207 research outputs found

    Expression Of The Proto-oncogene C-fos Following Electrical Kindling In The Rat

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    Kindling is an example of permanent change in brain function that results from repeated elicitation of epileptiform neural activity. The molecular/genetic mechanisms by which kindling is produced and maintained are just beginning to be addressed. Recently two proto-oncogenes, c-fos and c-Ha-ras, have been identified as possible mediators of intracellular signal transduction and may mediate the kindling process. Additionally, c-fos, has been proposed as the gene responsible for turning on molecular events that might underlie the long-term neural changes that occur during kindling. The objective of the present study was to: (i) further investigate the enhancement of c-fos and c-Ha-ras levels following kindled seizures and (ii) investigate the role of c-fos in the plastic changes underlying kindling.;In this study, male hooded rats, were electrically kindled and the resulting c-fos and c-Ha-ras gene expression was quantified using Northern blot analysis. The results indicated that: (i) c-fos was constitutively expressed in forebrain and cerebellum, (ii) basal levels of c-fos were equivalent in naive and in fully kindled rats that has been seizure free for 3 weeks, (iii) an amygdala-pyriform kindled seizure massively and transiently increased c-fos levels, (iv) kindled seizure enhancement of c-fos was observed throughout forebrain and cerebellum, (v) enhancement of AD duration corresponded to enhanced c-fos levels, (vi) enhanced c-fos levels were observed in the amygdala-pyriform contralateral to the kindled site, and the enhancement did not depend on the occurrence of Ad in the contralateral amygdala-pyriform, (vii) electrical stimulations not resulting in AD increased c-fos levels, (viii) c-fos levels were increased by control stimulation, (ix) c-fos induction was partially refractory, (x) PTZ caused c-fos induction independent of a motor convulsion, and (xi) kindled seizures did not alter the expression of c-Ha-ras.;The most parsimonious explanation that accounts for the observations made in this study is that c-fos was expressed simply as a consequence of neural activity and not exclusively due to the specific neural activity (afterdischarge) required for kindling

    Fast oxygen dynamics as a potential biomarker for epilepsy

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    Canadian Institutes of Health Research (GCT: MOP#130495, JGH: MOP#125984).Peer ReviewedChanges in brain activity can entrain cerebrovascular dynamics, though this has not been extensively investigated in pathophysiology. We assessed whether pathological network activation (i.e. seizures) in the Genetic Absence Epilepsy Rat from Strasbourg (GAERS) could alter dynamic fluctuations in local oxygenation. Spontaneous absence seizures in an epileptic rat model robustly resulted in brief dips in cortical oxygenation and increased spectral oxygen power at frequencies greater than 0.08 Hz. Filtering oxygen data for these fast dynamics was sufficient to distinguish epileptic vs. non-epileptic rats. Furthermore, this approach distinguished brain regions with seizures from seizure-free brain regions in the epileptic rat strain. We suggest that fast oxygen dynamics may be a useful biomarker for seizure network identification and could be translated to commonly used clinical tools that measure cerebral hemodynamics

    Supraclavicular Subclavian Access for Sapien Transcatheter Aortic Valve Replacement: A Novel Approach

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    BACKGROUND: Within the trans-subclavian approach, procedural techniques can vary widely, and reported access generally refers to an infraclavicular axillary approach. We describe and report the use of a novel supraclavicular true subclavian approach for transcatheter aortic valve replacement (TAVR) exclusively for implantation of Sapien 3 valves. CASE PRESENTATION: We report our first five consecutive patients undergoing TAVR with a Sapien 3 valve using a standardized subclavian approach at a single center. In-hospital and 30-day complications were reported. The use of this approach resulted in successful implantation in 100% of patients in a safe manner with 0% mortality, stroke, and vascular injury during hospitalization and at 30 day follow-up. The in-hospital pacemaker implantation rate was 20%. The average length of stay was 3 days. CONCLUSIONS: TAVR with Sapien implant can be safely performed with a standardized supraclavicular subclavian approach in patients with unfavorable femoral access

    Unworking Milton: Steps to a Georgics of the Mind

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    Traditionally read as a poem about laboring subjects who gain power through abstract and abstracting forms of bodily discipline, John Milton’s Paradise Lost (1667, 1674) more compellingly foregrounds the erotics of the Garden as a space where humans and nonhumans intra-act materially and sexually. Following Christopher Hill, who long ago pointed to not one but two revolutions in the history of seventeenth-century English radicalism—the first, ‘the one which succeeded[,] . . . the protestant ethic’; and the second, ‘the revolution which never happened,’ which sought ‘communal property, a far wider democracy[,] and rejected the protestant ethic’—I show how Milton’s Paradise Lost gives substance to ‘the revolution which never happened’ by imagining a commons, indeed a communism, in which human beings are not at the center of things, but rather constitute one part of the greater ecology of mind within Milton’s poem. In the space created by this ecological reimagining, plants assume a new agency. I call this reimagining ‘ecology to come.

    Systematic assessment of training-induced changes in corticospinal output to hand using frameless stereotaxic transcranial magnetic stimulation.

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    Measuring changes in the characteristics of corticospinal output has become a critical part of assessing the impact of motor experience on cortical organization in both the intact and injured human brain. In this protocol we describe a method for systematically assessing training-induced changes in corticospinal output that integrates volumetric anatomical MRI with transcranial magnetic stimulation (TMS). A TMS coil is sited to a target grid superimposed onto a 3D MRI of cortex using a stereotaxic neuronavigation system. Subjects are then required to exercise the first dorsal interosseus (FDI) muscle on two different tasks for a total of 30 min. The protocol allows for reliably and repeatedly detecting changes in corticospinal output to FDI muscle in response to brief periods of motor training

    Modelling the limits on the response of net carbon exchange to fertilization in a south-eastern pine forest

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    Using a combination of model simulations and detailed measurements at a hierarchy of scales conducted at a sandhills forest site, the effect of fertilization on net ecosystem exchange ( NEE ) and its components in 6-year-old Pinus taeda stands was quantified. The detailed measurements, collected over a 20-d period in September and October, included gas exchange and eddy covariance fluxes, sampled for a 10-d period each at the fertilized stand and at the control stand. Respiration from the forest floor and above-ground biomass was measured using chambers during the experiment. Fertilization doubled leaf area index (LAI) and increased leaf carboxylation capacity by 20%. However, this increase in total LAI translated into an increase of only 25% in modelled sunlit LAI and in canopy photosynthesis. It is shown that the same climatic and environmental conditions that enhance photosynthesis in the September and October periods also cause an increase in respiration The increases in respiration counterbalanced photosynthesis and resulted in negligible NEE differences between fertilized and control stands. The fact that total biomass of the fertilized stand exceeded 2·5 times that of the control, suggests that the counteracting effects cannot persist throughout the year. In fact, modelled annual carbon balance showed that gross primary productivity ( GPP ) increased by about 50% and that the largest enhancement in NEE occurred in the spring and autumn, during which cooler temperatures reduced respiration more than photosynthesis. The modelled difference in annual NEE between fertilized  and  control  stands  (approximately  200 1;g 2;C 3;m −2 y −1 )  suggest that the effect of fertilization was sufficiently large to transform the stand from a net terrestrial carbon source to a net sink.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73712/1/j.1365-3040.2002.00896.x.pd

    Acompanhamento de pacientes submetidos à cirurgia bariátrica : aspectos laboratoriais nos períodos pré e pós-operatório

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    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Farmácia, Florianópolis, 2017A obesidade é uma doença crônica e endócrino-metabólica caracterizada pelo acúmulo excessivo de triacilgliceróis no tecido adiposo, capaz de ser revertida ou amenizada através de intervenção cirúrgica. Epidemiologicamente têm sido descritas associações entre o excesso de peso, resistência à insulina e processo inflamatório crônico. Além disso, nas últimas décadas o sistema complemento foi associado a doenças metabólicas e cardiovasculares e intimamente relacionado com a obesidade e resistência à insulina. Sendo assim, a melhora do estado metabólico e a remissão da inflamação em pacientes obesos submetidos à cirurgia bariátrica foram avaliadas, bem como a associação dos fatores 3 e 4 (C3 e C4) do sistema complemento com a sensibilidade à insulina e a perda de peso após a cirurgia bariátrica. Para isso, a presença de comorbidades e as concentrações séricas de leptina, adiponectina, resistina e grelina foram avaliados em pacientes obesos mórbidos antes, 1, 3 e 6 meses após a cirurgia bariátrica. Também foram medidas as concentrações de IL-1ß, IL-6, TNF-a, proteína amiloide sérica A (SAA), proteína quimiotática de monócitos 1 (MCP-1), C3, C4, glicose, insulina, colesterol total, triacilglicerol, LDL- colesterol, HDL-colesterol e foi realizado o cálculo do modelo de avaliação da homeostase da resistência à insulina (HOMA-IR) durante o seguimento da cirurgia, bem como em comparação com um grupo de indivíduos não-obesos. Como resultado, observou-se uma redução significativa de peso acompanhada de melhora do perfil lipídico, da sensibilidade à insulina e das comorbidades. Ainda, houve diminuição de leptina e aumento de adiponectina no período pós-cirúrgico. IL-1ß, IL-6, TNF-a, MCP-1 e SAA não mostraram diferença no acompanhamento da cirurgia, porém SAA correlacionou-se com o IMC e apresentou-se muito mais alto no grupo de pacientes obesos. Além disso, C3 e C4 foram significativamente maiores em indivíduos obesos quando comparados aos indivíduos não-obesos e C3 e C4 foram positivamente correlacionados com HOMA-IR e as concentrações de C3 foram significativamente diminuídas após a cirurgia. Com base nesses resultados, a cirurgia bariátrica mostrou melhorar o estado metabólico melhorando as comorbidades associadas à obesidade e os biomarcadores de adiposidade leptina e adiponectina, mas não os demais hormônios e citocinas inflamatórias e C3 e C4 foram fortemente associados à sensibilidade à insulina.Abstract: Obesity is a chronic and endocrine-metabolic disease characterized by triacylglycerol accumulation in the adipose tissue, which can be reversed or improved through surgical intervention. Epidemiologically, associations between overweight, insulin resistance and chronic inflammatory process have been described. Furthermore, in the last decades the complement system was associated with metabolic and cardiovascular diseases and related to obesity and insulin resistance. Thus, metabolic status improvement and inflammation remission in obese patients undergoing bariatric surgery were evaluated, as well as the association of complement system factors 3 and 4 (C3 and C4) with insulin sensitivity and weight loss after bariatric surgery. For this, comorbidities and leptin, adiponectin, resistin and ghrelin serum concentrations were evaluated in morbidly obese patients before, 1, 3 and 6 months after bariatric surgery. IL-1ß, IL-6, TNF-a, serum amyloid A protein (SAA), monocyte chemotactic protein 1 (MCP-1), C3, C4, glucose, insulin, total cholesterol, triacylglycerol, LDL-cholesterol, HDL-cholesterol concentrations and the calculation of the homeostasis model of insulin resistance (HOMA-IR) were performed during the surgery follow-up, as well in a group of non-obese individuals. As a result, significant weight loss followed by improvement in lipid profile, insulin sensitivity and comorbidities were observed. Still, there was a decrease in leptin and an increase in adiponectin in the postoperative period. IL-1ß, IL-6, TNF-a, MCP-1 and SAA showed no difference after surgery, but SAA correlated with BMI and was much higher in obese patients. In addition, both C3 and C4 were significantly higher in obese individuals when compared to lean individuals and positively correlated with HOMA-IR. C3 concentrations were significantly decreased after surgery. Based on these results, bariatric surgery has been shown to improve metabolic status by improving obesity-associated comorbidities and adiposity biomarkers leptin and adiponectin but not the other hormones and inflammatory cytokines and C3 and C4 were strongly associated with insulin sensitivity
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