Search Results
Results 201 - 250 of 726
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Sullan Ruby May A - - 2010
Cholesterol is involved in endocytosis, exocytosis, and the assembly of sphingolipid/cholesterol-enriched domains, as has been demonstrated in both model membranes and living cells. In this work, we explored the influence of different cholesterol levels (5-40 mol%) on the morphology and nanomechanical stability of phase-segregated lipid bilayers consisting of dioleoylphosphatidylcholine/sphingomyelin/cholesterol (DOPC/SM/Chol) ...
Memon Nusrat N - - 2010
Six fish species-Cirrhinus mrigala (Morakhi), Labeo rohita (Danbhro), Catla catla (Thalli), Wallago attu (Jarko), Ctenopharyngodon idella (Grass), and Cyprimus carpio (Gulfam)--commonly found in the Pakistani Indus river, were selected for fat and cholesterol evaluation. Fat content was quantified by the Folch method and cholesterol content was determined by a simple ...
Sokolov Anna - - 2010
Recent studies have shown that cooperative interactions in endoplasmic reticulum (ER) membranes between Scap, cholesterol, and Insig result in switch-like control over activation of SREBP-2 transcription factors. This allows cells to rapidly adjust rates of cholesterol synthesis and uptake in response to even slight deviations from physiological set-point levels, thereby ...
Pescador Paula - - 2010
We describe the formation of lipid microtubes from a novel cholesterol-modified nucleoside in binary mixture with phospholipids. Stable cylindrical structures with an outer diameter of 2-3 microm and a length of 20-40 microm were formed. By varying the preparation conditions, thinner tubules with nanometre-scale diameters could also be obtained.
Khelashvili George - - 2010
We performed molecular dynamics (MD) simulations of hydrated bilayers containing mixtures of dimyristoylphosphatidylcholine (DMPC) and cholesterol at various ratios, to study the effect of cholesterol concentration on its orientation, and to characterize the link between cholesterol tilt and overall phospholipid membrane organization. The simulations show a substantial probability for cholesterol ...
Alwarawrah Mohammad - - 2010
The condensing effect of cholesterol in dioleoylphosphatidylcholine (DOPC) lipid bilayers was systematically investigated via atomistic molecular dynamics (MD) simulation. Fourteen independent 200 ns simulations, spanning the entire range of cholesterol mole fraction (x(c)) in DOPC bilayers (i.e., from x(c) = 0 to 0.66), were performed at 323 K. The molecular ...
Ouellet Hugues H Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158, - - 2010
The infectivity and persistence of Mycobacterium tuberculosis requires the utilization of host cell cholesterol. We have examined the specific role of cytochrome P450 CYP125A1 in the cholesterol degradation pathway using genetic, biochemical and high-resolution mass spectrometric approaches. The analysis of lipid profiles from cells grown on cholesterol revealed that CYP125A1 ...
Ibarguren Maitane - - 2010
Cholesterol incorporation into lipid bilayers, in the form of multilamellar vesicles or extruded large unilamellar vesicles, has been quantitated. To this aim, the cholesterol contents of bilayers prepared from phospholipid:cholesterol mixtures 33-75 mol% cholesterol have been measured and compared with the original mixture before lipid hydration. There is a great ...
Goksu Emel I - - 2010
The phase behavior of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) (1/1 mol ratio)/cholesterol (0-60 mol %) supported lipid bilayers agreed with a DOPC/DSPC/cholesterol ternary phase diagram by Zhao et al. when a mica support was used (Zhao, J.; Wu, J.; Heberle, F. A.; Mills, T. T.; Klawitter, P.; Huang, G.; Costanza, G.; Feigenson, ...
He Xin - - 2010
OBJECTIVE: Cholesterol 24-hydroxylase catalyzes the conversion of cholesterol to 24-hydroxycholesterol, which is a major pathway for cholesterol elimination from the brain, since 24-hydroxycholesterol can readily cross the blood brain barrier. The present study aimed to elucidate the distribution of cholesterol 24-hydroxylase in the monkey brain. METHODS: The distribution of cholesterol ...
Mondul Alison M AM Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, - - 2010
Low cholesterol levels and statin drugs may protect against prostate cancer with a worse prognosis. Their protective mechanism is unknown, but has been hypothesized to be related to cholesterol's role as a sex steroid hormone precursor. We evaluated whether serum testosterone and estradiol differ by cholesterol or cholesterol-lowering drug use. ...
Lee Jin - - 2010
This article identifies novel factors involved in cholesterol reduction by probiotic bacteria, which were identified using genetic and proteomic approaches. Approximately 600 Lactobacillus acidophilus A4 mutants were created by random mutagenesis. The cholesterol-reducing ability of each mutant was determined and verified using two different methods: the o-phthalaldehyde assay and gas ...
Tok Esra - - 2010
In the present study, the relationship between exopolysaccharide production and cholesterol removal rates of five strains of Lactobacillus delbrueckii subsp. bulgaricus isolated from home-made yoghurt was studied. Test strains were selected according to their exopolysaccharide production capacity. Influence of different bile concentrations on cholesterol removal was investigated. It was confirmed ...
Janout Vaclav V Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, - - 2010
The condensing action of cholesterol has been compared with that of a structural isomer having its hydroxyl group located at the C-25 position (i.e., 25-OH'), that is, an isomer favoring an "upside down" orientation in lipid membranes. Surface pressure-area isotherms of mixed monolayers made from 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)/cholesterol and DMPC/25-OH' have ...
Costello Alison L - - 2010
The effect of cholesterol (5-40mol%) on the magnetic induced orientation of sphingomyelin/cholesterol multilamellar vesicles (MLVs) was examined using static solid state (31)P NMR spectroscopy. The orientation was modeled assuming an ellipsoidal deformation of the vesicles and was monitored as a function of cholesterol concentration and temperature. In addition, the static ...
Lye H-S - - 2010
Fifteen strains of Lactobacillus and Bifidobacterium were screened based on their ability to adhere to hydrocarbons via the determination of cellular hydrophobicity. Lactobacillus acidophilus ATCC 314, L. acidophilus FTCC 0291, Lactobacillus bulgaricus FTCC 0411, L. bulgaricus FTDC 1311, and L. casei ATCC 393 showed greater hydrophobicity and, thus, were selected ...
Wang Nan - - 2010
Changes in cellular cholesterol can affect exocytosis, but the influence of cholesterol in fusion pore kinetics is unclear. Using carbon fiber amperometry, we monitored quantal catecholamine release from rat chromaffin cells. To bypass any possible effect of cholesterol perturbation on ion channels or the colocalization of voltage-gated Ca(2+) channels with ...
Kölsch Heike - - 2010
Cerebral and extracerebral cholesterol metabolism are altered in Alzheimer's disease (AD) as indicated by reduced plasma levels of the cholesterol elimination products 24S-hydroxycholesterol, which is of cerebral origin, and of 27-hydroxycholesterol, which is formed extracerebrally. However, it has to be evaluated, if changes of cholesterol metabolism in the whole body ...
Ivankin Andrey A Center for Molecular Study of Condensed Soft Matter (muCoSM), and Division of Physics, BCPS Department, Illinois Institute of Technology, Chicago, Illinois 60616, - - 2010
We report a structural study of cholesterol-DPPC (1,2-dipalmitoyl-sn-glycero-3-phophocholine) monolayers using x-ray reflectivity and grazing incidence x-ray diffraction. Reflectivity reveals that the vertical position of cholesterol relative to phospholipids strongly depends on its mole fraction (chi(CHOL)). Moreover, we find that at a broad range of chi(CHOL) cholesterol and DPPC form alloylike ...
Tada Satoshi - - 2010
BACKGROUND: We have previously reported an ultrasensitive fluorometric assay for measuring cellular cholesterol. Although this technique is reliable, the use of the assay has limitations due to the requirement for special equipment. It is therefore difficult to apply this assay for the routine determination of cellular cholesterol. METHODS: A colorimetric ...
Chaudhari Priti N - - 2010
Cholesterol oxidase activity was studied during biotransformation of cholesterol to androsta-1,4-diene-3,17-dione (ADD) by Chryseobacterium gleum. Spent LB media, containing cholesterol (3 mM approximately = 1 g l(-1)) where the bacterium was grown for 24 h, at 30 degrees C with constant shaking at 120 rpm, had the highest enzyme activity ...
Dai Jian - - 2010
The instability of cholesterol clusters and the Umbrella effect of cholesterol in dipalmitoylphosphatidylcholine (DPPC) and dioleoylphosphatidylcholine (DOPC) lipid bilayers were investigated via atomistic molecular dynamics (MD) simulation. Cholesterol clusters in phosphatidylcholine (PC) bilayers are found to be very unstable and to readily disperse into cholesterol monomers. This instability results from ...
Pucker Andrew D AD Ohio State University, Columbus, Ohio 43218-2342, - - 2010
The purpose of this work was to develop an enzymatic method of quantification of cholesterol and cholesterol esters derived from contact lenses, both in vitro and ex vivo. Lotrafilcon B (O2 Optix; CIBA Vision, Inc., Duluth, GA) and galyfilcon A (Acuvue Advance; Vistakon, Inc., Jacksonville, FL) silicone hydrogel contact lenses ...
Tierney Elaine - - 2010
Smith-Lemli-Opitz syndrome (SLOS) is an inborn error of cholesterol synthesis due to mutations of 7-dehydrocholesterol reductase (DHCR7). DHCR7 catalyzes the reduction of 7-dehydrocholesterol (7DHC) to yield cholesterol in the final step of cholesterol biosynthesis. Phenotypically patients with SLOS have multiple malformations, cognitive deficits, and behavioral difficulties. Impaired DHCR7 activity results ...
Harris J Robin - - 2010
Apart from the thiol-specific/cholesterol-dependent cytolysin family of toxins (see Chapter 20) there are a number of other unrelated bacterial toxins that also have an affinity for plasma membrane cholesterol. Emphasis is given here on the Vibrio cholerae cytolysin (VCC) and the cytolysins from related Vibrio species. The inhibition of the ...
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, ...
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