养阴清热活血中药对大鼠离体灌流颌下腺唾液分泌的作用

目的:中草药能通过增加唾液的分泌而缓解口腔干燥症状。本试验研究临床常用养阴清热中药促唾液分泌功能。方法:成年wistar大鼠用苯巴比妥钠麻醉后,外科分离颌下腺,转移至37℃恒温浴槽。使用蠕动泵(Cole-Palmer)进行灌流。氯化氨甲酰胆碱(CCh)对照灌流后,用缓冲液洗脱,后单独用含中药的缓冲液灌流及中药与CCh联合灌流,观察中药对颌下腺唾液分泌的影响。结果:养阴清热活血中药单独灌流,大多不能或仅能促进唾液少量分泌,而其灌流时加入CCh,则能明显促进唾液的分泌(唾液分泌曲线呈持续升高平台)。只有丹参在在不加入CCh的情况下也能促进唾液分泌。结论:养阴清热中药对离体颌下腺具有促分泌作用。中药促唾液分泌实验研究将为中药治疗口干症状及相关疾病的临床应用提供理论依据。     

用微型机的体外循环自动控制的实验研究

本工作是为开发婴儿用的人工心肺装置,特别是对灌流操作困难的早产儿安全实现体外循环的系统而进行的研究。控制系统由三台微型计算机所组成。其中一台用作控制脉动灌流泵,另一台为控制台操作用。而主要的一台微型机用于控制血流和血压。微型计算机通过人工心肺装置而完全控制血流和血压。在开始时人工心肺机自动地从每分钟26毫升/公斤的血流量增加到每分钟80毫升/公斤,并自     

离体兔小肠灌流水肿实验模型

离体兔小肠灌流水肿实验模型系采用美国生理学家Guyton(1979)描述的肠灌流标本。利用蛙下肢灌流水肿实验的灌流方法设计的一项教学实验。该实验以家兔小肠为标本,经肠系膜前动脉插管灌流,并通过改变灌流液的渗透压和灌流压而引起小肠壁液量的变化。其结果以标本重量曲线的形式描记下来,借以探讨渗透压和毛细血管压的改变与水肿形成的     

利用血管内超声视频图像获取冠状动脉截面积曲线

利用冠状动脉内超声的视频图像，依据相邻帧的连续性自动确定血管内壁的搜索范围，结合表征血管内壁平滑性的内部能量和表征超声图像灰阶分布的外部能量，采用动态规划方法通过寻找最大能量路径来检测血管内壁的最优包络，并由此计算血管的截面积。现提出了一种综合图像灰阶梯度和象素方差的外部能量表示，使得冠状动脉截面积曲线的提取方法在鲁棒性、准确性方面较仅用灰阶梯度作为外部能量有了较大的提高。     

家兔心脏短期缺血后再灌流时心功能的变化及SOD的影响

本实验利用家兔急性心肌缺血后早期再灌流动物模型,观察早期再灌流对心功能的影响,并利用自由基清除剂(超氧化物歧化酶,s0D)探索自由基在其中的可能作用。实验过程中测取心功能指标;观察结束后,分别从缺血区与非缺血区心内膜下取心肌电镜标本。实验发现,单纯再灌流组的心功能指标明显低于持续结扎组,SOD再灌流组的心功能比单纯再灌流组恢复得早、恢复程度高;缺血区心肌超微结构的损伤程度,依次为持续结扎组>单纯再灌流组>SOD再灌流组,非缺血区心肌超微结构只是单纯再灌流组变化较明显。结果表明,自由基对短期缺血后再灌流过程中心功能损伤起着一定的作用,其损伤范围随着再灌流的发生扩散到非缺血区。     

血液灌流治疗20例急性百草枯中毒患者的护理

目的探讨血液灌流对急性百草枯中毒患者的临床疗效,总结急性百草枯中毒治疗的有效手段及护理方法。方法回顾性分析20例百草枯中毒患者的血液灌流治疗方法、远期效果。结果除综合治疗外20例患者均给予HA230加HA330树脂型灌流器交替灌流连续使用3d,再使用HA330灌流器1次/d共3d血液灌流治疗方法,9例痊愈出院。结论血液灌流是急性百草枯中毒患者治疗的有效手段,正确有效的护理措施为患者的痊愈提供良好的保障。     

灌流式生物反应器内支架材料孔隙流场和壁面剪应力的数值分析

为获得支架材料孔隙受到的壁面剪应力的大小及分布、孔隙内压力分布以及支架材料与灌流小室之间不同缝隙时的灌流率。根据有限元方法建立了灌流式生物反应器小室内3种支架材料孔隙模型，用ansys软件分析了各种模型在不同工况下的灌流情况。结果表明，支架材料与灌流小室之间的孔隙决定灌流率，缝隙大于0.5mm时灌流率小于60％；支架材料孔隙壁面剪应力大小主要受灌流流量的影响，调节灌流流量是控制剪应力水平的主要手段。孔壁剪应力和孔内流体压力的分布均由支架材料孔隙的形状特征所决定。     

血液灌流联合血液透析治疗尿毒症皮肤瘙痒8例

目的探讨血液灌流串联血液透析治疗尿毒症顽固性皮肤瘙瘁的疗效。方法灌流器串联于透析器前端。联合治疗2小时结束灌流．取下灌流器再继续透析2—3小时,HD＋HP1次／2周。结果8例患者皮肤瘙痒症状均得到不同程度缓解。结论血液灌流串联血液透析治疗尿毒症皮肤瘙痒效果显著,且设备要求低,适于开展,     

钾对再灌流早期室颤阈变化的影响

本实验在69只家兔上比较观察了高钾动脉血、血浆和正常动脉血对局部缺血心肌再灌流早期室颤阈(VFT)变化的影响。实验结果表明,缺血心肌用正常动脉血再灌流可使其VFT在灌流1分内迅速下降,然后逐渐回升。其中氧的恢复和钾的改变对VFT下降程度影响不同。缺血后用血浆再灌流,其VFT下降程度与缺血后用正常动脉血再灌流相比无显著性差异;而用高钾动脉血再灌流比用正常动脉血再灌流VFT下降程度轻(P<0.05)。本实验结果提示,在再灌流心律失常产生中缺血时所积累的钾的突然冲洗和再分布可能起更重要的作用。     

不同灌注压和解痉剂对体外灌流兔肾的影响

目的: 观察不同灌注压和解痉剂对体外灌流肾脏灌流量的影响,为建立体外灌流保存肾脏模型作技术准备。方法: (1) 12只健康成年新西兰白兔肾脏, 分为3级, 分别在60 mmHg、100 mmHg、120 mmHg 3个灌注压下, 观察离体肾脏的灌流量; (2) 12只健康成年新西兰白兔肾脏, 分为3组, 分别在生理盐水、654-2、酚妥拉明作用下, 用筛选的最佳灌注压(100 mmHg)灌流, 观察不同解痉药物对肾脏灌流量及肾功能的影响。结果: (1) 100 mmHg组灌流量保持稳定, 灌流8 h时, 灌流量显著高于60 mmHg组及120 mmHg组; (2) 酚妥拉明组灌流量于灌流1、5、10 h显著高于654-2组和对照组, 且尿量无明显减少、肾静脉流出液钾浓度上升值和钠浓度下降值无明显变化。结论: (1) 兔肾体外灌流, 100 mmHg的灌注压较为适宜; (2) 654-2特别是酚妥拉明可增加灌流量、改善肾功能。     

Flow dependence and time constant of the change in nitric oxide concentration measured in the vascular media

It has been considered that the concentration of endothelium-derived nitric oxide (NO) in the arterial vascular wall changes in response to flow-induced shear stress. In the present study, using an NO-sensitive electrode, the aim was to directly evaluate the relationship between perfusion rate and NO concentration in the arterial vascular wall. The NO microelectrode (diameter: 100 microns) was inserted into the vascular media of isolated canine femoral arteries, and the vessel was perfused with a Krebs-Henseleit buffer solution. A flow-related change in NO concentration in the vascular media was then evaluated by changing perfusion rate. NO concentration attained a peak value with a first-order time delay by a stepwise increase in perfusion rate, and the peak-level NO concentration was linearly correlated with perfusion rate in each vessel (10-154 pA at 2.1-72.3 ml min-1; n = 7, r2 = 0.89-0.99, p < 0.03). The average time constant for an increase in NO current with a stepwise increase in perfusion rate was 24 +/- 3 s (n = 5). NO production was increased by perfusing a solution containing 1 mmol l-1 L-arginine and was attenuated by 100 mumol l-1 NG-nitro-L-arginine, indicating the intactness of the endothelium, proper insertion of the NO electrode and selective detection of NO by the electrode. It is concluded that the NO microelectrode is applicable to NO measurement in the vascular media where NO controls vascular tone and that the concentration of NO in the arterial vascular media changes with perfusion rate in a rate-dependent manner as well as with a time constant of about 24 s for a stepwise increase in flow.     

Flow dependence and time constant of the change in nitric oxide concentration measured in the vascular media

It has been considered that the concentration of endothelium-derived nitric oxide (NO) in the arterial vascular wall changes in response to flow-induced shear stress. In the present study, using an NO-sensitive electrode, the aim was to directly evaluate the relationship between perfusion rate and NO concentration in the arterial vascular wall. The NO microelectrode (diameter: 100 μm) was inserted into the vascular media of isolated canine femoral arteries, and the vessel was perfused with a Krebs-henseleit buffer solution. A flow-related change in NO concentration in the vascular media was then evaluated by changing perfusion rate. NO concentration attained a peak value with a first-order time delay by a stepwise increase in perfusion rate, and the peak-level NO concentration was linearly correlated with perfusion rate in each vessel (10–154 pA at 2.1–72.3 ml min⁻¹; n=7, r²=0.89–0.99, p<0.03). The average time constant for an increase in NO current with a stepwise increase in perfusion rate was 24±3 s (n=5). No production was increased by perfusing a solution containing 1 mmol l⁻¹ L-arginine and was attenuated by 100 μmol l⁻¹ N^G-nitro-L-arginine, indicating the intactness of the endothelium, proper insertion of the NO electrode and selective detection of NO by the electrode. It is concluded that the NO microelectrode is applicable to NO measurement in the vascular media where NO controls vascular tone and that the concentration of NO in the arterial vascular media changes with perfusion rate in a rate-dependent manner as well as with a time constant of about 24 s for a stepwise increase in flow.     

Autoregulation of superior mesenteric flow in fasted and fed dogs.

Pressure-flow relations in the intestinal vasculature were obtained by producing stepwise reductions of intestinal perfusion pressure with an adjustable metal clamp placed upon the descending thoracic aorta. To eliminate intervention of the baroreceptor reflex, systemic arterial pressure was maintained constant by a pressure compensation system connected to the two carotid arteries. In the fed dogs, autoregulatory vasodilatory responses to reduced perfusion pressure maintained flow within 5% of control in the 85-125 mmHg range. In 30% of the fed dogs, superior mesenteric flow actually increased as perfusion pressure was reduced in the pressure range 85-125 mmHg, indicating superregulation of flow in the intestinal vasculature. The degree of flow autoregulation in the fasted dog was less than in the fed dog. Moreover, superregulation of intestinal flow was not observed in any of the fasted animals. These data suggest an intimate link between parenchymal activity and local flow control in the small intestine.     

In vivo comparison of scanning technique and wavelength in laser Doppler perfusion imaging: Measurement in knee ligaments of adult rabbits

At present, there are only two laser Doppler perfusion imaging systems (LDls) manufactured for medical applications: a ‘tepwise’ and a ‘continuous’ scanning LDI. The stepwise scanning LDI has previously been investigated and compared with coloured microsphere determined standardised flow. The continuous scanning LDI is investigated and compared with the stepwise scanning LDI for its ability to measure in vivo, hypoaemic, ligament tissue blood flow changes. The continuous scanning system was supplied with two lasers, red and near infrared (NIR), allowing for additional assessment of the effect of wavelength on imaging ligament perfusion. Perfusion images were obtained from surgically exposed rabbit medial collateral ligaments (MCL). Continuous and stepwise LDI scans were compared using correlation and linear regression analysis of image averages and standard deviations. Using the same method of analysis, LDI measurements using red and NIR lasers indicated a high degree of correlation, at least over the ranges of perfusion assessed, indicating that red and NIR lasers measure similar regions of flow in the rabbit MCL. These experiments confirm that both LDI techniques provide a valid in vivo measure of dynamic changes in connective tissue perfusion and could have significant impact on the understanding and treatment of joint injury and arthritis.     

高精度腹腔热灌注治疗系统设备的开发研究

目的 介绍一种高精度腹腔热灌注治疗系统的总体设计原理及系统的总体构成方法.方法 高精度"BR-TRG-Ⅱ型腹腔热灌注治疗系统"由控制系统、外循环系统、热交换器、内循环系统4部分构成.从功能卜分为5个功能子系统:计算机主控子系统包括以AVR单片机为核心的主控制电路,数据采集和处理子系统,加热制冷子系统,循环子系统和报警子系统.结果 本系统具有专用计算机热疗软件,全程动态控制,可实现治疗参数设置、自适应温度控制、治疗数据显示、自动存储、报警等功能.动物实验及临床初步应用结果表明,该设备测温精度达±0.1℃,控温精度±0.16℃,腹腔液体灌注速度精确到5%,各项性能完全达到临床设计要求.结论 高精度"BR-TRG-Ⅱ型腹腔热灌注治疗系统"加温、恒温和降温完全达到临床设计要求,性能稳定、安全可靠、操作便利,便于临床推广应用.     

Does diffuse coronary atherosclerosis affect the relation between coronary stenoses and uptake of thallium-201 after exercise?

It has been proposed that diffuse coronary atherosclerosis influences the myocardial perfusion. We performed a study of 94 young men with previous myocardial infarction in order to find out whether the presence and extent of diffuse coronary atherosclerosis affected the relation between maximal stenosis and myocardial perfusion in areas remote from the infarction. The patients were examined by planar-imaging thallium-201 scintigraphy, following exercise, and coronary angiography within 6 months after myocardial infarction. The maximal distinct stenosis and diffuse coronary atherosclerosis, comprising both plaque size and extent, were semiquantitatively assessed. The correlation coefficients between maximal stenosis within the LAD, RCA, and LCX vascular territories and the corresponding initial uptake of thallium were 0.52 (P = 0.0001), 0.30 (P = 0.04), and 0.46 (P = 0.02), respectively. No change of the correlations was found, except for a slight increase of the r-value from 0.30 to 0.37 in regions corresponding to RCA, after controlling for the diffuse atherosclerosis score in a multiple stepwise regression analysis. These findings indicate no impact of diffuse coronary atherosclerosis on regional myocardial perfusion in areas remote from the infarction.     

The measurement of endometrial perfusion in norplant users: a pilot study

The use of progestogens without oestrogen is commonly associated with irregular menstrual bleeding. Oestrogens and progestogens are both thought to influence endometrial perfusion; changes in endometrial perfusion may contribute to vascular fragility and breakdown. In this study, endometrial perfusion was measured using laser-Doppler fluxmetry in women in the secretory phase of the menstrual cycle before and 4-6 weeks after insertion of the low-dose long-acting levonorgestrel contraceptive implant system, Norplant. Endometrial perfusion was also measured in women exposed to Norplant for up to 19 months. There was no significant difference between endometrial perfusion in control cycles (27.2 flux units +/- 5.5, SEM) and at 4-6 weeks after Norplant insertion (16.3 flux units +/- 5.0), a time when irregular bleeding and spotting are common. Endometrial perfusion was no different from controls after longer periods of Norplant exposure (35.7 flux units +/- 7.2). No direct relationships between endometrial perfusion and plasma concentrations of ovarian steroid hormones were demonstrated. Short-term endometrial vasomotion was largely abolished during Norplant exposure.     

Dynamic exercise in man as influenced by experimental restriction of blood flow in the working muscles

The effects of reduced muscle perfusion pressure on dynamic exercise performance and cardiovascular and respiratory functions were investigated. Eight subjects were studied during supine cycle ergometry at stepwise increasing workloads until exhaustion with and without the legs exposed to a supra-atmospheric pressure of 50 mmHg (Leg Positive Pressure, LPP), a novel and convenient means of reducing the perfusion pressure in the working muscles. In the LPP condition exercise performance was reduced by 40% which, judging from assessments of perceived exertion, was due to premature muscle fatigue, indicating local or overall underperfusion of the working muscles. At any given work load, the arterial pressure response was considerably stronger during LPP than in the control condition. LPP also caused greater increases in blood lactate concentration and pulmonary ventilation, the differences from control increasing with the work load. Furthermore, the ventilatory equivalent for O₂ at a given work load was markedly higher in the LPP than in the control condition, while exercise-induced decreases in end-tidal P_CO2 were considerably exaggerated by LPP. The augmented pressor response during flow-restricted exercise, together with the strong ventilatory response which was out of proportion to overall O₂ uptake, suggests increased activation of muscle chemoreflexes by accumulation of metabolic end products, the increased pressor response tending to reduce the local flow error in the working muscles.     

Regulation of myocardial oxygen consumption by perfusion pressure in isolated fibrillating canine heart

In order to evaluate whether perfusion pressure or coronary flow affect myocardial oxygen metabolism, oxygen consumption of the isolated fibrillating blood-perfused canine heart was investigated at perfusion pressures of 100, 150, and 200 mm Hg. To obtain different coronary flow rates at a given coronary perfusion pressure, -adrenergic blockade by phenoxybenzamine (10 mg/kg b.w.) was applied, resulting in an increase in coronary flow and a decrease in myocardial oxygen extraction. Myocardial oxygen consumption was increased by elevation of perfusion pressure in both the control and phenoxybenzamine-pretreated group. At the same level of perfusion pressure there was no significant difference between the oxygen consumption of control and phenoxybenzaminepretreated preparations. It can be concluded that in the isolated fibrillating canine heart oxygen consumption is primarily regulated by perfusion pressure, and is independent from coronary blood flow.     

家兔体外血浆灌流实验方法的建立

目的建立兔体外血浆灌流的动物实验方法,用于评价一种体外血浆脂类吸附过滤器。方法以高脂血症大耳白兔为模型动物,先后使用了2种不同面积的中空纤维型血浆分离器,通过5mL真空采血管离心和100mL生理盐水袋离心等方法,将血浆与血细胞分离,通过蠕动泵在体外建立血浆循环。结果0．3m2的血浆分离器能够将血浆与血细胞有效分离,顺利进行血浆循环;但是,由于该型号的血浆分离器的容积过大,动物失血过多,因肺水肿等原因导致动物死亡。0．1m2的小型血浆分离器不能将高脂血症动物血浆与血细胞分离;而使用采血管,采血速度不能控制,操作时间长,血细胞损失过多,动物死亡率高。利用100mL生理盐水袋作为离心分离容器,分批采血,采用15％的枸橼酸钠溶液抗凝,离心分离血浆与血细胞,血浆进行体外循环;同时严格控制采血速度、回输速度以及抗凝条件,成功地建立了兔体外血浆灌流实验方法和方案,操作简单,动物存活率高。结论利用100mL生理盐水袋分批采血,离：0法分离血浆与血细胞,建立血浆体外循环。操作简单,比膜血浆分离器费用低,动物存活率高,是进行血液净化相关材料评价的理想的兔体外血浆灌流模型。