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手术过程小心律障碍的发生率及其显著性是不同的。本文论述了在麻醉期和治疗期发生的不同种心率异常的性质和病因。 现述心房自律性的破坏及护理 1 心室搏动过速 心室搏动过速是由窦房鲇、心房及交界处的起搏点引起的快速的心率。窦房结心动过速是在小动物麻醉过程中观察到的最常见的心律障碍。大型狗的心率平均超过160次/分,小型狗超过180次/分,猫和小狗超过220次/分,这些都被划归为心动过速。如果与QRS波有关的P波、图形和位点正常的话,则为窦房结性心动过速。 相似文献
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目的 研究肾素-血管紧张素系统(renin angiotensin system,RAS)在甲状腺素诱导的心房电重构和离子通道重构中的作用,探讨RAS阻断剂对甲状腺素诱导的心房重构的影响.方法 40只新西兰大白兔分为4组(n=10):正常对照、甲状腺素、贝那普利及厄贝沙坦干预组.腹腔注射左旋甲状腺素(Levothyroxine,L-Thy)建立兔甲状腺素毒性模型,贝那普利组和厄贝沙坦组同时给予贝那普利或厄贝沙坦.4周后,通过心内电生理仪测定心房有效不应期,连续高频刺激诱发心房颤动(atrial fibrillation,AF),评价心房频率适应性和AF诱发率,荧光定量PCR检测L型Ca2+通道(Cav1.2和Cav1.3亚基)和lto电流相关亚基(kv1.4、kv4.2和kv4.3)mRNA表达,Western blot检测L型Ca2+通道α亚基和kv4.2蛋白表达.结果 贝那普利和厄贝沙坦明显降低AF诱发率并明显改善高甲状腺素诱导的频率适应性变化.贝那普利组(76.63±4.44)ms和厄贝沙坦组(79.00±4.95)ms心房有效不应期较甲状腺素组(75.13±5.41)ms无明显延长(P＞0.05).L型Ca2+通道蛋白表达在贝那普利组(1.15±0.24)和厄贝沙坦组(1.08±0.17)明显高于甲状腺素组(0.56±0.11)(P ＜0.01),但对高甲状腺素引起的Ito电流相关亚基变化无明显抑制作(P＞0.05).结论 RAS可能参与了高甲状腺素性诱导的心房电生理和离子通道改变,贝那普利和厄贝沙坦可以改善L-Thy诱导的心房电重构和离子通道重构,并降低高甲状腺素致AF性. 相似文献
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心钠素是通过自分泌、旁分泌、胞内分泌及周身分泌而产生的心源性的肽类激素,也称心房利钠多肽(atrial natriuretic peptide,ANP).ANP主要存在于哺乳动物的心房肌细胞的胞浆中,具有强大的利钠、利尿、扩张血管、减少血容量、降低血压、参与水盐代谢的作用,此外ANP在肺循环中也有重要的作用,可抑制去甲肾上腺素、血管紧张素、组胺、5-HT等引起的肺动脉和支气管收缩,同时还具有促进肺泡表面活性物质的分泌而改善肺通气防止肺水肿发生的功能;在脑组织视上核,ANP提高渗透压阈值,抑制渴阈从而使机体适应提高了渗透压的内环境;在胰脏,调整胰腺内分泌,促进胰腺外分泌,从而促进消化功能;在胃肠道促进对盐的吸收,从而促进吸收功能;还具有增强巨噬细胞吞噬,增强免疫功能等等. 相似文献
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研究心房钠尿肽基因敲除小鼠(ANP-/-小鼠)的生物学及病理学特性。ANP-/-小鼠与C57BL/6小鼠饲养于SPF级环境中,观察小鼠的繁育状况及其生物学特性,选取合适时间处死小鼠,通过HE染色观察脏器形态及组织结构。ANP-/-小鼠的繁殖周期比C57BL/6长,产仔率较低;ANP-/-小鼠肝脏、肺脏、脾脏较C57BL/6小鼠的有明显炎症反应,但是C57BL/6小鼠未见明显的病理改变。提示ANP基因的缺失可能与炎症发生有关。说明ANP-/-小鼠繁殖较慢、产仔率低,且正常繁殖的普通小鼠不会引起器官的病理学改变。但作为一种在心血管、代谢疾病上的动物模型,并与炎症甚至肿瘤有可能的未知联系的转基因动物,其很有研究和探索价值。 相似文献
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中国大沥沙皮狗 ,4月龄 ,雌性。屠宰发现 ,左右心房内壁上各附着白色柔软巨大囊状肿块 ,堕入心室。病理剖检 :见两肿块呈卵圆状、大小分别为2 .5× 1 .8× 0 .6cm和 2 .4× 1 .6× 0 .5cm,境界清楚 ,质地柔软 ,有光泽为白色半透明物。右心肿块蒂部与右心房壁相连 ,左心肿块蒂部与左心房内壁相连并和左心瓣膜发生粘连 ,占据左、右心室腔大部空间 ,切面光滑湿润、疏松。镜下观察 ,肿块由疏松散在的瘤细胞、大量粘液基质及纤细的嗜银纤维和胶原纤维构成。瘤细胞少 ,圆形、梭形或星形 ,胞浆少 ,胞体轮廓不清 ,有纤细突起 ;偶见较大的卵圆形瘤细… 相似文献
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近年来,奶牛泌乳能力显著提高,由此造成心脏负担过重.同时由于奶牛活动量不足,心脏机能未能相应地增强。奶牛心房纤动是诊疗中常见的病病。其临床症状多为食欲降低、活动能力减退,泌乳量减少等。所谓心房纤动,即由于心房的兴奋度增加,心肌肌原纤维不规则、频繁地收缩,使整个心房出现收缩失常,每次血液排出量减少,心跳不规律.这种状态如果持续时间过长,则引起心房肌发生病变,最终导致充血性心脏功能不全。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献