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“Slow flow” is one very important concept in modern fundamental and clinical biomedicine. Slow coronary flow is indicative of delayed filling of the terminal coronary artery vessels, occurring in the absence of significant coronary stenosis. This group patient of patients exhibits a high incidence of disability and represents a significant financial and material burden for the state and the healthcare system in general.The primary objective of our study was to examine patients with slow coronary flow.We studied the standard parameters recommended by the international health care system (electrocardiography (by Medica QRS-12, Germany), through the electrical activity of a patient’s heart by the electrical impulses (beating) of the heart; HC1(Germany); coagulogramma by Coatron M1 (Germany), troponin by AQT 90 (Germany); general blood test we used automatic human counting device HC1(Germany). Also, we investigate the original parameters (non-standard parameters, which we use in this pilot study) that we were first studied for this diagnosis and non-standard parameters.A general blood test showed that patients with slow flow had a higher blood leukocyte count than the control group, but the amount of hemoglobin was normal, the hematocrit was much higher than in the control group, and the platelet count was close to the lower limit of clinical standards.We obtained details of blood flow by coagulation situation, such as prothrombin time, prothrombin index, international normalized ratio, activated partial thromboplastin time, thrombin time, fibrinogen, and rheological properties such as index of erythrocyte aggregability, index of erythrocyte deformability, plasma viscosity, in silico blood rheological index.Blood flow can be considered as a superposition of vortices with similar frequencies and wave vectors that change after bifurcations or other obstacles in the vascular network. These factors together determine the conditions for structuring the flow of moving blood. Disruption or alteration of these factors results in slow flow. It has been found that the speed of blood flow in the coronary arteries depends on changes in the number and function of red blood cells. Slow flow is directly influenced by the aggregation and deformation of red blood cells, their number, and plasma viscosity. Consequently, the rheological status plays a crucial role in determining blood flow and its velocity. [ABSTRACT FROM AUTHOR]

BACKGROUND: Hemorheological parameters have been reported to be altered in cardiovascular disease. Major depression has been associated with increased risk of cardiovascular disease. OBJECTIVE: Our hypothesis is that hemorheological parameters are disturbed in major depressive disorder. METHODS: Major depressive disorder and control groups consisted of 50 subjects. Plasma viscosity, erythrocyte aggregation, erythrocyte deformability, hematological parameters and hematological parameters were examined. RESULTS: Plasma viscosity was statistically significantly higher, erythrocyte elongation index at 0.53 Pa and 0.95 Pa was lower, and MCV, MCH, and MCHC values were also lower in the major depression group (P < 0.05). Elongation index and plasma viscosity were correlated with depressive symptomatology. CONCLUSIONS: The increased plasma viscosity and decreased elongation index of erythrocytes indicate an unfavorable hemorheological situation in patients with major depressive disorder compared with healthy controls. The results of this study confirm the findings of studies finding a potential threat to cardiovascular health from major depressive disorder. Increased plasma viscosity and decreased erythrocyte elongation index in depressed patients may be risk factors for cardiovascular events and provide data on the causality of the association between depression and cardiovascular disease. [ABSTRACT FROM AUTHOR]

BACKGROUND: A challenge for coaches and athletes is to find the best combination of exercises during training. Considering its favorable effects, HIIT has been very popular recently. OBJECTIVE: The goal of this study was to investigate anthropometric features, performance, erythrocyte deformability, plasma viscosity (PV) and oxidative stress in response to acute and long-term (6 weeks) HIIT in adolescent basketball players. METHODS: 22 sportsmen between the ages of 14–16 were included. Tabata protocol was applied to the HIIT group in addition to their routine training program 3 days/week, for 6 weeks. Erythrocyte deformability was determined using an ectacytometer (LORCA), PV with a rotational viscometer. Total oxidant status (TOS), total antioxidant status (TAS) were measured by kits. RESULTS: HIIT for 6 weeks induced an improvement in performance tests and waist circumference. 6 weeks of HIIT resulted in a decrement, while the last exercise session yielded an increment in RBC deformability. PV and TOS of HIIT groups were decreased on the 6th week. CONCLUSIONS: Our results demonstrate that, HIIT in addition to the routine exercise program is beneficial for improving performance and blood fluidity as well as decreasing oxidative stress in basketball players. Therefore, HIIT seems as an efficient training strategy for highly-trained individuals. [ABSTRACT FROM AUTHOR]

Plasma viscosity (PV) is a key factor in microcirculatory flow resistance and capillary perfusion during hemodilution, we hypothesized a possible relationship between cardiac surgery-associated acute kidney injury (CSA-AKI) and PV. We conducted a prospective, observational, single-center study on 50 adult cardiac surgery patients with cardiopulmonary bypass (age 64 years, male sex 80%, baseline serum creatinine 1.04 mg/dL). We assessed perioperative characteristics, management, short-term outcomes, blood analysis, PV, serum creatinine, and diuresis. CSA-AKI was identified using KDIGO criteria. Data were collected at 10 time points during the first perioperative week. CSA-AKI occurred in 17 patients (34%): 12 (24%) stage 1, 1 (2%) stage 2, and 4 (8%) stage 3. Most patients (88%) developed CSA-AKI within 48 h post-surgery. Patients with CSA-AKI had higher body mass index (BMI), more frequent chronic kidney disease (CKD), and lower hemoglobin and hematocrit levels. The median baseline PV for the entire cohort was 1.50 cP on EDTA and 1.37 cP on citrate. No significant differences in PV levels were found between patients with CSA-AKI and normal kidney function, both at baseline and at the 48-h. Logistic and Cox regression analyses showed no significant relationship between PV and CSA-AKI. However, CSA-AKI was related to increased BMI, lower hemoglobin and hematocrit levels, and pre-existing CKD. The present study found no significant association between PV and CSA-AKI. Nevertheless, more research is needed to validate this finding and to investigate the role of PV in other clinical settings. [ABSTRACT FROM AUTHOR]

Thermal ablation treatment uses elevated (hyperthermia) or depressed (hypothermia) tissue temperature to destroy tumor cells. The efficacy and effectiveness of thermal ablation therapy is dependent on the tissue temperature which is significantly affected due to heat sink effect of blood flow near the infected site. In this study, Euler-Euler multiphase model is used to analyze the effect of plasma and RBC concentration on the heat sink effect of blood in a bifurcated vessel. This study is divided into two separate cases. First case refers to the study of heat sink effect produced by a tumor patient suffering from HVS (hyperviscosity syndrome) and a normal (without blood disorder) tumor patient during hyperthermia treatment. The second case analyses the effect of RBCs on blood heat transfer. Temperature distribution and transient Nusselt number, which are used to represent heat sink effect, are calculated and compared for different cases of blood disorders. From the results, it is found that a patient with HVS blood disorder produces a smaller heat sink effect during hyperthermia treatment compared to a normal tumor patient. Also, the level of RBC concentration in the blood stream has a minimal effect on heat transfer. [ABSTRACT FROM AUTHOR]

Oxidative stress plays a role in the pathogenesis of bone loss, causing low bone mineral density (BMD) and associated osteoporotic fractures. In our study, we aimed to investigate the relationship of SOD1 50-bp insertion(Ins)/deletion(Del) polymorphism that is involved in oxidative stress metabolism, Cu and Zn element concentrations, and plasma viscosity level, with postmenopausal osteoporosis and related vertebral fractures. The study included 167 voluntary individuals. The 50-bp Ins/Del polymorphism of SOD1 was determined by allele-specific PCR. Plasma Cu and Zn levels were measured by atomic absorption spectrophotometry (AAS). The plasma viscosity was determined using the Harkness Capillary Viscometer device. In our study, the distribution of SOD1 promoter 50-bp Ins/Del polymorphism did not indicate a significant difference between the groups and in postmenopausal osteoporosis patients with and without fractures (p > 0.05). The Ins/Ins genotype was found to be common in individuals in both groups. The Cu and Zn levels of the study group were found to be between the normal reference values (p > 0.05). It was determined that plasma viscosity increased significantly in the group of osteoporotic patients and in patients with postmenopausal osteoporosis with fractures (p < 0.01). In addition, plasma viscosity was found to significantly increase in patients with Ins/Ins genotype and fractures (p < 0.01). Postmenopausal osteoporosis and associated vertebral fracture were found not to be directly related to SOD1 50-bp polymorphism and Cu and Zn element levels. Plasma viscosity levels were found to increase due to the increase in oxidative stress products. Further studies are needed to clarify the roles and relationships of SOD genes and trace elements in the development of postmenopausal osteoporosis and vertebral fracture. [ABSTRACT FROM AUTHOR]

Background: The cessation of ovarian functions at menopause and the accompanying decline in the production of ovarian steroid hormones creates a unique set of health concerns for women. Reductions in sex steroid levels, particularly oestrogen, have been associated with various diseases and conditions, including bleeding disorders, coronary heart disease (CHD), osteoporosis, cognitive dysfunction, urinary incontinence, hot flushes, and mood changes, among others. Objective: To determine changes in haemorheological and clotting profile in post-menopausal women. Methods: Two hundred participants comprising one hundred and fifty post-menopausal women and fifty healthy pre-menopausal control subjects were studied. The investigations carried out include whole blood viscosity, plasma viscosity, fibrinogen concentration, Prothrombin time (PT), Activated partial thromboplastin time with kaolin (APTTK) levels and complete blood count using standard methods. Results: The mean age (p = 0.01), platelet count (p = 0.013), neutrophil (p = 0.03), neutrophil to lymphocyte ratio (p = 0.045) and platelet to lymphocyte ratio (p = 0.044) in postmenopausal women were significantly higher while lymphocyte count (p = 0.004) was significantly lower in postmenopausal compared to premenopausal women. Similarly, plasma oestradiol (p = 0.001), plasma viscosity (p = 0.03), relative blood viscosity (p = 0.03), whole blood viscosity (p = 0.03) and PTTK (p = 0.04) were significantly lower among postmenopausal women compared to premenopausal control subjects. Conclusion: Relative plasma viscosity correlated positively with age. There were significantly lower levels of haemorheological and clotting profile in post-menopausal women. These changes may be due to age or a decline in circulating oestrogen levels.

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Objective: Plasma viscosity is one of the critical factors that regulate microcirculatory flow but has received scant research attention. The main objective of this study was to evaluate plasma viscosity in cardiac surgery with respect to perioperative trajectory, main determinants, and impact on outcome. Methods: Prospective, single center, observational study, including 50 adult patients undergoing cardiac surgery with cardiopulmonary bypass between February 1, 2020 and May 31, 2021. Clinical perioperative characteristics, short term outcome, standard blood analysis, plasma viscosity, total proteins, and fibrinogen concentrations were recorded at 10 distinct time points during the first perioperative week. Results: The longitudinal analysis showed that plasma viscosity is strongly influenced by proteins and measurement time points. Plasma viscosity showed a coefficient of variation of 11.3 ± 1.08 for EDTA and 12.1 ± 2.1 for citrate, similarly to total proteins and hemoglobin, but significantly lower than fibrinogen (p <.001). Plasma viscosity had lower percentage changes compared to hemoglobin (RANOVA, p <.001), fibrinogen (RANOVA, p <.001), and total proteins (RANOVA, p <.001). The main determinant of plasma viscosity was protein concentrations. No association with outcome was found, but the study may have been underpowered to detect it. Conclusion: Plasma viscosity had a low coefficient of variation and low perioperative changes, suggesting tight regulation. Studies linking plasma viscosity with outcome would require large patient cohorts. [ABSTRACT FROM AUTHOR]

Diabetes mellitus (DM) is a complex, chronic metabolic disorder characterized by impaired regulation of blood glucose levels. Zinc (Zn) is an essential trace elements that plays a role in various physiological processes within the body, including those related to diabetes. The current study was investigated the effect of Zn supplementation on hemorheological parameters in a rat model of DM. After induction of DM, 32 male Wistar albino rats were divided into four groups: control, Zn, DM, and Zn+DM. Whole blood viscosity (WBV) was determined by using digital cone and plate viscometer and plasma viscosity (PV) was determined by a Coulter Harkness capillary viscometer. The rats in the DM Group showed a decrease in both Zn levels and body weight, as well as an increase in glucose levels when compared to the control group. Diabetic rats supplemented with Zn displayed lower blood glucose levels and higher concentrations of Zn compared to the DM Group. The higher PV and lower hematocrit level were measured in DM Group than control group and lower PV, higher hematocrit level were measured in Zn+DM group than DM Group. The WBV was measured at four different shear rates (57.6–115.2 - 172.8–230.4 s −1). A statistically significant increase was observed in the DM group compared to the control group. Additionally, a statistically significant decrease was observed in the Zn+DM Group compared to the DM Group at a shear rate of 230.4 s−1. Erythrocyte rigidity index (T k) and oxygen delivery index (ODI) were computed under conditions of high shear rate. The rats in the DM group exhibited a reduction in ODI and an elevation in T k in comparison to the control group. Conversely, the diabetic rats supplemented with Zn exhibited decreased T k and increased ODI compared to the DM Group. Zn supplementation seems to have a potential beneficial effect for protecting adverse affect of diabetes on hemorheogical parameters and for maintaining vascular health. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, a fundamental frequency of 13 MHz and a thickness-increased n-m-type electrode are adopted to improve the frequency response of a quartz crystal microbalance (QCM) to blood coagulation. The thrombin time (TT) and viscosity of standard plasma were measured with this specially designed QCM at different reaction temperatures, and the results were compared with those of a commercial coagulometer and capillary viscometer. The results showed that the frequency shift caused by blood coagulation is greatly enhanced and more than twice that of a traditional QCM. Also, a higher reaction temperature not only accelerates the coagulation reaction but also weakens the frequency response. A comparison between the plasma viscosity measured with the QCM and that measured with the capillary viscometer shows that the QCM can measure plasma viscosity well on the basis of the theory of the liquid attenuation layer. Our research indicates that QCM-based coagulation measurement can not only measure the coagulation time but also the plasma viscosity, which is meaningful for related fields. [ABSTRACT FROM AUTHOR]

BACKGROUND: Psoriasis is associated with an increased risk for cardiovascular disease (CVD). Methotrexate (MTX) is often used as a first-line system therapy and there is a need to determine its effect on whole blood viscosity (WBV) and plasma viscosity (PV) in psoriasis. METHODS: A prospective, single-center, interventional study with a total of 111 psoriatic patients who received MTX therapy from October 22, 2018, to December 28, 2019, and 111 age- and sex-matched healthy controls. Changes in WBV, PV, blood counts, liver and renal function were evaluated. RESULTS: Psoriatic patients had significantly higher levels of WBV and relative viscosity (RV) at low shear rate (LSR), erythrocyte aggregation index (EAI), and PV than sex and age-matched healthy controls. PV was positively correlated with erythrocyte sedimentation rate (ESR), ESR was positively correlated with high sensitive C-reactive protein (hCRP). But only hCRP was positively associated with psoriasis area severity index (PASI) score. MTX significantly decreased the levels of PV, ESR, hCRP, and blood pressure (BP) in male patients, and the level of WBV in female patients. CONCLUSION: Sex-specific downregulation of MTX on WBV, PV, hCRP, and BP, indicating that the effect of MTX on the risk of cardiovascular disease was related with sex. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Essential thrombocythemia (ET) is an entity of classic Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs), characterized by thrombocytosis with megakaryocytic hyperplasia where in the thrombocytes are increased with abnormal function. Thrombotic events are seen frequently and represent the main cause of morbidity and mortality in patients with MPNs, mainly polycythemia vera and ET. This study has aimed to research the effects of clonally increased thrombocytes on plasma viscosity (PV) levels among patients with ET and the relationship between PV and thromboembolism history, according to the hypotheses about the effects of PV in thromboembolic events among patients with ET. METHODS: A total of 55 patients were enrolled in the study group, 18 of who had been newly diagnosed with ET according to 2016 World Health Organization criteria and had not previously been treated. 37 of them had already been diagnosed with ET and had been treated. There were 47 healthy volunteers in the control group. 5 cc blood samples were taken from the patients into tubes including an anticoagulant to measure their PV levels. RESULTS: PV of the control group was found to be lower than in the study group and both each patient groups (p < 0.05). No relationship was found between the patient groups in terms of PV (p = 0.404). The mean PV levels of the 16 patients with a history of thromboembolism and the 39 patients with no such history were 2.42±0.17 cP and 2.33±0.20 cP, respectively. The mean PV levels were found to be similar according to their history of thromboembolism in all patient groups and in treated patients (p = 0.572 vs p = 0.991). CONCLUSION: We have found that PV levels were increased in clonally increased thrombocytes in patients with ET when compared with the control group. This is the first study in this field according to our knowledge. [ABSTRACT FROM AUTHOR]

BACKGROUND: Rheopheresis is a selective extracorporal double cascade filtration treatment, which can extract high molecular weight proteins being responsible for hyperviscosity. As the whole blood and plasma viscosity decrease microcirculation improves. OBJECTIVE: In this preliminary study we aimed to analyze additional beneficial effects of rheopheresis treatment with changes of pro-inflammantory cytokine levels in diabetic foot syndrome patients. METHODS: Two rheopheresis treatments were performed for 6 patients with diabetic foot ulcer and/or neuropathy on consecutive days. Before and after the treatments whole blood and plasma viscosity, as well as IL-6, IL-8, and TNF-alpha serum levels were determined, and complex angiological and ENG examinations were performed. RESULTS: Rheopheresis decreased the whole blood and plasma viscosity, and the serum levels of IL-6, IL-8, and TNF-alpha were markedly reduced. The life quality of the patients improved, the ulcers healed, the pain decreased. Daily dose of analgesics decreased in the follow-up period (6 months). The ENG showed improving amplitude and/or normalizing conduction speed. CONCLUSION: Application of rheopheresis in patients with diabetic foot syndrome has a beneficial effect, providing favorable rheological condition, normalizing cytokine profile and reducing the sensorineural symptoms. [ABSTRACT FROM AUTHOR]

Human blood is primarily composed of plasma and hematocrit, and the complications of diabetes change all these parameters by generating severe chronic complications. For patients with longterm disease, the study of blood rheology points out effects of hardening of red blood cells and changes in blood viscosity. These changes are generated by oxidative stress, which turns into a vicious cycle and worsens the disease condition. Bioelectrical impedance analysis (BIA) has been used to develop non-invasive glucose measurement devices for continuous monitoring. This work presents a mathematical modeling of the electrical impedance as a function of glucose concentration. It is obtained by interpolating the Drude, Krieger and Bruna mod- els. The plasma viscosity is related to blood conductivity whereas the equation parameters to the electrical impedance modulus. The proposed model predicted the glucose level closer to the gold standard one. [ABSTRACT FROM AUTHOR]

AIM: To investigate the effect of puerarin combined with lecithin complex iodine tablets on hemostasis in patients with fundus hemorrhage. METHODS: Totally 66 patients with fundus hemorrhage who entered into our hospital from April 2016 to March 2017 were collected and randomly divided into 2 groups: group A and group B, 33 cases(50 eyes)in each group. Group A was treated with lecithin complex iodine tablets, and group B was treated with puerarin combined with lecithin complex iodine tablets. Plasma viscosity index, serum homocysteine(Hcy), total cholesterol(TC)and triglyceride(TG)were measured and compared within 2 groups. The therapeutic effects and adverse reactions were compared between 2 groups. RESULTS: Before treatment, there were no significant differences in plasma viscosity, serum Hcy, TC and TG between 2 groups(P>0.05). After treatment, the high blood viscosity, low blood viscosity, low plasma viscosity, plasma viscosity, Hcy, TC and TG in 2 groups had decreased than before treatment(PPPP>0.05).CONCLUSION: The efficacy of puerarin combined with lecithin complex iodine tablets in the treatment of fundus hemorrhage is significant, which is related to improving plasma viscosity and decreasing serum Hcy, TC and TG.

β-Thalassemia especially transfusion-dependent thalassemia (TDT) associates with a hypercoagulable state, which is the main cause of thromboembolic events (TEE). Plasma viscosity and rheological parameters could be essential markers for determining hypercoagulable state in β-thalassemia patients. The traditional methods for measuring viscosity are often limited by large sample volumes and are impractical for routine clinical monitoring. The compact differential dynamic microscopy-based device (cDDM), an optical microscopy for quantitative rheological assessment, was developed and applied for prognosis of the hypercoagulable state in β-TDT with and without splenectomy. The device was performed plasma viscosity measurement using low plasma volume (8 μL) and revealed a value as modulus of complex viscosity |η(ω)| in 7 min. We also parallelly demonstrated the correlation of the viscosity and related-coagulable parameters: complete blood count, prothrombin time (PT), activated partial thromboplastin time (APTT), protein C (PC), protein S (PS), CD62P and CD63 expression, and platelet aggregation test. The thalassemia plasma exhibited a higher value of |η(ω)| than healthy plasma, which can represent a different viscoelastic property among the groups. Even all related-coagulable parameters indicated hypercoagulable state in both nonsplenectomies and splenectomies β-TDT patients when compared to control, only high platelet numbers significantly correlated to high plasma viscosity in the splenectomy group. However, the other coagulable parameters have shown a trend of positive relationship with high plasma viscosity in all β-1thalassemia TDT patients. The relative results suggested that our device would be an approach tool for early detection of hypercoagulable state in transfusion-dependent-β-thalassemia patients, which can help to prevent TEE and the critical consequent-complications.

Background: Plasma viscosity is an important biomarker both in diagnostics and treatment monitoring of plasma cell dyscrasias and other disorders with hyperviscosity syndrome as a clinical manifestation. Here, we investigate the performance of a new microfluidic-based viscometer for clinical use, establish a new reference range to be used with this instrument and determine the importance of sampling temperature.Methods: The microVisc™ viscometer was evaluated for within-run and between-run imprecision and bias using standardized reference material (Paragon controls) and Seronorm™ control material. The reference range was established for the adult population using EDTA-plasma from 120 healthy blood donors. Sampling temperature was investigated by drawing and transporting blood at room temperature and 37°C and comparing the viscosity between the two sampling methods.Results: The microfluidic-based viscometer performed well, and imprecision was comparable to ReoRox® G2 free oscillation rheometer. A new reference range for the adult Danish population was established as 1.2-1.5 mPa s at 37°C. Furthermore, sampling temperature at room temperature and 37°C was investigated, and there was no difference in results obtained.Conclusions: MicroVisc™ is suitable for measuring plasma viscosity in a clinical setting and results can be evaluated using the established reference range. Blood sampling for viscosity analysis can be performed as a standard procedure at room temperature. [ABSTRACT FROM AUTHOR]

The article presents Diagnostic value of plasma viscosity testing for patients with COVID-19. Topics discussed include unusual cluster of patients suffering from a pneumonia-inducing condition was first reported within Wuhan, Hubei Province, China, in late December 2019; and it was determined that the causative pathogen was a novel coronavirus termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

OBJECTIVE: The aim of this study was to analyse the effects of dance movement therapy exercises (DMT) on the rheological properties of blood in elderly women. METHODS: The study encompassed group of women (mean aged: 67 years), who were subjected to three-month dance movement therapy programme (n = 20). Blood samples from all the women were examined for their haematological, rheological, and biochemical parameters both prior to the study and three months thereafter. RESULTS: DMT did not cause statistically significant differences in the number of erythrocytes, thrombocytes, leukocytes and the haematocrit value. DMT affected the rheological parameters of the blood in elderly women, improving the erythrocyte deformability at the lowest shear stress value and reducing the half-time of the total aggregation. Plasma viscosity and concentration of fibrinogen did not change after dance therapy. CONCLUSIONS: DMT modulate rheological properties of blood of older women. The results of this study suggest that physical exercise program for older women can prevent unfavorable age-related changes. Some indicators such as the haematological parameters, plasma viscosity and fibrinogen level were not affected by DMT in older women, suggesting the maintenance of homeostasis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Selective Serotonin Reuptake Inhibitors (SSRIs), antidepressants commonly used in cardiovascular diseases (CVDs), inhibit the re-uptake of serotonin not only into neurons but also into platelets. Hence they increase the level of serotonin in plasma. OBJECTIVE: This study was aimed to clarify the effects of two selected SSRIs on plasma serotonin level, hemorheological parameters (hematocrit, erythrocyte deformability, erythrocyte aggregation and plasma viscosity) and selected oxidative stress markers (MDA, GSH, GSSG levels in plasma and erythrocytes). METHODS: Two different SSRIs (Fluvoxamine and Sertraline) were administered to male Sprague-Dawley rats in acute (5 days) or chronic fashion (21 days) at 20 mg/kg/day dose. RESULTS: Aggregation amplitude (AMP) decreased significantly in the chronic sertraline and acute fluvoxamine groups; aggregation half time (t1/2) decreased significantly in the chronic fluvoxamine group. Biochemical parameters indicating oxidative stress significantly increased in the chronic sertraline group. CONCLUSIONS: Since SSRI's are commonly used in patients with CVDs, complementary studies are needed to assess the impact of such changes in hemorheological parameters on the risk for CVD, and to reveal the effects of other SSRIs on hemorheological parameters. [ABSTRACT FROM AUTHOR]

Background. Yield shear stress (YSS) well characterizes the thixotropic status of blood, that exemplifies a reversible loss of blood fluidity due to a low shear rate. At the stable haematocrit ratio YSS depends mainly on the fibrinogen level. Aim. Since the role of other biochemical factors in the YSS phenomenon in cerebral ischaemia has not been well known, we have undertaken this problem in a group of stroke patients. Material and Methods. The study was carried out in 36 patients with acute ischaemic stroke and in 12 controls. YSS was estimated by means of microviscometric method. In all subjects the concentration of the following biochemical factors were assayed: albumin, IgG, IgA, IgM, apolipoprotein A, and B, cholesterol, triglycerides, LDL, HDL and fibrinogen. Then the thixotroipic effect of all biochemical factors and their correlations to fibrinogen were estimated by means of mathematical formulas. Results. We found a positive correlation in relation to the following thixotropic effects: for all subjects and separately for patients’ group: Alb(YSS) (p

AimThe aim of the present study was to investigate levels of some biochemical and whole blood count parameters and plasma viscosity in women with gestational diabetes mellitus (GDM) compared to healthy pregnant and healthy, non-pregnant women, and to evaluate the relationships between plasma viscosity.Material-MethodsThe patients consisted of 27 pregnant with GDM. The control groups consisted of 25 healthy pregnant and 24 healthy non-pregnant women. Blood glucose, insulin, glycosylated hemoglobin (HbA1c), total cholesterol, triacylglycerol, LDL-cholesterol, HDL-cholesterol, total protein, albumin, HbA1c, Hct, Hb, PLT, MPV were measured by auto-analyzer. Also, plasma viscosity levels were measured by capillary viscometer.ResultsThe levels of total protein, albumin, blood glucose, insulin, HOMAIR, HBA1c, total cholesterol, LDL-Cholesterol, HDL-Cholesterol and plazma viscosity in women with GDM group were found higher than those in healthy pregnant and non-pregnant women groups. In addition, the levels of triacylglycerol were significantly higher in GDM pregnants than those in the healthy pregnant women. There were significant positive correlations between plasma viscosity and total cholesterol levels of GDM patients. Additionally, there were significant positive correlations between plasma viscosity and LDL-cholesterol levels.ConclusionPlasma viscosity may contribute to useful information in early diagnosis and treatment, prevention of progression in GDM patients. It should be considered as an important parameter in clinical terms to ensure healthy fetal development.

Background: Cardiac syndrome X (CSX) is often described as angina or angina-like chest pain with a normal coronary arteriogram, yet the underlying pathophysiological mechanisms have not been fully elucidated. The aim of the current study was to determine alterations in blood rheology (erythrocyte aggregation and deformability, plasma viscosity - PV) in patients with CSX. Methods: The study comprised 26 CSX patients (55.77 ± 12.33 years) and 37 age- and sex-matched (56.32 ± 11.98 years) healthy controls. Erythrocyte aggregation and deformability were measured by an ektacytometer and PV with a rotational viscometer. Results: Erythrocyte deformability measured at 1.69 and 3.00 Pa was lower in the CSX patients compared to the controls (p = .0001 and.017, respectively). Erythrocyte aggregation index (AI) (72.758 ± 7.65 vs. 66.483 ± 6.63, p = .002) and PV measured at a shear rate of 375 s−1 (1.932 ± 0.225 vs. 1.725 ± 0.331, p = .019) were significantly higher in patients with CSX. When AI, RDW and erythrocyte deformability measured at 1.69 Pa were evaluated together, it was observed that the increase in AI and RDW augments the risk of having CSX (OR: 1.2 and 2.65, respectively), while the rise in deformability decreases this risk (OR = 0.02). Conclusions: Hemorheological impairments are associated with CSX. [ABSTRACT FROM AUTHOR]

Background. Yield shear stress (YSS) well characterizes the thixotropic status of blood, that exemplifi es a reversible loss of blood fluidity due to a low shear rate. At the stable haematocrit ratio YSS depends mainly on the fi brinogen level. Aim. Since the role of other biochemical factors in the YSS phenomenon in cerebral ischaemia has not been well known, we have undertaken this problem in a group of stroke patients. Material and Methods. The study was carried out in 36 patients with acute ischaemic stroke and in 12 controls. YSS was estimated by means of microviscometric method. In all subjects the concentration of the following biochemical factors were assayed: albumin, IgG, IgA, IgM, apolipoprotein A, and B, cholesterol, triglycerides, LDL, HDL and fi brinogen. Then the thixotroipic effect of all biochemical factors and their correlations to fi brinogen were estimated by means of mathematical formulas. Results. We found a positive correlation in relation to the following thixotropic effects: for all subjects and separately for patients' group: Alb(YSS) (p < 0.001), ApoA(YSS) (p < 0.001), ApoB(YSS) (p < 0.05), chol(YSS) (p < 0.01), HDL(YSS) (p < 0.05); for patients group without additional diseases: Alb(YSS) (p < 0.05), ApoA(YSS) (p < 0.005), chol(YSS) (p < 0.05), HDL(YSS) (p < 0.02), LDL(YSS) (p < 0.05). There were not any signifi cant correlations in controls. Conclusion. Results of the study indicated that in the interaction between the red cells and fi brinogen some additional factors appearing or activating during ischaemic process may play a role. [ABSTRACT FROM AUTHOR]

The hemorheological profile in multiple myeloma (MM) has been extensively studied. Our investigation regarded the behavior of whole-blood viscosity, plasma viscosity and erythrocyte deformability in MM. We enrolled 24 MM patients; 13 of them had been recently diagnosed and were at the initial stage of therapy, 6 were on consolidation/conservation therapy and 5 had achieved a complete remission. On fasting venous blood we evaluated whole-blood and plasma viscosity at high and low shear rates, haematocrit, the ratios between whole-blood viscosity (at high and low shear rate) and haematocrit×100, the ratio between plasma viscosity at low and high shear rate and the erythrocyte deformability examined by using laser diffractometry and expressed as elongation index. A significant increase in plasma viscosity at low shear rate and a marked decrease in haematocrit were observed in MM patients compared with normal controls. Also the ratio between the high shear rate whole-blood viscosity and haematocrit ×100 and the ratio between the low and high shear rate plasma viscosity were significantly increased in MM patients. A significant decrease in erythrocyte deformability, especially at low shear stresses, was found. We discuss some hypotheses that might explain the behavior of red blood cell deformability in MM, considering that its impairment, in addition to the increase of plasma viscosity, can alter the microcirculatory flow in these patients. [ABSTRACT FROM AUTHOR]

There is scarcity of information about the hemorheological pattern in subjects with Monoclonal Gammopathy of Undetermined Significance (MGUS). This preliminary research is focused on the behaviour of whole-blood and plasma viscosity, haematocrit and erythrocyte deformability in the above clinical condition. We enrolled 21 MGUS subjects (10 women and 11 men; mean age 66.4±11.6 years). In fasting venous blood we examined whole-blood and plasma viscosity at high and lowshear rates, haematocrit, the ratios between whole-blood viscosity (at high and lowshear rate) and haematocrit× 100, the ratio between plasma viscosity at low and high shear rate, and the erythrocyte deformability expressed as elongation index. By comparing normal controls to MGUS subjects a significant increase in whole-blood viscosity at high shear rate and in plasma viscosity at low shear rate were observed. In MGUS subjects the ratios between the high and low shear rate blood viscosity and haematocrit × 100, as well as the ratio between the low and high shear rate plasma viscosity were significantly higher. In MGUS subjects a marked decrease in erythrocyte deformability was also observed. The alteration of the hemorheological profile found in these subjects might be involved in the pathogenesis of thromboembolic events, which occur with a high frequency in MGUS. [ABSTRACT FROM AUTHOR]

Background: Endothelial nitric oxide synthase (eNOS) is generally expressed in endocardial cells, vascular endothelial cells and ventricular myocytes. However, there is no experimental study elucidating the relationship between cardiac eNOS expression and elevated plasma viscosity in low oxygen delivery pathological conditions such as hemorrhagic shock-resuscitation and hemodilution. This study tested the hypothesis that elevated plasma viscosity increases cardiac eNOS expression in a hemodilution model, leading to positive effects on cardiac performance. Materials and Methods: Two groups of golden Syrian hamster underwent an acute isovolemic hemodilution where 40% of blood volume was exchanged with 2% (low-viscogenic plasma expander [LVPE]) or 6% (high-viscogenic plasma expander [HVPE]) of dextran 2000 kDa. In control group, experiment was performed without hemodilution. All groups were performed in awake condition. Experimental parameters, i.e., mean arterial blood pressure (MAP), heart rate, hematocrit, blood gas content and viscosity, were measured. The eNOS expression was evaluated by eNOS Western blot analysis. Results: After hemodilution, MAP decreased to 72% and 93% of baseline in the LVPE and HVPE, respectively. Furthermore, pO 2 in the LVPE group increased highest among the groups. Plasma viscosity in the HVPE group was significantly higher than that in control and LVPE groups. The expression of eNOS in the HVPE group showed higher intensity compared to other groups, especially compared with the control group. Conclusion: Our results demonstrated that cardiac eNOS has responded to plasma viscosity modulation with HVPE and LVPE. This particularly supports the previous studies that revealed the positive effects on cardiac function in animals hemodiluted with HVPE.

Background/aim: Septic shock is an important health problem that vastly alters cardiovascular and hemodynamic status. Increased production of nitric oxide (NO) and endothelin is a counterpart of this endotoxemic state. This study was conducted to test the hypothesis that nonselective NO synthesis blocker (L-NAME), inducible NO synthesis blocker (L-canavanine), or endothelin receptor antagonist (bosentan) will reverse the effects of sepsis on hemorheological parameters. Materials and methods: Forty-eight male Sprague-Dawley rats were used in 8 groups: saline (control), endotoxin, bosentan, L-NAME, L-canavanine, endotoxin + bosentan, endotoxin + L-NAME, and endotoxin + L-canavanine. Blood was withdrawn at the 4th hour of endotoxemic state. Erythrocyte deformability and erythrocyte aggregation were determined by laser-assisted optical rotational cell analyzer at 37 °C. Plasma viscosity (mPa.s) was measured by a cone-plate viscometer with 0.5 mL of plasma. Results: Endotoxin administration significantly increased aggregation half-time and lowered erythrocyte aggregation amplitude and aggregation index compared to the control, indicating a slower and weaker aggregation pattern. L-NAME and L-canavanine alleviated the effects of endotoxin on erythrocyte aggregation without altering the values in the control animals. However, bosentan did not perform such a restoration. Conclusion: This finding suggests that these restoration effects of the blockers occur via their modulation of nitric oxide synthesis rather than through the endothelin pathway. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The aim of this study was to analyze the effects of dance therapy on selected hematological and rheological indicators in older women. METHODS:The study included 30women (aged 71.8±7.4), and the control group comprised of 10women of corresponding age.Women from the experimental group were subjected to a five-month dance therapy program (three 45-minute sessions per week); women from the control group were not involved in any regular physical activity. Blood samples from all the women were examined for hematological, rheological, and biochemical parameters prior to the study and five months thereafter. RESULTS: The dance therapy program was reflected by a significant improvement of erythrocyte count and hematocrit. Furthermore, the dance therapy resulted in a significant increase in the plasma viscosity, while no significant changes in glucose and fibrinogen levels were noted. CONCLUSIONS: Dance therapy modulates selected hematological parameters of older women; it leads to increase in erythrocyte count and hematocrit level. Dance therapy is reflected by higher plasma viscosity. Concentrations of fibrinogen and glucose are not affected by the dance therapy in older women, suggesting maintenance of homeostasis. Those findings advocate implementation of dance therapy programs in older women. [ABSTRACT FROM AUTHOR]

AIM: To evaluate hemorheological parameters in patients with fibromyalgia syndrome (FMS) in order to elucidate the etiology of the disease. METHODS: Twenty-three adult FMS patients and 20 healthy controls were enrolled in the study. Diabetics, hypertensives and those with any rheumatological disorder or use drugs or smoking cigarette were excluded from the study. Following parameters were analyzed in each subject; erythrocyte deformability, erythrocyte aggregation, plasma viscosity, complete blood count, fasting blood glucose, fibrinogen, albumin, globulin and lipid profile. RESULTS: Erythrocyte elongation indices indicating deformability of erythrocytes were higher in FMS patients (0.564±0.002 at 16.87mPa and 0.605±0.002 at 30mPa shear rate) than controls (0.558±0.001 at 16.87mPa and 0.600±0.003 at 30mPa shear rate). Erythrocyte aggregation speed was higher in FMS patients (2.1±0.1 s) than controls (2.3±0.2 s). Erythrocyte aggregation index was also higher in FMS patients (65.5±1.3) than controls (62.9±1.5). Erythrocyte aggregation amplitude and plasma viscosity values were similar in both groups (both p > 0.05). Among the complete blood count and biochemical parameters, only albumin levels were lower in the FM patients than controls (p < 0.05). CONCLUSION: Our results indicate higher erythrocyte deformability and quicker erythrocyte aggregation in FM patients. [ABSTRACT FROM AUTHOR]

Aim: Alcohol abuse is accepted as a serious public health problem worldwide, and is a well-known cause of systemic alterations in the organism. The aim of our study is to investigate whether heavy alcohol consumption results in increased blood viscosity in men. We compared the levels of blood viscosity with the age-matched healthy male volunteers. Material and Methods: In order to study the blood rheology of alcohol abusers, we measured blood viscosity in 20 male patients prior to the detoxification treatment. Blood viscosity measurement was performed using Harkness Capillary viscometer. Results: Comparison of blood viscosity yielded a statistically significant elevation (p<0.001) for alcoholic individuals. Conclusion: We conclude that, among other factors causing cardiovascular diseases, such as increased blood fibrinogen and triglyceride levels, increase in blood viscosity due to chronic heavy alcohol consumption is an exacerbating factor for coronary diseases in alcoholic individuals. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The accompanying thrombocytosis is referred to as the major factor associated with thromboembolism in iron deficiency anemia (IDA). Increased viscosity may increase the risk of thrombosis. We hypothesized that increased platelet count -with reactive thrombocytosis- might also affect plasma viscosity. We planned to evaluate the influence of normal and high platelet count on plasma viscosity in IDA patients. METHODS: The patient population consisted of fifty-three newly diagnosed and untreated women aged between 18 and 62 years with IDA. Group 1 consisted of 33 patients, platelet levels below 400 x 109/L. Group 2 consisted of 20 patients, platelet levels above 400 x 109/L. Measurements of plasma viscosity were performed using Brookfield viscometer. RESULTS: Mean plasma viscosity was found as 1.05 +- 0.08 mPa.s. in Group 1, and 1.03 +- 0.06 mPa.s. in Group 2. Mean plasma viscosity was not statistically different. White blood cell count was significantly higher in Group 2. Vitamin B12 levels were significantly higher in Group 2, while folic acid levels were higher in Group 1 (p=0.011 and p=0.033). Plasma viscosity was correlated with erythrocyte sedimentation rate (r=0.512 p=0.002) in Group 1 and inversely correlated with vitamin B12 (r=−0.480 p=0.032) in Group 2. CONCLUSION: Despite the significant difference between groups in terms of platelet count, no significant difference was detected in plasma viscosity and this finding could be explained as the following; 1-These platelets were not thrombocythemic platelets; 2-Similar to the theory about leukocytes, higher platelet counts – even non-thrombocythemic – may increase plasma viscosity; 3-Evaluating platelet count alone is not sufficient and the associating red-cell deformability should also be taken into account; and 4-Although other diseases that could affect viscosity are excluded, some definitely proven literature criteria such as fibrinogen, hyperlipidemia, and the inflammatory process should also be evaluated by laboratory and clinical measures.

Background : Previous studies have found that increasing plasma viscosity as whole blood viscosity decrease has beneficial effects in microvascular hemodynamics. As the heart couples with systemic vascular network, changes in plasma and blood viscosity during hemodilution determine vascular pressure drop and flow rate, which influence cardiac function. This study aimed to investigate how changes in plasma viscosity affect on cardiac function during acute isovolemic hemodilution. Materials and Methods: Plasma viscosity was modulated by hemodilution of 40% of blood volume with three different plasma expanders (PEs). Dextran 2000 kDa (Dx2M, 6.3 cP) and dextran 70 kDa (Dx70, 3.0 cP) were used as high and moderate viscogenic PEs, respectively. Polyethylene glycol conjugated with human serum albumin (PEG-HSA, 2.2 cP) was used as low viscogenic PE. The cardiac function was assessed using a miniaturized pressure-volume conductance catheter. Results: After hemodilution, pressure dropped to 84%, 79%, and 78% of baseline for Dx2M, Dx70 and PEG-HSA, respectively. Cardiac output markedly increased for Dx2M and PEG-HSA. Dx2M significantly produced higher stroke work relative to baseline and compared to Dx70. Conclusion: Acute hemodilution with PEG-HSA without increasing plasma viscosity provided beneficial effects on cardiac function compared to Dx70, and similar to those measured with Dx2M. Potentially negative effects of increasing peripheral vascular resistance due to the increase in plasma viscosity were prevented.

Background: We aimed to compare the effect of albumin 5% in half normal saline (half NS) versus normal saline (NS) infusion on the plasma viscosity in the near-normal physiological condition. According to the high oncotic pressure of albumin along with prolonged half-life of its molecules in comparison to NS in the intra-vascular compartment, it has been proposed that a more significant reduction of the plasma viscosity might be expected after the infusion of albumin. Methods: A total of 56 patients referring to the general operating room for their elective minor surgeries were evenly divided into two groups (V1, V2). It was calculated that 28 patients were needed to be enroll in each study group to detect a difference as big as 0.15 millipoise (mPa.s) with a statistical power of 80%. The V1 group received 1000 ml of NS but the V2 group received 1000 ml of recombinant albumin 5% in half NS within one hour, as fluid replacement therapy, during the intra-operative period. We have designed a simple measurement system according to Poiseuille’s formula by which the viscosity value could be measured reliably since the system was calibrated frequently using distilled water as a reference. Results: The mean value of the pre-operative plasma viscosity of the patients was 1. 73 ± 0.25 mPa.s and 1.76 ± 0.21 mPa.s in V1 and V2 groups respectively. After the infusion of the fluids, the mean viscosity values decreased to 1. 68 ± 0.30 mPa.s and 1.66 ± 0.17mPa.s in V1 and V2 groups respectively (p= 0.37).

BACKGROUND: Cigarette smoking deteriorates human health via vascular disorders, cancer and especially respiratory diseases. The aim of this study is to investigate effects of cigarette smoking on hemorheologic parameters, plasma osmolality and lung function in individuals without diagnosis of chronic obstructive pulmonary disease (COPD). METHODS: Patients diagnosed without COPD utilizing respiratory function test were enrolled in the study with three groups, ex-smokers (n = 21), current-smokers (n = 35) and never-smokers (n = 43). Hemorheologic parameters and plasma osmolality were measured in hemorheology laboratory. SPSS 17.0 was used for statistical analysis. RESULTS: Blood and plasma viscosity, fibrinogen and hematocrit levels, mean corpuscular volume and mean corpuscular hemoglobin concentration were significantly elevated in ex-smokers and current-smokers compared to never-smokers. The standardized red blood cell deformability and oxygen delivery index and lung function were statistically lower in currentsmokers than never-smokers. Pulmonary blood flowratewas statistically lower in current-smokers and ex-smokers than neversmokers. Plasma osmolality was statistically significantly higher in ex-smokers and current-smokers than never-smokers. CONCLUSIONS: Our findings clearly show that cigarette smoking has severe effects on hemorheologic parameters, plasma osmolality and lung function even in individuals without COPD. Blood and plasma viscosity with plasma osmolality might be useful markers to detect early hemorheologic-hemodynamic alterations in cigarette smokers. [ABSTRACT FROM AUTHOR]

Personality characteristics have been linked to various health outcomes. Personality characteristics and rheological parameters have been found to be independent correlates of cardiovascular diseases. The present study aimed to explore the possible relationship between the two independent factors, personality characteristics (Big Five traits and Type A behaviour pattern) and rheological parameters (blood viscosity, plasma viscosity and red cell rigidity), and it was expected that the factors would be positively correlated to each other. The study was conducted on the sample of 68 healthy young adults. Personality assessments and biomedical analysis of the blood sample of participants were carried out to test the possible correlates. Descriptive statistics and Pearson correlation analysis did not show any significant relationship between the factors. The findings indicate that personality characteristics and changes in rheological factors are independent of each other, and hence rheological parameters do not explain the relationship between personality and cardiovascular disease. Limitation and implications of the study are discussed. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Elastic properties of the vessel wall are associated with atherosclerosis and major cardiovascular events. Several physiological and pathological conditions can affect arterial elasticity, but few studies have considered the role of hemorheological parameters. The present study aimed to investigate the relationship between hemorheological parameters and vascular stiffness in the carotid artery district. METHODS: One hundred and two individuals were enrolled. Blood and plasma viscosity were measured by a cone-plate viscometer (Wells-Brookfield DV-III, Stoughton, U.S.A.). Echo-Doppler evaluation of carotid arteries was performed in order to calculate elastic indexes (strain, β-stiffness index and distensibility). The association between hemorheological parameters and carotid elasticity indexes was assessed by simple and multiple regression analyses. RESULTS: In simple correlation analysis, only blood viscosity was directly associated with β-stiffness index (r = 0.20, p = 0.05) and inversely with strain (r= -0.26,p = 0.01) and distensibility (r= - 0.34,p = 0.001). After adjusting for cardiovascular risk factors, blood viscosity, but not plasma viscosity or hematocrit, was independently associated carotid arterial measures, together with age, obesity, hypertension, and dyslipidemia. CONCLUSIONS: The results of the present study demonstrate a strong association between blood viscosity and common carotid elasticity indexes. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Structure and mechanical properties of red blood cells are markedly influenced by pathophysiology of many diseases which in turn potentially impair microcirculatory blood flow. The physiological association between blood rheological parameters and red blood cell indices was investigated in otherwise healthy unselected mid-age women prior to elective gynaecological surgery. METHODS: Red Blood Cell-deformability (RBC 1.2, 3.0; 6.0, 12.0; 30.0, 60.0) during exposure to low (RBC 1.2, 3.0), moderate (RBC 16.0, 12.0) and high shear forces (RBC 30.0, 60.0; Rheodyn; Myrenne), -aggregation (MA1; Myrenne) during low shear (E1; 4-1 S) and in stasis (E0) and plasma viscosity (Pv; KSV 1; Fresenius) were correlated with red blood cell indices (RBC-I: MCV, MCH and MCHC) and subjects' characteristics in 286 healthy women the day before undergoing gynaecologic standard surgery. Women with known pregnancy, malign-, infective-, chronic-disease or extreme BMI (<16; >40 Kg/m²) were excluded from this trial. RESULTS: From June 2014 to December 2014 a total of 286 healthy women (age: 46.5 ± 17.6 y; BMI: 25.5 ± 5.2kg/m²) were eligible for inclusion into this prospective evaluation. Pv (mean±SD: 1.17 ±0.12 mPa s) and RBC aggregation (E0:12.6±6.3; E1:17.9±7.3) were not significantly correlated with RBC-I but with age and BMI. In contrast, RBC-deformability correlated significantly with MCV and MCH but significantly inversely correlated with MCHC. Deformability significantly increased with age but was unaffected by BMI of women. The correlation between RBC-I and RBC deformability was most remarkable during moderate shear force exposure. Neither haemoglobin nor haematocrit were correlated with RBC deformability or RBC-I. CONCLUSIONS: Cell volume and haemoglobin content had a strong impact on deformability in apparently healthy mid age women, whereas low MCHC and large MCV were associated with an increase in deformability while high MCHC and small MCV correlated with increased rigidity of RBC. BMI had no impact on deformability while age was associated with an increase in all determinants of blood viscosity. RBC aggregability was not affected by MCV, MCHC or MCH in mid-age women. [ABSTRACT FROM AUTHOR]

BACKGROUND: Postmenopausal women often develop hemorheological disorders which may affect the systemic blood circulation and present a cardiovascular risk factor. OBJECTIVE:We evaluated effects of secoisolariciresinol (SECO), a phytoestrogen, on hemorheological parameters and lipid peroxidation in a model of the age-related and/or surgical menopause induced by ovariectomy in rats. METHODS: Arterial blood was sampled from sham-operated female rats, ovariectomized rats (OVX), and OVX treated with SECO (OVXSECO) (20 mg/kg/day intragastrically for two weeks). Plasma estrogen concentration and the following hemorheological parameters were measured: RBC aggregation (half-time of aggregation, T1/2; amplitude of aggregation, AMP; aggregation index, AI), RBC deformability (elongation index, EI), whole blood viscosity at the shear rate of 3-300 s-1, plasma viscosity, hematocrit, plasma fibrinogen. Lipid peroxidation was evaluated by measuring conjugated dienes (CD) and thiobarbituric acid reactive substances (TBARS) in plasma. RESULTS: Ovariectomy in rats caused a 60% decrease in plasma estrogen level and triggered the development of macro- and microhemorheological abnormalities. Blood viscosity increased by 12-31%, RBC elongation index reduced by 16-28%, and T1/2 and AI increased by 35% and 29% respectively. The increase in blood viscosity correlated predominantly with reduced RBC deformability. Plasma CD and TBARS were elevated by 47% and 104% respectively. SECO therapy for OVX rats reduced blood viscosity by 9-18% and T1/2 by 32%, and increased EI by 4-17%. SECO therapy disrupted the correlation between blood viscosity and RBC deformability. Lipid peroxidation was significantly inhibited, as shown by the reduction in CD and TBARS plasma concentrations by 89% and 70% respectively. SECO did not affect plasma viscosity, estrogen or fibrinogen levels. CONCLUSIONS: SECO treatment for OVX rats improves blood macro- and microrheological parameters, possibly through antioxidant protection of RBC. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the influence of occupational lead (Pb) exposure on lipid peroxidation, protein carbonylation, and plasma viscosity in workers. The examined group included 283 healthy male employees of manufacturing facilities using zinc and Pb. The mean blood concentrations of Pb and zinc protoporphyrin as well as the mean urine δ-aminolevulinic acid levels were used as markers of exposure for the examined group. Taking into account the obtained mean values of blood lead level, the examined group was divided into three subgroups. When comparing the control group with the subgroups, Pb exposure markers were significantly elevated in all the three subgroups. Concentrations of conjugated dienes (CD), lipid hydroperoxides, malondialdehyde (MDA), and protein carbonyl groups were also significantly increased. Conversely, the levels of total protein and protein sulfhydryls were significantly decreased in the subgroups compared with the controls. The plasma viscosity was significantly elevated in the subgroups. A dose–response between Pb levels and plasma viscosity was not observed. Pb supposedly elevates MDA and CD in a dose-dependent manner. In conclusion, occupational Pb exposure induces oxidative stress that results in lipid and protein damage. Moreover, Pb-induced oxidative stress is likely the primary factor that elevates plasma viscosity, despite decreased protein levels. [ABSTRACT FROM AUTHOR]

Acute carbon monoxide (CO) poisoning seriously hinders oxygen delivery to tissues. This harmful effect ofCOmay be aggravated by accompanying changes in the viscosity of blood.We had previously reported increased plasma viscosity in people chronically exposed to CO. This study was planned to test our hypothesis that acute CO poisoning increases blood viscosity. For this purpose four main parameters contributing to blood viscosity -hematocrit, erythrocyte deformability, erythrocyte aggregation and plasma viscosity - were determined in patients with acute CO poisoning and compared with healthy controls. Plasma viscosity and erythrocyte aggregation tendency were lower in the CO group (p < 0.05). Erythrocyte deformability was also lower inCOgroup (p < 0.05). Our results indicate that acuteCOpoisoning has diverse effects on hemorheological parameters such as attenuating hematocrit value, plasma viscosity, erythrocyte aggregation tendency and erythrocyte deformability. [ABSTRACT FROM AUTHOR]

We previously reported that low intensity endurance training in sedentary patients suffering from the metabolic syndrome improves blood rheology, mostly due to a decrease in plasma viscosity correlated with an increase in cardiorespiratory fitness. We investigated whether these findings can be extended to type-2 diabetics. 22 diabetics (11 women and 10 men, age: 52.00±2.9 yr, BMI: 32.47±1.17 kg/m²) were tested before and after 2 months. Eight of them were trained (2 to 3×45 min/wk) at the power intensity where lipid oxidation reaches a maximum (LIPOX max) and thirteen served as controls. Over this period the only significant hemorheological effect of training was a decrease in RBC aggregation "M" (-1.25±0.357 p = 0.01) in the trained group. Subjects who lost weight exhibited a decrease in plasma viscosity (from 1.46±0.013 to 1.38±0.02 p < 0.01). Changes in waist circumference are associated with changes in hematocrit (r =-0.952 p = 0.01); plasma viscosity (r =-0.91; p = 0.03); RBC aggregation ("M" r = 0.940; p = 0.02). Subjects can also be divided into those who improved their aerobic capacity VO2max and those whose VO2max decreased or remained unchanged. An increase in VO2max is associated with a decrease in whole blood viscosity (r =-0.79 p = 0.06) explained by an improvement in RBC rigidity "Tk" (r =-0.963 p = 0.002). This study suggests that in Type 2 diabetic patients: (a) viscosity factors might be less responsive to training than in non diabetic individuals; (b) visceral fat loss is the main determinant of changes in hematocrit, plasma viscosity and RBC aggregation; (c) improvements in aerobic capacity improves blood viscosity via an increase in RBC deformability. [ABSTRACT FROM AUTHOR]

Tinnitus is a sensation of ringing in the ears in the absence of any physical source in the environment. Between 9-35% of adults experience some form of tinnitus. Common causes of tinnitus include noise, head injury, ototoxic substances, as well as disorders of blood and blood vessels. Vascular causes include: head-neck tumours, turbulent blood flow, problems with blood supply and inner ear cell damage. The aspect of rheology in terms of tinnitus has not been described yet. In the present study, which comprised 12 patients aged 30 to 74 years presenting with tinnitus, rheological properties of whole blood and plasma were assessed. All the subjects underwent audiological and neurological evaluation. The Quemada model was used to describe the variability of red blood cell shape, as well as their tendency to form aggregates. On the basis of the experimental study, statistically different results of haemorheological measurements were observed in the evaluated group in comparison to a reference group.

BACKGROUND: Platelet reactivity changes with shear stress, which in turn depends on whole blood and plasma viscosity (PV). Platelets interact with fibrinogen during thrombus formation, and fibrinogen is a determinant of PV. The respective role of PV and fibrinogen on platelet function is still unclear. METHODS: 30 patients undergoing vascular surgery were admitted to this study. In each patient we measured PV using a coneon-plate viscosimeter, functional fibrinogen using thromboelastometry, and platelet reactivity to thrombin receptor activating peptide (TRAP) stimulation using multi-electrode aggregometry. Routine coagulation parameter were measured. RESULTS: At the univariate analysis, platelet reactivity was positively associated with mean platelet volume (R2 = 0.15, P = 0.033) and PV (R2 = 0.35, P = 0.0006), and negatively associated with serum bilirubin (R2 = 0.20, P = 0.013) and international normalized ratio (INR) (R2 = 0.19, P = 0.017). At the multivariable analysis, only PV (P = 0.001) and INR (P = 0.019) remained independent predictors of platelet reactivity. CONCLUSION: PV is directly and independently associated with platelet reactivity, whereas functional fibrinogen is not. Aspirin treatment is inadequate to correct thrombin-induced platelet aggregation. In presence of hyperviscosity, patients at high cardiovascular risk, may benefit from more aggressive anti-platelet treatments. [ABSTRACT FROM AUTHOR]

Periodontal diseases are frequently associated with cardiovascular diseases (CVD). On the other hand, occurrence of CVD has also been related with increased blood viscosity. This study was planned to investigate four main hemorheological parameters contributing to blood viscosity -hematocrit, erythrocyte deformability, erythrocyte aggregation and plasma viscosity - and also some biochemical parameters (hs-CRP, fibrinogen, globulin etc.) in patients with periodontal disease. We hypothesized that poor periodontal health would be associated with deterioration of hemorheological properties. According to periodontal health status, subjects were divided into three groups as control (healthy), with plaque induced gingivitis and with chronic periodontitis. All groups included 15 males who had not received periodontal therapy in the last six months before the study, were non-smokers, had no systemic diseases and were not on any medication. Erythrocyte deformability and erythrocyte aggregation were measured with laser-assisted optical rotational cell analyzer (LORCA). Plasma viscosity was measured by a cone-plate viscometer. Data were analyzed with Kruskal-Wallis, Mann-Whitney U Test and Spearman Correlation Coefficient. Plasma viscosity (1.36±0.01 mPa.s in the control group and 1.43±0.02 mPa.s in the chronic periodontitis group, P < 0.01), erythrocyte aggregation tendency (aggregation index, amplitude and t½ were 58.82±1.78%, 20.22±0.40 au, 2.80±0.25 s respectively in the control group, and 67.05±1.47%, 22.19±0.50 au, 1.84±0.15 s in the chronic periodontitis group, P < 0.01), hs-CRP, fibrinogen and globulin levels were significantly higher, whereas HDL level was significantly lower in the chronic periodontitis group (P < 0.05) compared to the control group. All of these conditions may contribute to cardiovascular morbidity and mortality observed in people with periodontal disease, via increasing blood viscosity. [ABSTRACT FROM AUTHOR]

Rheohaemapheresis aims to normalize major rheological parameters and is used to treat patients with dry age-related macular degeneration (AMD). While effective, this approach is invasive and requires specially trained personnel. Therefore, the search for novel effective compounds with hemorheological properties that can be taken orally to treat AMD is justified. The use of a robust rodent model of AMD with high blood viscosity is crucial to test the efficacy of potential hemorheological drugs to treat this disease. The objective of this study was to investigate whether OXYS rats, generally used as an animal model of AMD, have hyperviscosity syndrome. The results of this study show that blood viscosity in OXYS rats at low (3-10 s-1) and high (45-300 s-1) shear rates were 14-20% and 7-10% higher than in Wistar rats, while hematocrit and plasma viscosity were not different. Red blood cells (RBCs) in OXYS rats were more prone to aggregation as shown by 39% shorter half-time than in Wistar rats. RBCs were also more rigid in OXYS than in Wistar rats as shown by 21-33% lower index of elongation at the shear stress of 1-7 Pa. These data indicate that OXYS rats have hyperviscosity syndrome as the result of abnormal RBC deformability and aggregation. We propose to use OXYS rats as an animal model for preclinical studies to test compounds with hemorheological properties aimed to treat AMD. [ABSTRACT FROM AUTHOR]