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ABSTRACT: Diabetes is associated with many hemorheological alterations. The decrease of RBC deformability, increase of aggregability, vasoconstriction, increase of blood viscosity and decrease of oxygen supply have a significant effect on wound healing, such as in foot ulcers. Basically, there is endothelial dysfunction and alteration of permeability; these impair wound healing in diabetic patients. Microcirculation still functions and there is blood flow, even when there is a decrease in vessel diameter, without anatomical lesions in vessel walls. It is necessary to maintain a good oxygen supply. Analyzing microcirculation and hemorheology in diabetes and considering methodologies to treat diabetic foot ulcers (e.g., hyperbaric oxygen therapy, laser, and vacuum) may help in the treatment of patient pathologies.
Advances in experimental medicine and biology 01/2011; 701:263-9. · 1.09 Impact Factor
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ABSTRACT: The microcirculation is an important system, containing resistance arterioles, capillaries and venules, whose main function is to transport oxygen and nutrients to the tissues. Endothelial cells are the main cell types of the microcirculation; their homeostasis is modulated by constant shear stress. Altered hemorheology induces a change in the production of vasodilator and vasoconstrictor agents. The most important pattern inducing endothelium dysfunction is an increase in oxidative stress, which decreases the amount of nitric oxide and favors microvascular phlogosis. In this review we will consider the main scientific reports about the cardiovascular risk factors such as smoking, hypercholesterolemia, hyperviscosity, hypertension, diabetes, stress and increased homocysteine levels, all having as common etiopathogenetic factor alterations in microcirculation and in tissue oxygenation. We also focus on their influence on endothelial cells, inducing endothelial changes and dysfunction related to altered oxygen supply and linked to increased oxidative stress. Also important are endothelial stem cells, that are able to repair vascular endothelial damage, especially in cardiovascular patients, with or without endothelial dysfunction. Under these circumstances the numbers of these stem cells are altered, which means there is a decrease in regeneration capability (post ischaemia modified albumin, etc.). This could be an important negative prognostic factor. Microcirculation and tissue oxygenation are very important factors strongly linked to hemorheology, especially in cardiovascular patients, and their alterations could cause impairment, or initiate cardiovascular pathologies.
Advances in experimental medicine and biology 01/2010; 662:33-9. · 1.09 Impact Factor
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ABSTRACT: Our aim was to perform a preliminary study of blood flow in the peripheral microcirculation in patients with heart failure. Cardiac patients were investigated to establish possible microcirculatory changes due to this pathology. We evaluated 16 patients (non-smokers, dislipidemic with hypercholesterolemia), receiving oral treatment and in NYHA class 2.3 +/- 0.5. A dilated cardiomyopathy (DCM) group was evaluated before cardiac resynchronization therapy (CRT) obtained by biventricular intra-cardiac defibrillator (ICD) implantation, and again 3 months after its implantation. We measured the ejection fraction (EF), peripheral blood flow (using laser Doppler) at the left wrist on the volar side, capillary morphology (using computerized videocapillaroscopy) on the nail bed of the 4th finger of the left hand, rheological status (using the LORCA), as well as hematocrit, hemoglobin concentration, red blood cell (RBC) surface acetylcholinesterase (AchE), and homocysteine. Our data show that in the DCM vs. control group, peripheral flow did not depend only on the heart: throughout the study, blood flow did not change significantly compared to controls and was increased after CRT. There was no decrease in aggregation time. The blood flow did not alter RBC deformability or RBC surface AchE. Due to the lower oxygenation and to a non-significant increase in the number of capillaries after CRT, DCM patients are at higher cardiovascular risk than healthy subjects.
Advances in experimental medicine and biology 01/2010; 662:41-7. · 1.09 Impact Factor
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ABSTRACT: We evaluated morphological changes in several pathologies using computerized videocapillaroscopy, and related hemorheological patterns using the laser assisted optical rotational red cell analyzer (LORCA). In addition, tissue oxygenation was measured using two oximeters with Combi sensors (Periflux 5000, Perimed). The study included four groups of patients (pts) that were compared with a control group. Group A Controls (n=25: 15 males [M] and 10 females [F] aged 36 +/- 3 years); Group B Diabetic pts n=32 (IDDM pts n=20: 12 M and 8 F aged 43 +/- 4 years; NIDDM pts n=12: 6 M and 6 F aged 45 +/- 3 years); Group C Glaucoma pts n=30 (16 M and 14 F aged 42 +/- 5 years); Group D Liver failure pts n=6 (3 M and 3 F aged 44 +/- 5 years); Group E Hypertensive pts n=50 (smokers n=28: 12 M and 16 F aged 40 +/- 4 years, and nonsmokers n=22: 12 M and 10 F aged 38 +/- 3 years). In all patients hemorheological measurements were made using the LORCA (including red blood cell [RBC] deformability and aggregability), morphology was evaluated using computerized videocapillaroscopy (magnification 200 x), and transcutaneous oxygen partial pressure measurements (TcpO2) were made with the Periflux 5000. In patients with diabetic microangiopathy: the capillary loops in 50% (16/32) of these pts showed formations such as 'deer horns', 72% (23/32) showed formations such as 'elephant nose', and in 45% (14/32) formations such as a 'cork screw'; in diabetics with POAD an important capillary rarefaction was found in 26% (9/32) of the pts. In glaucoma patients, in 84% (25/30) we observed 'capillary meandering' and images such as 'a comb'. In patients with more complicated pathology capillary rarefaction was found in 70% (21/30) of the patients. An improvement in the perfusion of non-functional loops was found in deceased patients who had suffered liver failure one week after liver transplantation in 90% (5/6) of the studied cadavers. In non-smoking hypertensives morphological changes were found in 25% (6/22) of the patients, and in hypertensive smokers in 47% (13/28). RBC deformability was detected using LORCA and expressed as the Elongation Index (EI), and RBC aggregability was detected using LORCA and expressed in t 1/2 (seconds) indicating the RBC aggregability peak. Group A controls: EI 0.59 +/- 0.02; t 1/2 3 +/- 1 sec; Group B: IDDM EI 0.55 +/- 0.01; t 1/2 : 2 +/- 0.5 sec p < 0.05; NIDDM EI 0.56 +/- 0.01; t 1/2 2 +/- 0.2 sec p < 0.04; Group C glaucoma: EI 0.56 +/- 0.01; t 1/2 2 +/- 0.3 sec p < 0.05; Group D liver failure: EI 0.56 0.02; t 1/2 2 +/- 0.4 sec p < 0.03; Group E hypertensives: smokers EI 0.56 +/- 0.02; t 1/2 2 +/- 0.6 sec p < 0.04; non-smokers EI 0.57 +/- 0.02; t 1/2 2 +/- 0.6 sec p < 0.04 compared with controls. We also measured the TcpO2 at the dorsum of the right foot as a standard site representing peripheral control of microvasculature perfusion. Group A 96 +/- 11 mmHg; Group B IDDM 74 +/- 9 mmHg p < 0.05; NIDDM 76 +/- 8 mmHg p < 0.05; Group C glaucoma 75 +/- 9 mmHg p < 0.05; Group D liver failure 69 +/- 6 mmHg p < 0.05; Group E hypertensives: smokers 70 +/- 5 mmHg p < 0.05, non-smokers 77 +/- 9 mmHg p < 0.05 compared with controls. This study presents an interesting and complete methodology to evaluate the microcirculation in different pathologies that induce changes in the microvasculature.
Advances in experimental medicine and biology 01/2007; 599:7-15. · 1.09 Impact Factor
