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Objective To investigate the effect of Tripterygium wilfordii polyglycosides(TWPS) on inflammatory response found in mouse models with Sjgren's syndrome(SS). Methods Mice were randomly divided into control group, Sjgren's syndrome model group, hydroxychloroquine sulfate treatment group (20 mg/kg hydroxychloroquine sulfate intragastric administration), TWPS low-dose, medium-dose and high-dose groups (10, 20, 30 mg/kg TWPS), TWPS + Wortmanin (PI3K/Akt/eNOS signaling pathway inhibitor) group (30 mg/kg TWPS and 0.6 mg/kg Wortmannin viajugular vein).Saliva flow rate, water intake, whole blood viscosity and plasma viscosity were recorded. Serum IL-6, IL-17, IgG and eNOS were detected by ELISA. Western blot was used to detect PI3K/Akt/eNOS pathway related proteins. Results Compared with control group, the saliva flow rate of the model group decreased and the quantity of drinking water increased(P＜0.05). Compared with model group, saliva flow rate increased and water consumption decreased in low, medium and high dose TWPS groups, which alleviated the change of model group(P＜0.05). Compared with the low, medium and high dose TWPS +Wortmanin groups, saliva flow rate decreased and water intake increased (P＜0.05). The whole blood and plasma viscosity of model group increased compared with control group(P＜0.05). The whole blood and plasma viscosity of TWPS low-dose, medium-dose and high-dose groups were lower than that of model group(P＜0.05). The whole blood and plasma viscosity of TWPS+Wortmanin group was higher than that of low, medium and high dose TWPS groups(P＜0.05). Compared with the control group, the levels of serum IL-6, IL-17 and IgG in model group were increased, while the level of eNOS was decreased(P＜0.05). The serum levels of IL-6, IL-17 and IgG in TWPS low-dose, medium-dose and high-dose groups were lower than those in model group, while the levels of eNOS were higher than those in model group(P＜0.05). The serum level of IL-6, IL-17 and IgG in TWPS +Wortmanin group increased as compared to those in low, medium and high dose TWPS +Wortmanin group, while the level of eNOS decreased as compared to those in low, medium and high dose TWPS +Wortmanin group(P＜0.05). The level of p-PI3K/PI3K, p-Akt/Akt and p-ENOS /eNOS in model group was lower than those in control group(P＜0.05). Compared with model group, p-PI3K/PI3K, p-Akt/Akt and p-ENOS/eNOS levels of TWPS in low, medium and high dose groups all increased(P＜0.05); The level of p-PI3K/PI3K, p-Akt/Akt and p-ENOS /eNOS in TWPS +Wortmanin group was lower than those in low, medium and high dose TWPS groups(P＜0.05). Conclusions TWPS alleviates inflammatory response and improves symptoms of mouse models with Sjgren's syndrome.

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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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]

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.

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. 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]

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 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).

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.

Blood rheology is an important determinant of blood flow but is probably one of the most neglected areas in clinical literature and practice. Blood viscosity changes according to shear rates and depends on cellular and plasma factors. RBCs' aggregability and deformability are the main determinants of local flow characteristics in areas with lower and higher shear rates, but plasma viscosity is the main regulatory factor of flow resistance in the microcirculation. In individuals with altered blood rheology, the mechanical stress to vascular walls induces endothelial injury and vascular remodelling, and promotes atherosclerosis. Increased values of whole blood viscosity and plasma viscosity are correlated with cardiovascular risk factors and adverse cardiovascular events. The long-term effects of physical exercise can produce a hemorheological fitness that protects against cardiovascular diseases., (© 2021 Liana Valeanu et al., published by Sciendo.)

As the underlying mechanisms of the adverse effects of cold spells on cardiac events are not well understood, we explored the effects of cold spells on plasma viscosity, a blood parameter linked to cardiovascular disease. This cross-sectional study involved 3622 participants from the KORA S1 Study (1984–1985), performed in Augsburg, Germany. Exposure data was obtained from the Bavarian State Office for the Environment. Cold spells were defined as two or more consecutive days with daily mean temperatures below the 3rd, 5th, or 10th percentile of the distribution. The effects of cold spells on plasma viscosity were explored by generalized additive models with distributed lag nonlinear models (DLNM). We estimated cumulative effects at lags 0–1, 0–6, 0–13, 0–20, and 0–27 days separately. Cold spells (mean temperature <3rd, <5th or <10th percentile) were significantly associated with an increase in plasma viscosity with a lag of 0–1 days [%change of geometric mean (95% confidence interval): 1.35 (0.06–2.68), 1.35 (0.06–2.68), and 2.49 (0.34–4.69), respectively], and a lag of 0–27 days [18.81 (8.97–29.54), 17.85 (8.29–28.25), and 7.41 (3.35–11.0), respectively]. For the analysis with mean temperature <3rd or 10th percentile, we also observed significant associations at lag 0–20 days [8.34 (0.43–16.88), and 4.96 (1.68, 8.35), respectively]. We found that cold spells had significant immediate and longer lagged effects on plasma viscosity. This finding supports the complex interplay of multiple mechanisms of cold on adverse cardiac events and enriches the knowledge about how cold exposure acts on the human body. [Display omitted] • This is a cross-sectional study to explore the effect of cold spells on plasma viscosity. • We explored the effects of different cold spell definitions on plasma viscosity. • Cold spells were significantly associated with increases in plasma viscosity. [ABSTRACT FROM AUTHOR]

Hematocrit (HCT), the volume fraction of cells in whole blood, is one of the most important variables that affect the viscosity of whole blood. Matrai's HCT-correction model (Matrai model) provides a method of HCT-correction so that the blood viscosity can be compared at a standard HCT of 45%. Since the Matrai model requires the plasma viscosity, there is a need to have another method for HCT correction of the blood viscosity in cases when the plasma viscosity is not available. The present study introduced a new method of HCT correction using the whole blood viscosity measured over a range of shear rates without plasma viscosity. For validation of the new method, three different human blood samples were used. Each blood sample was reconstituted to eight different HCT levels (from 25 to 60%) and the blood viscosity at each HCT level was measured over a range of shear rates, including the blood viscosity at HCT 45%. HCT-correction results from the Matrai model and the present model were compared with the blood viscosity measured at HCT 45%. The present model gave significantly better HCT corrections (i.e., about 3 times less error) than the Matrai model. [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, pO2 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. [ABSTRACT FROM AUTHOR]

We recently proposed a unifying hypothesis to reconcile unexpected findings in exercise hemorheology and the classical concepts of 'hemorheologic fitness' and the 'triphasic effects of exercise', based on the 'healthy primitive lifestyle' paradigm. This paradigm assumes that evolution has selected genetic polymorphisms leading to insulin resistance as an adaptative strategy to cope with continuous low intensity physical activity and a special alimentation moderately high in protein, rich in low glycemic index carbohydrates, and poor in saturated fat. According to this protocol the true physiological picture would be that of an individual whose exercise and nutritional habits are close from this lifestyle, both sedentary subjects and trained athletes representing situations on the edge of this model. Unfortunately samples of people truly adhering to this ancestral lifestyle are hard to obtain. In order to address this picture we tried to compare databases obtained with our preceding published studies. As a model of the 'healthy primitive lifestyle' we selected patients trained at low intensity (LI) and given an advice of protein intake around 1.2 g/kg/day. Results show a continuum for plasma viscosity which seems to be lower in athletes than LI-trained and even more sedentaries. When sedentary subjects become obese the most obvious characteristic is an increase in red blood cell (RBC) aggregation correlated to the size of fat stores. It is clear that 3 months of LI are not a perfect model of 'healthy primitive lifestyle', but these data suggest that the most important effect of LI regular exercise is to decrease plasma viscosity and that sedentarity increases RBC aggregation mostly when it results in increased fat storage. [ABSTRACT FROM AUTHOR]

Abstract: The present study measured plasma viscosity using three different viscometers: Ostwald capillary-tube viscometer, Brookfield rotating viscometer, and scanning capillary-tube viscometer (SCTV). The plasma viscosity data obtained using Ostwald viscometer at 37°C with the conversion constant provided by its manufacturer were in good agreement with those obtained using Brookfield viscometer at 37°C. In addition, the plasma viscosity data obtained using SCTV were in excellent agreement with those from Brookfield viscometer. However, when the Ostwald viscometer is used for plasma viscosity measurements at the room temperature, one should be cautioned because the conversion constant provided by manufacturers may not be applicable to the room temperature as the surface tension of plasma depends on temperature, affecting the accuracy of the plasma viscosity measurement. [Copyright &y& Elsevier]

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. Material and 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 109L. 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. [ABSTRACT FROM AUTHOR]

Background: Hemorheology is the study of low properties of blood and its elements (plasma and formed elements). Blood viscosity is correlated with cerebral blood low and cardiac output, and increased viscosity may increase the risk of thrombosis or thromboembolic events. Objective: To analyze and identify social, behavioral, and hemorheological factors related to smoking among young males in the community in Al-Jouf, Saudi Arabia. Methods: Three hundred and twenty one male subjects (smokers (195), ex smokers (105) and never smokers (21)) with different age groups were enrolled into the study as a randomized sample. Social information was collected from all study groups. Hematocrit (HCT), Whole Blood Viscosity (WBV) and Plasma Viscosity (PV) were measured at room temperature. The relationships of variables with whole blood or plasma viscosity were analyzed by SPSS 17.0 and Origin 6.0 statistical software. Results: Percentage of cigarette smokers is high compared to ex and never smoked persons. The common reason for smoking was the influence of the family which can be parent imitation, family careless, family breakdown or other reasons. The smoking leads to a rise in hematocrit and alters the rheological properties by increasing whole blood viscosity and plasma viscosity levels. Together these changes cumulate in a significant deterioration of the low properties of blood. Conclusions: Alterations of blood rheology in turn can promote atherothrombogenesis in several ways. Smoking increases the risk of vascular diseases through its effects on blood rheology. Further prospective and public health studies would be required to deal with common reasons which influence smoking behavior as well as to deal with the blood rheological changes. [ABSTRACT FROM AUTHOR]

. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective. To identify the features of PMR that may predict the duration of steroid therapy, the occurrence of relapses and the late development of GCA. [ABSTRACT FROM PUBLISHER]

Endothelial function is modulated by wall shear stress acting on the vessel wall, which is determined by fluid velocity and the local viscosity near the vessel wall. Red blood cell (RBC) aggregation may affect the local viscosity by favoring axial migration. The aim of this study was to investigate the role of RBC aggregation, with or without altered plasma viscosity, in the mechanically induced nitric oxide (NO)-related mechanisms of endothelial cells. Human umbilical vein endothelial cells (HUVEC) were cultured on the inner surface of cylindrical glass capillaries that were perfused with RBC suspensions having normal and increased aggregation at a nominal shear stress of 15 dyn/cm2. RBC aggregation was enhanced by two different approaches: 1) poloxamer-coated RBC suspended in normal, autologous plasma, resulting in enhanced aggregation but unchanged plasma viscosity and 2) normal RBC suspended in autologous plasma containing 0.5% dextran (mol mass 500 kDa), with a similar level of RBC aggregation but higher plasma viscosity. Compared with normal cells in unmodified plasma, perfusion with suspensions of poloxamer-coated RBC in normal plasma resulted in decreased levels of NO metabolites and serine 1177 phosphorylation of endothelial nitric oxide synthase (eNOS). Perfusion with normal RBC in plasma containing dextran resulted in a NO level that remained elevated, whereas only a modest decrease of phosphorylated eNOS level was observed. The results of this study suggest that increases of RBC aggregation tendency affect endothelial cell functions by altering local blood composition, especially if the alterations of RBC aggregation are due to modified cellular properties and not to plasma composition changes. [ABSTRACT FROM AUTHOR]

Summary: The interactions of epilepsy and antiepileptic therapy an one hand and cardiovascular system on the other hand are multiple and complex. Antiepileptic drugs (AEDs) cause alterations of serum lipids and of the fatty acid composition of the membranes. Homocystein, known to induce vascular endothelial damage was found to be elevated in patients on valproate (VPA) and carbamazepine (CBZ) therapy. Marked coronary artherosclerosis and myocardial infarction may already occur in children treated with CBZ. Community based studies corroborated a higher incidence of myocardial infarction, peripheral vascular diseases hypercholesterinemia, left ventricle hypertrophy and stroke in patients with epilepsy. In this context, we wanted to elevate changes of microcirculation related to AEDs commonly prescribed such as VPA and CBZ. Capillary microscopy is a non-invasive technique for measuring the velocity of red blood cells and for determining nutritional blood flow in the capillaries of the skin. It can easily be performed in children. The aim of this study was to look for possible effects an antiepileptic monotherapy with carbamazepine or valproate has on the peripheral microcirculation in epileptic children. We were able to examine 14 children with CBZ and 24 children with VPA, recruited in our neuropediatric Unit. The results were compared to normative values, determined in former analyses of 207 healthy children. We found significant differences in capillary density, tortuous index of the capillaries, capillary diameter and flow rate of erythrocytes for both antiepileptic drugs. Additionally, there were changes in plasma viscosity and the aggregation of erythrocytes. These microcapillary effects could be of special interest in the relationship of a long-term antiepileptic therapy and the development of vascular diseases. We suggest that the influence of AEDs on microcirculation should also be considered in further studies on cardiovascular changes in patients with antiepileptic long-term medication. [Copyright &y& Elsevier]

Summary: Background: The initial step in establishing the cause of an effusion is to determine whether the fluid is a transudate or exudate. Plasma viscosity is influenced by the concentration of plasma proteins and lipoproteins with the major contribution resulting from fibrinogen. In this study we aimed to evaluate the role of pleural fluid viscosity in discrimination of transudate and exudates. Materials and Methods: We studied prospectively 63 consecutive patients with pleural effusion in whom diagnostic or therapeutic thoracentesis had been performed. The criteria of Light were applied to differentiate transudates from exudates: 33 patients (23 male, 13 female, mean years) had exudates and 30 patients (17 male, 13 female, mean ) had transudates (due to congestive heart failure). Measurements of pleural fluid and plasma viscosity were performed using a viscometer. Results: There was no statistically significant difference between patients with transudate and exudates in respect to plasma viscosity. However, pleural viscosities of the patients with exudates were significantly higher than those of patients with transudate (1.37±0.16mPa vs 0.93±0.03mPas , respectively). Pleural viscosity has a high sensitivity, specificity (94%, 93%, respectively), positive and negative predictive value (97%, 97%, respectively) for the discrimination of transudative or exudatetive pleural fluid. Conclusion: We have demonstrated for the first time that pleural viscosity of the exudative effusion is higher than that of transudative effusion with high sensitivity, specificity, positive and negative predictive value. Regarding the simplicity of this measurement, it may play a valuable role in the accurate and fast discrimination of pleural fluid. [Copyright &y& Elsevier]

The normal transmyocar-dial tissue hematocrit distribution (i.e., subepicardial greater than subendocardial) is known to be affected by red blood cell (RBC) aggregation. Prior studies employing the use of infused large macro- molecules to increase erythrocyte aggregation are complicated by both increased plasma viscosity and dilution of plasma. Using a new technique to specifically alter the aggregation behavior by covalent attachment of Pluronic F-98 to the surface of the RBC, we have determined the effects of only enhanced aggregation (i.e., Pluronic F-98-coated RBC5) versus enhanced aggregation with increased plasma viscosity (i.e., an addition of 500 kDa dextran) on myocardial tissue hematocrit in rapidly frozen guinea pig hearts. Although both approaches equally increased aggregation, tissue hematocrit profiles differed markedly: 1) when Pluronic F-98-coated cells were used, the normal transmyocardial gradient was abolished, and 2) when dextran was added, the hematocrit remained at subepicardial levels for about one-half the thickness of the myocardium and then rapidly decreased to the control level in the subendocardial layer. Our results indicate that myocardial hematocrit profiles are sensitive to both RBC aggregation and to changes of plasma viscosity associated with increased RBC aggregation. Furthermore, they suggest the need for additional studies to explore the mechanisms affecting RBC distribution in three-dimensional vascular beds. [ABSTRACT FROM AUTHOR]

Background: The measurement of plasma viscosity (PV) has long been recognized to be important for the diagnosis of paraproteinemia and it is widely used recently for the assessment of peripheral vascular disorders, diabetes mellitus and malignant diseases. The WHO recommended method for measuring PV is the electronic Harkness viscometer, but it is expensive and not widely available. Objective: A simplified, cheaper and accurate technique using the red cell pipette is worth trying as a rapid bedside test. Methods: The relative plasma viscosity (RPV) was measured in 30 patients with multiple myeloma and 150 healthy adults. The method applied was that of Wright and Jenkins in which a comparison of the vertical flow of plasma to distilled water using the red cell pipette is used to measure the relative viscosity of plasma. The erythrocyte sedimentation rate for both the patients and control was performed for comparison. Results: The mean RPV in multiple myeloma patients was highly raised compared to normal and that increment is highly significant statistically (p<0.001). These results are considered highly supportive of the diagnosis of myeloma. In the other hand, although the results of ESR were statistically significant, it cannot be differentiated from those due to other disorders. Conclusion: The measurement of RPV has proved to be simple and reliable and may be used at the bed side to detect the activity and to assess the diagnosis of multiple myeloma. [ABSTRACT FROM AUTHOR]

Objective 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. Methods Thirty postmenopausal patients underwent continuous estradiol transdermal supplementation at a dose of 50 μg/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. Results 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. Conclusions 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. [ABSTRACT FROM AUTHOR]

: ObjectiveTo investigate plasma viscosity, a hemorheologic variable, in oligomenorrheic and eumenorrheic hirsute women.: DesignDescriptive study.: SettingEndocrinology and metabolism clinic.: Patient(s)Twenty five hirsute women with oligomenorrhea and eumenorrhea and 30 age- and weight-matched healthy, eumenorrheic, nonhirsute women.: Main outcome measure(s)Plasma viscosity.: Result(s)Plasma viscosity was significantly elevated in hirsute women compared with eumenorrheic nonhirsute women. Significant correlations were observed between plasma viscosity and fasting insulin level, cholesterol level, and diastolic blood pressure.: Conclusion(s)Hirsute women with oligomenorrhea or eumenorrhea had a significantly elevated plasma viscosity compared with healthy controls. [Copyright &y& Elsevier]

Aims Aim of the study was to investigate the association between various markers of systemic inflammation and a detailed history of smoking in a large representative sample of the general population.Methods and results The effects of chronic smoking on white blood cell (WBC) count, fibrinogen, albumin, plasma viscosity (PV), and high-sensitivity C-reactive protein (CRP) were measured in 2305 men and 2211 women, age 25–74 years, participating in the third MONICA Augsburg survey 1994/95. In men, current smokers showed statistically significantly higher values for WBC count, fibrinogen, PV, and CRP, compared to never smokers, with intermediate, but only slightly increased values for ex-smokers and for occasional smokers. No consistent associations were seen with albumin. Duration of smoking was positively associated with markers of inflammation as were pack-years of smoking. Conversely, duration of abstinence from smoking was inversely related to these markers. Except for WBC count, no such associations were found in women.Conclusion Data from this large representative population show strong associations between smoking and various markers of systemic inflammation in men. They also show that cessation of smoking is associated with a decreased inflammatory response, which may represent one mechanism responsible for the reduced cardiovascular risk in these subjects. [ABSTRACT FROM PUBLISHER]

Objectives: Cigarette smoking causes cardiovascular (CV) disease, but the relative roles of nicotine and other components of tobacco smoke remain unclear. We investigated the effect of stopping smoking, by using nicotine replacement therapy (NRT), on haemorheology parameters.Design: Open, parallel-group trial (intervention group and control smokers).Setting: Clinic within university department of pharmacology.Subjects: One hundred and ninety-seven males, aged 25-45 years, smoking >20 cigarettes per day.Interventions: One hundred and sixty-four subjects were instructed to stop smoking and received NRT for 12 weeks and 33 acted as controls. After 12 weeks, NRT was discontinued, and all subjects were followed-up at 26 weeks. At the end of the study, the NRT group was divided into abstainers (self-reported, verified by exhaled carbon monoxide <10 ppm) and relapsers, who were unable to remain abstinent.Main Outcome Measures: Plasma viscosity, fibrinogen, erythrocyte deformability, reactive capillary blood flow, transcutaneous partial oxygen tension (tcpO2) and haematocrit, assessed at 4, 8, 12, and 26 weeks. Results. After 6 months, plasma fibrinogen (9.95 vs. 8.24 micromol x L(-1) at baseline; P < 0.003), reactive capillary flow (t-pmax: 9.3 vs. 11.2 s at baseline; P < 0.005), and tcpO2 (50.4 vs. 34.9 mmHg at baseline; P < 0.0001) were significantly improved in abstainers, but changes in plasma viscosity and erythrocyte deformability were inconclusive. Other CV risk factors, such as haematocrit and white blood cell count, decreased to a greater extent in abstainers than in relapsers. Expired carbon monoxide concentrations reflected the changes in smoking and decreased in abstainers from 30.4 ppm at baseline to 4.2 ppm; P < 0.0001). Conclusions. Smoking cessation improved CV parameters, and use of nicotine medications did not negate these improvements. [ABSTRACT FROM AUTHOR]

The high output heart failure is a clinical condition in which the systemic congestion is associated to a high output state, and it can be observed in a non-negligible percentage of hematological diseases, particularly in multiple myeloma, a condition in which the risk of adverse cardiovascular events may increase, with a worse prognosis for patients. For this reason, though an accurate literature search, we provided in this review a complete overview of different pathogenetic mechanisms responsible for high output heart failure in multiple myeloma. Indeed, this clinical finding is present in the 8% of multiple myeloma patients, and it may be caused by artero-venous shunts, enhanced angiogenesis, glutamminolysis, hyperammonemia and hemorheological alterations with increase in plasma viscosity. The high output heart failure in multiple myeloma is associated with significant morbidity and mortality, emphasizing the need for a multidisciplinary approach.

Abstract Introduction Many studies suggest that elevated triglyceride levels are associated with increased long-term risk of stroke, including transient ischemic attacks. In addition, elevated triglyceride levels independently contribute to plasma viscosity and decreased blood flow. However, no consensus has been reached regarding the significance of hypertriglyceridemia as an independent risk factor for ischemic stroke. Case presentation We report the case of a patient admitted to our hospital for sudden onset of coma. Laboratory test results revealed he had high blood glucose (28.2mmol/L), high glycated hemoglobin (11.4 percent), considerably high serum triglyceride levels (171.5mmol/L; type V hyperlipoproteinemia), and high plasma viscosity (1.90mPa/s) with normal β-hydroxybutyric acid levels. His triglyceride levels decreased after administering intravenous fluids. Our patient’s consciousness level improved gradually over three days. All serum lipid levels decreased seven days after admission. Conclusions The findings in our patient’s case are likely explained by triglyceride-mediated hyperviscosity causing a transient ischemic attack. In the present report we suggest that when several tests do not reveal the cause of stroke-like symptoms, measurement of plasma viscosity may be informative.

Rheological studies were made on the blood of 12 diabetic patients after a period of poor diabetic control (HbA 12.6±0.7% (mean ± SD); mean home capillary blood glucose level 11.7±1.2 mmol/l), and after at least three months of improved control (HbA 9.1±0.4%, p<0.01; mean home capillary blood glucose level 9.2±0.6 mmol/l). There were significant decreases in plasma fibrinogen levels (4.1±0.6 to 3.7±0.6 g/l, p <0.01), plasma viscosity (1.31±0.1 to 1.25±0.04, p<0.001), and whole blood viscosity at low (22.8±2.7 to 20.2±2.9, p<0.01) and high shear rates (3.4 ±0.2 to 3.1±0.2, p<0.01). Ten diabetics with clinically evident complications were matched with diabetics of similar age, sex, duration and current control of diabetes. There were no significant differnces in plasma or whole blood viscosities between the two groups. Hyperviscosity in diabetes seems strongly related to hyperglycaemia and to be influenced by the quality of diabetic control. [ABSTRACT FROM AUTHOR]

Blood viscosity (shear rates 100s and 0.94 s) and several of its major determinants (haematocrit, plasma fibrinogen and plasma viscosity) have been measured in 38 male insulin-treated diabetics, aged 18-50 years, and in 38 non-diabetic control subjects matched for age and smoking habit. Diabetics without fundoscopic retinopathy (n=20) had higher mean blood viscosity than controls at the high shear rate (7.07 cP vs 6.75 cP, p<0.05) and the low shear rate (21.2 cP vs 18.7 cP, p<0.025). These differences persisted after correction of blood viscosity to a standard haematocrit, and were associated with increased plasma viscosity (1.41 cP vs 1.34 cP, p<0.025) and plasma fibrinogen (2.9 g/L vs. 2.5 g/L, p<0.025). Diabetics with retinopathy (n=18) had higher mean blood viscosity than diabetics without retinopathy at the high shear rate (7.53 cP vs 7.07 cP, p<0.05) and the low shear rate (24.3 cP vs. 21.2 cP, p<0.05), associated with a higher haematocrit (p<0.05). Blood viscosity and haematocrit correlated with the duration of diabetes (r>0.32, p<0.05). [ABSTRACT FROM AUTHOR]