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1.
Vet Radiol Ultrasound ; 56(2): 204-11, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25395066

RESUMO

T2-weighted (T2w) sequences are commonly relied upon in magnetic resonance imaging protocols for the detection of brain lesions in dogs. Previously, the effect of fluid suppression via fluid-attenuated inversion recovery (FLAIR) has been compared to T2-weighting with mixed results. Short tau inversion recovery (STIR) has been reported to increase the detection of some CNS lesions in people. The purpose of the current study was to evaluate the effect of fat suppression on brain parenchymal contrast resolution and lesion detection in dogs. We compared three sequences: T2w images, STIR, and T2w FLAIR with chemical fat suppression (T2-FLAIR-FS) in dogs with meningoencephalitis. Dogs with meningoencephalitis and dogs with idiopathic epilepsy were retrospectively identified and anonymized. Evaluators recorded the presence or absence of lesions within 12 predetermined brain regions on randomized sequences, viewing and scoring each sequence individually. Additionally, signal-to-noise ratios, contrast-to-noise ratios, and relative contrast (RC) were measured in a reference population. Short tau inversion recovery sequences had the highest RC between gray and white matter. While descriptively more lesions were identified by evaluators on T2-FLAIR-FS images, there was no statistical difference in the relative sensitivity of lesion detection between the sequences. Nor was there a statistical difference in false lesion detection within our reference population. Short tau inversion recovery may be favored for enhanced anatomic contrast depiction in brain imaging. No benefit of the inclusion of a fat-suppressed T2-FLAIR sequence was found.


Assuntos
Encéfalo/patologia , Doenças do Cão/diagnóstico , Epilepsia/veterinária , Imagem por Ressonância Magnética/veterinária , Meningoencefalite/veterinária , Animais , Cerebelo/patologia , Meios de Contraste , Diencéfalo/patologia , Cães , Feminino , Lobo Frontal/patologia , Substância Cinzenta/patologia , Giro do Cíngulo/patologia , Aumento da Imagem/métodos , Imagem por Ressonância Magnética/métodos , Masculino , Mesencéfalo/patologia , Mielencéfalo/patologia , Lobo Occipital/patologia , Ponte/patologia , Estudos Retrospectivos , Razão Sinal-Ruído , Telencéfalo/patologia , Lobo Temporal/patologia , Substância Branca/patologia
2.
Eur J Pharmacol ; 676(1-3): 41-50, 2012 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-22178921

RESUMO

Palmitoylethanolamide (PEA), a peroxisome proliferator-activated receptor-α (PPAR-α) ligand, exerts antinociceptive and anti-inflammatory effects. PEA (3 and 6 nmol) was microinjected in the ventrolateral periaqueductal grey (VL PAG) of male rats and effects on nociceptive responses and ongoing and tail flick-related activities of rostral ventromedial medulla (RVM) ON and OFF cells were recorded. Intra-PAG microinjection of PEA reduced the ongoing activity of ON and OFF cells and produced an increase in the latency of the nociceptive reaction. These effects were prevented by a selective PPAR-α antagonist, GW6471 and by a large-conductance Ca(2+)-activated K(+) channel inhibitor, charybdotoxin. Cannabinoid 1 (CB(1)) receptor blockade by AM251 increased the PEA-induced effect both on the ongoing activity of the ON cell and on the latency to tail flick without affecting the effect of PEA on the OFF cell. Conversely, a transient receptor potential vanilloid type 1 (TRPV(1)) blocker, I-RTX, had no effect on the ON cell activity and tail flick latency, whereas it blocked the PEA-induced decrease in ongoing activity of the OFF cell. PEA decreased the burst and increased the latency of tail flick-evoked onset of ON cell activity in a manner antagonised by GW6471 and charybdotoxin. AM251 and I-RTX, instead, enhanced these latter effects. In conclusion, intra-VL PAG PEA induces antinociceptive effects associated with a decrease in RVM ON and OFF cell activities. PPAR-α receptors mediate, and CB(1) and TRPV(1) receptors antagonise, PEA-induced effects within the PAG-RVM circuitry.


Assuntos
Analgésicos/farmacologia , Mielencéfalo/citologia , Neurônios/efeitos dos fármacos , Nociceptividade/efeitos dos fármacos , Ácidos Palmíticos/farmacologia , Substância Cinzenta Periaquedutal/efeitos dos fármacos , Temperatura , Animais , Comportamento Animal/efeitos dos fármacos , Endocanabinoides , Etanolaminas , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Mielencéfalo/efeitos dos fármacos , Mielencéfalo/metabolismo , Neurônios/citologia , Neurônios/metabolismo , PPAR alfa/antagonistas & inibidores , PPAR alfa/metabolismo , Canais de Potássio Cálcio-Ativados/antagonistas & inibidores , Ratos , Ratos Wistar , Receptor CB1 de Canabinoide/antagonistas & inibidores , Canais de Cátion TRPV/antagonistas & inibidores
3.
Int J Dev Biol ; 55(6): 633-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21948712

RESUMO

Decorin, a proteoglycan, interacts with extracellular matrix proteins, growth factors and receptors. Decorin expression and spatio-temporal distribution were studied by RT-PCR and immunofluorescence, while decorin function was examined by blocking antibodies in the early chick embryo. Decorin was first detectable at stage XIII (late blastula). During gastrulation (stage HH3-4), decorin fluorescence was intense in epiblast cells immediately adjacent to the streak, and in migrating cells. Decorin fluorescence was intense in endoderm and strong at mesoderm-neural plate surfaces at stage HH5-6 (neurula). At stage HH10-11 (12 somites), decorin fluorescence was intense in myelencephalon and then showed distinct expression patterns along the myelencephalon axes by stage HH17. Decorin fluorescence was intense in neural crest cells, dorsal aorta, heart, somite and neuroepithelial cells apposing the somite, nephrotome, gut and in pancreatic and liver primordia. Antibody-mediated inhibition of decorin function affected the head-to-tail embryonic axis extension, indicating that decorin is essential for convergent extension cell movements during avian gastrulation. Decorin was also essential for retinal progenitor cell polarization, neural crest migration, somite boundary formation and cell polarization, mesenchymal cell polarization and primary endoderm displacement to the embryo periphery. The embryonic blood vessels were deformed, the dorsal mesocardium was thinned and the cardiac jelly was abnormally thickened in the heart. Decorin is known to modulate collagen fibrillogenesis, a key mechanism of matrix assembly, and cell proliferation. Decorin also appears to be essential for the coordination of cell and tissue polarization, which is an important feature in organ patterning of the embryo.


Assuntos
Embrião de Galinha/metabolismo , Decorina/biossíntese , Animais , Anticorpos Bloqueadores/imunologia , Blástula/metabolismo , Movimento Celular , Polaridade Celular , Embrião de Galinha/irrigação sanguínea , Decorina/imunologia , Decorina/metabolismo , Endoderma/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Imunofluorescência , Gastrulação , Regulação da Expressão Gênica no Desenvolvimento , Camadas Germinativas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Mesoderma/metabolismo , Mielencéfalo/embriologia , Crista Neural/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Somitos/metabolismo
4.
Stem Cells ; 29(8): 1294-303, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21630378

RESUMO

Chronic pain conditions are difficult to treat and are major health problems. Bone marrow stromal cells (BMSCs) have generated considerable interest as a candidate for cell-based therapy. BMSCs are readily accessible and are easy to isolate and expand ex vivo. Clinical studies show that direct injection of BMSCs does not produce unwanted side effects and is well tolerated and safe. Here, we show that a single systemic (intravenous) or local injection (into the lesion site) of rat primary BMSCs reversed pain hypersensitivity in rats after injury and that the effect lasted until the conclusion of the study at 22 weeks. The pain hypersensitivity was rekindled by naloxone hydrochloride, an opioid receptor antagonist that acts peripherally and centrally, when tested at 1-5 weeks after BMSC infusion. In contrast, naloxone methiodide, a peripherally acting opioid receptor antagonist, only rekindled hyperalgesia in the first 3 weeks of BMSC treatment. Focal downregulation of brainstem mu opioid receptors by RNA interference (RNAi) reversed the effect of BMSCs, when RNAi was introduced at 5- but not 1-week after BMSC transplantation. Thus, BMSCs produced long-term relief of pain and this effect involved activation of peripheral and central opioid receptors in distinct time domains. The findings prompt studies to elucidate the cellular mechanisms of the BMSC-induced pain relieving effect and translate these observations into clinical settings.


Assuntos
Transplante de Medula Óssea , Transplante de Células-Tronco Mesenquimais , Manejo da Dor , Células Estromais/transplante , Animais , Antígenos CD/metabolismo , Células da Medula Óssea/metabolismo , Forma Celular , Masculino , Células-Tronco Mesenquimais/metabolismo , Mielencéfalo/metabolismo , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Interferência de RNA , Ratos , Ratos Sprague-Dawley , Receptores Opioides mu/genética , Receptores Opioides mu/metabolismo , Células Estromais/metabolismo , Traumatismos dos Tendões/terapia
5.
Anat Rec (Hoboken) ; 290(12): 1459-79, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17957751

RESUMO

This article provides the first anatomically labeled, magnetic resonance imaging (MRI) -based atlas of the subadult and fetal Atlantic white-sided dolphin (Lagenorhynchus acutus) brain. It differs from previous MRI-based atlases of cetaceans in that it was created from images of fresh, postmortem brains in situ rather than extracted, formalin-fixed brains. The in situ images displayed the classic hallmarks of odontocete brains: fore-shortened orbital lobes and pronounced temporal width. Olfactory structures were absent and auditory regions (e.g., temporal lobes and inferior colliculi) were enlarged. In the subadult and fetal postmortem MRI scans, the hippocampus was identifiable, despite the relatively small size of this structure in cetaceans. The white matter tracts of the fetal hindbrain and cerebellum were pronounced, but in the telencephalon, the white matter tracts were much less distinct, consistent with less myelin. The white matter tracts of the auditory pathways in the fetal brains were myelinated, as shown by the T2 hypointensity signals for the inferior colliculus, cochlear nuclei, and trapezoid bodies. This finding is consistent with hearing and auditory processing regions maturing in utero in L. acutus, as has been observed for most mammals. In situ MRI scanning of fresh, postmortem specimens can be used not only to study the evolution and developmental patterns of cetacean brains but also to investigate the impacts of natural toxins (such as domoic acid), anthropogenic chemicals (such as polychlorinated biphenyls, polybrominated diphenyl ethers, and their hydroxylated metabolites), biological agents (parasites), and noise on the central nervous system of marine mammal species.


Assuntos
Encéfalo/anatomia & histologia , Golfinhos/anatomia & histologia , Feto/anatomia & histologia , Animais , Encéfalo/embriologia , Diencéfalo/anatomia & histologia , Diencéfalo/embriologia , Imagem por Ressonância Magnética , Masculino , Mesencéfalo/anatomia & histologia , Mesencéfalo/embriologia , Mielencéfalo/anatomia & histologia , Mielencéfalo/embriologia , Vias Neurais/anatomia & histologia , Vias Neurais/embriologia , Telencéfalo/anatomia & histologia , Telencéfalo/embriologia
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