273 research outputs found
Evaluation of thrombopoiesis kinetics by measurement of reticulated platelets and CD34+ cell subsets in patients with solid tumors following high dose chemotherapy and autologous peripheral blood progenitor cell support.
The transplantation of mobilised peripheral progenitor cells has resulted in shortening of neutrophil and platelet engrafment times following high-dose chemotherapy. Since reticulated platelet percentage (PR%) has been established as a measure of bone marrow platelet production, we performed this type of analysis on the thrombopoietic compartment during transplant-related chemotherapy. DESIGN AND METHODS: Kinetics of thrombopoiesis of 19 patients with solid tumors undergoing a single or double autologous peripheral blood progenitor cell transplant was characterized by evaluating the level of RP. The correlation between CD34(+) cell subsets and the time of highest percentage of RP was also evaluated. RESULTS: The percentage of RP increases since day +8 after single transplant reaching the peak (3.4%) at day +10. In the group of patients receiving double transplant, the RP value of peak observed after second transplant is not significantly different from that one observed after the first transplant (3 vs 3.7%). In a subgroup of patients both the number of CD34(+) cells/Kg infused and the percentage of CD34(+) CD61(+) cell subsets correlate with the day of RP peak. INTERPRETATION AND CONCLUSIONS: These results suggest that RP measurement is an early indicator of engraftment. Additionally, the observation that RP percentage is high at the time of platelet transfusion in 13 out of 20 cases of transfusions (the 7 cases with low RP value being transfused during the period of obligate thrombocytopenia) suggests that the evaluation of this parameter, together with the platelet count, can be used to monitor the need for platelet transfusion
Nature-derived compounds modulating Wnt/β-catenin pathway: a preventive and therapeutic opportunity in neoplastic diseases
Abstract The Wnt/β-catenin signaling is a conserved pathway that has a crucial role in embryonic and adult life. Dysregulation of the Wnt/β-catenin pathway has been associated with diseases including cancer, and components of the signaling have been proposed as innovative therapeutic targets, mainly for cancer therapy. The attention of the worldwide researchers paid to this issue is increasing, also in view of the therapeutic potential of these agents in diseases, such as Parkinson's disease (PD), for which no cure is existing today. Much evidence indicates that abnormal Wnt/β-catenin signaling is involved in tumor immunology and the targeting of Wnt/β-catenin pathway has been also proposed as an attractive strategy to potentiate cancer immunotherapy. During the last decade, several products, including naturally occurring dietary agents as well as a wide variety of products from plant sources, including curcunim, quercetin, berberin, and ginsenosides, have been identified as potent modulators of the Wnt/β-catenin signaling and have gained interest as promising candidates for the development of chemopreventive or therapeutic drugs for cancer. In this review we make an overview of the nature-derived compounds reported to have antitumor activity by modulating the Wnt/β-catenin signaling, also focusing on extraction methods, chemical features, and bio-activity assays used for the screening of these compounds
Chloridobis[diphenylglyoximato(1–)-κ2 N,N′](1H-imidazole-κN 3)cobalt(III) hemihydrate
The Co centre in the title compound, [Co(C14H11N2O2)2Cl(C3H4N2)]·0.5H2O, shows a slightly distorted octahedral coordination geometry. The glyoximate units of the molecule are linked by O—H⋯O hydrogen bonds with the H atom almost in the middle of the two O atoms. The crystal packing is stabilized through intermolecular N—H⋯O, N—H⋯N and O—H⋯Cl hydrogen bonds. The uncoordinated water molecule shows half-occupation
An enzymatic flow-based preparative route to vidarabine
The bi-enzymatic synthesis of the antiviral drug vidarabine (arabinosyladenine, ara-A), catalyzed by uridine phosphorylase from Clostridium perfringens (CpUP) and a purine nucleoside phosphorylase fromAeromonas hydrophila (AhPNP), was re-designed under continuous-flow conditions. Glyoxyl-agarose and EziGTM1 (Opal) were used as immobilization carriers for carrying out this preparative biotransformation. Upon setting-up reaction parameters (substrate concentration and molar ratio, temperature, pressure, residence time), 1 g of vidarabine was obtained in 55% isolated yield and >99% purity by simply running the flow reactor for 1 week and then collecting (by filtration) the nucleoside precipitated out of the exiting flow. Taking into account the substrate specificity of CpUP and AhPNP, the results obtained pave the way to the use of the CpUP/AhPNP-based bioreactor for the preparation of other purine nucleosides
Malaria chemoprophylaxis recommendations for immigrants to Europe, visiting relatives and friends - a Delphi method study
BACKGROUND: Numbers of travellers visiting friends and relatives (VFRs) from Europe to malaria endemic countries are increasing and include long-term and second generation immigrants, who represent the major burden of malaria cases imported back into Europe. Most recommendations for malaria chemoprophylaxis lack a solid evidence base, and often fail to address the cultural, social and economic needs of VFRs. METHODS: European travel medicine experts, who are members of TropNetEurop, completed a sequential series of questionnaires according to the Delphi method. This technique aims at evaluating and developing a consensus through repeated iterations of questionnaires. The questionnaires in this study included questions about professional experience with VFRs, controversial issues in malaria prophylaxis, and 16 scenarios exploring indications for prescribing and choice of chemoprophylaxis. RESULTS: The experience of participants was rather diverse as was their selection of chemoprophylaxis regimen. A significant consensus was observed in only seven of 16 scenarios. The analysis revealed a wide variation in prescribing choices with preferences grouped by region of practice and increased prescribing seen in Northern Europe compared to Central Europe. CONCLUSIONS: Improving the evidence base on efficacy, adherence to chemoprophylaxis and risk of malaria and encouraging discussion among experts, using techniques such as the Delphi method, may reduce the variability in prescription in European travel clinics
The Effect of Soundscapes and Lightscapes on the Perception of Safety and Social Presence Analyzed in a Laboratory Experiment
The present study evaluates the effect of soundscape and lightscape variations on the perceived safety and perceived social presence in a pedestrian area through laboratory experiments. Thirty-one participants were presented with nine different virtual scenarios, in which the same underpass was reproduced under different soundscape and lightscape conditions. The participants were asked to assess each scenario considering 10 items related to perceived safety and perceived social presence. A principal component analysis allowed the 10 items to be reduced to two principal components, namely “perceived safety” and “perceived social presence”. A two-way repeated measures ANOVA analysis was conducted to assess the effect of modifications of both the soundscape and lightscape on the two components. The obtained results showed that the soundscape had an effect on both the perceived safety (p < 0.05) and perceived social presence (p < 0.05), while the lightscape variations implemented in this experiment only had a statistically significant effect on the latter (p < 0.05). The results of such studies may be of interest for public design and management as they may be conducted by means of non-intrusive and cost-effective techniques
Dual targeting of the DNA damage response pathway and BCL-2 in diffuse large B-cell lymphoma
Standard chemotherapies for diffuse large B-cell lymphoma (DLBCL), based on the induction of exogenous DNA damage and oxidative stress, are often less effective in the presence of increased MYC and BCL-2 levels, especially in the case of double hit (DH) lymphomas harboring rearrangements of the MYC and BCL-2 oncogenes, which enrich for a patient’s population characterized by refractoriness to anthracycline-based chemotherapy. Here we hypothesized that adaptive mechanisms to MYC-induced replicative and oxidative stress, consisting in DNA damage response (DDR) activation and BCL-2 overexpression, could represent the biologic basis of the poor prognosis and chemoresistance observed in MYC/BCL-2-positive lymphoma. We first integrated targeted gene expression profiling (T-GEP), fluorescence in situ hybridization (FISH) analysis, and characterization of replicative and oxidative stress biomarkers in two independent DLBCL cohorts. The presence of oxidative DNA damage biomarkers identified a poor prognosis double expresser (DE)-DLBCL subset, characterized by relatively higher BCL-2 gene expression levels and enrichment for DH lymphomas. Based on these findings, we tested therapeutic strategies based on combined DDR and BCL-2 inhibition, confirming efficacy and synergistic interactions in in vitro and in vivo DH-DLBCL models. These data provide the rationale for precision-therapy strategies based on combined DDR and BCL-2 inhibition in DH or DE-DLBCL
Surface Plasmon Resonance as a Tool for Ligand Binding Investigation of Engineered GPR17 Receptor, a G Protein Coupled Receptor Involved in Myelination
The aim of this study was to investigate the potential of surface plasmon resonance (SPR) spectroscopy for the measurement of real-time ligand-binding affinities and kinetic parameters for GPR17, a G protein-coupled receptor (GPCR) of major interest in medicinal chemistry as potential target in demyelinating diseases. The receptor was directly captured, in a single-step, from solubilized membrane extracts on the sensor chip through a covalently bound anti-6x-His-antibody and retained its ligand binding activity for over 24h. Furthermore, our experimental setup made possible, after a mild regeneration step, to remove the bound receptor without damaging the antibody, and thus to reuse many times the same chip. Two engineered variants of GPR17, designed for crystallographic studies, were expressed in insect cells, extracted from crude membranes and analyzed for their binding with two high affinity ligands: the antagonist Cangrelor and the agonist Asinex 1. The calculated kinetic parameters and binding constants of ligands were in good agreement with those reported from activity assays and highlighted a possible functional role of the N-terminal residues of the receptor in ligand recognition and binding. Validation of SPR results was obtained by docking and molecular dynamics of GPR17-ligands interactions and by functional in vitro studies. The latter allowed us to confirm that Asinex 1 behaves as GPR17 receptor agonist, inhibits forskolin-stimulated adenylyl cyclase pathway and promotes oligodendrocyte precursor cell maturation and myelinating ability
Molecular investigation of coexistent chronic myeloid leukaemia and peripheral T-cell lymphoma-a case report
Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm underlain by the formation of BCR-ABL1-an aberrant tyrosine kinase-in the leukaemic blasts. Long-term survival rates in CML prior to the advent of tyrosine kinase inhibitors (TKIs) were dismal, albeit the incidence of secondary malignancies was higher than that of age-matched population. Current figures confirm the safety of TKIs with conflicting data concerning the increased risk of secondary tumours. We postulate that care has to be taken when distinguishing between coexisting, secondary-to-treatment and second in sequence, but independent tumourigenic events, in order to achieve an unbiased picture of the adverse effects of novel treatments. To illustrate this point, we present a case of a patient in which CML and peripheral T-cell lymphoma (PTCL) coexisted, although the clinical presentation of the latter followed the achievement of major molecular response of CML to TKIs
Co-founding ant queens prevent disease by performing prophylactic undertaking behaviour
Abstract Background Social insects form densely crowded societies in environments with high pathogen loads, but have evolved collective defences that mitigate the impact of disease. However, colony-founding queens lack this protection and suffer high rates of mortality. The impact of pathogens may be exacerbated in species where queens found colonies together, as healthy individuals may contract pathogens from infectious co-founders. Therefore, we tested whether ant queens avoid founding colonies with pathogen-exposed conspecifics and how they might limit disease transmission from infectious individuals. Results Using Lasius niger queens and a naturally infecting fungal pathogen Metarhizium brunneum, we observed that queens were equally likely to found colonies with another pathogen-exposed or sham-treated queen. However, when one queen died, the surviving individual performed biting, burial and removal of the corpse. These undertaking behaviours were performed prophylactically, i.e. targeted equally towards non-infected and infected corpses, as well as carried out before infected corpses became infectious. Biting and burial reduced the risk of the queens contracting and dying from disease from an infectious corpse of a dead co-foundress. Conclusions We show that co-founding ant queens express undertaking behaviours that, in mature colonies, are performed exclusively by workers. Such infection avoidance behaviours act before the queens can contract the disease and will therefore improve the overall chance of colony founding success in ant queens
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