965 resultados para 320704 Cellular Nervous System


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We report here two postmortem cases of dogs with intravascular lymphomatosis affecting the central nervous system. Intravascular lymphomatosis is represented by an exclusively intravascular proliferation of neoplastic lymphoid cells. To characterize the origin of the neoplastic cells, we have proceeded with immunohistochemical analysis to identify B and T lymphocytes and endothelial cells. The results showed predominance of cells from the T cell lineage, and no evidence of B cell origin was found. Few cells from one dog also exhibited cytoplasmatic staining for vimentin and Von Willebrand factor. Although in one case some immunophenotype diversity was observed, the massive presence of CD3 positive cells confirmed these neoplasms as intravascular lymphomatosis of T cell origin.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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To report the audiological outcomes of cochlear implantation in two patients with severe to profound sensorineural hearing loss secondary to superficial siderosis of the CNS and discuss some programming peculiarities that were found in these cases. Retrospective review. Data concerning clinical presentation, diagnosis and audiological assessment pre- and post-implantation were collected of two patients with superficial siderosis of the CNS. Both patients showed good hearing thresholds but variable speech perception outcomes. One patient did not achieve open-set speech recognition, but the other achieved 70% speech recognition in quiet. Electrical compound action potentials could not be elicited in either patient. Map parameters showed the need for increased charge. Electrode impedances showed high longitudinal variability. The implants were fairly beneficial in restoring hearing and improving communication abilities although many reprogramming sessions have been required. The hurdle in programming was the need of frequent adjustments due to the physiologic variations in electrical discharges and neural conduction, besides the changes in the impedances. Patients diagnosed with superficial siderosis may achieve limited results in speech perception scores due to both cochlear and retrocochlear reasons. Careful counseling about the results must be given to the patients and their families before the cochlear implantation indication.

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The aim of the present study was to investigate the participation of the sympathetic nervous system (SNS) in the control of glycerol-3-P (G3P) generating pathways in white adipose tissue (WAT) of rats in three situations in which the plasma insulin levels are low. WAT from 48 h fasted animals, 3 day-streptozotocin diabetic animals and high-protein, carbohydrate-free (HP) diet-fed rats was surgical denervated and the G3P generation pathways were evaluated. Food deprivation, diabetes and the HP diet provoke a marked decrease in the rate of glucose uptake and glycerokinase (GyK) activity, but a significant increase in the glyceroneogenesis, estimated by the phosphoenolpyruvate carboxykinase (PEPCK) activity and the incorporation of 1-[C-14]-pyruvate into glycerol-TAG. The denervation provokes a reduction (similar to 70%) in the NE content of WAT in fasted, diabetic and HP diet-fed rats. The denervation induced an increase in WAT glucose uptake of fed, fasted, diabetic and HP diet-fed rats (40%, 60%, 3.2 fold and 35%, respectively). TAG-glycerol synthesis from pyruvate was reduced by denervation in adipocytes of fed (58%) and fasted (36%), saline-treated (58%) and diabetic (23%), and HP diet-fed rats (11%). In these same groups the denervation reduced the PEPCK mRNA expression (75%-95%) and the PEPCK activity (35%-60%). The denervation caused a similar to 35% decrease in GyK activity of control rats and a further similar to 35% reduction in the already low enzyme activity of fasted, diabetic and HP diet-fed rats. These data suggest that the SNS plays an important role in modulating G3P generating pathways in WAT, in situations where insulin levels are low. (C) 2012 Elsevier Inc. All rights reserved.

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Introduction: Several presentations of neurologic complications caused by JC virus (JCV) in human immunodeficiency virus (HIV)-infected patients have been described and need to be distinguished from the "classic" form of progressive multifocal leukoencephalopathy (PML). The objectives of this study were: 1) to describe the spectrum and frequency of presentations of JCV-associated central nervous system (CNS) diseases; 2) identify factors associated with in-hospital mortality of patients with JCV-associated CNS disease; and 3) to estimate the overall mortality of this population. Material and methods: This was a retrospective study of HIV-infected patients admitted consecutively for JCV-associated CNS diseases in a referral teaching center in Sao Paulo, Brazil, from 2002 to 2007. All patients with laboratory confirmed JCV-associated CNS diseases were included using the following criteria: compatible clinical and radiological features associated with the presence of JCV DNA in the cerebrospinal fluid. JCV-associated CNS diseases were classified as follows: 1) classic PML; 2) inflammatory PML; and 3) JC virus granule cell neuronopathy (GCN). Results: We included 47 cases. JCV-associated CNS diseases were classified as follows: 1) classic PML: 42 (89%); 2) inflammatory PML: three (6%); and 3) JC virus GCN: four (9%). Nosocomial pneumonia (p = 0.003), previous diagnosis of HIV infection (p = 0.03), and imaging showing cerebellar and/or brainstem involvement (p = 0.02) were associated with in-hospital mortality. Overall mortality during hospitalization was 34%. Conclusions: Novel presentations of JCV-associated CNS diseases were observed in our setting; nosocomial pneumonia, previous diagnosis of HIV infection, and cerebellar and/or brainstem involvement were associated with in-hospital mortality; and overall mortality was high. (C) 2012 Elsevier Editora Ltda. All rights reserved.

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This study reports on the successful use of magnetic albumin nanosphere (MAN), consisting of maghemite nanoparticles hosted by albumin-based nanosphere, to target different sites within the central nervous system (CNS). Ultrastructural analysis by transmission electron microscopy (TEM) of the material collected from the mice was performed in the time window of 30 minutes up to 30 days after administration. Evidence found that the administered MAN was initially internalized and transported by erythrocytes across the blood-brain-barrier and transferred to glial cells and neuropils before internalization by neurons, mainly in the cerebellum. We hypothesize that the efficiency of MAN in crossing the BBB with no pathological alterations is due to the synergistic effect of its two main components, the iron-based nanosized particles and the hosting albumin-based nanospheres. We found that the MAN in targeting the CNS represents an important step towards the design of nanosized materials for clinical and diagnostic applications.

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During recent years a consistent number of central nervous system (CNS) drugs have been approved and introduced on the market for the treatment of many psychiatric and neurological disorders, including psychosis, depression, Parkinson disease and epilepsy. Despite the great advancements obtained in the treatment of CNS diseases/disorders, partial response to therapy or treatment failure are frequent, at least in part due to poor compliance, but also genetic variability in the metabolism of psychotropic agents or polypharmacy, which may lead to sub-therapeutic or toxic plasma levels of the drugs, and finally inefficacy of the treatment or adverse/toxic effects. With the aim of improving the treatment, reducing toxic/side effects and patient hospitalisation, Therapeutic Drug Monitoring (TDM) is certainly useful, allowing for a personalisation of the therapy. Reliable analytical methods are required to determine the plasma levels of psychotropic drugs, which are often present at low concentrations (tens or hundreds of nanograms per millilitre). The present PhD Thesis has focused on the development of analytical methods for the determination of CNS drugs in biological fluids, including antidepressants (sertraline and duloxetine), antipsychotics (aripiprazole), antiepileptics (vigabatrin and topiramate) and antiparkinsons (pramipexole). Innovative methods based on liquid chromatography or capillary electrophoresis coupled to diode-array or laser-induced fluorescence detectors have been developed, together with the suitable sample pre-treatment for interference removal and fluorescent labelling in case of LIF detection. All methods have been validated according to official guidelines and applied to the analysis of real samples obtained from patients, resulting suitable for the TDM of psychotropic drugs.

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Investigations on formation and specification of neural precursor cells in the central nervous system of the Drosophila melanogaster embryoSpecification of a unique cell fate during development of a multicellular organism often is a function of its position. The Drosophila central nervous system (CNS) provides an ideal system to dissect signalling events during development that lead to cell specific patterns. Different cell types in the CNS are formed from a relatively few precursor cells, the neuroblasts (NBs), which delaminate from the neurogenic region of the ectoderm. The delamination occurs in five waves, S1-S5, finally leading to a subepidermal layer consisting of about 30 NBs, each with a unique identity, arranged in a stereotyped spatial pattern in each hemisegment. This information depends on several factors such as the concentrations of various morphogens, cell-cell interactions and long range signals present at the position and time of its birth. The early NBs, delaminating during S1 and S2, form an orthogonal array of four rows (2/3,4,5,6/7) and three columns (medial, intermediate, and lateral) . However, the three column and four row-arrangement pattern is only transitory during early stages of neurogenesis which is obscured by late emerging (S3-S5) neuroblasts (Doe and Goodman, 1985; Goodman and Doe, 1993). Therefore the aim of my study has been to identify novel genes which play a role in the formation or specification of late delaminating NBs.In this study the gene anterior open or yan was picked up in a genetic screen to identity novel and yet unidentified genes in the process of late neuroblast formation and specification. I have shown that the gene yan is responsible for maintaining the cells of the neuroectoderm in an undifferentiated state by interfering with the Notch signalling mechanism. Secondly, I have studied the function and interactions of segment polarity genes within a certain neuroectodermal region, namely the engrailed (en) expressing domain, with regard to the fate specification of a set of late neuroblasts, namely NB 6-4 and NB 7-3. I have dissected the regulatory interaction of the segment polarity genes wingless (wg), hedgehog (hh) and engrailed (en) as they maintain each other’s expression to show that En is a prerequisite for neurogenesis and show that the interplay of the segmentation genes naked (nkd) and gooseberry (gsb), both of which are targets of wingless (wg) activity, leads to differential commitment of NB 7-3 and NB 6-4 cell fate. I have shown that in the absence of either nkd or gsb one NB fate is replaced by the other. However, the temporal sequence of delamination is maintained, suggesting that formation and specification of these two NBs are under independent control.

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Alzheimer's disease (AD) is a fatal neurodegenerative condition characterized clinically by progressive memory loss and irreversible cognitive deterioration. It has been shown that there is a progressive degeneration of the brain cholinergic neurons which leads to the appearance of cognitive symptoms of the disease. The aim of this work was the formulation of multifunctional nanocarriers for nasal administration of tacrine-HCl (THA). This route has many advantages; in particular is possible to convey the drug directly to the Central Nervous System, through the olfactory bulb. In particular, were prepared Albumin nanoparticles carrying beta cyclodextrin and two different beta cyclodextrin derivatives (hydroxypropyl beta cyclodextrin and sulphobutylether beta cyclodextrin), and Multifunctional liposomes, prepared using traditional excipients (cholesterol and phosphatidylcholine), partly enriched with α-tocopherol (Toc) and/or polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid) (Ω3). Both nanosystems were characterized in terms of size, Zeta potential and encapsulation efficiency. Were also evaluated their functional properties such as mucoadhesion and permeability, using an ex-vivo assay based on nasal sheep mucosa. On Liposomes were also assessed drug neuronal uptake, cell toxicity, antioxidant and, cytoprotective activity in the human neuronal cell line SH-SY5Y and finally tocopherol trans-membrane diffusion. Both the nanocarriers produced presented excellent properties and a high potential as new systems for CNS-delivery of anti-Alzheimer drugs via the nasal route.