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Results 401 - 450 of 3759
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Tsuji Petra A - - 2006
The use of dietary flavonoids as potential chemopreventive agents is a concept of increasing interest. Recent findings indicate that methylated flavones have the advantage of increased metabolic stability. One such compound, the naturally-occurring 5,7-dimethoxyflavone (5,7-DMF), has been shown to be a potential chemopreventive agent in human cancer originating from the ...
Ferdinandusse Sacha - - 2006
Peroxisomes play an important role in the biosynthesis of bile acids because a peroxisomal beta-oxidation step is required for the formation of the mature C24-bile acids from C27-bile acid intermediates. In addition, de novo synthesized bile acids are conjugated within the peroxisome. In this review, we describe the current state ...
Ahmad Shavej - - 2006
Mesalamine (5-aminosalicylic acid) is the drug of choice for the treatment of Crohn's disease. A scheme for the synthesis of 5-aminosalicylic acid (5-ASA) conjugates of dextrans was developed with a focus on Crohn's disease applications. Dextrans were oxidised using sodium periodate (NaIO(4)), where the aldehyde groups formed were coupled with ...
Matsukuma Karen E - - 2006
We discovered a nuclear receptor element in the FAS promoter consisting of an inverted repeat spaced by one nucleotide (IR-1) and located 21 bases downstream of a direct repeat sequenced by 4 nucleotides (DR-4) oxysterol liver X receptor response element. An IR-1 is present in promoters of several genes of ...
Narushima Seiko - - 2006
In humans and animals, intestinal flora is indispensable for bile acid transformation. The goal of our study was to establish gnotobiotic mice with intestinal bacteria of human origin in order to examine the role of intestinal bacteria in the transformation of bile acids in vivo using the technique of gnotobiology. ...
Goto Takaaki - - 2007
We developed a highly sensitive and quantitative method to detect bile acid 3-sulfates in human urine employing liquid chromatography/electrospray ionization-tandem mass spectrometry. This method allows simultaneous analysis of bile acid 3-sulfates, including nonamidated, glycine-, and taurine-conjugated bile acids, cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA), ursodeoxycholic acid (UDCA), ...
Gautrot Julien E - - 2007
Bile acid-based polymers are promising new materials for biomedical applications. The determination of their molar mass, as for other novel polymers, has been difficult, due to the lack of suitable standards for size exclusion chromatography (SEC). In order to solve this problem, a family of main-chain bile acid-based oligo-esters has ...
Jenkins Gareth J S - - 2007
Bile acids are often refluxed into the lower oesophagus and are candidate carcinogens in the development of oesophageal adenocarcinoma. We show here that the secondary bile acid, deoxycholic acid (DCA), is the only one of the commonly refluxed bile acids tested here, to show genotoxicity, in terms of chromosome damage ...
Keely Stephen J - - 2007
Bile acid epimers and side-chain homologues are present in the human colon. To test whether such bile acids possess secretory activity, cultured T84 colonic epithelial cells were used to quantify the secretory properties of synthetic epimers and homologues of deoxycholic acid (DCA) and chenodeoxycholic acid (CDCA). In our study, chloride ...
Ellis Ewa Cristine Siljevik - - 2006
It is known that thyroid hormones alter the bile acid metabolism in humans, however the effect on individual enzymes has been difficult to elucidate. This is mainly due to the lack of human liver cell lines producing bile acids. We used cultures of primary human hepatocytes to study the effects ...
Lee Tzung-Yan - - 2007
The accumulation of hydrophilic bile acids in the liver is considered to play a pivotal role in the induction of hepatic injury. Yin-Chen-Hao-Tang (YCHT) decoction is an aqueous extract from three different herbs: Artemisia capillaries Thunb (Compositae), Gardenia jasminoides Ellis (Rubiaceae), Rheum officinale Baill (Polygonaceae), which has been recognized as ...
Hannemann Frank - - 2007
Cytochromes P450 (P450) are hemoproteins encoded by a superfamily of genes nearly ubiquitously distributed in different organisms from all biological kingdoms. The reactions carried out by P450s are extremely diverse and contribute to the biotransformation of drugs, the bioconversion of xenobiotics, the bioactivation of chemical carcinogens, the biosynthesis of physiologically ...
D'Ovidio F - - 2006
Gastro-esophageal reflux and related pulmonary bile acid aspiration were prospectively investigated as possible contributors to postlung transplant bronchiolitis obliterans syndrome (BOS). We also studied the impact of aspiration on pulmonary surfactant collectin proteins SP-A and SP-D and on surfactant phospholipids--all important components of innate immunity in the lung. Proximal and ...
Schneider Stéphane M - - 2006
Taurine deficiency in patients on long-term parenteral nutrition may be involved in cholestasis. We aimed to assess plasma taurine and tauro-conjugated bile acids in adults with short-bowel syndrome and their response to intravenous taurine. Thirty-two adult patients, who had been on taurine-free parenteral nutrition for a mean of 59 (SE ...
Verreault Mélanie M Molecular Endocrinology and Oncology Research Center, CHUL Research Center and the Faculty of Pharmacy, Laval University, Québec, - - 2006
Glucuronidation, an important bile acid detoxification pathway, is catalyzed by enzymes belonging to the UDP-glucuronosyltransferase (UGT) family. Among UGT enzymes, UGT1A3 is considered the major human enzyme for the hepatic C24-glucuronidation of the primary chenodeoxycholic (CDCA) and secondary lithocholic (LCA) bile acids. We identify UGT1A3 as a positively regulated target ...
Briz Oscar - - 2006
In cholestasis, the accumulation of organic anions in hepatocytes is reduced by transporters (multidrug resistance-associated proteins and OSTalpha-OSTbeta) able to extrude them across the basolateral membrane. Here we investigated whether organic anion-transporting polypeptides (OATPs) may contribute to this function. Xenopus laevis oocytes expressing human carboxylesterase-1 efficiently loaded cholic acid (CA) ...
Paumgartner Gustav - - 2006
Bile secretion is dependent on the coordinated functions of a number of hepatobiliary transport systems. Cholestasis may be caused by an impairment of bile secretion, an obstruction of bile flow or a combination of the two. The common consequence of all forms of cholestasis is retention of bile acids and ...
Sokol Ronald J - - 2006
Cholestatic liver disorders account for a large proportion of chronic liver ailments in adults, children and infants, and are among the leading indications for liver transplantation in all age groups. Recent studies have begun to characterize the cellular and molecular mechanisms of hepatocyte injury caused by the retention of hydrophobic ...
Setchell Kenneth D R - - 2006
Bile acid synthetic defects represent a specific category of metabolic liver disease. This article highlights the history and summarizes our analytical approach to the diagnosis and treatment of genetic defects in bile acid synthesis. By the application of mass spectrometry as a screening tool, it is possible to perform rapid ...
Kandrac J - - 2006
In this article, the methods of isolation and determination of bile acids are reviewed. Methods for separation of bile acids from cattle and pig bile are given in detail. Isolation of a mixture of cholic acid and deoxycholic acids from cattle bile and their subsequent purification are described. The isolation ...
Kuhajda K - - 2006
This article surveys chemical transformations of selected bile acids. Chemical transformations were initially carried out with the aim of determining the structure of bile acids. More recently they have been concerned with bile acid interconversions as well as with the synthesis of steroid hormones, vitamins and therapeutc agents. Studies of ...
Smoum Reem - - 2006
Novel drug delivery vehicles based on the biodegradable, mucoadhesive polysaccharide chitosan covalently linked to a boronic acid protease inhibitor have been prepared and characterized. It was anticipated that these conjugates could protect a proteinaceous drug, such as salmon calcitonin, against proteolysis by serine proteases, an obstacle that prevents its oral ...
Suchy Frederick J - - 2006
Bile acids are the major determinant and driving force for the generation of bile flow. Bile acid transport across the canalicular membrane is primarily an ATP-dependent process. The predominant transporter is the bile salt excretory pump (BSEP, ABCB11), a member of the adenosine triphosphate-binding cassette (ABC) family of transporters. Regulatory ...
Kevresan S - - 2006
The biosynthesis of bile acids in mammalian liver and its regulation, together with the physiological role of bile acids, are reviewed in this article. Bile acids are biosynthesized from cholesterol in hepatocytes. Several steps are involved including epimerisation of the 3beta-hydroxyl group, reduction of the delta4 double bond to the ...
Kuhajda K - - 2006
An overview of the structure and the origin of naturally occurring bile acids is given. Most naturally occurring bile acids belong to the 5beta-series, with hydroxyl groups in the A, B, and C ring of the steroid system. Hydroxyl groups are mostly found at the C3, C6, C7, C12 and ...
Zollner Gernot - - 2006
Recent progress has enhanced our understanding of the pathogenesis of cholestatic liver diseases. Mutations in genes encoding for hepatobiliary transport systems can cause hereditary cholestatic syndromes and exposure to cholestatic agents (drugs, hormones, inflammatory cytokines) can lead to reduced expression and function of hepatic uptake and excretory systems in acquired ...
Bina James E - - 2006
Vibrio cholerae is an important human pathogen that causes the diarrheal disease cholera. Colonization of the human host is dependent upon coordinated expression of several virulence factors in response to as yet unknown environmental cues. Bile acids have been implicated in the in vitro regulation of several V. cholerae genes, ...
Iuliano A - - 2006
Three different bile acid-derived biphenyl phosphites were synthesized, starting from cholic and deoxycholic acids and biphenol, and their stereochemical features were checked by CD and NMR spectroscopies. On the basis of the spectroscopic results, the capability of the cholestanic system to induce a prevalent sense of twist on the biphenyl ...
Balakrishnan Anand - - 2006
The human apical sodium-dependent bile acid transporter (hASBT) is a potential target for drug delivery, but an understanding of hASBT substrate requirements is lacking. The objective of this study was to characterize hASBT interaction with its native substrates, bile acids, and to evaluate C-24 conjugation and steroidal hydroxylation on transport ...
Xia Xuefeng - - 2006
Cholangiocytes are exposed to high concentrations of bile acids at their apical membrane. A selective transporter for bile acids, the Apical Sodium Bile Acid Cotransporter (ASBT) (also referred to as Ibat; gene name Slc10a2) is localized on the cholangiocyte apical membrane. On the basolateral membrane, four transport systems have been ...
Glaser Shannon - - 2006
The objectives of this review are to outline the recent findings related to the morphological heterogeneity of the biliary epithelium and the heterogeneous pathophysiological responses of different sized bile ducts to liver gastrointestinal hormones and peptides and liver injury/toxins with changes in apoptotic, proliferative and secretory activities. The knowledge of ...
Lee R H - - 2006
OBJECTIVE: To establish the prevalence of intrahepatic cholestasis of pregnancy (ICP) in a primarily Latina population in the United States. STUDY DESIGN: Over a period of 16 months, a convenience sample of subjects admitted to labor and delivery in the third trimester was enrolled. Each subject completed a questionnaire rating ...
Mita Sachiko - - 2006
Vectorial transport of bile acids across hepatocytes is a major driving force for bile flow, and bile acid retention in the liver causes hepatotoxicity. The basolateral and apical transporters for bile acids are thought to be targets of drugs that induce cholestasis. Previously, we constructed polarized LLC-PK1 cells that express ...
Gowda G A Nagana - - 2006
Human gallbladder bile dissolved in dimethylsulfoxide provides sharp and resolved signals for major bile components in 1H NMR spectra. Characteristic well-resolved marker signals that invariably appear in 1H NMR spectra of bile were identified for cholesterol (H18 methyl signal at 0.643 ppm), lipids (glycerol CH signal at 5.064 ppm), total ...
Gowda G A Nagana - - 2006
1H and 13C NMR spectra of intact human bile were assigned using one-dimensional (1H and 13C) and two-dimensional (1H-1H and 1H-13C) experiments. Individual conjugated bile acids--glycocholic acid, glycodeoxycholic acid, glycochenodeoxycholic acid, taurocholic acid, taurodeoxycholic acid, and taurochenodeoxycholic acid--were identified. The bile acids were quantified accurately and individually in a single ...
McRae Mary Peace MP School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599-7360, - - 2006
Human immunodeficiency virus-infected patients on antiretroviral drug therapy frequently experience hepatotoxicity, the underlying mechanism of which is poorly understood. Hepatotoxicity from other compounds such as bosentan and troglitazone has been attributed, in part, to inhibition of hepatocyte bile acid excretion. This work tested the hypothesis that antiretroviral drugs modulate hepatic ...
Lampronti Ilaria - - 2006
In this study, we compared some bile acid derivatives and their platinum(II) complexes with respect to their ability to induce erythroid differentiation of human leukemic K562 cells. The complexes analyzed were cis-[(3-dehydrocholanoyliden-L-tartrate)-diammineplatinum(II)] (compound 1) and cis-[di(dehydrocholanoate)-bis(triphenylphosphine)-platinum(II)] (compound 3), together with their free ligands, respectively, 3-dehydrocholanoyliden-L-tartaric acid (compound 2) and dehydrocholanoic ...
Jung Diana - - 2006
The pregnane X receptor (PXR) is an essential component of the body's detoxification system. PXR is activated by a broad spectrum of xenobiotics and endobiotics, including bile acids and their precursors. Bile acids in high concentrations are toxic; therefore, their synthesis is tightly regulated by the farnesoid X receptor, and ...
Duret Guillaume - - 2006
OmpT and OmpU are general diffusion porins of the human intestinal pathogen Vibrio cholerae. The sole presence of OmpT in the outer membrane sensitizes cells to the bile component deoxycholic acid, and the repression of OmpT in the intestine may play an important role in the adaptation of cells to ...
Balakrishnan Anand - - 2006
The human apical sodium-dependent bile acid transporter (hASBT) is a potential target for drug delivery, but an understanding of hASBT substrate requirements is limited. The objective of this study was to evaluate the influence of ionic character and steric bulk in the C-24 region of bile acid conjugates in governing ...
Mennone Albert - - 2006
Mrp4 is a member of the multidrug resistance-associated gene family that is expressed on the basolateral membrane of hepatocytes and undergoes adaptive upregulation in response to cholestatic injury or bile acid feeding. However, the relative importance of Mrp4 in a protective adaptive response to cholestatic injury is not known. To ...
Zollner Gernot - - 2006
Cholestasis results in intrahepatic accumulation of cytotoxic bile acids which cause liver injury ultimately leading to biliary fibrosis and cirrhosis. Cholestatic liver damage is counteracted by a variety of intrinsic hepatoprotective mechanisms. Such defense mechanisms include repression of hepatic bile acid uptake and de novo bile acid synthesis. Furthermore, phase ...
Ferrari Cristina - - 2006
Formyl-peptide receptors (FPRs) belong to the family A of the G-protein coupled receptor superfamily and include three subtypes: FPR, FPR-like-1 and FPR-like-2. They have been involved in the control of many inflammatory processes promoting the recruitment and infiltration of leukocytes in regions of inflammation through the molecular recognition of chemotactic ...
Trottier Jocelyn - - 2006
Bile acids play important functions in the maintenance of bile acid homeostasis. However, due to their detergent properties, these acids are inherently cytotoxic and their accumulation in liver is associated with hepatic disorders such as cholestasis. During their enterohepatic circulation, bile acids undergo several metabolic alterations, including amidation, hydroxylation, sulfonation, ...
Kakiyama Genta - - 2006
By HPLC, a taurine-conjugated bile acid with a retention time different from that of taurocholate was found to be present in the bile of the black-necked swan, Cygnus melanocoryphus. The bile acid was isolated and its structure, established by (1)H and (13)C NMR and mass spectrometry, was that of the ...
Jiang Zhi-Ru - - 2006
AIM: To observe the effects of acid and bile acid exposure on cell proliferation and the expression of extracellular signal-regulated protein kinase (ERK) and peroxisome proliferator-activated receptor gamma (PPARgamma) in normal human esophageal epithelial cells in vitro. METHODS: In vitro cultured normal human esophageal epithelial cells were exposed to acidic ...
Huang Wendong W Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, - - 2006
Liver mass depends on one or more unidentified humoral signals that drive regeneration when liver functional capacity is diminished. Bile acids are important liver products, and their levels are tightly regulated. Here, we identify a role for nuclear receptor-dependent bile acid signaling in normal liver regeneration. Elevated bile acid levels ...
Yamamoto Yukio - - 2006
Estrogens are known to cause hepatotoxicity such as intrahepatic cholestasis in susceptible women during pregnancy, after administration of oral contraceptives, or during postmenopausal replacement therapy. Enterohepatic nuclear receptors including farnesoid X receptor (FXR), pregnane X receptor (PXR), and constitutive active/androstane receptor (CAR) are important in maintaining bile acid homeostasis and ...
Rani Kirti - - 2006
3alpha-Hydroxysteroid dehydrogenase (3alpha-HSD) from Pseudomonas testosteronei and diaphorase (lipoyl dehydrogenase) from Clostridium spp were immobilized individually onto alkylamine glass beads through glutaraldehyde coupling. A cost-effective enzymic colorimetric method for determination of bile acid in the serum and bile was developed employing mixture of the immobilized enzymes. The method was based ...
Hubbard Brian - - 2006
BACKGROUND & AIMS: Fatty Acid Transport Protein 5 (FATP5) is a liver-specific member of the FATP/Slc27 family, which has been shown to exhibit both fatty acid transport and bile acid-CoA ligase activity in vitro. Here, we investigate its role in bile acid metabolism and body weight homeostasis in vivo by ...
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