Microplate reader analysis of triatomine saliva effect on erythrocyte aggregation

Cardoso, Antônio Valadão; Pereira, Marta Máximo; Marcondes, Guilherme de Araújo; Ferreira, Adriana Rosa; Araújo, Patrícia Rosa de

doi:10.1590/s1516-14392007000100008

Cited by 11 publications

(4 citation statements)

References 9 publications

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“…Erythrocyte aggregation is characterized by significantly lower absorption values than nonaggregating samples. [35] The positive control caused the formation of aggregates of almost all erythrocytes with absorption (Abs) = 0.051 which was also indicated by the microscopic detection of clusters (stage 3) in Figure 7. In contrast, the negative control (5% glucose containing 10 × 10 -3 m 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid buffer (GlcHEPES) with erythrocytes) showed the highest Abs value (0.174 ± 0.031) and was classified as stage 1.…”

Section: Hemocompatibility Of Dextran and Cellulose Valproate Nanoparticlesmentioning

confidence: 68%

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Polysaccharide Nanoparticles Bearing HDAC Inhibitor as Nontoxic Nanocarrier for Drug Delivery

Lindemann

Kühne

Grune

et al. 2020

Macromolecular Bioscience

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The histone deacetylase inhibitors (HDACi) are potent drugs in the treatment of inflammatory diseases and defined cancer types. However, major drawbacks of HDACi, such as valproic acid (VPA), are limited serum half‐life, side effects and the short circulation time. Thus, the immobilization of VPA in a polysaccharide matrix is used to circumvent these problems and to design a suitable nanocarrier system. Therefore, VPA is covalently attached to cellulose and dextran via esterification with degree of substitution (DS) values of up to 2.20. The resulting hydrophobic polymers are shaped to spherical nanoparticles (NPs) with hydrodynamic diameter between 138 to 221 nm and polydispersity indices from 0.064 to 0.094 by nanoprecipitation and emulsification technique. Lipase treatment of the NPs leads to in vitro release of VPA and hence to an inhibition of HDAC2 activity in a HDAC2 assay. NPs are rapidly taken up by HeLa cells and mainly localize in the cytoplasm. The NPs are hemocompatible and nontoxic as revealed by the shell‐less hen’s egg model.

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Section: Hemocompatibility Of Dextran and Cellulose Valproate Nanoparticlesmentioning

confidence: 68%

“…Erythrocyte aggregation is characterized by significantly lower absorption values than nonaggregating samples. [ 35 ]…”

Section: Resultsmentioning

confidence: 99%

Polysaccharide Nanoparticles Bearing HDAC Inhibitor as Nontoxic Nanocarrier for Drug Delivery

Lindemann

Kühne

Grune

et al. 2020

Macromolecular Bioscience

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“…The hematocrit was selected after testing on various hematocrit through different studies (with human, swine and bovine blood samples) using the developed method, the Hct hematocrit = 1,5,10,20,30,40,50 and 60 were tested. In addition, the evaluation of substances such as fibrinogen and albumin [62,63], added in vitro, has also been tested in the past.…”

Section: Rigidity Of Red Blood Cells (Rbc)mentioning

confidence: 99%

An experimental erythrocyte rigidity index (Ri) and its correlations with Transcranial Doppler velocities (TAMMV), Gosling Pulsatility Index PI, hematocrit, hemoglobin concentration and red cell distribution width (RDW)

Cardoso

2020

PLoS ONE

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Brain artery velocities (Time-Averaged Maximum Mean Velocity, TAMMV) by Transcranial Doppler (TCD), hematocrit, hemoglobin, Red blood cell (RBC) Distribution Width (RDW) and RBC rigidity index (Ri), when reported together with their correlations, provide a accurate and useful diagnostic picture than blood viscosity measurements alone. Additionally, our study included a sixth parameter provided by TCD, the Gosling Pulsatility Index PI, which is an indicator of CBF (Cerebral Blood Flow) resistance. All these parameters are routine in Hematology except for values of Ri. The rigidity (Ri) of the RBC is the main rheological characteristic of the blood of Sickle Cell Anemia (SCA) patients and several pathologies. However, its quantification depends on many commercial and experimental techniques, none disseminated and predominant around the World. The difference in absorbance values of the blood, during the process of sedimentation in a microwell of a Microplate Reader, is a straightforward way of semi-quantifying the RBC rigidity Ri, since the fraction of irreversibly sickled red blood cells does not form rouleaux. Erythrocyte Rigidity Index (Ri) was calculated using initial absorbance A initial (6 s) and final A final (540 s), Ri = 1 / (Ai-Af). The Ri of 119 patients (2-17 y / o, M & F) SCA, SCC (Sickle Cell/hemoglobin C), SCD (Sickle Cell/hemoglobin D), Sβ0thal (Sickle Cell/hemoglobin Beta Zero Thalassemia) and 71 blood donors (20-65 y / o, M & F) were measured in our laboratory while the five parameters (TAMMV and PI by TCD, Hct, Hb and RDW) were obtained from medical records. The in vitro addition of hydroxyurea (HU, 50mg /dl, n = 51 patients, and n = 8 healthy donors) in the samples decreased the rouleaux adhesion strength of both donor and patients' blood samples, leading to extraordinarily high Ri values. The correlation between the studied parameters was especially significant for the direct relationships between Ri, TAMMV, and PI.

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“…Such structures are known as rouleaux and the process is termed RBC aggregation. Figure 1 shows a representative sample of bovine and porcine RBCs suspended in autologous plasma 1 . Bovine blood does not form rouleaux while porcine blood can form extensive network of rouleaux.…”

Section: The Phenomenon Of Red Blood Cell Aggregationmentioning

confidence: 99%

On the potential of using photoacoustic spectroscopy to monitor red blood cell aggregation

2012

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In this paper we examine the potential of using photoacoustic (PA) spectroscopy for the monitoring of red blood cell (RBC) aggregation phenomena. The process of RBC aggregation has been shown to occur during periods of increased plasma fibrinogen concentration and periods of decreased blood flow (leading to diminished shear forces on the aggregates). Current techniques used to monitor RBC aggregation are invasive and do not provide an accurate assessment of the aggregation process in-vivo. We present a theoretical model for investigating the potential of PA spectroscopy for detecting and characterizing the aggregation phenomenon. We show that the signal strength increases with RBC aggregation. Experimental confirmation of the theoretical predictions is provided. Our theoretical and experimental results suggest the PA spectroscopy is capable of monitoring RBC aggregation and providing important information about changes that occur during the aggregation process as it pertains to the dynamics of aggregate formation.

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Microplate reader analysis of triatomine saliva effect on erythrocyte aggregation

Cited by 11 publications

References 9 publications

Polysaccharide Nanoparticles Bearing HDAC Inhibitor as Nontoxic Nanocarrier for Drug Delivery

Polysaccharide Nanoparticles Bearing HDAC Inhibitor as Nontoxic Nanocarrier for Drug Delivery

An experimental erythrocyte rigidity index (Ri) and its correlations with Transcranial Doppler velocities (TAMMV), Gosling Pulsatility Index PI, hematocrit, hemoglobin concentration and red cell distribution width (RDW)

On the potential of using photoacoustic spectroscopy to monitor red blood cell aggregation

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