Search results for "blood viscosity"

Erythrocyte deformability and hemorheological profile in multiple myeloma

2018

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 ex…

Blood rheology effect of submaximal exercise on young subjects

2013

Nowadays cardiac and metabolic diseases are a matter of concern. Exercise is a valid treatment and method of prevention for not only adults, but also young subjects. Physical activity causes transient blood rheology impairment in adults. However little is known about the effects of exercise on blood flow characteristics in young subjects. The aim of the study was to assess the effects of a light aerobic exercise session on blood rheology in young subjects. Ten young subjects (aged 12-16 years) performed 1 hour of submaximal aerobic exercise (70% HRmax). Blood samples were drawn just before and after exercise. We determined blood and plasma viscosity, fibrinogen, erythrocyte deformability an…

Elevation of plasma viscosity induces sustained NO-mediated dilation in the hamster cremaster microcirculation in vivo

1997

We studied whether a flow-independent increase of luminal wall shear stress (WSS) could dilate hamster arterioles in vivo and which endothelial mediators are potentially involved. To this end the plasma viscosity was elevated by exchanging blood for dextran-erythrocyte solution thereby augmenting WSS. Diameters of small and large arterioles as well as red blood cell velocities were measured before and after exchange of blood for solutions of identical haematocrit containing either high- (HMWD) or low-molecular weight dextran (LMWD). The potential role of endothelial autacoids was investigated by local application of the NO-synthase inhibitor NG-nitro-L-arginine (L-NNA), the inhibitor of cyc…

Double-blind, crossover study of the clinical efficacy and the hemorheological effects of pentoxifylline in patients with occlusive arterial disease …

1984

The effect of a 3 month daily administration of 800 mg pentoxifylline (Trental 400 bds) or placebo was assessed under double blind crossover design in 18 patients (12 males and 6 females) with peripheral occlusive arterial disease in respect of painfree walking distance and various hemorheological and hemostasiological variables, platelet aggregation, serum cholesterol and triglycerides. In first treatment period walking distance significantly increased with pentoxifylline by 46% from baseline 121 ± 15 m and by 4% with placebo from baseline 134 ± 18 m. Pentoxifylline administration furthermore yielded significant decrease in whole blood and plasma viscosity and significant increase in eryt…

Hemorheological parameters in Monoclonal Gammopathy of Undetermined Significance (MGUS).

2018

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 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 expressed…

Clinical disorders responsible for plasma hyperviscosity and skin complications

2017

In this brief review, we have examined some clinical disorders which are associated to an altered hemorheological profile and at times accompanied by skin ulcers. This skin condition may be, in fact, observed in patients with primary plasma hyperviscosity such as multiple myeloma, Waldenstrom macroglobulinemia, cryoglobulinemia, cryofibrinogenemia, dysfibrinogenemia and connective tissue diseases. It must be underlined that the altered hemorheological pattern is not the only responsible for this skin complication but, as it worsens the microcirculatory flow, it contributes to determine the occurrence of the skin ulcers.

The evolution of the meaning of blood hyperviscosity in cardiovascular physiopathology: Should we reinterpret Poiseuille?

2009

In the 1960s and 1970s, a number of researchers (including ourselves) involved in the study of cardiovascular pathophysiology and particularly in the development of techniques to quantify blood flow, came across the observation that, along with vessel diameter, also blood viscosity plays an important role not only in theory but also in practice. Until then, viscosity was thought to play only a marginal role in determining blood flow, a concept which was based on the 1828 theories of Jean Louis Marie Poiseuille (Fig. 1, and [1]).1 In his well-known formula, named after its fathers Hagen2 and Poiseuille,

Hemorheological pattern in different groups of athletes submitted to cardio-pulmonary exercise test

2007

Hemorheology in the metabolic syndrome.

2011

Hemorheological abnormalities in human arterial hypertension

2014

Blood rheology is impaired in hypertensive patients. The alteration involves blood and plasma viscosity, and the erythrocyte behaviour is often abnormal. The hemorheological pattern appears to be related to some pathophysiological mechanisms of hypertension and to organ damage, in particular left ventricular hypertrophy and myocardial ischemia. Abnormalities have been observed in erythrocyte membrane fluidity, explored by fluorescence spectroscopy and electron spin resonance. This may be relevant for red cell flow in microvessels and oxygen delivery to tissues. Although blood viscosity is not a direct target of antihypertensive therapy, the rheological properties of blood play a role in the…