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Vitamin G. Grounding as Energetic Nutrition and Its Role in Oxidative Defense and Cardiovascular Disease
Published in Stephen T. Sinatra, Mark C. Houston, Nutritional and Integrative Strategies in Cardiovascular Medicine, 2022
Stephen T. Sinatra, Gaetan Chevalier, Drew Sinatra
The role of increased blood viscosity in the pathogenesis of occlusive arterial disease was clearly and succinctly described by Kensey.22 Endothelial dysfunction, mechanical shear forces, and alterations in blood flow mechanics at arterial bifurcations and areas of low blood flow eddies are correlated with plaque progression in the coronary vasculature. Similarly, blood viscosity is known to increase in numerous clinical situations, such as hypertension, smoking, lipid disorders, advancing age, and diabetes mellitus.
Rheology of Polycythemias T. C. Pearson
Published in Gordon D. O. Lowe, Clinical Blood Rheology, 2019
The median survival in these patients is between 18 months for females and 30 months for males.23 A number of factors have been suggested as significant in determining prognosis. These include lower arterial and mixed venous oxygen tensions, higher arterial and mixed venous carbon dioxide tensions, and RCM at entry to study.23,24 Right ventricular hypertrophy and right heart failure are both more common in patients who have developed significantly elevated PCV values.25 Not surprisingly, cardio-respiratory causes account for the majority of deaths in this group.26 The incidence of vessel occlusion in these patients appears to be lower than that seen in PPP,27 but arterial and venous thromboses certainly occur and some patients may present with cerebral ischemic symptoms.13 It has been argued that the incidence of occlusive vascular disease would be higher if the median survival was longer and respiratory and/or cardiac failure did not supervene, as occurs in the majority of patients. Death due to isolated vessel occlusion, such as cerebrovascular accident, myocardial infarction, or pulmonary embolus was approximately 15% in one study.26 Many patients have symptoms which have been attributed to hyperviscosity, such as poor concentration, lethargy, and headache, but whether these symptoms are specifically due to the high blood viscosity is uncertain.
Clinical Hemorheology
Published in Hau C. Kwaan, Meyer M. Samama, Clinical Thrombosis, 2019
Viscosimetric measurements on normal blood have shown that a decrease of shear rate, from physiological range to near zero shear, causes an approximately 30-fold increase in blood viscosity.9 This shear dependency of blood viscosity indicates that viscometric measurements should be made at controlled shear rates. Measurements at different rates of shear of the viscosity of whole blood and of RBC suspensions in an isotonic buffered solution (pH 7.4), containing 0.5% albumin to preserve RBC shape, lead to the estimation of the different determinants of blood viscosity (e.g., RBC aggregation, RBC deformability). Blood viscosity can be measured in capillary11 or rotational12 viscometers. There are both advantages and disadvantages for each type of instrument (sample size, sedimentation problems, edge effects).13
Numerical investigation of different viscosity models on pulsatile blood flow of thoracic aortic aneurysm (TAA) in a patient-specific model
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Amir Faraji, Mahdi Sahebi, Sadjad SalavatiDezfouli
These equations and corresponding parameters are obtained based on the experimental data (Cho and Kensey 1991). Figure 1 shows the blood viscosity values in different models as a function of the shear rate. As the figure shows, at low shear rates, the viscosity values in all of the non-Newtonian models are higher than the Newtonian model. According to Cho and Kensey (1991), Carreau model fits well with some experimental data in the entire range of the shear rate. The power law model estimates the viscosity value more than the other models (shear rate 0.5–170 s−1). The advantage of the power-law model is the simplicity of its formula. In high shear rates, Carreau and Casson models estimation of the viscosity value is so close to the Newtonian model. The advantage of the Casson model is the consideration of the blood yield stress in the viscosity calculations (Merrill et al. 1969). The power law and Herschel–Bulkley models predict the viscosity value very low at high shear rates. The laboratory experiments show constant values from 0.003 to 0.004 Pa.s for the viscosity of blood in the shear rates higher than 100 s−1 (Caballero and Laín 2015), which matches the value predicted by Newtonian, Carreau and Casson models (Figure 1).
Managing complications secondary to Waldenström’s macroglobulinemia
Published in Expert Review of Hematology, 2021
Ilias Pessach, Meletios A. Dimopoulos, Efstathios Kastritis
Increased blood viscosity results from increased plasma content of large molecules or blood cells. In WM, HVS is a result of the large amounts of IgM, which is an intravascular macromolecule with a molecular weight of 970 kDA; serum viscosity can increase significantly with IgM levels as low as 3 g/dL, while IgM levels of 6 g/dL or higher have been associated with more rapid development of HVS, with median time varying greatly among studies [33,37]. The symptomatic threshold, also, varies from patient to patient being clinically evident at diagnosis in only 10%-30% of patients with WM and typically presenting either with nonspecific neurologic manifestations, such as generalized fatigue, light-headedness, and dizziness, or even stroke, or with hemorrhagic complications from small venules (areas with minimal supporting tissue), manifested as epistaxis, visual disturbances from retinal hemorrhage or gum hemorrhage [38]. Monoclonal IgM with cryoglobulin properties may develop HVS in lower concentrations.
Compound Danshen Dripping Pill inhibits high altitude-induced hypoxic damage by suppressing oxidative stress and inflammatory responses
Published in Pharmaceutical Biology, 2021
Yunhui Hu, Jia Sun, Tongxing Wang, Hairong Wang, Chunlai Zhao, Wenjia Wang, Kaijing Yan, Xijun Yan, He Sun
It has been previously reported that coagulation parameters and blood rheology change significantly during hypobaric hypoxia (Reinhart et al. 1991; Toff et al. 2006; Jacqueline et al. 2010), in line with results of epidemiological studies indicating that high altitude poses a risk for developing thrombosis (Yanamandra et al. 2020). Previous research has indicated that Salvia miltiorrhiza and pseudo-ginseng (Panax notoginseng), the two main ingredients of CDDP, are effective in promoting blood circulation and dispersing stasis. Moreover, pharmacological studies have demonstrated that they reduce blood viscosity, accelerate erythrocyte flow, inhibit platelet adhesion and aggregation, and regulate both internal and external blood coagulation (Han et al. 2017; Li et al. 2018; Jia et al. 2019; Ren et al. 2019). In agreement with this large body of evidence, and using a rat hypobaric hypoxia model system, we find that exposure to hypobaric hypoxia causes elevated D-Dimer, erythrocyte aggregation index and parameters of blood rheology, which decreased to a normal level after CDDP treatment, especially in the high dose group. This suggests that the role of CDDP modulating coagulation parameters and blood rheology is not limited to cardiovascular disease, but operates also in acute high-altitude hypoxia.