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Leg venous hemodynamics and leg volumes during a 42-day -6 degrees head-down bedrest

ACTA ASTRONAUTICA 1995年第8-12期36卷 575-579页

作者： Louisy, F Schroiff, P Guezennec, CY Guell, A Centre National d'Etudes Spatiales 31055 Toulouse France

Seven healthy subjects were submitted to a 42-day head down bedrest, where leg venous compliance (venous distensibity index VDI) and leg volumes were assessed by mercury strain gauge plethysmography with venous occlusion and optoelectronic plethysmography, respectively. Plethysmographic and volometric measurements were made, before, during (at days 1, 4, 7, 14, 21, 26, 34 and 41), and after bedrest (days 1, 4, 7, 11 and 30 of the recovery period). Results showed a continuous decrease in leg volumes throughout bedrest, when VDI increased until day 26 of bedrest, and then decreased afterwards. The recovery period was characterized by a rapid return of VDI to prebedrest levels while leg volumes progressively normalised. These results showed that leg venous compliance changes are not always dependant upon skeletal muscle changes, and that factors other than size of muscle compartment are able to determine increases in leg venous compliance during long-term bedrest.

关键词：适应生理学卧床休息血量/生理学顺应性头低位血流动力学/生理学腿/血液供给腿/生理学肌骨骼/解剖学和组织学肌骨骼/血液供给肌骨骼/生理学肌平滑/血液供给肌平滑/生理学体积描记术失重模拟成年人人类男(雄)性

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Biomedical program of the ALTAIR French Russian flight onboard the MIR station

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ACTA ASTRONAUTICA 1995年第8-12期36卷 707-712页

作者： AndreDeshays, C Haignere, JP Guell, A Marsal, O Suchet, L Kotovskaya, A Gratchev, V Noskin, A Grigoriev, A CNES USSR IMBP Moscow USSR

One year after the achievemant of the 2 weeks ANTARES french-russian mission in the MIR station in July 1995 a 22 days ALTAIR mission,vith a french cosmonaut has been performed in July 1993, making use of the scientific payload remaining on board Taking benefit of the analysis of the previous mission, the experimental protocols were adapted to refine scientific objectives and Save? to the scientists the opportunity to enhance quantitatively and qualitatively their results. The french biomedical program, conducted in close scientific cooperation with IMBP and associated laboratories, was composed of 8 experiments out of which 2 were new with regards to the ANTARES program In the field of cardio-vascular physiology and fluid regulation, the experiments: ORTHOSTATISME, DIURESE have been renewed and complemented by the TISSU experiment (proposed by a german scientist) and a real-time tele-assistance program using US echography technic and ground support from the french CADMOS support control center located in Toulouse. With respect to neurosciences objectives, to the experiments VIMINAL (cognitive processes) and ILLUSIONS (study of proprioceptives cues), was added the SYNERGIES experiment to analyse the postural adjustements during movement. The IMMUNOLOGIE experiment carried on and the radiobiological experiment BIODOSE ended. Adding the results of the 2 missions ANTARES and ALTAIR, and the data obtained in between onboard with russian cosmonauts, the scientists have received a wealth of physiological data and gained reproducibility and confidence in their results.

关键词：适应生理学/生理学航天医学心血管去适应性心血管生理学认知法国血流动力学/生理学免疫细胞国际合作运动(Movement) 定向力俄罗斯宇宙飞行远程医学失重人类男(雄)性

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Early and intermediate-term complications of self-expanding stents limit its potential application in children with congenital heart disease

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JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 2000年第4期35卷 1007-1015页

作者： Cheung, YF Sanatani, S Leung, MP Human, DG Chau, AKT Culham, JAG Univ Hong Kong Grantham Hosp Div Pediat Cardiol Dept Pediat 125 Wong Chuk Hang Rd Aberdeen Peoples R China British Columbia Childrens Hosp Div Pediat Cardiol Vancouver BC V6H 3V4 Canada

OBJECTIVES We report on the early and intermediate-term follow-up results of self-expanding Wallstent (Schneider, Switzerland) implanted in children with congenital heart disease. BACKGROUND The inherent shortcomings of balloon-expandable stents prompted the trial of an alternative stent. METHODS Twenty patients underwent 22 implantations of 25 self-expanding Wallstents between December 1993 and June 1997 in two institutions. The mean age and weight were 10.8 +/- 4.5 years and 30.5 +/- 14.2 kg, respectively. The patients were divided into two groups: 1) Group I comprised 17 patients with pulmonary arterial stenoses, 2) Group II comprised four patients with venous stenoses (one belonged to both groups). Sixteen patients underwent recatheterization at a median of 5.8 months (range 0.5 to 31, mean 8.1 months) after stenting. Hemodynamic and angiographic changes after the interventional procedures and complications were documented. RESULTS All the stents were successfully deployed in the intended position. In Group I, the narrowest diameter of the stented vessel increased from 4.1 +/- 1.5 to 8 +/- 2 mm (95% increase, p < 0.0001) while the systolic pressure gradient across decreased from 24.6 +/- 15.8 to 12.1 +/- 11.4 mm Hg (51% decrease, p = 0.001). In Group II, the dimensional changes of the narrowest segment increased from 4.3 +/- 0.5 to 7.5 +/- 0.4 mm (75% increase, p = 0.003), and the pressure gradient reduced from 5.0 +/- 2.9 to 0.9 +/- 1.0 mm Hg (82% decrease, p = 0.04) across the stented venous channel. Distal migration of two optimally positioned stents occurred within 24 h of implantation. At recatheterization, significant neointimal ingrowth (>30% of the expanded diameter) was noted in 7 (28%) of the 25 implanted stents. This responded poorly to balloon dilation. Predisposing factors for the neointimal ingrowth included stents of smaller diameter (<9 mm) and longer period after implantation. CONCLUSIONS Self-expanding Wallstent could be deployed easily and saf

关键词：血管造影术血管成形术气囊/仪器和设备缩窄病理性/诊断显像缩窄病理性/治疗设备失效分析随访研究心脏缺损先天性/诊断显像心脏缺损先天性/治疗血流动力学/生理学假体设计肺动脉/畸形肺动脉/诊断显像肺静脉闭塞性疾病/诊断显像肺静脉闭塞性疾病/治疗再治疗支架治疗结果青少年儿童儿童学龄前女(雌)性人类男(雄)性

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MAGNETIC RESONANCE IMAGING 2000年第5期18卷 495-502页

作者： Stevens, AA Skudlarski, P Gatenby, JC Gore, JC Yale Univ Sch Med Dept Diagnost Radiol New Haven CT 06510 USA

Functional magnetic resonance imaging (fMRI) was used to investigate the spatial distribution of cortical activation in frontal and parietal lobes during auditory and visual oddball tasks in 10 healthy subjects. The purpose of the study was to compare activation within auditory and visual modalities and identify common patterns of activation across these modalities. Each subject was scanned eight times, four times each for the auditory and visual conditions. The tasks consisted of a series of trials presented every 1500 ms of which 4-6% were target trials. Subjects kept a silent count of the number of targets detected during each scan. The data were analyzed by correlating the fMRI signal response of each pixel to a reference hemodynamic response function that modeled expected responses to each target stimulus. The auditory and visual targets produced target-related activation in frontal and parietal cortices with high spatial overlap particularly in the middle frontal gyrus and in the anterior cingulate. Similar convergence zones were detected in parietal cortex. Temporal differences were detected in the onset of the activation in frontal and parietal areas with an earlier onset in parietal areas than in the middle frontal areas. Based on consistent findings with previous event-related oddball tasks, the high degree of spatial overlap in frontal and parietal areas appears to be due to modality independent or amodal processes related to procedural aspects of the tasks that may involve memory updating and non-specific response organization. (C) 2000 Elsevier Science inc. All rights reserved.

关键词：声刺激听觉/生理学脑图回波平面成像/方法额叶/生理学血流动力学/生理学顶叶/生理学光刺激时间因素视知觉/生理学青少年成年人女(雌)性人类男(雄)性

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Beta-adrenergic receptor agonists and cyclic nucleotide phosphodiesterase inhibitors: Shifting the focus from inotropy to cyclic adenosine monophosphate

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JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 1999年第2期34卷 318-324页

作者： Movsesian, MA Univ Utah Hlth Sci Ctr Div Cardiol Salt Lake City VA Med Ctr Salt Lake City UT 84132 USA

Clinical trials of beta-adrenergic receptor agonists and cyclic nucleotide phosphodiesterase inhibitors in heart failure have demonstrated a reduction in survival in treated patients despite initial inotropic responses. These findings have led many to infer that activation of the mechanisms through which contractility is increased has deleterious effects on failing myocardium. It should be remembered, however, that these agents act proximately by raising intracellular cyclic adenosine monophosphate (cAMP) content and stimulating protein phosphorylation by cAMP-dependent protein kinase, and that the proteins whose phosphorylation contributes to the inotropic responses may be different from the proteins whose phosphorylation contributes to the reduction in survival. Evidence in support of the latter interpretation is presented, and potential therapeutic approaches through which the phosphorylation of different proteins might be selectively affected are considered. (C) 1999 by the American College of Cardiology.

关键词： 3' 5'-环AMP磷酸二酯酶类/拮抗剂和抑制剂转录激活因子2 肾上腺素能β激动剂/副作用肾上腺素能β激动剂/药理学肾上腺素能β激动剂/治疗应用环AMP/生理学 cAMP反应元件结合蛋白质/生理学环AMP依赖性蛋白激酶类/代谢环核苷酸磷酸二酯酶类 3型心力衰竭/药物疗法心力衰竭/死亡率心力衰竭/病理生理学血流动力学/药物作用血流动力学/生理学心肌收缩/药物作用心肌收缩/生理学心肌/代谢磷酰化信号传导转录因子/生理学动物人类

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Three-dimensional color Doppler: A clinical study in patients with mitral regurgitation

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JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 1999年第6期33卷 1646-1654页

作者： De Simone, R Glombitza, G Vahl, CF Albers, J Meinzer, HP Hagl, S Univ Heidelberg Abt Herzchirurg D-69120 Heidelberg Germany Deutsch Krebsforschungszentrum D-6900 Heidelberg Germany

OBJECTIVES The purpose of this study was to assess the clinical feasibility of three-dimensional (3D) reconstruction of color Doppler signals in patients with mitral regurgitation. BACKGROUND Two-dimensional (2D) color Doppler has limited value in visualizing and quantifying asymmetric mitral regurgitation. Clinical studies on 3D reconstruction of Doppler signals in original color coding have not yet been performed in patients. We have developed a new procedure for 3D reconstruction of color Doppler. METHODS We studied 58 patients by transesophageal 3D echocardiography. The jet area was assessed by planimetry and the jet volumes by 3D Doppler. The regurgitant fractions, the volumes, and the angiographic degree of mitral regurgitation were assessed in 28 patients with central jets and compared with those of 30 patients with eccentric jets. RESULTS In all patients, jet areas and jet volumes significantly correlated with the angiographic grading (r = 0.73 and r = 0.90), the regurgitant fraction (r = 0.68 and r = 0.80) and the regurgitant volume (r = 0.66 and r = 0.90). In patients with central jets, significant correlations were found between jet area and angiography (r = 0.86), regurgitant fraction (r = 0.64) and regurgitant volume (r = 0.78). No significant correlations were found between jet area and angiography (r = 0.53), regurgitant fraction (r = 0.52) and regurgitant volume (r = 0.53) in the group of patients with eccentric jets. In contrast, jet volumes significantly correlated with angiography (r = 0.90), regurgitant fraction (r = 0.75)and regurgitant volume (r = 0.88) in the group of patients with eccentric jets. CONCLUSIONS Three-dimensional Doppler revealed new images of the complex jet geometry. In addition, jet volumes, assessed by an automated voxel count, independent of manual planimetry or subjective estimation, showed that 3D Doppler is also capable of quantifying asymmetric jets. (C) 1999 by the American College of Cardiology.

关键词：血流速度/生理学血量/生理学超声心动描记术三维/仪器和设备超声心动描记术经食管/仪器和设备可行性研究血流动力学/生理学图像处理计算机辅助/仪器和设备二尖瓣/诊断显像二尖瓣闭锁不全/诊断显像超声检查多普勒彩色/仪器和设备成年人老年人女(雌)性人类男(雄)性中年人

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JOURNALS OF GERONTOLOGY SERIES A-BIOLOGICAL SCIENCES AND MEDICAL SCIENCES 2000年第9期55卷 B440-B447页

作者： Chang, KC Peng, YI Dai, SH Tseng, YZ Natl Taiwan Univ Coll Med Dept Physiol Taipei Taiwan Natl Taiwan Univ Coll Med Dept Internal Med Taipei Taiwan

Both the maximal systolic elastance (E-max) and the theoretical mauimal flow ((Q)over dot(max)) can quantify the systolic mechanical behavior of the ventricular pump. Physically, E-max can reflect the intrinsic contractility of the myocardium as an intact heart. The quantity in (Q)over dot(max) is inversely related to the internal resistance of the left ventricle. How great the effects of age are on these E-max and (Q)over dot(max) has never been examined, however. This study was to determine the ventricular pumping mechanics in terms of the systolic elastance and resistance in male Fischer rats at 6, 12, 18, and 24 months of age. We measured left ventricular (LV) pressure and ascending aortic flow waves using a high-fidelity pressure sensor and an electromagnetic now probe, respectively. Those two parameters that characterize the systolic pumping mechanics of the left ventricle are obtained by making use of an elastance-resistance model. The basic hemodynamic condition in those animals with different ages is characterized by (i) no significant change in cardiac output and (ii) a decrease in basal heart rate, LV end-systolic pressure, as Hell as effective arterial volume elastance, Changes that take place in the left ventricle with age include a decline in E-max and an increase in (Q)over dot(max) especially at 24 months. These results demonstrate that the impaired intrinsic contractility of an aging heart may be compensated to some extent by the diminished ventricular internal resistance, such compensation in aging rats may maintain normal blood flow essential for the metabolic needs of tissues and/or organs before heart dysfunction and failure occur.

关键词：衰老/生理学算法方差分析主动脉/生理学血压/生理学血量/生理学心排血量/生理学弹性电磁学现象/仪器和设备无菌生物心率/生理学血流动力学/生理学心肌收缩/生理学大鼠近交F344 局部血流/生理学应力物理心缩期心室功能心室功能左/生理学心室压/生理学动物男(雄)性大鼠

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Antiadrenergic effect of chronic amiodarone therapy in human heart failure

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JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 1999年第6期33卷 1553-1559页

作者： Kaye, DM Dart, AM Jennings, GL Esler, MD Baker Med Res Inst Alfred Baker Med Unit Melbourne Vic Australia

OBJECTIVES The aim of the present study was to evaluate the influence of amiodarone on neurochemical parameters of sympathetic nervous activity in patients with congestive heart failure. BACKGROUND Unlike most antiarrhythmic agents, amiodarone has been shown to exert a beneficial effect on survival in some studies of patients with congestive heart failure. The pharmacology of this agent is complex, and as such, the mode of its action is unclear in humans. Some experimental studies suggest that amiodarone exerts a sympatholytic effect. METHODS To evaluate the effect of amiodarone on sympathetic nervous activity, we measured the total systemic and cardiac norepinephrine (NE) spillover rate by isotope dilution in 58 patients with severe heart failure (left ventricular ejection fraction 20 +/- 1%), 22 of whom were receiving chronic amiodarone treatment Release rates for dihydroxyphenylalanine (DOPA, a precursor of NE), and endogenous and radiolabeled dihydroxyphenylglycol (DHPG and H-3-DHPG, intraneuronal metabolites of NE and H-3-NE, respectively) were also determined to assess sympathetic neuronal integrity. RESULTS Amiodarone-treated patients had significantly lower cardiac spillover rates for NE (42%, p = 0.001), DOPA (74%, p < 0.001), DHPG (44%, p < 0.01) and H-3 DHPG (51%, p < 0.01) than those patients not treated with amiodarone Hemodynamic assessment of amiodarone-treated patients revealed higher cardiac out-put (4.4 +/- 0.2 vs. 3.7 +/- 0.2 liters/min, p < 0.01), and slightly lower pulmonary capillary wedge pressure (18 +/- 2 vs. 22 +/- 1, p = NS) than in untreated patients. After correction for the potential confounding effect of hemodynamic differences, amiodarone-treated patients continued to demonstrate significantly lower spillover rates of NE, DOPA and DHPG from the heart. CONCLUSIONS These data indicate that amiodarone may exert beneficial effects on the failing human heart and this action appears to be relatively cardioselective a through a sympatholytic

关键词：肾上腺素能拮抗剂/投药和剂量肾上腺素能拮抗剂/副作用胺碘酮/投药和剂量胺碘酮/副作用抗心律失常药/投药和剂量抗心律失常药/副作用儿茶酚胺类/血液心力衰竭/药物疗法心力衰竭/病理生理学血流动力学/药物作用血流动力学/生理学交感神经系统/药物作用交感神经系统/病理生理学治疗结果心室功能左/药物作用心室功能左/生理学成年人老年人女(雌)性人类男(雄)性中年人

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Contribution of baroreceptors and chemoreceptors to ventricular hypertrophy produced by sino-aortic denervation in rats

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JOURNAL OF PHYSIOLOGY-LONDON 1999年第3期516卷 885-895页

作者： Van Vliet, BN Chafe, LL Montani, JP Mem Univ Newfoundland Fac Med St John NF A1B 3V6 Canada Univ Fribourg Inst Physiol CH-1700 Fribourg Switzerland

1. To test whether sine-aortic denervation (SAD)-induced right ventricular hypertrophy (RVH) is a consequence of baroreceptor or chemoreceptor denervation, we compared the effects of aortic denervation (AD), carotid denervation (CD), SAD and a SAD procedure modified to spare the carotid chemoreceptors (mSAD), 6 weeks after denervation surgery in rats. A sham surgery group served as the control. 2. The blood pressure (BP) les el was unaffected by AD, CD or XAD, but increased (9%) following mSAD. The mean heart rate level was not affected. Short-term BP variability was elevated following AD (81 %), SAD (144 %) and mSAD (146 %), but not after CD. Baroreflex heart rate responses to phenylephrine were attenuated in all denervation groups. 3. Significant RVH occurred only following CD and SAD. These procedures also produced high mortality (CD and SAD) and significant increases in right ventricular pressures and haematocrit (CD). 4. Significant left ventricular hypertrophy occurred following CD, SAD and mSAD. Normalized left ventricular weight was significantly correlated with indices of BP variability. 5. These results suggest that SAD-induced RVH is a consequence of chemoreceptor, not baroreceptor, denervation. Our results also demonstrate that a mSAD procedure designed to spare the carotid chemoreceptors produced profound baroreflex dysfunction and significant left, but not right, ventricular hypertrophy.

关键词：肾上腺素能α激动剂/药理学主动脉/神经支配主动脉/生理学血压/生理学颈动脉体/生理学去神经支配血流动力学/生理学肥大右心室/病理生理学器官测量/生理学酚类/毒性苯福林/药理学压力感受器/生理学大鼠 Long-Evans 窦房结/生理学遥测术动物男(雄)性大鼠

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A comparison of the cold presser test and the diving test or coronary and systemic hemodynamics in patients with and without coronary artery disease

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INTERNATIONAL JOURNAL OF CARDIOLOGY 1999年第1期71卷 7-15页

作者： Tio, RA Monnink, SHJ Jessurun, GAJ Peels, JOJ van Boven, AJ van Gilst, WH Crijns, HGJM Univ Groningen Hosp Dept Cardiol Thoraxctr Groningen Netherlands State Univ Groningen Dept Pharmacol Groningen Netherlands

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