Characterization of native and oxidized human low-density lipoproteins by the Z-scan technique

Gómez, Sergio L.; Turchiello, Rozane de Fátima; Jurado, M.C.; Boschcov, Paulo; Gidlund, Magnus; Neto, A. M. Figueiredo

doi:10.1016/j.chemphyslip.2004.07.001

Cited by 38 publications

(24 citation statements)

References 46 publications

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“…1. As reported in a previous study, 20 the peak-to-valley amplitude, represented by the amplitude of the parameter θ, evaluates the degree of modification of the LDL particles in the sample: the higher the value of θ, the less modified the LDL particle is. The inset in Fig.…”

Section: Resultsmentioning

confidence: 94%

“…The Z-scan apparatus used here is the usual one described elsewhere. 20 Our setup uses a cw laser (Verdi V10, Coherent) of wavelength λ ¼ 532 nm. A mechanical chopper modulates the laser beam incident on the sample, providing nearly square pulses of ∼30 ms (i.e., 30 ms in the "on" state, with the laser lighting the sample, and 30 ms in the "off" state).…”

Section: Z-scan (Zs) In the Milliseconds Time-scale Regimementioning

confidence: 99%

“…Samples were encapsulated in tightly sealed rectangular glass cells (thickness 200 μm). For a more detailed description of the application of the ZS technique to lipoprotein biological systems, see Gomes et al 20 All samples were blinded and analyzed at the same time under the same conditions.…”

Section: Z-scan (Zs) In the Milliseconds Time-scale Regimementioning

confidence: 99%

“…20 This tool allows an objective assessment of the LDL's degree of oxidation in the patient's blood through the amplitude of the Z-scan response. To the best of our knowledge, there is no study in the literature that investigates over 12 months the effect of periodontal treatment on the atherogenic level of LDL and the presence of anti-oxLDL antibodies in patients with periodontitis under treatment.…”

Section: Introductionmentioning

confidence: 99%

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Measurement of the nonlinear optical response of low-density lipoprotein solutions from patients with periodontitis before and after periodontal treatment: evaluation of cardiovascular risk markers

Monteiro¹,

Jardini

Giampaoli³

et al. 2012

J. Biomed. Opt

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Abstract. The Z-Scan (ZS) technique in the thermal regime has been used to measure the nonlinear optical response of low-density lipoprotein (LDL). The ZS technique is carried out in LDL from 40 patients with chronic periodontitis before and after three, six, and 12 months of periodontal treatment. Clinical parameters such as probing depths, bleeding on probing, total and differential white blood cells counts, lipid profiles, cytokine levels, and antibodies against oxidized LDL are also determined and compared over time. Before the treatment, the ZS experimental results reveal that the LDL particles of these patients are heavily modified. Only after 12 months of the periodontal treatment, the ZS results obtained reveal behavioral characteristics of healthy particles. This conclusion is also supported by complementary laboratorial analysis showing that the periodontal treatment induces systemic changes in several inflammatory markers.

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Section: Resultsmentioning

confidence: 94%

Section: Z-scan (Zs) In the Milliseconds Time-scale Regimementioning

confidence: 99%

Section: Z-scan (Zs) In the Milliseconds Time-scale Regimementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Measurement of the nonlinear optical response of low-density lipoprotein solutions from patients with periodontitis before and after periodontal treatment: evaluation of cardiovascular risk markers

Monteiro¹,

Jardini

Giampaoli³

et al. 2012

J. Biomed. Opt

View full text Add to dashboard Cite

show abstract

“…al., 17 showed that the linear absorbance coefficient of LDL solutions decreases (in the range between 250 and 550 nm) with the increasing of sample's oxidation degree. This decrease could be associated to the consumption of carotenoids during the oxidation process.…”

Section: Introductionmentioning

confidence: 99%

Behavior of the thermal diffusivity of native and oxidized human low-density lipoprotein solutions studied by the Z-scan technique

et al. 2012

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2012Behavior of the thermal diffusivity of native and oxidized human low-density lipoprotein solutions studied by the Z-scan technique JOURNAL OF BIOMEDICAL OPTICS, BELLINGHAM, v. 17, n. 10, supl. Abstract. Modifications in low-density lipoprotein (LDL) have emerged as a major pathogenic factor of atherosclerosis, which is the main cause of morbidity and mortality in the western world. Measurements of the heat diffusivity of human LDL solutions in their native and in vitro oxidized states are presented by using the Z-Scan (ZS) technique. Other complementary techniques were used to obtain the physical parameters necessary to interpret the optical results, e.g., pycnometry, refractometry, calorimetry, and spectrophotometry, and to understand the oxidation phase of LDL particles. To determine the sample's thermal diffusivity using the thermal lens model, an iterative one-parameter fitting method is proposed which takes into account several characteristic ZS timedependent and the position-dependent transmittance measurements. Results show that the thermal diffusivity increases as a function of the LDL oxidation degree, which can be explained by the increase of the hydroperoxides production due to the oxidation process. The oxidation products go from one LDL to another, disseminating the oxidation process and caring the heat across the sample. This phenomenon leads to a quick thermal homogenization of the sample, avoiding the formation of the thermal lens in highly oxidized LDL solutions.

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Investigation of the Europium Emission Spectra of the Europium-Oxytetracycline Complex in the Presence of Human Low-Density Lipoproteins

et al. 2010

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Low-Density Lipoprotein (LDL), often known as "bad cholesterol" is one of the responsible to increase the risk of coronary arterial diseases. For this reason, the cholesterol present in the LDL particle has become one of the main parameters to be quantified in routine clinical diagnosis. A number of tools are available to assess LDL particles and estimate the cholesterol concentration in the blood. The most common methods to quantify the LDL in the plasma are the density gradient ultracentrifugation and nuclear magnetic resonance (NMR). However, these techniques require special equipments and can take a long time to provide the results. In this paper, we report on the increase of the Europium emission in Europium-oxytetracycline complex aqueous solutions in the presence of LDL. This increase is proportional to the LDL concentration in the solution. This phenomenum can be used to develop a method to quantify the number of LDL particles in a sample. A comparison between the performances of the oxytetracycline and the tetracycline in the complexes is also made.

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Characterization of native and oxidized human low-density lipoproteins by the Z-scan technique

Cited by 38 publications

References 46 publications

Measurement of the nonlinear optical response of low-density lipoprotein solutions from patients with periodontitis before and after periodontal treatment: evaluation of cardiovascular risk markers

Measurement of the nonlinear optical response of low-density lipoprotein solutions from patients with periodontitis before and after periodontal treatment: evaluation of cardiovascular risk markers

Behavior of the thermal diffusivity of native and oxidized human low-density lipoprotein solutions studied by the Z-scan technique

Investigation of the Europium Emission Spectra of the Europium-Oxytetracycline Complex in the Presence of Human Low-Density Lipoproteins

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