Search results for "LIPOPROTEIN"
showing 10 items of 982 documents
Neuronal Activity Drives Localized Blood-Brain-Barrier Transport of Serum Insulin-like Growth Factor-I into the CNS
2010
Upon entry into the central nervous system (CNS), serum insulin-like growth factor-1 (IGF-I) modulates neuronal growth, survival, and excitability. Yet mechanisms that trigger IGF-I entry across the blood-brain barrier remain unclear. We show that neuronal activity elicited by electrical, sensory, or behavioral stimulation increases IGF-I input in activated regions. Entrance of serum IGF-I is triggered by diffusible messengers (i.e., ATP, arachidonic acid derivatives) released during neurovascular coupling. These messengers stimulate matrix metalloproteinase-9, leading to cleavage of the IGF binding protein-3 (IGFBP-3). Cleavage of IGFBP-3 allows the passage of serum IGF-I into the CNS thro…
Plasma non-cholesterol sterols: a useful diagnostic tool in pediatric hypercholesterolemia.
2010
Current guidelines strongly recommend the identification of genetic forms of hypercholesterolemia (HC) during childhood. The usefulness of non–cholesterol sterols (NCS) in the diagnosis of genetic HC has not been fully explored. Plasma NCS were measured by gas chromatography/mass spectrometry (GC/MS) in 113 children with hypercholesterolemia affected by: autosomal dominant hypercholesterolemia (ADH), familial combined hyperlipidemia (FCHL), polygenic hypercholesterolemia (PHC), and in 79 controls to evaluate: i) plasma NCS profile in different genetic HC and ii) the usefulness of NCS for the diagnosis of HC beyond current clinical criteria. ADH was characterized by raised lathosterol/total …
Lipid accumulation and metabolism in polychaete spermatogenesis: Role of the large discoidal lipoprotein
2010
In most oviparous animals, lipoprotein-mediated lipid transport plays an important role in the nutrient supply for the oocyte. In male gametes, lipids are used as energy substrates in spermatozoa but nothing is yet known about their origin and metabolism throughout spermatogenesis. The lipid profiles analyzed from different stages of male germ cell development in the marine annelid Nereis virens were found to undergo a dramatic change from primary triacylglycerides at the beginning of germ cell development to cholesterol and phospholipids at the end of development as demonstrated by HPLC with evaporative light scattering detection and mass spectrometry. The uptake of a large discoidal lipop…
Gas chromatographic analysis of resveratrol in plasma, lipoproteins and cells after in vitro incubations
1998
Resveratrol is a trihydroxystilbene present in certain red wines. It may play a role in the inhibition of lipoprotein oxidation and platelet activity. We have developed the first method to measure resveratrol in animal and human samples and to study its incorporation in vitro. After adding epicoprostanol as an internal standard, samples are subjected to lipid extraction in the presence of antioxidant and under dim light to minimize both denaturation and isomerization of the trans-resveratrol to the cis-form. Extracts were purified by cold acetone precipitation and the resveratrol-containing acetone phase was evaporated under nitrogen. The resveratrol was analyzed as a trimethylsilyl derivat…
Impaired cellular cholesterol efflux by oxysterol-enriched high density lipoproteins.
1997
One of the proposed antiatherogenicity role of high-density lipoproteins (HDL) is believed to stimulate removal of cholesterol from the peripheral cells back to the liver for excretion. We have investigated the effects of oxidation-related modifications of HDL on their ability to stimulate cholesterol efflux from cultured cells. Human HDL (HDL3, 1.13 < d < 1.21 g/ml) have been modified either by malondialdehyde or by copper-mediated oxidation (Ox-HDL3). Compared with native HDL3, the modified HDL3 resulted in a significantly reduced efflux of labeled cholesterol from preloaded macrophages (P388D1 cell line). Analysis of lipid composition of Ox-HDL3 by gas chromatography revealed the presenc…
Electrothermal Atomic Absorption Spectrometric Diagnosis of Familial Hypercholesterolemia
2000
We have developed a new nonradioactive assay to identify human low-density lipoprotein receptor defects. It is based on the incubation of cultured cells with colloidal gold-LDL conjugates and quantitation of the gold associated with the cells by electrothermal atomic absorption spectrometry. After an oxidative treatment with nitric and hydrochloric acids, the biological matrix interferes neither with the gold recovery nor with the gold measurements, which are linear, at least from 0.15 to 3 ng of gold. When cells expressing a functional LDL receptor are incubated with increasing amounts of colloidal-gold LDL conjugates, the obtained saturation curve parallels that described when [125I]LDL i…
Semiquantitative multiplex PCR: a useful tool for large rearrangement screening and characterization
2006
Methods presently employed for detection of large rearrangements have several drawbacks, such as the amount of sample and time required, technical difficulty, or the probability of false-negative carriers. Using the low-density-lipoprotein receptor (LDLR) gene, whose mutations are responsible for familial hypercholesterolemia (FH), we have developed a procedure to detect large rearrangements in this gene based on semiquantitative PCR, with important improvements as compared to previous methods. Our method covers the complete LDLR gene and introduces an internal control in the reaction. The procedure discriminates the four different large rearrangements (two deletions and two insertions) tha…
Diagnostic algorithm for familial chylomicronemia syndrome
2016
International audience; Background: Familial chylomicronemia syndrome (FCS) is a rare genetic disease that leads to severe hypertriglyceridemia often associated with recurrent episodes of pancreatitis. The recognition and correct diagnosis of the disease is challenging due to its rarity, and to the lack of specificity of signs and symptoms. Lipid experts, endocrinologists, gastroenterologists, pancreatologists, and general practitioners may encounter patients who potentially have FCS. Therefore, cooperation between experts and improved knowledge of FCS is essential in improving the diagnosis. Currently, a consensus on best practice for the diagnosis of FCS is lacking. Methods: Aiming to def…
Changes in fatty acid compositions of total serum and lipoprotein particles, in growing rats given protein-deficient diets with either hydrogenated c…
1994
The present study examines the effects of dietary saturated (hydrogenated coconut oil) and polyunsaturated (salmon oil) fats on the composition and metabolism of lipoproteins in growing rats fed on protein-deficient diets. Four groups of rats were fed on the following diets for 28 d: 200 g casein+50 g coconut oil (COC)/kg, 20 g casein+50 g coconut oil (COd)/kg, 200 g casein + 50 g salmon oil (SAC)/kg, 20 g casein+50 g salmon oil (SAd)/kg. Both protein-deficient groups exhibited low concentrations of protein and triacylglycerol (in serum, very-low-density lipoprotein (VLDL), low-density lipoprotein-high-density lipoprotein, (LDL-HDL1) and HDL2-3), of cholesterol (in LDL-HDL1) and of phosphol…
Diagnosis of familial hypercholesterolemia in a large cohort of Italian genotyped hypercholesterolemic patients
2022
Background and aims: Familial hypercholesterolemia (FH) is the most relevant genetic cause of early cardiovascular disease (CVD). FH is suspected when low density lipoprotein cholesterol (LDL-C) levels exceed the 95th percentile of the population distribution. Different diagnostic scoring systems have been developed, as the Dutch Lipid Clinic Network (DLCN) score, used worldwide. The aim of the study is to describe the characteristics of FH patients of a large cohort of more than eight hundred genotyped subjects enrolled in an Italian Lipid Clinic, and evaluate the DLCN score performance applied retrospectively to the case study. Methods: 836 hypercholesterolemic patients with LDL-C > 4.…