31 research outputs found

    Using a Non-Image-Based Medium-Throughput Assay for Screening Compounds Targeting N-myristoylation in Intracellular Leishmania Amastigotes

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    We have refined a medium-throughput assay to screen hit compounds for activity against N-myristoylation in intracellular amastigotes of Leishmania donovani. Using clinically-relevant stages of wild type parasites and an Alamar blue-based detection method, parasite survival following drug treatment of infected macrophages is monitored after macrophage lysis and transformation of freed amastigotes into replicative extracellular promastigotes. The latter transformation step is essential to amplify the signal for determination of parasite burden, a factor dependent on equivalent proliferation rate between samples. Validation of the assay has been achieved using the anti-leishmanial gold standard drugs, amphotericin B and miltefosine, with EC50 values correlating well with published values. This assay has been used, in parallel with enzyme activity data and direct assay on isolated extracellular amastigotes, to test lead-like and hit-like inhibitors of Leishmania Nmyristoyl transferase (NMT). These were derived both from validated in vivo inhibitors of Trypanosoma brucei NMT and a recent high-throughput screen against L. donovani NMT. Despite being a potent inhibitor of L. donovani NMT, the activity of the lead T. brucei NMT inhibitor (DDD85646) against L. donovani amastigotes is relatively poor. Encouragingly, analogues of DDD85646 show improved translation of enzyme to cellular activity. In testing the high-throughput L. donovani hits, we observed macrophage cytotoxicity with compounds from two of the four NMT-selective series identified, while all four series displayed low enzyme to cellular translation, also seen here with the T. brucei NMT inhibitors. Improvements in potency and physicochemical properties will be required to deliver attractive lead-like Leishmania NMT inhibitors

    Paralemmin-1 is expressed in lymphatic endothelial cells and modulates cell migration, cell maturation and tumor lymphangiogenesis

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    The lymphatic system, the network of lymphatic vessels and lymphoid organs, maintains the body fluid balance and ensures the immunological surveillance of the body. In the adult organism, the de novo formation of lymphatic vessels is mainly observed in pathological conditions. In contrast to the molecular mechanisms governing the generation of the lymphatic vasculature during embryogenesis, the processes underlying pathological lymphangiogenesis are less well understood. A genome-wide screen comparing the transcriptome of tumor-derived lymphatic endothelial cells with that of blood vessel endothelial cells identified paralemmin-1 as a protein prominently expressed in lymphatic endothelial cells. Paralemmin-1 is a lipid-anchored membrane protein that in fibroblasts and neurons plays a role in the regulation of cell shape, plasma membrane dynamics and cell motility. Here, we show that paralemmin-1 is expressed in tumor-derived lymphatic endothelial cells as well as in lymphatic endothelial cells of normal, non-tumorigenic tissue. Paralemmin-1 represses cell migration and delays the formation of tube-like structures of lymphatic endothelial cells in vitro by modulating cell-substrate adhesion, filopodia formation and plasma membrane blebbing. While constitutive genetic ablation of paralemmin-1 expression in mice has no effect on the development and physiological function of the lymphatic system, the loss of paralemmin-1 impaired tumor-associated lymphangiogenesis. Together, these results newly identify paralemmin-1 as a protein highly expressed in lymphatic endothelial cells. Similar to its function in neurons, it may link the cytoskeleton to the plasma membrane and thereby modulate lymphatic endothelial cell adhesion, migration and lymphangiogenesis

    Effectiveness of the Advanced Practice Nursing interventions in the patient with heart failure: A systematic review

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    RATIONALE AND AIM: Advanced Practice Nurse (APN) is a specialist who has acquired clinical skills to make complex decisions for a better professional practice. In the United States, this figure has been developed in different ways, but in some European countries, it is not yet fully developed, although it may imply a significant advance in terms of continuity and quality of care in patients with chronic or multiple pathologies, including cardiac ones and, more specifically, heart failure (HF). The follow‐up of HF patients in many countries has focused on the medical management of the process, neglecting all the other comprehensive health aspects that contribute to decompensation of HF, worsening quality indicators or patient satisfaction, and there are not updated reviews to clarify the relevance of APN in HF, comparing the results of APN interventions with doctors clinical practice, since the complexity of care that HF patients need makes it difficult to control the disease through regular treatment. For this reason, this systematic review was proposed in order to update the available knowledge on the effectiveness of APN interventions in HF patients, analysing four PICO questions (Patients, Interventions, Comparison and Outcomes): whether APN implies a reduction in the number of hospital readmissions, if it reduces mortality, if it has a positive cost‐benefit relationship and if it implies any improvement in the quality of life of HF patients. DESIGN AND METHODS: A systematic review was performed based on the PRISMA statement, searching at four databases: PubMed, CINAHL, Scopus and Cuiden. Articles were selected based on the following criteria: English/Spanish language, up to 6 years since publication, and original quantitative studies of experimental, quasi‐experimental or observational character. Papers were excluded if they do not comply with CONSORT or STROBE checklists, and if they had not been published in journals indexed in JCR and/or SJR. For the analysis, two separate researchers used the Cochrane Handbook form for systematic reviews of intervention, collecting authorship variables, study methods, risks of bias, intervention and comparison groups, results obtained, PICO question or questions answered, and the main conclusions. RESULTS: A total of 43,754 patients participated in the 11 included studies for the development of this review, mostly from United States and non‐European countries, with a clearly visible lack of European publications. Regarding the results related to first PICO question, researches reviewed proved that APN implied a reduction in the number of hospital readmissions in patients with heart failure (up to 33%). Regarding the second question, mortality was always lower in groups assisted by APN versus in control groups (up to 7.8% vs. 17.7%). Regarding the third question, APN was cost‐effective in this type of patient as the cost reduction was eventually calculated in 1.9 million euros. Regarding the last question, quality of life of patients who have been cared for by an APN had notoriously improved, although one of the papers concluded that no significant differences were found. All the questions addressed obtained a positive answer; therefore, APN is a practice that reduced hospital readmissions and mortality in HF patients. The cost‐effectiveness is much better with APN than with usual care, and although the quality of life of HF patients seems to improve with APN, more studies are needed to support this focused on this
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