| 1. |
- Beshara, Soheir, et al.
(författare)
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Anemia associated with advanced prostatic adenocarcinoma : Effects of recombinant human erythropoietin
- 1997
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Ingår i: The Prostate. - 0270-4137 .- 1097-0045. ; 31:3, s. 153-160
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND METHODS: Nine patients with hormone-refractory metastatic prostatic adenocarcinoma and anemia were treated with recombinant human erythropoietin (rHuEpo) at a median dose of 150 U/kg BW 3 times a week subcutaneously. Baseline hemoglobin (Hb) ranged from 70 to 116 g/L, and the study duration was 12 weeks (median patient participation period was 8 weeks). RESULTS: Four patients demonstrated a median Hb increase of 20 g/L and were considered responders. Three patients showed a median increase of 17 g/L but required blood transfusion once, and were therefore considered as partial responders. Baseline erythropoietic status showed a significant correlation between serum Epo and Hb. Inadequate Epo production, evaluated by the observed/predicted log Epo ratio, was found in two patients. Defective bone marrow activity, demonstrated by low transferrin receptor (TfR), and hypoferremia in spite of abundant iron stores were also shown. Hemorheological investigations showed elevated plasma viscosity. CONCLUSIONS: Our results indicate that suppression of erythropoiesis can be mainly explained by the depressed marrow activity. The altered hemorheology might contribute to the anemia. This anemia could possibly be corrected with rHuEpo.
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| 2. |
- Fadul, Jamal E., et al.
(författare)
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Effects of LDL apheresis on blood rheology in two patients with homozygous familial hypercholesterolaemia
- 1997
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Ingår i: Blood Purification. - 0253-5068 .- 1421-9735. ; 15:3, s. 182-187
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Tidskriftsartikel (refereegranskat)abstract
- Changes in haemorheological and lipid variables were investigated in 2 patients with homozygous familial hypercholesterolaemia (FH) treated with low-density lipoprotein (LDL) apheresis using dextran sulphate adsorbent. The immediate effect of LDL apheresis was a fall in plasma fibrinogen by 50%, total and LDL cholesterol by 60%, plasma viscosity by 12% and whole blood viscosity by 17%. Before the 12th treatment session, plasma fibrinogen concentration remained reduced by 22%, whole blood viscosity by 17% and the plasma viscosity by 11% compared with the initial values. Total and LDL cholesterol in plasma also remained reduced by about 50%. We conclude that LDL apheresis, using dextran sulphate adsorbent, improves blood rheology. The decrease in plasma fibrinogen concentrations, plasma viscosity and LDL cholesterol might be factors contributing to the improved haemorheological properties.
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| 3. |
- Fadul, Jamal E. M., et al.
(författare)
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Effects of extracorporeal hemapheresis therapy on blood rheology
- 1997
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Ingår i: Journal of clinical apheresis. - 0733-2459 .- 1098-1101. ; 12:4, s. 183-186
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Tidskriftsartikel (refereegranskat)abstract
- The blood flow property is one of the factors determining blood perfusion and oxygen supply. The viscosity of the blood is primarily related to the hematocrit, but also to the amount of fibrinogen and other macromolecules present in the blood. Patients with ischemic heart disease have shown a rapid and safe improvement in their hemorheological state when treated with heparin-induced extracorporeal low-density lipoprotein (LDL) precipitation (HELP). In this study we used two extracorporeal hemapheresis methods, plasmapheresis (PP) and immunoadsorption (IA), in 15 patients (eight patients treated with PP and seven patients with IA) with various diseases. Hemorheological variables and plasma fibrinogen were measured before and after the first and before the third treatment performed at 3 consecutive days. The aim of our study was to investigate the immediate effects of these two treatment modalities on the flow properties of blood. Immediately after the first PP and IA session statistically significant declines in plasma fibrinogen concentration, plasma viscosity, whole blood viscosity, and erythrocyte aggregation tendency were found. These changes persisted before the third treatment session. The erythrocyte fluidity and hematocrit remained unchanged. We conclude that extracorporeal hemapheresis therapy, with plasmapheresis or immunoadsorption, affects the blood rheology by decreasing the plasma viscosity and erythrocyte aggregation tendency. The decrease in plasma fibrinogen is probably the main factor underlying that, but other factors such as a decrease in immunoglobulins may also be of importance.
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| 4. |
- Furuland, Hans, et al.
(författare)
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Hemorheological and hemodynamic changes in predialysis patients after normalization of hemoglobin with epoetin-alpha
- 2005
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Ingår i: Scandinavian Journal of Urology and Nephrology. - : Informa UK Limited. - 0036-5599 .- 1651-2065. ; 39:5, s. 399-404
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Changes in blood viscosity and total peripheral resistance may contribute to increased blood pressure during partial correction of renal anemia with erythropoietin. An increase in hemoglobin level is followed by decreases in cardiac output and left ventricular mass. We examined how normalization of hemoglobin in predialysis patients affects both hemorheological and hemodynamic variables. MATERIAL AND METHODS: Twelve moderately anemic predialysis patients (hemoglobin 115.9+/-7.8 g/l) received epoetin-alpha with the aim of achieving a normal hemoglobin level (135-160 g/l). Hemorheological variables were measured using rotational viscometry. Cardiac index was determined by means of Doppler echocardiography. RESULTS: After 48 weeks, the hematocrit level had increased from 37.9%+/-3.0% to 47.0%+/-3.1% (p<0.0001). Blood viscosity increased from 3.84+/-0.33 to 4.59+/-0.4 mPa x s (p<0.001). Blood viscosity standardized to a hematocrit level of 45% and a plasma viscosity of 1.31 mPa x s did not change. Plasma viscosity, erythrocyte aggregation tendency and erythrocyte fluidity remained unchanged. The cardiac index decreased from 2.64+/-0.57 to 2.19+/-0.72 l/min/m(2) (p<0.05). The total peripheral resistance index increased from 3270+/-985 to 4013+/-1046 (dyn x s/cm(5))m(2) (p<0.05). Blood pressure remained constant, but the amount of antihypertensive medication used increased by 30%. CONCLUSIONS: Hemoglobin normalization in predialysis patients raised blood viscosity and total peripheral resistance due to an increase in hematocrit level, without other consistent hemorheological changes. Antihypertensive therapy had to be increased in many patients to maintain an acceptable blood pressure. The cardiac index was reduced, which may have prevented further development of left ventricular hypertrophy.
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| 5. |
- Linde, Torbjörn, et al.
(författare)
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Blood viscosity and peripheral vascular resistance in patients with untreated essential hypertension
- 1993
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Ingår i: Journal of Hypertension. - 0263-6352 .- 1473-5598. ; 11:7, s. 731-736
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The viscosity of blood is increased in patients with essential hypertension. The aim of the present study was to investigate the importance of the different variables of blood rheology to total peripheral resistance, and to elucidate whether inappropriate regulation of the formation of erythropoietin could be important. DESIGN: Nineteen consecutive patients with untreated essential hypertension were examined and compared with a group of matched healthy volunteers. METHODS: The haemorheologic variables were assessed by rotational viscometry and the haemodynamic variables by bioimpedance cardiography. The serum concentrations of erythropoietin were determined by radioimmunoassay. RESULTS: The whole blood viscosity and peripheral resistance index were elevated in the hypertensive group. The two variables were positively correlated with each other (r = 0.68, P = 0.0015). The plasma viscosity and erythrocyte aggregation tendency were increased and the erythrocyte deformability, measured as fluidity, was decreased in the hypertensive patients. In the male subpopulation (n = 12) the aggregation tendency was positively, and the deformability negatively, correlated with body mass index. The serum concentrations of erythropoietin were equal in the two groups. CONCLUSIONS: The increased total peripheral resistance in patients with essential hypertension may in part be explained by an increased blood viscosity, but the possibility of an opposite cause-effect relationship must also be taken into consideration. The haemorheological abnormalities observed in the present patients cannot be explained by high serum levels of erythropoietin.
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| 6. |
- Linde, Torbjörn, et al.
(författare)
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Decreased blood viscosity and serum levels of erythropoietin after anti-hypertensive treatment with amlodipine or metoprolol : results of a cross-over study
- 1996
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Ingår i: Journal of Human Hypertension. - 0950-9240 .- 1476-5527. ; 10:3, s. 199-205
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Tidskriftsartikel (refereegranskat)abstract
- The increased viscosity of blood of hypertensive patients can be assumed to be a risk factor for the development of cardiovascular diseases. The aim of the present study was to elucidate whether anti-hypertensive treatment has any impact on blood theology. Twenty patients with previously untreated hypertension who consecutively attended our outpatient hypertension clinic were included in this prospective, open, cross-over study. The patients were randomly selected to treatment with amlodipine or metoprolol. The antihypertensive therapy was switched after 4 months. Haemorheological and haemodynamic variables were measured with rotational viscometry and impedance cardiography, respectively. Fifteen and 16 patients could be evaluated after amlodipine or metoprolol treatment respectively. The mean blood pressure (BP) decreased from 159 +/- 22/105 +/- 7 to 139 +/- 21/91 +/- 6 mm Hg on amlodipine and from 162 +/- 22/104 +/- 5 to 145 +/- 24/90 +/- 8 mm Hg on metoprolol therapy. After amlodipine treatment, the total peripheral resistance index decreased whereas metoprolol treatment was accompanied by a decrease in the cardiac index. Decreases in whole blood viscosity, haematocrit and serum erythropoietin were found after amlodipine as well as metoprolol treatment. After amlodipine the plasma viscosity decreased and the erythrocyte deformability increased in the majority of patients. Plasma fibrinogen decreased after metoprolol treatment. Despite the differences in haemodynamic mechanisms underlying the decrease in BP, amlodipine and metoprolol exert beneficial effects on blood viscosity. Haemodilution and a decrease in serum erythropoietin may be factors underlying this decrease in blood viscosity.
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| 7. |
- Linde, Torbjörn, et al.
(författare)
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The required dose of erythropoietin during renal anaemia treatment is related to the degree of impairment in erythrocyte deformability
- 1997
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Ingår i: Nephrology, Dialysis and Transplantation. - 0931-0509 .- 1460-2385. ; 12:11, s. 2375-2379
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Renal anaemia is rapidly corrected by recombinant human erythropoietin (rHuEpo) therapy, but the dose required varies greatly. Since impaired erythrocyte deformability may be one factor contributing to the development of renal anaemia, the interrelationship between that variable and the rHuEpo requirement was examined. METHODS: Twenty-five patients treated with hemodialysis and rHuEpo for at least 6 months were included in the study. The Hb value had been stable and the rHuEpo dose unchanged the last two months. Using a rotational viscometer, the fluidity of erythrocytes, separated from plasma and re-suspended in isotonic buffered saline to a standardized haematocrit, was taken as a measure of erythrocyte deformability. RESULTS: The average weekly dose of s.c. epoetin alpha was 186 +/- 93 U/kg body weight (range 56-370). The dose was correlated to the reticulocyte fraction (R = 0.69, P = 0.0001). When the rHuEpo dose was used as dependent variable and blood haemoglobin concentration, serum (S) albumin, S ferritin, S aluminium, S PTH, S urea, Kt/V/week, erythrocyte fluidity, and plasma viscosity were used as independent variables in a stepwise multiple regression analysis, only erythrocyte fluidity remained significantly negatively correlated to the rHuEpo dose (R = 0.5, P = 0.01). Despite a tendency towards higher doses of rHuEpo in patients with a C-reactive protein concentration exceeding 20 mg/l, the Hb was lower in these patients. CONCLUSIONS: We conclude that the interindividual differences in bone marrow response to rHuEpo were small in these patients. Impaired erythrocyte deformability and inflammation seem to be factors associated with increased rHuEpo requirement.
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| 8. |
- Metry, George, et al.
(författare)
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Effect of normalization of hematocrit on brain circulation and metabolism in hemodialysis patients
- 1999
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Ingår i: Journal of the American Society of Nephrology. - 1046-6673 .- 1533-3450. ; 10:4, s. 854-863
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Tidskriftsartikel (refereegranskat)abstract
- Full correction of anemia with recombinant human erythropoietin (rhEPO) has been reported to reduce the risk of cardiovascular morbidity and mortality and improve the quality of life in hemodialysis (HD) patients. Effects of normalization of hematocrit on cerebral blood flow and oxygen metabolism were investigated by positron emission tomography. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), oxygen extraction ratio (rOER), and metabolic rate for oxygen (rCMRO2) were measured in seven HD patients before and after correction of anemia and compared with those in six healthy control subjects. In addition, blood rheology before and on rhEPO therapy was measured in HD patients, which included blood viscosity, plasma viscosity, erythrocyte fluidity, and erythrocyte aggregability. The results showed that plasma viscosity was high (1.51+/-0.19 mPa x s) and erythrocyte fluidity was low (85.8+/-4.8 Pa(-1) x s(-1)), while whole blood viscosity was within the normal range (3.72+/-0.38 mPa x s) before rhEPO therapy. After treatment, the hematocrit rose significantly from 29.3+/-3.3 to 42.4+/-2.2% (P<0.001), accompanied by a significant increase in the whole blood viscosity to 4.57+/-0.16 mPa x s, nonsignificant decrease in erythrocyte fluidity to 79.9+/-7.4 mPa(-1) x s(-1) and nonsignificant change in plasma viscosity (1.46+/-1.3 mPa x s). Positron emission tomography measurements revealed that by normalization of hematocrit, rCBF significantly decreased from 65+/-11 to 48+/-12 ml/min per 100 cm3 (P<0.05). However, arterial oxygen content (caO2) significantly increased from 5.7+/-0.7 to 8.0+/-0.4 mmol/L (P<0.0001), rOER of the hemispheres significantly increased from 44+/-3 to 51+/-6% (P<0.05) and became significantly higher than healthy control subjects (P<0.05). In addition, rCBV significantly increased from 3.5+/-0.5 to 4.6+/-0.6 ml/100 cc brain tissue. The results showed that oxygen supply to the brain tissue increased with normalization of hematocrit, but it was accompanied by increased oxygen extraction in the brain tissue. This may be assumed to be related to the decrease of erythrocyte velocity in the cerebral capillaries as a result of the decreased blood deformability and the increased plasma viscosity.
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| 9. |
- Baskurt, Oguz, et al.
(författare)
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New guidelines for hemorheological laboratory techniques
- 2009
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Ingår i: Clinical hemorheology and microcirculation. - 1386-0291 .- 1875-8622. ; 42:2, s. 75-97
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Tidskriftsartikel (refereegranskat)abstract
- This document, supported by both the International Society for Clinical Hemorheology and the European Society for Clinical Hemorheology and Microcirculation, proposes new guidelines for hemorheological methods used in experimental and clinical studies. It is based on a similar document entitled: "Guidelines for measurement of blood viscosity and erythrocyte deformability" published in 1986 by the Expert Panel on Blood Rheology of the International Committee for Standardization in Hematology. Recent methods techniques and instruments, as well as new approaches to interpretation of results, are added to these new guidelines; wide spread adoption should improve comparability between hemorheological laboratories and increase the reliability of rheological tests.
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| 10. |
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