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Generotti A, Contreras R, Zounes B, Schade E, Kemme A, Rane Y, Liu X, Elwood D, Schultheis K, Marston J, McCoy J, Broderick K, Fisher P. Intradermal DNA vaccine delivery using vacuum-controlled, needle-free electroporation. Mol Ther Nucleic Acids 2023; 34:102070. [PMID: 38034030 PMCID: PMC10682253 DOI: 10.1016/j.omtn.2023.102070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 10/26/2023] [Indexed: 12/02/2023]
Abstract
Intradermal delivery of DNA vaccines via electroporation (ID-EP) has shown clinical promise, but the use of needle electrodes is typically required to achieve consistent results. Here, delivery of a DNA vaccine targeting the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is achieved using noninvasive intradermal vacuum-EP (ID-VEP), which functions by pulling a small volume of skin tissue into a vacuum chamber containing noninvasive electrodes to perform EP at the injection site. Gene expression and immunogenicity correlated with EP parameters and vacuum chamber geometry in guinea pigs. ID-VEP generated potent humoral and cellular immune responses across multiple studies, while vacuum (without EP) greatly enhanced localized transfection but did not improve immunogenicity. Because EP was performed noninvasively, the only treatment site reaction observed was transient redness, and ID-VEP immune responses were comparable to a clinical needle-based ID-EP device. The ID-VEP delivery procedure is straightforward and highly repeatable, without any dependence on operator technique. This work demonstrates a novel, reliable, and needle-free delivery method for DNA vaccines.
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Affiliation(s)
| | | | | | - Eric Schade
- Inovio Pharmaceuticals, Inc., San Diego, CA 92121, USA
| | - Andrea Kemme
- Inovio Pharmaceuticals, Inc., San Diego, CA 92121, USA
| | - Yatish Rane
- Texas Tech University, Department of Chemical Engineering, Lubbock, TX 79409, USA
| | - Xinggang Liu
- Inovio Pharmaceuticals, Inc., San Diego, CA 92121, USA
| | - Dustin Elwood
- Inovio Pharmaceuticals, Inc., San Diego, CA 92121, USA
| | | | - Jeremy Marston
- Texas Tech University, Department of Chemical Engineering, Lubbock, TX 79409, USA
| | - Jay McCoy
- Inovio Pharmaceuticals, Inc., San Diego, CA 92121, USA
| | | | - Paul Fisher
- Inovio Pharmaceuticals, Inc., San Diego, CA 92121, USA
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Acosta-Colman I, Vazquez M, Cabrera-Villalba S, Ayala-Lugo A, Acosta ME, Arevalo de Guillen I, Jolie V, Duarte M, Valinotti V, Contreras R, Avila G, Martinez T, Julià A, Marsal S. AB0015 STUDY OF VDR AND VDBP GENES AS CANDIDATE SUSCEPTIBILITY GENES FOR THE DEVELOPMENT OF IMMUNE-MEDIATED DISEASES IN THE PARAGUAYAN POPULATION. Ann Rheum Dis 2021. [DOI: 10.1136/annrheumdis-2021-eular.4299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background:Immune Mediated Inflammatory Diseases (IMIDs) are complex diseases that are believed to have a strong interaction between the genome and the environment as part of their aetiology. In studies using the candidate gene strategy, genetic variation in a gene where functionality has been associated with the pathophysiology of the disease under study is being analyzed. In the last decade, polymorphisms of the vitamin D receptor (VDR) and VDBP genes have been more emphatically studied in IMIDs in different populations, but the results reported have not yet been conclusive.Objectives:To identify an association between vitamin D receptor (VDR) and vitamin D-binding protein (VDBP) gene polymorphisms, and IMIDs in Paraguayan patients.Methods:Association study of VDR (SNPs rs731236, rs7975232, rs2228570) and VDBP (rs4588) gene polymorphisms with susceptibility to IMIDs in Paraguayan population. A total of 399 patients with IMIDs (i.e. Systemic Lupus Erythematosus (SLE), Scleroderma (ES), Rheumatoid Arthritis (RA), and Cutaneous Psoriasis (CPS) and 100 hypernormal controls (HC) from the same population were included in this study. Genotyping was performed using Taqman real-time PCR-based technology (Life Technologies, USA). Statistical analysis was performed using Rv3.0.1 statistical language software (www.R-project.org). A p value ≤ 0.05 was used for statistical significance.Results:A total of 399 individuals, 100 controls and 299 patients (99 RA, 100 SLE, 50 ES, and 50 PSO) were included. Seventy-six percent were female and 24% were male. The mean age was 43.7±14 years. Four SNPs were genotyped: rs731236, rs7975232, rs2228570, rs4588. The HWE test was not statistically significant for any of the 4 SNPs considered (P>0.05), confirming the quality of genotyping and the absence of technical bias. (Table 1).Table 1.Genotyping of SNPs of the VDR and VDBP gene in Paraguayan population with IMIDs.SNPIMIDMinor AlleleMajor AlleleMAFControlMAFCaseORIC.LIC.Hp allelicP.Geneticrs731236SLEGA0.50.40.640.420.970.0350.08rs731236RAGA0.50.410.690.461.050.0710.12rs731236SSGA0.50.420.710.421.180.180.37rs731236CPSGA0.50.380.60.361.010.0490.042rs2228570SLEAG0.360.381.140.741.740.60.45rs2228570RAAG0.360.310.830.531.280.40.56rs2228570SSAG0.360.361.020.61.7310.057rs2228570CPSAG0.360.391.160.681.960.610.83rs7975232SLECA0.360.320.820.531.260.40.072rs7975232RACA0.360.290.720.461.120.140.064rs7975232SSCA0.360.220.490.270.880.0120.0064rs7975232CPSCA0.360.411.210.722.030.450.016rs4588SLETG0.230.271.240.7720.420.48rs4588RATG0.230.220.930.561.530.810.84rs4588SSTG0.230.210.890.471.650.770.76rs4588CPSTG0.230.291.370.762.430.260.53Conclusion:There is evidence of nominal association between VDR SNPs: rs731236 (in SLE and CPS), and rs7975232 (in SS and CPS) and the presence of IMIDs disease in Paraguayan patients.Disclosure of Interests:None declared
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Sarre C, Nernpermpisooth N, Barrere C, Luz-Crawford P, Tejedor G, Contreras R, Vincent A, Jorgensen C, Nargeot J, Djouad F, Barrere-Lemaire S. PPARβ/δ is involved in the cardioprotective effect of mesenchymal stem cells. Archives of Cardiovascular Diseases Supplements 2020. [DOI: 10.1016/j.acvdsp.2020.03.077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Klopfenstein T, Zayet S, Lohse A, Balblanc JC, Badie J, Royer PY, Toko L, Mezher C, Kadiane-Oussou NJ, Bossert M, Bozgan AM, Charpentier A, Roux MF, Contreras R, Mazurier I, Dussert P, Gendrin V, Conrozier T. Tocilizumab therapy reduced intensive care unit admissions and/or mortality in COVID-19 patients. Med Mal Infect 2020; 50:397-400. [PMID: 32387320 PMCID: PMC7202806 DOI: 10.1016/j.medmal.2020.05.001] [Citation(s) in RCA: 155] [Impact Index Per Article: 38.8] [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: 04/29/2020] [Accepted: 05/04/2020] [Indexed: 02/08/2023]
Abstract
INTRODUCTION No therapy has yet proven effective in COVID-19. Tocilizumab (TCZ) in patients with severe COVID-19 could be an effective treatment. METHOD We conducted a retrospective case-control study in the Nord Franche-Comté Hospital, France. We compared the outcome of patients treated with TCZ and patients without TCZ considering a combined primary endpoint: death and/or ICU admissions. RESULTS Patients with TCZ (n=20) had a higher Charlson comorbidity index (5.3 [±2.4] vs 3.4 [±2.6], P=0.014), presented with more severe forms (higher level of oxygen therapy at 13L/min vs 6L/min, P<0.001), and had poorer biological findings (severe lymphopenia: 676/mm3 vs 914/mm3, P=0.037 and higher CRP level: 158mg/L vs 105mg/L, P=0.017) than patients without TCZ (n=25). However, death and/or ICU admissions were higher in patients without TCZ than in the TCZ group (72% vs 25%, P=0.002). CONCLUSION Despite the small sample size and retrospective nature of the work, this result strongly suggests that TCZ may reduce the number of ICU admissions and/or mortality in patients with severe SARS-CoV-2 pneumonia.
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Affiliation(s)
- T Klopfenstein
- Infectious Disease Department, Nord Franche-Comté Hospital, 90400 Trévenans, France.
| | - S Zayet
- Infectious Disease Department, Nord Franche-Comté Hospital, 90400 Trévenans, France.
| | - A Lohse
- Rheumatology Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - J-C Balblanc
- Rheumatology Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - J Badie
- Intensive Care Unit Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - P-Y Royer
- Infectious Disease Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - L Toko
- Infectious Disease Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - C Mezher
- Intensive Care Unit Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - N J Kadiane-Oussou
- Infectious Disease Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - M Bossert
- Rheumatology Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - A-M Bozgan
- Rheumatology Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - A Charpentier
- Rheumatology Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - M-F Roux
- Pharmacology Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - R Contreras
- Pharmacology Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - I Mazurier
- Biological Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - P Dussert
- Biological Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - V Gendrin
- Infectious Disease Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
| | - T Conrozier
- Rheumatology Department, Nord Franche-Comté Hospital, 90400 Trévenans, France
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Chumbita M, Contreras R, Pellice F, Vega V, Matus B. Urine cultures: Inappropiate use. Economic impact in a public hospital. Retrospective study. Int J Infect Dis 2018. [DOI: 10.1016/j.ijid.2018.04.3652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Court A, LeGatt A, Luz-Crawford P, Kurte M, Ortuzar M, Contreras R, Parra E, Pino-Lagos K, Figueroa F, Khoury M. Mitochondrial transfer from MSC to human T cells: A first evidence of a stem cell-mediated reprogramming of multiple immune cell function. Cytotherapy 2018. [DOI: 10.1016/j.jcyt.2018.02.273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
The SNAr reaction between 1-chloro-2,4-dinitrobenzene and morpholine was used as a model system to study solvation effects in a series of mixtures involving imidazolium based ionic liquids.
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Affiliation(s)
- J. Alarcón-Espósito
- Departamento de Química
- Facultad de Ciencias
- Universidad de Chile
- Casilla 653-Santiago
- Chile
| | - R. Contreras
- Departamento de Química
- Facultad de Ciencias
- Universidad de Chile
- Casilla 653-Santiago
- Chile
| | - P. R. Campodónico
- Centro de Química Médica
- Facultad de Medicina
- Clínica Alemana
- Universidad del Desarrollo
- Santiago
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Calfumán K, Gallardo-Fuentes S, Contreras R, Tapia RA, Campodónico PR. Mechanism for the SNAr reaction of atrazine with endogenous thiols: experimental and theoretical study. NEW J CHEM 2017. [DOI: 10.1039/c7nj02708g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The mechanism for the SNAr reaction of atrazine with endogenous thiols: a stepwise or concerted process?
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Affiliation(s)
- K. Calfumán
- Departamento de Química
- Facultad de Ciencias
- Universidad de Chile
- Santiago
- Chile
| | - S. Gallardo-Fuentes
- Departamento de Química
- Facultad de Ciencias
- Universidad de Chile
- Santiago
- Chile
| | - R. Contreras
- Departamento de Química
- Facultad de Ciencias
- Universidad de Chile
- Santiago
- Chile
| | - R. A. Tapia
- Departamento de Orgánica
- Facultad de Química
- Pontificia Universidad Católica de Chile
- Santiago 6094411
- Chile
| | - P. R. Campodónico
- Centro de Química Médica
- Facultad de Medicina
- Clínica Alemana Universidad del Desarrollo
- Santiago
- Chile
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Sánchez-Parra B, Figueiras AM, Abd El-Moneim D, Contreras R, Rouco R, Gallego FJ, Benito C. The role of two superoxide dismutase mRNAs in rye aluminium tolerance. Plant Biol (Stuttg) 2015; 17:694-702. [PMID: 25359673 DOI: 10.1111/plb.12281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 10/21/2014] [Indexed: 06/04/2023]
Abstract
Aluminium (Al) is the main factor that limits crop production in acidic soils. There is evidence that antioxidant enzymes such as superoxide dismutase (SOD) play a key role against Al-induced oxidative stress in several plant species. Rye is one of the most Al-tolerant cereals and exudes both citrate and malate from the roots in response to Al. The role of SOD against Al-induced oxidative stress has not been studied in rye. Al accumulation, lipid peroxidation, H₂O₂ production and cell death were significantly higher in sensitive than in tolerant rye cultivars. Also, we characterised two genes for rye SOD: ScCu/ZnSOD and ScMnSOD. These genes were located on the chromosome arms of 2RS and 3RL, respectively, and their corresponding hypothetical proteins were putatively classified as cytosolic and mitochondrial, respectively. The phylogenetic relationships indicate that the two rye genes are orthologous to the corresponding genes of other Poaceae species. In addition, we studied Al-induced changes in the expression profiles of mRNAs from ScCu/ZnSOD and ScMnSOD in the roots and leaves of tolerant Petkus and sensitive Riodeva rye. These genes are mainly expressed in roots in both ryes, their repression being induced by Al. The tolerant cultivar has more of both mRNAs than the sensitive line, indicating that they are probably involved in Al tolerance.
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Affiliation(s)
- B Sánchez-Parra
- Departamento de Genética, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
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Abd El-Moneim D, Contreras R, Silva-Navas J, Gallego FJ, Figueiras AM, Benito C. On the consequences of aluminium stress in rye: repression of two mitochondrial malate dehydrogenase mRNAs. Plant Biol (Stuttg) 2015; 17:123-33. [PMID: 24946232 DOI: 10.1111/plb.12219] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 04/29/2014] [Indexed: 05/23/2023]
Abstract
Plants have developed several external and internal aluminium (Al) tolerance mechanisms. The external mechanism best characterised is the exudation of organic acids induced by Al. Rye (Secale cereale L.), one of the most Al-tolerant cereal crops, secretes both citrate and malate from its roots in response to Al. However, the role of malate dehydrogenase (MDH) genes in Al-induced stress has not been studied in rye. We have isolated the ScMDH1 and ScMDH2 genes, encoding two different mitochondrial MDH isozymes, in three Al-tolerant rye cultivars (Ailés, Imperial and Petkus) and one sensitive inbred rye line (Riodeva). These genes, which have seven exons and six introns, were located on the 1R (ScMDH1) and 3RL (ScMDH2) chromosomes. Exon 1 of ScMDH1 and exon 7 of ScMDH2 were the most variable among the different ryes. The hypothetical proteins encoded by these genes were classified as putative mitochondrial MDH isoforms. The phylogenetic relationships obtained using both cDNA and protein sequences indicated that the ScMDH1 and ScMDH2 proteins are orthologous to mitochondrial MDH1 and MDH2 proteins of different Poaceae species. The expression studies of the ScMDH1 and ScMDH2 genes indicate that it is more intense in roots than in leaves. Moreover, the amount of their corresponding mRNAs in roots from plants treated and not treated with Al was higher in the tolerant cultivar Petkus than in the sensitive inbred line Riodeva. In addition, ScMDH1 and ScMDH2 mRNA levels decreased in response to Al stress (repressive behaviour) in the roots of both the tolerant Petkus and the sensitive line Riodeva.
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Affiliation(s)
- D Abd El-Moneim
- Departamento de Genética, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
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Wong GK, Goldacker S, Winterhalter C, Grimbacher B, Chapel H, Lucas M, Alecsandru D, McEwen D, Quinti I, Martini H, Milito C, Schmidt RE, Ernst D, Espanol T, Vidaller A, Carbone J, Fernandez-Cruz E, Lougaris V, Plebani A, Kutukculer N, Gonzalez-Granado LI, Contreras R, Kiani-Alikhan S, Ibrahim MAA, Litzman J, Jones A, Gaspar HB, Hammarstrom L, Baumann U, Warnatz K, Huissoon AP. Outcomes of splenectomy in patients with common variable immunodeficiency (CVID): a survey of 45 patients. Clin Exp Immunol 2013; 172:63-72. [PMID: 23480186 DOI: 10.1111/cei.12039] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2012] [Indexed: 01/29/2023] Open
Abstract
Splenectomy has been used in patients with common variable immunodeficiency disorders (CVID), mainly in the context of refractory autoimmune cytopenia and suspected lymphoma, but there are understandable concerns about the potential of compounding an existing immunodeficiency. With increasing use of rituximab as an alternative treatment for refractory autoimmune cytopenia, the role of splenectomy in CVID needs to be re-examined. This retrospective study provides the largest cohesive data set to date describing the outcome of splenectomy in 45 CVID patients in the past 40 years. Splenectomy proved to be an effective long-term treatment in 75% of CVID patients with autoimmune cytopenia, even in some cases when rituximab had failed. Splenectomy does not worsen mortality in CVID and adequate immunoglobulin replacement therapy appears to play a protective role in overwhelming post-splenectomy infections. Future trials comparing the effectiveness and safety of rituximab and splenectomy are needed to provide clearer guidance on the second-line management of autoimmune cytopenia in CVID.
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Affiliation(s)
- G K Wong
- West Midlands Primary Immunodeficiency centre, Birmingham Heartlands Hospital, UK
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Ferraro FR, Lanzoni B, Dalessandro E, Beccari G, Pasquato M, Miocchi P, Rood RT, Sigurdsson S, Sills A, Vesperini E, Mapelli M, Contreras R, Sanna N, Mucciarelli A. Dynamical age differences among coeval star clusters as revealed by blue stragglers. Nature 2012; 492:393-5. [DOI: 10.1038/nature11686] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 10/16/2012] [Indexed: 11/09/2022]
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Bonilla E, Contreras R, Medina-Leendertz S, Mora M, Villalobos V, Bravo Y. Minocycline increases the life span and motor activity and decreases lipid peroxidation in manganese treated Drosophila melanogaster. Toxicology 2012; 294:50-3. [PMID: 22330257 DOI: 10.1016/j.tox.2012.01.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 01/25/2012] [Accepted: 01/30/2012] [Indexed: 01/13/2023]
Abstract
The objective of this study was to investigate the effect of Minocycline in the life span, motor activity, and lipid peroxidation of Drosophila melanogaster treated with manganese. Two days after emerging from the pupa male wild-type D. melanogaster were fed for 13 days with corn media containing 15 mM manganese. Then, they were divided in six groups of 300 flies each: group (a) remained treated with manganese (Mn group); group (b) began treatment with Minocycline (0.05 mM) (Mn-Minocycline group); group (c) received no additional treatment (Mn-no treatment group); group (d) simultaneously fed with manganese and Minocycline (Mn+Minocycline group). Additionally, a control (group e) with no treatment and another group (f) fed only with Minocycline after emerging from the pupa were added. All the manganese treated flies (group a) were dead on the 25th day. The life span in group f (101.66±1.33 days, mean S.E.M.) and of group b (97.00±3.46 days) were similar, but in both cases it was significantly higher than in group e (68.33±1.76 days), group c (67.05±2.30 days) and in those of group d (37.33±0.88). Manganese (groups a and d) decreased motor activity in D. melanogaster. In the Minocycline fed flies (groups b and f) a higher motor activity was detected. In Mn-Minocycline and Mn+Minocycline treated flies a significant decrease of MDA levels was detected when compared to the Minocycline group indicating that Minocycline and Mn appear to have a synergistic effect. In conclusion, Minocycline increased the life span and motor activity and decreased MDA formation of manganese treated D. melanogaster, probably by an inhibition of the production of reactive oxygen species. Manganese also exerted an antioxidant effect as shown by the significant decrease of MDA levels when compared to control flies.
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Affiliation(s)
- E Bonilla
- Centro de Investigaciones Biomédicas, Departamento de Neurobiología, Instituto Venezolano de Investigaciones Científicas, Maracaibo, Venezuela.
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Gonzalez-Suarez M, Aizman A, Soto-Delgado J, Contreras R. Bond Fukui functions as descriptor of the electron density reorganization in π conjugated systems. J Org Chem 2012; 77:90-5. [PMID: 22126265 DOI: 10.1021/jo201465g] [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: 11/29/2022]
Abstract
The bond Fukui function is introduced and tested as a new reactivity index capable of predicting the evolution of bond breaking and formation processes during an organic reaction involving π conjugated systems. As an illustration, we examine many cases where substituted ethylenes and dienes may respond to different reagents to yield cycloaddition, Michael addition, and other reactions at double bonds.
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Affiliation(s)
- M Gonzalez-Suarez
- Departamento de Ciencias Físicas, Universidad Andrés Bello, República 220, Santiago, Chile.
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15
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Cerda-Monje A, Aizman A, Tapia RA, Chiappe C, Contreras R. Solvent effects in ionic liquids: empirical linear energy–density relationships. Phys Chem Chem Phys 2012; 14:10041-9. [DOI: 10.1039/c2cp40619e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Zúñiga G, Junqueira-Gonçalves M, Pizarro M, Contreras R, Tapia A, Silva S. Effect of ionizing energy on extracts of Quillaja saponaria to be used as an antimicrobial agent on irradiated edible coating for fresh strawberries. Radiat Phys Chem Oxf Engl 1993 2012. [DOI: 10.1016/j.radphyschem.2011.08.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Bonilla E, Contreras R, Medina-Leendertz S, Mora M, Villalobos V, Bravo Y. 3.258 RESVERATROL INCREASES THE LIFE SPAN OF MANGANESETREATED DROSOPHILA MELANOGASTER. Parkinsonism Relat Disord 2012. [DOI: 10.1016/s1353-8020(11)70929-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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DelaTorre W, Lopez S, Vega I, Contreras R, Vallejo* F. Ten years free of disease of differentiated thyroid carcinoma (DTC) with interdisciplinary approach in an Andean region of Quito. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.e16004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Contreras R, Ramírez J, Cuevas-García R, Gutiérrez-Alejandre A, Castillo-Villalón P, Macías G, Puente-Lee I. Preparation and characterization of Pt/HMFI–SBA-15 hybrid catalyst for tetralin transformation. Catal Today 2009. [DOI: 10.1016/j.cattod.2009.06.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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20
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Haque R, Schottinger JE, Kanter MH, Avila CC, Contreras R, Gordon MA, Quinn VP. Frequency of late-stage breast cancer diagnoses despite high mammography screening rates in an HMO. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.1526] [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] [Indexed: 11/20/2022] Open
Abstract
1526 Background: Kaiser Permanente Southern California (KPSC) led the nation in screening women for breast cancer (BCa) with a mammography rate of nearly 90% in 2007 according to 2008 Healthcare Effectiveness Data and Information Set (HEDIS) measures. Despite successes in improving screening rates in this health plan that serves 3+ million diverse members, the percentage of women diagnosed with late stage BCa (stage III, IV) remained stable, varying from 12.9% (N∼323) in 2003 to 10.8% (N∼270) in 2007. To identify patient and health care factors associated with late stage diagnosis and the impact of its enhanced screening implementation guidelines, KPSC undertook this study. Methods: This cross-sectional study included a cohort of 10,580 BCa patients from 2003–2007. We compared women diagnosed with late stage disease versus those with early stage disease (stages I, II). P values (2-sided) were based on the chi-square distribution. Adjusted odds ratios and 95% confidence intervals were estimated using unconditional logistic regression. Results: Factors that were positively associated with late stage diagnosis in the univariate analyses included age, lack of recent mammography screening, worse tumor features, 80+ years of age, minority race, lower geocoded household income, increased healthcare visits, and use of Pap testing (P < 0.01 for all variables). Factors significantly associated with late stage diagnosis in the multivariate model included only lack of recent mammography screening (OR = 1.35, 95% CI: 1.14–1.58) and worse tumor features including high grade (grade 3, OR = 2.58, 95% CI: 1.96–3.40), positive lymph nodes (OR = 53.49, 95% CI: 39.90–71.72), and HER-2+ tumors (OR = 1.40, 95% CI: 1.13–1.72). Conclusions: Targeting older women, those with lower utilization, and women who did not have a recent mammogram may help further lower the prevalence of late stage diagnoses. However, given the extent of the health plan's previous efforts to enhance BCa screening rates, a ceiling effect may limit additional benefit. Additional efforts to decrease the rate of advanced tumor stage at diagnosis may include improving interpretation of mammograms or earlier detection of aggressive tumors by enhanced BRCA genetic testing. No significant financial relationships to disclose.
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Affiliation(s)
- R. Haque
- Kaiser Permanente Southern California, Pasadena, CA
| | | | - M. H. Kanter
- Kaiser Permanente Southern California, Pasadena, CA
| | - C. C. Avila
- Kaiser Permanente Southern California, Pasadena, CA
| | - R. Contreras
- Kaiser Permanente Southern California, Pasadena, CA
| | - M. A. Gordon
- Kaiser Permanente Southern California, Pasadena, CA
| | - V. P. Quinn
- Kaiser Permanente Southern California, Pasadena, CA
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Affiliation(s)
| | | | | | | | - P. Fuentealba
- Departamento de Química, Universidad Técnica Federico Santa María, Casilla 110-V Valparaíso, Chile, Instituto de Química, Universidad de Antioquia, A. A. 1226, Medellín, Colombia, Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile., Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, Apartado Postal 55-534, 09340 D.F., México, México, Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
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22
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Van Beneden K, Coppieters K, Laroy W, De Keyser F, Hoffman IE, Van den Bosch F, Vander Cruyssen B, Drennan M, Jacques P, Rottiers P, Verbruggen G, Contreras R, Callewaert N, Elewaut D. Reversible changes in serum immunoglobulin galactosylation during the immune response and treatment of inflammatory autoimmune arthritis. Ann Rheum Dis 2008; 68:1360-5. [PMID: 18772190 DOI: 10.1136/ard.2008.089292] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES Improved DNA sequencer-aided fluorophore-assisted carbohydrate electrophoresis (DSA-FACE) technology was used to monitor the changes in the galactosylation status of serum immunoglobulins during the immune response and therapy of autoimmune arthritis. METHODS Collagen-induced arthritis (CIA) was induced in susceptible DBA/1 mice and the undergalactosylation status (UGS) of serum immunoglobulins was determined using the improved DSA-FACE technology. Prophylactic intravenous tolerisation with type II collagen as well as semitherapeutic treatment with dexamethasone (DEX) were performed and UGS was analysed. Next, the serum immunoglobulin glycosylation profiles of patients with rheumatoid arthritis (RA) and spondyloarthropathy (SpA) were studied and changes in the UGS scores during anti-tumour necrosis factor (TNF)alpha therapy followed. RESULTS In the longitudinal CIA study, the undergalactosylation state of immunoglobulins was found to be significantly correlated with the clinical arthritis scores. Upon collagen-specific tolerisation as well as glucocorticoid semitherapeutic treatment, improvement of the clinical arthritis scores correlated with decreased levels of UGS. It was also demonstrated that withdrawal of DEX was associated with an increased UGS score. Interestingly, reversibility in the UGS was also shown during treatment of patients with RA and SpA with anti-TNFalpha. CONCLUSIONS These findings demonstrate that the UGS of serum immunoglobulins changes during the disease course of CIA and that this UGS is inhibited by antigen-specific and antigen-independent treatment procedures. The observation that Ig galactosylation is a reversible process is also documented during treatment of patients with RA and SpA with anti-TNFalpha.
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Affiliation(s)
- K Van Beneden
- Department of Rheumatology, Laboratory of Molecular Immunology and Inflammation, Ghent University Hospital, 0K12 IB, De Pintelaan 185, B-9000 Ghent, Belgium
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23
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Contreras R, Kolster R, Voss HU, Ghajar J, Suh M, Bahar S. Eye-target synchronization in mild traumatic brain-injured patients. J Biol Phys 2008; 34:381-92. [PMID: 19669482 DOI: 10.1007/s10867-008-9092-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Accepted: 06/06/2008] [Indexed: 11/28/2022] Open
Abstract
Eye-target synchronization is critical for effective smooth pursuit of a moving visual target. We apply the nonlinear dynamical technique of stochastic-phase synchronization to human visual pursuit of a moving target, in both normal and mild traumatic brain-injured (mTBI) patients. We observe significant fatigue effects in all subject populations, in which subjects synchronize better with the target during the first half of the trial than in the second half. The fatigue effect differed, however, between the normal and the mTBI populations and between old and young subpopulations of each group. In some cases, the younger (<or=40 years old) normal subjects performed better than mTBI subjects and also better than older (>40 years old) normal subjects. Our results, however, suggest that further studies will be necessary before a standard of "normal" smooth pursuit synchronization can be developed.
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Affiliation(s)
- R Contreras
- Department of Physics and Astronomy, Center for Neurodynamics, University of Missouri, St. Louis, MO, USA.
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24
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Alarcón de Noya B, Ruiz R, Losada S, Colmenares C, Contreras R, Cesari IM, Noya O. Detection of schistosomiasis cases in low-transmission areas based on coprologic and serologic criteria The Venezuelan experience. Acta Trop 2007; 103:41-9. [PMID: 17606217 DOI: 10.1016/j.actatropica.2007.04.018] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2002] [Revised: 12/07/2006] [Accepted: 04/23/2007] [Indexed: 12/01/2022]
Abstract
Low and very-low intensities of infection hinder the diagnosis of schistosomiasis. Therefore, new parameters should be established in order to more accurately identify active cases and true infection prevalence, for the adequate implementation of a control program. After the survey and analysis of the epidemiological characteristics of five Venezuelan communities, we propose three criteria for the definition of a "schistosomiasis case", based on different diagnostic methods: stool examination, ELISA-soluble egg antigen with sodium metaperiodate (SMP-ELISA), alkaline phosphatase immunoassay (APIA) and the circumoval precipitin test (COPT). Briefly, criterion I: persons with Schistosoma mansoni eggs in stools; criterion II: persons without eggs in stools, with positive COPT, without previous antischistosome chemotherapy in the last year; and criterion III: persons without eggs in stools, with negative COPT, with two positive immunoenzymatic tests (SMP-ELISA and APIA), and with no previous chemotherapy. The incorporation of serological tests to epidemiologic surveillance in areas of low-transmission tries to compensate the underestimation of prevalence based only on parasitological diagnosis.
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Affiliation(s)
- B Alarcón de Noya
- Instituto de Medicina Tropical, Universidad Central de Venezuela, Venezuela.
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25
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Abstract
We introduce and test a nucleophilicity index as a new descriptor of chemical reactivity. The index is derived from a perturbation model for the interaction between the nucleophile and a positive test charge. The computational implementation of the model uses an isoelectronic process involving the minimum values of the electronic part of the perturbed molecular electrostatic potential. The working expression defining the nucleophilicity index encompasses both the electrostatic contributions and the second-order polarization effects in a form which is consistent with the empirical scales previously proposed. The index is validated for a series of neutral nucleophiles in the gas phase for which the nucleophilicity pattern has been experimentally established within a spectroscopic scale.
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Affiliation(s)
- A Cedillo
- Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Iztapalapa, DF 09340, México.
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26
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Pérez P, Domingo LR, Aizman A, Contreras R. Chapter 9 The electrophilicity index in organic chemistry. Theoretical and Computational Chemistry 2007. [DOI: 10.1016/s1380-7323(07)80010-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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27
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Meneses L, Fuentealba P, Contreras R. On the variations of electronic chemical potential and chemical hardness induced by solvent effects. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.10.124] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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28
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Guerra D, Castillo R, Andrés J, Fuentealba P, Aizman A, Contreras R. Homofugality: A new reactivity index describing the leaving group ability in homolytic substitution reactions. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.04.092] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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29
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Abstract
The electron localization function (ELF) has been separated in its sigma and pi components. The topological analysis of the new ELFsigma and ELFpi functions has been used to quantify the concept of resonance. The highest bifurcation values of these functions describe in a correct way the aromaticity of classical ring molecules and some new aromatic compounds as B6CO6, Al4(2-), and N5-. In the case of Al4(2-), an important sigma delocalization contribution has been found, which is in agreement with previous interpretation.
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Affiliation(s)
- J C Santos
- Departamento de Fisica, Facultad de Ciencias, Universidad de Chile, Casilla 653, Las Palmeras 3425, Nunoa, Santiago, Chile
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30
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Guerra D, Contreras R, Pérez P, Fuentealba P. Hardness and softness kernels, and related indices in the spin polarized version of density functional theory. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2005.11.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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31
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Lawrence JM, Lukacz ES, Nager CW, Contreras R, Luber KM. 565: Prevalence of Female Pelvic Floor Disorders by Age and Race/Ethnicity in a Managed Health Care Population. Am J Epidemiol 2005. [DOI: 10.1093/aje/161.supplement_1.s142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- J M Lawrence
- Kaiser Permanente Southern California, Pasadena, CA, 91101
| | - E S Lukacz
- Kaiser Permanente Southern California, Pasadena, CA, 91101
| | - C W Nager
- Kaiser Permanente Southern California, Pasadena, CA, 91101
| | - R Contreras
- Kaiser Permanente Southern California, Pasadena, CA, 91101
| | - K M Luber
- Kaiser Permanente Southern California, Pasadena, CA, 91101
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32
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Abstract
Four different ways to condense the Fukui function are compared. Three of them perform a numerical integration over different basins to define the condensed Fukui function, and the other one is the most traditional Fukui function using Mulliken population analysis. The basins are chosen to be the basins of the electron density (AIM), the basins of the electron localization function (ELF), and the basins of the Fukui function itself. The use of the last two basins is new and presented for the first time here. It is found that the last three methods yield results which are stable against a change in the basis set. The condensed Fukui function using the basins of the ELF is not able to give information on the reactivity of an acceptor molecule. In general, the condensed Fukui function using the basins of the density or the basins of the Fukui function describe the reactivity trends well. The latter is preferred, because it only contains information about the Fukui function itself and it gives the right information for donor as well as acceptor centers.
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Affiliation(s)
- W Tiznado
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
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33
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Domingo L, Perez P, Contreras R. A DFT Analysis of the Strain-Induced Regioselective[2+2]Cycloaddition of Benzyne Possessing Fused Four-Membered Ring. LETT ORG CHEM 2005. [DOI: 10.2174/1570178053399958] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [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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34
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Meneses L, Fuentealba P, Contreras R. Relationship between the electrophilicity of substituting agents and substrate selectivity in Friedel–Crafts reactions. Tetrahedron 2005. [DOI: 10.1016/j.tet.2004.11.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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35
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Aizman A, Contreras R, Pérez P. Relationship between local electrophilicity and rate coefficients for the hydrolysis of carbenium ions. Tetrahedron 2005. [DOI: 10.1016/j.tet.2004.11.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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36
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Breitling R, Kushnir S, Callewaert N, Pietrucha R, Contreras R, Beverley SM, Alexandrov K. A new protein-expression platform based on a eukaryotic parasite Leishmania tarentolae. Acta Crystallogr A 2004. [DOI: 10.1107/s0108767304099830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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37
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Contreras R, Andres J, Safont VS, Campodonico P, Santos JG. A Theoretical Study on the Relationship between Nucleophilicity and Ionization Potentials in Solution Phase. J Phys Chem A 2003. [DOI: 10.1021/jp0302865] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R. Contreras
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, Departament de Ciències Experimentals, Universitat Jaume I, Box 224, 12080 Castelló, Spain, and Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - J. Andres
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, Departament de Ciències Experimentals, Universitat Jaume I, Box 224, 12080 Castelló, Spain, and Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - V. S. Safont
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, Departament de Ciències Experimentals, Universitat Jaume I, Box 224, 12080 Castelló, Spain, and Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - P. Campodonico
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, Departament de Ciències Experimentals, Universitat Jaume I, Box 224, 12080 Castelló, Spain, and Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - J. G. Santos
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, Departament de Ciències Experimentals, Universitat Jaume I, Box 224, 12080 Castelló, Spain, and Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile
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38
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Affiliation(s)
- Junia Melin
- Departamento de Química and Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, and Departamento de Química, Universidad Autónoma Metropolitana, UAM-Iztapalapa, México DF, México
| | - F. Aparicio
- Departamento de Química and Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, and Departamento de Química, Universidad Autónoma Metropolitana, UAM-Iztapalapa, México DF, México
| | - M. Galván
- Departamento de Química and Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, and Departamento de Química, Universidad Autónoma Metropolitana, UAM-Iztapalapa, México DF, México
| | - P. Fuentealba
- Departamento de Química and Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, and Departamento de Química, Universidad Autónoma Metropolitana, UAM-Iztapalapa, México DF, México
| | - R. Contreras
- Departamento de Química and Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, and Departamento de Química, Universidad Autónoma Metropolitana, UAM-Iztapalapa, México DF, México
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39
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Gómez B, Chattaraj PK, Chamorro E, Contreras R, Fuentealba P. A Density Functional Study of the Claisen Rearrangement of Allyl Aryl Ether, Allyl Arylamine, Allyl Aryl Thio Ether, and a Series of Meta-Substituted Molecules through Reactivity and Selectivity Profiles. J Phys Chem A 2002. [DOI: 10.1021/jp020437o] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Badhin Gómez
- Departamento de Química and2Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653-Santiago, Chile, Department of Chemistry, Indian Institute of Technology, Kharagpur, 721 302, India, and Departamento de Química, Facultad de Ecología y Recursos Naturales, Universidad Andrés Bello, Santiago, Chile
| | - Pratim K. Chattaraj
- Departamento de Química and2Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653-Santiago, Chile, Department of Chemistry, Indian Institute of Technology, Kharagpur, 721 302, India, and Departamento de Química, Facultad de Ecología y Recursos Naturales, Universidad Andrés Bello, Santiago, Chile
| | - E. Chamorro
- Departamento de Química and2Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653-Santiago, Chile, Department of Chemistry, Indian Institute of Technology, Kharagpur, 721 302, India, and Departamento de Química, Facultad de Ecología y Recursos Naturales, Universidad Andrés Bello, Santiago, Chile
| | - R. Contreras
- Departamento de Química and2Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653-Santiago, Chile, Department of Chemistry, Indian Institute of Technology, Kharagpur, 721 302, India, and Departamento de Química, Facultad de Ecología y Recursos Naturales, Universidad Andrés Bello, Santiago, Chile
| | - P. Fuentealba
- Departamento de Química and2Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653-Santiago, Chile, Department of Chemistry, Indian Institute of Technology, Kharagpur, 721 302, India, and Departamento de Química, Facultad de Ecología y Recursos Naturales, Universidad Andrés Bello, Santiago, Chile
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40
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Desmet T, Nerinckx W, Stals I, Callewaert N, Contreras R, Claeyssens M. Novel tools for the study of class I alpha-mannosidases: a chromogenic substrate and a substrate-analog inhibitor. Anal Biochem 2002; 307:361-7. [PMID: 12202255 DOI: 10.1016/s0003-2697(02)00039-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [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]
Abstract
The use of chromogenic substrates for evaluation of class I alpha-mannosidase is described. 2('),4(')-Dinitrophenyl-alpha-D-mannopyranoside allows rapid and sensitive assays of enzymatic activities, e.g., of heterologously expressed alpha-1,2-mannosidase from Trichoderma reesei. Interaction constants of several ligands with alpha-mannosidases from class I and II could also be determined. Furthermore, novel types of inhibitors derived from D-lyxose are presented. Methyl-alpha-D-lyxopyranosyl-(1(')-->2)-alpha-D-mannopyranoside is a potent inhibitor of the alpha-1,2-mannosidase from T. reesei (K(i)=600 microM) and since it probably spans subsites -1/+1, this disaccharide could be valuable in crystallographic studies of class I alpha-mannosidases.
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Affiliation(s)
- T Desmet
- Laboratory for Biochemistry, Department of Biochemistry, Physiology, and Microbiology, Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium
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41
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Aizman A, Contreras R, Galván M, Cedillo A, Santos JC, Chamorro E. The Markovnikov Regioselectivity Rule in the Light of Site Activation Models. J Phys Chem A 2002. [DOI: 10.1021/jp020214y] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. Aizman
- Departamento de Química, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso, Chile, Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, A. P. 55-534, México, D. F. 09340, México, Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, and Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
| | - R. Contreras
- Departamento de Química, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso, Chile, Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, A. P. 55-534, México, D. F. 09340, México, Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, and Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
| | - M. Galván
- Departamento de Química, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso, Chile, Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, A. P. 55-534, México, D. F. 09340, México, Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, and Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
| | - A. Cedillo
- Departamento de Química, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso, Chile, Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, A. P. 55-534, México, D. F. 09340, México, Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, and Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
| | - J. C. Santos
- Departamento de Química, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso, Chile, Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, A. P. 55-534, México, D. F. 09340, México, Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, and Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
| | - E. Chamorro
- Departamento de Química, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso, Chile, Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, A. P. 55-534, México, D. F. 09340, México, Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile, and Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
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Chamorro E, Fuentealba P, Contreras R. Higher order derivatives for nuclear indexes in the framework of density functional theory. J Chem Phys 2001. [DOI: 10.1063/1.1394755] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Güizado-Rodríguez M, Ariza-Castolo A, Merino G, Vela A, Noth H, Bakhmutov VI, Contreras R. Weak intramolecular proton-hydride and proton-fluoride interactions: experimental (NMR, X-ray) and DFT studies of the bis(NBH(3)) and bis(NBF(3)) adducts of 1,3-dimethyl-1,3-diazolidine. J Am Chem Soc 2001; 123:9144-52. [PMID: 11552823 DOI: 10.1021/ja0111232] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bis(NBH(3)), bis(NBF(3)), and NBF(3)/NBH(3) adducts 1-3 were prepared from 1,3-dimethyl-1,3-diazolidine and characterized by the (1)H, (13)C, (11)B, (19)F, 2D (1)H(-13)C HETCOR and NOESY NMR spectra. The structures and conformations of the adducts were established by the variable-temperature (1)H NMR spectra, the X-ray diffraction method (adduct 2A), and density functional calculations at different theoretical levels. The experimental and theoretical data have revealed that bis adducts 1-3 prefer trans orientations of the borane groups (1A, 2A, 3A) in solution, the solid state, and the gas phase. The studies have shown that the energetic preference of trans adducts with respect to cis compounds, decreasing as 2A (2.9 kcal/mol) > 3A (2.7 kcal/mol) > 1A (1.4 kcal/mol), is dictated by spatially repulsive interactions between the CH(3), BH(3), and BF(3) groups. The results of DFT calculations agree well with an experimental trans/cis isomeric ratio of 9:1 determined in solutions of adduct 1. The calculated geometry and energy, as well as the topological analysis of electronic densities, show that trans adducts 1-3 should exist in gas phase as twist conformations T-2 stabilized by the intramolecular C-H(delta+)...(-delta)H-B or C-H(delta+)...(-delta)F-B interactions. These interactions are characterized as closed-shell. The energy of one proton-hydride and proton-fluoride intramolecular contact, estimated as 1.9 (1A-T-2) and 0.7 (2A-T-2) kcal/mol, respectively, classifies the "elongated" intramolecular interactions CH(delta+)...(-delta)HB and CH(delta+)...(-delta)FB as weak ones. It has been established that, on going from gas phase to a condensed phase (solution and solid), the twist-conformations T-2 transform to conformations T-1, probably by intermolecular dipole-dipole interactions. The data presented in this work show that despite a weakness of the "elongated" proton-hydride and proton-fluoride interactions, they can play a significant role in the stabilization of conformational molecular states, especially when cooperativity is in action.
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Affiliation(s)
- M Güizado-Rodríguez
- Departamento de Química, Centro de Investigación y de Estudios Avanzados, A.P. 14-740, C.P. 07000, México D.F, México
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Van Petegem F, Contreras H, Contreras R, Van Beeumen J. Trichoderma reesei alpha-1,2-mannosidase: structural basis for the cleavage of four consecutive mannose residues. J Mol Biol 2001; 312:157-65. [PMID: 11545593 DOI: 10.1006/jmbi.2001.4946] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [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: 11/22/2022]
Abstract
The process of N-glycosylation of eukaryotic proteins involves a range of host enzymes that delete or add saccharide monomers. While endoplasmic reticulum (E.R.) mannosidases cleave only one mannose to produce the Man8B isomer, an alpha-1,2-mannosidase from Trichoderma reesei can sequentially cleave all four 1,2-linked mannose sugars from a Man(9)GlcNAc(2) oligosaccharide, a feature reminiscent of the activity of Golgi mannosidases. We now report the structure of the T. reesei enzyme at 2.37 A resolution. The enzyme folds as an (alpha alpha)(7) barrel. The substrate-binding site of the T. reesei mannosidase differs appreciably from the Saccharomyces cerevisiae enzyme. In the former, shorter loops at the surface allow substrate protein to come closer to the catalytic site. There is more internal space available, so that different oligosaccharide conformations are sterically allowed in the T. reesei alpha-1,2-mannosidase.
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Affiliation(s)
- F Van Petegem
- Department of Biochemistry, Physiology and Microbiology, University of Ghent, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
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Callewaert N, Laroy W, Cadirgi H, Geysens S, Saelens X, Min Jou W, Contreras R. Use of HDEL-tagged Trichoderma reesei mannosyl oligosaccharide 1,2-alpha-D-mannosidase for N-glycan engineering in Pichia pastoris. FEBS Lett 2001; 503:173-8. [PMID: 11513877 DOI: 10.1016/s0014-5793(01)02676-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [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: 11/27/2022]
Abstract
Therapeutic glycoprotein production in the widely used expression host Pichia pastoris is hampered by the differences in the protein-linked carbohydrate biosynthesis between this yeast and the target organisms such as man. A significant step towards the generation of human-compatible N-glycans in this organism is the conversion of the yeast-type high-mannose glycans to mammalian-type high-mannose and/or complex glycans. In this perspective, we have co-expressed an endoplasmic reticulum-targeted Trichoderma reesei 1,2-alpha-D-mannosidase with two glycoproteins: influenza virus haemagglutinin and Trypanosoma cruzi trans-sialidase. Analysis of the N-glycans of the two purified proteins showed a >85% decrease in the number of alpha-1,2-linked mannose residues. Moreover, the human-type high-mannose oligosaccharide Man(5)GlcNAc(2) was the major N-glycan of the glyco-engineered trans-sialidase, indicating that N-glycan engineering can be effectively accomplished in P. pastoris.
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Affiliation(s)
- N Callewaert
- Unit of Fundamental and Applied Molecular Biology, Department of Molecular Biology, Ghent University, Ghent, Belgium
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Callewaert N, Geysens S, Molemans F, Contreras R. Ultrasensitive profiling and sequencing of N-linked oligosaccharides using standard DNA-sequencing equipment. Glycobiology 2001; 11:275-81. [PMID: 11358876 DOI: 10.1093/glycob/11.4.275] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.7] [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: 01/20/2023] Open
Abstract
The analysis of protein-linked glycans is of increasing importance, both in basic glycobiological research and during the production process of glycoprotein pharmaceuticals. In many cases, the amount of glycoprotein available for typing the glycans is very low. This, combined with the high branching complexity typical for this class of compounds, makes glycan typing a challenging task. We present here methodology allowing the medium-throughput analysis of N-glycans derived from low picomole amounts of glycoproteins using the standard DNA-sequencing equipment available in any life sciences laboratory. The high sensitivity of the overall analytical process (from glycoprotein to results) is obtained using state-of-the-art deglycosylation procedures combined with a highly efficient and reproducible novel postderivatization cleanup step involving Sephadex G10 packed 96-well filterplates. All sample preparation steps (enzymatic deglycosylation with PNGase F, desalting, derivatization with 8-amino-1,3,6-pyrenetrisulfonic acid, and postderivatization cleanup) are performed using 96-well-based plates. This integrated sample preparation scheme is also compatible with capillary electrophoresis and MALDI-TOF-MS platforms already in use in some glycobiology labs and anticipates the higher throughput that will be offered by the capillary-array-based DNA sequencers currently penetrating the market. The described technology should bring high-performance glycosylation analysis within reach of each life sciences lab and thus help expedite the pace of discovery in the field of glycobiology.
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Affiliation(s)
- N Callewaert
- Unit of Fundamental and Applied Molecular Biology, Department of Molecular Biology, Ghent University and Flanders Interuniversity Institute for Biotechnology, K.L.-Ledeganckstraat 35, 9000 Ghent, Belgium
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Güizado-Rodríguez M, Flores-Parra A, Sánchez-Ruiz SA, Tapia-Benavides R, Contreras R, Bakhmutov VI. Multinuclear NMR spectra, (1)H-T(1) relaxation, conformational behavior, and intramolecular H(delta-)....(delta+)H contacts of N-borane cyclic adducts in solution. Inorg Chem 2001; 40:3243-6. [PMID: 11399201 DOI: 10.1021/ic000890j] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M Güizado-Rodríguez
- Chemistry Department, Centro de Investigación y de Estudios Avanzados del IPN, A.P. 14-740, C.P. 07000, México D.F, Mexico
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