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Results 451 - 500 of 1750
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Schweigert Florian J - - 2002
Retinoids are important signalling molecules in the development of limbs and in the determination of the anterior-posterior orientation of the embryo. The present study examined the content and distribution of retinoic acid, retinol and retinyl esters in porcine embryos during early gestation (gestation days 22-30) macroscopically and microscopically by its ...
Chithalen James V - - 2002
Two mammalian hCYP26A expression systems have been used to analyze the metabolic products of CYP26A. Through the use of extensive HPLC, UV spectroscopy, and liquid chromatography/tandem mass spectrometry (LC-MS/MS) methodology, we have conclusively demonstrated that the complex mixture of products comprises 4-OH-all-trans-retinoic acid, 4-oxo-all-trans-retinoic acid, and 18-OH-all-trans-retinoic acid, and more ...
Muller Patrick - - 2002
All-trans-retinoic acid has been shown to have an antiproliferative effect in the estrogen receptor alpha-positive breast cancer cell line MCF-7. The mechanism of this effect is not well understood. We have previously shown that 17beta-estradiol down-regulates the basic helix-loop-helix factor Hairy and Enhancer of Split homologue-1 in MCF-7 and T47D ...
Niwa Tatsuya - - 2002
(+/-)-5,5'-Dimethoxysesamin, erythrinasinate, indole-3-carbaldehyde, (7R,8S)-dihydrodehydrodiconiferyl alcohol 9-O-beta-D-glucopyranoside, cis- and trans-N-(p-coumaroyl)serotonin, serotonin, 3,4-dihydroxybenzoic acid, and 3,4-dihydroxybenzaldehyde have been found in tobiko, a food by-product, and evaluation of their peroxynitrite scavenging activities has been done. Among these compounds, serotonin, trans-N-(p-coumaroyl)serotonin, 3,4-dihydroxybenzaldehyde, and 3,4-dihydroxybenzoic acid showed stronger activities than that of BHT (butylated hydroxytoluene) ...
Watanabe Motoko - - 2002
Mycobacterial alpha-, methoxy- and keto-mycolic acid methyl esters were separated by argentation chromatography into mycolates with no double bond, with one trans double bond or with one cis double bond. Meromycolic acids were prepared from each methyl mycolate fraction by pyrolysis, followed by silver oxide oxidation, and analysed by high-energy ...
Wang Lan - - 2002
Retinoic acid decreases collagen production by hepatic stellate cells. This study investigated the effects of retinoic acid receptor beta (RARbeta) and retinoid X receptor alpha (RXRalpha) on the regulation of the alpha(2)(I) collagen promoter. Retinoic acid and the RARbeta and RXRalpha expression vectors suppressed the promoter in transfected stellate cells ...
Nilsson Charlotte B - - 2002
This review summarizes the available data on the effects of dioxins on retinoid levels, retinoid-related enzyme activities, and toxicological endpoints that have been correlated to retinoid effects. Similarities between dioxin toxicity and retinoid deficiency as well as retinoid excess are pointed out. Several possible levels of interaction between the dioxin ...
McMullen Mary H - - 2002
Glycine N-methyltransferase (GNMT) is a key protein in the liver that functions to regulate S-adenosylmethionine (SAM) and the SAM/S-adenosylhomocysteine ratio. Significant GNMT expression is also present in the kidney and pancreas. Inappropriate regulation of GNMT may have negative consequences on methyl group and folate metabolism. We have demonstrated that retinoid ...
Belden Tara L - - 2002
Hypercalcemia is a potential dosage-related adverse effect of 13-cis-retinoic acid in patients with neuroblastoma. Severe hypercalcemia requiring dosage reduction has been reported in children receiving 13-cis-retinoic acid 200 mg/m2/day and in those with concurrent renal impairment receiving 160 mg/m2/day. A 12-year-old girl without renal dysfunction, diagnosed with neuroblastoma, developed severe ...
Radominska-Pandya Anna - - 2002
We utilized [20-methyl-(3)H]-9-cis-retinoic acid ([(3)H]9-cis-RA) as a direct photoaffinity probe for the characterization of human recombinant retinoid X receptor beta protein (RXRbeta). The photoaffinity labeling was light- and concentration-dependent, saturable, and protected by unlabeled 9-cis-RA in a concentration-dependent manner, indicating that binding occurred in the RXR retinoid binding site. all-trans-Retinoic ...
Niederreither Karen - - 2002
Retinoic acid, the active derivative of vitamin A (retinol), is a hormonal signaling molecule that acts in developing and adult tissues. The Cyp26a1 (cytochrome p450, 26) protein metabolizes retinoic acid into more polar hydroxylated and oxidized derivatives. Whether some of these derivatives are biologically active metabolites has been debated. Cyp26a1(-/-) ...
Osafune Kenji - - 2002
The earliest form of embryonic kidney, the pronephros, consists of three components: glomus, tubule and duct. Treatment of the undifferentiated animal pole ectoderm of Xenopus laevis with activin A and retinoic acid (RA) induces formation of the pronephric tubule and glomus. In this study, the rate of induction of the ...
Budhu Anuradha S - - 2002
Cellular retinoic acid-binding protein II (CRABP-II) is an intracellular lipid-binding protein that associates with retinoic acid with a subnanomolar affinity. We previously showed that CRABP-II enhances the transcriptional activity of the nuclear receptor with which it shares a common ligand, namely, the retinoic acid receptor (RAR), and we suggested that ...
Arnhold Thomas - - 2002
Previous studies in our laboratory showed a synergistic interaction of synthetic ligands selective for the retinoid receptors RAR and RXR in regard to teratogenic effects produced in mice (M. M. Elmazar et al., 2001, TOXICOL: Appl. Pharmacol. 170, 2-9). In the present study the influence of phytol and phytanic acid ...
Zhuang Run - - 2002
9-cis-Retinoic acid activates retinoid X receptors, which serve as heterodimeric partners with other nuclear hormone receptors, yet the enzymology of its physiological generation remains unclear. Here, we report the identification and molecular/enzymatic characterization of a previously unknown member of the short-chain dehydrogenase/reductase family, CRAD3 (cis-retinoid/androgen dehydrogenase, type 3), which catalyzes ...
Montplaisir Veronique - - 2002
The molecular basis for the specificity of aldehyde dehydrogenases (ALDHs) for retinal, the precursor of the morphogen retinoic acid, is still poorly understood. We have expressed in Escherichia coli both retinal dehydrogenase (RALDH), a cytosolic aldehyde dehydrogenase originally isolated from rat kidney, and the highly homologous phenobarbital-induced aldehyde dehydrogenase (PB-ALDH). ...
Sztrolovics Robert - - 2002
The mechanisms of aggrecan degradation in adult human articular, adult bovine nasal and fetal bovine epiphyseal cartilage in response to either interleukin-1beta (IL-1beta) or retinoic acid were compared using an explant culture system. Bovine nasal cartilage cultured with either IL-1beta or retinoic acid exhibited significant release of glycosaminoglycan (GAG). For ...
Kagechika Hiroyuki - - 2002
Retinoids, all-trans-retinoic acid (1a) and its analogs, act as specific modulators of cellular differentiation and proliferation, through binding to and activating specific nuclear receptors, retinoic acid receptors (RARs) and retinoid X receptors (RXRs). Retinoids have chemotherapeutic roles in dermatology and oncology, but their usefulness is restricted by the high toxicity ...
Kotake-Nara Eiichi - - 2002
Acyclo-retinoic acid, a novel acyclic analogue of all-trans-retinoic acid, has been previously isolated as one of the in vitro oxidation products of lycopene. The effect of acyclo-retinoic acid on the growth of human prostate cancer cells was compared with those of the four retinoids: all-trans-retinoic acid, geranylgeranoic acid, 9-cis-retinoic acid ...
Dawson Marcia I - - 2002
This review presents a historical overview of the discoveries of retinoic acid receptor (RAR) and retinoid X receptor (RXR) class- and subtype-selective synthetic retinoids. These synthetic retinoids are conformationally restricted by having aromatic rings in place of the tetraene bond systems of all-trans- and 9-cis-retinoic acids. Events leading to the ...
Gavalas Anthony - - 2002
The retinoic acid (RA)-dependent mechanisms that orchestrate the development of the hindbrain have been the focus of intense studies over the last decade. A wide range of model systems and experimental approaches have been used to provide important insights into hindbrain patterning. A recent paper could help to unify seemingly ...
Pignatello Michael A - - 2002
The remarkable toxicity of (E)-4-[2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthylenyl)-1-propenyl] benzoic acid (TTNPB) compared to all trans-retinoic acid (tRA) is due to multiple factors, including reduced affinities for cytosolic binding proteins (CRABPs), resistance to metabolism, and prolonged nuclear receptor activation. To further investigate the role of half-life in retinoid toxicity, experiments were performed to determine ...
Moulder John E - - 2002
Studies have shown that angiotensin-converting enzyme inhibitors and an angiotensin II receptor blocker can delay, but cannot reverse, the progression of experimentally induced radiation nephropathy. In an effort to find a method for reversing injury, three agents were tested in a rat model of radiation nephropathy. Pirfenidone (a phenyl-pyridone antifibrotic) ...
Irie Toshiaki - - 2002
Retinoids in the eggs of four teleosts, chum salmon (Oncorhynchus keta), black porgy (Acanthopagrus schlegeli), marbled flounder (Pleuronectes yokohamae), and stingfish (Inimicus japonicus), were analyzed by high performance liquid chromatography. Retinal (RAL1) or both RAL1 and 3,4-didehydroretinal (RAL2) were major or exclusive retinoids in the eggs of every species examined. ...
Barrios-De-Tomasi J - - 2002
Gonadotropins are synthesized and released in different molecular forms. In this article, we present evidence that the glycosylation variants of human pituitary FSH exhibit differential and divergent effects at the target cell level and that less sialylated, short-lived variants may exert significant effects in in vivo conditions. Less acidic/sialylated glycoforms ...
Watabe Hidenori - - 2002
The effects of all-trans retinoic acid on the differentiation and proliferation of immature melanocyte precursors were studied. NCC-melb4 cells are an immortal cloned cell line established from mouse neural crest cells using a single-cell cloning method. These cells were positive for tyrosinase-related protein 1, tyrosinase-related protein 2 and KIT, but ...
Bauer Barry J - - 2002
Small angle neutron scattering (SANS) is used to measure the size and the dispersion of synthetic polymers in matrix-assisted laser desorption/ionization (MALDI) matrixes. Deuterated polystyrene (DPS) and dithranol in tetrahydrofuran were deposited by electrospray onto a substrate for small angle neutron scattering (SANS) measurements. DPS with 6050 and 27,000 g ...
Higaki Shuichi - - 2002
We studied the effects of minocycline on Propionibacterium granulosum. P. granulosum lipase activity was detected from acne lesions. Production of propionic and butyric acids by P. granulosum was well suppressed by all tested media with added minocycline; the higher the concentration of minocycline in the medium, the less of these ...
Berkó Szilvia - - 2002
Our research has a double purpose. On the one hand, doctors have expressed the need to formulate a rectal suppository dosage form from diuretic ethacrynic acid, which would add to the choice of treatment methods and thereby increase the possibilities of individual cure. On the other hand, the liberation and ...
Hermanns J F - - 2002
BACKGROUND: So-called darkened age spots encompass distinct pathological processes. The efficacy of topical depigmenting agents is difficult to objectivate. OBJECTIVE: To assess the hypopigmenting effect of three cosmetic formulations using objective biometrological methods. METHODS: 50 women of South-East Asian ancestry were enrolled in this pilot study. They had solar lentigines ...
Schoff Patrick K - - 2002
A cell line stably transfected with reporter genes activated by retinoic acid was used to test a paper mill effluent for the presence of retinoids or components that interfere with retinoic acid-stimulated gene transcription. No retinoids were detected in effluent or control water. However, effluent water significantly decreased reporter activity ...
Söderlund M Berggren - - 2002
This investigation was undertaken to assess biological variation, especially the within-subject variations of all-trans retinoic acid, 13-cis retinoic acid and retinol in human serum. Diurnal variation and variation over a week, a month and a year were studied in 11 males (aged 21-54 years) and 17 females (aged 22-63 years), ...
Pazos Y - - 2001
The thallium-accelerated Suzuki coupling reaction of tetraenyl iodide 19 and cyclohexenyl boronate 18 afforded ethyl 9-cis-retinoate (12) in high yield. Both coupling partners of the Suzuki reaction are better reacted immediately after generation from their precursors, tetraenylstannane 10 and cyclohexenyl iodide 13. The geometrically homogeneous tetraenylstannane 10, comprising the polyenic ...
Wolf G - - 2001
Retinol is stored in liver in the form of its esters. The retinol-esterifying enzyme lecithin:retinol acyltransferase (LRAT) catalyzes the conversion of retinol into its storage form. Expression of the LRAT mRNA is induced by retinoic acid (RA), or by dietary vitamin A, and is downregulated upon vitamin A depletion. RA ...
Standeven A M - - 2001
Hypertriglyceridemia is a major side-effect of retinoid therapy in humans. We previously reported that agonists for the retinoic acid receptors (RARs), but not the retinoid X receptors (RXRs), elevate serum triglycerides in male Fischer rats, and that, surprisingly, the RAR/RXR pan-agonists 9-cis-retinoic acid and AGN 191659 [(E)-5-[2-(5,6,7,8-tetrahydro-3,5,5,8,8-pentamethyl-2-naphthyl)propen-1-yl]-2-thiophenecarboxylic acid] induce 2- ...
Cuhadaroglu C - - 2001
The retinoic acid derivatives are used for disorders of keratinization such as psoriasis. Acitretin, which is a synthetic, aromatic derivative of retinoic acid, is frequently used to treat psoriasis. The retinoic acid syndrome (RAS), described with all-trans-retinoic acid (ATRA) in patients with promyelocytic leukemia, is characterized by fever and respiratory ...
Hashidoko Y - - 2001
The 4-hydroxycinnamate decarboxylase (4-HCD)-inducing activity of several substrate analogs toward Klebsiella oxytoca was investigated. Four E-cinnamate-class compounds, E-4-hydroxycinnamic acid (1), caffeic acid (2), ferulic acid (3) and E-2,4-dihydroxycinnamic acid (4), all of which were accepted as substrates, all of which were accepted as substrates of 4-HCD, enable K. oxytoca cells ...
Berkovitz B K - - 2001
Retinoic acid is an important signalling molecule in embryological development and continues to be important in the adult animal because it modulates growth and differentiation in many epithelial tissues. The distribution of the enzyme retinaldehyde dehydrogenase-2 (RALDH 2), which is involved in the synthesis of retinoic acid, was studied using ...
Cho C S - - 2001
All trans-retinoic acid (RA)-loaded poly(L-lactic acid) (PLA) nanoparticles coated with galactose-carrying polymer, as hepatocyte-specific targeting material using galactose ligands as recognition signals to asialoglycoprotein receptors were prepared by the diafiltration method. Effects of released RA from its loaded nanoparticles on morphology and DNA synthesis of hepatocytes were studied. Receptor-mediated endocytosis ...
Blaner W S - - 2001
Retinoids (vitamin A and its derivatives) are potent substances for regulating the expression of many different genes within the body. The gene regulatory activities of retinoids are mediated primarily by the all-trans and 9-cis isomers of retinoic acid. Although 13-cis-retinoic acid (isotretinoin) does not have the potent gene regulatory activity ...
Ulven S M - - 2001
Studies using bioassays in normal mice and gene activation in transgenic reporter mice have demonstrated peaks of retinoic acid receptor (RAR) signaling in the brachial and lumbar regions of the spinal cord. Recently, Solomin et al. (Solomin et al. [1998] Nature 395:398-402) detected a retinoid X receptor (RXR) signal in ...
Zhao W L - - 2001
Arsenic trioxide (As2O3) has recently been identified as an effective drug in the treatment of newly diagnosed and relapsed acute promyelocytic leukemia (APL) without cross-resistance to all-trans retinoic acid and achieved complete remission rates of 80-90% according to most reports. With intravenous infusion at a dose of 0.08-0.16 mg/kg daily, ...
Zhu Y K - - 2001
Proteolytic degradation of extracellular matrix is thought to play an important role both in emphysema and in tissue development and repair. Retinoic acid has been suggested to modify tissue injury, and in an animal model of emphysema may induce alveolar repair. Since cytokines can induce matrix metalloproteinase (MMP) production in ...
Kang S - - 2001
Premature skin aging, or photoaging, results largely from repeated exposure to ultraviolet (UV) radiation from the sun. Photoaging is characterized clinically by wrinkles, mottled pigmentation, rough skin, and loss of skin tone; the major histologic alterations lie in dermal connective tissue. In recent years, a great deal of research has ...
Nau H - - 2001
This paper reviews the teratogenicity of isotretinoin in regard to aspects of species variation, toxicokinetics, and metabolism. Particular emphasis is given to the hypothesis that most effects of isotretinoin (13-cis-retinoic acid) are mediated by isomerization to the all-trans-retinoic acid. This mechanism of action would provide a basis for the understanding ...
Kim S Y - - 2001
All-trans-retinoic acid (atRA) is a promising anticancer and antiwrinkle drug. However, its clinical application is limited because it is rapidly metabolized by the induced cytochrome P450 (P450). In this study, farnesol derivatives are proposed as new inhibitors to prevent P450-mediated metabolism. The farnesol derivatives were suc-farnesol and mal-farnesol, which were ...
Lampen A - - 2001
Retinoids are essential for growth and cell differentiation of epithelial tissues. The effects of the food compounds phytol, the phytol metabolite phytanic acid, and the fatty acid docosahexaenoic acid (DHA) on the retinoid signaling pathway in intestinal cells were studied. Phytol inhibited the formation of all-trans-retinoic acid (RA) from dietary ...
Toma E - - 2001
BACKGROUND: An increasing rate of highly-active antiretroviral therapy (HAART)-associated metabolic and morphological abnormalities has been reported in HIV-infected persons. Some of them resemble retinoid-related adverse events, indicating alteration(s) of retinol metabolism or of retinoic acid-mediated signalling. OBJECTIVE: To evaluate retinol levels in patients with or without HAART and to assess ...
Ogata S - - 2001
We have found that niacin-related compounds, particularly picolinic acid, induced apoptosis in human leukemia cells. In this paper, we investigated whether various picolinic acid-related compounds had apoptosis-inducing activities or not. Particularly, fusaric acid, picolinaldehyde, nicotinaldehyde, 2-aminopyridine, and 3-aminopyridine also induced apoptosis in HL-60 cells. These results suggest that pyridine substituted ...
Khalil Z - - 2001
Previous studies using an antibody to cis-urocanic acid and mast-cell-depleted mice implicated both cis-urocanic acid and mast cells in the mechanisms by which ultraviolet B light suppresses systemic contact hypersensitivity responses in mice. In the absence of a direct stimulatory effect of cis-urocanic acid on connective tissue mast cells, an ...
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