Search results for "DEFORMABILITY"

Erythrocyte deformability evaluated by laser diffractometry in polycythemia vera.

2012

We evaluated the erythrocyte deformability in a group of subjects with polycythemia vera (PV) using a Rheodyn-SSD Laser Diffractometer, at the shear stresses of 6, 12, 30 and 60 Pa. Our data showed a significant decrease of red cell deformability, expressed as elongation index (EI), in PV subjects compared with normal controls. These results suggest that the hyperviscosity syndrome accompanying this myeloproliferative disease may be considered a mixed form, resulting from the association of a polycythemic condition with a sclerocythemic disorder.

Erythrocyte deformability in morbid obesity before bariatric surgery. Influence of abdominal obesity.

2010

Although there are several studies dealing with erythrocyte deformability (ED) in obese patients, research on this topic in morbidly obese subjects is scarce. In these studies ED seems to be decreased, although the cause remains unknown. A case-control study in 76 morbid obese subjects (23 women and 53 men, aged 44 ± 13 years) and in 79 normal-weight controls (30 women and 49 men, aged 43 ± 13 years) was undertaken. ED has been determined by ektacytometric techniques in a Rheodyn SSD, by means of the elongation index (EI) at 12, 30 and 60 Pascals, along with anthropometric, lipidic, metabolic and inflammatory parameters. EI was statistically lower in morbidly obese subjects than in controls…

Pioglitazone in addition to metformin improves erythrocyte deformability in patients with Type 2 diabetes mellitus

2010

The aim of the present study was to compare the effect of PIO (pioglitazone) or GLIM (glimepiride) on erythrocyte deformability in T2DM (Type 2 diabetes mellitus). The study covered 23 metformin-treated T2DM patients with an HbA1c (glycated haemoglobin) >6.5%. Patients were randomized to receive either PIO (15 mg, twice a day) or GLIM (1 mg, twice a day) in combination with metformin (850 mg, twice a day) for 6 months. Blood samples were taken for the measurement of fasting glucose, HbA1c, fasting insulin, intact proinsulin, adiponectin and Hct (haematocrit). In addition, the erythrocyte EI (elongation index) was measured using laser diffractoscopy. Both treatments significantly impr…

Hemorheological profile in primary and secondary Raynaud's phenomenon. Influence of microangiopathy.

2013

Raynaud's phenomenon (RP) is an episodic peripheral circulatory disorder characterized by local artery spams in subjects exposed to cold or emotional stress. It is not well-established whether RP patients show an altered rheological profile, mostly due to patient classification and clinical severity. We aimed to compare the hemorheological profile in patients with primary and secondary RP with a healthy control group. Eighteen primary RP, 22 secondary RP and 22 healthy controls, were included in the study. RP patients were also divided according to the presence of digital ulcers (7 with, 33 without). Biochemical and hemorheological variables were analyzed, including glucose, triglycerides, …

Properties of the Binary Neutron Star Merger GW170817

2019

On August 17, 2017, the Advanced LIGO and Advanced Virgo gravitational-wave detectors observed a low-mass compact binary inspiral. The initial sky localization of the source of the gravitational-wave signal, GW170817, allowed electromagnetic observatories to identify NGC 4993 as the host galaxy. In this work, we improve initial estimates of the binary's properties, including component masses, spins, and tidal parameters, using the known source location, improved modeling, and recalibrated Virgo data. We extend the range of gravitational-wave frequencies considered down to 23 Hz, compared to 30 Hz in the initial analysis. We also compare results inferred using several signal models, which ar…

IS IT IMPORTANT TO SEPARATE LEUCOCYTES AND PLATELETS BEFORE MEASURING THE FILTERABILITY OF RED BLOOD CELLS?

1985

Stimulation of endothelial nitric oxide synthase by proinsulin C-peptide.

2003

There is increasing evidence for biological functions of human C-peptide. Recently, we have described that proinsulin C-peptide increases nutritive capillary blood flow and restores erythrocyte deformability in type 1 diabetic patients, whereas it has no such effect in non-diabetic subjects. The aim of the current study was to elucidate cellular mechanisms of this vasodilator effect in vitro by measuring the nitric oxide (NO)-mediated increase of cGMP production in a RFL-6 reporter cell assay and by demonstrating endothelial calcium influx with the Fluo-3 technique. C-peptide increased the release of NO from endothelial NO synthase (eNOS) in bovine aortic endothelial cells in a concentratio…

Rheological blood behaviour is not related to gender in morbidly obese subjects.

2012

To the Editor. We have read with interest the recently published article by Wiewiora et al. [7] regarding hemorheological differences related to gender in morbidly obese subjects. In this study authors found several hemorheological differences between male and female. In this sense, males showed higher blood viscosity and higher erythrocyte deformability than females and native blood viscosity correlated with several erythrocyte aggregation parameters evaluated with the Laser-Assisted Optical Rotational Cell Analyser (LORCA) [3]. In studies with small sample sizes (18 men and 20 women) there is always the risk that differences in certain variables may appear by chance or by imbalances in th…

Association of erythrocyte deformability with red blood cell distribution width in metabolic diseases and thalassemia trait.

2016

Abstract Increased red blood distribution width (RDW) in anemia is related to disturbances in the cellular surface/volume ratio, usually accompanied by morphological alterations, while it has been shown in inflammatory diseases that the activity of pro-inflammatory cytokines disturbing erythropoiesis increases RDW. Recently it has been reported that higher RDW is related with decreased erythrocyte deformability, and that it could be related with the association of RDW and increased risk of cardiovascular diseases. In order to analyze the influence of morphological alterations and proinflammatory status on the relationship between RDW and erythrocyte deformability, we analyzed erythrocyte de…

Erythrocyte Phospholipid and Polyunsaturated Fatty Acid Composition in Diabetic Retinopathy

2014

Background: Long chain polyunsaturated fatty acids (LCPUFAs) including docosahexaenoic acid and arachidonic acid are suspected to play a key role in the pathogenesis of diabetes. LCPUFAs are known to be preferentially concentrated in specific phospholipids termed as plasmalogens. This study was aimed to highlight potential changes in the metabolism of phospholipids, and particularly plasmalogens, and LCPUFAs at various stages of diabetic retinopathy in humans. Methodology and Principal Findings: We performed lipidomic analyses on red blood cell membranes from controls and mainly type 2 diabetes mellitus patients with or without retinopathy. The fatty acid composition of erythrocytes was det…