861 resultados para Neonatal emergencies


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本研究探讨了新生期的触觉刺激(tactile stimulation,TS)和母婴分离(maternal separation,MS)经历对大鼠成年后空间工作记忆和空间参考记忆的影响,以及对海马-前额叶神经通路的突触可塑性产生的效应。Wistar品系的母鼠分娩后,以split-litter方法对仔鼠进行分组:NTS组的仔鼠不接受触觉刺激和母婴分离;TS组的仔鼠在出生后第2-9天(postnatal day 2-9,PND2-9),或者PND10-17内,每天接受短暂(约30s)的人为抓握,并进行体表标记;TS/MS组的仔鼠在PND2-9,或者PND10-17内,接受TS组相同方式的抓握并在不同体表部位进行标记后,被单独地放入一个杯子中,杯中有取自鼠巢的垫料,每天与母鼠分离1h后返回鼠巢。按照常规方法饲养这些在新生期有不同经历的大鼠,待其成年后(3月龄),采用交互延缓作业(纠正错误法和不纠正错误法)、空间分辨作业及反转学习作业测试雄性大鼠的学习记忆功能,并观察多巴胺D1受体激动剂A77636对不同组成年雄鼠的工作记忆是否产生影响。采用活体电生理方法,高频刺激海马腹侧部在前额叶记录突触效能长时程增强(long-term potentiation,LTP),对PND2-9有不同经历的成年大鼠(雌雄兼用)的海马-前额叶LTP进行比较。 结果:(1)各组仔鼠间在PND30、PND60和PND90的体重都没有显著性差异,表明本研究中的新生期TS处理和MS处理不影响仔鼠的体重发育。 (2)在交互延缓作业-纠正错误法中,各组成年雄鼠在0s延缓期的达标天数没有显著性差异;0s延缓期达标后,再经过30天的训练,PND2-9TS组和PND10-17TS组的成年雄鼠达到的最长延缓期明显高于NTS组,而且在30s—50s延缓期内达标(正确率≥86.7%)的大鼠数量明显较多(与NTS组相比)。采用交互延缓作业-不纠正错误法,各组成年雄鼠在0s延缓期的训练成绩没有显著性差异,但是,PND2-9TS组和PND10-17TS组的成年雄鼠在40s延缓期的训练正确率明显高于NTS组,表明新生期的TS处理明显改善成年雄性大鼠成年后的空间工作记忆。 (3)各组成年雄鼠在空间分辨作业及反转学习作业中的成绩没有明显差异,表明新生期TS经历对雄鼠成年后空间学习记忆的影响是任务依赖性的:与前额叶有关的空间工作记忆功能比较容易受到新生期TS经历的影响,而空间参考记忆相对不容易受到新生期TS经历的影响。 (4)多巴胺D1受体激动剂A77636只有1个剂量(0.1mg/kg)对NTS组成年雄鼠的交互延缓作业成绩具有明显的改善效应。对PND2-9TS组成年雄鼠的交互延缓作业成绩,A77636的0.1mg/kg和1mg/kg剂量都具有明显改善效应。对PND10-17TS组成年雄鼠的交互延缓作业成绩,A77636的0.01mg/kg、0.1mg/kg和1mg/kg剂量都具有明显改善效应。与NTS组相比,A77636对这2个TS组成年雄性大鼠的有效改善剂量范围较宽,提示新生期TS处理经历对雄性大鼠成年后空间工作记忆的改善效应与其前额叶的多巴胺D1受体功能上调有关。 (5)与NTS组相比,PND2-9TS组雄性和雌性成年大鼠的海马-前额叶神经通路的LTP幅度都明显增加。由于海马-前额叶神经通路在空间工作记忆功能中起重要作用,新生期TS经历增强大鼠成年后的海马-前额叶神经通路的突触可塑性,为新生期TS经历增强大鼠成年后的空间工作记忆提供了电生理学的证据。TS成年大鼠海马-前额叶LTP增强可能与其前额叶的D1受体功能上调有关。 (6)本研究中,TS/MS组的新生期仔鼠在PND2-9或者PND10-17内,除了接受与TS组相同方式的抓握并在不同部位标记外,每天与母鼠分离1h,因此通过不同日龄段的TS/MS组与TS组的比较,拟对新生期MS处理的效应进行评估。结果发现,无论是对成年雄性大鼠的各项行为测试(空间分辨作业、交互延缓作业、A77636影响交互延缓作业的量效曲线),还是对成年雌性大鼠的行为测试(明/暗箱作业、一次性被动回避反应,论文Ⅱ),或者对海马-前额叶神经通路的LTP,新生期的MS处理对本研究中的所有测试指标在统计上都没有显著性的差异,说明新生期每天1h的母婴分离经历对大鼠成年后的学习记忆等行为及前额叶突触可塑性没有产生明显的影响,对前额叶D1受体功能也没有明显影响。 (7)对所有测试指标,本研究采用的2个仔鼠日龄段PND2-9和PND10-17之间的统计比较没有明显差异,提示PND2-9和PND10-17甚至整个泌乳期都是仔鼠神经系统对外界环境刺激比较敏感的发育关键期。 结论:新生期的触觉刺激经历改善雄性大鼠成年后的空间工作记忆,增强海马-前额叶神经通路的突触可塑性和前额叶D1受体功能;新生期短时间的母婴分离经历对大鼠成年后的空间工作记忆和前额叶突触可塑性等没有产生明显的影响,可能具有一定的生物学适应意义。

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BACKGROUND: Hypoxia and ischemia induce neuronal damage, decreased neuronal numbers and synaptophysin levels, and deficits in learning and memory functions. Previous studies have shown that lycium barbarum polysaccharide, the most effective component of barbary wolfberry fruit, has protective effects on neural cells in hypoxia-ischemia. OBJECTIVE: To investigate the effects of Naotan Pill on glutamate-treated neural cells and on cognitive function in juvenile rats following hypoxia-ischemia. DESIGN, TIME AND SETTING: The randomized, controlled, in vivo study was performed at the Cell Laboratory of Lanzhou University, Lanzhou Institute of Modern Physics of Chinese Academy of Sciences, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from December 2005 to August 2006. The cellular neurobiology, in vitro experiment was conducted at the Institute of Human Anatomy, Histology, Embryology and Neuroscience, School of Basic Medical Sciences, Lanzhou University, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from March 2007 to January 2008. MATERIALS: Naotan Pill, composed of barbary wolfberry fruit, danshen root, grassleaf sweetflag rhizome, and glossy privet fruit, was prepared by Gansu Provincial Rehabilitation Center, China. Rabbit anti-synaptophysin, choline acetyl transferase polyclonal antibody, streptavidin-biotin complex kit and diaminobenzidine kit (Boster, Wuhan, China), as well as glutamate (Hualian, Shanghai, China) were used in this study. METHODS: Cortical neural cells were isolated from neonatal Wistar rats. Neural cell damage models were induced using glutamate, and administered Naotan Pill prior to and following damage. A total of 54 juvenile Wistar rats were equally and randomly assigned into model, Naotan Pill, and sham operation groups. The left common carotid artery was ligated, and then rat models of hypoxic-ischemic injury were assigned to the model and Naotan Pill groups. At 2 days following model induction, rats in the Naotan Pill group were administered Naotan Pill suspension for 21 days. In the model and sham operation groups, rats received an equal volume of saline. MAIN OUTCOME MEASURES: Neural cell morphology was observed using an inverted phase contrast microscope. Survival rate of neural cells was measured by MTT assay. Synaptophysin and choline acetyl transferase expression was observed in the hippocampal CA1 region of juvenile rats using immunohistochemistry. Cognitive function was tested by the Morris water maze. RESULTS: Pathological changes were detected in glutamate-treated neural cells. Neural cell morphology remained normal after Naotan Pill intervention. Absorbance and survival rate of neural cells were significantly greater following Naotan Pill intervention, compared to glutamate-treated neural cells (P < 0.05). Synaptophysin and choline acetyl transferase expression was lowest in the hippocampal CA1 region in the model group and highest in the sham operation group. Significant differences among groups were observed (P < 0.05). Escape latency and swimming distance were significantly longer in the model group compared to the Naotan Pill group (P < 0.05). CONCLUSION: Naotan Pill exhibited protective and repair effects on glutamate-treated neural cells. Naotan Pill upregulated synaptophysin and choline acetyl transferase expression in the hippocampus and improved cognitive function in rats following hypoxia-ischemia.

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设计了基于CAN协议的AUV内部通讯总线系统 .系统通过协议转换器的模块化、可配置性设计满足AUV系统对其内部通讯总线的开放性要求 .协议转换器内部的容错处理能力以及紧急事件处理节点的设计为增强AUV系统的可靠性和容错能力、为避免AUV在深海工作环境下丢失增加有力的保障措施

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The presence of tissue specific precursor cells is an emerging concept in organ formation and tissue homeostasis. Several progenitors are described in the kidneys. However, their identity as a true stem cell remains elusive. Here, we identify a neonatal kidney-derived c-kit(+) cell population that fulfills all of the criteria as a stem cell. These cells were found in the thick ascending limb of Henle's loop and exhibited clonogenicity, self-renewal, and multipotentiality with differentiation capacity into mesoderm and ectoderm progeny. Additionally, c-kit(+) cells formed spheres in nonadherent conditions when plated at clonal density and expressed markers of stem cells, progenitors, and differentiated cells. Ex vivo expanded c-kit(+) cells integrated into several compartments of the kidney, including tubules, vessels, and glomeruli, and contributed to functional and morphological improvement of the kidney following acute ischemia-reperfusion injury in rats. Together, these findings document a novel neonatal rat kidney c-kit(+) stem cell population that can be isolated, expanded, cloned, differentiated, and used for kidney repair following acute kidney injury. These cells have important biological and therapeutic implications. STEM Cells 2013;31:1644-1656

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária