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Results 201 - 250 of 2113
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Bera Tanmay - - 2012
The concentration level of bile acids is a clinical biomarker for the diagnosis of intestinal diseases because individuals suffering from intestinal diseases have a sharply increased concentration of bile acids at micromolar levels. Here, we report the detection of lithocholic acid (LCA) in aqueous solution by using surfactant-stabilized 4-n-pentyl-4'-cyanobiphenyl (5CB) ...
Hu Guohua - - 2012
The objective of this study was to investigate the possibility of using hemicellulose from rice bran to scavenge cholesterol and bile acid in vitro study. This paper demonstrates that rice bran hemicellulose A (RBHA), rice bran hemicellulose B (RBHB) and rice bran hemicellulose C (RBHC) have the potential for binding ...
Gomez-Mendoza Miguel - - 2012
Bile acids (BAs) are a family of natural steroids biosynthesized from cholesterol in the liver that tend to form aggregates in solution. A fluorescent derivative of cholic acid, namely 3-Dns-ChA, was employed as a reporter to establish the speciation diagrams of the most abundant BAs that can be found mainly ...
Stanimirov B - - 2012
In addition to their well-established role in the digestion and absorption of dietary lipids, bile acids (BAs) are recognized as signalling molecules in a wide range of metabolic processes. Bile acids regulate their own metabolism and enterohepatic circulation by activating the farnesoid X receptor (FXR). BAs have been shown to ...
Seki Yoshitaka - - 2012
BACKGROUND AND AIMS: In two Japanese infants with neonatal cholestasis, 3-oxo-Δ(4)-steroid 5β-reductase deficiency was diagnosed based on mutations of the SRD5B1 gene. Unusual bile acids such as elevated 3-oxo-Δ(4) bile acids were detected in their serum and urine by gas chromatography-mass spectrometry. We studied effects of oral chenodeoxycholic acid treatment. ...
Abu-Hayyeh Shadi - - 2012
Bile acids have been traditionally thought of as having an important role in fat emulsification. It is now emerging that they act as important signalling molecules that not only autoregulate their own synthesis but also influence lipid and glucose metabolism. Although, the mechanisms that underlie the regulation of bile acid ...
Hirsova Petra - - 2012
Epigallocatechin gallate (EGCG) has been shown to be protective in various experimental models of liver injury, although opposite effects have also been reported. Since its effect on biliary physiology has not been thoroughly investigated, the present study evaluated effect of EGCG on bile flow and bile acid homeostasis in rats. ...
Cheng Jie J Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, - - 2013
Isoniazid is the first-line medication in the prevention and treatment of tuberculosis. Isoniazid is known to have a biphasic effect on the inhibition-induction of CYP2E1 and is also considered to be involved in isoniazid-induced hepatotoxicity. However, the full extent and mechanism of involvement of CYP2E1 in isoniazid-induced hepatotoxicity remain to ...
Henkel Anne S AS Division of Hepatology, Department of Medicine, Northwestern University, Chicago, Illinois, USA. - - 2013
The bile salt export pump, encoded by ABCB11, is the predominant canalicular transport protein for biliary bile acid secretion. The level of ABCB11 expression in humans is widely variable yet the impact of this variability on human disease is not well defined. We aim to determine the effect of hepatic ...
Reese Vanessa C - - 2013
In the human hepatoma cell line HepG2, retinoic acid, clofibric acid, and bile acid treatment can only modestly increase hepatitis B virus (HBV) biosynthesis. Utilizing the human embryonic kidney cell line 293T, it was possible to demonstrate that the retinoid X receptor α (RXRα) plus its ligand can support viral ...
Travaglini Leana - - 2012
An amino acid-substituted bile acid forms tubular aggregates with inner and outer diameters of about 3 and 6 nm. The diameters are unusually small for surfactant self-assembled tubes. The results enhance the spectrum of applications of supramolecular tubules and open up possibilities for investigating a novel class of biological amphiphiles.
Bhowmik Salil Kumar - - 2012
To characterize the impact of gut microbiota on host bile acid metabolism, we investigated the metabolic profiles of oxysterols and bile acids (BAs) in a conventional rat model (SD) (n=5) and its pseudo germ-free (GF) equivalent (n=5). GF rats were developed by the oral administration of bacitracin, neomycin and streptomycin ...
Griffin LaToya M LM Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, - - 2013
Inhibition of the bile salt export pump (BSEP) can cause intracellular accumulation of bile acids and is a risk factor for drug-induced liver injury in humans. Antiretroviral protease inhibitors lopinavir (LPV) and ritonavir (RTV) are reported BSEP inhibitors. However, the consequences of LPV and RTV, alone and combined (LPV/r), on ...
Magnusson Maria - - 2012
OBJECTIVE: To examine whether there is an association between bile acids and coagulation factors in children with chronic liver disease. METHODS: Forty-five patients (age 2.8 months-18.8 years) were included in this cross-sectional observational study carried out at a single tertiary referral center. Coagulation factors, prothrombin time, albumin, and total fasting ...
Ali Mahmoud S - - 2012
OBJECTIVES/HYPOTHESIS: To assess if, as previously reported in the literature, bile acids inhibit pepsin activity, resulting in pepsin having a less important role in laryngopharyngeal damage in reflux disease. STUDY DESIGN: Prospective translational research study. METHODS: A total of 78 patient's fasting gastric juice samples were obtained from routine endoscopy. ...
Wiemuth Dominik - - 2012
Bile acid-sensitive ion channel (BASIC) is a member of the DEG/ENaC gene family of unknown function. Rat BASIC (rBASIC) is inactive at rest. We have recently shown that cholangiocytes, the epithelial cells lining the bile ducts, are the main site of BASIC expression in the liver and identified bile acids, ...
Pavlović Nebojša - - 2012
The use of probiotics, alone or in interaction with bile acids, is a modern strategy in the prevention and treatment of hypercholesterolemia. Numerous mechanisms for hypocholesterolemic effect of probiotics have been hypothesized, based mostly on in vitro evidence. Interaction with bile acids through reaction of deconjugation catalyzed by bile salt ...
Gonzalez Frank J - - 2012
Enterohepatic circulation is responsible for the capture of bile acids and other steroids produced or metabolized in the liver and secreted to the intestine, for reabsorption back into the circulation and transport back to the liver. Bile acids are secreted from the liver in the form of mixed micelles that ...
Woolbright Benjamin L BL Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, United - - 2012
Cholestasis results in a buildup of bile acids in serum and in hepatocytes. Early studies into the mechanisms of cholestatic liver injury strongly implicated bile acid-induced apoptosis as the major cause of hepatocellular injury. Recent work has focused both on the role of bile acids in cell signaling as well ...
Hagey Lee R - - 2012
A key intermediate in the biosynthetic pathway by which C(24) bile acids are formed from cholesterol has long been considered to be varanic acid, (24ξ,25ξ)-3α,7α,12α-24-tetrahydroxy-5β-cholestan-27-oic acid. The (24R,25R)-epimer of this tetrahydroxy bile acid, in the form of its taurine N-acyl amidate, was thought to be the major biliary bile acid ...
Chen Yingjie Y Clinical Laboratory, The Second Hospital of Shandong University, Jinan, - - 2013
In this study we have developed a rapid method for the shotgun analysis of bile acids in intestinal fluid. The method is semi-quantitative, and requires little sample preparation. Bile salts might contribute to the pathogenesis of Crohn's disease. In a pilot study we demonstrate the method by analysing the bile ...
Poupon Raoul - - 2012
Chronic cholestasis and liver inflammation are the two main pathophysiological components of the two major classes of disease - primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) - leading to bile duct destruction and ultimately to cirrhosis and liver failure. Ursodeoxycholic acid (UDCA), initially introduced as a therapeutic approach ...
Corpechot Christophe - - 2012
The dihydroxylated bile acid ursodeoxycholic acid (UDCA) has now been regarded for 20 years as the standard treatment for primary biliary cirrhosis (PBC), a chronic cholestatic immune-mediated condition marked by progressive destruction of small intrahepatic bile ducts, impaired biliary secretion, hepatocellular retention of toxic endogenous bile acids and, ultimately, the ...
Crawford Robert W - - 2012
Intestinal inflammation changes the luminal habitat for microbes through mechanisms that have not been fully resolved. We noticed that the FepE regulator of very long O-antigen chain assembly in the enteric pathogen Salmonella enterica serotype Typhimurium (S. Typhimurium) conferred a luminal fitness advantage in the mouse colitis model. However, a ...
Le Devedec Frantz - - 2012
Bile acids are amphiphilic endogenous steroids that act as anionic surfactants in the digestive tract and aggregate in aqueous solutions. Non-ionic surfactants were synthesized by grafting oligo(ethylene glycol) chains of various lengths (pegylation) to three bile acids (lithocholic, deoxycholic, and cholic acid) using anionic polymerization. The aggregation properties of the ...
Toshima Naoko - - 2012
Like mammals, insects need to ingest proteins from foods because they cannot synthesise several amino acids. Amino acids are also essential nutrients for Drosophila melanogaster, especially for female egg production, but how flies detect amino acids and how the feeding response to amino acids is regulated are unknown. In this ...
Pappalardo Andrea - - 2012
A pair of diastereomeric salen cavitands and their uranyl complexes combine a chiral (R,R) salen bridge, and an inherent chiral tris-bridged quinoxaline cup within the same molecule. Whereas the free ligands show a preference for the same enantiomer of an alpha-amino acid pair, the corresponding UO2 complexes display opposite enantiodiscrimination ...
Borkar Prashant - - 2012
Novel synergistic effects between Lewis and Brønsted acids in Prins cyclization are reported. Non-reactive Lewis acids and non-reactive Brønsted acids, which failed to perform Prins cyclization when used alone, have shown remarkable synergistic effects when used in combination to perform the reaction successfully.
Sardella Roccaldo - - 2012
The employment of the flow N-acyl amidation of natural bile acids (BAs) required the in-line connection with suitable analytical tools enabling the determination of reaction yields as well as of the purity grade of the synthesized glyco- and tauro-conjugated derivatives. In this framework, a unique HPLC method was successfully established ...
O'Reilly Elaine - - 2012
Conformationally restricted amino acids are important components in peptidomimetics and drug design. Herein, we describe the synthesis of a novel, non-proteinogenic constrained delta amino acid containing a cyclobutane ring, cis-3(aminomethyl)cyclobutane carboxylic acid (ACCA). The synthesis of the target amino acid was achieved in seven steps, with the key reaction being ...
Fukuhara Gaku - - 2012
A new cyclodextrin-polythiophene conjugate (CDPT) has been prepared by attaching permethyl-α-cyclodextrins to polythiophene (PT) through a hexamethylene tether. Circular dichroism spectral examination of CDPT revealed that only a weak positive Cotton effect (Δε=0.1 M(-1)  cm(-1) ) was induced at the main band of the PT in dimethyl sulfoxide and similarly weak ...
Ishida Naoki - - 2012
Chiral dehydropiperidinones were synthesized in enantiopure form from α-amino acids and alkynes via azetidin-3-ones.
Bai Wen-Ju WJ Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, - - 2012
A general method to construct 3-methyl-4-O-methylated tetramic acids displaying a C-5 stereocenter is presented. The synthetic sequence employs a SmI(2)-mediated cyclization, whereby the chirality of the emerging tetramic acid core is retained from the starting chiral amino acid. Application to palau'imide is discussed.
Ohmori Taketo - - 2012
The effect of alkali treatment on the isomerization of amino acids was investigated. The 100×D/(D+L) values of amino acids from peptide increased with increase in the number of constituent amino acid residues. Furthermore, the N-terminal amino acid of a dipeptide was isomerized to a greater extent than the C-terminal residue.
Ilisz István - - 2012
Amino acids are essential for life, and have many functions in metabolism. One particularly important function is to serve as the building blocks of peptides and proteins, giving rise complex three dimensional structures through disulfide bonds or crosslinked amino acids. Peptides are frequently cyclic and contain proteinogenic as well as ...
Podwysocka D - - 2012
β-Amino acids containing α,β-hybrid peptides show great potential as peptidomimetics. In this paper, we describe the synthesis and affinity to μ-opioid and δ-opioid receptors of α,β-hybrids, analogs of the tetrapeptide Tyr- d-Ala-Phe-Phe-NH(2) (TAPP). Each amino acid was replaced with an l- or d-β(3) -h-amino acid. All α,β-hybrids of TAPP analogs ...
Zheng Huajun - - 2012
The amino acid biosynthesis pathway and proteolytic system of Lactobacillus delbrueckii subsp. bulgaricus 2038 (L. bulgaricus 2038), a mainstay of large-scale yogurt production, were modeled based on its genomic sequence. L. bulgaricus 2038 retains more potential for amino acid synthesis and a more powerful proteolytic system than other L. bulgaricus ...
Chen Jianian - - 2012
Dual- and multi-functional drug delivery systems, especially ligand-modified nanoparticles (NPs) loaded with chemotherapeutic agents are paid much attention to due to their excellent behavior in vitro and in vivo. Bifunctional NPs (BF-NPs), which were based on PLGA-PEG and modified with folic acid and cell penetrating peptide R(7) simultaneously, were developed. ...
Robal Terje - - 2012
Angiopoietin-like protein 4 (Angptl4), a potent regulator of plasma triglyceride metabolism, binds to lipoprotein lipase (LPL) through its N-terminal coiled-coil domain (ccd-Angptl4) inducing dissociation of the dimeric enzyme to inactive monomers. In this study, we demonstrate that fatty acids reduce the inactivation of LPL by Angptl4. This was the case ...
Voortman Trudy - - 2012
Gastrointestinal (GI) peptide hormones play an important role in short-term regulation of food intake and blood glucose levels. Modulating their release is of potential relevance for weight management and possibly diabetes. As currently available models are hard to extrapolate to the human situation, we investigated the use of porcine intestinal ...
Boone Tyler J - - 2012
Phosphoglycerate kinase (PGK), present on the surface of group B streptococcus (GBS), has previously been demonstrated to bind the host proteins actin and plasminogen. The actin and plasminogen binding sites of GBS-PGK were identified using truncated GBS-PGK molecules, followed by peptide mapping. These experiments identified two actin and plasminogen binding ...
Calder Philip C - - 2012
Atherosclerosis has an important inflammatory component and acute cardiovascular events can be initiated by inflammatory processes occurring in advanced plaques. Fatty acids influence inflammation through a variety of mechanisms; many of these are mediated by, or associated with, the fatty acid composition of cell membranes. Human inflammatory cells are typically ...
Wernisch Stefanie - - 2012
The intramolecular distances of anion and cation exchanger sites of zwitterionic chiral stationary phases represent potential tuning sites for enantiomer selectivity. In this contribution, we investigate the influence of alkanesulfonic acid chain length and flexibility on enantiomer separations of chiral acids, bases, and amphoteric molecules for six Cinchona alkaloid-based chiral ...
Pitteloud Jean-Philippe - - 2012
A simple and efficient one-pot procedure that enables rapid access to orthogonally protected N,N'-diaminoalkylated basic amino acid building blocks fully compatible with standard Boc and Fmoc solid-phase peptide synthesis is reported. Described synthetic approach includes double reductive alkylation of N (α)-protected diamino acids with N-protected amino aldehydes in the presence ...
Islam Mohammad Monirul - - 2012
Protein solubility is usually characterized in terms of a hydrophobicity scale, which refers to the free energy of transfer of a molecule from an aqueous to a nonpolar solution and is not a "solubility propensity scale" per se. Using a "host-guest" approach, we measured the effects of short poly-amino-acid tags ...
Brown Alaina M AM Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, - - 2012
Type II polyproline helices (PPII) are a fundamental secondary structure of proteins, common in globular and nonglobular regions and important in cellular signaling. We developed a propensity scale for PPII using a host-guest system with sequence Ac-GPPXPPGY-NH(2), where X represents any amino acid. We found that proline has the highest ...
Yamamoto Tetsuya - - 2012
The palladium-catalyzed cross-coupling of chlorotrifluoroethylene and arylboronic acids proceeds in the presence of a base and H(2)O to provide α,β,β-trifluorostyrene derivatives in satisfactory yields.
Bergfeld Anne K - - 2012
The outermost positions of mammalian cell-surface glycans are predominantly occupied by the sialic acids N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc). To date, hydroxylation of CMP-Neu5Ac resulting in the conversion into CMP-Neu5Gc is the only known enzymatic reaction in mammals to synthesize a monosaccharide carrying an N-glycolyl group. In our ...
Pellegrino Sara - - 2012
A very efficient synthesis of orthogonally protected 1H-azepine-4-amino-4-carboxylic acid, abbreviated as Azn, a conformationally restricted analogue of ornithine, was realized. It was obtained on a gram scale in good overall yield in five steps, three of which did not require isolation of the intermediates, starting from the readily available 1-amino-4-oxo-cyclohexane-4-carboxylic ...
Louwagie Mathilde - - 2012
Accurate quantification of pure peptides and proteins is essential for biotechnology, clinical chemistry, proteomics and systems biology. The reference method to quantify peptides and proteins is amino acid analysis (AAA). This consists in an acidic hydrolysis followed by chromatographic separation and spectrophotometric detection of amino acids. Although widely used, this ...
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