Search results for "PC"

Regional Cerebral Blood Flow in Cases of Brain Tumor

1969

The present series consists of 21 patients with brain tumors: 12 malignant gliomas, 4 oligo- dendro gliomas, 3 meningeomas and 2 metastases, studied by the133Xe-gamma-clearance rCBF method. In 16 patients at least 3 determinations of rCBF were performed: a) in the resting state, R; b) during hyperventilation, HV, and c) during hypertension, HT. Of the remaining 5 patients, 1 was studied only during R, while the other 4 were submitted either to HV or to HT additionally to the R study. The average age of this series of patients was 47 years, the youngest being 19 and the oldest 64. rCBF studies had to be performed under general anesthesia (N2O + O2, Engstrom respirator) in 5 instances in whic…

Segmentando el mercado de internautas atendiendo a su nivel de afinidad: (I)fuerte, (II)medio y (III)débil

2017

Esta investigación pretende confrontar el Marketing con Causa con el Marketing de Afinidad. Para ello se descompone la audiencia de una campaña de Marketing con Causa viral en segmentos de internautas con distinto nivel de afinidad: i) fuerte (con experiencia previa de marca y de causa); ii) medio (con experiencia previa o de marca o de causa); iii) débil (sin experiencia previa ni de marca ni de causa). El objetivo es justificar la utilidad de este criterio como vía para optimizar el resultado de la comunicación segmentada. Con dicho fin, se ha estudiado un caso real planteado de forma experimental midiendo las actitudes de una muestra de 276 internautas antes y después de visualizar un sp…

Nucleo-cytoplasmic shuttling of RNA-binding factors: mRNA buffering and beyond.

2022

Gene expression is a highly regulated process that adapts RNAs and proteins content to the cellular context. Under steady-state conditions, mRNA homeostasis is robustly maintained by tight controls that act on both nuclear transcription and cytoplasmic mRNA stability. In recent years, it has been revealed that several RNA-binding proteins (RBPs) that perform functions in mRNA decay can move to the nucleus and regulate transcription. The RBPs involved in transcription can also travel to the cytoplasm and regulate mRNA degradation and/or translation. The multifaceted functions of these shuttling nucleo-cytoplasm RBPs have raised the possibility that they can act as mRNA metabolism coordinator…

The selection of serum-independent PC12 cells for a more-reliable manganese cytotoxicity test.

2007

A major issue concerning the protocols of heavy metal cytotoxicity tests with PC12 cells was the hypothesis that serum in the culture medium might sequester the metal, thus altering the results obtained. However, serum withdrawal impairs the viability of PC12 cells themselves, thus impeding cytotoxicity testing in the absence of serum. In this study, we repeatedly selected undifferentiated, totally non-adherent PC12 cells in Petri dishes. Surprisingly, we discovered that these cells could survive and proliferate in serum-free medium. Moreover, features such as NGF-responsiveness, resazurin reduction potential, doubling rate, protein content, and basal caspase-3 enzyme activity, were equiva…

The effect of cadmium on brain cells in culture

2009

Cadmium is a long-living heavy metal, abundantly present in the environment, which accumulates in the body. In this study, we investigated the effects of cadmium on the expression of molecular chaperones, and of certain cell-specific proteins, in a variety of brain cell types in culture, namely primary cultures of rat cortical neurons and astrocytes, a brain capillary endothelial cell line (RB4E.B cells), and pheochromocytoma cells (PC12), induced or not to differentiate by NGF treatment. The metal induces a dose-dependent increase of Hsp70 in all cell types. Responses to the metal are cell-specific in the case of Hsc70 and Hsp90: i) in astrocytes, as well as in PC12 cells, cadmium has no s…

Korupcija Latvijas Republikas vietvarās

2022

Šī bakalaura darba uzdevums ir analizēt un dot ieskatu tā lasītājam par korupcijas jēdziena un sankciju izmaiņām laika gaitā, kādi ir korupcijas izskaušanas centieni, panāktie līdzšinējie rezultāti, un kādas izmaiņas normatīvajos aktos ir iespējamas vai nepieciešamas sekmīgākai noziedzīgā nodarījuma prevencijai. Lai arī ir veikti krietni uzlabojumi centienos novērst koruptīva rakstura noziedzīgus nodarījumus valsts pārvaldē, joprojām pastāv riski, kurus tik viegli likvidēt nevar, it īpaši mazajās pašvaldībās, kur sabiedriskā iesaiste politiskos procesos ir mazāka nekā lielajās pašvaldībās un arī politiskā konkurence ir ievērojami apsīkusi, atsevišķās mazajās pašvaldībās vieniem un tiem paši…

Changes in Cement Paste and Mortar Fluidity after mixing induced by PCP: A parametric study

2006

International audience; The interaction mechanism between polycarboxylate-type superplasticizer (PCP) and cement hydration is not fully understood and incompatibilities between concrete and additive are sometimes observed. In some cases, the fluidity tends to increase (“overfluidification”) few minutes after mixing. This is a problem because the overfluidification leds to bleeding of the concrete which could be critical on job site. Our study consisted first in highlighting the phenomenon of “over-fluidification” by slump flow tests on mortar. Next, the time evolution of the rheological behaviour of cement pastes in the presence of PCP was analysed thanks to a rheometry protocol in order to…

The Process-inducing Activity of Transmembrane Agrin Requires Follistatin-like Domains

2009

Clustering or overexpression of the transmembrane form of the extracellular matrix proteoglycan agrin in neurons results in the formation of numerous highly motile filopodia-like processes extending from axons and dendrites. Here we show that similar processes can be induced by overexpression of transmembrane-agrin in several non-neuronal cell lines. Mapping of the process-inducing activity in neurons and non-neuronal cells demonstrates that the cytoplasmic part of transmembrane agrin is dispensable and that the extracellular region is necessary for process formation. Site-directed mutagenesis reveals an essential role for the loop between beta-sheets 3 and 4 within the Kazal subdomain of t…

Role of the cellular prion protein in oligodendrocyte precursor cell proliferation and differentiation in the developing and adult mouse CNS

2012

There are numerous studies describing the signaling mechanisms that mediate oligodendrocyte precursor cell (OPC) proliferation and differentiation, although the contribution of the cellular prion protein (PrP c) to this process remains unclear. PrP c is a glycosyl-phosphatidylinositol (GPI)-anchored glycoprotein involved in diverse cellular processes during the development and maturation of the mammalian central nervous system (CNS). Here we describe how PrP c influences oligodendrocyte proliferation in the developing and adult CNS. OPCs that lack PrP c proliferate more vigorously at the expense of a delay in differentiation, which correlates with changes in the expression of oligodendrocyt…

2020

The acid sphingomyelinase (ASM)/ceramide system exhibits a crucial role in the pathology of major depressive disorder (MDD). ASM hydrolyzes the abundant membrane lipid sphingomyelin to ceramide that regulates the clustering of membrane proteins via microdomain and lipid raft organization. Several commonly used antidepressants, such as fluoxetine, rely on the functional inhibition of ASM in terms of their antidepressive pharmacological effects. Transient receptor potential canonical 6 (TRPC6) ion channels are located in the plasma membrane of neurons and serve as receptors for hyperforin, a phytochemical constituent of the antidepressive herbal remedy St. John’s wort. TRPC6 channels are invo…