Hemorheology by Microchannel Method in Males with Metabolic Syndrome

Phase Behavior and Rheological Properties of Poly(vinyl alcohol)/AES/Water System

In this work, the phase behavior of the poly(vinyl alcohol) (PVA)/alkyl ethoxysulfate (AES)/water ternary system is investigated at 25 °C. The PVA/AES/water ternary phase diagram is conducted which shows that there are two main phases corresponding to the solid phase and the hexagonal liquid crystalline phase (H) in the ternary system. Besides these two phases, a high-viscosity liquid phase (L₂) and a micellar phase (L₁) can also be found in the phase diagram, although they just occupy small areas. Polarizing optical microscopy and small-angle X-ray scattering are used to characterize the different lyotropic liquid crystal types. Moreover, the viscosity distribution and oscillation tests are also performed by means of the rheometer. High elastic modulus (G') and viscous modulus (G″) can be found in the H and the L₂ phase, whereas both moduli are low in the L₁ region. The PVA/AES/water ternary phase diagram provides a good guide for accelerating the selection of the detergent formula, whereas the rheological tests provide an application guidance for industrial operations. Beyond tis, the L₁ region is considered to be a reasonable range for slurry making because of its good fluidity and low viscoelasticity. This research enriches the content of polymer-surfactant aggregates and promotes the development of solid detergent manufacturing industry.

Impaired blood rheology is associated with endothelial dysfunction in patients with coronary risk factors

To investigate the relationship between blood rheology and endothelial function in patients with coronary risk factors, brachial arterial flow-mediated vasodilatation (FMD), an index of endothelial function and blood passage time (BPT), an index of blood rheology, and fasting blood cell count, glucose metabolism, and plasma fibrinogen, lipid, C-reactive protein, and whole blood viscosity levels were measured in 95 patients with coronary risk factors and 37 healthy controls. Brachial arterial FMD after reactive hyperemia was assessed by ultrasonography. BPT was assessed using the microchannel method. In healthy controls, BPT significantly correlated with FMD (r = - 0.325, p <  0.05), HDL cholesterol (r = - 0.393, p <  0.05), body mass index (BMI; r = 0.530, p <  0.01), and plasma fibrinogen concentration (r = 0.335, p <  0.05). In a multivariate regression analysis adjusted for all clinical variables, BPT remained significantly associated with BMI and fibrinogen, but not with FMD, in healthy controls. In patients with coronary risk factors, BPT significantly correlated with FMD (r = - 0.331, p <  0.01), HDL cholesterol (r = - 0.241, p <  0.05), BMI (r = 0.290, p <  0.01), hematocrit (r = 0.422, p <  0.001), white blood cell count (r = 0.295, p <  0.01), platelet count (r = 0.204, p <  0.05), and insulin (r = 0.210, p <  0.05). In a multivariate regression analysis adjusted for all clinical variables, BPT remained strongly associated with FMD and hematocrit in patients with coronary risk factors. These data indicate that BPT is closely associated with FMD in patients with coronary risk factors and suggest that the measurement of blood rheology using the microchannel method may be useful in evaluating brachial arterial endothelial function as a marker of atherosclerosis in these patients.

Rivaroxaban attenuates leukocyte adhesion in the microvasculature and thrombus formation in an experimental mouse model of type 2 diabetes mellitus

INTRODUCTION

Thrombosis is a major complication in diabetes mellitus. Since Factor Xa inhibitors are not only inhibit the coagulation system but also attenuate the leukocyte-endothelial interaction in acute inflammation models, the purpose of this study is to confirm the similar effects of rivaroxaban in a mouse model of type 2 diabetes mellitus.

MATERIALS AND METHODS

In the treatment groups, either 5 or 10mg/kg of rivaroxaban dissolved in DMSO was orally given to KK-A(y) mice for 7 weeks (n=6 in each group). KK-A(y) mice fed by chow containing DMSO without rivaroxaban for 7 weeks were served for the control group (n=6). Following clamping of the mesenteric vein for 20 minutes, intravital microscopic observation of the intestinal microcirculation and the measurement of bleeding time after the needle puncture were carried-out. In another series, the calculation for blood cell counts and the measurement of blood fluidity using micro channel array flow analyzer (MC-FAN) were performed.

RESULTS

The initial event in the microvasculature is the leukocyte adhesion on endothelium. Then, the leukocytes make clusters and the platelets are involved in. These leukocyte-platelet conjugates aggregate and form thrombus. The leukocyte adherence and the microthrombus formation was significantly suppressed with the treatment of 10 mg/kg of rivaroxaban compared to the control group (P<0.05). While, the bleeding time was significantly extended with the treatment with 10mg/kg of rivaroxaban (P<0.01). The blood fluidity was maintained best with the treatment of 10 mg/kg rivaroxaban.

CONCLUSIONS

Rivaroxaban attenuates the leukocyte-platelet-endothelial interaction, which leads to the attenuation of microthrombus formation in a mouse model of diabetes mellitus.

Blood viscosity as a forgotten factor and its effect on pulmonary flow

Background

The effect of smoking on blood viscosity is widely known. There are, however, few studies on the effect of blood viscosity on pulmonary circulation.

Methods

We aimed to observe the relationship between blood viscosity and pulmonary circulation among smokers and non-smokers. The study comprised 114 subjects in three groups: group 1, ex-smokers; group 2, smoked at least 10 packs/year and still smoking; group 3, never smoked. Blood viscosity (BV), pulmonary blood flow (PBF), and right ventricular systolic pressure (RVSP) were measured in all subjects.

Results

PBF was significantly lower in group 1 compared with group 3 (p < 0.05). BV in group 1 was significantly higher than group 3 (p < 0.05) while BV in group 2 was significantly higher than group 3 (p < 0.05). PBF in group 2 was significantly lower than group 3 (p = 0.01).

Conclusions

We believe that BV is a significant and forgotten factor that plays an important role in pulmonary and cardiovascular diseases. BV may affect PF even during the course of smoking, and before the clinical onset of chronic obstructive pulmonary disease (COPD). Therefore, individuals at risk of pulmonary hypertension could be detected earlier with a simple blood test.

The biology behind the atherothrombotic effects of cigarette smoke

Cigarette smoke is an aerosol that contains >4,000 chemicals, including nicotine, carbon monoxide, acrolein, and oxidant compounds. Exposure to cigarette smoke induces multiple pathological effects in the endothelium, several of which are the result of oxidative stress initiated by reactive oxygen species, reactive nitrogen species, and other oxidant constituents of cigarette smoke. Cigarette-smoke exposure interferes adversely with the control of all stages of plaque formation and development and pathological thrombus formation. The reactive oxygen species in cigarette smoke contribute to oxidative stress, upregulation of inflammatory cytokines, and endothelial dysfunction, by reducing the bioavailability of nitric oxide. Plaque formation and the development of vulnerable plaques also result from exposure to cigarette smoke via the enhancement of inflammatory processes and the activation of matrix metalloproteases. Moreover, exposure to cigarette smoke results in platelet activation, stimulation of the coagulation cascade, and impairment of anticoagulative fibrinolysis. Many cigarette-smoke-mediated prothrombotic changes are quickly reversible upon smoking cessation. Public health efforts should urgently promote our understanding of current cigarette-smoke-induced cardiovascular pathology to encourage individuals to reduce their exposure to cigarette smoke and, therefore, the detrimental consequences of associated atherothrombotic disease.

The influence of metabolic syndrome and chronic kidney disease on hemorheology assessed by the microchannel method

Metabolic syndrome (MetS) and chronic kidney disease (CKD) are individual risk factors for cardiovascular disease (CVD). Abnormal hemorheology may be associated with CVD in both disorders. The present study investigated the impact of MetS and CKD on hemorheology. We studied 138 adults (women/men=63/75, mean age=52.2 years), who included 87 participants with MetS and 33 with CKD. The hemorheology was assessed by the index of 'whole blood passage time (WBPT)' using the Micro Channel array Flow ANalyzer (MC-FAN). The WBPT values of MetS participants were significantly higher than those of non-MetS participants (52.5±13.1 vs. 46.3±7.7 sec, p=0.03). The WBPT values of CKD participants were significantly higher than those of non- CKD (55.5±12.7 vs. 48.6±11.0 sec, p=0.003). The significant influence of MetS and CKD on WBPT was qualified by their effect modification to WBPT (p=0.04). There was a significantly greater influence of the combination of MetS and CKD on WBPT (59.9±13.4 sec) in comparison to the influence of non-MetS and CKD (46.6±3.5) or non-CKD and MetS (50.0±12.2). The influence of the combination of MetS and CKD was clearer in men, relative to women. Abnormal hemorheology as assessed using MC-FAN may be enhanced by the combination of MetS and CKD.

High blood viscosity is closely associated with cigarette smoking and markedly reduced by smoking cessation

BACKGROUND

Cigarette smoking is an independent risk factor for cardiovascular events such as myocardial infarction and stroke. To date, a useful and convenient method of predicting such events in smokers has not been established. The rheological properties of blood assessed by the microchannel method reflect the blood's viscosity and the state of microthrombus formation, which may predict cardiovascular thrombotic events.

METHODS AND RESULTS

Blood fluidity was assessed in 74 smoking patients (54 men, 20 women, mean age 57.9 years) by measuring the blood passage time (BPT) in an aliquot (100 µl) of blood using the Micro Channel Array Flow Analyzer. BPT was significantly related with smoking variables such as daily consumption of tobacco (r = 0.236, P = 0.044), Brinkman's index (r = 0.252, P = 0.033), the Fagerstrom Test for Nicotine Dependence (r = 0.257, P = 0.029), and the score of a self-rating depression scale (r = 0.236, P < 0.05). Multivariate regression analysis revealed that an independent BPT determinant was daily consumption of tobacco (r = 0.326, P = 0.045). Furthermore, smoking cessation markedly decreased BPT from 63.0 s to 49.7 s (P = 0.002) at 3 months after the start of therapy.

CONCLUSIONS

Unfavorable blood rheology is closely associated with cigarette smoking and may reflect increased cardiovascular risk in smokers. The study results also suggest that such risk can be reduced after only 3 months of smoking cessation.

Determinants of blood rheology in healthy adults and children using the microchannel array flow analyzer

PURPOSE

The reference values of blood rheology in healthy participants, especially children, are not available. The purpose of this study was to determine the blood passage time (BPT) as an index of blood rheology, in healthy children and adults, using the microchannel array flow analyzer, and to investigate the hematological factors that define BPT.

METHODS

Participants were 61 healthy children (35 boys, 26 girls; age 5-6 years) and 71 healthy adults (24 men, age 35.2 +/- 14.1 years; 47 women, age 44.7 +/- 14.1 years, mean +/- standard deviation [SD]). Blood passage time and various hematological variables (blood cell count, serum lipids, and fibrinogen) were measured and compared among the 4 study groups.

RESULTS

Blood passage time values were significantly higher in adult men (48.8 +/- 5.8 seconds) than in boys (41.9 +/- 4.0 seconds), girls (43.7 +/- 7.8 seconds), and adult women (42.4 +/- 4.8 seconds). Stepwise regression analysis identified erythrocyte count and hemoglobin (Hb) as the significant and independent determinants of BPT (P < .05).

CONCLUSION

Our study demonstrates that BPT is significantly longer in healthy adult men than in adult women and children, and that erythrocyte count and Hb are significant determinants of blood rheology.

Relationship between alcohol habits and hemorheology by a micro channel method in a general population

BACKGROUND

Hemorheology plays an important role in the development of cardiovascular disease. The Micro Channel array Flow Analyzer (MC-FAN) (Hitachi Haramachi Electronics Co., Ltd., Bentencho, Japan) is currently considered a useful new device to analyze hemorheology. However, the relationships between various lifestyle habits and hemorheology, especially using MC-FAN, have still not been thoroughly investigated.

HYPOTHESIS

The study was undertaken to determine whether there could be some correlations of lifestyle factors to hemorheology by MC-FAN.

METHODS

A total of 250 asymptomatic Japanese subjects (male:female = 100:150; mean age = 49.7 y) without any medication were enrolled in the present study. Hemorheology was assessed by the whole blood passage time (WBPT) and was corrected by the saline passage time using MC-FAN. Subjects' lifestyle factors, such as smoking habits, alcohol habits, and physical activity, were self-reported.

RESULTS

Partial correlation analysis for WBPT, after controlling for age, gender, hematocrit, white blood cell count, body mass index, blood pressure, blood biochemical measures, and all lifestyle habits, revealed a significant and inverse correlation between alcohol habits of 1-3 go (amount of alcohol intake) and WBPT (r = - 0.191, p = 0.003), in addition to a significant positive correlation between serum low-density lipoprotein (LDL) cholesterol and WBPT.

CONCLUSIONS

These data suggest that alcohol habits may beneficially affect hemorheology by MC-FAN, expanding the protective effect of light-to-moderate alcohol consumption against cardiovascular disease.

Unfavorable blood rheology is closely associated with arterial stiffness in obese patients

Little information on the relationship between blood rheology and atherosclerosis indicators in obese patients is available. We examined blood rheology as assessed by the blood passage time (BPT) with the microchannel method in 109 obese patients. BPT was correlated well with the extent of each metabolic syndrome component. A multivariate regression analysis revealed that the independent contributors to BPT were pulse-wave velocity, an index of arterial stiffness, body mass index and red blood cell. Furthermore, weight reduction intervention significantly decreased BPT. Assessment of rheology may be associated with pulse-wave velocity, and useful to manage obese patients.