Search results for "choline"
showing 10 items of 1138 documents
Vibrio cholerae cytolysin: assembly and membrane insertion of the oligomeric pore are tightly linked and are not detectably restricted by membrane fl…
2000
AbstractHemolytic strains of Vibrio cholerae secrete a cytolysin that, upon binding as a monomer, forms pentameric pores in animal cell membranes. Pore formation is inhibited at low temperature and in the absence of cholesterol. We here posed the following questions: firstly, can oligomerization be observed in the absence of pore formation? Secondly, is membrane fluidity responsible for the effect of temperature or of cholesterol upon pore formation? The first issue was approached by chemical cross-linking, by electrophoretic heteromer analysis, and by electron microscopy. None of these methods yielded any evidence of a non-lytic pre-pore oligomer. The second question was addressed by the u…
Time-resolved fluorescence and fourier transform infrared spectroscopic investigations of lateral packing defects and superlattice domains in composi…
2003
Time-resolved fluorescence and Fourier transform infrared spectroscopies were used to investigate the lateral organization of lipids in compositionally uniform and fully equilibrated 1-palmitoyl-2-oleoyl-phosphatidylcholine/cholesterol (POPC/CHOL) liposomes prepared by a recently devised low-temperature trapping method. Independent fluorescence decay lifetime and rotational dynamics parameters of diphenylhexatriene (DPH) chain-labeled phosphatidylcholine (DPH-PC) in these liposomes were recovered from the time-resolved fluorescence measurements as a function of cholesterol molar fraction (X(CHOL)) at 23 degrees C. The results indicate significantly greater lifetime heterogeneity, shorter av…
A New Dosimeter Methacholine Challenge Protocol Based On A Single Methacholine Concentration
2010
On the Electrostatic Component of the Adhesional Interaction between Solid Substrates and Langmuir Monolayers
1991
The work of adhesion between Langmuir monolayers and solid surfaces in a hydrophilic Langmuir-Blodgett configuration has been measured as function of the surface charge densities σ of the contacting surfaces. It was derived from the equilibrium meniscus height which was measured with the transfer fluorescence microscope. The surface charge density of the contacting surfaces was varied by changing the subphase pH. With both surfaces negatively charged (dimyristoylphosphatidylethanolamine onto SiO2-substrates) and low charge densities (σ < 1 e−/100 A2)) we observe a decrease of the adhesion with increasing charge density. At high charge densities (dimyristoylphosphatidic acid onto SiO2-substr…
Pharmacokinetics of oligodeoxynucleotides encapsulated in liposomes: effect of lipid composition and preparation method
2000
1. The effect of the method employed to prepare liposomes and their lipid composition were evaluated in terms of the encapsulation efficiency and pharmacokinetic features of two oligodeoxynucleotides of a 21 mer: the normal (N-Odn) and the phosphorothioate (S-Odn) oligodeoxynucleotide. 2. Liposomes were prepared by the classical method of multilamellar vesicles (MV) and by the dehydration-rehydration method (DR). Two lipid mixtures were used to prepare liposomes--the predominant lipid being phosphatidylcholine (PC) and sphingomyelin (SM) respectively. 3. The DR method for liposome preparation provided the highest encapsulation efficiency, regardless of liposome lipid composition and the typ…
Acute renal failure and liver dysfunction after subcutaneous injection of 3-sn-phosphatidylcholine (Lipostabil®)-case report.
2011
INTRODUCTION Drug-induced tubulointerstitial nephritis and acute tubular necrosis are common, and are often caused by drugs especially antibiotics or non-steroidal anti-inflammatory drugs. Drug-induced liver dysfunction and renal failure after subcutaneous injection of phosphatidylcholine was not reported so far. 3-sn-Phosphatidylcholine has been described as a cell lysis reaction-inducing drug. Its in vitro data indicated a relevant toxicity potential. In particular human cell types such as fibroblast-like preadipocytes, vascular and skeletal muscle cells, or renal epithelial cells react more sensitive than other human cell types. CASE REPORT We present a 28-year-old woman who received 3.5…
Rapamycin-Loaded Polymeric Nanoparticles as an Advanced Formulation for Macrophage Targeting in Atherosclerosis
2021
Recently, rapamycin (Rapa) represents a potential drug treatment to induce regression of atherosclerotic plaques
Effects of Some Directly-Acting Smooth Muscle Relaxant Drugs on Isolated Human Preparations of the Upper Urinary Tract
1985
It is generally assumed that drugs which induce relaxation of smooth muscles may be of clinical importance in some urological disorders; such drugs are indeed widely used, for example in the therapy of unstable bladders or to facilitate the passage of ureteral stones. Antispasmodic action may be classified in neurotropic and musculo-tropic action; the former acting on the autonomic nervous system and the latter directly on smooth muscle cells. Examples for the first type of action are anticholinergic drugs or alpha-adrenoceptor-antagonists, whereas papaverine is a classic drug with the second type of action.
Pharmacokinetic rationale for switching from donepezil to galantamine.
2001
Galantamine, the most recently approved acetylcholinesterase inhibitor (AChEI) for use in the United States, has allosteric modulating activity at nicotinic receptors and inhibits acetylcholinesterase. This dual mechanism of action may make galantamine an attractive option for patients with Alzheimer's disease who have not benefited from their current therapy; thus, methods for switching patients from donepezil or rivastigmine to galantamine are needed. Protocols for switching patients from one AChEI to another must consider both the time required for washout of the first drug and the rate of dose escalation of the second drug. Both issues depend on the pharmacodynamics, pharmacokinetics, a…