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Lopez LC, Dong T, Fallis DW, Durning SJ. LTCOS Data Management: CHPE and PDC. Mil Med 2023; 188:122-124. [PMID: 37201500 DOI: 10.1093/milmed/usad057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/21/2023] [Accepted: 02/14/2023] [Indexed: 05/20/2023] Open
Abstract
The purpose of this short essay is to describe the data management processes utilized in the Long Term Career Outcome Study at the Center for Health Professions Education and the Postgraduate Dental College of the Uniformed Services University. It includes descriptions of our workflow, how we obtain the data, challenges, and recommendations based on our experience for data managers and institutions to follow. This descriptive writing may help guide practice for other institutions looking to streamline their data management plan.
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Affiliation(s)
- Luis C Lopez
- Postgraduate Dental College, Uniformed Services University, Bethesda, MD 20814, USA
| | - Ting Dong
- Department of Medicine, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD 20814, USA
| | - Drew W Fallis
- Postgraduate Dental College, Uniformed Services University, Bethesda, MD 20814, USA
| | - Steven J Durning
- Department of Medicine, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD 20814, USA
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Kleiner G, Barca E, Ziosi M, Emmanuele V, Xu Y, Hidalgo-Gutierrez A, Qiao C, Tadesse S, Area-Gomez E, Lopez LC, Quinzii CM. CoQ 10 supplementation rescues nephrotic syndrome through normalization of H 2S oxidation pathway. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3708-3722. [PMID: 30251690 DOI: 10.1016/j.bbadis.2018.09.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 08/03/2018] [Accepted: 09/05/2018] [Indexed: 12/11/2022]
Abstract
Nephrotic syndrome (NS), a frequent chronic kidney disease in children and young adults, is the most common phenotype associated with primary coenzyme Q10 (CoQ10) deficiency and is very responsive to CoQ10 supplementation, although the pathomechanism is not clear. Here, using a mouse model of CoQ deficiency-associated NS, we show that long-term oral CoQ10 supplementation prevents kidney failure by rescuing defects of sulfides oxidation and ameliorating oxidative stress, despite only incomplete normalization of kidney CoQ levels and lack of rescue of CoQ-dependent respiratory enzymes activities. Liver and kidney lipidomics, and urine metabolomics analyses, did not show CoQ metabolites. To further demonstrate that sulfides metabolism defects cause oxidative stress in CoQ deficiency, we show that silencing of sulfide quinone oxido-reductase (SQOR) in wild-type HeLa cells leads to similar increases of reactive oxygen species (ROS) observed in HeLa cells depleted of the CoQ biosynthesis regulatory protein COQ8A. While CoQ10 supplementation of COQ8A depleted cells decreases ROS and increases SQOR protein levels, knock-down of SQOR prevents CoQ10 antioxidant effects. We conclude that kidney failure in CoQ deficiency-associated NS is caused by oxidative stress mediated by impaired sulfides oxidation and propose that CoQ supplementation does not significantly increase the kidney pool of CoQ bound to the respiratory supercomplexes, but rather enhances the free pool of CoQ, which stabilizes SQOR protein levels rescuing oxidative stress.
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Affiliation(s)
- Giulio Kleiner
- Department of Neurology, Columbia University Medical Center, New York, NY, United States
| | - Emanuele Barca
- Department of Neurology, Columbia University Medical Center, New York, NY, United States
| | - Marcello Ziosi
- Department of Neurology, Columbia University Medical Center, New York, NY, United States
| | - Valentina Emmanuele
- Department of Neurology, Columbia University Medical Center, New York, NY, United States
| | - Yimeng Xu
- Department of Pathology, Columbia University Medical Center, New York, NY, United States
| | | | - Changhong Qiao
- Irving Institute for Clinical and Translational Research, Columbia University Medical Center, New York, NY, United States
| | - Saba Tadesse
- Department of Neurology, Columbia University Medical Center, New York, NY, United States
| | - Estela Area-Gomez
- Department of Neurology, Columbia University Medical Center, New York, NY, United States
| | - Luis C Lopez
- Department of Physiology, Faculty of Medicine, University of Granada, Granada, Spain
| | - Catarina M Quinzii
- Department of Neurology, Columbia University Medical Center, New York, NY, United States.
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Quinzii CM, Luna-Sanchez M, Ziosi M, Hidalgo-Gutierrez A, Kleiner G, Lopez LC. The Role of Sulfide Oxidation Impairment in the Pathogenesis of Primary CoQ Deficiency. Front Physiol 2017; 8:525. [PMID: 28790927 PMCID: PMC5525000 DOI: 10.3389/fphys.2017.00525] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 07/07/2017] [Indexed: 11/23/2022] Open
Abstract
Coenzyme Q (CoQ) is a lipid present in all cell membranes. One of the multiple metabolic functions of CoQ is to transport electrons in the reaction catalyzed by sulfide:quinone oxidoreductase (SQOR), the first enzyme of the oxidation pathway of sulfides (hydrogen sulfide, H2S). Early evidence of a defect in the metabolism of H2S in primary CoQ deficiency came from yeast studies in Schizosaccharomyces pombe strains defective for dps1 and ppt1 (homologs of PDSS1 and COQ2, respectively), which have H2S accumulation. Our recent studies in human skin fibroblasts and in murine models of primary CoQ deficiency show that, also in mammals, decreased CoQ levels cause impairment of H2S oxidation. Patient fibroblasts carrying different mutations in genes encoding proteins involved in CoQ biosynthesis show reduced SQOR activity and protein levels proportional to the levels of CoQ. In Pdss2kd/kd mice, kidney, the only organ clinically affected, shows reduced SQOR levels and downstream enzymes, accumulation of H2S, and glutathione depletion. Pdss2kd/kd mice have also low levels of thiosulfate in plasma and urine, and increased C4–C6 acylcarnitines in blood, due to inhibition of short-chain acyl-CoA dehydrogenase. Also in Coq9R239X mice, the symptomatic organ, cerebrum, shows accumulation of H2S, reduced SQOR, increase in thiosulfate sulfurtransferase and sulfite oxidase, and reduction in the levels of glutathione and glutathione enzymes, leading to alteration of the biosynthetic pathways of glutamate, serotonin, and catecholamines. Coq9R239X mice have also reduced blood pressure, possible consequence of H2S-induced vasorelaxation. Since liver is not clinically affected in Pdss2 and Coq9 mutant mice, the effects of the impairment of H2S oxidation in this organ were not investigated, despite its critical role in metabolism. In conclusion, in vitro and in vivo studies of CoQ deficient models provide evidence of tissue-specific H2S oxidation impairment, an additional pathomechanism that should be considered in the understanding and treatment of primary CoQ deficiency.
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Affiliation(s)
- Catarina M Quinzii
- Department of Neurology, Columbia University Medical CenterNew York, NY, United States
| | - Marta Luna-Sanchez
- Department of Physiology, Faculty of Medicine, University of GranadaGranada, Spain.,MRC Mitochondrial Biology UnitCambridge, United Kingdom
| | - Marcello Ziosi
- Department of Neurology, Columbia University Medical CenterNew York, NY, United States
| | | | - Giulio Kleiner
- Department of Neurology, Columbia University Medical CenterNew York, NY, United States
| | - Luis C Lopez
- Department of Physiology, Faculty of Medicine, University of GranadaGranada, Spain
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Garcia-Diaz B, Barca E, Balreira A, Lopez LC, Tadesse S, Krishna S, Naini A, Mariotti C, Castellotti B, Quinzii CM. Lack of aprataxin impairs mitochondrial functions via downregulation of the APE1/NRF1/NRF2 pathway. Hum Mol Genet 2015; 24:4516-29. [PMID: 25976310 DOI: 10.1093/hmg/ddv183] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 05/12/2015] [Indexed: 11/13/2022] Open
Abstract
Ataxia oculomotor apraxia type 1 (AOA1) is an autosomal recessive disease caused by mutations in APTX, which encodes the DNA strand-break repair protein aprataxin (APTX). CoQ10 deficiency has been identified in fibroblasts and muscle of AOA1 patients carrying the common W279X mutation, and aprataxin has been localized to mitochondria in neuroblastoma cells, where it enhances preservation of mitochondrial function. In this study, we show that aprataxin deficiency impairs mitochondrial function, independent of its role in mitochondrial DNA repair. The bioenergetics defect in AOA1-mutant fibroblasts and APTX-depleted Hela cells is caused by decreased expression of SDHA and genes encoding CoQ biosynthetic enzymes, in association with reductions of APE1, NRF1 and NRF2. The biochemical and molecular abnormalities in APTX-depleted cells are recapitulated by knockdown of APE1 in Hela cells and are rescued by overexpression of NRF1/2. Importantly, pharmacological upregulation of NRF1 alone by 5-aminoimidazone-4-carboxamide ribonucleotide does not rescue the phenotype, which, in contrast, is reversed by the upregulation of NRF2 by rosiglitazone. Accordingly, we propose that the lack of aprataxin causes reduction of the pathway APE1/NRF1/NRF2 and their target genes. Our findings demonstrate a critical role of APTX in transcription regulation of mitochondrial function and the pathogenesis of AOA1 via a novel pathomechanistic pathway, which may be relevant to other neurodegenerative diseases.
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Affiliation(s)
| | - Emanuele Barca
- Department of Neurology, UOC of Neurology and Neuromuscular Disorders, Department of Neuroscience, University of Messina, Messina 98100, Italy
| | | | - Luis C Lopez
- Department of Neurology, Institute of Biotechnology, Biomedical Research Center (CIBM), Health Science Technological Park (PTS), University of Granada, Armilla, Granada 18100, Spain and
| | | | - Sindhu Krishna
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - Ali Naini
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - Caterina Mariotti
- Unitâ di Genetica delle Malattie Neurodegenerative e Metaboliche, Fondazione IRCCS Istituto Neurologico 'Carlo Besta', Milan 20126, Italy
| | - Barbara Castellotti
- Unitâ di Genetica delle Malattie Neurodegenerative e Metaboliche, Fondazione IRCCS Istituto Neurologico 'Carlo Besta', Milan 20126, Italy
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Garone C, Garcia-Diaz B, Emmanuele V, Lopez LC, Tadesse S, Akman HO, Tanji K, Quinzii CM, Hirano M. Deoxypyrimidine monophosphate bypass therapy for thymidine kinase 2 deficiency. EMBO Mol Med 2015; 6:1016-27. [PMID: 24968719 PMCID: PMC4154130 DOI: 10.15252/emmm.201404092] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Autosomal recessive mutations in the thymidine kinase 2 gene (TK2) cause mitochondrial DNA depletion, multiple deletions, or both due to loss of TK2 enzyme activity and ensuing unbalanced deoxynucleotide triphosphate (dNTP) pools. To bypass Tk2 deficiency, we administered deoxycytidine and deoxythymidine monophosphates (dCMP+dTMP) to the Tk2 H126N (Tk2(-/-)) knock-in mouse model from postnatal day 4, when mutant mice are phenotypically normal, but biochemically affected. Assessment of 13-day-old Tk2(-/-) mice treated with dCMP+dTMP 200 mg/kg/day each (Tk2(-/-200dCMP/) (dTMP)) demonstrated that in mutant animals, the compounds raise dTTP concentrations, increase levels of mtDNA, ameliorate defects of mitochondrial respiratory chain enzymes, and significantly prolong their lifespan (34 days with treatment versus 13 days untreated). A second trial of dCMP+dTMP each at 400 mg/kg/day showed even greater phenotypic and biochemical improvements. In conclusion, dCMP/dTMP supplementation is the first effective pharmacologic treatment for Tk2 deficiency.
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Affiliation(s)
- Caterina Garone
- Department of Neurology, Columbia University Medical Center, New York, NY, USA Human Genetics Joint PhD Program, University of Bologna and Turin, Turin, Italy
| | - Beatriz Garcia-Diaz
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Valentina Emmanuele
- Department of Neurology, Columbia University Medical Center, New York, NY, USA Pediatric Clinic University of Genoa IRCCS G. Gaslini Institute, Genoa, Italy
| | - Luis C Lopez
- Instituto de Biotecnología, Centro de Investigación Biomédica, Universidad de Granada Parque Tecnológico de Ciencias de la Salud, Armilla, Spain
| | - Saba Tadesse
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Hasan O Akman
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Kurenai Tanji
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Catarina M Quinzii
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Michio Hirano
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
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6
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Knechtle B, Morales NPH, González ER, Gutierrez AAA, Sevilla JN, Gómez RA, Robledo ARE, Rodríguez ALM, Fraire OS, Andonie JL, Lopez LC, Kohler G, Rosemann T. Effect of a multistage ultraendurance triathlon on aldosterone, vasopressin, extracellular water and urine electrolytes. Scott Med J 2012; 57:26-32. [PMID: 22408212 DOI: 10.1258/smj.2011.011287] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Prolonged endurance exercise over several days induces increase in extracellular water (ECW). We aimed to investigate an association between the increase in ECW and the change in aldosterone and vasopressin in a multistage ultraendurance triathlon, the 'World Challenge Deca Iron Triathlon' with 10 Ironman triathlons within 10 days. Before and after each Ironman, body mass, ECW, urinary [Na(+)], urinary [K(+)], urinary specific gravity, urinary osmolality and aldosterone and vasopressin in plasma were measured. The 11 finishers completed the total distance of 38 km swimming, 1800 km cycling and 422 km running within 145.5 (18.8) hours and 25 (22) minutes. ECW increased by 0.9 (1.1) L from 14.6 (1.5) L prerace to 15.5 (1.9) L postrace (P < 0.0001). Aldosterone increased from 70.8 (104.5) pg/mL to 102.6 (104.6) pg/mL (P = 0.033); vasopressin remained unchanged. The increase in ECW was related neither to postrace aldosterone nor to postrace vasopressin. In conclusion, ECW and aldosterone increased after this multistage ultraendurance triathlon, but vasopressin did not. The increase in ECW and the increase in aldosterone were not associated.
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Affiliation(s)
- B Knechtle
- Gesundheitszentrum St Gallen, St Gallen, Switzerland.
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7
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Acuna Castroviejo D, C. Lopez L, Escames G, Lopez A, A. Garcia J, J. Reiter R. Melatonin-mitochondria Interplay in Health and Disease. Curr Top Med Chem 2011; 11:221-40. [DOI: 10.2174/156802611794863517] [Citation(s) in RCA: 175] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Accepted: 12/07/2009] [Indexed: 11/22/2022]
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Lopez LC, Acuna-Castroviejo D, Pino AD, Tejada M, Escames G. Mitochondrial Disorders Therapy: The Utility of Melatonin~!2009-11-18~!2010-01-21~!2010-06-23~! ACTA ACUST UNITED AC 2010. [DOI: 10.2174/1874196701003010053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Daskalova SM, Pah AR, Baluch DP, Lopez LC. The Arabidopsis thaliana putative sialyltransferase resides in the Golgi apparatus but lacks the ability to transfer sialic acid. Plant Biol (Stuttg) 2009; 11:284-99. [PMID: 19470101 DOI: 10.1111/j.1438-8677.2008.00138.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A common feature of the animal sialyltransferases (STs) is the presence of four conserved motifs, namely large (L), small (S), very small (VS) and motif III. Although sialic acid (SA) has not been detected in plants, three orthologues containing sequences similar to the ST motifs have been identified in the Arabidopsis thaliana L. database. In this study, we report that the At3g48820 gene (Gene ID: 824043) codes for a Golgi resident protein lacking the ability to transfer SA to asialofetuin or Galbeta1,3GalNAc and Galbeta1,4GlcNAc oligosaccharide acceptors. Restoration of deteriorated motifs S, VS and motif III by constructing chimeric proteins consisting of the 28-308 amino acid region of the A. thalianaAt3g48820 ST-like protein and the 264-393 amino acid region of the Oryza sativa L. AK107493 ST-like protein, or of the 28-240 amino acid region of the At3g48820 protein and the 204-350 amino acid region of the Homo sapiens L. alpha2,3-ST (NP_008858) was not able to recover sialyltransferase activity. Altering the appropriate amino acid regions of the A. thalianaAt3g48820 ST-like protein to those typical for the mammalian motif III (HHYWE) and VS motif (HDADFE) also did not have any effect. Our data, together with previous results, indicate that A. thaliana in particular, and plants in general, do not have transferases for SA. Substrates for the plant ST-like proteins might be compounds involved in secondary metabolism.
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Affiliation(s)
- S M Daskalova
- The Biodesign Institute, Arizona State University, Tempe, AZ, USA.
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Conte A, Buonocore GG, Sinigaglia M, Lopez LC, Favia P, d'Agostino R, Del Nobile MA. Antimicrobial activity of immobilized lysozyme on plasma-treated polyethylene films. J Food Prot 2008; 71:119-25. [PMID: 18236671 DOI: 10.4315/0362-028x-71.1.119] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this study we tested the antimicrobial activity of polyethylene films modified by means of plasma processes that were followed by the chemical immobilization of lysozyme, an antimicrobial enzyme. To chemically immobilize the enzyme in its active form at the surface of polyethylene, substrates that had been plasma treated under different experimental conditions were soaked in lysozyme solutions at different concentrations. The immobilization of the enzyme was checked, and the antimicrobial activity of the films was investigated by observing the death rate of Micrococcus lysodeikticus cells suspended in phosphate buffer in contact with the films. The results clearly indicate that plasma-treated films loaded with lysozyme are active against the selected microorganism. A modified version of the Gompertz equation was used to quantitatively valuate the dependence of the antimicrobial activity of the films under both plasma treatment conditions and lysozyme concentrations.
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Affiliation(s)
- A Conte
- Department of Food Science, University of Foggia, Via Napoli, 25-71100 Foggia, Italy
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11
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Buonomenna MG, Lopez LC, Favia P, d'Agostino R, Gordano A, Drioli E. New PVDF membranes: The effect of plasma surface modification on retention in nanofiltration of aqueous solution containing organic compounds. Water Res 2007; 41:4309-16. [PMID: 17631942 DOI: 10.1016/j.watres.2007.06.033] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 05/31/2007] [Accepted: 06/05/2007] [Indexed: 05/11/2023]
Abstract
New nanofiltration membranes were prepared by non-solvent-induced phase inversion from a PVDF/DMF/water system. The effect of exposure time before coagulation on the membrane characteristics (morphology, thickness, overall porosity, tensile strength) was investigated. PVDF membrane prepared at a fixed exposure time of 45s (PF45) was further plasma surface modified (RF 13.56 MHz) (PF45psm), introducing amino groups on the membrane. The performances of PF45, PF45psm and of a commercial nanofiltration membrane (N30F) were tested in the removal of two dyes from aqueous solution, characterized by different charge and molecular weight (congo red and methylene blue). The observed rejections depended more on the charge of the compound than on their molecular weights and results were optimized for the plasma modified membrane (PF45psm) with respect to unmodified (PF45) and commercial N30F membranes. In particular, methylene blue was retained for 100% by PF45psm with a relative flux of 65% compared to 38% of rejection and 59% of relative flux observed for N30F.
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Affiliation(s)
- M G Buonomenna
- Research Institute on Membrane Technology (ITM-CNR), Via P. Bucci, Cubo 17/c, 87030 Rende (CS), Italy.
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Abstract
Melatonin is an ancient molecule present in unicellular organisms at the very early moment of life. Initially identified as a secretory product of the pineal gland in mammals and in other species, it was considered a hormone related to reproduction. The evidence that melatonin is produced in many organs and tissues of the body, reaching concentrations higher than in the blood, support the multiplicity of the melatonin actions. The best-known actions of melatonin, currently supported by experimental and clinical data, include antioxidant and anti-inflammatory abilities, some of them involving genomic regulation of a series of enzymes. Besides, melatonin displays anticonvulsant and antiexcitotoxic properties. Most of the beneficial consequences resulting from melatonin administration may depend on its effects on mitochondrial physiology. The physiological effects of melatonin on normal mitochondria, its role to prevent mitochondrial impairment, energy failure, and apoptosis in oxidatively-damaged mitochondria, and the beneficial effects of the administration of melatonin in experimental and clinical diseases involving mitochondrial dysfunction and cell death, are revised.
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Affiliation(s)
- Dario Acuna-Castroviejo
- Departamento de Fisiologia, Instituto de Biotecnologia, Universidad de Granada, Avenida de Madrid 11, E-18012 Granada, Spain.
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13
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Antonio JM, Gracioso JS, Toma W, Lopez LC, Oliveira F, Brito ARMS. Antiulcerogenic activity of ethanol extract of Solanum variabile (false "jurubeba"). J Ethnopharmacol 2004; 93:83-8. [PMID: 15182909 DOI: 10.1016/j.jep.2004.03.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2002] [Revised: 02/20/2004] [Accepted: 03/16/2004] [Indexed: 05/09/2023]
Abstract
The ethanol extract (EE) of the aerial parts of Solanum variabile Mart. (Solanaceae) was investigated for its ability to prevent ulceration of the gastric and duodenal mucosa at different doses. Its ability to heal chronic ulcer processes was also evaluated. When the HCl/ethanol solution was used to induce gastric ulcer, the EE produced a significant dose-dependent reduction of lesion formation of 51, 74 and 89%, at doses of 250, 500 and 1000 mg/kg, respectively. The 100 mg/kg dose had no significant activity. The EE also significantly reduced the gastric lesions induced by the combination of indomethacin and bethanechol (60 and 72%) at doses of 500 and 1000 mg/kg and also reduced stress-induced gastric ulcer (41%) but only at the doses of 1000 mg/g (P < 0.05). The pylorus-ligature experiment demonstrated that the highest EE dose affected significantly the gastric juice parameters by increasing pH values from 4.08 (negative control) to 5.42 and decreasing acid output from 7.16 (negative control) to 4.26 mEq.mL, 4h. A decrease of gastric contents from 370 mg (negative control) to 240 mg was also observed. The results obtained in the chronic gastric ulcer model indicated that a single oral dose of Solanum variabile (1000 mg/kg) administered for 14 consecutive days accelerated the ulcer healing by 46% compared to a 55% effect of cimetidine. Also, at the dose of 1000 mg/kg, the EE inhibited the onset of duodenal lesions by 64%. The data suggest that the EE of Solanum variabile has a significant preventive, curative and duodenal anti-ulcer effect.
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Affiliation(s)
- J M Antonio
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brazil
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Rank J, Lopez LC, Nielsen MH, Moretton J. Genotoxicity of maleic hydrazide, acridine and DEHP in Allium cepa root cells performed by two different laboratories. Hereditas 2002; 136:13-8. [PMID: 12184484 DOI: 10.1034/j.1601-5223.2002.1360103.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The purpose of this paper was to compare the results of the Allium cepa chromosome aberration assay between two laboratories under the same test protocol and at the same time, use chemicals and onions obtained in their own homeland. For this study three chemicals were selected: di(2-ethylhexyl)phthalate (DEHP), maleic hydrazide, and acridine. Both laboratories found genotoxicity with a positive dose-response relationship for maleic hydrazide and acridine. However, for DEHP the results were quite different--one of the laboratories found this compound not genotoxic but the other found a positive response. Although the comparative study was inconclusive for DEHP, it was successful for the maleic hydrazide, acridine and also for the positive control (methyl methanesulfonate). Further studies need to be performed in the case of DEPH.
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Affiliation(s)
- J Rank
- Department of Environment, Technology and Social Studies, Roskilde University, Denmark.
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15
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Puschel K, Thompson B, Coronado GD, Lopez LC, Kimball AM. Factors related to cancer screening in Hispanics: a comparison of the perceptions of Hispanic community members, health care providers, and representatives of organizations that serve Hispanics. Health Educ Behav 2001; 28:573-90. [PMID: 11575687 DOI: 10.1177/109019810102800505] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Hispanics have lower rates of screening for cervical, breast, and colon cancer than non-Hispanics. Activities to increase cancer screening in this population may not be informed by Hispanics, which may have implications for success rates of interventions. In this study, the perceptions about cancer screening behaviors in Hispanics are compared among three groups: a random sample of respondents (75% Hispanic) to a population-based survey, health care providers (primarily non-Hispanic), and representatives of organizations that serve Hispanics (36% Hispanic). While there was agreement that socioeconomic factors were important for cancer screening, differing views were expressed regarding the importance of cultural factors for cancer screening among Hispanics. Interventions developed by those who serve the Hispanic population may be based on inaccurate perceptions about the beliefs and practices of the population served. For effective interventions, it will be necessary to understand the factors important to Hispanics for cancer screening.
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Affiliation(s)
- K Puschel
- Community and Family Medicine Department, Universidad Catolica de Chile, Santiago
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Babudri F, Farinola GM, Lopez LC, Martinelli MG, Naso F. A Synthetic Strategy Leading to Monodisperse PPV Oligomers by Coupling Reactions of Vinyltrimethylsilanes. J Org Chem 2001; 66:3878-85. [PMID: 11375010 DOI: 10.1021/jo001795v] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel strategy for the synthesis of well-defined oligo(phenylenevinylene)s was developed. The procedure is entirely based upon two coupling processes, both involving vinyltrimethylsilanes. Bis(styryl)benzenes 2a-g bearing two octyloxy groups in the central aromatic ring and various substituents on the external aromatic rings were prepared in good yield by a regio- and stereoselective coupling reaction of 1 with different arenediazonium tetrafluoroborates. Oligomers with a more extended conjugated system, 4a-c, and with m-phenylene subunits 13a,b, were also readily obtained by conversion of the unsaturated trimethylsilyl derivatives 3a,c,d to the corresponding boron derivatives and a subsequent coupling reaction with compounds 2a and 2c.
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Affiliation(s)
- F Babudri
- Centro CNR di Studio sulle Metodologie Innovative di Sintesi Organiche, Dipartimento di Chimica, Università di Bari, via Amendola 173, 70126 Bari, Italy
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Abstract
Migrant seasonal farm workers (MSFWs) in south Texas are predominantly Mexican American and represent one of the most impoverished and medically underserved populations in the United States. La Frontera is a collaborative partnership between the University of Texas Health Science Center at San Antonio, migrant organizations, and HIV service delivery organizations to study and address special needs of MSFWs in Hidalgo and Maverick counties of south Texas. The purpose of this qualitative study is to explore the health-seeking experiences of HIV-positive MSFWs living in the La Frontera service area. Denzin's interpretive interactionism methodology guided the study. Thirteen participants were interviewed and audiotaped as they described their experiences. Findings from content analysis of the interviews revealed a description of the life of an HIV-positive MSFW as la desesperacion (a separate way of life). After their diagnosis of HIV/AIDS, the major themes in their lives were living in secrecy (a silent cry), finding and receiving health care, and accepting the disease (may it be the will of God).
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Affiliation(s)
- B Aranda-Naranjo
- Frontera Project, University of Texas Health Science Center, USA
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18
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Abstract
A survey of 208 girls and 191 boys attending a public high school in southwestern New Mexico was conducted to examine students' use of smokeless tobacco products. One Mexican-American girl identified herself as a user of chewing tobacco. Of the boys 8% (17) indicated that they used chewing tobacco and 7% (15) reported that they dipped snuff. 6% (12) indicated use of both snuff and chewing tobacco. The boys included 153 Mexican-Americans of whom 7% used smokeless tobacco and 26 Anglo-Americans of whom 34% were users.
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Affiliation(s)
- L C Lopez
- Department of Social Sciences, Western New Mexico University, Silver City 88062, USA
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19
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Abstract
A telephone survey was conducted to compare the extent of smokeless tobacco consumption by Anglo-Americans and Mexican-Americans. Using systematic random sampling, one out of every 25 phone numbers was selected from the Grant County, New Mexico, telephone directory. Two hundred and ten individuals were interviewed. All of the female respondents, including 46 Mexican-Americans and 81 Anglo-Americans, indicated that they did not use smokeless tobacco. Twenty-five percent of the 51 Anglo-American males and 26% of the 30 Mexican-American males identified themselves as consumers of smokeless tobacco. A chi-square analysis revealed no significance difference between the number of Mexican-Americans and Anglo-Americans among the male self-identified users of smokeless tobacco.
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Affiliation(s)
- L C Lopez
- Western New Mexico University, Silver City 88062
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20
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Lopez LC. Smokeless tobacco consumption by Mexican-American University students. Psychol Rep 1994; 75:279-84. [PMID: 7984739 DOI: 10.2466/pr0.1994.75.1.279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A modified version of the Illinois Department of Public Health Smokeless Tobacco Survey was administered to 220 women and 134 men attending a state university in New Mexico. The respondents included 65 male and 83 female Mexican-Americans as well as 118 female and 59 male Anglo-Americans. All Mexican-American women identified themselves as nonusers of smokeless tobacco. Of the Anglo-American women, one indicated that she used snuff, and 3 disclosed that they chewed tobacco. 33% of the Anglo-American men and 18% of the Mexican-American men stated that they used smokeless tobacco products. A chi-squared analysis showed this difference was significant. Implications are discussed.
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Affiliation(s)
- L C Lopez
- Psychology Department, Western New Mexico University, Silver City 88062
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21
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Elshaw EB, Young EA, Saunders MJ, McGurn WC, Lopez LC. Utilizing a 24-hour dietary recall and culturally specific diabetes education in Mexican Americans with diabetes. Diabetes Educ 1994; 20:228-35. [PMID: 7851238 DOI: 10.1177/014572179402000309] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Two objectives were established for this study: 1) to assess the impact of a culturally specific, intensive diabetes education program on dietary patterns, and 2) to assess nutrient consumption relative to the Recommended Dietary Allowances. The study population consisted of elderly Mexican Americans with diabetes living in Harlingen and Brownsville, Texas. The experimental group (n = 78) participated in an intense, 2-hour nutrition education session, while the control group (n = 74) did not. The education session was conducted for groups of eight subjects via videotapes and interactive discussion. All groups experienced significant weight loss except the women in the experimental group. After the education program, however, the experimental women had increased the percentage of calories consumed daily from carbohydrate. Mean calcium consumption was substantially less than the RDA in all groups, and inadequate amounts of ascorbic acid and vitamin A often were consumed. Intensive, frequent, long-term follow-up appears essential for more sustained results.
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22
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Evans SC, Lopez LC, Shur BD. Dominant negative mutation in cell surface beta 1,4-galactosyltransferase inhibits cell-cell and cell-matrix interactions. J Biophys Biochem Cytol 1993; 120:1045-57. [PMID: 8432725 PMCID: PMC2200081 DOI: 10.1083/jcb.120.4.1045] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In addition to its traditional location within the Golgi complex, beta 1,4-galactosyltransferase (GalTase) is also present on the cell surface, where it is thought to function as a cell adhesion molecule by binding to extracellular oligosaccharide ligands. Recent studies suggest that cells contain two forms of GalTase with distinct cytoplasmic domains. The longer form of GalTase contains a 13-amino acid cytoplasmic extension and is preferentially targeted to the plasma membrane, relative to the shorter GalTase protein that is confined primarily to the Golgi compartment. In this study, we created a dominant negative mutation that interferes with the function of cell surface GalTase by transfecting into cells cDNAs encoding truncated versions of the long form of GalTase containing the complete cytoplasmic and transmembrane domains, but devoid of the catalytic domain. In both F9 embryonal carcinoma cells and Swiss 3T3 fibroblasts, overexpressing the truncated long GalTase (TLGT) protein displaced the endogenous cell surface GalTase from its association with the cytoskeleton, resulting in a loss of intercellular adhesion and cell spreading specifically on matrices that use GalTase as a cell surface receptor. In contrast, overexpressing the analogous truncated short GalTase (TSGT) protein did not affect cell morphology or GalTase activity. In control assays, inducing the TLGT protein had no effect on cell interactions with fibronectin (which is independent of GalTase), or on the cytoskeleton attachment of another matrix receptor (beta 1 integrin), or on overall glycoprotein synthesis, thus eliminating nonspecific effects of the TLGT protein on cellular adhesion and metabolism. These results represent the first molecular manipulation of cell surface GalTase expression and confirm its function as a cell adhesion molecule. These studies further suggest that the cytoskeleton contains a defined, saturable number of binding sites for GalTase, which enables it to function as an adhesion molecule.
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Affiliation(s)
- S C Evans
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston 77030
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23
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Abstract
A telephone survey was conducted in order to assess the prevalence of smokeless tobacco consumption in Grant County, New Mexico. Systematic random sampling was used, and 1 out of 25 phone numbers were selected from the county telephone directory. One hundred seventy-eight respondents were surveyed. Thirty-three percent of 96 males and 7% of 82 females identified themselves as smokeless tobacco users.
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Affiliation(s)
- L C Lopez
- Department of Education and Psychology, Western New Mexico University, Silver City 88061
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24
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Abstract
beta-1,4-Galactosyltransferase (GalTase) is present on the surface of mouse sperm, where it functions during fertilization by binding to oligosaccharide residues in the egg zona pellucida. The specific oligosaccharide substrates for sperm GalTase reside on the glycoprotein ZP3, which possesses both sperm-binding and acrosome reaction-inducing activity. A variety of reagents that perturb sperm GalTase activity inhibit sperm binding to the zona pellucida, including UDP-galactose, N-acetylglucosamine, alpha-lactalbumin, and anti-GalTase Fab fragments. However, none of these reagents are able to cross-link GalTase within the membrane nor are they able to induce the acrosome reaction. On the other hand, intact anti-GalTase IgG blocks sperm-zona binding as well as induces the acrosome reaction. Anti-GalTase IgG induces the acrosome reaction by aggregating GalTase on the sperm plasma membrane, as shown by the inability of anti-Gal-Tase Fab fragments to induce the acrosome reaction unless cross-linked with goat anti-rabbit IgG. These data suggest that zona pellucida oligosaccharides induce the acrosome reaction by clustering GalTase on the sperm surface.
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Affiliation(s)
- M B Macek
- Department of Biochemistry and Molecular Biology, University of Texas, M.D. Anderson Cancer Center, Houston 77030
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25
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Lopez LC, Youakim A, Evans SC, Shur BD. Evidence for a molecular distinction between Golgi and cell surface forms of beta 1,4-galactosyltransferase. J Biol Chem 1991; 266:15984-91. [PMID: 1714903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
beta 1,4-Galactosyltransferase (GalTase) is present on the plasma membrane of many cell types in addition to its traditional location within the Golgi compartment. Recently, the GalTase gene has been shown to encode two proteins that are identical throughout their length except that one has an additional 13-amino acid extension in its amino-terminal cytoplasmic domain. We present evidence here suggesting that the longer GalTase protein, containing this unique 13-amino acid peptide, is preferentially targeted to the plasma membrane, and the shorter GalTase protein resides primarily within the Golgi compartment. S1 nuclease protection assays of RNA from a variety of cells and tissues show that the relative abundance of the short and long GalTase mRNAs correlates with GalTase-specific activities in the Golgi and plasma membranes, respectively. Furthermore, transfection of cDNAs encoding either the long or short GalTase protein into F9 embryonal carcinoma cells suggests that the long GalTase protein is preferentially expressed on the cell surface. These results propose a molecular distinction between the Golgi and cell surface forms of GalTase as well as a novel mechanism for targeting glycoproteins to the cell surface.
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Affiliation(s)
- L C Lopez
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston 77030
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26
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Abstract
265 students attending a southwestern university were surveyed about their use of smokeless tobacco products. 27% of 84 male respondents indicated they consumed smokeless tobacco. The women did not report routine use of smokeless tobacco.
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Affiliation(s)
- L C Lopez
- Department of Education and Psychology, Western New Mexico University, Silver City 88062
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27
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Lopez LC, Maillet CM, Oleszkowicz K, Shur BD. Cell surface and Golgi pools of beta-1,4-galactosyltransferase are differentially regulated during embryonal carcinoma cell differentiation. Mol Cell Biol 1989; 9:2370-7. [PMID: 2503706 PMCID: PMC362310 DOI: 10.1128/mcb.9.6.2370-2377.1989] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
beta-1,4-Galactosyltransferase (GalTase) has two functionally distinct subcellular distributions. In the Golgi apparatus, GalTase participates in the glycosylation of secretory and membrane-bound glycoproteins, whereas on the cell surface it mediates specific aspects of intercellular adhesion. For this study, a murine GalTase clone was obtained by screening a lambda gt10 cDNA library made from F9 embryonal carcinoma cells with a heterologous bovine GalTase cDNA probe. The murine GalTase cDNA probe was used in conjunction with assays of GalTase activity to investigate the expression and distribution of GalTase during differentiation of F9 stem cells into secretory endodermal epithelium. During the initial phase of F9 cell differentiation, GalTase mRNA levels remained relatively constant; however, as differentiation progressed, as assayed by expression of the differentiation-specific marker laminin B1, GalTase mRNA levels and enzyme activity rose dramatically. Furthermore, subcellular fractionation of these cells showed that the increased GalTase levels were specifically associated with the Golgi apparatus, whereas GalTase specific activity on the plasma membrane remained constant. These results show that levels of cell surface and Golgi GalTase change relative to one another during F9 cell differentiation and suggest that these functionally distinct pools of GalTase are independently and differentially regulated.
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Affiliation(s)
- L C Lopez
- Department of Biochemistry and Molecular Biology, University of Texas M. D. Anderson Cancer Center, Houston 77030
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28
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Abstract
The identity of cDNA encoding beta 1,4 galactosyltransferase (EC 2.4.1.38) has been controversial, since two independent and unrelated cDNAs have been cloned (GTcDNA-1 and -2), both of which are thought to encode beta 1,4 galactosyltransferase. We have resolved this issue by examining the expression of the corresponding mRNAs in tissues possessing varying levels of galactosyltransferase activity. The expression of GTcDNA-1 parallels the level of galactosyltransferase activity assayed enzymatically, while the expression of GTcDNA-2 is unrelated to the level of enzyme activity, being virtually undetectable in tissues with abundant galactosyltransferase activity. GTcDNA-2, therefore, does not likely encode beta 1,4 galactosyltransferase, but rather, encodes a product that indirectly influences enzyme activity following cellular transfection.
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Affiliation(s)
- L C Lopez
- Department of Biochemistry and Molecular Biology, University of Texas, M.D. Anderson Cancer Center, Houston 77030
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29
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Abstract
Self-reports on smokeless tobacco consumption were obtained from 438 students attending a small Midwestern liberal arts college. While use among 249 female students was negligible, 9% of 189 male respondents reported routine use of smokeless tobacco products.
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30
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Abstract
Gamete recognition in the mouse is mediated by galactosyltransferase (GalTase) on the sperm surface, which binds to its appropriate glycoside substrate in the egg zona pellucida (Lopez, L. C., E. M. Bayna, D. Litoff, N. L. Shaper, J. H. Shaper, and B. D. Shur, 1985, J. Cell Biol., 101:1501-1510). GalTase has been localized by indirect immunofluorescence to the dorsal surface of the anterior sperm head overlying the intact acrosome. Sperm binding to the zona pellucida triggers induction of the acrosome reaction, an exocytotic event that results in vesiculation and release of the outer acrosomal and overlying plasma membranes. Consequently, we examined the fate of sperm surface GalTase after the acrosome reaction. Contrary to our expectations, surface GalTase is not lost during the acrosome reaction despite the loss of its membrane domain. Rather, double-label indirect immunofluorescence assays show that GalTase is redistributed to the lateral surface of the sperm, coincident with the acrosome reaction. This apparent redistribution of GalTase was confirmed by direct enzymatic assays, which show that 90% of sperm GalTase activity is retained during the acrosome reaction. No GalTase activity is detectable on plasma membrane vesicles released during the acrosome reaction. In contrast, removal of plasma membranes by nitrogen cavitation releases GalTase activity from the sperm surface, showing that GalTase redistribution requires a physiological acrosome reaction. The selective redistribution of GalTase to a new membrane domain from one that is lost during the acrosome reaction suggests that GalTase is repositioned for some additional function after initial sperm-zona binding.
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Affiliation(s)
- L C Lopez
- Department of Biochemistry and Molecular Biology, University of Texas, M. D. Anderson Hospital and Tumor Institute, Houston 77030
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Bayna EM, Runyan RB, Scully NF, Reichner J, Lopez LC, Shur BD. Cell surface galactosyltransferase as a recognition molecule during development. Mol Cell Biochem 1986; 72:141-51. [PMID: 3102942 DOI: 10.1007/bf00230641] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Recent results from our laboratory suggest that a variety of cellular interactions during development are mediated, in part, by the binding of a cell surface enzyme, galactosyltransferase (GalTase), to its specific lactosaminoglycan (LAG) substrate on adjacent cell surfaces and in the extracellular matrix. Our present interest in surface GalTase developed from earlier biochemical studies of a series of morphogenetic mutations in the mouse which map to the T/t-complex. These studies identified a specific defect in the regulation of surface GalTase activity on morphogenetically abnormal cells, while eight other enzymes showed normal activity. This led us to consider the unique function of surface GalTase in those cell interactions that are influenced by mutations of the T/t-complex. By using a multidisciplinary approach, which included genetic, biochemical and immunological probes, we have found that GalTase functions as a surface receptor during fertilization, early embryonic cell adhesions, and embryonic cell migration on basal lamina matrices. Recently, we have examined the expression of surface GalTase during spermatogenesis, as well as the fate of sperm GalTase following the acrosome reaction. This paper summarizes the results of these studies, as well as others, which suggest that GalTase functions as a surface receptor during those cell interactions regulated by the T/t-complex alleles.
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32
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Lopez LC, Bayna EM, Litoff D, Shaper NL, Shaper JH, Shur BD. Receptor function of mouse sperm surface galactosyltransferase during fertilization. J Cell Biol 1985; 101:1501-10. [PMID: 2995408 PMCID: PMC2113901 DOI: 10.1083/jcb.101.4.1501] [Citation(s) in RCA: 201] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Past studies from this laboratory have suggested that mouse sperm binding to the egg zona pellucida is mediated by a sperm galactosyltransferase (GalTase), which recognizes and binds to terminal N-acetylglucosamine (GlcNAc) residues in the zona pellucida (Shur, B. D., and N. G. Hall, 1982, J. Cell Biol. 95:567-573; 95:574-579). We now present evidence that directly supports this mechanism for gamete binding. GalTase was purified to homogeneity by sequential affinity-chromatography on GlcNAc-agarose and alpha-lactalbumin-agarose columns. The purified enzyme produced a dose-dependent inhibition of sperm binding to the zona pellucida, relative to controls. To inhibit sperm/zona binding, GalTase had to retain its native conformation, since neither heat-inactivated nor Mn++-deficient GalTase inhibited sperm binding. GalTase inhibition of sperm/zona binding was not due to steric blocking of an adjacent sperm receptor on the zona, since GalTase could be released from the zona pellucida by forced galactosylation with UDPGal, and the resulting galactosylated zona was still incapable of binding sperm. In control experiments, when UDPGal was replaced with the inappropriate sugar nucleotide, UDPglucose, sperm binding to the zona pellucida remained normal after the adsorbed GalTase was washed away. The addition of UDPGal produced a dose-dependent inhibition of sperm/zona binding, and also dissociated preformed sperm/zona adhesions by catalyzing the release of the sperm GalTase from its GlcNAc substrate in the zona pellucida. Under identical conditions, UDP-glucose had no effect on sperm binding to the zona pellucida. The ability of UDPGal to dissociate sperm/zona adhesions was both time- and temperature-dependent. UDPGal produced nearly total inhibition of sperm/zona binding when the zonae pellucidae were first galactosylated to reduce the number of GalTase binding sites. Finally, monospecific anti-GalTase IgG and its Fab fragments produced a dose-dependent inhibition of sperm/zona binding and concomitantly blocked sperm GalTase catalytic activity. Preimmune IgG or anti-mouse brain IgG, which also binds to the sperm surface, had no effect. The sperm GalTase was localized by indirect immunofluorescence to a discrete plasma membrane domain on the dorsal surface of the anterior head overlying the intact acrosome. These results, along with earlier studies, show clearly that sperm GalTase serves as a principal gamete receptor during fertilization.
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Abstract
Statistical analyses of DNA sequences of the preproglucagon genes from bovine, human, hamster, and anglerfish suggest that a gene duplication creating two anglerfish genes (AF I and II) occurred about 160 Myr ago, long after the separation of fish and mammals. The analyses further suggest that the internal duplication producing the glucagon and glucagon-like peptide II (GLP-II) regions occurred about 1.2 billion years ago, which would indicate that the GLP-II region was present in the ancestral anglerfish sequence but was silenced or deleted before the gene duplication separating AF I and II. The glucagon-like peptide I (GLP-I) was derived from a duplication of the ancestral glucagon region about 800 Myr ago. The rate of synonymous substitution in these genes is approximately 4.3 x 10(-9) substitutions per year per synonymous site. The rate of nonsynonymous substitution in the signal peptide region is about 1.1 x 10(-9) substitutions per year per nonsynonymous site, a high rate comparable to that in the C-peptide region of preproinsulin. The rate of nonsynonymous substitution in the glicentin-related pancreatic polypeptide (GRPP) region is 0.63 x 10(-9) for the comparisons between mammalian species and 1.8 x 10(-9) for the comparisons between fish and mammals; the moderate rate in mammals suggests a physiological role for GRPP. The glucagon region is extremely conservative; no nonsynonymous substitution is observed in the mammalian genes, and a nonsynonymous rate of 0.18 x 10(-9) was obtained from the comparisons between fish and mammals. In the GLP-I region, the rate of nonsynonymous substitution was estimated to be 0.08 x 10(-9) for the comparisons between mammalian species and 0.30 x 10(-9) for the comparisons between fish and mammals. In the GLP-II region, the rate was estimated to be 0.25 x 10(-9) for the comparisons between mammalian species. Thus, GLP-I and II are also very conservative, which suggests an important physiological role for these peptides.
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Affiliation(s)
- L C Lopez
- Department of Biochemistry and Molecular Biology, University of Texas System Cancer Center, M.D. Anderson Hospital and Tumor Institute, Houston 77030
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Abstract
The major sperm protein (MSP) of the nematode Caenorhabditis elegans is a low-molecular-weight (15,000) basic protein implicated in the pseudopodial movement of mature spermatozoa. Its synthesis occurs in a specific region of the gonad and is regulated at the level of transcription (M. Klass and D. Hirsh, Dev. Biol. 84:299-312, 1981; S. Ward and M. Klass, Dev. Biol. 92:203-208, 1982; Klass et al., Dev. Biol. 93:152-164, 1982). A developmentally regulated gene family has been identified that codes for this MSP. Whole genomic blots, as well as analysis of genomic clone banks, indicate that there are between 15 and 25 copies of the MSP gene in the nematode genome. Southern blot analysis also indicates that there is no rearrangement or amplification within the MSP gene family during development. No evidence was found of methylation at various restriction sites surrounding the MSP gene family, and similarly, no correlation between methylation and expression was observed. Three distinct members of this MSP gene family have been cloned, and their nucleotide sequences have been determined. Differential screening of a cDNA clone bank made from polyadenylated mRNA from adult males yielded 45 male-specific clones, 32 of which were clones of MSP genes. One of these cDNA clones was found to contain the entire nucleotide sequence for the MSP, including part of the 5' leader and all of the 3' trailing sequence. Genomic clones bearing copies of the MSP genes have been isolated. At least one of the members of this gene family is a pseudogene. Another member of the MSP gene family that has been cloned from genomic DNA contains the entire uninterrupted structural sequence for the MSP in addition to a 5' flanking sequence containing a promoter-like region with the classic TATA box, a sequence resembling the CAAT box, and a putative ribosome-binding sequence. The 3' trailing sequences of the genomic and the cDNA clones contain an AATAAA polyadenylation site.
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35
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Schroeder WT, Lopez LC, Harper ME, Saunders GF. Localization of the human glucagon gene ( GCG) to chromosome segment 2q36→37. Cytogenet Genome Res 1984; 38:76-9. [PMID: 6546710 DOI: 10.1159/000132034] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Hybridization of a 3H-labeled bovine glucagon cDNA plasmid to human metaphase chromosomes revealed significant labeling of the distal portion of the long arm of chromosome 2. A large portion (37%) of the cells analyzed exhibited labeling of the 2. A significant percentage (40%) of the labeled sites on the 2 were in segment 2q36----37. Therefore, the human glucagon gene (GCG), was assigned to this segment. Localization of the glucagon gene, whose chromosomal assignment was previously not known, demonstrates the general applicability of in situ hybridization as a powerful gene mapping technique.
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36
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Lopez LC, Frazier ML, Su CJ, Kumar A, Saunders GF. Mammalian pancreatic preproglucagon contains three glucagon-related peptides. Proc Natl Acad Sci U S A 1983; 80:5485-9. [PMID: 6577439 PMCID: PMC384282 DOI: 10.1073/pnas.80.18.5485] [Citation(s) in RCA: 134] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
We have isolated cDNA clones encoding bovine pancreatic preproglucagon. Twenty-five putative preproglucagon clones were selected by screening 3,100 clones of a fetal bovine pancreas cDNA library with a synthetic oligodeoxynucleotide probe. The probe was a mixture of synthetic 17-base DNA oligomers constructed to correspond to the six carboxyl-terminal amino acids (residues 24-29) of mature glucagon. Restriction mapping of six of these clones suggested that they represented a single mRNA species. Primary sequence analysis of one clone containing a 1,200-base-pair DNA insert revealed that it contained an essentially full-length copy of glucagon mRNA. Analysis of the cDNA suggested a protein coding sequence of 540 nucleotides and 5'- and 3'-untranslated regions of 90 and 471 nucleotides, respectively. This cDNA sequence encoded a 20-amino acid signal sequence followed by one for glicentin, a 69-amino acid polypeptide containing an internal glucagon moiety that has been found in porcine intestines. Glicentin is followed by two additional glucagon-like peptides, each flanked by paired basic amino acids (Lys, Arg) characteristic of prohormone processing. These polypeptide sequences show striking homology with those for glucagon and other members of the glucagon family of peptides.
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