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Results 201 - 250 of 701
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Gimpl Gerald - - 2010
Cholesterol is a major constituent of the plasma membrane in eukaryotic cells. It regulates the physical state of the phospholipid bilayer and is crucially involved in the formation of membrane microdomains. Cholesterol also affects the activity of several membrane proteins, and is the precursor for steroid hormones and bile acids. ...
Jové Mariona - - 2010
BACKGROUND: Experimental evidences demonstrate that vegetable derived extracts inhibit cholesterol absorption in the gastrointestinal tract. To further explore the mechanisms behind, we modeled duodenal contents with several vegetable extracts. RESULTS: By employing a widely used cholesterol quantification method based on a cholesterol oxidase-peroxidase coupled reaction we analyzed the effects on ...
Capyk Jenna K - - 2009
Cyp125 (Rv3545c), a cytochrome P450, is encoded as part of the cholesterol degradation gene cluster conserved among members of the Mycobacterium tuberculosis complex. This enzyme has been implicated in mycobacterial pathogenesis, and a homologue initiates cholesterol catabolism in the soil actinomycete Rhodococcus jostii RHA1. In Mycobacterium bovis BCG, cyp125 was ...
Chun Yoon Sun YS Department of Physiology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, South - - 2010
Ubiquitously expressed Mg(2+)-inhibitory cation (MIC) channels are permeable to Ca2+ and Mg2+ and are essential for cell viability. When membrane cholesterol level was increased by pre-incubating cells with a water-soluble form of cholesterol, the endogenous MIC current in HEK293 cells was negatively regulated. The application of phosphatidylinositol 4,5-bisphosphate (PIP2) recovered ...
Huang Huan H Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843, - - 2010
While plasma membrane cholesterol-rich microdomains play a role in cholesterol trafficking, little is known about the appearance and dynamics of cholesterol through these domains in living cells. The fluorescent cholesterol analog 6-dansyl-cholestanol (DChol), its biochemical fractionation, and confocal imaging of L-cell fibroblasts contributed the following new insights: i) fluorescence properties ...
Zidar Jernej - - 2009
This paper reports an all-atom molecular dynamics simulation of lipid bilayers with different cholesterol/sphingomyelin molar ratios. Our results reveal structural and dynamic changes suggesting the random distribution of lipids along the bilayer planes is supplanted at cholesterol concentrations above 30 mol % by the formation of a liquid-ordered phase, which ...
Horner Michael A - - 2009
Cholesterol homeostasis is required to maintain normal cellular function and avoid the deleterious effects of hypercholesterolemia. Here we show that the Drosophila DHR96 nuclear receptor binds cholesterol and is required for the coordinate transcriptional response of genes that are regulated by cholesterol and involved in cholesterol uptake, trafficking, and storage. ...
Gómez-Gil Leticia - - 2009
The presence of cholesterol is critical in defining a dynamic lateral structure in pulmonary surfactant membranes. However, an excess of cholesterol has been associated with impaired surface activity of surfactant. It has also been reported that surfactant protein SP-C interacts with cholesterol in lipid/protein interfacial films. In this study, we ...
Vockeroth Dan - - 2010
Mechanical ventilation may lead to an impairment of the endogenous surfactant system, which is one of the mechanisms by which this intervention contributes to the progression of acute lung injury. The most extensively studied mechanism of surfactant dysfunction is serum protein inhibition. However, recent studies indicate that hydrophobic components of ...
Zeng X Q - - 2010
To isolate new lactobacilli strain with cholesterol-lowering effect and analyse its probiotic properties and possible mechanisms of cholesterol removal. The strain with cholesterol-lowering effect was isolated from pickled juice. The acid and bile tolerance and antimicrobial activity were tested. The free cholalic acid, the cholesterol in supernatant fluid, washing buffer ...
Pollegioni Loredano - - 2009
Cholesterol oxidase is a bacterial FAD-containing flavooxidase that catalyzes the first reaction in cholesterol catabolism. Indeed, this enzyme catalyzes two reactions: the oxidation of the C(3)-OH group of cholesterol (and other sterols) to give cholest-5-en-3-one; and its isomerization to cholest-4-en-3-one. In the past several years, the structural and functional characterization ...
Nesbitt Natasha M - - 2010
Mycobacterium tuberculosis, the causative agent of tuberculosis, is an intracellular pathogen that shifts to a lipid-based metabolism in the host. Moreover, metabolism of the host lipid cholesterol plays an important role in M. tuberculosis infection. We used transcriptional profiling to identify genes transcriptionally regulated by cholesterol and KstR (Rv3574), a ...
Aeffner S - - 2009
We have developed an X-ray scattering setup which allows to study membrane fusion intermediates or other nonlamellar lipid mesophases by laboratory-scale X-ray sources alone, thus taking advantage of unrestricted beamtime compared to synchrotron sources. We report results of a study of pure lipid bilayers and phospholipid/cholesterol binary mixtures. Stalks, putative ...
Sandeep P - - 2009
Cerebrotendinous xanthomatosis is one of the rare forms of treatable hereditary neurodegenerative disorders. It is due to a defect in hydroxylation of cholesterol side chain that impairs oxidative cleavage of cholesterol leading to excess accumulation of cholesterol. Here we present such a case which presented to us with recurrent generalized ...
Wu Chunping C Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, - - 2009
Direct and rapid analysis of cholesterol was accomplished in the ambient environment using reactive desorption electrospray ionization (DESI) mass spectrometry. This was achieved by electrospraying reagent solutions in the form of high velocity charged droplets at surfaces such as dried serum samples and animal tissue sections. Betaine aldehyde, incorporated into ...
Lange Yvonne Y Department of Pathology, Rush University Medical Center, Chicago, Illinois 60612, USA. - - 2009
A few membrane-intercalating amphipaths have been observed to stimulate the interaction of cholesterol with cholesterol oxidase, saponin and cyclodextrin, presumably by displacing cholesterol laterally from its phospholipid complexes. We now report that this effect, referred to as cholesterol activation, occurs with dozens of other amphipaths, including alkanols, saturated and cis- ...
Bennett W F Drew - - 2009
The relative stability of cholesterol in cellular membranes and the thermodynamics of fluctuations from equilibrium have important consequences for sterol trafficking and lateral domain formation. We used molecular dynamics computer simulations to investigate the partitioning of cholesterol in a systematic set of lipid bilayers. In addition to atomistic simulations, we ...
Singh Dev K - - 2009
Our earlier studies have shown that channel activity of Kir2 subfamily of inward rectifiers is strongly suppressed by the elevation of cellular cholesterol. The goal of this study is to determine whether cholesterol suppresses Kir channels directly. To achieve this goal, purified prokaryotic Kir (KirBac1.1) channels were incorporated into liposomes ...
Chen Dong-Feng - - 2009
We recently identified that cholesterol myristate in traditional Chinese medicine (TCM) is the active compound that increases proliferation of mesenchymal stem cell (MSCs). The present study is further to determine what signal pathway involves in effect of cholesterol myristate. Reverse transcription-PCR, Western blot and ELISA analysis show that cholesterol myristate ...
Brzostek Anna - - 2009
It is expected that the obligatory human pathogen Mycobacterium tuberculosis must adapt metabolically to the various nutrients available during its cycle of infection, persistence, and reactivation. Cholesterol, which is an important part of the mammalian cytoplasmic membrane, is a potential energy source. Here, we show that M. tuberculosis grown in ...
Yoneyama Yohei - - 2009
The rapidly increasing demand for cultured fish as a food resource requires simple, effective methods for controlling fish health in culture conditions. Plasma total cholesterol levels are significantly related to fish mortality following bacterial challenge, and are thus a good indicator of the general health of fish. We developed a ...
Yu Z - - 2009
PURPOSE:The first 3 weeks of life is the peak time of oligodendrocytes development and also the critical period of cholesterol increasing dramatically in central nervous system in rats. Neonatal hypoxia-ischemia (HI) brain damage happening in this period may disturb the brain cholesterol balance as well as white matter development. MATERIALS ...
Fester Lars - - 2009
Cholesterol of glial origin promotes synaptogenesis (Mauch et al., (2001) Science 294:1354-1357). Because in the hippocampus local estradiol synthesis is essential for synaptogenesis, we addressed the question of whether cholesterol-promoted synapse formation results from the function of cholesterol as a precursor of estradiol synthesis in this brain area. To this ...
Khelashvili George G Department of Physiology and Biophysics, Weill Medical College of Cornell University, New York, New York 10021, USA. - - 2009
An unresolved question about GPCR function is the role of membrane components in receptor stability and activation. In particular, cholesterol is known to affect the function of membrane proteins, but the details of its effect on GPCRs are still elusive. Here, we describe how cholesterol modulates the behavior of the ...
Ooi Esther M M - - 2009
AIMS: We investigated the associations between indices of cholesterol metabolism and features of the metabolic syndrome (MS) in the presence and absence of type-2 diabetes (T2DM). METHODS: Men with the MS (N=140) and 10 age- and sex-matched controls were recruited. Plasma lathosterol and campesterol were measured by gas chromatography-mass spectrometry, ...
Chang Jennifer C JC Seattle Biomedical Research Institute, 307 Westlake Ave N, Ste 500. Seattle, WA 98109, - - 2009
Recently, cholesterol was identified as a physiologically important nutrient for Mycobacterium tuberculosis survival in chronically infected mice. However, it remained unclear precisely when cholesterol is available to the bacterium and what additional bacterial functions are required for its metabolism. Here, we show that the igr locus, which we previously found ...
Lin Fu - - 2010
Saponins are a class of compounds containing a triterpenoid or steroid core with some attached carbohydrate modules. Many saponins cause hemolysis. However, the hemolytic mechanism of saponins at the molecular level is not yet fully understood. In an attempt to explore this issue, we have studied dioscin-a saponin with high ...
Miner Maurine D MD Seattle Biomedical Research Institute, Seattle, WA 98109, - - 2009
Mycobacterium tuberculosis (MTB) acquisition and utilization of nutrients within the host cell is poorly understood, although it has been hypothesized that host lipids probably play an important role in MTB survival. Cholesterol has recently been identified as an important lipid for mycobacterial infection. The mce4 transport system is required for ...
Gómez-Gil L - - 2009
Cholesterol is the major neutral lipid in lung surfactant, accounting for up to 8-10% of surfactant mass, while surfactant protein SP-C ( approximately 4.2 kDa) accounts for no more than 1-1.5% of total surfactant weight but plays critical roles in formation and stabilization of pulmonary surfactant films. It has been ...
Wentworth Anita D AD Department of Chemistry and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, - - 2009
Ongoing efforts to unravel the origins of the cholesterol 5,6-secosterols (1a and 1b) in biological systems have revealed that the two known chemical routes to these oxysterols, ozonolysis of cholesterol (3) and Hock-cleavage of 5-alpha-hydroperoxycholesterol (4a), are distinguishable based upon the ratio of the hydrazone derivatives (2a and 2b) formed ...
Ogden Phillip B - - 2009
This paper details the use of cholesterol as a mobile phase additive and stationary phase complexing agent in reversed-phase liquid chromatography. Cholesterol loading onto a typical C18 stationary phase is examined. It is found that, when using a standard 150 mm x 4.6mm column, between 5.0 and 50.0 mg of ...
Garvik Olav - - 2009
The fluorescent sterol dehydroergosterol (DHE) is often used as a marker for cholesterol in cellular studies. We show by vesicle fluctuation analysis that DHE has a lower ability than cholesterol to stiffen lipid bilayers suggesting less efficient packing with phospholipid acyl chains. Despite this difference, we found by fluorescence and ...
Krasilnikov Oleg V - - 2009
The rate of transbilayer movement (flip-flop) of cholesterol was estimated using planar bilayers with defined initial asymmetry, formed by the opposing monolayers technique. Vibrio cholerae cytolysin (VCC) was utilized as a molecular tool for measuring the cholesterol concentration in the cis leaflet of asymmetric bilayers. To quantify cholesterol flip-flop in ...
Kölsch Heike - - 2009
BACKGROUND: Cholesterol 24S-hydroxylase (CYP46) catalyzes the conversion of cholesterol to 24S-hydroxycholesterol, the primary cerebral cholesterol elimination product. Only few gene variations in CYP46 gene (CYP46A1) have been investigated for their relevance as genetic risk factors of Alzheimer's disease (AD) and results are contradictory. METHODS: We performed a gene variability screening ...
Chang Jinyoung - - 2009
Cholesterol is a major component of biological membranes and is known to affect vesicle fusion. However, the mechanism by which cholesterol modulates SNARE-dependent intracellular fusion is not well understood. Using the fluorescence assay and dye-labeled SNAREs and the fluorescent lipids, we dissected cholesterol effects on individual fusion steps including SNARE ...
Tong Jiansong J Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, - - 2009
Neurotransmitter release at the synapse requires membrane fusion. The SNARE complex, composed of the plasma membrane t-SNAREs syntaxin 1A and SNAP-25 and the vesicle v-SNARE synaptobrevin, mediates the fusion of 2 membranes. Synaptic vesicles contain unusually high cholesterol, but the exact role of cholesterol in fusion is not known. In ...
Hildebrandt Ellen - - 2009
BACKGROUND: Helicobacter pylori specifically takes up cholesterol and incorporates it into the bacterial membrane, yet little is currently known about cholesterol's physiological roles. We compared phenotypes and in vivo colonization ability of H. pylori grown in a defined, serum-free growth medium, F12 with 1 mg/ml albumin containing 0 to 50 ...
Cha Seongwon - - 2009
BACKGROUND: While INSIG2 has been reported to be associated with BMI in many populations, conflicting results have prevented consensus over its role. In analyses of mice and cell cultures the gene has been found to be involved in the regulation of cholesterol synthesis; however, no relationship has been found with ...
Richardson Kris - - 2009
Elevated plasma cholesterol is a heritable trait and a risk factor for the development of cardiovascular disease. Although several major biochemical pathways regulating cholesterol metabolism have been identified, questions regarding the details of this regulation remain. In fact, common genetic polymorphisms in candidate genes explain only 5 to 7% of ...
Muhammet Sinan M - - 2009
A new amperometric cholesterol biosensor was prepared by immobilizing cholesterol oxidase by a glutaraldehyde crosslinking procedure on polypyrrole-polyaniline (ppy-pani) composite film on the surface of a platinum electrode. In order to prepare a biosensor for the determination of cholesterol, electropolymerization of pyrrole and aniline on Pt surface was performed with ...
Russell David W DW Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. - - 2009
Cholesterol 24-hydroxylase is a highly conserved cytochrome P450 that is responsible for the majority of cholesterol turnover in the vertebrate central nervous system. The enzyme is expressed in neurons, including hippocampal and cortical neurons that are important for learning and memory formation. Disruption of the cholesterol 24-hydroxylase gene in the ...
Huang Zhaohua Z Department of Bioengineering and Therapeutic Sciences, University of California at San Francisco, San Francisco, CA 94143-0912, - - 2009
Extreme makeover of cholesterol: Cholesterol exchange is a major reason for the instability of liposomes in blood. The formation of a covalent hybrid between cholesterol and glycerophosphocholine preserves the bilayer-stabilizing effect of free cholesterol but prevents its transfer from the bilayer. Thus, disterolphospholipids (e.g. 1) are valuable new components for ...
Melzak Kathryn A - - 2009
Acoustic devices are sensitive to the mole fraction of cholesterol present in liposomes adsorbed to the device surface as a result of the different mechanical properties of the liposomes. This fact was exploited to develop an acoustic assay to determine the relative affinity of cholesterol for different lipid mixtures. In ...
Umar Ahmad - - 2009
This paper reports the fabrication of highly-sensitive cholesterol biosensor based on cholesterol oxidase (ChOx) immobilization on well-crystallized flower-shaped ZnO structures composed of perfectly hexagonal-shaped ZnO nanorods grown by low-temperature simple solution process. The fabricated cholesterol biosensors reported a very high and reproducible sensitivity of 61.7 microA microM(-1)cm(-2) with a response ...
Lebouvier Thibaud - - 2009
The lipid components of the senile plaque (SP) remain largely unknown. Senile plaques were said to be enriched in cholesterol in a few studies using the cholesterol probe filipin and a histoenzymatic method based upon cholesterol oxidase activity. We provide data that strongly suggest that these results are false-positive: the ...
Li, Zi-Chi
The purpose of this study was to investigate the effect of dietary cholesterol upon plasma cholesterol concentration and cholesterogenesis; and the aspect of equilibration of newly synthesized cholesterol between plasma and red blood cell (RBC) in humans. Eight healthy subjects (seven men and one woman) at the age of 55.5 ...
Shih Wei-Chung - - 2009
A prototype chronoamperometric biosensor for the determination of total cholesterol was developed that consists of a homemade potentiostat and disposable strips immobilized with Fe(3)O(4), cholesterol oxidase (ChOx), and cholesterol esterase (ChE). The principle of sensing cholesterol is based on the detection of reduction signal of hydrogen peroxide generated in two ...
Ranucci Elisabetta - - 2008
Poly(amidoamine) (PAA) networks that are obtained by the use of cystamine as a cross-linking agent in the reaction with 2,2'-dithiodipyridine turn into linear PAAs with dithiopyridyl side groups that easily undergo an exchange reaction with thiocholesterol. The resultant products represent the first examples of amphiphilic PAA-cholesterol conjugates in which lipophilic ...
Zhao Changzhi - - 2008
A cholesterol biosensor based on direct electron transfer of a hemoglobin-encapsulated chitosan-modified glassy carbon electrode has been developed for highly sensitive and selective analysis of serum samples. Modified by films containing hemoglobin and cholesterol oxidase, the electrode was prepared by encapsulation of enzyme in chitosan matrix. The hydrogen peroxide produced ...
Bollag Wendy B WB Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA 30912, USA. - - 2008
The first step in steroidogenesis is cholesterol mobilization from cytosolic lipid droplets to the initiating rate-limiting enzyme complex located on the inner mitochondrial membrane. Angiotensin II (AngII), the primary agonist of aldosterone secretion from adrenal glomerulosa cells, is known to induce cholesterol mobilization to mitochondria. However, the role of the ...
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