地塞米松对豚鼠耳蜗缺血再灌注损伤后细胞凋亡的影响

目的:研究地塞米松对缺血再灌注损伤及细胞凋亡的防治作用。方法:健康豚鼠,随机分成正常组、假手术组、地塞米松干预后假手术组、模型组和干预组(地塞米松术前腹腔注射)。后2组各在缺血30 min、再灌注6 h及24 h取材。用TUNEL法观察耳蜗缺血及不同时间段内再灌注的细胞凋亡情况,并与地塞米松干预后进行比较。结果:干预组的螺旋神经节及螺旋器(Corti器)较模型组在每个时间点上凋亡小体减少。结论:地塞米松可通过抑制诱导型一氧化氮合酶使凋亡细胞明显减少。     

阿司匹林预处理对缺血再灌注豚鼠耳蜗XAF1蛋白表达的影响

目的观察阿司匹林(aspirin,ASA)预处理对豚鼠耳蜗缺血再灌注损伤(ischemia-reperfusion injury,IRI)后XAF1蛋白(XIAP-associated factor 1,XAF1)表达的影响。方法健康豚鼠64只,随机分成正常组、假手术组、模型组和干预组(术前腹腔注射阿司匹林注射液50mg/kg,每天一次,共7d),模型组和干预组再各分成3个亚组:IRI6h组、24h组和48h组。用HE染色法观察IRI不同时间段耳蜗各部位的形态改变,免疫组织化学法检测内耳XAF1的表达,Western blotting检测XAF1的表达量。结果正常组、假手术组耳蜗形态正常,XAF1在螺旋神经节细胞质为阳性表达;模型组耳蜗形态改变,螺旋神经节细胞XAF1阳性表达水平高于正常组、假手术组(<0.05);干预组XAF1表达水平较模型组减弱。结论阿司匹林预处理对IRI内耳的保护作用可能与下调XAF1蛋白表达相关。     

豚鼠耳蜗缺血再灌注损伤后FasL蛋白的表达及其与细胞凋亡的关系

目的探讨豚鼠耳蜗缺血再灌注损伤后细胞凋亡的情况、凋亡相关蛋白FasL表达的改变以及二者之间的关系。方法健康豚鼠40只随机分成正常组、假手术组和模型组,模型组再分为缺血30min、再灌注6h及24h三组。用组织化学方法观察缺血及再灌注不同时间段耳蜗各部位的组织学改变,用免疫组织化学法检测内耳FasL的表达,用原位凋亡法(TUNEL法)检测内耳细胞凋亡的情况。结果正常组、假手术组内耳罕见凋亡细胞,FasL为弱阳性表达;模型组Corti器、血管纹、螺旋神经节在缺血及再灌注每个时间段均有细胞凋亡,FasL为阳性表达,与正常组比较明显增多(<0.05)。结论 FasL参与了豚鼠耳蜗缺血再灌注损伤后细胞凋亡的发生。     

豚鼠耳蜗缺血再灌注损伤后iNOS活性与细胞凋亡关系

目的：探讨椎基底动脉缺血再灌注耳蜗组织损伤方式及可能的损伤机制。方法：健康豚鼠72只，随机分成正常组、假手术组、模型组，每组各8只。用组织化学方法观察缺血再灌注不同时间耳蜗各部位的组织改变；用免疫组织化学法（ABC）检测各组动物耳蜗中诱导型一氧化氮合酶的表达和变化；用原位凋亡法（TUNEL法）观察耳蜗的细胞凋亡情况。结果：缺血再灌注的内外毛细胞变形缺损、血管纹变薄等；诱导型一氧化氮合酶在缺血及再灌注的表达增强；正常组及假手术组没有或仅有个别部位出现细胞凋亡，缺血及再灌注各组内外毛细胞及螺旋神经节部位凋亡细胞明显增多。结论：再灌注期间细胞凋亡数较缺血期间明显增多，其原因为包括一氧化氮在内的多种氧自由基表达增高所致。     

豚鼠耳蜗缺血再灌注损伤后Fas蛋白的表达及其与细胞凋亡的关系

目的:研究豚鼠耳蜗缺血再灌注损伤后凋亡相关蛋白Fas蛋白表达,以及与细胞凋亡的关系.方法:健康豚鼠随机分成正常组、假手术组、模型组.组织学方法观察缺血再灌注不同时间点耳蜗各部位的组织学改变;免疫组织化学法检测内耳Fas的表达;原位凋亡法(TUNEL法)观察耳蜗缺血及不同时间段内再灌注的细胞凋亡情况.结果:正常组及假手术组没有或仅有个别部位出现细胞凋亡,Fas为弱阳性表达;模型组Corti器、血管纹、螺旋神经节在每个时间点上均有细胞凋亡,Fas为阳性表达.结论:Fas的过度表达可能是耳蜗缺血再灌注后细胞凋亡的重要原因.     

光化学诱导豚鼠耳蜗微循环障碍的实验研究

目的建立耳蜗微循环障碍模型并探讨其损伤机制。方法用四碘四氯荧光素二钠经豚鼠股静脉注射,波长(540±30)nm的绿色光照射耳蜗,通过耳蜗切片、螺旋韧带石蜡定向包埋切片、耳蜗铺片、透射电镜等技术在不同时问段对豚鼠耳蜗病变进行观察。结果光化学诱导耳蜗微血管血栓形成,组织缺血、坏死,且随时间的延长病变逐渐加重。结论光化学诱导可建立耳蜗微循环障碍的模型,对研究内耳疾病有一定意义。     

丹参对豚鼠耳蜗缺血再灌注损伤后细胞凋亡及Fas表达的蛋白影响

目的:探讨丹参对豚鼠耳蜗缺血再灌注损伤(Ischemia reperfusion injury I/RI)后细胞凋亡及Fas蛋白表达的影响.方法:健康豚鼠72只,雌雄不拘.随机分成正常组、假手术组、丹参干预假手术组、模型组和干预组(术前腹腔注射丹参注射液,每天一次共7d),后两组各在缺血30min、再灌注6h及24h取材.用组织化学方法观察缺血及再灌注不同时间段耳蜗各部位的组织学改变;用免疫组织化学法检测内耳Fas的表达;用原位凋亡法(TUNEL法)检测内耳细胞凋亡情况.结果:正常组、假手术组、丹参干预假手术组内耳罕见调亡细胞,Fas为弱阳性表达;模型组Corti器、血管纹、螺旋神经节在缺血及再灌注每个时间点均有细胞凋亡,Fas为阳性表达,与正常组比较有统计学意义(P＜0.05);干预组Corti器、血管纹、螺旋神经节在缺血及再灌注每个时间点均有细胞凋亡,Fas为阳性表达,程度较模型组减弱.与模型组比较有统计学意义(P＜0.05).结论:Fas参与了耳蜗I/RI后细胞凋亡的发生,丹参可能通过抑制Fas蛋白的表达使凋亡细胞减少而对I/RI后的耳蜗起保护作用.     

耳蜗圆窗记录的蜗神经同步放电活动

目的:探讨豚鼠耳蜗神经活动频谱(ASECA)1kHz处出现的特征谱峰(简称ASECA-1kHz)的起源及其与听神经放电活动的关系。方法:采用不同刺激声在同侧及对侧刺激条件下记录清醒豚鼠ASECA-1kHz的改变。结果:(1)中心频率高于8kHz,且强度低于其耳间衰减值的窄带噪声进行对侧声刺激则导致ASECA-1kHz幅值下降;(2)带宽高于或低于1.5kHz的同侧噪声刺激引起ASECA-1kHz相应地增加或降低;(3)对侧纯音刺激(强度不大于耳间衰减值)对ASECA不产生影响,但频率高于4kHz的同侧纯音刺激引起ASECA-1kHz下降。此外,声刺激引起的ASECA-1kHz改变的时程图与Kiang等所记录的听神经纤维对声刺激反应的直方图非常相似。结论:豚鼠ASECA-1kHz起源于耳蜗基底周对高频声响应的有限投射区域(12.5-25kHz),且代表该区域内听神经纤维的同步自发放电活动。     

心钠素免疫反应在豚鼠耳蜗中的整体分布

目的 :研究豚鼠耳蜗中心钠素 (ANP)免疫反应的分布状态 ,为探讨ANP在耳蜗中的作用提供形态学基础。方法 :采用免疫组织化学ABC法检测ANP在正常豚鼠耳蜗各组织中的分布特征。结果 :在耳蜗 1～ 4回的血管纹、螺旋缘、Corti’s器、螺旋神经节和中间阶外壁的螺旋韧带均发现有ANP反应 (ANP IR)阳性产物 ;而耳蜗骨壁、前庭膜、鼓阶外壁的螺旋韧带和鼓阶的下壁ANP IR为阴性。结论 :耳蜗中的ANP在内耳淋巴液的生成和声信号的传导以及耳蜗血流量的调节等方面可能担负着重要的作用     

NO、NOS与耳蜗缺血再灌注损伤的研究进展

内耳疾病是耳鼻咽喉科常见病、多发病，而内耳微循环障碍是最主要的致病因素之一。研究内耳微循环障碍的发病机理和病变学基础具有重要意义。脑缺血不仅常见于脑血管意外，还和一些全身性疾病，如高血压、高血脂、冠心病、糖尿病等导致的微小动脉病变相关。脑缺血可引起听觉传导功能障碍或突发性感音神经性聋。而脑缺血-再灌注（Ischemia reperfusion I／R）损伤常可使原有的损伤进一步加重。     

Representation of the cochlea in the neocortex of guinea pigs

Summary By recording unit clusters and local evoked responses in the auditory cortex of guinea pigs the cortical representation of best frequencies was studied. In penetrations vertical to the cortical surface best frequencies were similar. Parallel to the cortical surface, however, different frequencies were found in the antero-posterior direction, whereas medio-laterally best frequencies usually remained in the same range (isofrequency stripes). Two auditory cortical fields could be distinguished, which are tonotopically organized. With increasing sound intensity the cortical response field for a given frequency and thus the frequency overlap increased. All along the isofrequency stripes in the medio-lateral direction, the stimulation of the contralateral ear produces larger responses than the same stimulus delivered to the ipsilateral ear.Partly supported by the Deutsche Forschungsgemeinschaft, SFB 33     

缺血后处理对急性心肌缺血／再灌注家猪心脏的作用

目的研究缺血后处理对实验家猪心肌梗死范围及血压心率的影响,探讨在体条件下,缺血后处理是否具有缩小家猪缺血心脏的心肌梗死范围。方法采用标准家猪缺血／再灌注模型,在缺血后再灌前,分别给予4个周期和8个周期的短暂再灌注／再缺血作缺血后处理,TTC法确定心肌梗死范围。结果缺血后处理组8-30PostC心肌梗死范围（10．5±0．5）％,缺血后处理组4-30PostC心肌梗死范围及对照组分别为（36．7±3．7）％和（33．5±7．6）％（P〈0．01）,8个周期的缺血后处理组家猪心肌梗死面积明显小于对照组以及4个周期组,各组家猪的心率和平均动脉压无明显差异。结论缺血后处理可明显缩小家猪缺血心脏的心肌梗死范围。     

银杏叶提取物对心肌缺血再灌注微循环的保护作用

复制家兔缺血再灌注模型,采用显微电视和微机图像处理系统对20只家兔球结膜微血管口径、流速、流量等参数进行定量分析.结果:银杏叶提取物(GBE)组在结扎即刻、30分钟、再灌注30分钟等时相,与生理盐水组比较,微动脉、微静脉口径(3、4级)、微静脉流速、流量、毛细血管密度均增加,交换距离缩小(P<0.05).提示:GBE对心肌缺血再灌注微循环有显著的保护作用.其机制可能与扩张微血管口径、改善血流灌注有关.     

银杏叶提取物改善兔心肌缺血／再灌注损伤及微循环障碍的作用

在兔心脏缺血／再灌注（I／R）损伤模型上．对照观察了银杏叶提取物（GBE）的作用。发现：与I／R组相比，I／R＋GBE组血浆中一氧化氛（NO）、超氧化物歧化酶（SOD）、6－酿－前列腺素F1α（6－K－PGF1α）浓度明显升高，而血栓素B2（TXB2）、丙二醛（MDA）明显下降。GBE组血管增多，肿胀内皮细胞减少，线粒体件胀减轻。痉挛球结膜微血管扩张，扩散距离缩小。结果表明：GBE具有明显的扩张微血管作用，尤其对微动脉更明显。这可能由于它能够刺激血管内皮细胞释放NO及PGI2并减少其失活。GBE可被认为是心血管NO释放的刺激剂，用于防治心肌I／R损伤是有效的。     

Effects of Prolonged Warm and Cold Ischemia in a Solitary Kidney Animal Model after Partial Nephrectomy: An Ultrastructural Investigation

Ischemia–reperfusion injury can be detrimental to the solitary kidney, especially when it is accompanied by ablation. To the authors’ knowledge, the effects of partial nephrectomy with prolonged application of ischemia have never been described at the ultrastructural level. Therefore, the authors used an animal model and focused on putative structural effects in the glomerular basement membrane and the podocytes. They demonstrate the advantageous role of cold ischemia, even in up to 120?min. In contrast, more than 60?min of warm ischemia leads to catastrophic lesions in all the cellular structures, as is reflected by mortality due to acute renal failure.     

Bimodal Oscillation Frequencies of Blood Flow in the Inflammatory Colon Microcirculation

Rhythmic changes in blood flow direction have been described in the mucosal plexus of mice with acute colitis. In this report, we studied mice with acute colitis induced either by dextran sodium sulfate or by trinitrobenzenesulfonic acid. Both forms of colitis were associated with blood flow oscillations as documented by fluorescence intravital videomicroscopy. The complex oscillation patterns suggested more than one mechanism for these changes in blood flow. By tracking fluorescent nanoparticles in the inflamed mucosal plexus, we identified two forms of blood flow oscillations within the inflammatory mouse colon. Stable oscillations were associated with a base frequency of approximately 2 cycles/sec. Velocity measurements in the upstream and downstream vessel segments indicated that stable oscillations were the result of regional flow occlusion within the mucosal plexus. In contrast, metastable oscillations demonstrated a lower frequency (0.2–0.4 cycles/sec) and appeared to be the result of flow dynamics in vessels linked by the bridging mucosal vessels. These blood flow oscillations were not directly associated with cardiopulmonary movement. We conclude that both the stable and metasable oscillating patterns reflect flow adaptations to inflammatory changes in the mucosal plexus. Anat Rec, 2009. © 2008 Wiley‐Liss, Inc.     

Microangioarchitecture of the guinea pig common bile duct and duodenal papilla: A scanning electron and light microscopic study

Background: The microvascular pattern of the duodenal papilla is unknown. Since the duodenal papilla is located in the transition zone between the stomach and duodenum, and because it regulates bile transfer into the duodenum, a particular microangioarchitecture can be expected. Therefore, we examined the microvasculature of the papilla using guinea pigs as a model. Methods: The microvascularization of the duodenal papilla and common bile duct was studied in 26 adult guinea pigs (Cavia porcellus), using scanning electron microscopy of microvascular corrosion casts and critical point dried specimens, and light microscopy of tissue sections. Results: The duodenal papilla is located in the cranial portion of the duodenum, approximately 5 mm beyond the pyloric valve. At the most luminal aspect of the cast papilla, ring-shaped capillaries, resembling those of the cast gastric mucosa, are present. Deeper parts of the papilla are provided with villi. Subepithelial capillaries of the papilla are 15 μm thick in average. These capillaries have a dual blood supply either via the straight long arterioles arising from the submucosa or by the pericryptal capillaries. The common bile duct comprises numerous mucoid glands with their pits surrounded by ring-shaped capillaries in corresponding casts. Conclusions: The special arrangement of different capillary patterns, together with their luminal size and the dual blood supply, favor their protective role from the gastric chyme. © 1994 Wiley-Liss, Inc.     

Blood Flow Patterns Spatially Associated with Platelet Aggregates in Murine Colitis

In the normal murine mucosal plexus, blood flow is generally smooth and continuous. In inflammatory conditions, such as chemically‐induced murine colitis, the mucosal plexus demonstrates markedly abnormal flow patterns. The inflamed mucosal plexus is associated with widely variable blood flow velocity as well as discontinuous and even bidirectional flow. To investigate the mechanisms responsible for these blood flow patterns, we used intravital microscopic examination of blood flow within the murine mucosal plexus during dextran sodium sulphate‐and trinitrobenzenesulfonic acid‐induced colitis. The blood flow patterns within the mucosal plexus demonstrated flow exclusion in 18% of the vessel segments (P < 0.01). Associated with these segmental exclusions was significant variation in neighboring flow velocities. Intravascular injection of fluorescent platelets demonstrated platelet incorporation into both fixed and rolling platelet aggregates. Rolling platelet aggregates (mean velocity 113 μm/sec; range, 14–186 μm/sec) were associated with reversible occlusions and flow variations within the mucosal plexus. Gene expression profiles of microdissected mucosal plexus demonstrated enhanced expression of genes for CCL3, CXCL1, CCL2, CXCL5, CCL7, CCL8, and Il‐1b (P < 0.01), and decreased expression of CCL6 (P < 0.01). These results suggest that platelet aggregation, activated by the inflammatory mileau, contributes to the complex flow dynamics observed in acute murine colitis. Anat Rec, 292:1143–1153, 2009. © 2009 Wiley‐Liss, Inc.     

天麻对大鼠肾缺血再灌注损伤中SOD、MDA作用的研究

目的　探讨天麻在大鼠肾缺血再灌注损伤中的抗氧化作用 .方法　通过建立大鼠急性肾缺血再灌注损伤模型 ,测定天麻对肾缺血再灌注后肾组织SOD活力与MDA含量的变化 .结果　与对照组相比 ,使用天麻后 ,在再灌注 6h、12h和 2 4h后肾组织SOD活力明显升高 (p值分别 <0 .0 1,0 .0 5 ,0 .0 1) ,MDA含量明显降低 (p值分别 <0 .0 5 ,0 .0 1,0 .0 5 ) .结论　天麻在大鼠肾缺血再灌注损伤模型中 ,有抗自由基损伤和减轻脂质过氧化的作用 .     

荧光显微镜观察封闭式脊髓窗内的大鼠脊髓微循环

目的 探讨应用荧光显微镜通过改进的封闭式脊髓窗,观察大鼠脊髓背侧软脊膜微循环状态的可行性及效果.方法 用8周龄雄性SD大鼠,暴露T9至T11棘突,咬除T10棘突和椎板,暴露硬脊膜;在T9和T11棘突上安装固定器辅助物.用牙科丙烯酸树脂和玻璃片为原料在T10节段安装改进的封闭脊髓窗.采血并离心(2 000 ×g)收集红细胞,将100 μL压积的红细胞用Dil荧光染料(5 mg/L)体外孵育,静脉注射人体内;用罗丹明6G(0.3 g/L)静脉注射,体内标记白细胞.大鼠脊柱用微循环观测椎体固定器进行固定.用动物活体荧光成像显微系统进行观测和记录.结果 通过该系统可以观测大鼠软脊膜上微血管的形态和分布特点、血管密度;可以观测到Dil标记的红细胞在血管内的黏附和流速,观察和记录罗丹明6G标记的白细胞在血管壁的黏附滚动.结论 改进式的封闭脊髓窗和微循环观测椎体固定器,可用于对大鼠软脊膜上微血管进行观察和检测.