作者想感谢加拿大医学研究，健康研究机构（MOP53116）和阿尔伯塔省遗产基金会的工作补助，并建立基金，分别支持发展的实验模型。

1。麻醉<ol><li>设置在2L/MIN麻醉机的流率。连接的排气真空抽吸。 </li><li>电荷与麻醉气体（异氟烷）在5％（〜3分钟）的面罩。 </li><li>新生仔猪将诱导与吸入异氟醚的5％，在100％的氧气（〜3分钟）。 </li><li>保持在2％至3％的异氟醚麻醉。经0.5％为适宜的异氟烷的精细调整，然而，它的范围可以从0.5到5％的条件取决于仔猪。 </li><li>一旦已经建立血管通路，吸入麻醉，可切换使用芬太尼（5-50微克/公斤/小时）和咪达唑仑（200-500微克/公斤/小时）注射静脉麻醉。泮库溴铵（50-100微克/公斤/小时），可能会被要求在手术过程中控制肌肉过度运动，而调整麻醉药物的能力，观察动物的状态被保存。 </li><li>仔猪监测脉搏血氧饱和度（经皮氧小号aturation在95-100％）和心电图（心脏速率为130-170次/分）。 </li><li>仔猪的直肠温度保持在38-40°C加热毯和辐射保暖台。 </li><li>定期评估麻醉状态的仔猪在整个实验期间使用的神经（瞳孔大小，撕裂，身体动作），行为（搅拌），心血管疾病（室性心动过速和高血压）和呼吸（呼吸急促）的参数是合适的。最小的麻痹。以往的经验的麻醉和瘫痪仔猪进行评估将是有益的。 </li><li>该协议是一种非生存的程序euthanization动物用过量的戊巴比妥钠（100毫克/千克）静脉注射实验结束时。 </li></ol> 2。在腹股沟手术放置血管导管（图1） <ol><li>在右侧腹股沟做一个长2-3cm的切口。 </li><li>解剖1cm的右股静脉和1cm的权利T股动脉。把两个3:0字符串大约每艘船只。 </li><li>右股静脉穿刺置管结扎远端的静脉。将亚皆老街导管（3.5或5法国，双腔）（Covidien公司，曼斯菲尔德，MA）至15厘米，这将放置在右心房。把两个字符串，以确保导管。该导管可以用于维护流体和药物输注（二级端口）和中心静脉/右心房压力测量（主端口）。 </li><li>右股动脉导管结扎远端的动脉。抬起近端串停止的血流量。亚皆老街导管（3.5或法语，单腔）插入到5厘米。这将放置在连续平均动脉压的测量和采集血样的基础设施肾主动脉的动脉导管。把两个字符串，以确保导管。 </li><li>关闭的皮肤。 </li></ol> 3。建立机械通风系统（图2） <ol><li>一个长2-3cm水平切口在脖子上。 </li><li>解剖和暴露1cm的气管。把两个1:0字符串周围的气管。 </li><li>进气管，插入气管内管在1cm（3.0或3.5）。接上了呼吸机，并开始机械通气。固定气管导管。 </li><li>解剖和暴露的颈总动脉。合抱之船过渡时间超声流量探头（2SB 2RB，跨音速的公司，Ithica，NY）连续测量血流量。 </li></ol> 4。放置肠系膜上的流量探针（图3）和左侧肾（图4）的动脉<ol><li>额外剂量的芬太尼（5-10微克/千克）和乙酰丙嗪（0.01-0.02毫克/公斤）前必须进行皮肤切口。 </li><li>长翼肋缘下切口和，仔细解剖肌肉层。 </li><li>公开腹主动脉。 </li><li>血管处理（血管痉挛）和淋巴管损伤最小化。 </li><li>解剖0.5-1CM肠系膜上动脉和把它周围的一个跨音速流动探头（3SB）。 </li><li> 0.5-1CM左肾动脉进行分析，并把它周围的一个跨音速流动探头（2SB）。 </li><li>关闭皮肤和固定流量探针。 </li></ol> 5。放置肺动脉导管（图5）和流量探针（图6） <ol><li>额外剂量的芬太尼（5-10微克/千克）和乙酰丙嗪（0.01-0.02毫克/公斤）前必须进行皮肤切口。 </li><li>在右侧卧位躺下的动物。 </li><li>在左第四肋间开胸手术。 </li><li>关注的乳内动脉和静脉，结扎，如果需要的话。 </li><li>使用牙齿的棉签按了左肺，并根据需要增加氧气。 </li><li>打开心包。 </li><li>确定动脉导管未闭，肺动脉主动脉。 </li><li>动脉导管未闭结扎放置一个片段，或由一个厚厚的“3-O丝绸领带在其原产地。 </li><li>免费的主肺动脉，并通过AV血管性吊索使用厚的领带“0”。 </li><li>执行（5-0 prolene线）荷包缝合在该基地的位置肺动脉导管。 </li><li>插入一个20G Angiocath（与3以下1厘米从导管的前端侧孔）通过荷包到最大为1厘米。 </li><li>检查自由流动静脉血液。 </li><li>连接压力传感器，检查肺动脉压和波形。 </li><li>拧紧钱袋，保护肺的导管。 </li><li>主肺动脉周围放置一个跨音速流的探头（6SB）。 </li><li>将超声波之间的流动的探头和动脉，以便实现最佳的信号转导的凝胶。 </li><li>用湿盐水纱布覆盖伤口。 </li></ol> 6。缺氧复氧协议<ol><li>吸入氧浓度降低至10％，通过增加吸入氮气的浓度诱导低氧血症。 </li><li>调整吸入氧10％和15％之间的浓度，以获得氧分压20-40毫米汞柱或2动脉血氧饱和度为30-40％，2小时。 </li><li>执行动脉血流分析，以评估二氧化碳分压，并相应地调整呼吸率。 </li><li>随着低氧血症的感应，在第一个小时稳步诱导心动过速（和心输出量）的反应。 </li><li>继续监测常见的颈动脉，肠系膜上和左肾动脉的血流量的变化。 </li><li>在第二个小时的缺氧，低氧应激稳步降低心输出量增加30％至40％的基线，平均动脉压30〜35毫米汞柱，动脉血pH值6.95-7.05。 </li><li>低氧应激可能提前终止，或适当延长15分钟。 </li><li>增加吸入氧浓度100％硬生生地突然停止氮气，同时继续纯氧。 </li><li>监测心输出量，平均动脉压等血流动力学第米，为快速恢复。 </li><li>可以用100％的氧气的复苏，持续0.5小时。在这段时间内，减少吸入氧浓度迅速至21％。 </li><li>继续复氧21％的氧气，实验的剩余期限。吸入氧浓度，可滴定至25％，如果需要的话。 </li><li>适当的实验期间，可能需要10毫升/公斤乳酸林格氏液流体丸药。它的使用有标准流程。 </li></ol> 7。代表性的成果： 在新生仔猪在第一个小时的缺氧诱导低氧血症，应增加心输出量（肺血流）120％-130％的基线（ 图7A）和心脏率（ 图7B）。通常情况下，心输出量应达到的峰值补偿之间的第一次0.5小时和1小时的缺氧。另外，血液流应该成​​为集中从而降低了我senteric和肾灌注，但保留或常见的颈动脉血流增加（ 图8）。在缺氧的第二个小时，有稳步下降，心输出量，发展低血压（ 图9A），带或不带心律失常发生心脏速率减慢。低氧诱导肺动脉高压，肺动脉压增加（ 图9B），这有时可能会降低作为心输出量减小在最后30分钟的缺氧。 在复苏，血流动力学参数将立即恢复常氧基线，除了在第一个小时的复氧肾血流量逐渐恢复。然而，血流动力学参数，特别是对心输出量和平均动脉压会逐渐下降，在第一个2小时的复氧的70％-75％左右，却有基线和35-45毫米汞柱，分别。这心血管dysfuncti是至少部分心肌顿抑及认股权证心血管支持治疗，如血管和正性肌力药物。 <img alt="图1" src="/files/ftp_upload/3166/3166fig1.jpg" /> 图1：腹股沟切口股动脉和静脉导管的位置<img alt="图2" src="/files/ftp_upload/3166/3166fig2.jpg" /> 图2：颈部切口放置气管内管和一个常见的颈动脉周围的气流探测器<img alt="图3" src="/files/ftp_upload/3166/3166fig3.jpg" /> 图3：侧面切口隔离肠系膜上动脉<img alt="图4" src="/files/ftp_upload/3166/3166fig4.jpg" /> 图4：后刀面切口左肾动脉与隔离<img alt="图5" sRC =“/ files/ftp_upload/3166/3166fig5.jpg”/&gt; 图5：开胸肺动脉导管的位置<img alt="图6" src="/files/ftp_upload/3166/3166fig6.jpg" /> 图6：开胸手术的跨音速流动探头的位置围绕主肺动脉<img alt="图7" src="/files/ftp_upload/3166/3166fig7.jpg" /> 图7：（A）心输出量（肺血流）和（B）心脏对缺氧复氧率的时间变化<img alt="图8" src="/files/ftp_upload/3166/3166fig8.jpg" /> 图8：时间变化的血流量（A）常见的颈动脉，肠系膜上（B）和（C）左肾动脉在缺氧复氧<img alt="图9" src="/files/ftp_upload/3166/3166fig9.jpg" /> 图9：时间变化（A），平均动脉压（B）肺动脉高压，缺氧复氧过程中

<ol>
	<li>Borke, W. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+myocardial+matrix+metalloproteinases+in+hypoxic+newborn+pigs+during+resuscitation:+effects+of+oxygen+and+carbon+dioxide.">Increased myocardial matrix metalloproteinases in hypoxic newborn pigs during resuscitation: effects of oxygen and carbon dioxide.</a> Eur. J. Clin. Invest. 34, 459-466 (2004).</li><li>Munkeby, B. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resuscitation+of+hypoxic+piglets+with+100%+O2+increases+pulmonary+metalloproteinases+and+IL-8.">Resuscitation of hypoxic piglets with 100% O2 increases pulmonary metalloproteinases and IL-8.</a> Pediatr. Res. 58, 542-548 (2005).</li><li>Haaland, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Posthypoxic+hypothermia+in+newborn+piglets.">Posthypoxic hypothermia in newborn piglets.</a> Pediatr. Res. 41, 505-512 (1997).</li><li>Haase, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resuscitation+with+100%+oxygen+causes+intestinal+glutathione+oxidation+and+reoxygenation+injury+in+asphyxiated+newborn+piglets.">Resuscitation with 100% oxygen causes intestinal glutathione oxidation and reoxygenation injury in asphyxiated newborn piglets.</a> Ann. Surg. 240, 364-373 (2004).</li><li>Stevens, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resuscitation+with+21%+or+100%+oxygen+is+equally+effective+in+restoring+perfusion+and+oxygen+metabolism+in+hypoxic+newborn+piglet+liver.">Resuscitation with 21% or 100% oxygen is equally effective in restoring perfusion and oxygen metabolism in hypoxic newborn piglet liver.</a> Shock. 27, 657-662 (2007).</li><li>Johnson, S. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=N-acetylcysteine+improves+the+hemodynamics+and+oxidative+stress+in+hypoxic+newborn+pigs+reoxygenated+with+100%+oxygen.">N-acetylcysteine improves the hemodynamics and oxidative stress in hypoxic newborn pigs reoxygenated with 100% oxygen.</a> Shock. 28, 484-490 (2007).</li><li>Chapados, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasma+cortisol+response+to+ACTH+challenge+in+hypoxic+newborn+piglets+resuscitated+with+21%+and+100%+oxygen.">Plasma cortisol response to ACTH challenge in hypoxic newborn piglets resuscitated with 21% and 100% oxygen.</a> Shock. 33, 519-525 (2010).</li><li>Cheung, P. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Platelet+dysfunction+in+asphyxiated+newborn+piglets+resuscitated+with+21%+and+100%+oxygen.">Platelet dysfunction in asphyxiated newborn piglets resuscitated with 21% and 100% oxygen.</a> Pediatr. Res. 59, 636-640 (2006).</li><li>Martin-Ancel, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+organ+involvement+in+perinatal+asphyxia.">Multiple organ involvement in perinatal asphyxia.</a> J. Pediatr. 127, 786-793 (1995).</li><li>Swindle, M. M., Smith, A. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+anatomy+and+physiology+of+the+pig.">Comparative anatomy and physiology of the pig.</a> Scan. J. Lab. Anim. Sci. Suppl. 25, 11-22 (1998).</li><li>Chapados, I., Cheung, P. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Not+all+models+are+created+equal:+Animal+models+to+study+hypoxic-ischemic+encephalopathy+of+the+newborn.">Not all models are created equal: Animal models to study hypoxic-ischemic encephalopathy of the newborn.</a> Neonatology. 94, 300-303 (2008).</li><li>Liu, J. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+post-resuscitation+treatment+with+N-acetylcysteine+on+cardiac+recovery+in+hypoxia-injured+newborn+pigs.">Effects of post-resuscitation treatment with N-acetylcysteine on cardiac recovery in hypoxia-injured newborn pigs.</a> PLoS ONE. 5, e15322-e15322 (2010).</li><li>Cheung, P. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardio-renal+recovery+of+hypoxic+newborn+pigs+after+18%,+21%+and+100%+reoxygenation.">Cardio-renal recovery of hypoxic newborn pigs after 18%, 21% and 100% reoxygenation.</a> Intensive Care Med. 34, 1114-1121 (2008).</li><li>Temesvari, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+the+blood-brain+barrier+permeability+in+neonatal+cytotoxic+brain+edema:+laboratory+and+morphological+findings+obtained+on+newborn+piglets+with+experimental+pneumothorax.">Modulation of the blood-brain barrier permeability in neonatal cytotoxic brain edema: laboratory and morphological findings obtained on newborn piglets with experimental pneumothorax.</a> Biol. Neonate. 46, 198-208 (1984).</li><li>Domoki, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reventilation+with+room+air+or+100%+oxygen+after+asphyxia+differentially+affects+cerebral+neuropathology+in+newborn+pigs.">Reventilation with room air or 100% oxygen after asphyxia differentially affects cerebral neuropathology in newborn pigs.</a> Acta. Paediatr. 95, 1109-1115 (2006).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Part+15:+Neonatal+resuscitation:+2010+American+Heart+Association+guidelines+for+cardiopulmonary+resuscitation+and+emergency+cardiovascular+care.">Part 15: Neonatal resuscitation: 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care.</a> Circulation. 122, S909-S919 (2010).</li></ol>

没有利益冲突的声明。

目前的实验协议有一个优势，在缺氧复氧过程中，检查全身和局部的血流动力学变化新生儿的主题。我们还可以检查用于改善心血管功能在恢复过程中各自的效果的干预。我们和其他人的经验和发现新生儿窒息，在心血管，肺，神经系统，胃肠道，肝5 6，肾，肾上腺7和血液系统的影响的研究报道。重要的是要了解心血管功能的连续的测量数据与信息的基础上，它在技术上...

a swine model of neonatal asphyxia

全球每年有超过100万新生儿死于窒息。窒息新生儿常见的有包括低血压，灌注赤字，缺氧缺血性脑病，肺部高血压，vasculopathic小肠结肠炎，肾功能衰竭和血栓栓塞并发症多器官功能衰竭。动物模型的开发，以帮助我们了解新生儿窒息的病理生理学和药理学。在啮齿动物和新生羔羊相比，新生仔猪已被证明是一个有价值的模型。新生仔猪有几个优势，包括类似的发展36-38周的人类胎儿具有可比性的身体系统，车身尺寸大（约1.5-2公斤出生），使仪器仪表和监测的动物和控制的混杂变量缺氧和血流动力学紊乱。 在这里，我们描述一个实验性协议，以模拟新生儿窒息，让我们检查系统·麦克风和区域的血流动力学变化窒息和复氧过程以及相应的干预效果。此外，该模型具有的优势，同时研究多器官功能衰竭或功能障碍和身体各个系统的相互作用。实验模型是一个非生存的过程，涉及到外科手术器械新生仔猪（1-3日龄和体重1.5-2.5公斤，混合品种），允许设立机械通气，血管（动脉和中央静脉）访问导管的位置不断在不同的动脉，包括主肺动脉，颈总动脉，肠系膜上动脉和左侧肾动脉血管内的压力和血流量监控和流量的探头（跨声速公司）。使用这些手术仪表仔猪30-60分钟，由Z &lt;10％的血流动力学参数的变化和正常的血液气体稳定后，我们开始了一个实验性的协议重度低氧血症是通过正常碳酸肺泡缺氧引起的。通风，有10-15％的氧气通过增加吸入氮气浓度为2h，旨在为动脉血氧饱和度为30％至40％，仔猪。这种程度的低氧血症会产生严重的代谢性酸中毒，全身性低血压和心源性休克，重要器官灌注不足的临床窒息。缺氧随后复氧与100％的氧气为0.5小时，然后21％的氧气为3.5小时。药物干预可以在适当的时候推出及其影响的调查，在一项双盲，随机块的方式。

Watch this Scientific Journal Video about A Swine Model of Neonatal Asphyxia at JoVE.com

A Swine Model of Neonatal Asphyxia

大动物模型具有良好的平移值在新生儿窒息的生理学和药理学考试。新生仔猪，，模拟新生儿窒息，有全身和局部的血流动力学，氧的运输，生化和病理的途径和相关研究的优势，我们开发了一个实验性协议。

新生儿窒息了猪模型

Annually more than 1 million neonates die worldwide as related to asphyxia. Asphyxiated neonates commonly have multi-organ failure including hypotension, ...

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14.2K 次观看.  University of Alberta. 大动物模型具有良好的平移值在新生儿窒息的生理学和药理学考试。新生仔猪，，模拟新生儿窒息，有全身和局部的血流动力学，氧的运输，生化和病理的途径和相关研究的优势，我们开发了一个实验性协议。

视频: A Swine Model of Neonatal Asphyxia

A Piglet Model of Neonatal Hypoxic-Ischemic Encephalopathy

Birth asphyxia, which causes hypoxic-ischemic encephalopathy (HIE), accounts for 0.66 million deaths worldwide each year, about a quarter of the world&#8217;s 2.9 million neonatal deaths. Animal models of HIE have contributed to the understanding of the pathophysiology in HIE, and have highlighted the dynamic process that occur in brain injury due to perinatal asphyxia. Thus, animal studies have suggested a time-window for post-insult treatment strategies. Hypothermia has been tested as a treatment for HIE in pdiglet models and subsequently proven effective in clinical trials. Variations of the model have been applied in the study of adjunctive neuroprotective methods and piglet studies of xenon and melatonin have led to clinical phase I and II trials1,2. The piglet HIE model is further used for neonatal resuscitation- and hemodynamic studies as well as in investigations of cerebral hypoxia on a cellular level. However, it is a technically challenging model and variations in the protocol may result in either too mild or too severe brain injury. In this article, we demonstrate the technical procedures necessary for establishing a stable piglet model of neonatal HIE. First, the newborn piglet (&#60; 24 hr old, median weight 1500 g) is anesthetized, intubated, and monitored in a setup comparable to that found in a neonatal intensive care unit. Global hypoxia-ischemia is induced by lowering the inspiratory oxygen fraction to achieve global hypoxia, ischemia through hypotension and a flat trace amplitude integrated EEG (aEEG) indicative of cerebral hypoxia. Survival is promoted by adjusting oxygenation according to the aEEG response and blood pressure. Brain injury is quantified by histopathology and magnetic resonance imaging after 72 hr.

Hypoxic-ischemic encephalopathy following perinatal asphyxia can be studied using animal models. We demonstrate the procedures necessary for establishing a piglet model of neonatal hypoxic-ischemic encephalopathy.

新生儿缺氧缺血性脑病的小猪模型

Birth asphyxia, which causes hypoxic-ischemic encephalopathy (HIE), accounts for 0.66 million deaths worldwide each year, about a quarter of the ...

科研

医学

A Neonatal Mouse Spinal Cord Compression Injury Model

Spinal cord injury (SCI) typically causes devastating neurological deficits, particularly through damage to fibers descending from the brain to the spinal cord. A major current area of research is focused on the mechanisms of adaptive plasticity that underlie spontaneous or induced functional recovery following SCI. Spontaneous functional recovery is reported to be greater early in life, raising interesting questions about how adaptive plasticity changes as the spinal cord develops. To facilitate investigation of this dynamic, we have developed a SCI model in the neonatal mouse. The model has relevance for pediatric SCI, which is too little studied. Because neural plasticity in the adult involves some of the same mechanisms as neural plasticity in early life1, this model may potentially have some relevance also for adult SCI. Here we describe the entire procedure for generating a reproducible spinal cord compression (SCC) injury in the neonatal mouse as early as postnatal (P) day 1. SCC is achieved by performing a laminectomy at a given spinal level (here described at thoracic levels 9-11) and then using a modified Yasargil aneurysm mini-clip to rapidly compress and decompress the spinal cord. As previously described, the injured neonatal mice can be tested for behavioral deficits or sacrificed for ex vivo physiological analysis of synaptic connectivity using electrophysiological and high-throughput optical recording techniques1. Earlier and ongoing studies using behavioral and physiological assessment have demonstrated a dramatic, acute impairment of hindlimb motility followed by a complete functional recovery within 2 weeks, and the first evidence of changes in functional circuitry at the level of identified descending synaptic connections1.

This article describes a method for generating a reproducible spinal cord compression injury (SCI) in the neonatal mouse. The model provides an advantageous platform for studying mechanisms of adaptive plasticity that underlie spontaneous functional recovery.

新生儿小鼠脊髓压迫损伤模型

Spinal cord injury (SCI) typically causes devastating neurological deficits, particularly through damage to fibers descending from the brain to the spinal ...

Myocardial Infarction in Neonatal Mice, A Model of Cardiac Regeneration

Myocardial infarction induced by coronary artery ligation has been used in many animal models as a tool to study the mechanisms of cardiac repair and regeneration, and to define new targets for therapeutics. For decades, models of complete heart regeneration existed in amphibians and fish, but a mammalian counterpart was not available. The recent discovery of a postnatal window during which mice possess regenerative capabilities has led to the establishment of a mammalian model of cardiac regeneration. A surgical model of mammalian cardiac regeneration in the neonatal mouse is presented herein. Briefly, postnatal day 1 (P1) mice are anesthetized by isoflurane and placed on an ice pad to induce hypothermia. After the chest is opened, and the left anterior descending coronary artery (LAD) is visualized, a suture is placed around the LAD to inflict myocardial ischemia in the left ventricle. The surgical procedure takes 10-15 min. Visualizing the coronary artery is crucial for accurate suture placement and reproducibility. Myocardial infarction and cardiac dysfunction are confirmed by triphenyl-tetrazolium chloride (TTC) staining and echocardiography, respectively. Complete regeneration 21 days post myocardial infarction is verified by histology. This protocol can be used to as a tool to elucidate mechanisms of mammalian cardiac regeneration after myocardial infarction.

This protocol describes a highly reproducible model of cardiac regeneration by surgical induction of myocardial infarction in the left ventricle of postnatal day 1 mice. The method involves induction of hypothermic anesthesia and ligation of the left anterior descending coronary artery.

心肌梗死新生小鼠，心肌再生的模型

Myocardial infarction induced by coronary artery ligation has been used in many animal models as a tool to study the mechanisms of cardiac repair and ...

A Chronic Cardiac Ischemia Model in Swine Using an Ameroid Constrictor

Cardiovascular disease remains the number one cause of mortality in the United States. There are numerous approaches to treating these diseases, but regardless of the approach, an in vivo model is needed to test each treatment. The pig is one of the most used large animal models for cardiovascular disease. Its heart is very similar in anatomy and function to that of a human. The ameroid placement technique creates an ischemic area of the heart, which has many useful applications in studying myocardial infarction. This model has been used for surgical research, pharmaceutical studies, imaging techniques, and cell therapies.
There are several ways of inducing an ischemic area in the heart. Each has its advantages and disadvantages, but the placement of an ameroid constrictor remains the most widely used technique. The main advantages to using the ameroid are its prevalence in existing research, its availability in various sizes to accommodate the anatomy and size of the vessel to be constricted, the surgery is a relatively simple procedure, and the post-operative monitoring is minimal, since there are no external devices to maintain. This paper provides a detailed overview of the proper technique for the placement of the ameroid constrictor.

The purpose of this protocol is to demonstrate the placement of a delayed constricting device (an ameroid constrictor) around a coronary artery in a swine model. This device creates an ischemic area of the heart that is useful for studying new diagnostic imaging techniques and new methods of treatment.

应用 Ameroid 的猪慢性心肌缺血模型

Cardiovascular disease remains the number one cause of mortality in the United States. There are numerous approaches to treating these diseases, but ...

Tachycardia-Induced Cardiomyopathy As a Chronic Heart Failure Model in Swine

A stable and reliable model of chronic heart failure is required for many experiments to understand hemodynamics or to test effects of new treatment methods. Here, we present such a model by tachycardia-induced cardiomyopathy, which can be produced by rapid cardiac pacing in swine.
A single pacing lead is introduced transvenously into fully anaesthetized healthy swine, to the apex of the right ventricle, and fixated. Its other end is then tunneled dorsally to the paravertebral region. There, it is connected to an in-house modified heart pacemaker unit that is then implanted in a subcutaneous pocket. 
After 4 - 8 weeks of rapid ventricular pacing at rates of 200 - 240 beats/min, physical examination revealed signs of severe heart failure - tachypnea, spontaneous sinus tachycardia, and fatigue. Echocardiography and X-ray showed dilation of all heart chambers, effusions, and severe systolic dysfunction. These findings correspond well to decompensated dilated cardiomyopathy and are also preserved after the cessation of pacing.
This model of tachycardia-induced cardiomyopathy can be used for studying the pathophysiology of progressive chronic heart failure, especially hemodynamic changes caused by new treatment modalities like mechanical circulatory supports. This methodology is easy to perform and the results are robust and reproducible.

Here, we present a protocol to produce tachycardia-induced cardiomyopathy in swine. This model represents a potent way to study the hemodynamics of progressive chronic heart failure and the effects of applied treatment.

心动过速诱发的心肌病作为猪慢性心力衰竭模型的研究

A stable and reliable model of chronic heart failure is required for many experiments to understand hemodynamics or to test effects of new treatment ...

Severe Burn Injury in a Swine Model for Clinical Dressing Assessment

Wound healing is a dynamic repair process and is the most complex biological process in human life. In response to burn injury, alterations in biological pathways impair the inflammation response, resulting in delayed wound healing. Impaired wound healing frequently occurs in patients with diabetes leading to unfavorable outcomes such as amputation. Hence, dressings having beneficial effect in promoting burn wound repair are needed. However, studies on burn wound treatment are limited due to lack of proper animal models. Our previous study demonstrated wound-healing performance in rat and swine models using a minimally invasive surgical technique. This study aimed to demonstrate a swine model of severe burn injury that eliminates wound contraction and more closely approximates the human processes of re-epithelialization and new tissue formation. This protocol provides a detailed procedure for creating consistent burn wounds and examining the wound-healing performance under the treatment of an experimental dressing in a swine model. Six burn wounds were created symmetrically on the dorsum, which were covered with a clinical dressing composed of four layers: an inner contact layer of experimental materials, an inner intermediate layer of waterproof film, an outer intermediate layer of gauze, and an outer layer of adhesive plaster. Upon the completion of experiments, wound closure, wound area, and Vancouver Scar Scale score were examined. The samples of skin resected from each animal post-sacrifice were histologically prepared and stained using hematoxylin and eosin staining. Antibacterial activity of each dressing in the context of wound healing was also examined. The application of the clinical dressing to the wounds in swine model mimics the biological processes of human wound healing with respect to the processes of epithelialization, cellular proliferation, and angiogenesis. Therefore, this swine model provides an easy-to-learn, cost-effective, and robust method to assess the effect of clinical dressings in severe burn injury.

To closely mimic the mode of burn injuries requires the interplay between clinical observation and studies in animal models. In this study, a swine model of severe burn injury was established to assess an experimental dressing in physiological and pathophysiological settings.

猪临床敷料评价模型中的严重烧伤

Wound healing is a dynamic repair process and is the most complex biological process in human life. In response to burn injury, alterations in biological ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

用线 Myography 测定小鼠肠系膜动脉的等轴收缩力

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

Establishing a Swine Model of Post-myocardial Infarction Heart Failure for Stem Cell Treatment

Although advances have been achieved in the treatment of heart failure (HF) following myocardial infarction (MI), HF following MI remains one of the major causes of mortality and morbidity around the world. Cell-based therapies for cardiac repair and improvement of left ventricular function after MI have attracted considerable attention. Accordingly, the safety and efficacy of these cell transplantations should be tested in a preclinical large animal model of HF prior to clinical use. Pigs are widely used for cardiovascular disease research due to their similarity to humans in terms of heart size and coronary anatomy. Therefore, we sought to present an effective protocol for the establishment of a porcine chronic HF model using closed-chest coronary balloon occlusion of the left circumflex artery (LCX), followed by rapid ventricular pacing induced with pacemaker implantation. Eight weeks later, the stem cells were administered by intramyocardial injection in the peri-infarct area. Then the infarct size, cell survival, and left ventricular function (including echocardiography, hemodynamic parameters, and electrophysiology) were evaluated. This study helps establish a stable preclinical large animal HF model for stem cell treatment.

We sought to establish a swine model of heart failure induced by left circumflex artery blockage and rapid pacing to test the effect and safety of intramyocardial administration of stem cells for cell-based therapies.

建立干细胞治疗心肌梗塞心力衰竭的猪模型

Although advances have been achieved in the treatment of heart failure (HF) following myocardial infarction (MI), HF following MI remains one of the major ...

Myocardial Infarction by Percutaneous Embolization Coil Deployment in a Swine Model

Myocardial infarction (MI) is the leading cause of mortality worldwide. Despite the use of evidence-based treatments, including coronary revascularization and cardiovascular drugs, a significant proportion of patients develop pathological left-ventricular remodeling and progressive heart failure following MI. Therefore, new therapeutic options, such as cellular and gene therapies, among others, have been developed to repair and regenerate injured myocardium. In this context, animal models of MI are crucial in exploring the safety and efficacy of these experimental therapies before clinical translation. Large animal models such as swine are preferred over smaller ones due to the high similarity of swine and human hearts in terms of coronary artery anatomy, cardiac kinetics, and the post-MI healing process. Here, we aimed to describe an MI model in pig by permanent coil deployment. Briefly, it comprises a percutaneous selective coronary artery cannulation through retrograde femoral access. Following coronary angiography, the coil is deployed at the target branch under fluoroscopic guidance. Finally, complete occlusion is confirmed by repeated coronary angiography. This approach is feasible, highly reproducible, and emulates the pathogenesis of human non-revascularized MI, avoiding the traditional open-chest surgery and the subsequent postoperative inflammation. Depending on the time of follow-up, the technique is suitable for acute, sub-acute, or chronic MI models.

Myocardial infarction (MI) animal models that emulate the natural process of the disease in humans are crucial to understanding pathophysiological mechanisms and testing the safety and efficacy of new emergent therapies. Here, we describe an MI swine model created by deploying a percutaneous embolization coil.

猪模型中经皮栓塞线圈部署的心肌梗死

Myocardial infarction (MI) is the leading cause of mortality worldwide. Despite the use of evidence-based treatments, including coronary revascularization ...

A Neonatal BALB/c Mouse Model of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is the most severe gastrointestinal (GI) disease that often occurs in premature infants, especially very low birth weight infants, with high mortality and unclear pathogenesis. The cause of NEC may be related to inflammatory immune regulatory system abnormalities. An NEC animal model is an indispensable tool for NEC disease immune research. NEC animal models usually use C57BL/6J neonatal mice; BALB/c neonatal mice are rarely used. Related studies have shown that when mice are infected, Th2 cell differentiation is predominant in BALB/c mice compared to C57BL/6J mice. Studies have suggested that the occurrence and development of NEC are associated with an increase in T helper type 2 (Th2) cells and are generally accompanied by infection. Therefore, this study used neonatal BALB/c mice to induce an NEC model with similar clinical characteristics and intestinal pathological changes as those observed in children with NEC. Further study is warranted to determine whether this animal model could be used to study Th2 cell responses in NEC.

Necrotizing enterocolitis (NEC) is the most severe gastrointestinal (GI) disease that often occurs in premature infants, especially very low birth weight infants, with high mortality and unclear pathogenesis. The cause of NEC may be related to inflammatory immune regulatory system abnormalities. An NEC animal model is an indispensable tool for NEC disease immune research. NEC animal models usually use C57BL/6J neonatal mice; BALB/c neonatal mice are rarely used. Related studies have shown that when mice are infected, Th2 cell differentiation is predominant in BALB/c mice compared to C57BL/6J mice. Studies have suggested that the occurrence and development of NEC are associated with an increase in T helper type 2 (Th2) cells and are generally accompanied by infection. Therefore, this study used neonatal BALB/c mice to induce an NEC model with similar clinical characteristics and intestinal pathological changes as those observed in children with NEC. Further study is warranted to determine whether this animal model could be used to study Th2 cell responses in NEC.

一种新生儿BALB/c坏死性小肠结肠炎小鼠模型

Necrotizing enterocolitis (NEC) is the most severe gastrointestinal (GI) disease that often occurs in premature infants, especially very low birth weight ...