ARTICLE | doi:10.20944/preprints202103.0708.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Adolescents; high sensitivity C-reactive protein; Insulin-like growth factor binding proteins; Obesity; Oxidized Low-Density Lipoprotein; Predictive diagnostics
Online: 29 March 2021 (16:33:20 CEST)
Insulin-like growth factor binding proteins (IGFBPs) are critical modulators of the metabolism. In adults, IGFBPs are associated with obesity and insulin resistance but the association of IGFBPs with metabolic homeostasis in children and adolescents is not fully characterized. In this study we investigated the association of plasma IGFBPs (IGFBP-1, 3 and 7) with weight status, central adiposity and cardiovascular disease markers Hs-CRP and Ox-LDL. A total of 420 adolescents (age 11-14 years) were randomly recruited from public middle schools in Kuwait. IGFBPs were measured using bead-based multiplexing while Hs-CRP and Ox-LDL were measured using ELISA. IGFBP-1 levels were significantly lower in obese and overweight participants compared to normal weight children. Only IGFBP-1 was negatively associated with waist circumference to height (WC/Ht) ratio. IGFBP-1 was negatively correlated with Hs-CRP while IGFBP-3 and IGFBP-7 were negatively correlated with Ox-LDL. These data demonstrate a robust negative association of IGFBP-1, but not IGFBP-3 or -7, with overweight and obesity, and the inflammation marker Hs-CRP. Central adiposity (WC/Ht ratio) was a stronger predictor of IGFBP-1 than BMI-for-age z-score. IGFBP-1 could thus be used as a sensitive predictive diagnostic tool for obesity and its subsequent effects in screening and monitoring of obesity-related metabolic complications in adolescents.
REVIEW | doi:10.20944/preprints201809.0285.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: oxidized LDL; cNOS; iNOS; endothelial dysfunction
Online: 17 September 2018 (07:45:14 CEST)
The release of nanomolar concentrations of nitric oxide (NO) by endothelial cells (EC), via activation of constitutive NO synthase (eNOS), represents the pre-requisite for the vaso-protective role of vascular endothelium. On the other hand, exaggerated release of NO as a consequence of activation of inducible NO synthase (iNOS), leads to endothelial dysfunction and, at the late stages, to the development of atherothrombosis. Oxidyzed LDLs (OxyLDL) represent the major candidate to trigger biomolecular processes accompanying endothelial dysfunction and vascular inflammation leading to atherosclerosis development though the pathophysiological mechanism still remains to be elucidated. Here, we summarize recent evidence suggesting that oxyLDL produce significant impairment in the balance in the eNOS/iNOS machinery, downregulating eNOS via HMGB1-TLR4-Caveolin-1 pathway. On the other hand, a sustained activation of the scavenger receptor LOX-1 leads to NFkB activation which, in turn, increases iNOS, leading to EC oxidative stress. Finally, these events are associated to reduced protective autophagic response and accelerated apoptotic EC death which activates atherosclerotic development. Taken togheter, these informations shed new light into the pathophysiological mechanisms of oxy-LDL-related impairment of EC functionality and open new perspective in atherothrombosis prevention.
ARTICLE | doi:10.20944/preprints202309.0138.v1
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: chitosan; oxidized sucrose; polysaccharide hydrogel; antimicrobial activities
Online: 4 September 2023 (07:37:31 CEST)
Oxidized sucrose (OS) reacts with amino group-containing polysaccharides, including chitosan, without catalyst, resulting in hydrogels entirely composed of carbohydrates. The presence of imine bonds with low structural stabilities and unreacted aldehydes in the structures of these hydrogels hinder their application as biomaterials. Therefore, herein, the chitosan hydrogels (CTSGs) obtained after the crosslinking of chitosan with OS were reduced using sodium borohydride to convert imine bonds to secondary amines and aldehydes to alcohols. Structures of CTSGs were comprehensively characterized by Fourier transform infrared and 13C nuclear magnetic resonance spectroscopies, and results implied that the degree of crosslinking (CR) depended on the OS feed amount used during CTSG preparation. Properties of CTSGs were significantly dependent on CR; with an increase in CR, thermal stabilities and dynamic moduli of CTSGs increased, whereas their swelling properties decreased. CTSGs exhibited antimicrobial properties against the gram-negative bacterium Escherichia coli, and their performances were also dependent on CR. Results indicated the potentials of CTSGs completely based on carbohydrates as antimicrobial hydrogels for various medical and pharmaceutical applications. We believe that this study will contribute to the development of hydrogels for application in the food, medical, and pharmaceutical fields.
ARTICLE | doi:10.20944/preprints202305.2013.v1
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: oxidized starch; canna starch; thermoplastic starch; plasticizer
Online: 29 May 2023 (12:45:26 CEST)
In this study, effects of molecular structure transformation of canna starch (CS) in oxidation condition on physicochemical characteristics of thermoplastic starch were examined. Thermoplastic starch (TPS) samples of CS and respective oxidized starch (in 1, 3 and 5% of sodium hypochlorite, w/w) were prepared by using an internal mixer with the presence of 30 wt% of glycerol as plasticizer. The physicochemical, morphological, thermal, and mechanical properties of native starch-based TPS (NTPS) and oxidized starch-based TPS (OTPS) samples were evaluated. The content of carboxyl and carbonyl groups in oxidized canna starch (OCS) increased with the increase in the content of oxidant, leading to an improvement in the plasticization of CS. FTIR spectra of OTPS samples showed the stronger interaction between oxidized starch and plasticizer. SEM images of fracture surface indicated that the morphology of OTPS samples were smoother than that of NTPS samples. XRD patterns confirmed that the crystallite type of starches was also clearly changed after extrusion process and the decrease in crystallinity of OTPS samples is attributed to effects of both oxidation and plasticization. DSC results indicated that Tg of OTPS was greatly influenced by the carbonyl and carboxyl content and the higher content of these groups in oxidized starched could help the plasticization becomes easier. The better plasticization in OTPS samples resulted in the better mechanical properties and thermal stability of OTPS. The outcome suggested that the use of oxidized starch is an effective method to improve the plasticization in preparing thermoplastic starch.
ARTICLE | doi:10.20944/preprints202209.0371.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: olive phenolics; hydroxytyrosol; oxidized LDL; ox-LDL; isoprostanes; F2-isoprostanes
Online: 23 September 2022 (10:23:51 CEST)
In the present study we report the efficacy of food matrices derived from olives in preventing oxidation of low-density lipoprotein cholesterol (LDL) and lipid peroxidation. To this end, 12 healthy volunteers were divided into 3 groups and cross-received a single dose of olive phenolics, mainly hydroxytyrosol (HT), provided as a liquid dietary supplement (30.6 or 61.5 mg HT), or as fortified extra virgin olive oil (12.19 mg HT + tyrosol). Blood and urine samples were collected at baseline and up to 12 hours after ingestion. Plasma oxidized LDL levels were measured by ELISA using a monoclonal antibody, while F2-isoprostanes were quantified in urine by UHPLC-MS/MS. Despite the great variability between individuals, a tendency to reduce lipoxidation reactions has been observed after olive phenolics intake in both, blood and urine. In addition, the subgroup of individuals with the highest baseline lipoxidation level showed a decrease in F2-isoprostanes (p < 0.05) after taking the food supplements, as well as a marked decrease in oxidized LDL levels (p < 0.01) after intake of the food supplement with the lowest HT dose. These promising results suggest that HT supplementation could be a useful aid in preventing lipoxidation. Additionally, people with a redox imbalance could benefit even more from supplementing with bioavailable HT.
ARTICLE | doi:10.20944/preprints202311.0743.v1
Subject: Chemistry And Materials Science, Other Keywords: U-232; Am-241; radioactivity; radionuclide removal; oxidized carbon fabrics; water treatment
Online: 13 November 2023 (11:06:50 CET)
The adsorption of actinide ions (Am(III) and U(VI)) from aqueous solutions by pristine and oxidized carbon fabrics has been investigated by means of batch experiments at different pH values (4, 7 and 9) and temperatures (25, 35 and 45 °C) under ambient atmospheric conditions. The experimental results indicate that both pH and fabric texture affect the adsorption rate and the relative removal efficiency, which results at 70% and 100% for Am(III) and U(VI), respectively. The Kd (L/kg) values for U(VI) have been generally found to be higher (2 < log10(Kd)< 3) than the corresponding values for the Am(III) adsorption (1.5 < log10(Kd) < 2). The data obtained from the experiments regarding the temperature effect imply that the relative adsorption for both actinides increases with temperature and that the adsorption is an endothermic and entropy-driven reaction. Application of the fabrics to remove the two actinides from contaminated seawater samples shows that both the relative removal efficiency and the Kd values decrease significantly due to the presence of competitive cations (e.g., Ca2+ and Fe3+) and complexing anions (CO32-) in the respective waters. Nevertheless, the removal efficiency is still remarkable (50% and 90% for Am(III) and U(VI), respectively), demonstrating that these materials could be attractive candidates for the treatment of radionuclide/actinide contaminated waters.
ARTICLE | doi:10.20944/preprints202308.1833.v1
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: aerobic exercise; elderly Korean women; arterial stiffness; cell adhesion molecule; oxidized-LDL
Online: 29 August 2023 (04:20:09 CEST)
The purpose of this study was to determine the effects of aerobic exercise on carotid to femoral pulse wave velocity (cf-PWV), cell adhesion molecules (intracellular adhesion molecules (ICAM-1), vascular cell adhesion molecules (VCAM-1), and endothelial selectin (E-selectin), and oxidized-LDL in elderly women aged 70–85 years, and to identify the effect of and correlation with vascular stiffness. Forty participants were recruited and divided into three groups; vascular stiffness (VSG, n=14), obesity (OG, n=14), and normal (NG, n=12). All groups were given a 16-week intervention of aerobic exercise, and the data collected before and after exercise were analyzed using SPSS Ver. 23.0. Two-way repeated-measures ANOVA was used to evaluate between-group and time-dependent interaction effects. One-way ANOVA was used to evaluate between-group variations. In addition, the significance was tested using a post-hoc test (Scheffe). The within-group variations by time before and after exercise were examined using a paired t-test, and correlation analysis was performed using Pearson correlation coefficients. Simple regression analysis was performed for variables showing significant differences. The results indicated interaction effects for cf-PWV (p<.001), VCAM-1 (p<.01), E-selectin (p<.05) and oxidized LDL (p<.001). The rate of change of cf-PWV was positively correlated with that of VCAM-1 (r=.352, p<.05) and that of oxidized-LDL (r=.325, p<.05) with statistical significance. To determine the effect of the rate of change of cf-PWV on the rate of change of VCAM-1, the variables were tested, and the coefficient of determination in the regression analysis was .124, indicating that 12.4% of the tested variables fit the standard regression line. The variables for the effect of the rate of change of cf-PWV on the rate of change of oxidized LDL were also tested, and the coefficient of determination in the regression analysis was .106, indicating that 10.6% of the tested variables fit the standard regression line. Thus, the 16-week regular and consistent aerobic exercise program had significant effects on the cf-PWV, ICAM-1, VCAM-1, E-selectin, and oxidized-LDL in elderly Korean women with vascular stiffness, suggesting improvements in vascular stiffness, based on which the intervention is predicted to contribute to the prevention of vascular dysfunction by lowering the risk of cardiovascular disease due to atherosclerosis, as well as having a positive effect in the prevention of impairment of vascular endothelial cells.
ARTICLE | doi:10.20944/preprints202310.0890.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: Oxidized sodium alginate, nano-hydroxyapatite, tanning agent, flame retardant, clean technology, sustainable leather.
Online: 13 October 2023 (11:17:12 CEST)
In this study, sodium alginate (SA) was oxidized with potassium periodate to produce an alginate-based tanning agent. Using OSA as a biodegradable tanning agent and a nano-hydroxyapatite (nano-HAp) low concentration suspension to give flame retardancy to leather, eco-design concepts were applied to establish a chrome-, aldehyde-, and phenol-free tanning process. Micro-DSC, 1H NMR, attenuated total reflection mode Fourier transform infrared spectroscopy (FTIR-ATR), and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) were used to investigate the complex matrix collagen-OSA-nano-HAp. Micro-differential scanning calorimetry (micro-DSC) was used to assess OSA's ability to interact with collagen and stabilize the collagen-OSA matrix, while 1H unilateral nuclear magnetic resonance (NMR) was used to investigate the aqueous environment and limitations around collagen molecules caused by their association with OSA and nano-HAp. Industrial standard tests were used to assess mechanical properties and fire resistance of the new leather prototype. The findings reported here indicate that both OSA and nano-HAp are suitable alternatives for cleaner tanning technologies and more sustainable leather.
ARTICLE | doi:10.20944/preprints202310.0059.v2
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: 17β-estradiol; total testosterone; oxidized low-density lipoproteins; high-sensitive C-reactive protein; Acute Myocardial Infarction
Online: 4 October 2023 (07:58:34 CEST)
Estrogens play a protective role during early life stages. However, endogenous 17β-estradiol (E2) can accelerate atherosclerosis progression in low-grade inflammatory conditions like established atherosclerosis. Our single-center cohort study assessed sex-specific associations of gonadal hormones with oxidative stress, inflammation, and myocardial injury markers in 111 patients (37% women) diagnosed with acute myocardial infarction (MI) between July 2011 and December 2013. Blood samples were collected within 48 hours of symptom onset, and we measured sex steroids (E2, total testosterone [T]), oxidized low-density lipoproteins, high-sensitive C-reactive protein (CRP), white blood cell counts (WBC), and cardiac enzymes (creatine kinase [CK], the CK Muscle-Brain fraction [CK-MB], and high-sensitive troponin T [hsTnT]). The SYNTAX score gauged coronary disease severity from coronary angiography results. In men with acute MI, peak cardiac enzyme levels were predicted by post-percutaneous coronary intervention (PCI) E2 plasma levels (OR 1.011, p=0.047 - CK; OR 1.018, p=0.013 - CK- MB; OR 1.019, p=0.005 - TnT), peak WBC count (OR 1.487, p=0.015 - CK ; OR 1,709, p=0,005 - CK- MB; OR 1.391, p=0.012 - TnT), and peak CRP plasma levels (OR 1.040, p=0.033 - CK; OR 1.024, p=0.029 - CK-MB; OR 1.063, p=0.006 - TnT). T levels and E2/T ratio were associated with post-PCI CRP in these men (OR 0.980, p = 0.024 - T, OR 1.010, p = 0.076 - CRP). For women, peak WBC was a marker of highest testosterone (OR 1.348, p = 0.062), and only WBC was a significant indicator of myocardial injury extent (OR 1.426, p=0.039 - CK; OR 1.384, p=0.036 - CK-MB; OR 1.299, p=0.048 - TnT). During acute MI, elevated endogenous estradiol levels correlate with myocardial necrosis severity in men, while in women, increased leukocyte levels indicate acute myocardial damage. Elevated plasma T is associated with increased WBC in women. In men, post-PCI plasma CRP specifically indicates endogenous T levels and E2/T ratio during the acute phase.
ARTICLE | doi:10.20944/preprints202301.0583.v2
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: factor XIII; foam cells; macrophages; vascular smooth muscle cells; oxidized LDL; enzyme-modified LDL; transglutaminase; atherosclerotic plaque; cross-linking
Online: 2 February 2023 (11:52:20 CET)
The potentially active A subunit of coagulation factor XIII (FXIII-A) is an intracellular transglutaminase expressed in various cell types including platelets and monocytes/macrophages. It is involved in stabilizing protein structures by cross-linking through Nε-(?-L-glutamyl)-L-lysyl iso-peptide bonds. Macrophages are major cellular constituents of the atherosclerotic plaque and are important in determining its structural/functional features. Two of their important functions are the accumulation of oxidized LDL in the lipid core, and by cross-linking structural proteins they may stabilize the plaque and protect the thrombi of atherogenic origin against fibrinolytic degradation. It is important to know whether these functions operate in parallel utilizing the same cellular compartments. First, we showed that monocyte-derived human macrophages significantly increase their FXIII-A content when up-taking oxidized LDL. This phenomenon is very likely independent of the process of transformation into foam cells, as the transformation of vascular smooth muscle cells into foam cells fails to result in the expression of FXIII-A. FXIII containing macrophage-like cells are abundant in the plaque and FXIII-A is also present in the extracellular core. Several cells co-stained for FXIII-A and for Oil Red O suggest that expression of FXIII-A and lipid up-take are common features of macrophages present in the atherosclerotic plaque.