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J Kastrup

Publications and source records attributed to J Kastrup.

At least 37 records · Page 2Linked to original sources
PubMed2000

Plasma disappearance of albumin and impact of capillary thickness in idiopathic dilated cardiomyopathy and after heart transplantation.

BACKGROUND-The increased plasma disappearance of albumin has previously been described in decompensated congestive heart failure (CHF); this disappearance normalized after diuretic treatment. Cardiac transplantation (HTX) and current medical treatment affect microvascular structure and function. We investigated the plasma disappearance of albumin and the impact of microvascular thickness and electrostatic properties in patients with compensated CHF and after HTX. METHODS AND RESULTS-The fraction of intravascular albumin that passes to the extravascular space per unit time, as determined from the plasma disappearance of intravenously injected (131)I-labeled albumin, was increased to 7.8+/-1.7% in 16 patients with CHF compared with 18 controls (6.5+/-1.9%, P<0.05); these levels normalized after HTX (5.8+/-2.6%, P<0.01, n=17). The change in ratio between (131)I-albumin and simultaneously injected negatively charged glycosylated (125)I-albumin (selectivity index, >1/hour in controls) was lower in patients with HTX (0.993+/-0. 022/hour) than in controls (1.008+/-0.019/hour; P<0.05), which indicated a relatively increased plasma disappearance of negatively charged albumin in HTX patients. Capillary basement membrane thickness was evaluated semiquantitatively from skin biopsies and showed no difference in the 3 groups (control, CHF, and HTX patients). However, in all 3 study groups, subjects with thicker capillary basement membranes had lower albumin escape rates (6.1+/-1. 8%, n=32, versus 7.6+/-2.6% in subjects without thickening of capillary basement membranes, n=19; P<0.05). CONCLUSIONS-The plasma disappearance of albumin increased in patients with compensated CHF and it normalized after HTX. The present normalized capillary basement thicknesses in patients with CHF and the direct association between this parameter and plasma albumin disappearance indicate that previous compensatory microvascular basement membrane growth results in restricted permeability. Microvascular electrostatic properties did not relate to plasma albumin disappearance.

Adult↗
PubMed2000

Plasma clearance of polyfructosan and extracellular body fluid distribution in idiopathic dilated cardiomyopathy and after heart transplantation.

The total extracellular fluid volume and distribution in plasma and interstitial spaces, and the microvascular permeability properties were studied in 16 nonedematous patients with congestive heart failure (CHF) due to idiopathic dilated cardiomyopathy and 17 such patients who underwent heart transplantation (HT) by analyzing the 3-hour plasma disappearance curve of polyfructosan. Eighteen healthy subjects served as controls. Polyfructosan (3.5 kD) is an extracellular marker and inulin analog transported almost solely by diffusion. The initial capillary membrane plasma clearance (i.e., the permeability-surface area product), the interstitial plasma clearance determined at 10 minutes (clearance[10), and the extracellular volume were determined from the polyfructosan curves. I-131-albumin was used as a plasma volume reference. Permeability-surface area product was elevated in both patient groups (6.6 +/- 1.9 ml/ kg/min in the CHF group and 6.7 +/- 2.0 ml/kg/min in the HT group vs 5.1 +/- 1.3 ml/kg/min in controls, p <0.01 for both), whereas clearance(10) was normalized in the HT group (4.5 +/- 0.9 ml/kg/min in the HT group, 4.4 +/- 0.7 ml/kg/min in controls vs 5.0 +/- 0.9 ml/kg/ min in the CHF group, p <0.1 and p <0.05, respectively). The normalization of interstitial plasma clearance of polyfructosan was associated with time since HT (r = 0.49, p <0.05). Plasma volumes were similar in all 3 groups (41 +/- 8 ml/kg in controls, 44 +/- 13 in the CHF group and 39 +/- 8 in the HT group). In contrast, total extracellular volume was elevated in both patients groups (177 +/- 27 ml/kg in the CHF group and 173 +/-27 in the HT group vs 152 +/- 12 in controls, p <0.01). The results strongly suggest a microvascular permeability defect in both patient groups that perhaps plays a role in the extravascular distribution of the excess extracellular fluid volume.

Adult↗
PubMed2000

Assessment of continuous skeletal muscle blood flow during exercise in humans.

The ability to measure regional blood flow from exercising skeletal muscles is of great interest. However, noninvasive techniques such as venous occlusion plethysmography and pulsed Doppler duplex ultrasonography only allow determination of blood flow at rest. The aim of our study was to investigate the influence of position on continuous measured skeletal muscle blood flow response in the upright and supine positions during graded maximal exercise by means of the local (133)Xenon washout technique with portable CdTe(Cl) detectors. Fifteen healthy subjects (8 women and 7 men, mean age 46 +/- 11 years) performed graded maximal bicycle exercise in both supine and upright positions in random order on 2 subsequent days. Blood flow in the musculus tibialis anterior was measured using the local (133)Xenon washout technique. A total of 55-110 MBq of (133)Xenon dissolved in isotonic saline was injected intramuscularly and the gamma emission was registered by light-weight portable CdTe(Cl) detectors. During supine exercise skeletal muscle blood flow increased continuously with increasing work load. However, during upright exercise blood flow increased only at the initial three work loads, then it decreased gradually. Immediately after exercise blood flow returned to preexercise values for both positions. The skeletal muscle blood flow at maximum work load for each subject was 74% (relative flow values) (P < 0.05) higher in the supine compared with the upright position. There was no significant difference in absolute or relative blood flow values at similar time points. Exercise time was longer in the supine (1345 +/- 548 s) compared with the upright position (1148 +/- 453 s) (P < 0.005). The local (133)Xenon washout technique with portable CdTe(Cl) detectors allows continuous determination of skeletal muscle blood flow during graded bicycle exercise in supine and upright positions. Furthermore, blood flow at maximum work load and exercise time was increased in supine compared with upright exercise.

Adult↗
PubMed2000

The phosphatase domains of CD45 are required for ligand induced T-cell receptor downregulation.

Down-regulation of the T-cell receptor (TCR) plays an important role in modulating T-cell responses, both during T-cell development and in mature T cells. At least two distinct pathways exist for TCR down-regulation: down-regulation following TCR ligation; and down-regulation following activation of protein kinase C (PKC). Ligand-induced TCR down-regulation is dependent on protein tyrosine kinase (PTK) activity and seems to be closely related to T-cell activation. In addition, previous studies have indicated that ligand-induced TCR down-regulation is dependent on the expression of CD45, a transmembrane protein tyrosine phosphatase. The role of the different domains of CD45 in TCR down-regulation was investigated in this study. We found that the phosphatase domains of CD45 are required for efficient ligand-induced TCR down-regulation. In contrast, the extracellular domain of CD45 is dispensable for ligand-mediated TCR down-regulation. Finally, PKC-mediated TCR down-regulation was found to be independent of both the extra-and intracellular domains of CD45.

Binding Sites↗
PubMed2000

QTc interval length and QT dispersion as predictors of mortality in patients with non-insulin-dependent diabetes.

Patients with non-insulin-dependent diabetes (NIDDM) are at independent risk of cardiovascular death. The reason is only partially understood. The aim of our study was therefore to evaluate the impact of corrected QT interval length (QTc) and QT dispersion (QT-disp) on mortality in a cohort of 324 Caucasian NIDDM patients. A resting 12-lead ECG was recorded at baseline. Maximum (QT-max) and minimum QT (QT-min) intervals were measured, and QT-max was corrected for heart rate (QTc-max). QT-disp was defined as the difference between QT-max and QT-min. QTc-max was 454 (376-671) ms(1/2) (median (range)) and QT-disp 61 (0-240) ms. Prolonged QTc interval (PQTc), defined as QTc-max > 440 ms(1/2), was present in 67% of the patients and prolonged QT-disp (PQT-disp), defined as QT-disp > 50 ms, was present in 51%. During the 9-year follow-up period, 100 patients died (52 from cardiovascular diseases). Thirty-seven percent of the patients with PQTc died compared with 17% with normal QTc interval (p<0.001). The Cox proportional hazard model, including putative risk factors at baseline, revealed the following independent predictors of all cause mortality; QTc-max (p<0.05), age (p<0.0001), albuminuria (p<0.01), retinopathy (p<0.01), HbA1c (p<0.05), insulin treatment (p<0.01), total cholesterol (p<0.01), serum creatinine (p<0.05) and presence of cardiac heart disease based on Minnesota coded ECG (p<0.001). Whereas QT-disp was not a predictor, QTc-max interval was an independent predictor of cardiovascular mortality. Our study showed a high prevalence of QTc and QT-disp abnormalities and indicated that QTc-max but not QT-disp is an independent predictor of all cause and cardiovascular mortality in NIDDM patients.

Albuminuria↗
PubMed2000

Percutaneous transradial coronary angiography and angioplasty in patients with occlusive atherosclerotic iliofemoral disease.

Not all coronary angiograms can be acquired through the femoral route. The transradial catheterisation procedure in patients with occlusive atherosclerotic iliofemoral disease is described. Transfemoral left-sided cardiac catheterisation was performed in approximately 99.5% of patients referred for coronary angiography, while out of 48 patients in whom transfemoral access was impossible, transradial coronary angiography was successful in 37. With the exception of one, all patients with coronary artery disease had lesions of the right coronary artery, more than 70% had multivessel disease and 14% had stenosis of the left main coronary artery. Ten patients had angioplasty performed during the same procedure. Complications occurred in 5 out of 39 cases, 2 (5%) of these were severe. Although the femoral route was used in more than 99% of an unselected population referred for coronary angiography, it was found that transradial angiography and angioplasty can be performed in patients with occlusive atherosclerotic iliofemoral disease with considerable success and an acceptable complication rate.

Adult↗
PubMed2000

Calf blood flow during prolonged tilt in idiopathic dilated cardiomyopathy and after cardiac transplantation.

In severe congestive heart failure (CHF), abnormal reflex control of calf blood flow during brief head-up tilt that appears to normalize after transplantation (HTX) may be present during prolonged observation also. Therefore, we studied the effect of prolonged (30 min) 50 degrees head-up tilt on calf skeletal muscle blood flow measured by the local (133)Xe washout method in CHF and after HTX and in patients with the presence vs. absence of native right atrium (+PNA and -PNA, respectively). During brief head-up tilt, skeletal muscle blood flow increased 13 +/- 42% in 9 severe CHF patients in contrast to a -28 +/- 22% decrease (P < 0.01) in 11 control subjects, -24 +/- 30% decrease in 15 moderate CHF patients (P < 0.05), -25 +/- 14% decrease in 12 patients with recent HTX (P < 0.01), and -21 +/- 24% decrease in 8 patients with distant HTX (P = 0.06). However, during sustained tilt, blood flow declined to similar levels of that in the other groups in severe CHF. HTX -PNA vs. +PNA showed blunted skeletal muscle vasomotor control (P < 0.05) and a higher systolic blood pressure (139 +/- 14 vs. 125 +/- 15 mmHg, P < 0.05) and heart rate (92 +/- 10 vs. 83 +/- 8 beats/min, P < 0.05). Thus paradox vasodilatation of calf skeletal muscle in severe CHF is present only during brief but not prolonged tilt. This may be one explanation of the rare presence of orthostatic intolerance in CHF and implies only a minor possible role for the abnormality in edema pathogenesis. Removal of all right atrium in HTX has an important hemodynamic impact that may possibly affect later clinical outcome.

Adult↗
PubMed2000

Cardiovascular and neuroendocrine responses to water immersion in compensated heart failure.

The hypothesis was tested that cardiovascular and neuroendocrine (norepinephrine, renin, and vasopressin) responses to central blood volume expansion are blunted in compensated heart failure (HF). Nine HF patients [New York Heart Association class II-III, ejection fraction = 0.28 +/- 0.02 (SE)] and 10 age-matched controls (ejection fraction = 0.68 +/- 0.03) underwent 30 min of thermoneutral (34.7 +/- 0.02 degrees C) water immersion (WI) to the xiphoid process. WI increased (P < 0.05) central venous pressure by 3.7 +/- 0.6 and 3.2 +/- 0.4 mmHg and stroke volume index by 12.2 +/- 2.1 and 7.2 +/- 2.1 ml. beat(-1). m(-2) in controls and HF patients, respectively. During WI, systemic vascular resistance decreased (P < 0.05) similarly by 365 +/- 66 and 582 +/- 227 dyn. s. cm(-5) in controls and HF patients, respectively. Forearm subcutaneous vascular resistance decreased by 19 +/- 7% (P < 0.05) in controls but did not change in HF patients. Heart rate decreased less during WI in HF patients, whereas release of norepinephrine, renin, and vasopressin was suppressed similarly in the two groups. We suggest that reflex control of forearm vascular beds and heart rate is blunted in compensated HF but that baroreflex-mediated systemic vasodilatation and neuroendocrine responses to central blood volume expansion are preserved.

Adaptation, Physiological↗
PubMed1999

Effects of passive tilting on capillary filtration in the lower leg in idiopathic dilated cardiomyopathy and after heart transplantation for the same condition.

Abnormal reflex control of the peripheral microvasculature during orthostasis in congestive heart failure (CHF) and after heart transplantation (HT) may cause failure of microvascular homeostasis and peripheral edema. We explored the effect of passive head-up tilt on lower leg capillary filtration measured by strain-gauge plethysmography in 24 patients with CHF, in 20 patients after HT (12 patients with preserved native right atrium, 8 patients without native right atrium), and in 18 controls. We hypothesized that an impaired peripheral microvascular reflex during orthostasis in CHF and HT might allow increased arterial hydrostatic pressure to increase pressure at the capillary level. To identify an impact of changes in arterial hydrostatic pressure, capillary fluid filtration was expressed per mm Hg arterial hydrostatic pressure (capillary filtration coefficient(arterial pressure) [CFC(AP)]) and was measured (1) during elevated venous pressure alone (50 mm Hg venous stasis in supine position), and (2) during elevated hydrostatic pressure at both the venous and arterial side of the vascular tree (head-up tilt with a vertical distance from the right atrium to the strain-gauge of 68 cm of water [50 mmHg]). Elevated venous pressure alone resulted in the highest CFC(AP) in controls (0.79+/-0.28 ml/min x 100 ml mm Hg x 10(-3)+/-SD) versus those with CHF (0.44+/-0.23, p <0.0001) and those after HT (0.54+/-0.22, p <0.01). However, during head-up tilt, CFC(AP) was similar in all 3 groups, because CFC(AP) decreased in controls (to 0.49+/-0.22, p <0.0001), in contrast to unchanged CFC(AP) in those with CHF (0.43+/-0.24) and in those with HT (0.50+/-0.21). HT patients with complete removal of the native right atrium had higher CFC(AP) (0.62+/-0.17) during head-up tilt than patients with preserved native right atrium (0.36+/-0.16, p <0.005). In conclusion, patients with CHF and those after HT have increased capillary filtration to a lesser degree than controls during elevated venous pressure alone. However, during orthostasis this apparent edema-protective mechanism vanishes, probably because of compromised microvascular reflex control. During daily upright activities, this may be one important factor in the edema pathogenesis. The phenomenon is particularly distinct in HT patients without preserved native right atrium.

Adult↗
PubMed1999

TCRzeta is transported to and retained in the Golgi apparatus independently of other TCR chains: implications for TCR assembly.

It is generally assumed that TCR assembly occurs in the endoplasmic reticulum (ER), and ER retention/degradation signals have been identified in several of the TCR chains. These signals are probably responsible for retention of incompletely assembled TCR complexes and free TCR chains in the ER. This study focused on the intracellular localization and transport of partially assembled TCR complexes as determined by confocal microscopy analyses. We found that none of the TCR chains except for TCRzeta were allowed to exit the ER in T cell variants in which the hexameric CD3gammaepsilonTi alphabetaCD3 deltaepsilon complex was not formed. Interestingly, TCRzeta was exported from the ER independently of other TCR chains and was predominantly located in a compartment identified as the Golgi apparatus. Furthermore, in the TCRzeta-negative cell line MA5.8, the hexameric CD3gammaepsilonTi alphabetaCD3 deltaepsilon complex was allowed to exit the ER and was also predominantly located in the Golgi apparatus. However, neither hexameric TCR complexes nor TCRzeta chains were efficiently expressed at the cell surface without the other. The observations that TCRzeta and hexameric TCR complexes are transported from the ER to the Golgi apparatus independently of each other and that these partial TCR complexes are unable to be efficiently expressed at the cell surface suggest that final TCR assembly occurs in the Golgi apparatus.

Biological Transport↗
PubMed1999

Skin microvascular distensibility and structural microangiopathy in idiopathic dilated cardiomyopathy and after heart transplantation.

Peripheral microvascular function plays an important role in patients with congestive heart failure (CHF). Decreased microvascular distensibility in skin and structural microangiopathy of the lower leg have been demonstrated in CHF due to idiopathic dilated cardiomyopathy. Whether microvascular skin distensibility reverses after heart transplantation and is related to the structural microangiopathy has not been elucidated before now. Distensibility (stiffness) of resistance vessels in the skin was measured using the local isotope washout method in a histamine-relaxed vascular bed at the dorsum of the foot. The structure of terminal arterioles was determined from skin biopsies. The measurements were performed in two studies. A cross-sectional study included 20 patients with clinical moderate CHF (NYHA II), 11 severe CHF patients (NYHA III and IV), and 28 patients 9 +/- 6 months (mean +/- SD) after heart transplantation (HTX). Furthermore, 12 patients were studied in a longitudinal study before (CHF) and 3 +/- 1 months (HTX-3) and 14 +/- 4 months (HTX-14) after HTX. A control group of 24 healthy subjects was included. In the cross-sectional study, distensibility in skin was reduced with increasing severity of CHF (severe CHF 22 +/- 10% and moderate CHF 38 +/- 21% vs controls 54 +/- 14%; P < 0.0001 and P < 0.01, respectively). Distensibility was reduced in patients after HTX (HTX, 41 +/- 18%) compared to controls (P < 0.01). In the longitudinal study, distensibility was decreased before transplantation (20 +/- 10%, P < 0.0001 vs controls) and increased gradually after HTX to 35 +/- 16% at 3 months (P < 0.01 vs CHF, P < 0.005 vs controls) and to 40 +/- 12% at 14 months (P < 0.05 vs controls, P < 0.01 vs HTX-3, P < 0.005 vs CHF). Structural microangiopathy was demonstrated in CHF, but not in HTX, in the cross-sectional study. However, a normalization could not be demonstrated after HTX in the longitudinal study. We conclude that the decreased microvascular skin distensibility (increased stiffness) gradually reverses after HTX. Furthermore, the structural microangiopathy seems to improve gradually.

Adult↗
PubMed1999

Exercise skeletal muscle blood flow is related to peripheral microvascular stiffness in idiopathic dilated cardiomyopathy.

Peripheral microvascular function plays an important role in congestive heart failure (CHF). Decreased exercise blood flow and microvascular dysfunction have been described in CHF and both factors are regarded as parameters that might influence exercise capacity in these patients. Whether these factors are related to or can be characterized in clinical severity of CHF has not been elucidated in this population. Skeletal muscle blood flow (SMBF) was measured continuously noninvasively, by means of the local isotope washout technique using (133)Xenon, in musculus tibialis anterior during graded maximal supine bicycle exercise. The distensibility in skeletal muscle was measured in a papaverine-relaxed vascular bed using (99m)Tc-pertechnetate. The investigation included 20 patients with moderate CHF (NYHA II), 11 patients with severe CHF (NYHA III, IV) due to idiopathic dilated cardiomyopathy (IDCM), and 31 age-matched healthy subjects. The maximal SMBF level was significantly lower in severe CHF (3.6 +/- 2.5 (ml x (100 g x min)(-1))) compared with moderate CHF (8.6 +/- 5.1 (ml x (100 g x min)(-1)); P < 0.005) and controls (11.0 +/- 4.1 (ml x (100 g x min)(-1)); P < 0.0001), but similar between moderate CHF and controls. Distensibility in skeletal muscle was decreased in severe CHF (12 +/- 8%) compared with controls (44 +/- 17%; P < 0.0001 vs severe CHF) and decreased with increasing severity of CHF (moderate CHF, 23 +/- 14%; P < 0.0005 vs controls). In CHF patients, a relationship was demonstrated between skeletal muscle distensibility and the maximal SMBF (P < 0.0001; r = 0.70). Moreover, maximal SMBF correlated directly to exercise time (P < 0.005; r = 0.54). Patients with CHF have reduced exercise SMBF, which may be a limiting factor for the reduced maximal exercise capacity. Moreover, microvascular distensibility in skeletal muscle is reduced and correlates to maximal exercise SMBF. Furthermore, maximal SMBF correlates to exercise time. This implies that increased skeletal muscle microvascular stiffness may contribute to the reduced blood flow during exercise and SMBF may partly limit exercise performance in CHF patients due to IDCM.

Adult↗
PubMed1999

Endothelin and von Willebrand factor as parameters of endothelial function in idiopathic dilated cardiomyopathy: different stimuli for release before and after heart transplantation?

BACKGROUND: Congestive heart failure (CHF) and heart transplantation (HTX) are characterized by endothelial dysfunction as indicated by elevation of markers of endothelial function, including endothelin and von Willebrand factor (vWF). However, previous studies included both patients with idiopathic dilated cardiomyopathy and ischemic heart disease; the latter condition shows endothelial dysfunction, per se. The 2 endothelial factors have different origin and may provide different information about endothelial dysfunction in CHF and after HTX caused by idiopathic dilated cardiomyopathy. METHODS: We investigated plasma endothelin and vWF, the relation between these 2 factors, and determinants of endothelin and vWF plasma levels in 32 healthy controls, 25 patients with CHF, and 22 patients who had HTX; both conditions were caused by idiopathic dilated cardiomyopathy. RESULTS: Plasma endothelin was elevated in CHF (6.8 +/- 3.4 pg/mL) and after HTX (6.1 +/- 2.1) compared with healthy controls (4.0 +/- 1.0, P <.0001 for both). VWF was also elevated in CHF (1.6 +/- 0.6 U/mL) and after HTX (2.6 +/- 1.0) compared with healthy controls (1.0 +/- 0.5, P <.0001 for both). VWF was increased after HTX compared with CHF (P <.001), in contrast to similar endothelin levels in CHF and after HTX. Plasma endothelin and vWF correlated in both CHF (r = 0.65, P <.001) and HTX (r = 0.66, P <. 001) but not in controls. In CHF, New York Heart Association functional class was an independent determinant of vWF (P <.0001) and furosemide dose of endothelin (P <.0001). In cardiac transplant recipients, plasma albumin was an independent determinant of vWF (P <.01), and plasma sodium and furosemide dose were independent determinants of endothelin (P <.01). CONCLUSIONS: Plasma endothelin and vWF were directly correlated in both CHF and after HTX caused by idiopathic dilated cardiomyopathy. However, the production of the 2 factors appeared to be stimulated by different mechanisms and provided different information about endothelial function, as indicated by the different determinants and different response to heart transplantation.

Adult↗
PubMed1999

Reversal of peripheral microvascular dysfunction during long-term treatment with the angiotensin-converting enzyme inhibitor fosinopril in congestive heart failure.

BACKGROUND: Treatment with angiotensin-converting enzyme (ACE) inhibitors in congestive heart failure (CHF) improves cardiac and peripheral hemodynamic function and exercise performance. However, studies on the effects of long-term treatment with an ACE inhibitor on the neurogenic and nonneurogenic regulation and structural microangiopathy of the peripheral microvasculature in CHF are lacking. METHODS AND RESULTS: We investigated the effect of 12 weeks of treatment with the ACE inhibitor fosinopril on peripheral microvascular function in a double-blind, placebo-controlled study of 12 patients treated with fosinopril and 10 patients treated with placebo. All had moderate CHF. Microvascular blood flow and resistance were calculated after application of the local isotope washout method in relaxed and nonrelaxed calf vascular beds in the supine position and during head-up tilt. Skeletal muscle vascular resistance was reduced in the fosinopril group (46 +/- 6 to 30 +/- 1 mm Hg.mL-1.100 g.min +/- standard error; P < .05) and differed compared with the effect of placebo (P < .05) where no change was seen (37 +/- 11 to 55 +/- 13 mm Hg.mL-1.100 g.min; not significant [NS]). Also, skin minimal vascular resistance was reduced during fosinopril treatment (13 +/- 0.6 to 11 +/- 0.7 mm Hg.mL-1.100 g.min; P < .05) and differed compared with the effect of placebo (P < .05) with absence of change (12 +/- 1.6 to 14 +/- 1.4 mm Hg.mL-1.100 g.min; NS). CONCLUSIONS: These results suggest that long-term ACE inhibitor treatment with fosinopril in patients with CHF improves hemodynamic status to as far as the peripheral microvascular level in both the relaxed and nonrelaxed microcirculation of the lower leg.

Aged↗
PubMed1999

Exercise blod flow and microvascualr distensibility in skeletal muscle normalize after heart transplantation.

This study investigated the effect of heart transplantation (HTX) on reduced exercise blood flow and microvascular stiffness in patients with congestive heart failure (CHF). Skeletal muscle blood flow (SMBF) during graded maximal supine bicycle exercise and microvascular distensibility (i.e., stiffness) were measured in musculus tibialis anterior by the isotope washout method. Measurements were performed in a cross-sectional study with 31 CHF patients and 28 patients, mean 9 months after HTX, and in a longitudinal study in 12 CHF patients before, 3 months, and 14 months after HTX, and in 31 healthy controls. Maximal SMBF: In the cross-sectional study, maximal SMBF was reduced in severe CHF patients (3.6 +/- 2.5 mL (100 g min)(-1)) and increased after HTX (7.7 +/- 4.8; p < 0.01 versus controls (11 +/- 4.1). Maximal SMBF was reduced in CHF patients (5.8 +/- 4.0) and reversed to normalization 3 months after HTX (10.3 +/- 4.4) in the longitudinal study. Microvascular distensibility: The distensibility was reduced (severe CHF, 12 +/- 8%; moderate CHF, 23 +/- 14%) in the cross-sectional study and increased after HTX towards normalization (38 +/-20%; controls: 44 +/- 17). In the longitudinal study, distensibility in CHF patients (14 +/- 6%) increased gradually to 32 +/- 12% (p < 0.005) at 3 months and normalized 14 months after HTX (46 +/- 17%). HTX gradually reversed the reduced SMBF and microvascular distensibility in CHF patients towards normalization.

Adult↗
PubMed1999

Regional blood flow in the calf and plasma endothelin during prolonged orthostasis in humans.

This study tested the hypothesis that circulating plasma levels of the vasoconstrictor endothelin increase during prolonged orthostasis in association with changes in both calf regional blood flow, systemic arterial blood pressure and heart rate, and that the 133Xenon wash-out method can be used for prolonged registration of skeletal muscle blood flow. The simultaneous effects of prolonged orthostasis on plasma endothelin, calf skeletal muscle and subcutaneous blood flow, heart rate and arterial blood pressure were investigated in 13 healthy subjects before, during and after 30 min of 50 degree head-up tilt. Blood flow rate was measured by the local 133Xenon wash-out method in the supine position and during 50 degree head-up tilt. The method was evaluated for skeletal muscle for prolonged observation in the supine position in five subjects and compared with blood flow rates measured with plethysmography. Plasma endothelin was unchanged during head-up tilt, despite a maximal reduction in skeletal muscle blood flow rate of 47% (p<0.001) and subcutaneous blood flow rate of 80% (p<0.01) and a maximal increase in heart rate of 15% (p<0.001) and diastolic (12%, p<0.01) blood pressure. The skeletal muscle wash-out curves for 133Xenon were monoexponential from 30 min after injection and at least during the next hour and correlated with total limb blood flow rate assessed simultaneously with plethysmography (r=0.76, p<0.0001). Circulating endothelin does not appear to be in the first line of regulation of calf microcirculation, systemic arterial blood pressure or heart rate during prolonged orthostasis. The 133Xenon wash-out method can be used for prolonged measurement of skeletal muscle blood flow.

Adult↗
PubMed1999

High numbers of clonal CD19+ cells in the peripheral blood of a patient with multiple myeloma.

Recent studies concerning the numbers of circulating clonal B cells in patients with multiple myeloma (MM) have reported conflicting data regarding the exact levels of clonal B cells and the existence of clonal cells in the CD34 compartment. In this report we show that high numbers of clonal cells with a phenotype of late-stage B cells or pre-plasma cells were present in the peripheral blood (PB) of a patient with MM. During treatment the initial high level of PB clonal cells was markedly reduced and remained low (<1%) post transplant, even after disease progression. In addition, we found that the MM clone did not include a B-progenitor population defined by CD34.

Antigens, CD19↗