Red Blood Cells In Microcirculation Research Articles

Antioxidant associated chemoprophylaxis effect of natural spice and green vegetable on hepatotoxicity.

This is a case control and cohort study, conducted at Department of Biochemistry in FUAST, compressing 24 number of albino Wistar rats. Illicium verum (star anise) natural spice and green vegetable broccoli are used for chemo-preventive herbal treatment in relation with vitamin C antioxidant activity. Hepatotoxicity was induced in liver of model rats by giving interperitoneally single injection of 200 mg/kg bod weight (B.W) of N-nitrosodiethylamine and orally giving 1 mg/kg BW phenobarbital for 14 days during disease prorogation period. The vitamin C analysis from Illicium verum (star anise), green broccoli, orange juice, orange peel and orange pulp was done by iodometric quantitative and qualitative titration method. Rats were given compound according to their bodyweight as 1 mg/kg B.W. After 14 days (Disease Promotion and Propagation Period) and 28 days (Disease cure period) of treatment behavioral activity was monitored by locomotors activity in open field experiment, stimulatory activity in home cage and anxiolytic effects observed in light and dark apparatus and also in T maze. Behavioral activity were significantly increased in Illicium verum and green broccoli treated rats. Hematological study including hemoglobin (Hb), white blood cells (WBC), red blood cells (RBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW) and Platelets was done by abbot laboratory analyzer cell. The value of Hb and RBC was also significantly increased in star anise and broccoli treated rats, showed proper function of RBC in microcirculation. WBC was also in normal range revealed that no disease regards to bone marrow and leukemia's. The biochemical activity of rats including urea, creatinine, total protein, albumin, globulin, A/G ratio, amylase and calcium in blood serum were analyzed while, liver health or performance was also determined by LFT (liver function test). Behavioral and laboratorial variables were analyzed by using SPSS v. 20 and p-value < 0.05 was considered statistically significant. The study report noticeable significant effect of Illicium verum and broccoli on hepatotoxicity of experimental model. Recent experimental study statistical outcomes show reciprocal relationship between the consumption of vegetable diet and natural spice with the risk of Hepatotoxicity. Thus, the aim of the study is to enhance the function of star anise or illicium verum natural spice and green vegetable broccoli as an anticancer or chemoprophylaxis agent.

Effect of mechanical properties of red blood cells on their equilibrium states in microchannels

The equilibrium positions of red blood cells (RBCs) and their steady motions in microchannel affect the hemodynamics in vivo and microfluidic applications on a cellular scale. However, the dynamic behavior of a single RBC in three-dimensional cylindrical microchannels still needs to be classified systematically. Here, with an immersed boundary method, the phase diagrams of the profiles and positions of RBCs under equilibrium states are illustrated in a wide range of Capillary numbers. The effects of initial positions are explored as well. Numerical results present that the profiles of RBCs at equilibrium states transform from snaking, tumbling to slipper, or parachute with the increase in flow rates, and whether RBCs finally approach slipper or parachute motion under large shear rates is dependent on their initial positions. With the increase in tube diameters, the equilibrium positions of RBCs are closer to tube walls relatively. Although both the increase in membrane shear modulus and the viscosity ratio are regarded as the stiffening of RBCs, the change of membrane property does not affect the dependence of the profiles and positions of RBCs at equilibrium states on the shear rates of the flow obviously, but with the increase in viscosity ratio, RBCs move further away from the centerline of the tube associating with more asymmetric characteristics in their stable profiles. The present results not only contribute to a better understanding of the dynamic behavior and multiple profiles of single RBC in microcirculation, but also provide fundamentals in a large range of Capillary numbers for cell sorting with microfluidic devices.

How to tame a giant oscillation

Experiments and simulations show that trains of droplets in microfluidic networks undergo synchronized oscillations, and that strategies to prevent these oscillations can help maintain uniform distribution of red blood cells in microcirculation.

Numerical analysis of cytoadhesion of malaria-infected red blood cells in microcirculation

Numerical analysis of cytoadhesion of malaria-infected red blood cells in microcirculation

Confined tube flow of low viscosity emulsions: Effect of matrix elasticity

This study is addressed to the effect of the elasticity of the continuous phase on confined flow of low viscosity emulsions, a topic of interest in several applications. A Newtonian silicone oil was used as the dispersed phase, while three different water-based fluids, a Newtonian and two Boger fluids, were used as the continuous phase. All the fluids have the same viscosity (ca. 0.05 Pa s). Emulsions were prepared by feeding the two phases to a T-junction followed by a membrane. When the continuous phase was a Boger fluid, the average drop size of the so obtained emulsions was higher (as compared to the Newtonian continuous phase) and a bimodal distribution was observed. Such lower mixing efficiency for a Boger continuous phase is in line with the result for an isolated droplet that breakup is hindered by matrix elasticity. High-speed microscopy visualization of the emulsions flowing through a microcapillary allowed one to determine the velocity profiles and the droplet spatial distribution as a function of the shear rate. In all the experiments, the formation of a droplet-rich core and of a droplet-devoid wall region Δ was observed, with a significant enhancement when the continuous phase was a Boger fluid (where values of Δ as high as 37% of capillary radius were found). So, confinement here refers to the fact that, although the droplets are much smaller than capillary radius, the droplet-free layer takes up a significant fraction of the capillary radius. The observed nonhomogeneous droplet spatial distribution was not due to a transient entry effect, as shown by imaging the emulsions flow at different sections from the capillary inlet, but can be explained by a balance between collision-induced drop diffusion and wall lift force. The former acts to homogenize droplet spatial distribution, while the latter tends to push droplets away from the wall and is enhanced by matrix elasticity. These effects lead to the accumulation of larger droplets around the center of the channel, while smaller droplets are pushed toward the periphery. The velocity profiles for the Boger continuous phase were flat in the droplet-rich core, thus suggesting that the confined emulsions behave as a Bingham fluid. The corresponding yield stress was determined by data fitting of the velocity profiles and rather large values were so obtained. This result is consistent with the high values, close to the maximum packing for spherical particles in binary dispersions, of the droplet volume fraction in the core, which were estimated by measuring the thickness of the droplet-devoid annular region as a function of the applied flow rate and making a volume balance. Overall, the results of this work bear strong analogies with the confined flow of other concentrated suspensions of deformable particles, such as red blood cells in microcirculation, where the formation of a cell-free layer at the wall, which is referred to as margination, has important pathophysiological implications. These findings suggest that low viscosity emulsions with an elastic matrix under confined flow can be used as a tunable model system of biomedical relevance.

Quantifying the biophysical characteristics of Plasmodium-falciparum -parasitized red blood cells in microcirculation

The pathogenicity of Plasmodium falciparum (Pf) malaria results from the stiffening of red blood cells (RBCs) and its ability to adhere to endothelial cells (cytoadherence). The dynamics of Pf-parasitized RBCs is studied by three-dimensional mesoscopic simulations of flow in cylindrical capillaries in order to predict the flow resistance enhancement at different parasitemia levels. In addition, the adhesive dynamics of Pf-RBCs is explored for various parameters revealing several types of cell dynamics such as firm adhesion, very slow slipping along the wall, and intermittent flipping. The parasite inside the RBC is modeled explicitly in order to capture phenomena such as "hindered tumbling" motion of the RBC and the sudden transition from firm RBC cytoadherence to flipping on the endothelial surface. These predictions are in quantitative agreement with recent experimental observations, and thus the three-dimensional modeling method presented here provides new capabilities for guiding and interpreting future in vitro and in vivo studies of malaria.

Production of prostaglandins E 1 and E 2 by adult human red blood cells

We showed that human adult red blood cells (RBCs) produce prostaglandin E 1 (PGE 1) and E 2 (PGE 2). RBCs that were mechanically stressed in the presence of extracellular Ca 2+ by being injected rapidly through a fine needle produced PGE 1 and PGE 2 within 30 min after this mechanical stress. The amounts of PGE 1 and PGE 2 produced by 1 × 10 9 mechanically stressed RBCs were approximately 50 pg and 100 pg, respectively, which were determined in the cytosolic fraction from sonicated RBCs using a competitive enzyme immunoassay method. A Western blot analysis using anti-cyclooxygenase-2 antibody revealed a band at the 70-kDa position in the samples from RBCs producing PGE 1 and PGE 2. Treatment with 10 μg/mL indomethacin completely inhibited the productions of PGE 1 and PGE 2. The present results may indicate a new role of RBCs in microcirculation.