scholarly journals Concentration Polarization of High-Density Lipoprotein and Its Relation with Shear Stress in an In Vitro Model

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Meng ◽  
Fengxu Yu ◽  
Huaiqing Chen ◽  
Jianmin Zhang ◽  
Eryong Zhang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Carotid Artery ◽  
High Density Lipoprotein ◽  
High Speed ◽  
Concentration Polarization ◽  
Density Lipoprotein ◽  
Carotid Bifurcation ◽  
High Density ◽  
Vitro Model

The purpose of this study was to determine the concentration polarization of high-density lipoprotein (HDL) at the surface of the carotid artery under conditions of steady flow and to establish its relationship with shear stress using an in vitro vascular simulation model of carotid bifurcation. Shear stress, HDL concentration at the surface, and the ratio of HDL concentration at the surface to concentration in bulk flow were measured at different locations within the model under high-speed (1.451 m/s) and low-speed (0.559 m/s) flow. HDL showed concentration polarization at the surface of the carotid artery model, particularly in the internal carotid artery sinus. With decreasing flow velocity, the shear stress at the surface also decreased, and HDL concentration polarization increased. The concentration polarization of HDL was negatively and strongly correlated with shear stress at both low- (r=−0.872,P<.001) and high-speed flow (r=−0.592,P=.0018).

Rapid transformation of [3H]cholesteryl ester m rat high-density lipoprotein: in vivo and in vitro studies

Steroids ◽  
1990 ◽  
Vol 55 (7) ◽  
pp. 308-313
Author(s):  
I.J. Goldberg ◽  
R.S. Rosenfeld ◽  
I. Paul ◽  
L.K. Miller ◽  
M.L. Tiell
Keyword(s):  
High Density Lipoprotein ◽  
Cholesteryl Ester ◽  
Density Lipoprotein ◽  
High Density ◽  
In Vitro Studies ◽  
Rapid Transformation

scholarly journals Light and electron microscopical observations of the effects of high-density lipoprotein on growth of Plasmodium falciparum in vitro

Parasitology ◽  
2004 ◽  
Vol 128 (6) ◽  
pp. 577-584 ◽  
Author(s):  
H. IMRIE ◽  
D. J. P. FERGUSON ◽  
M. CARTER ◽  
J. DRAIN ◽  
A. SCHIFLETT ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
High Density Lipoprotein ◽  
Light And Electron Microscopy ◽  
Density Lipoprotein ◽  
Acid Synthesis ◽  
High Density ◽  
High Concentrations ◽  
Electron Microscopical ◽  
Necessary And Sufficient

Human serum high-density lipoprotein (HDL) is necessary and sufficient for the short-term maintenance of Plasmodium falciparum in in vitro culture. However, at high concentrations it is toxic to the parasite. A heat-labile component is apparently responsible for the stage-specific toxicity to parasites within infected erythrocytes 12–42 h after invasion, i.e. during trophozoite maturation. The effects of HDL on parasite metabolism (as determined by nucleic acid synthesis) are evident at about 30 h after invasion. Parasites treated with HDL show gross abnormalities by light and electron microscopy.

scholarly journals In Vitro Generation of Human High-Density-Lipoprotein-Resistant Trypanosoma brucei brucei

2006 ◽  
Vol 5 (8) ◽  
pp. 1276-1286 ◽  
Author(s):  
Sara D. Faulkner ◽  
Monika W. Oli ◽  
Rudo Kieft ◽  
Laura Cotlin ◽  
Justin Widener ◽  
...  
Keyword(s):  
High Density Lipoprotein ◽  
Trypanosoma Brucei ◽  
Density Lipoprotein ◽  
High Density ◽  
Surface Glycoprotein ◽  
Trypanosoma Brucei Brucei ◽  
African Trypanosomes ◽  
Expression Site ◽  
Human High Density Lipoprotein

ABSTRACT The host range of African trypanosomes is influenced by innate protective molecules in the blood of primates. A subfraction of human high-density lipoprotein (HDL) containing apolipoprotein A-I, apolipoprotein L-I, and haptoglobin-related protein is toxic to Trypanosoma brucei brucei but not the human sleeping sickness parasite Trypanosoma brucei rhodesiense. It is thought that T. b. rhodesiense evolved from a T. b. brucei-like ancestor and expresses a defense protein that ablates the antitrypanosomal activity of human HDL. To directly investigate this possibility, we developed an in vitro selection to generate human HDL-resistant T. b. brucei. Here we show that conversion of T. b. brucei from human HDL sensitive to resistant correlates with changes in the expression of the variant surface glycoprotein (VSG) and abolished uptake of the cytotoxic human HDLs. Complete transcriptome analysis of the HDL-susceptible and -resistant trypanosomes confirmed that VSG switching had occurred but failed to reveal the expression of other genes specifically associated with human HDL resistance, including the serum resistance-associated gene (SRA) of T. b. rhodesiense. In addition, we found that while the original active expression site was still utilized, expression of three expression site-associated genes (ESAG) was altered in the HDL-resistant trypanosomes. These findings demonstrate that resistance to human HDLs can be acquired by T. b. brucei.

Assessment of the carotid artery intima-media complex through ultrasonography and the relationship with Pathobiological Determinants of Atherosclerosis in Youth

2015 ◽  
Vol 26 (7) ◽  
pp. 1333-1342 ◽  
Author(s):  
Thacira D. A. Ramos ◽  
Tatianne M. E. Dantas ◽  
Mônica O. S. Simões ◽  
Danielle F. Carvalho ◽  
Carla C. M. Medeiros
Keyword(s):  
Blood Pressure ◽  
Body Mass Index ◽  
Cardiovascular Risk ◽  
Carotid Artery ◽  
High Density Lipoprotein ◽  
High Density Lipoprotein Cholesterol ◽  
Density Lipoprotein ◽  
High Density ◽  
Z Score ◽  
High Cardiovascular Risk

AbstractObjectiveTo evaluate the presence of carotid thickening and its relationship with the Pathobiological Determinants of Atherosclerosis in Youth score.MethodsWe carried out a cross-sectional study involving 512 brazilian adolescents. Variables such as sex, body mass index, concentrations of non-high-density lipoprotein and high-density lipoprotein cholesterol, blood pressure, blood glucose and glycated haemoglobin A1c levels that make up the score, and carotid thickening through the intima-media complex measured by ultrasound were evaluated. We adopted two cut-off points to evaluate carotid thickening, being considered altered for those higher or equal to the z-score 2+ and ⩾75th percentile. The association was assessed using the χ2 test and univariate and multivariate logistic regression analyses.ResultsHigh cardiovascular risk was present in 10.2% of the adolescents; carotid thickness was present in 4.3% determined by the z-score 2+ and in 25.0% determined by the 75th percentile. When measured by the z-score, carotid thickening was associated with high systolic blood pressure (p=0.024), high-non-high density lipoprotein cholesterol (p=0.039), and high cardiovascular risk assessed by the score and by the 75th percentile, with body mass index >30 (p=0.005). In the multivariate analysis, high cardiovascular risk was found to be independently associated with the presence of carotid thickness evaluated by the z-score, with risk four times greater (p=0.010) of presenting with this condition compared with individuals with low risk, and this fact was not observed when factors were analysed alone.ConclusionThe presence of high cardiovascular risk in adolescents assessed by the Pathobiological Determinants of Atherosclerosis in Youth score was associated with marked thickening of the carotid artery in healthy adolescents.

Synthesis of recombinant high density lipoprotein with apolipoprotein A-I and apolipoprotein A-V

2011 ◽  
Vol 392 (5) ◽  
Author(s):  
Xinbo Zhang ◽  
Baosheng Chen
Keyword(s):  
High Density Lipoprotein ◽  
Low Density Lipoprotein ◽  
Atherosclerotic Lesion ◽  
Density Lipoprotein ◽  
High Density ◽  
Over Expression ◽  
Apolipoprotein A ◽  
Atherosclerotic Lesion Development

Abstract It has been shown that apolipoprotein A-V (apoA-V) over-expression significantly lowers plasma triglyceride levels and decreases atherosclerotic lesion development. To assess the feasibility of recombinant high density lipoprotein (rHDL) reconstituted with apoA-V and apolipoprotein A-I (apoA-I) as a therapeutic agent for hyperlipidemic disorder and atherosclerosis, a series of rHDL were synthesized in vitro with various mass ratios of recombinant apoA-I and apoA-V. It is interesting to find that apoA-V of rHDL had no effect on lipoprotein lipase (LPL) activation in vitro and very low density lipoprotein (VLDL) clearance in HepG2 cells and in vivo. By contrast, LPL activation and VLDL clearance were inhibited by the addition of apoA-V to rHDL. Furthermore, the apoA-V of rHDL could not redistribute from rHDL to VLDL after incubation at 37°C for 30 min. These findings suggest that an increase of apoA-V in rHDL could not play a role in VLDL clearance in vitro and in vivo, which could, at least in part, attribute to the lost redistribution of apoA-V from rHDL to VLDL and LPL binding ability of apoA-V in rHDL. The therapeutic application of rHDL reconstituted with apoA-V and apoA-I might need the construction of rHDL from which apoA-V could freely redistribute to VLDL.

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