Reduction Of Plasma Viscosity Research Articles

The place of glucosylated enteral solution in the correction of hemorheological abnormalities in acute poisoning by psychopharmacological drugs

Introduction. In acute exogenous poisoning, hemorheological abnormalities are observed. Various extracorporeal, physico-chemical methods are used to correct them. There is an opinion that the enteral route of administration of corrective agents may be a more physiological way to restore homeostatic imbalances.Aim. To conduct a comparative assessment of the effect of glucosylated enteral solution and standard infusion therapy on hemorheological abnormalities in acute poisoning by psychopharmacological drugs.Material and methods. Patients with acute poisoning by psychopharmacological drugs who were treated at the N.V. Sklifosovsky Research Institute for Emergency Medicine in 2017–2021 were examined. Of these, 23 people, in whose treatment the enteral correction program was used, made up the study group, and 22 patients (the comparison group) underwent a standard set of therapeutic measures. Indicators of hemorheological status were examined on the 1st, 3rd and 5th days against the background of ongoing therapy. Statistical data analysis was carried out using the Statistica 10 software package (StatSoft, Inc., USA).Results. The use of a glucosylated enteral solution led to a reduction in plasma viscosity under normal hematocrit conditions at all follow-up periods. In patients of both groups, there was a decrease in blood viscoelasticity under conditions of high shear potential at all stages of the study, which indicates impaired red blood cell deformability. This process was more pronounced in individuals of the comparison group. The conducted studies have shown that the use of infusion therapy and glucosylated enteral solution in the early stages of acute poisoning by psychopharmacological drugs generally has a unidirectional positive effect on hemorheological indicators, contributing to the stabilization of blood circulation. At the same time, the effect of glucosylated enteral solution therapy is faster and more pronounced.Conclusions. The use of glucosylated enteral solution and infusion therapy as a supportive treatment in the early period of acute poisoning by psychopharmacological drugs in most cases has a unidirectional effect on hemorheological parameters. In cases of glucosylated enteral solution therapy, there was an outrunning positive dynamics on the part of the majority of the studied hemorheological parameters. Glucosylated enteral solution can be the method of choice as a maintenance therapy after the end of detoxification process for acute poisoning by psychopharmacological drugs.

Therapeutic Plasma Exchange is Safe and Efficacious in Normalizing Increased Plasma Viscosity Associated with COVID-19

BackgroundCOVID-19 associated hyperviscosity is a potential driver for the increased rates of thrombotic complications and multi-organ failure associated with severe COVID-19. Limited experience suggests a promising role for Therapeutic Plasma Exchange (TPE) in COVID-19 management based on the hypothesis that clinical benefit is derived from reduction in plasma viscosity. However, systematic study evaluating the safety and efficacy of TPE in these patients has not been done.ObjectiveTo evaluate the safety and efficacy of TPE in a subset of critically ill patients with COVID-19 and elevated blood viscosity in a randomized controlled trial (RCT).Study Design and MethodsThis study was conducted in the intensive care units (ICUs) of 3 hospitals in our health system, with a limited initial enrollment target of 20 patients. Participants included adult COVID-19 patients with moderate elevation in plasma viscosity (2.3-3.5 centipoise) or significant hyperfibrinogenemia (>800 mg/dL) that were not improving despite standard supportive care. Patients with bacterial or fungal coinfection or moribund patients were specifically excluded. Upon enrollment, patients were randomized 1:1 to the treatment group (1 plasma volume TPE with frozen plasma (FP) replacement on 2 consecutive days) or control group (continued standard of care (SOC)). Primary measures included the safety/tolerability of TPE and change in plasma viscosity levels after TPE versus SOC. Secondary measures included evaluation of various clinical and laboratory parameters, including fibrinogen and other coagulation-related markers, mortality, bleeding and thromboembolic complications, ICU length of stay and time to discharge after enrollment.ResultsPreliminary analysis of collected data demonstrates that TPE is safe and well-tolerated in these patients, with adverse events limited to one mild occurrence of tachycardia that improved upon decreasing the flow rate. There was significant decrease in plasma viscosity in the TPE treatment group, compared to the SOC control group. Secondary measures of select laboratory parameters also show a significant decrease in fibrinogen, von Willebrand factor (vWF), Factor VIII, and erythrocyte sedimentation rate in the TPE treatment group. No significant differences were seen in levels of fibrin monomer, total IgG, total IgM, total protein, or total albumin between the two groups. Data collection and analysis for clinical parameters are ongoing. Conclusions and RelevanceHere we report preliminary results suggesting that TPE is safe and effective for normalizing plasma viscosity in critically ill COVID-19 patients. Concomitant removal of large plasma proteins (fibrinogen, vWF) hints at their role in driving the increased viscosity associated with severe disease, which may contribute to clotting and end-organ damage in COVID-19. Based on lack of change in total IgG/IgM levels, TPE is not anticipated to hinder the patient’s humoral immunity by removing existing anti-SARS-CoV-2 specific antibodies. These results warrant further studies on the utility of TPE to mitigate critical illness in COVID-19 patients.

Justification for use of pentoxifylline in the complex therapy against COVID-19

During COVID-19 pandemic, the world scientific community is seeking for efficient and high-quality means to battle the virus itself and its complications. Unfortunately, so far there is no specific methods to treat COVID-19. The main therapeutic strategies include supporting and controlling approaches. So prevention is the best way to eliminate the viral contagion. In the view of this, the scientists paid their attention to pentoxofylline which has been well-known in medicinal practice for a long time. Pentoxifylline is methylxanthine-derived which has been used for the last three decades to treat remittent limp. When used in clinical doses (max. daily dose — 1200 mg), it improves rheological blood values: it reduces plasma viscosity mostly due to decrease fibrinogen level; it leads to increase of erythrocyte elasticity and decrease of thrombocyte aggregation; it provides the increase of blood filtration due to inhibition of neutrophil activation. Viral infections are usually related to the constant formation of the oxidized products and COVID-19 is not an exception as well. Post-mortem analysis of the people affected with SARS-CoV showed the massive formation of the oxidized phospholipids (OxPL) during acute lung injury (ALI). By showing its anti-oxidant and anti-inflammatory properties, pentoxifylline renews glutathione level, supports mitochondrial viability, inhibits TNF-α production, saves the functions of vascular endothelium which in its turn reduces the length of stay at the hospital and ICU, frequency of multi-organ dysfunctions, mechanical ventilation time and mortality rate. Academic works show that pentoxifylline has anti-inflammatory, anti-oxidant, immune-modulating, anti-viral properties; it also has positive effect on respiratory symptoms alleviation which supports the idea that it can used as the adjuvant therapy for COVID-19 patients. Moreover, it can be also used to treat thrombotic complications at the severe COVID-19.

MicroRNA-23b-3p participates in steroid-induced osteonecrosis of the femoral head by suppressing ZNF667 expression

BackgroundClinical treatment with high-dose of steroid hormone causes steroid-induced osteonecrosis of the femoral head (SONFH), whereas the internal regulation mechanism remains elusive. Numerous studies have reported that microRNAs participated in the development of SONFH through modulating gene expression. The aim of the current study was to clarify the function of microRNA-23b-3p (miR-23b-3p) and ZNF667 in SONFH. Experimental designBioinformatics prediction and luciferase reporter system were utilized to confirm the target relation between miR-23b-3p and ZNF667. To examine the function of miR-23b-3p in vivo, rat SONFH models were established by specific inducers. The morphological changes, plasma viscosity, blood lipid, and inflammatory cytokines were measure by corresponding experiments. ResultsMiR-23b-3p and ZNF667 was negatively correlated in SONFH patient tissues, miR-23b-3p was down-regulated, while ZNF667 was up-regulated. MiR-23b-3p targeted ZNF667, the expression level of ZNF667 was suppressed by miR-23b-3p activation whereas strengthened by miR-23b-3p inhibition. SONHF rats with overexpressed miR-23b-3p displayed alleviated symptoms, including reduced plasma viscosity, declined blood lipids, decreased levels of pro-inflammatory cytokines and improved bone integrality. Moreover, elevation of ZNF667 reversed the repression of SONFH induced by miR-23b-3p overexpression. ConclusionsWe found that miR-23b-3p played a protective role in SONFH by targeting ZNF667, which provided a novel reference for SONFH prevention and therapy.

A critical review of pyritinol

Pyritinol (pyrithioxine) is a combination of two molecules of vitamin B6 (pyridoxine) with disulfide linkage. Its pharmacokinetic profile mimics that of its parent compound. Because it crosses the blood–brain barrier, its major clinical utility is in brain-related disorders. Pyritinol regulates signalling pathways of various neurotransmitters including acetylcholine, γ-aminobutyric acid, N-methyl-d-aspartate, etc. Pyritinol has also been shown to act as an antioxidant and anti-inflammatory agent, and also reduces plasma viscosity. It is indicated in paediatric populations to treat learning disabilities, developmental dysphasia, postnatal hypoxia and other cognitive disorders. In adults, it is indicated for improving cognition and memory, Alzheimer’s disease, multi-infarct dementia and rheumatoid arthritis. It has also been investigated in many other clinical conditions, but results are inconclusive. The positive results of many animal studies have not been replicated into consistent clinical success. This review aims to discuss potential uses of pyritinol and its future prospects.

Impact of a cold wave on disease course, hemodynamics, carbohydrate metabolism, and blood rheological properties in cardiac patents

To study the impact of cold waves on disease course, hemodynamics, lipid and carbohydrate metabolisms, oxidative stress, and blood rheological properties in patients with cardiovascular diseases (CVD). 24 men and 36 women (their mean age was 62.9±9.7 years) were examined; coronary heart disease (CHD) and hypertension were present in 40 and 95% of the patients, respectively; selected therapy remained unchanged throughout the entire period. The investigators measured blood pressure and pulse wave velocity (PWV), carried out biochemical blood tests, estimated plasma oxidized low-density lipoproteins (oxLDL) and malondialdehyde (MDA) and erythrocyte superoxide dismutase (SOD) activity, calculated a MDA/SOD ratio, determined blood viscosity; as well as assessed quality of life using a visual analogue scale (VAS) and a specially developed questionnaire. Female sex, CHD, type 2 diabetes mellitus (DM-2) were independent predictors of cardiovascular events (CVEs) in the frost period. The persons who had experienced CVEs in frost had higher baseline PWV. CVEs, such as hypertensive crisis, emergency calls, cardiac arrhythmias, and the larger number of adverse reactions, were more commonly recorded in frost. There was an increase in blood glucose levels, a decrease in oxLDL, a rise in η2/η1, and a reduction in plasma viscosity during frost and elevated glycation end product levels at visit 2. Conclusion. The cold wave is associated with the larger number of CVEs in some patients with CVD during selected therapy. CHD, DM-2, female sex are independent predictors of CVE in patients with CVD during the winter period. In this period, there were increases in the levels of glucose, glycation end products, and erythrocyte aggregation, and a reduction in plasma viscosity.

Influence of the Onion as an Essential Ingredient of the Mediterranean Diet on Arterial Blood Pressure and Blood Fluidity

Mediterranean diet has got a favourable effect on life expectancy. One of the crucial components of the diet are onions. In an open and a randomized, placebo-controlled, double-blind, cross-over phase-I study a spontaneous pharmacological effect 5 h after administration of an onion-olive-oil maceration capsule formulation on arterial blood pressure could be demonstrated in apparently healthy subjects. In addition to a decrease in arterial blood pressure, a significant reduction in plasma viscosity and haematocrit were observed. These results are indicating a vasodilative effect of the onion-olive-oil-maceration product. The stickiness of the platelets was reduced. The effects were stronger in subjects with reduced blood fluidity compared to those subjects with normal rheological parameters.

Hemorheological Effects of Ortho-Isobornyl Phenol Derivative under Conditions of Brain Ischemia in Rats

Hemorheological activity of 4-methyl-2,6-di-isobornyl phenol, a new o-isobornyl phenol derivative, was studied under conditions of experimental prolonged partial cerebral ischemia. Brain ischemia is associated with hemorheological disorders which can be characterized as blood hyperviscosity syndrome: increased viscosity of the whole blood (within a wide range of shear rates), plasma viscosity, fibrinogen content in blood plasma, and platelet aggregation; deterioration of platelet deformability and reduced availability of oxygen for tissues. A course (5 days) of intragastric 4-methyl-2,6-di-isobornyl phenol (100 mg/kg) prevented the development of blood hyperviscosity syndrome by modulating blood macrorheology (reduction of plasma viscosity and fibrinogen content) and microrheology (reduction of erythrocyte aggregation and improvement of their deformability).

Long-term LDL apheresis does not stably improve hemorheology in hypercholesterolemic patients with coronary artery disease

Hemorheological abnormalities are independent cardiovascular risk indicators and adversely affect the outcome of cardiovascular disease. Single LDL apheresis treatment was shown to improve blood and plasma viscosity, red cell aggregation and deformability. However, the long-term effects of LDL apheresis on hemorheology are still unknown. Therefore, we investigated hemorheological parameters in 23 patients (11 women, 12 men) with angiographically established coronary heart disease and drug-resistant hypercholesterolemia regularly treated with LDL apheresis for 7.6+/-3.1 years. Hemorheological measurements (whole blood viscosity, plasma viscosity, red blood cell aggregation at stasis and low shear rate) were analyzed in all patients before and after the initial LDL apheresis as well as before a current LDL apheresis. Single LDL apheresis resulted in significantly reduced plasma viscosity, whole blood viscosity and erythrocyte aggregation index. However, long-term apheresis had no sustained effect on plasma and whole blood viscosity. Our data indicate that in contrast to its beneficial short-term effects, long-term LDL apheresis does not stably improve hemorheology.

Akute Wirkungen der extrakorporalen LDL-Cholesterin- und Fibrinogen-Elimination auf Blutrheologie und Mikrozirkulation*

Long-term intermittent heparin-induced extracorporeal low-density lipoprotein (LDL)-cholesterol precipitation was performed in three men - aged 32, 52 and 56 years - with severe familial hypercholesterolaemia and angiographically demonstrated coronary heart disease. This significantly lowered by 65-70% their LDL-cholesterol concentration and by 48-54% their fibrinogen concentration. Fibrinogen elimination reduced plasma viscosity by 13-14% and clearly raised the transcutaneously measured partial pressure of oxygen by 33-50%. Clinically the improved microcirculation achieved a decrease in angina symptoms: the walking distance of the 52-year-old man increased from about 100 m to 4000 m, the daily need of glyceryl trinitrate falling from an average of 12 to 4 aerosol doses.

To Drink or Not to Drink? That Is the Question

Numerous studies have used a J-shaped or U-shaped curve to describe the relationship between alcohol use and total mortality. The nadir of the curves based on recent meta-analysis suggested optimal benefit at approximately half a drink per day. Fewer than 4 drinks per day in men and fewer than 2 per day in women appeared to confer benefit. Reductions in cardiovascular death and nonfatal myocardial infarction were also associated with light to moderate alcohol intake. Although some studies suggested that wine had an advantage over other types of alcoholic beverages, other studies suggested that the type of drink was not important. Heavy drinking was associated with an increase in mortality, hypertension, alcoholic cardiomyopathy, cancer, and cerebrovascular events, including cerebrovascular hemorrhage. Paradoxically, light-to-moderate alcohol use actually reduced the development of heart failure and did not appear to exacerbate it in most patients who had underlying heart failure. Numerous mechanisms have been proposed to explain the benefit that light-to-moderate alcohol intake has on the heart, including an increase of high-density lipoprotein cholesterol, reduction in plasma viscosity and fibrinogen concentration, increase in fibrinolysis, decrease in platelet aggregation, improvement in endothelial function, reduction of inflammation, and promotion of antioxidant effects. Controversy exists on whether alcohol has a direct cardioprotective effect on ischemic myocardium. Studies from our laboratory do not support the concept that alcohol has a direct cardioprotective effect on ischemic/reperfused myocardium. Perhaps the time has come for a prospectively randomized trial to determine whether 1 drink per day (or perhaps 1 drink every other day) reduces mortality and major cardiovascular events.

The Association Between Viscosity and Cardiovascular Risk may Reflect the Central Systolic Stress Response to Light Activity: An Exercise Haemodynamic Study

nIncreased blood viscosity is associated with early atherogenesis and increased cardiovascular (CV) risk. Whilst the mechanism of these associations is unclear, it may be related to increased arterial wave reflection during activities of daily living. This study aimed to test this hypothesis.Methods: Twenty patients (14 males; aged 61 p 12 years) with polycythaemia rubra vera (n = 16) or haemachromatosis (n = 4) were studied at rest and during cycle exercise at 50% of maximal heart rate, before and after venesection (500 ml, volume replaced with saline) to elicit an acute decrease in plasma viscosity at stable blood pressure (BP). Radial tonometry was used to derive central BP and augmentation index (AIx) as a marker of arterial wave reflection. Healthy controls (n = 20) underwent the same protocol without venesection.Results:Venesection caused a significant decrease in plasma viscosity (1.46 p 0.10n1.41 p 0.11), protein and haemoglobin (p l 0.05 for all) in the patient group, but these parameters did not significantly change in the controls (p g 0.50 for all). Exercise AIx was significantly reduced in response to venesection (from 31 p 11n25 p 10%; p l 0.001), despite lack of significant change in mean arterial pressure, central or peripheral BP (p g 0.05 for all). Haemodynamics were not significantly changed in controls.Conclusions:Acute reduction in plasma viscosity lowers arterial wave reflection during light activity. Thus, the increased CV risk associated with viscosity may be related to central hypertension during daily activities.

A daily glass of red wine induces a prolonged reduction in plasma viscosity: a randomized controlled trial

Moderate red wine consumption has been associated with decreased risk of coronary heart disease. Reduced plasma viscosity and fibrinogen levels have been launched as possible contributors to this risk reduction. The effect of moderate red wine consumption on plasma viscosity, however, has not been investigated in a prospective, randomized trial. We wanted to evaluate the effect of moderate red wine consumption on plasma viscosity, fibrinogen concentration and fibrinogen subfractions. Healthy, nonsmoking volunteers were assigned to consume one glass of red wine daily for 3 weeks in a prospective, randomized cross-over study. In the second 3-week period the volunteers abstained from alcohol use. The plasma viscosity, fibrinogen concentration and the distribution of the main fibrinogen subfractions were determined at inclusion, after wine drinking and after abstention. Plasma viscosity was reduced by 0.026 and 0.024 mPa.s in the two groups following wine intake (95% confidence interval, 0.009-0.043, P = 0.004; 95% confidence interval, 0.0083-0.039, P = 0.003). The decrease in plasma viscosity was maintained following 3 weeks of abstention. The fibrinogen concentration was reduced by 0.17 g/l following wine drinking in the group starting with abstention (95% confidence interval, 0.04-0.29, P = 0.01). The distribution of the fibrinogen subfractions remained unaltered. We conclude that a daily glass of red wine for 3 weeks significantly reduces plasma viscosity. Fibrinogen concentrations are also significantly reduced, when preceded by an abstention period. The decreased viscosity levels are maintained after 3 weeks of abstention, suggesting a sustained viscosity lowering effect of red wine.

Transdermal HRT and Doppler findings in normotensive and hypertensive postmenopausal patients

To evaluate the effects of transdermal hormone replacement therapy (HRT) on plasma viscosity, serum levels of thromboxane B2 (TXB2) and vascular impedance in the uterine, bladder wall, internal carotid and ophthalmic arteries in normotensive and hypertensive postmenopausal patients. Thirty postmenopausal patients underwent continuous estradiol transdermal supplementation at a dose of 50 microg/day and 12-day courses of medroxyprogesterone acetate 10 mg/day every 2 months. The women were divided into two groups according to their blood pressure: normotensive women (Group 1, n=14) and hypertensive subjects (Group 2, n=16). Before starting HRT and after 6 months of therapy, the patients underwent: transvaginal ultrasonographic examination of the pelvic organs; Doppler examination of the blood flow velocities in the uterine, bladder wall, internal carotid and ophthalmic arteries; and analysis of plasma viscosity and plasma TXB2. After 6 months of HRT plasma viscosity had decreased in both groups (mean reduction in Group 1, (14+/-1)%, P=0.005; mean reduction in Group 2, (10+/-1)%, P=0.005) as had the TXB2 levels (mean reduction in Group 1, (93+/-2)%, P<0.001; mean reduction in Group 2, (92+/-3)%, P<0.001). The mean percentage reduction in plasma viscosity was smaller in hypertensive women than in normotensive women (P<0.05). There was also a significant reduction in vascular impedance in the uterine artery (mean reduction in Group 1, (16+/-1)%, P=0.005; mean reduction in Group 2, (19+/-1)%, P=0.005), the bladder wall arteries (mean reduction in Group 1, (23+/-2)%, P=0.005; mean reduction in Group 2, (18+/-1)%, P=0.005), the internal carotid artery (mean reduction in Group 1, (25+/-1)%, P=0.005; mean reduction in Group 2, (26+/-1)%, P=0.005) and the ophthalmic artery (mean reduction in Group 1, (24+/-2)%, P=0.005; mean reduction in Group 2, (16+/-1)%, P=0.005). The percentage reduction in vascular impedance did not differ significantly between the two groups. Our results show that transdermal HRT is effective in reducing plasma viscosity, TXB2 levels and vascular impedance in the peripheral and central vessels both in normotensive and hypertensive postmenopausal patients.

Blood Viscosity of the Neonate

After completing this article, readers should be able to: 1. List the determinants of blood viscosity in the neonate. 2. List the causes of polycythemia and hyperviscosity in the neonate. 3. List the signs, symptoms, and diagnostic criteria for polycythemia and hyperviscosity. 4. Describe steps for prevention and treatment of polycythemia and hyperviscosity in the neonate. Blood viscosity is defined as resistance to the movement of blood. In a circular vessel or tube, the resistance (R) increases with increasing viscosity (V) of the moving fluid and with the resistance resulting from the vessel geometry (Z): R=Z · V. Thus, blood viscosity describes the contribution of blood rheologic factors to blood flow resistance. However, blood viscosity depends on several factors, and the importance of these factors differs among various vessels. The major determinants of blood viscosity are the hematocrit, plasma viscosity, red blood cell (RBC) aggregation, RBC deformability, leukocyte properties, vessel diameter, and the shear forces acting on the RBC. (1) The hematocrit generally is assumed to be the most important determinant of blood viscosity. Blood viscosity rises exponentially with increasing hematocrit (Fig. 1). A marked rise in blood viscosity is seen when the hematocrit exceeds 0.65 L/L, which typically is defined as the threshold for hyperviscosity of the blood. However, in narrow arteries and arterioles and in capillaries, the plasma viscosity becomes the dominant determinant of blood viscosity. The fetal hematocrit increases from 0.33 L/L in the 12th week of gestation to 0.45 L/L in the 30th week and 0.50 L/L in the 40th week at term. At birth, the hematocrit may rise markedly as a result of “blood transfusion” from the placenta to the neonate. (2) A postnatal hematocrit of 0.45 to 0.65 L/L is considered normal in the healthy term neonate. Figure 1. Blood viscosity in tubes that have a diameter of 50 …

Rheological determinants of end-organ damage

Various studies demonstrated an interdependence between rheological parameters and advanced stages not only of ischaemic heart disease and peripheral arterial occlusive disease, but also of chronic obstructive lung disease. In ischaemic heart disease, rheological alterations in the poststenotic circulation can result in impairment of the oxygen supply of the myocardium. Rheological therapies aim for a reduction in plasma viscosity and improved microcirculatory flow by means of a reduction of the elevated levels of fibrinogen. As an example, intermittent therapy with urokinase has been established as a treatment of refractory angina pectoris. Treatment with fibrates also can result in an improvement of microcirculation due to reduced hepatic fibrinogen synthesis. Treatment with statins leads to an improvement of microcirculation due to effects on serum lipids. In patients with chronic obstructive lung disease and cor pulmonale who, secondary to chronic hypoxia, develop polycythaemia and disturbances in pulmonary microcirculation, isovolumic haemodilution may result in a reduction of pulmonary arterial pressure with consecutively increased cardiac output and improved exercise capacity.

Evidence for Maximal Treatment of Atherosclerosis: Drastic Reduction of Cholesterol and Fibrinogen Restores Vascular Homeostasis

This article summarizes the clinical and biochemical evidence for maximal treatment of atherosclerosis by a simultaneous 60% to 70% reduction of plasma low-density lipoprotein cholesterol (LDL cholesterol), fibrinogen, and lipoprotein a concentrations with heparin-mediated extracorporeal LDL/fibrinogen precipitation (HELP) apheresis and statins. Apheresis has proven efficient and safe in the treatment of more than 1,000 patients since 1984 and has been applied in children and adults for the treatment of homozygous and heterozygous familial hypercholesterolemia, coronary artery disease, ischemic cardiomyopathy, generalized atherosclerosis, or transplant-associated arteriosclerosis after cardiac transplantation. Simultaneous removal of the main atherogenic plasma compounds has an immediate impact on myocardial and peripheral vasomotion by increasing myocardial blood flow, coronary flow reserve, cerebral CO2-reactivity, and muscle oxygen tension. Removal of fibrinogen and cholesterol reduces plasma viscosity by 20% and erythrocyte aggregation by 60% which gives rise to applying the HELP apheresis in various microcirculatory disorders. Pilot studies on acute retinal ischemia, critical limb ischemia, and sudden hearing loss confirm this observation.

Capillary Microscopic and Rheological Dimensions for the Diagnosis of von Willebrand Disease in Comparison to other Haemorrhagic Diatheses

SummaryIt is known that angiodysplasia influence macrocirculation as well as microcirculation in patients with vWD. In the present study it was examined if intravital capillary microscopic dimensions (morphologic and dynamic) in skin (nailfold) in combination with rheologic parameters could give indications for the presence of vWD in patients with haemorrhagic diathesis.Patients with vWD (n = 100; 92 type 1: definite type 1:78 and possible type 1:14; 8 type 2A) have in comparison to patients with other haemorrhagic diathesis [thrombocytopathy (n = 122), thrombocytopenia (n = 101), severe haemophilia A (n = 50) and severe haemophilia B (n = 20), congenital dysfibrinogenaemia (n = 22), oral anticoagulation with phenprocoumone (n = 112)] and to apparently healthy subjects (n = 100) a significantly increased capillary torquation (median index: 3.5), a venolar and an arteriolar capillary dilatation (median: 16.5 µm; median: 15.1 µm) and the highest part of microscopic bleedings (extravasates) with 40% in the video capillary microscopy as morphological changes. Only the congenital dysfibrinogenaemia appears with a larger dilatation in venolar capillaries (median: 14.5 µm). Microscopic bleedings are much less common in other haemorrhagic diatheses with a frequency between 4% and 13%.In the vWD a significantly reduced duration of reactive hyperaemia (median: 150 sec). This is the only dynamic change that can be taken as a possible hint for a loss of flexibility within the precapillary vessels. A significantly reduced plasma viscosity (&lt; 1.25 mPas) is typical for the vWD due to the increase of the shear stress in blood plasma because of the reduction of vWF-activities. Changes of the capillary morphology (dilatation, extravasates, capillary torquation) and the hypoplasmaviscosity are most sensitive for the vWD (75%, 65%, 40%, 80%) with a fairly high specifity (up to 93%) and a positive predictive value of 99%.As a conclusion it seems reasonable to discuss the introduction of video capillary microscopy as a screening test for haemostasiological and angiological centers.

Treatment of severe hypertriglyceridemia lowers plasma viscosity

Elevated plasma viscosity is a predictor of atherosclerotic vascular disease and is a potential mechanism by which hypertriglyceridemia increases cardiovascular risk. Previous studies of plasma viscosity reduction in hypertriglyceridemic patients used medications that lowered both triglyceride and fibrinogen levels. Because fibrinogen is a major determinant of viscosity, it is unclear whether triglyceride reduction alone is sufficient to reduce plasma viscosity. The purpose of this study was to determine whether triglyceride-lowering therapy reduces plasma viscosity. This was a prospective study of 24 adult patients with severe hypertriglyceridemia (≥5.67 mmol/l). Fasting lipid, total serum protein, fibrinogen, plasma viscosity and serum viscosity levels were measured before and after therapy with 1200 mg/ d of gemfibrozil. Triglyceride levels decreased by 70% ( P<0.001). Mean plasma and serum viscosity levels decreased by 0.082 mPa/s ( P=0.003) and 0.086 mPa/s ( P=0.013), respectively. Fibrinogen levels did not change significantly. Triglyceride-lowering therapy reduced plasma and serum viscosity without changes in fibrinogen levels. Since serum samples are deplete of fibrinogen, the serum viscosity reduction observed is corroborative evidence for an independent effect of triglyceride-lowering therapy on plasma viscosity. This observation provides a physiological rationale for triglyceride-lowering therapy in patients at risk for atherosclerotic vascular disease, the chylomicronemia syndrome and pancreatitis.

Haemorheological changes in mixed cryoglobulinaemia during apheresis treatment

Thirty-four patients affected by mixed cryoglobulinaemia have been submitted to treatment by apheresis (plasma exchange or double cascade filtration). The authors have monitored clinical, laboratory and, above all, haemorheological changes following therapy. The final results have shown mainly a reduction of plasma viscosity and consequently an improvement of the haemorheology of the affected organs. In conclusion, apheresis may be considered a successful therapy in patients with severe renal or neurological diseases due to mixed cryoglobulinaemia.