2,727 research outputs found
The Effect of the Association between Donepezil and Choline Alphoscerate on Behavioral Disturbances in Alzheimer's Disease: Interim Results of the ASCOMALVA Trial
BACKGROUND:
Behavioral and psychological symptoms of dementia (BPSD) are a group of psychological reactions, psychiatric symptoms, and behaviors commonly found in Alzheimer's disease (AD). Four clusters of BPSD have been described: mood disorders (depression, anxiety, and apathy), psychotic symptoms (delusions and hallucinations), aberrant motor behaviors (pacing, wandering, and other purposeless behaviors), and inappropriate behaviors (agitation, disinhibition, and euphoria). Most of them are attributed to acetylcholine deficiency.
OBJECTIVE:
To evaluate if a higher amount of acetylcholine obtained by associating donepezil and choline alphoscerate might have a favorable effect on BPSD.
METHODS:
BPSD were measured at baseline and after 24 months in 113 mild/moderate AD patients, included in the double-blind randomized trial ASCOMALVA, by the Neuropsychiatric Inventory (NPI). Two matched groups were compared: group A treated with donepezil (10 mg/day) plus choline alphoscerate (1200 mg/day), and group B treated with donepezil (10 mg/day) plus placebo.
RESULTS:
Data of NPI revealed a significant decrease of BPSD severity and distress of the caregiver in patients of group A compared with group B. Mood disorders (depression, anxiety and apathy) were significantly decreased in subjects treated with donepezil and choline alphoscerate, while their severity and frequency was increased in the other group.
CONCLUSIONS:
Patients treated with donepezil plus choline alphoscerate showed a lower level of behavioral disturbances than subjects treated with donepezil only, suggesting that the association can have beneficial effect
Energy-Spin Trajectories in AdS_5 x S^5 from Semiclassical Vertex Operators
We study the relation between vertex operators in AdS_5 x S^5 and classical
spinning string solutions. In the limit of large quantum numbers the treatment
of vertex operators becomes semiclassical. In this regime, a given vertex
operator carrying a certain set of quantum numbers defines a singular solution.
We show in a number of examples that this solution coincides with the classical
string solution with the same quantum numbers but written in a different
two-dimensional coordinate system. The marginality condition imposed on an
operator yields a relation between the energy and the other quantum numbers
which is shown to coincide with that of the corresponding classical string
solution. We also argue that in some cases vertex operators in AdS_5 x S^5
cannot be given by expressions similar to the ones in flat space and a more
involved consideration is required.Comment: 23 pages, 1 Figur
Proapoptotic activity of new glutathione S-transferase inhibitors
Selected 7-nitro-2,1,3-benzoxadiazole derivatives have been recently found very efficient inhibitors of glutathione S-transferase (GST) PI-1,(5) an enzyme which displays antiapoptotic activity and is also involved in the cellular resistance to anticancer drugs. These new inhibitors are not tripeptide glutathione-peptidomimetic molecules and display lipophylic properties suitable for crossing the plasma membrane. In the present work, we show the strong cytotoxic activity of these compounds in the following four different cell lines: K562 (human myeloid leukemia), HepG2 (human hepatic carcinoma), CCRF-CEM (human T-lymphoblastic leukemia), and GLC-4 (human small cell lung carcinoma). The LC50 values are in the micromolar/submicromolar range and are close to the ICs values obtained with GSTPI-1, suggesting that the target of these molecules inside the cell is indeed this enzyme. The cytotoxic mechanism of 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol, the most effective GSTPI-1 inhibitor, has been carefully investigated in leukemic CCRF-CEM and K562 cell lines. Western blot and immunoprecipitation analyzes have shown that 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanoI promotes in both cell lines the dissociation of the GSTPI-1 in a complex with c-jun NH2-terminal kinase (JNK). This process triggers a reactive oxygen species (ROS) -independent activation of the JNK-mediated pathway that results in a typical process of apoptosis. Besides this main pathway, in K562 cells, a ROS-mediated apoptosis partially occurs (about 30%) which involves the p38(MAPK) signal transduction pathway. The low concentration of this new compound needed to trigger cytotoxic effects on tumor cells and the low toxicity on mice indicate that the new 7-nitro-2,1,3-benzoxadiazole derivatives are promising anticancer agents
The MRN complex is transcriptionally regulated by MYCN during neural cell proliferation to control replication stress
The MRE11/RAD50/NBS1 (MRN) complex is a major sensor of DNA double strand breaks, whose role in controlling faithful DNA replication and preventing replication stress is also emerging. Inactivation of the MRN complex invariably leads to developmental and/or degenerative neuronal defects, the pathogenesis of which still remains poorly understood. In particular, NBS1 gene mutations are associated with microcephaly and strongly impaired cerebellar development, both in humans and in the mouse model. These phenotypes strikingly overlap those induced by inactivation of MYCN, an essential promoter of the expansion of neuronal stem and progenitor cells, suggesting that MYCN and the MRN complex might be connected on a unique pathway essential for the safe expansion of neuronal cells. Here, we show that MYCN transcriptionally controls the expression of each component of the MRN complex. By genetic and pharmacological inhibition of the MRN complex in a MYCN overexpression model and in the more physiological context of the Hedgehog-dependent expansion of primary cerebellar granule progenitor cells, we also show that the MRN complex is required for MYCN-dependent proliferation. Indeed, its inhibition resulted in DNA damage, activation of a DNA damage response, and cell death in a MYCN- and replication-dependent manner. Our data indicate the MRN complex is essential to restrain MYCN-induced replication stress during neural cell proliferation and support the hypothesis that replication-born DNA damage is responsible for the neuronal defects associated with MRN dysfunctions.Cell Death and Differentiation advance online publication, 12 June 2015; doi:10.1038/cdd.2015.81
PAMELA results on the cosmic-ray antiproton flux from 60 MeV to 180 GeV in kinetic energy
The satellite-borne experiment PAMELA has been used to make a new measurement
of the cosmic-ray antiproton flux and the antiproton-to-proton flux ratio which
extends previously published measurements down to 60 MeV and up to 180 GeV in
kinetic energy. During 850 days of data acquisition approximately 1500
antiprotons were observed. The measurements are consistent with purely
secondary production of antiprotons in the galaxy. More precise secondary
production models are required for a complete interpretation of the results.Comment: 11 pages, 3 figures, 1 table. Accepted for publication in Physical
Review Letter
Circumstellar disks and planets. Science cases for next-generation optical/infrared long-baseline interferometers
We present a review of the interplay between the evolution of circumstellar
disks and the formation of planets, both from the perspective of theoretical
models and dedicated observations. Based on this, we identify and discuss
fundamental questions concerning the formation and evolution of circumstellar
disks and planets which can be addressed in the near future with optical and
infrared long-baseline interferometers. Furthermore, the importance of
complementary observations with long-baseline (sub)millimeter interferometers
and high-sensitivity infrared observatories is outlined.Comment: 83 pages; Accepted for publication in "Astronomy and Astrophysics
Review"; The final publication is available at http://www.springerlink.co
Cytotoxic activity of the novel Akt inhibitor, MK-2206, in T-cell acute lymphoblastic leukemia.
T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplastic disorder arising from T-cell progenitors. T-ALL accounts for
15% of newly diagnosed ALL cases in children and 25% in adults. Although the prognosis of T-ALL has improved, due to the use of
polychemotherapy schemes, the outcome of relapsed/chemoresistant T-ALL cases is still poor. A signaling pathway that is
frequently upregulated in T-ALL, is the phosphatidylinositol 3-kinase/Akt/mTOR network. To explore whether Akt could represent a
target for therapeutic intervention in T-ALL, we evaluated the effects of the novel allosteric Akt inhibitor, MK-2206, on a panel of
human T-ALL cell lines and primary cells from T-ALL patients. MK-2206 decreased T-ALL cell line viability by blocking leukemic cells
in the G0/G1 phase of the cell cycle and inducing apoptosis. MK-2206 also induced autophagy, as demonstrated by an increase in
the 14-kDa form of LC3A/B. Western blotting analysis documented a concentration-dependent dephosphorylation of Akt and its
downstream targets, GSK-3a/b and FOXO3A, in response to MK-2206. MK-2206 was cytotoxic to primary T-ALL cells and induced
apoptosis in a T-ALL patient cell subset (CD34þ/CD4/CD7), which is enriched in leukemia-initiating cells. Taken together, our
findings indicate that Akt inhibition may represent a potential therapeutic strategy in T-ALL
Alleviating the new user problem in collaborative filtering by exploiting personality information
The final publication is available at Springer via http://dx.doi.org/10.1007/s11257-016-9172-zThe new user problem in recommender systems is still challenging, and there is not yet a unique solution that can be applied in any domain or situation. In this paper we analyze viable solutions to the new user problem in collaborative filtering (CF) that are based on the exploitation of user personality information: (a) personality-based CF, which directly improves the recommendation prediction model by incorporating user personality information, (b) personality-based active learning, which utilizes personality information for identifying additional useful preference data in the target recommendation domain to be elicited from the user, and (c) personality-based cross-domain recommendation, which exploits personality information to better use user preference data from auxiliary domains which can be used to compensate the lack of user preference data in the target domain. We benchmark the effectiveness of these methods on large datasets that span several domains, namely movies, music and books. Our results show that personality-aware methods achieve performance improvements that range from 6 to 94 % for users completely new to the system, while increasing the novelty of the recommended items by 3-40 % with respect to the non-personalized popularity baseline. We also discuss the limitations of our approach and the situations in which the proposed methods can be better applied, hence providing guidelines for researchers and practitioners in the field.This work was supported by the Spanish Ministry of Economy and
Competitiveness (TIN2013-47090-C3). We thank Michal Kosinski and David Stillwell for
their attention regarding the dataset
AMP-dependent kinase/mammalian target of rapamycin complex 1 signaling in T-cell acute lymphoblastic leukemia: therapeutic implications.
The mammalian target of rapamycin (mTOR) serine/threonine
kinase is the catalytic subunit of two multi-protein complexes,
referred to as mTORC1 and mTORC2. Signaling downstream
of mTORC1 has a critical role in leukemic cell biology by
controlling mRNA translation of genes involved in both cell
survival and proliferation. mTORC1 activity can be downmodulated
by upregulating the liver kinase B1/AMP-activated
protein kinase (LKB1/AMPK) pathway. Here, we have explored
the therapeutic potential of the anti-diabetic drug, metformin
(an LKB1/AMPK activator), against both T-cell acute lymphoblastic
leukemia (T-ALL) cell lines and primary samples
from T-ALL patients displaying mTORC1 activation. Metformin
affected T-ALL cell viability by inducing autophagy and
apoptosis. However, it was much less toxic against proliferating
CD4þ T-lymphocytes from healthy donors. Western blot
analysis demonstrated dephosphorylation of mTORC1 downstream
targets. Unlike rapamycin, we found a marked inhibition
of mRNA translation in T-ALL cells treated with metformin.
Remarkably, metformin targeted the side population of T-ALL
cell lines as well as a putative leukemia-initiating cell subpopulation
(CD34þ/CD7/CD4) in patient samples. In conclusion,
metformin displayed a remarkable anti-leukemic activity,
which emphasizes future development of LKB1/AMPK activators
as clinical candidates for therapy in T-ALL.
Leukemia (2012) 26, 91–100; doi:10.1038/leu.2011.269;
published online 4 October 201
Eculizumab treatment: stochastic occurrence of C3 binding to individual PNH erythrocytes
C5 blockade by eculizumab prevents complement-mediated intravascular hemolysis in paroxysmal nocturnal hemoglobinuria (PNH). However, C3-bound PNH red blood cells (RBCs), arising in almost all treated patients, may undergo extravascular hemolysis reducing clinical benefits. Despite the uniform deficiency of CD55 and of CD59, there are always two distinct populations of PNH RBCs, with (C3+) and without (C3-) C3 binding
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