The cardiopulmonary effects of romifidine in dogs with and without prior or concurrent administration of glycopyrrolate     

Melissa D Sinclair DVM  DVSc  Dipl ACVA    Wayne N McDonell DVM  PhD  DVA  Dipl ACVA    Mike O'Grady DVM  MSc  Dipl ACVIM    Glenn Pettifer† DVM  DVSc  Dipl ACVA 《Veterinary anaesthesia and analgesia》2002,29(1):1-13

Objective To determine the electrocardiographic and cardiopulmonary effects of romifidine with and without prior or concurrent administration of glycopyrrolate. Study design Randomized crossover experimental study. Animals Six (three male, three female) cross‐bred dogs weighing 23 ± 2.4 kg. Methods Baseline cardiopulmonary measurements were obtained in conscious dogs and one of five treatments was administered. Glycopyrrolate (G) 0.01 mg kg^?1, or saline (S) 0.5 mL, were administered IM as premedication (Gp or Sp), or G was administered concurrently (Gc) with romifidine (RO). Treatments were as follows T1, Sp + RO 40 µg kg^?1; T2, Gp + RO (40 µg kg^?1); T3, Sp + RO 120 µg kg^?1; T4, Gp + RO (120 µg kg^?1); T5, Sp + Gc + RO (120 µg kg^?1). Romifidine or RO + Gc was administered subcutaneously 20 minutes after premedication (time 0), and further measurements were taken 10, 20, 30, 60 and 90 minutes after RO. The main treatment effect was evaluated using two‐way anova for repeated measures, followed by one‐way anova and a post‐hoc least squares difference test with a modified Bonferroni correction (p < 0.02). A Student's t‐test was used to compare the effect of romifidine at 20 and 60 minutes versus baseline values (p < 0.05). Results Both low‐ and high‐dose RO (T1, T3) significantly decreased heart rate (HR), respiratory rate (RR), cardiac index (CI) and stroke volume index, and increased arterial blood pressure (SAP), systemic vascular resistance (SVR), pulmonary arterial occlusion pressure (PAOP) and central venous pressure. High‐dose RO produced greater increases in SVR and SAP measurements. Neither dose of RO produced an alteration in blood gas values or the alveolar to arterial oxygen gradient. Glycopyrrolate significantly increased HR and CI from 10 to 90 minutes between T1/T2 and T3/T4. Increases in SAP were dose related with significant differences between T1/T3 and T2/T4 at 90 and 10 minutes, respectively, and were highest in animals receiving Gp or Gc. High‐dose RO groups (T3, T4) had higher values for SVR than low‐dose RO groups (T1, T2), unrelated to G administration. There was an increase in PAOP in all treatments. The oxygen extraction ratio was increased with all treatments: larger increases were observed in T1, T3 and T4 compared with only minimal changes in T2. Concurrent G administration was associated with an increased frequency of high‐grade second‐degree atrioventricular heart block with variable conduction at 10 and 20 minutes. Conclusions Romifidine produced effects consistent with other selective α₂‐adrenoreceptor agonists. Glycopyrrolate offset the decrease in HR and partially offset the decrease in CI associated with RO administration. Glycopyrrolate premedication produced an initial tachycardia and added to the increase in SAP associated with RO. Concurrent G administration was associated with a higher frequency of dysrhythmias and is not recommended. Despite the decrease in RR, RO sedation did not alter blood gas values. Clinical relevance It appears likely that G administration prior to or concurrent with RO produces an increase in myocardial workload and oxygen demand suggesting that this combination should not be used in dogs with cardiomyopathy or heart failure. The improvement in oxygen extraction ratio with T2 suggests that G may be beneficial with lower doses of RO, nevertheless, the use of G and RO in cardiovascularly compromised patients is not advised.  相似文献   

利率市场化之真实含义     

姬亚岚  顾蕾 《浙江林学院学报》2002,19(1):76-80

随着中国正式加入世贸组织，利率市场化改革已势在必行。之前，央行已制定出了利率市场化的大体框架并分步实施。当前流行于各类刊物的一些观点对利率市场化含义的理解尚不够准确。流行观点依据新老自由主义理论，强调市场“均衡利率”水平的重要性，忽略了利率结构问题。所谓的“均衡利率”实际上是不存在的，利率市场化改革的真实含义应当是：由中央银行决定基准利率水平，由市场决定利率结构。在银行业引入竞争机制是必要的前提。参9  相似文献   

中草药对王鸽繁殖性能的影响   总被引：4，自引：1，他引：3  

艾国良  陈可毅 《湖南农业大学学报(自然科学版)》1997,23(2):158-160

利用催情中草药提高王鸽繁殖性能，将６０对种鸽分成对照和试验组，进行了５个产蛋周期的试验。与对照组相比，试验组的产蛋周期缩短了４￣５ｄ，孵化率、仔鸽成活率均提高了３％左右，２８日龄时平均体重增加３０ｇ左右，３０对种鸽年获利多１０００余元。  相似文献   

金属腐蚀速度的计算机辅助测定(Ⅰ)数值实验研究     

谢乃贤  周安宏  谢斌 《湖南农业大学学报(自然科学版)》1997,24(5)

研究了在极化曲线测定的基础上，采用最优化方法测定腐蚀参数的方法，选用了３种非线性拟合的方法（高斯牛顿法、麦夸特法及离散型拉氏变换法），用能产生指定标准偏差的极化曲线模拟数值实验，对３种方法的实用性，从标准偏差、测量点的位置和数目、体系转移系数值等对方法的收敛性和计算结果的影响进行了考察．  相似文献   

杂交水稻制种建立母本最佳穗层结构的探讨   总被引：3，自引：1，他引：2  

杨孚初 《杂交水稻》1997,12(2):7-9

将制种田中喷施“九二０”后的母本穗层划分为高层穗、表层穗、平颈穗、包颈穗４个层次。对各种类型穗层的受粉原理、自然受粉状态，与结实率的关系进行了研究分析，提出了母本最佳穗层结构模式，以及在实践中可以采取稀播壮秧、密植等６项农艺措施和配套措施，来建立起母本最佳穗层结构  相似文献   

The Influence of Plant Water Stress on Net Photosynthesis and Yield of Sunflower (Helianthus annuus L.)     

J. J. Human    D. Du Toit  H. D. Bezuidenhout  L. P. De  Bruyn 《Journal of Agronomy and Crop Science》1990,164(4):231-241

The effect of plant water stress on net photosynthesis, leaf growth, yield and yield-related components were investigated in a single experiment in order to determine in which way water deficits affect sunflower yields.
Sunflower plants, grown under controlled temperature regimes, were stressed during budding, anthesis and seed filling by withholding water until the leaf water potential reached -1600 and -2000 kPa. Leaf area of unstressed plants significantly exceeded that of plants under severe stress during all growth stages investigated. The CO₂ uptake rate per unit leaf area as well as the total uptake rate per plant, significantly diminished with stress, while this effect drastically increased during the reproductive phase of the plant. Although this resulted in significantly smaller heads and kernels, it did not affect the number of seeds borne in the inflorescence. Severe stress during anthesis and seed filling resulted in more empty kernels. Moderate and severe stress during budding significantly lowered both grain and oil yields while plants that experienced moderate stress during anthesis and seed filling significantly outyielded those under severe stress.  相似文献   

青冈常绿阔叶林的太阳辐射分布特征     

潘晓东  陈启  王常  常杰  陈增鸿  刘珂 《浙江大学学报(农业与生命科学版)》1997,(1)

通过野外定位观测，对青冈（Ｃｙｃｌｏｂａｌａｎｏｐｓｉｓｇｌａｕｃａ）常绿阔叶林太阳辐射分布特征进行了研究．结果表明，青冈林反射辐射、透射辐射和吸收辐射的季节动态与太阳总辐射的季节动态相似，各辐射分量均为夏季最大，冬季最小，四季中群落的反射率、透射率和吸收率分别为１６％～２２％、９％～１２％和６７％～７４％．林冠层对光强的衰减率达８０％～９０％，且衰减率随太阳高度角的增大而增大．群落中部以下光强的衰减很小  相似文献   

KDY型输油泵运行故障分析及改进措施     

何立新  靳新卫 《油气储运》2007,26(9):51-52

针对KDY型输油泵运行中存在的润滑油泄漏、轴窜动量大、泵腰部拆卸不便、易损坏轴承和轴瓦等缺陷进行了原因分析,对泵的原设计提出了相应的改进措施。应用效果表明,改进后的KDY型输油泵的泵效已由原来的65%上升至80%,月润滑油泄漏量降至4kg,延长了止推轴承和轴瓦的使用寿命。  相似文献   

微波辐射技术在淀粉改性中的应用   总被引：4，自引：0，他引：4  

张冶  马涛 《农产品加工．学刊》2006,(1):33-35,77

简要介绍微波技术的原理,以及目前在淀粉改性方面的应用状况及发展趋势。  相似文献   

内蒙古典型草原地区常见植物光合、蒸腾速率和水分利用效率的比较研究   总被引：8，自引：1，他引：7  

杜菁昀  杜占池  崔骁勇 《草业科学》2003,20(6):11-15

在所测78种植物中，光合(Ph)、蒸腾速率(Tr)和水分利用效率(WUE)的平均值，分别以反枝苋、藜和西伯利亚滨藜最高。在不同分类系统中，Ph、Tr和WUE个指标，C4植物大于C3植物；双子叶植物通常大于单子叶植物；藜科植物高于其他科植物；1—2年生草本高于其他生活型植物；撂荒地植物一般高于其他植被类型的植物。方差分析表明，光合速率的差异显著性水平在各分类系统中均高于蒸腾速率和水分利用效率。  相似文献