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1.
PLoS One ; 15(7): e0235663, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32716914

RESUMO

The Alzheimer's Disease Neuroimaging (ADNI) database is an expansive undertaking by government, academia, and industry to pool resources and data on subjects at various stage of symptomatic severity due to Alzheimer's disease. As expected, magnetic resonance imaging is a major component of the project. Full brain images are obtained at every 6-month visit. A range of cognitive tests studying executive function and memory are employed less frequently. Two blood draws (baseline, 6 months) provide samples to measure concentrations of approximately 145 plasma biomarkers. In addition, other diagnostic measurements are performed including PET imaging, cerebral spinal fluid measurements of amyloid-beta and tau peptides, as well as genetic tests, demographics, and vital signs. ADNI data is available upon review of an application. There have been numerous reports of how various processes evolve during AD progression, including alterations in metabolic and neuroendocrine activity, cell survival, and cognitive behavior. Lacking an analytic model at the onset, we leveraged recent advances in machine learning, which allow us to deal with large, non-linear systems with many variables. Of particular note was examining how well binary predictions of future disease states could be learned from simple, non-invasive measurements like those dependent on blood samples. Such measurements make relatively little demands on the time and effort of medical staff or patient. We report findings with recall/precision/area under the receiver operator curve after application of CART, Random Forest, Gradient Boosting, and Support Vector Machines, Our results show (i) Random Forests and Gradient Boosting work very well with such data, (ii) Prediction quality when applied to relatively easily obtained measurements (Cognitive scores, Genetic Risk and plasma biomarkers) achieve results that are competitive with magnetic resonance techniques. This is by no means an exhaustive study, but instead an exploration of the plausibility of defining a series of relatively inexpensive, broad population based tests.


Assuntos
Doença de Alzheimer/diagnóstico , Biomarcadores/metabolismo , Encéfalo/diagnóstico por imagem , Aprendizado de Máquina , Neuroimagem/métodos , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Apolipoproteína A-V/sangue , Área Sob a Curva , Biomarcadores/sangue , Bases de Dados Factuais , Progressão da Doença , Humanos , Imageamento por Ressonância Magnética , Análise de Componente Principal , Curva ROC
2.
J Ophthalmol ; 2016: 8734309, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26942004

RESUMO

Zeaxanthin at nonlethal dosages (3-10 µM) significantly inhibited the cell migration of cultured uveal melanoma cells (C918 cell line) as determined by wound healing assay and Boyden chamber assay. Matrigel invasion assay showed that cell invasion of uveal melanoma cells could be significantly inhibited by zeaxanthin. Secretion of MMP-2 by melanoma cells was significantly inhibited by zeaxanthin in a dose-dependent manner as measured by ELISA kit. Zeaxanthin also significantly inhibited the NF-κB levels in nuclear extracts of the UM cells, which is the upstream of the MMP-2 secretion. These results suggest that zeaxanthin might be a potentially therapeutic approach in the prevention of metastasis in uveal melanoma.

3.
Surg Radiol Anat ; 38(5): 619-23, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26470871

RESUMO

PURPOSE: Unexpected clinical outcomes following transection of single nerves of the internal acoustic meatus have been reported. Therefore, this study aimed to investigate interneural connections between the nervus intermedius and the adjacent nerves in the cerebellopontine angle. METHODS: On 100 cadaveric sides, dissections were made of the facial/vestibulocochlear complex in the cerebellopontine angle with special attention to the nervus intermedius and potential connections between this nerve and the adjacent facial or vestibulocochlear nerves. RESULTS: A nervus intermedius was identified on all but ten sides. Histologically confirmed neural connections were found between the nervus intermedius and either the facial or vestibulocochlear nerves on 34 % of sides. The mean diameter of these small interconnecting nerves was 0.1 mm. The fiber orientation of these nerves was usually oblique (anteromedial or posterolateral) in nature, but 13 connections traveled anteroposteriorly. Connecting fibers were single on 81 % of sides, doubled on 16 %, and tripled on 3 %, six sides had connections both with the facial nerve anteriorly and the vestibular nerves posteriorly. On 6.5 % of sides, a connection was between the nervus intermedius and cochlear nerve. For vestibular nerve connections with the nervus intermedius, 76 % were with the superior vestibular nerve and 24 % with the inferior vestibular nerve. CONCLUSIONS: Knowledge of the possible neural interconnections found between the nervus intermedius and surrounding nerves may prove useful to surgeons who operate in these regions so that inadvertent traction or transection is avoided. Additionally, unanticipated clinical presentations and exams following surgery may be due to such neural interconnections.


Assuntos
Ângulo Cerebelopontino/anatomia & histologia , Nervo Facial/anatomia & histologia , Vias Neurais/anatomia & histologia , Osso Temporal/inervação , Nervo Vestibulococlear/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Variação Anatômica , Cadáver , Ângulo Cerebelopontino/cirurgia , Dissecação , Nervo Facial/cirurgia , Feminino , Humanos , Complicações Intraoperatórias/prevenção & controle , Masculino , Microcirurgia/efeitos adversos , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos
4.
Childs Nerv Syst ; 31(1): 15-28, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25395307

RESUMO

INTRODUCTION: Liliequist's membrane is an arachnoid membrane that forms a barrier within the basilar cisternal complex. This structure is an important landmark in approaches to the sellar and parasellar regions. The importance of this membrane was largely recognized after the advance of neuroendoscopic techniques. Many studies were, thereafter, published reporting different anatomic findings. METHOD: A detailed search for studies reporting anatomic and surgical findings of Liliequist's membrane was performed using "PubMed," and included all the available literature. Manual search for manuscripts was also conducted on references of papers reporting reviews. RESULTS: Liliequist's membrane has received more attention recently. The studies have reported widely variable results, which were systematically organized in this paper to address the controversy. CONCLUSION: Regardless of its clinical and surgical significance, the anatomy of Liliequist's membrane is still a matter of debate.


Assuntos
Aracnoide-Máter/anatomia & histologia , Neurocirurgia , Humanos , PubMed/estatística & dados numéricos , Espaço Subaracnóideo/anatomia & histologia
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