PubMed Health⌕ Search

Biomedical subjects

A M Ehrly

Publications and source records attributed to A M Ehrly.

At least 19 recordsLinked to original sources
PubMed1992

[The effect of co-dergocrine mesylate on erythrocyte deformability of hyperosmolar blood in vitro].

Addition of low doses of co-dergocrine mesilate (CAS 8067-24-1), a drug containing a mixture of hydrated ergot alkaloids to hyperosmolar blood in vitro leads to a dose-dependent increase in erythrocyte filterability through a 8 mu filter system. The concentrations of co-dergocrine mesilate used in the present experiments ranged from 0.04675-6.0 mg/100 ml blood. Blood samples were incubated for 90 min at 37 degrees C, measuring temperature was 37 degrees C. It could be shown that the drug-induced increase in erythrocyte filterability was not dependent on the presence of leucocytes. At higher osmolarity values, when the erythrocytes were more rigid, higher concentrations of codergocrine mesilate were needed in order to obtain a comparable improvement in red cell deformability.

Ergoloid Mesylates↗
PubMed1992

Hematocrit dependent changes of muscle tissue oxygen supply in the lower limb muscle of patients with intermittent claudication.

Hematocrit dependent changes of muscle tissue oxygen supply at rest and after exercise were detected in 23 patients with chronical arterial occlusive disease stage IIb according to Fontaine. In these patients with a concomitant high hematocrit a stepwise isovolemic hemodilution by vena esection and subsequent infusion of 10% hydroxyethylstarch solution (200/0.5%) was achieved intraindividually. Measurements of muscle tissue oxygen pressure (pO2) values in the lower limb muscle using a standardized pedalergometric exercise test as well as pain free walking distance with a treadmill were performed. Improvement of muscle tissue pO2 supply after pedalergometric exercise as well as muscular performance on the treadmill were found at an average hematocrit value of 40.50%, whereas muscle tissue oxygen supply and pedalergometric performance were markedly reduced at hematocrit 50.60% as well as 33.75%. Thus it is likely that an improvement of muscle tissue oxygen supply in severe intermittent claudication can be achieved by isovolemic hemodilution to hematocrit values about 40-41%.

Blood Viscosity↗
PubMed1991

Exercise-induced variations in muscle tissue oxygen pressure in claudicants: effects of buflomedil.

The amount of oxygen actually supplied to the ischemic muscle tissue of patients with intermittent claudication was quantified before and after a standardized pedal ergometric test. Muscle tissue pO2 was measured with micro-platin needle electrodes directly in the lower limb muscles at rest and 3, 10, 20 and 60 min after a 4-min work load. Time-dependent variations in the behavior of pO2 values as well as changes in the shapes of pooled pO2 histograms make it possible to monitor the effect of therapeutic measures. In claudicants (stage IIb) with ascertained occlusions or stenosis of the femoral artery or the pelvis region, it was demonstrated that the delayed increase in tissue pO2 after exercise could be improved by the infusion of 400 mg buflomedil. Comparison between the time-related pooled histograms confirmed improvement of oxygen supply under the influence of this drug.

Adult↗
PubMed1991

[Effect of stepwise hypervolemic versus isovolemic hemodilution in patients with intermittent claudication on muscle oxygen pressure during exercise].

In patients with intermittent claudication and concomitant high hematocrit values a stepwise hypervolemic hemodilution versus isovolemic hemodilution (intravenous infusion of 500ml 10% hydroxyethylstarch solution (HES)(mean molecular weight 200.000/substitution degree 50%) or vensection and subsequent infusion of 10% HES (200/0.5)) were performed intraindividually. Measurements of muscle tissue oxygen pressure (pO2) values using a standardized pedalergometric exercise test as well as the pain free walking distance using a standardized treadmill were performed. Optimal results of muscle tissue oxygen pressure (pO2) behaviour after pedalergometric exercise test as well as muscular performance on the treadmill were found using isovolemic hemodilution at an average hematocrit value of 40.60%. In contrast, hypervolemic hemodilution at a comparable hematocrit level (40.50%) induced a "retarded reactive hyperoxia" and only a moderate increase of painfree walking distance.

Adult↗
PubMed1991

Optimal hematocrit in patients with intermittent claudication. Exercise-induced muscle tissue oxygen pressure after stepwise hemodilution.

In patients with severe intermittent claudication and concomitant high hematocrit values a hypervolemic (stepwise infusion of 500 ml 10% hydroxyethylsolution: mean molecular weight 200.000/substitution degree 0.5) or isovolemic hemodilution (stepwise venesection and subsequent infusion of 10% hydroxyethylstarch solution 200/0.5) was performed intraindividually. Measurements of muscle tissue oxygen pressure (pO2) values using a standardized pedalergometric exercise test were performed. The optimal results of muscle tissue pO2 behaviour after pedalergometric exercise were found at average hematocrit values of 40%-41% when isovolemic hemodilution was applied. Hypervolemic hemodilution improves muscle tissue oxygen supply at rest, but shows a retarded reactive hyperoxia under exercise conditions. Thus it is likely that in patients with severe intermittent claudication an optimal tissue oxygen supply can be obtained in the case of isovolemic hemodilution at hematocrit values of about 40-41%.

Exercise Test↗
PubMed1991

[Hemodilution, hemorheology and oxygen supply].

There is no doubt that hemorheological hemodilution in patients with ischaemic diseases improves the tissue oxygen supply, provided certain preconditions for therapy modalities are granted. As can be concluded from the title of this summary it is basically possible, not only to improve the blood flow properties but also - what is even more important - to optimize the oxygen supply of ischaemic tissue through hemodilution therapy. In the case of chronical arterial occlusive disease of the legs it was for the first time possible to establish a haematocrit value of about 40% as a guideline for the decrease of haematocrit in the course of hemodilution. This value, however, cannot be applied to other hemodilution schemes, other plasma substitutes, other states of chronical arterial occlusive disease or even other organs without specific examination. Before further comprehensive studies are initiated for instance of hemorheological hemodilution therapy in patients with cerebral ischaemia, optimal conditions should be experimentally determined in order to improve the prospects of the studies - as was proved in the case of intermittent claudication. Drawing from 25 years of clinical and scientific experience with hemodilution I would like to emphasize that today its therapeutic mechanism has been investigated to a high degree and its effectiveness in patients with peripheral ischaemic diseases as well as retinal ischaemic diseases can be considered as largely guaranteed. Contradictory results of clinical studies of cerebral ischaemia demand new clinical studies which not only should be improved as regards their design but also should contain concrete guidelines on the modalities of hemodilution therapy including the "optimal" haematocrit values which are to be reached.

Blood Flow Velocity↗
PubMed1988

Influence of videofilm-induced emotional stress on the flow properties of blood.

The hemorheologic effects of emotional stress induced by a videofilm were investigated in 10 healthy volunteers. Blood samples were obtained from the antecubital vein before, during, and after the end of the videofilm. Blood pressure and heart rate were simultaneously measured. There was a statistically significant increase in blood and plasma viscosity during and immediately after the end of the videofilm, which correlated with an increase in plasma catecholamine concentrations. This hemorheologic behavior can be explained as a result of an endogenous hemoconcentration that takes place if the Starling equilibrium of intravascular vs extravascular fluid is changed. These observations could lead to new aspects of the pathophysiology of acute myocardial infarction initiated by severe emotional stress.

Adult↗
PubMed1988

[Effect of a 10% and 6% hydroxyethyl starch solution (molecular weight 200,000/0.62) in comparison with a 10% dextran solution (molecular weight 40,000) on flow properties of blood and tissue oxygen pressure in patients with intermittent claudication].

In a randomized, double-blind cross-over study in 10 patients with intermittent claudication, 2 concentrations (6% and 10%) of a hydroxyethyl starch (HES) solution of mean molecular weight 200,000 and of substitution degree 0.62 were compared to a 10% low-molecular-weight dextran solution of mean molecular weight 400,000. In addition to several hemorheological parameters, the behavior of the tissue oxygen pressure directly in the ischemic lower leg muscles of patients with chronic arterial occlusive vascular disease (stage IIb) was examined. 500 ml of the solutions described above were infused over a period of 30 min. Parameters such as tissue oxygen pressure and flow properties of blood were determined before infusion, immediately upon terminating infusion and 30, 60, 90, 120 and 180 min thereafter. A reduction of hematocrit values and of whole blood viscosity was observed, which was most pronounced with the 10% solutions. The plasma viscosity increased significantly with both the 10% dextran solution as well as with the 10% HES solution. This behavior was less pronounced with the 6% solution. Measurement of the erythrocyte aggregation yielded an increase in values after infusion which was more significant for the 10% than for the 6% HES solution. The tissue oxygen pressure, as a measure of the tissue oxygen supply, remained more or less constant during hypervolemic hemodilution, despite reduced hematocrit values in the dextran group and in the 10% HES group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Influence of pentoxifylline on muscle tissue oxygen tension (pO2) of patients with intermittent claudication before and after pedal ergometer exercise.

Ten patients with Stage II chronic arterial occlusive disease (intermittent claudication) took part in a randomized, intraindividual crossover study involving acute intravenous administration of 200 mg pentoxifylline or physiological saline solution (placebo). The tissue oxygen tension (pO2) response (pO2 kinetics) following treatment with placebo revealed a nominal but statistically nonsignificant increase in arithmetic mean and median pO2 immediately after the end of exercise. Values thereafter reverted approximately to the initial values recorded at rest. Comparison of the pooled pO2 histograms during the individual periods before and after the end of exercise, however, revealed a broadening of the histogram base, reflecting both higher pO2 values and, more particularly, increased numbers of hypoxic and anoxic pO2 values. This is interpreted as an expression of nonhomogeneous capillary perfusion (maldistribution). Following administration of pentoxifylline to the same patients, there was a statistically significant increase in mean and median pO2 at ten and twenty minutes after the end of exercise. Even after thirty and sixty minutes, these values were in some cases still clearly higher than the initial preexercise values. Study of the pooled pO2 histograms discloses a right shift compared with the initial preexercise histograms. This suggests that pentoxifylline exerts a positive effect on maldistribution by making capillary perfusion more homogeneous. The results support the conclusion that, in the context of reactive hyperemia after muscular exercise, tissue oxygen supply is markedly improved by pentoxifylline in comparison with saline solution. The measurement of tissue pO2 before and at intervals after pedal ergometer exercise is a new objective technique for assessing the efficacy of blood flow-promoting therapy, permitting close simulation of the pathophysiological situation in the muscles of the lower leg in intermittent claudication.

Arterial Occlusive Diseases↗
PubMed1986

Erythrocyte aggregation in clinical medicine.

Red cell aggregation is one of the part of the properties of blood which determine blood flow in the impaired microcirculation. Erythrocyte aggregation does influence not only the viscosity at low rates of shear but leads to a vicious circle which again impairs the blood flow in the microcirculation. In the other hand it seems obvious that red cell aggregation leads to an inhomogenous distribution of microcirculatory blood flow (maldistribution) thereby decreasing the oxygen transport tissue. In a great number of diseases red cell aggregation is increased and in some diseases this fact is responsible for clinical symptoms. This view is supported by the therapeutic benefit seen in patients with paraproteinaemia as well as in patients with vascular diseases treated with plasmapheresis or defibrinogenation, respectively. There is no doubt about, a reduction of red cell aggregation by desaggregating drugs to improve microcirculatory blood flow and do increase the oxygen supply to tissue. It is however hard to differentiate between the influence of red cell aggregation and/or plasma viscosity on the impaired microcirculation since both parameters are closely connected in most of these diseases.

Blood Viscosity↗
PubMed1985

Influence of intravenous infusions of hydroxyethylstarch (HES) (MW 40,000 and 450,000) on the blood flow properties of healthy volunteers.

Infusions of hydroxyethylstarch (HES) solutions as plasma substitutes and flow improvers play an increasing role in the treatment of various diseases. Little is known about the effect of HES solutions of different molecular weights on the flow properties of blood i.e. blood viscosity, plasma viscosity, erythrocyte aggregation and erythrocyte deformability (filtrability). In the present study the influence of 500 ml-infusions of a 6% solution of HES (MW 450,000) has been compared to that of 6% solutions of HES 40,000. Infusions of 500 ml of HES 450,000 into healthy persons induced a hemodilution with a subsequent decrease in whole blood viscosity whereas the plasma viscosity increased. Red cell aggregation increased as well, red cell deformability was slightly impaired. Infusions of 500 ml of HES 40,000 into healthy persons were followed by a hemodilution with a decrease in blood and plasma viscosity, a decrease in erythrocyte aggregation and a slight improvement of red cell deformability. The reason for this difference in behaviour and its therapeutical consequences are discussed.

Adult↗
PubMed1982

[Improvement of the flow properties of the blood of patients by low-molecular hydroxyethyl starch (Expafusin)].

10 patients with various diseases causing elevated ESR-values and impaired flow properties of blood received infusions of 500 ml of low molecular weight hydroxyethylstarch (HES 6%, Expafusin) within approximately 30 minutes. Measurements of rheological parameters for several hours after infusion showed a statistically significant decrease of apparent whole blood viscosity and of plasma viscosity. RBC aggregation was slightly, but statistically significantly reduced, whereas RBC filterability remained unchanged. These data obtained with blood from patients with altered flow properties of blood agree very well with former results obtained in healthy volunteers.

Adult↗