170,901 research outputs found
Cerebrovascular assessment for the risk prediction of Alzheimer’s disease.
No full textCerebrovascular Assessment for the Risk Prediction of Alzheimer's Disease.
Silvestrini M, Viticchi G, Altamura C, Luzzi S, Balucani C, Vernieri F.
Neurological Clinic, Marche Polytechnic University, Ancona, Italy.
Increasing evidence is emerging that vascular disease and its risk factors play a
role in the development of Alzheimer's disease (AD) and affect the probability of
an adverse outcome. The aims of this review are to explore the relationship
between vascular risk factors and AD and to discuss the potential use of vascular
markers in the clinical approach to cognitive impairment. Moreover, we present
evidence about the potential use of ultrasonographic and neuroradiologic markers
of cognitive impairment in order to establish possible treatment strategies in
subjects with a clinical profile at risk of developing AD
THE INTERPLAY BETWEEN CDK1/CLBS AND PP2A/CDC55 IN ADAPTATION TO THE SPINDLE ASSEMBLY CHECKPOINT (SAC)
No full textAbstract
The spindle assembly checkpoint (SAC) monitors that all sister chromatids are correctly attached to microtubules of the mitotic spindle during prometaphase. The correct attachment is known as biorientation, and it is the prerequisite for proper partitioning of the duplicated DNA from the mother to the two daughter cells. Until the last kinetochores are bioriented, the SAC arrests progression into anaphase by inhibiting the Anaphase Promoting Complex or Cyclosome (APC/C) bound to its coactivator Cdc20, therefore stabilizing the cohesin rings that hold pairs of sister chromatids together.
When the SAC is continuously activated, cells remain arrested in prometaphase for some hours, but not indefinitely; even if the checkpoint is not satisfied, eventually cells separate the duplicated DNA material and progress into anaphase. This phenomenon is known as adaptation to the SAC and is poorly understood from the molecular viewpoint.
By using budding yeast (S. cerevisiae) as a model organism, in this work I show that adaptation to the SAC requires phosphorylation of the APC/C, which is stimulated by the Cyclin dependent kinase 1 (Cdk1) bound to its mitotic regulatory subunit, Clb2, and is opposed by the phosphatase PP2ACdc55.
I propose that PP2ACdc55 and the APC/C are implicated in a double negative feedback loop of reciprocal inhibition, which regulates transition into anaphase in adapting cells: when accumulating Clb2 provides sufficient Cdk1:Clb2 activity to allow initial activation of APC/CCdc20, the antagonist of the APC/C, PP2ACdc55, starts to be inhibited. This strongly reinforces APC/CCdc20, and leads to a rapid and irreversible transition into anaphase
Sarcopenia and monocyte-to-lymphocyte ratio as prognostic factors in early-stage breast cancer
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Sucrose and raffinose contents and acquisition of desiccation tolerance in immature maize embryos
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fMRI-vs-MEG evaluation of post-stroke interhemispheric asymmetries in primary sensorimotor hand areas
No full textGrowing evidence emphasizes a positive role of brain ipsilesional (IL) reorganization in stroke patients with partial recovery. Ten patients affected by a monohemispheric stroke in the middle cerebral artery territory underwent functional magnetic resonance (fMRI) and magnetoencephalography (MEG) evaluation of the primary sensory (S1) activation via the same paradigm (median nerve galvanic stimulation). Four patients did not present S1 fMRI activation [Rossini, P.M., Altamura, C., Ferretti, A., Vernieri, F., Zappasodi, F., Caulo, M., Pizzella, V., Del Gratta, C., Romani, G.L., Tecchio, F., 2004. Does cerebrovascular disease affect the coupling between neuronal activity and local haemodynamics? Brain 127, 99-110], although inclusion criteria required bilateral identifiable MEG responses. Mean Euclidean distance between fMRI and MEG S1 activation Talairach coordinates was 10.1 ± 2.9 mm, with a 3D intra-class correlation (ICC) coefficient of 0.986. Interhemispheric asymmetries, evaluated by an MEG procedure independent of Talairach transformation, were outside or at the boundaries of reference ranges in 6 patients. In 3 of them, the IL activation presented medial or lateral shift with respect to the omega-shaped post-rolandic area while in the other 3, IL areas were outside the peri-rolandic region. In conclusion, despite dissociated intensity, the MEG and fMRI activations displayed good spatial consistency in stroke patients, thus confirming excessive interhemispheric asymmetries as a suitable indicator of unusual recruitments in the ipsilesional hemisphere, within or outside the peri-rolandic region. © 2006 Elsevier Inc. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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