2,534 research outputs found
Prescription sequence symmetry analysis: assessing risk, temporality, and consistency for adverse drug reactions across datasets in five countries
published_or_final_versio
Targeting quiescent leukemic stem cells using second generation autophagy inhibitors
In chronic myeloid leukemia (CML), tyrosine kinase inhibitor (TKI) treatment induces autophagy that promotes survival and TKI-resistance in leukemic stem cells (LSCs). In clinical studies hydroxychloroquine (HCQ), the only clinically approved autophagy inhibitor, does not consistently inhibit autophagy in cancer patients, so more potent autophagy inhibitors are needed. We generated a murine model of CML in which autophagic flux can be measured in bone marrow-located LSCs. In parallel, we use cell division tracing, phenotyping of primary CML cells, and a robust xenotransplantation model of human CML, to investigate the effect of Lys05, a highly potent lysosomotropic agent, and PIK-III, a selective inhibitor of VPS34, on the survival and function of LSCs. We demonstrate that long-term haematopoietic stem cells (LT-HSCs: LinβSca-1+c-kit+CD48βCD150+) isolated from leukemic mice have higher basal autophagy levels compared with non-leukemic LT-HSCs and more mature leukemic cells. Additionally, we present that while HCQ is ineffective, Lys05-mediated autophagy inhibition reduces LSCs quiescence and drives myeloid cell expansion. Furthermore, Lys05 and PIK-III reduced the number of primary CML LSCs and target xenografted LSCs when used in combination with TKI treatment, providing a strong rationale for clinical use of second generation autophagy inhibitors as a novel treatment for CML patients with LSC persistence
Bilayer manganites: polarons in the midst of a metallic breakdown
The exact nature of the low temperature electronic phase of the manganite
materials family, and hence the origin of their colossal magnetoresistant (CMR)
effect, is still under heavy debate. By combining new photoemission and
tunneling data, we show that in La{2-2x}Sr{1+2x}Mn2O7 the polaronic degrees of
freedom win out across the CMR region of the phase diagram. This means that the
generic ground state is that of a system in which strong electron-lattice
interactions result in vanishing coherent quasi-particle spectral weight at the
Fermi level for all locations in k-space. The incoherence of the charge
carriers offers a unifying explanation for the anomalous charge-carrier
dynamics seen in transport, optics and electron spectroscopic data. The
stacking number N is the key factor for true metallic behavior, as an
intergrowth-driven breakdown of the polaronic domination to give a metal
possessing a traditional Fermi surface is seen in the bilayer system.Comment: 7 pages, 2 figures, includes supplementary informatio
Improved cardiovascular diagnostic accuracy by pocket size imaging device in non-cardiologic outpatients: the NaUSiCa (Naples Ultrasound Stethoscope in Cardiology) study
Miniaturization has evolved in the creation of a pocket-size imaging device which can be utilized as an ultrasound stethoscope. This study assessed the additional diagnostic power of pocket size device by both experts operators and trainees in comparison with physical examination and its appropriateness of use in comparison with standard echo machine in a non-cardiologic population
Polarons and confinement of electronic motion to two dimensions in a layered transition metal oxide
A very remarkable feature of the layered transition metal oxides (TMOs),
whose most famous members are the high-temperature superconductors (HTSs), is
that even though they are prepared as bulk three-dimensional single crystals,
they display hugely anisotropic electrical and optical properties, seeming to
be insulating perpendicular to the layers and metallic within them. This is the
phenomenon of confinement, a concept at odds with the conventional theory of
solids and recognized as due to magnetic and electron-lattice interactions in
the layers which must be overcome at a substantial energy cost if electrons are
to be transferred between layers. The associated energy gap or 'pseudogap' is
particularly obvious in experiments where charge is moved perpendicular to the
planes, most notably scanning tunneling microscopy (STM) and polarized infrared
spectroscopy. Here, using the same experimental tools, we show that there is a
second family of TMOs - the layered manganites La2-2xSr1+2xMn2O7 (LSMO) - with
even more extreme confinement and pseudogap effects. The data, which are the
first to resolve atoms in any metallic manganite, demonstrate quantitatively
that because they are attached to polarons - lattice and spin textures within
the planes -, it is equally difficult to remove carriers from the planes via
vacuum tunneling into a conventional metallic tip, as it is for them to move
between Mn-rich layers within the material itself
Hand-carried ultrasound performed at bedside in cardiology inpatient setting β a comparative study with comprehensive echocardiography
BACKGROUND: Hand-carried ultrasound (HCU) devices have been demonstrated to improve the diagnosis of cardiac diseases over physical examination, and have the potential to broaden the versatility in ultrasound application. The role of these devices in the assessment of hospitalized patients is not completely established. In this study we sought to perform a direct comparison between bedside evaluation using HCU and comprehensive echocardiography (CE), in cardiology inpatient setting. METHODS: We studied 44 consecutive patients (mean age 54 Β± 18 years, 25 men) who underwent bedside echocardiography using HCU and CE. HCU was performed by a cardiologist with level-2 training in the performance and interpretation of echocardiography, using two-dimensional imaging, color Doppler, and simple calliper measurements. CE was performed by an experienced echocardiographer (level-3 training) and considered as the gold standard. RESULTS: There were no significant differences in cardiac chamber dimensions and left ventricular ejection fraction determined by the two techniques. The agreement between HCU and CE for the detection of segmental wall motion abnormalities was 83% (Kappa = 0.58). There was good agreement for detecting significant mitral valve regurgitation (Kappa = 0.85), aortic regurgitation (kappa = 0.89), and tricuspid regurgitation (Kappa = 0.74). A complete evaluation of patients with stenotic and prosthetic dysfunctional valves, as well as pulmonary hypertension, was not possible using HCU due to its technical limitations in determining hemodynamic parameters. CONCLUSION: Bedside evaluation using HCU is helpful for assessing cardiac chamber dimensions, left ventricular global and segmental function, and significant valvular regurgitation. However, it has limitations regarding hemodynamic assessment, an important issue in the cardiology inpatient setting
Best Linear Unbiased Prediction of Genomic Breeding Values Using a Trait-Specific Marker-Derived Relationship Matrix
With the availability of high density whole-genome single nucleotide polymorphism chips, genomic selection has become a promising method to estimate genetic merit with potentially high accuracy for animal, plant and aquaculture species of economic importance. With markers covering the entire genome, genetic merit of genotyped individuals can be predicted directly within the framework of mixed model equations, by using a matrix of relationships among individuals that is derived from the markers. Here we extend that approach by deriving a marker-based relationship matrix specifically for the trait of interest
Hand-held echocardiography: added value in clinical cardiological assessment
BACKGROUND: The ultrasonic industry has recently produced echocardiographic Hand Held Devices (miniaturized, compact and battery-equipped echocardiographic systems). Their potential usefulness has been successfully assessed in a wide range of clinical conditions. The aim of the study was to verify if the routine use of a basic model of echocardiographic Hand Held Device (HHD) could be an important diagnostic tool during outpatient cardiologic consulting or in non-cardiologic hospital sections. METHODS: 87 consecutive patients were included in this study; they underwent routine physical examination, resting ECG and echocardiographic evaluation using a basic model of HHD performed by trained echocardiographists; the cardiologist, whenever possible, formulated a diagnosis. The percentage of subjects in whom the findings were judged reasonably adequate for final diagnostic and therapeutic conclusions was used to quantify the "conclusiveness" of HHD evaluation. Successively, all patients underwent a second echocardiographic evaluation, by an examiner with similar echocardiographic experience, performed using a Standard Echo Device (SED). The agreement between the first and the second echocardiographic exam was also assessed. RESULTS: Mean examination time was 6.7 Β± 1.5 min. using HHD vs. 13.6 Β± 2.4 min. using SED. The echocardiographic examination performed using HHD was considered satisfactory in 74/87 patients (85.1% conclusiveness). Among the 74 patients for whom the examination was conclusive, the diagnosis was concordant with that obtained with the SED examination in 62 cases (83.8% agreement). CONCLUSION: HHD may generally allow a reliable cardiologic basic evaluation of outpatient or subjects admitted to non-cardiologic sections, more specifically in particular subgroups of patients, with a gain in terms of time, shortening patient waiting lists and reducing healthy costs
Cancer cells that survive radiation therapy acquire HIF-1 activity and translocate towards tumour blood vessels
Tumour recurrence frequently occurs after radiotherapy, but the characteristics, intratumoural localization and post-irradiation behaviour of radioresistant cancer cells remain largely unknown. Here we develop a sophisticated strategy to track the post-irradiation fate of the cells, which exist in perinecrotic regions at the time of radiation. Although the perinecrotic tumour cells are originally hypoxia-inducible factor 1 (HIF-1)-negative, they acquire HIF-1 activity after surviving radiation, which triggers their translocation towards tumour blood vessels. HIF-1 inhibitors suppress the translocation and decrease the incidence of post-irradiation tumour recurrence. For the first time, our data unveil the HIF-1-dependent cellular dynamics during post-irradiation tumour recurrence and provide a rational basis for targeting HIF-1 after radiation therapy
The role of complement in ocular pathology
Functionally active complement system and complement regulatory proteins are present in the normal human and rodent eye. Complement activation and its regulation by ocular complement regulatory proteins contribute to the pathology of various ocular diseases including keratitis, uveitis and age-related macular degeneration. Furthermore, a strong relationship between age-related macular degeneration and polymorphism in the genes of certain complement components/complement regulatory proteins is now well established. Recombinant forms of the naturally occurring complement regulatory proteins have been exploited in the animal models for treatment of these ocular diseases. It is hoped that in the future recombinant complement regulatory proteins will be used as novel therapeutic agents in the clinic for the treatment of keratitis, uveitis, and age-related macular degeneration
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