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脑循环功能检测技术近三十年进展 总被引:1,自引:0,他引:1
脑循环功能的异常改变往往早于形态学和影像学改变,这对于脑血管的早期检测以及治疗过程中疗效的评价有显著意义。国内外脑循环功能检测技术的发展已有30年左右的历史,本文综述了脑循环动力学参数的生理背景及脑循环功能检测技术近年来的发展。 相似文献
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摘要 目的:探究血管内超声评价川崎病晚期患儿颈动脉功能、颈动脉内膜-中膜厚度和组织特征的临床价值。方法:选取81例川崎病晚期患儿作为本研究的川崎病组,同时选择同一时期的81例健康体检者作为本研究的对照组。所有受试者均通过血管内超声检查,对比分析两组一般临床资料、颈动脉功能、颈动脉内膜-中膜厚度、组织特征、颈动脉血流动力学和血管内皮功能。结果:川崎病组和对照组儿童的一般临床资料比较,差异均无统计学意义(P>0.05)。川崎病组患儿颈动脉血管僵硬度、脉搏波传导速度、颈动脉内膜-中膜厚度、血管的压力-应变弹性系数、硬度指数、颈动脉阻力指数和颈动脉僵硬度均显著高于对照组,而血管顺应性、血管径向应变率、动脉最大剪切率、颈动脉最小剪切率、颈动脉搏动指数和血管内皮依赖性舒张功能则显著小于对照组(P<0.05)。结论:血管内超声可有效评价川崎病晚期患儿颈动脉功能、颈动脉内膜-中膜厚度和组织特征,能够为后续疾病的治疗及预后提供重要参考,值得推广使用。 相似文献
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心脏和脑血管疾病是医学研究的热点。本文整合心脏、体循环和脑循环,构建了循环系统的整体动力学模型,力图揭示心脏和脑循环功能的相互影响。结论表明,从血液动力学角度,不但心脏特性变化会对脑循环产生影响,脑血管异常也会对心血管功能(如血压)发生作用。 相似文献
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陈荣信 《上海生物医学工程》1995,(1)
脑血管疾病是威胁人类生命和健康的三大疾病之一。目前用于检测脑血管功能、诊断脑血管疾病的临床仪器基本上有两类:一类观察脑血管几何形态(如MRI、CT等),可直接观察脑血管的病变,另一类可检测脑血管局部区域血流量分布或局部血管中的血流速度(如同位素示踪法、TCD等)。但至今仍没有有效的可直接检测、反映脑血管硬化程度、阻力大小及其他脑血管动力学特征的检测手段。 相似文献
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基于集中参数模型的脑血管疾病数值模拟 总被引:3,自引:0,他引:3
脑血管疾病的血流动力研究一直是和脑血管疾病的预防和诊断密切相关的,由于脑部血流循环是一个四端输入的网络,其复杂性导致它的血液动力学规律和体循环有着本质的差别,讨论脑循环这模型和临床应用有着重要的意义,本文使用集中参数模型来模拟三种常见的脑血管疾病;脑动脉硬化,脑梗塞,锁骨下动脉盗血,考察其对相应脑血管的压力和流量的影响,结果显示脑部血液循环的代偿功能在发病情况下的重要作用,本文通过分析数值模拟结果,对不同疾病的血液动力学特征进行研究,给脑血管疾病的临床诊断提供血液动力学方面的参考。 相似文献
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沉水植物茎叶微界面特性研究进展 总被引:1,自引:0,他引:1
沉水植物茎叶-水界面是浅水湖泊的重要界面之一,对湖泊生物地球化学循环和水环境质量具有重要影响。富营养化水体中,大量的附着物常富集在沉水植物茎叶表面,形成了特殊的生物-水微界面。对该微界面特性进行深入研究,有助于揭示沉水植物在微环境层面对富营养化水体中物质循环的调控过程和机制。沉水植物茎叶微界面具有促进水体养分转化、改变环境因子及可溶性物质的空间分布,增加物质运输的阻力和距离、降低植物光合作用、调控重金属等生态功能;微界面结构及环境因子受水体营养盐浓度、沉水植物种类及生长阶段等因素的影响。对微界面结构功能的主要研究方法进行了分析总结,并对沉水植物茎叶微界面的研究前沿进行了展望。 相似文献
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Miyashita M Ito N Ikeda S Murayama T Oguma K Kimura J 《Biosensors & bioelectronics》2009,24(5):1336-1340
The highly sensitive urine glucose meter based on amperometric glucose sensor was developed and commercialized. It shows remarkable performances of wide measurement range in 0-2000 mgdl(-1), rapid response time as 6s and robustness against influence by interferents like ascorbic acid or acetaminophen. Correlation between the developed urine glucose meter and commercialized clinical-use urine glucose analyzer showed excellent linear relationship. The monitoring of postmeal blood glucose levels by assess of urine glucose of actual subjects was performed with the developed urine glucose meter. The experimental results suggest the urine glucose level 120 min following the meal should be the appropriate index for diabetes or impaired glucose tolerance to control blood glucose level. The new portable meter was developed, and is expected for flexible use at places other than home or office. 相似文献
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The use of portable chemistry analyzers is an attractive option for obtaining clinical pathology panels in mice, because these analyzers require only small volumes of whole blood. However, in studies with other animals, portable analyzers do not always agree with results obtained using standard laboratory equipment. The authors evaluated the use of the i-STAT handheld portable clinical analyzer compared to the use of standard nonportable laboratory instruments in mice. As shown with other species, the i-STAT results did not always agree with standard laboratory instruments; however, the i-STAT does show reliability for certain chemistry assays. 相似文献
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Twelve patients with severe persistent cardiogenic shock complicating acute myocardial infarction underwent single crossover treatment with intravenous dopamine and salbutamol to determine the more beneficial therapy. Salbutamol (10 to 40 microgram/min) reduced systemic vascular resistance and progressively increased both cardiac index and stroke index. Heart rate increased from 95 to 104 beats/min. Changes in mean arterial pressure and pulmonary artery end-diastolic pressure were small and insignificant. Dopamine infusion at rates of 200 and 400 micrograms/min also increased cardiac index and stroke index. Systemic vascular resistance fell slightly but mean arterial pressure rose from 57 to 65 mm Hg. Heart rate increased from 95 to 105 beats/min. Changes in pulmonary artery end-diastolic pressure were again small and insignificant. Dopamine infusion at 800 micrograms/min caused an appreciable increase in systemic vascular resistance; a further increment in mean arterial pressure was observed, though cardiac index fell slightly. Heart rate and pulmonary artery end-diastolic pressure rose steeply. Salbutamol, a vasodilator, increased cardiac output in patients with cardiogenic shock complicating acute myocardial infarction but did not influence blood pressure. If correction of hypotension is essential dopamine in low doses may be the preferred agent. Doses of 800 microgram/min, which is within the therapeutic range, worsen other manifestations of left ventricular dysfunction. 相似文献
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Rosolová H Simon J Mayer O Racek J Dierzé T Jacobsen DW 《Physiological research / Academia Scientiarum Bohemoslovaca》2002,51(1):93-98
Mild hyperhomocysteinemia has been established as a new independent risk factor for atherosclerosis and thrombosis. The metabolic syndrome of insulin resistance is associated with a high risk of coronary heart disease. Our objective was to determine if any relationship exists between the metabolic syndrome of insulin resistance in non-diabetic subjects and total serum homocysteine levels. Sixty-six healthy volunteers (33 males and 33 females) were selected from the population of Pilsen. Insulin resistance was measured by the Insulin Suppression Test using Octreotide. Steady-state plasma glucose concentrations at the end of the test period provided a quantitative measure of insulin resistance. Serum homocysteine level was estimated by high-pressure liquid chromatography. Serum folate and vitamin B12 were estimated using commercial kits on an Abbott IMx analyzer. All other laboratory tests were performed by standard methods in a routine biochemical laboratory. Subjects with the highest tertile of steady-state plasma glucose showed a significantly higher body mass index, blood pressure, fasting plasma triglyceride levels, plasminogen activator inhibitor-1 and lower HDL-cholesterol, i.e. an insulin resistance pattern. These subjects had significantly lower serum homocysteine levels compared with non-insulin resistant subjects. The negative association of insulin resistance and serum homocysteine was unexpected. The contribution of plasma folate levels to serum homocysteine levels and serum creatinine was significantly negative and positive, respectively. 相似文献
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Alessandra Nunes Faria Fernando Flexa Ribeiro Filho Sandra Roberta Gouveia Ferreira Maria Teresa Zanella 《Obesity (Silver Spring, Md.)》2002,10(12):1203-1206
Objective: The relationship among body fat distribution, blood pressure, serum leptin levels, and insulin resistance was investigated in hypertensive obese women with central distribution of fat. Research Methods and Procedures: We studied 74 hypertensive women (age, 49.8 ± 7.5 years; body mass index, 39.1 ± 5.5 kg/m2; waist-to-hip ratio, 0.96 ± 0.08). All patients were submitted to 24-hour blood pressure ambulatory monitoring (24h-ABPM). Abdominal ultrasonography was used to estimate the amount of visceral fat (VF). Fasting blood samples were obtained for serum leptin and insulin determinations. Insulin resistance was estimated by homeostasis model assessment insulin resistance index (HOMA-r index). Results: Sixty-four percent of the women were postmenopausal, and all patients showed central distribution of fat (waist-to-hip ratio > 0.85). The VF correlated with systolic 24h-ABPM values (r = 0.28, p = 0.01) and with HOMA-r index (r = 0.27; p = 0.01). VF measurement (7.5 ± 2.3 vs. 5.9 ± 2.2 cm, p < 0.001) and the systolic 24h-ABPM (133 ± 14.5 vs. 126 ± 9.8 mm Hg, p = 0.04), but not HOMA-r index, were significantly higher in the postmenopausal group (n = 48) than in the premenopausal group (n = 26). No correlations were observed between blood pressure levels and HOMA-r index, leptin, or insulin levels. In the multiple regression analysis, visceral fat, but not age, body fat mass, or HOMA-r index, correlated with the 24h-ABPM (p = 0.003). Discussion: In centrally obese hypertensive women, the accumulation of VF, more often after menopause, is associated with higher levels of blood pressure and insulin resistance. The mechanism through which VF contributes to higher blood pressure levels seems to be independent of leptin or insulin levels. 相似文献
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M B Fowler A D Timmis J P Crick R Vincent D A Chamberlain 《BMJ (Clinical research ed.)》1982,284(6309):73-76
Nine patients with critically reduced cardiac output after acute myocardial infarction underwent a single cross-over comparison of dobutamine and salbutamol to compare the haemodynamic effects of these drugs, which have, respectively, predominantly beta 1-adrenergic and beta 2-adrenergic agonist activity. The responses were used to select the more appropriate treatment for individual patients. Only relatively small responses were obtained: those with poorest baseline measurements tended to show the least effect. When the results from the series were averaged, dobutamine (250-750 microgram/min) caused a small but progressive increase in cardiac index (1.8 to 2.2 1/min/m2) throughout the dose range. Systemic blood pressure was not increased, and calculated systemic vascular resistance fell from 25 to 19 units. Heart rate rose from 107 to 118 beats/min and stroke index from 17 to 19 ml/beat/m2. Pulmonary artery end-diastolic pressure fell from 18 to 15 mm Hg. Salbutamol (10-40 microgram/min) produced a similar progressive increase in cardiac index, from 1.6 to 2.21/min/m2. Systemic blood pressure was not altered, and systemic vascular resistance fell from 25 to 20 units. Heart rate rose from 105 to 119 beats/min and stroke index from 16 to 19 ml/beat/m2. Pulmonary artery end-diastolic pressure did not fall. Dobutamine and salbutamol have closely similar haemodynamic effects when used in cardiogenic shock after acute myocardial infarction. Both drugs increase cardiac index but heart rate also rises, and the increase in stroke index is relatively small. Mean arterial pressure is altered little by either agent, but dobutamine (in contrast with dopamine) tends to reduce pulmonary artery end-diastolic pressure, which may be beneficial. 相似文献
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SO2-bronchitis, papaine-emphysema and paraquat fibrosis were induced in Wistar rats. Blood pressure, cardiac index, total peripheral resistance, arterial blood gas values, parameters of acid-base balance were determined. Effects of 0.1 and 0.3 microgram.-1.min-1 isoproterenol iv. infusion were examined. Morphologic alterations of the lungs were verified by histopathological examinations. All the parameters investigated were found to be normal in the control rats. The treated groups differed from the normal ones: an increased blood pressure was observed in emphysema and fibrosis. A decreased cardiac index was characteristic of chronic bronchitis, high cardiac index of emphysema, high TPR of bronchitis and arterial hypoxaemy of fibrosis. The groups reacted differently to beta adrenergic stimulation: in bronchitic and fibrotic rats the cardiac index was augmented, whereas in emphysematous ones the increase proved to be smaller. The effects of isoproterenol infusion can be related to the altered beta-receptor function in the various experimental pulmonary diseases. 相似文献
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Brian M. Goldstein Robert A. Gabel Florence J. Huggins Peter Cervoni David L. Crandall 《Life sciences》1984,35(13):1373-1378
A dose-dependent decrease in mean arterial blood pressure was produced in spontaneously hypertensive rats by intravenous PAF infusion. Heart rate was monitored, while cardiac index and regional blood flow were quantitated during maintenance of the PAF-induced hypotension using the radioactive microsphere method. Our results suggest that PAF administration is associated with specific changes in vascular resistance, since estimated blood flow was decreased to certain organs or tissues, but remained unchanged in others. Therefore, the hypotension observed during PAF infusion is dose-dependent, and is contributed to by decreases in vascular resistance in specific organs. 相似文献
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Hinghofer-Szalkay HG László Z Rössler A 《Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology》1995,2(1):P19-P20
This study investigates the time course of hemodynamic variables during and after simulated orthostasis (lower body suction at 55mmHg for 30 mins: LBNP-55). Individual strategies of blood pressure defense could be observed; LBNP-55 increased heart rate and reduced stroke volume, but was non-hypotensive. During 20 minutes post-LBNP, heart rate was decreased as well as stroke volume index below pre-LBNP values. The reduced cardiac index together with unchanged mean arterial pressure gave a highly significant increase of peripheral resistance after LBNP. The validity of stroke volume results under the experimental conditions given needs to be clarified. 相似文献