异烟肼预防食管良性狭窄的实验与应用研究

探讨异烟肼预防食管良性狭窄的作用。方法分动物实验及临床应用两部分,动物实验采用家犬２０只,分为３组,按Ｄａｖｉｓ动物模型致伤为深Ⅱ度食管腐蚀伤,采用异烟治疗,临床应用系对２６例食管食性狭窄患者采取扩张术后异烟治疗以预防食管再狭窄。结论异烟能够防治食管良性狭窄,在临床工作中有一定的推广价值。     

瞬间反应式二次谐波显像评价正常犬肝脏超声学造影的实验研究

目的：评价瞬间反应二次谐波显像（Ｔｒａｎｓｉｅｎｔ ｒｅｓｐｏｎｓｅ ｓｅｃｏｎｄ ｈａｒｍｏｎｅｃ ｉｍａｇｉｎｇ,ＴＲＳＨＩ）对正常肝脏声学造影的增强效果及动态变化规律,并与常规连续二次谐波显像进行对比分析。方法：６只健康杂种犬 经外周静脉注射氟碳声学造影剂,分别用常规二次谐波显像和瞬间反应式二次谐波显像扫描肝脏。造影效果评价使用视觉评分和视频密度分析。结果：常规二次谐波显像有４次Ｉ级增强、４     

Actions of 4-chloro-3-ethyl phenol on internal Ca2+ stores in vascular smooth muscle and endothelial cells

1. Recently, 4-chloro-3-ethyl phenol (CEP) has been shown to cause the release of internally stored Ca²⁺, apparently through ryanodine-sensitive Ca²⁺ channels, in fractionated skeletal muscle terminal cisternae and in a variety of non-excitable cell types. Its action on smooth muscle is unknown. In this study, we characterized the actions of CEP on vascular contraction in endothelium-denuded dog mesenteric artery. We also determined its ability to release Ca²⁺, by use of Ca²⁺ imaging techniques, on dog isolated mesenteric artery smooth muscle cells and on bovine cultured pulmonary artery endothelial cells.
2. After phenylephrine-(PE, 10 μM) sensitive Ca²⁺ stores were depleted by maximal PE stimulation in Ca²⁺-free medium, the action of CEP on refilling of the emptied PE stores was tested, by first pre-incubating the endothelium-denuded artery in CEP for 15 min before Ca²⁺ was restored for a 30 min refilling period. At the end of this period, Ca²⁺ and CEP were removed, and the arterial ring was tested again with PE to assess the degree of refilling of the internal Ca²⁺ store.
3. In a concentration-dependent manner (30, 100 and 300 μM), CEP significantly reduced the size of the post-refilling PE contraction (49.4, 28.9 and 5.7% of control, respectively) in Ca²⁺-free media. This suggests that Ca²⁺ levels are reduced in the internal stores by CEP treatment. CEP alone did not cause any contraction either in Ca²⁺-containing or Ca²⁺-free Krebs solution.
4. Restoring Ca²⁺ in the presence of PE caused a large contraction, which reflects PE-induced influx of extracellular Ca²⁺. The contraction of tissues pretreated with 300 μM CEP was significantly less compared with controls. However, tissues pretreated with 30 and 100 μM CEP were unaffected. Washout of CEP over 30 min produced complete recovery of responses to PE in Ca²⁺-free and Ca²⁺-containing medium suggesting a rapid reversal of CEP effects.
5. Concentration-response curves were constructed for PE, 5-hydroxytryptamine (5-HT) and K⁺ in the absence of and after 30 min pre-incubation with 30, 100 and 300 μM CEP. In all cases, CEP caused a concentration-dependent depression of the maximum response to PE (84.8, 43.4 and 11.6% of control), 5-HT (65.4, 25.7 and 6.9% of control) and K⁺ (77.6, 41.1 and 10.8% of control).
6. Some arterial rings were pre-incubated with ryanodine (30 μM) for 30 min before the construction of PE concentration-response curves. In Ca²⁺-free Krebs solution, ryanodine alone did not cause any contraction. However, 58% (11 out of 19) of the tissues tested with ryanodine developed contraction (6.9±1.2% of 100 mM K⁺ contraction, n=11) in the presence of external Ca²⁺. EC₅₀ values for PE in ryanodine-treated tissues (1.7±0.25 μM, n=16) were not significantly different from controls (2.5±0.41 μM, n=22). Maximum contractions to PE (118.5±4.4% of 100 mM K⁺ contraction, n=16) were also unaffected by ryanodine when compared to controls (129±4.2%, n=23).
7. When fura-2 loaded smooth muscle cells (n=13) and endothelial cells (n=27) were imaged for Ca²⁺ distribution, it was observed that 100 and 300 μM CEP in Ca²⁺-free medium caused Ca²⁺ release in both cell types. Smooth muscle cells showed a small decrease in cell length. Addition of EGTA (5 mM) reversed the effect of CEP on intracellular Ca²⁺ to control values.
8. These data show, for the first time in vascular smooth muscle and endothelial cells, that CEP releases Ca²⁺ more rapidly than ryanodine. Unlike ryanodine, CEP caused no basal contraction but depressed contractions to PE, 5-HT and K⁺. The lack of basal contraction may result from altered responsiveness of the contractile system to intracellular Ca²⁺ elevation.

     

犬失血性休克早期血浆3种酶活性值的变化

用１０只犬复制失血性休克模型,观察休克前、休克３０ｍｉｎ及回输血后３０ｍｉｎ时,血浆中心肌相关酶—肌酸激酶（ＣＫ）、谷草转氨酶（ＧＯＴ）、α－羟丁酸脱氢酶（ＨＢＤ）活性值的变化。结果发现：失血性休克３０ｍｉｎ时,ＣＫ、ＧＯＴ较休克前显著下降（Ｐ＜０．０５,Ｐ＜０．０１）;ＨＢＤ值也下降,但无统计学意义（Ｐ＞０．０５）。输血后３０ｍｉｎ时,ＣＫ、ＧＯＴ、ＨＢＤ值回升,与休克３０ｍｉｎ时比显著升高（Ｐ＜０．０５）,与休克前比无显著性差别（Ｐ＞０．０５）。提示：失血性休克早期心肌细胞可能存在有一种保护性反应,心肌细胞没有发生明显损伤。     

Ophthalmic and visual profile of guide dog owners in Scotland

BACKGROUND/AIMS: Out of an estimated 90,000 visually impaired people in Scotland, 509 make use of a guide dog. Initial research in Northern Ireland suggests that the ophthalmic profile of guide dog owners (GDOs) is highly specific. The aim of this study was to compare the ophthalmic and visual characteristics of Scottish GDOs with other groups of visually impaired people. METHODS: A random sample of GDOs from central and northern Scotland (n = 82) underwent a detailed assessment of residual vision (distance and near acuity, visual fields, contrast, and glare sensitivity). Comparative data were obtained from two populations of visually impaired non-GDOs-one group attending hospital ophthalmic and low vision clinics (n = 50) the other social services rehabilitation clients (n = 35). All participants completed a questionnaire to elicit ophthalmic history, age, and registration details. RESULTS: GDOs were found to be significantly younger and more profoundly visually impaired than non-GDOs. The main causes of visual impairment were retinitis pigmentosa (23%), optic atrophy (15%), and retinopathy of prematurity (7%). Ninety nine per cent of GDOs were registered blind and had been visually impaired for an average of 39 years. Only 31% were totally blind. CONCLUSION: GDOs represent a unique minority of the visually impaired population. Epidemiological registration trends would suggest that the numbers of young profoundly visually impaired people are unlikely to increase relative to their elderly counterparts. This has implications on the future demand for guide dog ownership.     

Evaluation of a new solution containg trehalose for twenty-hour canine lung preservation

We examined the efficacy of two new preservation solutions containing trehalose-an extracellular type (ET-K) of solution and an intracellular type (IT-K) of solution — in relation to that of Euro-Collins (EC) solution in 20-h canine lung preservation. Canine lungs were flushed with one of the three solutions (n=5 for each solution) after pretreatment with PGE₁ (20 g/kg) and were stored for 20 h at 4°C. The left lungs were transplanted and evaluated to 6 h post transplant. In the ET-K group, the arterial oxygen tension after reperfusion was significantly higher than in the IT-K and EC groups. The pulmonary vascular resistance, wet/dry weight ratio, and histological evaluation of each transplanted lung in the ET-K group were also better than in the IT-K and EC groups. This indicates that ET-K solution is useful for 20-h preservation of canine lung grafts.     

Renal nerve and blood pressure responses to stimulation of cardiac receptors in dogs and cats by bradykinin

Summary It has been recently demonstrated in anesthetized, sinoaortic denervated-vagotomized (SAD+V_x) cats that epicardial or intracoronary (IC) bradykinin (BK) evokes an increase in efferent renal nerve activity (RNA) and a pressor response which is mediated by the cardiac sympathetic afferent nerves. The purpose of this study was to compare the effect of epicardial, IC, and left atrial (LA) administration of BK on arterial blood pressure (ABP) and RNA in intact and SAD+V_x cats and dogs. A total of seven cats and eight dogs anesthetized with chloralose were prepared with a left circumflex coronary arterial catheter (dogs) or a LA catheter (cats). Changes in ABP and RNA were determined in both dogs and cats when 1 to 100 g/ml of BK was applied to the anterior surface of the left ventricle or injected IC or LA (0.3 and 3.0 g/kg BK) in the intact and SAD+V_x state. In both the intact and SAD +V_x cat, a pressor response was consistently elicited with epicardial BK. In the SAD+V_x state, epicardial BK increased ABP by 33.4±4.7 mm Hg (p<.001). RNA followed this same trend showing a consistent and significant increase with both LA and epicardial BK (+24.8±8.4% in the SAD+V_x state; P<.05). Changes in RNA in dogs were highly variable with epicardial and IC BK in intact and in SAD V_x dogs, resulting in insignificant changes in this parameter. The results of this study demonstrate that the reflex effects of stimulation of cardiac sympathetic afferents by BK are species specific and need not evoke an increase in peripheral sympathetic outflow.Supported by National Institutes of Health Gran #HL-22594 and American Heart Association Grant # 81672.     

罗红霉素在犬体内的代谢转化罗红霉素在犬体内的代谢转化

目的考察罗红霉素在犬体内的代谢转化及po和iv给药途径对药物代谢的影响。方法采用液相色谱-质谱(LC-MSⁿ)联用技术,检测在iv或po给予单剂量罗红霉素后犬胆汁中的罗红霉素及其代谢物。代谢物经LC/MSⁿ方法分离和分析,并通过与对照品比较质谱和色谱行为确定其结构。结果共检测到13种罗红霉素代谢物,包括N-去甲基和N, N-双去甲基衍生物、肟醚侧链O-去烷醚基衍生物、脱红霉糖衍生物、罗红霉素及其代谢物的Z式几何异构体衍生物。结论罗红霉素在犬体内主要经历4种代谢途径;罗红霉素及其代谢物的几何异构与脱红霉糖代谢在口服和注射两种给药途径间存在显著的差异。     

RP-HPLC法测定犬血浆中苦参碱含量

目的:建立RP-HPLC法测定犬血浆中苦参碱的含量。方法:采用色谱柱为Shim-packCLC-ODS柱(6mm×150mm,5μm);流动相为甲醇∶水∶乙二胺(70∶30∶0.02),流速1.2mL/min,检测波长220nm。以地西泮为内标,测定血浆中苦参碱的浓度。结果:苦参碱浓度在0.3125~40.0μg/mL范围内线性关系良好(r=0.9996),最低检测浓度为15ng/mL,回收率和精密度均符合要求。结论:本法操作简便,灵敏度高,回收率好。