46 research outputs found

    1H, 15N, and 13C chemical shift assignments of calcium-binding protein 1 with Ca2+ bound at EF1, EF3 and EF4

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    Calcium-binding protein 1 (CaBP1) regulates inositol 1,4,5-trisphosphate receptors (InsP3Rs) and a variety of voltage-gated Ca2+ channels in the brain. We report complete NMR chemical shift assignments of the Ca2+-saturated form of CaBP1 with Ca2+ bound at EF1, EF3 and EF4 (residues 1–167, BMRB no. 16862)

    Acellular Bone Marrow Extracts Significantly Enhance Engraftment Levels of Human Hematopoietic Stem Cells in Mouse Xeno-Transplantation Models

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    Hematopoietic stem cells (HSC) derived from cord blood (CB), bone marrow (BM), or mobilized peripheral blood (PBSC) can differentiate into multiple lineages such as lymphoid, myeloid, erythroid cells and platelets. The local microenvironment is critical to the differentiation of HSCs and to the preservation of their phenotype in vivo. This microenvironment comprises a physical support supplied by the organ matrix as well as tissue specific cytokines, chemokines and growth factors. We investigated the effects of acellular bovine bone marrow extracts (BME) on HSC in vitro and in vivo. We observed a significant increase in the number of myeloid and erythroid colonies in CB mononuclear cells (MNC) or CB CD34+ cells cultured in methylcellulose media supplemented with BME. Similarly, in xeno-transplantation experiments, pretreatment with BME during ex-vivo culture of HSCs induced a significant increase in HSC engraftment in vivo. Indeed, we observed both an increase in the number of differentiated myeloid, lymphoid and erythroid cells and an acceleration of engraftment. These results were obtained using CB MNCs, BM MNCs or CD34+ cells, transplanted in immuno-compromised mice (NOD/SCID or NSG). These findings establish the basis for exploring the use of BME in the expansion of CB HSC prior to HSC Transplantation. This study stresses the importance of the mechanical structure and soluble mediators present in the surrounding niche for the proper activity and differentiation of stem cells

    Validation of <i>N</i>-myristoyltransferase as Potential Chemotherapeutic Target in Mammal-Dwelling Stages of <i>Trypanosoma cruzi</i>

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    BACKGROUND:Trypanosoma cruzi causes Chagas disease, an endemic and debilitating illness in Latin America. Lately, owing to extensive population movements, this neglected tropical disease has become a global health concern. The two clinically available drugs for the chemotherapy of Chagas disease have rather high toxicity and limited efficacy in the chronic phase of the disease, and may induce parasite resistance. The development of new anti-T. cruzi agents is therefore imperative. The enzyme N-myristoyltransferase (NMT) has recently been biochemically characterized, shown to be essential in Leishmania major, Trypanosoma brucei, and T. cruzi¸ and proposed as promising chemotherapeutic target in these trypanosomatids. METHODOLOGY/PRINCIPAL FINDINGS:Here, using high-content imaging we assayed eight known trypanosomatid NMT inhibitors, against mammal-dwelling intracellular amastigote and trypomastigote stages and demonstrated that three of them (compounds 1, 5, and 8) have potent anti-proliferative effect at submicromolar concentrations against T. cruzi, with very low toxicity against human epithelial cells. Moreover, metabolic labeling using myristic acid, azide showed a considerable decrease in the myristoylation of proteins in parasites treated with NMT inhibitors, providing evidence of the on-target activity of the inhibitors. CONCLUSIONS/SIGNIFICANCE:Taken together, our data point out to the potential use of NMT inhibitors as anti-T. cruzi chemotherapy

    Fungal infection-related mortality versus total mortality as an outcome in trials of antifungal agents

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    BACKGROUND: Disease specific mortality is often used as outcome rather than total mortality in clinical trials. This approach assumes that the classification of cause of death is unbiased. We explored whether use of fungal infection-related mortality as outcome rather than total mortality leads to bias in trials of antifungal agents in cancer patients. METHODS: As an estimate of bias we used relative risk of death in those patients the authors considered had not died from fungal infection. Our sample consisted of 69 trials included in four systematic reviews of prophylactic or empirical antifungal treatment in patients with cancer and neutropenia we have published previously. RESULTS: Thirty trials met the inclusion criteria. The trials comprised 6130 patients and 869 deaths, 220 (25%) of which were ascribed to fungal infection. The relative risk of death was 0.85 (95% CI 0.75–0.96) for total mortality, 0.57 (95% CI 0.44–0.74) for fungal mortality, and 0.95 (95% CI 0.82–1.09) for mortality among those who did not die from fungal infection. CONCLUSION: We could not support the hypothesis that use of disease specific mortality introduces bias in antifungal trials on cancer patients as our estimate of the relative risk for mortality in those who survived the fungal infection was not increased. We conclude that it seems to be reliable to use fungal mortality as the primary outcome in trials of antifungal agents. Data on total mortality should be reported as well, however, to guard against the possible introduction of harmful treatments

    In vitro activities of voriconazole (UK-109, 496), fluconazole, itraconazole and amphotericin B against 132 non-albicans bloodstream yeast isolates (CANARI study)36735

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    The aim was to evaluate the in vitro activity of voriconazole compared with those of amphotericin B, itraconazole and fluconazole against 132 bloodstream isolates of Candida non-albicans and Saccharomyces cerevisiae species. The minimal inhibitory concentrations (MICs) were determined by an adapted National Committee for Clinical Laboratory Standards (NCCLS) M27-A method using RPMI 1640 as test medium supplemented with 2% glucose. MIC end-points were determined with a spectrophotometer after incubation for 48 h at 35 degrees C. Optical density data were used for the calculation of the MIC end-points. For amphotericin B, the end-point was defined as the minimal antifungal concentration that exerts 90% inhibition compared with the control well growth. For the azoles, the end-points were determined at 50% inhibition of growth. Amphotericin B is highly active with 97% of isolates inhibited by &lt; or =1 microg ml(-1). Decreased susceptibility or resistance to fluconazole was the rule among C. krusei, which is intrinsically resistant to fluconazole. For C. glabrata isolates, resistance to fluconazole and itraconazole was measured in 13% and 17% of the isolates respectively. Voriconazole was quite active in vitro against all the isolates with a MIC90% of &lt; or =1 microg ml(-1) and we conclude that it may be useful in the treatment of non-albicans bloodstream infections</p
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