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Results 701 - 750 of 1771
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Mizuma T - - 1998
Stability of furosemide glucuronide, the major metabolite of furosemide, was studied in order to accurately assess the glucuronidation of furosemide. Furosemide glucuronide was purified by high-performance liquid chromatography, and the mass spectrum of furosemide glucuronide showed the molecular ion peaks [M-H]- at 505 and 507 (m/z). Furosemide glucuronide was photodegraded ...
Fang J Y - - 1998
Induction of apoptosis has been implicated as an anticarcinogenic mechanism of both folic acid and retinoic acid. The ability of retinoic acid or folic acid to induce gastric cancer cell apoptosis was investigated in the human gastric cancer cell lines MKN-45 and MKN-28, and DNA fragmentation was studied in situ ...
Barua A B - - 1998
Retinoids are unstable compounds being readily oxidized and/or isomerized to altered compounds, especially in the presence of oxidants including air, light, and excessive heat. They are labile toward strong acids and solvents that have dissolved oxygen or peroxides. In this review, procedures for handling and storage of retinoids and biological ...
Sinning A R - - 1998
Retinoic acid, the biologically active form of vitamin A, is a critical player in normal development. The concentration of retinoic acid is highly regulated by the embryo to prevent either a deficit or an excess of this molecule, conditions that have been shown to produce cardiac defects that vary depending ...
Papadimou E - - 1998
The effect of two naturally occurring (retinol and all-trans retinoic acid) and two synthetic (isotretinoin and acitretin) analogs of vitamin A (retinoids) on tRNA biogenesis was investigated employing the RNase P of Dictyostelium discoideum as an in vitro experimental system. RNase P is an ubiquitous and essential enzyme that endonucleolytically ...
Randolph R K - - 1998
The accessibility of plasma retinol and retinoic acid to the epidermis may be influenced by the number and metabolic capacity of fibroblasts in papillary dermis. The metabolism of retinol-binding protein-bound all-trans-retinol, and albumin-bound all-trans-retinoic acid, by fibroblasts cultured on plastic dishes or in type I collagen gels, was examined. There ...
Hanson K M - - 1998
The premature photoaging of the skin is mediated by the sensitization of reactive oxygen species after absorption of ultraviolet radiation by endogenous chromophores. Yet identification of UV-A-absorbing chromophores in the skin that quantitatively account for the action spectra of the physiological responses of photoaging has remained elusive. This paper reports ...
Wang X D - - 1998
Chronic ethanol intake may interfere with retinoid signal transduction by inhibiting retinoic acid synthesis and by enhancing activator protein-1 (AP-1) (c-Jun and c-Fos) expression, thereby contributing to malignant transformation. To determine the effect of ethanol on hepatic retinoid levels, retinoic acid receptors (RARs) and AP-1 (c-Jun and c-Fos) gene expression, ...
Bouman H G - - 1998
Stage 34 chicken hearts have shown a spectrum of looping disturbances, changed hemodynamics, and changed growth of both right ventricular myocardium and atrioventricular cushion tissue after retinoic acid treatment. To obtain more information about the onset of the malformations we studied stage 24, the stage between the previously studied stage ...
Hanif R M - - 1998
The tetrahydrogeraniol (THG) derivative, ethyl-(3,7-dimethyl octyl thio) acetate (EDOTA) was prepared by reacting tetrahydrogeranyl bromide (obtained by reaction of 40% hydrobromic acid and concentrated sulfuric acid) with ethyl 2-mercaptoacetate, while 3,7-dimethyl octyl propionate (DOP) was synthesized by a common esterification reaction by reacting THG with propionic acid in the presence ...
Hinman V F - - 1998
In vertebrates, excess all-trans retinoic acid (RA) applied during axis formation leads to the apparent truncation of anterior structures. In this study we sought to determine the type of defects caused by ectopic RA on the development of the ascidian Herdmania curvata. We demonstrate that H. curvata embryos cultured in ...
Kierdorf U - - 1998
Unilateral injection of 10 mg all-trans retinoic acid (in 1 ml of castor oil) into the early pedicle anlage of a male fallow deer resulted in accelerated growth of the cranial appendage, and altered pedicle and first antler shape on the treatment side, whereas pedicle and antler growth on the ...
Falasca L - - 1998
The usefulness of cultured hepatocytes is limited by the gradual loss of their typical physiological functions that occurs in vitro, mainly due to the absence of microenviromental conditions found in vivo. In this study we describe the effect of retinoic acid on the re-establishment of morphological characteristics and on the ...
Makori N - - 1998
Hindbrain and craniofacial development during early organogenesis was studied in normal and retinoic acid-exposed Macaca fascicularis embryos. 13-cis-retinoic acid impaired hindbrain segmentation as evidenced by compression of rhombomeres 1 to 5. Immunolocalization with the Hoxb-1 gene product along with quantitative measurements demonstrated that rhombomere 4 was particularly vulnerable to size ...
Lappin M B - - 1998
Exposure to UVB results in the isomerization of trans-urocanic acid (UCA), localized in the stratum corneum, to cis-UCA. Cis-UCA can mediate at least some of the immunosuppressive effects of UVB, though the mechanism of cis-UCA action remains incompletely defined. Here, we review the evidence that cis-UCA acts through alterations in ...
Hug D H - - 1998
Irradiation of skin by sunlight or ultraviolet B (UVB, 290-320 nm) brings about a downregulation of cell-mediated immunity. An action spectrum for photoimmune suppression in mice indicates that trans-urocanic acid absorbs UV photons and is isomerized to the cis-isomer in the stratum corneum. Cis-urocanic acid is subsequently shown to suppress ...
Ju B G - - 1998
In the regenerating urodele limb, catheptic activity has been known to be present in the stump tissue undergoing histolysis, and it has been implicated in the modification of some intracellular and extracellular matrix molecules. In this study, we compared spatial and temporal gene expression profiles of cathepsin D in normal, ...
Chatellard-Gruaz D - - 1998
Keratinocytes differentiating in vitro exhibit greater cytosolic capacity for retinoic acid synthesis from retinol or retinaldehyde as compared to nondifferentiated cells (Siegenthaler et al. 1990. Biochem. J. 268: 371-378), and increased expression of CRABP-II (Siegenthaler et al. 1988. Exp. Cell Res. 178: 114-126). Based on these observations, the content and ...
Conlon B J - - 1998
OBJECTIVE: To determine whether concurrent intravenous administration of the loop diuretic ethacrynic acid potentiates the toxicity of the aminoglycoside antibiotic gentamicin applied topically on the round window. STUDY DESIGN: The authors studied the effects on cochlear sensitivity of co-administered intracardiac ethacrynic acid (40 mg/kg) and high-dose topical gentamicin solution (100%) ...
Son J S - - 1998
The role of jasmonic acid was studied in biotransformation of (--)-isopiperitenone to (--)-7-hydroxyisopiperitenone using alpha suspension cells were treated with (--)-isopiperitenone, mRNA of a cytochrome P450 was induced in a similar time-course pattern as the biotransformation shown in a previous study (Park et al., 1997). The induction of P450 mRNA ...
Rolin S - - 1998
In vitro differentiation of Trypanosoma brucei from the bloodstream to the procyclic form is efficiently induced by the combination of cold shock from 37 to 27 degrees C and the addition of citrate/cis-aconitate (CCA) to the incubation medium. Here it is reported that exposure of pleomorphic bloodstream trypanosomes to mild ...
Zhang Q Y - - 1998
The sites of expression in the small intestine and the function of CYP2J4, a recently identified rat cytochrome (P450) isoform found to be predominantly expressed in the small intestine, were characterized. Immunoblot analysis with a polyclonal antibody to heterologously expressed CYP2J4 revealed that expression of CYP2J4 was at the highest ...
Muccio D D - - 1998
We recently synthesized several conformationally constrained retinoic acid (RA) analogues [8-(2'-cyclohexen-1'-ylidene)-3, 7-dimethyl-2,4,6-octatrienoic acids with different alkyl substituents at 2' (R1) and 3' (R2) positions on the cyclohexene ring] (Muccio et al. J. Med. Chem. 1996, 39, 3625) as cancer chemopreventive agents. UAB8 (R1 = Et; R2 = iPr), which contains ...
Jugert F K - - 1998
Vitamin D and vitamin A acid share metabolic pathways thereby influencing their benefit as a given drug. Little is known concerning their metabolic interactions in epidermal cells. We compared the influence of 1,25-dihydroxycholecalciferol (vitamin D3 - VD3) and its synthetic analogue secocholestra-trien-1,3,24-triol (tacalcitol - TAC) in combination with different calcium ...
Parrow V - - 1998
Retinoic acid and its isomers are the major morphogens in vertebrate development. For mammals, it was previously considered that circulating retinoic acid was recruited from the uterine environment, to influence embryonic differentiation, morphogenesis and development. Here we report that retinoic acid is endogenous to the blastocyst of the domestic pig, ...
Broekhuizen M L - - 1998
The distribution of the vagal nerve was studied in whole-mount specimens and serial sections of chick embryos after retinoic acid treatment. White Leghorn chick embryos were treated at stage 15 either with 1 microg all-trans retinoic acid (n=11), or with the solvent dimethylsulphoxide (sham-operated embryos, n=8). Eight embryos served as ...
Anderson R J - - 1998
Vitamin A and its derivatives have been postulated to play an important role in renal tubulogenesis and compensatory hypertrophy. This study examined the effects of two carboxylic derivatives of vitamin A on Lewis lung carcinoma-porcine kidney-1 (LLC-PK1) renal tubular epithelial cell mito- and motogenesis and cell size. It was found ...
Dinter A - - 1998
Pharmacological agents have proven useful for gaining fundamental insights into the biology of the Golgi apparatus. This review summarizes pertinent and recent work on the effects on this organelle of monensin, brefeldin A, bafilomycin, ilimaquinone, okadaic acid, retinoic acid, and nocodazole. The molecular targets of monensin, brefeldin A, ilimaquinone, and ...
Hanley K - - 1998
Peroxisome proliferator activated receptors (PPAR) belong to the superfamily of nuclear hormone receptors that heterodimerize with the retinoid X receptor and regulate transcription of several genes involved in lipid metabolism and adipocyte differentiation. Because of the role of 1,25-dihydroxyvitamin D3 and retinoic acid working through similar receptors (the vitamin D ...
Reeve V E - - 1998
T cell-mediated immune function, here measured as the contact hypersensitivity reaction, is readily suppressed by moderate exposure of mice to ultraviolet B (UVB) or solar-simulated radiation (SSUV), or by topical application of cis-urocanic acid. The effect of ultraviolet A (UVA) radiation on immune function has been unclear. Here we have ...
McDougal A - - 1998
The effects of several pesticides, mammary carcinogens, and antiestrogens on 17beta-estradiol (E2), 16alpha- and 2-hydroxylase activities, and 16alpha-/2-hydroxyestrone (OHE1) ratios were investigated in MCF-7 cells using a radiometric assay. The mammary carcinogens 7,12-dimethylbenz[a]anthracene (DMBA) and benzo[a]pyrene (BaP), respectively, increased and decreased 16alpha-/2-OHE1 ratios at some concentrations. The 16alpha-/2-OHE1 metabolite ratios ...
Fenaux P P Service des Maladies du Sang, CHU, Lille, - - 1998
The introduction of treatment with tretinoin (all-trans retinoic acid) and its combination with antineoplastic therapy has improved the outcome of acute promyelocytic leukaemia (APL). Retinoic acid syndrome is the major adverse effect of tretinoin and it occurs in about 25% of treated APL patients in the absence of prophylactic measures ...
Chen H - - 1998
The purpose of this study was to investigate whether and to what extent the steric isomerization of retinoic acids in conceptal tissues can be attributed to enzymatic catalysis in addition to thiol-dependent, nonenzymatic catalysis. Conversions of 13-cis-retinoic acid and 9-cis-retinoic acid to all-trans-retinoic acid catalyzed by cell-free preparations of conceptal ...
Kozawa O - - 1998
We previously reported that prostaglandin E1 (PGE1) induces the synthesis of interleukin-6 (IL-6) via cAMP production in osteoblast-like MC3T3-E1 cells, and that, on the other hand, prostaglandin F2alpha (PGF2alpha) stimulates IL-6 synthesis via activation of protein kinase C. In the present study, we examined the effect of retinoic acid on ...
Lee-Kim Y C YC Research Institute of Food and Nutritional Sciences, Yonsei University, Seoul, - - 1998
Long chain ω3 and ω6 fatty acids and taurine have been suggested to have structural and/or functional roles in the brain. In this study the levels of fatty acids and taurine in breast milk and their correlations were investigated in 46 lactating women from an area 100 km north-east of ...
Bennani Youssef L. - - 1998
The syntheses of two labeled homologues of (2E,4E,6E)-7-(3,5-di-tert-butylphenyl)-3-methylocta-2,4,6-trienoic acid (ALRT1550, 2), [(13)CD(3)]ALRT1550 (3) and [(3)H]ALRT1550 (4), are described in this report. ALRT1550 is an exceptionally potent antiproliferative agent which is currently in phase I/II clinical trials for acute chemotherapy. Both homologues were prepared from commercially available 3,5-di-tert-butylbenzoic acid. Homologue [(13)CD(3)]ALRT1550 ...
Dräger U C - - 1998
In the developing vertebrate, retinoic acid is distributed in patterns that are highly regulated, both in the spatial and temporal domains. These patterns are generated by the localized expression of retinoic acid-synthesizing aldehyde dehydrogenases, which form the origins of retinoic acid-diffusion gradients in the surrounding tissues. The developing eye, known ...
Buscaglia C A - - 1998
Trypanosoma cruzi trans-sialidase consists of a C-terminal domain composed essentially of immunodominant amino acid repeat units (SAPA-repeats) and an amino region responsible for the enzymatic activity (catalytic domain). To investigate the possible function(s) of SAPA-repeats, recombinant trans-sialidases either containing or lacking the C-terminal region were tested in mice. The presence ...
Bailly J - - 1998
The metabolism of radio-labelled retinol, retinal and retinoic acid by fresh human skin as well as by human dermal fibroblasts have been investigated in vitro. Surgically removed human skin biopsies were placed at the air liquid interface, and treated topically for 24 h with retinoids. At the end of the ...
Freyaldenhoven M A - - 1998
(E)-Retinoic acid (RA) was shown to stimulate the rate of 2,2'-azobis(2-amidinopropane) (AAPH)-initiated autoxidation of linoleic acid (18:2) in sodium dodecyl sulfate (SDS) micelles. RA-dependent stimulation of 18:2 autoxidation was characterized by enhanced rates of dioxygen uptake which were linear with retinoid concentration. In contrast, 5,6-epoxy-RA, a major oxidation product of ...
Drvota V - - 1998
The thyroid hormone receptors (TR) and the retinoic acid receptors share a high degree of homology and their signaling pathways interplay. Thyroid hormone (T3) is known to be associated with various pathological heart conditions. Retinoids are known to ameliorate symptoms in hyperthyroid patients. The aim of this study was to ...
Abu-Abed S S - - 1998
We have cloned a mouse cDNA homolog of P450RAI, a cytochrome P450 belonging to a new family (CYP26), which has previously been isolated from zebrafish and human cDNAs and found to encode a retinoic acid-inducible retinoic acid hydroxylase activity. The cross-species conservation of the amino acid sequence is high, particularly ...
Narayanan B A - - 1998
Retinoids, including natural vitamin A and its analogs, have been closely studied as chemopreventive drugs. The mechanism of action of retinoids, however, is not completely understood. Our study evaluated the effects of all-trans (high affinity ligand for both RAR and RXR receptors) and 9-cis retinoic acid (binds only with RXR ...
Kuratani S - - 1998
The effect of all-trans retinoic acid on embryogenesis was studied in a cyclostome, Lampetra japonica. Treatment with 0.05-0.5 microM retinoic acid on early gastrula and early neurula resulted in loss of the pharynx and in the rostral truncation of the neural tube. The mouth, pharynx, esophagus, heart, endostyle, and rostral ...
Szondy Z - - 1998
Vitamin A deficiency has been known for a long time to be accompanied with immune deficiency and susceptibility to a wide range of infectious diseases. Increasing evidence suggests that retinoic acids derived from vitamin A are involved in the functional regulation of the immune system. Of the two groups of ...
Menéndez A - - 1998
A 10-year-old boy with acute promyelocytic leukemia (APL) was treated with all-trans-retinoic acid (ATRA) at a dose of 60 mg/m2/day. Recombinant erythropoietin was also used. The patient parents and other relatives, all Jehova's Witnesses, refused any type of hemotherapy. After 43 days of ATRA treatment complete remission was obtained without ...
Piérard-Franchimont C - - 1998
Topical all-trans-retinoic acid (RA) has been reported to decrease the in vivo skin response to sodium lauryl sulfate (SLS). The converse was also shown with a synergistic effect of RA following prior applications of SLS. The reason for such effects is not clear. We employed measures of transepidermal water loss ...
Fresno M J - - 1998
Retinoic acid constitutes an active that is already being used extensively in the fight against cutaneous aging. After a period in which certain scientific publications questioned its use, today there is no doubt that retinoic acid continues to be an active with wide possibilities of use when it is formulated ...
Bast G E - - 1998
BACKGROUND: Retinoic acid, a metabolite of retinol, is formed in the skin of various species. PURPOSE: Formation rates have not been determined in a dynamic skin perfusion model which may show the dehydrogenation of retinol to be rate limited. METHODS: (all-trans-) Retinol acetate, retinol, or retinoic acid was applied dermally ...
Wille J J - - 1998
The immunosuppressive effect of topical ethacrynic acid (ECA) was tested on both the induction and elicitation phases of contact sensitization in a mouse model. ECA (0.5% in vehicle) reduced the sensitization response by >50% when the sensitizer was either dinitrochlorobenzene (DNCB), oxazalone (OX) or para-phenylenediamine (PPD), and was applied 1 ...
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