scholarly journals Detection of Low Density Lipoprotein—Comparison of Electrochemical Immuno- and Aptasensor

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7733
Author(s):  
Daria Rudewicz-Kowalczyk ◽  
Iwona Grabowska
Keyword(s):  
Gold Electrode ◽  
Limit Of Detection ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Serum Samples ◽  
Redox Active ◽  
Ssdna Aptamer ◽  
Sh Group ◽  
First Time

An elevated level of low density lipoprotein (LDL) can lead to the cardiovascular system-related diseases, such as atherosclerosis and others. Therefore, fast, simple, and accurate methods for LDL detection are very desirable. In this work, the parameters characterizing the electrochemical immuno-and aptasensor for detection of LDL have been compared for the first time. An immunosensor has been designed, for which the anti-apolipoprotein B-100 antibody was covalently attached to 4-aminothiophenol (4-ATP) on the surface of the gold electrode. In the case of an aptasensor, the gold electrode was modified in a mixture of ssDNA aptamer specific for LDL modified with –SH group and 6-mercaptohexanol. Square-wave voltammetry has been used for detection of LDL in PBS containing redox active marker, [Fe(CN)6]3−/4−. Our results show the linear dependence of [Fe(CN)6]3−/4− redox signal changes on LDL concentration for both biosensors, in the range from 0.01 ng/mL to 1.0 ng/mL. The limit of detection was 0.31 and 0.25 ng/mL, for immuno- and aptasensor, respectively. Whereas slightly better selectivity toward human serum albumin (HSA), high density lipoprotein (HDL), and malondialdehyde modified low density lipoprotein (MDA-LDL) has been observed for aptasensor. Moreover, the other components of human blood serum samples did not influence aptasensor sensitivity.

scholarly journals Rabbit and rat C-reactive proteins bind apolipoprotein B-containing lipoproteins.

1984 ◽  
Vol 159 (2) ◽  
pp. 604-616 ◽  
Author(s):  
I F Rowe ◽  
A K Soutar ◽  
I M Trayner ◽  
M L Baltz ◽  
F C de Beer ◽  
...  
Keyword(s):  
Acute Phase ◽  
Apolipoprotein B ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Plasma Lipoproteins ◽  
Free Form ◽  
Low Density ◽  
Serum Samples ◽  
Acute Phase Serum

Immobilized rabbit and rat C-reactive protein (CRP) were found to selectively bind apolipoprotein B (apoB)-containing lipoproteins (low density lipoprotein, LDL and very low density lipoprotein, VLDL) from whole serum in a manner similar to that previously reported with human CRP. In acute phase human serum the CRP is in a free form, not complexed with lipoprotein or any other macromolecular ligand, and in acute phase serum from most rabbits fed on a normal diet the rabbit CRP was also free. However, in acute phase serum or heparinized plasma from hypercholesterolemic rabbits part or all of the CRP was found by gel filtration and immunoelectrophoretic techniques to be complexed with beta-VLDL, an abnormal apoB-containing plasma lipoprotein present in these animals. The presence of extent in different serum samples of CRP complexed with lipoprotein correlated closely with the serum apoB concentration. The formation of complexes between native, unaggregated rabbit CRP in solution and apoB-containing lipoproteins was readily demonstrable experimentally both with the isolated proteins and in whole serum. In all cases these interactions were calcium-dependent and inhibitable by free phosphoryl choline. The present findings extend earlier work in man and the rabbit and indicate that among the C-reactive proteins from different species, which are structurally highly conserved, the capacity for selective binding to apoB-containing plasma lipoproteins is also a constant feature. These interactions may therefore be related to the in vivo function of CRP in all species and this function may in turn be relevant to pathological conditions, such as atherosclerosis, in which lipoproteins are important.

ZnO nanoparticles and β-cyclodextrin containing molecularly imprinted polymers for gravimetric sensing of very-low-density lipoprotein

2021 ◽  
Author(s):  
Amara Nasrullah ◽  
Sumaira Roshan ◽  
Usman Latif ◽  
Adnan Mujahid ◽  
Ghulam Mustafa ◽  
...  
Keyword(s):  
Human Serum ◽  
Zno Nanoparticles ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Clinical Importance ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Imprinted Polymer ◽  
Serum Samples ◽  
Molecularly Imprinted

Abstract The elevated level of very-low-density lipoprotein (VLDL) in the blood is associated with coronary heart disease; therefore, its detection is of significant clinical importance. In this work, molecularly imprinted polymer (MIP) layers fabricated with ZnO nanoparticles are developed for gravimetric sensing of VLDL. The use of methacrylic acid (MAA) and β-cyclodextrin (β-CD) as functional co-monomers in an optimized ratio of 1:1 for MIP synthesis controls the hydrophilicity/hydrophobicity; thus, yielding highly tailored recognition sites having adequate stability. The as-prepared ZnO nanoparticles are characterized by scanning electron microscopy (SEM), Fourier transformation infrared (FTIR), and X-ray diffraction (XRD) before incorporating into the MIP matrix. The template concentration in MIP is also varied to select its optimal amount, i.e., 50 µL of 50 µg/mL VLDL solution for enhanced sensor performance. Sensor measurements reveal that the ZnO-MIP has a sensitivity of 19.285 Hz.ng-1mL-1 for VLDL, which is about 16-fold higher than the reference ZnO-NIP (non-imprinted polymer) channel. Furthermore, the ZnO-MIP sensor exhibits high selectivity for VLDL as the sensor response is 6 and 3 times higher compared to α1-acid glycoprotein and human serum albumin (HSA), respectively. Finally, the performance of the developed sensor setup is evaluated for the detection of VLDL in human serum samples indicating its potential for reliable analysis of VLDL in complex biofluids.

The Production and Use of Monoclonal Antibodies to Measure Apolipoprotein B by a Competitive Enzyme-Linked Immunoassay

1987 ◽  
Vol 24 (3) ◽  
pp. 301-308 ◽  
Author(s):  
M Waterson ◽  
L Samuel ◽  
M Norman
Keyword(s):  
Monoclonal Antibodies ◽  
High Density Lipoprotein ◽  
Apolipoprotein B ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Cross Reactivity ◽  
Radial Immunodiffusion ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Serum Samples

The production of monoclonal antibodies to human lipoproteins is described. One of these antibodies, which was shown to be specific to apolipoprotein B, was used to develop a competitive enzyme-linked immunoassay for apolipoprotein B in serum samples. The antibody selected recognises apolipoprotein B in both low density and very low density lipoprotein particles, but there is no cross-reactivity with high density lipoprotein. There is no requirement for labelling of antigen or antibody used in the assay, and results obtained correlate well ( r=0·88) with measurements on serum samples using a radial immunodiffusion assay for apolipoprotein B.

Immunoseparation method for measuring low-density lipoprotein cholesterol directly from serum evaluated

1995 ◽  
Vol 41 (2) ◽  
pp. 232-240 ◽  
Author(s):  
J R McNamara ◽  
T G Cole ◽  
J H Contois ◽  
C A Ferguson ◽  
J M Ordovas ◽  
...  
Keyword(s):  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Accurate Method ◽  
Low Density ◽  
Serum Samples ◽  
Fresh Serum ◽  
Wide Range ◽  
Absolute Bias ◽  
Highly Correlated

Abstract Low-density lipoprotein (LDL) cholesterol can not be calculated from other lipid measurements when samples are obtained from nonfasting individuals or when triglycerides are > or = 4.0 g/L. We have evaluated a direct LDL cholesterol assay for analyzing 115 fresh serum samples obtained from fasting and nonfasting dyslipidemic patients with triglycerides < or = 35.85 g/L, who were receiving diet and (or) drug treatments. Results were highly correlated with those by ultracentrifugation (r = 0.97), with a mean/median bias of -2.9%/0.7% (-0.001/0.010 g/L) and an absolute bias of 9.5%/6.4% (0.119/0.090 g/L). The assay correctly classified LDL cholesterol concentrations < 1.30 g/L 81% of the time, 1.30-1.60 g/L 76% of the time, and > or = 1.60 g/L 94% of the time. Precision studies provided within- and between-run CVs in the range of 1.2-3.8% and 2.0-5.1%, respectively. Our data indicate that this assay is an accurate method for measuring LDLC directly from fresh serum obtained from fasting or nonfasting subjects with a wide range of triglyceride values.

scholarly journals Defective catabolism of low-density lipoprotein by fibroblasts from patients with I-cell disease

1982 ◽  
Vol 202 (1) ◽  
pp. 183-190 ◽  
Author(s):  
J C Williams ◽  
D B Weinstein ◽  
A L Miller ◽  
D Steinberg
Keyword(s):  
Low Density Lipoprotein ◽  
Lipoprotein Metabolism ◽  
Density Lipoprotein ◽  
Acid Proteinase ◽  
Low Density ◽  
Cell Disease ◽  
Mucolipidosis Ii ◽  
First Time ◽  
I Cells

Skin fibroblast cultures from patients with I-cell disease (mucolipidosis II) are characterized by multiple lysosomal enzyme deficiencies The present studies deal with the consequences of these deficiencies with respect to the metabolism of plasma low-density lipoproteins. Degradation of the protein moiety was defective in I-cells compared with control cells, but the binding and internalization of low density lipoprotein were much less affected. Measurements of low-density lipoprotein degradation in homogenates demonstrated directly for the first time a deficiency of acid proteinase activity in I-cell fibroblasts. Comparison of results in 6-h incubations with those in 24-h incubations showed accumulation of intracellular low-density lipoprotein in I-cell fibroblasts and an accelerating rate of degradation, possibly attributable to intracellular accumulation of low-density lipoprotein substrate. The significance of these findings with respect to low-density lipoprotein metabolism in vivo is discussed.

scholarly journals Cascade screening for familial hypercholesterolemia-identification of the C308Y mutation in multiple family members and relatives for the first time in mainland China

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Weirong Jin ◽  
Qiuwang Zhang ◽  
Bei Wang ◽  
Lili Pan ◽  
Hongyou Qin ◽  
...  
Keyword(s):  
Dna Sequencing ◽  
Familial Hypercholesterolemia ◽  
Low Density Lipoprotein ◽  
Family Members ◽  
Mainland China ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipid Profiling ◽  
Cascade Screening ◽  
First Time

Abstract Background Familial hypercholesterolemia (FH), an autosomal dominant genetic disorder, is underdiagnosed and undertreated. The majority of FH cases are caused by low density lipoprotein receptor (LDL-R) gene mutations. The C308Y mutation in LDL-R results in approximately 70% loss of LDL-R activity, leading to the elevation of low density lipoprotein-cholesterol (LDL-C) and an increased risk of premature coronary heart disease (CHD). The aim of this study was to identify FH cases by cascade screening in family members and relatives of a 37-year old male with premature CHD and hypercholesterolemia. Methods Clinical exam, blood lipid profiling and genomic DNA sequencing of all exons of LDL-R were performed for the proband and his 14 family members and relatives. FH diagnosis was carried out using the Dutch Lipid Clinic Network (DLCN) criteria. Results Lipid profiling showed that 9 individuals, including the proband, had hypercholesterolemia. All these 9 subjects had a G > A substitution at nucleotide 986 in exon 7 resulting in the C308Y mutation as determined by DNA sequencing, and all those carrying the mutation were diagnosed as having definite FH under the DLCN criteria. However, most (7/9) did not have suggestive clinical manifestations of CHD. Conclusions The C308Y mutation was discovered in multiple family members and relatives for the first time in mainland China. Cascade screening is key for the confirmatory diagnosis of FH. Our hypothesis that the C308Y is a common variant in the population of Southern China origin warrants further validation by screening for the C308Y mutation in a large population.

scholarly journals GLYCATED LOW-DENSITY LIPOPROTEIN IN DIABETIC AND NON-DIABETIC PATIENTS

2019 ◽  
pp. 123-126
Author(s):  
OMAR ABDULWAHID AL-ANI ◽  
ABDURRAHMAN AL-BAZZAZ
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Oxidative Modification ◽  
Diabetic Group ◽  
Enzyme Linked Immunosorbent Assay ◽  
Diabetic Patients ◽  
Low Density ◽  
Serum Samples ◽  
Diabetes Center

Objective: The importance of measuring the blood level of modified low-density lipoprotein (LDL) molecules is an effective method of identifying people at risk of coronary atherosclerosis; this is because, in the early stages of atherosclerosis, lipolysis and oxidative modification have a role in promoting the uptake of these lipids through macrophages; therefore, this research aims to measure the level of glycated LDL (Gly-LDL) in the blood and its association with metabolic parameters of diabetic patients (diabetes mellitus) and non-diabetic (hyperlipidemia). Methods: At a University Diabetes Center in Riyadh, we using routine automatic analysis methods, fasting serum samples were analyzed for 31 patients with Type-2 diabetes and 31 non-diabetic patients for LDL, high-density lipoprotein (HDL), total cholesterol, glycated hemoglobin, glucose, and triglycerides (TG), and using enzyme-linked immunosorbent assay to analyze Gly-LDL for the same sample. Results: The level of serum Gly-LDL in non-diabetic was higher than in diabetic patients (p=0.037). Gly-LDL level correlated significantly with LDL in the diabetic group (p=0.035) and was insignificant with other parameters; moreover, it is significantly correlated with HDL (p=0.048), TG (p=0.035), and very LDL (p=0.03) in the non-diabetic group and insignificant with other parameters. Conclusion: Measuring rates of Gly-LDL can be used in the early detection of cardiovascular disease, especially in people with diabetes, as they are more susceptible to modified and oxidized LDL.

Low-density lipoprotein modification by normal, myeloperoxidase-deficient and NADPH oxidase-deficient granulocytes and the impact of redox active transition metal ions

Redox Report ◽  
2002 ◽  
Vol 7 (2) ◽  
pp. 111-119 ◽  
Author(s):  
Claudia E. Gerber ◽  
Gernot Bruchelt ◽  
Gerhard Ledinski ◽  
Joachim Greilberger ◽  
Dietrich Niethammer ◽  
...  
Keyword(s):  
Transition Metal ◽  
Nadph Oxidase ◽  
Metal Ions ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Transition Metal Ions ◽  
Low Density ◽  
Redox Active ◽  
Active Transition ◽  
The Impact

scholarly journals Comparative Analysis between Martin’s Formula and Friedewald’s Formula with Direct Homogenous Assay for Estimating Low Density Lipoprotein Cholesterol Level in Nepalese Population

2021 ◽  
Vol 10 (1) ◽  
pp. 36-41
Author(s):  
Bishal Raj Joshi ◽  
Shikha Rizal
Keyword(s):  
Regression Analysis ◽  
Triglyceride Level ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Percentage Error ◽  
Low Density ◽  
Serum Samples ◽  
Cross Sectional ◽  
Lipoprotein Level ◽  
Direct Assay

Background: Low density lipoproteinforms a basis of decision making in treatment of hypercholesterolemic patients and primary target of intervention. Its cost effective and accurate measurementis a need for every clinical laboratories and different calculation methods has been adopted as a replacement to direct assays. This study aims to evaluate the Martin’s formula and Friedewald’s formula in a sample of Nepalese population compared against direct homogenous assay. Materials and Methods: This is a cross-sectional study conducted in Department of Biochemistry from Feb 2020 to January 2021. Serum samples of the participants were analysed for total cholesterol, triglyceride, high density lipoprotein and low density lipoprotein. Martin’s and Friedewald’s formula were applied to get calculated value of low density lipoprotein from both methods. Passing and Bablok regression analysis was used for methods comparison. Results: The mean age of participants was 54.2 ± 8.9 years. Passing-Bablok regression analysis showed Friedewald’s formula performed better than Martin’s formula as per systematic and proportional bias when compared with directassay. However at lowerserum low density lipoprotein level, underestimation of low density lipoprotein compared to direct assay was more common in Friedewald’s formula. At high triglyceride level more percentage error of difference of mean from direct assay was found for Friedewald’s formula. Conclusion: When compared to direct assay, Friedewald’s formula was found to be in better agreement than Martin’s formula. Martin’s formula had advantage over Friedewald’s formula at lower serum low density lipoprotein level and higher triglyceride level where Friedewald’s formula mostly underestimated low density lipoprotein.

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