| 1. |
- Gustavsson, Carl Gunnar, et al.
(författare)
-
Blood viscosity in relation to blood haemoglobin concentration in healthy subjects and in patients with different cardiovascular diseases
- 1994
-
Ingår i: Clinical Hemorheology. - New York, USA : Pergamon Press. - 0271-5198. ; 14:5, s. 677-683
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract Blood viscosity was measured at different shear rates using a rotational viscometer, and the correlation between blood viscosity and blood haemoglobin concentration was studied. In 10 healthy controls correlation coefficients were: 0,966 at shear rate 40,0 s-1, 0,931 at 19,6 s-l, 0,817 at 2,3 s-1 and 0,816 at 0,8 s-l , p<0,01 to p < 0,001. The regression lines for these relationships were then applied to the patient groups to calculate what blood viscosity should be predicted solely from the individual haemoglobin concentration, "predicted blood viscosity". In 34 patients with cardiovascular diseases (20 patients with coronary artery disease (CAD), 8 patients with idiopathic dilated cardiomyopathy and 6 patients with primary pulmonary hypertension) the correlation between blood viscosity and haemoglobin concentration was less good, for the total patient material 0,748 to 0,613, p < 0,001 at all shear rates, and for the CAD patients 0,664 to 0,428, p < 0,05 at 3 out of 4 shear rates. Apparently the poorer correlation in the patients was due to a larger influence from factors unrelated to haemoglobin concentration/haematocrit, as the quotients between individually measured and predicted blood viscosity correlated with measured blood viscosity when the haematocrit factor had been eliminated by in vitro standardisation of sample haematocrits to 45%. Key words: Blood viscosity; Haemorheology; Haemoglobin concentration; Microcirculation.
|
|
| 2. |
- Gustavsson, Carl Gunnar, et al.
(författare)
-
Changed blood rheology in patients with idiopathic dilated cardiomyopathy
- 1994
-
Ingår i: Angiology. - New York, USA : Westminster Publications, Inc.. - 0003-3197 .- 1940-1574. ; 45:2, s. 107-111
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract Rheologic properties of blood were studied in 8 patients with dilated cardiomyopathy (DCM) and in 10 healthy subjects. Whole-blood viscosity was measured at four different shear rates, by means of a computer-controlled rotational viscometer. The patients had significantly higher blood viscosity at all shear rates, both at their natural hematocrits and after an in vitro adjustment of sample hematocrits to 45%. Erythrocyte filterability (5 μm pore size) was significantly lower, fibrinogen concentration significantly higher, and HDLcholesterol concentration significantly lower in the patient group. No significant differences were found regarding hematocrit, mean corpuscular volume, haemoglobin concentration, leukocyte count and filterability (8 μm pore size), plasma viscosity, and total cholesterol concentration. The measured hemorheologic abnormalities may contribute to the previously reported reduction of coronary blood flow reserve in DCM patients and to myocardial microcirculatory disturbances, which have been suggested as a cause for DCM.
|
|
| 3. |
- Gustavsson, Carl G, et al.
(författare)
-
Vein blood rheology alterations immediately after coronary angiography with iohexol, and one month later.
- 1996
-
Ingår i: Clinical Hemorheology. - New York, USA : Pergamon Press. - 0271-5198. ; 16:6, s. 737-743
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract The effects of coronary angiography with iohexol upon vein blood rheology were studied before, immediately after and one month after angiography. Haematocrit decreased from 40.5 % to 39.0 % immediately after angiography (p < 0.01). When this was compensated for by in vitro standardisation of sample haematocrits to 45% there was a blood viscosity increase by 10.9 - 15.0 %, at the four studied shear rates 0.8 s-1, 2.3 s-1, 19.6 s-1, and 40.0 s-1 (p < 0.05 - p < 0.01). In unadjusted samples, i.e. at the patients natural haematocrits, there was only a slight and statistically non-significant blood viscosity increase. Plasma viscosity decreased immediately after angiography, and was even lower 1 month after angiography. The haematocrit reduction correlated significantly with the iohexol doses (correlation coefficient -0.852, p < 0.001), whereas no significant correlation was found between the contrast volumes and the alterations of blood and plasma viscosity. Except for plasma viscosity, there were no significant differences when the values before angiography and one month later were compared. Key words: Blood viscosity; Contrast media; Iohexol; Coronary angiography; Haematocrit; Haemorheology
|
|
| 4. |
- Persson, Sylvi Ulrika, et al.
(författare)
-
Studies on blood rheology in patients with primary pulmonary hypertension
- 1991
-
Ingår i: Angiology. - New York, USA : Westminster Publications, Inc.. - 0003-3197 .- 1940-1574. ; 42:10, s. 836-842
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract The rheologic properties of blood were studied in 6 patients with primary pulmonary hypertension (PPH) and compared with those of a control group of 10 healthy subjects. Blood viscosity was studied with a rotational viscometer and blood cell deformability with a filtrometer giving values for clogging particles (CP) and red cell transit time (RCTT). Blood viscosity at varying shear rates was found to be increased both at natural (p<0.025-0.005) and standardized hematocrit, 45% (p<0.05 at 40 s-1) in patients with PPH. Red cell deformability was reduced as indicated by a significant increase of RCTT (p<0.01). Increased values for hematocrit (p<0.001), hemoglobin concentration (p< 0.001), and erythrocyte count (p<0.005) were found and decreased values for mean corpuscular hemoglobin concentration (MCHC) (p< 0.025) and HDL cholesterol (p<0.005). Plasma viscosity, white cell deformability, white cell count, mean corpuscular volume (MCV), and plasma fibrinogen concentration did not significantly differ from the values found in the control group. It is concluded that patients with PPH have impaired blood rheology. The hemorheologic abnormalities in these patients may be of hemodynamic significance.
|
|
| 5. |
- Cwikiel, Magdalena, et al.
(författare)
-
Changes of blood viscosity in pateints treated with 5-fluorouracil : A link to cardiotoxicity?
- 1995
-
Ingår i: Acta Oncologica. - Norway. - 0284-186X .- 1651-226X. ; 34:1, s. 83-85
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract Cardiotoxicity is a serious but relatively unknown side-effect of treatment with 5-fluorouracil (5-FU). The underlying mechanism of 5-FU cardiotoxicity has not been defined. The aim of the present study was to determine whether hemorheological factors might in part explain 5-FU cardiotoxicity. Changes of blood and plasma viscosity, fibrinogen and hematocrit were studied in 11 patients treated by 5-FU. The study showed a decrease in blood and plasma viscosity during treatment with 5-FU, probably caused by a decrease of plasma fibrinogen. Reversible cardiotoxic effects were demonstrated in four patients.
|
|
| 6. |
- Larsson, Hans, et al.
(författare)
-
Changes in the functional state of the erythrocyte membrane : Significance for red cell filterability and blood viscosity
- 1990
-
Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - 0036-5513 .- 1502-7686. ; 50, s. 177-181
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract Blood samples from nine healthy men were studied to determine the effect of ouabain and elevated serum calcium concentration on blood viscosity, measured by a rotational viscometer, and on red cell filterability by the St George's Filtrometer, giving values for clogging particles (CP) and red cell transit time (RCTT). Blood viscosity at a standardized haematocrit of 45% and red cell filterability was investigated in blood samples incubated for 1 h with Ringer's solution only (control), with ouabain (0.70 mmol/l) in plasma, or with serum calcium concentration increased by 3.0 mmol/l by addition of CaCl2 Incubation with ouabain significantly reduced erythrocyte K+ concentration and increased that of Na+. Ouabain caused a decrease in blood viscosity (p<0.05-0.005) compared to controls, although there was no decrease in red cell filterability parameters. When incubating with calcium, CP and RCTT increased significantly indicating ”stiffer” red cells, but there was no increase in blood viscosity. It is concluded that blood viscosity may be influenced by red cell factors not detected by CP or RCTT, which in turn appear to reflect red cell deformability with greater sensitivity and specificity than blood viscosity. It is concluded also that the functional state of the cell membrane may be of significance for the rheological properties of erythrocytes. Key words: Blood cell deformability; Blood rheology; Calcium; Ouabain; Plasma viscosity; Red cell membrane; Sodium-potassium pump.
|
|
| 7. |
- Larsson, Hans, et al.
(författare)
-
Studies on blood pressure, pulse rate, laboratory parameters, blood and plams viscosity in 55 patients with impaired glucose tolerance (borderline diabetes)
- 1999
-
Ingår i: Biorheology. - Amsterdam,The Netherlands : IOS Press. - 0006-355X .- 1878-5034. ; 36:1/2, s. 87-88
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract As a substudy to a broader investigation concerning clinical parameters in patients with impaired glucose tolerance blood and plasma viscosity were studied in 55 patients in ages from 39 to 81 years (mean age 62,4 years). These patients were selected from a large health study in southern Sweden where they presented with impaired glucose tolerance but without signs of vascular disease. At the time of our study these 55 patients were still not, 20 years after their first oral glucose tolerance test, classified as ouvert diabetes. Our intention was to study effects of minor disturbances of glucose tolerance on blood rheology. The patients had a laboratory profile close to that of patients with ouvert type 2 diabetes. Compared to a ontrol group of healthy individuals they had higher values for blood and plasma viscosity at all shear rates (p<0.001), higher values for b-glucose, ESR, triglycerides, s-GT (p<0.05-0.005) and lower values for s-creatinine p<0.001). It was also found that diastolic pressure, both at rest and after exercise, was positively correlated to plasma viscosity. This holds true also for systolic arm pressure. Pulse rate at rest and after exercise showed a negative correlation to blood rheology parameters. The pool of data is very large and further analyses are under way. So far our data show that even minor abnormalities of glucose metabolism are harmful and create a risk for vascular disease.
|
|
| 8. |
- Larsson, Hans, et al.
(författare)
-
Studies on blood viscosity during the menstrual cycle and in the postmenopausal period in healthy women
- 1989
-
Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - 0001-6349 .- 1600-0412. ; 68, s. 483-486
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract Blood viscosity was measured in 14 healthy, menstruating women, aged 17-51 years and in 10 healthy, postmenopausal women, aged 55-64 years. The fertile women were studied once a week during a normal menstrual cycle and the postmenopausal women twice with an interval of 2 weeks. Blood viscosity was measured at natural hematocrit as well as at hematocrit 45%. In the postmenopausal women no changes in blood viscosity were found. In the fertile women, blood viscosity at hematocrit 45% was lowest at the start of the menstrual bleeding and increased to a peak at day 7 (p < 0.01), with a similar pattern when measured at natural hematocrit. Plasma viscosity also had its lowest value at the onset of menstrual bleeding, increasing to a maximum at day 21. Changes in plasma triglycerides, but not in fibrinogen or cholesterol, seemed to contribute to this increase. Plasma factors only partly explained the variations in blood viscosity, and changes in red cell properties were also found to be of importance. The clinical significance of these rheological changes remains to be established, but at least theoretically there may be an increased risk for thromboembolism, e.g. at surgery, during days 5-15 of the cycle. In studies on blood flow and rheological conditions in fertile women, it seems advisable to standardize for time in the menstrual cycle.
|
|
| 9. |
- Persson, Sylvi Ulrika, et al.
(författare)
-
A filtrometric study on red blood cells after storage in frozen form
- 1994
-
Ingår i: Clinical Hemorheology. - New York, USA : Pergamon Press. - 0271-5198. ; 14:6, s. 831-840
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract Background: For transfusion purpose, red blood cells can be frozen with glycerol for a long time. After thawing the red cells are washed, the intracellular glycerol is exchanged with water, and then the cells can be transfused. Most of the red blood cells that have been frozen have a potential for normal longterm survival after transfusion, but some of them become altered during the preservation procedure and are removed from the recipient's circulation, one possible mechanism for this being trapping of red cells in the spleen due to reduced deformability. The aim of this study was to investigate the sensitivity of the St George's filtrometer to detect possible deformability defects in frozen, thawed and deglycerolized red blood cells. Results: The suspension of deglycerolized cells showed a significant reduction in filterability indicating the presence of cells with reduced deformability. IrFR was decreased (p<0.05), RCTT increased (p<0.05) and CP increased (p<0.001) . We found a reduction of filterability in these cells roughly corresponding to the presence of 0.01-0.1% glutaraldehyde treated cells. When 10% of the erythrocytes in a blood sample were hemolyzed and thus in ghost form IrFR and RCTT were unaffected, while CP was significantly increased (p<0.05) . Conclusions: A suitable sampling technique may, however, minimize the influence from ghosts in blood samples used for filtrometry after freezing. Thus, in evaluating different freezing techniques filtrometry with the St George's instrument seems to have a high capacity to detect and quantify preservation injuries leading to decreased deformability in the red blood cells. Key words: Blood storage; Erythrocyte deformability; Erythrocyte membrane; Glycerol; Hemorheology; Transfusion.
|
|
| 10. |
- Persson, Sylvi Ulrika
(författare)
-
Blood pressure reactions to insulin treatment in patients with type 2 diabetes
- 2007
-
Ingår i: International Journal of Angiology. - New York, USA : Pulsus Group Inc.. - 0392-9590 .- 1827-1839. ; 16:4, s. 135-138
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract BACKGROUND: The institution of insulin therapy may be easy and uncomplicated in some Type 2 diabetics, but in others, mainly the obese patients, problems often arise (e.g. poor compliance, worsening B-cell function and/or insulin resistance). METHODS: As a substudy of a broader investigation, concerning hemorheological effects of insulin treatment in insufficiently controlled type 2 diabetics, blood pressure was recorded in 12 patients at baseline, after two months and after four months on insulin. RESULTS: After two months on insulin analyses of triglycerides, high density lipoprotein cholesterol and total cholesterol indicated metabolic improvement (p<0.05 to 0.001) and a surprisingly uniform increase of blood pressure values (p<0.05 to 0.01) was found. At the same time, the serum sodium concentration increased (p<0.01) and was positively correlated to both systolic and diastolic blood pressure (p<0.01). After four months on insulin, blood pressure returned to pre-treatment values or even lower (p<0.05 to 0.01). Serum sodium also decreased to pretreatment values. No significant changes of the flow behaviour of blood were seen after institution of insulin. CONCLUSIONS: The number of patients was small and the study was not primarily designed to examine blood pressure. The preliminary conclusion from this study, however, is that the initiation of insulin treatment in poorly controlled type 2 diabetics causes a temporary and possibly clinically significant elevation of blood pressure. A changed renal handling of sodium caused by insulin, may be one of several possible explanations to the results, but further studies are warranted to confirm the findings. Key words: Blood pressure; Insulin therapy; NIDDM; Sodium excretion.
|
|
