADHF were validated by standardized physician review of the medical record. Anemia was classified using WHO criteria (<12 g/dL for women, < 13 g/dL for men), and heart failure type was determined by the ejection fraction (<40% for HFrEF, ≥ 40% for HFpEF). Hospital length of stay and 1-year mortality outcomes were analyzed by multivariable regression, weighted to account for the sampling design, and adjusted for demographics and clinical covariates. Over 6 years, 15,461 (weighted) hospitalized events for ADHF (59% HFrEF) occurred in the ARIC catchment, based on 3,309 sampled events. Anemia was associated with a mortality hazard ratio of 2.1 (95% CI: 1.6 – 2.7) in patients classified with HFpEF, and 1.4 (95% CI: 1.1 – 1.7) among those with HFrEF; p for interaction = 0.05. The mean increase in length of hospital stay associated with anemia was 3.5 days (95% CI: 3.4 – 3.6) for patients with HFpEF, compared with 1.8 days (95% CI: 1.7 – 1.9) for those with HFrEF; p for interaction <0.0001. In conclusion, the incremental risks of death and lengthened hospital stay associated with anemia are more pronounced in ADHF patients classified with HFpEF than HFrEF
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